额尔齐斯河流域生态系统格局及变化

本文首先对额尔齐斯河流域气候，地貌，水文等环境因子特征进行了评述，进而阐述了流域生态系统的特征和格局以及在自然和人为干扰作用下的变化。分析结果表明在自然干扰作用下流域生态系统的格局与流域水文情势变化相适应，处于准稳定变化状态，而在人为对流域水文情势扰动下，流域生态系统的格局间接地受到影响。从而产生新的格局，其作用的强度，持久性和生态系统的格局变化程度过错大于大于自然干扰作用下的变化。引额调水工程对额尔齐斯河流域河谷生态系统内部单元格局变化具有重要影响。     

巴旦杏在甘肃河西地区引种培育问题的探讨

该文通过分析巴旦杏在甘肃河西地区引种培育过程中出现的问题,总结出用容器育苗和大田开沟点播相结合来培育接穗,以山桃为砧木嫁接巴旦杏的引种驯化技术.结果表明,容器培育接穗比直接大田点播出苗率、成活率分别提高了10%和15%;巴旦杏与山桃嫁接表现出极好的亲和性,嫁接成活率为90%.     

长豇豆品种同功酶的遗传多样性分析

用电泳技术分析了长豇豆21个品种种苗的过氧化氢酶(CAT)和淀粉酶(AMY)的同功酶酶谱.从中分析了3个表现出品种之间多样性的位点.根据这些位点上带型的差异,可以区分供试的所有长豇豆品种.图谱上品种之间的差异位点,可以用于资源品种亲缘关系分析和纯度鉴定.     

In vitro growth inhibition effects of rhHGF/cHGF on SMMC-7721 human HCC cell line

AIM:To examine the effects of recombinant human hepatocyte growth factor(rhHGF) and native calf HGF(cHGF) on SMMC-7721 human hepatocellular carcinoma(HCC) cell line. METHODS:Human HCC cell line culture, photometric assay, and flow cytometric assay were used in this study .RESULTS:A similar type of dose-dependent cell growth inhibition effect on SMMC-7721 human HCC cells by rhHGF(5-20 μg/L) as well as by cHGF(25-100 mg/L) had been found, with the maximal effect at the highest concentration used. Approximately over 50% of the cells treated with rhHGF(5 μg/L, 10 μg/L, 20 μg/L) accumulated in the quiescent G₀/G₁ phase of the cell cycle over incubation periods for 3 d. CONCLUSION:The growth of SMMC-7721 human HCC cells was strongly inhibited by both rhHGF and cHGF. This might be because the cells exposed to HGF became arrested in the G₀/G₁ phase.     

A reactive pattern of ischemia-induced nestin protein in the rat brain

AIM:To explore the expressive profile of nestin protein in the focal ischemic brain and to study the recovery mechanism of brain focal infarct.METHODS:Cellular morphology,time-course and distribution pattern of nestin positive response were immunohistochemically examined in different brain regions of 36 adult male SD rats. RESULTS:Nestin positive response of different brain regions in sham operated rats was present in small- and micro-vasculartures and the third ventricle bottom and ependyma. A large number of nestin positive cells were detected in ischemic brain, and were more remarkable in the cortical areas of parietal lobe and preoptic area as well as ischemic caudoputamen. Stellate nestin positive cells were located in the deep layer of ischemic cortex, but fibrillary cells were located in the shallow layer. Nestin positive cells in the ischemic caudoputamen showed the same changes of morphology as those cells in the deep layer of ischemic cortex. Morphological and number alterations of nestin positive cells were the most remarkable at 1 weeks post-ischemia, which showed more hypertrophy and proliferation in morphology, and a marked increase in number was present in the ischemic cerebral cortex and the ischemic caudoputamen. These alterations of nestin positive cells persisted up to 6 weeks post-ischemia, and then, the nestin positive response in the ischemic brain decreased gradually.CONCLUSION:Focal cerebral ischemia induces nestin re-expression on reactive astrocytes, which may be very important to the self-recovery of cerebral infarct.     

