360名儿童血铅和血锌的检测及相关性分析

铅和锌是微量元素中对人体特别是儿童的生长发育有很大影响的因素。随机检测了 6间幼儿园 3 60名 3～ 6岁儿童的血锌和血铅含量水平 ,血铅 >0 1 μg/mL的儿童占 2 7 2 2 %。对高铅儿童的血锌水平与血铅正常儿童的血锌水平进行相关性比较 ,在分年龄组的比较中 ,3岁组与 6岁组存在显著性差异 (P <0 0 5 ) ;在分性别的比较中 ,男童的血锌水平存在显著性差异 (P <0 0 5 )。     

1570例学龄前儿童血铅水平调查

为了解顺德伦教学龄前儿童血铅水平及铅中毒发病情况 ,以便及时采取有效措施 ,根据整群分层随机抽样 ,检测了本区学龄前儿童血铅水平 ,并进行了流行病学分析。结果表明 ,本次调查学龄前儿童 1 5 70例 ,血铅水平为 (1 0 8 6± 79 8) μg/L ,儿童铅中毒患病率为 5 0 76% ;男童血铅水平及铅中毒患病率都高于女童 ,但无明显统计学差异 (P >0 0 5 ) ;年龄越大血铅水平相对越高 ,铅中毒患病率也越高 ,并存在明显差异 (P <0 0 1 )。提示顺德伦教学龄前儿童血铅水平及铅中毒患病率维持在较高水平 ,应及时采取有效措施 ,防治儿童铅中毒。     

镇海城关儿童血铅水平及相关因素调查分析

为了解镇海城关 1～ 6岁儿童血铅水平现状及相关因素 ,进一步进行儿童铅中毒的防治提供依据 ,对城关 1～ 6岁、在区妇幼保健院体检 1 5 71名健康儿童进行了血铅测定并对其家庭生活环境及个人情况等相关因素进行了问卷调查。结果表明 ,本次调查 1 5 71名儿童中 ,血铅平均数为2 5 8μg/gHb ,其中高于 3μg/gHb儿童 5 31人 ,占 33 8% ,而且年龄越小 ,血铅超标率越高 ,P<0 0 1。儿童血铅并与居住地与汽车马路的间距、生活环境中油漆接触均有密切关系 ,P <0 0 1。血铅增高 ,儿童多动症、贫血发生率明显上升 ,P <0 0 1。可见镇海城关地区儿童血铅水平及儿童流行率已较高 ,应引起高度重视     

佛山市儿童铅中毒现状的调查

[目的 ]旨在了解佛山市儿童铅中毒的现状。 [方法 ]采用阳极溶出伏安法 ,测定佛山市41 6名 1～ 1 4岁儿童的血铅值。 [结果 ]儿童铅中毒率为 3 3 41 % ,不同性别儿童铅中毒率有明显差异 (P <0 0 1 ) ,不同年龄组血铅中毒率无明显差异 (P >0 0 5 )。 [结论 ]儿童铅中毒在不同地区存在一定差异。儿童铅中毒已不只是医学问题 ,应引起全社会的广泛关注。     

锌原卟啉与儿童铅中毒和贫血关系的研究

[目的 ]探讨锌原卟啉测定诊断儿童铅中毒与贫血可能性。 [方法 ]测定了 2 3 5名儿童血ZPP、Hb、BPb。 [结果 ]ZPP值 2 3 9± 1 0 2 μg/gHb ,增高率 1 3 61 % ;血铅水平 8 94± 4 62 μg/dL ,铅中毒率 41 0 7%。Hb平均浓度 1 1 2 5 0± 1 0 5 5g/L ,贫血患病率 3 1 48%。ZPP与Hb呈高度负相关 (P <0 0 1 ) ,与BPb无相关性 (P >0 0 5 )。血铅水平正常组与铅中毒组ZPP值差异无显著意义(P >0 0 5 )。Hb正常组与贫血组ZPP值差异有显著意义 (P <0 0 1 )。 [结论 ]ZPP升高可作为缺铁性贫血的诊断指标 ,但在血铅水平较低的地区 ,则不宜用ZPP作为儿童铅中毒的筛查指标。     

