邻苯二甲酸二乙基己酯(DEHP)对小鼠的氧化损伤及黄豆异黄酮对其保护作用的研究

邻苯二甲酸二乙基己酯(DEHP)是环境中广泛存在的污染物,作为一种内分泌干扰物,已严重威胁到人类健康和生态环境安全。每天用250、500和1000mg·kg-1·d-1的DEHP对雄性昆明小鼠进行灌胃处理,连续处理30d后,分别考察了小鼠的器官相对质量、丙二醛(MDA)和谷胱甘肽(GSH)的含量以及睾丸组织学等指标的变化。结果显示,小鼠的肝、肺组织肿大,睾丸严重萎缩,并呈剂量依赖性。肝脏MDA含量显著增加,肝脏和血液GSH水平显著下降。从睾丸组织学分析结果可见,精子生长发育条件已受到破坏,例如睾丸细胞坏死和凋亡,生精小管上皮细胞大量脱落等。DEHP对未成熟的雄性小鼠有氧化损伤作用和生殖毒性,特别是在较高剂量(500and1000mg·kg-1·d-1)时。为了探讨大豆异黄酮(SI)对DEHP诱导的氧化损伤和睾丸损伤的保护作用,将暴露于1000mg·kg-1·d-1DEHP的小鼠,用100mg·kg-1·d-1剂量的SI平行处理。结果显示,SI作为抗氧化剂和雌激素调节剂可明显减弱DEHP所致的氧化应激和睾丸毒性。     

Thermochemical pretreatment of meat and bone meal and its effect on methane production

Since the solubilization of meat and bone meal (MBM) is a prerequisite in many MBM disposal approaches, enhancement of the solubilization by means of thermochemical pretreatment was investigated in this study at two temperatures (55°C and 131°C) and six sodium hydroxide (NaOH) concentrations (0, 1.25, 2.5, 5, 10 and 20 g/L). The MBM volatile solid (VS) reduction ratio was up to 66% and 70% at 55°C and 131°C, respectively. At the same temperature, the VS reduction ratio increased with the increase in the dosage of NaOH. The study on the methane (CH₄) production potential of pretreated MBM shows that the addition of NaOH at 55°C did not cause the inhibition of the succeeding CH₄ production process. However, CH₄ production was inhibited by the addition of NaOH at 131°C. The CH₄ production potential was in the range of 389 to 503 mL CH₄/g VS MBM and 464 to 555 mL CH₄/g VS MBM at 55°C and 131°C, respectively.     

The biochemical activity of soil contaminated with fungicides

Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pH_KCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide – treated as a control), RD (dose recommended by the manufacturer) and 300?×?RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10?g kg^?1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300?×?RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil.     

Comparison of the Photodegradation of Imazethapyr in Aqueous Solution,on Epicuticular Waxes,and on Intact Corn (Zea Mays) and Soybean (Glycine Max) Leaves

A direct, controlled comparison of the photodegradation of imazethapyr has been made between imazethapyr in aqueous solutions, imazethapyr on the surface of epicuticular waxes of corn and soybean plants, and imazethapyr on the surface of intact corn and soybean plant leaves. In some experiments, the imazethapyr solutions were allowed to evaporate partially or fully after application to better model environmental conditions. The photodegradation of imazethapyr was fastest in aqueous solutions (k?=?0.16?±?0.02?h^?1) and slowest on the surface of corn and soybean plants (k_corn?=?0.00048?±?0.001?h^?1 and k_soy?=?0.00054?±?0.003?h^?1). Experiments allowing evaporation during irradiation have intermediate rate constants (e.g., k_corn?=?0.082?±?0.005?h^?1). Finally, identification of photoproducts was also examined on epicuticular waxes of corn and soybean plants for the first time.     

生物炭与炭基肥对大豆根际土壤细菌和真菌群落的影响

土壤微生物在农田土壤生态系统中发挥重要作用,然而秸秆生物炭与炭基肥处理对微生物群落的影响以及对农田生态环境的意义尚不清楚.以黄淮海平原豆-麦轮作为研究对象,采用荧光定量PCR和Illumina高通量测序技术比较不同施肥方式对土壤细菌和真菌群落的丰度、组成和多样性差异,探究秸秆还田、生物炭以及炭基肥添加对根际土壤微生物群...     

