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   11950篇
  免费   914篇
  国内免费   34篇
耳鼻咽喉   93篇
儿科学   420篇
妇产科学   227篇
基础医学   1608篇
口腔科学   191篇
临床医学   1390篇
内科学   2418篇
皮肤病学   188篇
神经病学   1353篇
特种医学   430篇
外科学   1415篇
综合类   94篇
一般理论   9篇
预防医学   1087篇
眼科学   187篇
药学   1026篇
中国医学   13篇
肿瘤学   749篇
  2023年   161篇
  2022年   197篇
  2021年   447篇
  2020年   255篇
  2019年   392篇
  2018年   403篇
  2017年   307篇
  2016年   371篇
  2015年   350篇
  2014年   426篇
  2013年   600篇
  2012年   871篇
  2011年   796篇
  2010年   436篇
  2009年   391篇
  2008年   664篇
  2007年   639篇
  2006年   605篇
  2005年   547篇
  2004年   505篇
  2003年   446篇
  2002年   367篇
  2001年   226篇
  2000年   201篇
  1999年   199篇
  1998年   100篇
  1997年   82篇
  1996年   84篇
  1995年   68篇
  1994年   56篇
  1993年   69篇
  1992年   148篇
  1991年   136篇
  1990年   130篇
  1989年   156篇
  1988年   120篇
  1987年   121篇
  1986年   115篇
  1985年   78篇
  1984年   80篇
  1983年   58篇
  1982年   45篇
  1981年   42篇
  1980年   35篇
  1979年   55篇
  1978年   35篇
  1977年   32篇
  1976年   26篇
  1975年   27篇
  1971年   29篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Background: Traumatic brain injury (TBI) results in verbal recall deficits and impaired processing of emotion encoded in facial appearance, prosody and the linguistic content of messages. Emotion facilitates memory (emotional memory advantage) for non-brain injured (NBI) individuals but the impact of emotion on verbal recall for linguistically encoded stimuli in TBI has not been explored.

Aims: The purpose of this study was to determine the effects of stimulus emotional content on verbal recall of words and paragraphs in TBI compared to NBI individuals.

Methods and procedures: Six 10-item lists, each with five emotional and five neutral words, and six paragraphs (three emotional, three neutral) were counterbalanced and presented in random order to 20 individuals with TBI and 44 NBI. The number of words from lists and the number of content units from paragraphs were compared for the two groups.

Outcomes and results: The NBI participants recalled more words from the lists and content units from the paragraphs than the individuals with TBI. Both groups recalled significantly more emotional than neutral words. NBI but not TBI participants had significantly greater recall for information in paragraphs with emotional content.

Conclusions: Participants with TBI showed impaired recall of words and paragraph content. Emotion facilitated word and paragraph content recall for neurotypical individuals but emotional memory advantage was limited to words for the TBI participants.  相似文献   

3.
4.
5.
6.
Children show a clear preference, throughout development, for high energy density foods, and particularly for sweet and/or fat products. Most parents disapprove of this behavior, in the present context of high obesity prevalence and widespread acceptance of thinness as a model. Children’s appetite for such foods has adaptive value, so far as the growing child has not lost his/her ability for energy adjustment. A few studies suggest that excessive control over children’s food choices contributes to a loss of the child’s capacity to energy adjustment. Education models that include both the teaching of rules and adjustments to the child’s requests seem to facilitate the acquisition of adequate eating behaviors, which favor a varied diet and body weight control.  相似文献   
7.
Abstract The aim of the present clinical trial was to test tolerability during 2 treatments with EMDOGAIN® in a large number of patients. An open, controlled study design in 10 Swedish specialist clinics was chosen, with a test group of 107 patients treated with EMDOGAIN® in connection with periodontal surgery at 2 surgical test sites per patient. The procedures were performed 2 to 6 weeks apart on one-rooted teeth with at least 4 mm deep intraosseous lesions. A control group of 33 patients underwent flap surgery without EMDOGAIN® at I comparable site. In total 214 test and 33 control surgeries were performed. Serum samples were obtained from test patients for analysis of total and specific antibody levels. 10 of the patients had samples taken before and after the first surgery. 56 other samples were taken after one treatment with EMDOGAIN®, and 63 after 2 treatments. None of the samples, not even from allergy-prone patients after 2 treatments, indicated deviations from established baseline ranges. This indicates that the immunogenic potential of EMDOGAIN® is extremely low when applied in conjunction with periodontal surgery. Comparison between the test and control groups demonstrated the same type and frequency of post-surgical experiences, i.e., reactions caused by the surgical procedure itself. Clinical probing and radiographic evaluation was performed at baseline and 8 months postsurgery. About half of the patients (44 test and 21 control) were also evaluated after 3 years. There was a significant difference between the test and control results at 8 months post surgery. and this difference had increased further at the 3 year follow-up. The 2.5–3 mm increase in attachment and bone level after treatment with EMDOGAIN® was of the same magnitude as seen in the studies with split-mouth design aiming for lest of effectiveness of EMDOGAIN®.  相似文献   
8.
Using the buttock flap in 29 white Yorkshire pigs, blood flow and O2 consumption were measured at dermal temperatures between 35 degrees C and 15 degrees C. Flow was measured with an electromagnetic flowmeter and O2 consumption was calculated as the product of blood flow and the difference in flap A-VO2. Baseline flow was 6.6 +/- .9 (SE) ml/100 g/min at 35 degrees C and 3.1 +/- .02 (SE) ml/10 g/min at 15 degrees C. Blood flow through the flap stopped completely at a dermal temperature of 14 degrees C. Oxygen consumption was 0.16 +/- .02 (SE) ml/100 g/min at 35 degrees C and 0.04 +/- 0.01 (SE) ml/100 g/min at 15 degrees C. At 20 degrees C blood flow was 4.3 ml/100 g/min and metabolism was .04 ml/100 g/min. In other words, blood flow was 65% of baseline, while O2 consumption was only 25% of baseline. The therapeutic effect of local cooling at 20 degrees C deserves further investigation. The cessation of flow at 14 degrees C may be caused by increased plasma viscosity.  相似文献   
9.
10.
Urticaria is a common condition, seldom of allergic origin. It is however not always possible to find the provoking allergen. The aim of the present study was to analyze if there was a relationship between urticaria and sensitization to common airborne allergens. A representative sample of 402 12 to 13-yr-old children answered a questionnaire on allergic diseases, 397 were interviewed by the study nurse and 371 underwent skin prick tests to cat, dog, horse, birch, timothy-grass, house dust mites and Cladosporium mould. Specific IgE-antibodies were analyzed to birch pollen and cat dander. Urticaria was more common in sensitized children, but the relationship between urticaria and sensitization was only statistically significant for birch pollen sensitization (OR 1.99, 95% CL 1.04-3.83), when tested in a multiple logistic regression model with the specified allergens as independent variables. A similar pattern was seen for birch-specific IgE-antibody levels, which was higher in children reporting urticaria than in those without. IgE-levels to cat dander did not show such a difference. Urticaria was statistically significantly associated with sensitization to birch-pollen, but not to other common inhalant allergens. We propose that intake of birch-pollen cross-reactive food-stuffs may be a neglected cause of urticaria and relapsing urticaria, in birch-pollen sensitized subjects.  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