• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 35
  • 26
  • 15
  • 10
  • 8
  • 5
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 171
  • 74
  • 61
  • 60
  • 46
  • 29
  • 26
  • 24
  • 24
  • 23
  • 22
  • 22
  • 19
  • 18
  • 18
  • 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.
81

Phytochemicals from Graviola fruit selectively inhibit breast cancer cells growth involving EGFR signaling pathway

Dai, Yumin 01 June 2010 (has links)
There is a growing interest in using naturally-occurring compounds as cancer chemopreventive or chemotherapeutic agents. This study investigated the anticancer potential of the graviola fruit extract (GFE) on specific human breast cancer (BC) cells. GFE was found in our preliminary screening to selectively inhibit the growth of certain human BC cells (MDA-MB-468) but did not affect non-transformed breast epithelial MCF-10A cells. GFE treatment was very effective against the growth of MDA-MB-468 BC cells with an IC50 of 4.8 µg/ml. In vitro, effects of GFE treatment on MDA-MB-468 BC cells were further examined for apoptosis and cell proliferation. Apoptosis, determined qualitatively and quantitatively, was enhanced and accompanied by caspase-3 activation. GFE treatment also induced cell cycle arrest at the G1 cell cycle phase and significantly reduced the percentage of MDA-MB-468 cells in S-phase following 24h of exposure. Moreover, the results from analysis of the mRNA expression of epidermal growth factor receptor (EGFR), which plays an important role in regulating cell development and death, by qRT-PCR, suggested that GFE-induced selective growth inhibition of MDA-MB-468 BC cells is associated with a significant inhibition of EGFR gene expression in the cells. In vivo, dietary treatment with GFE significantly inhibited MDA-MB-468 tumor growth implanted in mice by reducing tumor wet weight and significantly reduced EGFR and p-ERK protein expression in tumors. Overall, GFE attenuated cell proliferation, induced apoptosis, modulated cell cycle regulation and downregulated EGFR gene expression both in vitro and in vivo. These discoveries support the further studies to fully elucidate the antitumor potential of GFE and its components as a dietary agent for BC. / Master of Science in Life Sciences
82

Evaluation of GNU Radio Platform Enhanced for Hardware Accelerated Radio Design

Karve, Mrudula Prabhakar 05 January 2011 (has links)
The advent of software radio technology has enabled radio developers to design and implement radios with great ease and flexibility. Software radios are effective in experimentation and development of radio designs. However, they have limitations when it comes to high-speed, high-throughput designs. This limitation can be overcome by introducing a hardware element to the software radio platform. Enhancing GNU Radio for Hardware Accelerated Radio Design project implements such a scheme by augmenting an FPGA co-processor to a conventional GNU Radio flow. In this thesis, this novel platform is evaluated in terms of performance of a radio design, as well as hardware and software system requirements. A simple and efficient Zigbee receiver design is presented. Implementation of this receiver is used as a proof-of-concept for the effectiveness and design methodology of the modified GNU Radio. This work also proposes a scheme to extend this idea for design of ultra-wideband radio systems based on multiband-OFDM. / Master of Science
83

In vivo- und in vitro-Funktionsanalysen von Bax Inhibitor-1 bei humanen Karzinomzellen / In vivo and in vitro functional analysis of Bax Inhibitor-1 in human carcinoma cells

Kang, Tae-Won 03 May 2007 (has links)
No description available.
84

Nová koncepce zahraniční politiky Korejské republiky po roce 2008: Globální Korea / The New Concept of the Foreign Policy of the Republic of Korea after 2008: Global Korea

Beroun, Vladimír January 2009 (has links)
The thesis deals with a new concept of foreign policy conducted by the President of the Republic of Korea Lee Myung-bak. With special emphasis on the aspects of previous period, the thesis analyzes the formation of the global status of the Republic of Korea in international relations after 2008. Furthermore, it describes the political development of country's international status in its ups and downs and evaluates the causes and consequences of its way to develop international relations. On the level of international system, the thesis interprets in depth selected current international issues in East Asia, relations with neighboring countries as well as economic and cultural issues that directly determine the reconfiguration of existing foreign policy of the Republic of Korea.
85

Mise en place d'une couche physique pour les futurs systèmes de radiocommunications hauts débits UWB (Ultra Wide Band)

Aubert, Louis-Marie 08 November 2005 (has links) (PDF)
L'UWB (Ultra Wide Band) consiste à transmettre des signaux entre 3.1 et 10.6 GHz avec une puissance limitée à -41.3 dBm/MHz. Pour les communications hauts débits (100 à 500 Mbit/s) et courtes portées (1 à 10 m), les solutions de l'état de l'art reposent sur des traitements numériques complexes. Mitsubishi ITE propose une solution alternative multi-bandes (MB) impulsionnelle basée sur un récepteur non-cohérent. La démodulation OOK est effectuée par une détection d'énergie originale avec un seuillage adapté dynamiquement suivant les conditions de propagation. La parallélisation complète de ce système MB-OOK permet à la fois d'éviter les interférences inter-symboles et de récupérer la quasi totalité de l'énergie disponible. En outre, l'approche impulsionnelle limite les évanouissements du signal sur canal multi-trajets. La comparaison des systèmes MB-OOK et MB-OFDM démontre la pertinence de la solution proposée pour des applications très hauts débits, courte portée et faible consommation.
86

