全文获取类型
收费全文 | 387643篇 |
免费 | 36572篇 |
国内免费 | 26871篇 |
专业分类
耳鼻咽喉 | 3493篇 |
儿科学 | 4537篇 |
妇产科学 | 5498篇 |
基础医学 | 45322篇 |
口腔科学 | 6834篇 |
临床医学 | 53027篇 |
内科学 | 57320篇 |
皮肤病学 | 3770篇 |
神经病学 | 21053篇 |
特种医学 | 14599篇 |
外国民族医学 | 236篇 |
外科学 | 39503篇 |
综合类 | 64302篇 |
现状与发展 | 87篇 |
一般理论 | 22篇 |
预防医学 | 25515篇 |
眼科学 | 11256篇 |
药学 | 39981篇 |
381篇 | |
中国医学 | 22658篇 |
肿瘤学 | 31692篇 |
出版年
2024年 | 1260篇 |
2023年 | 5879篇 |
2022年 | 15194篇 |
2021年 | 19181篇 |
2020年 | 14436篇 |
2019年 | 12617篇 |
2018年 | 13310篇 |
2017年 | 12001篇 |
2016年 | 11194篇 |
2015年 | 17053篇 |
2014年 | 21323篇 |
2013年 | 19305篇 |
2012年 | 28330篇 |
2011年 | 31499篇 |
2010年 | 20526篇 |
2009年 | 16261篇 |
2008年 | 21290篇 |
2007年 | 21236篇 |
2006年 | 21019篇 |
2005年 | 20038篇 |
2004年 | 13356篇 |
2003年 | 12196篇 |
2002年 | 10384篇 |
2001年 | 9059篇 |
2000年 | 9423篇 |
1999年 | 9840篇 |
1998年 | 5896篇 |
1997年 | 5943篇 |
1996年 | 4654篇 |
1995年 | 4190篇 |
1994年 | 3465篇 |
1993年 | 2254篇 |
1992年 | 2944篇 |
1991年 | 2527篇 |
1990年 | 2213篇 |
1989年 | 1930篇 |
1988年 | 1631篇 |
1987年 | 1404篇 |
1986年 | 1151篇 |
1985年 | 936篇 |
1984年 | 540篇 |
1983年 | 390篇 |
1982年 | 248篇 |
1981年 | 243篇 |
1980年 | 191篇 |
1979年 | 224篇 |
1978年 | 84篇 |
1977年 | 89篇 |
1974年 | 104篇 |
1973年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Context: Baicalin has many pharmacological activities, including protective function against myocardial ischemia by antioxidant effects and free radical scavenging activity. However, its rapid elimination half-life in plasma and poor water solubility limits its clinical efficacy.Objective: Novel baicalin-loaded PEGylated nanostructured lipid carriers (BN-PEG-NLC) were developed to improve bioavailability of BN, to prolong retention time in vivo and to enhance its protective effect.Methods: In this study, BN-PEG-NLC were prepared by the emulsion-evaporation and low temperature-solidification method using a mixture of glycerol monostearate and polyethylene glycol monostearate as solid lipids, and oleic acid as the liquid lipid. The physicochemical properties of NLC were characterized. The pharmacokinetic and pharmacodynamic behaviors of BN-PEG-NLC or BN-NLC were evaluated in acute MI rats.Results and discussion: The particle size, zeta potential, and entrapment efficiency for BN-PEG-NLC were observed as 83.9?nm, ?32.1?mV, and 83.5%, respectively. The release profiles of BN from both BN-PEG-NLC and BN-NLC were fitted to the Ritger–Peppas modal, which presented burst release initially and prolonged release afterwards. Pharmacokinetics results indicated that BN-PEG-NLC exhibited a 7.2-fold increase in AUC in comparison to BN solution, while a 3-fold increase in comparison to BN-NLC. Biodistribution results revealed that BN-PEG-NLC exhibited higher heart drug concentration compared with BN-NLC as well as BN solution. In the present study, BN-PEG-NLC significantly ameliorated infarct size.Conclusion: The results of the present study imply that PEG-NLC could be the biocompatible carriers for heart-targeted drug delivery to improve myocardial ischemia. 相似文献
73.
