胎儿大脑化学元素的时序变化特征与成人疾病成因的探讨

为探讨胎儿大脑化学元素的时序变化特征与成人疾病源于胎儿期的成因，分析了4～10月龄胎儿大脑21个元素与发育时序的关系，并与心、肝、肺、肾、脾、胃相比较。结果表明，胎儿大脑21个元素的浓度多数低于成人，并随月龄而变化。与发育时序的关系可分为3种类型，其中呈显著正相关和相关不显著的元素占76．2％，在7种组织中比例最高，呈显著负相关的元素在所有组织中比例最低。呈显著正相关的4个元素除Mn的变化与肺相同外，Cu、Cr、Ti与其他组织均不相同；呈显著负相关的5个元素，Zn、Ca、P、Sr在7种组织中有相同趋势，而V仅与脾一致。提示胎儿大脑在生长发育过程中对营养物质的贮存功能有限，当环境-母体-食物链系统营养缺乏时，组织对营养缺乏的敏感性不尽相同。在优先保证大脑需要的生物学原则下，Zn、Cr、Ca(P、Sr)、Se缺乏时，胎儿某些组织的结构和功能可能产生永久性“程序化”改变，至成人期这些元素营养不足时，胎儿期的“程序化”改变被放大，增加了成人疾病发生的危险性。     

大骨节病,克山病共存区及特异病区血硒及有关生化指标的测定

测定了陕西彬县大骨节病区、克山病存区，云南牟定单纯克山病区、陕西安康“高硒”大骨节病区及四川南部低硒无病区人血硒、维生素Ｃ及磷含量。结果表明，以低硒为中心的代谢紊乱是克山病、大骨节病区人群共同具有的基本生化特征，低硒仍是两病发病的重要因素；病区人群缺硒的同时伴有维生素Ｃ的缺乏或相对缺乏；大骨节病区人群低硒较克册病区人群更加明显，两病区儿童低硒较成人更加明显。     

胎儿肝、肾上腺微量元素的时序变化与抗氧化酶活性的关系

为探讨胎儿发育过程中组织器官抗氧化酶活性和微量元素的关系，分析了不同月龄胎儿肝、肾上腺中Cu、Zn、Fe、Mn、Se的含量和抗氧化酶活性，并分别与月龄进行相关分析。结果表明，肝、肾上腺中Cu、Zn、Fe、Mn、Se与抗氧化酶活性之间显示有依存关系，为揭示人体胚胎微量元素与酶的关系及其分子生物学机制提供了依据。     

胎儿肾发育中化学元素的时序变化特征与意义

为探讨胎儿肾脏化学元素含量的时序变化特征和生长发育的关系及其生理功能，分析了4－10个月龄胎儿肾脏中21个化学元素的含量，用统计学方法研究其时序变化规律和与胚胎某些发育特征的关系。结果表明，胎儿肾脏的发育和元素含量是一个变量，元素与发育时序的关系可区分为显著正相关、负相关和相关不显著3类。可见胎儿肾脏化学元素含量和时序变化规律可为调控胎儿－新生儿和妊娠－哺乳期妇女营养平衡提供依据，为诠释胎儿期物质代谢的某些特征和功能提供信息。     

碘缺乏病病区胎儿及孕妇硒含量和硒—谷胱甘肽过氧化物酶活性研究

测定了麻江县和贵出市郊两地胎儿组织，胎儿和孕妇血硒含量和谷胱甘肽过氧化物酶活性，同时测定了生态环境中硒含量，结果发现，麻江地区环境硒含量低，孕妇血硒水平和红细胞ＧＰｘ活性明显低于贵阳地区，胎儿组织及血Ｓｅ含量和ＧＰｘ活性也有一致性低于贵阳地区的趋势显示麻江人群因摄硒不足而存在的硒代谢紊乱。调查的两地区均连续碘盐防治十年以上，但麻江地区人群仍处在高促甲状腺激素水平，学龄儿童甲肿率还显著高于贵阳，这些     

肥胖与微量元素

肥胖的人往往与微量元素都有较密切的关系,肥胖的人都是由必需微量元素不足或缺乏所引起,肥胖与血糖也有密切的联系。特别是必需微量元素的不足或缺乏会出现如下症状：人体内糖耐量降低、多血糖症加重、尿糖、低血糖症、胰岛素循环加速、胰岛素受体数量明显减少,胰岛素结合能力明显降低、血脂代谢明显紊乱、机体免疫能力明显受损、人体脂肪的含量明显增加等。     

