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   6585篇
  免费   323篇
  国内免费   20篇
耳鼻咽喉   31篇
儿科学   163篇
妇产科学   123篇
基础医学   909篇
口腔科学   180篇
临床医学   461篇
内科学   1606篇
皮肤病学   137篇
神经病学   513篇
特种医学   311篇
外科学   914篇
综合类   41篇
预防医学   228篇
眼科学   201篇
药学   412篇
中国医学   11篇
肿瘤学   687篇
  2023年   29篇
  2022年   61篇
  2021年   114篇
  2020年   41篇
  2019年   84篇
  2018年   110篇
  2017年   97篇
  2016年   92篇
  2015年   113篇
  2014年   146篇
  2013年   172篇
  2012年   282篇
  2011年   300篇
  2010年   150篇
  2009年   170篇
  2008年   308篇
  2007年   328篇
  2006年   248篇
  2005年   277篇
  2004年   287篇
  2003年   269篇
  2002年   313篇
  2001年   263篇
  2000年   299篇
  1999年   196篇
  1998年   67篇
  1997年   73篇
  1996年   53篇
  1995年   61篇
  1994年   46篇
  1993年   44篇
  1992年   168篇
  1991年   143篇
  1990年   154篇
  1989年   141篇
  1988年   128篇
  1987年   142篇
  1986年   134篇
  1985年   130篇
  1984年   77篇
  1983年   64篇
  1982年   48篇
  1979年   57篇
  1978年   38篇
  1975年   29篇
  1974年   46篇
  1973年   29篇
  1972年   38篇
  1971年   29篇
  1969年   33篇
排序方式: 共有6928条查询结果,搜索用时 15 毫秒
1.
2.
The nuclear DNA content of paraffin-embedded specimens of primary non-small-cell lung carcinomas was analysed using flow cytometry in 210 patients (80 squamous cell carcinomas, 99 adenocarcinomas, 19 large cell carcinomas and 15 others). The relationship between nuclear DNA content and prognostic factors was studied using multivariate analysis with Cox's proportional hazard model. 1) The frequency of DNA aneuploidy was 77.3% among 210 patients, and it significantly (p less than 0.05) increased with advanced stage and the presence of lymph node metastasis. 2) The patients with DNA aneuploid tumors had a significantly (p less than 0.001) less favorable prognosis than those with DNA diploid tumors among 179 patients with non-small-cell lung carcinomas. Similar results were demonstrated in 79 patients with stage I carcinomas and in 85 patients who underwent absolute curative resection. 3) Multivariate analysis using Cox's proportional hazard model showed that DNA ploidy was an independent prognostic factor for survival. Especially in the patients with absolute curative resection, DNA ploidy was the most important prognostic factor. In conclusion, flow cytometric nuclear DNA content analysis provided useful biological information, and DNA ploidy was an important and major independent prognostic factor in non-small-cell lung carcinoma.  相似文献   
3.
Abstract:  We retrospectively studied the occurrence of vesicoureteral reflux (VUR)-associated pyelonephritis using renal biopsies obtained from the transplanted kidneys, and correlated the histological changes with clinical parameters. Out of a total of 131 renal biopsies performed between 1990 and 2001 on renal transplant patients at the department of Urology of Nagasaki University Graduate School of Biomedical Sciences, 12 patients showed pyuria more than twice in a single year. Seven of these 12 patients were available for determining VUR by voiding cystourethrography (VCUG). Cystoureterography demonstrated VUR in three of seven studied patients with pyuria. A histopathological examination revealed dilatation of both proximal and distal tubules in renal biopsies of transplant patients with VUR, compared to renal biopsies of transplant patients without VUR, or non-transplanted patients with thin membrane disease. One of the patients with VUR showed advanced features of chronic pyelonephritis in four consecutive biopsies at different time points, suggesting a late stage of reflux nephropathy in the transplanted kidney. We conclude from our study that the occurrence of VUR-related pyelonephritis may be one of the important long-term complications in the survival of renal allografts.  相似文献   
4.
5.
6.
A 74-year-old female with hereditary xanthinuria and xanthine stones is reported. She has a family history of consanguineous parents and a past history of right side nephrectomy due to a xanthine renal stone and vesicolithotomy of 3 bladder stones approximately 5 X 4 X 4 cm in size at the age of 58 and 71, respectively. Her young brother exhibited a slightly elevated urinary excretion of oxypurines. Laboratory examination showed a low serum level (0.3 mg/dl) and urinary excretion (1.56 mg/day) of uric acid, and high plasma and urine levels of oxypurines. No xanthine oxidase activity was detectably in duodenal mucosa by biopsy specimen obtained by duodenofiberscopy. Now she has another stone approximately 5 X 4 X 4 cm in her bladder. There have been are few elderly cases of hereditary xanthinuria with recurrent giant urolithiasis.  相似文献   
7.
We present a Merkel-cell carcinoma patient with chronic renal failure requiring haemodialysis and evaluate the pharmacokinetics of carboplatin and etoposide during haemodialysis. The area under the concentration-time curve of carboplatin was increased by prolonging the interval between administration and haemodialysis. However, that of etoposide was not changed. Carboplatin showed good membrane permeability in haemodialysis, while etoposide showed no permeability. In conclusion, the pharmacokinetics of carboplatin could be controlled by haemodialysis and the interval between chemotherapy and haemodialysis. However, the pharmacokinetics of etoposide were not affected.  相似文献   
8.
9.
Clinical value and limitation of resting reinjection of small dose of thallium (37 MBq) for the assessment of myocardial viability were evaluated. The results were compared with the degree of wall motion improvement by revascularization to infarcted myocardium supplied by chronic total vessels in 12 patients with old myocardial infarction. Thallium uptake was visually scored and judged as normal, reversible defect (Group 1), new fill in after reinjection (Group 2A), and no fill in even after reinjection (Group 2B). Among 53 segments with initial perfusion abnormality, 21 segments reverted to almost normal, while 32 segments remained abnormal on redistribution images. New fill in after reinjection was observed in 11 segments of 32 segments showing persisting defect on stress and delayed image (37%). Wall motion score index of Group 2A improved significantly higher than Group 2B (p less than 0.01) and almost equal to Group 1, suggesting the utility of reinjection for the assessment of tissue viability which may be underestimated by conventional imaging. But significant wall motion improvement (greater than or equal to 0.6 mean SD/chords) was observed in 6 segments (29%) of 21 segments showing neither redistribution nor fill in after reinjection. These data indicate that small dose of thallium reinjection may enhance detection of viable but jeopardized myocardium, although some underestimation of viability remained to be resolved.  相似文献   
10.
A 4 month-old boy who had double-inlet left ventricle, severe subaortic stenosis, hypoplastic ascending aorta and coarctation of the aorta revealed severe respiratory failure. An urgent Norwood operation was done. The procedure consisted of enlargement of the ascending aorta and main pulmonary artery and a systemic-pulmonary shunt using 5 mm PTFE tube. Postoperative course was uneventful.  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