Dissertations / Theses: 'Bio-based systems'

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Partington, Lee Ian. "Molecular wire based bio-electrochemical sensing systems." Thesis, University of Hull, 2016. http://hydra.hull.ac.uk/resources/hull:15133.

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This thesis aims to develop rapid, quantitative point of care sensing systems that exploit molecular wire platforms to enable the electrochemical detection of multiple target biomarkers, thereby empowering new technologies for the diagnosis of various medical conditions. Accordingly, the first chapter provides an overview of clinically important biomarkers for pregnancy and cardiovascular disease. The second chapter of this thesis details the electrochemical concepts underpinning subsequent chapters, with the third chapter providing an experimental overview. The first two research chapters develop a nano-structured, molecular wire platform based on diazonium salt electrochemistry coupled with immobilisation of antibodies conjugated to a suitable electroactive label. Here, the abundance of amine functionalities present at the antibody paratope enable the statistically large number of redox tags to be present at the antibody-antigen binding site, empowering the exquisitely selective and strong affinity of the antibody for a suitable antigen to be monitored quantitatively, through assessing the extent with which the redox labels are partially blocked in the presence of the antigen. In Chapter 4, experiments are contrasted with bespoke theory developed in order to unravel the thermodynamic and kinetic factors that empower this methodology to be singularly sensitive for the pregnancy biomarker human chorionic gonadotropin (hCG). It is demonstrated that quantitative analysis of hCG detection in artificial urine does not suffer interference. Chapter 5 adapts this approach to survey other biomarkers including β-hCG and brain natriuretic peptide. Combinatorial immunoassays are also investigated through the use of two types of antibodies, each tagged with a different redox label. Chapter 6 exploits the electroactive spin-trapping molecule TEMPO for the detection of biomolecules that have been damaged through oxidative stress. Last, Chapter 7 presents an overall conclusion to the work presented in this thesis.

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Scata', Marialisa. "Security Analysis of ICT Systems based on Bio-Inspired Models." Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/1095.

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In recent years, information and communication technology (ICT) has been characterized by several evolving trends and new challenges. The design and management of each information system must address is- sues related to planning an ICT infrastructure. The design of an ICT infrastructure can not ignore the technological and social analysis, to be also linked to the economic aspects, and now also linked to the sustainability. Dwawing inspiration from biology that has led to useful approaches to problem solving, this Ph.D. dissertation propose and develop a risk analysis model and security analysis and management model. This Ph.D. thesis proposes and shows a new kind of research topic, Bio-Inspired Telecommunication Security. It will be key to reach efficiency of the future networks and to obtaine a sustainable ICT infrastructure in terms of energy consumption, economic investment and in terms of privacy and security.

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Korukonda, Harika. "A Generic Agent Based Modeling Tool for Simulating Bio-Molecular Systems." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1296594324.

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Liu, Hongyuan. "Embedded test and condition monitoring technology for cell-based bio-sensor systems." Thesis, Lancaster University, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533077.

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Hagman, Linda. "How do biogas solutions influence the sustainability of bio-based industrial systems?" Licentiate thesis, Linköpings universitet, Industriell miljöteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-152878.

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Biomass is a valuable and limited resource that should be used efficiently. The potential of replacing fossil-based products with bio-based ones produced in biobased industrial systems is huge. One important aim of increasing the share of biobased products is to improve the sustainability of systems for production and consumption. Therefore, it is important to evaluate what solutions are available to improve the sustainability performance of bio-based industrial systems, and if they also bring negative impacts. The thesis focuses on assessing the role of biogas solutions in developing sustainable bio-based systems. Such assessments are often quite narrow in their scope and focus on quantitative environmental or economic aspects. This thesis aims at also including feasibility related aspects involving the contextual conditions that are assessed more qualitatively. Biogas solutions are identified as a versatile approach to treat organic materials which are generated in large volumes in bio-based industrial systems. The results show that biogas solutions in bio-based industrial systems (i) improve circular flows of energy and nutrients, (ii) are especially viable alternatives when the quality of the by-product streams become poorer, and (iii) may improve the profitability of the bio-based industrial system. To perform better assessments of these systems, it seems valuable to broaden the set of indicators assessed and include feasibility-related indicators, preferably through the involvement of relevant stakeholders as they contribute with different perspectives and can identify aspects that influence the sustainability in different areas. Future studies could benefit from applying those broader assessments on more cases to build on a more generalisable knowledge base.

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Sierra, Gonzalez Jaime Humberto. "Financing innovation in bio-pharma : a sectoral systems approach." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/financing-innovation-in-biopharma-a-sectoral-systems-approach(d49171fb-d842-4bf9-ac10-994e2a953443).html.

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The literature on the financing of innovative projects follows two trends: one contemplates that either the prospective fundees or the potential funders use their preferences to choose the other party out of a range of theoretical possibilities; the other refers to project owners or investors that actively look for an “opportunity” and try to talk the other party into entering the funding relationship. These views, however, cannot explain several facts such as: why projects rejected by some funders are accepted by others, why IPOs and markets are not attractive to all players or why that changes over time and across settings, how can State funds support a sector across regions, or how players’ and setting features and time affect funding criteria. A critique of these explanations sees three main shortcomings: lack of balance (i.e.,one party’s initiative prevails), bias (i.e., criteria of the domineering party prevail), and disembeddedness (i.e., milieu factors and changes over time are ignored). We think that an analysis supported by a sectoral approach may contribute to build a more articulate, integral insight about the funding of innovation. The bio-pharmaceutical sector was chosen because it exhibits amazing complexity related to the heterogeneity embodied by a multifaceted network of players (e.g., universities, companies, potential financiers, regulation bodies), to the nature and development path of innovative projects, and to the competitive/collaborative interactions framed in a particular setting. Hence, a qualitative approach based on the case study of the sector is the choice for this study. Case data are collected through semi-structured interviews with thirty participants that have played different roles in organisations of the bio-pharmaceutical sector or are highly experienced VC practitioners. Our findings allow us to propose an enhanced characterisation of innovation financing by showing that: i) Investors’ understanding of a sector is essential for funding decisions and can be updated through networking; ii) Networks facilitate firms-funders contact, coordination among funders, enhancement of financiers’ knowledge about the sector, and venture owners’ knowledge of track record and potential benefits of investors; iii) Interactions involve other actors in different roles and support network-based learning; iv) Funding decisions are impacted by the geographic availability of sources/mechanisms of finance and by their readiness to fund specific venture stages; v) Investors’ specificities matter; vi) Trends of change impact the availability of funding sources/mechanisms since they imply a reorganisation of the relations and interactions among players in the sector. Therefore, we propose a systemic analytic explanation where the strategy of funders (generalist or dedicated), therefore their role in a particular setting, is essentially defined in relation to the structure and dynamics of their knowledge consolidation system; then, we derive a number of implications for firm managers, investors, and policy-makers. Finally, the main limitations of this work and some further questions for future research are stated.

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Thome, De Faria Cassio. "Robust Model-Based Control of Nonlinear Systems for Bio-Inspired Autonomous Underwater Vehicles." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23792.

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The growing need for ocean surveillance and exploration has pushed the development of novel autonomous underwater vehicle (AUV) technology. A current trend is to make use of bio-inspired propulsor to increase the overall system efficiency and performance, an improvement that has deep implications in the dynamics of the system. The goal of this dissertation is to propose a generic robust control framework specific for bio-inspired autonomous underwater vehicles (BIAUV). These vehicles utilize periodic oscillation of a flexible structural component to generate thrust, a propulsion mechanism that can be tuned to operate under resonance and consequently improve the overall system efficiency. The control parameter should then be selected to keep the system operating in such a condition. Another important aspect is to have a controller design technique that can address the time-varying behaviors, structured uncertainties and system nonlinearities. To address these needs a robust, model-based, nonlinear controller design technique is presented, called digital sliding mode controller (DSMC), which also takes into account the discrete implementation of these laws using microcontrollers. The control law is implemented in the control of a jellyfish-inspired autonomous underwater vehicle.
Ph. D.

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Alushi, Anita <1992&gt. "The European Knowledge Based Bio-Economy: Call for the evolution of innovation systems." Master's Degree Thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/9782.

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The socio-economic global challenges we are facing have pushed European policy makers to take action driving Europe towards a more sustainable, long-term growth. This can be achieved by embracing the bioeconomy path. Starting from an introduction of the concept of knowledge based bio-economy, the study shows that new knowledge and innovation are at the base of this imperative transformation. An analysis of National Innovation Systems, which represent the tool for creating new knowledge and innovation, leads to the acknowledgment of a techno-institutional complex and carbon lock-in. Path dependence has affected our systems and radical innovations are required for disrupting firmly established, but unsustainable technological trajectories. An open innovation approach is illustrated as a possible way to go to facilitate the shift towards the bioeconomy and to this end, the role of policy makers is stressed. European initiatives aiming at a knowledge based bio-economy are introduced.

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Atcher, Ubiergo Joan. "Disulfide-based dynamic combinatorial libraries of macrocyclic pseudopeptides as bio-inspired complex chemical systems." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/305491.

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Dynamic combinatorial chemistry proposes the creation of a library of compounds (dynamic combinatorial library, DCL) inter-connected through reversible chemical processes. The concentrations in a DCL are determined by differences in the free energy between the constituents and, therefore, the variations in the composition of the library contain valuable information about changes in the stability of the members. The adaptive nature of DCLs can be intimately correlated with a very simple expression of molecular evolution. The main objective of this thesis is to use DCLs as bio-inspired complex chemical systems for the minimalistic experimental modeling of different processes of biological interest. In Chapter 1, fourteen new pseudopeptidic dithiols were designed, synthesized and fully characterized in order to be used as bipodal building blocks (BBs). Their design is based on a C2-symmetric scaffold consisting of a central m-phenylenediamine chromophore that rigidly joins two identical arms, each formed by an amino acid with a mercaptoacetyl moiety attached to the N-terminus. The pseudopeptidic nature provides the BBs with peptide-like information, differently charged functional groups and chiral information. In Chapter 2, suitable experimental conditions were developed for the generation of disulfide-based DCLs from the mixture of the synthesized BBs. For this purpose, the use of DMSO as a co-solvent has beneficial effects in the thiol-disulfide dynamic covalent chemistry. Apart from the general gain in the aqueous solubility of the organic molecules, it promotes the thiol oxidation, highly reducing the reaction time for the disulfide formation. Besides, it accelerates the disulfide exchange, allowing the system to fully equilibrate even at slightly acidic pH. In Chapter 3, a minimalistic DCL was used to reproduce adaptive trends described for the evolution of biological systems. Thus, the addition of salt to a dynamic library of macrocyclic pseudopeptides induces the amplification of those species concentrating anionic amino acids, with the Asp derivatives showing a better salt-adaptation than the Glu counterparts. Structural studies suggest a folded conformation for the amplified members and reveal the selection of those species showing a smaller accessible surface area. The adaptive process is driven by the increase of the ionic strength and has a remarkable resemblance with the natural evolution of the proteins of halophilic microorganisms for surviving in hypersaline media. In Chapter 4, the same external stimulus was studied in a larger DCL consisting of 21 differently charged dimeric macrocycles. The salt-induced adaptation of this complex system was characterized in a top-down fashion by the dynamic deconvolution into the minimal components. Additionally, structural studies were performed for selected species. The salt-response of the members of the library can be classified in different families attending to the charges, and the behavior of each member is determined by a combination of its structural information and the co-adaptive relationships with the other members of the complex network. Finally, in Chapter 5, a simple DCL consisting of homo- and heterochiral dimeric pseudopeptides was used to study how the chiral information is transmitted from the molecular to the macromolecular level. A decrease in the polarity of the medium induces a homochiral self-sorting process driven by polar intramolecular interactions. Additionally, the homochiral selectivity also increases with the temperature, indicating a positive entropic contribution. Preliminary NMR experiments suggest significantly different conformations for the homo- and heterochiral species. Overall, the adaptive nature of DCLs, together with a suitable bio-inspired design, have demonstrated to allow the minimalistic experimental modeling of different processes of biological interest such as the natural evolution of the halophilic proteins, the co-adaptive relationships in a complex network and the homochiral self-sorting phenomenon.
Les quimioteques dinàmiques (DCLs de “dynamic combinatorial libraries”) estan formades per una mescla de compostos interconnectats per mitjà de processos químics reversibles. Aquests sistemes dinàmics presenten la capacitat d’adaptar la seva composició a la presència d’un estímul extern. L’objectiu principal d’aquesta tesi és utilitzar DCLs com a sistemes químics complexos pel modelatge experimental de diversos processos d’interès biològic. En el Capítol 1 es van dissenyar, sintetitzar i caracteritzar catorze ditiols amb informació estructural de tipus peptídic, cadenes laterals amb diferents càrregues i informació quiral. A continuació, en el Capítol 2, es van establir unes condicions experimentals adequades per a generar DCLs de disulfurs a partir de l’oxidació dels ditiols sintetitzats. En aquest sentit, l’ús de DMSO com a codissolvent orgànic va demostrar tenir una sèrie d’efectes beneficiosos. Seguidament, en el Capítol 3, es va utilitzar una DCL minimalista de disseny bioinspirat per a reproduir tendències adaptatives pròpies de processos evolutius biològics. Així, es va observar que els canvis que provoca l’increment de la salinitat en la composició d’una DCL de pseudopèptids macrocíclics, tenen una notable similitud amb l’evolució natural de les proteïnes dels microorganismes halòfils. En el Capítol 4 es va estudiar l’efecte del mateix estímul extern en la composició d’una DCL complexa formada per espècies amb diferents càrregues. S’evidencià que el comportament de cada membre de la quimioteca està determinat per la seva informació estructural i per les múltiples relacions coadaptatives que aquest estableix amb la resta de membres de la xarxa molecular. Finalment, en el Capítol 5, es va utilitzar una DCL minimalista formada per espècies estereoisomèriques per estudiar el fenomen d’autoordenació homoquiral.

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Hernandez, Rylee. "Turbidity Removal Efficiency and Toxicity Issues Associated with the Chitosan-Based Dual Bio-Polymer Systems." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5299.

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Stormwater runoff can be a great concern in the State of Florida due to the impact the quality of the runoff water can have on the natural water bodies. Stormwater runoff can carry pollutants and sediments which can cause both physical and biological risks in an aquatic ecosystem such as a lake, river, or pond. Polymers, namely the chitosan-based dual polymer system, can be used remove the sediment from this runoff to ensure the safety of the state's water bodies. Three soils are used in this testing: AASTO soil classifications A-3(sandy soil) and A-2-4 (silty-sand), and a soil with a fine-grained limerock component. An optimum dose of the chitosan-based dual polymer system is first determined using jar testing. The optimum dose is the dose that reduces the final turbidity to 29 NTUS or below and creates significant flocs. The under dose and over dose are calculated based on the optimum dose. Using these dosages, field scale tests are conducted using two different treatment methods: a semi-passive treatment method and a passive treatment method. Whole effluent toxicity and residual chitosan tests are then conducted on the effluent from the field scale treatment methods. The passive treatment method is the best field scale treatment method when using the silty-sand and the soil with a fine-grained limerock component. The semi-passive treatment method is the best field scale treatment method when using the sandy soil. The passive treatment method with the silty-sand achieves a final turbidity of 123.9 NTUS (88.45% removal). The passive treatment method with the soil with a fine-grained limerock component achieves a final turbidity of 132 NTUS (83.86% removal). The semi-passive treatment method with the sandy soil achieves a final turbidity of 31.43 NTUS (82.04% removal). There is only significant toxicity associated with the tests using the effluent from the passive treatment method with the soil with a fine-grained limerock component which only uses the cationic polymer.
ID: 031001545; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: Manoj Chopra.; Title from PDF title page (viewed August 22, 2013).; Thesis (M.S.Env.E.)--University of Central Florida, 2012.; Includes bibliographical references (p. 402-405).
M.S.Env.E.
Masters
Civil, Environmental, and Construction Engineering
Engineering and Computer Science
Environmental Engineering

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Alazhari, Mohamed. "The effect of microbiological agents on the efficiency of bio-based repair systems for concrete." Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.720665.