Untersuchungen zur Optimierung der Belastungssteuerung im Krafttraining durch Kombination verschiedener Methoden der trainingsbegleitenden Leistungsdiagnostik / Examination of the optimization of the strain diagnostic in weighttraining through combination of different methods of the trainingperformance diagnosis

Lottmann, Amke 03 July 2002 (has links)
No description available.
87

Development of the surface-enhanced infrared spectroscopic approach and surface-enhanced Raman spectroscopy coupled with electrochemistry to study reaction mechanism of membrane proteins / Développement d'approches spectroscopiques infrarouge exaltées de surface et Raman couplée à l'électrochimie pour l'étude du mécanisme réactionnel des protéines membranaires

Grytsyk, Natalia 01 December 2017 (has links)
Cette thèse concerne le développement d’approches spectroscopiques infrarouge et Raman exaltées de surface: la spectroscopie infrarouge exaltée de surface (SEIRAS) combinée avec une cellule de perfusion et la spectroscopie Raman exaltée de surface (SERS) couplée avec l’électrochimie. Dans le cadre du premier projet, différentes protéines ont été étudiées : lactose perméase (LacY), complexe I et IM30. Nous avons déterminé le pKa de Glu325 dans LacY sauvage et dans différents mutants portant des mutations dans le centre actif de translocation des protons. Sauvage complexe I a été oxydé avec différents agents oxydants et réduit avec NADH. Spectres différentiels correspondants ont été analysés. Des changements conformationnels dans la protéine IM30, induits par la présence des ions Mg2+, ont été observés.Dans le cadre du deuxième projet, une cellule spectroélectrochimique contenant une grille d’or a été adaptée pour étudier des protéines redox actives. Cette grille d’or sert à la fois de substrat SERS et d’électrode de travail. Cyt c, Hb et Mb ont d'abord été utilisés pour valider la configuration, puis l'approche a été étendue pour étudier une protéine membranaire. / This thesis concerns the development of surface-enhanced infrared and Raman spectroscopic approaches: surface-enhanced infrared absorption spectroscopy (SEIRAS) combined with perfusion cell and surface-enhanced Raman spectroscopy (SERS) combined with electrochemistry. Within the first project different proteins were studied: Lactose Permease (LacY), complex I and IM30.The pKa of Glu325 in LacY WT and in different mutants carrying mutations in the proton translocation active center was determined. WT complex I was oxidized with different oxidizing agents and reduced with NADH. Corresponding redox-induced conformational changes were studied. The evidence was given that Mg2+ ions induce conformational changes in the protein IM30.Within the second project the spectroelectrochemical cell containing gold grid electrode was adopted for the studies of redox active proteins. This gold grid serves both as working electrode and as SERS active substrate. First Cyt c, Hb and Mb were used to validate the setup and then the approach was extended to study a membrane protein.
88

Avaliação “in vitro” do efeito antitumoral e antiangiogênico de uma metaloprotease isolada da peçonha de Bothrops pauloensis

Guimarães, Denise de Oliveira 16 September 2016 (has links)
O câncer de mama é uma neoplasia altamente maligna e continua a ser a segunda principal causa de mortalidade entre as mulheres. Os efeitos antitumorais de metaloproteinases e desintegrinas de veneno de serpentes têm sido investigados em vários tipos de células tumorais. Neste estudo, foram avaliados os efeitos antitumorais e anti-angiogênicos induzidos pela Bothropoidina, uma metaloproteinase desintegrina-like isolada da peçonha de Bothrops pauloensis em células de câncer de mama humano MDA-MB-231 e células endoteliais. Após 24 horas de tratamento com 100pg/mL de Bothropoidina foi constatado um efeito citotóxico moderado de 30% em MDA-MB-231 contra 10% de citotoxicidade em MCF10A (uma linha de células da mama não tumorigênica), uma diferença significativa que sugere uma possível preferência desta proteína por alvos em células tumorais. Observou-se apoptose e apoptose tardia após tratamento com Bothropoidina (10pg/mL e 40pg/mL) em células MDA-MB-231. Além disso, esta toxina não só inibiu a adesão de células MDA-MB-231 de uma forma dose dependente, como a migração celular em aproximadamente 45%. Bothropoidina reduziu a viabilidade e adesão de células endoteliais em Matrigel e inibiu a angiogênese in vitro estimulada por bFGF em Matrigel, mostrando um número de vasos formados significativamente menor em relação ao controle. Os resultados demonstraram que Bothropoidina tem um potente efeito antitumoral e antiangiogênico in vitro, representando uma ferramenta biotecnológica para elucidar o efeito antitumoral de metaloproteinases desintegrinas-like em células cancerígenas. / Breast cancer is a highly malignant carcinoma and remains the second leading cause of mortality among women. The antitumor effects of metalloproteinases and disintegrins from snake venom on various types of cancer cells have been investigated. In this study, we evaluated the antitumor and antiangiogenic effects on MDA-MB-231 human breast cancer cells and endothelial cells induced by Bothropoidin, a disintegrin-like metalloproteinase isolated from Bothrops pauloensis snake venom. At 24h after treatment at 100pg/mL, Bothropoidin exerted a moderate cytotoxic effect of 30% on MDA-MB-231 versus 10% cytotoxicity against MCF10A (a non-tumorigenic breast cell line), a significant difference that suggests a possible preference by this protein for targets in cancer cells. Early and late apoptosis of MDA-MB-231 was observed after Bothropoidin treatment (10gg/mL and 40gg/mL). Furthermore, this toxin inhibited not only the adhesion of MDA-MB-231 cells in a dose-dependent manner but also cell migration by approximately 45%. In addition, Bothropoidin decreased endothelial cells viability and adhesion in Matrigel and inhibited in vitro angiogenesis in Matrigel stimulated by bFGF, showing significantly fewer formed vessels. The results demonstrated that Bothropoidin has potent in vitro antitumor and antiangiogenic effect and represents a biotechnological tool for elucidating the antitumor effect of disintegrins-like metalloproteinases in cancer cells. / Dissertação (Mestrado)
89

