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31.
酿酒葡萄成熟特性的研究   总被引:1,自引:0,他引:1  
葡萄浆果成熟过程中,存在着多方面的变化。只有含糖量、含酸量的变化最有规律,最能代表葡萄品种的成熟特性。含糖量的变化与logistic曲线、含酸量的变化与对数曲线拟合性最好。不同品种成熟特性的差异,主要表现为含糖量上升速率与含酸量下降速率的不同。气象因素能明显影响葡萄的成熟特性,最终造成同一品种在不同地区成熟度的差异。  相似文献   
32.
鸭梨酶促褐变的生化机制及底物鉴定   总被引:29,自引:0,他引:29  
吴耕西  周宏伟 《园艺学报》1992,19(3):198-202
  相似文献   
33.
自五十年代以来,应用于东亚飞蝗蝗区估计蝗蝻种群密度的抽样方法,是样方为10平方尺的筒单随机抽样。本文是以抽样数、抽样消耗、相对精确度为标准,对三种抽样模型、三个抽样单位进行了比较。根据这些结果,我们提出了在当前蝗蝻密度较低的情况下,应采用样方为100平方尺的最适配额分层抽样。这种抽样方法在精确度方面可以高出现用的抽样方法2倍以上。而抽样时间消耗可相对节约一半以上。  相似文献   
34.
棉籽壳对黄萎病菌的抑菌作用和抑菌物质的分析   总被引:2,自引:0,他引:2  
根据过去观察,棉籽壳有明显抑制黄萎病菌的作用。本试验初步证明这一抑菌物质具有丹宁类物质的某些特性。不同铃龄各部位的抑菌强度总趋势,与用高锰酸钾滴定法测得的丹宁类物质含量趋势一致,即不论大、中、小铃,感病及抗病品种,种壳的抑菌作用均大于胎座。初步认为种壳中较高浓度的丹宁类物质是种子内部带菌率极低的主要原因之一。纯丹宁在棉籽饼粉酒精洋莱培养基中的抑菌作用较供试的其它培养基小,说明此培养基用于种子带菌分离的优越性。棉花枯萎病菌对丹宁的耐受力显著高于黄萎病菌。  相似文献   
35.
36.
Several investigators have suggested that the blood-vessel system in the equine periodontal ligament does not only serve nutritional needs, but also specific functional needs, e.g. in terms of a shock absorbing system. In order to supplement the previous data, corrosion casts of the periodontal blood vessels were studied with special attention to the spatial arrangement and connections of the vessels. The heads of eight warm-blooded horses (age 2.5–23 years, seven female, one male), which had been killed for medical reasons, were dissected. The arteria alveolaris inferior and the a. infraorbitalis were perfused with 100 ml Heparin (20 000 IU) followed by 100 ml tap water. After storage at 4°C for 24–96 h, 10–200 ml methacrylate resin (BiodurTM E20) were injected by use of a cartridge pistol for approx. 1 h. After polymerization for 24 h at 60°C, the jaws were frozen and cut with a steel band saw in a horizontal, sagittal or transversal plane to obtain segments that exposed the periodontal space. The specimens were macerated in detergent at 60°C until the soft tissues had vanished. Care was taken to keep the periodontal vessels complete and in topographical integrity. The vascular casts were mesoscopically examined by use of a dissection microscope (magnification 5.8×–40×). The blood vessels in the periodontal space connected with vessels in three other sites:
  • (1)

    occlusal – with the blood vessels of the gingiva;

      相似文献   
37.
李富军  张新华  翟衡 《果树学报》2005,22(5):450-453
以红星苹果穴Malusdomesticacv.Starking雪和肥城桃穴Prunuspersicacv.Feicheng雪果实为试材,结合乙烯利和1-甲基环丙烯(1-MCP)处理,分别研究了2者软化的酶学基础,并就其差别作了探讨。结果表明:红星果实软化中起主要作用的酶为内切和外切多聚半乳糖醛酸酶(endo-和exo-PG);肥城桃果实软化的前20d则以纤维素酶(EGase)为主,20d后软化以endo-PG为主。研究同时发现,脂氧合酶(LOX)在这2种果实软化的启动阶段都起了明显的促进作用。1-MCP通过对红星果实中PG、肥城桃果实贮藏前期EGase和后期endo-PG活性的抑制,以及对2者软化启动阶段LOX活性的抑制,延缓了果实硬度的下降。  相似文献   
38.
AIM:To explore the effects of PMA(phorbol-12-myristate-13-acetate, a tumor promoter, mimicking the action of diacylglycerol on PKC)and laminin on the adhesion and the proliferation of human hepatocellular carcinoma cells, and provide a new clue to liver cancer treatment.METHODS:Human hepatocellular carcinoma cell line(BEL-7402)was used to identify the endogenous laminin and protein kinase C-α(PKC-α) expression, and the effects of laminin and PMA on the adhesion and the proliferation were also investigatedin vitro.RESULTS:By the effect of exogenous laminin, human hepatocellular carcinoma cell (BEL-7402) possessed endogenous laminin expression and increased the adhesion and the proliferation, which was showed the synergistic action by the effect of PMA in combination. By the action of PMA alone, the proliferation and the PKC-α expression increased by exogenous laminin were decreased, and the adhesion and the endogenous laminin expression were increased.CONCLUSIONS:The finding suggested that the adhesion and the proliferation of human hepatocellular carcinoma cell were closely related to the effects of endogenous or exogenous laminin, which were associated with cPKC-α activity. Therefore, the application of anti-laminin antibody in combination with PKC antagonist might be a new clue to find out the therapy for liver cancer.  相似文献   
39.
AIM:To investigate multi-potential of rat bone marrow mesenchymal stem cells (rBMMSC) and mutation inclination, the rBMMSC were long passaged in vitro. METHODS:Cellular cycles of different passages were assayed by FACSan flow cytometry and karyotypes of passage 6, passage 25 and passage 45 were compared by G-binding analysis. RESULTS:The early passages and long-term passages all showed strong proliferation; passage 6, passage 25 and passage 45 all showed normal karyotype. CONCLUSION:Long-term culture and passage of rBMMSC still remains strong proliferation. With this capability, the mutation inclination is not enhanced.  相似文献   
40.
AIM:To investigate the effects of FK506 on anti-glomerular basement membrane(GBM) nephritis in rats. METHODS: Anti-GBM nephritis model was elaborated by rabbit anti-rat GBM antibody injection in SD rats in this study. The rats were divided into three groups: FK506 treated group(0.5 mg·kg-1·d-1, sc), untreated nephritis control group and normal control group. FK506 was administered daily six hours after injection of anti-GBM IgG. All the rats were observed urinary protein at the 4th day, the 14th day and the 21st day. At the same time, the kidney specimens were collected, and T cell transforming function was also monitored.RESULTS:Rats injected with rabbit anti-GBM Ab developed heavy proteinuria by 4 days, and serum creatinine and serum urea appeared which kept on the rising. Glmerular hypercellularity, crescents, and protein casts were observed in nephritic rats. By electron microscopy, the thickening of GBM and loss of foot processes were seen. T cell transforming function was higher than normal. But, all pathological changes obviously turned for the better in FK506 treated group. CONCLUSION:FK506 could inhibit the progression of rat anti-GBM nephritis.  相似文献   
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