全文获取类型
收费全文 | 15288篇 |
免费 | 1104篇 |
国内免费 | 372篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 207篇 |
妇产科学 | 165篇 |
基础医学 | 1698篇 |
口腔科学 | 139篇 |
临床医学 | 624篇 |
内科学 | 2250篇 |
皮肤病学 | 245篇 |
神经病学 | 860篇 |
特种医学 | 313篇 |
外国民族医学 | 1篇 |
外科学 | 1030篇 |
综合类 | 2069篇 |
预防医学 | 716篇 |
眼科学 | 160篇 |
药学 | 2366篇 |
中国医学 | 3045篇 |
肿瘤学 | 824篇 |
出版年
2024年 | 53篇 |
2023年 | 177篇 |
2022年 | 364篇 |
2021年 | 414篇 |
2020年 | 336篇 |
2019年 | 684篇 |
2018年 | 679篇 |
2017年 | 489篇 |
2016年 | 351篇 |
2015年 | 396篇 |
2014年 | 634篇 |
2013年 | 799篇 |
2012年 | 766篇 |
2011年 | 867篇 |
2010年 | 665篇 |
2009年 | 647篇 |
2008年 | 650篇 |
2007年 | 726篇 |
2006年 | 628篇 |
2005年 | 470篇 |
2004年 | 443篇 |
2003年 | 464篇 |
2002年 | 404篇 |
2001年 | 432篇 |
2000年 | 290篇 |
1999年 | 245篇 |
1998年 | 169篇 |
1997年 | 174篇 |
1996年 | 104篇 |
1995年 | 101篇 |
1994年 | 84篇 |
1993年 | 76篇 |
1992年 | 67篇 |
1991年 | 63篇 |
1990年 | 61篇 |
1989年 | 53篇 |
1987年 | 50篇 |
1985年 | 271篇 |
1984年 | 389篇 |
1983年 | 265篇 |
1982年 | 268篇 |
1981年 | 244篇 |
1980年 | 204篇 |
1979年 | 219篇 |
1978年 | 171篇 |
1977年 | 97篇 |
1976年 | 165篇 |
1975年 | 135篇 |
1974年 | 90篇 |
1973年 | 82篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Aims
Aqueous extracts from the roots of Glycyrrhiza glabra L. (Fabaceae) are widely used for treatment of stomach ulcer. The clinical proven effects are related to the presence of anti-inflammatory 12-keto-triterpensaponins in the extracts. Apart from that the influence of Glycyrrhiza glabra extract on the bacterial adhesion of Helicobacter pylori to stomach tissue was to be investigated. Additionally the influence of Glycyrrhiza glabra secondary compounds on the bacterial adhesion of Porphyromonas gingivalis, a major pathogen for induction of periodontal inflammations was to be investigated.Methodology
In vitro cytotoxicity against Helicobacter pylori was investigated by agar diffusion assay; antiadhesive properties of aqueous extract, raw polysaccharides and purified polysaccharide fractions was investigated by means of an in situ adhesion assay with FITC-labelled bacteria on tissue slides of human stomach resectates.Results
Aqueous extract (1 mg/mL) of Glycyrrhiza glabra significantly inhibited the adhesion of Helicobacter pylori to human stomach tissue. This effect was related to the polysaccharides isolated from the extract, with one purified acidic fraction (0.25 SPB) as main active polymer. Purified polysaccharides did not exhibit direct cytotoxic effects against Helicobacter pylori and did not influence hemagglutination. Additionally raw polysaccharides from Glycyrrhiza glabra were shown to have strong antiadhesive effects against Porphyromonas gingivalis.Conclusion
Aqueous extracts and polysaccharides from the roots of Glycyrrhiza glabra are strong antiadhesive systems, which may be used as potent tools for a further development of cytoprotective preparations with anti-infectious potential. 相似文献993.
