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1.
中药前胡核磁共振氢谱法鉴定   总被引:1,自引:1,他引:0  
使用^1H-NMR法对19种前胡乙醚提取物进行了测试和解析,其中9种前胡的化学成分未见报道。根据主要化学成分香豆素的类型,将含角型二氢吡喃香豆素的10种前胡归入白花前胡类;含线型二氢吡喃香豆素或线型二氢呋喃香豆素的8种前胡归秋紫花前胡类。研究结果表明,^1H-NMR法是鉴别中药前胡的快速、简便而可靠的检测方法。  相似文献   
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濒危植物毛柄小勾儿茶种子休眠与萌发生理的初步研究   总被引:12,自引:1,他引:11  
毛柄小勾儿茶(Berchemiella wilsonii (Schneid.)Nakai var.pubipetiolata H.Qian)为中国特有种,国家三级保护植物。TTC染色法测得毛柄小勾儿茶种子的生活力较低,仅为32%,空粒和无生活力的种子分别为28%和40%,说明毛柄小勾儿茶发育完全的种子较少。种子吸水速度试验证明毛柄小勾儿茶种皮透水性较差,不利于种子萌发时对水分的吸收,发芽抑制物的生物鉴定结果表明,毛柄小勾儿茶种子的不同部位都存在发芽抑制物,且种胚中的含量最高,不利于种子的萌发,使毛柄小勾儿茶种子处于休眠状态之中。几种不同浓度GA。溶液浸种24h的预处理可以不同程度地提高毛柄小勾儿茶种子的发芽率和发芽指数,其中300mg/L GA3的效果最显著,并且300mg/L GA3的预处理可以在萌发初期(萌发前3天)显著地提高毛柄小勾儿茶种子中过氧化物酶、过氧化氢酶和脱氢酶的活性。毛柄小勾儿茶种子生活力低,且处于休眠状态,再加上与种子发芽力有关的几种酶的活性较低,致使毛柄小勾儿茶种子的发芽率较低,同时这些也是从种子萌发生理方面导致毛柄小勾儿茶濒危的重要原因。  相似文献   
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Abstract. We compared the diversity, phytogeography, and plant communities in two mid-latitude alpine tundras with comparable aerial and elevational extents: Changbaishan Summit in eastern Asia and Indian Peaks in western North America. Despite wide separation, the two areas shared 72 species. In all, 43% of the species on Changbaishan Summit are also distributed in the alpine zones of western North America, while 22% of the species on Indian Peaks are also distributed in the alpine zones of eastern Asia. Almost all the shared species also occur in the Beringian region. Phytogeographical profiles of species and genera showed that 69% of species and over 90% of genera in both alpine tundras belong to the three phytogeographical categories: cosmopolitan, circumpolar, and Asian-North American. We attributed the current floristic relationship between these widely separated areas to the periodic past land connection between the two continents during the Tertiary and Pleistocene. Indian Peaks has a closer floristic relationship with the Arctic tundra than does Changbaishan Summit. Indian Peaks also has 45% higher species richness and lower vegetation cover than Changbaishan Summit. Plant communities from the two areas were completely separated in the two-way indicator species analysis and non-metric multidimensional scaling on floristic data at both species and generic levels, whereas ordination of communities by soil data produced a greater overlap. The plant communities on Changbaishan Summit in general have lower alpha diversity, higher beta diversity (lower between-community floristic similarity), and more rare species than does Indian Peaks. Mosaic diversity does not differ in the two alpine tundras, although the analysis suggests that Changbaishan Summit communities are more widely spaced on gradients than the Indian Peaks communities.  相似文献   
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摘要 目的:观察电针深刺八髎穴对脾肾阳虚型溃疡性结肠炎(UC)患者的治疗效果,并探讨其作用机制。方法:选取自2020年3月~2021年2月期间天津市人民医院收治的80例脾肾阳虚型UC患者。采用随机数字表法分为对照组和研究组2组,各为40例,对照组接受常规西医治疗,研究组在常规西医治疗基础上联合电针深刺八髎穴治疗,对比两组患者疗效、中医证候积分、血清炎症因子水平、Th17/Treg细胞。结果:与对照组相比,研究组可进一步提高临床总有效率(P<0.05)。治疗2周后,研究组畏寒肢冷、腹部冷痛、晨起泄泻评分低于对照组(P<0.05)。治疗2周后,研究组血清?酌-干扰素(IFN-γ)、白介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平低于对照组(P<0.05)。治疗2周后,研究组Th17细胞水平、Th17/Treg比值低于对照组,Treg细胞水平高于对照组(P<0.05)。结论:电针深刺八髎穴可促进脾肾阳虚型UC患者症状改善,同时该治疗方案还具有调节Th17/Treg细胞免疫平衡,降低血清炎症因子水平的作用。  相似文献   
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陕西乾县第四次全国中药资源普查报告   总被引:1,自引:0,他引:1       下载免费PDF全文
以全国第四次中药资源普查为契机,通过查阅相关文献资料和野外实地走访调查,对陕西乾县药用植物资源的种类、栽培情况和药材的市场流通情况进行了初步的调查。此次调查完成36个样地共180个样方套,发现药用植物226种,涉及57科198属,其中国家重点调查品种49种,调查栽培品种8种,完成了6种药材的市场流通调查。此次普查基本摸清了乾县野生和种植中药资源的本底情况,该县域内药用植物资源物种数较第三次全国中药资源普查更丰富多样,中药材种植产业有广阔的发展前景。  相似文献   
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Multidrug resistance (MDR) refers to the cross-resistance of cancer cells to one drug, accompanied by other drugs with different mechanisms and structures, which is one of the main obstacles of clinical chemotherapy. Overexpression of P-glycoprotein (P-gp) was an extensively studied cause of MDR. Therefore, inhibiting P-gp have become an important strategy to reverse MDR. In this study, two series of triazole-tetrahydroisoquinoline-core P-gp inhibitors were designed and synthesized. Among them, compound I-5 had a remarkable reversal activity of MDR activity and the preliminary mechanism study was also carried out. All the results proved that compound I-5 was considered as a promising P-gp-mediated MDR reversal candidate.  相似文献   
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Abstract. We compared the species composition and species density of vascular plants in the understorey vegetation of boreal forest between Picea mariana (Black spruce) and Populus tremuloides (Trembling aspen) stands in British Columbia, Canada, and related differences in species composition and species density between the two forest types to dominant canopy tree species as well as a wide variety of environmental factors. We analysed 231 stands, distributed in three different climatic regions representing drier, wetter, and milder variations of montane boreal climate. Of these stands 118 were dominated by P. mariana and 113 by P. tremuloides. P. tremuloides stands had higher species density than P. mariana stands in all climatic regions, but species density of each dominance type varied among climatic regions. The floristic composition of the understorey vegetation was markedly different for P. mariana and P. tremuloides dominated stands. A detailed study on the effect of canopy dominance and local environmental factors on the understorey vegetation of the boreal forest was conducted using 88 stands from one of the three climatic regions. Using a combination of ordination and variation partitioning by constrained ordination we demonstrated a small but unique effect of canopy dominance type on the understorey vegetation, while a larger amount of compositional variation was shared with other factors. Our results accord with a scenario in which differences in primary environmental factors and humus form properties, the latter accentuated by the canopy dominants themselves, are the most important causes of higher species density in P. tremuloides stands than in P. mariana stands, as well as differences in species composition among the two canopy dominance types. Processes and time scales involved in the small but significant direct and indirect effects of the canopy dominant on understo‐ rey species composition are discussed.  相似文献   
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