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   6203篇
  免费   419篇
  国内免费   16篇
耳鼻咽喉   28篇
儿科学   198篇
妇产科学   139篇
基础医学   1085篇
口腔科学   67篇
临床医学   694篇
内科学   1157篇
皮肤病学   188篇
神经病学   578篇
特种医学   146篇
外科学   498篇
综合类   81篇
一般理论   4篇
预防医学   794篇
眼科学   170篇
药学   330篇
中国医学   17篇
肿瘤学   464篇
  2023年   49篇
  2022年   57篇
  2021年   158篇
  2020年   86篇
  2019年   122篇
  2018年   156篇
  2017年   126篇
  2016年   149篇
  2015年   166篇
  2014年   223篇
  2013年   325篇
  2012年   408篇
  2011年   496篇
  2010年   263篇
  2009年   244篇
  2008年   430篇
  2007年   373篇
  2006年   398篇
  2005年   431篇
  2004年   355篇
  2003年   352篇
  2002年   307篇
  2001年   61篇
  2000年   53篇
  1999年   48篇
  1998年   60篇
  1997年   53篇
  1996年   49篇
  1995年   42篇
  1994年   39篇
  1993年   47篇
  1992年   35篇
  1991年   25篇
  1990年   28篇
  1989年   25篇
  1988年   26篇
  1987年   16篇
  1986年   21篇
  1985年   23篇
  1984年   26篇
  1983年   23篇
  1982年   24篇
  1981年   15篇
  1980年   16篇
  1979年   15篇
  1978年   12篇
  1976年   15篇
  1975年   23篇
  1974年   14篇
  1973年   17篇
排序方式: 共有6638条查询结果,搜索用时 234 毫秒
91.
Botulinum neurotoxins (BoNTs) cause the life-threatening neurological illness botulism in humans and animals and are divided into seven serotypes (BoNT/A–G), of which serotypes A, B, E, and F cause the disease in humans. BoNTs are classified as “category A” bioterrorism threat agents and are relevant in the context of the Biological Weapons Convention. An international proficiency test (PT) was conducted to evaluate detection, quantification and discrimination capabilities of 23 expert laboratories from the health, food and security areas. Here we describe three immunological strategies that proved to be successful for the detection and quantification of BoNT/A, B, and E considering the restricted sample volume (1 mL) distributed. To analyze the samples qualitatively and quantitatively, the first strategy was based on sensitive immunoenzymatic and immunochromatographic assays for fast qualitative and quantitative analyses. In the second approach, a bead-based suspension array was used for screening followed by conventional ELISA for quantification. In the third approach, an ELISA plate format assay was used for serotype specific immunodetection of BoNT-cleaved substrates, detecting the activity of the light chain, rather than the toxin protein. The results provide guidance for further steps in quality assurance and highlight problems to address in the future.  相似文献   
92.
93.
Klinefelter syndrome (KS) is a common genetic condition that is currently under-diagnosed. The phenotype is broad, with physical, medical and psychosocial features ranging from mild to severe. When a child is diagnosed with KS, the parents may spend months to years searching for a diagnosis. This study used a qualitative methods approach to explore parents'' experiences of having a child with KS and receiving a diagnosis. Fifteen semistructured one-to-one in-depth interviews were conducted to explore their experiences and views. The interviews were then transcribed, coded and thematically analysed. The interviews revealed that parents had diverse experiences related to: the timing of the diagnosis of their child and reasons why their child was investigated for KS; the information that was provided at the time of diagnosis; the supports that were available and the concerns that parents held for the future of their child. The conclusions from this study were that parents'' experiences of having a child with KS and receiving a diagnosis were complex and multifaceted. This experience was shaped by the timing of when the diagnosis was received, who provided the diagnosis, what information was provided from health-care professionals and that which parents may have encountered on the internet. The long-term experiences for parents were also impacted by the level of support they received. These findings have implications for the process by which KS is recognised by the health-care community and supports available for families.  相似文献   
94.
95.
96.
97.
Objectivethis study was performed to determine the predictive capacity of four different bioelectrical impedance analysis (BIA) devices in the assessment of adolescents, with and without a protocol.Methodsa cross-sectional study was performed with 215 adolescents aged 10 to 14 years, of both genders, evaluated through anthropometry and body composition by dual energy X-ray absorptiometry (DXA) and by four different BIA devices, with and without a protocol. The following tests were used: Kolmogorov-Smirnov's, chi-squared, Student's t or Mann-Whitney's, Kruskal-Wallis's, Wilcoxon's, and kappa index. The ROC curves were constructed and the sensitivity, specificity, and positive and negative predictive values were calculated.Resultsof the 215 adolescents, 44.2% had excessive body fat. The tetrapolar BIA device equipped with eight tactile electrodes showed more sensitivity and results that were closer to those obtained by DXA (area under the ROC curve [AUC] = 0.964 with protocol and AUC = 0.973 without protocol, p < 0.001), as well as greater agreement (k = 0.67 with protocol and k = 0.63 without protocol, p < 0.001). The evaluation without protocol was similar to that by DXA in most investigated situations (p > 0.05).ConclusionBIA is capable of predicting alterations in adolescents’ body composition. When it is impossible to perform the assessment with a protocol, its results may be useful in population studies.  相似文献   
98.
99.
Maternal and Child Health Journal - Intimate partner violence (IPV) around the time of pregnancy is a risk factor for adverse pregnancy and birth outcomes. The supplemental nutrition program for...  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