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   5993篇
  免费   400篇
  国内免费   7篇
耳鼻咽喉   52篇
儿科学   131篇
妇产科学   100篇
基础医学   620篇
口腔科学   205篇
临床医学   659篇
内科学   1435篇
皮肤病学   68篇
神经病学   527篇
特种医学   256篇
外科学   1010篇
综合类   59篇
一般理论   1篇
预防医学   507篇
眼科学   84篇
药学   323篇
中国医学   3篇
肿瘤学   360篇
  2023年   50篇
  2022年   68篇
  2021年   185篇
  2020年   85篇
  2019年   145篇
  2018年   208篇
  2017年   113篇
  2016年   112篇
  2015年   155篇
  2014年   177篇
  2013年   274篇
  2012年   379篇
  2011年   417篇
  2010年   205篇
  2009年   166篇
  2008年   295篇
  2007年   271篇
  2006年   270篇
  2005年   247篇
  2004年   244篇
  2003年   171篇
  2002年   183篇
  2001年   123篇
  2000年   124篇
  1999年   103篇
  1998年   37篇
  1997年   35篇
  1995年   31篇
  1994年   34篇
  1992年   74篇
  1991年   91篇
  1990年   87篇
  1989年   80篇
  1988年   90篇
  1987年   73篇
  1986年   70篇
  1985年   67篇
  1984年   59篇
  1983年   35篇
  1981年   35篇
  1980年   37篇
  1979年   57篇
  1978年   48篇
  1977年   45篇
  1976年   39篇
  1975年   35篇
  1974年   48篇
  1973年   43篇
  1972年   40篇
  1970年   35篇
排序方式: 共有6400条查询结果,搜索用时 31 毫秒
11.
Radiotherapy has been successful in treating localized prostate cancer; however, a subset of patients will experience disease recurrence. Determination of the recurrence location must be made using pretreatment and posttreatment clinical variables, imaging, and postradiotherapy biopsy. Patients presumed to have local-only recurrence, optimal clinical risk factors, and an extended life expectancy may be considered for salvage local treatment. Current options include salvage surgery, cryoablation, and brachytherapy. Although they are associated with higher morbidity than primary therapy, salvage treatments can be effective and can still provide patients with a good oncologic and functional outcome. As these modalities continue to improve and patient selection is optimized, better results will evolve.  相似文献   
12.
13.
14.
The purpose of this study was to use a meta-analytical technique to examine the efficacy of surgical repair of pectus excavatum on pulmonary function. Studies were retrieved via computerized literature searches, cross-referencing from original and review articles. Inclusion criteria were as follows: (1) reporting quantitative measures of preoperative and postoperative pulmonary function; (2) published in the English language; (3) indexed between January 1960 and September 2005; (4) reporting the duration between which preoperative and postoperative assessments were conducted; and (5) describing the pulmonary assessment procedures. The titles and abstracts of potentially relevant articles were reviewed to determine whether they met the criteria for inclusion. Twelve studies representing 313 pectus excavatum patients met the inclusion criteria and were used for the meta-analysis. Random-effects modeling yielded a mean weighted effect size (ES) for pulmonary function which was statistically nonsignificant (ES=0.08, 95% CI=-0.20 to 0.35; P=0.58). The findings of the present study indicated that surgical repair of pectus excavatum does not significantly improve pulmonary function. These findings, however, may be a result of testing pulmonary function under conditions in which pectus excavatum does not manifest itself.  相似文献   
15.
Lesion of the anteroventral portion of the third cerebral ventricle causes hypernatremia, adipsia, and attenuation of the pressor response to intravenous administration of angiotensin II and norepinephrine. In addition, these lesions prevent the development of several experimental models of hypertension. In this study, a lesion of the third cerebral ventricle region was made in 14 dogs. In seven dogs in which hypernatremia developed the lesions included the organum vasculosum of the lamina terminalis; seven animals in which the circumventricular organ was spared by the lesion remained normonatremic. Vascular responsiveness of isolated right carotid artery rings to angiotensin II and phenylephrine was assessed 3 days after lesioning the anteroventral portion of the third cerebral ventricle. In endothelium-denuded ring vessels, vasoconstrictor responses to phenylephrine were significantly decreased in animals both with and without inclusion of the organum vasculosum of the lamina terminalis. A similar effect was observed in intact vessels of dogs in which the circumventricular organ was spared but not in those with lesions that included this area. In contrast, angiotensin II-induced vasoconstriction was significantly decreased in the arteries with intact endothelium of both groups of lesioned animals. These data show that lesion of the anteroventral third ventricle area alters alpha 1-adrenergic and angiotensin II vascular responsiveness in isolated carotid artery rings with the possible participation of the endothelium.  相似文献   
16.
An open label randomized trial conducted in rural Kentucky compared the efficacy and safety of cefixime (CFX), 8 mg/kg once daily, with those of penicillin V (PEN), 250 mg 3 times daily, in 110 pediatric patients with Group A beta-hemolytic streptococcal pharyngitis. Forty-eight CFX and 47 PEN patients were evaluable for efficacy. At the end of therapy bacteriologic eradication was 45 of 48 (94%) and 36 of 47 (77%) in the CFX and PEN V groups, respectively (P < 0.05). Up to 6 weeks posttherapy 10 (21%) CFX patients and 21 (45%) PEN patients had positive Group A beta-hemolytic Streptococcus cultures (P < 0.05). Concordant serotypes were identified from 4 of 7 CFX and 15 of 17 PEN patients with positive repeat cultures. All discordant serotypes (5 of 31) were identified at greater than 19 days posttherapy. Symptomatic treatment failures (concordant serotypes) occurred in 1 (2%) CFX and 8 (17%) PEN patients (P < 0.05). Drug-related adverse experiences consisted of 2 cases of mild diarrhea and loose stools in the CFX group and none in the PEN group. No clinically significant laboratory test abnormalities occurred in either group. CFX, once daily, was as safe as and significantly more effective than PEN given 3 times daily for the treatment of Group A beta-hemolytic streptococcal pharyngitis.  相似文献   
17.
The validity of a self-administered diet history questionnaire has been estimated using as the reference data the mean of three 4-day diet records collected over the year prior to the administration of the questionnaire, in 1985–1986. Subjects were women ages 45–70 years, participants in the Women's Health Trial Feasibility Study, a multi-center clinical trial in which some women were randomized to be taught to adopt and maintain a low-fat diet, while others maintained their usual diet. The questionnaire produced group mean nutrient estimates closely approximating the values obtained by three 4-day records, e.g. in the usual-diet group, 37.7% of calories from fat by both food records and by questionnaire, and in the low-fat, group, 21.3% of calories from fat by food records and 23.7% of calories from fat by questionnaire. Correlations between questionnaire and diet records for per cent of calories from fat were 0.67 and 0.65 respectively in the two groups; most correlations were in the 0.5–0.6 range, and were similar to those achievable by a single 4-day food record.  相似文献   
18.
19.
20.
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