2,986 research outputs found

    Tributyltin and Zebrafish: Swimming in dangerous water

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    Zebrafish has been established as a reliable biological model with important insertion in academy (morphologic, biochemical, and pathophysiological studies) and pharmaceutical industry (toxicology and drug development) due to its molecular complexity and similar systems biology that recapitulate those from other organisms. Considering the toxicological aspects, many efforts using zebrafish models are being done in order to elucidate the effects of endocrine disruptors, and some of them are focused on tributyltin (TBT) and its mechanism of action. TBT is an antifouling agent applied in ship's hull that is constantly released into the water and absorbed by marine organisms, leading to bioaccumulation and biomagnification effects. Thus, several findings of malformations and changes in the normal biochemical and physiologic aspects of these marine animals have been related to TBT contamination. In the present review, we have compiled the most significant studies related to TBT effects in zebrafish, also taking into consideration the effects found in other study models.This study was supported by Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (PP-SUS-FAPERJ E-26/110.282/2014; JCNE-FAPERJ, E-26/201.520/2014; APQ1-FAPERJ, E-26/111.485/2014), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES/Ciências sem Fronteiras/Pesquisador Visitante Especial/88881.062218/2014-0), and Conselho Nacional de Desenvolvimento Científico (CNPq, PQ-Nível 2, 305872/2016-8). Funding was obtained from FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT-Funda??o para a Ci?ncia e a Tecnologia/Minist?rio da Ci?ncia, Tecnologia e Inova??o in the framework of the project "Institute for Research and Innovation in Health Sciences" (POCI-01-0145-FEDER-007274) and by the project "Advancing cancer research: from basic knowledgement to application"; NORTE-01-0145-FEDER-000029; Projetos Estruturados de I&D&I, funded by Norte 2020-Programa Operacional Regional do Norte. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscrip

    Extra polarization states of cosmological gravitational waves in alternative theories of gravity

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    Cosmological Gravitational Waves (GWs) are usually associated with the transverse-traceless part of the metric perturbations in the context of the theory of cosmological perturbations. These modes are just the usual polarizations `+' and `x' which appear in the general relativity theory. However, in the majority of the alternative theories of gravity, GWs can present more than these two polarization states. In this context, the Newman-Penrose formalism is particularly suitable for evaluating the number of non-null GW modes. In the present work we intend to take into account these extra polarization states for cosmological GWs in alternative theories of gravity. As an application, we derive the dynamical equations for cosmological GWs for two specific theories, namely, a general scalar-tensor theory which presents four polarization states and a massive bimetric theory which is in the most general case with six polarization states for GWs. The mathematical tool presented here is quite general, so it can be used to study cosmological perturbations in all metric theories of gravity.Comment: 26 pages, 1 figure. Accepted for publication in Classical and Quantum Gravity

    CrAlSiN barrier layer to improve the thermal stability of W/CrAlSiNx/ CrAlSiOyNx/SiAlOx solar thermal absorber

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    The influence of adding CrAlSiN barrier layer between the back-reflector tungsten (W) and stainless-steel substrate on thermal stability has been investigated. In previous work, after the annealing in vacuum at 600 ºC, tungsten diffusion from the back-reflection layer towards the stainless-steel substrate was found. In this study, a barrier layer was added and its influence upon the W diffusion was studied. Several designs of multilayer solar selective absorber for high temperature applications were used to test the thermal and chemical stability and oxidation resistance after vacuum annealing. These samples were characterized by Scanning Electron Microscopy (SEM), Rutherford Backscattering Spectrometry (RBS), X-ray diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR) and UV–VIS–NIR spectroscopy. All absorber tandems show good thermal stability after vacuum annealing at 600 ºC and the changes in optical constants solar absorptance (α) and thermal emittance (ε) are negligible. In some cases, small changes in the reflectance curves after the first step of annealing were seen. Some changes were found in the oxide layer, due to the incomplete oxidized Si atoms, as confirmed by FTIR analyses. This cannot justify the increase of NIR reflectance observed in the optical stacks after annealing, which can be due to the phase changes of the back-reflector tungsten layer. All layers of stacks are amorphous, except the tungsten layer, which is polycrystalline and shows a columnar growth. The addition of a CrAlSiNP= 0.11 Pa barrier layer between tungsten and stainless-steel substrate proved to be a good solution to control the diffusion of W atoms towards the substrate, whereas using higher nitrogen partial pressure in the high and the low absorption layers reduce the diffusion of Cr from those layers to surface.The authors acknowledge the support of FCT in the framework of the Strategic Funding UID/FIS/04650/2013 and the financial support of FCT, POCI and PORL operational programs through the project POCI01-0145-FEDER-016907 (PTDC/CTM-ENE/2882/2014), co-financed by European community fund FEDER.info:eu-repo/semantics/publishedVersio

