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   3274篇
  免费   237篇
  国内免费   136篇
耳鼻咽喉   29篇
儿科学   20篇
妇产科学   19篇
基础医学   439篇
口腔科学   57篇
临床医学   295篇
内科学   192篇
皮肤病学   22篇
神经病学   372篇
特种医学   117篇
外科学   136篇
综合类   702篇
预防医学   525篇
眼科学   63篇
药学   207篇
  23篇
中国医学   378篇
肿瘤学   51篇
  2024年   8篇
  2023年   38篇
  2022年   90篇
  2021年   144篇
  2020年   123篇
  2019年   77篇
  2018年   84篇
  2017年   97篇
  2016年   103篇
  2015年   113篇
  2014年   175篇
  2013年   236篇
  2012年   193篇
  2011年   234篇
  2010年   168篇
  2009年   191篇
  2008年   188篇
  2007年   202篇
  2006年   188篇
  2005年   186篇
  2004年   117篇
  2003年   94篇
  2002年   85篇
  2001年   57篇
  2000年   59篇
  1999年   30篇
  1998年   42篇
  1997年   38篇
  1996年   29篇
  1995年   26篇
  1994年   19篇
  1993年   21篇
  1992年   13篇
  1991年   23篇
  1990年   12篇
  1989年   17篇
  1988年   7篇
  1987年   14篇
  1986年   12篇
  1985年   16篇
  1984年   14篇
  1983年   12篇
  1982年   7篇
  1981年   8篇
  1980年   11篇
  1979年   6篇
  1978年   5篇
  1977年   6篇
  1976年   6篇
  1968年   1篇
排序方式: 共有3647条查询结果,搜索用时 62 毫秒
31.
The diagnosis of erythema migrans (EM) is not always easy, and reports of culture- or PCR-confirmed diagnosis as well as reports of EM with simultaneous disseminated disease are few. Characteristics and incidence of EM in addition to frequency of early dissemination of B. burgdorferi were studied in the archipelago of South-Western Finland prospectively using questionnaires, skin biopsies and blood samples. Clinical EM was recognized in 82 patients (incidence 148/100,000 inhabitants/year). Of skin biopsy samples, 35.5% were positive by PCR (the majority B. garinii), and 21.5% by cultivation (all B. garinii). Of blood samples, 3.8% were positive by PCR, and 7.7% by cultivation. Of the patients, 30.9% were seropositive at the first visit, and 52.9% 3 weeks later. Of the patients with laboratory confirmed diagnosis, the EM lesion was ring-like in 31.8% and homogeneous in 65.9%. Dissemination of B. burgdorferi, based on culture or PCR positivity of blood samples, was detected in 11.0% of the patients. The frequency of generalized symptoms was nearly the same in patients with as in those without dissemination (22.2% vs 27.4%). Only 21.4% of the patients with culture-positive EM recalled a previous tick bite at the site of the EM lesion. We conclude that EM lesions are more often homogeneous than ring-like. B. burgdorferi may disseminate early without generalized symptoms.  相似文献   
32.
目的探讨大学生成就目标定向、自我效能感和状态焦虑之间的关系。方法随机抽取350名大学生进行问卷调查。结果①女生的状态焦虑水平显著高于男生,而自我效能感显著低于男生;文科学生焦虑水平显著高于理科学生。②合作取向目标和状态焦虑之间呈显著负相关,自我-趋向型目标和状态焦虑之间呈显著正相关;自我效能感和状态焦虑之间呈显著负相关;自我效能感和成就目标定向总分及合作取向目标、社会亲密目标、任务目标、自我-趋向型目标之间呈显著正相关,和自我-逃避型目标相关不显著。③自我-趋向型目标及自我效能感直接影响状态焦虑,合作取向目标和任务目标通过自我效能感间接影响状态焦虑。结论成就目标定向、自我效能感和状态焦虑之间关系密切。  相似文献   
33.
Previous studies have shown that patients with arm and hand paresis following stroke recruit an additional degree of freedom (the trunk) to transport the hand during reaching and use alternative strategies for grasping. The few studies of grasping parameters of the impaired hand have been case studies mainly focusing on describing grasping in the presence of particular impairments such as hemi-neglect or optic ataxia and have not focussed on the role of the trunk in prehension. We hypothesized that the trunk movement not only ensures the transport of the hand to the object, but it also assists in orienting the hand for grasping when distal deficits are present. Nineteen patients with chronic hemiparesis and seven healthy subjects participated in the study. Patients had sustained a stroke of non-traumatic origin 6–82 months previously (31±22 months) and had mild or moderate to severe arm paresis. Using a whole hand grasp, subjects reached and grasped a cylinder (35 mm) that was placed sagittally (T1) or at a 45° angle to the sagittal midline in the ipsilateral workspace (T2), both at about 90% arms length (10 trials per target). Eight infrared emitting diodes were placed on bony landmarks of the hand, arm and trunk and kinematic data were recorded by an optical motion analysis system (Optotrak) for 2–5 s at 120 Hz. Hand position and orientation were recorded by a Fastrack Polhemus system. Our results show that during goal-directed prehension tasks, individuals with hemiparesis oriented the hand more frontally for grasping and used more trunk anterior displacement or rotation to transport the hand to the target compared to healthy subjects. Despite these changes, the major characteristics of reaching and grasping such as grip aperture size, temporal coordination between hand transport and aperture formation and the relative timing of grip aperture were largely preserved. For patients with more severe distal impairments, the amount of trunk displacement was also correlated with a more frontal hand orientation for grasping. Furthermore, in healthy subjects and patients without distal impairments, the trunk movement was mostly related to proximal arm movements while in those with distal impairments, trunk movement was related to both proximal and distal arm movements. Data support the hypothesis that the trunk movement is used to assist both arm transport and hand orientation for grasping when distal deficits are present.  相似文献   
34.
