Texte remanié de: Thèse 3 °cycle--Sciences sociales--Paris--Ecole des hautes études en sciences sociales, 1985.

Texte remanié de: Tesis doct.--Universidad del País vasco.

Akademisk avhandling--Göteborg, 1994. / Résumé en anglais. Bibliogr. p. 329-348.

Orientador: Daniela Ponce / Resumo: Introdução: Hemodiálise (HD) é a modalidade de terapia renal substitutiva mais amplamente utilizada no mundo e o uso de cateteres venosos centrais (CVC) tem aumentado como forma primária de acesso vascular para HD. Apesar da vantagem de obtenção imediata de acesso, a forte associação do CVC com infecções de corrente sanguínea (ICS), elevada morbidade e mortalidade vem direcionando inúmeros estudos com a finalidade de prevenir infecções relacionadas ao CVC na população em HD, destacando-se estudos com uso de lock terapia profilática. Diversas substâncias foram testadas em lock terapia profilática, porém a comparação entre drogas com ação antimicrobiana e antibióticos foi pouco estudada, sem determinação da melhor solução para profilaxia. Os objetivos deste trabalho foram comparar a eficácia do uso de antibioticoterapia em lock gentamicina + cefazolina versus o uso de taurolidina + citrato em relação às taxas ICS relacionadas a cateteres tunelizados e às complicações relacionadas à lock terapia (resistência bacteriana e oclusão trombótica). Métodos: Estudo Quasi-experimental, prospectivo e comparativo em dois centros de diálise, incluindo CVC tunelizados para HD com inserção no momento do estudo. Foram implantados 145 CVC em 127 pacientes, seguidos durante 15 meses consecutivos. Os pacientes foram alocados em cada grupo de acordo com o centro de hemodiálise pertencente: Grupo 1: 65 pacientes (77 CVC) em uso de antibiótico em lock (gentamicina 7,2 mg/ml + cefazolina 12 mg/ml + h... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Background: Hemodialysis (HD) is the most widely used renal replacement therapy modality, and the use of central venous catheters (CVC) has increased as primary form of vascular access for hemodialysis. Despite the immediate possibility of use, there is a strong association between CVC and bloodstream infection (BSI) high morbidity and mortality, so several trials have been directed at the prevention of catheter-related bloodstream infection (CRBI) on dialysis population, highlighting studies using prophylactic lock therapy. A number of substances has been tested as prophylactic lock therapy, but the comparison between antimicrobials and antibiotic drugs was not tested enough, and the best prophylactic lock solution remain undetermined. The aim of the study was to compare the efficacy of catheter-restricted filling using antibiotic solution (cefazolin plus gentamicin plus heparin) versus antimicrobial solution (taurolidine plus citrate) regarding CRBI rates and to identify its adverse effects, including bacterial resistance and thrombotic events. Methods: A Quasi-experimental study. Prospective and comparative, developed in two dialysis centers, including incidents long permanence CVC for HD. 145 CVC were implanted in 127 patients HD and followed up for 15 months. The patients were allocated in each group according the hemodialysis center: Group 1: 65 patients (77 CVC) using antibiotic lock solution (gentamicin 7,2mg /ml + cefazolin 12mg /ml + heparin 3500 IU /ml). Group 2: 6... (Complete abstract click electronic access below) / Doutor

