High performance liquid chromatography as a tool in the definition of abnormalities in monoamine and tryptophan metabolites in cerebrospinal fluid from patients with neurological disorders

In this study we report the levels of 3-methoxy-4-hydroxyphenylglycol, 3,4-dihydroxyphenylacetic acid, homovallinic acid, tryptophan, 5-hydroxyindole-3-acetic acid and serotonin in lumbar cerebrospinal fluid (CSF) from patients with multiple sclerosis, cerebrovascular disease and muscular tension headache the later, as healthy controls. The separation of these substances was performed on a reversed phase column by ion pair high performance liquid chromatography and detection was made by a glassy carbon electrode set at +900 mV vs Ag+/AgCl. The whole separation was achieved within 25 min. Concentrations of all substances (10-1000 pmole/L) were linearly proportional to areas obtained. The system is sensitive, stable and reproducible. The significance of CSF levels of these metabolites from patients groups compared with healthy controls are discussed.     

Modulation of Spin Distribution and Spin Transport by a Magnetic Field in a Quasi-One-Dimensional System with Spin--Orbit Coupling

The distributions of spin and currents modulated by magnetic field in a transverse parabolic confined two-dimensional electronic system with a Rashba spin--orbit coupling have been studied numerically. It is shown that the spin accumulation and the spin related current are generated by magnetic field if the spin--orbit coupling is presented. The distributions of charge and spin currents are antisymmetrical along the cross-section of confined system. A transversely applied electric field does not influence the characteristic behaviour of charge- and spin-dependent properties.     

我国区域绿色技术创新效率的分类测度和提升模式研究——基于非期望产出的SBM-SupSBM模型

本文首先运用考虑非期望产出的SBM-SupSBM模型估计我国各省市绿色技术创新效率并进行分类:稳定上升类、平稳类、大幅度波动类以及下降类。之后从企业内部和外部两方面对绿色技术创新效率提升的影响因素提出假设,着重考虑大幅度波动类别省份的效率提升。运用面板数据模型各影响因素进行验证,结论显示:企业规模对绿色技术创新效率波动较大的省份起到显著的抑制作用,环境规制和技术进步对绿色技术创新效率波动较大的省份作用不明显。针对分析结果,提出结论:在提升绿色技术创新效率的过程中,应注重企业规模和技术进步的协同作用,以及技术的开放程度。     

Theoretical studies on the reaction path and dynamics of the reaction CH_3+H_2O→CH_4+OH

The reaction path, the dynamical properties along the reaction path and CVT rate constants are computed by the ab initio MO method, the reaction path Hamiltonian theory and the variational transition state theory. The results show that the effect of the electron correlation energy on activation barrier is large, the recrossing and tunneling effects exist in the reaction.     

The solvent extraction of iron from steel solutions with 2-hexylpyridine prior to the determination of trace elements

The distribution of iron(III) between aqueous hydrochloric acid and 0.1M 2-hexylpyridine in benzene was examined as a function of acid concentration in the aqueous solution, the metal concentration being kept constant, and as a function of increasing ferric chloride concentration at a constant acidity of hydrochloric acid. The distribution coefficient of Fe(III) (tracer) is dependent on the square of the 2-hexylpyridine concentration in the benzene phase. Negatively charged complexes of the type FeCl(2-)(5) may be the species extracted. The formation of a mixture of 1:1 and 1:2 complexes with 2-hexylpyridine is indicated. Salting-out effects of a number of salts have been investigated. Separation factors of several metal ions relative to iron(III) in 7M hydrochloric acid are also reported. The results indicate that iron(III) can be selectively separated from a large number of elements, and the method has been utilized for the preconcentration of non-ferrous metal ions in mild steels by selective separation of iron, before their subsequent determination by emission spectrometry.     

A Novel, Simple and Efficient Synthesis of Ferrocenyl Enones and Alkynols

Propargylic alcohols are versatile precursors to many organic molecules including natural products and pharmaceutical compounds.[1] In our continuing interest in the development of practical methods for synthesis of ferrocene derivatives, we decided to investigate the efficiencies of ferrocenylacetylene addition to aromatic aldehydes under t-BuOKcatalyzed condition.[2] Interestingly, we found that the usually reliable coupling reaction between terminal alkyne of type 1 and aromatic aldehydes of type 2 does not furnish the expected propargylic alcohols, but that the isomeric aryl enones 3are found in high yield and very short reaction time (10～20 min). This provided a promising protocol for preparation of ferrocenyl chalcones in a practical, economical and mild sense compared with the traditional method. To the best of our knowledge, this unusual reaction was first observed for the addition of ferrocenylacetylene to aldehyde in a base-catalyzed manner (Eq. 1).     

H2SO4-H2O中硝酸铜对脱硫石膏晶须生长的影响

以处理后的脱硫石膏为原料,在H₂SO₄-H₂O体系中以Cu(NO₃)₂为晶形控制剂采用水热法制备脱硫石膏晶须,探讨了Cu(NO₃)₂对脱硫石膏晶须生长的影响机理。结果表明:Cu(NO₃)₂对脱硫石膏有明显促溶作用,其中Cu²⁺可减小溶液中各离子的活度系数,使溶液中的Ca²⁺浓度增大。NO^-₃通过静电作用在Ca²⁺周围聚集并对SO^2-₄产生屏蔽作用,导致脱硫石膏继续溶解并使Ca²⁺和SO^2-₄的浓度处于相对稳定状态,有利于半水脱硫石膏晶体的形核与生长。此外,Cu²⁺还可在晶须的生长过程中选择性吸附在晶须表面,生成CuSO₄,促进了脱硫石膏的结晶生长,最终在Cu(NO₃)₂用量为2.0%(质量分数)时制备的脱硫石膏晶须长径比约为73。