    Treatment of class II furcation defects with autogenous bone graft associated with Bichat’s fat pad: case report

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    The periodontal treatment of teeth with furcation defect is clinically challenging. In cases of class II furcation defects, the regenerative surgery shows low morbidity and good prognosis when correctly indicated. The aim of the presentstudy is to report a treatment option for class II furcation defect through autogenous bone graft associated with the Bichat’s fat pad. Case report: A 59-year-old female patient was diagnosed with class II furcation defect in the left mandibular first molar. The treatment comprised surgical reconstruction of the defect with a combination of maxillary tuberosity bone graft and Bichat’s fat pad. The clinical and radiographic follow-up of 180 days showed bone formation inthe furcation area and absence of probing depth. Conclusion: An association of autogenous graft form the maxillary tuberosity with a Bichat’s fat pad proved to be a safe, low cost, and effective therapy for the regenerative treatment of class II furcation.The periodontal treatment of teeth with furcation defect is clinically challenging. In cases of class II furcation defects, the regenerative surgery shows low morbidity and good prognosis when correctly indicated. The aim of the presentstudy is to report a treatment option for class II furcation defect through autogenous bone graft associated with the Bichat’s fat pad. Case report: A 59-year-old female patient was diagnosed with class II furcation defect in the left mandibular first molar. The treatment comprised surgical reconstruction of the defect with a combination of maxillary tuberosity bone graft and Bichat’s fat pad. The clinical and radiographic follow-up of 180 days showed bone formation inthe furcation area and absence of probing depth. Conclusion: An association of autogenous graft form the maxillary tuberosity with a Bichat’s fat pad proved to be a safe, low cost, and effective therapy for the regenerative treatment of class II furcation

    Decoding negative affect personality trait from patterns of brain activation to threat stimuli

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    INTRODUCTION: Pattern recognition analysis (PRA) applied to functional magnetic resonance imaging (fMRI) has been used to decode cognitive processes and identify possible biomarkers for mental illness. In the present study, we investigated whether the positive affect (PA) or negative affect (NA) personality traits could be decoded from patterns of brain activation in response to a human threat using a healthy sample. METHODS: fMRI data from 34 volunteers (15 women) were acquired during a simple motor task while the volunteers viewed a set of threat stimuli that were directed either toward them or away from them and matched neutral pictures. For each participant, contrast images from a General Linear Model (GLM) between the threat versus neutral stimuli defined the spatial patterns used as input to the regression model. We applied a multiple kernel learning (MKL) regression combining information from different brain regions hierarchically in a whole brain model to decode the NA and PA from patterns of brain activation in response to threat stimuli. RESULTS: The MKL model was able to decode NA but not PA from the contrast images between threat stimuli directed away versus neutral with a significance above chance. The correlation and the mean squared error (MSE) between predicted and actual NA were 0.52 (p-value=0.01) and 24.43 (p-value=0.01), respectively. The MKL pattern regression model identified a network with 37 regions that contributed to the predictions. Some of the regions were related to perception (e.g., occipital and temporal regions) while others were related to emotional evaluation (e.g., caudate and prefrontal regions). CONCLUSION: These results suggest that there was an interaction between the individuals' NA and the brain response to the threat stimuli directed away, which enabled the MKL model to decode NA from the brain patterns. To our knowledge, this is the first evidence that PRA can be used to decode a personality trait from patterns of brain activation during emotional contexts

    Evolução das principais doenças em lavouras de cafeeiros no município de Lavras, MG, nos anos agrícolas 2011-2012 e 2012-2013 - Projeto SIMAFF.

