353 research outputs found

    Gas separation properties of new polyoxadiazole and polytriazole membranes

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    The gas separation properties of new aromatic poly-1,2,4-triazole and poly-1,3,4-oxadiazole membranes have been systematically investigated. Various functional groups were incorporated as pendent groups onto the polymer backbone of poly-1,2,4-triazoles. A wide permeability/selectivity spectrum was covered with the choice of functional groups incorporated into the polymer backbone of poly-1,3,4-oxadiazoles. High permeabilities were found for poly-1,3,4-oxadiazoles with a 1,1,3-trimethyl-3-phenylindane (PIDA-POD) and a 4,4′(2,2′-diphenyl)hexafluor propane (HF-POD) unit in the polymer backbone, while incorporation of a 4,4′-diphenyl ether unit (DPE-POD) results in a polymer with a low permeability but an extremely high selectivity. While the permeabilities vary over four orders of magnitude, the solubility remains almost constant and, therefore, the increase in permeability is mainly due to an increase in diffusivity. The permeability is discussed in terms of the polymer free volume

    Estado Da Arte Da Literatura Científica Sobre Hancornia Speciosa: Tendências E Lacunas

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    Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The economic and scientific interest in Hancornia speciosa (mangabeira) has been growing in recent years, mainly due to the marketing of fruit and extraction of natural compounds with high pharmacological potential. In this study, a scientometric survey about mangabeira was carried out in order to promote and direct future studies on the species. As a result, low scientific productivity associated with this species was found, with only 131 articles published in the last 69 years. In addition, this study identified some trends in bibliographic production on mangabeira, among them: the increasing number of articles over the years; scientific dissemination in nationwide journals; the main focus of this study is associated with agronomic studies; the experimental approach is more frequent and usually associated with populations of restricted geographical distribution; and the scientific production is mainly from education institutions. Furthermore, this study also allowed the identification of some gaps in knowledge about mangabeira, among them the difficulty in describing and characterizing botanical lines; lack of analysis of the genetic diversity of widely distributed populations; lack of management and conservation projects for the species; lack of description of cultivation, collection and preservation techniques of fruits; and lack of identification of natural compounds responsible for its pharmacological activity. It is expected that the data generated in this study will serve to direct future studies on H. speciosa. © 2016, Sociedade Brasileira de Fruticultura. All rights reserved.384CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPEG, Fundação de Amparo à Pesquisa do Estado de GoiásFINEP, Financiadora de Estudos e ProjetosCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Andrological, pathologic, morphometric, and ultrasonographic findings in rams experimentally infected with Brucella ovis

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    AbstractBrucella ovis is considered the most important infectious cause of reproductive disorders in sheep. The disease is characterized by epididymitis, subfertility and infertility in rams. B. ovis occasionally results in abortion in ewes, as well. The aim of this study was to evaluate kinetic changes in the reproductive organs of rams experimentally infected with B. ovis. Nine rams were experimentally inoculated intrapreputially with 2mL of a suspension containing 1.2×109CFU (colony-forming units)/mL of B. ovis (strain ATCC25840). In addition, 50μL of a suspension containing 1.2×1010CFU/mL of the same B. ovis strain was inoculated into each conjunctival sac, resulting in 3.6×109CFU total per ram. Six of nine infected rams had developed clinical changes in the tail of the epididymis at 30 days post-infection (dpi), but these changes regressed in 50% of these rams. Ultrasound demonstrated an increase in the area of the tail of the epididymis (P<0.001), reduction in the area of the testes (P<0.001), and an increased length and width of the seminal vesicles (P<0.001) during the course of infection. A sperm granuloma was diagnosed on the basis of ultrasonography findings. Microscopically, there was epididymitis, testicular degeneration, and seminal vesiculitis. Inflammatory cells were detected in the semen even before the development of epididymitis. Moreover, inflammatory cells were also found in the semen of asymptomatic rams, indicating that the presence of leukocytes in the ejaculate is a valuable method for screening potential carriers of infections in the genital tract

    Modelling of strain effects in manganite films

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    Thickness dependence and strain effects in films of La1xAxMnO3La_{1-x}A_xMnO_3 perovskites are analyzed in the colossal magnetoresistance regime. The calculations are based on a generalization of a variational approach previously proposed for the study of manganite bulk. It is found that a reduction in the thickness of the film causes a decrease of critical temperature and magnetization, and an increase of resistivity at low temperatures. The strain is introduced through the modifications of in-plane and out-of-plane electron hopping amplitudes due to substrate-induced distortions of the film unit cell. The strain effects on the transition temperature and transport properties are in good agreement with experimental data only if the dependence of the hopping matrix elements on the MnOMnMn-O-Mn bond angle is properly taken into account. Finally variations of the electron-phonon coupling linked to the presence of strain turn out important in influencing the balance of coexisting phases in the filmComment: 7 figures. To be published on Physical Review

