Over the last decade, microfluidics has emerged as a distinct new field with promising applications for diverse research areas. The ability to precisely control fluids at the microscale allows the execution of a variety of programmable semi-automatic operations on the same device, effectively forming a lab-on-a-chip. In particular, droplet-based microfluidic systems – which reliably generate highly uniform microdroplets at a high throughput – enable the controlled compartmentalization of biological material and have the potential to influence mainstream biomedical research. In this thesis, a microfluidic platform is presented that allows the encapsulation of viable cells in agarose microcapsules for applications in cell–based therapy. As an improvement to pre-existing methods of cell encapsulation, the proposed system combines continuous high throughput cell-encapsulation with on-chip microcapsule gelation and purification.

La thèse vise à apprécier les effets de la mise en oeuvre d'un dispositif d'ExAO comparativement à d'autres modalités plus classiques de TP (laboratoire traditionnel et exposé d'expériences). L'apprentissage concerné est celui du concept de réaction chimique par des élèves de 5ème au Liban. Les élèves soumis aux trois modalités pédagogiques ont été confrontés à deux reprises à une épreuve commune de connaissances (prétest et post-test). Les données analysées portent de plus sur les comptes rendus d'expérience réalisés par les élèves des trois groupes. Les résultats attestent d'un effet positif plus important de la modalité de travail par ExAO. Du point de vue quantitatif les élèves de ce groupe ont nettement plus progressé que les autres eu égard à la plupart des dimensions de l'apprentissage concerné. D'un point de vue qualitatif, il s'avère en outre que ces élèves ont fait preuve d'un meilleur niveau de compréhension du contenu du TP réalisé. / The thesis aims at assessing the effects of the implementation of MBL compared with two other classic lab work methods (the presentation of lab work and lab work displaying). The course given to students in grade 7 in Lebanon focuses on the concept of chemical reaction. The students in all three groups sat for both a pre-test and a post-test of knowledge, created specifically for this study. The analyzed data cover also the reports made by students of all three groups.The results are consistent with a positive effect of the modality of MBL work. From a quantitative point of view, the students in this group are significantly more advanced than others in relation to the most relevant dimensions of learning. From a qualitative point of view, it also turns out that these students have demonstrated a greater level of understanding of the content of lab work achieved.

The growing markets for analytical techniques in areas such as pathogen detection, clinical analysis, forensic investigation, environmental analysis and food analysis require the development of devices with simultaneous high performance, speed, simplicity and low cost. Analysis of deoxyribonucleic acid (DNA) has been enhanced by use of the polymerase chain reaction (PCR) technique, which is now a widely used tool for in vitro amplification of nucleic acids. In this work, a miniaturised PCR system comprising a microfluidic PCR chip, novel heating method and fluorescence detection unit was developed. PCR chip with reactants were shunted along three temperature zones in a fine polycarbonate chip. The polycarbonate PCR chip was fabricated using milling and thermal fusion binding for sealing of the cover. Thermal-cycling within the microfluidic chip was achieved by programmable shunting of the chip between three double side temperature zones with different temperatures to accomplish the denaturation, annealing and elongation steps necessary for PCR amplification. This thermal-cycling model potentially improves PCR efficacy because it increases the ramping rates for heating and cooling the PCR mixture. The detection unit comprises a photo-detector and Light Emitting Diode (LED) as the source of excitation. The detection limit of the system was determined on the PCR chip using Fluorescein isothiocyanate (FITC) as a fluorophore dye. The detection limit achieved was 7.8 pg ml-1 or (19.7 pmol) of FITC. The chromosomal DNA used in this work was extracted from non-pathogenic K-12 subtype of Escherichia coli (E. coli). The investigations showed that the system was capable of performing PCR amplification with different annealing temperature ranging from 54 to 68 °C, targeting three different sizes of PCR products of 250, 552 and 1500 bp. The prototype thermal-cycler and PCR chip were used successfully to amplify the three sizes and the results were compared with same fragments amplified on a conventional PCR .thermal-cycler machine. The method used for comparison was gel electrophoresis. In addition, a fluorescence detection system was employed for detecting of PCR products using SYBR Green I fluorescent dye. The whole system allows for developments of low cost, easy to use and portable instruments.

