Lignan glucoside from Sinopodophyllum emodi and its cytotoxic activity

A new lignan glycoside was isolated from the n-butanol extract of the roots and rhizomes of Sinopodophyllum emodi.On the basis of spectral evidences,its structure was established and named as 4,5-didemethylpodophyllotoxin 7’-O-β-D-glucopyranoside. This compound showed cytotoxicity against four human cancer cell lines(Hela,K562,SH-SY5Y and CNE) in vitro.     

应用壳聚糖-分子筛复合材料选择性吸附卷烟烟气中低分子醛酮

制备了3种壳聚糖-分子筛复合材料,并使用扫描电镜和ASAP 2020全自动吸附仪观测了复合材料的微观形态及其物理性质。对分别添加3种壳聚糖-分子筛复合材料、分子筛及壳聚糖的卷烟复合滤咀对主流烟气中低分子醛酮类化合物和其它有害物质(如焦油、尼古丁及一氧化碳等)的吸附效果进行了试验。结果表明:添加了壳聚糖-分子筛复合材料、分子筛及壳聚糖的卷烟滤咀对主流烟气中低分子醛酮类化合物均有较好的吸附作用,对焦油、烟碱量无明显影响;3种壳聚糖-分子筛复合材料对主流烟气中醛酮类化合物的吸附能力均优于其两种单体材料,该复合材料对一氧化碳有一定的吸附,且对抽吸品质有所改善,口感柔和,烟气刺激性降低。     

How to estimate the effect of an intense meteor shower on human space activities

In the present age, the potential threat to space projects coming from some intense meteor storms has been noticed. Especially, the increasing activities of mankind in space for scientific, commercial and military purposes have led to an increase in safety-related problems about the satellites, space stations and astronauts. Several new techniques for observing meteors and meteor showers have been developed. However, how to estimate even predict the effect of an intense meteor shower should be further studied. The initial definition about a meteor storm based on visual observations with a Zenithal Hourly Rate of over one thousand seems insufficient, since it only means a storm or burst of meteors in numbers. In 2006 the author suggested a synthetical index of the potential threats about intense activities of meteors; however, it is too complex to determine several parameters. In this paper, the author suggests a Special True Number Flux Density (STNFD). Set a certain energy-limit, or a certain electric-charge-limit, and then calculate the number flux density. Through the comparison between two of the 10 strong meteor showers in recent years it is found that the important factor affecting the space flight security is not only the number of meteoroids, but also their velocities, their average energy and the population index r. Calculations show that Giacobinids, even June Bootids, should be one of the most hazardous meteor showers.     

ICP-AES雾化法氢化法联合同时测定人血清中三十种元素

本文探讨了用ICP-AES雾化法氢化法联合同时测定人血清中三十种元素的方法。本法最低检出量基本满足血清样品的测定要求。方法回收率在95—105%之间,重复测定的相对误差小于5%。对于探索血清元素含量与疾病的关系及临床诊断有一定价值。     

火焰原子吸收法测定血清中三种元素的三种前处理方法比较

本文就火焰原子吸收法测定血清中K、Fe、Mg三种元素常用的三种前处理方法,即用去离子水稀释、用1%硝酸稀释、用硝酸-高氯酸消化进行了比较,并用数理统计方法进行差异显著性测验,证明三种前处理方法所得结果一致。其中1%硝酸稀释法操作简便快速,适于批量样品的分析。     

Synthesis, Characterization, Spectroscopic and Electro-chemical Properties of New Mono- and Binuclear Copper(I) Complexes with Substituted 2,2''''-Bipyridine

Introduction Copper(I) complexes have received much attention for their being less expensive and environmentally friendly, various coordination geometry, rich photo-chemical and photophysical properties.1-7 It is well known that copper complexes with diimine (2,2'-bipy- ridine, 1,10-phenanthroline and their substituted deriva-tives designated as diimine) generally exhibit low en-ergy metal-to-ligand charge-transfer (MLCT) states lo-cated in the regions of 350650 nm (e ≈ 103—104 dm3昺ol-1昪…     

A Novel Biomolecular Immobilization Matrix Based on Nanoporous ZnO／Chitosan Composite Film for Amperometric Hydrogen Peroxide Biosensor

The performance of an enzyme electrode often depends on the method of enzyme immobilization when fabricating biosensors1. Therefore, the technique used to immobilize the enzyme is one of the key factors in developing a reliable biosensor. Organic-inorganic composite (or hybrid) materials have emerged in recent years. It combines the physicochemical attributes of components and improves their features. Organic components benefit the formation of defect-free inorganic membranes and make it less …     

On K_0-groups of operator algebras on Banach spaces

This paper merges some classifications of G-M-type Banach spaces simplifically, discusses the condition of K0(B(X)) = 0 for operator algebra B(X) on a Banach space X, and obtains a result to improve Laustsen's sufficient condition, gives an example to show that X ≈ X2 is not a sufficient condition of K0(B(X)) = 0.     

The Reduction of a Natural Diterpene Containing a, B-Unsaturated Keto Group

Hedychenone (1), a diterpene containing a, B-unsaturated keto group, was reduced by aluminum-mercury alloy, and a dimerized product (2) was obtained as the major product. The coupling occurred at B position of the keto group.