首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   82篇
  免费   3篇
  国内免费   8篇
  2023年   3篇
  2021年   1篇
  2020年   2篇
  2016年   3篇
  2015年   1篇
  2014年   4篇
  2013年   4篇
  2012年   4篇
  2011年   7篇
  2010年   8篇
  2009年   5篇
  2008年   4篇
  2007年   8篇
  2006年   7篇
  2005年   6篇
  2004年   1篇
  2003年   4篇
  2002年   5篇
  2001年   4篇
  2000年   4篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1992年   1篇
  1990年   1篇
排序方式: 共有93条查询结果,搜索用时 15 毫秒
81.
高效液相色谱法测定五味子乙素含量   总被引:11,自引:2,他引:9  
裴毅  聂江力 《植物研究》2005,25(3):373-375
采用高效液相色谱法,测定了五味子果实中五味子乙素的含量,检测波长为254 nm,标准曲线线性关系R2为0.9907,相对标准偏差为0.48%,平均加样回收率为99.14%。结果表明,此方法准确度较高,为五味子生药及成品药中五味子乙素含量测定提供了一种切实可行的方法。  相似文献   
82.
Summary Regeneration of plants via somatic embryogenesis was achieved from zygotic embryo explants isolated from mature seeds of Schisandra chinensis. Merkle and Sommer's medium, fortified with 2,4-dichlorophenoxyacetic acid (2,4-D; 9.04 μM) and zeatin (0.09 μM), was effective for induction of embryogenic callus. The development of a proembryogenic mass and somatic embryos occurred on Murashige and Skoog medium (MS) free of plant growth regulators. The embryogenic callus induced on Merkle and Sommer's medium supplemented with 2,4-D (9.04 μM) and zeatin (0.09 μM) showed development of the maximum number of somatic embryos when transferred to MS medium free of plant growth regulators. The maximum maturation and germination of cotyledonary somatic embryos (46.3%) occurred on MS medium supplemented with 2,4-D (0.45 μM) and N6-benzyladenine (1.11 μM). The somatic embryo-derived plants were successfully hardned, with a survival rate of approximately 67%, and established in the field.  相似文献   
83.
Schisandrin B (Sch B), a dibenzocyclooctadiene derivative isolated from Fructus Schisandrae, has been shown to produce antioxidant effect on rodent liver and heart. A mouse model of tert-butylhydroperoxide (t-BHP) induced cerebral toxicity was adopted for examining the antioxidant potential of Sch B in the brain. Intracerebroventricular injection of t-BHP caused a time-dependent increase in mortality rate in mice. The t-BHP toxicity was associated with an increase in the extent of cerebral lipid peroxidation and an impairment in cerebral glutathione antioxidant status, as evidenced by the abrupt decrease in reduced glutathione (GSH) level and the inhibition of Se-glutathione peroxidase activity at 5 min following t-BHP challenge. Sch B pretreatment (1 or 2 mmol/kg/day × 3) produced a dose-dependent protection against t-BHP induced mortality. The protection was associated with a decrease in the extent of lipid peroxidation and an enhancement in glutathione antioxidant status in brain tissue detectable at 5 min post t-BHP challenge, with the assessed biochemical parameters being returned to normal values at 60 min in Sch B pretreated mice at a dose of 2 mmol/kg. The ensemble of results suggests the antioxidant potential of Sch B pretreatment in protecting against cerebral oxidative stress.  相似文献   
84.
中国五味子分布范围及气候变化影响预测   总被引:2,自引:0,他引:2  
结合文献资料、标本记录和实际调查绘制了中国五味子分布图,并基于五味子分布范围和21个环境因子,运用Maxent软件预测了IPCC A2和A1B两种气候变化情景下21世纪50和80年代中国五味子分布范围.结果表明:五味子分布于中国15省/市(区),涉及151个县,随着纬度和经度的降低,面积逐渐减少,黑龙江、辽宁、内蒙古和吉林4省(区)是五味子主要分布区域;五味子在中国的潜在分布面积为145.12×104 km2,较好生境面积占48.6%,主要分布在长白山山脉、大兴安岭、小兴安岭以及河北省与辽宁省相邻区域;最佳生境面积仅占0.3%,主要分布在辽宁省的宽甸满族自治县、本溪满族自治县、桓仁满族自治县以及吉林省的安图县、和龙市和内蒙古自治区牙克石市.在A1B和A2两种情景下,未来五味子潜在分布区逐渐减少,A2情景的五味子潜在分布区下降比率大于AIB情景;至21世纪50年代,A1B和A2情景下五味子潜在分布区将缩减为当前潜在分布区面积的84.0%和81.5%;至21世纪80年代,A2情景下五味子潜在分布区仅为当前的0.5%,B2情景下五味子潜在分布区减至当前的1/2.  相似文献   
85.
Fractionation of the EtOH extract from the fruits of Schisandra sphenanthera resulted in the isolation of seven new sesquiterpenoids, 1 – 7 , in addition to the known metabolites 8 – 23 . Among them, schiscupatetralin A ( 1 ) possesses an unprecedented structure with a C? C bond between cuparenol and tetralin. The isolated new compounds were evaluated for their anti‐HSV‐1 and anti‐inflammatory activities. The results revealed that compound 4 exhibited anti‐HSV‐1 activity, while compound 6 showed a significant anti‐inflammatory activity.  相似文献   
86.