Novel variable influence on projection (VIP) methods in OPLS, O2PLS, and OnPLS models for single- and multi-block variable selection : VIPOPLS, VIPO2PLS, and MB-VIOP methods

Galindo-Prieto, Beatriz January 2017 (has links)
Multivariate and multiblock data analysis involves useful methodologies for analyzing large data sets in chemistry, biology, psychology, economics, sensory science, and industrial processes; among these methodologies, partial least squares (PLS) and orthogonal projections to latent structures (OPLS®) have become popular. Due to the increasingly computerized instrumentation, a data set can consist of thousands of input variables which contain latent information valuable for research and industrial purposes. When analyzing a large number of data sets (blocks) simultaneously, the number of variables and underlying connections between them grow very much indeed; at this point, reducing the number of variables keeping high interpretability becomes a much needed strategy. The main direction of research in this thesis is the development of a variable selection method, based on variable influence on projection (VIP), in order to improve the model interpretability of OnPLS models in multiblock data analysis. This new method is called multiblock variable influence on orthogonal projections (MB-VIOP), and its novelty lies in the fact that it is the first multiblock variable selection method for OnPLS models. Several milestones needed to be reached in order to successfully create MB-VIOP. The first milestone was the development of a single-block variable selection method able to handle orthogonal latent variables in OPLS models, i.e. VIP for OPLS (denoted as VIPOPLS or OPLS-VIP in Paper I), which proved to increase the interpretability of PLS and OPLS models, and afterwards, was successfully extended to multivariate time series analysis (MTSA) aiming at process control (Paper II). The second milestone was to develop the first multiblock VIP approach for enhancement of O2PLS® models, i.e. VIPO2PLS for two-block multivariate data analysis (Paper III). And finally, the third milestone and main goal of this thesis, the development of the MB-VIOP algorithm for the improvement of OnPLS model interpretability when analyzing a large number of data sets simultaneously (Paper IV). The results of this thesis, and their enclosed papers, showed that VIPOPLS, VIPO2PLS, and MB-VIOP methods successfully assess the most relevant variables for model interpretation in PLS, OPLS, O2PLS, and OnPLS models. In addition, predictability, robustness, dimensionality reduction, and other variable selection purposes, can be potentially improved/achieved by using these methods.
90

Munksund 5 : En rättsutredning gällande miljöbalkens efterbehandlingsansvar vid en miljöförorening

Johansson, Malin January 2019 (has links)
Munksund 5 är namnet på en timmerbogseringsbåt som sedan år 1964 ligger under vattenytan i Piteälven. Båten sägs ha förlist med upp emot 6 000 liter tjockolja kvar i tankarna. Det finns idag ingen registrerad ägare till båten. Sommaren 2018 observerades en stor oljefläck i närheten av båtens position. Det bekräftar en miljöförorening men det är fortfarande inte fastställt att oljan kom från Munksund 5. Syftet med denna uppsats har varit att undersöka hur miljöbalken reglerar efterbehandlingsansvaret vid en miljöförorening. Frågeställningarna som väglett arbetet är vad principen om att förorenaren betalar innebär samt vem som kan anses ha avhjälpandeansvaret efter Munksund 5. För att uppfylla syftet med uppsatsen har den rättsdogmatiska metoden använts. Utgångspunkten för metoden är att studera de allmänt accepterade rättskällorna. Av resultatet framgår att det är avgörande om Munksund 5 är att anse som en fristående delverksamhet eller som en integrerad verksamhet med sågverket, för att ansvar ska kunna riktas mot den tidigare verksamhetsutövaren. Det allmänna kommer att få stå för hela, eller stor del, av kostanden för de eventuella efterbehandlingsåtgärderna.

Page generated in 0.0369 seconds