Determination of levels of adenosine phosphates in blood by ion chromatography

A new method was developed for simultaneous determination of levels of AMP,ADP and ATP in blood by anion-exchange chromatography.The three adenosine phosphates were separated by Dionex IonPac AG18(50 mm×4 mm) guard column and IonPac AS 18(250 mm×4 mm) analytical column using a gradient method and detected with a suppressed conductivity detector. The detection limits(S/N=3) of AMP,ADP and ATP were 38,47,108 ng/L,respectively.The relative standard deviations of retention time,peak area and peak height were all less than 1.87%and a good linear relationship was obtained.This method was applied to analyze human blood samples.     

Tissue engineering and peripheral nerve regeneration (Ⅲ)——Sciatic nerve regeneration with PDLLA nerve guide

The biodegradation rate and biocompatibility of poly(d, / -lactide) (PDLLA) in vivo were evaluated. The aim of this study was to establish a nerve guide constructed by the PDLLA with 3-D microenvironment and to repair a 10 mm of sciatic nerve gap in rats. The process of the nerve regeneration was investigated by histological assessment, electrophysiological examination, and determination of wet weight recovery rate of the gastrocnemius muscle. After 3 weeks, the nerve guide had changed from a transparent to an opaque status. The conduit was degraded and absorbed partly and had lost their strength with breakage at the 9th week of postoperation. At the conclusion of 12 weeks, proximal and distal end of nerves were anastomosed by nerve regeneration and the conduit vanished completely. The results suggest that PDLLA conduits may serve for peripheral nerve regeneration and PDLLA is a sort of hopeful candidate for tissue engineering.     

气相色谱法分析食用蟹味油

method for analysis of the edible oil with crab taste by gas chromatography has been developed. The sample was directly introduced on a Silicone XE-60 capillary column . 25m×0. 25mm×0. 5μm, with a one-ramp temperature programming (hold 10min at 80℃, increased upto 180℃ at 20℃/min and then hold 20min) and detected by FID. For the component identification mass spectrometry was used. The above condition was chosen after in comparison with a PEG-20M column.     

IMMOBILIZED CIBACRON BLUE F3G—A ON CROSSLINKED POLY9VINYL ALCOHOL） FOR AFFINITY CHROMATOGRAPHY

Immobilized triazine dye affinity chromatography has been widely used for protein purification.In this paper,Cibacron Blue F3G-4 was immobilized,through a spacer arm,onto a rigid hydroplhilic porous polymer by reacting an epoxy-group-containing poly(vinyl alcohol)with 6-aminohexyl-N‘-Cibacron Blue F3G-A,which was obtained by reacting Cibacron Blue F3G-4 with excess of 1,6-diaminohexane,in a pH 8.6buffer,The epoxy-group-containing poly(vinyl alcohol)was prepared by treating macroporous poly(vinyl alcohol)with excess epichlorohydrin in the presence of NaOH in dimethyl sulfoxide.The macroporous poly(vinyl alcohol)was prepared by hydrolysis of macroporous crosslinked poly(vinyl acetate),which was synthesized by suspension copolymerization of vinyl acetate and triallyl isocyanurate in the presence of butyl acetate and n-heptane as diluents.The Cibacron Blue F3G-A-immobilized poly(vinyl alcohol)was packed in a stainless steel column (250×5mm I.D.)and the chromatographic behaviors of several proteins(cytochrome c, lysozyme,bovine serum albumin,insulin,and lactate dehydrogenase)were determined.     

Synthesis and Analytical Application of Bis（2-diazoaminobenzothiazoyl）-benzidine to Determination of Mercury Ion by Fluorimetry

A new fluorescent reagent bis(2-diazoaminobenzothiazoyl)-benzidine(BDABTB) was synthesized by combining benzothiazole with benzidine and triazene reagent. The product was confirmed by elemental analysis, 1H NMR and FTIR. The excitation and emission wavelengths of BDABTB were 214 and 338 nm in a basic medium, respectively. The fluorescence was quenched by Hg2+ selectively and sensitively. The linear range of Hg2+ was 1.0×10-8―1.0×10-5 mol/L with a detection limit of 5.0×10-10 mol/L. It has been used to deter...     

高效液相色谱法测定盐酸羟甲唑啉滴鼻剂的稳定性

The stability of oxymetazoline hydrochloride nasal solution was determined by HPLC and the initialaverage rate method. The procedure was carripd out on a 250mm×4. 6mm column with 5μm ODS using wa-ter-methanol-sodium acetate solution(lmol/L)-glacil acetic acid-triethylamine as mobile phase,with UV de-tection at 280nm. The elution was performed at the flow rate of lmL/min. The results show that the expirydate of this preparation is about three years at room temperature.     

Studies on Blends of Nylon 6 and a Thermotropic Liquid Crystalline Polyarylester(Ⅱ)——Morphology and Rheology

Blends of nylon 6 (PA6) and a semirigid thermotropic liquid crystalline polyarylester (THH) were prepared by coprecipitation. The changing of the morphology of the blends with their compositions was observed by means of a polarizing microscope and scanning electron microscope. The THH phases in the blends changed gradually from spherical droplets to fibrils with the increase of THH content. The flow behavior of the blends are quite different from that of the parent polymers and a very dramatic reduction in the melt viscosity of blends containing 5% THH was observed. The formation possibility of in-situ reinforcement composites of PA6 blends with a semirigid LCP is discussed in the present paper.     

Structure,Chemical State and Luminescent Properties of Ce,Gd:YAG Transparent Ceramic for Flip-chip White LED Application

Ce,Gd:YAG transparent ceramic was prepared by tape casting and solid state reaction method. Meanwhile, its crystal structure, chemical state and luminous properties were discussed. The prepared samples are identified as pure garnet structure by the XRD results. The valence states of tetravalent and trivalent Ce ions were identified distinctly by X-ray photoelectron spectroscopy. A strong broad band yellow emission was found in photoluminescence(PL) spectra. The quantum yield reached 90.2% at room temperature. When collaborated with a 1.0 mm × 1.0 mm flip-chip, a luminous efficiency(LE) as high as 116.5 lm/W with a correlated color temperature(CCT) of 6627 K at a power dissipation of 1.13 W at 350 m A was demonstrated, indicating that Ce,Gd:YAG transparent ceramics had a promising potential for high power white light-emitting diodes.     

A NOVEL THIOPHENE-DERIVED N_2O_2 MACROCYCLE AND ITS Ag(I) COMPLEX: SYNTHESIS AND CHARACTERIZATION

A novel macrocycle containing thiophene (L) was prepared first by the interaction of 2,5-bis-(chloromethyl)-thiophene (A) and salicylaldehyde to give 2, 5-bis-(2-formylphenoxymethyl)-thiophene (B), and then by the nontemplate cyclocondensation of 1,3-diaminopropane with (B) followed by a "onepot" reduction without isolation of the diimine intermediate. The corresponding silver complex, AgLClO_4, was also prepared. The macrocycle was characterized by IR, elemental analysis, MS and ~1HNMR.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Investigation of Kinetics of Solid-Phase Synthesis of Lithium Orthosilicate

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m²g^-1 instead of aerosil with one of 175 m²g^-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.     

小环化合物中饱和碳质子化学位移的计算

小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:     

解决能源问题的新途径--光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。