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   4033篇
  免费   246篇
  国内免费   9篇
耳鼻咽喉   14篇
儿科学   199篇
妇产科学   86篇
基础医学   492篇
口腔科学   56篇
临床医学   400篇
内科学   900篇
皮肤病学   85篇
神经病学   366篇
特种医学   318篇
外科学   295篇
综合类   34篇
一般理论   1篇
预防医学   451篇
眼科学   72篇
药学   180篇
中国医学   10篇
肿瘤学   329篇
  2023年   24篇
  2022年   26篇
  2021年   79篇
  2020年   56篇
  2019年   106篇
  2018年   125篇
  2017年   56篇
  2016年   72篇
  2015年   96篇
  2014年   127篇
  2013年   194篇
  2012年   224篇
  2011年   236篇
  2010年   161篇
  2009年   163篇
  2008年   220篇
  2007年   221篇
  2006年   217篇
  2005年   197篇
  2004年   186篇
  2003年   162篇
  2002年   127篇
  2001年   69篇
  2000年   61篇
  1999年   53篇
  1998年   87篇
  1997年   90篇
  1996年   73篇
  1995年   61篇
  1994年   67篇
  1993年   69篇
  1992年   26篇
  1991年   32篇
  1990年   31篇
  1989年   53篇
  1988年   54篇
  1987年   37篇
  1986年   44篇
  1985年   42篇
  1984年   17篇
  1983年   32篇
  1982年   29篇
  1981年   28篇
  1980年   30篇
  1979年   12篇
  1978年   20篇
  1977年   19篇
  1976年   17篇
  1975年   23篇
  1967年   4篇
排序方式: 共有4288条查询结果,搜索用时 281 毫秒
1.
2.
3.
4.
Conventional risk factors have very low predictive power in identifying haemodialysis patients at high risk of vascular accidents. A role for apolipoprotein E isotypes was looked for in a small, but rigorously defined, cohort of longterm haemodialysis patients. In individuals with high vascular risk, as identified by higher common carotid intima/media thickness, we found an excess of apolipoprotein E4 alleles. This preliminary result requires confirmation in large patient cohorts.   相似文献   
5.
Most lesions in FD and their attendant functional disability occur within the first decade; 90% of lesions are present by 15 years, and the median age when assistive devices are needed is 7 years. These findings have implications for prognosis and determining the timing and type of therapy. INTRODUCTION: Fibrous dysplasia of bone (FD) is an uncommon skeletal disorder in which normal bone is replaced by abnormal fibro-osseous tissue. Variable amounts of skeletal involvement and disability occur. The age at which lesions are established, the pace at which the disease progresses, if (or when) the disease plateaus, and how these parameters relate to the onset of disability are unknown. To answer these questions, we performed a retrospective analysis of a group of subjects with FD. MATERIALS AND METHODS: One hundred nine subjects with a spectrum of FD were studied for up to 32 years. Disease progression was assessed in serial (99)Tc-MDP bone scans by determining the location and extent of FD lesions using a validated bone scan scoring tool. Physical function and the need for ambulatory aids were assessed. RESULTS: Ninety percent of the total body disease skeletal burden was established by age 15. Disease was established in a region-specific pattern; in the craniofacial region, 90% of the lesions were present by 3.4 yr, in the extremities, 90% were present by 13.7 yr, and in the axial skeleton, 90% were present by 15.5 yr. Twenty-five of 103 subjects eventually needed ambulatory aids. The median age at which assistance was needed was 7 yr (range, 1-43 yr). The median bone scan score for subjects needing assistance was 64.3 (range, 18.6-75) compared with 23.1 (range, 0.5-63.5) in the unassisted subjects (p < 0.0001). Among subjects needing assistance with ambulation, 92% showed this need by 17 yr. CONCLUSIONS: The majority of skeletal lesions and the associated functional disability occur within the first decade of life. The implication is that the window of time for preventative therapies is narrow. Likewise, therapeutic interventions must be tailored to where the patient is in the natural history of the disease (i.e., progressive disease [young] versus established disease [older subjects]). These findings have implications for prognosis, the timing and type of therapy, and the development of trials of new therapies and their interpretation.  相似文献   
6.
Studies were done to compare the acute effects of streptozotocin-induced diabetes and sucrose consumption on micturition, bladder mass and contractile responses of bladder strips to field stimulation and contractile agonists. Micturition changes occurred gradually in diabetic rats, reached maximal values within 7 to 14 days, and were accompanied by significant increases in bladder mass after 7 days. Bladder strips from diabetics responded to field stimulation, carbachol and KCl with significantly greater contractions than did those from controls within 7 days. Sucrose-drinking rats had maximal increases in fluid consumption and micturition frequency on the first night after starting treatment. Increases in micturition volumes were slower to develop than in diabetics. Bladder mass was significantly increased 30 and 60 days after starting sucrose treatment. Bladder strips from sucrose-drinking rats responded to field stimulation and carbachol with significantly greater contractions than did those from controls only after 60 days. Monitoring of drinking and micturition patterns established that diabetic rats drink and urinate during both the dark and light cycles. In contrast, control and sucrose-drinking rats drink and urinate principally at night. The results demonstrate that differences in bladder function between diabetic and sucrose drinking rats are apparent during the first month after treatment begins. The data suggest that the effects of diabetes and sucrose consumption on contractile bladder function are related to the diuresis-induced increases in bladder mass.  相似文献   
7.
8.
9.
10.
A 56-yr-old woman with long-standing rheumatoid arthritis exhibited jaundice, pruritus and abdominal discomfort after 8 yr of periodic gold sodium thiomalate injections amounting to a cumulative dose in excess of 2.5 gm. Histopathological examination of the liver biopsy specimen showed submassive loss of parenchyma, collapse of reticulin and mixed cellular inflammatory infiltrates. Macrophages contained dark granules, which displayed the characteristics of aurosomes when examined by transmission electron microscopy and electron microprobe analysis. It is likely that hepatocellular injury occurred when the lysosomal storage capacity for gold was exceeded.  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