Simulations of extensional flow in microrheometric devices

We present a detailed numerical study of the flow of a Newtonian fluid through microrheometric devices featuring a sudden contraction–expansion. This flow configuration is typically used to generate extensional deformations and high strain rates. The excess pressure drop resulting from the converging and diverging flow is an important dynamic measure to quantify if the device is intended to be used as a microfluidic extensional rheometer. To explore this idea, we examine the effect of the contraction length, aspect ratio and Reynolds number on the flow kinematics and resulting pressure field. Analysis of the computed velocity and pressure fields show that, for typical experimental conditions used in microfluidic devices, the steady flow is highly three-dimensional with open spiraling vortical structures in the stagnant corner regions. The numerical simulations of the local kinematics and global pressure drop are in good agreement with experimental results. The device aspect ratio is shown to have a strong impact on the flow and consequently on the excess pressure drop, which is quantified in terms of the dimensionless Couette and Bagley correction factors. We suggest an approach for calculating the Bagley correction which may be especially appropriate for planar microchannels

Acute reversible inactivation of the bed nucleus of stria terminalis induces antidepressant-like effect in the rat forced swimming test

<p>Abstract</p> <p>Background</p> <p>The bed nucleus of stria terminalis (BNST) is a limbic forebrain structure involved in hypothalamo-pituitary-adrenal axis regulation and stress adaptation. Inappropriate adaptation to stress is thought to compromise the organism's coping mechanisms, which have been implicated in the neurobiology of depression. However, the studies aimed at investigating BNST involvement in depression pathophysiology have yielded contradictory results. Therefore, the objective of the present study was to investigate the effects of temporary acute inactivation of synaptic transmission in the BNST by local microinjection of cobalt chloride (CoCl₂) in rats subjected to the forced swimming test (FST).</p> <p>Methods</p> <p>Rats implanted with cannulae aimed at the BNST were submitted to 15 min of forced swimming (pretest). Twenty-four hours later immobility time was registered in a new 5 min forced swimming session (test). Independent groups of rats received bilateral microinjections of CoCl₂(1 mM/100 nL) before or immediately after pretest or before the test session. Additional groups received the same treatment and were submitted to the open field test to control for unspecific effects on locomotor behavior.</p> <p>Results</p> <p>CoCl₂injection into the BNST before either the pretest or test sessions reduced immobility in the FST, suggesting an antidepressant-like effect. No significant effect of CoCl₂was observed when it was injected into the BNST immediately after pretest. In addition, no effect of BNST inactivation was observed in the open field test.</p> <p>Conclusion</p> <p>These results suggest that acute reversible inactivation of synaptic transmission in the BNST facilitates adaptation to stress and induces antidepressant-like effects.</p

Termómetros Clínicos

Na prática clínica, várias decisões relacionadas com o diagnóstico e tratamento resultam da análise dos valores da temperatura corporal, sendo a medição deste parâmetro habitualmente realizada com instrumentos de medição, designados por termómetros clínicos. A correta medição da temperatura corporal assume relevância na prática diária dos cuidados de saúde, sendo um parâmetro regularmente avaliado no diagnóstico e monitorização do estado de saúde de um indivíduo.info:eu-repo/semantics/publishedVersio

Instrumentos de Medição da Pressão Arterial

No setor da saúde, as medições e os instrumentos de medição desempenham um papel fundamental no quotidiano dos cidadãos. Variadíssimas decisões clínicas são fundamentadas por resultados de medições, e suportadas na evidência dos mesmos. Por razões de diversa índole, os resultados obtidos a partir de sistemas de medição podem apresentar variabilidade que conduzem a erros de diagnóstico e de tratamento, comprometendo o rigor da medição e os recursos disponíveis. Neste contexto, o presente trabalho tem como finalidade divulgar conceitos gerais e específicos, aplicados a instrumentos e sistemas de medição, apresentando-se como um documento de consulta e um guia para a implementação de boas práticas no âmbito da Metrologia na Saúde.info:eu-repo/semantics/publishedVersio

d=3 Bosonic Vector Models Coupled to Chern-Simons Gauge Theories

We study three dimensional O(N)_k and U(N)_k Chern-Simons theories coupled to a scalar field in the fundamental representation, in the large N limit. For infinite k this is just the singlet sector of the O(N) (U(N)) vector model, which is conjectured to be dual to Vasiliev's higher spin gravity theory on AdS_4. For large k and N we obtain a parity-breaking deformation of this theory, controlled by the 't Hooft coupling lambda = 4 \pi N / k. For infinite N we argue (and show explicitly at two-loop order) that the theories with finite lambda are conformally invariant, and also have an exactly marginal (\phi^2)^3 deformation. For large but finite N and small 't Hooft coupling lambda, we show that there is still a line of fixed points parameterized by the 't Hooft coupling lambda. We show that, at infinite N, the interacting non-parity-invariant theory with finite lambda has the same spectrum of primary operators as the free theory, consisting of an infinite tower of conserved higher-spin currents and a scalar operator with scaling dimension \Delta=1; however, the correlation functions of these operators do depend on lambda. Our results suggest that there should exist a family of higher spin gravity theories, parameterized by lambda, and continuously connected to Vasiliev's theory. For finite N the higher spin currents are not conserved.Comment: 34 pages, 29 figures. v2: added reference

