全文获取类型
收费全文 | 58974篇 |
免费 | 7185篇 |
国内免费 | 3338篇 |
专业分类
耳鼻咽喉 | 245篇 |
儿科学 | 487篇 |
妇产科学 | 236篇 |
基础医学 | 1934篇 |
口腔科学 | 336篇 |
临床医学 | 3509篇 |
内科学 | 2742篇 |
皮肤病学 | 647篇 |
神经病学 | 1149篇 |
特种医学 | 691篇 |
外国民族医学 | 6篇 |
外科学 | 1938篇 |
综合类 | 15744篇 |
现状与发展 | 8篇 |
一般理论 | 1篇 |
预防医学 | 2822篇 |
眼科学 | 504篇 |
药学 | 8848篇 |
91篇 | |
中国医学 | 26617篇 |
肿瘤学 | 942篇 |
出版年
2024年 | 607篇 |
2023年 | 1306篇 |
2022年 | 2398篇 |
2021年 | 3078篇 |
2020年 | 2976篇 |
2019年 | 1823篇 |
2018年 | 1515篇 |
2017年 | 2496篇 |
2016年 | 2635篇 |
2015年 | 2436篇 |
2014年 | 5408篇 |
2013年 | 4394篇 |
2012年 | 5305篇 |
2011年 | 5318篇 |
2010年 | 4445篇 |
2009年 | 3261篇 |
2008年 | 2633篇 |
2007年 | 3029篇 |
2006年 | 2450篇 |
2005年 | 2026篇 |
2004年 | 1650篇 |
2003年 | 1402篇 |
2002年 | 1210篇 |
2001年 | 1079篇 |
2000年 | 885篇 |
1999年 | 643篇 |
1998年 | 447篇 |
1997年 | 455篇 |
1996年 | 374篇 |
1995年 | 320篇 |
1994年 | 261篇 |
1993年 | 164篇 |
1992年 | 184篇 |
1991年 | 170篇 |
1990年 | 120篇 |
1989年 | 93篇 |
1988年 | 98篇 |
1987年 | 68篇 |
1986年 | 61篇 |
1985年 | 50篇 |
1984年 | 52篇 |
1983年 | 27篇 |
1982年 | 37篇 |
1981年 | 23篇 |
1980年 | 16篇 |
1979年 | 16篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 9篇 |
1975年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
采用聚乙烯硫酸(PVS)沉淀法测定血清低密度脂蛋白胆固醇(LDL-C)值,同时应用Friedewald公式计算LDL-C含量,并对两法结果进行比较分析,提出当甘油三脂(TG)<4.52mmol/L时,F公式计算法可代替PVS法,当TG>4.52mmol/L时,不宜用F公式计算LDL-C的值。 相似文献
42.
Summary— The regulation and role of the intracellular Ca2+ pools were studied in rat peritoneal mast cells. Cytosolic free calcium concentration ([Ca2+ ]i) was monitored in fura-2 loaded mast cells. In the presence of Ca2+ and K+, compound 48/80 induced a biphasic increase in [Ca2+ ]i composed of a fast transient phase and an apparent sustained phase. The sustained phase was partially inhibited by the addition of Mn2+ . DTPA, a cell-impermeant chelator of Mn2+ , reversed this inhibition, suggesting that a quenching of fura-2 fluorescence occurs in the extracellular medium. In the absence of extracellular Ca2+ , the transient phase, but not the sustained one, could be preserved, provided that mast cells were depolarized. The transient phase was completely abolished by thapsigargin, a microsomal Ca2+ -ATPase inhibitor. Maximum histamine release induced by either compound 48/80 or antigen was obtained in the absence of added Ca2+ only when mast cells were depolarized. These histamine releases were inhibited by low doses (< 30 nM) of thapsigargin. Thapsigargin at higher doses induced histamine release which was unaffected by changing the plasma membrane potential, but was completely dependent on extracellular Ca2+ , showing that a Ca2+ influx is required for thapsigargin-induced exocytosis. Together, these results suggest that the mobilization of Ca2+ from thapsigargin sensitive-intracellular pools induced by compound 48/80 or antigen is sufficient to trigger histamine release. The modulation of these pools by the plasma membrane potential suggest their localization is close to the plasma membrane. 相似文献
43.
