Dissertations / Theses on the topic 'Microfluidic technique'
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DIVAKAR, RAMGOPAL. "ROOM TEMPERATURE ADHESIVE BONDING TECHNIQUE FOR MICROFLUIDIC BIOCHIPS." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1027950500.
Full textOwens, Tracie LeeAnne. "Engineering amphiphilic fabrics for microfluidic applications." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42908.
Full textLi, Haifeng. "An evanescent-wave based particle image velocimetry technique." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26472.
Full textCommittee Chair: Yoda, Minami; Committee Member: Aidun, Cyrus; Committee Member: Breedveld, Victor; Committee Member: Fedorov, Andrei; Committee Member: Zhu, Cheng. Part of the SMARTech Electronic Thesis and Dissertation Collection.
Rabehi, Amine. "Electromagnetic microsystem for the detection of magnetic nanoparticles in a microfluidic structure for immunoassays." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS129/document.
Full textThe detection and quantification of a biological agent or entity has become paramount to anticipate a possible health threat (epidemic or pandemic), environmental threat or to combat other contextual threats (bioterrorism, chemical and biological weapons, drugs). Consequently, developing a portable cost effective device that could detect and quantify such threats is the research focus of the joint multidisciplinary project between UPMC (Paris 6) laboratories and RWTH university in Aachen, Germany. In the framework of this project, we have studied the multidisciplinary aspects of an electromagnetic microsystem for immunologic detection based on magnetic nanoparticles (MNP) in a microfluidic lab-on-chip (LoC). Because of their extractability and sortability, magnetic nanoparticles are adapted for examination of biological samples, serving as markers for biochemical reactions. So far, the final detection step is mostly achieved by well-known immunochemical or fluorescence-based techniques which are time consuming and have limited sensitivity. Therefore, magnetic immunoassays detecting the analyte by means of magnetic markers constitute a promising alternative. MNP covered with biocompatible surface coating can be specifically bound to analytes, cells, viruses or bacteria. They can also be used for separation and concentration enhancement. The novel frequency mixing magnetic detection method allows quantifying magnetic nanoparticles with a very large dynamic measurement range. In this thesis, emphasis is put on the miniaturized implementation of this detection scheme. Following the development of analytical and multiphysics simulations tools for optimization of both excitation frequencies and detection planar coils, first multilayered printed circuit board prototypes integrating all three different coils along with an adapted microfluidic chip has been designed and realized. These prototypes have been tested and characterized with respect to their performance for limit of detection (LOD) of MNP, linear response and validation of theoretical concepts. Using the frequency mixing magnetic detection technique, a LOD of 15ng/mL for 20 nm core sized MNP has been achieved with a sample volume of 14 μL corresponding to a drop of blood. Preliminary works for biosensing have also been achieved with a state of the art of surface functionalization and a developed proposed biochemical immobilization procedure and preliminary tests of its validation
Johnson, Chrisopher W. A. "Design and development of a site specific protein patterning technique for use in a microfluidic antibody separation device." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/157341/.
Full textLu, Heng. "Development of droplet-based microfluidic tools for toxicology and cancer research." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB064.
Full textThis thesis project consists in developing droplet-based microfluidic tools for toxicology and cancer research. Owing to its large numbers of discretized volumes, sensitivity of detection of droplet-based microfluidics for biological molecules such as DNA and antibody is much higher than bulk assays. This high throughput format is particularly suitable for experiments where a robust dose-response curve is needed, as well as for single cell analysis with applications in genomic or sequencing and epigenetics. All above makes droplet-based microfluidics a powerful tool for toxicology and cancer research. In a first part of the work, an accurate cell counting method, named “microfluidics hemocytometry”, has been developed. A new counting algorithm was proposed to count the cells within each droplet. Escherichia Coli and two different human cell lines (HL60 and H1975) were used to validate our strategy. The number of each type of cells in droplets was determined with a high consistency between theory (Poisson distribution) and experimental results. With these robust results, a droplet-based microfluidic protocol has then been established to inquiry both cell viability and proliferation for the two human cell lines. The results are in good agreement with the one of the literature. For the toxicology, 3 different biological models, including microsomes (extracted from baculovirus-infected insect cell expressing human CYP3A4), HepG2-CYP3A4 (genetically modified to express the human CYP3A4 gene) and HepaRG liver cells lines were evaluated for enzymatic activity of cytochromes P450 (CYP3A4), a routinely used enzyme for drug candidate screening. Microsome-based assays were used to validate a fluorogenic inhibition assay. However neither microsome-based assay nor the assay using CYP3A4 expressing HepG2 gave satisfying results in droplet-based format. However, HepaRG cells, a hepatic function-conserved cell line with most cytochrome and related nuclear receptors, demonstrated high relevance both for enzymatic activity testing and CYP3A4 expression induction study. For cancer research, 4 different picoliter droplet-based PCR assays were developed for the detection and quantification of mutations (NRAS, DNMT3A, SF3B1 and JAK2) present in Myelodysplastic syndromes, a heterogeneous group of clonal bone marrow hematopoietic stem cell disorders characterized by ineffective hematopoiesis and peripheral cytopenias. Furthermore, a single cell multistep PCR assay using encapsulation of target DNA in agarose droplets was proposed
Nikcevic, Irena. "Development of techniques and materials for microfluidic devices." Cincinnati, Ohio : University of Cincinnati, 2008. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1212155007.
