土壤镉暴露对玉米和大豆的生态毒性评估

以中国东北黑土为培养基,通过室内急性毒性实验,采用Trimmed Spearman-Karber方法计算EC50值(半抑制浓度),并分析作物的生物累积系数(BAF),定量化评估了土壤中镉对玉米和大豆的生态毒性及生物有效性.测量终点为种子发芽率、根长和幼茎长.结果表明,土壤镉暴露给农作物带来一定的负生长效应.种子发芽率不是评估土壤镉生态毒性的敏感因子,根生长是敏感的毒性测量终点.镉在植株体内的累积及迁移与作物种类和土壤镉浓度有关.玉米植株体内累积了较大量的镉,而大豆植株体内镉由根向幼茎的迁移较为显著.     

PFOS/PFOA对斑马鱼(Danio rerio)胚胎致毒效应研究

采用斑马鱼胚胎毒性测试方法,研究了PFOA/PFOS对斑马鱼的急性毒性和生命早期阶段生长发育的影响.结果表明,PFOS/PFOA对斑马鱼有明显毒性作用,LC₅₀(48 h)分别为1005 mg/L和107 mg/L,LC₅₀(96　h)分别为499 mg/L和71 mg/L.PFOS/PFOA抑制斑马鱼胚胎发育,可导致胚胎发育畸形,甚至死亡,高浓度(＞240 mg/L)PFOS损伤细胞膜,导致胚胎分裂中的细胞发生自溶而卵凝结死亡,抑制胚胎原肠胚的形成.在各种亚致死效应中,脊柱畸形对PFOS暴露最敏感,其EC₅₀=9.14 mg/L,PFOA暴露最敏感亚致死性毒理学终点为96　h孵化,对应EC₅₀=328.0 mg/L.PFOA/PFOS导致胚胎发育延迟,具有发育毒性.     

Two unbalanced segregation products due to a maternal t(7;16)inv(16)

We report a prenatal case of a maternally inherited abnormal chromosome 16, originally interpreted as a pericentric inversion only, but after family studies re-interpreted as a pericentric inversion (16) accompanied by an unbalanced (7;16) translocation. Because of the inversion 16 and an elder son with developmental delay and craniofacial dysmorphic features, in the past karyotyped as 46,XY, the chromosomes 16 of the mother and son were carefully re-examined. Using a whole chromosome 16 paint and sub-telomere probes of 16p and 16q, the karyotype of the mother was shown to be 46,XX,inv(16)(p11.2q23.2).ish t(7;16)(q36;p13.3)inv(16). Subsequently one chromosome 16 of the elder son appeared to be a der(16)t(7;16)(q36;p13.3). This is probably the result of a meiotic crossover between the chromosomes 16 in the mother. The prenatal karyotype was finally interpreted as 46,XY,inv(16)(p11.2q23.2).ish der(16)t(7;16)(q36;p13.3)inv(16). This is the same cytogenetic imbalance as his elder brother: a partial trisomy of chromosome 7 (q36→qter) and a partial monosomy of chromosome 16 (p13.3→pter). Copyright © 2001 John Wiley & Sons, Ltd.     

沉积物中六氯苯对颤蚓(淡水单孔蚓)的毒性效应研究

以淡水底栖动物颤蚓(淡水单孔蚓)为受试生物,研究了沉积物中六氯苯(HCB)对淡水单孔蚓14 d和28 d的毒性效应.结果表明,沉积物中HCB对颤蚓致死效应较低,当HCB浓度为190 mg· kg-,连续暴露28 d时,致死率低于8％.但HCB对颤蚓具有较强的慢性毒性效应,当HCB浓度为190 mg·kg-1,连续暴露28 d时,身体自断率高达90％,并且随着浓度升高和暴露时间延长,颤蚓自断率明显增高.HCB对颤蚓自断14 d和28 d的EC50分别为＞190 mg·kg-1和97.1 mg· kg-1.HCB对颤蚓行为(运动和挖掘)产生明显抑制作用.随着HCB浓度增加和暴露时间延长,颤蚓运动强度减弱,并伴随摄食量减少与体重减轻现象.     

