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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

Effect of selective COX-2 inhibitors on hepatic progenitor cells and the pathologies of experimental hepatocarcinogenesis

Davies, Richard January 2007 (has links)
[Truncated abstract] Hepatocellular carcinoma (HCC) is the major malignancy complicating chronic liver disease. New therapies for the prevention of HCC are required due to the limited success and high tumour recurrence rates of existing treatments. Emerging evidence suggests that HCC arise from the transformation of adult liver progenitor cells (LPCs), which have the capacity to differentiate into hepatocytes and biliary cells during liver regeneration. LPC activation precedes neoplasia in experimental hepatocarcinogenesis. LPCs share antigenic epitopes with HCCs, including α-fetoprotein (AFP) and M2- pyruvate kinase (M2PK). In animal models of hepatocarcinogenesis, attenuation of the LPC response reduces the incidence of HCC following prolonged liver injury via a tumour necrosis factor (TNF) dependent mechanism. As TNF is a pro-inflammatory cytokine, these data suggest that anti-inflammatory agents may be effective in inhibiting LPC activation and hepatocarcinogenesis. Cyclo-oxygenase-2 (COX-2) is an inducible enzyme that mediates the production of many prostaglandins during inflammation and carcinogenesis. Recent investigations show that the administration of selective COX-2 inhibitors (SC2Is) may reduce the incidence of a variety of tumours including breast, colon and skin. The broad aim of this thesis was to conduct a series of detailed studies on the effects of a SC2I on LPC activation and the hepatic pathologies associated with hepatocarcinogenesis in order to test the hypothesis that S2CIs may be a beneficial therapy that can reduce liver injury and pre-neoplastic changes in the choline-deficient, ethionine supplemented (CDE) murine model of hepatocarcinogenesis. Administration of a SC2I (SC-236) significantly inhibited a variety of hepatic cell populations that expand during the first month of the CDE mouse model of hepatocarcinogenesis (a choline deficient, ethionine supplemented diet). Numbers of M2PK-positive LPCs (which are more hepatocytic in morphology and are also COX-2 positive) and inflammatory cells were all significantly reduced by SC-236. In contrast, numbers of A6-positive LPCs (which are more biliary cell-like in morphology and do not express COX-2) were unchanged. ... In summary, these data suggest that COX-2 inhibitors such as SC-236 inhibit LPC activation and a variety of pre-neoplastic liver pathologies as a result of COX-2 dependent and independent mechanisms that may be mediated through inhibition of Akt phosphorylation and induction of apoptosis. Moreover, SC2Is may be useful as preventative treatment strategies for HCC in patients with chronic liver disease.
22

Acurácia da ultrassonografia transcraniana colorida no diagnóstico de forame oval patente / Transcranal color coded sonography for detection of patent foramen ovale in young patients with stroke

