反复呼吸道感染儿童血锌检测分析

为探讨低锌对儿童反复呼吸道感染的影响 ,检测了 1 2 3例儿童指血锌 (Zn)值 ,并采用t检验 ,与正常儿童组进行血锌值比较。结果表明 ,反复呼吸道感染组血Zn值 48 69± 4 89μmol/L ,正常儿童组血Zn值 5 7 46± 1 9 1 8μmol/L ,经t检验 ,t>t0 0 1( 12 1) ,P <0 0 1 ,具有极其显著差异。提示儿童锌缺乏明显导致儿童免疫力下降 ,削弱机体对病毒及细菌的抵抗力 ,适当补锌有助于预防和治疗上呼吸道感染     

L-赖氨酸锌兔体内生物利用度研究

用原子吸收分光光度法和氨基酸自动分析仪法分别测定兔血清锌浓度和血清L-赖氨酸含量．结果表明．L-赖氨酸锌中锌的相对生物利用度明显优于硫酸锌．而其中的L-赖氨酸的相对生物利用度与L-赖氨酸组比较无明显差异．     

Mechanical Properties and Structure of Zinc-Containing Latex-Silicate Composites

The sol-gel technology is highly efficient for improving mechanical and thermal properties of polydiene elastomers by creating in them additional inorganic networks composed mainly of silica or silicates. The incorporation of modifying Zn ions into polydiene latex-silica systems increases considerably their mechanical characteristics due to an increase of the interaction between the organic and inorganic networks. Interpenetrating polydiene-silica networks were prepared by cohydrolysis of tetraethoxysilane and zinc acetate in natural Qualitex or synthetic butadiene-styrene latexes and then by aging and drying the liquid compositions at room temperature and vulcanizing at 90°C. Their structure and properties were studied by the IR spectroscopy, TMA and by tensile testing of the prepared films. The studied system was shown to be extremely suitable for obtaining latex films with improved elastic and strength characteristics. For example, the elastic modulus values of the Qualitex films containing 2–5% SiO₂ and 0.1–0.2% ZnO, are 4–9 and 6–11 times higher than those of the films prepared without zinc and of the pure latex films respectively. The possible structure roles of zinc ions at various stages of film preparation and vulcanization are discussed on the base of the results of IR and TMA studies.     

Syntheses and X-Ray Crystal Structures of 2-Aminoindenes and Aminocymantrenes

Substituted 2-aminoindenes have been synthesized in almost quantitative yields by reactions of amines such as methylpiperazine, trimethylethylenediamine, 1,4-diaza-cycloheptane and N,N′-dimethylethylenediamine with 2-indanone. The 2-aminoindenes can be deprotonated and reacted with BrMn(CO)₃(Py)₂ to produce the respective aminoindenyl-cymantrenes in yields between 55–70%. The X-ray crystal structures of 2-(methylpiperazine)indenyl-cymantrene 5 (P1 , a = 12.667(3) Å, b = 16.630(3) Å, c = 17.382(3) Å, α = 72.70(3)°, β = 74.59(3)°, γ = 88.66(3)°, V = 3364.1(12) Å ³, Z = 8, R1(2σ(I)) = 4.02%, wR2(2σ(I)) = 10.30%) and the HClO₄ adduct of 2-(trimethylethylenediamine)-indenyl-cymantrene 6 (Cc, a = 23.722(5) Å, b = 6.9080 Å, c = 13.264 Å, β = 111.77(3)°, V = 2018.6(7) Å 3, Z = 4, R1(2σ(I)) = 2.94%, wR2(2σ(I)) = 7.90%) were determined. In both complexes the indenyl-carbon bonded to nitrogen displays significantly longer bonds to manganese [223.5(3)–225.8(3) pm] than the other four carbon atoms [213.3(3)–219.1(3) pm]. The short indenyl-nitrogen bonds of 136.2(4) and 137.8(4) pm are indicative of a substantial multiple bond character. The complexation of Zn²⁺ by the nitrogen atoms of 6 results in significant shifts of the CO stretching frequencies.     

微量元素对胎儿发育影响的临床研究

为了解小于胎龄儿的血锌、铜、铅的变化 ,对 3 8例小于胎龄儿 (其中 1 2例有先天缺陷 )进行了血锌、铜、铅三种微量元素检测 ,并与 3 1例健康足月适于胎龄儿比较。结果表明 ,3 8例小于胎龄儿血锌、铜、铅结果分别为 49 4± 1 9 88μmol/L、 1 0 7± 3 3 μmol/L、 1 5± 0 83 μmol/L ;与正常对照组 (分别为 62 3 9± 1 5 2 9μmol/L、 1 1 0 2± 1 73 μmol/L、 0 82± 0 3 9μmol/L)比较 ,血锌明显低于正常组 ,t=-2 88,P <0 0 1 ;血铅明显高于对照组 ,t =4 6,P <0 0 1 ,有显著性差异。两组血铜无明显差异。小于胎龄儿血锌降低 ,血铅增高 ,而且其先天性缺陷者占3 5 .5 8% ,证明胎儿的低锌高铅状态对其生长发育有重要影响。     