Summary Orbital motion of the head with the face directed towards the axis of rotation is a stimulus to the otolith organs which is in the opposite rightwards-leftwards sense to the rotational stimulus to the semicircular canals. This can be experienced, for example, by a child held at arms length en face and swung from side to side. As one swings, say to the right, the child's head rotates to its right yet moves linearly to its left. Eye movement responses to a transient orbital movement were observed whilst subjects fixated earth-fixed targets, i) a near target placed between the head and the axis whose relative displacement is in the same direction as head rotation, and ii) a far target placed beyond the axis whose relative motion is in the opposite direction to head rotation. The motion stimuli evoked slow phase eye movements at 45 ms latency, always in the opposite direction to head rotation, thus compensating for the motion of the far target but in the wrong direction for fixating the near target. Theoretically, fixating the near target demands a predominance of the otolith ocularreflex, which would give an eye movement in the correct direction. However, despite visual cues, it seems that if the canal and otolith-ocular reflexes are evoked in opposing directions, the otolith reflex fails to operate at a sensitivity sufficiently high to reverse the direction of the canal-reflex.  相似文献   
35.
36.
Touch and pressure stimulation of the body surface can strongly influence apparent body orientation, as well as the maintenance of upright posture during quiet stance. In the present study, we investigated the relationship between postural sway and contact forces at the fingertip while subjects touched a rigid metal bar. Subjects were tested in the tandem Romberg stance with eyes open or closed under three conditions of fingertip contact: no contact, touch contact (<0.98 N of force), and force contact (as much force as desired). Touch contact was as effective as force contact or sight of the surroundings in reducing postural sway when compared to the no contact, eyes closed condition. Body sway and fingertip forces were essentially in phase with force contact, suggesting that fingertip contact forces are physically counteracting body sway. Time delays between body sway and fingertip forces were much larger with light touch contact, suggesting that the fingertip is providing information that allows anticipatory innervation of musculature to reduce body sway. The results are related to observations on precision grip as well as the somatosensory, proprioceptive, and motor mechanisms involved in the reduction of body sway.  相似文献   
37.
38.
ObjectivesThe aim of this study was to investigate the impact of mixed cognitive intervention training using spaced retrieval training, and errorless learning in participants with early onset dementia. This was based on reality orientation therapy for cognitive function, depression, and occupational performance of patients.MethodsTwo early onset vascular dementia patients (> 65 years) with mild or moderate impairment were enrolled in a pre-test - post-test single-subject research design study. Prior to the study, the caregivers were interviewed about meaningful times, people, places, and areas of interest for the participant. A list of individual training words were selected based upon this information, and the participant was instructed to recall them after a 45-second, 90-second, 6-minute, and 12-minute delay. Baseline (3 sessions), intervention (20 sessions), and a second baseline period (3 sessions) were conducted. Activities of daily living were measured, and cognition was measured using the Consortium to Establish a Registry of Alzheimer’s Disease Korean version, whilst depression was measured using the Korean Form Geriatric Depression Scale, and task performance and satisfaction measured by the Canadian Occupational Performance Measure.ResultsAfter intervention, both participants showed improvements in activities of daily living (ADL), word list memory/recognition, trail making A, occupational performance, and satisfaction improvement, which was clinically significant in 1 participant who also had a reduced score in the scale of depression classifying him as not depressed.ConclusionSpaced retrieval training and errorless learning based on reality orientation therapy is an effective intervention in patients with early onset dementia and mild or moderate impairment.  相似文献   
39.
目的比较Legiolert酶底物法与传统培养法对公共场所水体样本中嗜肺军团菌的检出效果。方法分别利用Legiolert酶底物法与传统培养法对采集于公共场所的冷却水、淋浴水样本进行嗜肺军团菌检测,并对分离株进行验证及血清分型。结果共采集并检测样品68份,传统培养法与Legiolert酶底物法的检出率分别为5.88%(4/68)及35.29%(24/68),差异有统计学意义(χ2=16.41,P<0.01)。两种方法的检测符合率为64.71%(44/68),检测效果的差异有统计学意义(配对χ2=16.41,P=0.000)。分离出的25株嗜肺军团菌血清型以LP1为主(14/25)。结论Legiolert酶底物法对公共场所水体样本中嗜肺军团菌的检出率高于传统培养法。  相似文献   
40.
目的 :阐明神经束支定位法在远端尺神经损伤修复中的作用。方法 :选择 4 2例远端尺神经损伤病例 ,进行神经内束支分离 ,双极电刺激定位后束膜吻合 ,与 17例外膜吻合组对照。结果 :束支分离定位法在远端尺神经损伤修复中的成功率为 90 .5%,治疗组较对照组感觉恢复率有提高 ,但无明显差异 ( P>0 .0 5) ,运动功能恢复率显著提高 ( P<0 .0 1)。结论 :神经内束支分离定位应用于远端尺神经损伤修复是可行的 ,并能提高其功能恢复率。  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