离子液体[C_(16)mim]Cl对泥鳅胚胎与仔鱼的毒性

为了研究离子液体[C_(16)mim]Cl的生物毒性作用,以泥鳅(Misgurnus anguillicaudatus Cantor)胚胎和仔鱼为受试动物,分别以胚胎发育的囊胚期、原肠胚期、神经胚期和尾芽期4个发育时期以及孵出期和孵出3 d的仔鱼作为处理的起始点进行急性毒性试验。结果显示,随着[C_(16)mim]Cl浓度的增加和处理时间的延长,泥鳅胚胎的孵化率逐渐下降,畸形率则在逐步升高;其中,刚孵出的仔鱼24 h与48 h的半数致死浓度(LC_(50))及安全浓度(SC)分别为0.555、0.453、0.091 mg/L;孵出3 d的仔鱼24 h与48 h的LC_(50)及SC分别为0.444、0.273、0.031 mg/L。表明在较低剂量内,离子液体[C_(16)mim]Cl对泥鳅胚胎及其仔鱼的发育表现出明显的致畸与致死作用,并且该毒性作用具有显著的剂量-效应关系。     

提取地衣真菌总DNA的简便方法

利用液氮破碎地衣体的上下表皮层及藻层，再用氯化苄在弱碱条件下破坏真菌细胞壁，从而获得地衣真菌总ＤＮＡ．此方法简便、省时、价廉，获得的总ＤＮＡ蛋白质污染少，产量高，可进一步进行ＰＣＲ扩增．     

Interactive Effect of Soil Salinity and Water Stress on Growth and Chemical Compositions of Pistachio Nut Tree

ABSTRACT

The effects of three sodium chloride (NaCl) levels (0, 1200, and 2400 mg kg^{? 1} soil) and three irrigation intervals (3, 7, and 14 d) on the growth and chemical composition of two Pistacia vera rootstocks (‘Sarakhs’ and ‘Qazvini’) were investigated under greenhouse conditions. Eight-week-old pistachio seedlings were gradually exposed to salt stress which afterward, water stress was initiated. At any irrigation interval, plant height and shoot and root dry weights of both rootstocks were reduced with increasing salinity. However, increasing irrigation intervals alleviated the adverse effects of soil salinity. A negative relationship observed between relative shoot growth and electrical conductivity of soil saturation extract (EC_e) confirmed the above findings. Under 3-d irrigation interval, the EC_e required to cause a 50% growth reduction was lower than those under 7- and/or 14-d irrigation intervals. Shoot and root chemical analyses indicated that the salinity as well as irrigation regime affected the concentration and distribution of sodium (Na⁺), potassium (K⁺), and chloride (Cl^?) in pistachio. The concentration of Na⁺, K⁺ and C1^? ions increased with a rise in NaCl level, and was generally declined with increasing irrigation interval. Based on plant height, shoot and root dry weights and the concentrations of Na⁺, K⁺, and C1^? in the plant tissues, at lowest irrigation intervals ‘Sarakhs’ shows a higher sensitivity to soil salinity than ‘Qazvini’, but with increasing irrigation interval, ‘Sarakhs’ and ‘Qazvini’ can be classified as resistant and sensitive to salinity, respectively.     

河南西峡黑烟镇自然保护区药用植物氯、硫、氟元素的含量分布规律研究

通过对西峡黑烟镇自然保护区24种中药材叶片中氯、硫、氟元素含量进行测定,结果发现,药用植物体内3种化学元素成分随植物器官的不同和同一器官的发育期不同而呈现出差异,其氯、硫、氟元素的分布为叶茎根果实(种子),同时还与植物的生活型有关,表现出草本植物乔木植物的规律性。根据研究结果,筛选出一批大气污染的净化植物和抗性植物。     

脆弱刚毛藻对水体中三种苯系物的去除效果

采用L934正交设计法,研究了脆弱刚毛藻[Cladophora fracta (Dillw.) Kuetz.]对水体中3种苯系物苯、甲苯和二甲苯的去除作用.结果表明,脆弱刚毛藻对苯、甲苯和二甲苯的去除率分别为46.6写,13.6%和7.4 Yo.分析不同处理条件对脆弱刚毛藻对苯去除率的影响,各因素极差值大小依次为:温度>处理时间>藻体重量,温度是影响去除笨效果的主要因素.在刚毛藻去除甲苯的实验中,各因素R值大小依次为处理时间>藻体重量>温度,主要影响因素是处理时间.而对于二甲苯,藻体重量则是最主要的因素.     

中华鳖胃的显微和亚显微结构

中华鳖的胃壁由粘膜层、粘膜下层、肌层和浆膜组成。肌层较厚,环形肌特别发达。胃腺为 单管状或分支管状腺。仅由壁细胞和粘液细胞组成,壁细胞数量很多,在贲门腺和幽 门腺也有大量分布,壁细胞的亚显微结构和特征是：有明显的细胞内小管;滑面内质网十分发达,有许多微管泡系;细胞的侧面还见到细胞间小管;线粒体,高尔基复合体、粗面内质网也十分丰富,而且胞质中有大而圆的分泌颗粒。     

贵州植烟土壤氯素特征与含氯钾肥施用探讨

2000年氯素普查结果,全省主要植烟土壤氯含量很低,平均含量4.60mg/kg;各烟区和各土类含氮量差异不明显,变幅分别为4.26mg/kg～51.13mg/kg和4.30mg/kg～4.88mg/kg,且氯含量动态变化不大。针对贵州土壤、烟叶的含氯水平及生态条件,分析了贵州烤烟生产合理施用氯化钾的可行性及建议。     

淹水胁迫对杨桐幼苗生理生化性质的影响

以1年生杨桐实生苗为试验材料,设置4个梯度的淹水胁迫,分析其生理生化指标对淹水胁迫的响应。结果表明:淹水条件下杨桐超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、质膜透性、可溶性蛋白质量分数、可溶性糖质量分数显著上升,分别比对照上升了75.0%、30.0%、25.1%、140.3%和101.6%,叶绿素a、叶绿素b质量分数显著下降,分别比对照下降39.8%和29.3%。w(叶绿素a)∶w(叶绿素b)和相对含水量有不同程度的降低,但不显著。对9个抗涝指标进行主成分分析,发现3个主成分贡献率为88.58%。     

OAV法在临床医学科技查新中的应用研究

“对象—属性—值三元组法”（简称OAV法）是知识工程中的一种知识表达方法，可用来描述任何一种知识单元或事实。文章从理解查新项目内容、制定检索策略、分析查新结论等程序探讨该种表达方法在临床医学科技查新工作中的应用，并讨论应用过程中相关问题。