929 resultados para Xenophanes, approximately 570 B.C.-approximately 478 B.C.
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The author is supported by an NSERC PDF.
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Peer reviewed
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With the increasing fungi resistance compared with existing drugs on the market and the side effects reported by some compounds with antioxidant properties and enzymatic inhibitors, in particular against α-amylase and α-glucosidase, the discovery of new compounds with biological potential, becomes a need. In this context, natural products can be an important source for the discovery of new active molecular architectures. Then, this study aimed to evaluate the antioxidant activity, the enzymatic inhibitory activity of α-amylase and α-glucosidase, the antifungal and cytotoxic activities of ethanolic extract (EE) the leaves of Banisteriopsis argyrophylla (Malpighiaceae) and their fractions, obtained by liquid-liquid extraction using solvents of increasing polarity. The antioxidant activity was evaluated by the free radical DPPH scavenging method (2,2-diphenyl-1-picrylhydrazyl) and the ethyl acetate fractions (FAE) and n-butanol (FB) were the most active, confirmed by the peak current and the oxidation potential obtained by differential pulse voltammetry (DPV). The inhibitory activity of the α-amylase and α-glucosidase was analyzed considering the reactions between substrates α-(2-chloro-4-nitrophenyl)-β-1,4-galactopiranosilmaltoside (Gal-α-G2-CNP) and 4-nitrophenyl-α-D-glucopyranoside (p-NPG), respectively. Initially, it was found that the EE showed considerable activity against α-amylase (EC50 = 2.89±0.1 μg m L–1) compared to the acarbose used as positive control (EC50 = 0.08±0.1 μg mL–1) and that did not showed promising activity against the α-glucosidase. After this observation we evaluated the inhibitory activity of α-amylase fractions, with FAE (EC50 = 2.33±0.1 μg mL–1) and FB (EC50 = 2.57 ± 0.1 μg mL–1) showing the best inhibitions. The antifungal activity was evaluated against Candida species, and the FAE had better antifungal potential (MIC's between 93.75 and 11.72 μg mL–1) compared with amphotericin as positive standard (MIC = 1.00 and 2.00 μg L–1 for C. parapsilosis and C. krusei used as controls, respectively). The EE (CC50 = 360.00 ± 12 μg mL–1) and fractions (CC50's> 270.00 μg mL–1) were considerably less toxic to Vero cells than the cisplatin used as positive control (CC50 = 7.01 ± 0 6 μg mL–1). The FAE showed the best results for the activities studied, this fraction was submitted to ultra performance liquid chromatography coupled with mass spectrometry (UPLC-MS)), and the following flavonoids have been identified: (±)-catechin, quercetin-3-O-β-D-Glc/ quercetin-3-O-β-D-Gal, quercetin-3-O-β-L-Ara, quercetin-3-O-β-D-Xyl, quercetin-3-O-α-L-Rha, kaempferol-3-O-α-L-Rha, quercetin-3-O-(2''-galoil)-α-L-Rha, quercetin-3-O-(3''-galoil)-α-L-Rha and kaempferol-3-O-(3''-galoil)-α-L-Rha,. FAE was submitted to column chromatography using C18 phase, and (±)-catechin was isolated (FAE-A1, 73 mg) and three fractions consisting of a mixture of flavonoids were obtained (FAE-A2, FAE-A3 and FAE-A4). These compounds were identified by thin layer chromatography (TLC) and (–)-ESI-MS. The (±)-catechin fraction showed an MIC = 2.83 μg ml–1 in assay using C. glabrata, with amphotericin as positive control. The fractions FAE-A2, FAE-A3, FAE-A4, showed less antifungal potential in tested concentrations. The identified flavonoids are described in the literature, regarding their antioxidant capacity and (±)-catechin, quercetin-3-O-Rha and kaempferol-3-O-Rha are described as α-amylase inhibitors. Thus, B. argyrophylla is an important species that produces compounds with antioxidant potential that can be related to the traditional use as anti-inflammatory and also has antifungal compounds and inhibitors of α-amylase. Therefore, these leaves are promising resources for the production of new drugs.
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General note: Title and date provided by Bettye Lane.
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General note: Title and date provided by Bettye Lane.
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Contains songs, partly from English operas, and instrumental music.
