10 research outputs found

    Advances in Bioengineering

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    The technological approach and the high level of innovation make bioengineering extremely dynamic and this forces researchers to continuous updating. It involves the publication of the results of the latest scientific research. This book covers a wide range of aspects and issues related to advances in bioengineering research with a particular focus on innovative technologies and applications. The book consists of 13 scientific contributions divided in four sections: Materials Science; Biosensors. Electronics and Telemetry; Light Therapy; Computing and Analysis Techniques

    21st Century Nanostructured Materials

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    Nanostructured materials (NMs) are attracting interest as low-dimensional materials in the high-tech era of the 21st century. Recently, nanomaterials have experienced breakthroughs in synthesis and industrial and biomedical applications. This book presents recent achievements related to NMs such as graphene, carbon nanotubes, plasmonic materials, metal nanowires, metal oxides, nanoparticles, metamaterials, nanofibers, and nanocomposites, along with their physical and chemical aspects. Additionally, the book discusses the potential uses of these nanomaterials in photodetectors, transistors, quantum technology, chemical sensors, energy storage, silk fibroin, composites, drug delivery, tissue engineering, and sustainable agriculture and environmental applications

    Microfluidics and Nanofluidics Handbook

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    The Microfluidics and Nanofluidics Handbook: Two-Volume Set comprehensively captures the cross-disciplinary breadth of the fields of micro- and nanofluidics, which encompass the biological sciences, chemistry, physics and engineering applications. To fill the knowledge gap between engineering and the basic sciences, the editors pulled together key individuals, well known in their respective areas, to author chapters that help graduate students, scientists, and practicing engineers understand the overall area of microfluidics and nanofluidics. Topics covered include Finite Volume Method for Numerical Simulation Lattice Boltzmann Method and Its Applications in Microfluidics Microparticle and Nanoparticle Manipulation Methane Solubility Enhancement in Water Confined to Nanoscale Pores Volume Two: Fabrication, Implementation, and Applications focuses on topics related to experimental and numerical methods. It also covers fabrication and applications in a variety of areas, from aerospace to biological systems. Reflecting the inherent nature of microfluidics and nanofluidics, the book includes as much interdisciplinary knowledge as possible. It provides the fundamental science background for newcomers and advanced techniques and concepts for experienced researchers and professionals

    Étude des effets photosensibilisés de nouvelles molécules de synthèse : applications potentielles en photochimiothérapie antitumoral cutanée

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    Tese de doutoramento (co-tutela), Medicina (Dermatologia e Venereologia), Université Picardie Jules Verne, Universidade de Lisboa, 2011La thérapie photodynamique (PDT) cutanée est utilisée pour traiter les kératoses actiniques, la maladie de Bowen et les carcinomes basocellulaires. Malgré des résultats prometteurs, elle manque d'efficacité pour les lésions profondes et l'amélioration des photosensibilisateurs est d'actualité. Nous avons étudié les propriétés photophysiques et photosensibilisatrices de porphyrines tricationiques substituées. Elles sont fluorescentes et leur état excité triplet a une grande durée de vie et un rendement quantique élevé à l'exception du conjugué poly-S-lysine. L'oxygène singulet est formé quantitativement depuis ce triplet. L’étude chez des kératinocytes cutanés humains hyperproliférants de l'incorporation et de la photocytotoxicité montrent que 3 d'entre eux soutiennent favorablement la comparaison avec la protoporphyrine IX induite par l'acide δ-aminolévulinique (traitement actuel en PDT cutanée). Ils se localisent dans des vésicules d'endo- et pinocytose mais pas dans le noyau ni les mitochondries. La structure de leur chaîne substituée conditionne l'incorporation, la localisation et donc la phototoxicité. Les mécanismes de mort cellulaire étudiés avec le dérivé le plus efficace montrent l'absence de fixation de l'annexine V, d'activation des caspases, de condensation de la chromatine et donc d'apoptose. L'apparition de vésicules LC3-positives dans ces cellules transfectées par GFP-LC3 et la dégradation de p62 démontrent l’implication de l’autophagie dans la photocytotoxicité avec une régulation négative par JNK. En conclusion, ce sont des photosensibilisateurs intéressants nécessitant des études complémentaires dans des modèles cellulaires et animaux

