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   31890篇
  免费   2593篇
  国内免费   72篇
耳鼻咽喉   539篇
儿科学   1295篇
妇产科学   1024篇
基础医学   4365篇
口腔科学   843篇
临床医学   2786篇
内科学   7420篇
皮肤病学   767篇
神经病学   3267篇
特种医学   1073篇
外国民族医学   3篇
外科学   3929篇
综合类   555篇
一般理论   43篇
预防医学   2308篇
眼科学   636篇
药学   1778篇
中国医学   9篇
肿瘤学   1915篇
  2021年   414篇
  2020年   270篇
  2019年   454篇
  2018年   502篇
  2017年   366篇
  2016年   406篇
  2015年   466篇
  2014年   655篇
  2013年   992篇
  2012年   1267篇
  2011年   1339篇
  2010年   809篇
  2009年   704篇
  2008年   1222篇
  2007年   1314篇
  2006年   1312篇
  2005年   1240篇
  2004年   1237篇
  2003年   1134篇
  2002年   1201篇
  2001年   1099篇
  2000年   1165篇
  1999年   985篇
  1998年   384篇
  1997年   347篇
  1996年   350篇
  1995年   315篇
  1994年   311篇
  1993年   324篇
  1992年   871篇
  1991年   808篇
  1990年   692篇
  1989年   754篇
  1988年   689篇
  1987年   717篇
  1986年   663篇
  1985年   689篇
  1984年   542篇
  1983年   465篇
  1982年   302篇
  1980年   264篇
  1979年   458篇
  1978年   309篇
  1977年   266篇
  1976年   284篇
  1975年   270篇
  1974年   297篇
  1973年   294篇
  1972年   267篇
  1971年   260篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
92.
Epidemiology and etiology of bladder cancer.   总被引:5,自引:0,他引:5  
Urinary bladder cancer has long been associated with specific etiologic factors, and our knowledge of these factors has increased during this century. The most important factor, even in industrialized societies, is cigarette smoking. Specific chemicals have also been identified as causing bladder cancer, as have a variety of occupational exposures to less well-defined specific agents. In other parts of the world, the association of bladder cancer with Balkan nephropathy, endemic blackfoot disease, and schistosomiasis provides additional leads for investigating, and potentially preventing, the process of carcinogenesis in humans. Many of the critical observations in our understanding of bladder cancer have been made by practicing physicians, and this is likely to continue. It is essential that physicians dealing with bladder cancer patients be attuned to potential etiologic factors, including cigarette smoking, various industrial exposures, or drug exposures to further our understanding of this issue. Bladder cancer is a potentially preventable disease and an important one, as indicated by the total number of cases and the extent of morbidity and death attributable to it around the world.  相似文献   
93.
94.
95.
One of the most exciting developments in pediatric dermatology has been the use of the flashlamp-pumped, 585-nm, pulsed dye laser for treatment of vascular birthmarks. In many cases the results are miraculous. The increase in self-esteem and happiness of many children and adolescents has been overwhelming; for some, depression has been lifted, stuttering has ceased, social involvement has increased, and antidepressants have been discontinued. There are many success stories to tell.
Despite the remarkable effects of the pulsed dye laser and the medical and psychosocial indications for its use, the issue of pain control remains significant. We have no perfect outpatient pediatric anesthetic. Most methods carry either some risk or, if not hazardous, often are not very effective for controlling pain. Needless to say, a diversity of opinions exist on how to manage discomfort from this treatment modality. Therefore, we thought it would be useful to share the experiences and opinions of several dermatologists who have extensive experience with the pulsed dye laser.  相似文献   
96.
