Dissertations / Theses on the topic 'Continuous cell line'

Il progetto fondato sul Continuous Improvement, all’interno del quale è stata sviluppata l’esperienza di tirocinio presso l’azienda inglese Celli UK di proprietà del gruppo italiano Celli S.p.a., vede come obiettivo principale quello di implementare ed attuare le tecniche sulle quali si basa la filosofia della Lean Manufacturing, con il fine ultimo di apportare miglioramenti tangibili attinenti al reparto produttivo e misurarne i risultati. L’elaborato della tesi è incentrato sulla riprogettazione ed ingegnerizzazione di una linea di assemblaggio di un particolare modello di spillatrice di birra (DM3), ritenuta critica per l’efficienza globale del reparto produttivo. Inoltre, viene illustrato come vengono messi in pratica strumenti Lean in relazione alla stessa linea target. I risultati ottenuti sono stati misurati tramite determinati KPI relativi alla riduzione del Tempo Ciclo di assemblaggio, all’efficienza della linea ed alla riduzione di pre-assemblaggi. È stato inoltre calcolato il cut-off period dell’investimento che è stato necessario tramite il payback. Oltre a ciò, durante il periodo di tirocinio, è stato implementato un nuovo sistema gestionale per il quale è servito migrare tutti i dati inerenti ai prodotti, le distinte base e le route dal gestionale obsoleto al più recente software ERP Microsoft Dynamics. Successivamente è proseguito il lavoro di creazione degli stessi per i nuovi prodotti acquistati e/o venduti.

The role of the plasma membrane potential is most commonly associated with the generation of action potentials in excitable cells, however, experimental evidence suggests that this membrane potential is also linked to various behaviours in all cells (Blackiston et al., 2009). These cell behaviours include cell proliferation, cell migration and even cell survival. The membrane potential has been thought to influence these cell behaviours upstream of the classical transduction pathways. Recent evidence suggests that the membrane potential is dynamic rather than static and this dynamic behaviour may encode information on cell behaviours. The whole cell patch clamping technique coupled with the continuous wavelet transform (CWT) technique was used to investigate the presence of fluctuations and oscillations in the membrane potential of Jurkat cells and HMEC-1 cells. The underlying nature of the membrane potential dynamics of Jurkat cells was investigated by perturbing the extracellular concentration of either K+ , Na+ or Cl- . The membrane potential dynamics of proliferating, non-proliferating and activated Jurkat cells was investigated by either varying the culture medium or treating the cells with the concavalin A mitogen. The membrane potential dynamics of HMEC-1 endothelial cells was also investigated. The magnitude of the static membrane potential of proliferating Jurkat cells was significantly more depolarised that non-proliferating Jurkat cells – a trend which has been observed in a wide range of cell types. The membrane potential dynamics appear to be driven by the conductance of ions rather than the magnitude of the static membrane potential per se. In summary, this thesis has proven that the membrane potential varies with cell state and the CWT technique can be used to interrogate recordings of the membrane potential to ascertain information on the membrane potential dynamics that cannot be currently determined by other techniques.

L’elaborato nasce all’interno del progetto kaizen implementato nell’azienda Celli S.p.A. con sede in San Giovanni in Marignano (RN). L’elaborato è incentrato sulla riprogettazione dell’area produttiva ed in particolare delle due linee di assemblaggio manuali. L’intera analisi viene effettuata prendendo come riferimento un unico prodotto (impianto Lean – 086276), considerato particolarmente significativo ai fini dello studio. L’obiettivo della tesi è quello di analizzare e quantificare i cambiamenti derivanti dall’implementazione del progetto kaizen, standardizzare le operazioni di assemblaggio ed identificare i nuovi KPI necessari al monitoraggio dell’efficienza della linea. I risultati ottenuti hanno portato a miglioramenti in termini di diminuzione del TC, dei movimenti NVA e del numero di premontaggi realizzati. Al termine del progetto di tesi è stato inoltre calcolato il cut-off period dell’investimento tramite il payback.

