成年小鼠雄性生殖细胞的冷冻保存

在含10％小牛血清（NBS）的DMEM培养基中，分别各添加5％，10％，15％，20％和25％的二甲基亚砜（DMSO）,丙二醇（PG），乙二醇（EG）和甘油（G），对成年小鼠睾丸生殖细胞冷冻保存；复苏后台盼蓝染色测定细胞复苏率。结果显示，5％－25％DMSO冻存液组的细胞复苏率分别为88.5%,88.0%,65.6%及51.3%;5%-25%PG冻存液组的细胞复苏率分别为87.2%,86.4%,79.0%,73.4%及40.1%.;5%-25%EG冻存液组的细胞复苏率分别为6.6%,80.9%,60.8%,51.3%及30.0%;5%-25%G冻存液组的细胞复苏率分别为86．5％，86．3％，65．3％，36．0％及31．4％。其中各抗冻剂5％和10％组的细胞复苏率最高，与15％组相比均存在显著或极显著差异。4种抗冻剂的最高细胞复苏率之间无显著差异。DMSO，PG，EG和G分别冷冻保存成年小鼠睾丸生殖细胞对的最小损失率分别为4．8％，6．1％，6．7％，6．8％。结果表明，采用慢速冷冻时，DMSO，PG，EG及G均适宜用作成年小鼠睾丸生殖细胞的抗冷冻剂，最佳使用含量均为5％－10％。成年小鼠睾丸生殖细胞分别在含5％－10％的DMSO，PG，EG和G的DMEM（含10％NBS）冻存液中，2步慢速降温，液氮储存，37℃水浴复苏，是一种具有较高复苏率的冷冻保存方法。     

Comparative development of mouse tooth germs transplanted in subrenal capsule and oral submucosa

AIM: To compare 2 environments, the subrenal capsule and oral submucosa, for producing well-formed teeth from mouse tooth germs and for exploring the ideal environment for tooth regeneration. METHODS: Two groups were set up. Group A was transplanted with the mouse embronic day (ED) 14.5 first mandibular molar tooth germs into the subrenal capsule, while group B was transplanted with the ED14.5 first mandibular molar tooth germs into the oral submucosa. After 3 weeks and 4 weeks, the host mice were sacrificed, and the transplanted explants were evaluated with morphologic observation, histological structures, hardness and elastictic modulus tests, and chemical compositions. RESULTS: (1) The explants isolated from both environments showed the tooth-like structures, but as to the group B, the crown was smaller, and the shape of the cusps was not significant. (2) HE staining showed that the dentin and enamel in group A were thicker than those in group B in which the ameloblasts and odontoblasts were differentiated not very well. (3) In the test of enamel hardness, only the hardness of 4 weeks in group B was lower than normal mouse tooth. In the test of enamel modulus, the elastic modulus of enamel in 3 weeks of group A was slightly lower than normal mouse tooth, but the difference was not significant.The elastic modulus of enamel in 4 weeks of group A and group B was significantly lower than normal mouse tooth and 3 weeks of group B. The hardness and elastic modulus of dentin in 3 groups was not significant. (4) Raman spectroscopy showed 2 groups grew in harmony in general, they all had the largest peak in the point of 961 cm^-1, but the 3 weeks of group B had an obvious peak in the point of 2 947 cm^-1. CONCLUSION: For the development of ED14.5 tooth germs, we obtain almost the whole tooth in subrenal capsule transplantation after 3 or 4 weeks. The buccal submucosa environment still has a certain influence on the tooth germ development, although there are some differences about the tooth development between this environment and subrenal capsule environment.     

The genomes of Arachis hypogaea 2. The implications in interspecific breeding

Summary The existence of structural differentiation between genomes in section Arachis of the genus Arachis has important implications in the utilization of diploid wild species in this section as a germplasm resource. Maximum expression of desirable characters may not be achieved unless tetrasomic dose levels can be achieved. Possible breeding strategies discussed include natural and induced gene exchange between genomes and chromosome substitution which could be brought about by manipulation of ploidy level and where appropriate the use of ionizing radiation. Such strategies could be tested in the improvement of resistance to the Cercospora leafspots.Paper number 5561 of the Journal Series of the North Carolina Agricultural Experimental Station, Raleigh, NC 27650.     