Role of nitrification inhibitor DMPP( 3,4-dimethylpyrazole phosphate) in NO3--N accumulation in greengrocery(Brassica campestris L. Ssp. Chinensis )and vegetable soil

The influence of nitrification inhibitor(NI) 3,4-dimethylpyrazole phosphate (DMPP) on nitrate accumulation in greengrocery ( Brassica campestris L. ssp. chinensis) and vegetable soil at surface layer were investigated in field experiments in 2002 and 2003.Results showed that NI DMPP took no significant effect on yields of edible parts of greengrocery, but it could significantly decrease NO3^--N concentration in greengrocery and in vegetable soil at surface layer. In addition, NI DMPP could reduce the NO3^--N concentration during the prophase stage of storage.     

A.eutrophus 利用有机废水生产聚羟基烷酸

对真养产碱杆菌(     

PFOS/PFOA对斑马鱼(Danio rerio)胚胎致毒效应研究

采用斑马鱼胚胎毒性测试方法,研究了PFOA/PFOS对斑马鱼的急性毒性和生命早期阶段生长发育的影响.结果表明,PFOS/PFOA对斑马鱼有明显毒性作用,LC50(48 h)分别为1 005 mg/L和107 mg/L,LC50(96 h)分别为499 mg/L和71 mg/L.PFOS/PFOA抑制斑马鱼胚胎发育,可导致胚胎发育畸形,甚至死亡,高浓度(>240 mg/L)PFOS损伤细胞膜,导致胚胎分裂中的细胞发生自溶而卵凝结死亡,抑制胚胎原肠胚的形成.在各种亚致死效应中,脊柱畸形对PFOS暴露最敏感,其EC50=9.14 mg/L,PFOA暴露最敏感亚致死性毒理学终点为96 h孵化,对应EC50=328.0 mg/L.PFOA/PFOS导致胚胎发育延迟,具有发育毒性.     

Exposure-response of Cr(III)-organic complexes to Saccharomyces cerevisiae

Hexavalent chromium [Cr(VI)] bioreduction produces soluble Cr(III)-organic complexes. The Cr(III)-organic complexes are relatively stable once they are formed, and no data about their toxicity were reported. Therefore, this study aims to investigate the bioavailability and toxicity of the soluble Cr(III)-organic complexes. Saccharomyces cerevisiae L-1 wild type yeast strain was chosen as the model organism and Cr(III)-citrate was selected as the representative compound of the Cr(III)-organic complexes. The short-term chronic aquatic toxicity tests of the Cr(III)-citrate was explored by measuring growth inhibition, direct viable cell count, dry biomass, biosorption, and the amount of CO₂ production. Cr(III)-citrate exerted a toxicity of 51 mg/L with an EC ₅₀, which was calculated from the percent growth inhibition. These toxicity data would be helpful to define the toxic potential of the organo-chromium-III compounds in the environment.     

卤代苯化合物水溶解度及正辛醇/水分配系数的三维构效关系研究

对卤代苯化合物的水溶解度(-lg Sw)和正辛醇/水分配系数(lg Kow)分别进行了基于三维结构的比较分子场(Co MFA)和比较分子相似性指数(Co MSIA)分析,建立了三维定量结构-性质相关(3D-QSPR)模型,并将所获结果与密度泛函理论(DFT)方法得到的2D-QSPR模型进行了比较.结果表明:-lg Sw的Co MFA和Co MSIA模型交叉验证相关系数Q2分别为0.902和0.940,决定系数R2分别为0.982和0.986,模型稳定性和估算能力较好;lg Kow的Co MFA和Co MSIA模型Q2分别为0.926和0.988,R2分别为0.983和0.997;本研究所建的3D-QSPR模型的估算能力优于2D-QSPR模型;Co MFA和Co MSIA模型三维等势图表明,取代基的疏水效应对该类化合物的水溶解性能及正辛醇/水分配系数的影响更为显著,立体效应次之,静电场效应影响较小.     

