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   800篇
  免费   55篇
  国内免费   63篇
耳鼻咽喉   36篇
儿科学   48篇
妇产科学   9篇
基础医学   93篇
口腔科学   28篇
临床医学   108篇
内科学   184篇
皮肤病学   20篇
神经病学   21篇
特种医学   97篇
外科学   76篇
综合类   38篇
预防医学   53篇
眼科学   4篇
药学   55篇
中国医学   2篇
肿瘤学   46篇
  2022年   10篇
  2021年   19篇
  2020年   8篇
  2019年   19篇
  2018年   24篇
  2017年   15篇
  2016年   18篇
  2015年   22篇
  2014年   30篇
  2013年   40篇
  2012年   18篇
  2011年   26篇
  2010年   33篇
  2009年   38篇
  2008年   34篇
  2007年   65篇
  2006年   35篇
  2005年   26篇
  2004年   18篇
  2003年   14篇
  2002年   14篇
  2001年   12篇
  2000年   6篇
  1999年   17篇
  1998年   36篇
  1997年   37篇
  1996年   24篇
  1995年   24篇
  1994年   30篇
  1993年   20篇
  1992年   5篇
  1991年   12篇
  1990年   3篇
  1989年   19篇
  1988年   24篇
  1987年   14篇
  1986年   4篇
  1985年   10篇
  1984年   7篇
  1983年   4篇
  1982年   10篇
  1981年   12篇
  1980年   8篇
  1978年   7篇
  1977年   8篇
  1976年   13篇
  1975年   5篇
  1970年   3篇
  1967年   3篇
  1966年   3篇
排序方式: 共有918条查询结果,搜索用时 0 毫秒
41.
42.
Hypertension and headache   总被引:2,自引:0,他引:2  
  相似文献   
43.
44.
We present a simple method for preparing an ear wick for treating otitis externa in ENT outpatient clinics. In our experience, this method is efficient, economical and clean, and ensures an equal distribution of the medication along the wick.  相似文献   
45.
46.
The purpose of our study was to systematically evaluate gastric acid output in children with long-lasting gastro-esophageal reflux (GER) in order to assess its mechanism and the need for anti-acid treatment. The investigation was carried out in 20 males and 10 females, aged 7.5 +/- 3.8 years, with prolonged (>15 months) clinical manifestations of GER. All underwent routine ambulatory 24-h esophageal pH-monitoring and measurement of gastric acid secretion including gastric basal (BAO) (micromol/kg/h), maximal (MAO) and peak acid outputs (PAO) after pentagastrin (6 microg/kg sec) stimulation. Children with heartburn or abdominal pain underwent upper fiber-endoscopy. In group A (moderate GER, n=12), patients had a normal reflux index (pH<4 below 5.2% of total recording time) despite abnormal Euler and Byrne scoring (median 57, 95% confidence interval 53.5-73.4). In group B (severe GER, n=18, among whom 5 were with grade III esophagitis), reflux index was >5.2%. When considering all children, esophageal pH (%) was significantly correlated with MAO and PAO, r=0.33, p=0.05 and r=0.37, p=0.04, respectively. Children of group B exhibited significantly higher BAO (75, 53.96-137.81), MAO (468, 394.1-671.3) and PAO (617, 518.8-782.3) than those of group A, BAO (27, 10.8-38.5), MAO (266, 243.2-348.2) and PAO (387, 322.5-452.7), p<0.05). The five children of group B with severe esophagitis exhibited significantly higher BAO, MAO and PAO than the other 13 children from the same group and those of group A, p<0.05. Children with long-lasting and severe GER hyper-secrete gastric acid. Individual variations in gastric acid secretion probably account for variations in gastric acid inhibitor requirements. Anti-secretory treatment is justified in children with long-lasting GER and high pH-metric reflux index.  相似文献   
47.
48.
杜晓川  贾红梅  莫显斌 《医学争鸣》1999,20(9):S046-S046
1 病例报告 男,7岁.因双下肢不等长,右膝及右踝关节骨性肿大就诊.无明显外伤史,亦无红、肿、热、痛病史.查体:发育正常,营养良好.双下肢不等长,左60cm,右64cm,有跛行.右膝及右踝内侧肿大,肤色正常,关节活动无异常.X线:右侧半身诸关节(肩、肘、腕、髋、膝、踝)骨骺及干骺发育均较左侧增大,肢体较长,骨骺出现亦较对侧提早.如右尺骨茎突骨骺较左侧提早出现(图1).右肘关节肱骨小头骨骺较左侧增大(图2).右髋臼发育浅平,边缘毛糙,右股骨头骨骺较左侧明显增大,其距泪滴之距离较左侧大1.0cm,呈…  相似文献   
49.

INTRODUCTION

Severe symptomatic aortic stenosis is associated with a poor prognosis, with most patients dying 2–3 years after diagnosis. We analysed the proportion of patients with severe aortic stenosis not referred for aortic valve replacement (AVR) in a UK-based population and the clinical factors contributing to this.

METHODS

Retrospective analysis of patients with echocardiographic evidence of severe aortic stenosis was performed at a university teaching hospital.

RESULTS

A total of 178 consecutive patients with severe aortic stenosis (AVA: <1cm2, mean pressure gradient: ≥40mmHg, or visually severe on echocardiography) were included in the study. Eighty-three patients did not have AVR (95% confidence interval: 39–54%). The cohort included 146 symptomatic patients (82%) and 32 (18%) who were asymptomatic. The most common reason for non-referral in symptomatic patients was ‘high operative risk’ and in asymptomatic patients ‘no symptoms’. Of the patients who did not have AVR, only 19% (n=16) were referred for a surgical opinion. None of the patients in the asymptomatic group underwent echocardiographic stress imaging. The thirty-day operative mortality rate in the AVR group was 2.3%. Symptomatic patients who underwent AVR had superior survival, even after adjusting for co-morbidities (p<0.001).

CONCLUSIONS

A considerable proportion of patients with severe aortic stenosis are not referred for surgery although they have a clear indication for AVR. Patients are often estimated as being too high risk or having prohibitive co-morbidities. Among asymptomatic patients, stress imaging was rarely used despite its useful role prognostically and in deciding the best time for intervention.  相似文献   
50.

Background

Adequate vitamin D concentrations during pregnancy are necessary to neonatal calcium homeostasis, bone maturation and mineralization. The aim of study is to evaluate serum vitamin D concentrations in mothers and their newborns and effect of vitamin D deficiency on pregnancy outcomes.

Methods

552 pregnant women were recruited from Tehran University educating hospitals in the winter of 2002. Maternal and cord blood samples were taken at delivery. The serum was assayed for 25-hydroxyvitamin D3, calcium, phosphorus and parathyroid hormone.

Results

The prevalence of vitamin D deficiency in maternal and cord blood samples were 66.8% and 93.3%, respectively (<35 nmol/l). There was significant correlation between maternal and cord blood serum concentrations of vitamin D. In mothers with vitamin D deficiency, cord blood vitamin D concentrations was lower than those from normal mothers (P = .001). Also, a significant direct correlation was seen between maternal vitamin D intake and weight gain during pregnancy.

Conclusion

Consideration to adequate calcium and vitamin D intake during pregnancy is essential. Furthermore, we think it is necessary to reconsider the recommendation for vitamin D supplementation for women during pregnancy.  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