Full textRajah, Luke. "Biophysical and microfluidic techniques for investigating protein aggregation." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608030.
Full textNIKCEVIC, IRENA. "Development of techniques and materials for microfluidic devices." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1212155007.
Full textPuccetti, Giacomo <1988>. "Optical Techniques for Experimental Tests in Microfluidics." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amsdottorato.unibo.it/7534/.
Full textChen, Chih-chen. "Microfluidic elastomeric platforms for probing single cells /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/8029.
Full textHelton, Kristen Lloyd. "Preconditioning saliva to measure small analytes in a microfluidic biosensor /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/8078.
Full textPark, Jaesung. "Study of microfluidic measurement techniques using novel optical imaging diagnostics." Diss., Texas A&M University, 2005. http://hdl.handle.net/1969.1/4953.
Full textSudarsan, Arjun Penubolu. "Multivortex micromixing: novel techniques using Dean flows for passive microfluidic mixing." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4686.
Full textDu, Ke. "Noval nanoindentation-based techniques of MEMS and microfluidics applications." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002778.
Full textDu, Ke. "Novel Nanoindentation-Based Techniques for MEMS and Microfluidics Applications." Scholar Commons, 2008. https://scholarcommons.usf.edu/etd/220.
Full textEdel, Joshua B. "Development of single molecule and particle detection techniques for microfluidic analysis." Thesis, Imperial College London, 2004. http://hdl.handle.net/10044/1/11215.
Full textOgilvie, Iain R. G. "Novel fabrication techniques for microfluidic based in-situ oceanographic nutrient sensors." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/342947/.
Full textStapountzis, Margarita Antonia. "Development of fluorescence lifetime measurement techniques for use in microfluidic channels." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/14619.
Full textCorbin, Inge. "Analysis of Improvised Explosives by Electrospray Ionization - Mass Spectrometry and Microfluidic Techniques." FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2551.
Full textDey, Abhishek. "Frequency Tunable Antennas and Surface Microwave Imaging System Using Microfluidic Reconfiguration Techniques." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6491.
Full textFoley, Jennifer Olivia. "Design and development of surface plasmon resonance imaging microfluidic assays /." Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/7982.
Full textKamholz, Andrew Evan. "Quantitative analysis of diffusion and chemical reaction in pressure-driven microfluidic channels /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/8020.
Full textJacksén, Johan. "Improved techniques for CE and MALDI-MS including microfluidic hyphenations foranalysis of biomolecules." Doctoral thesis, KTH, Analytisk kemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-27342.
Full textQC 20101214
Viberg, Pernilla. "Development of non-adherent single cell culturing and analysis techniques on microfluidic devices." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1441.
Full textReuter, Marcel. "Bacterial protein complexes studied by single-molecule imaging and single-cell micromanipulation techniques in microfluidic devices." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/6192.
Full textWang, Chao. "Microfluidics for particle manipulation : new simulation techniques for novel devices and applications." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:8125980e-0603-4425-b0fa-89a4fdfdf464.
Full textKong, Cher Rong Matthew. "Contactless liquid flow control for miniaturised analytical techniques on continually rotating centrifugal microfluidic platforms." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=117150.
