266 research outputs found

    Families of Canonical Transformations by Hamilton-Jacobi-Poincar\'e equation. Application to Rotational and Orbital Motion

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    The Hamilton-Jacobi equation in the sense of Poincar\'e, i.e. formulated in the extended phase space and including regularization, is revisited building canonical transformations with the purpose of Hamiltonian reduction. We illustrate our approach dealing with orbital and attitude dynamics. Based on the use of Whittaker and Andoyer symplectic charts, for which all but one coordinates are cyclic in the Hamilton-Jacobi equation, we provide whole families of canonical transformations, among which one recognizes the familiar ones used in orbital and attitude dynamics. In addition, new canonical transformations are demonstrated.Comment: 21 page

    A catalog of natural products occurring in watermelon— Citrullus lanatus

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    Sweet dessert watermelon ( Citrullus lanatus ) is one of the most important vegetable crops consumed throughout the world. The chemical composition of watermelon provides both high nutritional value and various health benefits. The present manuscript introduces a catalog of 1,679 small molecules occurring in the watermelon and their cheminformatics analysis for diverse features. In this catalog, the phytochemicals are associated with the literature describing their presence in the watermelon plant, and when possible, concentration values in various plant parts (flesh, seeds, leaves, roots, rind). Also cataloged are the chemical classes, molecular weight and formula, chemical structure, and certain physical and chemical properties for each phytochemical. In our view, knowing precisely what is in what we eat, as this catalog does for watermelon, supports both the rationale for certain controlled feeding studies in the field of precision nutrition, and plant breeding efforts for the development of new varieties with enhanced concentrations of specific phytochemicals. Additionally, improved and comprehensive collections of natural products accessible to the public will be especially useful to researchers in nutrition, cheminformatics, bioinformatics, and drug development, among other disciplines

    Uso de meio seletivo para identificação de cepas de Burkholderia cepacia em amostras de trato respiratório de pacientes portadores de fibrose cística

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    Burkholderia cepacia colonizes cystic fibrosis (CF) patients. We evaluated the impact of the use of a selective medium in the rate of B. cepacia recovery from respiratory samples of CF patients. During a 6-month period, respiratory samples were collected from 106 CF patients and cultivated on selective media including a B. cepacia selective medium. Confirmation of the identity of B. cepacia isolates was carried out by species specific PCR and determination of genomovar status performed by a sequential PCR approach. Results of B. cepacia isolation during this period were compared to the preceding two years, when the sample processing was identical except for the lack of the B. cepacia selective medium. B. cepacia was isolated in 11/257 (4.2%) of the samples using the selective medium, in contrast with the preceding two years, when it was isolated in 6/1029 samples (0.58%), p < 0.0001. Identity of all 11 isolates was confirmed by PCR and genomovar determination was accomplished in all but one isolate. These results suggest that the use of a selective medium increases recovery rate of B. cepacia from respiratory samples.A Burkholderia cepacia coloniza os pacientes portadores de fibrose cística (FC). Avaliamos o impacto do uso de um meio seletivo no isolamento de B. cepacia em amostras de secreção respiratória de pacientes portadores de FC. Durante um período de 6 meses, amostras de trato respiratório foram colhidas de 106 pacientes com FC e cultivadas em meios seletivos incluindo um meio para isolamento de B. cepacia. A identidade das cepas de B. cepacia foi confirmada através de PCR espécie específica e a determinação do genomovar ou subespécie realizada através de reações seqüenciais de PCR. Os resultados de isolamento de B. cepacia durante este período foram comparados com os dois anos precedentes, quando o processamento das amostras era idêntico, exceto pela utilização do meio seletivo para B. cepacia. B. cepacia foi isolada em 11/257 (4,2%) amostras usando o meio seletivo, e em apenas 6/1029 (0,58%) nos dois anos precedentes (p < 0,0001). A identidade destas 11 cepas foi confirmada e a determinação do genomovar obtida em 10/11. Estes resultados sugerem que o uso do meio seletivo aumenta a freqüência de isolamento de B. cepacia em amostras de trato respiratório de pacientes portadores de FC