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The induction of calcium precipitation via bacterial action has been studied increasingly in past years for self-(healing/sealing) concrete applications. Several of these studies have presented promising conclusions that microbiologically induced calcite precipitation might be a useful approach for remediation and rehabilitation of shallow cracks on existing structures. Such studies have noted the necessity to encapsulate the ingredients (bacteria, nutrients and organic precursors) separately for self-healing concrete using microbiologically induced calcite precipitation. However, during mixing there is a chance that capsules or other carriers of self-healing agents may release their cargoes and affect the properties of the concrete. Based on the above-mentioned information, the objective of this research was to evaluate whether or not shallow concrete cracks can be remediated using a bacteria-based system of repair. This research also aims to develop a new bacterial agent for use in the remediation of concrete cracks and to understand the effect of bacterial agents on the properties of cement-based mortar. The scope of this research is diverse; it requires an understanding of the factors that affect durability, water permeability, and cement properties such as initial and final setting time as well as the quality and quantity of the precipitated materials from the bacteria-based healing/sealing system. This research is broadly divided into four stages. In spite of a number of studies on the mechanism and efficiency of bacterial self-(healing/sealing) concrete, stage one investigates the effect of bacterial self-(healing/sealing) agents on the properties of fresh and hardened concrete. This information is critical for further research and implementation of this novel material. As with any additives, this may have a negative effect on the concrete’s final properties. This will be viewed with skepticism and limited uptake. This stage included the effects of the self-(healing/sealing) agents individually and as a combined medium on the mechanical properties of fresh concrete, the hydration kinetics, and early and final setting times, as well as strength and microstructure development over time. In addition, the effects of self-(healing/sealing) agents on hardened concrete were investigated to determine whether or not capsule rupture in response to a crack would have a detrimental effect on concrete properties in the area surrounding the crack. The results showed that self-(healing/sealing) agents such as sodium citrate greatly influenced hydration kinetics when the concentration exceeded 0.05% of the cement mass. Although the self-(healing/sealing) agents at 0.5% by binder mass retarded lightly of setting time, they had little negative effect on either 3- or 28-day strength. Calcium acetate, the dominant self-(healing/sealing) agent, acts as an accelerator while other components of the medium can have detrimental effects on the properties of fresh and hardened concrete. However, provided the quantity of self-healing/sealing agents released is below a certain threshold, it is unlikely that any detrimental effects will limit the application of bacterial self-healing/sealing concrete. Stage two included applying the main components of the self-sealing agents (calcium lactate and yeast extract) with the ingredients of the mortar mix and as a combined medium with mortar mix (two-stage bio-concrete/mortar) to investigate the ability of B. cohnii, B. halodurans and B. pseudofirmus to induce calcite precipitation through the cracks. The results showed that the sealing materials using each one of the three bacteria with the main components of self-sealing agents were very weak and were not distributed along the crack. Moreover, the primary components of self-sealing agents in 5% bio-cement mortar of the combined medium by binder mass distributed in entire samples were unable to seal cracks. Results showed that the samples dissolved in water, meaning that with more self-healing agent (SHA-1) ingredients added to the bio-mortar, the weaker and more ineffective it was with cement. Remediating cracks of hardening concrete with three different types of bacteria (B. cohnii, B. halodurans, and B. pseudofirmus) was performed during Stage three. Factors affecting the quantity and quality of healed materials included start and end healing time, the growth of each bacterium, and the viability of each bacterium in alkaline environment, all of which were also studied experimentally. Results showed that the three bacteria can produce calcium carbonate in a self-healing/sealing process, although B. pseudofirmus is the most suitable, efficient, and economical for remediating concrete cracks. The delivery of bacteria spores inside the concrete environment has always been the most challenging task. The main objective of stage four is to study the possibility of using successful previous delivery system used to remediate concrete cracks by using mineral agent to be used as delivery systems of bacteria spores. This study investigated three different encapsulate techniques within cement mortar namely calcium alginate beads (CAB), vascular tubes, and perlite. Results showed that CAB is very weak and very light due to low density, which cause decrease in their size, floating on the surface of mortar and poor distribution in mortar matrix. In spite of some passive mode effect variables such as tube length and diameter, the viscosity of bacteria solutions and their agents (SHA) and the ability of the glass tube to resist internal stresses were investigated. The results showed there was not enough data to demonstrate its ability to heal cracks. The mechanical and physical properties of uncoated and coated perlite, the ability of perlite to carry bacteria and its SHA, and the ability of bacteria and its SHA to form calcite out of perlite were investigated. The results demonstrated the ability of perlite to inoculate bacteria and its SHA, and the ability of this system to heal cracks. It is clear from the above perlite is the most suitable delivery system.

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Sahari, Ali Akbar. "Development of Bacteria-Based Bio-Hybrid Delivery Systems: Fabrication, and Characterization of Chemotaxis and Quorum Sensing." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/64995.

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Bio-hybrid approaches have recently provided a possible solution to address the challenge of on-board actuation, control and communication modules for micro/nanoscale cargo-carrying vehicles by integrating live prokaryotic or eukaryotic cells with synthetic objects. More specifically, because micro/nanoparticles are able to transport cargos efficiently and bacteria can play the role of targeted and selective delivery agents, a hybrid of these two can advance the current strategies for environmental monitoring, drug delivery and medical imaging. The main goal of this dissertation was to fabricate, assemble, and characterize different components of a mobile network of bacteria-based bio-hybrid systems for long-term applications in drug delivery and biosensing. First, a new library of bacteria-enabled delivery systems was developed by coupling live engineered bacteria with non-spherical particles and the transport of these bacteria-based systems was investigated in the absence and presence of chemical cues using microfluidic platforms. Next, a quorum-sensing (QS) based bacterial cell-cell communication network was characterized in a high-throughput manner in order to understand the coordinated behavior of the bacterial species ferrying the cargoes. Lastly, the QS behavior of a chemotactic population of the bacterial species in response to the endogenously produced signaling molecules was studied. The work presented in this dissertation lays the foundation for a well-characterized generation of bacteria-assisted cargo delivery devices with enhanced transport properties and capable of executing pre-programmed multi-agent coordinated tasks upon their arrival at the target site.
Ph. D.

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Staub, Dillon. "Bio-Inspired Hardware Security Defenses: A CRISPR-Cas-Based Approach for Detecting Trojans in FPGA Systems." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1563872470616901.

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CONTI, DANIELE. "Neuromorphic systems based on memristive devices - From the material science perspective to bio-inspired learning hardware." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2711511.

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Hardware computation is facing in the present age a deep transformation of its own paradigms. Silicon based computation is reaching its limit due to the physical constraints of transistor technology. As predicted by the Moore’s law, downscaling of transistor dimensions doubled each year since the 60s, leading nowadays to the extreme of 16-nm channel width of the present state-of-the-art technology. No further improvement is possible, since laws of physics impose a different electrical behavior when lower dimensions are attempted. Multiple solutions are then envisaged, spanning the range from quantum computing to neuromorphic computing. The present dissertation wants to be a preliminary study for understanding the opportunities enabled by neuromorphic computing based on resistive switching memories. In particular, brain inspires technology and architecture of new generation processors because of its unique properties: parallel and distributed computation, superposition of processing and memory unit, low power consumption, to cite only some of them. Such features make brain particularly efficient and robust against degraded data, further than particularly suitable to process and store in memory new nformation. Despite many research projects and some commercial products are already proposing brain-like computing processors, like spiNNaker or IBM’s Bluenorth, they only mimic the brain functioning with standard Silicon technology, that is inherently serial and distinguish between processing and memory unit. Resistive switching technology on the other hand, would allow to overcome many of these issues, enabling a far better match between biological and artificial neuromorphic computation. Resistive switching are, generally speaking, Metal-Insulator-Metal structures able to change their electrical conductance as a consequence of the history of applied electric signal. In such sense, they behave exactly as synapses do in a biological neural networks. For this reason, resistive switching when modeled as memristor, i.e. memory-resistor, can act as artificial synapses and, moreover, are particularly suitable to be interfaced with artificial Silicon neurons that are designed to replicate the biological behavior when excited with electric pulses. Anyhow, from the technological standpoint, there is still no standard on the design and fabrication of resistive switching, so that multiple structure and materials are investigated. In this dissertation, it is reported an analysis of multiple resistive switching devices, based on various materials, i.e. TiO2, ZnO and HfO, and device architectures, i.e. thin film and nanostructured devices, with the scope of both characterizing and comprehending the physics behind resistive switching phenomena. Furthermore, numerical simulations of artificial spiking neural networks, embedding Silicon neurons and HfO-based resistive switching are designed and performed, in order to give a systematic analysis of the performances reached by this new kind of computing paradigm.

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Al, Buhussain Ali. "Design and Analysis of an Adjustable and Configurable Bio-inspired Heuristic Scheduling Technique for Cloud Based Systems." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34794.

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Cloud computing environments mainly focus on the delivery of resources, platforms, and infrastructure as services to users over the Internet. More specifically, Cloud promises user access to a scalable amount of resources, making use of the elasticity on the provisioning of recourses by scaling them up and down depending on the demand. The cloud technology has gained popularity in recent years as the next big step in the IT industry. The number of users of Cloud services has been increasing steadily, so the need for efficient task scheduling is crucial for improving and maintaining performance. Moreover, those users have different SLAs that imposes different demands on the cloud system. In this particular case, a scheduler is responsible for assigning tasks to virtual machines in an effective and efficient matter to meet with the QoS promised to users. The scheduler needs to adapt to changes in the cloud environment along with defined demand requirements. Hence, an Adjustable and Configurable bio-inspired scheduling heuristic for cloud based systems (ACBH) is suggested. We also present an extensively comparative performance study on bio-inspired scheduling algorithms namely Ant Colony Optimization (ACO) and Honey Bee Optimization (HBO). Furthermore, a networking scheduling algorithm is also evaluated, which comprises Random Biased Sampling (RBS). The study of bio-inspired techniques concluded that all the bio-inspired algorithms follow the same flow that was later used in the development of (ACBH). The experimental results have shown that ACBH has a 90% better execution time that it closest rival which is ACO. ACBH has a better performance in terms of the fairness between execution time differences between tasks. HBO shows better scheduling when the objective consists mainly of costs. However, when there is multiple optimization objectives ACBH performs the best due to its configurability and adaptability.

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Triana, Dopico Julián. "Model-based analysis and metabolic design of a cyanobacterium for bio-products synthesis." Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/39351.

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The current investigation is aimed at the reconstruction and analysis of genome-scale metabolic models. Specifically, it is focused on the use of mathematical-computational simulations to predict the cellular metabolism behavior towards bio-products production. The photosynthetic cyanobacterium Synechococcus elongatus PCC7942 was studied as biological system. This prokaryotic has been used in several studies as a biological platform for the synthesis of several substances for industrial interest. These studies are based on the advantage of autotrophic systems, which basically requires light and CO2 for growth. The main objective of this thesis is the integration of different types of biological information, whose interaction can be extract applicable knowledge for economic interests. To this end, our study was addressed to the use of methods for modeling, analyzing and predicting the behavior of metabolic phenotypes of cyanobacterium. The work has been divided into chapters organized sequentially, where the starting point was the in silico metabolic reconstruction network. This process intent to join in a metabolic model of all chemical reactions codified in genome. The stoichiometric coefficients of each reactions, can be arranged into a sparse matrix (stoichiometric matrix), where the columns corresponds to reactions and rows to metabolites. As a result of this process the first model was obtained (iSyf646) than later was updated to another (iSyf714). Both were generated from data ¿omics published in databases, scientific reviews as well as textbooks. To validate them, each one of the stoichiometric matrix together with relevant constraints were used by simulation techniques based on linear programming. These reconstructions have to be flexible enough to allow autotrophic growth under which the organism grows in nature. Once the reconstructions were validated, environmental variations can be simulated and we were able to study its effects through changes in outline system parameters. Subsequently, synthetic capabilities were evaluated from the in silico models in order to design metabolic engineering strategies. To do this a genetic variation was simulated in reactions network, where the disturbed stoichiometric matrix was the object of the quadratic optimization methods. As a results sets of optimal solutions were generated to enhanced production of various metabolites of energetic interest such as: ethanol, n-butanol isomers, lipids and hydrogen, as well as lactic acid as the compound which is an interest to the industry. Furthermore, functionally coupled reactions have been studied and have been weighted to the importance in the production of metabolites. Finally, genome-scale metabolic models allow us to establish criteria to integrate different types of data to help of find important points of regulation that may be subject to genetic modification. These regulatory centers have been investigated under drastic changes of illumination and have been inferred operational principles of cyanobacterium metabolism. In general, this thesis presents the metabolic capabilities of photosynthetic cyanobacterium Synechococcus elongatus PCC7942 to produce substances of interest, being a potential biological platform for clean and sustainable production.
Triana Dopico, J. (2014). Model-based analysis and metabolic design of a cyanobacterium for bio-products synthesis [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39351
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van, Overmeeren Johannes R. S. "Development of waterborne and mild curing DWRs, formulated with fully bio-based substances." Thesis, KTH, Fiber- och polymerteknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-289161.

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”Durable water repellents (DWR) är textilimpregneringar som bidrar med vattenavvisande egenskaper som håller länge på funktionella tyg. Tyvärr är dessa hydrofobiska ytbehandlingar vanligtvis en källa till skadliga och persistenta kemikalier och de även är producerade från fossilbaserade resurser. Eftersom medvetenheten kring de här problemen har ökat, har innovativa, miljövänliga och biologiskt nedbrytbara alternativ tagits fram. Hittills finns dock inga produkter gjorda av 100% förnybara råvaror. I ett försök att utveckla en biobaserad, icke-giftig DWR som aktiveras under milda förhållanden, lades fokus på utveckling av en lagringsstabil sprayimpregneringsprodukt för hemmabruk. Vid formulering av emulsionerna/dispersionerna utvärderades en stor mängd biobaserade och kommersiellt tillgängliga hydrofobiska och amfifila molekyler med avseende den vattenavvisande effekt som de bidrog med på den behandlade textilen. Samtidigt bedömdes de producerade formuleringarna noggrant för att skapa förståelse om effekterna från ingredienserna och deras relation till produktens stabilitet. De kandidatprodukter som valdes ut och undersöktes vidare hade lovande vattenavvisande egenskaper och visade rimlig hållbarhetstid på åtminstone en månad i 40 °C. Standardiserade sprayscores på 3 (där 1 är sämst och 5 är bäst) nåddes efter 24 timmars hängtorkning i rumstemperatur. Dessutom uppnåddes sprayscore på 5 efter en kort, icke-industriell torktumling på låg temperatur och den behölls efter minst tio tvättar på syntetiska textiler. Utvalda produkter påverkade inte märkbart tygets andningsförmåga och majoriteten hade ingen influens på textilens mjukhet och färg. Förutom uppskalningsexperiment och partikelstorleksmätningar, granskades resultat med en tillämpningsstudie av formuleringarna på femton olika tygtyper. Produkternas effekter på utseende och känsla dokumenterades för de olika textilierna. Egenskaper som kontaktvinklar, sprayscores och tvättbeständighet bestämdes och jämfördes med en kommersiellt tillgänglig produkt.
Durable water repellents (DWR) are textile finishes that provide long-lasting water repelling properties to functional garments. However, these hydrophobic finishes are commonly a source of polluting and persistent chemicals and are produced from fossil resources. As a result of increasing awareness, innovation towards environmentally friendly and biodegradable alternatives has progressed, yet no 100% renewable sourced products are available. In an attempt to create a bio-based, non-toxic DWR, that is curable under mild conditions, focus was put on the development of a shelf stable spray impregnation product intended for consumer use. By formulating dispersion/emulsion systems, a wide variety of commercially available, renewable sourced amphiphilic and hydrophobic molecules were evaluated on their effect on the water repelling performance of treated textile fabrics. Simultaneously, the produced systems were assessed carefully to create understanding on the effect of substances and their corresponding ratios on the stability. Promising candidate products that were selected for further investigation showed reasonable stability for 1 month at 40 °C. Industrial standard spray ratings of 3 (where 1 is worst and 5 is best) after hang drying at room temperature could be reached within 24 hours. On top of that, spray ratings of 5 could be reached after short time, non-industrial tumble drying at low temperatures, which could even be retained for at least ten laundering cycles on synthetic textiles. The selected finishes did not have a measurable effect on the breathability of the treated fabrics, while the majority did not considerably affect the hands-feeling or colour of the textiles. Besides several scaling up experiments and particle size measurements, extrapolation of the findings was carried out by testing the developed formulations on fifteen different types of textiles. Effects on appearance and feel were documented, additionally, contact angle, spray score, and wash durability were determined and compared with a commercially available product.