    Towards rapid 3D direct manufacture of biomechanical microstructures

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    The field of stereolithography has developed rapidly over the last 20 years, and commercially available systems currently have sufficient resolution for use in microengineering applications. However, they have not as yet been fully exploited in this field. This thesis investigates the possible microengineering applications of microstereolithography systems, specifically in the areas of active microfluidic devices and microneedles. The fields of micropumps and microvalves, stereolithography and microneedles are reviewed, and a variety of test builds were fabricated using the EnvisionTEC Perfactory Mini Multi-Lens stereolithography system in order to define its capabilities. A number of microneedle geometries were considered. This number was narrowed down using finite element modelling, before another simulation was used to optimise these structures. 9 × 9 arrays of 400 μm tall, 300 μm base diameter microneedles were subjected to mechanical testing. Per needle failure forces of 0.263 and 0.243 N were recorded for the selected geometries, stepped cone and inverted trumpet. The 90 μm needle tips were subjected to between 30 and 32 MPa of pressure at their failure point - more than 10 times the required pressure to puncture average human skin. A range of monolithic micropumps were produced with integrated 4 mm diameter single-layer 70 μm-thick membranes used as the basis for a reciprocating displacement operating principle. The membranes were tested using an oscillating pneumatic actuation, and were found reliable (>1,000,000 cycles) up to 2.0 PSIG. Pneumatic single-membrane nozzle/diffuser rectified devices produced flow rates of up to 1,000 μl/min with backpressures of up to 375 Pa. Another device rectified using active membrane valves was found to self-prime, and produced backpressures of up to 4.9 kPa. These devices and structures show great promise for inclusion in complex, fully integrated and active microfluidic systems fabricated using microstereolithography alone, with implications for both cost of manufacture and lead time

    Proceedings of the Scientific-Practical Conference "Research and Development - 2016"

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    talent management; sensor arrays; automatic speech recognition; dry separation technology; oil production; oil waste; laser technolog

    Towards rapid 3D direct manufacture of biomechanical microstructures

    Get PDF
    The field of stereolithography has developed rapidly over the last 20 years, and commercially available systems currently have sufficient resolution for use in microengineering applications. However, they have not as yet been fully exploited in this field. This thesis investigates the possible microengineering applications of microstereolithography systems, specifically in the areas of active microfluidic devices and microneedles. The fields of micropumps and microvalves, stereolithography and microneedles are reviewed, and a variety of test builds were fabricated using the EnvisionTEC Perfactory Mini Multi-Lens stereolithography system in order to define its capabilities. A number of microneedle geometries were considered. This number was narrowed down using finite element modelling, before another simulation was used to optimise these structures. 9 × 9 arrays of 400 μm tall, 300 μm base diameter microneedles were subjected to mechanical testing. Per needle failure forces of 0.263 and 0.243 N were recorded for the selected geometries, stepped cone and inverted trumpet. The 90 μm needle tips were subjected to between 30 and 32 MPa of pressure at their failure point - more than 10 times the required pressure to puncture average human skin. A range of monolithic micropumps were produced with integrated 4 mm diameter single-layer 70 μm-thick membranes used as the basis for a reciprocating displacement operating principle. The membranes were tested using an oscillating pneumatic actuation, and were found reliable (>1,000,000 cycles) up to 2.0 PSIG. Pneumatic single-membrane nozzle/diffuser rectified devices produced flow rates of up to 1,000 μl/min with backpressures of up to 375 Pa. Another device rectified using active membrane valves was found to self-prime, and produced backpressures of up to 4.9 kPa. These devices and structures show great promise for inclusion in complex, fully integrated and active microfluidic systems fabricated using microstereolithography alone, with implications for both cost of manufacture and lead time.EThOS - Electronic Theses Online ServiceEngineering and Physical Sciences Research Council (EPSRC)GBUnited Kingdo
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