This dissertation focuses on developing 3D printing as a fabrication method for microfluidic devices. Specifically, I concentrate on the 3D printing approach known as Digital Light Processing stereolithography (DLP-SLA) in which serially projected images are used to sequentially photopolymerize layers to build a microfluidic device. The motivation for this work is to explore a much faster alternative to cleanroom-based microfabrication that additionally offers the opportunity to densely integrate microfluidic elements in compact 3D layouts for dramatic device volume reduction. In the course of my research, an optical approach was used to guide custom resin formulation to help create the interconnected hollow regions that form a microfluidic device. This was based on a new a mathematical model to calculate the optical dose delivered throughout a 3D printed part, which also explains the effect of voids. The model was verified by a series of 3D printed chips fabricated with a commercial 3D printer and a custom resin. Channels as small as 108 µm x 60 µm were repeatably fabricated. Next, highly compact active fluidic components, including valves, pumps, and multiplexers, were fabricated with the same 3D printer and resin. The valves achieved a 10x size reduction compared with previous results, and were the smallest 3D printed valves at the time. Moreover, by adding thermal initiator to thermally cure devices after 3D printing, the durability of 3D printed valves was improved and up to 1 million actuations were demonstrated.To further decrease the 3D printed feature size, I built a custom 3D printer with a 385 nm LED light source and a 7.56 µm pixel pitch in the plane of the projected image. A custom resin was also developed to take advantage of the new 3D printer's features, which necessitated developing a UV absorber screening process which I applied to 20 candidate absorbers. In addition, a new mathematical model was developed to use only the absorber's molar absorptivity measurement to predict the resin optical penetration depth, which is important for determining the z-resolution that can be achieved with a given resin. The final resin formulation uses 2-nitrophenyl phenyl sulfide (NPS) as the UV absorber. With this resin, along with a new channel narrowing technique, I successfully created flow channel cross sections as small as 18 µm x 20 µm.With the custom 3D printer, smaller valves and pumps become possible, which led to the invention of a new method of creating large numbers of high density chip-to-chip microfluidic interconnects based on either simple integrated microgaskets (SIMs) or controlled-compression integrated microgaskets (CCIMs). Since these structures are directly 3D printed as part of a device, they require no additional materials or fabrication steps. As a demonstration of the efficacy of this approach, 121 chip-to-chip interconnects in an 11 x 11 array for both SIMs and CCIMs with an areal density of 53 interconnects per square mm were demonstrated, and tested up to 50 psi without leaking. Finally, these interconnects were used in the development of 3D printed chips with valves having 30x smaller volume than the valves we previously demonstrated. These valves served as a building block for demonstrating the miniaturization potential of an active fluid mixer using our 3D printing tools, materials, and methods. The mixer provided a set of selectable mixing ratios, and was designed in 2 configurations, a linear dilution mixer-pump (LDMP) and a parallelized dilution mixer-pump (PDMP), which occupy volumes of only 1.5 cubic mm and 2.6 cubic mm, respectively.