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Mora, Anne-Sophie. "Élaboration de revêtements époxy pour contact alimentaire à empreinte environnementale réduite A perspective approach on the amine reactivity and the hydrogen bonds effect on epoxy-amine systems vanillin-derived amines for bio-based thermosets synthesis of biobased reactive hydroxyl amines by amination reaction of cardanol-based epoxy monomers synthesis of pluri-functional amine hardeners from bio-based aromatic aldehydes for epoxy amine thermosets cardanol-based epoxy monomers for high thermal properties thermosets." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2019. http://www.theses.fr/2019ENCM0012.

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Les travaux de thèse présentés sont issus d’une collaboration industrielle avec la société Nouvelle Sogatra, spécialisée dans la conception, la fabrication et la commercialisation de revêtements de protection bi-composants répondant aux normes d’alimentarité. L’objectif principal de ce projet est de proposer de nouveaux revêtements époxydiques performants en utilisant des produits biosourcés et, dans l’idéal, moins dangereux pour l’Homme et pour l’environnement. Ces travaux de thèse s’axent autour de l’identification de nouvelles méthodologies de synthèse de durcisseurs aminés biosourcés qui soient facilement applicables industriellement.L’amination directe des groupements époxy par ouverture de cycle en présence d’ammoniaque ainsi que l’amination réductrice via la synthèse d’imine ont été sélectionnées comme voies de synthèse pour leur facilité d’application et leur caractère respectueux de l’environnement. Pour cela, des précurseurs commerciaux biosourcés et/ou à toxicité réduite ont été sélectionnés. De nouveaux durcisseurs aminés ont été synthétisés à partir de bio ressources telles que la vanilline, le cardanol et le benzaldéhyde. Ces durcisseurs ont ensuite été utilisés pour la synthèse de système époxy-amine thermodurcissables dont les propriétés physico-chimiques et thermodynamiques ont été caractérisées
The presented PhD works were initiated by an industrial collaboration with the company Nouvelle Sogatra, specialized in the design, manufacturing and marketing of two component protective coatings for food contact. The aim of this project is to offer new high-performance epoxy thermosets from bio based reactants and, ideally with a low impact on the health and the environment. This PhD works focus on the identification of new synthesis methodologies of bio-based amine hardeners, which could be easily industrialized.The direct epoxy amination by ring opening using ammonia and the reductive amination via imine synthesis were selected as synthesis routes for their simple utilization and their eco friendly character. Hence, bio based and/or reduced toxicity commercial precursors were selected. New amine hardeners were synthesized from bio resources, such as vanillin, cardanol and benzaldehyde. These hardeners were then used to synthesize epoxy-amine thermosets, whose thermomechanical and physicochemical properties were characterized

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Xu, Linlin. "Wireless Hybrid Bio-Sensing withMobile based Monitoring System." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-143211.

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Personal telehealth plays a crucial role in addressing global challenges of aging population and rising cost for health care. Tiny and wirelessly connected medical sensors, for example embedded in clothes or on the body, will be an integrated part of lifestyle, and will allow hospitals to remotely diagnose patients in their home. In this thesis, a wireless bio-sensing with smart phone based monitoring system is proposed to provide a home based telehealth care for continuous monitoring. The system consists of two main parts: a wireless sensor and a health application on the smart phone. This thesis is to design the first part of the system - a wireless temperature and electrocardiography (ECG) sensor. The sensor integrates ECG front-end analog block, a micro-controller and a Bluetooth low energy (BLE) connectivity IC on a single board. To achieve the miniaturization of the sensor and users’ comfort in mind, the sensor is designed as a miniaturized hybrid system utilizing flexible batteries and printed electrodes. This can efficiently detect ECG signals and transfer them to a smart phone through BLE link.

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Espeleta, Gonzalez David <1995&gt. "DEVELOPMENT OF NOVEL PROTEIN-BASED DRUG DELIVERY SYSTEMS." Master's Degree Thesis, Università Ca' Foscari Venezia, 2021. http://hdl.handle.net/10579/19858.

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Cancer is a vast group of diseases caused by mutations in the human DNA that result in an uncontrollable growth of cells which can spread around the body. Cancer is one of the leading causes of mortality worldwide. Advancements in CTXs allowed the development of effective treatments. However, most CTX agents present poor pharmacokinetic and safety profiles. Development of appropriate drug carriers is one of the potential solutions for counteracting these drawbacks. The aim of this thesis is to make advancements in the engineering of a protein based carrier, with higher binding affinity to the CTX agents. Furthermore, explore the expression of fusion proteins with the aim of improving the characteristics of the delivery system. In the first phase of the project, 55 genes, corresponding to human serum albumin (HSA) mutants previously engineered to have higher binding affinity to doxorubicin or 9-aminocamptothecin, were cloned by Gibson assembly (GA). 52 of these mutants were then successfully expressed in a yeast display system, which will be used for future binding affinity experiments. For the second part of this thesis, a cloning system using restriction enzymes (RE) was designed in order to produce a series of HSA oligomers. The HSA dimer was successfully cloned, expressed, and purified. However it showed a complete degradation over time. Therefore, alternative cloning strategies or changes in the design of the linker between the monomers should be employed.

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MAZZITELLI, Stefania. "Cell encapsulation systems based on hybrid hydrogels." Doctoral thesis, Università degli studi di Ferrara, 2012. http://hdl.handle.net/11392/2389279.

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The entrapment of cells into biomaterials is one of the most appealing and usefulness tool in tissue engineering and cell based therapy applications. Cell encapsulation procedures allow the immunoisolation of cells from the surrounding environment, after their transplantation and the maintenance of the normal cellular physiology. In the current PhD work, various microencapsulation cell procedures are reported, based on a gas driven mono-jet device, a vibrating-nozzle procedure and microfluidics. All the analysed procedures were critically evaluated and applied to cells from different sources. The obtained microcapsules were characterized by excellent morphological characteristics and a very narrow size distribution. Interestingly, the results demonstrated that the microencapsulation procedures did not alter the morphology, viability and functions of the embedded cells. Moreover, the production of engineered microcapsules or microfibres has been also developed with the aim of enhancing mechanical characteristics, viability and functional life-span of the entrapped cells. In conclusion, the encapsulation technologies, here presented, represent a promising strategy for the treatment of many pathologies open to further development and scaling up towards regulatory agencies approval.

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Thiele, Johannes C. "Deep learning in event-based neuromorphic systems." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS403/document.

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Inférence et apprentissage dans les réseaux de neurones profonds nécessitent une grande quantité de calculs qui, dans beaucoup de cas, limite leur intégration dans les environnements limités en ressources. Les réseaux de neurones évènementiels de type « spike » présentent une alternative aux réseaux de neurones artificiels classiques, et promettent une meilleure efficacité énergétique. Cependant, entraîner les réseaux spike demeure un défi important, particulièrement dans le cas où l’apprentissage doit être exécuté sur du matériel de calcul bio-inspiré, dit matériel neuromorphique. Cette thèse constitue une étude sur les algorithmes d’apprentissage et le codage de l’information dans les réseaux de neurones spike.A partir d’une règle d’apprentissage bio-inspirée, nous analysons quelles propriétés sont nécessaires dans les réseaux spike pour rendre possible un apprentissage embarqué dans un scénario d’apprentissage continu. Nous montrons qu’une règle basée sur le temps de déclenchement des neurones (type « spike-timing dependent plasticity ») est capable d’extraire des caractéristiques pertinentes pour permettre une classification d’objets simples comme ceux des bases de données MNIST et N-MNIST.Pour dépasser certaines limites de cette approche, nous élaborons un nouvel outil pour l’apprentissage dans les réseaux spike, SpikeGrad, qui représente une implémentation entièrement évènementielle de la rétro-propagation du gradient. Nous montrons comment cette approche peut être utilisée pour l’entrainement d’un réseau spike qui est capable d’inférer des relations entre valeurs numériques et des images MNIST. Nous démontrons que cet outil est capable d’entrainer un réseau convolutif profond, qui donne des taux de reconnaissance d’image compétitifs avec l’état de l’art sur les bases de données MNIST et CIFAR10. De plus, SpikeGrad permet de formaliser la réponse d’un réseau spike comme celle d’un réseau de neurones artificiels classique, permettant un entraînement plus rapide.Nos travaux introduisent ainsi plusieurs mécanismes d’apprentissage puissants pour les réseaux évènementiels, contribuant à rendre l’apprentissage des réseaux spike plus adaptés à des problèmes réels
Inference and training in deep neural networks require large amounts of computation, which in many cases prevents the integration of deep networks in resource constrained environments. Event-based spiking neural networks represent an alternative to standard artificial neural networks that holds the promise of being capable of more energy efficient processing. However, training spiking neural networks to achieve high inference performance is still challenging, in particular when learning is also required to be compatible with neuromorphic constraints. This thesis studies training algorithms and information encoding in such deep networks of spiking neurons. Starting from a biologically inspired learning rule, we analyze which properties of learning rules are necessary in deep spiking neural networks to enable embedded learning in a continuous learning scenario. We show that a time scale invariant learning rule based on spike-timing dependent plasticity is able to perform hierarchical feature extraction and classification of simple objects of the MNIST and N-MNIST dataset. To overcome certain limitations of this approach we design a novel framework for spike-based learning, SpikeGrad, which represents a fully event-based implementation of the gradient backpropagation algorithm. We show how this algorithm can be used to train a spiking network that performs inference of relations between numbers and MNIST images. Additionally, we demonstrate that the framework is able to train large-scale convolutional spiking networks to competitive recognition rates on the MNIST and CIFAR10 datasets. In addition to being an effective and precise learning mechanism, SpikeGrad allows the description of the response of the spiking neural network in terms of a standard artificial neural network, which allows a faster simulation of spiking neural network training. Our work therefore introduces several powerful training concepts for on-chip learning in neuromorphic devices, that could help to scale spiking neural networks to real-world problems

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POLO, N. CUEVAS. "MASS SPECTROMETRY BASED PROFILING OF TWO DIFFERENT BIOLOGICAL SYSTEMS FOR POSSIBLE CLINICAL APPLICATION." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/246228.

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Several techniques including two-dimensional electrophoresis, imaging, mass spectrometry, and bioinformatics are used in proteomics to identify, quantify, and characterize proteins for clinical applications. The main aim is to identify proteins involved in pathological processes and to understand how illness can lead to altered protein expression in order to develop new diagnostic and prognostic tests, to identify new therapeutic targets, and eventually to allow the design of individualized patient treatment. For this purpose this dissertation is divided into two main chapters. Chapter one concerns the development of a novel method to isolate exosomes. Normal human urine contains large numbers of exosomes, which are 40 to 100 nm vesicles that originate in multivesicular bodies from every renal epithelial cell type facing the urinary space. Exosomes are rich in potential biomarkers, especially membrane proteins such as transporters and receptors that may be up- or downregulated during disease states. Differential centrifugation methods are commonly used to purify exosomes from urine. Here, we developed a new method to isolate exosomes by solubilizing exosomes in 1 % Sarkosyl, an anphyphilic detergent, followed by a carbon fractionation. We used LC-MS/MS to profile the proteome of human urinary exosomes. Overall, the analysis unambiguously identified 1618 proteins, showing an enrichment of 61.3% in exosomal proteins, after performing a Gene Ontology analysis. Thus, our modified exosome precipitation method is a simple, fast, highly scalable, and effective alternative for the isolation of exosomes. It may facilitate either the identification of exosomal biomarkers from urine or the production of drug delivery devices. Chapter two concerns the identification of proteins in adhesive material of the capsalid Neobenedenia girellae by a proteomic approach based on de novo sequencing and database search to overcome the lack of information concerning the genome of these parasites. Glandular secretions were obtained by a new method, set up in our laboratory, which allowed collecting a small amount of secretion without any contamination from other tissues either from the parasites as well as from the skin of the host. The proteomic analysis reveals that the adhesive is mainly composed of cytoskeletal proteins (actin, keratin and tubulin) but contains also ATP-synthase, 78 kDa glucose regulated protein and albumin. This work reports for the first time the characterization of a novel bioadhesive material used by capsalid parasites to adhere to fish. Such information broadens our knowledge of the molecular mechanisms involved in adhesiveness of parasites to hosts. Moreover, it offers new clues in understanding the mechanism of stickiness and adhesion of cytoskeleton components, often involved in both physiological and pathological processes, including neurodegenerative diseases.

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Fouad, Marwa. "Towards Template Security for Iris-based Biometric Systems." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/22736.

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Personal identity refers to a set of attributes (e.g., name, social insurance number, etc.) that are associated with a person. Identity management is the process of creating, maintaining and destroying identities of individuals in a population. Biometric technologies are technologies developed to use statistical analysis of an individual’s biological or behavioral traits to determine his identity. Biometrics based authentication systems offer a reliable solution for identity management, because of their uniqueness, relative stability over time and security (among other reasons). Public acceptance of biometric systems will depend on their ability to ensure robustness, accuracy and security. Although robustness and accuracy of such systems are rapidly improving, there still remain some issues of security and balancing it with privacy. While the uniqueness of biometric traits offers a convenient and reliable means of identification, it also poses the risk of unauthorized cross-referencing among databases using the same biometric trait. There is also a high risk in case of a biometric database being compromised, since it’s not possible to revoke the biometric trait and re-issue a new one as is the case with passwords and smart keys. This unique attribute of biometric based authentication system poses a challenge that might slow down public acceptance and the use of biometrics for authentication purposes in large scale applications. In this research we investigate the vulnerabilities of biometric systems focusing on template security in iris-based biometric recognition systems. The iris has been well studied for authentication purposes and has been proven accurate in large scale applications in several airports and border crossings around the world. The most widely accepted iris recognition systems are based on Daugman’s model that creates a binary iris template. In this research we develop different systems using watermarking, bio-cryptography as well as feature transformation to achieve revocability and security of binary templates in iris based biometric authentication systems, while maintaining the performance that enables widespread application of these systems. All algorithms developed in this research are applicable on already existing biometric authentication systems and do not require redesign of these existing, well established iris-based authentication systems that use binary templates.

