微量元素影响幼儿智力发育多因素分析

研究了3609名1～岁儿童头发中微量元素与儿童智力发育不全的关系.结果表明,智力发育不全(IQ值55～69)儿童的发Zn为(68.24±16.56)×10-6、Pb为(14.73±8.68)×10-6;高智商(IQ值109～131)儿童的发Zn为(98.62±20.47)×10-6、Pb为(7.92±6.31)×10-6.正常儿童头发中Zn含量[(83.16±19.35)×10-6]显著高于智力发育不全儿童[(80.08±18.47×10)-6,P＜0.05].而正常儿童头发中Pb含量[(12.67±7.48)×10-6则明显低于智力发育不全儿童[(13.25±7.57)×10-6,P＜0.05].正常女童发Zn明显高于智力发育不全儿童的发Zn(P＜0.05).正常女童发Mn、Pb明显低于智力发育不全儿童的发Mn(P＜0.05)、Pb(P＜0.05).正常男童的发Zn、Cu明显高于智力发育不全儿童的发Zn(P＜0.05)、Cu(P＜0.05).正常男童的发Pb明显低于智力发育不全儿童的发Pb(P＜0.05).低锌高铅可能是儿童智力发育不全的重要致病原因.     

1051例儿童头发中微量元素的研究和相关性分析

为探讨儿童头发中 6种元素之间的相关性关系 ,应用电感耦合高频等离子体发射光谱仪(ICP -AES)测定了 6种元素的含量 ,并用SAS或SPSS软件 ,经计算机处理。结果表明 ,1 0 5 1例儿童头发中Zn、Fe、Cu、Ca、Mn和Pb含量分别为 (91 96± 2 0 0 5 )× 1 0 -6,(3 1 3 6± 5 5 2 )× 1 0 -6,(1 1 78± 2 69)× 1 0 -6,(677 3 8± 1 0 8 94)× 1 0 -6,(2 73± 1 0 4)× 1 0 -6和 (1 1 0 1± 3 62 )× 1 0 -6。儿童头发中 ,Zn与Pb含量呈非常显著负相关 ,P <0 0 1 ;Cu与Mn和Pb呈非常显著正相关 ,P <0 0 1 ;Ca与Pb呈非常显著正相关 (P =0 0 0 1 ) ;Mn与Pb呈非常显著正相关 ,P <0 0 1。     

父母职业对幼儿头发中微量元素水平的影响

测定了深圳市父母不同职业的 894名 1～ 7岁幼儿头发中的Zn、Cu、Fe、Ca、Mn、Pb的含量。结果表明 ,父母为干部与父母为工人的幼儿头发中的Fe有显著性差异 (P <0 0 5) ,其含量分别为 (2 9 2± 4 9)× 10 -6和 (30 0± 5 6 )× 10 -6;父母为干部与父母为工人的幼儿头发中的Mn有非常显著性差异 (P <0 0 0 1) ,其含量分别为 (1 7± 0 7)× 10 -6和 (1 9± 1 0 )× 10 -6;父母为干部与父母为工人的幼儿头发中的Pb有显著性差异 (P <0 0 5) ,其含量分别为 (12 3±7 6 )× 10 -6和 (13 2± 7 5)× 10 -6。本文还列出了幼儿头发中元素的含量比较图。     

幼儿头发中微量元素含量相关性研究

为探讨儿童头发中微量元素是否有协同或拮抗作用,测定了646名1－3岁和3803名4－7岁儿童头发中的Zn,Fe,Cu,Ca,Mn和Pb含量,并研究了各元素间的相互关系,结果表明：1－3岁幼儿头发中Zn,Fe,Cu,Ca,Mn和Pb各元素间均呈正相关,4－7岁儿童的发锌含量与发铅含量呈非常显著负相关（P值均＜0．001）,其它各元素间均呈正相关。     

糖尿病人头发中的铬、锰、铁与铜含量水平

采用催化极谱方法分析了 98例 (糖尿病人 47例 ,对照组健康人 5 1例 )头发样品中的微量元素铬 (Cr)、锰 (Mn)、铁 (Fe)、铜 (Cu)、锌 (Zn)、硒 (Se)和宏量元素钙 (Ca)、镁 (Mg)含量水平。结果显示 ,糖尿病人头发样品中的Cr( 0 99± 0 75 )× 1 0 - 6 、Mn( 1 3 0± 0 90 )× 1 0 - 6 和Cu( 8 5 0± 1 40 )× 1 0 - 6 分别显著低于对照组头发样品中的Cr( 1 5 5± 0 97)× 1 0 - 6 、Mn( 2 3 0± 1 60 )×1 0 - 6 和Cu( 1 0 40± 2 90 )× 1 0 - 6 ,Cr、Mn、Cu的显著性水平分别为P =0 0 0 1 ,P <0 0 0 1和P <0 0 0 1。而糖尿病人头发样品中的Fe( 1 9 0 0± 9 0 0 )× 1 0 - 6 ,则显著高于对照组头发样品中的Fe( 1 6 0 0± 8 0 0 )× 1 0 - 6 ,其显著性水平P为 0 0 2 3。但糖尿病人与健康人头发样品中的Zn、Se、Ca和Mg含量水平之间的差别并不显著。这些结果与其他一些研究所得的结论基本一致。     

