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   11563篇
  免费   1135篇
  国内免费   538篇
耳鼻咽喉   16篇
儿科学   485篇
妇产科学   82篇
基础医学   1179篇
口腔科学   47篇
临床医学   951篇
内科学   2331篇
皮肤病学   46篇
神经病学   635篇
特种医学   256篇
外国民族医学   5篇
外科学   1346篇
综合类   1923篇
现状与发展   3篇
预防医学   893篇
眼科学   31篇
药学   1540篇
中国医学   1067篇
肿瘤学   400篇
  2024年   67篇
  2023年   253篇
  2022年   516篇
  2021年   551篇
  2020年   427篇
  2019年   421篇
  2018年   374篇
  2017年   403篇
  2016年   418篇
  2015年   404篇
  2014年   570篇
  2013年   802篇
  2012年   559篇
  2011年   640篇
  2010年   516篇
  2009年   460篇
  2008年   426篇
  2007年   474篇
  2006年   495篇
  2005年   420篇
  2004年   384篇
  2003年   379篇
  2002年   290篇
  2001年   271篇
  2000年   257篇
  1999年   203篇
  1998年   185篇
  1997年   183篇
  1996年   186篇
  1995年   167篇
  1994年   185篇
  1993年   147篇
  1992年   122篇
  1991年   96篇
  1990年   109篇
  1989年   110篇
  1988年   87篇
  1987年   69篇
  1986年   59篇
  1985年   81篇
  1984年   74篇
  1983年   65篇
  1982年   63篇
  1981年   55篇
  1980年   54篇
  1979年   39篇
  1978年   27篇
  1977年   21篇
  1976年   15篇
  1971年   12篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.

Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.

Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.

Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion.  相似文献   
3.
4.
5.
6.
BackgroundPercutaneous endoscopic gastrostomy (PEG) is required for Levodopa/Carbidopa Intestinal Gel (LCIG) delivery in patients with advanced Parkinson's disease (PD) as well as for enteral feeding in a variety of neurological disorders. Buried Bumper Syndrome (BBS) is a serious complication of PEG. The frequency of BBS in patients receiving LCIG treatment has never been reported.ObjectivesTo compare the frequency of BBS in patients on LCIG treatment or on enteral feeding over the past 12 years and identify possible risk factors.MethodsWe reviewed prospectively recorded data from 2009 to 2020 on two case-series: LCIG-treated PD patients and non-PD patients on enteral nutrition. We identified all BBS incidences. Patients’ characteristics, clinical manifestations, BBS management, possible risk factors and outcomes were analyzed.ResultsDuring the 12 years, 35 PD patients underwent PEG insertion for LCIG infusion, and 123 non-PD patients for nutritional support. There were eight cases of BBS in six PD patients (17.1%). Six of them were effectively managed without treatment discontinuation. Of the enteral feeding patients, only one developed BBS (0.8%) (p < 0.001). We identified inappropriate PEG site aftercare, weight gain, early onset PD, longer survival, treatment duration, dementia and PEG system design as potential risk factors for BBS development.ConclusionsBBS occurs more frequently in LCIG patients than in patients receiving enteral feeding. If detected early, it can be successfully managed, and serious sequalae or treatment discontinuation can be avoided. Regular endoscopic follow-up visits of LCIG-treated patients and increased awareness in patients and clinicians are recommended.  相似文献   
7.
The spatial distribution of enteroparasitosis in an indigenous village from Paraná was evaluated to identify areas of risk for these infections. A cross-sectional study (from November 2010 to June 2011) was performed using Three Faecal Test® and Kato &; Katz method and a questionnaire on housing and hygiene conditions was administered. Local geostatistical analyses were performed to determine the spatial distribution of intestinal parasitic infections. The overall prevalence of enteroparasites was 67.2?% (457/680), and the most prevalent taxa were Ascaris lumbricoides (48.8?%) and Trichuris trichiura (44.7?%). The prevalence of heavy infection by soil-transmitted helminths was 3.6?% and the families lived in houses with an average of 5.1 residents and < 2 bedrooms per household. The average number of species per individual present spatial heterogeneity with the highest values (≥0.8) in areas with high clustering of residences. The visualization of the spatial distribution of intestinal parasites in this indigenous village is an important contribution to determining health risk areas and planning decisions and services.  相似文献   
8.
9.
10.
工作相关肌肉骨骼疾患(WMSDs)是常见的慢性非传染性疾病。WMSDs已成为影响工人健康、降低工人生命质量和造成经济损失的重要因素,可见于多个行业、工种。本文对WMSDs流行现状及人体工效学负荷相关研究进行综述,以期找到职业人群保护的可行方法。  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