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   343篇
  免费   27篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   1篇
妇产科学   6篇
基础医学   47篇
口腔科学   3篇
临床医学   23篇
内科学   130篇
皮肤病学   2篇
神经病学   32篇
特种医学   21篇
外科学   49篇
综合类   3篇
预防医学   12篇
眼科学   3篇
药学   16篇
肿瘤学   22篇
  2024年   1篇
  2023年   14篇
  2022年   22篇
  2021年   15篇
  2020年   11篇
  2019年   13篇
  2018年   21篇
  2017年   10篇
  2016年   13篇
  2015年   12篇
  2014年   16篇
  2013年   21篇
  2012年   32篇
  2011年   38篇
  2010年   13篇
  2009年   7篇
  2008年   12篇
  2007年   13篇
  2006年   14篇
  2005年   15篇
  2004年   15篇
  2003年   13篇
  2002年   8篇
  2001年   4篇
  2000年   3篇
  1999年   2篇
  1998年   1篇
  1997年   7篇
  1993年   1篇
  1991年   1篇
  1987年   1篇
  1969年   1篇
  1967年   1篇
排序方式: 共有371条查询结果,搜索用时 15 毫秒
21.
The study aimed to evaluate lifestyle factors among Information Technology (IT) workers from Romania before and during the pandemic. We used an online applied questionnaire, filled in by 1638 respondents, that assessed nutrition status-Body Mass Index (BMI), weight and diet change, physical activity, alcohol consumption, number of hours working in front of the computer, stress, and sleep. Multivariate logistic regression was used to establish the lifestyle factors that lead to weight gain. Although the level of physical activity (PA) was low before the pandemic, the results of our study showed a further decrease in physical activity. In total, 61.1% of men and 71.1% of women performed PA for less than 30 min per day. Weight gain was reported in 50.5% of men and 45.3% of women (mean weight gain was 5.11 ± 3.52 kg) as a result of increased screen time (with a mean of 3.52 ± 4.29 for females and 3.05 ± 2.09 for males, p > 0.05 h per day) and the reported changes in diet. Despite the popularity of home-cooked foods, the intake of vegetables and fruit remained low. The quality of sleep was poor for 55.7% of the respondents. Public health and corporation policies are required to encourage a healthy lifestyle and avoid chronic diseases.  相似文献   
22.
In population groups where head pose cannot be assumed to be constant during a magnetic resonance spectroscopy examination or in difficult‐to‐shim regions of the brain, real‐time volume of interest, frequency, and shim optimization may be necessary. We investigate the effect of pose change on the B0 homogeneity of a (2 cm)3 volume and observe typical first‐order shim changes of 1 μT/m per 1° rotation (chin down to up) in four different volumes of interest in a single volunteer. An echo planar imaging volume navigator was constructed to measure and apply in real‐time within each pulse repetition time: volume of interest positioning, frequency adjustment, and first‐order shim adjustment. This volume navigator is demonstrated in six healthy volunteers and achieved a mean linewidth of 4.4 Hz, similar to that obtained by manual shim adjustment of 4.9 Hz. Furthermore, this linewidth is maintained by the volume navigator at 4.9 Hz in the presence of pose change. By comparison, a mean linewidth of 7.5 Hz was observed, when no correction was applied. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.  相似文献   
23.
A sexual dimorphism in hypertension has been observed in both human and laboratory animal studies. The mechanisms by which male sex hormones regulate cardiovascular homeostasis are still not yet fully understood and represent the subject of this study. The possible involvement of androgen receptors in the development of hypertension and end-organ damage in transgenic rats harboring the mouse Ren-2 renin gene [TGR(mREN2)27] was studied. Male TGR(mREN2)27 rats were treated with the androgen receptor antagonist Flutamide starting at 4 wk of age. Also, an androgen receptor mutation (testicular feminization mutation [tfm]) was introduced in these rats by crossbreeding male TGR(mREN2)27 rats with tfm rats. The resulting offspring male rats that contain the tfm mutation are insensitive to androgens. Flutamide treatment or tfm mutation produced a significant attenuation of the development of hypertension. Besides a reduction in cardiac hypertrophy, urinary albumin excretion was blunted and no histologic characteristics of end-organ damage were observed in the kidney after Flutamide treatment. Testosterone levels increased 15-fold after Flutamide treatment and 2.7-fold by the tfm mutation. Also, plasma estrogens and luteinizing and follicle-stimulating hormones were significantly increased. Plasma renin concentrations and activity but not plasma angiotensinogen were reduced. Our results indicate that androgens contribute not only to the development of hypertension, but even more importantly to end-organ damage in TGR(mREN2)27 rats.  相似文献   
24.
25.
The standard method of immunomagnetic separation for isolating pathogenic bacteria from food and environmental matrices processes 1 ml volumes. Pathogens present at low levels (<0.5 pathogenic bacteria/g) will not be consistently detected by this method. Here a multiple sample flow through immunomagnetic separator has been designed and tested to process large volume samples (50 to 250 ml). Preliminary results show >97% recovery of polydisperse magnetic particles (diameter range 1 to 8 microm) containing 29-33% w/w Fe3O4 content. Between 70 and 130 times more of the pathogenic bacteria Escherichia coli O157 is recovered from PBS compared with the standard 1 ml method. Also, the recovery of E. coli O157 from beef mince homogenates, after a 4 h incubation at 42 degrees C, is between 80 and 180 times higher than the standard 1 ml method.  相似文献   
26.
Management of hemophilic pseudotumor of thumb in a child   总被引:1,自引:0,他引:1  
A case of hemophilic pseudotumor of the thumb in a child is reported. Combined treatment with radiation therapy and factor VIII replacement resulted in complete resolution of the lesion with no recurrence at the 6-month follow-up. The combination of radiotherapy and factor replacement should be strongly considered in the treatment of bone pseudotumors in children.  相似文献   
27.
28.
In a retrospective analysis of 150 incompletely resected NSCLC patients treated with adjuvant external beam radiotherapy 32 (21.3%) survived 3 years with no symptoms of disease. Ipsilateral mediastinal/hilar lymph node involvement and macroscopic incomplete surgery were the prognostic factors that unfavourably influenced survival in Cox's proportional hazards model. Postoperative external beam radiotherapy was the efficient adjuvant treatment method in microscopically incompletely resected NSCLC, predominantly with no nodes involvement, but had no benefit in those with macroscopic incomplete surgery.  相似文献   
29.
30.
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