Synthesis and Crystal Structure of a Novel Zinc Complex [Zn(OH_2)(HDPA)_2]·3H_2O

1INTRODUCTION In recent years,dicarboxylic acids have been wide-ly used as poly-dentate ligands involved in various metal chelation reactions to form transition or rare earth metal complexes with interesting properties in material science[1~3]and biological systems[4~7].For example,Kim,Y.and his coworkers focus on the syn-theses of copper(II)complexes containing ligands of malonate and pyrazine to study their electronic con-ductivity and magnetic property[8].The importance of Tr(II)/dic…     

Thermal stability of new zinc acetate-based complex compounds

New zinc acetate based complex compounds (of general formula Zn(CH₃COO)₂·1?2L·nH₂O) containing one or two molecules of urea, thiourea, coffeine and phenazone were prepared namely: Zn(CH₃COO)₂·2.5H₂O, Zn(CH₃COO)₂·2u·0.5H₂O, Zn(CH₃COO)₂·tu·0.5H₂O, Zn(CH₃COO)₂·2tu, Zn(CH₃COO)₂·cof·2.5H₂O, Zn(CH₃COO)₂·2cof·3.5H₂O, Zn(CH₃COO)₂·2phen·1.5H₂O. The compounds were characterized by IR spectroscopy, chemical analysis and thermal analysis. Thermal analysis showed that no changes in crystallographic modifications of the compounds take place during (heating in nitrogen before) the thermal decompositions. The temperature interval of the stability of the prepared compounds were determined. It was found that the thermal decomposition of hydrated compounds starts by the release of water molecules. During the thermal decomposition of anhydrous compounds in nitrogen the release of organic ligands take place followed by the decomposition of the acetate anion. Zinc oxide and metallic zinc were found as final products of the thermal decomposition of the zinc acetate based complex compounds studied. Carbon dioxide and acetone were detected in the gaseous products of the decomposition of the compounds if ZnO is formed. Carbon monoxide and acetaldehyde were detected in the gaseous products of the decomposition, if metallic Zn is formed. It is supposed that ZnO and Zn resulting from Zn acetate complex compounds here studied, possess different degree of structural disorder. Annealing takes place by further heating above 600°C.     

Synthesis and Crystal Structure of an Azide Bridged Binuclear Zinc(Ⅱ) Dimer Containing Taurine Schiff Base [Zn_2(C_8H_9N_2O_3S)_2·(N_3)_2·(H_2O)_2]_2·_2H_2O

1 INTRODUCTION The investigation of Shiff base complexes con- taining sulfur and complexes of amino acid Schiff bases[1, 2] has recently aroused considerable interest due to their antiviral, anticancer and antibacterial activities. Taurine, known as 2-aminosulfonic acid, is indispensable to human beings and plays an im- portant role in physiological functions. In this con- tribution, we present the synthesis and crystal struc- ture of a new binuclear Zn(II) dimmer with a tri- dentate Sc…     

Cellulose hydrolysis using zinc chloride as a solvent and catalyst

Cellulose gel with < 10% of crystallinity was prepared by treatment of microcrystalline cellulose, Avicel, with zinc chloride solution at a ratio of zinc chloride to cellulose from 1.5 to 18 (w/w). The presence of zinc ions in the cellulose gels enhanced the rate of hydrolysis and glucose yield. The evidence obtained from X-ray diffraction, iodine absorption experiments; and Nuclear Magnetic Resonance spectra analysis suggested the presence of zinc-cellulose complex after Avicel was treated with zinc chloride. Zinc-cellulose complex was more susceptible to hydrolysis than amorphous cellulose. Under the experimental condition, cellulose gels with zinc ions were hyrolyzed to glucose with 95% theoretical yield and a concentration of 14% (w/v) by cellulases within 20 h. The same gel was hydrolyzed by acid to glucose with 91.5% yield and a concentration of 13.4% (w/v).     

Xylan hydrolysis in zinc chloride solution

Xylan is the major component of hemicellulose, which consists of up to one-third of the lignocellulosic biomass. When the zinc chloride solution was used as a pretreatment agent to facilitate cellulose hydrolysis, hemicellulose was hydrolyzed during the pretreatment stage. In this study, xylan was used as a model to study the hydrolysis of hemicellulose in zinc chloride solution. The degradation of xylose that is released from xylan was reduced by the formation of zinc-xylose complex. The xylose yield was >90% (w/w) at 70°C. The yield and rate of hydrolysis were a function of temperature and the concentration of zinc chloride. The ratio of zinc chloride can be decreased from 9 to 1.3 (w/w). At this ratio, 76% of xylose yield was obtained. When wheat straw was pretreated with a concentrated zinc chloride solution, the hemicellulose hydrolysate contained only xylose and trace amounts of arabinose and oligosaccharides. With this approach, the hemicellulose hydrolysate can be separated from cellulose residue, which would be hydrolyzed subsequently to glucose by acid or enzymes to produce glucose. This production scheme provided a method to produce glucose and xylose in different streams, which can be fermented in separated fermenters.