254 research outputs found

    Solos ferruginosos em áreas de canga, sinclinal do gandarela, quadrilátero ferrífero (MG).

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    O presente trabalho visa contribuir na caracterização de solos relacionados a áreas de canga (ferricrete, ironstone) no Quadrilátero Ferrífero (Minas Gerais, Brasil), para melhor entendimento sobre seus processos de gênese e da dinâmica ambiental desses ecossistemas. A Sinclinal do Gandarela abriga as maiores extensões de canga e ecossistemas relacionados preservados em Minas Gerais, e constitui importante local de recarga dos mananciais que abastecem a Região Metropolitana de Belo Horizonte. Foram descritos, coletados e analisados 6 perfis de solo, sob diferentes fitofisionomias, ocorrendo numa sequência de topos da serra do Gandarela, sobre a mesma litologia (itabiritos da Fm. Cauê - Gr. Itabira). Em laboratório foi separada a fração terra fina (< 2 mm) e quantificados a composição granulométrica, pH em água, complexo sortivo, carbono orgânico, e óxidos de ferro, alumínio e silício pelo ataque sulfúrico. Todos os solos estudados são argilosos, de cores vermelhas, com teores muito elevados de óxidos de ferro indicados pelo ataque sulfúrico, distróficos ou álicos, com altos teores de carbono orgânico, e ocorrência expressiva de concreções ferruginosas na fração grosseira, em geral em proporção superior a 50% em volume. A matéria orgânica constitui elemento chave na manutenção e ciclagem de nutrientes nos ecossistemas relacionados aos solos estudados. Todos os solos estudados são classificados como Oxisols pela Soil Taxonomy, mas de acordo com o Sistema Brasileiro de Classificação de Solos, alguns enquadram-se como Latossolos e outros como Plintossolos. O enquadramento taxonômico segundo critérios atuais do SiBCS restringe sua utilização como estraficador ambiental na realidade estudada

    Produção de frutos de pedra-ume-caá em função de condições meteorológicas em Manaus-AM.

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    O objetivo do presente trabalho foi avaliar o comportamento da produção de frutos de pedra-ume-caá, espécie medicinal amazônica, em função das variações das condições meteorológicas em Manaus-AM

    Cognitive-behavioral treatment with behavioral activation for smokers with depressive symptomatology: Study protocol of a randomized controlled trial

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    Background: Smoking is an important risk factor for mental health-related problems. Numerous studies have supported a bi-directional association between cigarette smoking and depression. Despite the advances in understanding the comorbidity between both problems, the most effective psychological treatment that simultaneously targets smoking and depressive symptomatology remains unclear. The objective of this study is to assess the effectiveness of a cognitive-behavioral intervention for smoking cessation with components of behavioral activation for managing depressed mood. Method: A single blind, three-arm, superiority randomized controlled trial is proposed. Participants will be smokers over 18years old, who smoke at least 8 cigarettes per day. Participants will be randomized to one of three conditions, using a 2:2:1 allocation ratio: 1) standard cognitive-behavioral smoking cessation treatment; 2) standard cognitive-behavioral smoking cessation treatment plus behavioral activation; or 3) a three-month delayed treatment control group. The primary outcome measures will be biochemically verified point-prevalence abstinence (carbon monoxide in expired air) and significant change from baseline in depressive symptoms to the end of treatment, and at the 3-, 6-, and 12-month follow-up. Discussion: This study aims to assess the efficacy of a cognitive-behavioral intervention with behavioral activation components for smoking cessation and depressive symptoms, compared to a standard cognitive-behavioral intervention to quit smoking. As the relation between depressive symptoms, even at subclinical levels, and quitting smoking difficulties is well known, we expect that such intervention will allow obtaining higher abstinence rates, lower relapse rates, and mood improvement. Trial registration:ClinicalTrials.gov: NCT02844595. Retrospectively registered 19th July, 2016. The study started in January 2016, and the recruitment is ongoing

    Compósitos de colagénio/apatite de origem marinha para aplicação em engenharia de tecidos mineralizados

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    Devido ao aumento de lesões associadas ao envelhecimento da população, a regeneração do tecido ósseo tem sido alvo de estudo. Apesar da vasta investigação neste sentido, os auto-enxertos continuam a prevalecer como tratamento de primeira linha, apesar das suas limitações. A extração de compostos de recursos marinhos para uso em abordagens de engenharia de tecidos emerge como uma alternativa promissora para regeneração de lesões ósseas. Neste capítulo apresenta-se um biomaterial promissor para aplicação em engenharia de tecidos duros tendo como base uma estratégia de valorização de sub-produtos marinhos, nomeadamente pele e dentes de tubarão.Os autores agradecem o apoio financeiro recebido da União Europeia através do Programa INTERREG—POCTEP, no âmbito dos Projetos 0687_NOVOMAR_1_P e 0245_IBEROS_1_E, através do Programa de cooperação transnacional Espaço Atlântico, no âmbito do Projeto MARMED (2011-1/164) e através do 7º Programa-Quadro de Investigação e Desenvolvimento Tecnológico (FP7), através do Projeto POLARIS (REGPOT-CT2012-316331). Os autores gostariam de agradecer também ao Centro Tecnológico del Mar (CETMAR, Vigo, Espanha) e COPEMAR SA (Espanha) pelo fornecimento dos subprodutos de tubarão. G.S.D agradece ao Programa Norte2020 (Portugal2020) pela bolsa de doutoramento (NORTE-08-5369-F SE-000044) e R.P. agradece à Fundação para a Ciência e a Tecnologia pelo contrato IF/00347/2015

