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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.
81

Perfil bioquímico, metabolismo oxidativo e função de polimorfonucleares em equinos alimentados com óleo mineral, de soja, arroz, linhaça ou peixe / Biochemical profile, oxidative metabolism and polymorphonuclear cells function of horses fed with mineral, soybean, ricebran, linseed or fish oils

Weigel, Rebeca Alves 12 May 2014 (has links)
A domesticação dos equinos e a sua utilização para esportes fez com que a nutrição destes animais passasse por mudanças significativas. O alto requerimento energético pode ser suprido com forragem conservada e grandes quantidades de amido. Este manejo, porém, predispõe os equinos a problemas digestivos e metabólicos, podendo levar a cólica, endotoxemia e laminite. Outra forma de atingir o requerimento energético é a adição de gordura na dieta, já que óleos vegetais e animais podem conter até três vezes mais energia que grãos em igual volume. Sabe-se que óleos de diferentes fontes diferem quanto a propriedades relacionadas aos seus componentes ativos; óleos podem conter componentes como ω-3, ω-6, γ-orizanol em diferentes quantidades e estes compostos podem influenciar o metabolismo. O presente estudo teve por objetivo avaliar o efeito de óleos de diferentes origens e composição sobre o metabolismo bioquímico, oxidativo e função de células polimorfonucleares de equinos. Durante 15 semanas foram utilizados cinco equinos machos, mestiços, que receberam ou óleo mineral, ou óleo de soja, ou óleo de arroz, ou óleo de linhaça, ou óleo de peixe, em delineamento experimental quadrado latino 5x5. Cada período experimental foi composto por três semanas. Foram avaliados perfil bioquímico, metabolismo oxidativo e \"burst\"-respiratório de granulócitos. Houve efeito do tratamento sobre os teores de triglicérides, fração HDL de colesterol e hemoglobina, contagem de eritrócitos, hematócrito e na intensidade de produção de EROs por granulócitos estimulados com Sa-PI. Das variáveis do perfil bioquímico, pode-se observar que a adição dos óleos de soja, arroz, linhaça e peixe na dieta reduziu os triglicérides plasmáticos, a inclusão de óleos em até 5% da MS nas dietas não representou grande desafio oxidativo, apenas as concentrações de hemoglobina foram menores no tratamento com óleo de soja. O óleo de linhaça aumentou o teor de ácido linolênico plasmático e teve efeito sobre a produção de EROs in vitro por granulócitos dos equinos. / Sports use made significant changes in horses nutrition necessary. The high energy requirement is supplied with conserved forage, and large amounts of starch. This management, however, predisposes horses to digestive and metabolic disorders, leading to colic endotoxemia and laminitis. Another way to achieve the energy requirement is adding fat to the diet, as vegetable and animal oils may contain up to three times more energy than grains in equal volume. It is known that oils from different sources differ in their active components related properties, thay may contain ω-3, ω-6, γ-oryzanol, in different quantities and these compounds can influence metabolism. The aim of this study was to evaluate the effect of different oils from different origins and composition on the maintenance of the horses biochemical and oxidative metabolism and on polymorphonuclear cells function. A Latin square design was made with five crossbreed horses fed during three weeks with the five treatments: mineral (control), soy, rice, linseed and fish oil. Biochemical profiles, oxidative metabolism respiratory-burst of granulocytes were evaluated. Treatment effect was found on the triglycerides, HDL cholesterol and hemoglobin levels, erythrocyte count, hematocrit and intensity of ROS production by granulocytes stimulated with Sa-PI. Conclusions: The addition of oil to the diet reduced plasma triglycerides, fat diets didnt offer major oxidative challenge and hemoglobin showed to be a more sensitive oxidative marker. Linseed oil increases the plasma levels of linolenic acid and had effects on the production of in vitro ROS by granulocytes of horses.
82

