全文获取类型
收费全文 | 6541篇 |
免费 | 381篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 216篇 |
妇产科学 | 125篇 |
基础医学 | 871篇 |
口腔科学 | 126篇 |
临床医学 | 515篇 |
内科学 | 1180篇 |
皮肤病学 | 78篇 |
神经病学 | 564篇 |
特种医学 | 375篇 |
外国民族医学 | 1篇 |
外科学 | 1339篇 |
综合类 | 35篇 |
预防医学 | 458篇 |
眼科学 | 137篇 |
药学 | 359篇 |
中国医学 | 1篇 |
肿瘤学 | 500篇 |
出版年
2023年 | 38篇 |
2022年 | 75篇 |
2021年 | 130篇 |
2020年 | 96篇 |
2019年 | 121篇 |
2018年 | 146篇 |
2017年 | 122篇 |
2016年 | 146篇 |
2015年 | 174篇 |
2014年 | 213篇 |
2013年 | 231篇 |
2012年 | 420篇 |
2011年 | 419篇 |
2010年 | 263篇 |
2009年 | 244篇 |
2008年 | 303篇 |
2007年 | 343篇 |
2006年 | 338篇 |
2005年 | 335篇 |
2004年 | 338篇 |
2003年 | 314篇 |
2002年 | 280篇 |
2001年 | 153篇 |
2000年 | 146篇 |
1999年 | 141篇 |
1998年 | 100篇 |
1997年 | 62篇 |
1996年 | 47篇 |
1995年 | 34篇 |
1994年 | 39篇 |
1993年 | 28篇 |
1992年 | 100篇 |
1991年 | 87篇 |
1990年 | 61篇 |
1989年 | 92篇 |
1988年 | 57篇 |
1987年 | 62篇 |
1986年 | 62篇 |
1985年 | 49篇 |
1984年 | 37篇 |
1983年 | 31篇 |
1982年 | 29篇 |
1981年 | 22篇 |
1980年 | 22篇 |
1979年 | 45篇 |
1978年 | 25篇 |
1977年 | 27篇 |
1976年 | 23篇 |
1974年 | 21篇 |
1971年 | 19篇 |
排序方式: 共有6939条查询结果,搜索用时 171 毫秒
1.
Qian Zhang Larry D. Mesner Gina M. Calabrese Naomi Dirckx Zhu Li Angela Verardo Qian Yang Robert J. Tower Marie-Claude Faugere Charles R. Farber Thomas L. Clemens 《The Journal of clinical investigation》2021,131(7)
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass. 相似文献
2.
Timo Rath Lukas Pfeifer Clemens Neufert reas Kremer Moritz Leppkes Arthur Hoffman Markus F Neurath Steffen Zopf 《World journal of gastroenterology : WJG》2020,26(16):1962-1970
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode. 相似文献
3.
4.
5.
6.
7.
Simultaneous angiographic late stent thrombosis in two different coronary vessels after withdrawal of the combined anti-platelet therapy 总被引:2,自引:2,他引:0
8.
Stefan Wirth Ekkehard Euler Ulrich Linsenmaier Sandro-Michael Heining Dorothea Kotsianos Klaus-Jürgen Pfeifer Wolf Mutschler Maximilian Reiser 《Computer aided surgery》2004,9(1-2):27-38
OBJECTIVE: To analyse the image quality and diagnostic effectiveness of a new C-arm-based 3D imaging method (C-arm-CT) for intraoperative evaluation of screw osteosyntheses adjacent to a peripheral joint. MATERIALS AND METHODS: Insertion of screws into four cadaveric specimens simulated the surgical treatment of talus neck fractures. Ten orthopedic surgeons and 10 radiologists evaluated X-ray, C-arm fluoroscopy, C-arm-CT and CT images. RESULTS: The best image quality was obtained with X-rays (p < 0.001), followed by C-arm fluoroscopy (2D) and CT, with the C-arm-CT (3D) being rated lowest (p < 0.001). The most correct diagnoses were obtained with CT and C-arm-CT (with no statistical difference between them), while C-arm-fluoroscopy was inferior (p < 0.001) and X-rays were the worst (p < 0.05). CONCLUSIONS: Even if the image quality of C-arm-CT is definitely inferior to that of CT, screw misplacements can be reliably detected using C-arm-CT. As compared to the current standard procedures (intraoperative fluoroscopy and postoperative radiography), C-arm-CT performed better. C-arm-CT is ideally suited to the intraoperative diagnosis of high-contrast inquiries like bone fragments and OS material, especially at the extremities. Coupling of the new 3D imaging to existing navigation systems is possible. C-arm-CT will support the further development and implementation of open and minimally invasive surgical procedures. 相似文献
9.
RiBSG Dr. iur. Thomas Clemens 《MedR Medizinrecht》2007,25(5):328-328
Ohne Zusammenfassung 相似文献
10.