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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Réponse immunitaire innée et adaptative du porc face au virus du syndrome dysgénésique et respiratoire porcin / Innate and adaptive immune responses against Porcine Reproductive and Respiratory Syndrome virus (PRRSV)

Bordet, Elise 16 October 2018 (has links)
Le virus du syndrome dysgénésique et respiratoire porcin (SDRPv) est un pathogène à l’origine de problèmes respiratoires et de reproduction. La réponse immunitaire face au SDRPv est caractérisée par une virémie persistante et un retard dans la mise en place des anticorps neutralisants. Les macrophages alvéolaires (AM) sont la cible principale du virus mais plusieurs études in vitro suggèrent une infection des cellules dendritiques (DC). Dans ce manuscrit, de nouvelles cibles cellulaires du virus ont été découvertes dans le poumon et dans les ganglions trachéo-bronchiques. Les cellules du parenchyme pulmonaire AM-like sont infectés in vivo par le SDRPv de Type 1 alors que les cDC1, cDC2 et moDC du poumon ne sont pas infectées. La souche Lena Type 1.3 se distingue des autres souches par sa capacité à induire une polarisation vers une réponse Th1 in vitro. Une expérience de transfert de lymphocytes T mémoires in vivo suggèrent une réponse cellulaire accrue et délétère lors de l’infection par la souche Lena. Trois populations de macrophages ont été identifiées dans les ganglions et nommées : macrophages périfolliculaires (PFMacro), macrophages des cordons lymphatiques (cordMacro) et macrophages efférents (effMacro). Les effMacro et les PFMacro sont infectés par les souches européennes. Quant à la réponse humorale, 5 stades de différenciation des LB dans les ganglions ont été identifiés et une étude de l’impact de l’infection sur la différenciation des lymphocytes B est en cours. / Porcine reproductive and respiratory syndrome virus (PRRSV) is a single-stranded RNA virus that causes reproductive failure and respiratory problems in swine. Immune response against PRRSV is characterized by a persistent viremia and a delay in neutralizing antibodies’ production. Main targets of PRRSV are Alveolar Macrophages (AM) but in vitro studies suggest that PRRSV could replicate in dendritic cells (DC). In this manuscript, new cellular targets of PRRSV in the lung and the tracheo-bronchial lymph nodes have been depicted. This work revealed that pulmonary parenchymal AM-like are susceptible to PRRSV in vivo. Moreover, study of DC infection in the lung reveals that cDC1, cDC2 and moDC are not infected by Type 1 PRRSV. In tracheo-bronchial lymph nodes, 3 populations of pig macrophages (Macro) have been identified and called perifollicular macrophages (PFMacro), lymphatic cord macrophages (cordMacro) and efferent macrophages (effMacro). In vivo infection revealed that PFMacro and effMacro are susceptible to Type 1 PRRSV infection. In order to understand the delay in humoral response establishment, 5 populations of B cells have been identified in the lymph nodes. The interaction of SDRPv with these populations is under study.
122

Biópsia de linfonodo sentinela na recidiva locorregional do melanoma maligno revisão sistemática /

