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   651篇
  免费   38篇
  国内免费   5篇
耳鼻咽喉   5篇
儿科学   49篇
妇产科学   4篇
基础医学   30篇
口腔科学   15篇
临床医学   72篇
内科学   105篇
皮肤病学   1篇
神经病学   6篇
特种医学   142篇
外科学   176篇
综合类   30篇
预防医学   20篇
眼科学   2篇
药学   18篇
肿瘤学   19篇
  2022年   1篇
  2021年   3篇
  2020年   1篇
  2019年   2篇
  2018年   9篇
  2017年   6篇
  2016年   6篇
  2015年   10篇
  2014年   18篇
  2013年   19篇
  2012年   8篇
  2011年   4篇
  2010年   10篇
  2009年   8篇
  2008年   12篇
  2007年   13篇
  2006年   17篇
  2005年   17篇
  2004年   15篇
  2003年   12篇
  2002年   15篇
  2001年   18篇
  2000年   14篇
  1999年   18篇
  1998年   30篇
  1997年   34篇
  1996年   35篇
  1995年   34篇
  1994年   32篇
  1993年   20篇
  1992年   17篇
  1991年   15篇
  1990年   16篇
  1989年   21篇
  1988年   28篇
  1987年   25篇
  1986年   28篇
  1985年   25篇
  1984年   18篇
  1983年   14篇
  1982年   6篇
  1981年   12篇
  1980年   5篇
  1979年   5篇
  1978年   4篇
  1977年   3篇
  1976年   5篇
  1975年   2篇
  1972年   1篇
  1970年   3篇
排序方式: 共有694条查询结果,搜索用时 15 毫秒
41.
Surgical treatment of hepatic and pulmonary metastases from colon cancer   总被引:4,自引:0,他引:4  
BACKGROUND: Surgical resection of isolated hepatic or pulmonary metastases secondary to colorectal cancer has been shown to yield acceptable long-term survival. However, results are inconclusive for surgical resection of both hepatic and pulmonary metastases. METHODS: We reviewed the records of all patients who underwent surgical resection of both hepatic and pulmonary metastases from colorectal cancer between 1980 and 1998. RESULTS: A total of 58 patients underwent resection of both hepatic and pulmonary metastases secondary to colorectal cancer. All patients had local control of their primary cancer before metastasectomy. There were no operative deaths. Morbidity occurred in 12% of patients. Follow-up was complete in all patients, with a median duration of 62 months (range, 6 to 201 months). The 5- and 10-year survivals were 30% and 16%, respectively. A premetastasectomy carcinoembryonic antigen level greater than 5 ng/mL increased the risk of early death (p = 0.029). Neither the number of pulmonary lesions nor the time interval between the primary surgery and the metastasectomy had a significant impact on survival (p = 0.67). At 5 years, 55% of patients were free of disease. Four patients had lymph node involvement at the time of pulmonary resection and all 4 patients died within 22 months of their pulmonary metastasectomy. CONCLUSIONS: Resection of both hepatic and pulmonary metastases secondary to colorectal cancer in highly selected patients is safe and results in long-term survival. Thoracic lymph node involvement and elevated carcinoembryonic antigen levels before pulmonary metastasectomy are associated with reduced survival.  相似文献   
42.
43.
High mobility group proteins 1 and 2 recognize chromium-damaged DNA   总被引:2,自引:0,他引:2  
Chromium (Cr) is a human carcinogen and a potent DNA damaging agent. Incubation of DNA with CrCl3 resulted in dose-dependent binding of Cr to DNA and, at concentrations >20 microM, altered the electrophoretic mobility of a 100 bp oligonucleotide. We also demonstrate that high mobility group (HMG) proteins 1 and 2 bind Cr-damaged DNA (Cr-DNA). Protein binding was lesion density-dependent, with maximal binding to DNA treated with 100 microM CrCl3. HMG2 binds to Cr-DNA with a calculated Kd of approximately 10(-9) M. These proteins also bound DNA obtained from chromate-treated cells. These results suggest that the covalent attachment of Cr to DNA induces alterations in DNA structure which are recognized by HMG1 and HMG2. Therefore, these proteins may function as Cr-damaged DNA recognition proteins in vivo and as a consequence of binding, may play a role in directing the cellular response to Cr-DNA adduct formation.   相似文献   
44.