Milena Carvalho Libardi 26 January 2016 (has links)
Introdução:O Forame Oval Patente (FOP) é a comunicação direita-esquerda (CDE) ou shunt direita-esquerda (SDE) mais comum e frequentemente encontrada em adultos jovens com Acidente Vascular Cerebral (AVC) relacionado ao mecanismo de embolia paradoxal. A Ecocardiografia Transesofágia (ETE) é considerada o padrão para visualização direta do FOP. O Doppler Transcraniano com o teste de microbolhas é frequentemente usado para detectar CDE com boa correlação com o ETE para o diagnóstico de FOP. Mais recentemente, a Ultrassonografia Transcraniana Colorida (TCCS) com inclusão do modo-B e fluxo de cor tem superado o DTC (que é realizado \"as cegas\") em muitas aplicações clínicas mas a acurácia do TCCS para a detecção de CDE e FOP não tem sido sistematicamente avaliada. Objetivo: Determinar se o TCCS é uma ferramenta acurada para identificar tanto FOP quanto CDE. Métodos: Foram recrutados 106 pacientes prospectivamente com Acidente Vascular Cerebral Isquêmico menores de 55 anos admitidos na Unidade de Emergência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP). Os pacientes foram submetidos aos exames de ETE, DTC e TCCS e todos os exames incluíram a técnica do teste de microbolhas. Os examinadores foram cegos para os resultados desses exames e foi calculado a concordância Kappa de Cohen inter-examinadores para o TCCS e DTC. A acurácia para o TCCS foi calculada em comparação ao ETE. Resultados: Foram detectados CDE em 54 (50.9%) dos pacientes (idade média 43.9 ± 8.2 anos) com Kappa de Cohen de 0.92 (IC 95% 0.78-1.0) quando realizados TCCS e TCD. TEE e TCSS foram positivos em 23/98 (23.4%) e ETE negative em 20/98 (20.4%). Em 30 (28.3%) o ETE revelou FOP. O TCSS teve uma sensibilidade de 88.4%(IC 95% 0.68-0.97) e especificidade de 72.2%(IC 95% 0.60-0.81) e uma razão de verossimilhança positive de 3.18 (IC 95% 2.14-4.73) para o diagnóstico de FOP. Conclusão: TCCS e DTC tiveram excelente concordância. TCCS tem uma boa acurácia para a detecção de FOP e CDE em pacientes jovens com Acidente Vascular Isquêmico / Introduction: Patent Foramen Ovale (PFO) is the most common right-to-left shunt (RLS) and is often found in young patients with stroke related to paradoxical embolism. ContrastEnhanced Transesophageal Echocardiography (TEE) is considered a gold standard to visualize PFO. Transcranial Doppler (TCD) with bubble test is often used to detect RLS with good correlation to TEE for the diagnostic of PFO. More recently, Transcranial Color Coded Sonography (TCCS) which included B-mode and color coded imaging has overcome blind TCD in many clinical applications but the accuracy of TCCS for detection of RLS and PFO has not been systematically evaluated. Hypothesis: To determine if the TCCS is an accurate tool to identify both PFO and RLS. Methods: We investigate 106 patients with ischemic stroke under 55 years-old admitted from 2012 to 2014 in a tertiary academic hospital. Patients were evaluated with TEE, TCD and TCCS, and all exams included a saline bubble test. The examiners were blinded for the other tests results. Kappa agreement was calculated inter-examiners for TCCS and TCD. Accuracy of TCCS was calculated in comparison to TEE. Results: We detected a RLS in 54 (50.9%) patients (age mean 43.9 ± 8.2) with kappa agreement 0.92 (95%CI 0.78-1.0) when performed TCCS and TCD. TEE and TCSS were positive in 23/98 (23.4%) and TEE did not reveal contrast in 20/98 (20.4%). In 30 (28.3%) patients only TEE revealed a PFO. TCSS had a sensitivity of 88.4% (95%CI 0.68-0.97), specificity of 72.2% (95%CI 0.60-0.81) and positive likelihood ratio of 3.18 (2.14-4.73) of the diagnosis of PFO. Conclusion: TCCS and TCD had an excellent agreement. TCCS has a good accuracy for the detection of PFO and RLS in young patients with stroke
23

Systém pro automatické filtrování testů / System for Automatic Filtering of Tests

Lysoněk, Milan January 2020 (has links)
Cílem této práce je vytvořit systém, který je schopný automaticky určit množinu testů, které mají být spuštěny, když dojde v ComplianceAsCode projektu ke změně. Navržená metoda vybírá množinu testů na základě statické analýzy změněných zdrojových souborů, přičemž bere v úvahu vnitřní strukturu ComplianceAsCode. Vytvořený systém je rozdělen do čtyř částí - získání změn s využitím verzovacího systému, statická analýza různých typů souborů, zjištění souborů, které jsou ovlivněny těmi změnami, a výpočet množiny testů, které musí být spuštěny pro danou změnu. Naimplementovali jsme analýzu několika různých typů souborů a náš systém je navržen tak, aby byl jednoduše rozšiřitelný o analýzy dalších typů souborů. Vytvořená implementace je nasazena na serveru, kde automaticky analyzuje nové příspěvky do ComplianceAsCode projektu. Automatické spouštění informuje přispěvatelé a vývojáře o nalezených změnách a doporučuje, které testy by pro danou změnu měly být spuštěny. Tím je ušetřen čas strávený při kontrole správnosti příspěvků a čas strávený spouštěním testů.
24

GUI nástroj na měření zranitelností systémů pomocí knihovny OpenSCAP / GUI Tool for Vulnerability Measurement Based on OpenSCAP Library

Oberreiter, Vladimír January 2011 (has links)
This work describes the SCAP standards (Security Content Automation Protocol) determining the level of computer security and the OpenSCAP library providing a framework to the SCAP standards. It also describes the way of designing and creating security tool using the OpenSCAP library. This tool enables to search for known, potential system vulnerabilities and check the system configuration according to previously set criteria.
25