Les laboratoires sur puce sont des dispositifs miniaturisés qui offrent la possibilité d'intégrer en ligne toutes les étapes de la chaîne analytique tout en réduisant les volumes d’échantillon et les temps d’analyse. Ainsi, ils constituent potentiellement un outil de diagnostic particulièrement adapté pour l’analyse de biomarqueurs phosphorylés, pour lesquels une préconcentration est nécessaire en raison de leur faible abondance dans les fluides biologiques. C’est pourquoi, de nouvelles méthodes, dédiées à l'enrichissement de phosphopeptides, ont été développées ces dernières années et en particulier celles utilisant des supports solides basées sur la chromatographie d’affinité sur des ions métalliques immobilisés (IMAC). Parmi les supports solides intégrables en microsystème, les monolithes organiques constituent une option privilégiée grâce à la possibilité d’être synthétisés in situ. Le but de ce travail de thèse était donc de développer un laboratoire sur puce intégrant une préconcentration des phosphopeptides sur support monolithique basé sur le principe de l’IMAC et leur séparation électrophorétique en ligne.Dans un premier temps, nous avons développé deux approches innovantes qui ont permis de synthétiser pour la première fois un monolithe à base d’éthylène glycol méthacrylate phosphate (EGMP) et de bisacrylamide (BAA) par voie photochimique dans des microsystèmes. La première stratégie développée dans des puces en verre repose sur la synthèse du monolithe à l’aide d’un microscope à épifluorescence. La deuxième approche est basée sur les propriétés photochimiques d’un nouvel amorceur qui a permis de synthétiser et d’ancrer le monolithe, en une seule étape, aux parois des puces en polydiméthylsiloxane (PDMS). Une caractérisation de ce monolithe en termes de morphologie, de perméabilité, de porosité et de surface spécifique a ensuite été réalisée. Ceci a permis de démontrer le potentiel de ce monolithe pour la préconcentration.Dans un deuxième temps, une méthode de séparation par électrophorèse couplée à une détection par fluorescence a été développée sur puce en verre. Celle-ci a permis de séparer un mélange de phosphopeptides modèles fluorescents possédant différents sites et degrés de phosphorylation. Les phosphopeptides ont été détectés en moins de 2 min avec une excellente résolution (R>3) et une bonne efficacité (plateaux théoriques compris entre 11000 et 25000). Enfin, le couplage en ligne du module de préconcentration monolithique et de séparation/détection a été réalisé. Sur ce dispositif miniaturisé, une préconcentration basée sur l’IMAC-Zr4+ a ainsi été développée. L’efficacité de la capture et de l’élution des phosphopeptides a été démontrée et des facteurs de préconcentration supérieurs à 340 ont été obtenus. En conclusion, ce laboratoire sur puce ouvre des perspectives très prometteuses dans le domaine du diagnostic de pathologies dont le processus physiopathologique implique des phosphopeptides.Mots clés : laboratoire sur puce, microsystème, phosphopeptide, IMAC, monolithe, photopolymérisation, préconcentration, électrophorèse sur puce / A lab on-a-chip is a miniaturized device that integrates onto a single chip different analytical steps (preconcentration, separation, detection...) with minimal sample consumption and short analysis time. They are potentially beneficial in phosphorylated biomarker analysis for which a preconcentration step is necessary because of their low abundance in biological fluids. That's why selective enrichment methods of phosphopeptides have been developed in recent years in particular those based on solid supports like Immobilized Metal Affinity Chromatography (IMAC). Among the solid supports, organic polymer monoliths present practical advantages when used in microchips due to their ease of preparation and in situ polymerization. The aim of this work was to develop a lab-on-a-chip integrating a monolithic support for online IMAC-based preconcentration and electrophoretic separation of phosphopeptides.In the first part, we developed two innovative approaches which allowed us to synthesize, for the first time, an ethylene glycol methacrylate phosphate-co-bisacrylamide (poly (EGMP-co-BAA)) monolith by a photo-driven process in microsystems. The first monolith synthesis approach was developed in glass microchannels using an inverted epifluorescence microscope as UV-irradiation source. The second approach was based on the photochemical properties of a new initiator which allowed the simultaneous synthesis and anchorage of the monolith in native polydimethylsiloxane (PDMS) microchips. A characterization (morphology, permeability, porosity and specific surface area) of (poly (EGMP-co-BAA)) monolith was then performed which demonstrated the potential of this monolith for preconcentration.Then a glass microchip electrophoresis method coupled to a detection by fluorescence was developed to separate a mixture of phosphopeptides fluorescent models differing with the position and number of phosphorylation sites. The phosphopeptides were detected in less than 2 min with excellent resolution (R> 3) and good efficiencies ranging from 11000 to 25000 plates. Finally, an integrated microdevice was developed by combining online preconcentration based on IMAC-Zr4+ and separation/detection of phosphopeptides. The performance of this integrated microdevice to capture and to elute the phosphopeptides was demonstrated and signal enhancement factors (SEF) higher than 340 were obtained. This lab-on-a-chip device opens news perspectives for phosphoproteomic applications and the diagnostic of diseases where the pathophysiological process involves phosphopeptides

This paper is to present a student interior design laboratory manual for Perspective Drawing 134. A mechanical and freehand approach to the grid method of perspective is used. Chapter I reviews the significance of the problem, definitions of terms of perspective, data sources and method of procedure. Chanter II explains a brief overview of perspective from primitive man to its present use in interior design. Chapter III reviews the general principles of perspective. Chapter IV presents the grid method to one-point and two-point perspective, both mechanical and freehand approaches. Included are step by step illustrations and explanations of the method. Chapter V summarizes the intent of this study.

