67 research outputs found

    Correlations between distribution coefficients of various biomolecules in different polymer/polymer aqueous two-phase systems

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    Distribution coefficients for a variety of proteins and certain other biomolecules (peptides, amino acids, and carbohydrates) (overall 27 different solutes) were measured in aqueous two-phase systems (ATPSs) dextran (Dex)–polyethylene glycol (PEG) and Dex–Ucon 50-HB-5100 (Ucon—a random copolymer of ethylene glycol and propylene glycol) both containing 0.15MNaCl in 0.01Mphosphate buffer, pH 7.4, at 23 ◦C. Distribution coefficients of some selected solutes were also measured in the above two-phase systems at three different polymer concentrations for each system. It was established that the distribution coefficients for all the proteins examined in the ATPSs are correlated according to the so-called Collander linear equation.Fundação para a Ciência e a Tecnologia (FCT)FEDE

    “On the collander equation”: protein partitioning in polymer/polymer aqueous two-phase systems

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    Distribution coefficients of randomly selected proteins were measured in aqueous two-phase systems (ATPSs) formed by different combinations of Dextran-75 (Dex), Ficoll-70, polyethylene glycol-8000 (PEG), hydroxypropyl starch-100 (PES), and Ucon50HB5100 (Ucon, a random copolymer of ethylene glycol and propylene glycol) at particular polymer concentrations, all containing 0.15 M NaCl in 0.01 M phosphate buffer, pH 7.4. Most of the proteins in the PEG-Ucon system precipitated at the interface. In the other ATPSs, namely, PES-PEG, PES-Ucon, Ficoll-PEG, Ficoll-Ucon, and in Dex-PEG and Dex-Ucon described earlier the distribution coefficients for the proteins were correlated according to the solvent regression equation: ln Ki = aio ln Ko + bio, where Ki and Ko are the distribution coefficients for any protein in the ith and oth two-phase systems. Coefficients aio and bio are constants, the values of which depend upon the particular compositions of the two-phase systems under comparison.Fundo Europeu de Desenvolvimento Regional (FEDER)Fundação para a Ciência e a Tecnologia (FCT

    EFFECT OF WOOD CARBONIZATION IN THE ANATOMICAL STRUCTURE AND DENSITY OF CHARCOAL FROM Eucalyptus

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    O presente trabalho objetivou avaliar as modifica\ue7\uf5es anat\uf4micas que ocorrem com a carboniza\ue7\ue3o da madeira e determinar as propriedades anat\uf4micas, densidade b\ue1sica da madeira e densidade aparente do carv\ue3o vegetal de clones de Eucalyptus , al\ue9m de elucidar as poss\uedveis correla\ue7\uf5es significativas existentes. A microscopia eletr\uf4nica de varredura foi efetuada nas se\ue7\uf5es transversal, longitudinal tangencial e longitudinal radial da madeira e do carv\ue3o vegetal. Neste, foi feita a an\ue1lise morfol\uf3gica dos poros e densidade aparente. De uma forma geral, as caracter\uedsticas anat\uf4micas como forma de poros, raios e fibras da madeira apresentaram pouca ou nenhuma modifica\ue7\ue3o devido \ue0 carboniza\ue7\ue3o, e a superf\uedcie do carv\ue3o apresentou estruturas bem definidas. As modifica\ue7\uf5es nos elementos celulares da madeira foram principalmente referentes aos par\ue2metros quantitativos, como espessura da parede das fibras e di\ue2metro dos poros. Os clones avaliados apresentaram densidade b\ue1sica da madeira satisfat\uf3ria para a produ\ue7\ue3o de carv\ue3o vegetal. Os par\ue2metros anat\uf4micos correlacionaram-se significativamente com a densidade b\ue1sica da madeira e densidade aparente do carv\ue3o vegetal, destacando-se, neste estudo, a fra\ue7\ue3o parede das fibras.This study aimed to evaluate the anatomical changes that occur with charred wood and determine the anatomical properties, basic wood density and apparent density of charcoal Eucalyptus clones, besides elucidating the possible existing significant correlations. The scanning electron microscopy was performed in the transverse, longitudinal and tangential longitudinal and radial wood charcoal sections. In the morphological analysis of the pores and the apparent density was made. In general, the anatomical features such as pore radius and the wood fibers showed little or no change due to carbonization of coal surface and showed well defined structures. The changes in cellular elements of wood were mainly related to the quantitative parameters such as wall thickness and pore diameter fibers. The clones showed satisfactory basic density of wood for charcoal production. The anatomical parameters were significantly correlated with basic wood density and apparent density of charcoal, especially, in this study, the fraction of the fiber wall

    Induction of chronic non-inflammatory widespread pain increases cardiac sympathetic modulation in rats

