共查询到19条相似文献，搜索用时 93 毫秒
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不同药物对大鼠心肌缺血模型作用效果的比较 总被引：2，自引：0，他引：2
利用硝酸甘油、二硝酸异山梨醇、人参二醇组总皂甙有人参皂甙单体Rb1观察它们对大鼠心肌缺血模型的影响。结果表明：人参二醇组总皂甙及人参皂甙单体Rb1在一定剂量条件下对心肌缺血的恢复作用要明显高于硝酸甘油及二硝酸异山梨醇（异舒吉），反映在疗效显著、时间短，从而能够有效地抑制大鼠心肌缺血。 相似文献
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珠子参(Panax japonicus C.A.Meyer var.major(Burk.)Wu et Feng)是五加科人参属植物,产于东喜马拉雅至我国西部山区。在云南西北部海拔3000—4000米的亚高山针叶林和落叶阔叶林下可呈片生长。民间用其根茎治疗跌打损伤、筋骨疼痛、毒蛇咬伤,及止咳祛痰、止血等。最近,我们从珠子参根茎中分离到七个皂甙成分,经鉴定其中五个为已知化合物,即:人参甙(ginsenside)Ro(9)、竹节参甙(chikuse_tsuaponin)Ⅳ_α(10)、20-O-葡萄糖基-人参甙R_f(20-O-gluco-ginsenoside Rf)(5)、 相似文献
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从重楼属植物五指莲Paris axialis H.Li.根茎中分离到三个甾体皂甙,经化学降解,质谱,核磁共振谱分析,证明其中两个甙为新的化合物,即偏诺皂甙元-3-O-β-D-葡萄吡喃糖基(1→3)[α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖甙(Ⅰ)和24α-羟基偏诺皂甙元-3-O-β-D-葡萄吡喃糖基(1→3)][α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖(Ⅲ);另一个鉴定为薯芋皂甙元-3-O-β-D-葡萄吡喃糖基(1→3)[α-L-鼠李吡喃糖基(1→2)]-β-D-葡萄吡喃糖甙(Ⅱ)。 相似文献
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本文针对丹东地区家参质量的气相色谱评价方法进行研究。对人参中的主要作用成份达玛烷型皂甙的主要水解产物人参三醇和人参二醇在一定的气相色谱条件下进行分析检测。并对人参的鲜样和干样进行提取比较。该项研究为丹东地区的家参产业的进一步发展提供了科学的方法和手段 相似文献
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蒋自立 《遵义师范学院学报》2012,14(4):84-86
利用7种植物病原真菌对人参皂苷Rb1进行生物转化,通过薄层层析法检测,结果表明：有6种真菌能将人参皂苷Rb1转化为Rd1但只有齐整小核菌的转化高效而彻底,其他几种转化效率低或副产物多。 相似文献
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在解变力作用下的物理问题,常常利用变力的算术平均值(F_1+F_2)/2来定量地求解.这种平均力求解是有条件的,即:计算冲量I=(?)((F_1+F_2)/2)t中,F应是t的一次函数;计算做功W=(?)s=((F_1+F_2)/2)s中,F应是s的一次函数. 相似文献
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从羽裂华蟹甲草的根(siacalin tangutica maxim)中分离得到6个化合物,根据波谱数据和标样对照分别鉴定为:(1)硬酯酸,(2)正十六酸,(3)常春皂甙元-3-O-α-L-吡喃鼠李糖基(1→2)-α-L-吡喃阿拉伯糖甙,(4)Acteoside,(5)"-谷甾醇,(6)"-谷甾醇甙。本文为首次报道该植物的化学成份。 相似文献
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人参皂苷药理活性的研究进展 总被引：33，自引：0，他引：33
人参化学成分复杂 ,生物活性广泛 ,药理作用独特 ,目前从人参中提取出的成分有皂苷、糖类、蛋白质、低分子肽、多胺、氨基酸、有机酸、维生素、脂肪酸、果胶、β-谷甾醇等。医学和药理研究证明 ,人参皂苷为人参的主要有效成分之一 ,它是人参根的主要生理活性物质。目前 ,用色谱法从人参及其地上部分共分离得到 39个人参皂苷。把总皂苷称为人参皂苷Ｒｘ ,按硅胶薄层色谱Ｒｆ 值的大小顺序由小到大将每一组分命名为Ｒｏ、Ｒａ、Ｒｂ1、Ｒｂ2 、Ｒｂ3 、Ｒｃ、Ｒｄ、Ｒｅ、Ｒｆ、Ｒｇ1、Ｒｇ2 、Ｒｇ3 、Ｒｈ1、Ｒｈ2 和Ｒｈ3 等。但最近几年对… 相似文献
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本实验考察了基因工程茵Ecoli TOP10F’重组质粒pBAD／gⅢA—NTF2的稳定性。结果表明,该基因工程菌在连续传代30代后,质粒的目的基因片断没有缺失,具有结构稳定性;在无抗生素选择压力下,经传10代后,菌株的质粒没发生质粒丢失现象,20代后各代菌种质粒保有率低于100％,但50代后的菌种质粒保有率仍高达88％。因此,表现出一定的分离稳定性。该基因工程菌在优化培养基和优化条件下的整个发酵过程中,始终表现出良好的结构和分离稳定性。 相似文献
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拉格朗日中值定理是微积分学中一个重要定理,对于拉格朗日中值定理的证明,关键是构造一个辅助函数F(X),使F(X)满足罗尔定理的条件f(a)=f(b),由罗尔定理证得结果。 相似文献