Erkrankungen des Bewegungsapparates stellen in der heutigen Pferdehaltung und Pferdenutzung die häufigste Abgangsursache dar und generieren damit einen großen Bedarf an tierärztlicher orthopädischer Versorgung. Gleichzeitig bemängeln nationale und internationale Berufsverbände die praktischen und theoretischen Kenntnisse von Hochschulabsolventen der Veterinärmedizin, die sog. Ersttagskompetenzen, in diesen Fachbereichen. Die orthopädische Untersuchung des lahmen Pferdes stellt einen sehr wichtigen Lehrinhalt dar. Aufgrund der Komplexität orthopädischer Erkrankungen verlangt sie de Durchführenden sowohl detailliertes theoretisches Wissen als auch spezielle praktische Fähigkeiten ab. Dies ist sowohl in der traditionellen theoretischen als auch in der klinisch-praktischen Ausbildung des Studierenden am Patienten nicht immer ausreichend zu vermitteln. Um die Ausbildung in der „Orthopädie des Pferdes“ zu evaluieren und zu verbessern, wurde das vorliegende webbasierte Lernprogramm zur Lahmheitsuntersuchung des Pferdes erstellt. Im ersten Teil der Arbeit wurde erstmals ein webbasiertes Lernprogramm im Fachgebiet der Orthopädie des Pferdes konzipiert und erarbeitet. Nach der Fertigstellung des Lernprogramms wurde dieses bezüglich seines fachlichen Inhalts sowie der Gestaltung durch sog. „Experten“, orthopädisch arbeitende Pferdetierärzte, bewertet und entsprechend ihrer Verbesserungsvorschläge überarbeitet. Im zweiten Teil der Arbeit wurde einerseits die stattfindende Lehre an der Universität Leipzig sowie andererseits die Wirksamkeit und Effektivität des Lernprogramms durch Studierende der Veterinärmedizin des 6. Fachsemesters überprüft. Mit Hilfe von zwei Gruppen von Studierenden, Gruppe A (Testgruppe) mit Zugang zum Lernprogramm und Gruppe B (Kontrollgruppe) ohne Zugang, wurde der Effekt des Lernprogramms einerseits auf das fachspezifische Wissen sowie andererseits auf die Selbstsicherheit der Studierenden im diesem Themengebiet untersucht. Das übergeordnete Ziel dieser Arbeit war es, die stattfindende Lehre im Bereich der Orthopädie des Pferdes an der Universität Leipzig zu untersuchen und ggf. zu verbessern und damit die Ersttagskompetenz von Hochschulabsolventen in diesem Fachbereich zu erhöhen. Um dies zu erreichen, ist einerseits ein entsprechend gutes fachspezifisches Wissen, andererseits auch ein gewisses Maß an Selbstsicherheit und Routine für eine strukturierte und koordinierte Lahmheitsuntersuchung vonnöten. Das webbasierte Lernprogramm wurde mit Hilfe des Content Management Systems Drupal® erstellt. Im weiteren Verlauf der Arbeit wurde die Wirksamkeit und Effektivität des Lernprogramms durch Studierende (n = 44) an der VMF der Universität Leipzig überprüft. Die sich auf freiwilliger Basis beteiligenden Studierenden wurden per einfachem Losverfahren in zwei Gruppen aufgeteilt. Eine Gruppe erhielt Zugang zum Lernprogramm (Gruppe A, Testgruppe, n = 23) und eine Gruppe erhielt keinen Zugang (Gruppe B, Kontrollgruppe, n = 21). Auf diese Weise konnte der Effekt des Lernprogramms auf einerseits das fachspezifische Wissen sowie andererseits die Selbstsicherheit der Studierenden untersucht werden und mit der Kontrollgruppe verglichen werden. Das Sicherheitsgefühl der Studierenden der Testgruppe war nach der Arbeit mit dem Lernprogramm doppelt so stark ausgeprägt wie vor der Arbeit mit dem Lernprogramm. Dies stellt einen hoch signifikanten (p < 0,001) Zuwachs an Sicherheitsgefühl bei den Studierenden der Testgruppe dar. Auch das fachspezifische Wissen verbesserte sich deutlich durch die Arbeit mit dem Lernprogramm. Die Studierenden der Testgruppe gaben nach der Arbeit mit dem Lernprogramm signifikant (p = 0,022) mehr richtige Antworten im Quiz als die Studierenden der Kontrollgruppe. Aufgrund der Verbesserung des Sicherheitsgefühls sowie des fachspezifischen Wissens der Studierenden der Testgruppe ist von einer Verbesserung der Ersttagskompetenz im Vergleich zur Kontrollgruppe auszugehen. In der vorliegenden Arbeit konnte ein effektives webbasiertes Lernprogramm für die Lahmheitsdiagnostik beim Pferd erstellt werden. Aufgrund der erhobenen Ergebnisse kann die stattfindende Lehre effektiv durch das Lernprogramm im Sinne des blended learnings ergänzt werden. Computerbasierte Lehre hat gegenüber der traditionellen Lehre viele Vorteile und wird wahrscheinlich zukünftig eine immer größere Rolle in der gesamten Ausbildung von Studierenden der Veterinärmedizin spielen.