    HPV in women assisted by the family health strategy

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    OBJECTIVE: Estimate the prevalence of cervical HPV infection among women assisted by the Family Health Strategy and identify the factors related to the infection. METHODS: A cross-sectional study involving 2,076 women aged 20–59 years old residing in Juiz de Fora, State of Minas Gerais, who were asked to participate in an organized screening carried out in units were the Family Health Strategy had been implemented. Participants answered the standardized questionnaire and underwent a conventional cervical cytology test and HPV test for high oncogenic risk. Estimates of HPV infection prevalence were calculated according to selected characteristics referenced in the literature and related to socioeconomic status, reproductive health and lifestyle. RESULTS: The overall prevalence of HPV infection was 12.6% (95%CI 11.16–14.05). The prevalence for the pooled primer contained 12 oncogenic HPV types (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) was 8.6% (95%CI 7.3–9.77). In the multivariate analysis, it was observed that the following variables were significantly associated with a higher prevalence of HPV infection: marital status (single: adjusted PR = 1.40, 95%CI 1.07–1.8), alcohol consumption (any lifetime frequency: adjusted PR = 1.44, 95%CI 1.11–1.86) and number of lifetime sexual partners (≥ 3: adjusted PR = 1.35, 95%CI 1.04–1.74). CONCLUSIONS: The prevalence of HPV infection in the study population ranges from average to particularly high among young women. The prevalence of HPV16 and HPV18 infection is similar to the worldwide prevalence. Homogeneous distribution among the pooled primer types would precede the isolated infection by HPV18 in magnitude, which may be a difference greater than the one observed. The identification of high-risk oncogenic HPV prevalence may help identify women at higher risk of developing preneoplastic lesions.

    Supersymmetric Branes on AdS_5 x Y^{p,q} and their Field Theory Duals

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    We systematically study supersymmetric embeddings of D-brane probes of different dimensionality in the AdS_5xY^{p,q} background of type IIB string theory. The main technique employed is the kappa symmetry of the probe's worldvolume theory. In the case of D3-branes, we recover the known three-cycles dual to the dibaryonic operators of the gauge theory and we also find a new family of supersymmetric embeddings. The BPS fluctuations of dibaryons are analyzed and shown to match the gauge theory results. Supersymmetric configurations of D5-branes, representing domain walls, and of spacetime filling D7-branes (which can be used to add flavor) are also found. We also study the baryon vertex and some other embeddings which break supersymmetry but are nevertheless stable.Comment: LaTeX, 2 figures, 54 pages; v2: discussions sharpened at several points, new subsection and references adde

    High-level of viral genomic diversity in cervical cancers: a Brazilian study on human papillomavirus type 16

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    Invasive cervical cancer (ICC) is the third most frequent cancer among women worldwide and is associated with persistent infection by carcinogenic human papillomaviruses (HPVs). The combination of large populations of viral progeny and decades of sustained infection may allow for the generation of intra-patient diversity, in spite of the assumedly low mutation rates of PVs. While the natural history of chronic HPVs infections has been comprehensively described, within-host viral diversity remains largely unexplored. In this study we have applied next generation sequencing to the analysis of intra-host genetic diversity in ten ICC and one condyloma cases associated to single HPV16 infection. We retrieved from all cases near full-length genomic sequences. All samples analyzed contained polymorphic sites, ranging from 3 to 125 polymorphic positions per genome, and the median probability of a viral genome picked at random to be identical to the consensus sequence in the lesion was only 40%. We have also identified two independent putative duplication events in two samples, spanning the L2 and the L1 gene, respectively. Finally, we have identified with good support a chimera of human and viral DNA. We propose that viral diversity generated during HPVs chronic infection may be fueled by innate and adaptive immune pressures. Further research will be needed to understand the dynamics of viral DNA variability, differentially in benign and malignant lesions, as well as in tissues with differential intensity of immune surveillance. Finally, the impact of intralesion viral diversity on the long-term oncogenic potential may deserve closer attention.Funded by Grants # 2011/24035-2 and # 2012/23290-1, São Paulo Research Foundation (FAPESP

    Binding and uptake of H-ferritin are mediated by human transferrin receptor-1

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    Ferritin is a spherical molecule composed of 24 subunits of two types, ferritin H chain (FHC) and ferritin L chain (FLC). Ferritin stores iron within cells, but it also circulates and binds specifically and saturably to a variety of cell types. For most cell types, this binding can be mediated by ferritin composed only of FHC (HFt) but not by ferritin composed only of FLC (LFt), indicating that binding of ferritin to cells is mediated by FHC but not FLC. By using expression cloning, we identified human transferrin receptor-1 (TfR1) as an important receptor for HFt with little or no binding to LFt. In vitro, HFt can be precipitated by soluble TfR1, showing that this interaction is not dependent on other proteins. Binding of HFt to TfR1 is partially inhibited by diferric transferrin, but it is hindered little, if at all, by HFE. After binding of HFt to TfR1 on the cell surface, HFt enters both endosomes and lysosomes. TfR1 accounts for most, if not all, of the binding of HFt to mitogen-activated T and B cells, circulating reticulocytes, and all cell lines that we have studied. The demonstration that TfR1 can bind HFt as well as Tf raises the possibility that this dual receptor function may coordinate the processing and use of iron by these iron-binding molecules

