乌昌地区废旧轮胎回收利用现状调查及分析

选取新疆经济发展最快的乌昌地区为靶区,以现场调查资料为基础,根据国内外废旧轮胎回收利用发展变化特点,对该区域的废旧轮胎现状进行了统计分析,并对乌昌地区废旧轮胎的产生量进行了预测。通过对乌昌地区废旧轮胎回收市场特点的调查研究,指出了乌昌地区废旧轮胎回收市场目前存在的问题,提出了相应的建议和措施。     

Binding of trinitrotoluene (TNT) to water extractable humus

Solid-state ¹⁵N NMR was applied to the aqueous extracts of a ¹³C-enriched plant slurry (Lolium perenne), anaerobically incubated with ¹⁵N₃-trinitrotoluene (TNT). Almost all ¹⁵N₃-TNT transformation products became covalently bound to the plant-derived organic material extractable with water. DCPMAS ¹⁵N ¹³C NMR revealed a three-step reaction scheme. After reduction of TNT, the aryl amines are acetylated. Subsequent alkylation of the resulting amides strengthens the incorporation of TNT-transformation products into humic material. Comparable results have been recently obtained under aerobic conditions, which indicates that this pathway is a common process during biological TNT transformation.     

腐殖酸与稀土元素的作用及体系稳定性

 用稀土元素（La³⁺，Ce³⁺，Ho³⁺，Yb³⁺）标准溶液对湖泊沉积物腐殖酸进行非连续滴定，研究二者之间的络合反应能力及其结合产物在水溶液体系的稳定性。结果表明，腐殖酸结构中的活性点位在与三价稀土离子作用时表现出两种不同类型，在机制上采取两级络合反应。体系中沉淀生成与否主要取决于腐殖酸对稀土离子的容纳能力。     

出生前后全氟辛烷磺酸(PFOS)暴露对大鼠额叶皮质中IGF-Ⅰ、IGF-ⅠR和IGFBP-2 mRNA水平的影响

为研究出生前后不同时期全氟辛烷磺酸(PFOS)暴露对大鼠仔鼠额叶皮质胰岛素样生长因子-Ⅰ(IGF-Ⅰ)、胰岛素样生长因子-Ⅰ受体(IGF-ⅠR)和胰岛素样生长因子结合蛋白-2(IGFBP-2)mRNA水平的影响,将28只受孕Wistar大鼠按3:2:2的比例随机分到对照(C)、低剂量(L)和高剂量(H)组中,从妊娠第0天开始分别自由摄食含0、7.2、14.4mg·kg-(1以饲料中的PFOS计)的粉末状饲料进行连续染毒至出生后28天.采用交叉哺育的方法建立出生前后均不暴露(CC)、仅出生前暴露(LC和HC)、仅出生后暴露(CL和CH)、出生前后均暴露(LL和HH)于PFOS的动物模型.采用半定量RT-PCR法检测各组仔鼠额叶皮质IGF-Ⅰ、IGF-ⅠR和IGFBP-2mRNA水平的变化.结果表明,对照组仔鼠额叶皮质IGF-Ⅰ、IGFBP-2mRNA在PD14时处于较高水平,而在PD1和PD28时水平较低;IGF-ⅠRmRNA在PD1时只处于较低水平,随年龄的增加而逐渐升高.在PD1时,暴露组仔鼠IGF-Ⅰ、IGF-ⅠR、IGFBP-2mRNA水平显著高于对照组(p<0.05).在PD14时,除LC组仔鼠IGF-ⅠRmRNA水平显著高于对照组之外,其余各暴露组仔鼠3者mRNA水平均显著低于对照组(p<0.01).此外,出生后暴露PFOS组的仔鼠额叶皮质IGF-Ⅰ、IGFBP-2mRNA水平降低程度比出生前暴露PFOS组仔鼠更高.在PD28时,暴露组仔鼠IGF-Ⅰ、IGF-ⅠRmRNA水平显著低于对照组(p<0.01),而IGFBP-2mRNA水平与对照组之间的差异无显著性(p>0.05).出生前后不同时期暴露PFOS导致大鼠仔鼠额叶皮质IGF-Ⅰ、IGF-ⅠR和IGFBP-2mRNA水平变化,为PFOS发育神经毒性的研究提供了一定的线索.     