74.
A mixed‐method study of effects of a therapeutic play intervention for children on parental anxiety and parents' perceptions of the intervention
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
75.
An-feng TAO Zheng-hao XU Cheng-hao WU Yi WANG Wei-wei HOU Shi-hong ZHANG Zhong CHEN 《浙江大学学报(医学版)》2015,44(3):315
目的观察比较不同脉冲波形的低频率电刺激对海马电点燃癫痫模型小鼠的作用差异。方法采用电点燃刺激法建立小鼠癫痫模型, 观察正弦波、单相方波、双相方波低频率电刺激对模型小鼠癫痫行为发作及后放电持续时间的影响, 并比较不同时间点给予正弦波低频率电刺激的抗癫痫作用。结果与对照组比较, 正弦波低频率电刺激30 s能降低小鼠海马电点燃癫痫发作等级(2.85 ± 0.27 vs 4.75 ±0.12, P < 0.05)、减少大发作概率(53.6% vs 96.5%, P < 0.01) 和缩短后放电持续时间[(16.22 ± 1.69) s vs (30.29 ± 1.12) s, P < 0.01], 而单相方波和双相方波低频率电刺激30 s没有明显的抗癫痫作用。常用的单相方波低频率电刺激15 min能降低小鼠海马电点燃发作等级(3.58 ± 0.16, P < 0.05)、减少大发作概率(66.7%, P < 0.01);但对海马后放电持续时间及大发作持续时间无影响(均 P>0.05)。此外, 电点燃刺激前预先给予或结束后3 s内给予正弦波低频率电刺激具有明显的抗癫痫作用( P < 0.05或 P < 0.01), 而电点燃刺激结束10 s给予正弦波低频率电刺激则无上述抗癫痫作用。 结论低频率电刺激抗癫痫作用受波形参数的影响, 其中正弦波低频率电刺激能有效抑制小鼠海马电点燃癫痫的发作。 相似文献
76.
77.
Shengxuan Cao Chen Wang Xin Ma Xu Wang Jiazhang Huang Chao Zhang Li Chen Xiang Geng Kan Wang 《Journal of orthopaedic research》2019,37(8):1860-1867
Patients with mechanic ankle instability experience increased tibiotalar and subtalar joint laxity. However, in vivo joint kinematics in functional ankle instability (FAI) patients and lateral ankle sprain (LAS) copers, especially during dynamic activities, are poorly understood. Ten FAI patients, 10 LAS copers, and 10 healthy controls were included in this study. A dual fluoroscopic imaging system was used to analyze the tibiotalar and subtalar joint kinematics during stair descent. Five key poses of stair descent were analyzed. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint positions in each degree of freedom were compared among the three groups. The tibiotalar joints of FAI patients and LAS copers were significantly more inverted than those of healthy controls during the foot strike (p = 0.016, = 0.264). The subtalar joints of FAI patients were significantly more anteriorly translated (pose 2, p = 0.003, = 0.352; pose 3, p < 0.001, = 0.454; pose 4, p = 0.004, = 0.334), inverted (pose 4, p = 0.027, = 0.234; pose 5,p = 0.034, = 0.221), and externally rotated (pose 4, p = 0.037, = 0.217; pose 5; p = 0.004, = 0.331) than those of healthy controls during the mid‐stance and the heel off. The FAI patients showed excessive tibiotalar inversion and subtalar joint hypermobility during stair descent. Meanwhile, the LAS copers maintained subtalar joint stability, and only showed excessive tibiotalar inversion in foot strike. These data provide insight into the mechanisms behind the development of FAI after initial LAS. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1860–1867, 2019 相似文献
78.
79.
80.