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刺五加化学成分及药理学研究进展 总被引:13,自引:0,他引:13
对国内外刺五加的相关文献资料进行了系统的整理,综述了刺五加的化学成分、药理作用等方面的研究进展,为刺五加进一步的研究和开发提供了较为详尽的资料参考。 相似文献
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土壤生物多样性对植物利用营养物质和水分的影响 总被引:2,自引:0,他引:2
土壤生物多样性影响土壤营养物质和水等自然资源的有效利用是农业生态系统的重要功能.有证据表明土壤微生物多样性可提高土壤营养物质和水的利用率.土壤动物对土壤营养物质和水的有效利用也产生了明显的影响,它主要是通过促进营养物质的转化和改善土壤水渗透率而间接实现的.从已有文献的报道来看,单从某一个方面来研究土壤生物多样性对土壤营养物质和水的有效利用的影响并不能全面地反应它们之间相互作用的规律.因此未来的研究应当把土壤生物多样性、土壤营养物质和水的供给与植物生物多样性、植物营养物质和水的利用率结合起来,这样才有可能从理论上对土壤生物多样性与营养物质和水的利用之间的关系有更加深刻的认识并运用到实践中. 相似文献
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六七月间,从太平洋而来的湿润季风并没有深入到位于银川东部19公里的水洞沟.骄阳烈烈,黄沙阵阵,沟壑纵横,支离破碎是对这片地处半干旱半沙漠地带的旧石器时代遗址并不夸张的写照.
然而,看似贫瘠的地方却往往驻扎最旺盛的生命力.就在那广袤灰黄荒原的一角,手铲簌簌落地的声音已经持续了一个月.那是一支融合着新面孔的考古队伍,怀揣着疑问从千里之外赶来.沙质的黄土随着铲尖的一起一落被层层剥开,沉睡在地层中的史前文明也逐渐显露出来. 相似文献
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生物技术产业是一个高投资、高风险的产业,在各种筹集资金、规避风险的方案中,申请专利成为各国科研工作者和企业家的首选.要成功的获得专利权,首先要了解哪些主题是能够得到专利保护的.各个国家和地区对专利授权的标准不尽相同,通过分析原因和举例说明的方式详细阐述了我国对生物技术领域不予授权的主题.只有不属于这些不可授权主题的发明创造,才有可能成功地获得专利授权. 相似文献
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SCID是一种罕见的先天性免疫缺陷疾病,以严重的T细胞和B细胞功能缺陷为特征.患者自身不具备免疫系统,只能在完全无菌的条件下生存,因此又称.气泡儿童".基因疗法研究的兴起和深入,给SCID的治疗提供了一条新的途径.该文综述了SCID及其基因疗法的研究进展,并对基因疗法的应用前景进行展望. 相似文献
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Survivin的研究现状与RNA干扰在基因治疗中的进展 总被引:1,自引:0,他引:1
Survivin是新近发现的凋亡抑制蛋白,在正常组织中不表达而在恶性肿瘤中高表达,与肿瘤的预后、复发、转移关系密切,具有调控细胞周期,凋亡和增殖的作用;还与对化疗的耐药性和放疗的敏感性有关;此外,与肿瘤新生血管的形成关系也十分密切.针对Survivin这些特性,应用新的基因治疗技术-RNA干扰技术降低Survivin的表达可对肿瘤组织的凋亡和增殖产生影响,由于RNA干扰技术具有的高效性,特异性,长效性,使它成为肿瘤基因治疗的重要方法,应用RNA干扰技术针对Survivin靶位降低Survivin的表达有望成为今后肿瘤基因治疗的方向. 相似文献
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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme
responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare
the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show
that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by
distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of
demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least
one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of
the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable
potent antiproliferative synthetic drugs. 相似文献
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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases 相似文献
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The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle. 相似文献
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Michael Hesse 《Plant Systematics and Evolution》1980,134(3-4):229-267
Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout. 相似文献
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Surveillance of Class Ⅰ Newcastle Disease Virus at Live Bird Markets and Commercial Poultry Farms in Eastern China Reveals the Epidemic Characteristics 下载免费PDF全文
Xiaolong Lu Xiaoquan Wang Tiansong Zhan Yifan Sun Xin Wang Naiqing Xu Tianxing Liao Yu Chen Min Gu Shunlin Hu Xiaowen Liu Xiufan Liu 《中国病毒学》2021,36(4):818-822
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正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various 相似文献