三种有机物料对铬污染土壤理化性质及小麦生长发育特征的影响

为研究玉米秸秆、菌渣和生物炭对Cr污染土壤的修复效果及相应小麦植株的响应,于2013-2014年在河南师范大学网室进行盆栽试验,在250mg·k~(-1)和400mg·k~(-1) Cr污染土壤中添加一定剂量的上述3种有机物料,研究它们对不同时期的土壤理化性质、小麦生长发育特征、土壤Cr生物有效性以及小麦籽粒Cr积累的影响。结果表明,添加玉米秸秆(6g·k~(-1))和生物炭(50g·kg~(-1))可使土壤pH降低,添加菌渣(140g·k~(-1))可显著提高250mg·k~(-1) Cr污染土壤pH值,但对400mg·k~(-1) Cr污染土壤pH值没有明显的促进作用;添加3种有机物料均可显著提高土壤有机质含量,促进小麦株高增加、叶绿素含量升高,使其光抑制减弱、光合活性增强,有效提高小麦产量,降低土壤有效态Cr和小麦籽粒Cr含量,但总体上菌渣作用效果最佳,生物炭次之,玉米秸秆最差。     

Direct embryotoxicity of chromium (III) exposure during preimplantation development

Chromium in its trivalent form (chromium (III)) is an essential component of a balanced diet, and its deficiency disturbs glucose and lipid metabolism in humans and animals. The prevailing view is that chromium (III) is notably less toxic than chromium (VI), which is genotoxic and carcinogenic. Thus, the biotransformation of environmental chromium (VI) to chromium (III) is a promising and environmentally friendly detoxification method. However, increasing evidence suggests that chromium (III) induces considerable cytotoxicity. However, the toxicity of chromium (III) to early embryos remains largely unknown. In the present study, we used in vitro fertilization (IVF) to produce mouse embryos and identified the direct embryotoxicity of chromium (III). On exposure to high concentrations of CrCl₃, blastocyst formation almost completely failed and a large proportion of embryos were arrested at the 2- to 4-cell stage. At low concentrations of CrCl₃, IVF embryos showed a significant decrease in blastocyst formation, reduced total cell numbers, aberrant lineage differentiation, increased oxidative stress, and apoptosis. We also found that chromium (III) exposure during the preimplantation stage, even at low concentrations, led to impaired post-implantation development. Thus, our study substantiates the direct embryotoxicity of chromium (III) during preimplantation development and prolonged impairment of development potential. The results further highlight the potential adverse effects of chromium (III) on public reproductive health with respect to increased environmental enrichment of and dietary supplementation with chromium (III) complexes.     

不同形式铬对SD大鼠生长性能、胴体组成和血清生化指标的影响

本文旨在研究纳米铬和吡啶羧酸铬对SD大鼠生长性能、胴体组成及血清生化指标的影响。试验以30只平均体重为(80±5)g的SD雄性大鼠为研究对象,随机分为3组,每组10只。对照组饲喂基础日粮,试验1、2组分别在基础日粮中以吡啶羧酸铬和纳米铬的形式添加300μg/kg铬,预试期7d,试验期36d。试验结果表明:(1)纳米铬处理使SD大鼠的日增重和饲料利用率分别提高了12.68%(P<0.05)和32.92%(P<0.05);吡啶铬处理有提高大鼠日增重和饲料利用率的趋势(P>0.05);(2)纳米铬处理使SD大鼠瘦肉重增加了15.11%(P<0.05),脂肪率降低了24.42%(P<0.05);吡啶铬处理使大鼠瘦肉重增加了18.76%(P<0.05);(3)纳米铬处理使SD大鼠血清中胰岛素、葡萄糖、尿素氮和甘油三酯水平较对照组分别降低了45.38%(P<0.05)、31.84%(P<0.05)、48.75%(P<0.05)和38.46%(P<0.05);吡啶铬处理则使大鼠血清尿素氮浓度较对照组降低了57.62%(P<0.05),高密度脂蛋白浓度升高了26.15%(P<0.05)。因此,纳米铬能够促进大鼠生长,改善胴体组成。     

