252 research outputs found

    Effect of temperature on the electro-oxidation of ethanol on platinum

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    We present in this work an experimental investigation of the effect of temperature (from 25 to 180 ºC) in the electro-oxidation of ethanol on platinum in two different phosphoric acid concentrations. We observed that the onset potential for ethanol electro-oxidation shifts to lower values and the reaction rates increase as temperature is increased for both electrolytes. The results were rationalized in terms of the effect of temperature on the adsorption of reaction intermediates, poisons, and anions. The formation of oxygenated species at high potentials, mainly in the more diluted electrolyte, also contributes to increase the electro-oxidation reaction rate.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Pesquisa (CNPq

    Comparison of the neuropsychological assessment in a girl with bilateral cerebrovascular disease (moyamoya) before and after surgical intervention

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    Moyamoya is a chronic progressive cerebrovascular disease with characteristic angiographic findings and a clinical picture with episodes of transient ischemic attacks, headache, seizures, hemiparesis, which may resolve after surgical treatment. We describe the case of a girl with the typical findings of the disease, comparing them before and after surgery with the use of neuropsychological tests, neurological examination and laboratory tests.A doença de moyamoya é anormalidade cerebrovascular crônica e progressiva identificada através das características angiográficas; estão presentes no quadro clínico episódios isquêmicos transitórios, cefaléia, crises convulsivas, hemiparesia, que podem desaparecer após tratamento cirúrgico. Nós descrevemos o caso de uma menina com características clássicas da doença, comparando-o em dois momentos, antes e depois da cirurgia, através de avaliações neurológicas, neuropsicológicas, e exames complementares.1036104

    Registros públicos

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    - Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.- Localização na estante: 347.136(81) R337

    Cell-Free Antigens from Paracoccidioides brasiliensis Drive IL-4 Production and Increase the Severity of Paracoccidioidomycosis

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    The thermally dimorphic fungus Paracoccidioides brasiliensis (Pb) is the causative agent of paracoccidioidomycosis (PCM), one of the most frequent systemic mycosis that affects the rural population in Latin America. PCM is characterized by a chronic inflammatory granulomatous reaction, which is consequence of a Th1-mediated adaptive immune response. In the present study we investigated the mechanisms involved in the immunoregulation triggered after a prior contact with cell-free antigens (CFA) during a murine model of PCM. The results showed that the inoculation of CFA prior to the infection resulted in disorganized granulomatous lesions and increased fungal replication in the lungs, liver and spleen, that paralleled with the higher levels of IL-4 when compared with the control group. The role of IL-4 in facilitating the fungal growth was demonstrated in IL-4-deficient- and neutralizing anti-IL-4 mAb-treated mice. The injection of CFA did not affect the fungal growth in these mice, which, in fact, exhibited a significant diminished amount of fungus in the tissues and smaller granulomas. Considering that in vivo anti-IL-4-application started one week after the CFA-inoculum, it implicates that IL-4-CFA-induced is responsible by the mediation of the observed unresponsiveness. Further, the characterization of CFA indicated that a proteic fraction is required for triggering the immunosuppressive mechanisms, while glycosylation or glycosphingolipids moieties are not. Taken together, our data suggest that the prior contact with soluble Pb antigens leads to severe PCM in an IL-4 dependent manner

    Distinct patterns of somatic alterations in a lymphoblastoid and a tumor genome derived from the same individual

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    Although patterns of somatic alterations have been reported for tumor genomes, little is known on how they compare with alterations present in non-tumor genomes. A comparison of the two would be crucial to better characterize the genetic alterations driving tumorigenesis. We sequenced the genomes of a lymphoblastoid (HCC1954BL) and a breast tumor (HCC1954) cell line derived from the same patient and compared the somatic alterations present in both. The lymphoblastoid genome presents a comparable number and similar spectrum of nucleotide substitutions to that found in the tumor genome. However, a significant difference in the ratio of non-synonymous to synonymous substitutions was observed between both genomes (P = 0.031). Protein–protein interaction analysis revealed that mutations in the tumor genome preferentially affect hub-genes (P = 0.0017) and are co-selected to present synergistic functions (P < 0.0001). KEGG analysis showed that in the tumor genome most mutated genes were organized into signaling pathways related to tumorigenesis. No such organization or synergy was observed in the lymphoblastoid genome. Our results indicate that endogenous mutagens and replication errors can generate the overall number of mutations required to drive tumorigenesis and that it is the combination rather than the frequency of mutations that is crucial to complete tumorigenic transformation

    Distinct patterns of somatic alterations in a lymphoblastoid and a tumor genome derived from the same individual

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    Although patterns of somatic alterations have been reported for tumor genomes, little is known on how they compare with alterations present in non-tumor genomes. A comparison of the two would be crucial to better characterize the genetic alterations driving tumorigenesis. We sequenced the genomes of a lymphoblastoid (HCC1954BL) and a breast tumor (HCC1954) cell line derived from the same patient and compared the somatic alterations present in both. The lymphoblastoid genome presents a comparable number and similar spectrum of nucleotide substitutions to that found in the tumor genome. However, a significant difference in the ratio of non-synonymous to synonymous substitutions was observed between both genomes (P = 0.031). Protein–protein interaction analysis revealed that mutations in the tumor genome preferentially affect hub-genes (P = 0.0017) and are co-selected to present synergistic functions (P < 0.0001). KEGG analysis showed that in the tumor genome most mutated genes were organized into signaling pathways related to tumorigenesis. No such organization or synergy was observed in the lymphoblastoid genome. Our results indicate that endogenous mutagens and replication errors can generate the overall number of mutations required to drive tumorigenesis and that it is the combination rather than the frequency of mutations that is crucial to complete tumorigenic transformation

    Global diversity of enterococci and description of 18 novel species

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    Bacteria of the genus Enterococcus colonize the guts of diverse animals. Some species have acquired multiple antibiotic resistances on top of a high level of intrinsic resistance and have emerged as leading causes of hospital-associated infection. Although clinical isolates of enterococcal species E. faecalis and E. faecium have been studied with respect to their antibiotic resistances and infection pathogenesis, comparatively little is known about the biology of enterococci in their natural context of the guts of humans and other land animals, including arthropods and other invertebrates. Importantly, little is also known about the global pool of genes already optimized for expression in an enterococcal background with the potential to be readily acquired by hospital adapted strains of E. faecalis and E. faecium , known facile exchangers of mobile genetic elements. We therefore undertook a global study designed to reach into maximally diverse habitats, to establish a first approximation of the genetic diversity of enterococci on Earth. Presumptive enterococci from over 900 diverse specimens were initially screened by PCR using a specific reporter gene that we found to accurately reflect genomic diversity. The genomes of isolates exceeding an operationally set threshold for diversity were then sequenced in their entirety and analyzed. This provided us with data on the global occurrence of many known enterococcal species and their association with various hosts and ecologies and identified 18 novel species expanding the diversity of the genus Enterococcus by over 25%. The 18 novel enterococcal species harbor a diverse array of genes associated with toxins, detoxification, and resource acquisition that highlight the capacity of the enterococci to acquire and adapt novel functions from diverse gut environments. In addition to the discovery and characterization of new species, this expanded diversity permitted a higher resolution analysis of the phylogenetic structure of the Enterococcus genus, including identification of distinguishing features of its 4 deeply rooted clades and genes associated with range expansion such as B-vitamin biosynthesis and flagellar motility. Collectively, this work provides an unprecedentedly broad and deep view of the genus Enterococcus , along with new insights into their potential threat to human health
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