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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.
21

Caracterização molecular e determinação da suscetibilidade de micobactérias de crescimento rápido no Rio Grande do Sul

Nunes, Luciana de Souza January 2014 (has links)
Surtos associados às micobactérias de crescimento rápido (MCR) têm sido cada vez mais relatados em todo o mundo, inclusive no Brasil. Entre as MCR, o complexo M. abscessus é o mais patogênico e relacionado a multirresistência. Considerando a importância de investigar as cepas de MCR presentes em nosso Estado, este estudo teve como objetivos avaliar o perfil molecular e de suscetibilidade caracterizando os isolados de MCR encaminhados para o Centro de Referência em Micobactérias do Estado (Instituto de Pesquisas Biológicas - Laboratório Central de Saúde Pública, IPB-LACEN/RS). Além disso, foram avaliados os mecanismos de resistência à FQ conferido pelos genes gyrA e gyrB. Foram encaminhadas para o IPB-LACEN/RS, entre 2007 a 2012, 74 isolados clínicos. No total, 43 isolados relacionados a surto e 31 isolados de MCR não relacionados a surtos foram analisados. Pela técnica de PRA-hsp65 foi possivel identificar 43 isolados como M. abscessus tipo 2, 21 isolados como M. fortuitum tipo 1 e 10 isolados como M. abscessus tipo 1. Através do sequenciamento parcial do gene rpoB, foi confirmada a identificação de M. abscessus tipo 2 como M. abscessus subsp. bolletii, M. abscessus tipo 1 como M. abscessus subsp. abscessus e M. fortuitum tipo 1 como M. fortuitum subsp. fortuitum. Pela técnica de tipagem PFGE todos os isolados de M. abscessus subsp. bolletii apresentaram o mesmo perfil clonal o qual pertence ao clone BRA100, já descrito mundialmente. Os isolados de M. abscessus subsp. abscessus e M. fortuitum subsp. fortuitum apresentaram perfis distintos de PFGE. O perfil de suscetibilidade aos antibióticos foi avaliado por microdiluição em caldo de acordo com CLSI (2011) e, todos os isolados foram sensíveis a amicacina e todos foram resistentes a doxiciclina e sulfametoxazol-trimetoprima. Para M. abscessus subsp. bolletii todos os isolados foram resistentes à ciprofloxacino, moxifloxacino e tobramicina e um padrão de susceptibilidade variável foi observado para cefoxitina (Sensível - 28%, Intermediário - 72%) e claritromicina (Sensível - 86%, Resistentes - 14%). Cabe mencionar que este é o primeiro relato de resistência a claritromicina para o clone BRA100. Para M. abscessus subsp. abscessus e M. fortuitum subsp. fortuitum todos os isolados foram resistentes a claritromicina; já para a cefoxitina e tobramicina um padrão de susceptibilidade variável foi observado. Todos os isolados de M. fortuitum subsp. fortuitum foram sensíveis à ciprofloxacino, em contraste aos isolados de M. abscessus subsp. abscessus que apresentaram 70% de resistência. Todas MCR, resistentes (ou intermediárias) para ciprofloxacino apresentaram uma Ala-83 em GyrA, em contraste com uma Ser-83 em todos os isolados de M. fortuitum subsp. fortuitum sensíveis a ciprofloxacino, mas com perfil de resistência variável a moxifloxacino. Nenhuma diferença foi encontrada em GyrB independentemente do perfil de sensibilidade de MCR. Em conclusão, nosso estudo relata a persistência de um único clone M. abscessus subsp. bolletii BRA100 relacionado aos surtos, altamente resistente, mesmo após a implementação nacional das medidas de controle de infecção para contenção