Anwar H. Gilani Abdul J. Shah Amina Zubair Sana Khalid Jawad Kiani Amir Ahmed Munawwer Rasheed Viqar U. Ahmad 《Journal of ethnopharmacology》2009
Aim of the study
The study was aimed to investigate the chemical composition and pharmacological basis for traditional use of essential oil of Nepeta cataria L. (Limiaceae) (Nc.Oil) in gastrointestinal and respiratory disorders.Materials and methods
Chemical analysis was carried out through GC-EIMS, 13C NMR and Kovats Retention Indices while pharmacological study was carried out in isolated tissues preparations.Results
Four major components; 1,8-cineol (21.00%), α-humulene (14.44%), α-pinene (10.43%) and geranyl acetate (8.21%) were identified among the 27 compounds in Nc.Oil. In isolated rabbit jejunum, Nc.Oil, papaverine and verapamil inhibited spontaneous and high K+(80 mM) precontractions, as well as shifted the Ca++ concentration–response curves (CRCs) to right, indicating calcium channel blocking activity. In isolated guinea-pig trachea, Nc.Oil and papaverine inhibited carbachol (1 μM) and K+ precontractions with similar potency, while verapamil was more potent against K+. Nc.Oil also potentiated isoprenaline inhibitory CRCs, similar to papaverine, indicating papaverine-like PDE inhibitor activity. In isolated guinea-pig atria, Nc.Oil caused cardiodepression at around 25–80 times higher concentrations, similar to papaverine.Conclusions
These data indicate that Nepeta cataria possesses spasmolytic and myorelaxant activities mediated possibly through dual inhibition of calcium channels and PDE, which may explain its traditional use in colic, diarrhea, cough and asthma. 相似文献994.
Occhiuto F Palumbo DR Samperi S Zangla G Pino A De Pasquale R Circosta C 《Phytotherapy research : PTR》2009,23(2):192-196
Oxidative stress-induced neuronal cell death has been implicated in different neurological disorders and neurodegenerative diseases such as Alzheimer's disease and Parkinson's. Using the Alzheimer's disease-associated hydrogen peroxide (H(2)O(2)), we investigated the neuroprotective efficacy of a natural mixture of phytoestrogenic isoflavones (genistein, daidzein, biochanin A and formononetin) from Trifolium pratense L. (Red clover) against oxidative stress-induced cell death in human cortical cell line HCN 1-A maintained in culture. Neuronal viability was determined by MTT or trypan blue test and neuronal integrity by morphological analysis.The results obtained indicate that exposure of HCN 1-A cell cultures to hydrogen peroxide resulted in a concentration-dependent decrease in neuron viability. Concentration of H(2)O(2) ranging from 50 to 200 microg/ml were toxic to these cultures. A 24-hour pretreatment with 0.5, 1 and 2 microg/ml isoflavones extract significantly increased cell survival as evidenced by MTT or trypan blue test and significantly prevented the morphological disruption caused by H(2)O(2) as shown by microscopical inspection, indicating that neurons treated with isoflavones were protected from the cell death induced by H(2)O(2) exposure. These findings imply that the neuroprotective effect of isoflavones extract is partly associated with its antioxidant activity. Further, results of these investigations indicate that although isoflavones extract exert a neuroprotective effect, it do not promoted cortical neuron process outgrowth. 相似文献
995.
996.
目的 观察清热祛瘀颗粒对冠心病伴颈动脉易损斑块患者的治疗作用。方法 82例稳定性劳力型心绞痛伴颈动脉易损斑块患者中医辨证属痰热血瘀型者,随机分为清热祛瘀颗粒加西医常规治疗的试验组(41例)和采用西医常规治疗加安慰剂治疗的对照组(41例),共观察25周。采用高频超声检测颈动脉复杂斑块的数目、简单斑块的数目、斑块的Crouse积分及颈动脉内中膜的厚度,观察清热祛瘀颗粒对颈动脉斑块及血浆高敏C反应蛋白(hs-CRP)、CD40L变化及肝肾功能。结果 试验组治疗后颈动脉复杂斑块的数目、斑块的Crouse积分、颈动脉内中膜的厚度较治疗前为低,差异均有统计学意义(P<0.05);颈动脉斑块的Crouse积分、颈动脉内中膜的厚度也较对照组治疗后为低,差异亦有统计学意义(P<0.05), 试验组治疗后hs-CRP及CD40L与治疗前及对照组治疗后比较,差异均有统计学意义(P<0.05,P<0.01)。治疗过程中未见明显不良反应。结论 清热祛瘀颗粒对冠心病伴颈动脉易损斑块患者的颈动脉斑块具有一定的稳定作用。 相似文献
997.
