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   22326篇
  免费   1671篇
  国内免费   2381篇
耳鼻咽喉   260篇
儿科学   165篇
妇产科学   73篇
基础医学   4520篇
口腔科学   2879篇
临床医学   1951篇
内科学   2455篇
皮肤病学   121篇
神经病学   5294篇
特种医学   859篇
外科学   2613篇
综合类   1957篇
现状与发展   8篇
预防医学   837篇
眼科学   874篇
药学   873篇
  6篇
中国医学   424篇
肿瘤学   209篇
  2023年   290篇
  2022年   444篇
  2021年   1044篇
  2020年   820篇
  2019年   725篇
  2018年   701篇
  2017年   821篇
  2016年   857篇
  2015年   738篇
  2014年   1390篇
  2013年   1759篇
  2012年   1218篇
  2011年   1246篇
  2010年   1117篇
  2009年   973篇
  2008年   1005篇
  2007年   943篇
  2006年   979篇
  2005年   847篇
  2004年   772篇
  2003年   736篇
  2002年   643篇
  2001年   562篇
  2000年   421篇
  1999年   426篇
  1998年   389篇
  1997年   408篇
  1996年   350篇
  1995年   318篇
  1994年   269篇
  1993年   243篇
  1992年   266篇
  1991年   258篇
  1990年   230篇
  1989年   194篇
  1988年   178篇
  1987年   182篇
  1986年   179篇
  1985年   204篇
  1984年   191篇
  1983年   109篇
  1982年   126篇
  1981年   124篇
  1980年   105篇
  1979年   88篇
  1978年   80篇
  1977年   68篇
  1976年   56篇
  1973年   58篇
  1972年   47篇
排序方式: 共有10000条查询结果,搜索用时 56 毫秒
1.
2.
Rhabdomyolysis is a syndrome of skeletal muscle injury with release of cellular constituents such as potassium,phosphate,urate and intracellular proteins such as myoglobin into the circulation,which may cause complications including acute kidney injury,electrolyte disturbance and cardiac instability.Abnormal liver function tests are frequently observed in cases of severe rhabdomyolysis.Typically,there is an increase in serum aminotransferases,namely aspartate aminotransferase and alanine aminotransferase.This raises the question of liver injury and often triggers a pathway of investigation which may lead to a liver biopsy.However,muscle can also be a source of the increased aminotransferase activity.This review discusses the dilemma of finding abnormal liver function tests in the setting of muscle injury and the potential implications of such an association.It delves into some of the clinical and experimental evidence for correlating muscle injury to raised aminotransferases,and discusses pathophysiological mechanisms such as oxidative stress which may cause actual liver injury.Serum aminotransferases lack tissue specificity to allow clinicians to distinguish primary liver injury from muscle injury.This review also explores potential approaches to improve the accuracy of our diagnostic tools,so that excessive or unnecessary liver investigations can be avoided.  相似文献   
3.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS.  相似文献   
4.
5.
Peripheral nerves connect brain and spinal cord with the extremities and inner organs, and nerves injury can lead the disability and social exclusion. Growth factors and other natural stimulators of regeneration processes look very promising as future medicines. In our study, we tested the influence of genetic constructions that contain genes of brain-derived neurotrophic factor and urokinase plasminogen activator on nerve's structure and function after traumatic and ischemic injuries. Injection of pVax1-hBDNF and pVax1-muPA after traumatic injury led to better restoration of nerve's structure and function compared to similar parameters of control group mice. In ischemic injury model pVax1-hBDNF and pVax1-muPA slowed and reduced the damage progression and stimulated nerve regeneration as well. However, the treatment with pVax1-muPA was less effective after the traumatic injury. As we chose a non-viral method of gene delivery during our study the optimal conditions of plasmid intramuscular delivery were also determined.  相似文献   
6.
7.
8.
In the work described here, our aim was to determine, in an elderly population, changes in muscle thickness (MT), cross-sectional area (CSA) and echo intensity (EI) of the quadriceps muscles at four time points (0, 5, 10 and 15 min; i.e., T0, T5, T10 and T15, respectively) after changing from a standing to supine position. Twenty-one elderly participants (14 men: 68.1 ± 4.6 y; 8 women: 66.8 ± 4.1 y) were evaluated at four time points. Rectus femoris CSA (RFCSA), MT and EI of the quadriceps femoris (QF) muscles were assessed. EI significantly increased from T0 to T5, T10 and T15 (p < 0.001), whereas no differences were observed between T5 and T15 in the rectus femoris (RFEI), vastus intermedius (VIEI) and quadriceps femoris (QFEI). No differences were observed between any time points in the RFCSA and MT of QF muscles. In summary, these results suggest that periods >5 min are not necessary to obtain consistent MT and EI measurements of quadriceps femoris muscles in the elderly population.  相似文献   
9.
10.
本文回顾了Er:YAG激光活化根管冲洗技术的最新研究进展,包括光子诱导光声流(photon initiated photoacoustic streaming,PIPS)技术和冲击波增强发射光声流(shock wave enhanced emission photoacoustic streaming,SWEEPS)技术,探讨Er:YAG激光预处理桩道的原理、优点以及对纤维桩粘接强度的影响,以期为临床选择适宜的桩道处理方法提供新思路。  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