佛山市顺德区幼儿头发中六种元素含量水平的研究

测定了佛山市顺德区1100名1～7岁学龄前儿童头发中6种元素含量。结果表明,该区幼儿头发中的Zn为(85.25+20.12)×10~(-6);Fe为(30.13±5.30)×10~(-6),Cu为(9.08±2.35)×10~(-6),Ca为(520.70±98.62)×10~6,Mn为(1.87±0.89)×10~(-6),Pb为(11.79±6.85)×10~(-6),并与周边地区作了比较。     

幼儿头发中锌与铅含量相关性分析研究

测定了 5 2 0例幼儿头发中锌 (Zn)和铅 (Pb)含量 ,分别为 ( 97 5 4± 2 8 1 9)× 1 0 - 6、( 1 5 2 2± 5 0 2 )× 1 0 - 6。相关分析表明 ,男女幼儿头发中Zn与Pb含量均存在着非常显著的负相关关系 ,P <0 0 0 1。这两种元素含量在男女幼儿之间没有显著差异。     

云当归与土壤中微量元素的测定及其相关性分析

采用电感耦合等离子体原子发射光谱(ICP-AES)法对云当归以及土壤中11种微量元素进行了分析.结果显示,土壤中微量元素的含量依次为Zn＞Cu＞Pb＞Fe＞Mg＞Mn＞Ni＞Cr＞ Cd＞ As＞ Hg;云当归中Mg、Fe、Mn、Zn中含量较高,而As、Cd、Cu、Pb、Hg等元素中含量相对较低,均低于药典标准.土壤中As与Cr、Pb与Zn存在极显著正相关(r=0.785,0.808);Mn与Cr存在极显著负相关(r=-0.733),As与Cu存在显著负相关(r=-0.631).云当归中Fe与Ni极显著正相关(r=0.731),Cd与Cu极显著负相关(r＝-0.714);Zn与Hg显著相关(r=0.655),Ni与As、Fe与Pb、Fe与Cd显著负相关(r=-0.658,-0.637,-0.673).云当归与土壤中的As存在显著相关(r=0.707).     

老年高血压患者头发中6种元素含量测定及分析

对探讨老年高血压与微量元素的关系,测定了40例老年高血压患者头发中Zn、Fe、Cu、Ca、Mn、pb含量。结果表明,高血压患者头发中Zn、Fe、Cu、Ca、Mn含量均降低,以Zn、Fe、Ca降低最明显（P＜0．01）。提示发Zn、Fe、Ca对高血压发生起一定的作用。     

广西侗族男性青少年头发五种元素含量与身高体重关系

采用随机抽样方法，对广西三江侗族7—16岁男性青少年头发中的Fe、Zn、Ca、Cu、Mg和身高、体重进行了检测，并用相关分析方法研究了身高、体重与头发中五种元素含量的相关关系。结果显示，身高、体重均与头发中的Zn和Ca呈负相关关系(P＜0．05)。说明Zn和Ca与青少年的生长发育密切相关。     

国内光催化研究进展简述

分1975~1985, 1985~1995和1995~2012三个时期简要介绍了国内光催化研究进展, 主要侧重于光催化材料及其改性、应用和反应机理方面的研究进展, 并指出了当前光催化领域存在的一些重要问题和未来的发展趋势, 涉及到光解水、CO₂还原、环境净化和选择性有机合成等方面.     

青蒿素研究进展

青蒿素是目前治疗疟疾的特效药。本文对自青蒿素发现以来的最新研究进展进行了比较详尽的综述。内容包括: 青蒿素的发现及历史, 青蒿素的来源, 青蒿素的全合成,青蒿素的生物合成, 青蒿素衍生物以及植物组织培养生产青蒿素。     

Reactions in droplets in microfluidic channels

Fundamental and applied research in chemistry and biology benefits from opportunities provided by droplet-based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet-based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights.     