de surtos por MNTs. Também foi possível correlacionar que mutações no aminoácido Ala-83 de GyrA estão diretamente relacionados com a resistência à ciprofloxacino em M. abscessus subsp. abscessus e M. abscessus subsp. bolletii. / Outbreaks associated with rapidly growing mycobacteria (RGM) have been increasingly reported worldwide, including in Brazil. Among RGM, the M. abscessus complex is consider the most pathogenic, besides being related to multidrug resistance. Considering the importance of investigating the RGM strains present in our state, this study aimed to characterize the molecular and susceptibility profile of RGM isolates referred to the Reference Center for Mycobacteria State (Instituto de Pesquisas Biológicas - Laboratório Central de Saúde Pública, IPB-LACEN/RS). Furthermore, the mechanisms of quinolone resistance conferred by gyrA and gyrB genes were evaluated. A total of 74 isolates was sent to IPB-LACEN/RS between 2007 and 2012. Forty-three of the analyzed isolates were related to outbreak and 31 isolates of RGM were unrelated to outbreaks. The technique of PRA- hsp65 identified 43 isolates as M. abscessus type 2, 21 isolates as M. fortuitum type 1 and 10 isolates as M. abscessus type 1. The partial sequencing of the rpoB gene confirmed the identification of M. abscessus type 2 as M. abscessus subsp. bolletii, M. abscessus type 1 as M. abscessus subsp. abscessus and M. fortuitum type 1 and M. fortuitum subsp. fortuitum. PFGE typing technique showed the same clonal profile for all isolates of M. abscessus subsp. bolletii which belongs to clone BRA100, already described worldwide. Isolates of M. abscessus subsp. abscessus and M. fortuitum subsp. fortuitum showed distinct PFGE profiles. The antibiotic susceptibility profile was evaluated by broth microdilution according to CLSI (2011), and all isolates were susceptible to amikacin and resistant to doxycycline and trimethoprimsulfamethoxazole. All isolates of M. abscessus subsp. bolletii were resistant to ciprofloxacin, moxifloxacin and tobramycin and presented variable susceptibility pattern to cefoxitin (Susceptible - 28%, Intermediate - 72%) and clarithromycin (Susceptible - 86%, Resistant - 14%). It is important to mention that this is the first report of clarithromycin resistance for clone BRA100. Strains of M. abscessus subsp. abscessus and M. fortuitum subsp. fortuitum were all resistant to clarithromycin, and presented a variable susceptibility profile to cefoxitin and tobramycin. All isolates of M. fortuitum subsp. fortuitum were susceptible to ciprofloxacin, in contrast to isolates of M. abscessus subsp. abscessus that showed a resistance rate of 70%. All RGM ciprofloxacin non-susceptible presented an Ala-83 in GyrA, contrasting to a Ser-83 in all isolates of M. fortuitum subsp. fortuitum susceptible to ciprofloxacin, however, with a variable resistance profile to moxifloxacin. No difference was found in GyrB, regardless of the RGM susceptible profile. In conclusion, our study reports the persistence of a single clone of M. abscessus subsp. bolletii BRA100 related to outbreak, highly resistant, even after national implementation of infection control measures to contain outbreaks by NTM. It was also possible to correlate that mutations in the amino acid Ala-83 of GyrA are directly related to ciprofloxacin and moxifloxacin resistance in M. abscessus subsp. abscessus and M. abscessus subsp. bolletii.
22