不同产地罗布麻叶中原花色素的含量测定 总被引:1,自引:0,他引:1
目的:测定不同产地罗布麻叶中原花色素的含量,并对不同产地的罗布麻叶进行比较。方法:采用分光光度法测定氯化花色素,测定波长为545nm。结果:天津产罗布麻叶中原花色素含量最高,新疆的最低。天津、山东、山西、陕西和新疆5个不同产地罗布麻叶中原花色素含量依次为10.95%,7.96%,7.30%,6.56%,2.16%。结论:不同产地罗布麻叶中的原花色素含量差异明显,应选择使用。 相似文献
998.
槌果藤软膏治疗银屑病的实验研究 总被引:1,自引:1,他引:0
目的:观察槌果藤软膏对银屑病动物模型的疗效及其抗炎、止痒等作用。方法:观察计数小鼠尾部给药后鳞片表皮颗粒层形成情况;计数处于有丝分裂中期的阴道基底细胞有丝分裂数,并换算成有丝分裂指数;观察记录右旋糖苷致小鼠瘙痒次数及瘙痒持续时间;测定二甲苯致小鼠耳廓肿胀程度;测定小鼠腹腔毛细血管炎性渗出。结果:槌果藤软膏对小鼠尾部鳞片表皮颗粒层的形成具有显著的促进作用;可明显抑制小鼠阴道上皮细胞有丝分裂;能明显缓解右旋糖苷引起的小鼠瘙痒;减轻二甲苯致小鼠耳肿胀程度并抑制小鼠腹腔毛细血管通透性增高。结论:槌果藤软膏对小鼠银屑病模型有显著的治疗作用,并具有抗炎、止痒等作用。 相似文献
999.
越鞠胶囊与贯叶连翘抗抑郁作用的对比研究 总被引:1,自引:0,他引:1
目的:研究越鞠胶囊、贯叶连翘的抗抑郁作用。方法:采用小鼠悬尾实验、小鼠强迫游泳实验、利血平诱导小鼠体温下降实验和开场实验研究越鞠胶囊、贯叶连翘的抗抑郁作用。结果:在小鼠悬尾实验中,越鞠胶囊大剂量组、贯叶连翘大、中剂量组能明显缩短模型小鼠的不动时间;在小鼠强迫游泳实验中,越鞠胶囊、贯叶连翘各剂量组能明显缩短模型小鼠的不动时间;在利血平诱导的体温下降实验中,越鞠胶囊大剂量组、贯叶连翘大、中剂量组能明显抑制小鼠体温的下降;实验表明贯叶连翘提取物的作用效价强度要大于越鞠胶囊。结论:越鞠胶囊、贯叶连翘有一定的的抗抑郁作用,贯叶连翘提取物的作用效价强度要大于越鞠胶囊。 相似文献
1000.
笔者对毛茛科铁线莲属植物化学成分研究进行了综述。铁线莲属植物化学成分比较复杂,化学结构类型包括三萜、黄酮、木脂素、香豆素、生物碱、挥发油、甾体、有机酸、大环化合物及酚类等,其中三萜皂苷、黄酮、木脂素是主要的结构类型。铁线莲属植物中的三萜皂苷主要为齐墩果酸型和常春藤皂苷元型,其中大部分为苷元的3位和28位均连有糖链的双糖链苷,只有少数为苷元的3位或28位接糖链的单糖链苷,有些皂苷的糖链上还有乙酰基(Ac)、咖啡酰基(CA)、异阿魏酰基(IF)、对甲氧基桂皮酰基(MC)和3,4-二甲氧基桂皮酰基(DMC)等取代基。其中的黄酮按结构类型可分为黄酮(苷)、黄酮醇(苷)、二氢黄酮(苷)、异黄酮(苷)和酮,既有氧糖苷,也有碳糖苷,其苷元主要为芹菜素、山柰酚、木犀草素和槲皮素。该属植物中的木脂素有Eupomtene型、环木脂素、单环氧木脂素、双环氧木脂素和木脂内酯。铁线莲属植物资源广泛,目前尚有必要进一步拓展其研究范围,以便更好地对其进行开发利用。 相似文献