Submitted by TRÍCYA NUNES VIEIRA BUELONI null (tbueloni@gmail.com) on 2018-03-28T00:50:38Z No. of bitstreams: 1 Tese doutorado versão repositório.pdf: 1144023 bytes, checksum: 6ce61134d85d148bb9fe48f97b75c860 (MD5) / Approved for entry into archive by ROSANGELA APARECIDA LOBO null (rosangelalobo@btu.unesp.br) on 2018-03-29T13:54:10Z (GMT) No. of bitstreams: 1 bueloni_tnv_dr_bot.pdf: 1144023 bytes, checksum: 6ce61134d85d148bb9fe48f97b75c860 (MD5) / Made available in DSpace on 2018-03-29T13:54:11Z (GMT). No. of bitstreams: 1 bueloni_tnv_dr_bot.pdf: 1144023 bytes, checksum: 6ce61134d85d148bb9fe48f97b75c860 (MD5) Previous issue date: 2018-02-23 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Introdução: Hemodiálise (HD) é a modalidade de terapia renal substitutiva mais amplamente utilizada no mundo e o uso de cateteres venosos centrais (CVC) tem aumentado como forma primária de acesso vascular para HD. Apesar da vantagem de obtenção imediata de acesso, a forte associação do CVC com infecções de corrente sanguínea (ICS), elevada morbidade e mortalidade vem direcionando inúmeros estudos com a finalidade de prevenir infecções relacionadas ao CVC na população em HD, destacando-se estudos com uso de lock terapia profilática. Diversas substâncias foram testadas em lock terapia profilática, porém a comparação entre drogas com ação antimicrobiana e antibióticos foi pouco estudada, sem determinação da melhor solução para profilaxia. Os objetivos deste trabalho foram comparar a eficácia do uso de antibioticoterapia em lock gentamicina + cefazolina versus o uso de taurolidina + citrato em relação às taxas ICS relacionadas a cateteres tunelizados e às complicações relacionadas à lock terapia (resistência bacteriana e oclusão trombótica). Métodos: Estudo Quasi-experimental, prospectivo e comparativo em dois centros de diálise, incluindo CVC tunelizados para HD com inserção no momento do estudo. Foram implantados 145 CVC em 127 pacientes, seguidos durante 15 meses consecutivos. Os pacientes foram alocados em cada grupo de acordo com o centro de hemodiálise pertencente: Grupo 1: 65 pacientes (77 CVC) em uso de antibiótico em lock (gentamicina 7,2 mg/ml + cefazolina 12 mg/ml + heparina 3500UI/ml). Grupo 2: 62 pacientes (68 CVC) em uso de taurolidina + citrato 4% + heparina 500UI/ml (taurolockTM –Hep 500). A densidade de incidência de infecção foi calculada pelo número de eventos por 1000 cateteres-dia. Curvas de sobrevida livre de ICS, IOS e complicação mecânica foram realizadas pelo método de Kaplan Meyer, bem como análise de regressão de Cox, incluindo as variáveis: grupo, sítio de cateter, tempo em hemodiálise até o implante, comorbidades, idade e doença de base. Resultados: Os dois grupos foram semelhantes quanto ao sexo, idade, doença de base, comorbidades e tempo em HD. Não houve diferença entre os grupos quanto às prevalências de IOS e de ICS e densidade de incidência de ICS (G1=0,79 e x G2=1,10 eventos por 1000 cateteres-dia, p=0,18) e de IOS (G1=2,45 x G2=1,83 eventos por 1000 cateteres-dia, p=0,37). Os grupos também foram semelhantes quanto ao tempo livre de infecção e retirada do CVC. Porém, os grupos diferiram quanto aos agentes etiológicos nas IOS, sendo os Gram positivos oxacilina resistentes mais frequentes no grupo 1 (38,7% x 5%, p=0,017) e quanto aos motivos da retirada do CVC, sendo a utilização da FAV maior no grupo 2 (0 x 33,3%, p<0,001) e a oclusão trombótica mais frequente no grupo 1 (52,6 x 25%, p=0,028). Na análise de regressão de Cox, o sítio em veia jugular foi fator protetor para retirada de cateter por todas as causas (HR: 0,41; IC 95% 0,19- 0,91) e por complicação mecânica (HR: 0,16; IC 95% 0,065-0,41) e apenas o IOS foi fator de risco para retirada do cateter por todas as causas (HR: 1,79; IC 95% 1,04-3,07) e por complicação mecânica (HR: 5,64; IC 95% 1,65-19,33). Conclusão: A eficácia de ambas as soluções (antibióticos e antimicrobianos não antibióticos) em lock foi semelhante na prevenção das infecções relacionadas ao CVC tunelizado para HD. Entretanto, no grupo gentamicina/cefazolina houve maior presença de cepas resistentes à oxacilina. O maior número de bactérias resistentes à oxacilina no grupo gentamicina/cefazolina alerta para riscos de indução de resistência bacteriana com uso profilático de lock com antibióticos em CVC de longa permanência. / Background: Hemodialysis (HD) is the most widely used renal replacement therapy modality, and the use of central venous catheters (CVC) has increased as primary form of vascular access for hemodialysis. Despite the immediate possibility of use, there is a strong association between CVC and bloodstream infection (BSI) high morbidity and mortality, so several trials have been directed at the prevention of catheter-related bloodstream infection (CRBI) on dialysis population, highlighting studies using prophylactic lock therapy. A number of substances has been tested as prophylactic lock therapy, but the comparison between antimicrobials and antibiotic drugs was not tested enough, and the best prophylactic lock solution remain undetermined. The aim of the study was to compare the efficacy of catheter-restricted filling using antibiotic solution (cefazolin plus gentamicin plus heparin) versus antimicrobial solution (taurolidine plus citrate) regarding CRBI rates and to identify its adverse effects, including bacterial resistance and thrombotic events. Methods: A Quasi-experimental study. Prospective and comparative, developed in two dialysis centers, including incidents long permanence CVC for HD. 145 CVC were implanted in 127 patients HD and followed up for 15 months. The patients were allocated in each group according the hemodialysis center: Group 1: 65 patients (77 CVC) using antibiotic lock solution (gentamicin 7,2mg /ml + cefazolin 12mg /ml + heparin 3500 IU /ml). Group 2: 62 patients (68 CVC) using taurolidine citrate + 4% + Heparin 500 IU /ml (Taurolock-TM-Hep 500). The incidence density of infection was calculated by the number of events per 1000 catheter-day. ICS, IOS and mechanical complication free survival curves were performed using the Kaplan Meyer method, as well as proportional hazards Cox model, including the following variables: group, catheter site, hemodialysis time to implant, comorbidities, age and CKD causal disease. Results: The two groups were similar for sex, age, causal disease, comorbidities and HD time. There was no difference between the groups regarding the prevalence of exit site infection (ESI) and BI as the same for the density of CRBI incidence (G1 = 0.79 events per 1000 day catheters x G2 = 1.10 events per 1000 day catheters, p =0.18) and ESI (G1 = 2.45 x G2 = 1.83 events per 1000 day catheters, p = 0.37). Infection free time and catheter withdrawal rate were similar between the groups. However, the groups differed for ESI agents, with gram-positive oxacillin-resistant more frequent in group 1 (31.8 x 5%, p = 0.003) and for the reasons for catheter removal, being AVF use more frequent in group 2 (0 x 33.3%, p<0.001) and mechanical complication in group 1 (52.6 x 25%, p= 0.028). In the Cox regression analysis, the jugular vein site was a protective factor for catheter removal from all causes (HR: 0.41, 95% CI 0.19-0.91) and mechanical complication (HR: 0, 16, 95% CI 0.065-0.41), and only IOS was a risk factor for catheter removal from all causes (HR: 1.79, 95% CI 1.04-3.07) and mechanical complication (HR: 5.64, 95% CI 1.65- 19.3). Conclusion: The efficacy of both lock solutions (antibiotics and antimicrobials no antibiotics) was similar in preventing infections related to tunneled CVC for hemodialysis. However, in group 1 there were more oxacilinresistant strains. The highest number of oxacilin-resistant bacteria in the gentamicin/cefazolin group warns against the risk of induction bacterial resistant with prophylactic use of lock with antibiotics in long-term CVC. / 2014/06140-1