Phytoaccumulation of chromium by some multipurpose-tree seedlings

A pot culture experiment was conducted in green house to study the potential of chromium (Cr) phytoaccumulatory capabilities of four promising agroforestry tree species viz., Albizia amara, Casuarina equisetifolia, Tectona grandis, and Leucaena luecocephala. Possibility of enhancement of Cr uptake by chemical (citric acid) and biological vesicular arbuscular mycorrhizal fungi (VAM) amendments were also tried. Biologically stable speciation of Cr trivalent (Cr(III) and hexavalent Cr(VI) were used. Cr(VI) was more toxic to the tree growth in terms of collar diameter (CD) increment in all the tree species than Cr(III). In general, roots accumulated more Cr than shoots in all the tree species. There was more than 10 fold increase in root Cr content in comparison with shoot Cr content in all the trees at all the concentration of Cr and all sources of Cr. Citric acid significantly increased the Cr content in the tissues of roots in all the species under both speciation of Cr. The highest increase in Cr content brought by 20 mM citric acid addition was in A. amara. Unlike citric acid, VAM treatment did not bring about a significant increase in the Cr content of all the tree species studied. Results suggest that Albizia amara is a potential Cr accumulator with citric acid as soil amendment. The potential of this tree as a Cr phytoaccumulator may be investigated in long-term studies.     

东北主要绿化树种对大气重金属污染物吸收能力的研究

本文于2003年9月到10月在哈尔滨市主要街道采集和分析主要绿化树种的树叶，研究测定了东北主要的24种乔木树种和6种灌木树种对大气重金属污染物铅、镉、铬、汞的吸收能力。结果表明：绿化树种对铅、镉、铬、汞具有一定的吸收能力，并依污染物和树种的不同而有明显差异；根据不同树种对不同大气重金属污染物吸收量的差异将其各分为三级，其中吸铅量高的树种有白桦、垂枝榆和京桃等；吸镉量高的树种有小黑杨、钻天杨、银中杨和旱柳等；吸铬量高的树种有黄菠萝、紫丁香、旱柳、黑皮油松、红皮云杉、京桃、榆叶梅和糖槭等；吸汞量高的树种有榆叶梅、蒙古栎、旱柳、接骨木、野梨和华北绣线菊等。本研究为在不同大气重金属污染条件下选择不同绿化树种提供了科学依据。表4参11。     

Determination of reaction rate parameters for the acid copper chromate fixation reactions on oak (Quercus castaneifolia C. A. Mey) sapwood

Acid copper chromate fixation reactions on oak (Quercus castaneifolia C. A. Mey) sapwood were characterized by at least two distinguished reaction periods which differ in their kinetic behavior, particularly reaction rate. In this research, chemical rate equation parameters were studied in detail as a function of chromium fixation time. Theoretically, the kinetic data were distinguished between the adsorption and reduction reactions and consequently, the rate parameters were determined for each stage distinctly. The obtained results showed that at the investigated thermal range (25–33°C), almost for every 3°C increase in temperature the reaction duration has decreased 20.4?min for the first reaction period and 78?min for the second reaction period. Besides that, in all sample replications, up to 58.3% of hydrogen ions function at the reduction reactions of the initial period, demonstrating that acidity (H⁺ ions) has a major effect on reaction rate constant. Accordingly, adsorption reactions of the hexavalent chromium at the starting point follow a pseudo-first-order kinetic reaction. Different to the adsorption reaction the Cr^VI reduction reaction is exothermic with a measured exothermal energy of 48.2?kJ/mol.     

