全文获取类型
收费全文 | 9485篇 |
免费 | 620篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 142篇 |
儿科学 | 207篇 |
妇产科学 | 272篇 |
基础医学 | 1338篇 |
口腔科学 | 94篇 |
临床医学 | 865篇 |
内科学 | 1711篇 |
皮肤病学 | 420篇 |
神经病学 | 655篇 |
特种医学 | 321篇 |
外科学 | 1546篇 |
综合类 | 130篇 |
一般理论 | 6篇 |
预防医学 | 751篇 |
眼科学 | 271篇 |
药学 | 583篇 |
中国医学 | 11篇 |
肿瘤学 | 816篇 |
出版年
2022年 | 59篇 |
2021年 | 141篇 |
2020年 | 58篇 |
2019年 | 120篇 |
2018年 | 149篇 |
2017年 | 96篇 |
2016年 | 118篇 |
2015年 | 150篇 |
2014年 | 235篇 |
2013年 | 376篇 |
2012年 | 464篇 |
2011年 | 466篇 |
2010年 | 277篇 |
2009年 | 270篇 |
2008年 | 440篇 |
2007年 | 489篇 |
2006年 | 492篇 |
2005年 | 469篇 |
2004年 | 480篇 |
2003年 | 502篇 |
2002年 | 461篇 |
2001年 | 63篇 |
2000年 | 67篇 |
1999年 | 81篇 |
1998年 | 110篇 |
1997年 | 111篇 |
1996年 | 83篇 |
1995年 | 82篇 |
1994年 | 88篇 |
1993年 | 87篇 |
1992年 | 53篇 |
1990年 | 57篇 |
1988年 | 51篇 |
1987年 | 69篇 |
1986年 | 58篇 |
1984年 | 67篇 |
1983年 | 78篇 |
1982年 | 88篇 |
1981年 | 94篇 |
1980年 | 73篇 |
1979年 | 58篇 |
1978年 | 52篇 |
1977年 | 53篇 |
1976年 | 53篇 |
1975年 | 51篇 |
1933年 | 53篇 |
1932年 | 52篇 |
1931年 | 50篇 |
1922年 | 51篇 |
1913年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
Computer-assisted LISS plate osteosynthesis of proximal tibia fractures: feasibility study and first clinical results. 总被引:1,自引:0,他引:1
Paul Alfred Grützner Frank Langlotz Guoyan Zheng Jan von Recum Christina Keil Lutz P Nolte Andreas Wentzensen Klaus Wendl 《Computer aided surgery》2005,10(3):141-149
Fluoroscopy is the most common tool for the intraoperative control of long-bone fracture reduction. Limitations of this technology include high radiation exposure for the patient and the surgical team, limited visual field, distorted images, and cumbersome verification of image updating. Fluoroscopy-based navigation systems partially address these limitations by allowing fluoroscopic images to be used for real-time surgical localization and instrument tracking. Existing fluoroscopy-based navigation systems are still limited as far as the virtual representation of true surgical reality is concerned. This article, for the first time, presents a reality-enhanced virtual fluoroscopy with radiation-free updates of in situ surgical fluoroscopic images to control metaphyseal fracture reduction. A virtual fluoroscopy is created using the projection properties of the fluoroscope; it allows the display of detailed three-dimensional (3D) geometric models of surgical tools and implants superimposed on the X-ray images. Starting from multiple registered fluoroscopy images, a virtual 3D cylinder model for each principal bone fragment is constructed. This spatial cylinder model not only supplies a 3D image of the fracture, but also allows effective fragment projection recovery from the fluoroscopic images and enables radiation-free updates of in situ surgical fluoroscopic images by non-linear interpolation and warping algorithms. Initial clinical experience was gained during four tibia fracture fixations that were treated by LISS (Less Invasive Stabilization System) osteosynthesis. In the cases operated on, after primary image acquisition, the image intensifier was replaced by the virtual reality system. In all cases, the procedure including fracture reduction and LISS osteosynthesis was performed entirely in virtual reality. A significant disadvantage was the unfamiliar operation of this prototype software and the need for an additional operator for the navigation system. 相似文献
64.
Edward D Moloney Jim J Egan Peter Kelly Alfred E Wood Leslie T Cooper 《The Journal of heart and lung transplantation》2005,24(8):1103-1110
Myocarditis is a major cause of end-stage heart failure and is responsible for up to 10% of cases of idiopathic dilated cardiomyopathy (IDC). Worldwide, approximately 45% of all heart transplants are performed for IDC and up to 8% for myocarditis. Early reports suggested that survival after transplantation for myocarditis was poor and patients had an increased risk of rejection. More recently, larger case series suggest that overall survival after transplantation for myocarditis is similar to survival after transplantation for other causes. However, certain disorders, including cardiac sarcoidosis and giant cell myocarditis (GCM), require heightened surveillance for post-transplantation disease recurrence. We present the case of a 42-year-old man with recurrence of GCM 8 years after transplantation and review the literature on the role of cardiac transplantation for patients with myocarditis. 相似文献
65.
