蚕蛹、蝎子、海肠中20种元素的ICP-AES测定和氨基酸含量测定

采用ICP-AES法直接快速测定蚕蛹、蝎子、海肠中20种元素含量,本法简单快速,灵敏度高,检出限低,精密度好,RSD为1.4%~6.8%。是同时检测食物中多元素的理想方法。与其它食物比较,这几种食物的钙、锰、铁、锌、铜、镁、钠、钾等元素含量极为丰富。用氨基酸测定仪测定了这几种食物中氨基酸和牛磺酸的含量,为它们的营养研究提供了理论依据。     

海南冰糖草中4种重金属元素含量分析

目的:建立海南产冰糖草中重金属元素含量测定方法,测定其重金属元素含量。方法:采用氢化物原子荧光法建立冰糖草中重金属砷、汞、铅、镉元素的分析检测方法。结果:4种重金属元素的线性相关系数为0.9991-0.9999,精密度小于2.74%,加标回收率为95%~102.3%,RSD≤3.36%。冰糖草中重金属元素含量均符合绿色中药标准。结论:该方法简便、准确、稳定,可用于冰糖草的质量控制。     

电感耦合等离子质谱法(ICP-MS)法测定茵栀黄注射液中有害元素铅、砷、镉、汞、铜的含量

建立了电感耦合等离子体质谱法(ICP-MS)测定茵栀黄注射液中Pb、As、Cd、Hg、Cu 5种元素的方法。样品经微波消解后,直接用ICP-MS同时测定上述5种元素,结果5种元素的检出限分别在5～1250 ng/L之间;线性良好,线性相关系数均为r≥0.999;精密度RSD3.5%;回收率在95.7%～107.5%之间。方法操作简便、分析速度快、灵敏度高,各项分析性能指标均达到要求,适用于茵栀黄注射液中有害元素的测定。     

电感耦合等离子体质谱法测定地质样品中16个元素

本方法建立了采用HNO3-H2SO4-HClO4-HF混合酸敞口消解试样,电感耦合等离子质谱仪同时测定地质样品中Ag、La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、U16种元素。讨论了各元素之间的干扰,并建立数学校正方程。通过对国家一级标准物质的测定,其结果表明:该方法的检出限、准确度、精密度均满足DZ/T0130-2006要求。银、铀及稀土元素的测量值与标准值之间的相对标准偏差均小于5%。     

微波消解ICP-MS法测定凤丹花中多种可溶性元素

采用微波消解-电感耦合等离子体质谱(ICP-MS)法测定两种凤丹花(凤丹白、凤丹粉)中8种可溶性元素Cr、As、Se、Cd、Sb、Ba、Hg、Pb的含量。结果表明:测定的两种凤丹花样品中,凤丹白中8种可溶性元素含量均高于凤丹粉中的含量;将检测结果与《食品中污染物限量》(GB 2762-2005)比较可知,两种凤丹花的各项指标普遍高于水果和叶菜类标准限量;与茶叶的唯一有害元素Pb的标准限量相比,两种凤丹花Pb含量远低于茶叶限量标准。本研究结果表明,凤丹花可作为茶品用于饮用,但作为食品食用有一定的限制。本方法的加标回收率范围为92.25%~106.75%;相对标准偏差RSD为1.3%~4.8%,表明试验精确度高,数值可靠。     

不同产地鼠曲草中微量元素和重金属元素的ICP-MS分析

建立不同产地鼠曲草(Gnaphalium affine)中9种微量元素和5种重金属元素的测定方法。样品经消解后，采用电感耦合等离子体质谱法测定：射频功率1000 W；雾化器流量0.88 L·min^-1；辅助气流1.2 L·min^-1；冷却气流量12.0 L·min^-1；重复3次。结果表明，各元素线性关系良好，相关系数(r)在0.9965～1.0000，方法检出限为0.0011～0.0734 ng·mL^-1，相对标准偏差为0.0%～20.9%(n=3)。该方法干扰少、检出限低、分析速度快，适用于鼠曲草中微量元素和重金属元素的测定。     

羊奶果种子脂肪酸组成和矿质元素分析

测定了羊奶果(Elaeagnus conferta Roxb.)种子脂肪酸组成以及矿质元素含量。结果表明:脂肪酸含量为1.98%,主要是油酸(C18:1)34.15%、亚油酸(C18:2)31.51%、软脂酸(C16:0)13.83%、硬脂酸(C18:0)2.88%。饱和脂肪酸:单不饱和脂肪酸:多不饱和脂肪酸含量比为1:2.23:2.75。矿质元素K高达7837.69mgkg-1,Fe为30.99mgkg-1、Zn为10.13mgkg-1,Na为259.5mgkg-1。     

不同产地黄芩中无机元素含量及其与根际土壤无机元素的关系

药用植物中各无机元素含量的不仅影响药用植物的生长发育,也是药材有效成分的构成因子。通过对全国范围内16个不同产地(即居群)的92个野生黄芩(Scutellaria baicalensis Georgi)样本及其相应的根际土壤中10种无机元素含量的分析,发现不同产地黄芩及其根际土壤无机元素都有很大变异,且不同产地黄芩根际土壤中无机元素的变异远大于黄芩药材中无机元素的变异。总体来看,黄芩中Mg(9级)含量较其他植物含量高;P(1级)、K(2级)、Mn(3级)含量与其他植物相比处处较低水平;黄芩对Sr(富集系数达到3.52)有较强富集。并且通过无机元素分布曲线分析建立了无机元素指纹谱,主成分分析筛选出黄芩主要特征无机元素为Mg、K、Ca、Fe、Zn。本研究还表明,黄芩对各元素的吸收能力受产地的影响较大,提示黄芩对无机元素的吸收与各产地根际土壤无机元素有一定关联性。     

不同产区太子参氨基酸含量测定及多元统计分析

本文采用高速氨基酸自动分析仪对太子参四大种植主产区(安徽、江苏、福建、贵州)的栽培品及河南的野生品,共13个批次太子参药材的氨基酸组成和含量进行测定。结果显示氨基酸含量基本顺序为:精氨酸(Arg)>谷氨酸(Glu)>天冬氨酸(Asp)>脯氨酸(Pro),其中安徽宣城产太子参样品(S2)的16种氨基酸总含量和7种人体必需氨基酸含量最高。以上述4种主要氨基酸作为指标,探讨了不同产区太子参药材的内在品质。采用聚类分析法对氨基酸含量进行多元统计分析,表明氨基酸含量分析可体现样品产区间和产区内的差异性,可区别野生品与栽培品。这些结果为发展太子参道地药材的质量标准控制提供了依据。     

二道坊河沉积物中重金属等元素富集特征的研究

以二道坊河沉积物为研究对象 ,采用相关与回归分析综合地研究了 1 4种元素在沉积物中的富集特征 .结果表明 :地球化学性质相近的元素 ,它们在沉积物中的相关系数大多达到了显著或极显著的水平 ;通过因子分析 ,求出了 4个主因子 ,它们代表沉积物中1 4种元素测定信息的 85% ,以第一、二主因子对应的特征向量为X、Y轴将 1 4个元素分成了 3类 ;建立了大部分元素与沉积物性质之间的多元回归方程 .     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various