44 research outputs found

    On the unusual gas composition in the Beta Pictoris debris disk

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    The metallic gas associated with the Beta Pic debris disk is not believed to be primordial, but arises from the destruction of dust grains. Recent observations have shown that carbon and oxygen in this gas are exceptionally overabundant compared to other elements, by some 400 times. We study the origin of this enrichment under two opposing hypothesis, preferential production, where the gas is produced with the observed unusual abundance (as may happen if gas is produced by photo-desorption from C/O-rich icy grains), and preferential depletion, where the gas evolves to the observed state from an original solar abundance (if outgassing occurs under high-speed collisions) under a number of dynamical processes. We include ... ... We find ... ...Comment: accepted to ApJ, revised text is highlighted in red color, the old figure 2 is removed, other figures are revise

    MicroRNAs miR-27a and miR-143 Regulate Porcine Adipocyte Lipid Metabolism

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    MicroRNAs (miRNAs) are non-coding small RNAs that play roles in regulating gene expression. Some miRNAs have been classed as epigenetic regulators of metabolism and energy homeostasis. Previous reports indicated that the miRNAs miR-27a and miR-143 were involved in lipid metabolism in human and rodents. To determine the roles of porcine miR-27a and miR-143 in adipocyte lipid metabolism, porcine adipocytes were cultured and allowed to induce differentiation for 10 days. The lipid-filled adipocytes were then transfected with miRNA mimics and inhibitors. We measured how the indicators of adipogenesis and adipolysis in porcine adipocytes were affected by the over-expression and by the inhibition of both miR-27a and miR-143. The results indicated that the over-expression of miR-27a could accelerate adipolysis releasing significantly more glycerol and free fatty acids than the negative control (P < 0.001), while the mimic of miR-143 expression, promoted adipogenesis by accumulating more triglycerides (P < 0.001) in the adipocytes. In addition, we demonstrated that there was good correlation (r > 0.98, P < 0.001) between the indicators of adipolysis in cell lysates and in the culture medium

    Analysis of Entropy Generation in the Flow of Peristaltic Nanofluids in Channels With Compliant Walls

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    Entropy generation during peristaltic flow of nanofluids in a non-uniform two dimensional channel with compliant walls has been studied. The mathematical modelling of the governing flow problem is obtained under the approximation of long wavelength and zero Reynolds number (creeping flow regime). The resulting non-linear partial differential equations are solved with the help of a perturbation method. The analytic and numerical results of different parameters are demonstrated mathematically and graphically. The present analysis provides a theoretical model to estimate the characteristics of several Newtonian and non-Newtonian fluid flows, such as peristaltic transport of blood

    Reliability and validity of a novel caregiver-assessed skills system based on the ALSO conception in children with autism spectrum disorders

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    Background: In responding to the potential challenges in the transition from childhood to adulthood for individuals with autism spectrum disorders (ASD) in China, a novel conception of "ALSO" was proposed to bridge the transitional needs and early intervention. To facilitate the application of ALSO in early intervention, ALSOLIFE skills assessment system (ALSOLIFE Assessment) was developed to enable caregivers to evaluate their children's skills guided by the ALSO conception. Given that the critical shortage of qualified professionals in China, many caregivers of children with ASD must function as home therapists. lb address the practical needs of Chinese families of children with ASD, ALSOLIFE; Assessment is designed as a free, online, technology-assisted, self-operated and behavioral intervention approaches supported system. The assessment report then further served as the basis for caregivers to deliver the tailored educational intervention to their children. Although ALSOLIFE Assessment provides caregivers a home-based intervention program, it is still unclear whether its evaluation is reliable and accurate. Therefore, we conduct this study to investigate the reliability and validity of the ALSOLIFE Assessment. Methods: A total of 1,050 children with ASD (1 to 10 years old) were recruited from 31 provinces of mainland China. Their caregivers participated simultaneously as ALSOLIFE Assessment evaluators. The testing results of Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP) and Psychoeducational Profile-3 (PEP-3) were also collected for a portion of the child participants (VB-MAPP, N=34; PEP-3, N=31) to check criterion-related validity. Results: The reliability and validity of the ALSOLIFE Assessment satisfied psychometric requirements after the reduction from 511 to 464 items. Exploratory factor analysis (EFA) of ALSOLIFE Assessment scoring data yielded six factors, and confirmatory factor analysis (CFA) verified the best fitting construct model is a bifactorial model with one general factor and six group factors. Compared to the VB-NLAPP and PEP-3, the ALSOLIFE Assessment exhibited good criterion-related validity across three levels: total scores, 6 skill domains, and 22 skill subdomains. The reliability tests indicated its strong internal consistency, test-retest reliability; and inter-rater reliability. Conclusions: The reliability and validity of the revised ALSOLIFE Assessment (464-items) satisfied psychometric requirements. It is essential to develop validated and comprehensive evaluation tools, embedded on the needs of Chinese families of children with ASD

    A Chinese Herbal Formula Ameliorates Pulmonary Fibrosis by Inhibiting Oxidative Stress via Upregulating Nrf2

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    This study aimed to explore the protective effects of a Chinese herbal formula, Jinshui Huanxian formula (JHF), on experimental pulmonary fibrosis and its underlying mechanisms. After being treated with single dose of bleomycin (5 mg/kg) intratracheally, rats were orally administered with JHF and pirfenidone from day 1 to 42, then sacrificed at 7, 14, 28, or 42 days post-bleomycin instillation. JHF ameliorated bleomycin-induced pathological changes, collagen deposition in the rat lung and recovered pulmonary function at different days post-bleomycin instillation. In lungs of JHF-treated rats, the levels of total superoxide dismutase, catalase and glutathione were higher, and myeloperoxidase and methane dicarboxylic aldehyde were lower than those in vehicle-treated rats, respectively. Additionally, JHF inhibited the expression of NADPH oxidase 4 (NOX4) and increased the Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) in lung tissues. In vitro, JHF and ruscogenin, a compound of Ophiopogonis Radix contained in JHF, significantly inhibited transforming growth factor β1 (TGF-β1)-induced differentiation of fibroblasts. Furthermore, JHF markedly decreased the level of reactive oxygen species in TGF-β1-induced fibroblast. In line with this, upregulation of NAD(P)H: quinone oxidoreductase 1 and heme oxygenase 1, and downregulation of NOX4 were found in JHF-treated fibroblast induced by TGF-β1. While on the other hand, Nrf2 siRNA could suppress the JHF-mediated inhibition effect on alpha-smooth muscle actin (α-SMA), and FN1 expression induced by TGF-β1 in fibroblasts. These results indicated that JHF performed remarkably therapeutic and long-term effects on pulmonary fibrosis in rat and suppressed the differentiation of fibroblast into myofibroblast through reducing the oxidative response by upregulating Nrf2 signaling. It might provide a new potential natural drug for the treatment of pulmonary fibrosis
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