Il presente elaborato si basa sull’esperienza di tirocinio svolta presso Celli UK, azienda parte del Gruppo Celli S.p.A. e con sede principale a Thirsk in Inghilterra. Il lavoro di tesi tratta l’implementazione di soluzioni in ottica lean manufacturing e di continuous improvement per risolvere alcune delle criticità riscontrate nelle linee di assemblaggio e nella gestione del magazzino. Preso come riferimento una delle linee più critiche, è stato eseguito il bilanciamento mediante l’assegnazione delle attività ai singoli operatori e la suddivisione della linea in più postazioni di lavoro. Una volta creato un flusso produttivo continuo, è stato reingegnerizzato il sistema di asservimento materiali. In merito alle problematiche del magazzino, è stato effettuato un’analisi costi-benefici riguardo l’uso di sistemi automatici di immagazzinamento verticale per la gestione dei prodotti in consignment stock. L’azienda ha quindi deciso di acquistarne uno, il quale è stato integrato al processo di stoccaggio esistente e al software gestionale adoperato. Le soluzioni adottate hanno permesso una migliore gestione a magazzino della merce in conto deposito e di avere una linea di assemblaggio più produttiva ed efficiente.

L’objectif de cette thèse était le développement d'un substitut bio-hybride pour la reconstruction du continuum tendon-os sur le principe de l’ingénierie tissulaire. Après une analyse bibliographique exhaustive des structures natives et de leur environnement, nous avons d'abord proposé la réalisation de chaque système séparément en utilisant des scaffolds en polycaprolactone réalises par electrospinning. Dans un premier temps, nous avons combiné l’electrospinning et l’electrospraying pour produire un scaffold composé de polycaprolactone et d’hydroapatite avec une structure en forme de nid d'abeille. Notre hypothèse était de doter le substitut d'une structure biomimétique favorisant l'adhésion, la colonisation et la différenciation cellulaire. L'analyse mécanique et biologique in vitro réalisée avec une lignée cellulaire progénitrice et des tests organotypiques a confirmé notre approche originale. Ensuite, le matériel ensemencé avec des cellules souches de moelle osseuse a été implanté avec succès par nos collaborateurs d'Amiens dans le but de traiter un défaut maxillo-facial chez un modèle de rongeur. Parallèlement, pour la reconstruction du tendon, nous avons réalisé différents scaffolds d'electrospinning, dont la taille et l'organisation (aléatoire/alignée) des fibres varient. Dans une perspective bio-inspirée, nous avons combiné les scaffold avec l'étirement dynamique pour reproduire l'entraînement physique. Sous ces stimulations mécaniques, établies d'abord avec la même lignée cellulaire progénitrice, nous avons démontré dans une deuxième étude que les CSM s'alignaient sur l'axe d'étirement et produisaient une matrice extracellulaire, ce qui a permis de conserver les propriétés mécaniques de la matrice biohybride pendant les deux semaines de la culture. Nous avons démontré que la différenciation cellulaire vers la lignée tendineuse et osseuse a été réalisée avec succès en l'absence de tout facteur de différenciation, étant spécifiquement lié aux propriétés des matériaux et à la mécanotransduction. Par conséquent, l'étape suivante, qui consiste à assembler les deux échafaudages avec une zone de transition, devrait conduire à la reconstruction de ce continuum osseux-tendon
The objective of this thesis was the development of a biohybrid substitute for the reconstruction of the bone-tendon continuum based on tissue engineering strategies. After an exhaustive bibliographic analysis of the native structures and their environment, we first proposed the realization of each system separately using electrospun polycaprolactone scaffolds. At first, we combined electrospinning with electrospraying techniques to produce a PCL-hydroapatite scaffold with honeycomb cavities. Our hypothesis was to provide the substitute with a biomimetic structure favoring cell adhesion, spreading and differentiation. The in vitro mechanical and biological analysis performed with a progenitor cell line and withorganotypic assays confirmed our original approach. Then, the material seeded with bone marrow stem cells was successfully implanted by our collaborators in Amiens with the objective of treating a maxillofacial defect in a rodent model. In parallel, for the tendon reconstruction, we investigated several electrospinning processes, varying fibers’ size and organization (random/aligned). In a bioinspired perspective, we combined the choice of the scaffold with dynamic stretching to reproduce physical training. Under those mechanical stimulations, established first with the same progenitor cell line, we demonstrated in a second study that MSCs aligned with the stretching axis and produced extracellular matrix, which in turn allowed to keep the mechanical properties of the biohybrid scaffold all over the 2 weeks of culture. We demonstrated that cell differentiation towards tendon and bone lineage was successfully achieved in the absence of any differentiation factor, being specifically related to materials properties and mechanotransduction. Therefore, the next step consisting in the assembly of both scaffolds with a transition area should lead to this bone-tendon continuum’s reconstruction