目的:探讨一种便于五味子资源产量和蕴藏量统计估算的新方法,并准确得出五味子果实可利用生物量回归方程。方法:采用实地样方调查、相关生物量数据测定和统计分析相结合的方法。结果:单一果穗重量与果穗长度、宽度和小浆果数量的多元线性回归方程为:Y=-12.66+0.1X1+0.489X2+0.265X3。结论:所得回归方程理论上可准确估算五味子果实可利用生物量,这一方法也可应用于其它聚合果和小浆果类药用植物资源调查中。  相似文献   
87.
通过查阅标本、文献,走访和实地考察等多种方式,对陕西省6市20县26乡镇五味子属野生植物资源现状及分布进行调查。结果表明,秦岭地区有6种五味子属植物,华中五味子(Schisandra sphenanthera)、红花五味子(Schisandra rubriflora)、大花五味子(Schisandra grandiflora)、铁箍散(Schisandra propinqua var.sinensis)、金山五味子(Schisandra glaucescens)和狭叶五味子(Schisandra lancifolia),分布于海拔500~2800 m之间,华中五味子数量多且分布广,大花五味子相对稀少。根据调研确定不同地区各种五味子的花期和果期,并制定分种检索表,补充了秦岭地区五味子属植物的分布状况。调查显示,分布区内五味子属野生植物资源遭到不同程度破坏,特别是稀少种亟待保护。本研究为道地药材的合理采收和可持续利用、加强对稀少物种的保护提出了建议。  相似文献   
88.
The chloroplast mat-K region and rpL16 intron region were sequenced for 14 species of Schisandraceae, representing both genera Kadsura Kaempf. ex Juss. and Schisandra Michx, to discuss the phylogeny of this family. Analyses were performed both in separate and combined sequence data sets (including the rbc-L sequence), with Illicium angustispealum A. C. Smith as the out-group. The results showed that the Schisandraceae are monophyletic. In all the analyses, Schisandra propinqua var. chinensis Oliva and Schisandra plena A. C. Smith were nested within Kadsura, which implies that the genera Kadsura and Schisandra are closely related. They might have originated from a common ancestor, but then evolved via different routes. The result inferred from the combined data showed a greater resolution within Schisandra than those from the two separate data sets. High bootstrap values supported the monophyly of most subgenera according to Law's system (1996). A combination of morphological, anatomical, and chemical analyses indicates that S. chinensis and S. rubriflora may be the primitive taxa in Schisandra.  相似文献   
89.
五味子属植物种子形态特征及其分类学意义   总被引:3,自引:0,他引:3  
在扫描电镜下观察了70多份五味子属种子样品,并拍摄了照片,其中34幅展示在文中。选取代表27个分类群,34个居群的36份种子样品,每份样品20粒,测量长、宽、厚,取平均值。采用“相对体积”这一新概念作为种子形态比较的一项指征。同时对种子整体照片所呈现的表面纹饰进行了分析归纳,将其分为4个类型:(1)平滑或基本平滑,(2)有明显的皱纹,或有或疏或密的疣状突起,(3)有密集而显著的乳头状突起,(4)密被不规则的、有结节的绳索状突起,突起物曲折蜿蜒,酷似哺乳动物的大脑。综合种子的大小、颜色、表面整体纹饰以及雄蕊群特征等分析的结果表明,少蕊组sect.Maximowiczia、五味子组sect.Schisandra和球蕊组sect.Sphaerostema的种子形态分别与其雄蕊群特征具有高度的相关性;而多蕊组sect.Pleiostema的情况稍微复杂一点,但种子形态与与其雄蕊群特征之间仍然有部分相关性。本文以种子的整体形态为基础讨论五味子属种子表面形态在该属分类上的意义。研究种子整体形态得到的证据与研究种子表面微形态得到的证据一致,不支持林祁(2000)和Saunders(2000)对五味子属的分类修订,也不支持刘玉壶(1996)将球蕊组sect.Sphaerostema划分成两个亚属的修订。  相似文献   
90.
By means of electron microscopy, we studied the development of pollen grain walls in Calendula officinalis L., Dimorphotheca aurantiaca DC., and Cichorium intybus L. (Asteraceae). As a reference, we studied the plants from the families Schisandraceae (Schisandra chinensis (Turcz.) Baill.), Lauraceae (Persea americana Mill.), Boraginaceae (Borago officinalis L.), and Cycadaceae (Encephalartos altensteinii Lehm.). In Asteraceae, we revealed two successively initiated layers of glycocalyx that form outer and inner layers of the ectexine. The formation of endexine is contributed by plasma membrane and small vesicles. Glycocalyx in the plants from the families Schisandraceae, Lauraceae, Boraginaceae, and Cycadaceae was found to consist of radially arranged helical cylindrical units, which are receptors of sporopollenin deposition. It is assumed that the receptor-independent accumulation of sporopollenin is also possible.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号