Lab-on-Chip, the miniaturization of the chemical and analytical lab, is an endeavor that seems to come out of science fiction yet is slowly becoming a reality. It is a multidisciplinary field that combines different areas of science and engineering. Within these areas, microfluidics is a specialized field that deals with the behavior, control and manipulation of small volumes of fluids. Agglutination assays are rapid, single-step, low-cost immunoassays that use microspheres to detect a wide variety molecules and pathogens by using a specific antigen-antibody interaction. Agglutination assays are particularly suitable for the miniaturization and automation that two-phase microfluidics can offer, a combination that can help tackle the ever pressing need of high-throughput screening for blood banks, epidemiology, food banks diagnosis of infectious diseases. In this thesis, we present a two-phase microfluidic system capable of incubating and quantifying agglutination assays. The microfluidic channel is a simple fabrication solution, using laboratory tubing. These assays are incubated by highly efficient passive mixing with a sample-to-answer time of 2.5 min, a 5-10 fold improvement over traditional agglutination assays. It has a user-friendly interface that that does not require droplet generators, in which a pipette is used to continuously insert assays on-demand, with no down-time in between experiments at 360 assays/h. System parameters are explored, using the streptavidin-biotin interaction as a model assay, with a minimum detection limit of 50 ng/mL using optical image analysis. We compare optical image analysis and light scattering as quantification methods, and demonstrate the first light scattering quantification of agglutination assays in a two-phase ow format. The application can be potentially applied to other biomarkers, which we demonstrate using C-reactive protein (CRP) assays. Using our system, we can take a commercially available CRP qualitative slide agglutination assay, and turn it into a quantitative High Sensitivity-CRP test, with a lower detection limit of 0.5 mg/L using light scattering. Agglutination assays are an incredibly versatile tool, capable of detecting an ever-growing catalog of infectious diseases, proteins and metabolites. A system such as that presented in this thesis is a step towards being able to produce high throughput microfluidic solutions with widespread adoption.

The focus of this work is crypto-ransomware; a variant of malware, an analysis of this malware&#8217;s network communication, and the identification of means by which it may be detected in the network. The thesis describes the methodology and environment in which the malware&#8217;s network communications were studied. The first part of the thesis provides a network traffic analysis of this type of malware with a focus on HTTP and DNS communication, including anomalies that can be observed in the network during this malware&#8217;s activity. The thesis also includes a discussion of the user behavior of devices infected by this type of malware. The resulting data was used to identify and describe four detection methods that are able to recognize the malware from its network communication using the HTTP protocol. Finally, a description of several signatures that can be used as indicators of a possible infection by this malware are provided.

The thesis deals with technologies of goods protection. It is focused on electronic technologies of goods protection, which call EAS (electronic article surveillance) in foreign literature. The goal of this thesis is support for instruction in electronic surveillance of goods. This document systematically describes principle and technical solution recent electronic technologies of goods protection. There are mentioned advantages and disadvantages too. The other chapter deals with basic operating mode and configuration parameters of loop systems, acoustic-magnetic system and radio system. On the basis of this was suggested laboratory task. This task is use for better understanding of principles electronic surveillance of goods. Some possible attacks of electronic surveillance of goods are described at the last chapter of this thesis. This attacks was also realized.