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   972篇
  免费   50篇
  国内免费   19篇
耳鼻咽喉   11篇
儿科学   40篇
妇产科学   15篇
基础医学   71篇
口腔科学   37篇
临床医学   76篇
内科学   280篇
皮肤病学   6篇
神经病学   55篇
特种医学   19篇
外科学   79篇
综合类   93篇
一般理论   6篇
预防医学   83篇
眼科学   53篇
药学   69篇
中国医学   2篇
肿瘤学   46篇
  2024年   2篇
  2023年   15篇
  2022年   96篇
  2021年   100篇
  2020年   45篇
  2019年   55篇
  2018年   53篇
  2017年   33篇
  2016年   26篇
  2015年   36篇
  2014年   59篇
  2013年   60篇
  2012年   75篇
  2011年   57篇
  2010年   29篇
  2009年   28篇
  2008年   38篇
  2007年   32篇
  2006年   27篇
  2005年   28篇
  2004年   38篇
  2003年   27篇
  2002年   26篇
  2001年   6篇
  2000年   5篇
  1999年   5篇
  1998年   4篇
  1997年   3篇
  1996年   7篇
  1995年   5篇
  1994年   2篇
  1993年   3篇
  1992年   2篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
  1988年   5篇
  1987年   1篇
  1986年   1篇
  1976年   1篇
  1972年   1篇
排序方式: 共有1041条查询结果,搜索用时 15 毫秒
91.
92.
93.
The objectives of this Community-based National Epidemiological Household Survey, conducted between 1990–1993, were to estimate the prevalence of overweight and obesity in Saudi Arabia and to examine its association with the socio-demographic characteristics of the adult population. A sample of Saudis 20 years and over was selected using a multistage stratified cluster sampling technique with probability proportionate to size. The selected subjects were requested to visit primary health care centers in their localities. Physicians in these clinics took measurements of heights and weights and collected other relevant data. Obesity was measured by the Body Mass Index, using the Quetelet Index. The results showed the sample of 10,651 subjects of which 50.8% were males, had a mean age of 35.8 years (SD = 14.27 years). The prevalence of overweight was 31.2% (95% confidence interval: 30.3%, 32.1%); 33.1% for males and 29.4% for females. For obesity, the overall prevalence was 22.1%; males 17.8% and females 26.6%. The study design suggested that these estimates could be closer to the true values. The multiple logistic regression analysis showed that age, residential area, region, income, gender, and education are statistically significant predictors of obesity. The prevalence of obesity was higher in females than males, lower in subjects living in rural areas with traditional lifestyles than those in more urbanized environments, and increased with increasing age. The observed prevalence and pattern of overweight and obesity with age and gender is similar to those observed in the Arab community and some Western nations. There is a need for increased physical activity and better nutrition education programs to reduce the extent of obesity and to pre-vent the serious health consequences, especially, in the middle age group.  相似文献   
94.
During a baseline survey of TST, 236 nurses underwent a two-step TST. Overall, 29 (12%) showed boosting. All age groups showed boosting; the rate was 9.7% in those younger than 35 years. Subjects older than 45 years were more likely to have a booster effect than younger individuals (29% vs 10.1%).  相似文献   
95.
In the era of antibiotics, Pott-Puffy Tumor PPT is a rarely recognized entity. An 11-year-old girl presented with headache, fever for one week, and frontal swelling for 3 days. On examination, she was febrile, congested nasal mucosa with yellowish nasal discharge and frontal swelling; tender not fluctuating with normal eye mobility. Computed tomography CT scan of brain and paranasal sinus revealed opacity of maxillary, left ethmoid, frontal sinus opacity and epidural collection in the right frontal region with post contrast enhancement. An extracranial superficial swelling with fluid collection at the same level of epidural collection. The patient underwent bilateral antral washout and left frontal sinus trephination, which had resulted into a complete resolving of symptoms and an avoidance of further invasive surgical intervention.  相似文献   
96.
97.
98.

Purpose

The clinical, endoscopic, and histologic findings of eosinophilic esophagitis (EoE) are well characterized; however, there have been very limited data regarding the radiologic findings of pediatric EoE. We report on the radiologic findings of pediatric EoE observed on barium esophagram and correlate them with the endoscopic findings.

Methods and materials

We identified children diagnosed with EoE in our center from 2004 to 2015. Two pediatric radiologists met after their independent evaluations of each fluoroscopic study to reach a consensus on each case. Clinical and endoscopic data were collected by retrospective chart review.

Results

Twenty-six pediatric EoE cases (age range 2–13 years; median 7.5 years) had barium esophagram done as part of the diagnostic approach for dysphagia. Thirteen children had abnormal radiologic findings of esophagus (50%): rings formation (n = 4), diffuse irregularity of mucosa (n = 8), fixed stricture formation (n = 3), and narrow-caliber esophagus (n = 10). Barium esophagram failed to show one of 10 cases of narrow-caliber esophagus and 10 of 14 cases of rings formation visualized endoscopically. The mean duration of symptoms prior to diagnosis of EoE was longer (3.7 vs. 1.7 year; p value 0.019), and the presentation with intermittent food impaction was commoner in the group with abnormal barium esophagram as compared to the group with normal barium esophagram (69% vs. 8%; p value 0.04).

Conclusion

Barium swallow study is frequently normal in pediatric EoE. With the exception of narrow-caliber esophagus, our data show poor correlation between radiologic and endoscopic findings.
  相似文献   
99.
Datta  R; Banach  D; Kojima  H; Talanian  RV; Alnemri  ES; Wong  WW; Kufe  DW 《Blood》1996,88(6):1936-1943
The response of human myeloid leukemia cells to treatment with 1-beta- arabinofuranosylcytosine (ara-C) includes the induction of apoptosis. Ara-C induced apoptosis is associated with proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) and protein kinase C (PKC) delta. However, the signals involved in this response are unknown. The present studies show that ara-C treatment of U-937 cells is associated with induction of a protease activity that cleaves the tetrapeptides Ac-DEVD- pNA and Ac-DMOD-pNA found at the cleavage sites of PARP and PKC delta, respectively. The ara-C-induced protease activity was sensitive to overexpression of the anti-apoptotic protein Bcl-xL and the baculovirus protein p35. By contrast, overexpression of the cowpox virus protein CrmA blocked apoptosis induced by engagement of the Fas receptor but not that induced by ara-C. CrmA overexpression also had no detectable effect on ara-C-induced cleavage of PKC delta. The results further show that ara-C induces activation of the CPP32 protease by a CrmA- insensitive and p35-sensitive mechanism. Similar results were obtained with cisplatinum, etoposide, and camptothecin. These findings indicate that ara-C and other DNA-damaging agents activate a CrmA-insensitive apoptotic pathway involving CPP32 and that these signals differ from those associated with apoptosis induced by the Fas receptor.  相似文献   
100.
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