Role of High Mobility Group A2 (HMGA2) in Prostate Cancer

Hawsawi, Ohuod 20 May 2019 (has links)
High mobility group A2 (HMGA2) is a non-histone protein highly expressed during the development but is low or absent in most adult tissues. Epithelial-mesenchymal transition (EMT) plays a critical role in prostate cancer progression and metastasis. HMGA2 has been shown to promote EMT in separate studies. Interestingly, wild-type HMGA2 and truncated (lacking the 3’UTR) HMGA2 isoforms are overexpressed in many cancers. However, there are no studies on the role of each isoform in prostate cancer progression. We hypothesized that wild-type and truncated HMGA2 promotes prostate cancer progression by different mechanisms. We analyzed the expression of HMGA2 in the prostate panel by western blot analysis and the localization in prostate tissue microarray by immunohistochemistry. We stably overexpressed wild-type and truncated HMGA2 cDNA in LNCaP cells and measured the expression and the localization of HMGA2 as well as EMT markers. We also performed the migration and cell viability assays. We analyzed phospho-ERK in cells overexpressing HMGA2 as well as inhibition with U0126 (MAPK inhibitor). To explore the role of truncated HMGA2, we measured the reactive oxygen species (ROS) concentration by DCFDA dye, as well as analyzing Jun-D as a putative downstream effector of HMGA2. Additionally, we knocked down Jun-D and performed the migration and cell viability assays. We treated ARCaP-M mesenchymal cells with camalexin, a 3-thizol-2-yl-indole (a natural product, as a candidate to target HMGA2) in vitro and in vivo in nude mice. Our results showed an increase in nuclear HMGA2 expression with prostate cancer progression as compared to normal tissue. LNCaP cells overexpressing wild-type but not truncated HMGA2 displayed nuclear localization and induced EMT via the ERK1/2 pathway, and this effect could be reversed by treating the cells with U0126. Conversely, truncated HMGA2 displayed cytoplasmic expression and increased prostate cancer migration via increasing Jun-D expression and ROS; this could be antagonized by Jun-D knockdown. Finally, treating ARCaP-M aggressive prostate cancer cells with camalexin reduce its expression in vitro and in vivo. In conclusion, both wild-type and truncated HMGA2 induce prostate cancer progression by different mechanisms which may be targeted by camalexin.
83

MULTI-DRONE CONTROL SYSTEM

Norlin, Simon, Songmahadthai, David January 2019 (has links)
Planning and controlling traffic for multiple drones in a system without intercommunication betweenthe drones is a daunting proposition. This paper presents a thesis work developing a multi-dronecontrol system capable of planning and executing missions in a 3-D aerial space. Generic 2-D pathplanning algorithms are extended into the 3-D space to handle multiple parts of the path planning,creating highways through a gridded area which is used as obstacles for other drones.Three path planning algorithm are compared with other each other wavefront, Astar and po-tential fields, scheduling is also documented to find the optimal drone amount that the system canhandle given an area of interest, this is done to see how often and for how long drones stand idle.Simulations and equations have been implemented to verify and compare results.
84

Development of a fungal virulence assay using <i>Caenorhabditis elegans</i> as a model host to identify mechanisms of host pathogen interactions.

Jain, Charu 23 April 2012 (has links)
Candida albicans is an opportunistic pathogen, which is responsible for causing systemic infection in immunocompromised patients in hospital settings (nosocomial infections). 90% of these nosocomial fungal infections are caused by C. albicans, and the estimated annual cost of treating them exceeds $1 billion per year. Despite this expenditure, there is a high mortality rate of 50%. There are two main routes of infections, first a mucosal infection that can spread and invades deeper into the tissues and gets disseminated into the bloodstream. Second, more frequently seen in hospital settings, is when Candida cells dislodge from a biofilm that has formed on intravenous devices or catheters. Treatment of these diseases is difficult due to a dearth of antifungal drugs and new strategies are required to explore mechanisms used by Candida in causing infection. One way of approaching these significant scientific challenges is to identify virulence determinants and mechanisms, which apart from providing insightful knowledge of fungal pathogenesis, can also be used as targets for antifungal drug development. The innate immune responses in humans, which are important for defense against fungal infections, are conserved in Caenorhabditis elegans. In order to identify Candida virulence factors, I have developed a C. elegans based pathogenesis assay, where nematodes were infected with fungi (both S. cerevisiae and C. albicans) and observed for disease phenotypes including death. This assay can be used to study several aspects of disease progression in worms from swelling (inflammation a bio-marker of infection) to colonization in the intestine, leading to intestinal distension and ultimately death of the host worm. The assay offers a fast and simple way of identifying unknown genes, which when established as a virulence determinant in the worm model, can be further studied in mammalian models. I demonstrate the utility of this assay in multiple ways. First as proof of principle using this assay I have identified a fungal mutant cap1, which is susceptible to reactive oxygen species (ROS), and fails to cause disease, except in bli-3 mutant worms that carry a mutation in an oxidase gene and is responsible for the oxidative stress. Second, we screened a library of ~1200 C. albicans mutants, and identified 7 genes, 3 known (CMP1, IFF11 and SAP 8), validating the assay and 4 novel genes (orf19.1219, orf19.6713, DOT4 and ZCF15) that play a role in fungal infection. Third use of this assay is to test potential drugs in a high throughput fashion. Families of related compounds were identified through a screen of 30,000 compounds, for their ability as potential inhibitors of C. albicans adhesion to biological and inert surfaces. These compounds were further tested in this assay for their ability to reduce infection of C. albicans in worms. The assay provides us with a method to test efficacy of antifungals in vivo. Finally, using the survival assay, a test for mortality caused by infection, we can observe disparity in the different C. albicans fluconazole resistant strains isolated from AIDS patients. In addition this assay after small modification can be potentially employed to screen the C. elegans RNAi library to identify the modulators of innate immune responses during fungal infection.
85