Peres, Gabriel. January 2020 (has links)
Orientador: Antônio José Maria Cataneo / Resumo: Introdução: No melanoma primário, a aplicabilidade da biópsia de linfonodo sentinela (BLS), seguida ou não de esvazimento linfonodal (EL) é conhecida. Na recidiva locorregional (RL) de melanoma, alguns serviços tendem a indicá-la, buscando estadiamento mais acurado para embasar condutas individualizadas aos pacientes, ainda que as evidências sejam insuficientes. Objetivo: Avaliar o sucesso da BLS no encontro do linfonodo sentinela (LNS) e sua positividade na RL. Comparar a sobrevida entre os pacientes com LNS positivo e negativo. Verificar diferença na sobrevida pós EL. Métodos: Revisão sistemática, através das bases MEDLINE via PUBMED, LILACS, SCOPUS, EMBASE e CENTRAL, buscando estudos experimentais e observacionais sobre BLS na RL de melanoma. Desfechos avaliados: sucesso na BLS pelo encontro do LNS, positividade para melanoma no LNS; sobrevida no subgrupo LNS positivo comparado com o negativo; sobrevida livre de doença no subgrupo LNS positivo comparada com o negativo; sobrevida dos pacientes submetidos ao EL. Para metanálises, utilizaram-se RevMan 5.3 e StatsDirect 3.0.121. Resultados: Foram identificados 1872 estudos, destes, seis estudos observacionais foram incluídos, totalizando 449 pacientes. O LNS foi encontrado em 98% das BLS (IC 95-100%, I2=53,7% - seis estudos). LNS com 32% de positividade para melanoma (IC 19-47%, I2= 84,6% - seis estudos). A chance de sobrevida global em cinco anos foi 2,49 vezes maior no subgrupo com LNS negativo (IC 95% 1,41-4,38, I2=0% - qua... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Background: In primary melanoma, the applicability of sentinel lymph node biopsy (SLB), followed or not by complete lymph node dissection (CLND) is known. In locoregional recurrence (LR) of melanoma, some groups may indicate it for more accurate staging to support individualized management, even with scarce evidence. Objective: To evaluate success in SLB and its positivity in LR. Compare survival between patients with positive and negative sentinel lymph node (SLN). Check for survival modification after CLND. Methods: Systematic review through databases such as MEDLINE via PUBMED, LILACS, SCOPUS, EMBASE and CENTRAL, searching for experimental and observational studies on SLB in melanoma LR. Outcomes assessed: success in SLB by finding the SLN, positivity for melanoma in the SLN; survival in the positive SLN subgroup compared to the negative one; disease-free survival in the positive versus negative SLN subgroup; survival of patients undergoing CLND. For meta-analyzes, RevMan 5.3 and StatsDirect 3.0.121 were used. Results: The total number of patients in six observational studies was 449, over 1872 studies indentified. The SNL was found in 98% of SLB (95-100% CI, I2 = 53.7%, 6 studies). SLB detected 32% positivity for melanoma on SNL (CI 19-47%, I2 = 84.6%, 6 studies). The chance of five year overall survival was 2,49 higher in the negative SNL subgroup (95% CI 1.41-4.38, I2 = 0%, 4 studies). Meta-analyzes were not performed due to lack of objective data for disease-free survi... (Complete abstract click electronic access below) / Doutor
123

Accelerating RSA Public Key Cryptography via Hardware Acceleration

Ramesh, Pavithra 10 April 2020 (has links)
A large number and a variety of sensors and actuators, also known as edge devices of the Internet of Things, belonging to various industries - health care monitoring, home automation, industrial automation, have become prevalent in today's world. These edge devices need to communicate data collected to the central system occasionally and often in burst mode which is then used for monitoring and control purposes. To ensure secure connections, Asymmetric or Public Key Cryptography (PKC) schemes are used in combination with Symmetric Cryptography schemes. RSA (Rivest - Shamir- Adleman) is one of the most prevalent public key cryptosystems, and has computationally intensive operations which might have a high latency when implemented in resource constrained environments. The objective of this thesis is to design an accelerator capable of increasing the speed of execution of the RSA algorithm in such resource constrained environments. The bottleneck of the algorithm is determined by analyzing the performance of the algorithm in various platforms - Intel Linux Machine, Raspberry Pi, Nios soft core processor. In designing the accelerator to speedup bottleneck function, we realize that the accelerator architecture will need to be changed according to the resources available to the accelerator. We use high level synthesis tools to explore the design space of the accelerator by taking into consideration system level aspects like the number of ports available to transfer inputs to the accelerator, the word size of the processor, etc. We also propose a new accelerator architecture for the bottleneck function and the algorithm it implements and compare the area and latency requirements of it with other designs obtained from design space exploration. The functionality of the design proposed is verified and prototyped in Zynq SoC of Xilinx Zedboard.
124

