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   14190篇
  免费   1421篇
  国内免费   517篇
耳鼻咽喉   31篇
儿科学   263篇
妇产科学   128篇
基础医学   1738篇
口腔科学   60篇
临床医学   3243篇
内科学   3511篇
皮肤病学   42篇
神经病学   882篇
特种医学   1547篇
外科学   830篇
综合类   1107篇
现状与发展   2篇
预防医学   1309篇
眼科学   40篇
药学   631篇
  13篇
中国医学   428篇
肿瘤学   323篇
  2024年   76篇
  2023年   308篇
  2022年   570篇
  2021年   777篇
  2020年   769篇
  2019年   669篇
  2018年   626篇
  2017年   645篇
  2016年   575篇
  2015年   556篇
  2014年   810篇
  2013年   1121篇
  2012年   702篇
  2011年   651篇
  2010年   612篇
  2009年   517篇
  2008年   565篇
  2007年   516篇
  2006年   457篇
  2005年   360篇
  2004年   342篇
  2003年   348篇
  2002年   273篇
  2001年   316篇
  2000年   269篇
  1999年   226篇
  1998年   205篇
  1997年   184篇
  1996年   206篇
  1995年   184篇
  1994年   133篇
  1993年   171篇
  1992年   177篇
  1991年   131篇
  1990年   116篇
  1989年   108篇
  1988年   128篇
  1987年   125篇
  1986年   94篇
  1985年   91篇
  1984年   65篇
  1983年   46篇
  1982年   65篇
  1981年   48篇
  1980年   63篇
  1979年   33篇
  1978年   20篇
  1977年   16篇
  1976年   21篇
  1975年   16篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Summary The chronotropic response to a single oral dose of propranolol in 23 healthy subjects has been related to the plasma propranolol concentration and the density of -adrenoceptors on peripheral polymorphonuclear leucocytes. The percentage reduction in exercise-induced tachycardia was significantly correlated with the log plasma propranolol concentration within subjects but not between subjects. Taking the concentration of the active metabolite 4-hydroxypropranolol into account did not improve the interindividual correlation. The reduction in exercise-induced tachycardia was significantly correlated with the maximum binding density of (125I)-hydroxybenzylpindolol on polymorphonuclear leucocyte membrane fragments measured before medication. A response index (% reduction in exercise-induced tachycardia/plasma propranolol concentration) was correlated with the maximum binding density of (125I)-hydroxybenzylpindolol (predrug) at 2 h (rs=0.72), 4 h (rs=0.84) and 6 h (rs=0.73) after dosing. The data suggest that interindividual variation in the response to propranolol after a single oral dose is determined by interindividual differences both in plasma propranolol and adrenoceptor density.  相似文献   
43.
目的观察健康青年人在等长收缩运动(IE)时血浆内啡肽(EOPs)的变化.方法选择健康自愿受试者40例,男女各20例,平均年龄(23.7±2.9)岁,研究设置二种模型即主观运动和被动运动.观察指标包括血浆中的亮氨酸脑啡肽(LEK)、β-内啡呔(β-END)和强啡呔(DYN).结果LEK、β-END、DYN在IE中均有不同程度的变化.结论在IE中LEK、DYN的变化程度较β-END明显(P<0.01).  相似文献   
44.
《Journal of hand therapy》2021,34(4):555-560
Study DesignThis is a basic science research.IntroductionIsolating excursion of the flexor digitorum profundus (FDP) in zones I and II is common practice in the current management after flexor tendon repair. During this procedure, the proximal interphalangeal joint is sometimes fully extended with unmeasured external forces at the middle phalanx when the distal interphalangeal joint is actively flexed.Purpose of the StudyThe purpose of the study was to investigate the incremental effect of external force with palmar blocking versus lateral blocking and increased angles of flexion on internal tendon forces at the repair site for a safer application of force by the treating therapist.MethodsEight human cadaveric fingers were studied. To simulate palmar or lateral finger blocking, a compression force of blocking was applied from 5N (510 grams) to 25N (2,550 grams) on the skin surface of the palmar or the lateral aspect of each of these middle phalanges in 5N increments. The tensile load on the FDP tendon during distal interphalangeal joint flexion from 0° to 60° was measured in 10° increments.ResultsDuring palmar blocking, the tensile load was significantly increased with increases in palmar blocking force. However, no significant increase in the tensile load on the FDP tendon was observed at any lateral blocking.DiscussionLateral blocking exercise can be performed with less tensile force on the FDP tendon when performing blocking exercise after flexor tendon injury repair.ConclusionsThis study supports the concept that lateral blocking with incremental joint angles allows a safer application of force for the healing tendon.  相似文献   
45.