The aetiology of 197 girls and 16 boys presenting with sexual precocity was reviewed. Ninety one girls and four boys had central precocious puberty (M:F 23:1); a cause was identified in all the boys but in only six girls. All boys with precocious puberty need detailed investigation; in girls investigation should be based on clinical findings, particularly the consonance of puberty.  相似文献   
45.
46.
Reduction of sound levels with antinoise in MR imaging   总被引:1,自引:0,他引:1  
Goldman  AM; Gossman  WE; Friedlander  PC 《Radiology》1989,173(2):549-550
A combination of active and passive techniques was used to reduce the sound levels in magnetic resonance imagers. These techniques were integrated into an existing audio system. Measurements of sound reduction varied with the protocol being used and averaged 9.9 dB with coaxial cabling and 14.2 dB with fiberoptic conduction of the feedback signal to a controller. Patient comfort and communication were improved.  相似文献   
47.
Successful anastomosis is essential for favorable esophagogastrectomy outcomes. Before July 2002, almost all esophagogastric anastomoses at our institution were hand-sewn. We then began using linear stapled anastomotic techniques. This review compares patient outcomes with both techniques. From July 2001 to June 2004, 280 consecutive esophagogastrectomy patients (235 men and 45 women) were reviewed (median age, 65 years). The anastomosis was intrathoracic in 206 patients (74%) and cervical in 74 (26%). Anastomoses were hand-sewn in 205 patients (73%) and linear stapled in 75 (27%). Stapled anastomoses were intrathoracic in 33 patients (16%) and cervical in 42 (57%). Anastomotic leaks occurred in 30 patients (11%); 26 (12.7%) in the hand-sewn and 4 (5.3%) in the linear stapled group (P = .008). Leaks were asymptomatic in 17 patients (57%). Dilatation was required in 70 hand-sewn anastomoses (34%) and in 11 stapled (14.6%) (P = .001). Hand-sewn anastomoses were more likely to leak and require dilatation; odds ratios and 95% confidence intervals were 5.35 (1.67–19.27) and 3.58 (1.66–8.34), respectively. A linear stapled anastomosis is safe and associated with both a significantly lower leak rate and the need for dilatation compared with hand-sewn anastomosis. This nonrandomized series suggests that linear stapled anastomosis is the preferred technique regardless of anastomotic location. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation).  相似文献   
48.
BACKGROUND: Aqueous contrast swallow study is recommended as a screening procedure for the evaluation of esophageal anastomotic integrity following esophagectomy. The aim of this study was to assess the accuracy of water-soluble contrast swallow screening as a predictor of clinically significant anastomotic leak in patients with esophagectomy. PATIENTS AND METHODS: The records of 505 consecutive patients undergoing esophagectomy in Mayo Clinic from January 1991 through December 1995 were retrospectively reviewed. 464 (92%) patients had water-soluble contrast swallows performed in the early postoperative period (median postoperative day 7, range 4-11 days). RESULTS: A total of 39 radiological leaks were obtained but only 17 of these had clinical signs of anastomotic leakage. Furthermore, 25 patients who had normal swallow study developed a clinical anastomotic leak. There were therefore 22 (4.7%) false positive and 25 (5.4%) false negative results giving values for the specificity, sensitivity and false negative error rate of the radiological examination of 94.7, 40.4, and 59.5% respectively. Aspiration of the contrast agent was noted on fluoroscopy in 30 (6.5%) patients. Only 2 (0.4%) patients developed aqueous contrast agent-caused aspiration pneumonia. There was no procedure-related mortality. CONCLUSION: While radiological assessment of esophageal anastomoses in the early postoperative period using aqueous contrast agents appears to be a relatively safe procedure, the poor sensitivity and high false negative error rate of this technique, when performed on postoperative day 7 and in a series with clinical anastomotic leak rate of 9%, is insufficient for it to be worthwhile as a screening procedure.  相似文献   
49.
50.
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