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    No Brasil, os órgãos de pesquisa envolvidos com a cultura cafeeira sempre têm procurado investimentos para os avanços tecnológicos para a produção, qualidade e competitividade no mercado nacional e internacional. Nesse sentido, a EMBRAPA/Café vem coordenando um projeto cuja finalidade consiste em realizar o monitoramento agrometeorológico, fenológico e fitossanitário do café arábica nos estados de Minas Gerais, São Paulo e Paraná, sendo que, essas informações serão disponibilizadas via internet no sistema denominado SIMAFF-Café. O SIMAFF-Café terá como principal função subsidiar os cafeicultores e/ou órgãos competentes quanto ao acompanhamento produtivo do cafeeiro, permitindo assim tomar decisões nesse agronegócio. Portanto, várias áreas de lavouras cafeeiras amostrais dos Estados envolvidos estão sendo constantemente monitoradas desde o início do projeto (novembro/2011). Especificamente para Lavras, MG, região Sul do Estado, quanto às doenças do cafeeiro, acompanhou-se, mensalmente, nos anos agrícolas 2011-2012 e 2012-2013, as suas respectivas evoluções para cada ano agrícola na fazenda denominada ?Macaco?. O acompanhamento das possíveis doenças auxilia o produtor na tomada de decisões quanto ao controle e até mesmo no manejo nutricional da lavoura. A escolha dos talhões atendeu à metodologia da Fundação PROCAFÉ sediada em Varginha, MG e adotada como padrão pelo SIMAFF. Foram selecionadas duas variedades Catuaí (CT) e Icatu (IC). No ano 2011-2012 para a ocorrência da ferrugem, em ambas as variedades, o auge da infestação foi entre abril e junho, sendo o CT mais intensamente infestado. Já no ano agrícola 2012-2013 os índices de ferrugem apresentaram valores atípicos para os meses compreendidos entre outubro e maio. Para ambos os anos agrícolas, a infestação por Cercóspora foi mais intensa para a variedade Catuaí, destacando os meses de novembro e dezembro. Quanto ao ataque da Phoma, no ano de 2011-2012, o Icatú atingiu índices de infestação ligeiramente superiores ao Catuaí, sendo que os maiores índices ocorreram entre maio e junho, atingindo até 60 % no IC, espaçamento largo (L) e carga alta (A). Contudo no ano 2012-2013, esse comportamento tendeu a se inverter, sendo que os maiores valores de infestação ocorreram em outubro e entre fevereiro e março

    Monitoramento fenológico do cafeeiro em lavouras de Lavras, MG, nos anos agrícolas 2011-2012 e 2013 - Projeto SIMAFF.

