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   29682篇
  免费   2175篇
  国内免费   1143篇
耳鼻咽喉   296篇
儿科学   231篇
妇产科学   202篇
基础医学   6396篇
口腔科学   698篇
临床医学   2696篇
内科学   4044篇
皮肤病学   162篇
神经病学   3758篇
特种医学   1443篇
外国民族医学   1篇
外科学   3783篇
综合类   3239篇
现状与发展   8篇
预防医学   1038篇
眼科学   638篇
药学   2992篇
  3篇
中国医学   985篇
肿瘤学   387篇
  2024年   91篇
  2023年   397篇
  2022年   781篇
  2021年   1014篇
  2020年   952篇
  2019年   862篇
  2018年   885篇
  2017年   821篇
  2016年   770篇
  2015年   862篇
  2014年   1418篇
  2013年   1674篇
  2012年   1357篇
  2011年   1520篇
  2010年   1301篇
  2009年   1281篇
  2008年   1297篇
  2007年   1355篇
  2006年   1250篇
  2005年   1090篇
  2004年   1057篇
  2003年   1018篇
  2002年   847篇
  2001年   736篇
  2000年   621篇
  1999年   582篇
  1998年   649篇
  1997年   667篇
  1996年   587篇
  1995年   501篇
  1994年   458篇
  1993年   418篇
  1992年   404篇
  1991年   396篇
  1990年   329篇
  1989年   297篇
  1988年   267篇
  1987年   233篇
  1986年   191篇
  1985年   262篇
  1984年   232篇
  1983年   131篇
  1982年   205篇
  1981年   186篇
  1980年   147篇
  1979年   132篇
  1978年   123篇
  1977年   105篇
  1976年   101篇
  1975年   41篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
A definition and systems view of anaerobic capacity   总被引:3,自引:0,他引:3  
The purpose of this paper is both to define terms used in exercise physiology, i.e. anaerobic capacity, anaerobic work capacity and anaerobic potential, and develop a systems perspective of anaerobic capacity. Philosophical argument is used to support the proposed definitions and systems view, which is an approach to assist in the universal acceptance of such terms amongst scientific investigators, coaches and athletes, and provide a focus on physiological mechanisms associated with anaerobic capacity which may be the subject of future investigation.  相似文献   
32.
Seven middle-aged men with manifest type II diabetes mellitus underwent an endurance training programme for 10–15 weeks. The maximal aerobic capacity, as well as the endurance capacity, was improved by 10% (p<0.05). The intramuscular glycogen store increased by more than 80% (p<0.05) from 350 μmol/g dw (dry weight), and the activities of citrate synthase and 3-hydroxy-acyl-CoA dehydrogenase increased by more than 50% (p<0.05) and 30% (p<0.05). The activity of glycogen synthase was decreased by approximately 20% (p<0.05), whereas lactate dehydrogenase remained unchanged. Capillaries/fibre and fibre area increased by more than 50% (p<0.05) and 30% (p<0.05) leaving the area of supply constant. Training did not influence fasting blood lipids and glucose, glycosylated hemoglobin, oral glucose tolerance, and insulin response to an oral glucose load measured 72 hours post-exercise. It is concluded that patients with manifest type II diabetes, as normoglycaemic individuals, adapt to physical training. However, no persistent effect on glucohomeostasis and lipaemia is produced by short-term training in the diabetic patients.  相似文献   
33.
Sixty-three women participated in a study in Calgary, Alberta to assess the rate of arm recovery and factors affecting it up to one year after axillary node dissection for breast cancer. Outcomes included objective measures of swelling, mobility, and strength, and subjective assessments of pain (at rest and with movement) and stiffness. Approximately 42% of women had residual impairment of at least one type one year after surgery, the most common problems being pain (16%) and reduced grip strength (16%). Except for lymphedema, measurements one year after surgery showed little change from measurements at 6 months, suggesting that the shorter follow-up may be appropriate for assessing the long term effects of axillary dissection. Lymphedema was the only sequela which increased over time. The results provide parameter estimates for designing studies to evaluate the role of physiotherapy after axillary dissection.  相似文献   
34.
We used 31P magnetic resonance spectroscopy to compare the response of rat skeletal muscle to three kinds of proton load. During exercise (tetanic sciatic nerve stimulation), protons from lactic acid were buffered passively and consumed by net hydrolysis of phosphocreatine (PCr). During recovery from exercise, the pH-dependent efflux of protons produced by PCr resynthesis could be partially inhibited by amiloride or 4,4′-diisothiocyanostilbene-2,2′-disulphonate (DIDS), implicating both sodiudproton and bicarbonatelchloride exchange, but was not inhibited by simultaneous respiratory acidosis. In early recovery, up to 30% of proton efflux was mediated by lactatelproton cotransport. During acute respiratory acidosis at rest, the eventual change in muscle pH was consistent with passive buffering and was unaffected by amiloride or DIDS, implying no significant contribution of proton fluxes.  相似文献   
35.
过去,为了保证前段的血液供应,外直肌全麻痹的手术治疗要分2~3次完成,考虑到全麻痹的外直肌已无功能,我们提出在这种条件下可以不动含睫状前动脉的外直肌,只退后内直肌和将上,下直肌的外侧1/2移到外直肌的附着处,如此安排,可以一次手术完成治疗,这样可以缩短治疗时间,减少病人的痛苦和负担,我们治疗了7例8眼,结果比较满意。  相似文献   
36.
37.
Summary This study determined the energy charge, adenosine and inosine content of human bladder smooth muscle in comparison with striated muscle of the same individual. Biopsies were obtained from 21 women who were subjected to urethrocystopexy because of urinary stress incontinence. We found that the ATP content of bladder smooth muscle was only about one-eighth of that of striated muscle. The energy charge of bladder smooth muscle was 0.78±0.13, which is low compared with striated muscle (0.92±0.02). The adenosine content of bladder smooth muscle was 6.7 times higher than striated muscle and the adenosine/ATP ratio was 1∶9 compared with 1∶450 for striated muscle. These findings were in accordance with our previous studies on uterine smooth muscle.  相似文献   
38.
39.
Signals generated from muscles other than the muscle(s) of interest (cross talk) can confound the interpretation of surface electromyograms (EMGs). In this study, the amount of cross talk in surface EMGs of human hamstring muscles was estimated using a protocol in which the quadriceps femoris was electrically stimulated via the femoral nerve. EMGs were recorded from the vastus lateralis and the medial and lateral hamstring muscle groups. The amplitude of the EMG response of the vastus lateralis to electrical stimulation was adjusted to match that of its maximum voluntary effort (MVE) under isometric conditions. Subsequent power density spectrum analysis showed that the median frequencies of the signals generated by electrical stimulation and MVE were not significantly different. In conventional bipolar recordings, cross talk in lateral hamstring EMGs averaged 17.1% MVE and in medial hamstring EMGs 11.3% MVE (average-rectified values). The double differential technique significantly reduced cross talk to 7.6% MVE for the lateral hamstrings, and to 4.2% MVE for the medial hamstrings. The double differential technique appears to be more selective than the bipolar technique when recording EMGs from muscles with highly active neighbors and thus should be used in such situations. Software simulations of the double differential technique also appear to be more selective than the bipolar technique and may be used when the number of amplifiers available is limited.  相似文献   
40.
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