特安瑞林(Treplorelin)的致突变与致畸作用的研究陆其明(上海医科大学公共卫生学院,200032)特安瑞林(Treplorelin,D-Trp-6-LHRH)是一种用于治疗子宫肌瘤的新药,其药理作用能促进性腺激素释放,使子宫内膜脱落和子宫肌瘤... 相似文献
44.
Background : A retrospective analysis of 103 case records from 1978 to 1996 with a provisional diagnosis of Buerger's disease was undertaken at the Department of Surgery, University of Hong Kong, Queen Mary Hospital. The aim of the study was to elucidate the clinical course and evaluate the results of surgical intervention of Buerger's disease in Hong Kong Chinese people. Methods : Fourteen patients were subsequently excluded from the study because of inability to fulfil our diagnostic criteria. Data on clinical presentation, investigations, indications and results of surgical intervention were reviewed. Sympathectomies and arterial reconstructions were performed on 42 and four patients, respectively, for critical ischaemia or rest pain. Outcome was analysed with respect to the rate of ulcer healing, pattern of recurrence and limb loss. Results : The patients were all young male heavy smokers with a mean age of 36.5 years. The majority of patients (80%) presented with ischaemic ulceration or gangrene. Vascular reconstruction was undertaken in four patients and satisfactory long-term results were obtained in three patients. Sympathectomy was able to relieve symptoms in 87% of operated patients and ischaemic ulceration healed in 2.6 (mean) ± 1.7 (SD) months after the operation. If the patient continued to smoke, surgical intervention did not exempt the patient from a relapse or amputation. Conclusion : Sympathectomy provides short-term pain relief and promotes ulcer healing in patients with Buerger's disease but carries no long-term benefit. Complete abstinence from smoking is the only means of arresting the progression of the disease. 相似文献
45.
本文用中草药红背丝绸醇提物、乙酸乙脂提取物和单体CA-1201 三种不同成分对ET-1 在动物整体及离体水平生物学效应的拮抗作用进行了研究。结果发现:这三种成分对ET-1 致小鼠进行死亡有保护作用,使得小鼠的死亡率及死亡数下降;并可拮抗ET-1 致胸主动脉的缩血管效应,醇提物和乙酸乙脂提取物(10- 7母液)拮抗ET 缩血管效应分别为57.27% 和58.61% ;CA-1201 10- 8和10- 9 M 亦能拮抗ET-1 的缩血管效应;醇提物和乙酸乙脂提取物口服及CA-1201 静脉注射后能拮抗ET-1 的升压作用,拮抗ET-1 作用均呈现明显的剂量依赖性。提示中草药红背丝绸不同成分可拮抗ET-1 的生物学效应。 相似文献
46.
47.
理气类中药对大鼠离体胃平滑肌条的作用 总被引:9,自引:0,他引:9
目的:观察理气类中药对大鼠离体胃平滑肌条运动的影响。方法:将肌条放置在灌流肌槽中,用生理记录仪记录肌条的收缩活动。结果:陈皮、枳实对胃各部位平滑肌条均为抑制效应,香附、薤白、木香、柿蒂、乌药对胃底肌条为兴奋效应,但对其他部位肌条则表现为兴奋或抑制不同的效应,沉香仅降低胃窦环行肌收缩波平均振幅,对其他肌条无影响。结论:理气类中药对大鼠离体胃平滑肌条既有兴奋作用,也有抑制作用。 相似文献
48.
49.
本文简述了中药炮炙的根据、原理、方法以及各种不同辅料和炮炙方法对饮片药性与作用的影响。说明不同的炮炙方法可以直接影响和改变中药的药性和作用,影响到临床疗效,因此,必须重视中药饮片的炮炙工作。以确保临床安全有效的用药。 相似文献
50.
本文采用高效液相色谱法测定了四种中成药中淫羊藿甙的含量。以十八烷基硅烷键合硅胶为填料,柱温30℃;甲醇-0.2mol/L磷酸二氢钠水溶液(磷酸调pH=2.7)(57:43)为流动相,1ml/min;检测波长为268nm,淫羊藿甙色谱峰形对称、分离度好。所测补肾强身片、龟龄集、壮骨关节丸和前列宁冲剂中淫羊藿甙的含量分别为0.105%,0.0995%,0.0566%,0.313%。 相似文献