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Anaya, Vejar Maribel. "Design and validation of structural health monitoring system based on bio-inspired algorithms." Doctoral thesis, Universitat Politècnica de Catalunya, 2016. http://hdl.handle.net/10803/396370.

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The need of ensure the proper performance of the structures in service has made of structural health monitoring (SHM) a priority research area. Researchers all around the world have focused efforts on the development of new ways to continuous monitoring the structures and analyze the data collected from the inspection process in order to provide information about the current state and avoid possible catastrophes. To perform an effective analysis of the data, the development of methodologies is crucial in order to assess the structures with a low computational cost and with a high reliability. These desirable features can be found in biological systems, and these can be emulated by means of computational systems. The use of bio-inspired algorithms is a recent approach that has demonstrated its effectiveness in data analysis in different areas. Since these algorithms are based in the emulation of biological systems that have demonstrated its effectiveness for several generations, it is possible to mimic the evolution process and its adaptability characteristics by using computational algorithms. Specially in pattern recognition, several algorithms have shown good performance. Some widely used examples are the neural networks, the fuzzy systems and the genetic algorithms. This thesis is concerned about the development of bio-inspired methodologies for structural damage detection and classification. This document is organized in five chapters. First, an overview of the problem statement, the objectives, general results, a brief theoretical background and the description of the different experimental setups are included in Chapter 1 (Introduction). Chapters 2 to 4 include the journal papers published by the author of this thesis. The discussion of the results, some conclusions and the future work can be found on Chapter 5. Finally, Appendix A includes other contributions such as a book chapter and some conference papers.
La necesidad de asegurar el correcto funcionamiento de las estructuras en servicio ha hecho de la monitorización de la integridad estructural un área de gran interés. Investigadores en todas las partes del mundo centran sus esfuerzos en el desarrollo de nuevas formas de monitorización contínua de estructuras que permitan analizar e interpretar los datos recogidos durante el proceso de inspección con el objetivo de proveer información sobre el estado actual de la estructura y evitar posibles catástrofes. Para desarrollar un análisis efectivo de los datos, es necesario el desarrollo de metodologías para inspeccionar la estructura con un bajo coste computacional y alta fiabilidad. Estas características deseadas pueden ser encontradas en los sistemas biológicos y pueden ser emuladas mediante herramientas computacionales. El uso de algoritmos bio-inspirados es una reciente técnica que ha demostrado su efectividad en el análisis de datos en diferentes áreas. Dado que estos algoritmos se basan en la emulación de sistemas biológicos que han demostrado su efectividad a lo largo de muchas generaciones, es posible imitar el proceso de evolución y sus características de adaptabilidad al medio usando algoritmos computacionales. Esto es así, especialmente, en reconocimiento de patrones, donde muchos de estos algoritmos brindan excelentes resultados. Algunos ejemplos ampliamente usados son las redes neuronales, los sistemas fuzzy y los algoritmos genéticos. Esta tesis involucra el desarrollo de unas metodologías bio-inspiradas para la detección y clasificación de daños estructurales. El documento está organizado en cinco capítulos. En primer lugar, se incluye una descripción general del problema, los objetivos del trabajo, los resultados obtenidos, un breve marco conceptual y la descripción de los diferentes escenarios experimentales en el Capítulo 1 (Introducción). Los Capítulos 2 a 4 incluyen los artículos publicados en diferentes revistas indexadas. La revisión de los resultados, conclusiones y el trabajo futuro se encuentra en el Capítulo 5. Finalmente, el Anexo A incluye otras contribuciones tales como un capítulo de libro y algunos trabajos publicados en conferencias.

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Chen, Hung Tat. "A portable electronic nose micro-system based on bio-inspired log-spike processing /." View abstract or full-text, 2009. http://library.ust.hk/cgi/db/thesis.pl?ECED%202009%20CHEN.

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Travan, Andrea. "Nanocomposite systems based on metal nanoparticles and polysaccharides for biomedical applications." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3629.

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2008/2009
Questo lavoro riguarda lo sviluppo di materiali nanocompositi per applicazioni biomediche e si configura all’ interno del progetto europeo “Newbone” (EU-FP6); in particolare, lo scopo principale della tesi era realizzare un rivestimento biocompatibile e dotato di proprietà antibatteriche per protesi ortopediche. Sono stati preparati sistemi nanocompositi basati su un polisaccaride derivato dal chitosano (Chitlac) che permette di ottenere soluzioni colloidali di nanoparticelle (argento e oro) con proprietà antibatteriche. Parallelamente, è stato studiato un particolare meccanismo chimico di riduzione degli ioni argento ad opera dei residui di lattitolo del Chitlac; le proprietà ottiche delle nanoparticelle ottenute attraverso questo meccanismo sono state valutate attraverso spettroscopia Raman, evidenziando la possibilità di avere un incremento del segnale grazie al verificarsi dell’ effetto SERS. Essendo state riscontrate migliori proprietà biologiche del sistema a base di argento (Chitlac-nAg) rispetto a quello a base di oro in termini di efficacia antimicrobica e biocompatibilità, Chitlac-nAg è stato scelto per i successivi studi di realizzazione del rivestimento per la protesi. Test sul meccanismo antimicrobico della soluzione ChitlacnAg hanno dimostrato l’interazione tra le nanoparticelle e la membrana batterica. Allo stesso tempo, poiché la mancanza di barriere fisiche può favorire la diffusione delle nanoparticelle all’ interno delle cellule eucariote con rischio di effetti citotossici causati dalla loro internalizzazione, si è voluto realizzare delle strutture tridimensionali a base di Chitlac in grado di intrappolare le nanoparticelle. A questo scopo, sono state sfruttate le proprietà di gelificazione del polisaccaride alginato in modo da ottenere un sistema semi-solido in miscela con Chitlac-nAg; il materiale ottenuto possiede marcate proprietà antibatteriche senza però risultare tossico per le cellule eucariote, come dimostrato da test in vitro e in vivo. Questo risultato è particolarmente importante in relazione allo stato dell’ arte sull’ argomento. Poiché la parte portante della protesi è costituita da un polimero metacrilico, al fine di rivestire questo materiale di substrato è stata messa a punto una tecnica basata sull’ attivazione della superficie e successiva deposizione del rivestimento a base di Chitlac. Questa tecnica permette di ottenere un rivestimento nanocomposito costituito da nanoparticelle di argento incorporate nella matrice di Chitlac. Grazie a questo strato bioattivo la superficie della protesi acquisisce un’ efficace attività antibatterica che si manifesta quando i batteri entrano in diretto contatto con il materiale. Inoltre, test in vitro hanno dimostrato che le cellule eucariote aderiscono e proliferano sul rivestimento nanocomposito, suggerendo quindi una buona integrazione del materiale nei tessuti attorno all’ impianto. La combinazione di tali proprietà ha determinato la scelta di questo rivestimento per il test in vivo su “minipig” a conclusione del progetto europeo: questo test è al momento in via di svolgimento e da esso ci si può attendere una conferma degli incoraggianti risultati ottenuti dagli studi in vitro.
The present work is focused on the development of nanocomposite systems for biomedical applications and has been carried out in the framework of the European Project called “Newbone” (EU-FP6); in particular, the main goal of the thesis was to realize biocompatible coatings for orthopedic prosthesis endowed with antimicrobial properties. Nanocomposite systems based on a chitosan-derived polysaccharide (Chitlac) that stabilizes metal nanoparticles (silver and gold) have been prepared in colloidal solutions which possess broad spectrum antibacterial properties. As a complementary work, it was studied and defined a particular chemical mechanism of silver ions reduction carried out by the lactose moieties of Chitlac; the optical properties of the metallic nanoparticles obtained through this mechanism were tested by means of Raman spectroscopy, thus detecting considerable enhancements of the signal due to the SERS effect (Surface Enhanced Raman Scattering). Given the better biological properties of silver-based systems (Chitlac-nAg) with respect to gold in terms of antimicrobial efficacy and biocompatibility, only the former metal was chosen in the following steps towards the preparation of the nanocomposite coating for the prosthesis. Studies on the biocidal mechanism of the Chitlac-nAg solution ascribed the activity to the interaction metal-bacteria membrane. On the other hand, since the lack of physical barriers to nanoparticle diffusion into eukaryotic cells determines the risk of a massive uptake with cytotoxic outcomes, we focused our attention toward the preparation of Chitlac-based threedimensional structures entrapping silver nanoparticles. To this end, the gel forming properties of the polysaccharide alginate were exploited allowing the production of a semi-solid system in a mixture with Chitlac-nAg: this material displays potent antibacterial properties without showing cytotoxic effects towards eukaryotic cells, as verified by in vitro and in vivo tests. Such result was particularly important in relation to the state of the art in this research field. Since the core material of the prosthesis is made of methacrylic thermosets, in order to coat this substrate material we have devised a technique based on surface activation followed by deposition of the Chitlac-based layer. Such technique allows obtaining a nanocomposite coating where silver nanoparticles are entrapped within the Chitlac matrix. This bioactive layer endows the thermoset surface with considerable antimicrobial properties, as bacteria are rapidly killed upon direct contact with the material. At the same time, in vitro tests proved that eukaryotic cells adhere and proliferate on the nanocomposite coating, which indicates the possibility to have good integration of the material in the tissues surrounding the implant. The combination of these properties determined the choice of our coating for the final in vivo test in a minipig model as a conclusion of the European project; this test is in progress at the moment and it will hopefully confirm the encouraging studies in vitro.
XXII Ciclo
1981

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Mao, An. "AN INVESTIGATION OF USING PYROLYSIS BIO-OIL AS PART OF THE BINDER SYSTEM FOR WOOD-BASED COMPOSITES." MSSTATE, 2009. http://sun.library.msstate.edu/ETD-db/theses/available/etd-03262009-092337/.

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The objective of this research was to investigate the feasibility of using the pyrolysis bio-oil as part of a binder system for wood-based composites. Liquid products obtained from pyrolysis process of pine wood were mixed with reactants, such as isocyanate. The adhesive binder system was blended with flakes to fabricate flakeboard. The effect of the resin content and the mix ratio of the adhesive on the physical and mechanical properties of the flakeboard were examined. Dynamic mechanical analysis (DMA) was also employed to investigate the thermal properties of the adhesives. The results indicated that a bio-oil content of 25% showed comparable properties to those produced by pure pMDI adhesive. A good correlation between the DMA results and the mechanical properties of the flakeboard was also obtained. The increase of bio-oil content in the adhesive system improved the curing speed but reduced the adhesive stiffness.

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Guo, Bin. "A bio-inspired electronic nose micro-system based on integrated gas sensor array and log-spike processing /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20GUO.

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30

Wang, Jingyu. "Contribution to study and implementation of a bio-inspired perception system based on visual and auditory attention." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1039/document.

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L'objectif principal de cette thèse porte sur la conception d'un système de perception artificiel permettant d'identifier des scènes ou évènements pertinents dans des environnements complexes. Les travaux réalisés ont permis d'étudier et de mettre en œuvre d'un système de perception bio-inspiré basé sur l'attention visuelle et auditive. Les principales contributions de cette thèse concernent la saillance auditive associée à une identification des sons et bruits environnementaux ainsi que la saillance visuelle associée à une reconnaissance d'objets pertinents. La saillance du signal sonore est calculée en fusionnant des informations extraites des représentations temporelles et spectrales du signal acoustique avec une carte de saillance visuelle du spectrogramme du signal concerné. Le système de perception visuelle est quant à lui composé de deux mécanismes distincts. Le premier se base sur des méthodes de saillance visuelle et le deuxième permet d'identifier l'objet en premier plan. D'autre part, l'originalité de notre approche est qu'elle permet d'évaluer la cohérence des observations en fusionnant les informations extraites des signaux auditifs et visuels perçus. Les résultats expérimentaux ont permis de confirmer l'intérêt des méthodes utilisées dans le cadre de l'identification de scènes pertinentes dans un environnement complexe
The main goal of these researches is the design of one artificial perception system allowing to identify events or scenes in a complex environment. The work carried out during this thesis focused on the study and the conception of a bio-inspired perception system based on the both visual and auditory saliency. The main contributions of this thesis are auditory saliency with sound recognition and visual saliency with object recognition. The auditory saliency is computed by merging information from the both temporal and spectral signals with a saliency map of a spectrogram. The visual perception system is based on visual saliency and recognition of foreground object. In addition, the originality of the proposed approach is the possibility to do an evaluation of the coherence between visual and auditory observations using the obtained information from the features extracted from both visual and auditory patters. The experimental results have proven the interest of this method in the framework of scene identification in a complex environment

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Lorenzetti, Jean-Valère. "Composés phénoliques du liège vierge (Quercus suber L.) : extraction, caractérisation et application aux retardateurs de flamme intumescents pour le bois." Electronic Thesis or Diss., Corte, 2024. http://www.theses.fr/2024CORT0021.