Vulnerability of Indian mustard (<Emphasis Type="Italic">Brassica juncea</Emphasis> (L.) Czernj. Cosson) to climate variability and future adaptation strategies

A simulation study has been carried out using the InfoCrop mustard model to assess the impact of climate change and adaptation gains and to delineate the vulnerable regions for mustard (Brassica juncea (L.) Czernj. Cosson) production in India. On an all India basis, climate change is projected to reduce mustard grain yield by ～2 % in 2020 (2010–2039), ～7.9 % in 2050 (2040–2069) and ～15 % in 2080 (2070–2099) climate scenarios of MIROC3.2.HI (a global climate model) and Providing Regional Climates for Impact Studies (PRECIS, a regional climate model) models, if no adaptation is followed. However, spatiotemporal variations exist for the magnitude of impacts. Yield is projected to reduce in regions with current mean seasonal temperature regimes above 25/10 °C during crop growth. Adapting to climate change through a combination of improved input efficiency, additional fertilizers and adjusting the sowing time of current varieties can increase yield by ～17 %. With improved varieties, yield can be enhanced by ～25 % in 2020 climate scenario. But, projected benefits may reduce thereafter. Development of short-duration varieties and improved crop husbandry becomes essential for sustaining mustard yield in future climates. As climatically suitable period for mustard cultivation may reduce in future, short-duration (<130 days) cultivars with 63 % pod filling period will become more adaptable. There is a need to look beyond the suggested adaptation strategy to minimize the yield reduction in net vulnerable regions.     

传承经典,以经(经典)至进(改进)

源远流长的民间游戏,是我国文化宝库中的一支瑰丽奇葩,也是珍贵的文化遗产。民间游戏有一定的娱乐性、教育性、随意性。民间游戏内容丰富:有促进语言发展的,有反应传统文化的、有促进肢体动作的。只要简单材料,甚至没有材料都能随时随地组织玩。民间游戏组织形式灵活多样:有单独的,有多人的,还有能锻炼幼儿之间的协商、合作能力的。民间游戏有易学、易会、易传的特点,也符合幼儿好动、好学、好模仿、好游戏的心理特点。     

两株凯伦藻对轮虫急性毒性的研究

本实验初步研究了两株凯伦藻Karenia selliformis和Karenia umbella对褶皱臂尾轮虫（Brachionus plicatilis）的毒性效应。通过设置不同浓度的藻细胞培养液,在48 h内对褶皱臂尾轮虫进行急性毒性观察试验,研究结果表明,K.selliformis和K.umbella对褶皱臂尾轮虫具有明显的毒性作用。在短时间内（2 h）,两种凯伦藻的毒性效应均与细胞密度呈现较好的正相关性（K.selliformis,R2=0.96;K.umbella,R2=0.92）。对轮虫2 h的半致死浓度（LD₅₀）分别为2750/mL（K.selliformis）和14011/mL（K.umbella）,显示K.selliformis对褶皱臂尾轮虫的急性毒性作用较之K.umbella更强。通过进一步比较两种凯伦藻的藻液、细胞过滤液和藻细胞破碎液的毒性结果显示,仅藻液有毒害作用,而去细胞过滤液和藻细胞破碎液对轮虫没有毒害作用,说明与藻细胞的直接接触是导致轮虫死亡的关键因素。     

Methods for project-based mechanisms (JI/CDM)—relevance of IPCC inventory guidelines

A baseline for a project consists of estimates of annual emissions of greenhouse gases (GHG) for a given time period without implementing the project. A general three-step process for determining the baseline is suggested. The emission reduction of the project is given by the difference between the baseline and the monitored annual emissions. A preferred method, direct measurement of the emission reduction, is possible for some types of projects. Methods for estimating the annual baseline emissions are not necessary for the latter category, and a definition of this project category is suggested. IPCC Guidelines for National GHG Inventories categorise the emission sources so that only direct emissions from consumption of fuel and feedstock are calculated. There are thus no emission factors for indirect emissions (e.g. electricity consumption or km transported) or emission factors that depend on technology only, independent of consumption of fuel and feedstock. Technology-dependent emission factors may thus need to be developed for estimating indirect emissions and multi-project baselines. Consistency should be sought with the IPCC Guidelines when estimating annual baseline emissions and in monitoring project emissions to ensure comparability with the National Inventories.     