Susceptibilidade antimicrobiana e tipagem molecular de Mycobacterium fortuitum isoladas de amostras clínicas de origem humana / Antimicrobial susceptibility and molecular typing of Micobacterium fortuitum isolated from clinical specimens of human origin

Wesley Schiavo 06 November 2012 (has links)
Introdução: A revisão da literatura disponível no PubMed evidencia que há relatos de surtos de infecções por micobactérias de crescimento rápido ocorridos no Brasil, mas não há dados nacionais que permitam orientar o tratamento empírico até que o perfil de sensibilidade e a identificação da espécie estejam disponíveis. Não há estudo nacional com amostragem significativa de M. fortuitum nem tampouco análise da relação clonal entre isolados de vários pontos do território nacional. Este trabalho pretende trazer contribuições quanto ao entendimento da disseminação de clones de M. fortuitum no Brasil, assim como o perfil de sensibilidade dessa espécie no Brasil. Material e métodos: Foram utilizadas no estudo 121 isolados pertencentes ao banco de micobactérias do Fleury Medicina e Saúde, referentes ao período de janeiro de 2001 a dezembro de 2010. A identificação da espécie for determinada por sequenciamento parcial do gene rpoB, a clonalidade foi avaliada por eletroforese em campos alternados e a susceptibilidade antimicrobiana foi avaliada utilizando-se placas de microdiluição RAPMYCOI. Resultados e conclusões: Foram detectados três grupos clonais, sendo dois presentes na cidade de Campinas e o terceiro na cidade de Florianópolis. Foi observada a persistência do grupo clonal MFBRA2 na cidade de Campinas por seis anos. A maioria dos casos isolados em diferentes estados brasileiros pertence a grupos clonais distintos. O índice de similaridade de Dice mínimo para a identificação de um grupo clonal de M. fortuitum ao analisar fragmentos de restrição gerados por XbaI deve ser de 98%. Todos os isolados testados foram sensíveis à amicacina, tigeciclina, imipenem, ciprofloxacina, moxifloxacina, sulfametoxazol-trimetoprim e linezolida, o que permite seu uso no tratamento empírico das infecções por M. fortuitum. Houve uma baixa taxa de sensibilidade à doxiciclina o que não subsidia seu uso em tratamento empírico. A taxa de sensibilidade de 89% para claritromicina não permite seu uso empírico no tratamento das infecções por M. fortuitum. / Introduction: The literature available on PubMed shows that there are reports of outbreaks of infections caused by rapidly growing mycobacteria occurred in Brazil, but there is no national data to guide empiric treatment until the susceptibility profile and identification of the species are available. No national study of significant sample of M. fortuitum nor analysis of the clonal relationship between isolates from various parts of the country. This work aims to bring contributions to the understanding of the spread of clones of M. fortuitum in Brazil, as well as the susceptibility pattern of this species in Brazil. Material and methods: We studied 121 isolates belonging to the mycobacteria collection from Fleury Medicina e Saúde, collected during the period from January 2001 to December 2010. Species identification was determined by partial sequencing of the rpoB gene, clonality was assessed by pulsed field gel electrophoresis and antimicrobial susceptibility was assessed using microdilution plates RAPMYCOI. Results and conclusions: There were three clonal groups, with two present in the city of Campinas and the third in Florianopolis. We observed the persistence of the clonal group MFBRA2 in Campinas for six years. Most cases isolated in different Brazilian states belong to different clonal groups. Our data indicate that Dice\'s similarity index for identification of a M. fortuitum clonal group should be at least 98% when analyzing restriction fragments generated by XbaI. All isolates tested were susceptible to amikacin, tigecycline, imipenem, ciprofloxacin, moxifloxacin, linezolid, and trimethoprim-sulfamethoxazole, which allows its use in the empirical treatment of infections caused by M. fortuitum. There was a low sensitivity to doxicycline which does not subsidize its use in empiric treatment. The rate of 89% sensitivity does not allow the empirical use of clarithromycin in the treatment of infections caused by M. fortuitum.
23

Caracterização molecular e determinação da suscetibilidade de micobactérias de crescimento rápido no Rio Grande do Sul