Antifungal activity of schinol and a new biphenyl compound isolated from Schinus terebinthifolius against the pathogenic fungus Paracoccidioides brasiliensis

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to isolate and identify the antifungal compounds from the extracts of <it>Schinus terebinthifolius </it>(Anacardiaceae) against clinical isolates of the pathogenic fungus <it>Paracoccidioides brasiliensis</it>.</p> <p>Methods</p> <p>The hexane and dichlomethane fractions from leaves and stems of <it>S. terebinthifolius </it>were fractionated using several chromatography techniques to afford four compounds.</p> <p>Results</p> <p>The compounds isolated from <it>S. terebinthifolius </it>were identified as schinol (<b>1</b>), a new biphenyl compound, namely, 4'-ethyl-4-methyl-2,2',6,6'-tetrahydroxy[1,1'-biphenyl]-4,4'-dicarboxylate (<b>2</b>), quercetin (<b>3</b>), and kaempferol (<b>4</b>). Compounds <b>1 </b>and <b>2 </b>were active against different strains of <it>P. brasiliensis</it>, showing a minimal inhibitory concentration value against the isolate Pb B339 of 15.6 μg/ml. The isolate Pb 1578 was more sensitive to compound <b>1 </b>with a MIC value of 7.5 μg/ml. Schinol presented synergistic effect only when combined with itraconazole. The compounds isolated from S. <it>terebinthifolius </it>were not able to inhibit cell wall synthesis or assembly using the sorbitol assay.</p> <p>Conclusion</p> <p>This work reveals for the first time the occurrence of compound <b>2 </b>and discloses activity of compounds <b>1 </b>and <b>2 </b>against several clinical isolates of <it>P. brasiliensi</it>s. These results justify further studies to clarify the mechanisms of action of these compounds.</p

Beneficios en la microbiota intestinal después de la suplementación con inulina y la goma guar parcialmente hidrolizada: un ensayo clínico aleatorizado en mujeres con estreñimiento

Introduction: Prebiotics positively affect gut microbiota composition, thus improving gut function. These properties may be useful for the treatment of constipation.Objectives: This study assessed the tolerance and effectiveness of a prebiotic inulin/partially hydrolyzed guar gum mixture (I-PHGG) for the treatment of constipation in females, as well as its influence on the composition of intestinal microbiota and production of short chain fatty acids.Methods: Our study enrolled 60 constipated female health worker volunteers. Participants reported less than 3 bowel movements per week. Volunteers were randomized to treatment with prebiotic or placebo. Treatment consisted of 3 weeks supplementation with 15 g/d I-PHGG (fiber group) or maltodextrin (placebo group). Abdominal discomfort, flatulence, stool consistency, and bowel movements were evaluated by a recorded daily questionnaire and a weekly interview. Changes in fecal bacterial population and short chain fatty acids were assessed by real-time PCR and gas chromatography, respectively.Results: There was an increased frequency of weekly bowel movements and patient satisfaction in both the fiber and placebo groups with no significant differences. Total Clostridium sp significantly decreased in the fiber group (p = 0.046) and increased in the placebo group (p = 0.047). There were no changes in fecal short chain fatty acid profile.Conclusions: Consumption of I-PHGG produced clinical results comparable to placebo in constipated females, but had additional protective effects on gut rnicrobiota by decreasing the amount of pathological bacteria of the Clostridium genera.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo, Fac Med, Sch Med, Dept Gastroenterol,Surg Gastroenterol Discipline, BR-01246903 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biociences, Santos, BrazilGANEP Nutr Humana, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biociences, Santos, BrazilFAPESP: 07/58600-2Web of Scienc

Using Neural Networks for Relation Extraction from Biomedical Literature

Using different sources of information to support automated extracting of relations between biomedical concepts contributes to the development of our understanding of biological systems. The primary comprehensive source of these relations is biomedical literature. Several relation extraction approaches have been proposed to identify relations between concepts in biomedical literature, namely, using neural networks algorithms. The use of multichannel architectures composed of multiple data representations, as in deep neural networks, is leading to state-of-the-art results. The right combination of data representations can eventually lead us to even higher evaluation scores in relation extraction tasks. Thus, biomedical ontologies play a fundamental role by providing semantic and ancestry information about an entity. The incorporation of biomedical ontologies has already been proved to enhance previous state-of-the-art results.Comment: Artificial Neural Networks book (Springer) - Chapter 1