336 research outputs found

    Effect of Lactobacillus plantarum and prebiotics in reduction of aflatoxin B1 in milk

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    The aim of this study was to evaluate the influence of Lactobacillus plantarum isolated and associated with prebiotics (inulin, oligofrutose, β-glucan and polydextrose) on the aflatoxin B1 (AFB1) reduction in artificially contaminated milk.info:eu-repo/semantics/publishedVersio

    Effectiveness of XP-endo finisher in the reduction of bacterial load in oval-shaped root canals

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    This study investigated the effectiveness of XP-Endo Finisher (XPF) associated with XP-Endo Shaper (XPS) or Reciproc Blue (RB) files in reducing bacterial load in oval-shaped root canals (RC) during chemomechanical preparation (CMP) using 0.9% saline solution (NaCl) or 2.5% sodium hypochlorite (NaOCl). Eighty mandibular incisors with single oval-shaped RC were contaminated with Enterococcus faecalis. The teeth were randomly assigned to eight experimental groups (n = 10) according to the CMP, as follows: G1: XPS, G2: XPS + XPF, G3: RB, and G4: RB + XPF. CMP was performed with NaCl or NaOCl. The reduction of bacterial load was assessed by colony-forming unit count before (S1) and after (S2) CMP. Data normality was verified by using Shapiro-Wilk test. ANOVA, Tukey's test, and Bonferroni post-hoc test were used at a 5% significance level. Culturable bacteria were present in all S1 samples (p>0.05). All instrumentation techniques were effective in reducing bacterial load, irrespective of the irrigating solution (p < 0.05). With the use of NaCl, RB was more effective than XPS (p = 0.035). With the use of NaOCl, XPS and RB presented similar effectiveness (p = 0.779). XPF enhanced the bacterial reduction of both systems tested (p < 0.05). The use of NaOCl improved the CMP, irrespective of the instrumentation technique used (p < 0.05). In conclusion, XPS and RB files are effective in reducing bacterial levels in oval-shaped RC. The use of XPF as a method of agitation of the irrigating solution improved the cleaning efficiency of both file systems tested. Mechanical preparation performed with saline solution decreased culturable bacteria from the root canal, but antimicrobial substances such as NaOCl should be used to achieve a significantly better disinfection33CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP308162/2014-5não tem2015/23479-

    Influence of delay between dental bleaching with 35% hydrogen peroxide and orthodontic brackets on the bond strength at the enamel/adhesive interface

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    The aim of this study was to evaluate the influence of waiting time between the bleaching with 35% hydrogen peroxide and orthodontic brackets bonding on shear bond strength (SBS) in enamel. Eighty bovine teeth were randomly divided into four groups (G): G1(negative control) and G2, G3 and G4 (experimental groups). The experimental groups were submitted to bleaching. Prior to orthodontic brackets bonding to enamel the procedure was adopted different waiting times, as follows: G2 (1 day); G3 (7 days) and G4 (14 days). It was performed enamel etching (30s), washing water (30s), application of adhesive system followed by photoactivation (20s). A thin layer of composite resin was placed between the adhesive and the brackets. The applied pressure was measured by tensiometer (300N/40s). The composite resin was light-cured (40s). After 24 hours the shear test was held (0.5mm/min). To compare the SBS it was used ANOVA one-way followed by Tukey test (? = 0.05). The Adhesive Remaining Index (ARI) was analyzed using the Kruskal-Wallis test. The SBS values were significantly lower in G2 (15.51 MPa) and G3 (17.77 MPa) compared to G1 (30.14 MPa) and G4 (28.50 MPa) (p<0.05). The ARI revealed significant difference between the G3 and the other groups (p<0.05). It was concluded that the bond strength in enamel in the interfaces/adhesive system/composite resin/orthodontic brackets was more effective 14 days after the bleaching with 35% hydrogen peroxide