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The purpose of this study was to compare the effects of four item selection rules—(1) Fisher information (F), (2) Fisher information with a posterior distribution (FP), (3) Kullback-Leibler information with a posterior distribution (KP), and (4) completely randomized item selection (RN)—with respect to the precision of trait estimation and the extent of item usage at the early stages of computerized adaptive testing. The comparison of the four item selection rules was carried out under three conditions: (1) using only the item information function as the item selection criterion; (2) using both the item information function and content balancing; and (3) using the item information function, content balancing, and item exposure control. When test length was less than 10 items, FP and KP tended to outperform F at extreme trait levels in Condition 1. However, in more realistic settings, it could not be concluded that FP and KP outperformed F, especially when item exposure control was imposed. When test length was greater than 10 items, the three nonrandom item selection procedures performed similarly no matter what the condition was, while F had slightly higher item usage. 相似文献
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Huan-huan Pang Meng-yi Li Yuan Wang Min-ke Tang Chang-hua Ma Jian-mei Huang 《Journal of Zhejiang University. Science. B》2017,18(4):343-352
Fufang Xueshuantong (FXT) is a well-known Chinese herbal formula which has been used to treat cardiovascular and ophthalmic diseases, especially diabetic retinopathy. Panax notoginseng (Burkill) F.H. Chen (PN) is the main herb of FXT, whose major bioactive constituents are ginsenosides. However, the scientific basis of the compatibility of FXT is still ambiguous. The present study investigated the scientific basis of the compatibility of FXT by comparing the pharmacokinetics of marker compounds after oral administrations of PN and FXT. A high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method was developed for simultaneous detection of notoginsenoside R1 (NR1), ginsenoside Rg1 (GRg1), and ginsenoside Rb1 (GRb1) in rat plasma. The pharmacokinetic studies of FXT and PN were performed using the established method with the pharmacokinetic parameters being determined by non-compartmental analysis. The results showed that the pharmacokinetic parameters (maximum concentration, area under the curve (AUC0–t ), clearance, and mean residence time) of NR1, GRg1, and GRb1 were significantly different after oral administration of FXT (P<0.05) compared with PN. The AUC0–t values of GRg1 and GRb1 were 1.7- and 3.4-fold greater, respectively, in FXT than in PN. The compatible herbs of FXT could prolong the retention time and increase the systemic exposure of NR1, GRg1, and GRb1 compared with PN in vivo, providing some scientific basis for the compatibility and clinical use of FXT. 相似文献
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1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｉｎｒｅｃｅｎｔｙｅａｒｓ ,ｈｉｇｈ ｐｏｗｅｒｌａｓｅｒｄｉｏｄｅｓｈａｖｅｂｅｅｎｅｍｐｌｏｙｅｄａｓｐｕｍｐｉｎｇｓｏｕｒｃｅｓｗｉｔｈａｖｉｅｗｔｏｄｅｖｅｌｏｐｃｏｍｐａｃｔｕｐ ｃｏｎｖｅｒｓｉｏｎｖｉｓｉｂｌｅ ｌａｓｅｒｓｙｓｔｅｍｓ .Ｔｈｅｆｒｅ ｑｕｅｎｃｙｃｏｎｖｅｒｓｉｏｎｏｆｉｎｆｒａｒｅｄｌｉｇｈｔｔｏｖｉｓｉｂｌｅｌｉｇｈｔｈａｓｂｅｅｎｅｘｔｅｎｓｉｖｅｌｙｉｎｖｅｓｔｉｇａｔｅｄｆｏｒｒａｒｅ ｅａｒｔｈｄｏｐｅｄｃｒｙｓｔａｌｓａｎｄｇ… 相似文献
