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   6383篇
  免费   434篇
  国内免费   31篇
耳鼻咽喉   34篇
儿科学   235篇
妇产科学   147篇
基础医学   860篇
口腔科学   119篇
临床医学   584篇
内科学   1402篇
皮肤病学   114篇
神经病学   637篇
特种医学   135篇
外国民族医学   1篇
外科学   620篇
综合类   67篇
一般理论   4篇
预防医学   689篇
眼科学   81篇
药学   441篇
中国医学   19篇
肿瘤学   659篇
  2024年   7篇
  2023年   80篇
  2022年   165篇
  2021年   275篇
  2020年   189篇
  2019年   219篇
  2018年   255篇
  2017年   196篇
  2016年   213篇
  2015年   201篇
  2014年   299篇
  2013年   341篇
  2012年   613篇
  2011年   624篇
  2010年   337篇
  2009年   264篇
  2008年   385篇
  2007年   416篇
  2006年   374篇
  2005年   363篇
  2004年   288篇
  2003年   248篇
  2002年   204篇
  2001年   29篇
  2000年   11篇
  1999年   18篇
  1998年   48篇
  1997年   29篇
  1996年   22篇
  1995年   19篇
  1994年   24篇
  1993年   9篇
  1992年   7篇
  1991年   9篇
  1990年   7篇
  1989年   9篇
  1988年   5篇
  1987年   9篇
  1986年   3篇
  1985年   5篇
  1984年   5篇
  1983年   3篇
  1982年   8篇
  1980年   2篇
  1979年   2篇
  1978年   4篇
  1977年   1篇
  1975年   1篇
  1974年   1篇
  1969年   1篇
排序方式: 共有6848条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.

Objective

We present a case of acrodermatitis enteropathica in a full-term, breast-fed, 7-mo-old infant born from consanguineous parents with a family history of acrodermatitis enteropathica.

Methods

The patient presented with periorificial and symmetric acral lesions, which prompted us to review the clinical features of acrodermatitis enteropathica and its pathogenesis. Laboratory investigations showed low zinc levels in the infant’s and mother’s sera and in the mothers’ milk.

Results

A diagnosis of acrodermatitis enteropathica was made. A mutation screening of the SLC39A4 gene in the patient and his mother showed heterozygosity for the deletion c.1223_1227delCCGGG. The diagnosis of transient symptomatic zinc deficiency was then established.

Conclusion

Transient symptomatic zinc deficiency is generally reported in premature infants but should also be considered in full-term, breast-fed infants, as in the present case.  相似文献   
995.
The aim of this study was to evaluate if there were alterations in FSH plasma levels in female outdoor workers (traffic policewomen and drivers) exposed to chemical urban stressors vs. control group. After excluding subjects with main confounding factors, traffic policewomen, drivers and indoor workers were matched by age, working life, socioeconomic status, marital status, menstrual cycle day, age of menarche, habitual consumption of Italian coffee and soy. A total of 129 female subjects were included in the study: some 63 workers studied during proliferative phase and 66 during secretory phase of menstrual cycle. Proliferative phase of menstrual cycle: FSH mean values were significantly higher in traffic policewomen compared to controls (p < 0.05). Results suggest that in outdoor workers exposed to urban chemical stressors there are alterations in FSH levels; therefore FSH may be used as an early biological marker, valuable for the group, used in occupational set.  相似文献   
996.
997.
998.
BackgroundGreat interest has been raised recently by the design of new adoptive immunotherapeutic strategies based on the in vivo infusion of ex vivo-expanded and activated natural killer (NK) cells. The development of good manufacturing practice (GMP) methods for the efficient production of fully functional NK cells is mandatory for clinical application.ResultsNK-cell populations expanded on average 15.7±4.7 fold by day 14, with a viability of 96% ±0.5. At the end of the incubation period, 97% ±1.1 of the expanded population was CD56+ NK cells; these effector cells showed significant up-regulation of the activating receptors NKG2D and DNAM-1. Functional tests demonstrated that expanded NK cells are fully functional with no difference whether tested before cryopreservation or after thawing.DiscussionThese data provide the basis for developing new NK-cell-based immunotherapeutic strategies for the treatment of patients with cancer.  相似文献   
999.
BACKGROUND:Fraction of exhaled nitrous oxide (FeNO) is a known marker of airway inflammation and a topic of recent investigation for asthma control in children.OBJECTIVE:To investigate the relationship among FeNO and bronchodilator response measured by spirometry and types of inhaled corticosteroids (ICS).METHODS:A one-year review of children tested with spirometry and FeNO in a regional pediatric asthma centre was conducted.RESULTS:A total of 183 children were included (mean [± SD] age 12.8±2.8 years). Fluticasone was used most commonly (n=66 [36.1%]), followed by ciclesonide (n=50 [27.3%]). Most children (n=73 [39.9%]) had moderate persistent asthma. Increased FeNO was associated with percent change in forced expiratory volume in 1 s (FEV1) after bronchodilator adjusted for allergic rhinitis, parental smoking and ICS type (B=0.08 [95% CI 0.04 to 0.12]; P<0.001). Similarly, FeNO was associated with percent change in forced expiratory flow at 25% to 75% of the pulmonary volume (FEF25–75) after bronchodilator adjusted for parental smoking and ICS type (B=0.13 [95% CI 0.01 to 0.24]; P=0.03). FeNO accounted for only 16% and 9% of the variability in FEV1 and FEF25–75, respectively. Mean-adjusted FeNO was lowest in fluticasone users compared with no ICS (mean difference 18.6 parts per billion [ppb] [95% CI 1.0 to 36.2]) and there was no difference in adjusted FeNO level between ciclesonide and no ICS (5.9 ppb [95% CI −9.0 to 20.8]).CONCLUSION:FeNO levels correlated with bronchodilator response in a regional pediatric asthma centre. However, FeNO accounted for only 16% and 9% of the variability in FEV1 and FEF25–75, respectively. Mean adjusted FeNO varied according to ICS type, suggesting a difference in relative efficacy between ICS beyond their dose equivalents.  相似文献   
1000.
The objective of this study was to characterize HIV-serodiscordant heterosexual couples and to evaluate acceptance for HIV testing and HIV prevalence in nonindex partners. We conducted a cross-sectional study with quantitative and qualitative components. Two cohorts of 1767 HIV-positive people were screened to identify heterosexual HIV-serodiscordant couples. HIV-positive partners (index) were administered a questionnaire; CD4, viral load (VL), and antiretroviral therapy (ART) history were gathered from clinical records. HIV-negative/unknown status partners (nonindex) were invited for a similar questionnaire and HIV testing. In-depth interviews with three HIV-serodiscordant couples were conducted. Two hundred and ninety-seven index partners agreed to enroll in this study. The median duration of the relationship was 10 years, and 81% were sexually active. All but two index partners were on ART, and 98% had VL < 1000 copies/mL. Only 111 (37%) nonindex partners came for HIV testing, and all of them tested HIV-negative. In addition, only 41% of nonindex partners had HIV testing in the last one year. The main reasons for the nonindex partners not to come for HIV testing were “no interest” (n = 117, 63%) and “nondisclosure of HIV status” (n = 46, 25%). The latter was substantiated and explained by the qualitative outcome of this study, suggesting relation to stigma against HIV-positive people. Our results support the WHO recommendation for starting ART for treatment and prevention in HIV-serodiscordant couples at any CD4 count. Furthermore, we recommend the dissemination of data showing that no HIV transmission in heterosexual couples through sex practice has been observed provided VL is suppressed. This could be a powerful tool for effective fight against stigma and self-stigma in people living with HIV.  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