410 research outputs found
Antibothropic Action of Camellia sinensis Extract Against the Neuromuscular Blockade by Bothrops jararacussu Snake Venom and Its Main Toxin, Bothropstoxin-I
Detecção e prevalência de rotavírus e astrovírus em manifestações clínicas do trato gastrintestinal
-A gastrenterite é reconhecida pela Organização Mundial de Saúde como um grave problema de saúde pública, que acomete principalmente crianças
nos primeiros anos de vida. A doença é responsável por taxas acentuadas de morbidade em todo o mundo, e esse quadro se agrava nos países em
desenvolvimento, onde a taxa de mortalidade também é elevada. Os vírus são importantes agentes etiológicos da doença diarréica aguda, dentre os
quais encontramos os rotavírus (RTV) e os astrovírus (AstrV). Ambos são transmitidos pela via fecal-oral e causam sintomas como diarréia, vômito,
dor abdominal e febre. Os RTV são responsáveis por 20 a 50% dos casos graves requerem hospitalização de crianças, enquanto os AstrV estão
envolvidos em cerca de 2 a 8% dos casos, acometendo crianças e adultos. O objetivo deste trabalho foi verificar a associação de RTV e AstrV em
casos de doença diarréica infantil aguda, bem como caracterizar as amostras de RTV circulantes em Juiz de Fora. Para tal foram coletados 183
espécimes fecais, provenientes em sua maioria de crianças de 0-5 anos, atendidas nas redes pública e privada de atendimento, entre janeiro de 2007
e setembro de 2008. Suspensões fecais a 10% em tampão Tris-HCl-Ca-, pH 7,2, clarificadas, foram submetidas à técnica de extração do RNA viral. A
triagem das amostras positivas para RTV, bem como a caracterização dos perfis eletroforéticos foi realizada, utilizando-se a técnica de eletroforese
em gel de poliacrilamida (EGPA). A presença de AstrV foi pesquisada em 110 amostras negativas para RTV, através da reação em cadeia da
polimerase, precedida de transcrição reversa (RT-PCR). Das 183 amostras analisadas foram detectadas 13,7% (25/183) de positivas para RTV,
sendo 2,1% (2/96) em 2007 e 26,4% (23/87) em 2008. Em relação aos AstrV foi verificada uma prevalência de 2,7% (3/110) no período estudado,
sendo 2,5% (2/89) em 2007 e 4,8% (1/21) em 2008. A maioria das amostras positivas para RTV e AstrV(60,7% = 17/28) foram detectadas em
crianças com até 36 meses de idade. A análise eletroforética das amostras positivas para RTV, mostrou a presença de perfis curtos e longos,
compatíveis com RTV do grupo A. Em comparação com anos anteriores foi observada uma baixa prevalência de RTV em 2007, o que pode ser uma
conseqüência da incorporação da vacina Rotarix no Calendário Nacional de Vacinação, em março de 2006. A pesquisa de AstrV é pioneira em Juiz
de Fora, e embora a prevalência tenha sido baixa, provavelmente refletindo o pequeno número de amostras analisadas, encontra-se dentro da faixa
preconizada na literatura. A investigação da etiologia das gastrenterites virais e da prevalência dos vírus entéricos associados à doença é
fundamental para a obtenção de dados epidemiológicos que contribuam para o desenvolvimento de estratégias de prevenção, bem como para
estudos de impacto após vacinação da população infantil
Optical Properties And Antiangiogenic Activity Of A Chalcone Derivate
Chalcones and their derivatives exhibit numerous pharmacological activities such as antibacterial, antifungal, cytotoxic, antinociceptive and anti-inflammatory. Recently, they have been assessed aiming for novel application in nonlinear optics and in the treatment of immune diseases and cancers. In this study, we investigate the optical properties of synthetic chalcona 1E,4E-1-(4-chlorophenyl)-5-(2,6,6-trimethylcyclohexen-1-yl)penta-1,4-dien-3-one (CAB7β) and its antiangiogenic potential using the chorioallantoic membrane (CAM) with the S180 sarcoma cell line. Experimental and theoretical results show intense absorption in the UVA-UVC region, which is associated with a π → π* transition with intramolecular charge transfer from the trimethyl-cyclohexen-1-yl ring to the chlorophenyl ring. Quantum chemical calculations of the first hyperpolarizability, accounting for both solvent and frequency dispersion effects, are in very good concordance with hyper-Rayleigh scattering measurements. In addition, two-photon absorption allowed band centered at 650 nm was observed. Concerning antiangiogenic activity, CAB7β causes a significant reduction in the total number, junctions, length and caliber of blood vessels stimulated by S180 cells reducing the presence of blood vessels, inflammatory cells and others elements related to angiogenic process. It is found that CAB7β is a versatile compound and a promising candidate for linear and nonlinear optical applications, in therapy against sarcoma and phototherapy
Investigação de patógenos virais associados à gastrenterite infantil aguda
A gastrenterite de etiologia viral está associada com altas taxas de morbidade, no mundo, sendo nos países em desenvolvimento, responsável também, por altos índices de mortalidade infantil. Este trabalho objetiva detectar a presença de rotavírus, adenovírus e astrovírus em casos de doença diarréica, acompanhar a dinâmica populacional dos rotavírus e avaliar a prevalência e a sazonalidade dessas infecções. A detecção de rotavírus e adenovírus foi realizada através da técnica de ensaio imunoenzimático (EIE). As amostras de rotavírus foram submetidas à eletroforese em gel de poliacrilamida (PAGE) para avaliação dos perfis eletroforéticos e acompanhamento da dinâmica populacional. A detecção de astrovírus foi realizada através da reação em cadeia da polimerase (RT-PCR). Das 338 amostras fecais testadas para rotavírus, foram detectadas 61 positivas (18,04%). A análise eletroforética mostrou a circulação de amostras com perfis característicos de rotavírus do grupo A, todos longos em 2005 e longos e curtos, com predominância dos últimos, em 2006. Das 316 amostras testadas para a presença de adenovírus e das 131 testadas para astrovírus, foram detectadas 17 (5,38%) e 2 (1,53%), respectivamente. Os resultados demonstram a participação destes vírus em casos de gastrenterite infantil e apontam para a importância da continuidade deste estudo