Nunes, Luciana de Souza January 2014 (has links)
Surtos associados às micobactérias de crescimento rápido (MCR) têm sido cada vez mais relatados em todo o mundo, inclusive no Brasil. Entre as MCR, o complexo M. abscessus é o mais patogênico e relacionado a multirresistência. Considerando a importância de investigar as cepas de MCR presentes em nosso Estado, este estudo teve como objetivos avaliar o perfil molecular e de suscetibilidade caracterizando os isolados de MCR encaminhados para o Centro de Referência em Micobactérias do Estado (Instituto de Pesquisas Biológicas - Laboratório Central de Saúde Pública, IPB-LACEN/RS). Além disso, foram avaliados os mecanismos de resistência à FQ conferido pelos genes gyrA e gyrB. Foram encaminhadas para o IPB-LACEN/RS, entre 2007 a 2012, 74 isolados clínicos. No total, 43 isolados relacionados a surto e 31 isolados de MCR não relacionados a surtos foram analisados. Pela técnica de PRA-hsp65 foi possivel identificar 43 isolados como M. abscessus tipo 2, 21 isolados como M. fortuitum tipo 1 e 10 isolados como M. abscessus tipo 1. Através do sequenciamento parcial do gene rpoB, foi confirmada a identificação de M. abscessus tipo 2 como M. abscessus subsp. bolletii, M. abscessus tipo 1 como M. abscessus subsp. abscessus e M. fortuitum tipo 1 como M. fortuitum subsp. fortuitum. Pela técnica de tipagem PFGE todos os isolados de M. abscessus subsp. bolletii apresentaram o mesmo perfil clonal o qual pertence ao clone BRA100, já descrito mundialmente. Os isolados de M. abscessus subsp. abscessus e M. fortuitum subsp. fortuitum apresentaram perfis distintos de PFGE. O perfil de suscetibilidade aos antibióticos foi avaliado por microdiluição em caldo de acordo com CLSI (2011) e, todos os isolados foram sensíveis a amicacina e todos foram resistentes a doxiciclina e sulfametoxazol-trimetoprima. Para M. abscessus subsp. bolletii todos os isolados foram resistentes à ciprofloxacino, moxifloxacino e tobramicina e um padrão de susceptibilidade variável foi observado para cefoxitina (Sensível - 28%, Intermediário - 72%) e claritromicina (Sensível - 86%, Resistentes - 14%). Cabe mencionar que este é o primeiro relato de resistência a claritromicina para o clone BRA100. Para M. abscessus subsp. abscessus e M. fortuitum subsp. fortuitum todos os isolados foram resistentes a claritromicina; já para a cefoxitina e tobramicina um padrão de susceptibilidade variável foi observado. Todos os isolados de M. fortuitum subsp. fortuitum foram sensíveis à ciprofloxacino, em contraste aos isolados de M. abscessus subsp. abscessus que apresentaram 70% de resistência. Todas MCR, resistentes (ou intermediárias) para ciprofloxacino apresentaram uma Ala-83 em GyrA, em contraste com uma Ser-83 em todos os isolados de M. fortuitum subsp. fortuitum sensíveis a ciprofloxacino, mas com perfil de resistência variável a moxifloxacino. Nenhuma diferença foi encontrada em GyrB independentemente do perfil de sensibilidade de MCR. Em conclusão, nosso estudo relata a persistência de um único clone M. abscessus subsp. bolletii BRA100 relacionado aos surtos, altamente resistente, mesmo após a implementação nacional das medidas de controle de infecção para contenção de surtos por MNTs. Também foi possível correlacionar que mutações no aminoácido Ala-83 de GyrA estão diretamente relacionados com a resistência à ciprofloxacino em M. abscessus subsp. abscessus e M. abscessus subsp. bolletii. / Outbreaks associated with rapidly growing mycobacteria (RGM) have been increasingly reported worldwide, including in Brazil. Among RGM, the M. abscessus complex is consider the most pathogenic, besides being related to multidrug resistance. Considering the importance of investigating the RGM strains present in our state, this study aimed to characterize the molecular and susceptibility profile of RGM isolates referred to the Reference Center for Mycobacteria State (Instituto de Pesquisas Biológicas - Laboratório Central de Saúde Pública, IPB-LACEN/RS). Furthermore, the mechanisms of quinolone resistance conferred by gyrA and gyrB genes were evaluated. A total of 74 isolates was sent to IPB-LACEN/RS between 2007 and 2012. Forty-three of the analyzed isolates were related to outbreak and 31 isolates of RGM were unrelated to outbreaks. The technique of PRA- hsp65 identified 43 isolates as M. abscessus type 2, 21 isolates as M. fortuitum type 1 and 10 isolates as M. abscessus type 1. The partial sequencing of the rpoB gene confirmed the identification of M. abscessus type 2 as M. abscessus subsp. bolletii, M. abscessus type 1 as M. abscessus subsp. abscessus and M. fortuitum type 1 and M. fortuitum subsp. fortuitum. PFGE typing technique showed the same clonal profile for all isolates of M. abscessus subsp. bolletii which belongs to clone BRA100, already described worldwide. Isolates of M. abscessus subsp. abscessus and M. fortuitum subsp. fortuitum showed distinct PFGE profiles. The antibiotic susceptibility profile was evaluated by broth microdilution according to CLSI (2011), and all isolates were susceptible to amikacin and resistant to doxycycline and trimethoprimsulfamethoxazole. All isolates of M. abscessus subsp. bolletii were resistant to ciprofloxacin, moxifloxacin and tobramycin and presented variable susceptibility pattern to cefoxitin (Susceptible - 28%, Intermediate - 72%) and clarithromycin (Susceptible - 86%, Resistant - 14%). It is important to mention that this is the first report of clarithromycin resistance for clone BRA100. Strains of M. abscessus subsp. abscessus and M. fortuitum subsp. fortuitum were all resistant to clarithromycin, and presented a variable susceptibility profile to cefoxitin and tobramycin. All isolates of M. fortuitum subsp. fortuitum were susceptible to ciprofloxacin, in contrast to isolates of M. abscessus subsp. abscessus that showed a resistance rate of 70%. All RGM ciprofloxacin non-susceptible presented an Ala-83 in GyrA, contrasting to a Ser-83 in all isolates of M. fortuitum subsp. fortuitum susceptible to ciprofloxacin, however, with a variable resistance profile to moxifloxacin. No difference was found in GyrB, regardless of the RGM susceptible profile. In conclusion, our study reports the persistence of a single clone of M. abscessus subsp. bolletii BRA100 related to outbreak, highly resistant, even after national implementation of infection control measures to contain outbreaks by NTM. It was also possible to correlate that mutations in the amino acid Ala-83 of GyrA are directly related to ciprofloxacin and moxifloxacin resistance in M. abscessus subsp. abscessus and M. abscessus subsp. bolletii.
24