单壁碳纳米管材料对水稻幼苗的毒性效应

随着碳纳米管材料(CNTs)被广泛地应用于工业和商业等多个领域,其将不可避免地进入到大气、水和土壤环境中,从而对生态系统结构和功能产生一些负面影响.为明确进入水环境中的碳纳米管材料对农业生产的潜在危险,本实验采用水培法,研究了不同浓度(10、20、40mg·L~(-1))的单壁碳纳米管材料(SWCNTs)对萌发期内水稻的发芽率、根长耐性指数和幼苗生长期内水稻的鲜重、叶绿素和可溶性蛋白的影响,以及单壁碳纳米管材料在水稻根部的累积.结果表明,在萌发期,胁迫处理4 d后,与对照相比,10、20、40 mg·L-1SWCNTs处理组对水稻发芽率没有任何抑制作用,但会延迟种子的发芽时间;水稻根长耐性指数随着单壁碳纳米管材料浓度的增加而下降.在幼苗生长期,胁迫处理30 d后,与对照相比,水稻鲜重随着单壁碳纳米管材料浓度的增加而分别下降14.2%、21.0%和38.8%;与此相类似,水稻叶绿素和可溶性蛋白质含量随着单壁碳纳米管材料浓度的增加而下降;另外,通过透射电镜观察(TEM)发现,SWCNTs颗粒分布在水稻幼苗根尖表皮细胞的细胞壁中.SWCNTs对水稻生长起抑制作用,且随着浓度的增加抑制作用逐渐增强.     

己烯雌酚在斑马鱼胚胎中的生物蓄积及毒性机制研究

采用HPLC和斑马鱼胚胎发育方法,测定了己烯雌酚（DES）在标准模式种斑马鱼胚胎体内的蓄积规律及胚胎毒性效应,并利用定量活性-结构分析（QSAR）和基因芯片技术,探讨了DES对斑马鱼胚胎的致毒机制.结果表明,在0.2 mg/L DES中暴露24、 48和72 h后,胚胎体内的DES含量分别为（25.78±4.95）、（54.88±7.10）和（71.93±10.55）μg/g;不同起始染毒时间（0 hpf和8 hpf）条件下,亚致死最敏感指标均为72 h孵化率抑制,EC₅₀分别为（0.14±0.09）和（0.33±0.14） mg/L,说明胚胎在发育囊胚期（发育8　h）前对DES暴露更为敏感.QSAR研究发现,DES相对其它酚类类雌激素对斑马鱼胚胎具有较高的毒性,这与它具有较高的TE值（51.121 7　eV）相关;基因芯片研究发现,5　μg/L DES暴露21　d后能导致斑马鱼成鱼部分基因表达异常.DES对斑马鱼具有一定的胚胎毒性和遗传毒性,而生化反应是致毒的关键步骤.     

厌氧消化1号模型(ADM1)简介

介绍了2002年2月国际水质学会(IWA)推出的厌氧消化1号模型(ADM1).该模型主要描述了厌氧消化中的生化和物化过程,共涉及厌氧体系中的七大类微生物、19个生化动力学过程、3个气液传质动力学过程,共有26个组分和8个隐式代数变量,能够对厌氧生物处理工艺进行较好的预测和模拟.ADM1还提供了开放的建模平台以及与活性污泥模型(ASM)的接口,可广泛应用于对各种厌氧-好氧组合工艺的过程模拟.