Full textDans notre société industrielle, la conception de techniques pour la quantification d'espèces chimiques dans l'environnement, les humains et les dérivés de la production manufacturière est primordiale. Au départ, ces techniques avaient été élaborées à partir d'instruments sophistiqués et se basaient sur des procédures complexes. Il serait donc avantageux de pouvoir réduire les coûts d'analyse et simplifier les procédures expérimentales, tout en maintenant un niveau élevé de la qualité des données recueillies. De plus, il est souvent souhaitable de pouvoir effectuer ces mesures rapidement, et si possible sur le site où l'échantillon à analyser est recueilli. Toutes ces caractéristiques bénéfiques des méthodes analytiques peuvent être obtenues, dans certains cas, à travers la miniaturisation. L'intérêt pour la miniaturisation a mené à une croissance rapide des systèmes microfluidiques, un domaine d'études qui se concentre sur l'utilisation de petits volumes de liquide et des systèmes de détection spécialement adaptés à ces volumes réduits. Tout système microfluidique doit intégrer une méthode de transfert des liquides à travers différentes étapes de traitements chimiques ou physiques. Une méthode de pompage particulièrement intéressante utilise la force centrifuge, ce qui permet d'éliminer l'utilisation de pompes ou connections externes au système où s'effectue l'analyse chimique. Jusqu'à présent, les systèmes employant la force centrifuge ont été limités par le nombre d'étapes analytiques consécutives, le liquide ne pouvant se déplacer que dans une seule direction définie par la force centrifuge appliquée.Pour cette thèse, plusieurs techniques de manipulation des liquides sur un système microfluidique à base de force centrifuge ont été dévelopées et caractérisées. Ces techniques ont été utilisées pour miniaturiser les méthodes analytiques classiques pour ensuite les intégrer à des plateformes microfluidiques à base de force centrifuge, l'objectif final étant la surveillance d'espèces chimiques dans l'environnement. Une technique de pompage par déplacement de deux phases liquides et une technique de pompage pneumatique à base de force centrifuge sont démontrées. La technique pneumatique à base de force centrifuge qui a été développée augmente de façon significative les capacités de la boîte à outils des systèmes microfluidiques à base de force centrifuge. Ce nouveau système permet d'effectuer simultanément des opérations essentielles dans les systèmes microfluidiques telles que le transfert de liquides sans valves, les dosages, la commutation du débit des liquides, les micromélanges par agitation ainsi que la recirculation des liquides. Cette technique se base sur l'application sans contact d'une pression pneumatique en utilisant de l'air comprimé sur un système microfluidique à base de force centrifuge en rotation constante. Ceci permet un contrôle complet du débit des liquides en combinant les effets de la pression pneumatique et de la force centrifuge. Le processus de fabrication de ce nouveau système est grandement simplifié par l'ajout du système pneumatique car cela diminue le nombre de valves à intégrer dans le système. De plus, son efficacité est accrue grâce à la possibilité d'effectuer des analyses de façon automatisée. Cette approche pneumatique a été appliquée à des mesures spectrophotométriques par la méthode des additions connues effectuées directement sur le disque. Dans le même ordre d'idées, un autre système employant la fonction pneumatique a été développé pour effectuer des extractions liquide-liquide entre une phase liquide et une phase organique. Ceci a démontré que la plateforme centrifuge est capable non seulement d'effectuer des réactions chimiques complexes en plusieurs étapes, mais aussi de répéter les cycles de réactions et autres processus.
Rezaei, Nejad Hojatollah. "Development of techniques for rapid isolation and separation of particles in digital microfluidics." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57956.
Full textApplied Science, Faculty of
Engineering, School of (Okanagan)
Graduate
Carr, Simon David. "Assessing the effects of radiotherapy on head and neck squamous cell carcinoma using microfluidic techniques." Thesis, University of Hull, 2013. http://hydra.hull.ac.uk/resources/hull:8396.
Full textEl-Sabbahy, H. "Development of preparative microfluidic techniques for lysis of microbial cells and affinity purification of proteins." Thesis, University College London (University of London), 2013. http://discovery.ucl.ac.uk/1419100/.
Full textHerbst, Maria [Verfasser], and Stephan [Akademischer Betreuer] Förster. "Microfluidic and X-ray techniques for investigations of nanoparticle nucleation and growth / Maria Herbst ; Betreuer: Stephan Förster." Bayreuth : Universität Bayreuth, 2021. http://d-nb.info/1229505393/34.