Emerging role of RNA-binding proteins in sporadic and rapid progressive Alzheimer’s disease

Younas, Neelam 14 January 2020 (has links)
No description available.
25

Plánování cesty v reálném čase / Real-time path planning

Bartozel, Zdeněk January 2019 (has links)
The thesis deals with the path planning and movement of the holonomic robot in a dynamic environment. The aim of this work is implementation of several algorithms based on Rapidly-explored random tree algorithm and their comparison in designed dynamic environment.
26

Návrh knihovny pro plánování trajektorie robotu / Design of path planning library for mobile robot

Novotný, Michal January 2008 (has links)
This thesis deals with analyses of problems of path planning by means Rapidly-exploring Random Trees (RRT) algorithm. The teoretic part described of basic terms and navigation mobile robots. There are localization, mapping and path planning parts of navigation. Then it is description overview of localization of methods and overview of robot path planning methods. The practical describes implementation of proposed method in Delphi. The best method for path planning of robot using RRT algorithm. For reservation universal communications interface is application creation like dynamic library.
27

Planning Method for a Reversing Single Joint Tractor-Trailer System

Ismail, Ofa January 2021 (has links)
This thesis investigates the design of a local planning method for a reversing single joint tractor-trailer system that can be used in a sampling-based motion planner. The motion planner used is a Rapidly-exploring Random Tree (RRT) developed by Scania. The main objective of a local planning method is to generate a feasible path between two poses, which is needed when expanding the search tree in an RRT. The local planning method described in this thesis uses a set of curves, similar to Reeds-Shepp curves, feasible for a single joint tractor-trailer system. The curves are found by solving a constrained optimization problem that adheres to the kinematic model of the system. The reference for the tractor is generated by discretizing the path between curves. The reference for the trailer is generated by simulating the mission backwards where the curve radiuses are used as input. Simulating the mission backwards circumvents the instability of the system when reversing. The generated references are then compared to references generated by a lattice-based motion planner. The length of the references generated by the RRT are smaller than those generated by the lattice-based motion planner in simple open environments. The RRT had issues finding a path in cases where the environment was complex while the lattice-based motion planner found a path in every scenario. The computational time was significantly lower for the RRT in all simulations. The RRT generates all references between any two given poses while the lattice-based motion planner approximate the start and goal poses to the closest vertex in the search-space.  The references generated by the RRT did not perform optimally when small turns were needed along the curves due to the distance needed for maneuvering the tractor. Therefore, a new optimization problem has to be defined for which the small turns are considered.
28

