799 research outputs found
Potenciais evocados motores em cirurgia da aorta toracoabdominal
A patologia aórtica toracoabdominal (aneurisma ou disseção) tem tido uma incidência crescente nas últimas décadas. A
cirurgia é o tratamento curativo, associando-se, porém, a uma elevada morbimortalidade perioperatória. A paraplegia é uma das
mais severas complicações, cuja incidência tem diminuído significativamente com a implementação de estratégias de proteção
medular.
A patologia aórtica toracoabdominal (aneurisma ou disseção) tem tido uma incidência crescente nas últimas décadas. A
cirurgia é o tratamento curativo, associando-se, porém, a uma elevada morbimortalidade perioperatória. A paraplegia é uma das
mais severas complicações, cuja incidência tem diminuído significativamente com a implementação de estratégias de proteção
medular.
Nenhum método isolado ou combinação de métodos provou ser inteiramente eficaz na prevenção da paraplegia. Constituem objectivos desta revisão, uma análise da evidência científica sobre o papel da neuromonitorização intraopera- tória com potenciais evocados motores no prognóstico neurológico de doentes submetidos a cirurgia aórtica toracoabdominal. Procedeu-se a uma pesquisa bibliográfica online (PubMed). As referências consideradas relevantes foram seleccionadas e revistas. A neuromonitorização intraoperatória com potenciais evocados motores (PEM) permite a detecção atempada de eventos isquémicos espinhais e uma intervenção dirigida que impeça o desenvolvimento da lesão medular, reduzindo significativamente a incidência de paraplegia pós-operatória. A monitorização com PEM pode sofrer várias interferências intraoperatórias, com eventual compromisso da sua inter- pretação. O bloqueio neuromuscular é o principal factor limitante de origem anestésica. É essencial atingir um equilíbrio entre as condições de monitorização e as necessidades anestésico-cirúrgicas, bem como avaliar o risco e o benefício da técnica para cada doente. A neuromonitorização com PEM melhora o prognóstico neurológico, desde que integrada numa estratégia de actuação multidisciplinar, que envolva múltiplos mecanismos protectores e que se adeque à realidade hospitalar
On the influence of lipid-induced optical anisotropy for the bioimaging of exo- or endocytosis with interference microscopic imaging
Some implementations of interference microscopy imaging use digital holographic measurements of complex scattered fields to reconstruct three-dimensional refractive index maps of weakly scattering, semi-transparent objects, frequently encountered in biological investigations. Reconstruction occurs through application of the object scattering potential which assumes an isotropic refractive index throughout the object. Here, we demonstrate that this assumption can in some circumstances be invalid for biological imaging due to the presence of lipid-induced optical anisotropy. We show that the nanoscale organization of lipids in the observation of cellular endocytosis with polarized light induces a significant change in far-field scattering. We obtain this result by presenting a general solution to Maxwell's equations describing light scattering of core-shell particles near an isotropic substrate covered with an anisotropic thin film. This solution is based on an extension of the Bobbert-Vlieger solution for particle scattering near a substrate delivering an exact solution to the scattering problem in the near field as well as far field. By applying this solution to study light scattering by a lipid vesicle near a lipid bilayer, whereby the lipids are represented through a biaxial optical model, we conclude through ellipsometry concepts that effective amounts of lipid-induced optical anisotropy significantly alter far-field optical scattering in respect to an equivalent optical model that neglects the presence of optical anisotropy
Freeze-dried jaboticaba peel powder rich in anthocyanins did not reduce weight gain and lipid content in mice and rats
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Jaboticaba, a native fruit from Brazilian Atlantic Forest, is an important source of anthocyanins. Anthocyanins have been recently identified as modulators of lipid metabolism and energy expenditure 'in vivo'. The purpose of this study was to evaluate the effect of the freeze-dried jaboticaba peel powder on obesity treatment in different experimental models. Obese Swiss mice and obese Sprague-Dawley rats were fed a high-fat diet supplemented with 1, 2 and 4% freeze-dried jaboticaba peel powder for 6 weeks. Energy intake, weight gain and body composition were determined, and the results were analyzed using variance and Tukey's tests (p<0.05). The energy intake was higher in mice groups supplemented with 2% and 4% of jaboticaba peel. In relation to weight gain, the mice supplemented with 2% of jaboticaba peel had higher total weight gain than the other experimental groups, while no significant difference in the fat mass accumulation was observed among the groups. The rats did not show significant differences in the evaluated parameters. These results suggest that the supplementation with freeze-dried jaboticaba peel powder, at concentrations of 1, 2 and 4%, was not effective in the reduction of energy intake, weight gain and body fat both in mice and in rats.6213743Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
General Messenger Gauge Mediation
We discuss theories of gauge mediation in which the hidden sector consists of
two subsectors which are weakly coupled to each other. One sector is made up of
messengers and the other breaks supersymmetry. Each sector by itself may be
strongly coupled. We provide a unifying framework for such theories and discuss
their predictions in different settings. We show how this framework
incorporates all known models of messengers. In the case of weakly-coupled
messengers interacting with spurions through the superpotential, we prove that
the sfermion mass-squared is positive, and furthermore, that there is a lower
bound on the ratio of the sfermion mass to the gaugino mass.Comment: 37 pages; minor change
Flavor of quiver-like realizations of effective supersymmetry
We present a class of supersymmetric models which address the flavor puzzle
and have an inverted hierarchy of sfermions. Their construction involves
quiver-like models with link fields in generic representations. The magnitude
of Standard-Model parameters is obtained naturally and a relatively heavy Higgs
boson is allowed without fine tuning. Collider signatures of such models are
possibly within the reach of LHC in the near future.Comment: LaTeX, 17 pages, 3 figures. V2: reference adde
Consensus Document on Coding of Cardiac Magnetic Resonance Examinations in Portugal
