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   2460篇
  免费   112篇
  国内免费   9篇
耳鼻咽喉   26篇
儿科学   22篇
妇产科学   27篇
基础医学   526篇
口腔科学   23篇
临床医学   194篇
内科学   329篇
皮肤病学   143篇
神经病学   176篇
特种医学   108篇
外科学   367篇
综合类   15篇
预防医学   121篇
眼科学   44篇
药学   193篇
中国医学   26篇
肿瘤学   241篇
  2023年   15篇
  2022年   21篇
  2021年   49篇
  2020年   32篇
  2019年   38篇
  2018年   57篇
  2017年   41篇
  2016年   50篇
  2015年   79篇
  2014年   86篇
  2013年   100篇
  2012年   173篇
  2011年   179篇
  2010年   105篇
  2009年   93篇
  2008年   117篇
  2007年   123篇
  2006年   130篇
  2005年   146篇
  2004年   106篇
  2003年   83篇
  2002年   81篇
  2001年   57篇
  2000年   45篇
  1999年   73篇
  1998年   22篇
  1997年   14篇
  1996年   17篇
  1995年   17篇
  1994年   10篇
  1993年   14篇
  1992年   29篇
  1991年   40篇
  1990年   45篇
  1989年   43篇
  1988年   30篇
  1987年   36篇
  1986年   25篇
  1985年   9篇
  1984年   13篇
  1983年   11篇
  1979年   8篇
  1975年   11篇
  1974年   12篇
  1973年   7篇
  1972年   12篇
  1971年   12篇
  1970年   7篇
  1969年   7篇
  1968年   7篇
排序方式: 共有2581条查询结果,搜索用时 10 毫秒
991.
The aims of this study were to evaluate the prevalence, severity and risk factors for atopic dermatitis in Korean pre-school children as determined by dermatological examination vs questionnaire survey. A total of 6,453 pre-school children from 59 kindergartens and 14 day-care centres were evaluated. Parents responded to an International Study of Asthma and Allergies in Childhood (ISAAC)-based questionnaire containing questions concerning 23 risk factors, as well as the prevalence, and severity of atopic dermatitis. Fourteen dermatologists then examined the participants according to the Korean diagnostic criteria for atopic dermatitis, and the Eczema Area and Severity Index (EASI) score. Atopic dermatitis prevalence determined by dermatological examination was lower than the questionnaire-based prevalence (9.2% vs 19.1%). Most patients (96.2%) had mild atopic dermatitis according to the EASI score (mean?±?SD 3.91?±?4.73; median 1.5; range 0.2-38.0). However, 17.4% had sleep disturbance, and 56.7% had not obtained complete remission of their rash over the previous 12 months. Among the 12 risk factors, "changing the patient's house to a newly built house during the first year of life" had significant odds ratio. In conclusion, the prevalence of atopic dermatitis in Korea in the ISAAC-based survey conducted by paediatricians was similar to that in several European countries, and lower than the 2006 Korean figure (28.9%). In addition, the prevalence of atopic dermatitis was lower when assessed by dermatological examination than by questionnaire.  相似文献   
992.
This study presents the production and purification of the positron emitting radionuclide 63Zn. A natural copper target was irradiated with 13.5 MeV protons, and 63Zn was purified by cation exchange chromatography using 0.05 N HCl‐85% acetone as eluent. The production yield reached 1.41 ± 0.19 GBq/μA?h at the end of bombardment and 169 ± 30 MBq/μA·h after purification, with more than 99.9% of radionuclidic purity with copper content around 0.04 μg/g. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   
993.
994.
995.
Niu KY  Ro JY 《Neuroscience letters》2011,487(2):223-227
The present study was conducted to examine cytokine profiles in the masseter muscle before and after complete Freund's adjuvant (CFA)-induced inflammation and possible sex differences in the cytokine levels. Age matched male and female Sprague Dawley rats were injected with CFA in the mid-region of the masseter muscle. Muscle tissue surrounding the injection site was extracted 6 h, 1, 3 and 7 days after the injection to measure TNF-α, IL-1β, IL-6 and IL-4 levels with Luminex multi-analyte profiling (xMAP) technology. The cytokine levels were compared to those obtained from naïve rats. CFA injection into the masseter muscle led to a significant time effect in the level of TNF-α compared to that of naïve rats. The pattern of changes in TNF-α level after CFA injection was significantly different between the male and female rats owing to the differences in basal levels. CFA injection induced significant time-dependent increases in the levels of IL-1β and IL-6 in the masseter muscle in both male and female rats. The level of IL-4 was slightly, but significantly, reduced in both sexes at 6 h and 3 days after CFA-induced inflammation. No significant sex differences were observed in the levels of IL-1β, IL-6 or IL-4. The results provided novel information about distinct cytokine profiles during CFA-induced muscle inflammation, and the basis for further pursuing contributions of each cytokine in pain processing and analgesic responses in both sexes.  相似文献   
996.

Purpose

The present study was aimed at evaluating the usefulness of box simulators for training novice endoscopists.

Materials and Methods

An explanation of the goals, contents, and features of the simulator was given to study participants. The participants then received "hands-on training" in gastrointestinal endoscopy techniques using a box simulator. Subsequently, they were asked to answer 19 structured questions about the simulator. Ratings were scored on a scale from 1 to 5 for questions concerning their first impression of the simulator. Questions on the usefulness of the simulator and the training course were answered as "agree", "disagree", or "no opinion".

Results

A total of 32 participants filled out the questionnaire. The mean scores on the simulator''s usefulness, features, and realistic movements before the training were between 1.5 and 2.0. There were no significant differences between the mean values of the scores given by novice users compared to non-novice users. However, after receiving training on the simulator, 90.6% of the participants considered the box simulator a generally useful tool for learning basic endoscopic techniques, and 90.6% agreed that the simulator was useful for improving hand-eye coordination.

Conclusion

Box simulators may be useful for training novice endoscopists in basic gastrointestinal endoscopic techniques.  相似文献   
997.
Bone mineral density (BMD) using dual energy radiography absorptiometry are commonly used for the diagnosis of osteoporosis. It is usually measured at the spine and also at one hip joint. Controversy still exists regarding the use of bilateral hip scanning. We analyzed the difference of BMD at bilateral hips in 384 postmenopausal women, retrospectively. The concordance and discordance rates of the lowest T-score and BMD between both hips were evaluated. The BMDs of the femoral neck and trochanter were significantly different between both hips (P < 0.05). There were also discrepancies between the lowest T-scores of both hips (P < 0.05). The discordance rates were about 30%. Due to significant differences in BMD between both hips at the femoral neck and trochanter and high discordance rate, bilateral hip measurements using DEXA are recommended to avoid underestimating osteoporosis.  相似文献   
998.
999.
1000.
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