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   3610篇
  免费   250篇
  国内免费   19篇
耳鼻咽喉   55篇
儿科学   208篇
妇产科学   54篇
基础医学   458篇
口腔科学   104篇
临床医学   233篇
内科学   833篇
皮肤病学   100篇
神经病学   250篇
特种医学   211篇
外科学   531篇
综合类   19篇
一般理论   1篇
预防医学   392篇
眼科学   33篇
药学   199篇
中国医学   35篇
肿瘤学   163篇
  2023年   18篇
  2022年   41篇
  2021年   95篇
  2020年   59篇
  2019年   100篇
  2018年   128篇
  2017年   88篇
  2016年   68篇
  2015年   86篇
  2014年   115篇
  2013年   153篇
  2012年   232篇
  2011年   225篇
  2010年   132篇
  2009年   116篇
  2008年   182篇
  2007年   177篇
  2006年   191篇
  2005年   159篇
  2004年   167篇
  2003年   167篇
  2002年   165篇
  2001年   139篇
  2000年   137篇
  1999年   123篇
  1998年   29篇
  1997年   34篇
  1996年   31篇
  1995年   24篇
  1994年   19篇
  1993年   23篇
  1992年   41篇
  1991年   36篇
  1990年   47篇
  1989年   37篇
  1988年   41篇
  1987年   39篇
  1986年   27篇
  1985年   24篇
  1984年   16篇
  1983年   13篇
  1982年   7篇
  1979年   19篇
  1977年   11篇
  1976年   11篇
  1975年   9篇
  1974年   8篇
  1972年   9篇
  1971年   7篇
  1970年   7篇
排序方式: 共有3879条查询结果,搜索用时 15 毫秒
1.
2.
3.
Objectives:  Among children with cerebrospinal fluid (CSF) pleocytosis, the task of separating aseptic from bacterial meningitis is hampered when the CSF Gram stain result is unavailable, delayed, or negative. In this study, the authors derive and validate a clinical decision rule for use in this setting.
Methods:  This was a review of peripheral blood and CSF test results from 78 children (<19 years) presenting to Children's Hospital Columbus from 1998 to 2002. For those with a CSF leukocyte count of >7/μL, a rule was created for separating bacterial from viral meningitis that was based on routine laboratory tests, but excluded Gram stain. The rule was validated in 158 subjects seen at the same site (Columbus, 2002–2004) and in 871 subjects selected from a separate site (Boston, 1993–1999).
Results:  One point each (maximum, 6 points) was assigned for leukocytes >597/μL, neutrophils >74%, glucose <38 mg/dL, and protein >97 mg/dL in CSF and for leukocytes >17,000/mL and bands to neutrophils >11% in peripheral blood. Areas under receiver-operator-characteristic curves (AROCs) for the resultant score were 0.98 for the derivation set and 0.90 and 0.97, respectively, for validation sets from Columbus and Boston. Sensitivity and specificity pairs for the Boston data set were 100 and 44%, respectively, at a score of 0 and 97 and 81% at a score of 1. Likelihood ratios (LRs) increased from 0 at a score of 0 to 40 at a score of ≥4.
Conclusions:  Among children with CSF pleocytosis, a prediction score based on common tests of CSF and peripheral blood and intended for children with unavailable, negative, or delayed CSF Gram stain results has value for diagnosing bacterial meningitis.  相似文献   
4.
Background and objectiveTo analyse frequency, characteristics and patient survival with lung cancer (LC) and Common Obstructive Pulmonary Disease (COPD), comparing them with patients that do not have COPD.Material and methodsA retrospective study, of patients diagnosed by means of cytohistology. Survival was estimated by the Kaplan-Meier method. Statistical analysis was carried out using SPSS 15.0.ResultsA total of 996 patients were diagnosed, 39.8% with COPD. Mean age70±9.19 years. GOLD stages: I 18.2%, II 53.6%, III 24%, IV 4.2%. The histological types: squamous cell carcinoma 48.2%, adenocarcinoma 22%, and small cell carcinoma 22.5%. Survival was longer in the COPD group.ConclusionsLC and COPD are combined in 39.8%. Squamous cell type is more frequent and survival was longer in the COPD group.  相似文献   
5.
This study aimed to determine whether a weight-adjusted dose of subcutaneous enoxaparin is as effective and safe as oral acenocoumarol for the secondary prophylaxis of pulmonary embolism. Three hundred and eighty consecutive noncancer outpatients hospitalized with an episode of symptomatic pulmonary embolism selected treatment with acenocoumarol or enoxaparin at a dose of 1 mg/kg once daily after being informed of the type of administration and expected frequency of laboratory monitoring for both medicinal products. Endpoints were symptomatic recurrent thromboembolic events evaluated by standard objective testing, and a composite endpoint of recurrent venous thromboembolism, major bleeding, and death from any cause. One hundred and ninety-nine patients (52%) chose acenocoumarol therapy and 181 chose enoxaparin monotherapy. Four patients in the enoxaparin group (2.2%) and six patients in the acenocoumarol group (3%) had an objective thromboembolic recurrence (hazard ratio, 1.35; 95% confidence interval, 0.38-4.79; P = 0.64). Nine patients in the enoxaparin group (5.0%) had a hemorrhagic complication compared with 11 in the acenocoumarol group (5.5%) (P = 0.81). The hospital length of stay was shorter with enoxaparin compared with acenocoumarol (11 versus 16 days, P = 0.0001). Enoxaparin is as effective and safe as acenocoumarol in the secondary prevention of recurrent thromboembolic disease and is associated with shorter hospitalization.  相似文献   
6.
7.
Benign noninflammatory bronchial stenosis: treatment with balloon dilation   总被引:11,自引:0,他引:11  
  相似文献   
8.
9.
10.
The possible beneficial effects on the lens and retina which Bendazac Lysine may have in the treatment of adult diabetic patients were investigated. Twenty patients, ranging in age from 54.80 ± 5.86 years old, were studied. The average duration of the diabetes was 11.32 ± 4.10 years. Thirteen patients had background retinopathy. The metabolic controls carried out during the study were satisfactory (HbA1<11%). Bendazac Lysine (500 mg three times a day) was administered for 6 months. Blood-retinal barrier permeability (VPR and VPRt) and lens transmittance (t) were evaluated prior to and 6 months after treatment by fluorophotometry. No statistically significant differences between the pre- and post-treatment values of the retina permeability were observed, however, there was a statistically significant improvement (p<0.05) (initial value: t= 0.813 ± 0.040 and final value: t=0.823 ± 0.037) in the lens transmittance. The authors conclude that Bendazac Lysine has a beneficial effect on the lens in the diabetic adult although no improvement in the permeability of the blood-retinal barrier has been observed.  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