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    No Brasil, os órgãos de pesquisa envolvidos com a cultura cafeeira sempre têm procurado investimentos para os avanços tecnológicos para a produção, qualidade e competitividade no mercado nacional e internacional. Nesse sentido, a EMBRAPA/Café vem coordenando um projeto cuja finalidade consiste em realizar o monitoramento agrometeorológico, fenológico e fitossanitário do café arábica nos estados de Minas Gerais, São Paulo e Paraná, sendo que, estas informações serão disponibilizadas via internet no sistema denominado SIMAFF-Café. O SIMAFF-Café terá como principal função subsidiar os cafeicultores e/ou órgãos competentes quanto ao acompanhamento produtivo do cafeeiro, permitindo assim tomar decisões nesse agronegócio. Portanto, várias áreas de lavouras cafeeiras amostrais dos Estados envolvidos estão sendo constantemente monitoradas desde o início do projeto (novembro/2011). Especificamente para Lavras, MG, região Sul do Estado, quanto à fenologia, acompanhou-se, mensalmente, nos anos agrícolas 2011-2012 e 2012-2013, o crescimento dos internódios plagiotrópicos (produtivos) e seus respectivos enfolhamentos na fazenda ?Macaco?. O crescimento dos internódios e o enfolhamento são variáveis que permitem avaliar as perdas de produtividade pela desfolha e a interrupção do crescimento causada por algum patógeno ou desbalanço nutricional. A escolha dos talhões atendeu à metodologia da Fundação PROCAFÉ sediada em Varginha, MG e adotada como padrão pelo SIMAFF. O crescimento internodal foi determinado em média por talhão, e o enfolhamento pelo número de folhas por internódio. De modo geral observando apenas as variedades, o Icatu teve maior enfolhamento nos dois anos agrícolas com decréscimo para o final do ano produtivo. Para cultivos adensados e de carga alta o Catuaí, com base nos anos agrícolas estudados, possui menores índices de enfolhamento que o Icatu, ocorrendo isso também em menor grau para os talhões de carga baixa. As médias dos números de nós por ramo do Catuaí foram maiores em 2011/2012 e menores em 2012/2013

    Monitoramento do ataque de pragas em cafeeiros no município de Lavras, MG, nos anos agrícolas 2011-2012 e 2012-2013 - Projeto SIMAFF.

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    No Brasil, os órgãos de pesquisa envolvidos com a cultura cafeeira sempre têm procurado investimentos para os avanços tecnológicos para a produção, qualidade e competitividade no mercado nacional e internacional. Nesse sentido, a EMBRAPA/Café vem coordenando um projeto cuja finalidade consiste em realizar o monitoramento agrometeorológico, fenológico e fitossanitário do café arábica nos estados de Minas Gerais, São Paulo e Paraná, sendo que, essas informações serão disponibilizadas via internet no sistema denominado SIMAFF-Café. O SIMAFF-Café terá como principal função subsidiar os cafeicultores e/ou órgãos competentes quanto ao acompanhamento produtivo do cafeeiro, permitindo assim tomar decisões nesse agronegócio. Portanto, várias áreas de lavouras cafeeiras amostrais dos Estados envolvidos estão sendo constantemente monitoradas desde o início do projeto (novembro/2011). Especificamente para Lavras, MG, região Sul do Estado, quanto à ocorrência de pragas do cafeeiro, acompanhou-se, mensalmente, nos anos agrícolas 2011-2012 e 2012-2013, os respectivos ataques do ácaro, bicho mineiro e broca do fruto, para cada ano agrícola na fazenda denominada ?Macaco?. O acompanhamento do ataque de pragas, como também para doenças, auxilia o produtor na tomada de decisões quanto ao controle e até mesmo no manejo nutricional da lavoura. A escolha dos talhões atendeu à metodologia da Fundação PROCAFÉ sediada em Varginha, MG e adotada como padrão pelo SIMAFF. Foram selecionadas duas variedades Catuaí (CT) e Icatu (IC). Não houve diferenças significativas em função do espaçamento e carga nos índices de infestação do bicho mineiro, ácaro e broca. O Catuaí foi mais infestado que o Icatú, com exceção da broca, sendo para o bicho mineiro de 2,73% em 2011/2012 e 2,29% em 2012/2013 no Catuaí contra 2,30% e 1,71% no Icatú, respectivamente. Seguindo a ordem, para o ácaro foi de 2,52% e 1,19% contra 1,88% e 1,04%. Para a broca o Icatú apresentou índice médio superior ao do Catuaí. O número de folhas infestadas apresentou valores abaixo do normal para o bicho mineiro e para o ácaro, somente para a broca os valores foram acima do normal

    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

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    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
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