Anti-inflammatory bibenzyls from the stems of Dendrobium huoshanense via bioassay guided isolation

Abstract

The stems of Dendrobium huoshanense have long been used to prevent various diseases, including inflammatory diseases. This study was aimed to explain the anti-inflammatory effect of D. huoshanense stems in LPS-induced RAW 264.7 macrophages and to discover potential anti-inflammatory compounds. Results exhibited that D. huoshanense stems ethanol extract could significantly inhibit LPS-induced production of NO, TNF-α and IL-1β. Based on bioassay guided strategy, four bibenzyls (1–4) were isolated from D. huoshanense stems for the first time. Anti-inflammatory assay showed 1–4 could remarkably inhibit the production of NO in LPS-induced macrophages. Moreover, quantitative RT-PCR analysis displayed that the mRNA levels of iNOs, TNF-α and IL-1β could also be significantly reduced by 1–4. These results suggested that D. huoshanense stems ethanol extract and bibenzyls 1–4 might be well developed as therapeutic agent to prevent inflammatory diseases.     

On the Variability of Heart Rate Variability—Evidence from Prospective Study of Healthy Young College Students

Heart rate variability (HRV) has been widely used as indices for autonomic regulation, including linear analyses, entropy and multi-scale entropy based nonlinear analyses, and however, it is strongly influenced by the conditions under which the signal is being recorded. To investigate the variability of healthy HRV under different settings, we recorded electrocardiograph (ECG) signals from 56 healthy young college students (20 h for each participant) at campus using wearable single-lead ECG device. Accurate R peak to R peak (RR) intervals were extracted by combing the advantages of five commonly used R-peak detection algorithms to eliminate data quality influence. Thorough and detailed linear and nonlinear HRV analyses were performed. Variability of HRV metrics were evaluated from five categories: (1) different states of daily activities; (2) different recording time period in the same day during free-running daily activities; (3) body postures of sitting and lying; (4) lying on the left, right and back; and (5) gender influence. For most of the analyzed HRV metrics, significant differences (p < 0.05) were found among different recording conditions within the five categories except lying on different positions. Results suggested that the standardization of ECG data collection and HRV analysis should be implemented in HRV related studies, especially for entropy and multi-scale entropy based analyses. Furthermore, this preliminary study provides reference values of HRV indices under various recording conditions of healthy young subjects that could be useful information for different applications (e.g., health monitoring and management).     

Numerical simulation of transonic limit cycle oscillations using high-order low-diffusion schemes

This paper simulates the NLR7301 airfoil limit cycle oscillation (LCO) caused by fluid–structure interaction (FSI) using Reynolds averaged Navier–Stokes equations (RANS) coupled with Spalart–Allmaras (S–A) one-equation turbulence model. A low diffusion E-CUSP (LDE) scheme with 5th order weighted essentially nonoscillatory scheme (WENO) is employed to calculate the inviscid fluxes. A fully conservative 4th order central differencing is used for the viscous terms. A fully coupled fluid–structural interaction model is employed. For the case computed in this paper, the predicted LCO frequency, amplitudes, averaged lift and moment, all agree excellently with the experiment performed by Schewe et al. The solutions appear to have bifurcation and are dependent on the initial fields or initial perturbation. The developed computational fluid dynamics (CFD)/computational structure dynamics (CSD) simulation is able to capture the LCO with very small amplitudes measured in the experiment. This is attributed to the high order low diffusion schemes, fully coupled FSI model, and the turbulence model used. This research appears to be the first time that a numerical simulation of LCO matches the experiment. The simulation confirms several observations of the experiment.     

~(60)Co-γ辐射制备载体型多孔聚合物气相色谱固定相

用~(60)Co-γ辐射法制备载体型多孔芳类聚合物气相色谱固定相,考察了影响其色谱性能的主要因素.它与目前常用的多孔高分子小球固定相相比,柱效高,热稳定性好,未觉察到静电效应,对烷烃分离速度快,分离度高,色谱峰形对称.     

简并和非简并定态微扰统一理论与能量二级修正公式

建立了简并态与非简并态微扰的统一理论,并推导出一般情况下(简并态)能量的二级修正及波函数的一级修正公式。     

n维空间任意两力学量同时具有确定值的判定定理

ｎ维空间任意两力学量同时具有确定值的判定定理查新未，王天真（陕西师范大学物理学系，西安７１００６２，第一作者，男，３６岁，副教授）在量子力学中，通常用两力学量算符的对易情况判断其是否同时具有确定值．这种方法有时判断不准，即在有些情况下，虽然两力学量算...     

船舶喷水推进装置特性曲线及其计算与绘制方法

本文对船舶喷水推进装置特性曲线的形式及计算绘制方法进行了探讨,并对喷水推进装置特性曲线作了必要的分析和介绍了它的使用方法。     

绵枣儿两个不同居群的核型研究

本文报道了安徽省芜湖和琅琊山产绵枣儿Ｓｃｉｌｌａ ｓｃｉｌｌｏｉｄｅｓ（Ｌｉｎｄｌ．）Ｄｒｕｃｅ的染色体数目和核型，其结果如下：芜湖材料有两个细胞型：ＡＡ和ＢＢ型，Ａ和Ｂ分别代表Ａ染色体组（ｘ＝８）和Ｂ染色体组（ｘ＝９）。细胞型I;２ｎ＝１６＋１Ｂｓ＝６ｍ＋２ｓｍ＋８ｓｔ＋１Ｂｓ；细胞型Ⅱ：２ｎ＝１８＋１Ｂｓ＝８ｍ＋２ｓｍ＋８ｓｔ＋１Ｂｓ，二者均属Ｓｔｅｂｂｉｎｓ“３Ｂ”核型。琅琊山材料仅发现一个细