Effects of tetrandrine and fructose-1, 6-diphosphate on the elevated intrasynaptosomal [Ca2+]i induced by excitatory amino acids

AIM: To study the effects of tetrandrine(Tet) and fructose-1, 6-diphosphate(FDP) on the elevated intrasynaptosomal [Ca²⁺]_i induced by excitatory amino acids(EAA). METHODS: A rapid method for preparing synaptosomes was used, and intrasynaptosomal free calcium([Ca²⁺]_i) was measured by using the fluorescent indicator quin-2. RESULTS: L-glutamate(Glu, 100 μmol/L), aspartate(Asp, 100 μmol·L^-1), N-methy1-D-aspartate(100 μmol/L) and Glu(50 μmol/L) plus Asp(50 μmol/L) all elevated intrasynaptosomal [Ca²⁺]_i in a dose-dependent manner. Pretreatment with Tet(10, 30, 60 μmol/L), FDP(15, 30, 75, 150 μmol/L), MK-801(10, 20 μmol/L) and Tet(15, 30 μmol/L) plus FDP(15, 30 μmol/L) all attenuated the increase in intrasynaptosomal [Ca²⁺]_i induced by EAAs mentioned as above in a dose-dependent manner, and the effect of Tet plus FDP was most significant. CONCLUSION: Both Tet and FDP inhibited a rise in intrasynaptosomal [Ca²⁺]_i induced by EAAs, which may be one of mechanisms that Tet and FDP pretect cerebral tissues against ischemia injury.     

冬虫夏草的研究概况

冬虫夏草是一种十分重要的药用真菌，具有广阔的开发前景。本文介绍了冬虫夏草的生物学习性、化学成分、药理作用及人工培育现状，并展望了冬虫夏草研究的前提。     

甲胺磷对褐飞虱酯酶时序变化的影响

褐飞虱经甲胺磷处理后 ,酯酶活性首先表现为受到抑制 ,然后上升 ,到达最大值后再下降并停留在一个相对对照较高的水平。在 1次处理的基础上 ,第 3天和第 7天再次处理 ,酯酶的变化进程与 1次处理相同 ,但最后的停留水平均高于 1次处理 ,分别为 1次处理的 1.35倍和 1.63倍左右。敏感性测定同样表明再次处理可以导致敏感性进一步下降 ,第 3天和第 7天再次处理 ,敏感性分别比 1次处理下降了0.35 1、0.696倍。     

丝兰属植物提取物降低鸡舍氨气浓度的效果试验

通过在21日龄的肉用仔鸡饲料中添加丝兰属植物提取物(其有效成分为丝兰皂角苷)，研究丝兰属植物提取物对降低鸡舍中氨气浓度和提高肉仔鸡生产性能的效果。试验结果表明，试验组鸡舍内氨气平均浓度为4．75mg／L，对照组鸡舍内氨气平均浓度为13．80mgl／L，试验组比对照组鸡舍内氨气平均浓度降低了9．05mg／L，经t检验，两鸡舍内氨气平均浓度差异显著(P＜0．05)，并且试验组比对照组饲料报酬提高了8.92％。     

应用小白鼠代替鸡对禽霍乱蜂胶灭活疫苗进行效检的研究

为寻找其他有效的禽霍乱蜂胶灭活疫苗的效检方法,应用小白鼠代替本动物鸡对禽霍乱蜂胶灭活疫苗进行效检.结果表明,小白鼠免疫时体重15～18 g,疫苗免疫剂量0.3 mL/只,免疫10 d后攻毒,攻毒时体重20～25 g,攻毒剂量5～9 CFU/只时,可代替本动物鸡对禽霍乱蜂胶灭活疫苗进行效检,判定标准为免疫组8/10以上保护,对照组5/5死亡为合格.本效检方法可缩短检验期限7 d,降低检验成本,具有敏感、特异、客观、简便等特点.