Role of oxidative modifications of LKB1 in promoting myocardial hypertrophy

Calamaras, Timothy Dean 22 January 2016 (has links)
The pathogenesis of heart failure (HF) involves compensatory left ventricular hypertrophy. Reactive oxygen species (ROS) are elevated in HF and mediate myocardial hypertrophy. ROS also mediate formation of lipid peroxidation byproducts, yet little is known about their role in promoting hypertrophy. One lipid peroxidation byproduct, 4-hydroxy-trans-2-nonenal (HNE) is a reactive aldehyde that forms covalent adducts on proteins. HNE levels are also elevated in HF and may mediate hypertrophy via HNE-adduct formation. LKB1 - a tumor suppressor protein - regulates cellular growth through activation of the downstream kinase AMPK. Activation of AMPK suppresses functions that consume ATP and simultaneously activates processes to generate energy. The LKB1 protein is inhibited by oxidants, but whether this results in myocardial hypertrophy is unclear. I hypothesized that HNE can directly promote cardiac hypertrophy via the modification of LKB1. In HEK293T cells I observed that HNE adducts inhibit activity of LKB1 through direct oxidative modification. Mutation of LKB1 Lys-96 or Lys-97 resulted in less HNE-LKB1 adduct formation. Mutation of LKB1 Lys-97 prevented the inhibitory effect of HNE, suggesting that HNE-adduction at this residue is sufficient to inhibit LKB1. In cardiomyocytes HNE inhibited both LKB1 and AMPK, increased phosphorylation of mTOR, p70S6K, and S6K, and increased protein synthesis. HNE also activated Erk1/2, which contributed to S6K activation but was not required for cellular growth. Hypertrophic S6K activation was dependent on mTOR. Mice fed a high-fat high-sucrose (HFHS) diet have myocardial hypertrophy that can be prevented by antioxidants. Hearts of HFHS mice have HNE-LKB1 adducts, inhibited LKB1 activity, yet no change in AMPK activation. Mice lacking aldehyde dehydrogenase 2 (ALDH2), an enzyme involved in HNE detoxification, have increased myocardial hypertrophy when fed HFHS diet yet have increased LKB1 activity. In summary HNE directly causes hypertrophy in cardiomyocytes. This occurs through inhibition of LKB1 and in part through Erk1/2 activation. In HFHS-fed mice HNE-LKB1 adduct formation is associated with decreased LKB1 activity. Impairing detoxification of reactive aldehydes in the ALDH2-KO mice is sufficient to increase myocardial hypertrophy, but this appears to be independent of LKB1. This study demonstrates a novel mechanism of cardiac hypertrophy caused by reactive aldehydes.
86

