男性型秃发患者发中K,Na,Ca,Mg元素含量分析

采用火焰原子吸收法对３０例男性型秃发患者及３８例毛发健康男性对照者发中宏量元素Ｋ、Ｎａ、Ｃａ、Ｍｇ的含量进行了测定。结果表明，男性型秃发患者发Ｋ含量明显高于对照组，具有统计学上的显著差异（Ｐ〈０．０１）。发Ｎａ、Ｃａ、Ｍｇ含量在两组间未见显著差异（Ｐ〉０．０５）。本文提示，体内某些宏量元素变化对男性型秃发可能产生一定影响。     

Powering the analytical glow discharge

The glow discharge may be powered by direct current (dc), radio frequency (rf) and pulsed discharge sources. Each has specific advantages and special features that should be considered by analysts using the various forms of glow discharge spectroscopy. This paper reviews some of the factors that contribute to the selection of a power source for the glow discharge.     

Background-free,fast protein staining in sodium dodecyl sulfate polyacrylamide gel using counterion dyes,zincon and ethyl violet

A background-free, fast protein staining method in polyacrylamide gel electrophoresis using an acidic dye, zincon (ZC) and a basic dye, ethyl violet (EV) is described. It is based on the counterion dye staining technique that employs two oppositely charged dyes to form an ion-pair complex in staining solution. The selective binding of free dye molecules to proteins in acidic solution produces bluish violet-colored bands. It is a rapid and end-point staining procedure, involving only fixing and staining steps that are completed in 1-1.5 h. The detection limit of this method is 8-15 ng of protein that is comparable to the sensitivity of the colloidal Coomassie Brilliant Blue G (CBBG) stain. Due to its sensitivity and speed, this stain may be more practical than any other dye-based stains for routine laboratory purposes.     

Organic phase conversion of bulk (wurtzite) ZnO to nanophase (wurtzite and zinc blende) ZnO

We describe the all-organic phase conversion of bulk commercial ZnO in the wurtzite modification to sub-30 nm ZnO that we find to be partially in the zinc blende [, a=4.568(3) Å] modification. The conversion involves refluxing ZnO in 2,4-pentanedione (acetylacetone) at 413 K to form the zinc 2,4-pentanedionate, which is decomposed by heating at 573 K in an appropriate high-temperature solvent such as dibenzylether to form nanophase ZnO. This nanophase, partially zinc blende ZnO can also be obtained in a single step by heating commercial zinc 2,4-pentanedionate in refluxing dibenzylether. Thermodiffractometry suggests that the conversion of zinc blende ZnO to wurtzite ZnO commences near 650 K.     

The Baylis-Hillman condensation of alpha,beta-conjugate cycloketones with aldehydes using diethylaluminum iodide alone as the promoter

The Baylis-Hillman condensation of three types of alpha,beta-conjugate cycloketones with aldehydes was successfully performed by using diethylaluminum iodide as the Lewis acid promoter alone without the direct use of a Lewis base. The reaction proceeded to completion at 0 degree C in CH2Cl2 within 24 h to give modest to good yields (53-72%).     

Correlating second harmonic optical responses of single Ag nanoparticles with morphology

Femtosecond laser excited second harmonic (SH) activity from single Ag nanoparticles is reported. A correlation of SH single-particle measurements with high-resolution imaging of particle morphology by TEM was achieved by creating position markers on an optical and electron transparent substrate (Si3N4 thin film, approximately 100 nm). We compared the SH activity of single Ag nanoparticles (nanospheres versus nanorods) and cluster structures (composed of two or multiple particles, e.g., dimers and trimers). The direct correlation of single-particle structures and SH activity, spectral and power dependence, strongly suggests one-photon resonant driven nonlinear oscillator response mechanism.     

The Studies of Lanthanide Shift Reagents in NMR Spectroscopy

The action of a series of lanthanide chelate complexes LnL₃, where Lu=La, Pr, Nd, Sm, Eu, Dy, Ho, Er and Yb; L= dbm (dibenzoylmethanato), dpm (dipivaloylmethanato), and acac acetylactonato), on nmr spectra of 2-butanol has been studied. The origin of shifting abilities and shifting sign of various lanthanide ions are explained by means of Bleaney's theory.     

Adsorption, desorption and activities of acid phosphatase on various colloidal particles from an Ultisol

Adsorption, desorption and activity of acid phosphatase on various soil colloidal particles and pure clay minerals were studied. Higher adsorption amounts and low percentage of desorption of acid phosphatase were found on fine soil clays (<0.2 μm). Electrostatic force and ligand exchange are the major driving forces that are involved in the adsorption of enzymes on soil clays. More enzyme molecules were adsorbed on soil clays in the presence of organic components. However, enzymes on organic clays were more easily released. One-third of the enzyme on goethite was adsorbed via ligand exchange process. Some other interactions, such as van der Waals force, hydrophobic force and hydrogen bonding may be more important in the adsorption of enzyme on kaolinite and the enzyme in this system cannot be easily removed. Coarse clays (0.2–2 μm) and inorganic soil clays had higher affinities for enzyme molecules than fine clays and organic clays, respectively. The activity of enzyme bound on soil clays was inhibited and the thermal stability was increased in the presence of organic matter. Data obtained in this study are helpful for a better understanding of the interactions of enzymes with inorganic and organic constituents in soil and associated environments.     

Fluorescent sensors for the enantioselective recognition of mandelic acid: signal amplification by dendritic branching

Novel chiral bisbinaphthyl compounds have been synthesized for the enantioselective fluorescent recognition of mandelic acid. By introducing dendritic branches to the chiral receptor unit, the fluorescence signals of the receptors are significantly amplified because of the light-harvesting effect of the dendritic structure. This has greatly increased the sensitivity of the sensors in the fluorescent recognition. Study of the three generation sensors demonstrates that the generation zero sensor is the best choice for the recognition of mandelic acid because of its greatly increased fluorescence signal over the core and its high enantioselectivity. This sensor is potentially useful for the high throughput screening of chiral catalysts for the asymmetric synthesis of alpha-hydroxycarboxylic acids.     

Metastasis-suppressor KAI1/CD82 induces homotypic aggregation of human prostate cancer cells through Src-dependent pathway

To investigate the functional role of KAI1/CD82, a metastasis suppressor for human prostate cancer, in the regulation of homotypic cell adhesion, we transfected KAI1 cDNA into DU 145 human prostate cancer cells and established stable transfectant clones with high KAI1/CD82 expression. The KAI1 transfectant cells exhibited significantly increased homotypic cell aggregation in comparison with the control transfectant cells. This aggregation of the KAI1 transfectants was further enhanced upon exposure to anti-CD82 antibody, suggesting that KAI1/CD82 may be involved in the intracellular signaling for the cell adhesion. Among several signal pathway inhibitors tested, PP1, an inhibitor of Src family kinases, significantly suppressed homotypic aggregation of the KAI1 transfectant cells. Ligation of KAI1/CD82 with anti-CD82 antibody increased endogenous Src kinase activity of the KAI1 transfectant cells. When different types of src expression constructs were retransfected into the KAI1-transfected DU 145 cells, kinase-negative mutant src transfectant cells exhibited much lower homotypic aggregation than the mock cells transfected with an empty vector. Moreover, homotypic aggregation of the mutant src transfectant cells was not enhanced by KAI1/CD82 ligation with anti- CD82 antibody. These results suggest that Src mediates the intracellular signaling pathway of KAI1/CD82 for the induction of homotypic adhesion of human prostate cancer cells.