首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2626篇
  免费   171篇
  国内免费   33篇
耳鼻咽喉   1篇
儿科学   51篇
妇产科学   34篇
基础医学   242篇
口腔科学   26篇
临床医学   237篇
内科学   503篇
皮肤病学   59篇
神经病学   226篇
特种医学   234篇
外国民族医学   1篇
外科学   298篇
综合类   80篇
一般理论   3篇
预防医学   98篇
眼科学   537篇
药学   103篇
中国医学   2篇
肿瘤学   95篇
  2022年   18篇
  2021年   33篇
  2020年   21篇
  2019年   22篇
  2018年   42篇
  2017年   37篇
  2016年   54篇
  2015年   47篇
  2014年   70篇
  2013年   124篇
  2012年   97篇
  2011年   132篇
  2010年   108篇
  2009年   79篇
  2008年   115篇
  2007年   135篇
  2006年   112篇
  2005年   102篇
  2004年   106篇
  2003年   107篇
  2002年   83篇
  2001年   56篇
  2000年   70篇
  1999年   68篇
  1998年   74篇
  1997年   71篇
  1996年   51篇
  1995年   41篇
  1994年   43篇
  1993年   47篇
  1992年   32篇
  1991年   41篇
  1990年   47篇
  1989年   57篇
  1988年   47篇
  1987年   47篇
  1986年   35篇
  1985年   22篇
  1984年   20篇
  1983年   14篇
  1982年   19篇
  1981年   18篇
  1980年   16篇
  1979年   19篇
  1977年   13篇
  1976年   13篇
  1975年   16篇
  1973年   13篇
  1972年   12篇
  1941年   11篇
排序方式: 共有2830条查询结果,搜索用时 0 毫秒
81.
Uncertainty has attended procedures for adjudging unfitness to stand trial in Victoria pursuant to the Crimes (Mental Impairment and Unfitness to be Tried) Act 1997 (Vic) and how “special hearings” should be conducted when a person is determined to be unfit to stand trial but does not wish to pursue the defence of not guilty because of mental impairment. In R v Langley [2008] VSCA 81, (2009) 19 VR 90 the Victorian Court of Appeal clarified the procedures to be employed at jury trials on such matters and quashed a decision not in conformity with proper procedures, making clear that denial of fairness to such accused persons has the potential to result in appealable error.  相似文献   
82.
83.
Pathologic myopia is a major cause of visual impairment worldwide. Pathologic myopia is distinctly different from high myopia. High myopia is a high degree of myopic refractive error, whereas pathologic myopia is defined by a presence of typical complications in the fundus (posterior staphyloma or myopic maculopathy equal to or more serious than diffuse choroidal atrophy). Pathologic myopia often occurs in eyes with high myopia, however its complications especially posterior staphyloma can also occur in eyes without high myopia.Owing to a recent advance in ocular imaging, an objective and accurate diagnosis of pathologic myopia has become possible. Especially, optical coherence tomography has revealed novel lesions like dome-shaped macula and myopic traction maculopathy. Wide-field optical coherence tomography has succeeded in visualizing the entire extent of large staphylomas. The effectiveness of new therapies for complications have been shown, such as anti-VEGF therapies for myopic macular neovascularization and vitreoretinal surgery for myopic traction maculopathy.Myopia, especially childhood myopia, has been increasing rapidly in the world. In parallel with an increase in myopia, the prevalence of high myopia has also been increasing. However, it remains unclear whether or not pathologic myopia will increase in parallel with an increase of myopia itself. In addition, it has remained unclear whether genes responsible for pathologic myopia are the same as those for myopia in general, or whether pathologic myopia is genetically different from other myopia.  相似文献   
84.
Graefe's Archive for Clinical and Experimental Ophthalmology - The present retrospective study was designed to test the hypothesis that the postoperative posterior to preoperative anterior...  相似文献   
85.
Local cooling is very common after bone and joint surgery. Therefore the knowledge of bone blood flow during local cooling is of substantial interest. Previous studies revealed that hypothermia leads to vasoconstriction followed by decreased blood flow levels. The aim of this study was to characterize if local cooling is capable of inducing reduced blood flow in bone tissue using a stepwise‐reduced temperature protocol in experimental rabbits. To examine bone blood flow we utilized the fluorescent microsphere (FM) method. In New Zealand white rabbits one randomly chosen hind limb was cooled stepwise from 32 to 2°C, whereas the contra lateral hind limb served as control. Injection of microspheres was performed after stabilization of bone and muscle temperature at each temperature level. Bones were removed, dissected and fluorescence intensity was determined to calculate blood flow values. We found that blood flow of all cooled regions decreased relative to the applied external temperature. At maximum cooling blood flow was almost completely disrupted, indicating local cooling as powerful regulatory mechanism for regional bone blood flow (RBBF). Postoperative cooling therefore may lead to strongly decreased bone blood flow values. As a result external cooling has capacity to both diminish bone healing and reduce bleeding complications. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1820–1827, 2013  相似文献   
86.

Background

Blood flow in various organs is determined by an autoregulatory mechanism that guarantees constant organ perfusion over a wide range of arterial blood pressure changes. This physiological principle has been proven for the kidney, brain and intestinal tract, but so far not for bone. This study was carried out to determine whether there is an autoregulatory mechanism of bone or not.

Methods

The fluorescent microsphere reference sample method was used to determine blood flow within the bone and kidneys. Eight anesthetized female New Zealand rabbits received left ventricular injections of fluorescent microspheres over a wide range of arterial pressure levels prior to removal of kidney, femur and tibia. Blood flow values were calculated by measurement of fluorescence intensity in kidney and bone and correlated to fluorescence intensity in the peripheral blood (reference sample).

Results

Despite a reduction of mean arterial pressure from 100 to 80 mmHg bone blood flow remained constant. Further reduction of mean arterial pressure results in a linear decrease in bone blood flow.

Conclusion

The correlation between arterial pressure and organ perfusion in the bone is similar to blood flow within the kidney, indicating the presence of an autoregulated blood flow mechanism within the bone tissue.  相似文献   
87.
88.
89.
90.
Sir, We were highly interested in the case report published by Nakauchi-Tanakaet al. (2003), reporting a factor VIII inhibitor in ovarianhyperstimulation syndrome (OHSS). Briefly, acquired haemophilia is a rare disease most often dueto the development of autoantibodies directed against factorVIII that interfere with its coagulant function. The incidenceis about 1 per million persons per year. Acquired haemophiliamay occur in association with autoimmune diseases such as systemiclupus erythematosus or rheumatoid arthritis, neoplastic diseases,drug hypersensitivity and pregnancy. However, 50% of the casesremain idiopathic. Post-partum factor VIII inhibitors most oftendisappear  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号