OBJECTIVE: To assess the procedural success and complication rates of the first 120 directional coronary atherectomy cases performed at two Toronto hospitals. DESIGN AND SETTING: Case series in tertiary referral centres. PATIENTS: One hundred and thirteen patients in whom 120 atherectomy procedures were attempted between July 1990 and April 1992. INTERVENTION: Directional coronary atherectomy. MAIN RESULTS: Angiographic success was obtained in 115 of 120 procedures (96%) involving 117 of 123 lesions (95%). Procedural success (angiographic success without death, myocardial infarction or coronary bypass surgery) was obtained in 110 of 120 procedures (92%). Adjunctive balloon angioplasty was required in 20 procedures (17%). There was one death at 36 h in an elderly patient who underwent an emergency procedure while in cardiogenic shock. Periprocedural non-Q wave myocardial infarction occurred in five patients. There were no Q wave myocardial infarctions. Three patients required coronary bypass surgery prior to discharge and vascular complications occurred in five patients. CONCLUSIONS: Directional coronary atherectomy can be performed with procedural success and complication rates comparable to conventional balloon angioplasty. Randomized trials are underway to determine if atherectomy results in a lower restenosis rate.  相似文献   
97.
98.
Composite resection of posterior pelvic malignancy.   总被引:5,自引:0,他引:5       下载免费PDF全文
Advanced pelvic cancer is a formidable challenge to surgical resection. These tumors commonly invade the bony pelvis, may involve other viscera, and usually have been irradiated previously. The authors are presenting experience with 76 patients who had composite resection of posterior or lateral pelvic malignancy. Fifty-eight patients had secondary cancers involving the musculoskeletal pelvis. This included 47 patients with advanced carcinoma of the rectum (41 curative, 6 palliative), 10 epidermoid cancers of the anorectum (8) or cervix (2), and 1 bladder cancer. Among the 18 patients with primary pelvic tumors were three patients with chordomas, six with bone tumors (osteosarcoma chondrosarcoma, grade III giant cell tumor), and nine with soft tissue tumors. All required major resection of the sacrum or pelvic side walls, and one half had an additional exenterative procedure. The overall mortality rate was 7.9%. Long-term estimated survival was 24% in patients having curative resection of recurrent rectal cancer, and 22.5% in 10 patients with advanced epidermoid cancer. Fifty per cent of patients with primary bone or soft tissue tumors survived from 13 to 88 months. Most patients had reasonable return of function, and were able to return to work or resume their normal previous lifestyle.  相似文献   
99.
PURPOSE: To evaluate the frequency and nature of spinal pathology, the frequency of clinically silent lesions, and the potential benefit of screening spinal MR in neurofibromatosis patients. PATIENTS AND METHODS: 28 neurofibromatosis type-1 (NF-1) patients and nine neurofibromatosis type-2 (NF-2) patients were studied with postcontrast spinal MR imaging. RESULTS: NF-1: One patient had a biopsy-proven low-grade glioma; five patients, intradural, extramedullary masses (N = 23); one patient, extradural masses (N = 2) (neurofibromas); 16 patients had bony abnormalities; and three patients thecal sac abnormalities. NF-2: Five patients demonstrated intramedullary masses (five/eight ependymomas); nine patients, intradural, extramedullary masses (meningiomas, schwannomas); and four patients, bony abnormalities. Eight/10 NF-1 and four/nine NF-2 patients had asymptomatic masses. CONCLUSION: Intradural disease is common, often asymptomatic, and often presents at a young age in NF-1 and NF-2 patients. Because of the propensity to develop significant asymptomatic as well as symptomatic intradural disease, screening of the entire spine with MR is recommended in both NF-1 and NF-2 patients.  相似文献   
100.
48 patients with stage I-II low-grade non-Hodgkin's lymphoma were treated by radiation and/or chemotherapy between 1970 and 1986. The histologic types were diffuse lymphocytic well differentiated, eleven patients; nodular lymphocytic poorly differentiated, 28 patients; nodular mixed, nine patients. Complete remission was obtained in 45 patients (94%). Overall survival was 83% and 68% at five and ten years, respectively. Five and ten-year relapse-free survival of complete responders was 71% and 57%, respectively. Univariate analysis of potential prognosticators showed the following to significantly increase the survival rate: one or two sites of disease (p less than 0.01), stage I (p less than 0.02), age less than 65 years (p less than 0.02), complete excision of tumor mass (p less than 0.03), and the use of radiotherapy (p less than 0.02). The extent of radiotherapy field did not affect survival. Multivariate analysis by the stepwise proportional hazards model of Cox showed that the use of radiotherapy was the factor which significantly produced better survival figures (p less than 0.03). It is concluded that two thirds of stage I-II low-grade lymphoma patients are potentially curable; radiotherapy plays a major role in the management.  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