全文获取类型
收费全文 | 294368篇 |
免费 | 59630篇 |
国内免费 | 13551篇 |
专业分类
耳鼻咽喉 | 3256篇 |
儿科学 | 6816篇 |
妇产科学 | 2637篇 |
基础医学 | 44150篇 |
口腔科学 | 8812篇 |
临床医学 | 38047篇 |
内科学 | 52277篇 |
皮肤病学 | 9677篇 |
神经病学 | 23351篇 |
特种医学 | 10850篇 |
外国民族医学 | 94篇 |
外科学 | 35266篇 |
综合类 | 38752篇 |
现状与发展 | 50篇 |
一般理论 | 50篇 |
预防医学 | 19695篇 |
眼科学 | 6191篇 |
药学 | 30189篇 |
198篇 | |
中国医学 | 13645篇 |
肿瘤学 | 23546篇 |
出版年
2024年 | 790篇 |
2023年 | 3217篇 |
2022年 | 8323篇 |
2021年 | 11813篇 |
2020年 | 12599篇 |
2019年 | 16856篇 |
2018年 | 16621篇 |
2017年 | 17558篇 |
2016年 | 17989篇 |
2015年 | 21044篇 |
2014年 | 23252篇 |
2013年 | 23684篇 |
2012年 | 21056篇 |
2011年 | 22258篇 |
2010年 | 21742篇 |
2009年 | 15827篇 |
2008年 | 14752篇 |
2007年 | 13568篇 |
2006年 | 12414篇 |
2005年 | 11235篇 |
2004年 | 8605篇 |
2003年 | 8420篇 |
2002年 | 7308篇 |
2001年 | 5969篇 |
2000年 | 5047篇 |
1999年 | 4106篇 |
1998年 | 2375篇 |
1997年 | 2477篇 |
1996年 | 1736篇 |
1995年 | 1702篇 |
1994年 | 1470篇 |
1993年 | 1002篇 |
1992年 | 1280篇 |
1991年 | 1135篇 |
1990年 | 994篇 |
1989年 | 929篇 |
1988年 | 784篇 |
1987年 | 700篇 |
1986年 | 671篇 |
1985年 | 501篇 |
1984年 | 419篇 |
1983年 | 326篇 |
1982年 | 290篇 |
1981年 | 252篇 |
1980年 | 210篇 |
1979年 | 216篇 |
1978年 | 199篇 |
1977年 | 220篇 |
1976年 | 199篇 |
1974年 | 167篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
本研究拟探讨染料木黄酮对前列腺癌细胞LNCaP和CWR22RV1的增殖、迁移和侵袭能力的影响。一、材料与方法1.材料:前列腺癌细胞株LNCaP和CWR22RV1(中国科学院上海生命科学研究院);Genistein(天津科瑞泰科技有限公司);RPMI 1640、胎牛血清(FBS)、胰蛋白酶(美国Gibco公司);E-钙黏蛋白(E-cadherin)、N-钙黏蛋白(N-cadherin)、波形蛋白(Vimentin,Abcam公司);聚氰基丙烯酸正丁酯(BCA)试剂盒、十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)上样缓冲液(×5)及蛋白质印迹法(Western blot)试剂盒(上海市碧云天生物公司);2.实验方法:采用噻唑蓝(MTT)实验、划痕实验和Transwell实验检测Genistein对细胞增殖、迁移及侵袭能力的影响。采用Western blot检测E-cadherin、N-cadherin、Vimentin、CD44和Oct-4的表达水平。 相似文献
93.
94.
95.
96.
97.
Yuanqing Yao Jun Qian Shunkang Rong Yuwen Huang Bo Xiong Gang Yang Dengqing Zhang Shimin Deng Jie Tan Que Zhu Changming Deng Dichuan Liu Haitao Ran Zhigang Wang Jing Huang 《Ultrasound in medicine & biology》2019,45(2):490-499
Stellate ganglion (SG) modification has been investigated for arrhythmia treatment. In this study, transesophageal SG imaging and intervention were explored using a homemade 30F integrated focused ultrasonic catheter in healthy mongrel canines in vivo. Anatomic details of SGs were ultrasonically imaged and evaluated. SG had a heterogeneous echoic structure and characteristic profiles sketched by hyper-echoic outlines in an ultrasonogram. Left SGs in the experimental group were successfully ablated through the esophagus under ultrasonic guidance provided by the catheter itself. Two weeks after the ablation, the QT and QTc of the experimental group decreased compared with those of the sham group and at baseline (both p values < 0.001). Histologic examination revealed that left SGs were destroyed. No major complications were observed. This approach may be further explored as a method for ganglia remodeling evaluation and as a strategy of ganglia modification for arrhythmia and for other diseases. 相似文献
98.
A typical time series in functional magnetic resonance imaging (fMRI) exhibits autocorrelation, that is, the samples of the time series are dependent. In addition, temporal filtering, one of the crucial steps in preprocessing of functional magnetic resonance images, induces its own autocorrelation. While performing connectivity analysis in fMRI, the impact of the autocorrelation is largely ignored. Recently, autocorrelation has been addressed by variance correction approaches, which are sensitive to the sampling rate. In this article, we aim to investigate the impact of the sampling rate on the variance correction approaches. Toward this end, we first derived a generalized expression for the variance of the sample Pearson correlation coefficient (SPCC) in terms of the sampling rate and the filter cutoff frequency, in addition to the autocorrelation and cross‐covariance functions of the time series. Through simulations, we illustrated the importance of the variance correction for a fixed sampling rate. Using the real resting state fMRI data sets, we demonstrated that the data sets with higher sampling rates were more prone to false positives, in agreement with the existing empirical reports. We further demonstrated with single subject results that for the data sets with higher sampling rates, the variance correction strategy restored the integrity of true connectivity. 相似文献
99.
Micro‐evolution of the hepatitis B virus genome in hepatitis B e‐antigen‐positive carriers: Comparison of genotypes B and C at various immune stages 下载免费PDF全文
100.