碩士
國立宜蘭大學
生物技術研究所碩士班
95
Lates calcarifer (bloch) belongs to the Lates genus, Centropomidae family, Perciformes order and Osteichthyes class. This tropical and sub-tropical fish is located in the coastal brackish water throughout Okinawa to the Indian Ocean. Lates calcarifer is massively cultured in Southeastern Asia and Southern Taiwan. Nervous Necrosis Virus (NNV), a member of the Betanodaviridae, is an icosahedral, non-enveloped RNA virus 25-30 nm in diameter. NNV mainly infects juveniles, destroying the nerves of the brain, leading to abnormal swimming and high mortality of infected fish, causing devastating economic impact to the aquaculture industry. Since the larvae of Lates calcarifier are highly susceptible to NNV, this research study developed primary and continuous cell lines from the liver, kidney, and the gas bladder of bloch. The liver and kidney cells were propagated over 90 passages while the gas bladder cell line was propagated over 150 passages, maintained in 5% FBS, L-15 medium, and grew quickly at both 28°C and 32°C. Epinephelus lanceolatus NNV was first used to test these different cell lines for susceptibility and results showed that Lates calcarifer gas bladder (LCGB) was highly susceptible. Then, wild type Plectropomus leopardus Nervous Necrosis Virus (PLNNV) was replicated in LCGB and the viral titer was 107 TCID50/mL. Large quantities of PLNNV was grown in LCGB, collected and purified, serving as the antigen for anti-NNV monoclonal antibodies production in BALB/c mice. After limiting dilution and screening, 3 different hybridomas secreting monoclonal antibodies against NNV were successfully produced. The 3 monoclonal antibodies were confirmed by Western blot and IPMA against purified NNV. Subsequently, cloning of PLNNV capsid gene and expression of recombinant proteins in E. coli was done in pQE30 vector and M15 host. A Western blot of the monoclonal antibodies against the recombinant protein proved all 3 monoclonal antibodies produced in this study were against the NNV capsid protein. These monoclonal antibodies are important tools to have for further researches on Nervous Necrosis Virus.