轻中度铅中毒儿童的干预治疗

为探讨轻中度铅中毒儿童的干预治疗的方法 ,将 96例血铅水平 10 0～ 4 0 0 μg/L的铅中毒儿童随机分成三组 :对照组为健康教育组 ;治疗A组为服钙组 ;治疗B组为混合组 :服食钙剂的同时 ,配合进行有关的健康教育。分别干预三个月后复查血铅水平。结果表明 ,三组儿童干预前后的血铅水平分别为 :对照组 (n =30 ) 2 0 6 0± 6 6 0 μg/L ,134 2± 4 2 9μg/L ,下降了 35% ;治疗A组(n =34) 2 0 8 5± 6 0 3μg/L ,12 4 0± 4 0 7μg/L ,下降了 4 1% ;治疗B组 (n =32 ) 2 2 5 9± 70 4 μg/L ,10 8 4± 33 8μg/L ,下降了 52 %。干预前各组间血铅水平没有差异 (P >0 0 5) ,而干预后对照组与治疗A组、对照组与治疗B组间比较 ,t分别为 0 970 (P >0 0 5)、2 6 36 (P <0 0 1) ,对照组与治疗B组之间有显著差异。提示健康教育及口服钙剂皆能明显降低轻中度铅中毒儿童的血铅水平 ,而两者同时配合进行 ,效果更加显著。     

儿童哮喘与血铅水平关系的研究

目的 :为探讨儿童铅中毒与哮喘的相互关系。方法 :采用电感耦合高频等离子体原子发射光谱法对 66例哮喘患儿及 60例健康儿童进行了血铅含量检测。结果 :( 1 )哮喘患儿血铅水平明显高于正常对照组 ;( 2 )血铅水平与哮喘严重度为正相关 ,r=0 0 93 ,P <0 0 5 ;( 3 )哮喘组与对照组儿童血铅水平t检验 ,有显著性差异 ,t=2 1 ,P <0 0 5。结论 :儿童哮喘存在着血铅水平升高 ,两者可能互为因果关系     

清远市学龄前儿童血铅水平分析

目的　探讨清远市学龄前儿童血铅水平、铅中毒分布特点及与其它元素的关系,为防治铅中毒损害提供依据,方法　在清远市城区,随机抽取在清远市妇幼保健院体检的5 5 3名1～6岁儿童为研究对象,采指端末梢血2 0 μL ,用原子吸收光谱仪测定血铅、钙、锌、铁、铜和锰的水平。结果　该市学龄前儿童血铅水平( 73 0±49 6) μg/L ,几何均值5 8 1 μg/L ,铅中毒流行率2 4 95 % ,以1 0 0～1 90 μg/L频率最高,占2 3 6% ,铅中毒流行率随年龄的增长而降低( χ2 =1 2 0 9,P <0 0 5 ) ;2岁组铅中毒流行率最高,血铅值与血钙、锌值呈显著负相关(r =-0 1 82 ,-0 1 5 0 ,P <0 0 5 )。结论　2岁组对铅污染较敏感;增加钙、锌元素的补充,能预防儿童铅中毒     

产母及新生儿血铅水平及影响因素的研究

为了解佛山市产母、新生儿血铅水平及其相关影响因素 ,采用电感耦合高频等离子体发射光谱法 ,于 2 0 0 2年 5～ 9月 ,取本院产科产母静脉血及其新生儿脐血 1 5 2例 ,进行血铅、钙、锌、铁、铜和锰水平测定 ,按妇幼保健管理卡内容 ,进行相关记录。结果表明 ,产母血铅水平90 1± 3 4 8μg/L ,BPb≥ 1 0 0 μg/L者占 2 0 3 9% ;新生儿脐血铅水平 89 2± 3 1 6μg/L ,铅中毒率为2 2 3 7% ;母子血铅值呈显著正相关 (r=0 85 7,P <0 0 1 ) ,产母血铅值与其血钙、铁值显著负相关 (r=0 2 66,-0 3 0 1 ,P <0 0 5 ) ;城郊产母及新生儿血铅水平显著高于城区。揭示市郊孕妇、新生儿血铅较高 ,血钙、锌、铁含量影响血铅水平     

广州市东山区0～6岁儿童血铅水平调查及对策探讨

为了解广州市东山区 0～ 6岁儿童血铅水平现状及其影响因素 ,探讨相应的预防策略 ,于2 0 0 2年 1～ 1 2月对东山区当年入托儿所、幼儿园 65 3名 0～ 6岁儿童进行了血铅等六种元素检测 ,并对被检测儿童家长发放调查问卷 ,进行了儿童个人情况及家庭生活环境等调查。结果表明 ,65 3名儿童血铅水平为 ( 89 2 3± 2 4 3 4) μg/L ,儿童铅中毒 (诊断标准≥ 1 0 0 μg/L)的比例是 46 7% ,儿童铅中毒以Ⅰ～Ⅱ级为主 ,我区儿童铅中毒流行率 46 7% ,低于我国城市儿童铅中毒的流行率5 1 7% ;高铅组儿童出现钙、锌、铁缺乏发生率较低铅组高 ,并有显著性差异。儿童铅暴露的主要危险因素依次为儿童在马路上逗留时间长 ,居住环境及经济状况条件差 ,不良的生活和饮食习惯 (与摄取铅有关 ) ,家长对铅中毒的认识不足。提示我区儿童血铅水平、铅中毒比例仍较高 ,应引起有关部门的注意     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.