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《British Journal of Educational Studies》2012,60(2):129-138
ABSTRACT Since 9/11 the European Court of Human Rights (the European Court) has raised anew the question of the relationship between religion and public education. In its reasoning, the European Court has had to consider competing normative accounts of the secular, either to accept or deny claims to religious liberty within Europe's public education system. This article argues that the trajectory on which the term ‘secularism’ had been used by the European Court pointed increasingly towards secular fundamentalism. This study is located at the cutting edge of religion, education and the law and builds on previous work in the field (Arthur, 1998, 2008). It examines, through extensive research of legal cases, the most important developments of the usage of secular and secular education in modern discourse and explores the background to these concepts. Unless otherwise stated, religion in this article shall refer to the Christian tradition because Christianity has been the historical context for the development of the concept of ‘secular’ in Europe. The paper outlines three models of secular education before moving on to scrutinise how the European Court has understood and evaluated various legal cases before it on the interaction between secular States, public education and notions of religious symbolism and influence. The paper will discuss the significance of the European Court's reasoning and decisions for public education within a secular State context and offer some conclusions on the implications of these decisions. It examines the legal principles that underpin the European Court's supervision of the State's role in the provision of education. It focuses on the chimeric goal of neutrality and highlights the risks attached to the use of an ideological conception of secularism that could lead potentially to the complete removal of the religious as a vital cultural and intellectual dimension of public education. 相似文献
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游离UMP系RNase催化PNA水解反应特有的水解产物,两者呈正相关．常规品种紫壳的幼穗和叶片无论在花粉母细胞形成期还是在花粉母细胞减数分裂期,在不同温度（育性条件）下,游离UMP的含量都很接近,统计学检验表明均无显著差异．1356S和衡农S—2在两个育性敏感时期,在不同育性条件下叶片中游离UMP含量也无显著差异．但幼穗在育性敏感时期──花粉母细胞形成期．花粉母细胞减数分裂期不育条件下游离UMP含量分别是可育条件下含量的3．20、2．99、3．12、3．23倍,极显著高于可育件下的含量,游离UMP含量的变化与RNase活力相吻合．两者的变化趋势-致． 相似文献
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雷州半岛南部近40万年以来的古植被与古生态——田洋湖钻孔孢粉数值分析 总被引：2，自引：0，他引：2
雷州半岛火山湖盆地第四系沉积的孢粉化石较完整地记录了近40万年以来的植被历史。本文用数值分析的方法探讨了田洋钻孔孢粉植物群的演变规律和古生态特征。根据有序样品最优分割的结果共综合成1个全新世孢粉带和7个更新世孢粉带(含14个亚带)。并利用R型聚类分析、对应分析探讨了各类建群植物的相互依存关系及其生态群特征。 相似文献