This thesis presents the research made on signal and data processing for THz imaging, with emphasis in noise analysis and tomography in amplitude contrast using a THz time-domain spectrometry system. A THz computerized tomography system was built, tested and characterized. The system is controlled from a personal computer using a program developed ad hoc. Detail is given on the operating principles of the system’s numerous optical and THz components, the design of a computer-based fast lock-in amplifier, the proposal of a local apodization method for reducing spurious oscillations in a THz spectrum, and the use of a parabolic interpolation of integrated signals as a method for estimating THz pulse delay. It is shown that our system can achieve a signal-to-noise ratio of 60 dB in spectrometry tests and 47 dB in tomography tests. Styrofoam phantoms of different shapes and up to 50x60 mm is size are used for analysis. Tomographic images are reconstructed at different frequencies from 0.2 THz to 2.5 THz, showing that volume scattering and edge contrast increase with wavelength. Evidence is given that refractive losses and surface scattering are responsible of high edge contrast in THz tomography images reconstructed in amplitude contrast. A modified Rayleigh roughness factor is proposed to model surface transmission scattering. It is also shown that volume scattering can be modelled by the material’s attenuation coefficient. The use of 4 mm apertures as spatial filters is compared against full beam imaging, and the limitations of Raleigh range are also addressed. It was estimated that for some frequencies between 0.5 THz and 1 THz the Rayleigh range is enough for the tested phantoms. Results on the influence of attenuation and scattering at different THz frequencies can be applied to the development of THz CW imaging systems and as a point of departure for the development of more complex scattering models.

No description available.

The aim of the master thesis is on lock-in amplifiers. Amplifier's basic parts and lock-in circuits description is listed in introductory chapters. The thesis offers overview of parameters of chosen devices available on the market and their possible usage. We describe HF2LI device functions and usage of ziControl software. With the aim to verify properties of the device and ziControl software, one of the last chapters focuses on manipulation with HF2LI device. The conducted experiments and achieved results are presented in the last chapter.

