380 research outputs found

    QCD corrections to single slepton production at hadron colliders

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    We evaluate the cross section for single slepton production at hadron colliders in supersymmetric theories with R-parity violating interactions to the next-to-leading order in QCD. We obtain fully differential cross section by using the phase space slicing method. We also perform soft-gluon resummation to all order in αs\alpha_s of leading logarithm to obtain a complete transverse momentum spectrum of the slepton. We find that the full transverse momentum spectrum is peaked at a few GeV, consistent with the early results for Drell-Yan production of lepton pairs. We also consider the contribution from gluon fusion via quark-triangle loop diagrams dominated by the bb-quark loop. The cross section of this process is significantly smaller than that of the tree-level process induced by the initial bbˉb\bar{b} annihilation.Comment: one new reference is adde

    Peripheral Sensitization

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    Peripheral sensitization indicates increased responsiveness and reduced threshold of nociceptive neurons in the periphery to the stimulation, which usually occurs after peripheral tissue injury and inflammation. As an integral part of pain, peripheral sensitization and its mechanisms have received much attention, and numerous types of neurotransmitters and chemicals related to peripheral sensitization were investigated. We developed an animal model of peripheral sensitization, and it provides evidence that some neurotransmitters, such as glutamate and substance P, release from adjacent peripheral nerves contributing to the peripheral sensitization of pathological pain. In this chapter, we reviewed the advances in peripheral sensitization, and it will provide a basis for new targets to attenuate pain of peripheral origin

    Viscosity of Polar-Nonpolar Gas Mixtures Empirical method

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    The adequacy of the familiar Sutherland expression for tho viscosity of gas mixtures is tested successfully for binary mixtures involving one component as polar. The limited calculations of this paper also reveal that the co-efficients of the Sutherland expression may be treated as approximately temperature independent. This interesting result may find great use in predicting values at high temperatures where no direct measurements are available

    Analysis of the effect of grouting parameters on pile-soil interaction of grouted piles

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    Reasonable control of grouting parameters was the key to improving the pile-soil interaction. However, quantitative analysis on the effect of grouting parameters on the pile-soil interaction was still lacking. This article developed an intelligent post-grouting system for precise control and quantitative analysis of grouting parameters. The conventional preparation method for shear tests were improved in this article. By changing the normal stress of the pile-soil interface during grouting, the test sample could simulate the grout distribution of the pile-soil interface at different depths. Through the improved experimental methods, a more accurate analysis of the mechanism for the pile-soil interaction was achieved. And the effectiveness of the intelligent post-grouting system was further verified by the case application. The results indicated that increasing the grout volume could improve the interface shear strength when the normal stress and grouting pressure were constant. This improvement effect caused by increasing grout volume decreased when the normal stress was high. Increasing the grouting pressure increased the interface shear strength when the normal stress and the grout volume remained constant. This improvement effect caused by increasing grouting pressure decreased when the grout volume was small. By appropriately controlling the two grouting parameters, the cohesion and the shear strength of the pile-soil interface were increased by 5.8–18.8 times and 1.16–2.91 times, respectively. The results indicated that the intelligent post-grouting system could accurately control the grouting parameters and effectively improve the pile-soil interaction of bored piles. The intelligent post-grouting system effectively reduced geotechnical engineering risks and improved the bearing capacity of pile

    UHRF1 is required for basal stem cell proliferation in response to airway injury

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    Cellular senescence is a cell fate characterized by an irreversible cell cycle arrest, but the molecular mechanism underlying this senescence hallmark remains poorly understood. Through an unbiased search for novel senescence regulators in airway basal cells, we discovered that the epigenetic regulator ubiquitin-like with PHD and ring finger domain-containing protein 1 (UHRF1) is critical for regulating cell cycle progression. Upon injury, basal cells in the mouse airway rapidly induce the expression of UHRF1 in order to stimulate stem cell proliferation and tissue repair. Targeted depletion of Uhrf1 specifically in airway basal cells causes a profound defect in cell cycle progression. Consistently, cultured primary human basal cells lacking UHRF1 do not exhibit cell death or differentiation phenotypes but undergo a spontaneous program of senescence. Mechanistically, UHRF1 loss induces G1 cell cycle arrest by abrogating DNA replication factory formation as evidenced by loss of proliferating cell nuclear antigen (PCNA) puncta and an inability to enter the first cell cycle. This proliferation defect is partially mediated by the p15 pathway. Overall, our study provides the first evidence of an indispensable role of UHRF1 in somatic stem cells proliferation during the process of airway regeneration

    Effect of weaning age on growth performance, feed efficiency, nutrient digestibility and blood-biochemical parameters in Droughtmaster crossbred beef calves

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    Objective The objective of this study was to determine the effect of weaning age on intake, performance, nutrition metabolism and serum parameters of beef calves. Methods Sixty Droughtmaster crossbred calves were assigned to 5 groups with 12 calves in each group. The calves in control group remained with the dams till the 22-week age, while the calves weaned at 28 d (4 wk), 42 d (6 wk), 56 d (8 wk), and 70 d (10 wk) of age were sent to group 4 wk, group 6 wk, group 8 wk, and group 10 wk, respectively, and then were fed on milk replacer till the 22-week age. Feed intake and body weight and size were record and blood metabolites were measured. And 24 calves of them (6 in each group) were picked randomly for digestion and metabolism trail. Feed, feces and urine sample were taken and measured. Results Dry matter intake of calves in group 4 wk was significantly lower than those in the remaining groups from wk 17 to 22 (p0.05) but was higher than that of group 4 wk (p<0.05). Calves in group 6 wk had higher final body weight and total gain than group 4 wk, but no difference of total gain with that of groups 8 wk, 10 wk, and control group. And weaning calves at 6-week age brought higher feed efficiency and average daily gain from wk 14 to wk 22, and higher dry matter and organic matter digestibility at 21 wk. Conclusion It is concluded that the weaning of calves at 6 weeks of age gave positive results
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