Imitation Learning based on Generative Adversarial Networks for Robot Path Planning

Yi, Xianyong 24 November 2020 (has links)
Robot path planning and dynamic obstacle avoidance are defined as a problem that robots plan a feasible path from a given starting point to a destination point in a nonlinear dynamic environment, and safely bypass dynamic obstacles to the destination with minimal deviation from the trajectory. Path planning is a typical sequential decision-making problem. Dynamic local observable environment requires real-time and adaptive decision-making systems. It is an innovation for the robot to learn the policy directly from demonstration trajectories to adapt to similar state spaces that may appear in the future. We aim to develop a method for directly learning navigation behavior from demonstration trajectories without defining the environment and attention models, by using the concepts of Generative Adversarial Imitation Learning (GAIL) and Sequence Generative Adversarial Network (SeqGAN). The proposed SeqGAIL model in this thesis allows the robot to reproduce the desired behavior in different situations. In which, an adversarial net is established, and the Feature Counts Errors reduction is utilized as the forcing objective for the Generator. The refinement measure is taken to solve the instability problem. In addition, we proposed to use the Rapidly-exploring Random Tree* (RRT*) with pre-trained weights to generate adequate demonstration trajectories in dynamic environment as the training data, and this idea can effectively overcome the difficulty of acquiring huge training data.
29

Sampling-based Path Planning for an Autonomous Helicopter

Pettersson, Per Olof January 2006 (has links)
Many of the applications that have been proposed for future small unmanned aerial vehicles (UAVs) are at low altitude in areas with many obstacles. A vital component for successful navigation in such environments is a path planner that can find collision free paths for the UAV. Two popular path planning algorithms are the probabilistic roadmap algorithm (PRM) and the rapidly-exploring random tree algorithm (RRT). Adaptations of these algorithms to an unmanned autonomous helicopter are presented in this thesis, together with a number of extensions for handling constraints at different stages of the planning process. The result of this work is twofold: First, the described planners and extensions have been implemented and integrated into the software architecture of a UAV. A number of flight tests with these algorithms have been performed on a physical helicopter and the results from some of them are presented in this thesis. Second, an empirical study has been conducted, comparing the performance of the different algorithms and extensions in this planning domain. It is shown that with the environment known in advance, the PRM algorithm generally performs better than the RRT algorithm due to its precompiled roadmaps, but that the latter is also usable as long as the environment is not too complex. The study also shows that simple geometric constraints can be added in the runtime phase of the PRM algorithm, without a big impact on performance. It is also shown that postponing the motion constraints to the runtime phase can improve the performance of the planner in some cases. / <p>Report code: LiU–Tek–Lic–2006:10.</p>
30

Multi-Resolution Obstacle Mapping with Rapidly-Exploring Random Tree Path Planning for Unmanned Air Vehicles

Millar, Brett Wayne 08 April 2011 (has links) (PDF)
Unmanned air vehicles (UAVs) have become an important area of research. UAVs are used in many environments which may have previously unknown obstacles or sources of danger. This research addresses the problem of obstacle mapping and path planning while the UAV is in flight. Online obstacle mapping is achieved through the use of a multi-resolution map. As sensor information is received, a quadtree is built up to hold the information based upon the uncertainty associated with the measurement. Once a quadtree map of obstacles is built up, we desire online path re-planning to occur as quickly as possible. We introduce the idea of a quadtree rapidly-exploring random tree (RRT), which will be used as the online path re-planning algorithm. This approach implements a variable sized step instead of the fixed-step size usually used in the RRT algorithm. This variable step uses the structure of the quadtree to determine the step size. The step size grows larger or smaller based upon the size of the area represented by the quadtree it passes through. Finally this approach is tested in a simulation environment. The results show that the quadtree RRT requires fewer steps on average than a standard RRT to find a path through an area. It also has a smaller variance in the number of steps taken by the path planning algorithm in comparison to the standard RRT.

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