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Diese Bachelorarbeit zeigt durch eine gezielte experimentelle Untersuchung Verbesserungsmöglichkeiten zur Dekontamination Verletzter bei chemischen, biologischen, radiologischen und nuklearen Gefahrenlagen am Beispiel des Abrollbehälters-Verletztendekontamination (AB-V Dekon) der Feuerwehr Braunschweig auf. Zusätzlich zur Analyse der aktuellen Gefährdungslage in Deutschland und einem internationalen Vergleich der Dekontaminationsmethoden werden ausgewählte Konzepte vorgestellt und hinsichtlich ihrer praktischen Anwendbarkeit bewertet. Auf Basis des Rahmenkonzeptes zur Dekontamination Verletzter wurde ein Versuchsaufbau zur Verletztendekontamination entwickelt, in dem 24 Probanden mit einer fluoreszierenden Simulationssubstanz vorbereitet und anschließend durch Einsatzkräfte dekontaminiert wurden. Die Bestimmung der Kontaminationen erfolgte dabei digital mittels eines bildgebenden Verfahrens. Im Fokus des Experimentes liegt insbesondere die Untersuchung und Optimierung der Effektivität des Prozesses sowie eine kritische Auseinandersetzung mit der derzeit empfohlenen Wassertemperatur von 28°C. Hierzu wurde das persönliche Empfinden der Probanden mittels eines Fragebogens hinsichtlich einer Erhöhung auf 35°C analysiert und eine Aufzeichnung der Körpertemperatur vorgenommen. Aus den gewonnenen Ergebnissen werden Handlungsempfehlungen entwickelt, die für die Aus- und Fortbildung der Hilfsorganisationenverwendet werden können und zu einer ganzheitlichen Verbesserung der Verletzendekontamination beitragen sollen.
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Background and aims: The prevalence of anti-HCV and HBsAg in Portugal has been shown to be elevated in high-risk groups, such as intravenous drug-users and incarcerated individuals. However, in the general population, prevalence remains largely unknown. The aims of this study were to estimate the prevalence of anti-HCV and HBsAg in the general Portuguese population and identify associated risk factors. Materials and methods: We carried out a nationwide, population-based cross-sectional study of adults resident in mainland Portugal. Serology for HBsAg, anti-HBc, anti-HBs, and anti-HCV was performed. Anti-HCV-positive individuals were tested for HCV RNA by PCR. Results: Of 1685 participants, 50.6% were men, mean age 50.2±18.3 years. In terms of hepatitis C, the prevalence of anti-HCV was 0.54% [95% confidence interval (CI): 0.2–0.9] and 0.12% (95% CI: 0.0–0.3) were viremic, with peak prevalence among individuals 35–64 years of age (0.8%), men (0.8%), and individuals from Lisbon and Tagus Valley region (1.9%). In terms of hepatitis B, the estimated prevalence of HBsAg was 1.45% (95% CI: 0.9–2.0). A higher prevalence was found in individuals who were 35–64 years old (2.2%), in men (2.5%), and in the Northern region (2.6%). The presence of positive serological markers of hepatitis C virus and hepatitis B virus infection did not correlate with elevated aminotransferases, race, place of birth, and alcohol consumption. Conclusion: These results suggest a low endemicity for both hepatitis B and hepatitis C in the general population, in contrast to a very high prevalence in risk groups, thus suggesting that targeted screening to high-risk groups may be more cost-effective than general population screening.
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Macroalgas epífitas de Zostera marina L. en Bahía Concepción, B. C. S. México.