Fuel cells are electrochemical energy devices that convert the chemical energy in a fuel into electrical energy. Although they are more efficient, clean, and reliable than fossil fuel combustion systems, they have not been widely adopted because of manufacturing challenges and high production cost. The most expensive component of a fuel cell is the membrane electrode assembly (MEA), which consists of an ionomer membrane coated with catalyst material. Best performing MEAs are currently fabricated by depositing and drying liquid catalyst ink on the membrane, however, this process is limited to individual preparation by hand due to the membrane’s rapid water absorption that leads to shape deformation and coating defects. This work models the swelling and drying phenomena of the membrane and coating during manufacturing, and then applies the results to develop and control a continuous coating line for the production of defect free fuel cell MEAs. A continuous coating line can reduce the costs and time needed to fabricate the MEA, incentivizing the commercialization and widespread adoption of fuel cells. Membrane swelling is a three-dimensional, transient, coupled mass transfer, heat transfer, and solid mechanics problem. Existing models describe the membrane’s behavior in operating conditions, but none predict the behavior during manufacturing. This work develops a novel physics-based model that describes the behavior of the membrane and coating in a continuous manufacturing scenario and incorporates effects that are missing from existing models. A model that can predict wrinkles, the most commonly observed defect during manufacturing, is presented. Simulation results from the above models are used to design and develop an improved continuous MEA coating process that includes pre-swelling and two-stage drying of the coated membrane. A prototype pilot-scale coating line to implement and test the improved coating process is designed and constructed. Finally, a Linear-Quadratic-Gaussian type controller is developed using the physics-based model of the manufacturing process to optimally control the temperature and humidity of the drying zones, and its effectiveness when implemented on the coating line is discussed.
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碩士
高雄醫學大學
醫學研究所碩士班
93
Microdialysis sampling coupled on-line with simultaneous electrothermal atomic absorption spectrometry (SIMAAS) for continuous monitoring of copper (Cu), manganese (Mn), nickel (Ni) and selenium (Se) in cell cultured suspension has been developed. The trace elements investigated in this study are considered to be markedly associated with oxidative stress in biomedicine. Two major works were carried out in this study. Firstly, the analytical conditions including temperature program and matrix modifiers have been developed for the determination of Cu, Mn, Ni and Se in saline solution. The results showed that 3 mg of Pd and 10 mg of Mg(NO3)2 were successfully used as the matrix modifiers to prevent target elements from evaporation and to eliminate the interference resulting from NaCl in 1200℃ of the pyrolysis step. The analytical performances such as linearity, accuracy, and precision were validated to confirm the reliability of the proposed method. Secondly, the utrapure saline solution (0.9% NaCl) was used as the perfusion solution at the flow rate of 1 mL/min through the microdialysis probe to develop the on-line microdialysis-SIMAAS system. The optimized conditions of on-line microdialysis- SIMAAS system were performed for continuous measurements of four trace elements in microdialysate. The probe recovery of on-line microdialysis-SIMAAS system measured by a saline solution contained Cu, Mn, Ni and Se was 57.9 ± 1.4%, 65.0 ± 1.0%, 65.5 ± 4.1%, and 67.9 ± 4.6%, respectively. The analytical performances for microdialysis system such as long-term stability, response, and spiked recovery were validated to confirm the reliability of on-line system. The use of an on-line microdialysis-SIMAAS system permitted the in situ, dynamic and continuous monitoring of extracellular diffusible Cu, Mn, Ni and Se in cell suspension after treated with trace elements.

Submitted in fulfilment of the requirements of the Degree of Master of Technology: Biotechnology, Durban University of Technology, 2010.
Photodynamic therapy is a promising treatment for cancer. It involves the combination of a photosensitizer and light of an appropriate wavelength (laser source) to cause the destruction of cancer cells. Phthalocynanines are second–generation photosensitizers with enhanced photophysical and photochemical properties. In this in vitro study the effect of aluminium (AlTSPc) or zinc (ZnTSPc) tetrasulfophthalocyanines in its inactive and active state (laser induced) on melanoma (skin cancer cells), fibroblast (healthy normal skin cells) and keratinocyte (healthy normal skin cells) cells was evaluated. For each of the cell lines approximately 3 x 104 cells/ml were seeded onto 24-well cell culture plates and allowed to attach overnight, after which cells were treated with different concentrations of AlTSPc or ZnTSPc. The photosensitizers were synthesized at Rhodes University. After 2 hrs, cells were irradiated with a diode laser at a wavelength of 672 nm and a beam diameter of 1 cm. The laser power varied between 20-30 mW and the irradiation time was calculated to deliver a light dose of 4.5 J/cm2. Post-irradiated cells were incubated for 24 hrs before cell viability was measured using the CellTiter-BlueTM Viability Assay. Also, the efficacy of the light dose and laser source used for the killing of approximately 50% of the melanoma cancer cells were investigated. AlTSPc and ZnTSPc decreased cell viability of melanoma cancer cells to approximately 50% with photosensitizer concentrations of 40 μg/ml and 50 μg/ml respectively. These photosensitizer concentrations caused a slight decrease in the percentage cell viability of fibroblast and keratinocyte cells. Results for the dark toxicity assay showed that iii both photosensitizers in the presence of high concentrations (60 μg/ml – 100 μg/ml) showed cytotoxicity effects on melanoma cancer cells in their inactive state. This was not observed in fibroblast and keratinocyte cells treated under the same experimental conditions. The optimal AlTSPc and ZnTSPc concentrations in combination with the light dose of 4.5 J/cm2 was the most efficient in killing the melanoma cancer cells with reduced killing effects on healthy normal fibroblast and keratinocyte cells when compared to other light doses (2.5 J/cm2, 7.5 J/cm2 and 10 J/cm2). The irradiation of cells photosensitized with the optimal photosensitizer concentrations with a femtosecond laser using similar laser parameters to continuous wave laser experiments resulted in a reduction in the cell viability of healthy normal fibroblast and keratinocyte cells compared to melanoma cancer cells. The presence of DNA degradation on agarose gel, morphological changes like blebbing and ultrastructural changes like nucleus condensation indicated that photodynamic therapy treated melanoma cancer cells with the optimal concentrations of AlTSPc and ZnTSPc induced cell death via apoptosis. This concludes that low concentrations of AlTSPc and ZnTSPc activated with an appropriate laser source can be used to induce cell death in melanoma cancer cells. Both AlTSPc and ZnTSPc exhibit the potential to be used as a photosensitizer in photodynamic therapy for the treatment of melanoma cancer with the occurrence of minimal damage to surrounding healthy tissue.

