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   2624篇
  免费   271篇
  国内免费   17篇
耳鼻咽喉   28篇
儿科学   92篇
妇产科学   43篇
基础医学   438篇
口腔科学   165篇
临床医学   302篇
内科学   551篇
皮肤病学   58篇
神经病学   215篇
特种医学   147篇
外科学   317篇
综合类   22篇
一般理论   3篇
预防医学   194篇
眼科学   51篇
药学   162篇
中国医学   3篇
肿瘤学   121篇
  2023年   37篇
  2022年   15篇
  2021年   42篇
  2020年   46篇
  2019年   50篇
  2018年   89篇
  2017年   90篇
  2016年   95篇
  2015年   113篇
  2014年   117篇
  2013年   228篇
  2012年   154篇
  2011年   148篇
  2010年   134篇
  2009年   73篇
  2008年   87篇
  2007年   108篇
  2006年   101篇
  2005年   91篇
  2004年   110篇
  2003年   78篇
  2002年   85篇
  2001年   36篇
  2000年   15篇
  1999年   21篇
  1998年   51篇
  1997年   34篇
  1996年   35篇
  1995年   36篇
  1994年   21篇
  1993年   16篇
  1992年   19篇
  1991年   18篇
  1990年   12篇
  1989年   22篇
  1988年   19篇
  1987年   17篇
  1986年   21篇
  1985年   19篇
  1984年   26篇
  1982年   22篇
  1981年   13篇
  1980年   19篇
  1979年   16篇
  1978年   15篇
  1977年   14篇
  1955年   39篇
  1954年   90篇
  1949年   22篇
  1948年   17篇
排序方式: 共有2912条查询结果,搜索用时 406 毫秒
71.
72.
73.
74.
Magnetic resonance imaging of peripheral joints in rheumatic diseases   总被引:2,自引:0,他引:2  
The need for better methods than the conventional clinical, biochemical and radiographical examinations in the management of inflammatory joint diseases is evident, since these methods are not sensitive or specific to early pathologies and subtle changes. Magnetic resonance imaging (MRI) offers improved sensitivity to early inflammatory and destructive changes in peripheral joints in rheumatoid arthritis (RA) and, even though less well documented, in other inflammatory joint diseases. Good evidence is available that MRI bone erosions represent true bone abnormalities and are predictors of radiographical outcome in RA. Similarly, there is solid evidence for MRI synovitis representing true synovial inflammation and being of considerable practical, clinical and radiological significance in RA. Describing the encouraging current knowledge regarding MRI for diagnosis, monitoring and prognosis, this chapter discusses the potential for the use of MRI in the clinical management of patients with suspected and diagnosed inflammatory joint diseases, as well as research priorities and clinical situations where the use of MRI could be suggested.  相似文献   
75.
76.
77.
To facilitate endoscopic access for rejection surveillance and stenting of the pancreas, we have abandoned the duodenojejunostomy (DJ) in favor of duodenoduodenostomy (DD) in pancreas transplantation (PTx). From September 2012 to September 2013 we performed 40 PTx with DD; 20 solitary‐PTx (S‐PTx) and 20 simultaneous pancreas and kidney transplantation (SPK). We compared the outcomes with results from 40 PTx‐DJ (10 S‐PTx and 30 SPK) from the preceding era. The DD‐enteroanastomoses were performed successfully. Endoscopic pancreas biopsies (endoscopic ultrasound examination [EUS]) yielded representative material in half of the cases. One exocrine fistula was treated by endoscopic stenting. PTxs‐DD were associated with a higher rate of thrombosis compared to PTx‐DJ (23% vs. 5%) and reoperations (48% vs. 30%), as well as inferior graft survival (80% vs. 88%). Time on waiting list, HLA A + B mismatches and reoperations were associated with graft loss. Only recipient age remained an independent predictor of patient death in multivariate analysis. PTx‐DD showed a higher rate of thrombosis and inferior results, but facilitated a protocol biopsy program by EUS that was feasible and safe. Given that technical difficulties can be solved, the improved endoscopic access might confer long‐term benefits, yet this remains to be proven.  相似文献   
78.
Sexuality is an often neglected area of quality of life in patients with rheumatic disease. Manifestations and symptoms of disease can impair sexual functioning, but this can be much improved by adequate intervention and counseling. Fertility is in general not reduced in rheumatic diseases, however, the time taken to achieve a pregnancy is often increased. An increased rate of pregnancy loss is observed in systemic lupus erythematosus and the antiphospholipid syndrome contributing to a reduced family size. Autoantibodies are present in most of the rheumatic diseases and can interfere with fertilization, implantation, embryonic development and placental function. Active disease disturbs the hypothalamic-pituitary-axis, giving rise to periods of gonadal dysfunction. Toxic effects of immunosuppressive drugs can induce transient or permanent gonadal failure in women and men.  相似文献   
79.
BACKGROUND: Experimental meningitis with Streptococcus pneumoniae serotypes 1, 3, and 9 has resulted in pronounced differences in disease severity, but clinical meningitis studies addressing serotype-related differences in case-fatality rates are lacking. METHODS: Study subjects were Danish patients with pneumococcal meningitis due to serotype 1 (n=38), 3 (n=69), or 9V (n=59) during 1990-2002 for whom clinical information was available. The 3 serotypes were tested for brain damage and cerebrospinal fluid (CSF) inflammatory kinetics in 2 experimental models of meningitis. RESULTS: Patients with serotype 1 had a significantly lower case-fatality rate (3%), compared with patients with serotypes 3 (23%) and 9V (32%) (P=.0047, log-rank test). Age and serotype were independent prognostic factors for fatal outcome. In experimental meningitis, the median number of areas per brain slide with brain damage was significantly lower in rats infected with serotype 1 than in rats infected with serotypes 3 and 9V. Three distinct patterns of brain damage were observed: serotype 1, cortical hemorrhage; serotype 3, cortical necrosis and abscess formation; and serotype 9V, subcortical (callosal) abscess formation. Serotype 1 caused the poorest bacterial growth and lowest CSF levels of white blood cells, tumor necrosis factor- alpha, and interleukin-8 (P<.05). CONCLUSION: Case-fatality rates of patients with pneumococcal meningitis, the degree and pattern of brain damage, and CSF cytochemical alterations in experimental pneumococcal meningitis differ according to serotype.  相似文献   
80.