Microfluidic and computational technologies to improve cell therapy manufacturing

Anandakumaran, Priya Nivashini January 2021 (has links)
Cell therapies are an emerging form of therapy, with the potential to treat and cure a variety of diseases. As more cell therapies become approved and commercialized, challenges remain in the manufacturing of these often single-batch products due to their complexity and patient-to-patient variability, which limit their cost-effectiveness and reproducibility. In this dissertation, we aim to improve the manufacturing of two different cell therapies, namely, organoid-based cell therapies using hydrogel scaffolds, and adoptive cell therapies using deep learning and microfluidics, to facilitate their widespread clinical use. First, we develop new tools to manufacture organoids, which are widespread in drug-screening technologies, but have been sparingly used for cell therapy as current approaches for producing self-organized cell clusters lack scalability or reproducibility. Here, we use alginate microwell scaffolds to form pre-vascularized organoids composed of endothelial cells and mesenchymal stem cells, where the size and structure can be readily tuned by varying the cell source, ratio of cells, or size of the microwells. Furthermore, by uncrosslinking the alginate scaffold, the organoids can be harvested in a gentle manner without damaging their structure or impairing their functionality. Finally, we assess the ability of the pre-vascularized organoids to restore vascular perfusion in a mouse model of hindlimb ischemia. By making use of the dynamic nature of hydrogels, this method can offer high yields of reproducible, self-organized multicellular aggregates for use in cell therapies. Next, we shift our focus to the identification of antigen-specific T cells, which is a critical step in the manufacturing of adoptive cell therapy. Conventional techniques for selecting antigen-specific T cells are time-consuming, making them difficult to adapt for large-scale manufacturing, and are limited to pre-defined antigenic peptide sequences. Here we train a deep learning model to rapidly classify videos of antigen-specific CD8+ T cells by distinguishing the distinct interaction dynamics (in motility and morphology) between cognate and non-cognate T cells and dendritic cells (DCs). The model is able to classify high affinity antigen-specific CD8+ T cells from OT-I mice with an area under the curve (AUC) of 0.91, and generalizes well to other types of high and low affinity CD8+ T cells. We also show that the experimental addition of anti-CD40 antibodies amplifies the differences between cognate and non-cognate T cells and DCs, thereby improving the model’s ability to discriminate between them. This workflow can be used to better understand the role of cognate T cell – DC interactions in the pathogenesis of cancer and autoimmune diseases, and can be integrated into a device to simplify and accelerate the selection of antigen-specific T cells for use in adoptive cell therapy. Finally, we sought to develop a device to address two other issues associated with the selection of antigen-specific T cells: low-throughput screening, and the inability to assess a mixed population of T cells against a library of antigens, both of which are necessary to identify rare T cells, and improve clinical outcomes of the corresponding cell therapy. A few specialized assays exist that can assess T cells against multiple antigens, but they are often limited by an increased manufacturing burden. Here, we develop a microfluidic artificial lymph node, which is inspired by the efficient selection of antigen-specific T cells in vivo. In particular, our flow-through design consists of multiple compartments, each containing microcarrier beads coated with DCs presenting a distinct antigen, such that T cells that are flowed sequentially through each compartment can stably arrest to cognate DCs, becoming captured in the appropriate compartment. We test a single-compartment device computationally using agent-based simulations, and experimentally using a mixed population of antigen-specific and wild-type (WT) (non-specific) T cells, and in both cases we observe a preferential accumulation of cognate, antigen-specific T cells. This proof-of-concept single-compartment device can be readily scaled up to systematically test many T cells against multiple antigens. Underlying this work is the development of technologies to enable the large-scale manufacturing of cell therapies. Cell therapies are undergoing a transformation to a new class of therapeutic modality, and there are many emerging questions, especially related to the scale-up and scale-out of production processes. Together, this work aims to engineer technologies to improve cell therapy manufacturing processes, facilitate their clinical translation, and ensure their availability to all patients who would benefit from them.
125

