学龄前儿童头发中九种元素分析

用原子吸收光谱法测定了长春市某幼儿园１２０名正常儿童头发中铁、锌、铜、锰、钙、镁、钠、钾、铅九种元素含量。对不同年龄、性别儿童发中各元素含量进行了对比分析,并对微量元素铁、锌、铜、锰含量与有关标准进行了比较,表明缺铁现象普遍存在,发铁缺乏率达９４．７４％以上。     

老年慢性支气管炎急性发作期病人头发微量元素的测定与分析

为观察老年慢性支气管炎急性发作期头发中微量元素的变化,测定了50例老年慢性支气管炎急性发作期患者和40例正常对照组头发中锌、铁、铜、钙、锰、铅6种元素含量。结果表明,慢性支气管炎急性发作期患者发中锌、铁、铜、钙含量明显低正常对照组（P＜0．01）。提示头发中微量元素减少与慢性支气管炎易反复感染有一定的关系。     

信宜市教育城幼儿园幼儿微量元素营养评估及分析

为了对信宜市教育城幼儿园幼儿微量元素营养进行评估,共采集了教育城幼儿园幼儿239例头发,其中男165例,女74例,用电感耦合等离子体发射光谱法测定头发中的钙、锌、铁、铜、锰和铅的含量,其结果分别为：钙584．844-178．76μg/g,锌178．10±83．38μg/g,铁61．67±17．49μg／g,铜14．03±8．92μg／g,锰2．86±1．73μg／g,铅7．13±2．83μg／g。按照世界卫生组织的四级评估标准进行评估,钙、锌和锰等元素没有发现中度以上的营养缺乏现象,其中铁只有0．4％重度营养缺乏,铜只有8．0％中度营养缺乏,有害元素铅没有发现中度以上超标现象。比对结果,信宜市教育城幼儿园幼儿微量元素营养水平,远优于当地及周边城市的幼儿园幼儿。幼儿园幼儿微量元素营养是否均衡,应作为幼儿园总体评估指标之一。     

兰州市城关区313名儿童血铅水平及其钙、铁、铜和锌的调查研究

为了解兰州市城关区儿童血铅水平及其钙、锌、铁、铜等微量元素分布状况,对兰州市城关区某幼儿园及同时期来我院儿保体检的正常儿童采耳用微量血无火焰原子吸收光谱法进行铅、钙、锌、铜、铁元素的测定。结果表明,本次调查儿童血铅≥10μg/dL者占93．9％,各年龄组间钙、锌、铜、铁有显著性差异。提示血铅水平与锌、钙存在相关关系。     

儿童反复呼吸道感染与发锌、铁、铜、钙关系分析

为了解反复呼吸道感染与头发微量元素的关系,测定了52例易感儿及41例健康儿童发锌,铁,铜,钙含量,结果显示,易感儿发锌含量极显著低于健康组（P＜0．01）,发钙偏低,0．05＞P＞0．01,发铁,铅含 量基本正常,两组无显著差异,本研究表明儿童反复呼吸道感染与缺锌,缺钙有关。     

精神发育迟滞儿童的头发微量元素检测及分析

为测定和分析精神发育迟滞儿童头发微量元素营养状态,选择来自某特殊学校学生（IQ均低于70）210例发样为观察组,采用原子吸收分光光度法测定发样中锌、铁、铜、钙、锰、铅、镁和铬含量.结果表明,本组210例精神发育迟滞儿童的发铅和发镁低于正常对照组,具有统计学意义.发锌稍高于对照组但无统计学意义,其它几种元素含量基本相似.可见特殊学校精神发育迟滞儿童的发铅和发镁比正常儿童低,其意义值得进一步分析.     

广州市芳村区240例正常婴幼儿头发中微量元素水平分析

测定了广州市芳村区２４０例正常婴幼儿头发中锌、铁、铜、钙、锰、铅、碘等７种元素的含量,并与广州婴幼儿头发元素的含量正常值进行了对照分析。结果表明,不同性别的芳村区婴幼儿头发中微量元素的含量与广州市正常值之间存在显著差异,Ｐ〈０．０１,说明芳村区婴幼儿体内微量元素的含量尚需从各种途径加以提高或控制,以促进儿童体格、智力等方面的发育。     

中山市火炬开发区1078例儿童头发微量元素临床研究

为了探讨微量元素对儿童健康的影响,检测了中山市火炬开发区1078名2个月－14岁儿童头发锌,锌,铜,钙,锰,铅,结果发现,不同年龄儿童同一元素的含量不同,婴,幼儿组发锌,铁,钙明显低于其他年龄组,同时缺锌,缺铁,铁钙,高铅是引起儿童厌食,佝偻病, 呼吸道感染的主要原因,建议针对病因开展儿童微量元素缺乏的防治工作。     

矮小身材儿童头发中8种微量元素分析

为了解矮小身材患儿头发中8种微量元素的含量,结合病史,探讨影响儿童生长发育迟缓的影响因素,采用火焰原子吸收法检测了78例矮小身材儿童头发中的锌、铁、铜、钙、镁、硒、锰和铅含量。结果显示,大多数儿童发锌含量低于正常;半数以上儿童发铁和发钙低于正常;约四成儿童发硒和发镁低于正常;约1／3儿童发铜及发锰含量低于正常。发铅含量高于正常者占46％。可见儿童身材矮小除遗传因素外,可能与营养不良、反复感染及体内多种元素失衡有关。     

2623例4～7岁儿童头发微量元素的检测分析

为掌握广东省惠阳市儿童微量元素及营养状况,为今后的微量元素缺乏病的临床诊断提供科学依据。对本市2623例4－7岁集体儿童进行随机检测头发中元素钙、铁、锌、铜、锰、铅的含量。结果表明,异常儿占51．12％,女孩占36．33％;城市集体儿童异常占55．21％,乡镇集体儿童异常占44．18％。提示不论是城市的儿童或是儿童均存在微量元素的缺乏或过高,都是保健的重点。     

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.     

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。     

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。     

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。     

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.

     

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).