Knee and hip osteoarthritis (OA) place a significant burden on the Canadian health system and are a major public health challenge. This brief commentary discusses the recently published Osteoarthritis Research Society International guideline and the American College of Rheumatology guideline for the management of OA. Special attention has been given to the role of manual therapy, exercise, and patient education for the treatment of knee and hip OA. This article also reviews the Good Life with osteoArthritis in Denmark (GLA:D®) treatment program for knee and hip OA and the implementation of this program in Canada. Lastly, the authors discuss the opportunity for the Canadian chiropractic profession to embrace treatment programs like GLA:D® and take an active role in the strengthening of the Canadian health system from a musculoskeletal perspective.  相似文献   
46.
IntroductionSystemic sclerosis/scleroderma (SSc) is a chronic autoimmune disease with connective tissue, multi-organ, and multisystem involvement. The disease has three main characteristics, namely vasculopathy, fibrosis, and autoimmunity. The effect of high-intensity interval training (HIIT) in aerobic exercise on other rheumatic diseases has been studied, for example in patients with rheumatoid arthritis (RA) and juvenile idiopathic arthritis (JIA). The purpose of this work is to investigate the effectiveness of HIIT of aerobics exercise on improving the inspiratory muscle, quality of life and functional ability for systemic sclerosis subjects.Material and methodsThe study was conducted on patients with confirmed systemic sclerosis who met the inclusion criteria. The research was carried out for 12 months in the outpatient clinic and gait laboratory of the Department of Physical Medicine and Rehabilitation.ResultsAfter HIIT in aerobic exercise, we found significant changes in inspiratory muscle (SNIP values 45.67 [30.92] vs. 54.25 [22.71]), handgrip (13.14 [4.42] vs. 15.63 [4.08]), walking speed (184.70 [26.86] vs. 246.6 [12.30]), metabolic equivalent (3.53 [0.30] vs. 4.21 [1.25]) and Scleroderma-Specific Health Assessment Questionnaire Disability Index for all visual analog scale (VAS) domains except Disability Index. Exercise approaches are characterized by repeated cycles of exercise interrupted by rest. For a range of clinical conditions, HIIT in aerobic exercise is known to remedy blood vessel function.ConclusionsOur results suggest that HIIT in aerobic exercise has improved functional ability, respiratory muscle strength, and quality of life in SSc subjects. Training twice a week in a 12-week HIIT program is considered to be safe for this population. We have to consider internal and external factors that influenced the result. A larger sample and further exploration of the feasibility of combined exercise in SSc patients should be the focus for future research.  相似文献   
47.
48.
恒力法测量运动对动物肌腱,韧带横截面积的影响   总被引:2,自引:0,他引:2  
本文介绍一种方便,适用的肌腱,韧带横截面积的测量工具-软组织横截面积测微计。通过对兔屈趾肌腱反复测量,其重复性精密度在0.044mm以内,变异系数在1.4%以下,用该测微计对大强度训练一段时间后的兔屈趾肌腱,跟腱和膝内侧副韧带的测量发现,训练训练后FDP,AC的横截面积减小,MCL有增大的趋势,据此,作用认为肌腱的变化与长期大强度训练后试件的“疲劳蠕变”有关,MCL的变化则与在体内的负荷形式有关。  相似文献   
49.
为了解QTcd、JTcd在心电图活动平板运动试验结果判断中的价值 ,对 10 0例活动平板运动试验阳性者及 80例阴性者运动前后的心电图QTcd、JTcd进行对比观察。结果表明 :运动前两组QTcd、JTcd差异均无显著性 ( P〉0 .0 5 ) ;运动后 2min运动试验阳性组与阴性组比较 ,QTcd、JTcd差异有高度显著性 (P <0 .0 1) ;阳性组运动试验后 2minQTcd、JTcd均较运动前显著延长 ( P <0 .0 1) ;阴性组运动后 2minQTcd、JTcd与运动前比较差异无显著性 ( P >0 .0 5 )。认为运动试验后QTcd、JTcd延长可作为判断运动试验结果的指标。  相似文献   
50.
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