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Ces travaux de thèse s’inscrivent dans la recherche de nouvelles solutions ignifuges durables, en réponse aux enjeux sécuritaires liés à l’augmentation des risques d’incendie dans le monde. L'utilisation croissante du bois dans la construction, couplée aux perturbations climatiques et aux enjeux sanitaires et environnementaux renforce le besoin de développer des agents ignifuges respectueux de l'environnement. Dans cette optique, les systèmes intumescents, qui forment une couche isolante expansive lors d’une exposition à la chaleur, se montrent particulièrement prometteurs. Ces derniers reposent en effet sur une réaction de condensation entre un agent libérateur d’acide et un agent riche en fonctions hydroxyles ce qui permet d’envisager l’incorporation de composés naturels dans ces derniers. Cette thèse vise ainsi à évaluer le potentiel de valorisation des composés phénoliques extraits du liège vierge (Quercus suber L.), un sous-produit sylvicole peu valorisé, dans des formulations intumescentes biosourcées.La première phase des travaux a porté sur l’extraction et la caractérisation chimique des composés phénoliques du liège vierge. Après une comparaison de différentes techniques, l’extraction assistée par pression s’est révélée la plus efficace, avec une vitesse d’extraction accrue (x 64 par rapport à la macération mécanique) et une consommation de solvant réduite (- 79 %). L’extrait aqueux, qui a présenté une bonne résistance thermique (54 % de masse résiduelle à 600 °C) et une forte teneur en polyphénols, a été sélectionné pour une étude approfondie. L’analyse par CLHP – SM a permis d’identifier et quantifier les composés majoritaires de l’extrait parmi lesquels sont retrouvés des ellagitanins (castalagine, vescalagine) et des acides phénoliques (acide ellagique, acide gallique). L’acide gallique a été sélectionné et utilisé comme produit standard de référence pour comparer les performances des systèmes ignifuges.Dans un deuxième temps, les extraits naturels de liège vierge ont été intégrés dans des formulations intumescentes en étant combinés au polyphosphate d’ammonium (APP) comme précurseur d’acide. Les analyses thermogravimétriques ont permis de développer un indice de performance basé sur la dégradation thermique des formulations, démontrant une forte synergie entre les extraits de liège et l’APP. L’observation macroscopique de l’intumescence a mis en évidence une expansion marquée des couches charbonnées issues du système intégrant l’extrait de liège riche en composés phénoliques.La dernière phase des travaux visait à évaluer l’efficacité des formulations dans des revêtements intumescents appliqués au bois de sapin. Lors des tests au calorimètre à cône à 50 kW.m-2, la formulation intégrant l’extrait de liège a permis une amélioration notable de la réaction au feu du bois. L’inflammation a par exemple été retardée de 40 secondes et le premier pic de dégagement de chaleur réduit de 65 %. Il a également été montré que les formulations biosourcées se démarquaient par leur meilleure cinétique d'expansion par rapport aux systèmes témoins. Cela constitue un atout majeur pour la protection contre les feux de végétation de forte intensité et à cinétique rapide. Pour évaluer cet apport, des essais innovants face à un feu de végétation semi-contrôlé (pleine échelle – plateforme EXPLORII) ont été réalisés. Ces derniers ont permis de mettre en lumière une meilleure capacité des systèmes biosourcés, en comparaison de systèmes témoin optimisés, à limiter l’échauffement du bois ce qui constitue une voie de valorisation prometteuse
This thesis focuses on the search for new sustainable fire-retardant solutions, in response to the increasing fire risks worldwide. The growing use of wood in construction, combined with climate change and environmental and health challenges, underscores the need to develop environmentally friendly fire-retardant agents. In this context, intumescent systems, which form an expansive insulating layer when exposed to heat, show significant promise. These systems rely on a condensation reaction between an acid-releasing agent and a hydroxyl-rich agent, making the incorporation of natural compounds feasible. This thesis aims to assess the potential of valorizing phenolic compounds extracted from virgin cork (Quercus suber L.), an underutilized forestry by-product, in bio-based intumescent formulations.The first phase of the work involved the extraction and chemical characterization of phenolic compounds from virgin cork. After comparing different techniques, pressure-assisted extraction proved the most effective, with an extraction rate 64 times faster than mechanical maceration and a 79% reduction in solvent use. The aqueous extract, which exhibited good thermal resistance (54% residual mass at 600 °C) and high polyphenol content, was selected for further study. HPLC-MS analysis identified and quantified major compounds in the extract, including ellagitannins (castalagin, vescalagin) and phenolic acids (ellagic acid, gallic acid). Gallic acid was selected and used as a reference standard to compare the performance of fire-retardant systems.In the second phase, natural virgin cork extracts were integrated into intumescent formulations, combined with ammonium polyphosphate (APP) as an acid precursor. Thermogravimetric analyses allowed the development of a performance index based on the thermal degradation of the formulations, demonstrating a strong synergy between the cork extracts and APP. Macroscopic observation of the intumescence revealed significant expansion of the char layers produced by the system incorporating cork extract rich in phenolic compounds.The final phase of the research aimed to evaluate the effectiveness of the formulations in intumescent coatings applied to spruce wood. Cone calorimeter tests at 50 kW.m-2 showed a notable improvement in the wood's fire performance when incorporating cork extract. Ignition was delayed by 40 seconds, and the first heat release peak was reduced by 65%. The bio-based formulations also stood out for their better expansion kinetics compared to control systems, a key advantage for protection against high-intensity, fast-spreading wildfires. To assess this potential, innovative large-scale tests against a semi-controlled vegetation fire (full scale – EXPLORII platform) were conducted. These tests highlighted the superior ability of bio-based systems, compared to optimized control systems, to limit wood heating, presenting a promising valorization pathway.In conclusion, this thesis demonstrates the potential of virgin cork as a source of bio-based compounds for fire-retardant formulations. While further improvements are needed, particularly in terms of extract purification and formulation optimization, this work opens the door to the sustainable valorization of bioresources for fire safety applications, contributing to a circular economy

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Briani, Cristiana. "A study of the biogeochemical cycle of the biogenic carbon to assess the circularity of bio-based products." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17413/.

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The level of circularity of a product or a process is an emerging characteristic in international labelling; however, only fossil-derived materials are evaluated through circularity indices, e.g. the Material Circularity Indicator, MCI, developed by Ellen MacArthur Foundation. This work proposes a complementary index which can serve as Correction Factor (CF) to the MCI, designed specifically for biologically based and renewable materials, such as bio-based products. This index, named MCICFbio, which focuses on the timings of the carbon’s biogeochemical cycle and the effects of human actions on its duration. The bio-based materials can store carbon for a period of time, determined by the lifespan of the bio-product itself. Therefore, MCICFbio quantifies the ‘carbon net savings’ as a function of the effect of the incorporation of Carbon (C) in bio-products on the C cycle duration, compared to a reference system with no bio-based materials production. MCICFbio ranges from 0 to 1, where 0 represents a total carbon loss, 1 total carbon conservation and 0.5 equilibrium, all values being referred to the duration of a cycle of the reference system. Thus, values above 0.5 indicate a gain with respect to the reference system in a given period. The chosen case study (AIB) is the production of bio-based mulch films, tested against two reference systems: a natural prairie (NPR) and a business-as-usual agro-industrial system (AIR). The mulch film life cycle is roughly one year, with a rapid manufacturing process, a short storage and a degradation period in situ assumed equal to five months. The modelling of carbon flows, stocks and feedbacks in different scenarios is conducted through a System Dynamics (SD) approach. Results show that the accumulation of carbon into mulch films delays the carbon release and results in MCICFbio = 0.66 for AIB against NPR and 0.85 for AIB against AIR. Assumptions and limitations of the index are discussed for future research.

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ROCCHETTI, GABRIELE. "GLUTEN - FREE FOOD SYSTEM: SCREENING OF POLYPHENOLS AND THEIR BIO ACCESSIBILITY THROUGH IN VITRO GASTROINTESTINAL PROCESSES AND METABOLOMICS - BASED STUDIES." Doctoral thesis, Università Cattolica del Sacro Cuore, 2019. http://hdl.handle.net/10280/57897.

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Circa l’1% della popolazione mondiale è colpita da celiachia. I celiaci sono costretti a seguire una dieta priva di glutine e molto spesso quest’ultima risulta essere sbilanciata e/o carente in molti nutrienti. Recentemente, l’uso di matrici alternative al frumento, come pseudocereali, legumi e cultivar di riso pigmentate sta riscuotendo grande interesse a causa del loro elevato quantitativo di composti bioattivi (polifenoli). Quindi, considerando l’importanza attuale dei polifenoli sia nella formulazione tecnologica che nella promozione di aspetti salutistici degli alimenti senza glutine, lo scopo di questa tesi è stata basata su: 1) profilazione dei polifenoli in matrici prive di glutine (farine non di frumento, legumi, pseudocereali e frutta secca) e loro proprietà antiossidanti in vitro; 2) valutazione dell’impatto di trattamenti termici e di fermentazioni microbiche sul profilo fenolico di queste matrici prive di glutine; 3) valutazione del ruolo dei polifenoli come inibitori degli enzimi amilolitici; e 4) valutazione del destino dei polifenoli caratterizzanti alimenti senza glutine durante processi in vitro simulanti digestione gastrointestinale e fermentazione fecale. I polifenoli sono stati analizzati sfruttando tecniche di metabolomica mirata/non-mirata.
Around 1% of world population is affected by coeliac disease. Coeliac people are constrained to follow a strict gluten free (GF) diet and very often this latter is unbalanced and lacks in many nutrients. In the last years, the exploitation of alternative crops or underutilized species, such as pseudocereals, legumes and pigmented cereal cultivars, is gaining interest because of their amount and profile of bioactive compounds, such as polyphenols. Therefore, considering the actual importance of polyphenols for both the formulation of GF foods and their health-promoting properties, the current PhD thesis was based on: 1) the profiling of polyphenols in GF raw materials (such as non-wheat flours, legumes, pseudocereals and nuts) and their in vitro antioxidant activities; 2) the evaluation of the impact of different heat treatments and microbial fermentations on the phenolic profile of GF raw materials; 3) the investigation of polyphenols in GF foods as inhibitors of digestive enzymes; and 4) the assessment of the fate of polyphenols characterizing GF foods during simulated in vitro gastrointestinal and fermentation processes. Polyphenols were analysed by means of targeted/untargeted metabolomics-based approaches (i.e., high resolution chromatography and mass spectrometry platforms).

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ROCCHETTI, GABRIELE. "GLUTEN - FREE FOOD SYSTEM: SCREENING OF POLYPHENOLS AND THEIR BIO ACCESSIBILITY THROUGH IN VITRO GASTROINTESTINAL PROCESSES AND METABOLOMICS - BASED STUDIES." Doctoral thesis, Università Cattolica del Sacro Cuore, 2019. http://hdl.handle.net/10280/57897.

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Circa l’1% della popolazione mondiale è colpita da celiachia. I celiaci sono costretti a seguire una dieta priva di glutine e molto spesso quest’ultima risulta essere sbilanciata e/o carente in molti nutrienti. Recentemente, l’uso di matrici alternative al frumento, come pseudocereali, legumi e cultivar di riso pigmentate sta riscuotendo grande interesse a causa del loro elevato quantitativo di composti bioattivi (polifenoli). Quindi, considerando l’importanza attuale dei polifenoli sia nella formulazione tecnologica che nella promozione di aspetti salutistici degli alimenti senza glutine, lo scopo di questa tesi è stata basata su: 1) profilazione dei polifenoli in matrici prive di glutine (farine non di frumento, legumi, pseudocereali e frutta secca) e loro proprietà antiossidanti in vitro; 2) valutazione dell’impatto di trattamenti termici e di fermentazioni microbiche sul profilo fenolico di queste matrici prive di glutine; 3) valutazione del ruolo dei polifenoli come inibitori degli enzimi amilolitici; e 4) valutazione del destino dei polifenoli caratterizzanti alimenti senza glutine durante processi in vitro simulanti digestione gastrointestinale e fermentazione fecale. I polifenoli sono stati analizzati sfruttando tecniche di metabolomica mirata/non-mirata.
Around 1% of world population is affected by coeliac disease. Coeliac people are constrained to follow a strict gluten free (GF) diet and very often this latter is unbalanced and lacks in many nutrients. In the last years, the exploitation of alternative crops or underutilized species, such as pseudocereals, legumes and pigmented cereal cultivars, is gaining interest because of their amount and profile of bioactive compounds, such as polyphenols. Therefore, considering the actual importance of polyphenols for both the formulation of GF foods and their health-promoting properties, the current PhD thesis was based on: 1) the profiling of polyphenols in GF raw materials (such as non-wheat flours, legumes, pseudocereals and nuts) and their in vitro antioxidant activities; 2) the evaluation of the impact of different heat treatments and microbial fermentations on the phenolic profile of GF raw materials; 3) the investigation of polyphenols in GF foods as inhibitors of digestive enzymes; and 4) the assessment of the fate of polyphenols characterizing GF foods during simulated in vitro gastrointestinal and fermentation processes. Polyphenols were analysed by means of targeted/untargeted metabolomics-based approaches (i.e., high resolution chromatography and mass spectrometry platforms).

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CRESCENTI, DANIELA. "TARGETED DELIVERY OF DIAGNOSTIC AGENTS TO NEOPLASTIC TISSUES: PRECLINICAL DEVELOPMENT OF NANOPARTICLES-BASED SYSTEMS FOR THE INTRAOPERATIVE LABELLING OF TUMOUR SITES." Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/915562.

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Nonostante i progressi fatti nel campo delle terapie mediche e chirurgiche, il cancro rappresenta ancora una maggiore causa di morte nel mondo: i pazienti sviluppano spesso resistenza alle terapie antitumorali e recidive a causa della non completa deplezione di tutte le cellule tumorali. Tra le terapie antitumorali, la chirurgia mira alla rimozione completa del tessuto neoplastico, tipicamente asportato insieme ad un margine di tessuto sano non tumorale circostante allo scopo di ridurre il rischio di recidive ed aumentare la sopravvivenza dei pazienti. Tuttavia, ad oggi la procedura chirurgica di resezione tumorale manca ancora di uno strumento oggettivo in grado di mappare esattamente, nel contesto intraoperatorio, le porzioni di tessuto interessate dalla crescita neoplastica. Scopo di questo progetto era quindi lo sviluppo preclinico di uno strumento in grado di definire e circoscrivere in maniera oggettiva l’area tumorale, per guidare i chirurghi in una rimozione intraoperatoria più sicura del tessuto tumorale. Nello sviluppare questo progetto, ci siamo occupati dello studio di sistemi innovativi di origine naturale per la veicolazione di farmaci, chiamati Vescicole Extracellulari (EV), con i quali veicolare agenti diagnostici in maniera specifica ai siti tumorali, allo scopo di consentire la rilevazione di tumori durante l’operazione chirurgica con maggior sensibilità e precisione. Abbiamo incapsulato dei coloranti fluorescenti all’interno di vescicole extracellulari ottenute da diverse fonti biologiche e caratterizzato la biodistribuzione della fluorescenza veicolata in modelli tumorali murini tramite sistemi di imaging in vivo ed ex vivo. In questo contesto sperimentale abbiamo individuato vescicole extracellulari isolate da pazienti oncologici che mostrano un tropismo selettivo per i tessuti neoplastici; questo tropismo tumorale risulta conservato tra vescicole extracellulari di origine tumorale ed è indipendente sia dal tipo di tumore che dalla specie di origine delle vescicole. In modelli di xenotrapianto (PDX) abbiamo dimostrato che le vescicole derivate da pazienti sono in grado di riconoscere i corrispondenti tumori umani e veicolare i traccianti fluorescenti all’interno delle cellule tumorali stesse, fornendo così una prova di principio del possibile utilizzo delle vescicole di pazienti in clinica. Grazie all’utilizzo di tecniche omiche, abbiamo identificato una “firma” proteica caratterizzante le vescicole dei pazienti e delle molecole candidate per spiegare il meccanismo di targeting dei tumori. Da questa firma abbiamo inoltre scoperto un nuovo promettente biomarcatore per la predizione del tumore del colon-retto attraverso la biopsia liquida. In conclusione, questo lavoro di tesi presenta la scoperta e la caratterizzazione di nanoparticelle patotropiche derivate dal sangue di pazienti oncologici come utili strumenti per la veicolazione selettiva di sostanze attive alle cellule tumorali. Le proprietà biologiche di queste vescicole autologhe e le loro innate abilità di riconoscere i tumori aprono la strada allo sviluppo di nuove strategie per diagnosi e terapie personalizzate in pazienti oncologici, dove le vescicole extracellulari vengono caricate con agenti diagnostici per la rilevazione dei tessuti neoplastici, agenti terapeutici (es. farmaci chemioterapici) per terapie antitumorali mirate o agenti teranostici per diagnosi e terapia combinate.
Despite the advances made in surgical and medical therapies, cancer is still a major cause of death in the world: patients often develop resistance to therapy and relapses due to the incomplete removal of cancer cells. In cancer therapy, the surgical tumour resection aims to remove the neoplastic tissue, along with a surrounding margin of normal non-tumoral tissue, in order to reduce the risk of relapses and improve patients’ survival. However, the procedure lacks an objective tool to intraoperative map the exact portion of tissue interested by the neoplastic growth. The aim of the present project was the preclinical development of an objective tool to label and circumscribe the tumour area, to guide surgeons in the intraoperative safe removal of cancer tissues. Here, we investigated novel drug delivery systems of natural origin named Extracellular Vesicles (EV) for the specific delivery of diagnostics at tumour sites, in order to allow the detection of tumours during the surgical procedure with increased sensitivity and accuracy. We encapsulated fluorescent dyes into EV from different biological sources and characterized the biodistribution of fluorescence in mouse models of cancer by in vivo and ex vivo imaging methodologies. In this experimental setting, we have identified EV isolated from cancer patients showing a selective tropism for neoplastic tissues; this tumour tropism is conserved among EV of tumoral origin and is independent from the tumour type and the species originating the vesicles. In PDX models we demonstrated that patient-derived EV recognize corresponding human tumours and deliver fluorescent agents inside cancer cells, providing a proof-of-principle demonstration of the possible translational use of patients’ EV in clinic. Taking advantage of omics technologies, we have identified a protein “signature” characterizing the PDEVs and candidate molecules for the mechanism of tumour targeting. From this signature we also discovered a novel promising biomarker for the prediction of CRC disease in liquid biopsy. In conclusion, this thesis presents the discovery and characterization of pathotropic nanoparticles derived from the blood of oncological patients as useful drug delivery tool to selectively target cancer cells. The biological properties of these autologous EV and their innate abilities to recognize tumours pave the way to the design of novel strategies of personalized diagnosis and therapies in cancer patients, where EV are loaded with diagnostics for the detection of neoplastic tissues, therapeutics (e.g. chemotherapeutic drugs) for targeted cancer therapies or theranostics for combined diagnostic and therapy.

