全文获取类型
收费全文 | 220557篇 |
免费 | 5392篇 |
国内免费 | 3604篇 |
专业分类
耳鼻咽喉 | 1418篇 |
儿科学 | 7013篇 |
妇产科学 | 3458篇 |
基础医学 | 21842篇 |
口腔科学 | 2264篇 |
临床医学 | 19051篇 |
内科学 | 37645篇 |
皮肤病学 | 1232篇 |
神经病学 | 18855篇 |
特种医学 | 10773篇 |
外国民族医学 | 23篇 |
外科学 | 32917篇 |
综合类 | 9922篇 |
现状与发展 | 15篇 |
一般理论 | 7篇 |
预防医学 | 20813篇 |
眼科学 | 4171篇 |
药学 | 14277篇 |
81篇 | |
中国医学 | 3438篇 |
肿瘤学 | 20338篇 |
出版年
2024年 | 120篇 |
2023年 | 766篇 |
2022年 | 1729篇 |
2021年 | 2608篇 |
2020年 | 1954篇 |
2019年 | 1657篇 |
2018年 | 23522篇 |
2017年 | 18741篇 |
2016年 | 20812篇 |
2015年 | 3036篇 |
2014年 | 3394篇 |
2013年 | 3048篇 |
2012年 | 10293篇 |
2011年 | 24685篇 |
2010年 | 21038篇 |
2009年 | 13269篇 |
2008年 | 21828篇 |
2007年 | 24088篇 |
2006年 | 2918篇 |
2005年 | 4639篇 |
2004年 | 4760篇 |
2003年 | 5583篇 |
2002年 | 3516篇 |
2001年 | 1349篇 |
2000年 | 1539篇 |
1999年 | 1354篇 |
1998年 | 971篇 |
1997年 | 990篇 |
1996年 | 700篇 |
1995年 | 663篇 |
1994年 | 606篇 |
1993年 | 355篇 |
1992年 | 412篇 |
1991年 | 389篇 |
1990年 | 402篇 |
1989年 | 315篇 |
1988年 | 280篇 |
1987年 | 240篇 |
1986年 | 172篇 |
1985年 | 138篇 |
1984年 | 68篇 |
1983年 | 58篇 |
1982年 | 43篇 |
1980年 | 52篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1935年 | 22篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 562 毫秒
11.
Jianhui Su Chaoyang Ma Chengxiang Liu Chuanzhong Gao Rongjing Nie 《International journal of food sciences and nutrition》2016,67(1):20-28
This study investigated the hypocholesterolaemic effects of bitter melon aqueous extracts (BMAE) in vitro, the inhibitory effects of BMAE on pancreatic cholesterol esterase (CEase) and incorporation of cholesterol into micelles were investigated. BMAE decreased the in vitro micellar solubility of cholesterol in a dose-dependent manner. The conformation of CEase was investigated by means of circular dichroism (CD) and fluorescence. The result revealed the decrease of α-helix contents, increase of β-sheet and exposure of aromatic amino acid residuals. The incorporation of cholesterol into micelles was inhibited by BMAE. A complex was observed by transmission electron microscopy (TEM), which indicated interaction between cholesterol and BMAE. The result revealed that BMAE can play a role in decreased intestinal cholesterol absorption via inhibition of CEase, and of micelle formation. 相似文献
12.
13.
目的评估血肌酐和尿常规的常规检测基础上联合血清胱抑素C和尿微量白蛋白检测在人类免疫缺陷病毒(HIV)感染者肾功能损伤检测中的应用价值。
方法以2019年2~5月于首都医科大学附属北京地坛医院感染一科住院的169例HIV感染者为研究对象,完善其尿常规、尿微量白蛋白、血肌酐、血清胱抑素C检测;分析尿蛋白及尿微量白蛋白的阳性检出率及其差异,血肌酐升高及血清胱抑素C升高的比例及其差异。计算应用替诺福韦酯(TDF)及合并丙型肝炎、高血压、糖尿病、肿瘤的肾功能损伤的相对危险度。
结果169例HIV感染者中尿常规示尿蛋白阳性者5例(3.0%),尿微量白蛋白升高者17例(10.1%),两者阳性检出率差异具有统计学意义(χ2 = 5.9、P = 0.007)。血肌酐升高者10例(5.9%),血清胱抑素C升高者20例(11.8%),两者阳性检出率差异具有统计学意义(χ2 = 3.0、P = 0.042)。在尿常规和血肌酐检测的基础上联合检测尿微量白蛋白和血清胱抑素C的总体阳性检出率为49例(30.0%)。CD4+ T淋巴细胞计数< 200个/μl与≥ 200个/μl组患者血清胱抑素C水平分别为0.94(0.83,1.05)mg/L、0.85(0.77,0.95)mg/L,差异具有统计学意义(Z =-3.02、P = 0.003)。应用TDF及合并丙型肝炎、高血压、糖尿病、肿瘤的肾功能损伤的相对危险度分别为1.1、1.5、1.9、2.2和1.4。
结论HIV感染者中,单纯以尿常规为依据评估有无蛋白尿,以血肌酐水平为依据评估肾小球滤过功能会低估肾功能损伤的患病率。在常规检测血肌酐和尿常规的基础上联合检测血清胱抑素C和尿微量白蛋白在提高HIV感染者肾功能损伤检出率方面具有重要的应用价值。低CD4+ T淋巴细胞计数、应用TDF及合并丙型肝炎、高血压、糖尿病、肿瘤均为肾功能损伤的危险因素。 相似文献
15.
16.
17.
N. S. Hari Narayana Moorthy Sergio F. Sousa Maria J. Ramos Pedro A. Fernandes 《Medicinal chemistry research》2016,25(7):1340-1357
Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets. 相似文献
18.
Valerie Iles 《Health care analysis》2016,24(2):105-118
This paper takes a somewhat slant perspective on flourishing and care in the context of suffering, death and dying, arguing that care in this context consists principally of ‘acts of work and courage that enable flourishing’. Starting with the perception that individuals, society and health care professionals have become dulled to death and the process of dying in Western advanced health systems, it suggests that for flourishing to occur, both of these aspects of life need to be faced more directly. The last days of life need to be ‘undulled’. Reflections upon the experiences of the author as carer and daughter in the face of her mother’s experience of death are used as basis for making suggestions about how care systems and professionals might better assist people in dealing with ‘the most grown up thing’ humans ever do, which is to die. 相似文献
19.
20.