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   2871288篇
  免费   200905篇
  国内免费   5326篇
耳鼻咽喉   40629篇
儿科学   95330篇
妇产科学   81224篇
基础医学   411444篇
口腔科学   81883篇
临床医学   254591篇
内科学   548870篇
皮肤病学   63648篇
神经病学   223137篇
特种医学   112312篇
外国民族医学   841篇
外科学   436800篇
综合类   62740篇
现状与发展   2篇
一般理论   882篇
预防医学   214445篇
眼科学   66635篇
药学   218926篇
  10篇
中国医学   6114篇
肿瘤学   157056篇
  2018年   28853篇
  2016年   25246篇
  2015年   28404篇
  2014年   39069篇
  2013年   59201篇
  2012年   79965篇
  2011年   85476篇
  2010年   50877篇
  2009年   47560篇
  2008年   80899篇
  2007年   86783篇
  2006年   88053篇
  2005年   85053篇
  2004年   82111篇
  2003年   79400篇
  2002年   77103篇
  2001年   135345篇
  2000年   138934篇
  1999年   117016篇
  1998年   32420篇
  1997年   28765篇
  1996年   28754篇
  1995年   27339篇
  1994年   25448篇
  1993年   23722篇
  1992年   92764篇
  1991年   90461篇
  1990年   89425篇
  1989年   86472篇
  1988年   79322篇
  1987年   78289篇
  1986年   74003篇
  1985年   70677篇
  1984年   52571篇
  1983年   44950篇
  1982年   26220篇
  1981年   23337篇
  1979年   48833篇
  1978年   34175篇
  1977年   29773篇
  1976年   27486篇
  1975年   30052篇
  1974年   35632篇
  1973年   34517篇
  1972年   32547篇
  1971年   30476篇
  1970年   28216篇
  1969年   27072篇
  1968年   24917篇
  1967年   22242篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Levels of the soluble form of the triggering receptor expressed on myeloid cells (sTREM)-1 are elevated in severe sepsis. However, it is not known whether sTREM-1 measurements can distinguish milder bacterial infections from noninfectious inflammation. The present authors studied whether serum sTREM-1 levels differ in community-acquired pneumonia, exacerbations of chronic obstructive pulmonary disease (COPD), asthma and controls, and whether sTREM-1 may be used as a surrogate marker for the need for antibiotics. Serum sTREM-1 levels in 150 patients with pneumonia, COPD and asthma exacerbations and 62 healthy controls were measured. Serum sTREM-1 levels were significantly elevated in pneumonia (median 295.2 ng x mL(-1)), COPD (280.3 ng x mL(-1)) and asthma exacerbations (184.0 ng x mL(-1)) compared with controls (83.1 ng x mL(-1)). Levels were higher in pneumonia and Anthonisen type 1 COPD exacerbations than in type 2 and 3 COPD and asthma exacerbations. The area under the receiver operating characteristics curve for sTREM-1 as a surrogate marker for the need for antibiotics was 0.77. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 were elevated predominantly in pneumonia and Anthonisen type 1 COPD exacerbations versus type 2 and 3 chronic obstructive pulmonary disease exacerbations, asthma and controls. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 has moderate but insufficient accuracy as a surrogate marker for the need for antibiotics in lower respiratory tract infections.  相似文献   
52.
There is some evidence suggesting that Parkinson's disease (PD) patients exhibit lower body weight when compared to age-matched healthy subjects. Low body mass index (BMI) is correlated with low bone mineral density, both of which are major risk factors for hip fractures. Possible determinants of weight loss in PD patients include hyposmia, impaired hand-mouth coordination, difficulty chewing, dysphagia, intestinal hypomotility, depression, decreased reward processing of dopaminergic mesolimbic regions, nausea, and anorexia as the side effects of medication, and increased energy requirements due to muscular rigidity and involuntary movements. It is unclear whether PD patients in general, or only a subgroup of those affected, definitely show lower BMI in the advanced stages of the disease. We therefore recommend that the body weight of PD patients be monitored monthly as the disease progresses, and that a patient's nutrition should be supplemented with sufficient amounts of vitamin D and calcium to reduce the risk of hip fractures and strengthen bone density. Because meal times may coincide with unpredictable off periods associated with akinesia and impaired hand-mouth coordination, PD patients also need flexible food schedules that accommodate the associated symptoms of this disease.  相似文献   
53.
54.
55.
56.
57.
58.
59.
Abstract: Background: Fetal pulse oximetry improves the assessment of fetal well‐being during labor. The objective of this study was to evaluate women's satisfaction with their experience with this additional technology. Methods: We surveyed women participating in the FOREMOST trial, a randomized controlled trial comparing the addition of fetal pulse oximetry (FPO) to conventional cardiotocograph (CTG) monitoring (intervention group), versus CTG‐only (control group), in the presence of nonreassuring fetal status during labor. Our survey evaluated 3 aspects of women's experience: labor, fetal monitoring, and participation in the research. The survey was administered within a few days of giving birth and repeated 3 months later. Results: No differences were found between the intervention and control groups for women's evaluations of their labor, fetal monitoring, research, or overall experiences when surveyed on both occasions. Within each study group, a small but statistically significant decline occurred in women's scores for their experience of labor and overall experience from the initial survey close to the time of giving birth, to 3 months later. The magnitude of differences in responses over time was similar for the both groups. Women were more satisfied after a spontaneous or assisted vaginal birth than after cesarean section. Length of time the research midwife was present had a significant positive effect on women's ratings of their experience several days after giving birth (p = 0.006), but no effect at 3 months. Conclusions: The addition of fetal pulse oximetry for the assessment of fetal well‐being during labor did not affect childbearing women's perceptions of fetal monitoring or their labor. Women evaluated their experience in the research process positively overall. Small changes occurred in women's perception of their satisfaction over time. (BIRTH 33:2 June 2006)  相似文献   
60.
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