硒和铬对蛋鸡脂质代谢及鸡蛋硒含量的影响

本试验旨在研究在蛋鸡日粮中添加酵母硒和吡啶羧酸铬及其互作对蛋鸡生产性能、脂质代谢及鸡蛋品质的影响.选用320只45周龄海赛克斯蛋鸡随机分为4组,每组4个重复,每个重复20只鸡,在基础口粮中分别添加0 mg/kg吡啶羧酸铬(Ⅰ组)、0.4 mg/kg吡啶羧酸铬(Ⅱ组)、0.5 mg/kg酵母硒(Ⅲ组)、0.4 mg/kg吡啶羧酸铬+0.5 mg/kg酵母硒(Ⅳ组),预饲1周,试验从46周龄持续到50周龄,试验期5周(35 d).结果表明,Ⅲ、Ⅳ组产蛋率极显著提高,料蛋比极显著降低(P<0.01).Ⅱ、Ⅳ组血清总胆固醇含量极显著降低(P<0.01),Ⅲ、Ⅳ组血清高密度胆固醇含量极显著升高(P<0.01).Ⅱ、Ⅲ、Ⅳ组蛋黄中的胆固醇含量与Ⅰ组差异极显著(P<0.01).Ⅲ、Ⅳ组与Ⅰ、Ⅱ组相比,鸡蛋硒含量极显著升高(P<0.01).Ⅲ、Ⅳ组在试验开始到第2周末鸡蛋硒含量极显著升高(P<0.01),从第2周末到第5周末,硒含量基本稳定,4个组均进入平台期.结果显示,吡啶羧酸铬极显著降低了血清及蛋黄中的胆固醇含量.酵母硒极显著提高了产蛋率,降低了料蛋比,并降低了蛋黄中胆固醇含量,提高了鸡蛋中的硒含量.同时添加吡啶羧酸铬和酵母硒极显著提高了产蛋率,降低了料蛋比,并降低了血清及蛋黄中的胆固醇含量,提高了血清中高密度胆同醇含量和鸡蛋中的硒含量.     

铬胁迫下三种基因型小麦萌发和抗氧化酶差异的研究

采用3种不同基因型小麦品种(新麦19、矮抗58和豫麦18),对其进行萌发期不同浓度Cr2(SO4)3胁迫处理.研究幼苗的发芽势、发芽率、根长、芽长、叶绿素、根系活力、MDA含量,以及抗氧化酶的变化.结果表明:随Cr浓度的增加,发芽势、发芽率和芽长均基本呈"先升后降"趋势;同一浓度Cr处理下,发芽率、发芽势和芽长均表现为新麦19>矮抗58>豫麦18,根长为豫麦18>新麦19>矮抗58;150 mg/L的Cr胁迫下,小麦幼芽叶绿素含量、幼根根系活力降低,MDA含量升高;随Cr浓度的升高,幼芽SOD、POD活性升高;SOD、POD活性在新麦19中变幅最小.     

EDTA对铬胁迫下黄瓜幼苗生长及生理特性的影响

为探究乙二胺四乙酸(EDTA)对缓解黄瓜幼苗铬胁迫的生理调控机制,以亨优小菜园为供试材料,采用土培方式,用120mg/L铬离子溶液模拟铬胁迫,研究不同浓度EDTA(W₁:1mmol/L、W₂:2mmol/L和W₃:4mmol/L)对铬胁迫下幼苗生长及生理特性的影响。结果表明,W₂和W₃处理促进幼苗株高和地上部干物质量的增加;同时W₂处理增加叶片光系统的光化学猝灭和非光化学猝灭系数;经过3种处理的幼苗叶片和根系过氧化物酶(POD)活性显著增强,而叶片丙二醛(MDA)含量在W₂和W₃处理下显著下降,根系MDA含量在W₃处理下显著降低;3种处理下幼苗叶片中可溶性蛋白含量有所下降,而脯氨酸含量一直增加。综上可知,1～2mmol/L EDTA在铬胁迫下可提高黄瓜幼苗叶片的光合作用,增强POD活性和渗透调节能力,减缓幼苗膜脂过氧化程度,促进幼苗地上部形态发育,从而有效缓解铬胁迫对幼苗的危害。     

不同糖源及铬对异育银鲫生长和糖耐量的影响

对人及家畜而言,糖是最廉价的饲料能源,但鱼对糖的利用能力较低,一般来说,海水鱼及冷水性鱼类饲料中适宜的可消化糖含量在20%以下,而淡水鱼类及温水性鱼类较高一些。投喂含可消化糖较高的饲料会导致鱼类肝大小及肝糖元含量随饲料糖含量增加而增加。鱼类对不同类型的糖利用能力也不同,鲤、真鲷[Ｆｕｒｕｉｃｈｉ和Ｙｏｎｅ1982]和罗非鱼[Ｔｕｎｇ和Ｓｈｉａｕ1991]对分子量大的淀粉的利用性较葡萄糖强,相反,硬头鳟对小分子量的葡萄糖利用能力较强[Ｈｕｎｇ等1989]。然而,鱼类对糖低利用性的确切机制尚不明确。糖耐量试验是用于诊断人类糖尿病…