花生壳、大豆壳和柚子皮对Cr3+、Cu2+和Ni2+的吸附研究

采用农林废弃物花生壳、大豆壳、柚子皮对重金属离子Cr3+、Cu2+和Ni2+进行吸附研究,探讨反应时间、吸附剂用量、pH、重金属离子初始浓度以及温度对吸附的影响.结果表明:柚子皮对Cr3+、Cu2+、Ni2+的吸附效果优于花生壳和大豆壳,其在20℃、pH 5.00、10.0 mg/kg条件下,反应360 min,Cr3+、Cu2+、Ni2+的吸附率分别可达83.20％、84.50％、59.10％;花生壳、大豆壳和柚子皮对Ni2+的吸附率远低于Cr3+和Cu2+;花生壳、大豆壳和柚子皮对Cr3+、Cu2+、Ni2+的吸附动力学可以用准二级动力学方程描述;吸附率随初始重金属离子浓度增加而降低,其吸附等温线可以用Langmuir方程描述;在一定范围内,吸附率随吸附剂用量增加而增加;溶液初始pH在2～5时,吸附率随pH增大而增加;Cu2、Ni2+的吸附量随温度的上升而逐渐减少,但Cr3+的吸附量随着温度的上升而略增加.     

温度、水分和盐度对转基因耐草甘膦大豆种子萌发和幼苗生长的影响

为了探明转CP4-EPSPS(5-烯醇丙酮酸莽草酸-3-磷酸合成酶)基因是否会对大豆种子及幼苗的抗逆性产生影响,进而为转基因耐草甘膦大豆的环境安全评价提供科学依据,通过室内试验研究了温度、水分和盐度对转基因耐草甘膦大豆ARG、受体大豆n-ARG及我国传统栽培大豆苏豆3号种子萌发与幼苗生长的影响。结果表明:在种子萌发阶段,ARG对高温胁迫和水分胁迫的抗性显著低于n-ARG和苏豆3号;ARG对盐分胁迫的抗性与n-ARG没有显著差异,但抗性明显弱于苏豆3号。幼苗生长阶段,在温度胁迫(高温40℃,低温15℃)和水分胁迫(渍水和干旱)条件下,ARG在株高增长量和生物量方面都没有表现出优势,相反,在某些方面反而抗性更弱。例如,在轻度干旱胁迫(相对含水量55%)条件下,ARG地上部干重明显小于n-ARG。ARG对盐分胁迫的抗性也弱于n-ARG及我国传统栽培大豆苏豆3号。总之,与非转基因受体大豆n-ARG和我国传统栽培大豆苏豆3号相比,转基因耐草甘膦大豆ARG在温度、水分和盐度逆境条件下的竞争性和入侵性不强。     

紫外辐射增强对大豆影响的进一步分析

紫外辐射增强对大豆影响的进一步分析郑有飞简慰民李秀芬旦巴（南京气象学院应用气象系，南京２１００４４）关键词紫外辐射；大豆；影响．随着大气臭氧层的不断减薄，地表接受的紫外辐射量不断增加，预计未来六十多年内，地表紫外线辐射量将增加４％—２０％［１，２］...     

不同方式实现短程硝化反硝化生物脱氮工艺的比较

采用序批式活性污泥法(SBR),以实际豆制品废水为处理对象,比较了控制温度(T=310.5℃)、溶解氧(DO=0.5mg/L)和pH值(7.8～8.7)3种途径实现短程硝化反硝化生物脱氮工艺.结果表明,无论从硝化速率、硝化时间、污泥沉降性能以及生物相上,控制溶解氧实现的短程硝化反硝化脱氮工艺均不如其他2种工艺.就该工艺存在的问题从活性污泥法反应动力学和微生物相上进行了理论探讨,3种途径实现短程硝化反硝化生物脱氮工艺在实际工程应用中均不同程度地存在一些问题.     

Single and joint stress of acetochlor and Pb on three agricultural crops in northeast China

In order to evaluate ecological risk of agrochemicals in agricultural environment, single and joint toxic effects of an important herbicide and a typical heavy metal on root elongation of crops were investigated. Seeds of the three crops including wheat （Triticum aestivum）, Chinese cabbage （Brassica pekimensis） and soybean （Glycine max） as the main crops in northeast China were exposed to acetochior as a herbicide and lead （Pb） as a heavy metal using the pot-culture method, and meadow brown soil as one of the main soils distributed in northeast China was applied in the investigation. The results indicated that the interactive effects of the two pollutants on root elongation of the three crops were very complicated although they had markedly significant （P〈0.01） linear interrelationships based on the regression analyses. When the concentration of added Pb^2＋ reached 200 mg/kg, acetochlor and Pb had an antagonistic effect on the inhibition of root elongation of the three crops. However, acetochlor and Pb had significantly （P〈0.05） synergic effects on the inhibition of root elongation when concentration of added Pb^2＋ was up to 1000 mg/kg. At the low concentration of added Pb, joint toxicity of acetochlor and Pb was more dependent on the concentration of Pb. Among the three crops, wheat was the most sensitive to the toxicity of Pb and Chinese cabbage was the most sensitive to the toxicity of acetochlor.