洛阳市蔬菜基地土壤中重金属含量抽样分析及评价

为了解洛阳市蔬菜基地土壤中重金属污染状况,对郊区白马寺镇蔬菜基地靠近公路、铁路、社区边和远离这些区域的菜地土壤抽样,采用原子吸收分光光度法测定了样品中的Cu、Zn、Pb、Cd、Cr 5种重金属元素含量,并根据国家土壤环境质量二级标准对检测结果进行单因子污染指数和综合污染指数评价。结果表明,土样中重金属Cu、Zn、Pb、Cd、Cr的平均含量分别为37.09、106.09、50.10、0.56、16.13 mg.kg-1。其中Cu、Zn、Pb、Cr含量均能达到清洁级,而Cd含量在靠近公路边、铁路边和社区边的抽样中明显高,接近或超出国家土壤环境质量二级标准值,在远离交通和社区的抽样中处于清洁级。由综合评价可知,在所采集的11个土壤样品中,4个样处于安全级水平,5个样处于警戒级水平,2个样处于轻度污染状态。可见,交通运输和社区生活是引起土壤重金属污染的重要因素。     

Cr/MSU-1催化剂中Cr含量对CO2氧化丙烷脱氢反应催化性能的影响

研究了CO2氧化丙烷脱氢制丙烯高效wCr/MSU-1 (w＝2, 4, 6, 8, 10, 质量分数, 以Cr2O3计算)催化剂中Cr含量对催化剂结构和催化活性的影响. 催化剂活性评价结果表明, 随Cr含量的增加, 催化剂的活性呈现先提高后降低的变化趋势. 在600 ℃条件下, 6.0Cr/MSU-1表现出最佳的催化反应活性, 其中丙烷、CO2转化率分别达到62.6%和22.1%. 为明确Cr含量对催化剂结构的具体影响, 对催化剂样品进行了XRD, UV-Vis和XPS表征: 催化剂样品的XRD表征发现Cr/MSU-1催化剂不仅能够保持良好的MSU-1分子筛的孔道结构, 而且活性金属Cr在载体表面具有很高的分散度, 随着Cr含量的增加催化剂表面形成明显的Cr2O3晶相; UV-Vis表征结果证实低Cr含量催化剂表面主要以Cr6＋的形式存在, 高Cr含量催化剂表面有明显的Cr3＋出现; 反应前后的催化剂XPS表征结果进一步证实催化剂表面的Cr6＋与催化反应活性具有良好对应关系. 基于上述结果, 我们认为Cr6＋是该催化剂重要的活性中心.     

基于超高效液相色谱-质谱分析的代谢组学在小檗碱治疗多囊卵巢综合征研究中的应用

多囊卵巢综合征（polycystic ovary syndrome,PCOS）是妇女最常见的内分泌和代谢紊乱性疾病,合理的药物治疗非常重要。本研究中,超重/肥胖的多囊卵巢综合征患者经过小檗碱治疗3个月,采集治疗前后的血样进行分析,利用超高效液相色谱-质谱联用技术（UHPLC-MS）对治疗前后血清中的内源性物质进行了相对含量测定。正交信号校正的偏最小二乘模式识别分析结果显示治疗前后有明显的区分。多变量分析结合非参数检验找出的与小檗碱治疗相关的差异代谢物均与脂类代谢有关。临床生化数据结合代谢组学数据显示,小檗碱治疗超重/肥胖型的多囊卵巢综合征患者可以增加机体胰岛素敏感性、改善脂类代谢。上述研究结果表明代谢组学是研究中药治疗疾病效果的有效工具之一。     

原子吸收光谱法测定赣南野生草菇中的7种金属元素

为开发和利用赣南野生草菇提供科学依据，采用原子吸收光谱法测定了其中Zn、Co、Ni、Cu、Fe、Cr和Mg7种金属元素的含量。结果表明，草菇中Zn、Co、Ni、Fe、Cr和Mg含量丰富，Cu含量较低，Zn与Cu值为7．4，与抗癌中药中微元素的含量有Zn高Cu低的关系相同，说明赣南野生草菇有较高的营养价值。     

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).