学龄儿童智商与微量元素含量关系研究

为了解头发微量元素含量与学龄儿童智商之间的关系,本文测定了深圳市某小学570名7－13岁低智商儿童和正常儿童的IQ值及其头发中七种元素（I、Zn、Fe、Cu、Ca、Mn、Pb）的含量,并对低智商儿童及正常儿童头发中的元素含量作了比较。结果表明,低智商儿童头发碘、锌、钙的含量显著低于正常儿童头发中的含量,而发铅则显著高于正常儿童的含量。说明儿童智商高低与机体碘、锌、钙以及铅的含量有密切关系。     

学龄学儿童血中六种元素含量与智商关系的研究

为了解学龄前儿童智商与血中微量元素含量之间的关系本文测定了佛山市幼儿园576名4-6岁儿童的IQ值及其血中六种元素（Zn、Fe、Cu、Ca、Mn、Pb）的含量，并对幼儿血中微量元素含量与IQ值的关系进行了探讨。结果表明，低智商儿童血中锌含量显著低于高智商儿童血中锌含量，而血铅则显著高于高智商儿童的血铅。说明学龄前儿童智商高低与机体锌及铅的含量有密切关系。     

Analysis on Trace Elements in Preschoolers' Peripheral Blood in Xi'an City

为探讨西安市学龄前儿童末梢血微量元素现状及其含量与年龄及性别的关系,对2 350例学龄前儿童末梢血中铜、锌、钙、镁、铁5种元素进行了测定,用SPSS 16.0做统计分析.结果表明,受检儿童末梢血中锌、钙、铁缺乏严重,铜和锌含量在年龄上具变化规律,且铜在性别间存在显著差异.提示应充分认识微量元素对儿童健康的重要性,定期对儿童进行微量元素监测,做好防治工作.     

西安市学龄前儿童末梢血微量元素检测结果分析

为探讨西安市学龄前儿童末梢血微量元素现状及其含量与年龄及性别的关系,对2 350例学龄前儿童末梢血中铜、锌、钙、镁、铁5种元素进行了测定,用SPSS 16.0做统计分析.结果表明,受检儿童末梢血中锌、钙、铁缺乏严重,铜和锌含量在年龄上具变化规律,且铜在性别间存在显著差异.提示应充分认识微量元素对儿童健康的重要性,定期对...     

营养不良儿童与发锌关系的研究

报告７１例６个月至７岁营养不良儿童与对照组１３７例健康儿童的发锌含量研究结果。调查结果表明，营养不良儿童发锌含量差异极其显著．Ｐ＜０．０１，表明微量元素锌对小儿的生长发育有明显的影响，符合文献报道的关于体辞水平与儿童营养不良的身体发育障碍显著相关．为临床应用锌剂综合治疗营养不良疾病提供科学依据。     

急性腹泻患儿血、发微量元素锌含量分析

为了观察急性腹泻患儿血、发中微量元素锌的变化,测定了32例急性腹泻患儿血、发中的微量元素锌并与正常儿童值进行对照。结果显示,急性腹泻患儿发锌含量明显低于正常对照组,且差异非常显著,P＜0．01,而血锌与正常对照组之间无显著差异。提出缺锌儿童易患腹泻病,认为合理补充微量元素锌,有助于该疾病的防治。     

微量元素与儿童行为关系探讨

用原子吸收分光光度法（ＡＡＳ）测定了１４３例小儿发中锌、铁、铜、钙、铅、镁等元素含量。探讨了微量元素对儿童行为的影响。     

南昌市某地区学龄前儿童血液中微量元素含量探讨

目的通过对南昌市某地区950名学龄前儿童血样分析,探讨该地区婴幼儿血中铜、锌、钙、镁、铁含量的正常水平及其与年龄、性别的关系。方法采用原子吸收分光光度法测定南昌某地区0~7岁学龄前儿童血液中微量元素铜、锌、钙、镁、铁的含量,对其结果进行统计学分析。结果血铁、锌在各年龄组间有显著性差异(P0.05),血铜、钙、镁在各年龄组间差异不显著(P0.05),铁、钙、镁的含量随年龄的增加呈下降趋势,但均在正常水平。结论既往儿童普遍存在的钙缺乏现象已得到纠正,各年龄组儿童锌、铁缺乏常见,儿童膳食中锌、铁的补充亦应得到进一步重视。     

轻度铅中毒对儿童微量元素及骨龄的影响

为探讨儿童轻度铅中毒对微量元素及骨龄的影响,采用钨舟原子化法和原子吸收光谱法分别检测了33例轻度铅中毒患儿血铅及微量元素水平,用X摄片进行骨龄测定,并进行了相关分析。结果表明,轻度铅中毒患儿微量元素钙、铁、锌降低,骨龄发育落后,血铅含量与钙、铁、锌水平呈负相关。提示轻度铅中毒使儿童骨龄落后,可能与微量元素间的失衡有关。     

广州员村地区0—6岁健康儿童头发微量元素分析

为观察不同年龄、性别健康儿童微量元素之间的关系，对广州员村地区７５４名０￣６岁儿童进行了头发微量元素锌、铁、铜以及宏量元素钙测定。结果表明：新生儿发锌明显高于其他年龄组；６个月￣１岁儿童发锌、铁、钙均低于其他年龄组，与各年龄组比较有显著差异；５￣６头儿童发铜低于其他年龄组，且女童发铜、钙高于男童（Ｐ〈０．０５），提示在不同年龄、性别儿童之间头发微量元素含量存在一定差异。     

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%.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.     

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.