Full textBarbre, Evan Allen. "LASER ETCHED PMMA MICROFLUIDIC CHIP DESIGN AND MANUFACTURE WITH APPLICATIONS IN CAPILLARY ZONE ELECTROPHORESIS." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/448.
Full textBishop, Sandra Charlotte. "Advanced capillary electrophoretic techniques for the detection of date-rape and club drugs for a forensic setting." Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1107528810.
Full textXu, Jiang. "Contribution à la fabrication de nanoparticules en utilisant des techniques microfluidiques et applications à la libération d'actifs." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0122/document.
Full textPolymeric nanoparticle (NP) drug carriers present a promising technology for controlled releasesince they are capable of improving the encapsulation efficiency and stability of the drugs inside theNPs and also able to provide effective drug levels over a longer period of time, compared totraditional therapy. However, before the NP drug delivery technology becomes a reality, importantparameters of NPs like size, drug loading ability and sustained release kinetics must be wellinvestigated and optimized in order to minimize the adverse effects of chemotherapeutic compoundsand prolong the drug releasing profile in a controlled manner.In order to accomplish this objective, this thesis proposed two novel methods for synthesis of NPs asdrug delivery carriers, with assistance from bulk and microfluidic technologies, for hydrophobic andhydrophilic drugs, individually.Encapsulation efficiency as high as 80% is reached with a mass loading of 20%. We extend ourapproaches to the encapsulation of iron oxide
Campagnolo, Lucie. "Optical feedback interferometry sensing technique for flow measurements in microchannels." Phd thesis, Institut National Polytechnique de Toulouse - INPT, 2013. http://tel.archives-ouvertes.fr/tel-01068169.
Full textDuford, David. "Instrumentation, fabrication techniques and method development for sample introduction, preparation and extraction on centrifugal microfluidic devices in motion." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110441.
Full textLes polluants ont des impacts importants sur la santé et l'environnement résultant à des restrictions accrues des limites législatives. Cette surveillance environnementale accrue pousse les chimistes analytiques vers l'automatisation et la miniaturisation des méthodes de référence actuelles. L'analyse d'échantillons environnementaux solides bénéficiera de cette envolée par le développement de nouveaux instruments et techniques de manipulation d'échantillon via des dispositifs microfluidiques centrifuges qui intègrent des réactions à étapes multiples sur un dispositif unique.Afin d'étudier et d'optimiser les dispositifs microfluidiques centrifuges en mouvement, des plateformes motorisées qui incluent une caméra, une lumière stroboscopique et une variété d'autres composantes périphériques ont été développées. Celles-ci ont permis le contrôle efficace des dispositifs tout au long des séquences giratoires et l'acquisition simultanée de séries de photographies en arrêt sur image.Des méthodologies sont présentées pour l'introduction, la préparation et l'extraction d'échantillons sur des dispositifs microfluidiques centrifuges en mouvement. Ceci fut réalisé grâce à la recherche de techniques de fabrication hybrides incluant l'utilisation d'imprimantes 3D menant au développement d'une interface permettant l'introduction de solutés à concentrations variables aux dispositifs en mouvement. De plus, l'interaction d'aimants mobiles intégrés avec une série d'aimants fixes placée sous les dispositifs en mouvement a mené au développement des techniques de préparation d'échantillons solides par force magnétique et d'extraction liquide-solide d'échantillons par force magnétique. De nouvelles méthodes automatisées et miniaturisées ont été développées pour l'analyse d'espèces environnementales importantes telles que les hydrocarbures polycycliques aromatisés et les pesticides dans des échantillons solides.
Shrestha, Ramesh. "Micro-Pipette Thermal Sensor: A Unique Technique for Thermal Characterization of Microfluids, Microspheres, and Biological Cells." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703406/.
Full textBushman, Sarah Mansfield. "The Development of Micro- and Nano-scale Techniques for Studying Cancer Cell Invasion." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492775878121827.
Full textTRICHUR, RAMACHANDRAN KRISHNAN. "DEVELOPMENT OF POLYMER MEMS STRUCTURES FOR LAB-ON-A-CHIPS USING UV-LIGA AND INJECTION MOLDING TECHNIQUES." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1061211852.
