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   1335460篇
  免费   100217篇
  国内免费   4287篇
耳鼻咽喉   16799篇
儿科学   43588篇
妇产科学   36359篇
基础医学   197839篇
口腔科学   35902篇
临床医学   129580篇
内科学   258114篇
皮肤病学   26389篇
神经病学   111881篇
特种医学   48174篇
外国民族医学   366篇
外科学   184169篇
综合类   28772篇
现状与发展   1篇
一般理论   460篇
预防医学   114368篇
眼科学   28980篇
药学   98830篇
  6篇
中国医学   3167篇
肿瘤学   76220篇
  2021年   10909篇
  2019年   11639篇
  2018年   16321篇
  2017年   12291篇
  2016年   13250篇
  2015年   15196篇
  2014年   20810篇
  2013年   32061篇
  2012年   44260篇
  2011年   46904篇
  2010年   27092篇
  2009年   24939篇
  2008年   42731篇
  2007年   45075篇
  2006年   45179篇
  2005年   43606篇
  2004年   41569篇
  2003年   39507篇
  2002年   38312篇
  2001年   60857篇
  2000年   62517篇
  1999年   52289篇
  1998年   14582篇
  1997年   13278篇
  1996年   13116篇
  1995年   12460篇
  1994年   11627篇
  1993年   10921篇
  1992年   41574篇
  1991年   40760篇
  1990年   39449篇
  1989年   37343篇
  1988年   34583篇
  1987年   33696篇
  1986年   32152篇
  1985年   30639篇
  1984年   23036篇
  1983年   19594篇
  1982年   11753篇
  1979年   20806篇
  1978年   14814篇
  1977年   12064篇
  1976年   11876篇
  1975年   12111篇
  1974年   14800篇
  1973年   14472篇
  1972年   13356篇
  1971年   12418篇
  1970年   11485篇
  1969年   10410篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
BACKGROUND: Impaired neuropsychological test performance, especially on tests of executive function and attention, is often seen in children diagnosed with autism spectrum disorders (ASD). Structures involved in fronto-striatal circuitry, such as the caudate nucleus, may support these cognitive abilities. However, few studies have examined caudate volumes specifically in children with ASD, or correlated caudate volumes to cognitive ability. METHODS: Neuropsychological test scores and caudate volumes of children with ASD were compared to those of children with bipolar disorder (BD) and of typically developing (TD) children. The relationship between test performance and caudate volumes was analyzed. RESULTS: The ASD group displayed larger right and left caudate volumes, and modest executive deficits, compared to TD controls. While caudate volume inversely predicted performance on the Wisconsin Card Sorting Test in all participants, it differentially predicted performance on measures of attention across the ASD, BD and TD groups. CONCLUSIONS: Larger caudate volumes were related to impaired problem solving. On a test of attention, larger left caudate volumes predicted increased impulsivity and more omission errors in the ASD group as compared to the TD group, however smaller volume predicted poorer discriminant responding as compared to the BD group.  相似文献   
102.
SETTING: Tuberculosis (TB) cases reported from nine districts of Madrid, where the percentage of immigrant population varied from 1.9% in 1996 to 12.2% in 2003. OBJECTIVE: To describe the trends in TB incidence from 1994 to 2003. DESIGN: Observational study. RESULTS: Between 1994-1995 and 2002-2003, the TB rate decreased from 48.5 (95% CI 45.8-51.1) to 23.3 per 100000 population (95% CI 21.5-25.1) (P < 0.001). The percentage of TB cases co-infected with HIV decreased from 55.9% in 1994 to 14.3% in 2003 (P < 0.001), whereas TB cases in foreigners increased from 2.6% in 1994 to 33.7% in 2003 (P < 0.001). CONCLUSION: Although the TB rates showed a marked decrease in the study period, the increasing impact of immigration contributed to slowing down the trend.  相似文献   
103.
104.
105.
PURPOSE: Recommendations of the interdisciplinary Safe Medication Use Expert Committee of the United States Pharmacopeia (USP) to assist health care professionals, manufacturers, and organizations in handling neuromuscular blocking agents (NMBAs) safely and effectively are discussed. SUMMARY: Review and analysis of the USP Medication Errors Reporting Program and MEDMARX program databases showed a continuing risk of patient harm or death due to errors with NMBAs. Medication errors involving wrong concentrations, wrong doses, wrong drugs, look-alike packaging, and sound-alike names, combined with lack of monitoring and communication, have been associated with the use of NMBAs in health care institutions. Serious adverse events occur when NMBAs are used without adequate safeguards. Recommendations for improving safety were developed through review and discussion of root causes and areas of concern with these medications. CONCLUSION: Medical errors with NMBAs continue to result in patient morbidity and mortality. Increased awareness and action on the part of all parties involved are needed to improve the safety of this class of medications.  相似文献   
106.
107.
108.
French asthma patients may be supervised by general practitioners (GPs) and/or specialists. Therefore, this study examined asthma management in patients exclusively supervised by specialists (SPE), GPs, (GP) and both (GP+SPE group), and compared the findings. Asthma patients were consecutively recruited in 348 pharmacies. Each patient completed a questionnaire providing data on personal characteristics, asthma management, perception of disease and asthma supervision. Asthma control was measured using the Asthma Control Test. Questionnaires were linked to computerised records of medications which had been dispensed before inclusion in the study. From the 1,256 patients (mean age = 36.1 yrs, 54.3% females), 11.4, 36.6, and 52.0% were placed in the SPE, GP, and GP+SPE groups, respectively. During the previous 4 weeks, most patients in the SPE group were properly controlled (52.2 versus 26.4 and 21.5% in GP and GP+SPE groups, respectively). The SPE group made more use of fixed combinations of long-acting beta agonist and inhaled corticosteroid, while receiving less short-acting beta agonists, antitussives and antibiotics. Striking differences in symptoms and asthma management were observed according to the type of asthma supervision. The current results strongly support the need to improve the management of asthma in primary care, and the coordination of care between general practitioners and specialists.  相似文献   
109.
110.
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