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Dezfouli, Mahya. "Barcoded DNA Sequencing for Parallel Protein Detection." Doctoral thesis, KTH, Genteknologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-159506.

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The work presented in this thesis describes methodologies developed for integration and accurate interpretation of barcoded DNA, to empower large-scale-omics analysis. The objectives mainly aim at enabling multiplexed proteomic measurements in high-throughput format through DNA barcoding and massive parallel sequencing. The thesis is based on four scientific papers that focus on three main criteria; (i) to prepare reagents for large-scale affinity-proteomics, (ii) to present technical advances in barcoding systems for parallel protein detection, and (iii) address challenges in complex sequencing data analysis. In the first part, bio-conjugation of antibodies is assessed at significantly downscaled reagent quantities. This allows for selection of affinity binders without restrictions to accessibility in large amounts and purity from amine-containing buffers or stabilizer materials (Paper I). This is followed by DNA barcoding of antibodies using minimal reagent quantities. The procedure additionally enables efficient purification of barcoded antibodies from free remaining DNA residues to improve sensitivity and accuracy of the subsequent measurements (Paper II). By utilizing a solid-phase approach on magnetic beads, a high-throughput set-up is ready to be facilitated by automation. Subsequently, the applicability of prepared bio-conjugates for parallel protein detection is demonstrated in different types of standard immunoassays (Papers I and II). As the second part, the method immuno-sequencing (I-Seq) is presented for DNAmediated protein detection using barcoded antibodies. I-Seq achieved the detection of clinically relevant proteins in human blood plasma by parallel DNA readout (Paper II). The methodology is further developed to track antibody-antigen interaction events on suspension bead arrays, while being encapsulated in barcoded emulsion droplets (Paper III). The method, denoted compartmentalized immuno-sequencing (cI-Seq), is potent to perform specific detections with paired antibodies and can provide information on details of joint recognition events. Recent progress in technical developments of DNA sequencing has increased the interest in large-scale studies to analyze higher number of samples in parallel. The third part of this thesis focuses on addressing challenges of large-scale sequencing analysis. Decoding of a huge DNA-barcoded data is presented, aiming at phase-defined sequence investigation of canine MHC loci in over 3000 samples (Paper IV). The analysis revealed new single nucleotide variations and a notable number of novel haplotypes for the 2nd exon of DLA DRB1. Taken together, this thesis demonstrates emerging applications of barcoded sequencing in protein and DNA detection. Improvements through the barcoding systems for assay parallelization, de-convolution of antigen-antibody interactions, sequence variant analysis, as well as large-scale data interpretation would aid biomedical studies to achieve a deeper understanding of biological processes. The future perspectives of the developed methodologies may therefore stem for advancing large-scale omics investigations, particularly in the promising field of DNA-mediated proteomics, for highly multiplex studies of numerous samples at a notably improved molecular resolution.

QC 20150203

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37

Baccour, Mohamed. "Monolithes à porosité multi-échelle comme supports pour la réduction enzymatique du CO2 en molécules d'intérêts." Thesis, Montpellier, Ecole nationale supérieure de chimie, 2018. http://www.theses.fr/2018ENCM0004.

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La conversion du dioxyde de carbone en molécules d'intérêts est un enjeu majeur de notre société moderne. Actuellement, ces réactions sont très coûteuses en énergie, impliquent de hautes pressions et températures et sont faiblement sélectives. Une alternative séduisante serait l’utilisation d’enzymes redox, i.e. des déshydrogénases, qui fonctionnent à pH neutre, température et pression ambiantes et sont très sélectives. Le frein à leur utilisation est leur stabilité et le fait qu’elles nécessitent la présence du cofacteur nicotinamide adénine dinucléotide (NAD+ / NADH), couteux et délicat à régénérer. L’immobilisation de déshydrogénases sur des supports poreux monolithiques est proposée dans ce travail de thèse dans l’objectif de développer des réacteurs en flux continu.Dans un premier temps, des monolithes siliciques à porosité hiérarchique macro- et mésoporeux ont été préparés. Des macropores plus larges allant jusqu’à 35-50 microns ont été obtenus. Dans un second temps, des synthèses de monolithes de carbone à porosité hiérarchique en une étape ou en plusieurs étapes par dépôt de carbone sur des monolithes siliciques (greffage de saccharose, suivi de polymérisation et carbonisation) ont été développées. Ce travail a permis un contrôle fin de la macro-, méso et microporosité. Des monolithes de carbone avec une surface spécifique supérieure à 1200 m2.g-1 ont notamment pu être obtenus. Ces matériaux présentent non seulement une macroporosité large (35-50 µm), mais également une mésoporosité bimodale. Au-delà d’une porosité multi-échelle, ces matériaux carbonés présentent l’avantage d’être conducteurs du courant électrique. Ils peuvent ainsi être utilisés comme support pour l’électrocatalyse enzymatique. Ces monolithes de carbones ont été utilisés pour l’immobilisation de formiates déshydrogénases connus pour pouvoir réduire le CO2 en présence du cofacteur NADH. La régénération du cofacteur est étudiée soit par voie électrochimique soit par voie biocatalytique à l'aide d'une deuxième enzyme la phosphite déshydrogénase. Des études de fonctionnalisation des monolithes carbonés pour la co-immobilisation des enzymes et du cofacteur ont également été initiées
Carbon dioxide (CO2) is a greenhouse gas that results, in part, from human activities and causes global warming and climate change. According to the International Energy Agency, global CO2 emissions from fossil-fuel combustion reached a record high of 31.3 gigatonnes in 2011. The concept of the methanol economy, advocated by Nobel laureate Prof. George A. Olah back in the 1990s, hinges on the chemical recycling of CO2 to methanol and derived, suggesting methanol as a key substitute fuel and starting material for valuable chemicals. The recycling conversion of CO2 could be a rational way to develop an anthropogenic short-term carbon cycle. With this aim, The design of functional porous architectures depicting hierarchical and interconnected pore networks has emerged as a challenging field of research. Particularly, porous monoliths offer many advantages and can be employed as flow-through reactors for separation, catalysis and biocatalysis. This study focuses on the design of monoliths with hierarchical porosity and high surface area. Firstly, silica monoliths with both homogeneous macro- and mesopores were prepared using sol-gel chemistry and spinodal decomposition using PEO polymers. Macropore (up to 30 microns) and mesopore (up to 20 nm) diameters of the monoliths were controlled by modifying various experimental parameters (PEO molecular weight, addition of surfactants, different basic post-treatments, different temperatures, etc.). Secondly, carbonaceous replica have been prepared through hydrothermal carbonization of sucrose, subsequent pyrolysis and silica etching. These materials present large interconnected flow-trough macropores, a bimodal mesoporosity, a high surface area (up to 1400 m2 g-1) and high meso- and macropore volumes.Different enzymes were immobilized onto the monoliths amongst which formate dehydrogenases. Flow-through reactors were engineered and continuous flow biocatalysis was performed. In such systems, straightforward processes for the in situ regeneration of the enzyme cofactor, i.e. 1,4-NADH wrer developped. Flow-through reactors and their use for the enzymatic reduction of carbon dioxide into formate were designed

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38

Terzi, Mahir. "Information-based Economy And E-government: Transformation In The Public Administration." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607146/index.pdf.

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&ldquo
Information-Based Economy&rdquo
, which is today&rsquo
s economy that is a proof and indicator of development level for the countries now on, comes on the scene with its new organizing model on the infrastructure of its own, which is called &ldquo
Information Society&rdquo
. The phenomenon of administration introduces to &ldquo
e-Government&rdquo
for reinforcing the roots of &ldquo
Information-Based Economy&rdquo
now. The objective of this study is to research the transformation of state, authoritarian and dominant power, that &ldquo
Information-Based Economy&rdquo
gives direction in the environment of &ldquo
Information Society&rdquo
and to determine the locus and focus of &ldquo
e-government&rdquo
as a new organizing model especially in the dilemma between administration and management, and in the dilemma between politics and administration by using the theories of public administration, keeping the variance of culture in mind. In addition, to have a systematic knowledge of the relation between &ldquo
Information-Based Economy&rdquo
, &ldquo
Information Society&rdquo
and &ldquo
e-Government&rdquo
as a whole composes of the theme of this thesis. For this purpose, questionnaire has been conducted in the Ministry of National Education, which is responsible for forming the society of the future, to understand whether there is a systematic knowledge on the relation between &ldquo
Information-Based Economy&rdquo
, &ldquo
Information Society&rdquo
and &ldquo
e-Government&rdquo
as a whole. Moreover, it has been aimed to discover what the mental formulations of participants are. Questionnaire results reveal that there is no systematic knowledge on the relation between &ldquo
Information-Based Economy&rdquo
, Information Society&rdquo
and &ldquo
e-Government&rdquo
as a whole in the Ministry of National Education, and that the participants are apt to perceive &ldquo
e-Government&rdquo
within the context in which they are in terms of professions, status and backgrounds. Questionnaire results also show that the responses given by the participants concerning &ldquo
e-Government&rdquo
are more or less the same due to the hierarchical organization of knowledge and official knowledge in particular.

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Chlela, Robert. "Durabilité d'un système composite biosourcé (matrice époxy-fibres de lin) pour applications de renforcement structural : approches expérimentale et fiabiliste." Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC2076.

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En France, le patrimoine bâti des ouvrages d’art et bâtiments est vaste et vieillissant. Des rapports récents établis par des experts dressent un constat alarmant de la situation et pointent la nécessité d’augmenter significativement les moyens alloués à la réhabilitation de ce patrimoine. Dans ce contexte, le renforcement structural par collage externe de matériaux composites s’est imposé depuis une vingtaine d’années comme une solution de choix pour la remise à niveau des ouvrages et l’extension de leur durée de vie. Cette thèse, financée par l'ANR, vise, en premier lieu à développer un système de renforcement composite inédit à empreinte environnementale réduite, et d’autre part, à construire d’une démarche fiabiliste permettant d’estimer la durée de vie des systèmes de renforcement et leur probabilité de défaillance à tout instant. Dans le présent manuscrit, les principales phases de développement du système bio-sourcé sont tout d’abord rappelées. On y rappelle notamment que la matrice époxy bio-sourcée a été formulée sur la base d’un cahier des charges établi à partir des caractéristiques de la matrice associée au procédé de renforcement Foreva® TFC, ainsi que les critères ayant guidé le choix du tissu de renforcement unidirectionnel en fibres de lin. Une seconde partie du manuscrit présente l’ensemble des résultats expérimentaux obtenus dans le cadre de la campagne de durabilité sur le système de renforcement bio-sourcé. Cette campagne s’appuie sur un plan d’expériences optimisé par la matrice de Hoke. Des plaques de composite stratifié ainsi que des dallettes de béton renforcées par ce composite ont ainsi été soumis à des vieillissements accélérés en conditions hygrothermiques ainsi qu’à un vieillissement naturel. Dans une première étape, les résultats de différentes caractérisations physico-chimiques réalisées sur le composite bio-sourcé à différentes échéances de vieillissement, mettent en évidence l’importance respective et les effets parfois antagonistes des mécanismes d’évolution microstructurale et des phénomènes de dégradation dans les différentes conditions de vieillissement. Dans une seconde étape, les évolutions des principaux indicateurs des performances mécaniques du composite et de l’interface béton-composite dans les différents milieux de vieillissement sont présentées et interprétées à la lumière des caractérisations physico-chimiques précédentes. Dans une troisième étape, des éléments de comparaison sont apportés entre le système composite bio-sourcé et un système traditionnel à fibres de carbone. La dernière partie du manuscrit est consacrée à la mise en œuvre de la démarche fiabiliste à partir de la base de données expérimentale collectée précédemment pour le système bio-sourcé. Une analyse statistique par la méthode ANOVA (analyse de la variance) est d’abord réalisée sur l’ensemble des données expérimentales. Deux modèles de dégradation ont ensuite été élaborés en vue de décrire l’évolution des indicateurs de performance dans le temps pour toute condition de vieillissement hygrothermique : un modèle analytique incluant de manière explicite les effets quadratiques et le couplage entre la température et l’humidité relative, et un modèle physique basé sur la loi d’Eyring. L’étape suivante a ensuite consisté à utiliser ces modèles pour estimer des durées de vie du système de renforcement bio-sourcé dans les conditions de vieillissement accéléré. Des critères de fin de vie du système ont été définis à partir des recommandations de dimensionnement proposées notamment par les guides ACI et AFGC. En vue d’évaluer la durée de vie en condition de service, une procédure spécifique a ensuite été proposée pour appliquer le modèle analytique dans le cas du vieillissement naturel. Enfin, une probabilisation du modèle analytique est réalisée de manière à déterminer la probabilité de défaillance du système de renforcement bio-sourcé à tout instant de sa durée de vie
In France, the built heritage of civil engineering and building structures is vast and ageing. Recent reports prepared by experts highlight this alarming situation and point out the need to significantly increase the resources allocated to the rehabilitation of this heritage. In this context, structural reinforcement by externally bonded composites has become an attractive solution for the rehabilitation of structures and the extension of their lifespan. This thesis, funded by the French Research Agency (ANR), aims to develop a new composite reinforcement system with a reduced environmental footprint, on one hand, and to build an original reliability approach to estimate the lifetime of reinforcement systems and their failure probability at any time, on the other hand. In this manuscript, the main phases of development of the bio-based system are first recalled. In particular, it is recalled that the formulation of the bio-sourced epoxy matrix was based upon the specifications and characteristics of the Foreva® TFC matrix, and the criteria that guided the choice of the unidirectional flax fibre reinforcement fabric are also presented. The second part of the manuscript presents all the experimental results obtained within the framework of the durability study on the bio-based strengthening system. This test campaign relies on a Design of Experiment optimized by Hoke’s matrix. Laminated composite plates and concrete slabs reinforced with these composites were subjected to accelerated ageing under hygrothermal conditions, and to natural ageing on an outdoor exposure site in Lyon as well, for a total duration of 24 months. In a first step, the results of various physico-chemical characterizations that were periodically conducted on the bio-based composites, highlighted the relative contributions of mechanisms involved in microstructural evolutions and degradation phenomena of both the polymer matrix and fiber/matrix interfaces. In a second step, the changes in the main performance indicators related to the composite and the concrete-composite interface subjected to the various ageing environments, are presented and interpreted in the light of the previous physico-chemical characterizations. In a third step, a comparison is made between the bio-based composite system and a traditional carbon fibre strengthening system. The last part of the manuscript is devoted to the implementation of the reliability approach, relying on the experimental database previously collected for the bio-based system. A statistical analysis by the ANOVA method is first carried out on all experimental data. Two degradation models were then developed to describe the evolutions of performance indicators over time for any hygrothermal ageing condition: an analytical model with explicit terms related to quadratic effects and coupling between temperature and relative humidity, and a physical model based on Eyring's law.In a next step, these models were used to estimate the lifetime of the bio-based strengthening system under accelerated ageing conditions. End-of-life criteria were first defined based on specifications proposed by different design guidelines, in particular by ACI and AFGC reports.In order to evaluate the lifetime under actual service conditions, a specific procedure was then proposed to apply the analytical model in the case of natural ageing. Finally, a probabilization of the analytical model is carried out in order to determine the probability of failure of the bio-based strengthening system at any time during its lifetime

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40

PILLAI, Vinoshene. "Intravital two photon clcium imaging of glioblastoma mouse models." Doctoral thesis, Scuola Normale Superiore, 2021. http://hdl.handle.net/11384/109211.