Role of cytochrome P450 in breast carcinogenesis

Singh, Subir January 2016 (has links)
Cytochrome P450 enzymes (CYP) are key oxidative enzymes that are crucial in several biological processes, such as metabolism of exogenous and endogenous substances, the biological transformation of drugs and xenobiotics and biosynthesis of steroids and fatty acid. Several CYP have been identified in extra hepatic tissues implying that these enzymes exert other biological functions, which might explain their association with a number of diseases including diabetes, obesity and cancer. Understanding of these functions may provide the platform for the development of new therapeutic approaches and this is the aim of this investigation, namely to delineate the role of CYP in breast carcinogenesis. Cancer cells exhibit high levels of glycolysis even in the presence of high oxygen concentration. Cancer cells have very high proliferating rates so they need more biosynthesis materials like nucleic acids, phospholipids, fatty acids and glycolysis is the main source of biosynthetic precursors. Energy metabolism has recently attracted the interest of several laboratories as targeting the pathways for energy production in cancer cells could be an efficient anticancer treatment. Previous studies have shown that reactive oxygen species (ROS) regulate the energy metabolism in cancer cells. CYP are one of the ROS source. Expression of CYP in extrahepatic implies that these enzymes exert other biological functions which have not yet been elucidated. These findings led us to hypothesise that cytochrome P450 enzymes might be involved in the determination of the pathway of cellular energy metabolism in breast cancer cells and in particular in directing tumour cells to produce energy through glycolysis rather than Oxidative phosphorylation (OXPHOS). To investigate the role of CYP in breast carcinogenesis, we followed the protein levels of CYP1B1, CYP1A1, CYP2E1, CYP2C8, CYP2C9 and CYP3A4 in MCF-7 (Michigan Cancer Foundation-7), T47-D, MDA-MB-231 (MD Anderson series 231 cell line) and MDA-MB-468 (MD Anderson series 468 cell line) breast cancer cells treated with glycolytic inhibitors 3-Bromopyruvate and 2-Deoxyglucose (3BP and 2DG). CYP were differentially expressed in breast cancer cells upon treatment with the glycolytic inhibitors (2DG and 3BP) in breast cancer cell lines bearing different genetic background and migratory capacity. The CYP mediated ROS generation was followed in breast cancer cells overexpressing CYP1B1, CYP2C8, CYP2C9 and CYP2E1 or treated with 3BP, 2DG and CYP1B1 specific inhibitor 2,3',4,5'-Tetramethoxystilbene (TMS) by H2DCFDA (2',7'-dichlorodihydrofluorescein diacetate) staining. The functional significance of the CYP1B1, CYP2C8, CYP2C9, CYP2E1 mediated modulation of the cellular redox state was investigated by recording changes of indicators of biological pathways known to be affected by the cellular redox state such as cell cycle, adenosine triphosphate (ATP) level, lactate level, mitochondrial potential, autophagy and endoplasmic reticulum (ER) stress. Furthermore, the effect of CYP1B1 and CYP2E1 induction by their inducers (Benzopyrene and Acetaminophen respectively) and inhibition by their specific inhibitors (TMS and chlormethiazole (CMZ) respectively) on cell survival was investigated. Migratory potential of breast cancer cells was investigated under the treatment of glycolytic inhibitors, CYP1B1 inducer and inhibitors. The results obtained provide evidence that CYP are potentially involved in the regulation of ROS, cell cycle, ATP level, lactate level, mitochondrial potential, autophagy, ER stress and migratory potential in a manner dependent on the genetic background of the cells and the stage of the breast cancer, supporting the notion that CYP are potential breast cancer biomarkers.
87

Síntese e atividade anti-Trichomonas vaginalis de chalconas

Trein, Marcia Rodrigues January 2017 (has links)
Tricomoníase é a doença sexualmente transmissível não-viral mais comum no mundo e pode gerar sérias consequências na saúde reprodutiva, câncer e transmissão e aquisição do HIV. Por esta razão, esta infecção resulta em um pesado fardo para os sistemas de saúde pública. O único tratamento aprovado para esta infecção, que consiste nos 5-nitromidazois metronidazol e tinidazol, apresenta efeitos adversos e há uma subestimada taxa de resistência da infecção, atualmente considerada uma doença negligenciada, a estes fármacos. Portanto, há uma necessidade urgente de novas alternativas terapêuticas para a tricomoníase. Chalconas são uma família de moléculas que apresenta várias aplicações biológicas, como atividade contra diversos patógenos, incluindo protozoários patogênicos. Este trabalho apresenta o potencial anti-Trichomonas vaginalis de derivados de chalcona sintetizados e seus efeitos sobre os trofozoítos. Os valores de IC50 dos compostos mais ativos variaram de 27,5 a 76,4 μM, e as moléculas 4’-hidroxichalcona e 3’-aminochalcona apresentaram os valores mais baixos (27,5 e 28,9 μM). Estes dois compostos foram citotóxicos contra a linhagem de células epiteliais vaginais HMVII, consequentemente apresentaram baixos Índices de Seletividade; contudo, ao se utilizar larvas de Galleria mellonella, como modelo de toxicidade in vivo, não foi observada diminuição da viabilidade após o tratamento. As moléculas também não provocaram hemólise em eritrócitos humanos em 1 e 24 horas. Os compostos não induziram significativa produção de espécies reativas de oxigênio (EROs) nos trofozoítos. Neutrófilos humanos apresentaram aumento na produção de EROs quando coincubados com trofozoítos tratados com os compostos. Os resultados indicam que as chalconas são uma família de moléculas com potencial atividade contra T. vaginalis. / Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer and HIV acquisition. For this reason, this infection results in a heavy burden for public health systems. Current approved treatment, which consists in 5-nitromidazole drugs, metronidazole and tinidazole, present adverse effects and there is underestimate drug resistance data on this parasitic infection, currently considered a neglected disease. Therefore, there is an urgent need for new alternatives for trichomoniasis treatment. Chalcones are a family of molecules that present various biological applications, such as activity against many pathogenic organisms including protozoan pathogens. This study presents the anti-Trichomonas vaginalis potential of synthetized chalcone derivatives and their effects on the trophozoites. IC50 values of the most active compounds ranged from 27.5 to 76.4 μM, and 4’-hydroxychalcone and 3’- aminochalcone presented the lowest values of IC50 (27.5 and 28.9 μM). These two compounds showed cytotoxicity against HMVII vaginal epithelial cells, thus presenting a low Selectivyty Index; however, when Galleria mellonella larvae were used as model for in vivo toxicity no significant decrease in viability after treatment was observed. The chalcones also did not induce hemolysis in human erythrocytes The compounds did not induce significant reactive oxygen species (ROS) production in the trophozoites. Human neutrophils have increased ROS production when exposed to treated trophozoites. Results indicate that chalcones are a family of molecules with potential activity against T. vaginalis.
88