Ovaldrehen

Volmer, Johannes 18 September 2006 (has links)
Ovaldrehen ist eine alte Drechseltechnik.<br/>Sie wurde seit einigen Jahren durch neue Ovaldrehmaschinen wiederbelebt. Diese Maschinen und ihr Zubehör sowie ihr Gebrauch werden beschrieben. Die Grundlagen bilden getriebetechnische und geometrische Analysen. <br/>Eine Galerie ovalgedrehter Gebrauchsgegenstände zeigt die Vielfalt der Anwendungsmöglichkeiten.<br/>Am Schluss steht ein Verzeichnis relevanter Literatur, Videos und Adressen im Internet und von Ovaldreh-Praxen.
26

Ovalturning

Volmer, Johannes 04 October 2006 (has links)
Ovalturning is an ancient woodturning art, recently revived by new ovalturning lathes designed and tested by the author. These lathe, their accessories and their usage and application are described in detail. The fundaments are kinematical mechanism analysis and the ellipse geometry. A gallery of oval turned items for usage shows partially the variety of ovalturning application. At the end is given a list of relevant literature, videos and addresses in the internet and of ovalturning practioners and schools. Second edition
27

Vývoj a hodnocení nové necementované revizní acetabulární komponenty totální endoprotézy kyčelního kloubu / typ TC / / Development and evaluation of new cementless revision acetabular components for total hip arthroplasty / type TC /

Šťastný, Eduard January 2014 (has links)
Development and evaluation of new cementless revision acetabular components for total hip arthroplasty / type TC / Objective: The aim of the clinical part of the study was to introduce a new revision oval cup type TC, and evaluate its reliability and utility in revision endoprosthesis. Due to the different structure of the implant, we aimed to objectively demonstrate the remodeling of bone tissue in its vicinity. In the experimental part of the work we verified the hypothesis that the use of locking screws has an effect on the bond strength of the implant with bone tissue, and therefore on the primary stability of the acetabular component. Method: We evaluated 31 patients that underwent revision hip surgery between 2004 and 2008. The mean follow-up was 7.1 years (range 5.3 to 9.3 years, minimum 5 years after surgery). Osteointegration of the implant and remodeling of bone tissue around the implant and its ribs were evaluated by digital radiography and computed tomography, and clinical results according to Harris. The experiment was based on the execution of pull-out tests after the implantation of TC cups in cadaveric bovine pelves. We evaluated the dependence of tensile forces in the axis of the implant on extraction of the metal cup from the bone bed. Four tests were conducted with the cup fixed...
28

Mise au point et évaluation microscopique d'une méthode d'obturation canalaire optimale / Microscopic and chemical assessments of the filling ability using five different filling techniques