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41

Marques, Márcia Cristina Teixeira. "Evaluation of the behaviour of bio-based nanostructures in food systems." Master's thesis, 2021. http://hdl.handle.net/1822/73455.

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Dissertação de mestrado em Biotecnologia
The growing consumers’ interest in healthier foods has led the food industry to develop functional foods specifically designed to improve human health, well-being, and performance. Curcumin is a natural polyphenol that presents numerous biological activities. However, curcumin has low water solubility, poor chemical stability, and low bioavailability. Lipid-based nanostructured delivery systems can be used to encapsulate curcumin. In this study, solid lipid nanoparticles (SLNs) encapsulating curcumin were developed and incorporated into a gelatine food matrix. SLNs (before and after incorporation in the gelatine) were characterized through mean diameter (Z-average diameter), polydispersity index (PDI) and zeta potential (ζ-potential) by Dynamic light scattering (DLS). Gelatine and gelatine-SLNs were evaluated through colour, texture, and rheology during 21 days of storage. In vitro digestion of the SLNs and gelatine-SLNs was performed and curcumin bioaccessibility, stability, and bioavailability were measured. The degree of hydrolysis (DH) of proteins and the production of free fatty acids (FFA) of gelatine and gelatine-SLNs were evaluated at gastric and intestinal phases, respectively. During 21 days, the Z-average diameter of the SLNs was maintained and the ζ-potential slightly decreased. The incorporation of the SLNs into gelatine did not significantly change neither the initial particle size nor PDI. ζ-potential of SLNs and gelatine-SLNs is different and this is due to the fact that gelatine has a slightly positive surface charge. The total colour difference (TCD) of the gelatine and gelatine-SLNs remained constant during 21 and 14 days of storage, respectively. The addition of SLNs did not lead to changes in the textural parameters of the gelatine, however, they promoted more solid behaviour to this food matrix. The value of DH of proteins in the gelatine and gelatine-SLNs were 47.8 % and 52.2 %, respectively. The total production of FFA of gelatine-SLNs was almost double of that of SLNs. Curcumin bioaccessibility and bioavailability were not statistically different between SLNs and gelatine-SLNs. However, the stability was higher in the gelatine-SLNs sample, suggesting that this food matrix provides a protective effect to curcumin. Finally, these results suggest that SLNs encapsulating curcumin and their incorporation in the gelatine food matrix is a promising application for the food industry.

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42

Jordaan, Adriaan Louis. "Bio-Swap: a biometrics-based solution to combat SIM swap fraud." Thesis, 2011. http://hdl.handle.net/10210/3707.

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M.Sc. (Computer Science)
The past couple of years have seen an explosion in the number of online fraud schemes – Total annual losses exceed tens of millions of Rands. Many people and organizations from all over the world have fallen victim to it. Nobody is safe; everybody is vulnerable. As we increasingly make use of the Internet and mobile technology to do our work and to perform chores such as online banking or shopping, we become even more vulnerable. Fraudsters make use of ever-more sophisticated techniques and clever schemes to target the unsuspecting end-users of mobile and Internet technology, and to trick them into surrendering their personal information so that electronic transactions can be carried out in their name. Examples include cheque and credit card fraud, phishing, identity theft and spyware, to name but a few. Services such as Internet- and cell phone banking especially, provide a haven of possibilities to make easy money because the technology is relatively new, and it is being used by evermore people who believe that it is fast, safe and secure and will therefore make their lives easier. One of the latest scams at the time of this writing is “SIM swap fraud”: Fraudsters target specific victims, perform SIM swaps on their cell phone numbers, and then proceed to empty the victims’ bank accounts. This is all done in a matter of minutes, so the victims only realize what has happened when it is too late to do anything about it. Needless to say, a solution must be found that will prevent unauthorized SIM swaps and strengthen online banking security. This dissertation does exactly that. It examines the digital world known as cyberspace, identifies how SIM swap fraudsters manage to defraud their targets, and presents a biometrics-based security system to combat SIM swap fraud.

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43

Kumar, Balmiki. "Development of Upconversion and Mesoporous Silica based Nanoparticle Systems for Therapeutic, Bioimaging and Bio-sensing Applications." Thesis, 2019. http://ethesis.nitrkl.ac.in/9871/1/2019_PHD_BKumar_513CY1067__Development.pdf.

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The advent of nanomedicine has been one of the most significant developments impacting the applied fields of physics, chemistry and life sciences, that took place in past few decades. Still being in early stage at present, nanomedicine is expected to have a revolutionary effect on health care in future. Research in nanomedicine covers wider areas, such as therapeutics (drug delivery, multifunctional therapeutics, vaccine development), diagnosis (point-of-care nanoplatforms, bioanalytics, bioimaging) and biomaterials (biological, non-biological, hybrid or biomimetic materials, etc.). Although nanomedicine offers some key advantages over the conventional medicine, there are certain challenges yet to be addressed to enhance the efficacy of nanomedicine. Current formulations of nanomedicine still lacks target specificity and therefore confining the therapeutic effect in the affected area is a major problem. A probable solution is to turn on and control the therapeutic action of nanomedicine within a particular target zone by the action of an external stimulus acting as a remote trigger, locally. In this context, herein, we have developed upconversion nanoparticles (UCNPs) and mesoporous silica (MS) based nanoparticles systems to demonstrate an enhancement of therapeutic efficacy using near infra-red (NIR) laser (980 nm), acting as an external stimulus to turn on and regulate the therapeutic effect in a non-invasive manner in vitro. In this dissertation, we have attempted to validate the enhanced therapeutic efficacy of our developed nanoformulations for distally located tumours such as colorectal cancer (CRC). Using the similar formulations, we have also integrated three different therapeutic modalities within a single nanoplatform that can be applied to treat cancers, which show resistance to a particular therapeutic modality due to mutative adaptations, often known as ‘multi-drug resistance’ (MDR). Also, these nanoplatforms have been explored for bioanalytical applications. The first chapter of this dissertation talks about general introduction of nanomedicine and justifies the purpose of the research described here with a brief background information about UCNP and mesoporous silica nanoparticles (MSN). The second chapter reported here involved tuning of the upconversion emission behaviour to generate a sharp and diverse emission profile that can effectively excite multiple photoactive agents, simulteneously. In this project the intense emission from UCNP was utilized to get an enhanced therapeutic output in the form of a non-invasive photodynamic therapy (PDT). The excitation of multiple photosensitizers by the upconversion core through FRET served the basis of enhanced reactive oxygen species (ROS) generation, which induced cancer cell death. This work successfully demonstrated that the system in report would be most suitable than the conventionally reported photodynamic platforms, where multiple triggers for enhanced therapeutic effects were desired. Also, the intense visible emission profile enabled the bioimaging of those particles incorporated within animal cells using a cost-efficient customised set-up in absennce of any sophisticated detector, such as photomultiplier tube (PMT). The enhanced PDT effects by photoactivation of two chemically different photosensitizers (PSs), triggered by the NIR upconversion emmisions from white emitting UCNP along with the facile upconversion imaging from the cells formed the main novel embodiments of this work.(ChemNanoMat, 2018, 4, 583-595). In the work presented as the third chapter, mesoporous silica nanoparticles capped with guar gum (GG) polymer was exploited for colon specific delivery of anticancer drug by utilizing a natural bioprocess of enzymatic degradation acting as the trigger for the delivery mechanism. This work, for the first time, demonstrated the use of a rigid framework of mesoporous silica nanoparticles along with guar gum polymer to achieve zero premature release behaviour at various pH conditions, encountered in the GI tract. This work provided an interesting insight to design an oral formulation towards colorectal cancer therapy with smart and controlled release behaviour. The results successfully established that the formulation was capable of arresting the cells in S-phase, thus, leading to the accumulation of the cells in the particular phase, typically found as the result of impaired DNA replication mechanism, ultimately causing the death of the cancerous cells. The present study presented first report on mesoporous silica (MSN) based colon targeted delivery for possible oral application. (Colloids Surf. B: Biointerfaces., 2017, 150, 352-361) Furthermore, in the next work presented as the fourth chapter, application of upconversion based therapeutic platform was manipulated to achieve dual modality for therapeutic effects, with an integrated approach of colon-targeted drug delivery and photodynamic therapy. Herein, the UCNPs were engineered to get a higher intensity emission output, using the core-shell based UCNP composition (CSU). Next, a photosensitizer (Rose Bengal) was chemically conjugated to the CSU followed by encapsulation using mesoporous silica (MS) layer. Chemotherapeutic drug 5FU was loaded inside MS layer through GG capping. The work in discussion was a first time demonstration of the novel nanoplatform fabrication strategy to enhance the therapeutic output by combining the enzyme triggered colon targeted delivery of therapeutic molecules with photodynamic therapy triggered by NIR laser. The nanoplatform was also employed for bioimaging using the customised setup designed in the previous work discussed above. For the first time, a bimodal therpeutic nanoplatform integrating enzyme triggered delivery of anticancer drug along with NIR triggered PDT with intended administration through oral route was reported; thus, forming the main novelty of this work. (Manuscript accepted in Nanotechnology, IOPScience, 2019). In the fifth chapter, an attempt was made to develop a multifunctional theranostic nanoplatform with triple therapeutic modalities (i.e., photodynamic therapy, chemotherapy and photothermal therapy) integrated in a single nanoplatform that can be triggered by single NIR wavelength. Herein, through a rational design, a novel multifunctional nanoplatform was developed to demonstrate synergistically enhanced therapeutic output even at low NIR power and administration dosage. The engineered upconversion nanocrystals showed a strong PL emission in a diverse wavelength range that allowed the successful incorporation of hyperthermic agent with photodynamic and on-demand chemotherapy. The as-fabricated system is the first time demonstration of an efficient integration of several therapeutic modalities via well-defined and precisely controlled mechanism wiithin a single nanoplatform activated by a single NIR wavelength as a trigger. This strategy would provide an alternative route to specifically treat those types of carcinomas that show resistance towards a certain therapeutic routes. The efficacy of the system was assessed in vitro on cancerous cell lines. Apart from the multiple synergistic therapeutic effect, the core-shell UCNPs demonstrated an excellent upconversion luminiscence (UCL) imaging characteristics, thus realizing the goal of developing an efficient multimodal therapy with image-guided approach. The main novel embodiment of this work reported an NIR responsive theranostic nanoplatform with precisely controlled triple therapeutic modalities, i.e. PDT, chemotherapy and PTT, integrated in a single nanoplatform. The multimodality was achieved by a single NIR trigger by synchronous activation of incorporated multiple photoactive agents. (Manuscript submitted in Journal of Physical Chemistry B, ACS, 2019). For bio-sensing application, a simple, sensitive, fluorescence-based assay for dopamine (DA) detection was developed in the sixth chapter using highly photoluminescent NIR activated blue-emitting core-shell upconversion (BCSU) nanoparticles. A MS layer was used as a shell to facilitate the adsorption of the analyte. The detection mechanism has been proved to be mediated by FRET based phenomenon. The detection limit for DA was calculated to be as low as 0.63 nM. The applicability of the nanoplatform for pH sensing was demonstrated fluorometrically. This work is the first demonstration of NIR-upconversion based DA and pH sensing using core-active shell UCNP and MS-based functionality in a nanoprobe. (Manuscript accepted in ChemistrySelect, Wiley, 2019) In the last chapter, a general conclusion alongwith the future scope of the research has been presented.

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44

Gassull, Daniel [Verfasser]. "Electrochemical sensing of surface reactions on Gallium Arsenide based semiconductor devices functionalized with bio-organic molecular systems / Daniel Gassull." 2007. http://d-nb.info/986097047/34.

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45

Radhakrishnan, Krishna. "Design & Fabrication of Bio-responsive Drug Carriers Based on Protamine & Chondroitin Sulphate Biopolymers." Thesis, 2014. http://etd.iisc.ac.in/handle/2005/2734.

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The present thesis focuses on the fabrication of bio-stimuli responsive micro- and nano-carriers for drug delivery applications. In particular, the objective of this work is to investigate the possibility of using polypeptide drug protamine and glycosaminoglycan drug, chondroitin sulphate as stimuli responsive components in the design of bioresponsive carriers. These biopolymers are biocompatible, biodegradable and clinically used for various applications. Two designs that incorporate these stimuli responsive components have been studied in this thesis. The first design involves hollow micro and nanocapsules that have been fabricated by incorporating the stimuli responsive biopolymers as wall components. Upon exposure to biological triggers, these hollow capsules disintegrate releasing the encapsulated drug. The second design consists of mesoporous silica nanoparticles-biopolymer hybrids. The mesoporous silica nanoparticles act as a gated scaffold that carries the drug molecules. The mesopores of these drug loaded nanoparticles are then blocked with the bioresponsive polymers. Upon exposure to the bio-triggers which consist of enzymes over-expressed in conditions such as cancer and inflammation, these “molecular gates” disintegrate allowing the drug trapped in the mesoporous silica nanoparticles to escape into the surroundings. The thesis has been divided into five chapters: Chapter 1 is an introduction to bio-responsive drug delivery. The broad classification of stimuli used in responsive drug delivery systems are visited. A brief discussion on the various types of bio-stimuli that can be utilized in designing bio-responsive systems is also included in this chapter. Chapter 2 defines the aims and scope of the thesis which is followed by an overview of the various design parameters involved in the fabrication of systems presented in this work. The major stimuli responsive components and the architectures incorporating these elements are discussed in detail here. A literature review of the various carrier designs involved in the study is provided , with special emphasis on stimuli responsive drug delivery. Chapter 3 gives an overview of the various materials and methods involved in this work. A summary of the various characterisation techniques used in the thesis is also included along with the details of the experiments that has been carried out. Chapter 4 provides an overview of the results and discussions of the thesis. The chapter has been divided into six sections: Chapter 4.1 deals with the fabrication of a hollow microcapsule system incorporated with protamine as the stimuli responsive element for bio-responsive drug delivery. The hollow microcapsules that were fabricated by Layer by Layer assembly of protamine and heparin display pH responsive variations in permeability and disintegrate in the presence of the enzyme trypsin that degrades protamine. The biologically triggered enzyme responsive drug release from these microcapsules is also demonstrated using enzymes secreted by colorectal cancer cells. Chapter 4.2 presents nanocapsules fabricated from protamine and heparin. The pH and enzyme responsive drug release of this systems is evaluated in vitro. A wall crosslinking strategy has been tested to control the rate of drug release under physiological pH conditions in the absence of the trigger. The cellular interactions of these nanocapsules loaded with an anticancer drug, doxorubicin was studied using cancer cell lines. Bioavailability studies of doxorubicin encapsulated in these nanocapsules were performed using a BALB/c mice model. Chapter 4.3 discusses the fabrication of a hollow microcapsule system that can disintegrate in response to dual biological stimuli. These carriers have been fabricated by incorporating protamine and chondroitin sulphate as the wall components. Due to the incorporation of two separate stimuli responsive components in the walls, these capsules are expected to be sensitive to the enzymes trypsin or hyaluronidase I. Chapter 4.4 deals with the fabrication of dual enzyme responsive hollow nanocapsule which can be targeted to deliver anticancer agents specifically inside cancer cells. The enzyme responsive elements integrated in the hollow nanocapsule walls can undergo degradation in presence of either of the enzymes trypsin or hyaluronidase I leading to the release of encapsulated drug molecules. The drug release from these nanocapsules which were crosslinked and functionalised with folic acid, is evaluated under varying conditions. The cellular uptake and intracellular drug delivery by these nanocapsules were evaluated in cervical cancer cell lines. Chapter 4.5 introduces a mesoporous silica nanoparticle − protamine hybrid system. The system consists of a mesoporous silica nanoparticle support whose mesopores are capped with protamine which effectively blocks the outward diffusion of the drug molecules from the mesopores of the mesoporous silica nanoparticles. Upon exposure to the enzyme trigger, the protamine cap disintegrates opening up the molecular gates and releasing the entrapped drug molecules. The drug release from this system is evaluated in different release conditions in the presence and absence of the enzyme trigger. The ability of these particles to deliver hydrophobic anticancer drugs and induce cell death in colorectal cancer cells has also been demonstrated. Chapter 4.6 discusses the fabrication of another mesoporous silica nanoparticles based bio-responsive drug delivery system consisting of mesoporous silica and chondroitin sulphate hybrid nanoparticles. The ability of the system to modulate drug release in response to hyaluronidase I is demonstrated. By utilizing a cervical cancer cell line, we have demonstrated the cellular uptake and intracellular delivery of hydrophobic drugs encapsulated in these particles. Interestingly, the system showed ability to enhance the anticancer activity of hydrophobic drug curcumin in these cancer cells. Chapter 5 gives a summary of the general conclusions drawn from the thesis work.

