土壤氯化钠含量对毛管水上升特性影响研究

通过室内不同氯化钠含量土壤的毛管水上升试验,分析了土壤中氯化钠含量对毛管水上升特性的影响.结果表明:随着土壤中氯化钠含量增大,相同入渗时间的毛管水上升高度和地下水补给量越小;入渗结束后,相同距离的土壤含水量减小.经分析,毛管水上升高度和地下水补给量之间存在密切的直线相关关系,二者分别与时间存在密切的幂函数关系.钠离子对...     

扩展青霉基因组DNA五种提取方法比较

为寻找一种适合于扩展青霉基因组DNA的提取方法,比较了固体培养、液体静置培养和液体振荡培养3种培养方式的提取效果,分别采用氯化苄法、蜗牛酶法、CTAB法、SDS法及异硫氰酸胍法提取扩展青霉菌基因组DNA,经DNA质量浓度测定及电泳分析,比较5种方法的差异,并利用扩展青霉的多聚半乳糖醛酸酶(Polygalacturonase)基因内一段保守序列,设计PCR引物,扩增大小为288 bp的特异目的基因,检测其灵敏性.结果表明:固体培养的方式较适合扩展青霉基因组DNA的提取,另外5种提取方法均能提取出扩展青霉菌基因组DNA,扩增出目的条带,其中氯化苄法和蜗牛酶法所提DNA的纯度均较好,但蜗牛酶法所提DNA量较少.因此,氯化苄法是5种提取方法中最可靠的DNA提取方法,所提DNA浓度高、纯度好、结果稳定,可作为PCR反应的模板进行特异性扩增,且该方法的最低检测限大约为1.01×10-1μg/mL.     

Furazolidone induces the activity of microsomal enzymes that metabolize furazolidone in chickens

The nitrofuran antibacterial agent furazolidone (FZ) is still used in veterinary medicine in some countries in the Middle and Far East. The present study aimed to show the effect of FZ on the activity of microsomal enzymes that metabolize FZ, and to identify the enzyme that contributes to FZ metabolism in chickens. Wistar rats and White Leghorn chickens were administered FZ once a day for four consecutive days. FZ metabolism was accelerated by FZ administration in chickens, but not in rats. The elevation of FZ metabolism coincided with the induction of NADPH cytochrome P450 reductase (CPR) activity in chickens, but such induction was not observed in rats. FZ metabolizing activities were inhibited in the presence of a CPR inhibitor (diphenylene iodonium chloride) but not by the addition of archetypal cytochrome P450 inhibitors (CO or n-octylamine). The preset study concluded that FZ accelerated its own metabolism in the chicken by induction of the activity of CPR.     

Microbial mineralization of atrazine and 2,4-dichlorophenoxyacetic acid in riparian pasture and forest soils

Microbial biomass and mineralization of atrazine [2-chloro-4(ethylamino)-6(isopropylamino)s-triazine] and 2,4-D (2,4-dichlorphenoxyacetic acid) were examined in the top 10 cm of riparian pasture soils and in the litter layer and top 10 cm of mineral soils of riparian forest ecosystems. The riparian forest litter had higher levels of active and total fungal biomass than forest or pasture mineral soils in winter, spring, and fall. Active bacterial biomass was higher in forest litter than in forest and pasture mineral soils in spring and autumn, and higher in forest mineral soils than in pasture soils in summer. Total bacterial biomass was higher in forest mineral soils than in pasture soils during all seasons. In spring, it was also higher in forest litter than in pasture soils. Atrazie and 2,4-D mineralization in pasture soils was exceeded by that in forest litter in spring and autumn and by that in forest mineral soils in summer and autumn. There was no correlation between either active or total fungal and bacterial biomass with pesticide degradation.     

NaCl和Na2CO3对星星草生长及营养液中主要矿质元素存在状态的影响

星星草生长在０－６００ｍｍｏｌ／ＬＮａＣｌ和０－２００ｍｍｏｌ／ＬＮａ２ＣＯ３的盐胁迫下，测定了其生长状况及营养液中主要矿质离子的游离度、活度等。结果表明：相同Ｎａ＾＋活度下，Ｎａ２ＣＯ３对星星草的生长尤其是根生长的抑制作用明显大于ＮａＣｌ。     

氯化胆碱对黄瓜子叶期幼苗的影响

以７日龄黄化黄瓜幼苗为材料，在控制条件下分别观察到７０μｍｏｌ／Ｌ氯化胆碱（ＣＣ）显著促进离体子叶转绿；５０～４００ｍｇ／Ｌ的ＣＣ显著促进离体子叶叶面积扩大，对离体子叶鲜重及干重增加也有促进效应，并观察到１００μｍｏｌ／Ｌ的ＣＣ能促进子叶──下胚轴切段上的不定根分化。     

The Pathology of Vinyl Chloride Exposed Mice

Outbred albino laboratory mice were exposed to 50 p.p.m. and 500 p.p.m. vinyl chloride by inhalation 6 hrs./day, 5 days/week during 52 and 26 weeks, respectively. Pathologic examination showed the presence of histologically benign alveologenic lung adenomas, haem-angiosarcomas in fat tissue as well as a few benign and malignant tumours at various sites. Only one liver haemangiosarcoma was noted. All animals exposed to 500 p.p.m. developed tumours; 71 % of the animals given 50 p.p.m. were tumour bearing. The frequency of all tumours, number of tumour foci and size of foci in both groups suggest a dose-dependent carcinogenic effect of vinyl chloride. Haemocoelia due to blood vessel rupture was a common cause of death. Telangiectasis of the liver was also observed in a few animals. The role of fat tissue as well as blood vessel involvement in the pathology of vinyl chloride is discussed.     

氯化钾对热应激肉仔鸡生产性能的影响

本试验测定了氯化钾对热应激肉仔鸡生产性能的影响。试验应用２ｌ０只星布罗肉仔鸡，随机分成７组，每组３０只。氯化钾按０％、　０．０６％、０．１２％、０．１８％、０．２４％、０．３０％和０．３６％添加到饮水中，试验温度为３２±１℃，试验期为３５天。结果表明饮水中添加０．２４％、一０．３０％氯化钾能显著提高热应激条件下肉仔鸡的生产性能。     

铝钎剂中活性剂的研究

本文指出长期以来,众多研究者一直提到的铝钎剂的活性剂是重金属氯化物的说法是不够确切的。实际上,大多数重金属氯化物不能作为活性剂。同时指出氯化物标准生成自由能判据,仅仅表明取代反应能否正向进行,而不能说明该氯化物是否可以作为活性剂。本研究提出:液态时与铝形成双液层的组元,或者液态时与铝能互相溶解,但在二元合金状态图的非铝端,形成熔点较低共晶物的组元,这些组元的氯化物,原则上可以作铝钎剂的活性剂。     

氯化胆碱对低盐处理下菠菜光合生理和抗氧化酶的效应

用300 mg/L氯化胆碱(CC)喷施低盐处理下的非盐生植物菠菜叶片,研究了CC对不同浓度NaCl处理的菠菜光合生理和抗氧化酶活性的变化。结果表明:300 mg/L氯化胆碱喷施后,显著促进低盐处理后菠菜净光合速率和抗氧化酶系统中的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性,叶绿素和蛋白质含量增加,超氧阴离子(O2.-)和丙二醛(MDA)含量明显低于未经CC喷施的。这说明CC可提高菠菜的耐盐性。