Background

Activated factor XII (FXIIa) is involved in vascular injury and repair, participating in inflammation, thrombosis, and fibrinolysis. We wanted to test the hypothesis that FXIIa may predict an acute coronary syndrome (ACS) after a myocardial infarction (MI) and to evaluate whether FXIIa is related to global markers of end-stage coagulation and inflammation, including fibrin monomer (FM) and ultrasensitive C-reactive protein (μCRP).

Methods

In a prospective study of 300 patients with acute MI, we evaluated the predictive value of FXIIa in blood samples drawn 4 to 6 days after admission. Cardiac death, re-MI, and troponin-T-positive unstable angina pectoris were registered during a median follow-up period of 1.5 years.

Results

In the upper quartile of FXIIa (Q4) (≥2.23 ng/mL) 32.0% of patients had an ACS as compared with 16.9% of patients with FXIIa in the three lower quartiles (Q1-3, P = .008). Relative risk of recurrent ACS for patients with FXIIa in the Q4 as compared with Q1-3 was 1.89 (95% CI, 1.22 to 2.93). A secondary ACS occurred earlier in patients with FXIIa in the Q4 as compared with those with FXIIa in the Q1-3 (P = .0039). Conventional risk factors as potential confounders were not associated with time to event. FXIIa did not correlate with FM or μCRP, and the FM and μCRP levels were of a similar magnitude in the Q4 as compared with the Q1 and the Q1-3 of FXIIa.

Conclusions

FXIIa predicts recurrent coronary events after MI. The prognostic ability of FXIIa was not reflected by markers of hypercoagulability or inflammation.  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