Um dos obstáculos a uma utilização mais frequente e apropriada da ressonância
magnética cardíaca (RMC) em Portugal tem sido a ausência de códigos específicos que descrevam adequadamente os exames tal como são efetuados actualmente. Este documento de consenso fornece recomendações para a atualização e uniformização dos códigos empregues na RMC. São igualmente feitas recomendações quanto às técnicas e códigos a utilizar nas indicações clínicas mais frequentes
Covid-19 Dynamic Monitoring and Real-Time Spatio-Temporal Forecasting
Background: Periodically, humanity is often faced with new and emerging viruses that can be a significant global threat. It has already been over a century post—the Spanish Flu pandemic, and we are witnessing a new type of coronavirus, the SARS-CoV-2, which is responsible for Covid-19. It emerged from the city of Wuhan (China) in December 2019, and within a few months, the virus propagated itself globally now resulting more than 50 million cases with over 1 million deaths. The high infection rates coupled with dynamic population movement demands for tools, especially within a Brazilian context, that will support health managers to develop policies for controlling and combating the new virus. /
Methods: In this work, we propose a tool for real-time spatio-temporal analysis using a machine learning approach. The COVID-SGIS system brings together routinely collected health data on Covid-19 distributed across public health systems in Brazil, as well as taking to under consideration the geographic and time-dependent features of Covid-19 so as to make spatio-temporal predictions. The data are sub-divided by federative unit and municipality. In our case study, we made spatio-temporal predictions of the distribution of cases and deaths in Brazil and in each federative unit. Four regression methods were investigated: linear regression, support vector machines (polynomial kernels and RBF), multilayer perceptrons, and random forests. We use the percentage RMSE and the correlation coefficient as quality metrics. /
Results: For qualitative evaluation, we made spatio-temporal predictions for the period from 25 to 27 May 2020. Considering qualitatively and quantitatively the case of the State of Pernambuco and Brazil as a whole, linear regression presented the best prediction results (thematic maps with good data distribution, correlation coefficient >0.99 and RMSE (%) <4% for Pernambuco and around 5% for Brazil) with low training time: [0.00; 0.04 ms], CI 95%. /
Conclusion: Spatio-temporal analysis provided a broader assessment of those in the regions where the accumulated confirmed cases of Covid-19 were concentrated. It was possible to differentiate in the thematic maps the regions with the highest concentration of cases from the regions with low concentration and regions in the transition range. This approach is fundamental to support health managers and epidemiologists to elaborate policies and plans to control the Covid-19 pandemics
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Gut microbiota modulation accounts for the neuroprotective properties of anthocyanins
High-fat (HF) diets are thought to disrupt the profile of the gut microbiota in a manner that may contribute to the neuroinflammation and neurobehavioral changes observed in obesity. Accordingly, we hypothesize that by preventing HF-diet induced dysbiosis it is possible to prevent neuroinflammation and the consequent neurological disorders. Anthocyanins are flavonoids found in berries that exhibit anti-neuroinflammatory properties in the context of obesity. Here, we demonstrate that the blackberry anthocyanin-rich extract (BE) can modulate gut microbiota composition and counteract some of the features of HF-diet induced dysbiosis. In addition, we show that the modifications in gut microbial environment are partially linked with the anti-neuroinflammatory properties of BE. Through fecal metabolome analysis, we unravel the mechanism by which BE participates in the bilateral communication between the gut and the brain. BE alters host tryptophan metabolism, increasing the production of the neuroprotective metabolite kynurenic acid. These findings strongly suggest that dietary manipulation of the gut microbiota with anthocyanins can attenuate the neurologic complications of obesity, thus expanding the classification of psychobiotics to anthocyanins
COVID-SGIS: A Smart Tool for Dynamic Monitoring and Temporal Forecasting of Covid-19
Background: The global burden of the new coronavirus SARS-CoV-2 is increasing at an unprecedented rate. The current spread of Covid-19 in Brazil is problematic causing a huge public health burden to its population and national health-care service. To evaluate strategies for alleviating such problems, it is necessary to forecast the number of cases and deaths in order to aid the stakeholders in the process of making decisions against the disease. We propose a novel system for real-time forecast of the cumulative cases of Covid-19 in Brazil. /
Methods: We developed the novel COVID-SGIS application for the real-time surveillance, forecast and spatial visualization of Covid-19 for Brazil. This system captures routinely reported Covid-19 information from 27 federative units from the Brazil.io database. It utilizes all Covid-19 confirmed case data that have been notified through the National Notification System, from March to May 2020. Time series ARIMA models were integrated for the forecast of cumulative number of Covid-19 cases and deaths. These include 6-days forecasts as graphical outputs for each federative unit in Brazil, separately, with its corresponding 95% CI for statistical significance. In addition, a worst and best scenarios are presented. /
Results: The following federative units (out of 27) were flagged by our ARIMA models showing statistically significant increasing temporal patterns of Covid-19 cases during the specified day-to-day period: Bahia, Maranhão, Piauí, Rio Grande do Norte, Amapá, Rondônia, where their day-to-day forecasts were within the 95% CI limits. Equally, the same findings were observed for Espírito Santo, Minas Gerais, Paraná, and Santa Catarina. The overall percentage error between the forecasted values and the actual values varied between 2.56 and 6.50%. For the days when the forecasts fell outside the forecast interval, the percentage errors in relation to the worst case scenario were below 5%. /
Conclusion: The proposed method for dynamic forecasting may be used to guide social policies and plan direct interventions in a cost-effective, concise, and robust manner. This novel tools can play an important role for guiding the course of action against the Covid-19 pandemic for Brazil and country neighbors in South America
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