Review of konjac glucomannan

The paper reviews the solution and gelling properties of konjac glucomannan (KGM) and its interactions with other hydrocolloids such as xanthan and carrageenan for food applications. Research activities in the area of KGM processing in environmentally friendly aqueous environments have been discussed for coatings and packaging applications. Guest Editor: Heidi Schreuder-Gibson, U.S. Army Natick RD&E Center, Kansas Street, Natick, Massachusetts 01760-5020     

Cobalt speciation assay for human serum,Part I. Method for measuring large and small molecular cobalt and protein-binding capacity using size exclusion chromatography with inductively coupled plasma-mass spectroscopy detection

A method utilizing size exclusion liquid chromatography (SEC) was developed to separate and quantify large molecular cobalt (Co) (e.g., albumin-Co) from cyanocobalamin (vitamin B₁₂) and small molecular Co (e.g., glutathione-Co and free Co) in human serum. Highly selective and sensitive detection using inductively coupled plasma–mass spectrometry was coupled with SEC to provide a method with reliable accuracy, precision, recoveries, stability, and a detection limit of 0.037 μg/L in undiluted serum. Other divalent metal cations known to compete with Co(II) for serum albumin-binding sites (such as iron, zinc, manganese, cadmium, copper, nickel, and lead) did not significantly alter Co(II) quantification. Co–protein binding capacity determination of individual serum samples indicated that addition of 2500 μg Co/L to undiluted human serum resulted in approximately 90% distribution to the large molecular Co peak, consistent with Co binding to high-affinity divalent metal binding sites on albumin. Since serum albumin binding partially sequesters biologically active Co(II) ions, this method provides an important tool for better understanding the kinetics and toxicology of Co compounds. Thus, the proposed method might play an important role in establishing Co dose–response relationships that affect the equilibrium concentrations of free ionic Co(II).     

Induction of mercury‐binding peptide in whole cells and anucleated cells of Acetabularia calyculus

The present study reports the isolation and partial purification of a mercury‐binding polypeptide in whole and anucleated cells of Acetabularia calyculus. Sephadex G‐75 Gel filtration showed that cells exposed to Hg exhibit a major peak of protein(s) concomitant with both, a major peak of Hg (revealed by atomic absorption spectroscopy), and the major peak of mercury‐thiolate complex (based on a high 254 nm absorbance) accompanied by high content of SH groups. SDS‐Page electrophoresis showed that this peak contains one major polypeptide of apparent molecular weight 27.000 dalton. These results are in agreement with our previous finding of unusually high bioconcentration factor of Hg in Acetabularia related to the induction of a polypeptide in both, whole and anucleated cells of Acetabularia, in presence of Hg.     

芳香烃菲与基因碱基的非共价结合及驱动机制

疏水芳香烃类化合物能够导致基因遗传性的变化,理解这些化合物对基因污染的前提是必须首先阐明污染物-基因碱基间相互作用及驱动机制.使用等温吸附-光纤固相萃取和定量-构效关系的方法,研究了模型化合物菲与4种基因碱基间的弱相互作用,并揭示了分子驱动机制.结果表明,p H=7.0条件下,腺嘌呤与菲间引力较弱;而鸟嘌呤、胞嘧啶和胸腺嘧啶对菲为分配吸附,引力较强.红外光谱和弱力等值面的分析表明,鸟嘌呤与腺嘌呤分子能够通过2组CN环(CN6环和5环)与菲的2个相互毗邻的苯核同时发生π-π引力作用;而胞嘧啶和胸腺嘧啶仅与菲弧角位置的碳原子通过电子"赠体-受体"发生静电引力作用.当环境体系变成酸性时,腺嘌呤对菲的吸附增强(分配,1/n=1),但胸腺嘧啶对菲的吸附变弱;碱性条件下,由于胞嘧啶和胸腺嘧啶存在羰基取代基,作为电子赠体的含氧嘧啶脱质子化,表面负电性增强,分子平面极化减弱,π电子更易于与菲弧角位的碳原子发生电子"赠体-受体"作用.能量计算的结果表明,对基因碱基作用位点的预测结果可信,属于自发的非共价成因的物理结合.该研究将为深入揭示芳香烃的基因污染提供理论基础,对于防治芳香烃污染、保障生态安全有重要意义.     

ATR-FTIR and XPS study on the structure of complexes formed upon the adsorption of simple organic acids on aluminum hydroxide

Information on the binding of organic ligands to metal （hydr）oxide surfaces is useful for understanding the adsorption behaviour of natural organic matter on metal （hydr）oxide. In this study, benzoate and salicylate were employed as the model organic ligands and aluminum hydroxide as the metal hydroxide. The attenuated total reflectance Fourier transform infrared （ATR-FTIR） spectra revealed that the ligands benzoate and salicylate do coordinate directly with the surface of hydrous aluminum hydroxide, thereby forming innersphere surface complexes. It is concluded that when the initial pH is acidic or neutral, monodentate and bridging complexes are to be formed between benzoate and aluminum hydroxide while bridging complexes predominate when the initial pH is alkalic. Monodentate and bridging complexes can be formed at pH 5 while precipitate and bridging complexes are formed at pH 7 when salicylate anions are adsorbed on aluminum hydroxide. The X-ray photoelectron （XP） spectra demonstrated the variation of C 1 s binding energy in the salicyate and phenolic groups before and after adsorption. It implied that the benzoate ligands are adsorbed through the complexation between carboxylate moieties and the aluminum hydroxide surface, while both carboxylate group and phenolic group are involved in the complexation reaction when salicylate is adsorbed onto aluminum hydroxide. The information offered by the XPS confirmed the findings obtained with ATR-FTIR.