Full textMitchell, Haydn Thomas. "AN INVESTIGATION OF POLY(N-ISOPROPYLACRYLAMIDE) FOR APPLICATIONS WITH MICROFLUIDIC PAPER-BASED ANALYTICAL DEVICES." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1248.
Full textPilát, Zdeněk. "Optical Micromanipulation Techniques Combined with Microspectroscopic Methods." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-234266.
Full textBishop, Sandra Charlotte. "Advanced Capillary Electophoretic Techniques for the Detection of Date-Rape and Club Drugs for a Forensic Setting." Ohio University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1107528810.
Full textVyas, Chandni Atul. "Rapid Detection of Biogenic Amines using Capillary Electrophoresis and Gradient Elution Isotachophoresis." Diss., Temple University Libraries, 2010. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/112673.
Full textPh.D.
The metabolism of amino acids produces important chemical signaling molecules called neurotransmitters, which are responsible for carrying out important actions within the human body. There are approximately one hundred identified neurotransmitters. Neurotransmitter study is important due to their involvement in biological, physiological, pharmacological, and pathological functions. Commonly employed methods for neurotransmitter detection are mainly based upon microdialysis. However, the methods suffer from disadvantages. Microdialysis fails to determine the absolute concentration of analytes and therefore requires it to be tied in with an analytical technique such as high performance liquid chromatography or capillary electrophoresis. Although high performance liquid chromatography is the most powerful analytical technique to date, it necessitates high maintenance and suffers from poor temporal resolution. While capillary electrophoresis affords more rapid separations than high performance liquid chromatography, it suffers from poor concentration limits of detection and requires large sample dilutions of highly conductive samples, such as biological fluids. Consequently, research is focused on detection of various amino acids and neurotransmitters employing novel analytical techniques along with traditional capillary electrophoresis. First, a method was developed using traditional capillary electrophoresis with laser induced fluorescence detection to detect two major excitatory neurotransmitters, glutamate and aspartate in planaria. The method was later applied to detect several biogenic amines using micellar electrokinetic chromatography with laser induced fluorescence detection in planaria to study the effect of feeding on the levels of biogenic amines within individual planaria homogenates. The concentration sensitivity issue of capillary electrophoresis led to the use of a new method for sensitive neurotransmitter measurements, gradient elution isotachophoresis. Gradient elution isotachophoresis is an efficient capillary-based enrichment and separation technique based on balancing hydrodynamic counter-flow against electrophoresis. Enrichment is achieved with the aid of high concentrations of leading electrolyte in the counter-flow solution that creates an ionic interface near the capillary inlet. Discrete electrolyte spacers or carrier ampholyte mixtures are used to separate analyte zones. The method was applied to the enrichment and separation of physiologically relevant concentrations of aspartate and glutamate labeled with dansyl chloride, phenyl isothiocyanate, or carboxyfluorescein, succinimidyl ester in artificial cerebrospinal fluid using ultraviolet absorbance detection. Finally, gradient elution isotachophoresis was combined with capillary zone electrophoresis to eliminate the use of spacers and provide rapid separations and enrichment. The technique was applied for the detection of biogenic amines in a glass microfluidic device.
Temple University--Theses
Samouda, Feriel. "Développement de la technique de vélocimétrie par marquage moléculaire pour l'étude expérimentale des micro-écoulements gazeux." Thesis, Toulouse, INSA, 2012. http://www.theses.fr/2012ISAT0034/document.
Full textThis thesis focuses on the development of Molecular Tagging Velocimetry (MTV) technique for the experimental analysis of internal microflows of gases. Gaseous microflows are rarefied flows characterized by a non-negligible Knudsen number. A literature review highlights a crucial need of experimental data on velocity fields within gaseous microflows. These data are required for a relevant discussion on the validity and limits of applicability of the different boundary conditions proposed in the slip flow, which is a regime often encountered in gaseous microsystems. An experimental setup has been designed for analyzing by MTV the velocity distribution in microchannels. The technique consists in detecting the displacement of acetone molecules, introduced as tracers in a gas flow; these molecules exhibit phosphorescence once excited by a UV light source. The various compromises taken into account for the setup design (choice of tracer, laser, channel material and design, camera and intensifier…), as well as the acquisition and processing techniques are detailed in the manuscript. The experimental analysis starts with a study of the acetone phosphorescence signal. Then, the MTV technique is validated by velocity field measurements in internal laminar flows through a rectangular minichannel in non-rarefied regime. The obtained results are successfully compared to the theoretical velocity profile of a Poiseuille flow. Finally, preliminary results obtained at lower pressures are presented and commented. The signal detection at a pressure level as low as 1 kPa is encouraging and draws various perspectives for the exploration of rarefied regimes
Tageson, Mackenzie Elizabeth. "FUNCTIONAL 3-D CELLULOSE & NITROCELLULOSE PAPER-BASED, MULITPLEX DIAGNOSTIC PLATFORMS WITHOUT COUPLING AGENTS." DigitalCommons@CalPoly, 2013. https://digitalcommons.calpoly.edu/theses/1128.