    Add-on inhaled budesonide in the treatment of hospitalised patients with COVID-19 : a randomised clinical trial

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    SARS-CoV-2 vaccines have been extremely effective to reduce the incidence of severe COVID19 [1-3], but effective and safe treatments of the acute infection are still limited [4, 5]. An uncontrolled pulmonary inflammatory response to SARS-CoV-2 is considered a key pathogenic mechanism of COVID19 progression [6], so systemic dexamethasone is recommended in severe cases [5, 7]. On the other hand, in very mild patients at home inhaled corticosteroids (ICS) may prevent disease progression [8-11]. Whether ICS prevent disease progression too in patients hospitalised because of COVID19 has not been explored before. Accordingly, we designed an investigator-initiated, open-label, randomised clinical trial (RCT) to explore the efficacy of adding inhaled budesonide to usual care to prevent disease progression in patients hospitalised because of COVID19 pneumonia. We also monitored carefully the safety of this intervention since there are concerns about the use of systemic corticosteroids in other viral (influenza) lung infections [12]

    Analysis of Tumor Metabolism Reveals Mitochondrial Glucose Oxidation in Genetically Diverse Human Glioblastomas in the Mouse Brain In Vivo

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    SummaryDysregulated metabolism is a hallmark of cancer cell lines, but little is known about the fate of glucose and other nutrients in tumors growing in their native microenvironment. To study tumor metabolism in vivo, we used an orthotopic mouse model of primary human glioblastoma (GBM). We infused 13C-labeled nutrients into mice bearing three independent GBM lines, each with a distinct set of mutations. All three lines displayed glycolysis, as expected for aggressive tumors. They also displayed unexpected metabolic complexity, oxidizing glucose via pyruvate dehydrogenase and the citric acid cycle, and using glucose to supply anaplerosis and other biosynthetic activities. Comparing the tumors to surrounding brain revealed obvious metabolic differences, notably the accumulation of a large glutamine pool within the tumors. Many of these same activities were conserved in cells cultured ex vivo from the tumors. Thus GBM cells utilize mitochondrial glucose oxidation during aggressive tumor growth in vivo

    Alguns dados sobre a Fauna entomológica da ilha das Flores - Açores

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    IV Expedição Científica do Departamento de Biologia - Flores 1989Com este trabalho, realizado em Julho de 1989 nas Flores - a ilha mais ocidental do Arquipélago dos Açores -, acrescentaram-se onze espécies de Lepidópteros à lista referenciada para aquela ilha, pertencendo uma à família Lycaenidae (Lampides boeticus L.), oito a familia Noctuidae (Agrotis ipsilon HFN., Brotolomia meticulosa L., Chrysodeixis chalcites ESPER., Heliothis armigera HBN., Noctua atlantica WARREN, Noctua pronuba L., Peridroma saucia HBN., Sesamia nonagrioides LEF.), uma à família Nymphalidae (Vanessa atalanta L.) e uma a família Pyralidae (Glyphodes unionalis HBN.). Entre os demais insectos, foram identificadas cerca de duas dezenas e meia de espécies, distribuídas pelas Ordens Dermaptera, Orthoptera, Dictyoptera, Heteroptera, Homoptera, Coleoptera, Neuroptera, Diptera, Hymenoptera e Collembola. Salienta-se ainda a importância, do ponto de vista agronómico, das pragas Mythimna unipuncta (HAWORTH) e Xestia c-nigrun L. naquela ilha.RÉSUMÉ: Avec ce travail, réalisé en Juillet 1989 a Flores - l'île plus occidental de l'archipel des Açores, onze espèces de Lépidoptères ont été ajoutées à la liste des espèces connus pour cette île, dont une appartient a la famille Lycaenidae (Lampides boelicus L.), huit à la famille Noctuidae (Agrotis ipsilon HFN., Brotolomia meticulosa L. Chrysodeicis chalcites ESPER., Heliothis armigera HBN., Noctua atlantica WARREN, Noctua pronuba L., Peridroma saucia HBN., Sesamia nonagrioides LEF.), une à la famille Nymphalidae (Vanessa atalanta L.) et une à la famille Pyralidae (Glyphodes unionalis HBN.). Parmi les autres insects ont été identifiés environ deux dizaines et demie d'espèces, lesquelles sont réparties par les Ordres Dermaptera, Orthoptera, Dictyoptera, Heteroptera, Homoptera, Coleoptera, Neuroptera, Diptera, Hymenoptera et Collembola. On remarque I'importance, du point de vue agronomique, des ravageurs Mythimna unipuncra (HAWORTH) et Xestia c-nigrum L. dans cette île
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