Le passage à l'échelle des applications multi-fil sur les systèmes multi-cœuractuels est limité par la performance des algorithmes de verrou, à cause descoûts d'accès à la mémoire sous forte congestion et des défauts de cache. Lacontribution principale présentée dans cette thèse est un nouvel algorithme,Remote Core Locking (RCL), qui a pour objectif d'améliorer la vitessed'exécution des sections critiques des applications patrimoniales sur lesarchitectures multi-cœur. L'idée de RCL est de remplacer les acquisitions deverrou par des appels de fonction distants (RPC) optimisés vers un fild'exécution matériel dédié appelé serveur. RCL réduit l'effondrement desperformances observé avec d'autres algorithmes de verrou lorsque de nombreuxfils d'exécution essaient d'obtenir un verrou de façon concurrente, et supprimele besoin de transférer les données partagées protégées par le verrou vers lefil d'exécution matériel qui l'acquiert car ces données peuvent souventdemeurer dans les caches du serveur.D'autres contributions sont présentées dans cette thèse, notamment un profilerpermettant d'identifier les verrous qui sont des goulots d'étranglement dansles applications multi-fil et qui peuvent par conséquent être remplacés par RCLafin d'améliorer les performances, ainsi qu'un outil de réécriture de codedéveloppé avec l'aide de Julia Lawall. Cet outil transforme les acquisitions deverrou POSIX en acquisitions RCL. L'évaluation de RCL a porté sur dix-huitapplications: les neuf applications des benchmarks SPLASH-2, les septapplications des benchmarks Phoenix 2, Memcached, ainsi que Berkeley DB avec unclient TPC-C. Huit de ces applications sont incapables de passer à l'échelle àcause de leurs verrous et leur performance est améliorée par RCL sur unemachine x86 avec quatre processeurs AMD Opteron et 48 fils d'exécutionmatériels. Utiliser RCL permet de multiplier les performances par 2.5 parrapport aux verrous POSIX sur Memcached, et par 11.6 fois sur Berkeley DB avecle client TPC-C. Sur une machine SPARC avec deux processeurs Sun Ultrasparc T2+et 128 fils d'exécution matériels, les performances de trois applications sontaméliorées par RCL: les performances sont multipliées par 1.3 par rapport auxverrous POSIX sur Memcached et par 7.9 fois sur Berkeley DB avec le clientTPC-C. / The scalability of multithreaded applications on current multicore systems is hampered by the performance of lock algorithms, due to the costs of access contention and cache misses. The main contribution presented in this thesis is a new lock algorithm, Remote Core Locking (RCL), that aims to improve the performance of critical sections in legacy applications on multicore architectures. The idea of RCL is to replace lock acquisitions by optimized remote procedure calls to a dedicated hardware thread, which is referred to as the server. RCL limits the performance collapse observed with other lock algorithms when many threads try to acquire a lock concurrently and removes the need to transfer lock-protected shared data to the hardware thread acquiring the lock because such data can typically remain in the server's cache. Other contributions presented in this thesis include a profiler that identifies the locks that are the bottlenecks in multithreaded applications and that can thus benefit from RCL, and a reengineering tool developed with Julia Lawall that transforms POSIX locks into RCL locks. Eighteen applications were used to evaluate RCL: the nine applications of the SPLASH-2 benchmark suite, the seven applications of the Phoenix 2 benchmark suite, Memcached, and Berkeley DB with a TPC-C client. Eight of these applications are unable to scale because of locks and benefit from RCL on an x86 machine with four AMD Opteron processors and 48 hardware threads. Using RCL locks, performance is improved by up to 2.5 times with respect to POSIX locks on Memcached, and up to 11.6 times with respect to Berkeley DB with the TPC-C client. On an SPARC machine with two Sun Ultrasparc T2+ processors and 128 hardware threads, three applications benefit from RCL. In particular, performance is improved by up to 1.3 times with respect to POSIX locks on Memcached, and up to 7.9 times with respect to Berkeley DB with the TPC-C client.

This thesis aims to find out trade-offs between security, privacy and convenience when it comes to smart locks. If users know about security and privacy risks associated with smart locks and how they perceive the trade-offs, if they think that the security and privacy risks are worth it for some added convenience. In this project both a literature review and online survey was used to gather information. The results are that there are conveniences with smart locks but that they come with potential security and privacy risks. That overall users seems to know that there are potential security and privacy risks and users seem to think that any potential security and privacy risks are worth taking for the sake of convince.