Full textMartim, Hamilton de. "Desenvolvimento de uma técnica para seleção de espermatozoides em amostra seminal não processada para utilização na injeção intracitoplasmática de espermatozoides." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/5/5153/tde-11092017-101455/.
Full textDuring intracytoplasmic sperm injection (ICSI) a motile spermatozoon with normal morphology is visually selected for insemination of an oocyte. Recent evidence indicates that even though the sperm appears morphologically normal, a possibility of defects at the molecular level still exists. The main objective of this work was to describe a novel approach capable of selecting mature spermatozoa from unprocessed semen sample in a one-step ICSI procedure. A modified extended drop was tested in a prospective comparative study. The \"Gota Estendida com Mecanismo Contracorrente - GEMC\" (Positive Rheotaxis Extended Drop - PRED) was assembled on a standard ICSI dish and consisted of six culture medium droplets (10 ?L). The precise merging of the drops created two reservoirs and a channel therefore the fluid flew through the channel. The addition of a PVP solution created a viscosity gradient in the final sector of the circuit. Semen samples were taken from 40 subfertile men. Each semen sample was divided into four aliquots: one aliquot for density gradient centrifugation (DGC), one aliquot for GEMC using fresh semen, one aliquot for GEMC using processed semen and one aliquot for the control. In GEMC a mean of 200 spermatozoa were collected consecutively, without selection, from the outlet reservoir with an injecting pipette as for conventional ICSI procedure. Sperm morphology was assessed and resulted in improvement compared to controls in all treatments. Chromatin immaturity was assessed using aniline blue assay. Regarding to chromatin immaturity, 100% of men had better results after DGC preparation and GEMC approach. This was reflected in a mean reduction from 28.65 ± 8.97% uncondensed chromatin in the native ejaculates to 17.29 ± 7.72% in DGC processed semen (P < 0.01). An even greater reduction was achieved after GEMC approach showing a mean of 0.89 ± 1.31% uncondensed chromatin compared to DGC processed sample (P < 0.01). A novel one-step ICSI approach joining sperm selection and recovery was developed and tested. This GEMC approach can select sperm easily and permits the direct use of native semen in ICSI. This approach can select sperm with lower chromatin immaturity than DGC method. Further studies need to access its relation to fertilization, embryo development, pregnancy, implantation and miscarriage rates
Paoli, Roberto. "Cell culture interfaces for different organ-on-chip applications: from photolithography to rapid-prototyping techniques with sensor embedding." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668376.
