p15基因真核表达重组体及人宫颈癌细胞转染的研究

将含人p15cDNA质粒pBS-SK-p15以EcoRI和XhoI进行双酶切，再与真核表达载体pCR^TM3经相同酶切点连接，转化感受态细菌，筛选，鉴定得到可在真核细胞中表达人p15基因的重组质粒PCR-hp15。以脂质体介导法转染人宫颈癌细胞，用G418筛选，得到转染的人宫颈癌细胞，转染细胞的恶变程度有所改善。     

鸡Bcl-2基因的克隆及其对卵泡颗粒细胞凋亡的影响

将鸡的 Bcl- 2基因克隆到真核表达载体 JL V中 ,构建了重组质粒 JL VB。 0 .2μg/孔 JL VB重组质粒经脂质体介导转染卵泡颗粒细胞 ,应用流式细胞术等方法分析了转染 Bcl- 2基因后原代细胞和传代细胞的生长与凋亡情况。与对照组相比 ,转染后的传代细胞分裂速度较快 (P<0 .0 1) ,凋亡比率较低 ,G2 / M S期细胞比例极显著高于对照组 (P<0 .0 1)。这些结果表明 ,Bcl- 2基因具有促进细胞分裂、抑制细胞凋亡、延长细胞寿命的作用 ,这种作用是直接的。在转染时间为 12 h、DNA量为 0 .3μg/孔的条件下 ,较好的脂质体介导用量为 1.2 μL/孔。     

貉,蓝狐,银狐的胃及十二指肠内嗜银细胞形态分布的研究

本文应用Ｆｏｒｔａｎａ—Ｍａｓｓｏｎ嗜银颗粒染色法研究了貉、蓝狐、银狐的胃及十二指肠内嗜银细胞的形态分布。结果表明：三种动物胃幽门腺中，嗜根细胞数量最多，呈锥状，嗜银颗粒较粗，密度大、染成深黑色。在胃底及胃贲门腺区、嗜银细胞数量少。在十二指肠部嗜银细胞呈蝌蚪形，嗜银颗粒细，呈黑褐色，密度较小。嗜银细胞的分布密度在三种动物中具有一定的差别。     

大鼠乳腺局部免疫的调节机制--泌乳期与静止期乳腺肥大细胞分布的比较

应用改良甲苯胺蓝染色法(MTB)观察了大鼠泌乳期和静止期乳腺肥大细胞的分布、形态、数量变化规律．并用阿尔新蓝一番红鉴别染色法(AB-S)进行了细胞化学分型研究。结果：AB-S染色显示，大鼠乳腺只存在黏膜型肥大细胞；无论是泌乳期还是静止期。乳腺肥大细胞大多分布于腺泡间和小叶问结缔组织中。细胞的形态各异，但细胞数量在静止期和泌乳期有显著差异。泌乳期的乳腺肥大细胞数量明显减少(P＜0．01)。乳腺肥大细胞的动态变化，可能与乳腺泌乳期腺泡上皮的生长和静止期腺泡问结缔组织细胞增生等结构变化有关。     

温度和时间对野桂花蜜淀粉酶值的影响

本实验以两种野桂花蜂蜜样品为实验材料,在不同温度和时间条件下处理,通过试管法测定蜂蜜中淀粉酶值。结果表明:随着温度的升高和处理时间的延长,蜂蜜中的淀粉酶值呈下降趋势。     

广西新黄鸡腔上囊和胸腺的发育及其T淋巴细胞的分布

10日龄鸡胚腔上囊开始形成囊腔和皱褶,并偶尔见到T淋巴样细胞;12日龄鸡胚出现淋巴滤泡;17日龄鸡胚滤泡髓质基本形成;3日龄雏鸡滤泡皮质出现。18日龄鸡胚开始形成DIA,随日龄的增长,DIA由腔上囊背侧近导管开口处逐渐扩展到导管背侧;7周龄前后到达与泄殖腔相连处。随着滤泡及DIA的形成,T淋巴样细胞分别出现于其中。滤泡中T淋巴样细胞的百分率,胚胎期大于孵出后。出生后T淋巴样细胞主要聚集于DIA内。9～11周龄腔上囊生长达到最大值,21.5～52周龄腔上囊消失。 14日龄鸡胚胸腺开始出现髓质,并可在其中检出ANAE细小颗粒型细胞,其百分率出生后大于胚胎期。但10～12日龄鸡胚胸腺中有大量的未成熟的胸腺细胞呈ANAE斑点型反应     