    Current screening methodologies in drug discovery for selected human diseases

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    The increase of many deadly diseases like infections by multidrug-resistant bacteria implies re-inventing the wheel on drug discovery. A better comprehension of the metabolisms and regulation of diseases, the increase in knowledge based on the study of disease-born microorganisms’ genomes, the development of more representative disease models and improvement of techniques, technologies, and computation applied to biology are advances that will foster drug discovery in upcoming years. In this paper, several aspects of current methodologies for drug discovery of antibacterial and antifungals, anti-tropical diseases, antibiofilm and antiquorum sensing, anticancer and neuroprotectors are considered. For drug discovery, two different complementary approaches can be applied: classical pharmacology, also known as phenotypic drug discovery, which is the historical basis of drug discovery, and reverse pharmacology, also designated target-based drug discovery. Screening methods based on phenotypic drug discovery have been used to discover new natural products mainly from terrestrial origin. Examples of the discovery of marine natural products are provided. A section on future trends provides a comprehensive overview on recent advances that will foster the pharmaceutical industry. © 2018 by the authors.Acknowledgments: This work was funded by the H2020-TWINN-2015 project BLUEandGREEN (grant 692419). We acknowledge the FCT Project UID/Multi/04423/2013 and the Interreg Atlantic Area project BLUEHUMAN (EAPA_151/2016) funded by the European Regional Development Fund

    Detection of periodontal pathogens in mothers of preterm birth and/or low weight

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    The present study aims to estimate the possible relationship between periodontal pathogens in the oral cavity and the birth of Preterm Birth (PTB) and/or Low Birth Weight (LBW). It?s a case- control study with the subgengival biofilm samples were collected from four sites up deeper until 48 hours postpartum and were processes by Polymerase Chain Reaction (PCR) for presence the periodontal pathogens Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Treponema denticola (Td),  Tannerella forsythia (Tf) e Aggregatibacter actinomycetemcomitans (Aa). The mothers were divided into case grup (babies weighing < 2500g and/or gestational age < 37 weeks) and control group (babies weighing ? 2500g and gestational age ? 37 weeks). Chi-square test and the measure of association obtained by Odds Ratio (OR) were used to estimate the association between the variables. Microbial analyses results showed no significant association between PTB and LBW with most periodontal pathogens in the oral cavity, even with association with the clinical presence of periodontitis. given the high presence of periodontal pathogens in the biofilm subgengival of recent mothers, it is suggested that the findings of this research serve as the basis for future studies on the pathophysiology involved in the relationship between periodontitis and PTB and/or LBW

    The effect of age and selenium on some biochemical parameters in rat liver

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    Two age groups, 3 and 15 mo, were used to investigate whether age-associated changes in some parameters related to lipid peroxidation occur in the liver of male Wistar rats and to observe possible effects of dietary selenium supplementation (0.25 and 0.50 ppm) for 12 mo on the same parameters. At these experimental conditions, the most important observation was that peroxidation did not change by aging, at least until 15 mo of age. In addition, the activity of Sedependent glutathione peroxidase (GSH-Px, EC 1.11.1.9) was higher in the liver of the older animals. It is suggested that the enzyme could have a role in the unchanged hepatic peroxidation observed in aged male rats. On the other hand, an effect of dietary selenium supplementation on those parameters was not observed, probably because the selenium levels were still at an adequate plateau