La obra narrativa de Samuel Ros

Prats Meseguer, Alfonso 04 July 2005 (has links)
No description available.
89

Identification And Functional Characterization Of Neuronal Nitric Oxide Synthase In Primary Human Brain Microvascular Endothelial Cells

Unknown Date (has links)
Objectives. Experimental stroke studies have shown that endothelial (eNOS) and neuronal (nNOS) nitric oxide synthase isoforms exhibit opposite effects on brain injury. nNOS has been identified recently in endothelial cells, however, its functional significance is unclear. Our objective was to identify the nNOS in brain microvascular endothelial cells (BMECs) and characterize its functional role. Methods and Results. Primary BMECs from humans (hBMECs) and rats (rBMECs) were used in our studies. Immunocytochemistry identified von Willebrand factor, eNOS, and nNOS in hBMECs. Western blot analysis using antibodies targeting N-terminal domain of nNOS revealed an approximately 130 kD immunoband of a potential nNOS splice variant in hBMECs as opposed to 160 kD nNOS specific immunoband in cultured rat cortical neurons. In contrast, antibodies targeting C-terminal domain of nNOS failed to show nNOS specific immunoband. PCR experiments using the species specific primers identified the mRNA of nNOS in hBMECs. Electron Spin Resonance (ESR) spectroscopy revealed reduction of superoxide levels in hBMECs by two structurally different nNOS inhibitors, (N-ω-Propyl-L-arginine; NPA and ARL-17477), compared with vehicle (ethanol) treated cells. In contrast, treatment with eNOS inhibitor (L-N5-(1-Iminoethyl) ornithine; NIO) significantly enhanced the superoxide levels in hBMECs compared with vehicle (DMSO) treated cells. Supplementation of tetrahydrobiopterin (BH4) resulted in reduced superoxide levels in the hBMECs whereas BH4 co-treatment had no effect on the superoxide levels in the NPA or ARL-17477 treated hBMECs. NO measurements in hBMECs by ESR spectroscopy showed greatly diminished magnitude of the NO signal by the treatment with NIO, compared to vehicle (DMSO) treatment, and whereas, treatment with NPA enhanced NO signal intensity compared to vehicle (ethanol) treated cells. Conclusions. We identified a constitutively active nNOS splice variant in hBMECs that is distinct from the nNOS expressed in neurons. In addition, we found that uncoupled nNOS, significantly contributes to basal superoxide generation in hBMECs that reduces the NO bioavailability. In contrast, eNOS is the only source of NO produced by the hBMECs. We conclude that hBMECs express a unique nNOS isoform distinct from the nNOS expressed in neurons and also exhibiting effects which are distinctly opposite of eNOS. / acase@tulane.edu
90

Användarhantering i ROS

Söderlund, David January 2008 (has links)
<p>Den här rapporten täcker ett examensarbete som gick ut på att kartlägga och utvärdera användarfilosofin i ROS som utvecklas av Sandvik Systems Development. ROS, RåvaruOptimeringsSystem, används som stöd till produktionen på Sandvik AB:s stålverk. Det primära målet som sattes upp för arbetet var att visa om det går att skapa en koppling mellan ROS och Sandviks Active Directory för att på så sätt slippa skilda lösenord mellan systemen. Rapporten följer arbetet från att ta fram modeller av nya metoder för användarhantering till implementering av några prototyper i en testmiljö. Rapporten tar även upp vilka nya metoder och tekniker som måste skapas för att en fullständig implementation av systemlösningen ska kunna göras.</p>

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