That consciousness is ubiquitous, and relevant to autopoietic self-organisation and embodiment within every living being and/or organism, is a prevalent idea in contemporary consciousness research. However, because ‘consciousness’ as a word is derived from con or cum, meaning ‘with’ or ‘together’ and scire, ‘to know’ or ‘to see’ it infers the experience of knowing with an ‘other’ and/or ‘others’. The narrative that follows, while expressing a life of its own, documents the interdisciplinary research conducted and questions who and/or to what ‘other’ might infer. My visual diary, Dust from dust: Microorganisms and other tales: An Artist’s diary, created as the visual component of a creative practice-as-research undertaking, was silently performed amidst ‘others’ in the Unisa gallery, in an attempt to render visible, the autopoietic, self-organising embodiment essential to the conscious self-developmental component of the project. Once upon a time, I grew bacterial yeast cells in a glass vitrine to observe how they self-organised their own embodiment and photographed the process. At the same time, I conducted interdisciplinary research into consciousness as a self-developmental process, and utilising the cellular symbiosis unfolding in the vitrine as a self-reflexive mirror, came to visualise how indispensable bodily feelings are to conscious self-development, and being-in-the-world-with-others processes. As a creative-practice-as-research undertaking, I grew, manipulated and photographed the cellular imagery in the vitrine over many years in an attempt to unfold personal bodily feeling associations the imagery held captive, while gathering photographic footage I considered capable of expressing the primordial nature of certain emotive feeling experiences. Once obtained, I choreographed and performed a stop-frame video, entitled Dust from Dust: Microorganisms and other tales. An artist’s diary. The stop-frame video, along with a catalogue that focuses on the processes engaged with, accompanies the written narrative. Once edited, I macroscopically projected different phases of the video into a three-walled enclosure in the UNISA Art gallery. The three videos, representing a facet of my praxis, ran concurrently over a two week period. The fourth facet, presented with the video projections to emphasise conscious self-development as an in-the-world-with-others process, was the glass vitrine. It was positioned in a darkened enclosure in the gallery space, opposite the video projections. This narrative documents how I projected myself into the cellular imagery developing in the glass vitrine, in a way akin to how the ancient alchemists ‘projected’ themselves into the prima materia with which they worked. While the alchemists seemingly worked unconsciously, and my praxis initially started somewhat unconsciously, the process developed into a conscious attempt to embody the research findings. So, while the video choreographed, champions a microbial cell story, by referring to it as an artist’s diary, I emphasise the subjective nature of my praxis as a whole. In this creative-practice-as-research undertaking, I address the significance of bodily feelings and their relevance to being-in-the-world-with-others processes. In doing so, I aim to offer insight into how and why feelings are essential to inter-subjectivity and/or sociality, self-organisation and conscious self-development, as well as how and why conscious self-development can lead to immersive experiences, which I interpret as embodied adaptation to the rich diversity and/or fullness of life itself.
Art History, Visual Arts and Musicology
D. Litt. et Phil. (Art History)