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本实验根据PRRSV结构蛋白的特性和IFNγ及IL-2这两种细胞因子的特性,构建表达PRRSVGP4-GP5、GP5-M、GP5-N、GP5-IFNγ、GP5-IL-2、N-IFNγ、N-IL-2的重组质粒。这些重组质粒在真核细胞中得到了表达。用这些真核表达质粒可以免疫小猪,通过检测其对猪体免疫应答的诱导能力和接种后动物对PRRSV的抵抗力来对基因疫苗的效能进行研究,以期筛选到有效的基因疫苗并为今后进一步的研究提供思路和理论基础。 相似文献
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Shyu DJ Chou WM Yiu TJ Lin CP Tzen JT 《Journal of agricultural and food chemistry》2004,52(5):1350-1356
A cDNA fragment encoding cystatin, a cysteine protease inhibitor, was obtained from maturing sesame seeds. The clone was constructed in a nonfusion or fusion vector and then overexpressed in Escherichia coli. The recombinant cystatins were found in the soluble fraction of cell extract and were demonstrated to be functionally active in a reverse zymographic assay. The corresponding endogenous 22 kDa cystatin of low abundance in mature seeds was purified to homogeneity via a papain-coupling affinity column and confirmed by western blotting with antibodies against the recombinant cystatin. Both endogenous and recombinant cystatin proteins showed effective inhibitory activities against papain with K(i) values of 7.89 x 10(-8) M and 2.77 x 10(-8) M, respectively. Immunodetection indicated that cystatin was specifically expressed in maturing seeds and rapidly degraded in germination. Accordingly, zymographic and inhibition analyses showed that sesame cystatin could not inhibit the de novo synthesized proteases in germinating seeds. It is suggested that sesame cystatin may play a role in the regulation of endogenous cysteine proteases during seed maturation and germination. 相似文献
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红皮云杉嫩枝扦插繁殖技术的研究 总被引:9,自引:0,他引:9
本文描述了红皮云杉嫩枝扦插繁殖技术。通过试验筛选出1种适合于红皮云杉嫩枝扦插的基质(插壤),2种使生根率达98%且根系发育良好的生根剂。同时,提出了把握扦播时机,合理运用生根剂浓度及处理时间的方法和技术措施。 相似文献
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Hibiscus protocatechuic acid or esculetin can inhibit oxidative LDL induced by either copper ion or nitric oxide donor 总被引:2,自引:0,他引:2
Lee MJ Chou FP Tseng TH Hsieh MH Lin MC Wang CJ 《Journal of agricultural and food chemistry》2002,50(7):2130-2136
Oxidation of low-density lipoprotein (LDL) could increase the incidence of atherosclerosis. Previous studies have shown that copper and sodium nitroprusside (SNP) possess the ability to oxidize LDL in a dose-dependent condition. They increase the existing negative charge in LDL and increase the electrophoretic mobility. In this study, we used protocatechuic acid (PCA) and/or esculetin (ECT) to define the antioxidative activity in oxidative LDL by relative electrophoretic mobility (REM) and thiobarbituric acid-relative substances (TBARS). The data showed that ECT and PCA possessed stronger antioxidative activity than vitamin E in oxidative LDL. A previous study showed that the level of oxidative LDL can be determined by the cholesterol degradation and fragmentation of Apo B. Our results showed that Cu(2+)-mediated oxidative LDL can induce 31% cholesterol degradation and significant fragmentation of Apo B. Both PCA and ECT exhibited remarkable ability to rescue the cholesterol degradation and Apo B fragmentation. Taken together, both PCA and ECT showed strong potency to inhibit oxidative LDL induced by copper or an NO donor. Additionally, their nontoxic characteristics elevated the possibility for their use in the daily diet; and should further prevent atherosclerosis effectively. 相似文献
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干发酵原料中固形物含量高,结构疏松,原料的压实度直接关系到发酵罐的利用率和生产成本。为了探讨原料压实度对厌氧干发酵过程的影响,该文以玉米秸秆粉为试验材料,研究了不同固形物含量(TS)条件下原料压实度对厌氧干发酵产气特性及物料特性变化的影响,结果表明:相同TS下,随着压实度的增加,日产气量(基于可挥发性固形物,VS)峰值降低且出峰时间略有滞后;原料压实度对累积产气量、日产气量变化趋势以及甲烷体积分数的影响不明显。基于发酵罐容积计算产气量时,原料压实度与日产气量峰值、累积产气总量以及累积甲烷产量均呈显著正相关。不同TS条件下的原料压实度对厌氧干发酵过程的影响程度不同,TS含量越高原料压实度对产气量的影响越明显。TS为20%和25%时,逐层压实发酵罐的单位容积累积产气量比自然填料罐分别提高了37.1%和60.2%。当发酵料初始TS为20%时,原料压实度的增加可促使物料中形成连续的液相,改善物料层间的传质,从而使发酵料上下层间的差异减小。当发酵料初始TS提高到25%时,原料压实度增加对传质特性无明显影响。综上所述,在该试验研究范围内,提高原料压实度可以保证玉米秸秆厌氧干发酵产气过程的正常进行,且可以显著提高发酵罐的容积利用率。该研究对厌氧干发酵原料压实度与发酵特性之间的关系进行了初步探讨,以期为有效提高厌氧干发酵罐的产能能力提供参考。 相似文献
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A program of research named Towards an Integrative Biology (TAIB) has recently been promoted by the International Union of Biological Sciences, involving multidisciplinary and interdisciplinary research. Studies of Miscanthus plants which emphasized the TAIB theme were undertaken. Miscanthus species are the most widely distributed and dominant species in Taiwan, growing everywhere from the coastal to mountainous areas, and from agricultural to polluted land. Particularly, the grasses grow well in habitats under environmental stresses. Physiological and genetic adaptations are fundamental mechanisms for these grasses' survival in stressful environments. Findings based on field measurements and laboratory analyses were able to elucidate some of the mechanisms of grasses adapted to stressful environments. Adaptive radiation occurred when most niches were open during the postglacial periods. Particularly, population discontinuity of the grasses was found on the Orchid and Green islets of Taiwan. Likewise, Miscanthus sinensis var. glaber and var. formosanus occupied lands from low to middle elevations of Taiwan, while Miscanthus transmorrisonensis appeared in the highlands above 2400 m. Phylogenetically, Miscanthus has evolved into various ecotypes, varieties and species in Taiwan as well as in other parts of Asia. The grass then evolved into Miscanthus floridulus , M. sinensis var. formosanus , Miscanthus flavidus , then to M. transmorrisonensis . Furthermore, the phylogeny of the Miscanthus sinensis complex of Taiwan was reconstructed by cladistic analysis on nucleotide sequences of nuclear ribosomal DNA internal transcribed spacers (nrDNA ITS) region and atpB - rbc L non-coding spacer of the chloroplast DNA. Rooted at M . floridulus the monophyly of M . sineneis was significantly supported by molecular evidence. The origin of this complex could be dated to the last glacial withdrawal about 20 000 years ago. 相似文献
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