Urinary steroid analysis of women with effluvium

Summary Urinary steroid metabolites were measured by capillary gas chromatography in 25 women (aged 33.3±12.0 years) with effluvium and 16 control healthy laboratory workers women (aged 34.6±8.4 years). There was significant elevation in the level of a number of steroids and steroid metabolites. The elevation of most steroid metabolites refers to the increased steroid secretion of the adrenal and the high cortisol metabolites levels may be do to stress in some of the patients with effluvium. Presented at: Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, September 3–5, 1997     

Measurements of Zeta Potential on Corroding,High-Purity Iron Particles: Influence of Corrosion Inhibitors

Adsorption of cetyl trimethyl ammonium bromide (CTAB), and two commercial inhibitor base chemicals; an oleic imidazoline salt (OI) and a phosphate ester (PE), onto high purity, corroding iron particles was studied by zeta potential measurements in a 0.1 Wt% sodium chloride (NaCl) solution under 1 bar CO₂ at 22°C. The particles were exposed to the inhibitor compounds for 24 hours before measurements were done. The results show that the measured zeta potential in the absence of inhibitor is zero at both pH 4.0 ± 0.2 and pH 5.8 ± 0.2. It is concluded that this might be caused by the electrochemical reactions occurring at the steel surface when placed in an electrical field. When adding inhibitor, which slows the electrochemical reactions at the steel surface, the zeta potential moves away from zero and an adsorption isotherm is obtained for all three inhibitors. The measured potential is probably a mixed potential where the apparent potential measured is a combination of the potential at the shear plane and a contribution form the electrochemical reactions occurring on the surface.     

Flame retardant polystyrene copolymers: preparation,thermal properties,and fire toxicities

A new phosphorous‐ and nitrogen‐containing reactive monomer, DMPMA, was first synthesized by nucleophilic substitution reaction of 2‐(6‐oxido‐6H‐dibenz[c,e][1,2]oxaphos‐phorin‐6‐yl) methanol, N‐hydroxymethyl acrylamide and methyldichlorophosphate. The copolymer of styrene (St) and DMPMA (poly(St‐co‐DMPMA)) was prepared and then characterized by Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis (TGA), microscale combustion calorimeter and steady‐state tube furnace (SSTF). The results proved that poly(St‐co‐DMPMA) was well synthesized, while the glass transition temperature of the copolymer was decreased with increasing DMPMA content. The TGA results showed that the initial degradation temperature of poly(St‐co‐DMPMA) decreased, but its char yield and decomposition temperature improved compared to that of pure polystyrene. After incorporating DMPMA, the fire performance of the copolymer was significantly improved. The results obtained from the SSTF indicated that the carbon monoxide and smoke yield density were increased due to the incomplete combustion of the copolymer. Copyright © 2014 John Wiley & Sons, Ltd.     

N,N,N'-不同基团三取代乙二胺衍生物的简便合成

以2-取代咪唑啉为起始原料,经过磺酰化反应,得到磺酰基咪唑啉2a-2e,然后进行甲基化反应得到1,2,3-三取代咪唑啉碘盐3a-3e。化合物3在室温下经过水解反应或还原反应,可得到两类不同基团N,N,N'-三取代乙二胺衍生物4或5。该反应具有条件温和、副产物少、产物得率高和后处理简单等优点,提供了一种有效的三步合成不同基团N,N,N'-三取代乙二胺衍生物的新方法。所合成产物通过NMR、IR和元素分析方法进行了结构确证。     

Antiviral drug nevirapine as a template for hydrated imidazoline ring expansion (HIRE): Rapid access to the diarene-fused 1,4,7-triazecine ring system

The tricyclic ring system of the antiviral drug nevirapine has been employed to test the workability of the hydrated imidazoline ring expansion (HIRE) reaction which was previously exemplified for [1.4]oxazepine and [1.4]thiazepine counterparts. The imidazoline nucleus was grafted onto the lactam moiety of nevirapine in two high-yielding steps. Subsequent N-alkylation and the HIRE reaction proceeded as envisioned and delivered rare ring-expanded diarene-fused 1,4,7-triazecines with a diversity of alkyl substituents at the lactam nitrogen atom. These findings extend the scope of the HIRE reaction to the medicinally prominent [1.4]diazepine chemical space.     

咪唑啉酰胺在含CO2溶液中的缓蚀机理

用电化学阻抗谱及极化测量，研究了在含ＣＯ２的ＮａＣｌ溶液中咪唑啉酰胺（ＩＭ）对铁的缓蚀性能研究，并探讨了它在铁表面的吸脱附行为．结果表明，ＩＭ的缓蚀作用是由它对铁的负催化所控制．它在铁表面的吸附服从Ｌａｎｇｍｕｉｒ吸附等温式．电位正移到脱附电位以上是ＩＭ阳极脱附的主要原因，这时它使表面电容Ｃｄ显著增加，传递电阻Ｒｔ明显减小     

Inhibition effect of azole derivate on corrosion activity of copper in rolling oil

Corrosion rates are influenced by the formation of inhibitor aggregates on the copper surface. Laser scanning confocal microscope was used to investigate the adsorbed structures of benzotriazole, N‐((6‐methyl‐1H‐benzo[d][1,2,3]triazol‐1‐yl)methyl)‐N‐octyloctan‐1‐amine (MBA) and 2,5‐bis (ethyldisulfanyl)‐1,3,4‐thiadiazole at copper surface in relation to their performance as a corrosion inhibitor. The increase of water contact angle in the presence of inhibitor indicates its strong adsorption to the copper, and laser scanning confocal microscope visualization confirms the formation of MBA aggregates. The aggregates change from hemispherical to cylindrical shape with MBA concentration increasing in rolling oil, resulting in a decrease in corrosion rates as determined by mass loss measurements. Compared with 2,5‐bis (ethyldisulfanyl)‐1,3,4‐thiadiazole, oil‐added MBA has a quicker adsorption and formation speed of cylindrical aggregates and a lower corrosion rate. The adsorption of inhibitors on copper surface obeys Langmuir isotherm and physisorption and chemisorption mechanism. Copyright © 2015 John Wiley & Sons, Ltd.     

Quantum-chemical analysis of the cluster models of coordination of imidazoline nitroxides on the silica surface

The results of ESR-spectroscopic and quantum-chemical studies of the coordination of 2,2,4,5,5-pentamethyl-3-imidazoline-N-oxyl and 2-phenyl-2,4,5,5-tetramethyl-3-imidazoline-N-oxyl with the surface acid sites (AS) of silica are analyzed. Cluster models of AS, corresponding to one- and two-point coordination and accepted in radiospectroscopy on the basis ofg-factors and constants of hyperfine splitting at the N nuclei in the resulting donor-acceptor complexes, are discussed. Within the framework of the unrestricted Hartree-Fock method using the MNDO approach, a comparative quantum-chemical analysis of the structural, spin, electrostatic, energy, and radiospectroscopic characteristics of the coordination of the model cluster AS to the imidazoline nitroxide probes is performed. For the two-center adsorption, three types of AS structures are considered, together with the paramagnetic surface complexes they form. A consistent semi-quantitative interpretation of the whole set of features found experimentally for the coordination of imidazoline nitroxides to the surface AS on silica is given. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1081–1086, June, 1998.     

8-烷基小檗碱的合成

对比研究了乙醚、二氧六环和四氢呋喃(THF)三种溶剂对8位长链烷基取代小檗碱衍生物中间体合成产率的影响. 以四氢呋喃(THF)为反应溶剂, 8-癸基和8-月桂基盐酸小檗碱的产率是以乙醚为溶剂的4倍以上.