Clinical and genetic analysis of two Chinese families with benign familial neonatal convulsions

Benign familial neonatal convulsions (BFNC) is a rare autosomal dominant inherited epilepsy syndrome. Two voltage-gated potassium channel genes, KCNQ2 and KCNQ3, have been identified as the genes responsible for BFNC. Here we report two Chinese families with clinical histories of typical BFNC. Using six microsatellite markers, two located at KCNQ2 locus and four at KCNQ3 locus, linkage analysis was performed in the two families, which excluded the linkage of BFNC to KCNQ3, but could not exclude the linkage to KCNQ2. Direct DNA sequencing of the KCNQ2 gene in the two families was performed, and two formerly unknown polymorphisms were identified, but no KCNQ2 mutation was found in the two families. Our study suggests the genetic heterogeneity in Chinese families with BFNC and proves the existence of a new gene locus for BFNC.     

低钾对番红花叶片中超氧物歧化酶、过氧化氢酶、过氧化物酶活性和膜脂过氧化的影响

用石至石进行番红花盆栽试验,观察到低钾水平(1mg/L)下,膜脂过氧化作用明显加强,MDA增加349%,导致膜伤害,膜相对透性增加648%.其原因是低钾条件下,SOD,CAT,POX等膜保护酶活性分别降低639%,588%,696%,活性氧代谢平衡失调所致     

高锰酸钾制备方法的比较研究

本文采用歧化法、氧化法、电解法对"高锰酸钾的制备"实验进行探究,通过比较得出最适合学生实验的方法,并设计实验方案。     

Phase transfer catalysis: some recent applications in organic synthesis

A survey dealing with the use of anhydrous potassium carbonate as an efficient base for promoting organic reactions under solid–liquid phase transfer catalysis (SL-PTC) conditions is reported. In particular, the generation in situ of trifluoro- and trichloroacetamidide, and reactions of these azaanions with 2-bromocarboxylic esters and epoxides, affording protected α-amino acids and β-amido alcohols, respectively, are described. The reduction of allylic nitroderivatives with CS₂ to oximes or nitriles under SL- and liquid–liquid PTC (LL-PTC) is also presented. Finally, new preparation methods and a study of the reactivity of quaternary onium fluorides, hydrogendifluorides and dihydrogentrifluorides, together with the use of dihydrogentrifluorides as hydrofluorinating agents under SL-PTC conditions, are reported.     

Transformations of electrophilic reagents in a diethyl phosphite-potassium carbonate-ethanol system

Transformations of alkyl halides, aldehydes, and activated alkenes in a (EtO)₂PHO−K₂CO₃−EtOH heterophase system were studied. The reactions are catalyzed by EtOK that formed and follow the known schemes of the interaction of hydrophosphoryl compounds with electrophiles. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 369–372, February, 1999.     

高分子材料中金属镉含量的测定

在聚乙烯醇存在下的酸性介质中,镉(Ⅱ)分别与碘化钾、罗丹明B形成水溶性的三元离子缔合物,据此提出了测定镉的高灵敏度的分光光度法。最大吸收波长在610nm处。相关系数γ=0.9990。用此方法测定了高分子材料(PP、PS、ABS)中的金属镉的含量。     

蛛丝和蚕丝的 SEM和 EDX 研究

应用扫描电镜观察蛛丝和蚕丝 10个样丝形态 ,并测量了这几种天然纤维的直径. 结合 X 射线光电子 能谱分析,对样丝的化学无素(氯、钾、钙、铁、硅、铬)及其含量(原子个数百分比)作了分析比较.     

四苯硼钾从水到水-二氧六环混合溶剂中的标准迁移自由能和介质效应

在温度298.15K时,用光度法测定了四苯硼钾在水及不同比例的水-二氧六环(DEDO)混合溶剂中的溶解度,进而对四苯硼钾从H2O到H2O-DEDO混合溶剂中的标准迁移自由能和介质效应进行了研究.结果表明,随物质的质量分数x(DEDO)的增大,ΔG0t呈现复杂的变化,当x<0.2,-ΔG0t随x的增大而增加;当x>0.2,-ΔG0t随x的增大而减小,在x=0.2附近,-ΔG0t出现极大值.当x>0.8时,ΔG0t变为正值,且随x的增大而急剧增加.对出现这种变化规律的原因进行了分析讨论.     

Taking into account nonselective absorption of light in atomic absorption analysis

We propose a method for quantitatively taking into account nonselective absorption for systems in which the vapor phase contains a single molecular form: sodium and potassium chlorides and iodides. We identified the absorption bands using modern quantum chemistry methods. We have demonstrated good agreement between the experimental data and the calculations. We have tested the correctness of the method we developed for the example of determining known silicon and iron contents in potassium chloride and sodium iodide. Differences between the results obtained and the true elemental contents were random. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 3, pp. 397–400, May–June, 2006.     

催化动力学光度法测定痕量亚硝酸根

基于在磷酸介质中，亚硝酸根对溴酸钾氧化氯酚红反应具有很高的催化活性，建立了测定痕量亚硝酸根的催化光度法，并讨论了其动力学条件。本方法的线性范围为０．０４－１４ｍｇ／Ｌ，检出限为０．００７ｍｇ／Ｌ，回收率为９８．７％－１０２％。方法简便，快速、选择性好用于地表水，食品及土壤样品中的亚硝酸根的测定，结果满意。