Mancino, Davide 08 July 2019 (has links)
Évaluer la capacité de remplissage des cinq différentes techniques d’obturation canalaire dans l’obturation des canaux ovales. Matériel et méthodes : Un total de 220 molaires mandibulaires, avec 1 canal dans la racine distale, a été sélectionné. Chaque canal a été mise en forme jusqu’à la longueur de travail en utilisant un système mono-instrument le WaveOne Gold Primary Les dents préparées ont été divisées au hasard en cinq groupes égaux (n = 40 par groupe) pour l'obturation: condensation à onde continue (CWC), technique avec tuteur GuttaCore (GC), technique avec tuteur Thermafil (TH), technique utilisant un cône unique (SC), condensation hydraulique à froid (CHC). Les pourcentages de GPFA, SFA et VA ainsi que la présence des matériaux d’obturation à l’intérieur des tubulis dentinaires (tag)à longueur de travail (LT) -4mm et -2 mm a été évalué à par microscopie numérique optique, microscopie électronique à balayage (SEM) et microanalyse par rayons X à dispersion d'énergie (EDX). Analyse statistique : Les données collectées ont été analysées avec la version 11.2 de SigmaPlot (Systat Software, Inc., San José, CA, USA). Les pourcentages de GPFA, SFA, VA correspondant aux différentes groupes ont été comparés en utilisant le test de Kruskal-Wallis avec α=0,05. Résultats: à LT-4 et LT-2 mm, cette étude à montré une différence statistiquement significative en terme de capacité d’obturation pour le cinq techniques. À LT-4, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA et SFA. En terme de VA, il y a une différence statistiquement significative avec les groupes SC et CHC tandis qu’aucune différence n’a été démontrée entre les groupes GC , TH et CWC . À LT-2, les groupes GC et TH ont montré une différence statistiquement significative par rapport aux trois autres groupes en terme de GPFA, SFA, VA. Conclusion : 
Cette étude montre clairement que les obturations par GC et TH sont en mesure de remplir les canaux ovales d’une manière plus appropriée que les autres techniques d’obturation. 
Les groupes GC et TH, à LT -4 et -2mm, présentaient des tags de gutta-percha à l’intérieur des tubulis dentinaires. La présence de tags de gutta-percha à l’intérieur des tubulis dentinaires (à la place de tags de ciment beaucoup plus vulnérables) pourrait se comporter comme une barrière physique, capable de sceller les bactéries à l’intérieur des tubulis et surtout non résorbable dans le temps. / Assess the filling ability in oval-shaped canals using five different filling techniques. Materials and Methods : 220 human mandibular first molars with one distal oval canal were selected. Distal Canals were shaped using WaveOne Gold Primary. The prepared teeth were randomly divided in four equal groups (n = 40) for obturation : Continuous Wave Condensation (CWC), GuttaCore carrier based technique (GC), Thermafil (TH) carrier based technique, Single Cone technique (SC), Cold hydraulic Condensation (CHC). The proportions of gutta-percha filled areas (GPFA), sealer filled areas (SFA), void areas (VA) and the tags into dentinal tubules at 4 mm and 2 mm were analyzed by Optical numeric microscope, SEM and EDX. Statistical analysis : they were compared by Kruskal-Wallis one-way ANOVA on ranks, with statistical significance set at α = 0.05. Results : At 4 and 2 mm from the apex, this study discloses statistically different filling ability for the five techniques. At 4 mm from the apex, the GC et TH groups showed significantly higher PGFAs than lateral condensation and System B techniques. The GC et TH groups showed a statistically significance difference compared with the others three groups in terms of higher PGFA, lower SFA. It showed a statistically significance difference with SC and CHC groups in term of VA. At 2 mm level from the apex, the GC et TH groups showed a statistically significance differece compared with the others three groups in terms of higher PGFA, lower SFA and VA. Conclusions : GC obturation is able to fill oval-shaped canals in a more appropriate way than the other filling techniques. GC was the only group which showed the presence of gutta-tags at 4 and 2 mm from the apex. The gutta- percha tags could behave as a physical barrier able to entomb bacteria.
29

Nástroj pro snazší zabezpečení počítačů s OS Linux / A Tool for Easily Securing Computers with Linux

Barabas, Maroš January 2009 (has links)
The purpose of this thesis is to explain new approaches to scanning and locking vulnerabilities in computer security and to design a new system to improve security of computers running the Linux operating system. The purpose of this system is to analyze remote operating systems and detect and lock down vulnerabilities by existing security standards.
30

An Experimental Investigation of Heat Transfer for Arrays of impingement Jets onto the Featured Surfaces with Cylindrical and Elliptical Raised Surfaces

Medina, Marc A 01 January 2016 (has links)
This study focuses on multi-jet impingement for gas turbine geometries in which the objective is to understand the influence of the roughness elements on a target surface to the heat transfer. Current work has proven that implementing roughness elements for multi-jet impingement target surfaces has increased heat transfer ranging anywhere from 10-30%. This study has chosen to investigate three different roughness elements, elliptical in cross-section, to compare to smooth surface geometries for multi-jet impingement. An experimental was taken for this study to extend the current knowledge of multi-jet impingement geometries and to further understand the heat transfer performance. A temperature sensitive paint (TSP) technique was used to measure the heat transfer on the target surface, in which the local temperature was measured to estimate area averaged heat transfer coefficient (HTC) and row averaged HTC. In order stay consistent with literature, non-dimensional parameters were used for geometry locations and boundaries. For this study, the Reynolds number range, based on jet diameter and mass flux, is 10-15k. The X/D (streamwise direction), Y/D (spanwise direction), Z/D (channel height direction), L/D (thickness of the jet plate) constraints for this study are 5, 6, 3, and 1 respectively. From the local heat transfer distributions of the different roughness elements, it is concluded that the inclusion of these elements increases heat transfer by 2-12% as compared to a flat/smooth target plate. It is therefore recommended from this study, that elements, elliptical in shape, provide favorability in heat transfer for gas turbine configurations.

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