Pan-Atlantic connectivity of marine biogeochemical and ecological processes and the impact of anthropogenic pressures, SO287, 11.12.2021 - 11.01.2022, Las Palmas (Spain) - Guayaquil (Ecuador)
The transit of RV SONNE from Las Palmas (departure: 11.12.2021) to Guayaquil, Ecuador (arrival: 11.01.2022) is directly related to the international collaborative project SO287-CONNECT of GEOMAR in cooperation with Hereon and the University of Bremen, supported by the German Federal Ministry of Education and Research (BMBF) between October 15 2021 and January 15 2024. The research expedition was conducted to decipher the coupling of biogeochemical and ecological processes and their influence on atmospheric chemistry along the transport pathway of water from the upwelling zones off Africa into the Sargasso Sea and further to the Caribbean and the equatorial Pacific. Nutrient-rich water rises from the deep and promotes the growth of plant and animal microorganisms, and fish at the ocean surface off West Africa. The North Equatorial Current water carries the water from the upwelling, which contains large amounts of organic material across the Atlantic to the Caribbean, supporting bacterial activity along the way. But how the nutritious remnants of algae and other substances are processed on their long journey, biochemically transformed, decomposed into nutrients and respired to carbon dioxide, has so far only been partially investigated.
Air, seawater and particles were sampled in order to provide new details about the large cycles of carbon and nitrogen, but also of many other elements such as oxygen, iodine, bromine and sulfur. Inorganic and organic bromine and iodine compounds are generally emitted naturally from the ocean into the atmosphere, promote cloud formation and affect climate, and some even reach the stratosphere where they contribute to ozone depletion. We measured how much of these compounds are released from the ocean, and at what locations and how they are transformed in the ocean and in the atmosphere. Sargassum algae, which have become a nuisance on beaches in the western and eastern Atlantic, support life and contribute to carbon cycling in the middle of the Atlantic, the Sargasso Sea and in the Caribbean, while their contribution to halogen cycling and marine bromine and iodine emissions was previously unknown. We investigated the influence of various natural parameters such as temperature and solar radiation on the biogeochemical transformation processes in order to understand the influence of climate change on these processes in incubation experiments with seawater and algae. We investigated how anthropogenic signals such as shipping traffic influence the nitrogen and sulphur cycle in the ocean, as well as the impact of nitrogen oxides from ship exhaust and sulphurous, acidic and dirty water from purification systems on organisms and biochemical processes. Plastic debris was sampled from the surface waters to investigate its contribution to global biogeochemical transformation processes. The working hypotheses of the research program were:
Bioavailability of dissolved organic carbon in surface waters decreases along the productivity gradient and transport pathway from the Eastern to the Western Tropical North Atlantic.
Nutrient gradients from East to West constrain the microbial utilization of organic matter- contributing to an accumulation of C-rich organic matter due to a) limited mineralization and b) enhanced exudation- also leading to gel-like particles accumulation in the western tropical North Atlantic and Sargasso Sea.
Tropospheric and stratospheric ozone are strongly impacted by biogeochemical and ecological processes occurring around and in the NA gyre system related to marine iodine and bromine cycles.
The long-range transport of natural and anthropogenic organic matter in water and of gases and aerosols in the air impact carbon-export, biogeochemical cycles in the water column, and the release of gases and particles from the ocean significantly.
4 SONNE -Berichte, SO287, Las Palmas - Guayaquil, 11.12.2021 - 11.01.202
The data and samples obtained specifically target carbon, nutrient and halogen cycling, the composition of phytoplankton, bacteria, the transport and sequestration of macro algae and the air-sea exchange processes of climate relevant gases and aerosols. The influence of ecological and transport processes, as well as anthropogenic impacts on the North Atlantic gyre system, specifically in the Sargasso Sea and the influence of ship emissions throughout the Atlantic towards the west and into the Pacific will be investigated with the data
Divulgação científica e o projeto momento ciência
O projeto Momento Ciência tem como propósito tornar o conhecimento cientifico acessível, promovendo a divulgação científica através do contato direto de alunos de ensino médio de escolas públicas do Distrito Federal e alunos recém aprovados, calouros, nos cursos de Ciências Biológicas e de Biotecnologia na Universidade de Brasília (UnB). Esse contato com a comunidade científica ocorre por meio de visitas aos laboratórios acadêmicos do Instituto de Ciências Biológicas (IB) da Universidade de Brasília. O projeto obteve resultados positivos e esperados ao longo da sua execução
The Science Performance of JWST as Characterized in Commissioning
This paper characterizes the actual science performance of the James Webb
Space Telescope (JWST), as determined from the six month commissioning period.
We summarize the performance of the spacecraft, telescope, science instruments,
and ground system, with an emphasis on differences from pre-launch
expectations. Commissioning has made clear that JWST is fully capable of
achieving the discoveries for which it was built. Moreover, almost across the
board, the science performance of JWST is better than expected; in most cases,
JWST will go deeper faster than expected. The telescope and instrument suite
have demonstrated the sensitivity, stability, image quality, and spectral range
that are necessary to transform our understanding of the cosmos through
observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures;
https://iopscience.iop.org/article/10.1088/1538-3873/acb29
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
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