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   39041篇
  免费   2857篇
  国内免费   120篇
耳鼻咽喉   366篇
儿科学   1080篇
妇产科学   697篇
基础医学   5597篇
口腔科学   649篇
临床医学   4061篇
内科学   8259篇
皮肤病学   778篇
神经病学   4051篇
特种医学   1406篇
外国民族医学   13篇
外科学   5336篇
综合类   444篇
一般理论   30篇
预防医学   3403篇
眼科学   738篇
药学   2731篇
中国医学   93篇
肿瘤学   2286篇
  2023年   312篇
  2022年   506篇
  2021年   983篇
  2020年   678篇
  2019年   905篇
  2018年   1080篇
  2017年   863篇
  2016年   980篇
  2015年   1026篇
  2014年   1400篇
  2013年   1737篇
  2012年   2735篇
  2011年   2852篇
  2010年   1610篇
  2009年   1352篇
  2008年   2185篇
  2007年   2333篇
  2006年   2223篇
  2005年   2018篇
  2004年   1914篇
  2003年   1615篇
  2002年   1494篇
  2001年   639篇
  2000年   658篇
  1999年   611篇
  1998年   350篇
  1997年   267篇
  1996年   258篇
  1995年   233篇
  1994年   193篇
  1993年   154篇
  1992年   337篇
  1991年   323篇
  1990年   328篇
  1989年   265篇
  1988年   268篇
  1987年   292篇
  1986年   311篇
  1985年   299篇
  1984年   234篇
  1983年   200篇
  1982年   137篇
  1981年   136篇
  1979年   255篇
  1978年   180篇
  1977年   163篇
  1976年   140篇
  1974年   142篇
  1973年   148篇
  1972年   135篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
11.
We thank Coceani and L'Abbate for their comments on our paper.We concur that ‘pathophysiology cannot be inferred fromcoronary lumenography alone’, and this was one of thekey motivations in conducting the present study.  相似文献   
12.
There have been major advances in PET technology that cumulatively have helped improve image quality, increased the range of applications for PET, and contributed to the more widespread use of PET. Examples of these technologic advances include whole-body imaging, 3-dimensional imaging, new scintillator materials, iterative reconstruction algorithms, combined PET/CT, and preclinical PET. New advances on the immediate horizon include the reintroduction of time-of-flight PET, which takes advantage of the favorable timing properties of newer scintillators; the integration of PET and MRI scanners into a dual-modality imaging system; and the possibility of further significant improvements in spatial resolution in preclinical PET systems. Sensitivity remains a limiting factor in many PET studies. Although, conceptually, huge gains in sensitivity are still possible, realizing these gains is thwarted largely by economic rather than scientific concerns. Predicting the future is fraught with difficulty; nonetheless, it is apparent that ample opportunities remain for new development and innovation in PET technology that will be driven by the demands of molecular medicine, notably sensitive and specific molecular diagnostic tools and the ability to quantitatively monitor therapeutic entities that include small molecules, peptides, antibodies, nanoparticles, DNA/RNA, and cells.  相似文献   
13.
14.
M Balázs  G Vadász  I Koncz  E Simon 《Orvosi hetilap》1991,132(39):2143-2146
15 patients with congestive gastropathy were reported including clinical and pathological characteristics of the disease. Every patient had alcoholic liver cirrhosis and portal hypertension. 6 patient's stomach was resected while in 2 further cases the disease was found at autopsy. In additional 7 cases the characteristic microvascular changes were observed in endoscopic biopsy specimens from the gastric mucosa. The authors presume that this disease has an acute and a chronic stage. In the acute stage dilated capillaries are present under the surface, not related to the inflammation of gastric mucosa. This phenomenon was described in the literature. In the chronic stage there are dilated and tortuous vessels in the submucosal layer surrounded by collagenous connective tissue. The authors suppose that the thick and fibrotic submucosal layer causes microcirculatory disturbances in the gastric mucosa. The impaired microcirculation may cause extensive ulcers with profuse and sometimes lethal bleeding.  相似文献   
15.
16.
17.
During a 17-month period we treated in situ 334 patients with ureteric stones with a second-generation electromagnetic lithotriptor. Anxiety and discomfort were relieved with diazepam and pethidine chloride only. Ureteral stenting was used in 8.1% of upper, 36.4% of mid- and 5.7% of lower ureteric stones. The retreatment rate was 15%, but no patient had more than 3 sessions. The success rate of the treatment at 3 months was 88% for upper, 65% for mid- and 83% for lower ureteric stones. Open surgery had to be performed in 5 cases and ureteroscopies in 6 cases.  相似文献   
18.
A comparative study of three subgroups of meniscal transplants was undertaken in the goat model: Group 1 (autograft) involved removal and immediate reimplantation of the meniscus; Group 2, fresh meniscal allografts; and Group 3, cryopreserved (30 days) meniscal allografts. Six months after surgery, tissues were evaluated for gross degenerative changes, proteoglycan concentration (as assessed by uronic acid), water content, vascularity, histology, and cell viability. The contralateral knee served as control for all comparisons. There was no statistical difference in the amount of arthritis present and all transplants demonstrated an essentially normal peripheral vascularity compared to controls. Sections revealed reduced numbers of cells in the central portions of the transplanted menisci and these viable cells demonstrated different behavior in multiplication in tissue culture compared to contralateral controls. Grossly and microscopically, the implanted menisci differed little from the controls. The measurement of proteoglycan concentration and water content of the transplanted meniscal cartilage suggest alterations that may affect the long-term mechanical properties. The autograft specimens showed the water content was very slightly increased (3% to 6%), while the proteoglycan concentration was increased (42% in terms of uronic acid). In contrast, the water content of the fresh allograft group and the cryopreserved group was increased 12% to 24%. Proteoglycan concentration in these groups was decreased up to 56% in portions of some menisci compared to controls. Fresh and cryopreserved meniscal allografts showed peripheral healing, revascularization, cellularity, and incorporation, and grossly appeared good at 6 months in the goat model. The biochemical changes in the extracellular matrix at 6 months raises questions on the long-term function of these transplanted menisci.  相似文献   
19.
The ultrasonographic characteristics of an epidermoid cyst of the testicle are presented. Since these, findings are similar to other published case reports, preoperative sonographic diagnosis of this lagon may be possible.  相似文献   
20.
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