玉米粉皮胚含量测定器的研制及测定方法的探讨

通过大量试验研制出与国际法（ＧＢ１０４６３－８９）配套的仪器－玉米粉皮胚含量测定器，并对国际法进行了适当改进，提高了方法的准确度。     

THE WAYS FOR IMPROVING INDOOR ENVIRONMENT AND AIR-CONDITIONING SYSTEMS IN DANCLING HALLS

Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.     

米胚芽贮藏条件与保鲜指标的研究

米胚芽在贮藏中,容易发生脂肪酸败和褐变。经研究,发现影响米胚芽贮藏性的主要因素是含水量、贮藏温度和包装方式。在22℃下,米胚芽的临界水分为7.6％。新鲜米胚芽用0.09mm聚乙烯膜密封包装,在18℃下可保鲜90天,在贮藏中,米胚芽粗脂肪和粗蛋白含量稳定,而呼吸强度、维生素及某些氨基酸含量有不同程度的减少。     

玉米胚芽粕和玉米蛋白饲料饲喂生长肥育猪效果的研究

以玉米胚芽粕和玉米蛋白饲料作为蛋白质补充饲料配制的饲粮对生长肥育猪的生产性能和屠宰性能的影响进行了探讨。将28头二元杂交去势公猪随机分为4组，每组7头，分别饲喂玉米胚芽粕和玉米蛋白饲料。经78d饲养试验，结果表明：饲粮中添加单一玉米胚芽粕和玉米蛋白（＜16％）饲料同普通饲料相比，公猪日增重、料肉比及眼肌面积、屠宰率均无显著变化（P＞0．05）。饲料中同时添加玉米胚芽粕和玉米蛋白饲料后，平均膘厚显著降低（P＜0．05）。用廉价的玉米胚芽粕和玉米蛋白饲料作为生长肥育猪饲粮中的蛋白质补充饲料是完全可行的。     

芳樟离体快繁与离体保存试管苗再生植株培养

以芳樟嫩茎为外植体,进行离体培养快繁技术研究.结果表明:在改良MS+2mg·L-1 6 BA+ 0. 1mg·L-1 NAA固体培养基中诱导不定芽,诱导率高;用附加 0. 2mg·L-1 GA3 或无GA3 的改良MS+2mg·L-1 6 BA+0. 1mg·L-1 IBA固体培养基交替培养,芽苗可大量增殖,繁殖系数高达 10-20倍,而且可以避免褐变和玻璃化现象;保存 2a的试管苗仍然保持再生芽的能力;芽苗用 1 /2MS+0. 8mg·L-1 IBA+ 0. 2mg·L-1 NAA + 20g·L-1蔗糖固体培养基培养,生根、壮苗效果最好.     

牛精子膜麦芽凝集素结合糖蛋白的分离与定位

牛精子膜用非离子去污剂 NP-40增溶,经固相凝集素亲和层析,初步分离了精子膜麦芽凝集素结合糖蛋白,经 SDS-聚丙烯酰胺凝胶电泳、银染色显示出了四条蛋白质带,分子量分别为78,60.42和33 kD。用分离到的糖蛋白制备抗血清,对牛精子进行免疫细胞化学标记,结果顶体区显示为强阳性,与麦芽凝集素亲和细胞化学的染色一致。用抗血清处理精子再进行亲和细胞化学染色时,顶体区的麦芽凝集素结合糖残基多数被封闭,揭示麦芽凝集素结合糖残基是构成抗原决定簇的成分。     

干细胞及其在人类医学上的应用前景

干细胞是指从胚胎、胎儿或成年个体各种组织中分离出来的多能性细胞 ,具有体外保持未分化状态的无限增殖能力 ,在不同条件下可诱导分化为不同的细胞类型、组织甚至器官。胚胎癌细胞、胚胎干细胞、胚胎生殖细胞和成年组织干细胞是目前研究的几类主要干细胞 ,它们除作为发育生物学研究的细胞模型外 ,在人类医学领域也具有潜在的应用价值