Měření v bezdrátové síti 802.11n se skrytými uzly / Measurements in an 802.11n radio network with hidden nodes

Vágner, Adam January 2013 (has links)
The current large concentration of wireless networks brings new horizons, but also new concerns. Failure to follow basic rules may produce far-reaching problems that could make more wrinkles to all affected managers and administrators. The aim of this thesis was to measure and compare the radio parameters of selected products and how they behave in neighboring interference and the speed they have while there are hidden nodes. The resulting values were measured in the laboratory network Wificolab and compared with the various support protocols. Possible effects on the specific situation are also analyzed in this thesis.
126

Additive Fertigung von Metallen – Einsatz des LaserCUSING®s im Bereich Automotive

Pastuschka, Lisa, Appel, Peter January 2016 (has links)
Die Additive Fertigung spielt heutzutage auch in der Automobilindustrie eine bedeutende Rolle. Eine Ausprägungsform, das pulverbett-basierte LaserCUSING®-Verfahren, bietet viele neue Möglichkeiten. Im Folgenden wird zunächst ein kurzer Überblick über das Verfahren gegeben und anschließend der Einsatz des LaserCUSING®s im Bereich Automotive anhand eines gemeinsamen Projekts der EDAG Engineering GmbH, des Laser Zentrums Nord, der BLM Group und der Concept Laser GmbH verdeutlicht. Hier wurde auf Basis des EDAG Light Cocoon ein topologisch optimierter und hybrid gefertigter Spaceframe entwickelt. Die Karosserieknoten wurden mittels LaserCUSING® additiv hergestellt.
127

Behavior and Design of Concrete Frame Corners: Strut-and-Tie Method Approach

Hwa-Ching Wang (9524555) 16 December 2020 (has links)
Reinforced concrete frame corners (that is, knee joints) subjected to closing moments plays an important role of transmitting stress between the two adjoining members. Being categorized as geometric discontinuity regions (D-regions), knee joints cannot be correctly analyzed and designed using traditional sectional analysis procedures. Instead, the strut-and-tie method is particularly suitable for such joints. Although strut-and-tie models provide the means to represent the distribution of stresses within a closing knee joint, questions arise when a curved-bar node is used to model the bar bend of the longitudinal reinforcement at the outer corner. The code-specified design expressions for curved-bar nodes have not been experimentally verified; therefore, the accuracy and conservativeness of the expressions remain unknown. This research project is aimed to provide insights to the proper application of the strut-and-tie method, through the concept of curved-bar nodes, to knee joints under closing moments.<br><br>An experimental program consisting of 24 specimens was conducted to investigate the effect of curved-bar nodes on knee joints under closing moments. An evaluation of the code-specified design expressions was included. The results demonstrate that the minimum code-specified bend radius is appropriate. The current requirements related to bond along the bar bend and clear side cover are shown to be conservative. Based on the test results, a procedure for constructing proper strut-and-tie models for closing knee joints is proposed and verified using an evaluation database consisting of 116 knee joint tests from the literature. Compared to other strength predictive methods and the code-specified strut-and-tie method, the proposed strut-and-tie method mitigates unconservativeness and delivers improved accuracy.<br>In addition to the experimental program and the proposed procedure, non-linear finite element analysis (FEA) using the software ATENA-3D was employed to conduct a parametric analysis as a supplement to the experimental data. Seventy-two numerical models were analyzed to further evaluate the code-specified expressions and the proposed strut-and-tie method. The FEA results are in a good agreement with the experimental observations and corroborate the conclusions from the experimental program regarding current code requirements. Moreover, the parametric analysis further supports the application of the proposed strut-and-tie methodology to knee joints under closing moments.
128