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A Gross Motor Function Measure (GMFM) é a medida de ouro para avaliar alterações na função motora ao longo do tempo ou em resposta a uma intervenção em crianças com Paralisia Cerebral (PC) (Russell D. , Rosenbaum, Avery, & Lane, 2002). Uma das barreiras à utilização mais frequente da GMFM é o seu tempo de administração, que dura entre 40 a 60 minutos. Para responder à necessidade de versões mais reduzidas da GMFM mas sem perder o seu carácter discriminativo e altamente sensível à mudança, foram publicadas as versões Gross Motor Function Measure- Item Sets (GMFM-66 IS) e a Gross Motor Function Measure Basal and Ceiling (GMFM-66-B&C), tornando a avaliação da função motora menos morosa, e assim melhorando a sua aplicabilidade. A GMFM-66 IS baseia-se num algoritmo para determinar quais os itens a serem avaliados e a GMFM-66 B&C tem como abordagem os efeitos de chão e teto de acordo com as idades e níveis do Sistema de Classificação da Função Motora Grosseira (SCFMG) (Brutton & Bartlett, 2011). O objetivo deste estudo foi criar as versões portuguesas da GMFM-IS e GMFM-B&C. Tratou-se de um estudo de natureza metodológica, descritivo, longitudinal em crianças com PC, dividido em duas fases: 1. Tradução e adaptação cultural e linguística da GMFM-66 IS e da GMFM-66 B&C; 2. Estudo de validação com análise da fiabilidade (coerência interna, reprodutibilidade e fiabilidade inter-observador), validade e poder de resposta. A amostra em estudo foi constituída por 100 crianças com PC com idades compreendidas entre os 2 e os 12 anos, representativa de todos os 5 níveis do Sistema de Classificação da Função Motora Global. As versões portuguesas da GMFM-66-IS e da GMFM-66-B&C apresentam equivalência conceptual e semântica com as versões originais revelando fácil aplicabilidade. Demonstrou-se que as versões reduzidas portuguesas da GMFM apresentam muito boa consistência interna, com valores globais do Alfa de Cronbach de 0,998, muito boa concordância entre os avaliadores (ICC de 0,998 para a GMFM-66-B&C e de 0,999 para a GMFM-66-IS), e com valores de fiabilidade intra-observador excelentes (ICC de 0,999 para a GMFM-66-B&C e de 1,000 para a GMFM-66-IS). Quanto ao poder de resposta os resultados não foram tão expressivos, provavelmente comprometidos por uma amostra demasiado pequena. As versões portuguesas da GMFM-66-IS e da GMFM-66-B&C revelaram ter características psicométricas adequadas à sua aplicação em PC, necessitando, no entanto, de mais investigação relativamente à sua capacidade de detetar mudança como resultado de intervenções.
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La leucémie lymphoblastique aiguë (LLA) représente environ 25% des cancers pédiatriques diagnostiqués chaque année. Dans 80 % des cas, une rémission complète est observée. Cependant, les patients résistants aux traitements ainsi que les patients en rechute présentent un mauvais pronostique. Les altérations épigénétiques sont des facteurs essentiels dans le développement et la progression de la maladie, ainsi qu’à la résistance aux traitements. Lors d’un criblage de médicaments approuvés par la FDA, nous avons découvert des molécules ayant des caractéristiques anticancéreux et épigénétiques. Pour évaluer l’activité de ces molécules, nous avons procédé à un criblage secondaire sur plusieurs lignées cellulaires leucémiques. Nous avons découvert qu’une de ces molécules, un glucoside cardiotonique appelé la proscillaridine A, avait une activité anticancéreuse spécifique pour des cellules leucémiques. Nous faisons donc l’hypothèse que la proscillaridine A pourrait avoir des effets épigénétiques et anticancéreux dans des modèles précliniques de LLA. Pour tester cette hypothèse, nous avons traité deux lignées cellulaires de LLA Nalm-6 (LLA pre-B) et Molt-4 (T-LLA) in vitro pendant 2 à 96 heures à des doses pertinentes sur le plan clinique. Nous avons alors pu observer une inhibition de croissance qui était dépendante de la dose administrée dans les deux lignées cellulaires, avec des valeurs de 50% d’inhibition de croissance (CI50) de 3.0 nM pour les Nalm-6 et de et 2.3 nM pour les Molt-4. De plus, nos études sur le cycle cellulaire par BrdU démontrent un arrêt en phase G2/M. Nous avons également détecté par immunobuvardage de type western des baisses significatives de l’acétylation de résidus de l’histone 3. Les niveaux d’expression des enzymes responsables de cette acétylation, les histones acétyltransférases CBP, P300 et TIP60 ainsi que de l’oncogène C-MYC étaient également diminuées. Par des analyses de séquençage de l’ARN, nous avons observé une augmentation de l’expression des gènes impliquées dans les processus d’apoptose et de différentiation cellulaire, ainsi qu’une diminution des gènes impliqués dans la prolifération cellulaire comme en particulier les gènes cibles de C-MYC. Ces résultats prometteurs suggèrent le potentiel prometteur de la proscillaridine A comme nouvelle thérapie pour les patients atteints de LLA.