Full textEn los últimos años está emergiendo una nueva propuesta para mejorar los modelos actuales en el estudio de nuevos fármacos. Mediante la fusión de cultivos celulares y microfluídica ha nacido un nuevo campo de aplicación denominado “Órgano-en-un-chip” (OOC), donde se recrea un entorno fisiológico capaz de reproducir unidades funcionales mínimas de diversos órganos del cuerpo humano. Un elemento importante para el desarrollo de dispositivos OOC es la reproducción de zonas de interacción entre varios tejidos formados por diferentes tipos celulares. Esta tesis, titulada “Interfaces de cultivo celular para diferentes aplicaciones de OOC: desde fotolitografía a técnicas de prototipado rápido con inclusión de sensores”, tiene como objetivo el diseño, simulación y evaluación de dispositivos OOC capaces de reproducir superficies de contacto de tejidos contiguos expuestos a flujo. El trabajo está enfocado a la exploración de nuevas técnicas de fabricación que permitan el prototipado rápido de dispositivos OOC, reduciendo costes, tiempo y mano de obra asociada a dicha fabricación. El objetivo final es demostrar la utilidad de los dispositivos como herramientas de investigación para problemas biológicos, aplicándolos en esta tesis al estudio del túbulo renal y de la barrera hematoencefálica. Para ello se han fabricado tres versiones de dispositivos: 1) OOCv1 fabricado por litografía suave en múltiples capas de PDMS; 2) OOCv2 fabricado con cortadora de vinilo y cortadora láser en múltiples capas de materiales termoplásticos y con electrodos integrados en la versión OOCv2.2; 3) OOCv3 fabricado mediante impresión 3D por esterolitografía. Todos los dispositivos están hechos de materiales biocompatibles de alta calidad óptica, con conectores fluídicos y una membrana comercial integrada. Los experimentos biológicos sobre túbulo renal, realizados en los dispositivos OOCv1 y OOCv2, han demostrado la viabilidad de los dispositivos, integrados con un sistema de flujo, para estudios de la metabolización de ácidos grasos en el riñón relacionados con condiciones diabetogénicas. Los experimentos biológicos sobre la barrera hematoencefálica han confirmado la viabilidad de OOCv2 para el cocultivo compartimentado de células endoteliales de cerebro y pericitos. La integración de electrodos en el OOCv2.2 ha demostrado ser una técnica fiable para la medición de la integridad de barreras biológicas de modo no-invasivo, libre de etiqueta (“label-free”), y a tiempo real gracias a la espectroscopía de impedancia.
Yu, Wei. "Development of an elongational-flow microprocess for the production of size-controlled nanoemulsions : application to the preparation of composite and hybrid polymeric microparticles." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAE027/document.
Full textThe aim of this work was to develop and to study the performances of a low pressure elongational-flow microprocess for the production of size-controlled polymerizable nanoemulsions with narrow size distributions. Nanodroplets diameter was easily tuned in the size range 50-300 nm by varying the process parameters, namely the reciprocating flow rate through the micromixer, the number of cycles and the characteristic dimension of the microchannel. Obtained nanoemulsions were in a second step thermally or UV-assisted polymerized to give colloidal suspensions of size-tunable polymer nanoparticles (87-360 nm). Then, a proper monomer, crosslinker and thermal- or photo-initiator were added to the continuous phase of these nanosupensions. The resulting mixtures were used as the dispersed phases of two different capillaries-based microfluidic droplet generators. The produced sizecontrolled microdroplets were finally UV polymerized online and plain as well as core-shell composite polymeric microparticles doped with lower scale polymer nanoparticles were obtained. Composite/hybrid polymeric core-shell microparticles were also synthesized for which gold nanoparticles in the core and silver nanoparticles in the shell were synthesized in situ from their salt precursors during microdroplets polymerization. This work has demonstrated the high efficiency of a novel low energy microfluidic emulsification device for the production of nanoemulsions which were used for the synthesis of morphologically complex polymeric materials
Paiola, Johan. "Écoulement d'un fluide à seuil dans un milieu poreux." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS031/document.
Full textElastic solids at rest, yield stress fluids flow like a liquid beyond a certain stress. Many industrial applications required the flow of these fluids in porous media, for example: the emulsion flow in oil recovery processes, the cementing operations in the ground, or the cleaning of sludge in a contaminated soil. For many applications, it could be interesting to know the pressure required for a desired flow rate. In such cases, the flow behavior of the fluid is complicated by the complexity of the geometry. The models developed to describe Darcy's law assume a rheological law applied locally, but these models poorly describe this type of flow. Furthermore, complex effects can be added like the wall slip or the thixotropy. In this thesis, we study the flow of carbopol (ETD 2050) through different geometries. First we show that the fluid, for some conditions, corresponds to model yield stress fluids. The experimental protocol used is very important and a thixotropic behavior can appear if it is not respected. This behavior appears especially when the fluid remains below the yield stress, the impact increases with the waiting time. We then compare the flow law obtained by rheometer in a straight channel obtained by microfabrication. We show the importance of the wall slip near the yield stress and the impact on the flow law. Finally, using a new method to measure the velocity fields developed during this thesis, we study the flow of carbopol in a porous medium. This porous medium of 5x5cm is obtained by microfabrication. The mean width of the channels is equivalent to the one of the straight channel. We show the emergence of a channeling flow through some channels of the porous medium. We then compare the flow law of the porous medium to the one obtained in the straight channel. It can be observed that the flow rate is lower in the porous medium than in the straight channel