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   4349篇
  免费   297篇
  国内免费   43篇
耳鼻咽喉   24篇
儿科学   64篇
妇产科学   30篇
基础医学   596篇
口腔科学   117篇
临床医学   298篇
内科学   1304篇
皮肤病学   63篇
神经病学   192篇
特种医学   122篇
外科学   712篇
综合类   16篇
预防医学   126篇
眼科学   124篇
药学   331篇
中国医学   11篇
肿瘤学   559篇
  2023年   53篇
  2022年   71篇
  2021年   202篇
  2020年   115篇
  2019年   116篇
  2018年   172篇
  2017年   106篇
  2016年   134篇
  2015年   130篇
  2014年   139篇
  2013年   179篇
  2012年   265篇
  2011年   293篇
  2010年   159篇
  2009年   131篇
  2008年   194篇
  2007年   246篇
  2006年   236篇
  2005年   221篇
  2004年   189篇
  2003年   175篇
  2002年   167篇
  2001年   94篇
  2000年   94篇
  1999年   92篇
  1998年   59篇
  1997年   40篇
  1996年   50篇
  1995年   27篇
  1994年   24篇
  1993年   16篇
  1992年   52篇
  1991年   55篇
  1990年   29篇
  1989年   29篇
  1988年   28篇
  1987年   30篇
  1986年   35篇
  1985年   39篇
  1984年   16篇
  1983年   23篇
  1982年   8篇
  1981年   13篇
  1979年   15篇
  1977年   10篇
  1976年   10篇
  1974年   11篇
  1971年   14篇
  1970年   9篇
  1969年   8篇
排序方式: 共有4689条查询结果,搜索用时 15 毫秒
71.
72.
In addition to BCR, various rare fusion partners for the ABL1 gene have been reported in leukemia. We have identified the fusion gene SNX2‐ABL1 in a pediatric case of acute lymphoblastic leukemia (ALL), which has only once previously been reported in an adult patient. Cytogenetic analysis detected this fusion gene arising from a t(5;9)(q22;q34) translocation. ALL cells carrying a SNX2‐ABL1 fusion exhibited a BCR‐ABL1+ ALL‐like gene expression profile. The patient poorly responded to dasatinib but partially responded to imatinib. Treatment using tyrosine kinase inhibitors requires further investigation to optimize the genotype‐based treatment stratification for patients with SNX2‐ABL1 fusion.  相似文献   
73.
74.
75.
76.
[Purpose] This study aimed to clarify the required number of measurements to calculate trunk muscle thickness at each position. [Participants and Methods] The participants were 30 elderly males aged >65 years. The right lumbar multifidus (L2), lumbar multifidus (L5), erector spinae, transversus abdominis, internal oblique, and external oblique muscle thicknesses were measured on longitudinal images obtained using ultrasonography in the lying, sitting, and standing positions. Two measurement values for each muscle thickness was used to calculate the intraclass correlation coefficient (1.1–1.5). [Results] The intraclass correlation coefficients of the abdominal muscle thickness measurements with “great reliabilities” were as follows: 1.3–1.5 for the external oblique muscle and 1.2–1.5 for the internal oblique and transversus abdominis muscles in the lying position; 1.3–1.5 for the external oblique and transversus abdominis muscles and 1.2–1.5 for the internal oblique muscle in the sitting position; the intraclass correlation coefficient in the standing position was 1.5 for the external oblique muscle 1.1–1.5 for the internal oblique muscle and 1.3–1.5 for the transversus abdominis muscle. In all the positions, the intraclass correlation coefficient of the measurements of the back-muscle thicknesses ranged from 1.1 to 1.5 for the right lumbar multifidus (L2), lumbar multifidus (L5), and erector spinae. [Conclusion] Depending on the posture, the abdominal muscles require multiple measurements, whereas the back muscles only require a single measurement.Key words: Intraclass correlation coefficient, Trunk muscle thicknesses, Ultrasonography  相似文献   
77.
78.
79.
Melatonin (MEL) has been reported to enhance cognitive processes, making it a potential treatment for cognitive decline. However, the role of MEL’s metabolites, N1‐acetyl‐N2‐formyl‐5‐methoxykynuramine (AFMK) and N1‐acetyl‐5‐methoxykynuramine (AMK), in these effects are unknown. The current study directly investigated the acute effects of systemic MEL, AFMK, and AMK on novel object recognition. We also analyzed MEL, AFMK, and AMK levels in hippocampus and temporal lobe containing the perirhinal cortex following systemic MEL and AMK treatment. AMK administered post‐training had a more potent effect on object memory than MEL and AFMK. AMK was also able to rescue age‐associated declines in memory impairments when object memory was tested up to 4 days following training. Results from administering AMK at varying times around the training trial and the metabolism time course in brain tissue suggest that AMK’s memory‐enhancing effects reflect memory consolidation. Furthermore, inhibiting the MEL‐to‐AMK metabolic pathway disrupted object memory at 24 hours post‐training, suggesting that endogenous AMK might play an important role in long‐term memory formation. This is the first study to report that AMK facilitates long‐term object memory performance in mice, and that MEL crosses the blood‐brain barrier and is immediately converted to AMK in brain tissue. Overall, these results support AMK as a potential therapeutic agent to improve or prevent memory decline.  相似文献   
80.
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