Interpretation of inorganic arsenic metabolism in humans in the light of observations made in vitro and in vivo in the rat

The toxicity of inorganic trivalent arsenic for living organisms is reduced by in vivo methylation of the element. In man, this biotransformation leads to the synthesis of monomethylarsonic (MMA) and dimethylarsinic (DMA) acids, which are efficiently eliminated in urine along with the unchanged form (As_i). In order to document the methylation process in humans, the kinetics of As_i, MMA and DMA elimination were studied in volunteers given a single dose of one of these three arsenicals or repeated doses of As_i. The arsenic methylation efficiency was also assessed in subjects acutely intoxicated with arsenic trioxide (As₂O₃) and in patients with liver diseases. Several observations in humans can be explained by the properties of the enzymic systems involved in the methylation process which we have characterized in vitro and in vivo in rats as follows: (1) production of As_i metabolites is catalyzed by an enzymic system whose activity is highest in liver cytosol; (2) different enzymic activities, using the same methyl group donor (S-adenosylmethionine), lead to the production of mono- and di-methylated derivatives which are excreted in urine as MMA and DMA; (3) dimethylating activity is highly sensitive to inhibition by excess of inorganic arsenic; (4) reduced glutathione concentration in liver moderates the arsenic methylation process through several mechanisms, e.g. stimulation of the first methylation reaction leading to MMA, facilitation of As_i uptake by hepatocytes, stimulation of the biliary excretion of the element, reduction of pentavalent forms before methylation, and protection of a reducing environment in the cells necessary to maintain the activity of the enzymic systems.     

Gemini表面活性剂合成进展

系统总结了近百种Gemini表面活性剂的合成路线和方法,并且按照其结构特点分门别类地进行比较和归纳,对今后Gemini表面活性剂的合成发展方向提出了一些看法,这对促进此类新颖表面活性剂的工业化进程将具有指导意义。     

Recent Advances in Analytical Methodology for in vivo Electrochemistry in Mammals

Electrochemistry is one of the most advanced techniques for monitoring neurochemical activities in the living brain because electrochemical approaches bear the advantageous features of high spatial and temporal resolutions, which facilitate its tremendous potential in investigating the highly spatially heterogeneous brain system and the fast dynamics of neurochemical activities. On the other hand, since brain is the most complicated organ in the sense of its numerous kinds of neurochemical species, high selectivity is always required for any analytical methods that approach the brain. In this review, we will discuss various electrochemical methodologies to achieve selective detection of neurochemicals in mammalian brain and the strategies developed mainly by our group towards selective monitoring of both electrochemically active and inactive neurochemicals. At the end, we will discuss possible solutions towards brain mapping of neurochemical species and combination of neurochemical detection strategy with electrophysiology as the direction of future development of electroanalysis in living brain.     

乙基香兰素研究前景

报导了近几十年来国内外关于乙基香兰素的研究进展与动态,并简单介绍了本文作者在该方面所取得的研究成果,参考文献33篇。     

Trends in education in analytical chemistry

Summary At the session of the WPAC of Fechem on education in analytical chemistry it was concluded that it is now essential to include chemometrics and basic knowledge of computers in all courses on analytical chemistry.

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Tendenzen in der analytisch-chemischen Ausbildung

Zusammenfassung Bei einer Tagung der WPAC über die Lehre auf dem Gebiet der analytischen Chemie wurde bei der Betrachtung neuer Aspekte festgestellt, daß vor allem Chemometrie und Grundkenntnisse in Computertechnik in die Ausbildung aufgenommen werden sollten.

     

钙与人体及临床

钙是宏量元素，是人体中含量较高的元素之一，体内99％的钙构成骨骼和牙齿以及维持骨骼结构，1％的钙调节人体重要生理功能。钙的含量过高或过低都与许多疾病有关，只有保持一种平衡状态，才能使机体处于正常环境。     

AGET ATRP in the Presence of Air in Miniemulsion and in Bulk

Summary: The recently developed initiation system, activators generated by electron transfer (AGET), is used in atom transfer radical polymerization (ATRP) in the presence of a limited amount of air. Ascorbic acid and tin(II ) 2‐ethylhexanoate are used as reducing agents in miniemulsion and bulk, respectively. An excess of reducing agent consumes the oxygen present in the system and, therefore, provides a deoxygenated environment for ATRP. ATRP of butyl acrylate is successfully carried out in miniemulsion and in the presence of air. During polymerization the radical concentration remains constant. The polymerization reaches over 60% monomer conversion after 6 h, which results in polymers with a predetermined molecular weight = 14 000 g · mol⁻¹ and a low polydispersity ( = 1.23). AGET ATRP of styrene is also successful in bulk in the presence of air, as evidenced by linear semi‐logarithmic kinetics, which leads to polystyrene with an of 13 400 g · mol⁻¹ and a low polydispersity index ( = 1.14).

Appearance of miniemulsion before and after the reducing agent ascorbic acid was added (left); and GPC traces representing molecular weights during the AGET ATRP of BA in miniemulsion in the presence of air (right).