58 research outputs found

    Periodically Modulated Magnetic Reconnection

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    We present the first evidence for periodically modulated reconnection at the electron scale in space, using unparalleled, high-cadence data from Magnetospheric Multiscale spacecraft. The periodic modulation is attributed to finite magnetic trapping imposed by the X-line, which generates discrete, dispersive electron stripes. The dispersive stripes, well reproduced by a trapping-loss transition model, periodically break the frozen-in condition and drive energy dissipation. Such an electron transition effect eliminates free electrons, enhances electron mixing, and causes highly structured, three-dimensional distributions that generate intense radio emissions. These illuminating results, suggesting that reconnection hosts inherent periodicity determined by three-dimensional electron physics, provide crucial insights into understanding reconnection-driven energy transport in space and astrophysical plasmas

    Association between different combination of measures for obesity and new-onset gallstone disease.

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    Body mass index(BMI) is a calculation index of general obesity. Waist circumference(WC) is a measure of body-fat distribution and always used to estimate abdominal obesity. An important trait of general obesity and abdominal obesity is their propensity to coexist. Using one single measure of obesity could not estimate persons at risk for GSD precisely.This study aimed to compare the predictive values of various combination of measures for obesity(BMI, WC, waist to hip ratio) for new-onset GSD.We prospectively studied the predictive values of various combination of measures for obesity for new-onset GSD in a cohort of 88,947 participants who were free of prior gallstone disease, demographic characteristics and biochemical parameters were recorded.4,329 participants were identified to have GSD among 88,947 participants during 713 345 person-years of follow-up. Higher BMI, WC and waist to hip ratio (WHtR) were significantly associated with higher risks of GSD in both genders even after adjustment for potential confounders. In males, the hazard ratio for the highest versus lowest BMI, WC, WHtR were 1.63(1.47~1.79), 1.53(1.40~1.68), 1.44(1.31~1.58), respectively. In females, the hazard ratio for the highest versus lowest BMI, WC, WHtR were 2.11(1.79~2.49), 1.85(1.55~2.22), 1.84(1.55~2.19), respectively. In male group, the combination of BMI+WC improved the predictive ability of the model more clearly than other combinations after adding them to the multivariate model in turn, while for females the best predictive combination was BMI+WHtR.Elevated BMI, WC and WHtR were independent risk factors for new-onset GSD in both sex groups after additional adjustment was made for potential confounders. In males, the combination of BMI+WC seemed to be the most predictable model to evaluate the effect of obesity on new-onset GSD, while the best combination in females was BMI+WHtR

    Retardation of Preputial Wound Healing in Rats with Hypospadias Induced by Flutamide

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    Objective: The aim of this study was to identify a theoretical support for the prevention of urethral fistula following hypospadias repair, by comparing the preputial wound healing process in Sprague-Dawley (SD) rats with and without hypospadias induced by flutamide. Methods: Fifteen pregnant SD rats were randomly divided into three groups. These rats in one group received the androgen receptor antagonist flutamide (25 mg/kg/day) from gestation days 11–17, to establish a rat model of hypospadias for further study of the molecular mechanisms of the hypospadias etiology. The pregnant rats in the control groups were not administered flutamide. The pups from the control and experiment groups underwent an incision on the dorsal prepuce on postnatal day 25 and were sacrificed on postoperative days 3, 7, and 14 to collect penis samples. The penis morphology was examined in all groups. Subsequently, transforming growth factor β1 (TGF-β1), α-smooth muscle actin (α-SMactin), and signal transducers and activators of the transcription 3 (STAT3) expression levels in the different groups were measured at the indicated time points postoperatively using qRT-PCR and Western blot. Results: There was less regeneration of the subcutaneous tissue in hypospadias rats than in the sham-operated group (P < 0.05) on postoperative day 3. No differences were found in the regeneration of the subcutaneous tissue between these groups on postoperative days 7 or 14. Additionally, there were no differences in the epithelial cell regeneration between the control and the hypospadias groups at any postoperative timepoint. Moreover, the expression levels of TGF-β1, α-SMactin, and STAT3 were all significantly lower in hypospadias group than that in the sham-operated group (P < 0.05). Conclusion: The results from the present work suggest that preputial wound healing is retarded in rats with hypospadias induced by flutamide and that this retardation might result from multi-gene regulation

    Effects of Natural Polyphenols on Skin and Hair Health: A Review

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    The skin is the largest organ of the body and plays multiple essential roles, ranging from regulating temperature, preventing infections, to ultimately affecting human health. A hair follicle is a complex cutaneous appendage. Skin diseases and hair loss have a significant effect on the quality of life and psychosocial adjustment of individuals. However, the available traditional drugs for treating skin and hair diseases may have some insufficiencies; therefore, a growing number of researchers are interested in natural materials that could achieve satisfactory results and minimize adverse effects. Natural polyphenols, named for the multiple phenolic hydroxyl groups in their structures, are promising candidates and continue to be of scientific interest due to their multifunctional biological properties and safety. Polyphenols have a wide range of pharmacological effects. In addition to the most common effect, antioxidation, polyphenols have anti-inflammatory, bacteriostatic, antitumor, and other biological effects associated with reduced risk of a number of chronic diseases. Various polyphenols have also shown efficacy against different types of skin and hair diseases, both in vitro and in vivo, via different mechanisms. Thus, this paper reviews the research progress in natural polyphenols for the protection of skin and hair health, especially focusing on their potential therapeutic mechanisms against skin and hair disorders. A deep understanding of natural polyphenols provides a new perspective for the safe treatment of skin diseases and hair loss

    Design of Pd–Zn Bimetal MOF Nanosheets and MOF-Derived Pd<sub>3.9</sub>Zn<sub>6.1</sub>/CNS Catalyst for Selective Hydrogenation of Acetylene under Simulated Front-End Conditions

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    Novel zinc–palladium–porphyrin bimetal metal–organic framework (MOF) nanosheets were directly synthesized by coordination chelation between Zn(II) and Pd(II) tetra(4-carboxyphenyl)porphin (TCPP(Pd)) using a solvothermal method. Furthermore, a serial of carbon nanosheets supported Pd–Zn intermetallics (Pd–Zn-ins/CNS) with different Pd: Zn atomic ratios were obtained by one-step carbonization under different temperature using the prepared Zn-TCPP(Pd) MOF nanosheets as precursor. In the carbonization process, Pd–Zn-ins went through the transformation from PdZn (650 °C) to Pd3.9Zn6.1 (~950 °C) then to Pd3.9Zn6.1/Pd (1000 °C) with the temperature increasing. The synthesized Pd–Zn-ins/CNS were further employed as catalysts for selective hydrogenation of acetylene. Pd3.9Zn6.1 showed the best catalytic performance compared with other Pd–Zn intermetallic forms

    Hazard ratios (HRs) and 95% confidence interval(CI) for risk of new onset gallstones disease according to WHtR tertiles.

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    <p>Hazard ratios (HRs) and 95% confidence interval(CI) for risk of new onset gallstones disease according to WHtR tertiles.</p

    Hazard ratios (HRs) and 95% confidence interval(CI) for risk of new-onset gallstone disease according to BMI subgroups.

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    <p>Hazard ratios (HRs) and 95% confidence interval(CI) for risk of new-onset gallstone disease according to BMI subgroups.</p
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