He’s Homotopy Perturbation Method and Fractional Complex Transform for Analysis Time Fractional Fornberg-Whitham Equation

In this article, time fractional Fornberg-Whitham equation of He’s fractional derivative is studied. To transform the fractional model into its equivalent differential equation, the fractional complex transform is used and He’s homotopy perturbation method is implemented to get the approximate analytical solutions of the fractional-order problems. The graphs are plotted to analysis the fractional-order mathematical modeling.     

Enantioseparation of amino acids by micellar capillary electrophoresis using binary chiral selectors and determination of D-glutamic acid and D-aspartic acid in rice wine

A new chiral capillary electrophoresis (CE) analytical method for the determination of six pairs of amino acid enantiomer-derivatized precapillary with 9-fluorenylmethoxycarbonyl chloride (FMOC) was developed. CE separation parameters such as the pH of background electrolyte, the boric acid concentration, the addition of D-fructose and isopropanol, and the effect of new binary chiral selectors on the electropherograms were investigated. Precapillary and in-capillary derivatization was compared as well. The results showed that enantiomeric separations were obtained with enantio-resolution (Rs) ranged from 2.61 to 9.99 for the FMOC-derivatized amino acid enantiomers except alanine with Rs 1.06. Precapillary derivatization method provides overall better Rs for nearly all the targets except FMOC-aspartate with efficiency up to 1.309?×?10⁶ plates and limit of detection (LOD) down to 2.5?μM. This method was successfully applied to analyze the concentration of the D/L-glutamic acid and D/L-aspartate in seven rice wine samples.     

天然产物色胺酮及其衍生物的仿生合成

以药用植物体内存在的生物合成前体吲哚醌和邻氨基苯甲酸为反应物,用POCl3作催化剂,仿生合成了天然产物色胺酮(1),结构表征结果与标准品一致.该反应所用原料易得,避免了使用较昂贵的靛红酸酐,适合实验室小规模简便合成.采用此方法合成了14个色胺酮衍生物,可见其具有广泛的适应性.     

How Do the Spatial Structure and Time Delay Affect the Persistence of A Polluted Species

In this article, we consider the effects of diffusion and time delay on the species in a polluted environment. Persistence-extinction thresholds are given for population in the toxicant stressed logistic growth model with discrete diffusion or time delay. It is proved that dispersal allows a larger threshold, that is, dispersal can increase the endurance effectiveness of the population subjected to toxicant, and time delay has no effect on the threshold result.     

基于气相色谱-质谱联用技术的水稻代谢轮廓分析方法的建立

开展了基于衍生化气相色谱-质谱联用的水稻代谢物分析方法的研究。采用D-最优试验设计对代谢物的提取溶剂进行优化,考察了水、甲醇、乙腈和异丙醇的提取效率,通过多元统计分析评价提取效能和溶剂配比的相关性,最终确立以80%(v/v)甲醇/水作为代谢物提取的最适溶剂。在此基础上对该方法的分析性能进行评价,发现绝大多数代谢物(＞90%)具有良好的精密度、重现性和稳定性(相对标准偏差小于30%),且占总峰面积88.0%的代谢物的响应值与其浓度间呈线性关系(相关系数＞0.9)。采用气相色谱-质谱联用方法从水稻种子中共鉴定出86个代谢物,涵盖糖、氨基酸、有机酸、甾体等多类浓度差异大的物质,适合于水稻的代谢表型差异研究。     

Effects of Muscle Fatigue and Recovery on Complexity of Surface Electromyography of Biceps Brachii

This study aimed to investigate the degree of regularity of surface electromyography (sEMG) signals during muscle fatigue during dynamic contractions and muscle recovery after cupping therapy. To the best of our knowledge, this is the first study assessing both muscle fatigue and muscle recovery using a nonlinear method. Twelve healthy participants were recruited to perform biceps curls at 75% of the 10 repetitions maximum under four conditions: immediately and 24 h after cupping therapy (−300 mmHg pressure), as well as after sham control (no negative pressure). Cupping therapy or sham control was assigned to each participant according to a pre-determined counter-balanced order and applied to the participant’s biceps brachii for 5 min. The degree of regularity of the sEMG signal during the first, second, and last 10 repetitions (Reps) of biceps curls was quantified using a modified sample entropy (E_ms) algorithm. When exercise was performed immediately or 24 h after sham control, E_ms of the sEMG signal showed a significant decrease from the first to second 10 Reps; when exercise was performed immediately after cupping therapy, E_ms also showed a significant decrease from the first to second 10 Reps but its relative change was significantly smaller compared to the condition of exercise immediately after sham control. When exercise was performed 24 h after cupping therapy, E_ms did not show a significant decrease, while its relative change was significantly smaller compared to the condition of exercise 24 h after sham control. These results indicated that the degree of regularity of sEMG signals quantified by E_ms is capable of assessing muscle fatigue and the effect of cupping therapy. Moreover, this measure seems to be more sensitive to muscle fatigue and could yield more consistent results compared to the traditional linear measures.     

2,2′-联咪唑合成的改进方法

优化了传统合成及提纯2,2＇-联咪唑的方法,使实验步骤缩减,并使产率和纯度有较大提高。     

基于柱前衍生-超高效液相色谱-质谱联用技术的植物提取液中氨基化合物代谢谱分析

氨基化合物在植物生长发育中起着重要作用。本文建立了一种基于柱前衍生-超高效液相色谱-质谱联用技术的植物提取液中氨基化合物代谢谱的分析方法。以烟草鲜叶为例,共检测出87种氨基化合物。其中43种氨基化合物的定量分析结果表明,方法的线性相关系数在0.993~0.999之间,线性范围可达到4个数量级,检出限为0.03~6.58 ng/mL,日内、日间精密度分别为0.7%~15.6%、0.8%~22.9%,回收率为74.4%~122.7%。采用该方法考察了打顶对不同部位烟草鲜叶中氨基化合物代谢谱的影响,结果显示打顶处理对上部叶影响最大,打顶后上部叶氮代谢主要流向生物碱合成方向。该方法充分利用了三重四极杆串联质谱和高分辨串联质谱技术的优势,可实现植物提取液中氨基代谢物的高选择性、高灵敏度分析。     

Metal-free cross-dehydrogenative C–N coupling of azoles with xanthenes and related activated arylmethylenes

A metal-free C(sp³)–H/N–H cross-coupling of azoles with xanthenes and related activated arylmethylenes is presented. Both the use of azoles and the activation pattern of C(sp³)–H sources are essential for this transformation. In the presence of 2.0 equiv of benzoyl peroxide (BPO), methylenes bearing a heteroatom-bridged bisaryl group reacted with various azolic N–H sources to afford C–N bond forming products in usually excellent or quantitative yields, and the diphenylmethane and methylenes coactivated by a phenyl group and an adjacent heteroatom are less reactive. Mechanistic investigations suggest that a radical/radical cross-coupling pathway might be involved.