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    Fibromyalgia (FM) is characterized by chronic non-inflammatory widespread pain (CWP) and changes in sympathetic function. In attempt to elucidate the pathophysiological mechanisms of FM we used a well-established CWP animal model. We aimed to evaluate changes in cardiac autonomic balance and baroreflex function in response to CWP induction in rats. CWP was induced by two injections of acidic saline (pH 4.0, n = 8) five days apart into the left gastrocnemius muscle. Control animals were injected twice with normal saline (pH 7.2, n = 6). One day after the second injection of acidic saline or normal saline, the animals had pulse interval (PI) and systolic arterial pressure (SAP) variability, and spontaneous baroreflex sensitivity (BRS) evaluated. After induction of CWP, there was an increase of power in the low frequency (LF) band of PI spectrum (12.75 +/- 1.04 nu), a decrease in the high frequency (HF) band (87.25 +/- 1.04 nu) and an increase of LF/HF ratio (0.16 +/- 0.01), when compared to control animals (7.83 +/- 1.13 nu LF; 92.16 +/- 1.13 nu HF; 0.08 +/- 0.01 LF/HF). In addition, there was an increase of power in the LF band of SAP spectrum (7.93 +/- 1.39 mmHg(2)) when compared to control animals (2.97 +/- 0.61 mmHg(2)). BRS was lower in acidic saline injected rats (0.59 +/- 0.06 ms/mmHg) when compared to control animals (0.71 +/- 0.03 ms/mmHg). Our results showed that induction of CWP in rats shifts cardiac sympathovagal balance towards sympathetic predominance and decreases BRS. These data corroborate findings in humans with FM. (C) 2011 Elsevier B.V. All rights reserved

    Mycobacterium tuberculosis lineage 4 comprises globally distributed and geographically restricted sublineages

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    Generalist and specialist species differ in the breadth of their ecological niches. Little is known about the niche width of obligate human pathogens. Here we analyzed a global collection of Mycobacterium tuberculosis lineage 4 clinical isolates, the most geographically widespread cause of human tuberculosis. We show that lineage 4 comprises globally distributed and geographically restricted sublineages, suggesting a distinction between generalists and specialists. Population genomic analyses showed that, whereas the majority of human T cell epitopes were conserved in all sublineages, the proportion of variable epitopes was higher in generalists. Our data further support a European origin for the most common generalist sublineage. Hence, the global success of lineage 4 reflects distinct strategies adopted by different sublineages and the influence of human migration.We thank S. Lecher, S. Li and J. Zallet for technical support. Calculations were performed at the sciCORE scientific computing core facility at the University of Basel. This work was supported by the Swiss National Science Foundation (grants 310030_166687 (S.G.) and 320030_153442 (M.E.) and Swiss HIV Cohort Study grant 740 to L.F.), the European Research Council (309540-EVODRTB to S.G.), TB-PAN-NET (FP7-223681 to S.N.), PathoNgenTrace projects (FP7-278864-2 to S.N.), SystemsX.ch (S.G.), the German Center for Infection Research (DZIF; S.N.), the Novartis Foundation (S.G.), the Natural Science Foundation of China (91631301 to Q.G.), and the National Institute of Allergy and Infectious Diseases (5U01-AI069924-05) of the US National Institutes of Health (M.E.)

    Comparative Genomic Analysis of Human Fungal Pathogens Causing Paracoccidioidomycosis

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    Paracoccidioides is a fungal pathogen and the cause of paracoccidioidomycosis, a health-threatening human systemic mycosis endemic to Latin America. Infection by Paracoccidioides, a dimorphic fungus in the order Onygenales, is coupled with a thermally regulated transition from a soil-dwelling filamentous form to a yeast-like pathogenic form. To better understand the genetic basis of growth and pathogenicity in Paracoccidioides, we sequenced the genomes of two strains of Paracoccidioides brasiliensis (Pb03 and Pb18) and one strain of Paracoccidioides lutzii (Pb01). These genomes range in size from 29.1 Mb to 32.9 Mb and encode 7,610 to 8,130 genes. To enable genetic studies, we mapped 94% of the P. brasiliensis Pb18 assembly onto five chromosomes. We characterized gene family content across Onygenales and related fungi, and within Paracoccidioides we found expansions of the fungal-specific kinase family FunK1. Additionally, the Onygenales have lost many genes involved in carbohydrate metabolism and fewer genes involved in protein metabolism, resulting in a higher ratio of proteases to carbohydrate active enzymes in the Onygenales than their relatives. To determine if gene content correlated with growth on different substrates, we screened the non-pathogenic onygenale Uncinocarpus reesii, which has orthologs for 91% of Paracoccidioides metabolic genes, for growth on 190 carbon sources. U. reesii showed growth on a limited range of carbohydrates, primarily basic plant sugars and cell wall components; this suggests that Onygenales, including dimorphic fungi, can degrade cellulosic plant material in the soil. In addition, U. reesii grew on gelatin and a wide range of dipeptides and amino acids, indicating a preference for proteinaceous growth substrates over carbohydrates, which may enable these fungi to also degrade animal biomass. These capabilities for degrading plant and animal substrates suggest a duality in lifestyle that could enable pathogenic species of Onygenales to transfer from soil to animal hosts.National Institute of Allergy and Infectious Diseases (U.S.)National Institutes of Health. Department of Health and Human Services (contract HHSN266200400001C)National Institutes of Health. Department of Health and Human Services(contract HHSN2722009000018C)Brazil. National Council for Scientific and Technological Developmen
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