头发微量元素及钙含量测定的应用价值评价

以125例2～5岁儿童为对象，测定其全血和头发铅、锌、铁、钙含量；以全血铅、锌、铁、钙含量为标准，应用诊断试验评价方法评价头发铅、锌、铁、钙测定的应用价值。结果表明，头发铅测定的灵敏度可达88．3％，应用串联试验，头发铅测定的特异度可提高至81．8％，阳性预测值达69．6％，阴性预测值达78．8％。头发锌测定的灵敏度可达86．1％，特异度为52．4％，阳性预测值75．6％，阴性预测值为68．8％。头发铁测定的灵敏度为72．0％，特异度为77．5％，阳性预测值为83．6％，阴性预测值为63．3％，头发钙测定的灵敏度为78．9％，特异度为69．1％，阳性预测值为69．8％，阴性预测值为78．4％。锌缺乏、铁缺乏、钙缺乏，或铅负荷过高，或数种微量元素缺乏及铅中毒并存是当前严重影响儿童健康成长的常见原因。运用现代检测技术早期发现微量元素缺乏及铅中毒患儿并及时采取防治措施对促进儿童正常生长发育至关重要。头发样品容易采集、运送和保存，因此头发微量元素含量测定适合在中小城镇及农村使用。但其应用价值应进行科学评价。     

血清必需元素测定中样品预处理方法的探讨

对血清必需元素测定的样品预处理方法进行了研究，用火焰原子吸收法测定了经不同处理的血清样品中的锌，铜，铁，钙，镁含量，结果显示，预处理方法不同，其测定结果有较大差异，变异系数，镁为７．９４％，锌，铜，铁，钙在１５．１９％～５３．５３％之间，并对各样品作了精密度和准确度实验。     

非完全消化-火焰原子光谱法测定奶粉中钙镁铁锌

用非完全消化法处理奶粉样品，建立了用火焰原子光谱法测定奶粉中钙、镁、铁、锌的快速分析方法。在低温下用浓硝酸消化奶粉至溶液透明，加乳化剂OP溶解消化过程中所产生的油脂，可获得一均匀、透明的样品溶液。以发射法测定钙，用吸收法测定镁、铁和锌。以Sr^2 作为测定钙、镁的释放剂。对样品消解每件及干扰进行了考察。测定结果的相对标准偏差小于2．4％，加标回收率在98．8％～102．0％之间。方法简便、准确。     

原子吸收光谱法测定三醋酸纤维素膜中铜铁

运用空气-乙炔火焰原子吸收光谱法同时测定银锌电池三醋酸纤维素膜中铜铁含量，并对测定条件和干扰因素进行了综合分析．该测定方法具有很好的灵敏度，干扰少，选择性和重现性好等优点．测定样品铜铁含量的相对标准偏差均小于1．0％．标准加入回收率均在97．3％-98．8％范围内．完全适用于银锌电池三醋酸纤维素膜中铜铁含量的控制和样品系统分析．     

母乳中钙、铁、锌含量与婴儿身高及体重关系的研究

对产后1－6个月的乳母及其婴儿分别进行了乳汗中钙、铁、锌含量测定和婴儿身高、体重测量。结果显示，母乳中钙、铁含量与国内资料接近， 而锌含量偏低；乳汁中的铁和锌含量随喂养时间延长而逐渐下降；钙含量在四个月半前无明显变化，五个月后呈下降趋势。相关统计结果表明，乳汁中的钙、铁与婴儿的身高、体重无显著相关（P＞0．05），锌与婴儿身高、体重呈显著正相关（P＜0．01）。     

火焰原子吸收光谱法测定液氨中的铁

应用火焰原子吸收光谱法对液氨中的铁含量进行测定。分析了测定条件。方法简便、快速。测定铁的线性范围为0-8．00mg／L,相关系数为0．9999。应用于样品测定,测定结果的相对标准偏差小于2％,加标回收率为97．4％-106．1％。     

铁镍镀层中铁镍组成的紫外-可见分光光度分析法

用紫外－可见分光光度法分析了电沉积在导电玻璃上的NiFe合金镀层，三价铁与EDTA和H2O2形成稳定的深紫色三元络合物；在氨性溶液中，当有氧化剂存在时，镍与丁二酮肟形成酒红色的络合物，用吸收光度法可分别在519nm和538nm波长处测定铁、镍的含量，对Fe和Ni的相对标准偏差分别为0．95％和1．2％，适用含量范围分别为1－50mg/L和0．5－20mg/L；对实际样品的测定结果与XPS分析的一致，该法也适用于其他样品中铁、镍含量的测定。     

小儿锌、铜、铁、钙缺乏症的调查及健康指导

为了解本地区小儿锌，铜，铁，钙缺乏的情况，以便更好地进行小儿营养膳食指导，对1994－2001年在我院儿科门诊就诊4891例小儿发中锌，铜,铁，钙含量进行了测定。结果表明，锌，钙，铁，铜缺乏率 ：38．5％，26．8％，16．7％，0．2％。锌缺乏率有随年龄增长而增高的趋势，而钙缺乏率则有下降趋势。可见锌，铁，钙营养不足仍是本地区小儿最主要的健康问题，应根据不同年龄进行有针对性健康教育及营养指导。     

平顶山老年人微量元素营养状况

用等离子发射光谱法检测了373位50岁以上老人头发中8种无机盐含量。结果表明，有71．2％的男性及48．5％的女性发钙含量低于正常参考值，有32．2％的男性及39．8％的女性发铁含量低于正常参考值；镁、铜、锌、磷含量低于参考值的人数均在10％以内。男、女发铅含量的均值分别是4．2μg和2．1μg，差异有统计学意义。提示钙、铁缺乏是老年营养的主要问题，男性发铅含量高于女性。     

青少年全血微量元素正常值探讨

由于国内尚无青少年全血铜、锌、铁、钙含量的正常值标准，为探讨其正常值范围，根据广州地区193名中学生全血铜、锌、铁、钙含量的测定结果，初步提出了广州地区13至18岁青少年全血铜、锌、铁、钙含量的正常值范围。结果表明，广州地区13至18岁青少年血铜含量均值为0．77bμg／g。正常值0．52～1．02μg／g；锌含量：13～岁均值5．22μg／g，正常值〉3．93μg／g；15～岁均值为5．54μg／g，正常值〉4．40μg／g；17～岁均值为5．68μg／g，正常值〉5．06μg／g；铁含量均值为500．00μg／g，正常值363．00～637．00μg／g；钙含量均值为78．70μg／g，正常值〉53．00μg／g。提示青少年除锌含量有必要按年龄组确定正常值范围之外，血铜、铁、钙含量的正常值范围可不按年龄和性别划分，均可合并计算。     

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%.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.     

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.