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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   3984篇
  免费   111篇
  国内免费   8篇
耳鼻咽喉   62篇
儿科学   131篇
妇产科学   140篇
基础医学   414篇
口腔科学   107篇
临床医学   357篇
内科学   754篇
皮肤病学   122篇
神经病学   169篇
特种医学   170篇
外国民族医学   8篇
外科学   467篇
综合类   79篇
预防医学   354篇
眼科学   108篇
药学   401篇
中国医学   14篇
肿瘤学   246篇
  2024年   18篇
  2023年   55篇
  2022年   158篇
  2021年   247篇
  2020年   144篇
  2019年   162篇
  2018年   223篇
  2017年   148篇
  2016年   133篇
  2015年   137篇
  2014年   169篇
  2013年   248篇
  2012年   301篇
  2011年   273篇
  2010年   190篇
  2009年   127篇
  2008年   154篇
  2007年   133篇
  2006年   137篇
  2005年   140篇
  2004年   124篇
  2003年   106篇
  2002年   81篇
  2001年   56篇
  2000年   51篇
  1999年   53篇
  1998年   15篇
  1997年   15篇
  1996年   16篇
  1995年   10篇
  1994年   7篇
  1993年   6篇
  1992年   12篇
  1991年   26篇
  1990年   22篇
  1989年   25篇
  1988年   14篇
  1987年   9篇
  1986年   21篇
  1985年   23篇
  1984年   10篇
  1983年   11篇
  1982年   8篇
  1980年   8篇
  1979年   10篇
  1978年   18篇
  1976年   5篇
  1975年   8篇
  1973年   5篇
  1965年   5篇
排序方式: 共有4103条查询结果,搜索用时 0 毫秒
991.
992.
BackgroundDiabetes mellitus has been shown in many studies to be associated with reduced bone mass and an increased risk of fracture. Currently, our understanding of how to use exercise effectively in diabetic patients in prevention of osteoporosis is incomplete and has prompted our interest to identify the type of effective osteogenic exercise.ObjectiveThe aim of this study was to compare the changes in handgrip strength and bone metabolism after 6 months between aerobic and resistance exercise training in non-insulin dependent diabetic patients in Jeddah area.ResultsThe mean values of serum calcium and Hand grip strength were significantly increased, while the mean values of parathyroid hormone were significantly decreased in both groups .Also, there were significant differences between mean levels of the investigated parameters in group (A) and group (B) after treatment.ConclusionAerobic exercise training on treadmill is appropriate to improve markers of bone metabolism and hand grip strength in non-insulin dependent diabetic patients.  相似文献   
993.
994.
This study comprised 42 patients with cancer bladder, who underwent radical cystectomy. The aim of work is to determine if HLA-G is expressed on tumor cells, derived from cancer bladder. We studied HLA-G-mRNA expression using RT-PCR and HLA-G cell surface expression by immunohistochemistry (IHC) staining technique. HLA-G was expressed in 28.6 % of cancer cases as determined by PCR and on 16.7% of cases determined by IHC staining. The sensitivity, specificity and accuracy of IHC were 58.3%, 96% and 81.7% respectively as compared to PCR results. There was a highly significant increase in the expression of HLA-G on cancer bladder cases with metastatic prostate infiltration (P= 0.021). It is concluded that HLA-G is ectopically expressed on cancer bladder malignant cells both at molecular and protein levels. However, it is not significantly associated with histologic type, tumor grade, stage, T category, schistosomiasis and lymph node involvement.  相似文献   
995.
996.
Subclinical atherosclerosis is increased in patients with rheumatoid arthritis (RA), as chronic systemic inflammation leads to accelerate atherosclerosis and increase arterial stiffness in theses patients. This study aimed to evaluate the association of serum interleukin-6 (sIL-6) and serum pentraxin 3(sPTX3) with subclinical atherosclerotic in patients with recent-onset rheumatoid arthritis. Sixty patients with recent onset RA (12-24 months) and 20 controls were investigated. Carotid ultrasound examination, assays for lipid profile, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor, sPTX3 and sIL-6 were done. RA patients demonstrated significantly higher carotid intima-media thickness (cIMT) values and increased carotid plaques than the control (P < 0.001 and P = 0.02, respectively). Levels of ESR, CRP, sPTX 3 and sIL-6 were significantly higher in RA patients than controls. RA related risk factors (disease duration, CRP, ESR, and duration of treatment with steroids), as well as sPTX 3, sIL-6 and cIMT were significantly higher in RA with atherosclerotic carotid plaques compared to those without atherosclerotic carotid plaques (all < 0.05). It is concluded that accelerated atherosclerosis in patients with recent-onset RA is associated with elevated levels of CRP, sPTX 3 and sIL-6.  相似文献   
997.