Variation in Nicotine Content of Cultured Cell Lines of Nicotiana Species and their Somatic and Sexual Hybrids

Several Nicotiana species, their intergeneric sexual and somatic hybrids were compared for their in vitro growth rate and nicotine content. Cell yield on a dry weight basis and HPLC analysis of their nicotine content revealed a very high variation within each cell line from parental, sexual and somatic hybrids for the two traits analyzed. The trigeneríc sexual hybrids (N. rustica × N. debneyi) × N. tabacum and only two of the N. rustica × N. tabacum somatic hybrid lines show a positive heterosis in nicotine content in vitro The in vitro growth rate and nicotine content did not demonstrate a statistically significant correlation.     

Development of arable weed seedbanks during the 6 years after the change from conventional to organic farming

All of the arable land of a farm in southern Germany was investigated during an 8-year period, starting 2 years before and ending 6 years after the change to organic farming. The first 3 years after the conversion, the total seed number in the soil increased from 4050 to 17 320 m⁻². From the fourth to the sixth year, it dropped back to 10 220 m⁻². The number of seeds increased particularly at sites with a low crop cover and a high density of weed plants at the soil surface. The increase predominantly occurring on the more fertile soils may have been caused by the rotation commencing with less competitive crops. Crops which increased the seedbank by 30–40% were winter cereals, sunflowers and lupins. Potatoes and sown fallow caused no significant change and grass–clover mixtures even reduced the number of seeds by 39%. Among 44 species occurring frequently enough for statistical analysis, 31 increased and only 3 decreased. The change of management particularly increased summer annual, perennial and dicotyledonous weeds. This can be attributed to both operations which are characteristic of organic farming (e.g. replacing herbicide applications by mechanical weed control) and to general modifications of the management practice which may also occur in non-organic farming systems (increasing the percentage of broad leaved and spring sown crops in crop rotation). The present study confirms investigations into the aboveground vegetation that indicate that arable organic farming favours plant species diversity and provides evidence that the conversion need not encourage the dominance of a few noxious weeds.     

新西兰白兔胃底腺等器官生后发育及超微结构变化的研究

通过组织学及电镜技术对新西兰白兔胃底腺、小肠绒毛及肠腺的发育进行了，结果表明：新西兰白兔胃底腺、肠腺和肠绒毛的生长表现出明显的阶段性，胃底腺高度生长的最快阶段约在初生至１周龄及２－６周龄，小肠绒毛高度、宽度及表面生长的最快阶段约在初生至１周龄及３－６周龄，肠腺高度生长的最快阶段与小肠绒毛的高度生长基本。     

农业科技论文篇幅与文摘字数的相关分析

从“中国期刊全文数据库”下载9种农林院校学报的农业类试验论文408篇，这些论文须由引言，材料与方法，结果分析和结论与讨论4部分组成，其文摘必须是报道性文摘，统计这些论文的篇幅（字数）及文摘的字数。利用SPSS软件分析论文篇幅和文摘字数的相关性，结果表明，农林院校学报论文文摘的平均字数为246.6字；论文篇幅与其文摘字数间存在显著或极显著的相关关系，不同中图分类号论文的回归模型表明，文摘字数随论文篇幅的变化率为0.021-0.044；408篇论文的篇幅（y)与文摘字数（x5)的回归方程为y=118.074611 0.030092x5,经检验，方程达极显著水平。根据回归方程，计算了置信度为0.05时不同篇幅论文的文摘字数的置信区间。