    Avaliação da higroscopicidade de fertilizantes e corretivos

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    Visando determinar a quantidade de água absorvida em função da umidade do ambiente e do tempo de exposição por alguns fertilizantes simples, misturas de fertilizantes e corretivos, foram colocadas em três ambientes de umidade relativa constante de 70,4%, 80,5% e 88,8% . As amostras foram pesadas após 0, 3, 6, 24, 48 e 72 horas determinando a porcentagem de água absorvida. A absorção de água pelos produtos aumentou com o aumento da umidade relativa do ar e do tempo de exposição. Todos os materiais absorveram alguma umidade no menor tempo e na menor umidade relativa estudados, isto é, 3 horas de 70,4%, porém essa absorção foi insignificante nos casos do sulfato de amônio, fosfato diamônico, fosfato natural parcialmente acidulado, cloreto de potássio, sulfato de potássio, calcário calcinado. Os fertilizantes nitrogenados, uréia e nitrocálcio, foram os que apresentaram maior higroscopicidade dentre os materiais estudados. Foi possível verificar também que a presença de 5% de calcário calcinado ou de vermiculita nas misturas de grânulos diminuiu sensivelmente sua higroscopicidade.The percentual of water absorbed by fertilizer materials, bulk blend fertilizer mixtures and agricultural liming materials was determined as a function of the environment relative humidity and time of exposition. Samples of these were exposed to three relative humidity environments: 70,4%, 80,5% and 77,8%, during 3, 6, 12, 24, 48, 72 hours, after drying at 50&deg;C for 24 hours. The water absorbed by all products increased with air relative humidity and exposition time. All the materials absorbed some humidity for the lowest exposition time and lowest relative humidity (3 hours and 70,4%) but was insignificant in the case of ammonium sulphate, diammonium phosphate, natural phosphate parcially acidulated, potassium chloride, potassium sulphate, limestone and hidrated lime. The urea and calcium nitrate presented major higroscopicity among the materials studied. The presence of 5% hidrated lime or vermiculite in bulk blend mixtures decreases significatively the higroscopicity

    Dance training improves cytokine secretion and viability of neutrophils in diabetic patients

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    Background. Evidence suggests that exercise improves neutrophil function. The decreased functional longevity of neutrophils and their increased clearance from infectious sites contribute to the increased susceptibility to infection and severity of infection observed in patients with diabetes. Objective. Herein, we investigated the effects of a dance program on neutrophil number, function, and death in type 2 diabetes mellitus (T2DM) patients and healthy volunteers. Methods. Ten patients with T2DM and twelve healthy individuals participated in a moderate-intensity dance training program for 4 months. The plasma levels of leptin, free fatty acids (FFAs), tumour necrosis factor-α (TNF-α), C-reactive protein (CRP), interleukin-1β (IL-1β), and interleukin-1 receptor antagonist (IL-1ra); neutrophil counts; extent of DNA fragmentation; cell membrane integrity; and production of TNF-α, interleukin-8 (IL-8), interleukin-6 (IL-6), and IL-1β in neutrophils were measured before and after training. Results. Training reduced plasma levels of TNF-α (1.9-fold in controls and 2.2-fold in patients with T2DM) and CRP (1.4-fold in controls and 3.4-fold in patients with T2DM). IL-1ra levels were higher in the control group (2.2-fold) after training. After training, neutrophil DNA fragmentation was decreased in patients with T2DM (90%), while the number of neutrophils increased (70% in controls and 1.1-fold in patients with T2DM). Conclusion. Dance training is a nonpharmacological strategy to reduce inflammation and improve neutrophil clearance in patients with T2DM

    Black hole thermodynamical entropy

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    As early as 1902, Gibbs pointed out that systems whose partition function diverges, e.g. gravitation, lie outside the validity of the Boltzmann-Gibbs (BG) theory. Consistently, since the pioneering Bekenstein-Hawking results, physically meaningful evidence (e.g., the holographic principle) has accumulated that the BG entropy SBGS_{BG} of a (3+1)(3+1) black hole is proportional to its area L2L^2 (LL being a characteristic linear length), and not to its volume L3L^3. Similarly it exists the \emph{area law}, so named because, for a wide class of strongly quantum-entangled dd-dimensional systems, SBGS_{BG} is proportional to lnL\ln L if d=1d=1, and to Ld1L^{d-1} if d>1d>1, instead of being proportional to LdL^d (d1d \ge 1). These results violate the extensivity of the thermodynamical entropy of a dd-dimensional system. This thermodynamical inconsistency disappears if we realize that the thermodynamical entropy of such nonstandard systems is \emph{not} to be identified with the BG {\it additive} entropy but with appropriately generalized {\it nonadditive} entropies. Indeed, the celebrated usefulness of the BG entropy is founded on hypothesis such as relatively weak probabilistic correlations (and their connections to ergodicity, which by no means can be assumed as a general rule of nature). Here we introduce a generalized entropy which, for the Schwarzschild black hole and the area law, can solve the thermodynamic puzzle.Comment: 7 pages, 2 figures. Accepted for publication in EPJ

    Cumulative incidence and risk factors for cutaneous squamous-cell carcinoma metastases in organ transplant recipients: the SCOPE-ITSCC metastases study, a prospective multi-center study.

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    Solid organ transplant recipients (SOTRs) are believed to have an increased risk of metastatic cutaneous squamous-cell carcinoma (cSCC), but reliable data are lacking regarding the precise incidence and associated risk factors. In a prospective cohort study, including 19 specialist dermatology outpatient clinics in 15 countries, patient and tumor characteristics were collected using standardized questionnaires when SOTRs presented with a new cSCC. After a minimum of 2 years of follow-up, relevant data for all SOTRs were collected. Cumulative incidence of metastases was calculated by the Aalen-Johansen estimator. Fine and Gray models were used to assess multiple risk factors for metastases. Of 514 SOTRs who presented with 623 primary cSCCs, 37 developed metastases with a 2-year patient-based cumulative incidence of 6.2%. Risk factors for metastases included location in the head and neck area, local recurrence, size >2cm, clinical ulceration, poor differentiation grade, perineural invasion and deep invasion. A high-stage tumor that is also ulcerated showed the highest risk of metastasis, with a 2-year cumulative incidence of 46.2% (31.9% - 68.4%). SOTRs have a high risk of cSCC metastases and well-established clinical and histological risk factors have been confirmed. High-stage, ulcerated cSCCs have the highest risk of metastasis. [Abstract copyright: Copyright © 2024. Published by Elsevier Inc.
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