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   1509671篇
  免费   115504篇
  国内免费   6785篇
耳鼻咽喉   19116篇
儿科学   49496篇
妇产科学   41833篇
基础医学   205812篇
口腔科学   41481篇
临床医学   134159篇
内科学   308670篇
皮肤病学   35932篇
神经病学   120580篇
特种医学   64727篇
外国民族医学   370篇
外科学   236118篇
综合类   32534篇
现状与发展   2篇
一般理论   415篇
预防医学   121052篇
眼科学   32025篇
药学   105572篇
  7篇
中国医学   2344篇
肿瘤学   79715篇
  2018年   16538篇
  2017年   14179篇
  2016年   15684篇
  2015年   18710篇
  2014年   23806篇
  2013年   32728篇
  2012年   45123篇
  2011年   42991篇
  2010年   26260篇
  2009年   27289篇
  2008年   38090篇
  2007年   41160篇
  2006年   42515篇
  2005年   48699篇
  2004年   48415篇
  2003年   43287篇
  2002年   36846篇
  2001年   69599篇
  2000年   69290篇
  1999年   61327篇
  1998年   17157篇
  1997年   15232篇
  1996年   16305篇
  1995年   16536篇
  1994年   15379篇
  1993年   14370篇
  1992年   52943篇
  1991年   51815篇
  1990年   50231篇
  1989年   47765篇
  1988年   44310篇
  1987年   43517篇
  1986年   41006篇
  1985年   39196篇
  1984年   29463篇
  1983年   24634篇
  1982年   14724篇
  1981年   13115篇
  1980年   12453篇
  1979年   26919篇
  1978年   19111篇
  1977年   15953篇
  1976年   14524篇
  1975年   15858篇
  1974年   18810篇
  1973年   17789篇
  1972年   16576篇
  1971年   15425篇
  1970年   14179篇
  1969年   13254篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Background  Patients with psoriasis experience remission and gradual reappearance of erythematous and scaly plaques and require individualized treatment over time. A goal of psoriasis treatment is to provide optimal efficacy with a flexible therapeutic regimen that may include treatment pauses.
Objectives  To determine whether patients receiving initial treatment with etanercept who then pause therapy would subsequently recapture response during re-treatment.
Patients and methods  A post-hoc analysis of 226 patients with moderate-to-severe psoriasis from a large multicentre trial was performed. Patients had received etanercept 50 mg twice weekly subcutaneously until a target clinical response had been achieved, then had paused treatment and eventually relapsed. They were then re-treated with etanercept 25 mg twice weekly. The number of patients recapturing a Physician Global Assessment (PGA) of psoriasis rating of ≤ 2 (clear, almost clear or mild) on first re-treatment was assessed. Patient satisfaction during the initial treatment and first re-treatment period was also determined.
Results  A total of 187 (83%) patients recaptured the target clinical response of a PGA of ≤ 2 after re-treatment. The majority of patients [219 of 226 (97%)] reported satisfaction with etanercept re-treatment. No new safety concerns emerged during re-treatment.
Conclusions  In this post-hoc analysis, patients with psoriasis who were re-treated with etanercept 25 mg twice weekly effectively recaptured clinical responses that patients found satisfactory. A flexible treatment option is available to dermatologists and patients for individualized care.  相似文献   
992.
Background  Hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC) is a synthetic fragrance ingredient. Case reports of allergy to HICC appeared in the 1980s, and HICC has recently been included in the European baseline series. Human elicitation dose–response studies performed with different allergens have shown a significant relationship between the patch-test threshold and the repeated open application test (ROAT) threshold, which mimics some real-life exposure situations. Fragrance ingredients are special as significant amounts of allergen may evaporate from the skin.
Objectives  The study aimed to investigate the relationship between elicitation threshold doses at the patch test and the ROAT, using HICC as the allergen. The expected evaporation rate was calculated.
Materials and methods  Seventeen HICC-allergic persons were tested with a dilution series of HICC in a patch test and a ROAT (duration up to 21 days). Seventeen persons with no HICC allergy were included as control group for the ROAT.
Results  The response frequency to the ROAT (in μg HICC cm−2 per application) was significantly higher than the response frequency to the patch test at one of the tested doses. Furthermore the response rate to the accumulated ROAT dose was significantly lower at half of the doses compared with the patch test. The evaporation rate of HICC was calculated to be 72% over a 24-h period.
Conclusions  The ROAT threshold in dose per area per application is lower than the patch test threshold; furthermore the accumulated ROAT threshold is higher than the patch test threshold, which can probably be explained by the evaporation of HICC from the skin in the open test.  相似文献   
993.
994.
995.
996.
997.
Immigrants, and especially those recently arrived in host countries, are a high-risk group for tuberculosis. In 2006 in France, nearly half of the new cases of tuberculosis were reported in this group. The incidence rate among people born abroad was about seven times higher than that observed in people born in France (38.9/105 vs 5.2/105). The incidence was also the highest in districts with a high proportion of socioeconomically vulnerable population, such as Paris and greater Paris area. The characteristics of French born and non-French born cases differed. Patients born abroad were less likely to have pulmonary tuberculosis (68.2% vs 78.2; p < 0.001) and were more likely to live in institutions (such as migrant shelters) and to harbor multiresistant tuberculosis strains. A national tuberculosis control program was launched in France in 2007, to decrease the prevalence of tuberculosis in targeted populations.  相似文献   
998.
An inverse relationship between workplace status and morbidity is well established; higher job status has been associated with reduced risks of heart disease, hypertension, and injury. Most research on job status, however, has focused on salaried populations, and it remains unclear whether job status operates similarly among hourly workers. Our objectives were to examine whether hourly status itself influences risk of hypertension after adjustment for socioeconomic confounders, and to explore the role of fine-scale job grade on hypertension incidence within hourly and salaried groups. We examined data for 14,999 aluminum manufacturing employees in 11 plants across the U.S., using logistic regression with adjustment for age, sex, race/ethnicity and other individual characteristics. Propensity score restriction was used to identify comparable groups of hourly and salaried employees, reducing confounding by sociodemographic characteristics. Job grade (coded 1 through 30, within hourly and salaried groups) was examined as a more refined measure of job status. Hourly status was associated with an increased risk of hypertension, after propensity restriction and adjustment for confounders. The observed effect of hourly status was stronger among women, although the propensity-restricted cohort was disproportionately male (96%). Among salaried workers, higher job grade was not consistently associated with decreased risk; among hourly employees, however, there was a significant trend, with higher job grades more protective against hypertension. Increasing the stringency of hypertension case criteria also increased the risk of severe or persistent hypertension for hourly employees.  相似文献   
999.
1000.
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