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46

Radhakrishnan, Krishna. "Design & Fabrication of Bio-responsive Drug Carriers Based on Protamine & Chondroitin Sulphate Biopolymers." Thesis, 2014. http://etd.iisc.ernet.in/handle/2005/2734.

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The present thesis focuses on the fabrication of bio-stimuli responsive micro- and nano-carriers for drug delivery applications. In particular, the objective of this work is to investigate the possibility of using polypeptide drug protamine and glycosaminoglycan drug, chondroitin sulphate as stimuli responsive components in the design of bioresponsive carriers. These biopolymers are biocompatible, biodegradable and clinically used for various applications. Two designs that incorporate these stimuli responsive components have been studied in this thesis. The first design involves hollow micro and nanocapsules that have been fabricated by incorporating the stimuli responsive biopolymers as wall components. Upon exposure to biological triggers, these hollow capsules disintegrate releasing the encapsulated drug. The second design consists of mesoporous silica nanoparticles-biopolymer hybrids. The mesoporous silica nanoparticles act as a gated scaffold that carries the drug molecules. The mesopores of these drug loaded nanoparticles are then blocked with the bioresponsive polymers. Upon exposure to the bio-triggers which consist of enzymes over-expressed in conditions such as cancer and inflammation, these “molecular gates” disintegrate allowing the drug trapped in the mesoporous silica nanoparticles to escape into the surroundings. The thesis has been divided into five chapters: Chapter 1 is an introduction to bio-responsive drug delivery. The broad classification of stimuli used in responsive drug delivery systems are visited. A brief discussion on the various types of bio-stimuli that can be utilized in designing bio-responsive systems is also included in this chapter. Chapter 2 defines the aims and scope of the thesis which is followed by an overview of the various design parameters involved in the fabrication of systems presented in this work. The major stimuli responsive components and the architectures incorporating these elements are discussed in detail here. A literature review of the various carrier designs involved in the study is provided , with special emphasis on stimuli responsive drug delivery. Chapter 3 gives an overview of the various materials and methods involved in this work. A summary of the various characterisation techniques used in the thesis is also included along with the details of the experiments that has been carried out. Chapter 4 provides an overview of the results and discussions of the thesis. The chapter has been divided into six sections: Chapter 4.1 deals with the fabrication of a hollow microcapsule system incorporated with protamine as the stimuli responsive element for bio-responsive drug delivery. The hollow microcapsules that were fabricated by Layer by Layer assembly of protamine and heparin display pH responsive variations in permeability and disintegrate in the presence of the enzyme trypsin that degrades protamine. The biologically triggered enzyme responsive drug release from these microcapsules is also demonstrated using enzymes secreted by colorectal cancer cells. Chapter 4.2 presents nanocapsules fabricated from protamine and heparin. The pH and enzyme responsive drug release of this systems is evaluated in vitro. A wall crosslinking strategy has been tested to control the rate of drug release under physiological pH conditions in the absence of the trigger. The cellular interactions of these nanocapsules loaded with an anticancer drug, doxorubicin was studied using cancer cell lines. Bioavailability studies of doxorubicin encapsulated in these nanocapsules were performed using a BALB/c mice model. Chapter 4.3 discusses the fabrication of a hollow microcapsule system that can disintegrate in response to dual biological stimuli. These carriers have been fabricated by incorporating protamine and chondroitin sulphate as the wall components. Due to the incorporation of two separate stimuli responsive components in the walls, these capsules are expected to be sensitive to the enzymes trypsin or hyaluronidase I. Chapter 4.4 deals with the fabrication of dual enzyme responsive hollow nanocapsule which can be targeted to deliver anticancer agents specifically inside cancer cells. The enzyme responsive elements integrated in the hollow nanocapsule walls can undergo degradation in presence of either of the enzymes trypsin or hyaluronidase I leading to the release of encapsulated drug molecules. The drug release from these nanocapsules which were crosslinked and functionalised with folic acid, is evaluated under varying conditions. The cellular uptake and intracellular drug delivery by these nanocapsules were evaluated in cervical cancer cell lines. Chapter 4.5 introduces a mesoporous silica nanoparticle − protamine hybrid system. The system consists of a mesoporous silica nanoparticle support whose mesopores are capped with protamine which effectively blocks the outward diffusion of the drug molecules from the mesopores of the mesoporous silica nanoparticles. Upon exposure to the enzyme trigger, the protamine cap disintegrates opening up the molecular gates and releasing the entrapped drug molecules. The drug release from this system is evaluated in different release conditions in the presence and absence of the enzyme trigger. The ability of these particles to deliver hydrophobic anticancer drugs and induce cell death in colorectal cancer cells has also been demonstrated. Chapter 4.6 discusses the fabrication of another mesoporous silica nanoparticles based bio-responsive drug delivery system consisting of mesoporous silica and chondroitin sulphate hybrid nanoparticles. The ability of the system to modulate drug release in response to hyaluronidase I is demonstrated. By utilizing a cervical cancer cell line, we have demonstrated the cellular uptake and intracellular delivery of hydrophobic drugs encapsulated in these particles. Interestingly, the system showed ability to enhance the anticancer activity of hydrophobic drug curcumin in these cancer cells. Chapter 5 gives a summary of the general conclusions drawn from the thesis work.

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47

Simões, Lívia de Souza. "Development of bio-based micro- and nanostructures from milk whey proteins, as a vehicle for controlled release and delivery of bioactive compounds in food matrices." Doctoral thesis, 2020. http://hdl.handle.net/1822/76804.

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Tese de Doutoramento em Engenharia Química e Biológica
β-lactoglobulin (β-Lg) is the major protein fraction of bovine whey serum and due to its gelation capacity, it has the ability to form micro- and nanostructures and entrap bioactive compounds. This thesis aims at providing information for the development and characterization of micro- and nanostructures from β-Lg, purified from a commercial whey protein isolate, to incorporate, protect and delivery of bioactive compounds with different water solubilities. The stability of β-Lg microand nanostructures was assessed under various environmental conditions as well as in food simulants and throughout an in vitro gastrointestinal model. Homogeneous and stable β-Lg structures were formed at pH 6 with thermal treatment at 80 °C for 15 min. In this conditions, β- Lg nanostructures (with diameter sizes ≤ 100 nm) and β-Lg microstructures (with diameters size between 200-300 nm) were formed with 5 mg mL-1 and 15 mg mL-1, respectively. Riboflavin and quercetin were used as hydrophilic and hydrophobic bioactive model compounds, respectively. The impact of environmental conditions (e.g. pH, temperature, ionic strength, and storage temperature) on stability of such structures were investigated. β-Lg structures maintaining their particle size, polydispersity index and surface charge under acidic, neutral or alkaline conditions, at thermal treatments up to 70 °C and during storage for 50 days. The release mechanism of bioactive model compounds from β-Lg structures a was assessed into two food simulants with different hydrophobicities under 4 °C and 25 °C, by fitting the Linear Superimposition Model to the experimental data. The relaxation is the main release mechanism of both bioactive model compounds. Caco-2 cell viability experiment demonstrated that riboflavin and quercetin at concentration up to 0.021 mg mL-1 and 0.016 mg mL-1, respectively, entrapped on β-Lg micro- and nanostructures did not have any impact on cell viability. In vitro gastrointestinal tract model showed that the entrapment of riboflavin and quercetin into β-Lg micro- and nanostructures increased stability, bioaccessibility, and bioavailability of both bioactive model compounds, when compared with these in their free form. In conclusion, strict control of the physicochemical conditions allowed the development of β-Lg structures with the desired characteristics and capable to act as delivery systems for hydrophilic and hydrophobic compounds, until the intestine.
β-lactoglobulina (β-Lg) constitui a principal fração proteica do soro bovino, principal agente gelificante capaz de formar micro- e nanoestruturas e incorporar compostos bioativos. Esta tese objetivou fornecer informações sobre desenvolvimento de micro- e nanoestruturas a partir da β-Lg purificada de um isolado de proteína do soro, para incorporar compostos bioativos com diferentes solubilidades. Avaliou-se a estabilidade β-Lg micro- e nanoestruturas em diferentes condições ambientas, o perfil de libertação dos compostos bioativos em diferentes simulantes alimentar e ao longo do in vitro trato gastrointestinal. β-Lg estruturas homogenias e estáveis foram formadas em pH 6, aquecidas a 80 °C por 15 min. Nessas condições, a concentração inicial de 5 mg mL-1 β- Lg foram obtidas β-Lg nanoestruturas (diâmetro ≤ 100 nm), e com 15 mg mL-1 β-Lg microestrutura (diâmetros entre 200-300 nm). Riboflavina e a quercetina foram empregados como modelo de compostos hidrofílico e hidrofóbico, respectivamente. Avaliou-se a estabilidade de tais estruturas em várias condições ambientais (e.g., pH, temperatura, força iônica e temperatura de armazenamento). β-Lg micro- e nanoestruturas mantiveram tamanhos e homogeneidade em condições ácidas, neutras ou alcalinas, sob tratamentos térmicos até 70 °C e durante o armazenamento por 50 dias. O mecanismo de libertação da riboflavina e quercetina através das β-Lg micro- e nanoestruturas foi avaliado em dois simulantes alimentares a 4 °C e 25 °C, através do ajuste do modelo matemático “Linear Superimposition Model” aos dados experimentais. A relaxação demonstrou ser o principal mecanismo de libertação dos dois compostos bioativos testados. A viabilidade em células Caco-2 não foi afetada para concentrações de até 0.021 mg mL-1 para riboflavina de 0.016 mg mL-1 para quercetina, quando incorporadas nas β-Lg micro- e nanoestruturas. Estudos in vitro no sistema gastrointestinal demostrou que as β-Lg micro- e nanoestruturas aumentou a bioacessibilidade, estabilidade e biodisponibilidade dos compostos bioativos modelos, quando comparadas com a sua forma livre. Em conclusão, demostrou-se que o controle rigoroso das condições ambientais permite o desenvolvimento de β-Lg estruturas com capacidade de serem utilizados como sistemas de entrega de compostos bioativos com diferentes solubilidades até o intestino.
This thesis was financially supported by FCT under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) - Brazil (205137/2014-8).

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48

Lin, Wen-Zheng, and 林汶正. "Bio-medical monitoring system based onProgrammable SoC Microcontroller." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/6m84me.

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碩士
中原大學
電機工程研究所
91
The objective of this dissertation is to carry out a bio-medical monitoring system based on the embedded System-on-a-Chip(SoC) tech. We design two systems, which are the simple ECG signal record system and complex pulse signal measurement system. Both systems are developed by Programmable SoC Microcontraller(PSoC),and discuss the advantages and faults between them. In this study, they can provide a standard industrial interface RS232 to real-time measure bio-signal and display in PC . In order to identity the performance of both systems, We test and verify separately for each function of the model for PSoC. The results showed that it meets our specification of systems. It is proved by the embedded SoC tech, the occupied area can be minimized, and the expense of the system can be reduced. Therefore, this way is convenient to use.

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49

Lee, Te-chyuan, and 李得全. "Rotation based multi-channel bio-luminescence detection system." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/21768204255897014134.

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碩士
中原大學
醫學工程研究所
96
This thesis study aims on the design and development of a rotation based multi-channel bio-luminescence detection system. The system mainly consists of a photomultiplier tube (PMT), a tube rotator, a control circuit and a cage. The PMT detects, amplifies and converts light photons to analog voltage signals. A microprocessor, MSP430F1611, is the core component of the control circuit. It transforms the analog signals into digital. The tube rotator includes a dark lucite disk that is rotated by a motor, which is also controlled by microprocessor. On the surface near the edge of the disk, three open holes were designed so that the diameter of the holes is just able to hold the designated tubes. The aforementioned components were assembled within the cage. Effort was made to ensure light photons can not be in and out the cover of the cage is closed. The detected signals are digitally transferred to a computer for curve plotting. The developed system was evaluated in the aspects of the background noise and the stability of the rotation speed. The background noise study was performed in a setup that the cage was closed and then the system was powered on. The result indicated the background noise was about 6 mV. The rotation speed of the lucite disk in the rotator is determined by the microprocessor. It issues a rotation speed index value (RSIV) representing the time duration of each angular movements (or steps). The index value is inversely proportion to the rotation speed. According to the experimental results, the operable RSIV range from 55 to 500 for the tube rotator used in this work. The rotation speed stability was determined by the angular steps that are required to move the disk from one tube hole to the next adjacent one. The study results show that the steps between any two adjacent tube holes are about 63 steps. Based on this finding, an experiment was carried out to study number of rotation cycles required to stabilize the speed when the tube rotator is in rest initially. The results indicate the rotator needs 2~3 cycles to stabilize its rotation speed approximately.

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50

"Integrated polymer based microfluidic system for bio-medical applications." Thesis, 2005. http://library.cuhk.edu.hk/record=b6074022.

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Over the past years, microfluidic systems have been rapidly developed from early single channel devices to current complex integrated analysis systems. The development in microfluidics has led to the realization of miniaturized applications in biomedical or chemical analysis. High throughput and automated microfluidic systems have made it possible to achieve biomedical or chemical instruments with new levels of performance and capability. However, because of the requirement of biomedical systems, disposed and optically transparent materials, high aspect ratio structures, and complicated fluidic connection are desirable. Conventional silicon microfabrication process may not overcome these limitations. In this work, micro molding replication technique is proposed as a low-cost polymer microfabrication technique. Based on this technique, four polymer based microfluidic devices, which are vortex micropump, discretized micromixer, carbon nanotube based flow sensor, and Surface Plasmon Resonance (SPR) imaging biosensor have been designed, fabricated and demonstrated. According to different applications, these individual devices can be integrated into an automated microfluidic analysis system to sense, regenerate, and deliver fluid volumes in the order of micro-liters. This miniaturized and integrated system can provide a high throughput, increased resolution, and better controllable environment. Using the integrated and automated microfluidic system, two biomedical experiments, including monitoring of bovine serum albumin (BSA) binding reaction with BSA antibodies, and cell adhesion properties under the influence of trypsin, have been conducted.
Lei Kin Fong Thomas.
"August 2005."
Adviser: Wen J. Li.
Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 4065.
Thesis (Ph.D.)--Chinese University of Hong Kong, 2005.
Includes bibliographical references (p. 88-98).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract in English and Chinese.
School code: 1307.

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