Automatická hp-adaptivita na sítích s visícími uzly libovolné úrovně ve 3D / Automatic hp-adaptivity on Meshes with Arbitrary-Level Hanging Nodes in 3D

Kůs, Pavel January 2011 (has links)
The thesis is concerned with theoretical and practical aspects of the hp- adaptive finite element method for solving elliptic and electromagnetic prob- lems described by partial differential equations in three spatial dimensions. Besides the standard element refinements, the hp-adaptivity allows indepen- dent adaptation of degrees of the polynomial approximation as well. This leads to exponentially fast convergence even for problems with singularities. The efficiency of the hp-adaptivity is enhanced even more by the ability of the algorithm to work with meshes with arbitrary-level hanging nodes. This generality, however, leads to great complexity of the implementation. There- fore, the thesis concentrates on the mathematical analysis of algorithms that have led to successful implementation of the method. In addition, the the- sis discusses the numerical integration in 3D and the implementation of the method itself. Finally, numerical results obtained by this new implemen- tation are presented. They confirm advantages of hp-adaptivity on meshes with arbitrary-level hanging nodes. 1
129

Sentinel Lymph Node Involvement by Epithelial Inclusions Mimicking Metastatic Carcinoma: A Diagnostic Pitfall

Sigei, Asha C., Bartow, Brooke B., Wheeler, Yurong 01 January 2020 (has links)
Objective: Background: Rare disease An epithelial inclusion cyst within a lymph node denotes a heterotopic phenomenon. Nodal epithelial inclusion cysts have been reported in a variety of anatomical locations including pelvic, abdominal, mediastinal, and axillary regions. While nodal melanocytic nevus (also known as nevus cell aggregates) is the most common heterotopic phenomena involving the axillary lymph nodes, the presence of benign epithelial inclusion cysts in axillary lymph nodes is a rare but well-reported finding. Such documentation is in part due to assessment of sentinel lymph nodes in breast cancer becoming standard of care. These epithelial inclusion cysts offer a diagnostic pitfall in evaluation of sentinel lymph node in the setting of breast carcinoma. They also complicate assessment of sentinel lymph node during intraoperative frozen sections analysis. Case Report: We report a case of co-existent of benign squamous-type and glandular-type epithelial inclusions cysts in 2 sentinel lymph nodes in a patient with grade III invasive ductal carcinoma involving the left breast. There have been at least 4 cases reported in literature in which benign epithelial inclusion cysts in sentinel lymph nodes were first mistakenly diagnosed as metastatic carcinoma both during intraoperative frozen section analysis and during review of permanent sections. The missed diagnosis could potentially occur intraoperatively during frozen section sentinel lymph node analysis secondarily due to lack of availability of the primary tumor for comparison and inability to use immunohistochemical stains. Conclusions: Pathologists should be aware of this pitfall especially in frozen section analysis of sentinel lymph node to avoid misdiagnosis and its associated potential grave consequences.
130

CH Selection via Adaptive Threshold Design Aligned on Network Energy

Behera, Trupti M., Nanda, Sarita, Mohapatra, Sushanta K., Samal, Umesh C., Khan, Mohammad S., Gandomi, Amir H. 15 March 2021 (has links)
Energy consumption in Wireless Sensor Networks (WSN) involving multiple sensor nodes is a crucial parameter in many applications like smart healthcare systems, home automation, environmental monitoring, and industrial use. Hence, an energy-efficient cluster-head (CH) selection strategy is imperative in a WSN to improve network performance. So to balance the harsh conditions in the network with fast changes in the energy dynamics, a novel energy-efficient adaptive fuzzy-based CH selection approach is projected. Extensive simulations exploited various real-time scenarios, such as varying the optimal position of the location of the base station and network energy. Additionally, the results showed an improved performance in the throughput (46%) and energy consumption (66%), which demonstrated the robustness and efficacy of the proposed model for the future designs of WSN applications.

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