肿瘤患者放疗前后血清八种微量元素含量的研究

对临床、病理、放射线或CT检查确诊的82名癌肿患者，在放疗前后和对42名健康人进行了微量元素铁、锌、铜、锰、硒，铬、钴、镍的分析。研究结果显示：1．癌肿患者血清铜、镍、锰、铬、钴的含量比健康人高，而血清锌、铁、硒的含量却比健康人低；2．血清Cu／Zn、Cr／Zn、Co／Zn、Ni／Zn的比值癌肿患者均比健康人高，而Fe、Zn、Se／Zn的比值却相反。因此，可根据血清铜升高、血清锌降低，血清铜／锌比值升高的特点。用于癌肿的早期诊断；3．癌肿患者放疔后血清铁、锌含量进一步下降，铜、锰、铬的含量也出现降低，唯有硒的含量有所上升。因此，放疗时应注意补充铁、锌、铜元素。     

“共生理念”下图形判定的发现与探索——以“探索直线平行的条件(第1课时)”为例

从课堂教学层面而言,“共生理念”下的课堂教学应与现实生活紧密联系,让学生体会到数学源于生活、用于生活;应围绕学生的最近发展区,确定学生合理的生长点,让学生在学习过程中不断积累生长的经验;应培养学生的科学精神和创新意识,让学生的精神在课堂中升华.本文以“探索直线平行的条件(第1课时)”为例,说明这种理念的实践应用与思考.     

人教版与北师大版关于“线段、直线、射线”内容的比较研究

“线段、射线、直线”是《义务教育数学课程标准(2011年版)》中“图形与几何”板块最基本的概念之一.本文采用内容分析法对人教版与北师大版“线段、直线、射线”及其相关内容进行了分析.     

Matrix Effects and Behaviors of Elements in Oxalic Acid Medium by Inductively Coupled Plasma Mass Spectrometry

Because of its high sensitivity, wide dynamic range and relative freedom from interferences, inductively coupled plasma mass spectrometry (ICP-MS) has been developed for the determination of trace and ultra-trace levels of elements in various fields1. Due…     

XPS中Tougaard法本底扣除初探

介绍了XPS(X-ray photoelectron spectroscopy)谱图中本底产生的机理以及Tougaard法本底扣除原理的简略推导过程,提出了可供编程的约化形式,使用VC语言编写程序试对不同样品(含金属、过渡金属及非金属)的谱图进行本底扣除,并与Shirley法、直线法本底扣除进行准确性的比较,提出了Tougaard方法试用于非金属粉末化合物样品的测试分析结果.     

A Novel Method for Quantification of Circulating DNA in Serum by Capillary Zone Electrophoresis

In this paper, we first presented a novel method for quantification of circulating DNA in human serum based on capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). The serum was digested by proteinase to release free DNA, and then CZE-LIF system was used for the quantification of total circulating DNA. This method was successfully used to quantify the circulating DNA levels in sera from healthy individuals and certain cancer patients.We found the significantly elevated circulating DNA levels in certain prostate cancer patients. Our results demonstrated that CZE-LIF system has good linearity, excellent sensitivity (0.5 ng/mL DNA),satisfactory reproducibility (RSDs in one day and between days were both less than 5%) and reliability, and is well suitable to the quantification of the circulating DNA in human serum or plasma.     

Solution Structure and Behavior of Benzophenone-based Achiral Bisphosphine Ligands in Noyori-Type Ru（Ⅱ）-Catalysts

We herein report on solution structural studies of Ru^Ⅱ catalysts （3a, 9） composed of achiral bisphosphine ligands （4, 8） and the enantiopure 1,2-diphenylethylenediamine （DPEN）. Complete chiral induction from enantiopure （R,R）-DPEN to achiral bisphosphine ligand 3a was observed in solution, with the complex adopting a single, stable and non-fluxional （even at 70 ℃） configuration. The coordination of the C=O moiety in 4 to the cationic Run center is considered to be of key importance in providing the higher thermodynamic and kinetic rotation barrier for the flexible bisphosphine ligand in the complex. The obtained enantioselectivity （91% enantiomeric excess） and sense of chiral induction in the hydrogenation of acetophenone were found to be solely dependent on the chirality of the 1,2-diamine. Consistent with the hydrogenation product, the （R,R）-DPEN induces a M-conformation （fight-handed） chirality for flexible phosphine ligand 4 in the complex, resulting in a 2,2-configuration about the Ru^Ⅱ center.     

《广义相对论入门讲座》连载③——黎曼几何中的张量

1黎曼几何的建立几何学起源于古埃及尼罗河水泛滥后土地的丈量.公元前300年左右的数学家欧几里得总结和发展前人积累的知识,完成了《几何原本》一书,搭起了欧几里得几何学的框架.欧氏几何,以它逻辑的严密,形式的完备和优美,两千年来为数学家和哲学家所倾倒.唯一使人感到美中不足的是它的第五公设,即平行公理.此公理说,"过直线外的一点,可以引一条、并且只能引一条直线与原直线平行(不相     

巧变形,妙解题

"希望杯"全国数学邀请赛试题越来越深受高中学生的亲眯,其原因就在于"希望杯"赛题的考查内容广而新,题型灵活多变、充满生机与活力,解题方法丰富多彩、别具一格.本文介绍一道2012年"希望杯"高二赛题的解法,供参考.