    As masterclasses internacionais em física de partículas em Portugal

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    Todos os anos, desde 2005, institutos de investigação e universidades de todo o mundo convidam estudantes do ensino secundário a experimentar a linha da frente da investigação fundamental. São as Masterclasses Internacionais em Física de Partículas, um programa do International Particle Physics Outreach Group (IPPOG) que oferece aos estudantes a oportunidade de serem cientistas por um dia, analisando dados reais recolhidos no acelerador LHC (Large Hadron Collider) do CERN, o Centro Europeu de Física de Partículas. Em 2015, participaram nas Masterclasses estudantes de 42 países, recebidos em 210 universidades e laboratórios. A participação de países de todo o mundo reflete a internacionalização das colaborações em Física de Partículas. Os estudantes vivenciam este aspeto na videoconferência com que terminam o seu dia de pesquisa, apresentando os resultados aos participantes de outros países, com a moderação de cientistas no CERN. Portugal participa desde a primeira edição, com a colaboração do LIP - Laboratório de Instrumentação e Física Experimental de Partículas, promotor nacional da atividade, e o apoio da Agência Ciência Viva. Em 2014, cerca de dois mil estudantes e centena e meia de professores participaram nas Masterclasses organizadas em 13 instituições do ensino superior um pouco por todo o País: de Faro a Braga e de Bragança a Ponta Delgada, passando por Beja, Évora, Lisboa, Covilhã, Coimbra, Aveiro, Porto e Vila Real. Foi ainda prestado apoio à realização das Masterclasses na Universidade de São Tomé e Príncipe. A dimensão e o sucesso das Masterclasses em Portugal não são a regra na generalidade dos países europeus, tendo-se notado um crescimento acentuado desde o inicio da realização de Escola de Física no CERN para professores em língua portuguesa. Nos últimos anos, verifica-se que cerca de 20% dos participantes nas Masterclasses são portugueses. Além da aquisição de conhecimentos ou da perceçâo do fascínio da investigação fundamental, aspetos como a cooperação internacional na ciência, a comunicação entre cientistas de diferentes línguas e culturas, ou a estreita relação de interdependência entre ciência fundamental e tecnologia, que o CERN tão bem representa, são aprendizagens a valorizar. Neste contexto, importa hoje sobretudo refletir sobre as formas de maximizar o ganho para todos os participantes

    A model for preservation of thymocyte-depleted thymus

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    DiGeorge syndrome is a disorder caused by a microdeletion on the long arm of chromosome 22. Approximately 1% of patients diagnosed with DiGeorge syndrome may have an absence of a functional thymus, which characterizes the complete form of the syndrome. These patients require urgent treatment to reconstitute T cell immunity. Thymus transplantation is a promising investigational procedure for reconstitution of thymic function in infants with congenital athymia. Here, we demonstrate a possible optimization of the preparation of thymus slices for transplantation through prior depletion of thymocytes and leukocyte cell lineages followed by cryopreservation with cryoprotective media (5% dextran FP 40, 5% Me2SO, and 5% FBS) while preserving tissue architecture. Thymus fragments were stored in liquid nitrogen at -196°C for 30 days or one year. The tissue architecture of the fragments was preserved, including the distinction between medullary thymic epithelial cells (TECs), cortical TECs, and Hassall bodies. Moreover, depleted thymus fragments cryopreserved for one year were recolonized by intrathymic injections of 3×106 thymocytes per mL, demonstrating the capability of these fragments to support T cell development. Thus, this technique opens up the possibility of freezing and storing large volumes of thymus tissue for immediate transplantation into patients with DiGeorge syndrome or atypical (Omenn-like) phenotype

    Manejo do dossel vegetativo e seu efeito nos componentes de produção da videira Merlot.

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    A poda verde é uma prática cultural utilizada para melhorar as condições do dossel vegetativo dos vinhedos, visando a favorecer a qualidade da uva e do vinho. Nesse sentido, realizou-se este experimento entre as safras de 1993/1994 e 1996/1997, com diferentes modalidades de poda verde, num vinhedo do cv. Merlot conduzido em latada. Houve 12 tratamentos e três repetições, sendo o delineamento experimental em blocos casualizados. Os tratamentos constituíram-se da testemunha e de 11 diferentes modalidades de poda verde, ou seja, desbrota, desponta e desfolha, algumas delas em diferentes épocas do ciclo vegetativo da videira. O componente principal 1, da análise de componentes principais (ACP) feita em cada ano, separadamente, mostra que o tratamento 10 (desbrota + desponta + desfolha realizada no início da floração, eliminando-se as folhas abaixo dos cachos) discriminou-se nos quatro anos, e os tratamentos 7 (desfolha realizada 21 dias antes da colheita, eliminando-se metade das folhas abaixo dos cachos) e 6 (desfolha realizada 21 dias antes da colheita, eliminando-se as folhas abaixo dos cachos), em três deles; a ACP da média dos quatro anos também evidencia essa discriminação entre eles. Constata-se que o tratamento 10 foi um dos que tiveram intensidade de poda verde mais intensa, caracterizando-se por variáveis indicativas de plantas com vigor e produtividade mais baixos que os demais
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