19 research outputs found

    Adsorption of mono- and multivalent cat- and anions on DNA molecules

    Get PDF
    Adsorption of monovalent and multivalent cat- and anions on a deoxyribose nucleic acid (DNA) molecule from a salt solution is investigated by computer simulation. The ions are modelled as charged hard spheres, the DNA molecule as a point charge pattern following the double-helical phosphate strands. The geometrical shape of the DNA molecules is modelled on different levels ranging from a simple cylindrical shape to structured models which include the major and minor grooves between the phosphate strands. The densities of the ions adsorbed on the phosphate strands, in the major and in the minor grooves are calculated. First, we find that the adsorption pattern on the DNA surface depends strongly on its geometrical shape: counterions adsorb preferentially along the phosphate strands for a cylindrical model shape, but in the minor groove for a geometrically structured model. Second, we find that an addition of monovalent salt ions results in an increase of the charge density in the minor groove while the total charge density of ions adsorbed in the major groove stays unchanged. The adsorbed ion densities are highly structured along the minor groove while they are almost smeared along the major groove. Furthermore, for a fixed amount of added salt, the major groove cationic charge is independent on the counterion valency. For increasing salt concentration the major groove is neutralized while the total charge adsorbed in the minor groove is constant. DNA overcharging is detected for multivalent salt. Simulations for a larger ion radii, which mimic the effect of the ion hydration, indicate an increased adsorbtion of cations in the major groove.Comment: 34 pages with 14 figure

    Umidade e congelamento de grãos de amaranto e sua capacidade de expansão térmica

    Get PDF
    O objetivo deste trabalho foi avaliar a influĂȘncia do teor de umidade, da temperatura de armazenamento e do momento da hidratação de grĂŁos de amaranto (Amaranthus cruentus L. ) sobre sua capacidade de expansĂŁo tĂ©rmica, bem como comparar as composiçÔes quĂ­micas de grĂŁos crus e pipocados. Os atributos diĂąmetro mĂ©dio ponderado, volume de expansĂŁo, densidade, rendimento, quantidade descartada e tempo de residĂȘncia de grĂŁos da variedade BRS Alegria foram avaliados de acordo com trĂȘs teores de umidade (9,5, 11,5 e 13,5%), duas formas de armazenamento, temperatura ambiente de ±28ÂșC e congelado a -18ÂșC, e dois momentos de hidratação, antes e apĂłs congelamento. Utilizou-se chapa metĂĄlica aquecida a 215ÂșC para pipocar os grĂŁos. GrĂŁos congelados com umidade de 13,5% tiveram maior diĂąmetro mĂ©dio ponderado e volume de expansĂŁo, e menor densidade e tempo de residĂȘncia. A umidade de 13,5% proporcionou os maiores rendimentos e expansĂŁo dos grĂŁos. O armazenamento a -18ÂșC produziu pipocas maiores e mais leves do que em condiçÔes ambientais. As pipocas apresentaram redução nos teores de proteĂ­nas e fibras insolĂșveis e aumento nos de lipĂ­deos e fibras solĂșveis, em relação ao grĂŁo cru. O congelamento dos grĂŁos a -18ÂșC e sua hidratação a 13,5% de umidade favorecem o pipocamento de grĂŁos de amaranto, com produção de pipocas de melhor qualidade

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

    Get PDF
    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Modelagem para a estimativa da orientação de linhas de plantio de cafeeiros Modelling for estimating the orientation of coffee planting rows

    No full text
    A quantidade de radiação solar interceptada por uma cultura Ă© uma importante variĂĄvel meteorolĂłgica que determina o crescimento e o desenvolvimento de uma cultura agrĂ­cola e, dentre os sistemas de produção, a orientação das linhas de plantio poderĂĄ ser um componente bastante relevante quanto Ă  interceptação da radiação solar direta (Rd) em ambas as faces. Portanto, este trabalho propĂ”e como objetivo um modelo para recomendar a orientação adequada das linhas de cafeeiro na implantação, baseando-se naquela a proporcionar uma uniformidade na quantidade de Rd interceptada e acumulada durante o ciclo agrĂ­cola da cultura, em ambas as faces da linha de plantio. Para o teste do modelo, foram coletados dados de produção em uma ĂĄrea experimental de cafĂ© irrigado por pivĂŽ central, na Fazenda SĂŁo ThomĂ©, em Pirapora-MG, em plantas alinhadas nas seguintes orientaçÔes, em relação ao norte geogrĂĄfico, positivo no sentido horĂĄrio e negativo ao contrĂĄrio: -90Âș, -45Âș, 0Âș e 45Âș. Os resultados indicaram que as melhores orientaçÔes para a produtividade foram, sucessivamente, as de -45Âș e 0Âș, enquanto o modelo proposto estimou a orientação de -24Âș 16' como sendo a melhor para o plantio das linhas de cafeeiro.<br>The quantity of solar radiation intercepted by a crop is an important meteorological variable that determines the growth and development of a crop and among the production systems, the orientation of planting rows could be a very important component regarding the interception of direct solar radiation (Rd) on both faces. Thus the objective of this study proposes a model to recommend the adequate orientation of the planting rows of coffee in the deployment, based on that providing uniformity in quantity of intercepted and accumulated Rd during the crop cycle on both faces of the planting row. In order to test the model, production data were collected in an experimental area of the coffee crop irrigated by a center pivot in San ThomĂ© Farm on Pirapora, state of Minas Gerais, Brazil, being this planting rows oriented in relation to geographic north, clockwise positive and negative rather, by 45Âș, -90Âș, -45Âș, and 0Âș. The results indicated that the best orientations for productivity were, successively, the -45 Âș and 0 Âș, while the proposed model estimates the orientation of -24Âș 16' as the best for planting rows of coffee crop
    corecore