Dr. med. Alfred Martin 《Journal of neurology》1922,75(1-3):103-110
Ohne Zusammenfassung 相似文献
66.
Alfred Falkenberg 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1883,19(2-3):338-338
Ohne Zusammenfassung 相似文献
67.
68.
Percutaneous absorption of 2,6-di-tert-butyl-4-nitrophenol (DBNP) in isolated perfused porcine skin.
Alfred O Inman Kenneth R Still Warren W Jederberg Robert L Carpenter Jim E Riviere James D Brooks Nancy A Monteiro-Riviere 《Toxicology in vitro》2003,17(3):289-292
DBNP (2,6-di-tert-butyl-4-nitrophenol) has been reported as a potential contaminant in submarines. This yellow substance forms when lubrication oil mist containing the antioxidant additive 2,6-di-tert-butylphenol passes through an electrostatic precipitator and is nitrated. Percutaneous absorption of 14C-DBNP was assessed in the isolated perfused porcine skin flap (IPPSF). Four treatments were studied (n=4 flaps/treatment): 40.0 microgram/cm(2) in 100% ethanol; 40.0 microgram/cm(2) in 85% ethanol/15% H(2)O; 4.0 microgram/cm(2) in 100% ethanol; and 4.0 microgram/cm(2) in 85% ethanol/15% water. DBNP absorption was minimal across all treatment groups, with the highest absorption detected being only 1.08% applied dose in an aqueous ethanol group. The highest mass of 14C-DBNP absorbed was only 0.5 microgram. The majority of the applied dose remained on the surface of the skin. This suggests that there is minimal dermal exposure of DBNP when exposed topically to skin. 相似文献
69.
Genetically modified fibroblasts induce angiogenesis in the rat epigastric island flap 总被引:2,自引:0,他引:2
H.-G. Machens Jeffrey R. Morgan Francois Berthiaume Peter Stefanovich Ralf Reimer Alfred C. Berger 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》1998,383(5):345-350
Methods: Gene therapy was tested for inducing functional angiogenesis in the superficial rat epigastric island flap to allow earlier
pedicle division. Autologous rat fibroblasts were grown, harvested, cultured and retrovirally transfected to produce platelet-derived
growth factor AA (PDGF-AA), an angiogenetically active protein. Stable gene expression was monitored by PDGF-AA enzyme-linked
immunosorbent assay (ELISA). One hundred and eighty animals were divided into three groups (I–III) and a bilateral flap created
in each animal. In all experiments, the right-sided flap was subjected to experimental treatment and the left-sided flap served
as control (1 ml saline 0.9%). During flap elevation, group I received 5×106 GMFB (genetically modified fibroblasts) plus 1 ml Dul-becco's modified Eagle's medium. Group II was treated with 5×106 NMFB (non-modified fibroblasts) plus 1 ml medium and group III received 1 ml medium only. The flaps were sutured back and
the vascular pedicle was bilaterally ligated and divided in each of ten animals during the following 6 days. After 7 days,
the flaps were harvested, the amount of necrosis measured and histologically examined. Results: The GMFB produced up to 560 times more PDGF-AA than the NMFB, measured by ELISA. The GMFB-treated flaps tolerated surgical
division of the vascular pedicle significantly earlier than groups II and III. Histologically, fibroblasts persisted in all
flaps of groups I and II, without major inflammatory reaction. In all GMFB-treated flaps, massive angiogenesis could be demonstrated.
Conclusion: By means of retroviral gene transfer, autologous rat fibroblasts can be genetically modified for stable expression of the
PDGF-A gene to produce high amounts of PDGF-AA, which is angiogenetically active. After injection into the panniculus carnosus,
these cells induce functional angiogenesis to permit earlier division of the vascular pedicle in this flap model.
Received: 5 January 1998 / Accepted: 17 June 1998 相似文献
70.
Antimycotic Agents, XX Bioisosteric 6-Arylpyrimidine Derivatives Condensation of N-(2-hydroxyethyl)-N-methylguanidine-sulfate ( 1 ) with the β-diketones 4a - e bearing 1-aryl substituents leads to the bioisosteric 2-[(2-hydroxyethyl)-methylamino]-6-arylpyrimidines 5a - e . Compounds 5a - c exhibit significant antimycotic in vivo and in vitro activities. 相似文献