    Ghrelin requires p53 to stimulate lipid storage in fat and liver

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    Ghrelin, a stomach-derived peptide, stimulates feeding behavior and adiposity. For its orexigenic action, ghrelin triggers a central SIRT1/p53/AMPK pathway. The tumor suppressor p53 also plays an important role in white adipose tissue (WAT), where it is up-regulated in the adipocytes of obese mice. It is not known, however, whether p53 has any role in mediating the peripheral action of ghrelin. In the present study, chronic peripheral ghrelin treatment resulted in increased body weight and fat-mass gain in wild-type mice. Correspondingly, mRNA levels of several adipogenic and fat-storage-promoting enzymes were up-regulated in WAT, whereas hepatic triglyceride content and lipogenic enzymes were also increased in wild-type mice following ghrelin treatment. In contrast, mice lacking p53 failed to respond to ghrelin treatment, with their body weight, fat mass, and adipocyte and hepatic metabolism remaining unchanged. Thus, our results show that p53 is necessary for the actions of ghrelin on WAT and liver, leading to changes in expression levels of lipogenic and adipogenic genes, and modifying body weight

    Marine collagen/apatite composite scaffolds envisaging hard tissue applications

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    The high prevalence of bone defects has become a worldwide problem. Despite the significant amount of research on the subject, the available therapeutic solutions lack efficiency.  Autografts, the most common used approaches to treat bone defects have limitations such as donor site morbidity, pain and lack of donor site. Marine resources emerge as an attractive alternative to extract bioactive compounds for further use in bone tissue engineering approaches. On one hand they can be isolated from by-products, at low costs, creating value from products that are considered waste for the fish transformation industry. One the other hand, religious constraints will be avoided. We isolated two marine origin materials, collagen from shark skin (Prionace glauca) and calcium phosphates from teeth of two different shark species (Prionace glauca and Isurus oxyrinchus), and further proposed to mix them to produce 3D composite structures for hard tissue applications. Two crosslinking agents, EDC/NHS and HMDI, were tested to enhance scaffoldsâ properties, with EDC/NHS resulting in better properties. The characterization of the structures showed that the developed composites could support attachment and proliferation of osteoblast-like cells. A promising scaffold for the engineering of bone tissue is thus proposed, based on a strategy of marine by-products valorisation.This work was funded by INTERREG under the POCTEP Project 0687_NOVOMAR_1_P and the Atlantic Area Transnational Cooperation Programme Project MARMED (2011-1/164), as well as by European Union FP7 under the project POLARIS (REGPOT-CT2012-316331).info:eu-repo/semantics/publishedVersio

    Psychological impact of anti-VEGF treatments for wet macular degeneration-a review.

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    To review the current literature on the psychological impact of anti-VEGF treatments for wet age-related macular degeneration (wAMD), in terms of patients' experiences of receiving these treatments, and the impact of these treatments for patients' mental health and quality of life.We critically analyzed current literature evaluating psychological impact of anti-VEGF treatments for wAMD. Primary searches of PubMed, Science Direct, and Web of Science were conducted in July and August of 2015. We reviewed all papers on the topic published until August 5, 2015.Our literature search found 14 papers addressing the psychological impact of anti-VEGF treatments for wAMD. Results highlighted potential anxieties and experiences of pain caused by receiving regular intravitreal injections. A positive visual outcome of anti-VEGF therapy is associated with positive vision-related QOL outcomes, although such association seems to be dependent on improvements on visual acuity. In the literature reviewed, patients receiving anti-VEGF treatments showed a prevalence rate of depression between 20 and 26 %.Although anti-VEGF treatments can cause some anxiety and being experienced as a stressful event, especially in the beginning of the treatment, preliminary findings suggest a potential benefit for long-term vision-related quality of life. Further longitudinal and qualitative research should bring more evidence on the positive and negative effects of these treatments on patients' long-term mental health

    Experimental characterization and test-beam results of MACACO III Compton camera

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    The IRIS group at IFIC-Valencia is developing a Compton camera prototype with the aim of applying it in hadron therapy treatment monitoring. Recently, a third version of the prototype MACACO (Medical Applications CompAct COmpton camera) has been built. The system is composed of three Lanthanum (III) bromide scintillator crystals coupled to silicon photomultipliers. To improve its performance for the final application, several detectors are tested, two different silicon photomultipliers (25 and 50 um) have been chosen as possible candidates. The 25 up photodetector provided better performance in therms of dynamic range, energy resolution (5.2/ FWHM at 511 keV) and stability with temperature variations. MACACO III has also been tested in the CNA cyclotron (Seville) with 18 MeV proton beam to produce 4.439 MeV gamma rays. Data have been acquired with a graphite target in five different positions at 2.5 nA nominal beam intensity. Images with 4.439 MeV photons have been reconstructed, demonstrating the system capability to reconstruct images at energies relevant for hadron therapy. Moreover, the system has been able to distinguish 1mm displacements in the target position
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