溴乙酰胺对钉螺超微结构的影响

本文应用电子显微镜技术观察了正常钉螺及溴乙酰胺作用后的钉螺头足部软体组织及肝脏组织的超微结构。头足部软体组织有上皮层、上皮下层及肌层。上皮层有三种细胞:无纤毛上皮细胞、纤毛上皮细胞及含有大量粘性分泌颗粒的腺体细胞。上皮层细胞内含有丰富的线粒体、内质网及张力细丝。基底膜将上皮细胞与上皮下层分开,上皮下层有含色素颗粒的细胞。肌层为梭形细胞,核居中央,无横纹。溴乙酰胺作用24小时后,钉螺头足部的上皮细胞与肝脏腺管细胞肿胀,核增大;染色质凝集,线粒体肿胀、嵴断裂呈空泡状,粗面内质网变粗呈短管状,排列混乱,或呈同心圆指纹状排列。这些病变与生化代谢结合进行了讨论。     

沱江的渔业自然资源

沱江为四川省的重要鱼产区之一。关于沱江渔业自然资源情况,以往只有些零星调查。本文在1983年至1984年对沱江干流水生态系统各重要营养层次生物现状进行全面调查研究的基础上,报道沱江渔业自然资源现状及鱼产能力。沱江有浮游植物6门84属、轮虫类10科22属43种、枝角类6科19属41种、桡足类3科12属25种、底栖动物63种、水生维管束植物70种、鱼类97种。依据以上生物饵料资源预测鱼产能力为每年240万公斤。     

白腹鼠的核型观察

生活于亚热带至寒温带海拔2200—3000米高山森林之中的白腹鼠(Rattus coxingi)是家鼠属(Genus Rattus)动物中分布比较狭窄的一个种类。我国白腹鼠仅在云南、四川、西藏、台湾等地的某些高山上可以发现,国外则分布于缅甸北部、中南半岛等地。至今,对白腹     

牛蛙的营养成份

我们在“牛蛙人工养殖”的研究过程中,分析了牛蛙的一般营养成份,并进行了氨基酸含量分析。     

Implications of the human genome initiative for the primary care physician

... Despite the need for physicians to be knowledgeable about and open to advances in genetic technology, little is known about the level of preparedness of primary care physicians to offer new genetic tests. Evidence suggests that several barriers exist to physicians adopting genetic tests. These include lack of knowledge, inability to interpret probabilistic information, low tolerance for uncertainty, negative attitudes about their responsibility for genetic counseling and testing, lack of confidence in their clinical skills, and unfamiliarity with ethical issues raised by testing. This paper will explore some of these barriers in further depth, discuss the ethical impact of physician unpreparedness on both patient care and the diffusion of genetic tests, and describe a study that is currently underway to investigate some of these issues.     

Calculation of the optimal surface area for amphiphile molecules using the hard core method

In this work, we have calculated the optimal surface area per amphiphile molecule using a two-dimensional gas of electric dipoles interacting with hard The optimal surface area can be evaluated according to a formula (in the two-body approximation) or as a root of an equation (in the three-body approximation). If the equation has more than one positive root, which is greater than the hard core area, then a polydisperse dimensional distribution of supramolecular aggregates is possible.     

Interfacial thermodynamics of protein adsorption, ion co-adsorption and ion binding in solution. II. Model interpretation of ion exchange in lysozyme chromatography

In this paper we present a model for the ion exchange effects in protein adsorption. The model is applied to chromatography of lysozyme on strong cation exchanger ‘mono S’. The experimental and general thermodynamic aspects have been discussed in Part 1, the preceding paper. The main modelling assumptions are (i) the charge regulation is confined to the small layer of contact between adsorbed protein and exchanger surface, (ii) the contact layer as a whole is electroneutral and (iii) the number of protein acid/base groups and exchanger surface acid groups which participate in the ion exchange is proportional to the area of the contact layer. The model is fitted to the experimental data by adjustment of only two or three parameters. The experimental co-adsorption numbers are very well reproduced. A few conspicuous features emerge: (i) the number of protein acid/base groups and exchanger surface acid groups in the contact layer varies with the medium conditions, such that the number is higher when the interaction between protein and exchanger surface is stronger. (ii) There is indirect evidence for structural alterations in the upper layers of the exchanger surface: the adsorbed protein is probably partly ‘buried’ in the surface.     

Induced dipole moment of purple membranes. Theoretical analysis

The induced dipole moment of a purple membrane parallel to the membrane surface was analysed based on the two-dimensional fluctuation theory of counterions. The observed polarizability previously measured by electric dichroism and its dependence on the membrane size were derived from theory for the case where the interaction between counterions was screened. The screening effect of salts on the induced dipole moment was estimated from the theory on diffuse double layers.     

几种因素对油菜茎尖培养中玻璃化作用的影响

按前文[植物生理学通讯,1990(3):35]方法继续研究几种影响油菜(Brassica napus )茎尖培养中玻璃化作用的因素,获得结果列于表1。     

茎用芥菜的离休培养及植株再生

植物名称:茎用芥菜(Brassica juncea var.tumida)。材料类别:幼叶、子叶。培养条件:以MS为基本培养基,诱芽培养基为:(1)MS BA 2mg/L(单位下同) NAA 0.2;(2)MS BA2 NAA0.5;(3)M8 BA4 NAA0.1.(4)MSS BA4 NAA 0.2;(5)MS BA4 NAA 1.0。生根培养基为:(6)MS NAA 0;(7)MS NAA 0.1;(8)MS NAA 0.5;(9)MS