PurposeTo report National Cancer Institute (NCI) experience in managing various benign and malignant renal tumors with nephron sparing surgery (NSS), and to assess its safety and feasibility.Patients and methodsLiterature review for NSS, and reviewing of the patients records who underwent NSS between the period from January-2000 to December-2009 at NCI-Cairo University was done. Tumor related characteristics, indication for NSS, operative techniques, postoperative complications, full histopathological data, and follow up results were reviewed.ResultsThe total number of patients was 15. Median age at surgery was 32 years (range from 1.5 to 65 years). Five patients had bilateral tumors. The mean radiologic tumor size was 4.7 ± 5.2 cm. All patients had normal preoperative kidney functions. Six patients had an absolute indication for NSS, while 6 patients had a relative indication, and 3 patients were elective. All 5 patients with bilateral tumors underwent bilateral simultaneous surgery. Cold ischemia was used in 7 patients, 1 patient was exposed to warm ischemia. Manual compression was used in 2 patients, and no vascular control was applied in 5 patients. Complications were encountered in 2 patients, one of them had urinary leakage which needed reoperation, and the other had subcutaneous hematoma which was treated conservatively. Histopathological analysis revealed Wilm’s tumor (7 patients), angiomyolipoma (4 patients), renal cell carcinoma (RCC) (3 patients), and Hydatid cyst (1 patient). All patients had negative surgical margin. For patients with Wilm’s tumor, the median follow up was 24.4 months (range from 5 to 94 months), two patients had local recurrence, and 1 patient had distant metastasis.For patients with RCC, The median follow up was 14.7 months (range from 5 to 33 months) with no local recurrence or distant metastasis. All patients had normal kidney functions during postoperative and follow up periods.ConclusionNSS is a feasible safe procedure that could be done with acceptable complications. It provides a good solution for patients with bilateral benign tumors and early localized RCC.  相似文献   
998.
999.

Background  

We hypothesize that implantation of left ventricular assist device through off-pump technique is feasible and has a comparable result to implantation on cardiopulmonary bypass and could improve one-year survival.  相似文献   
1000.
ObjectivesTo describe the incidence, clinical characteristics, microbiological profile and in-hospital outcome of infective endocarditis (IE) in our center.MethodsA prospective study that was conducted on 50 consecutive patients admitted to our cardiology department diagnosed as Duke definite IE. The study was conducted for a period of one year and started on the 1st of September 2009 till the end of August 2010. All patients were subjected to detailed history taking, clinical examination, blood culture and echocardiography.ResultsThe study was carried out on 29 males (58%) and 21 females (42%) with a mean age of 33 years. The mean duration of delay from onset of symptoms till diagnosis was 54 days. Native valve endocarditis was found in 34 patients (68%). Blood cultures were positive in 27 patients (54%). Staphylococci were the prevalent microorganisms (52%). In-hospital events included: heart failure in 29 patients (58%), systemic embolization in 13 patients (26%), para-valvular abscess in 8 patients (16%), septic pulmonary emboli in 7 patients (14%), dehiscence of prosthetic valves in 5 patients (10%) and renal failure in 2 patients (4%). Surgical intervention was indicated in 41 patients (82%). Only 16 patients (39%) had early surgical intervention. In-hospital mortality was 22%. However, the mortality rate improved in the patients who had undergone early surgical intervention (18.75% versus 32%).ConclusionsInfective endocarditis remains a major health problem. It carries high in-hospital events with a high mortality rate. Delayed diagnosis of the disease and culture negative IE are common. Staphylococci are the prevalent microorganisms. Early surgical intervention improves survival.  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