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   65168篇
  免费   4219篇
  国内免费   1353篇
耳鼻咽喉   996篇
儿科学   2229篇
妇产科学   986篇
基础医学   7464篇
口腔科学   1041篇
临床医学   4995篇
内科学   11778篇
皮肤病学   1079篇
神经病学   14889篇
特种医学   1595篇
外国民族医学   10篇
外科学   5695篇
综合类   3535篇
现状与发展   3篇
一般理论   6篇
预防医学   3776篇
眼科学   1328篇
药学   4838篇
  21篇
中国医学   2159篇
肿瘤学   2317篇
  2024年   174篇
  2023年   1338篇
  2022年   2371篇
  2021年   3510篇
  2020年   3147篇
  2019年   4046篇
  2018年   3821篇
  2017年   3031篇
  2016年   2291篇
  2015年   2247篇
  2014年   4812篇
  2013年   6313篇
  2012年   3925篇
  2011年   3744篇
  2010年   2862篇
  2009年   2670篇
  2008年   2480篇
  2007年   1970篇
  2006年   1611篇
  2005年   1309篇
  2004年   1341篇
  2003年   1148篇
  2002年   889篇
  2001年   729篇
  2000年   706篇
  1999年   579篇
  1998年   513篇
  1997年   543篇
  1996年   368篇
  1995年   280篇
  1994年   272篇
  1993年   244篇
  1992年   177篇
  1991年   178篇
  1990年   148篇
  1989年   124篇
  1988年   103篇
  1985年   606篇
  1984年   653篇
  1983年   414篇
  1982年   492篇
  1981年   429篇
  1980年   343篇
  1979年   334篇
  1978年   275篇
  1977年   221篇
  1976年   210篇
  1975年   232篇
  1974年   168篇
  1973年   174篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
For patients with Alzheimer's disease (AD), a recommendation to stop operating a motor vehicle can be a serious event complicated by a loss of self-esteem and personal dignity. Patients are often reluctant to give up an activity so essential, both practically and symbolically, to independent living. We describe here a patient with moderately progressed AD who lacked insight of his need to cease driving. Through an integrative treatment approach, combining behavioral and psychodynamic modalities, we helped him to formulate effective ways of coping with his loss of access to independent transportation. We favor a psychotherapeutic strategy that combines behavioral and managerial measures with dynamic patient interaction, thereby developing the patient's insight of the need to give up driving while fostering his sense of autonomy.  相似文献   
32.
The post-lumbar puncture syndrome (PLPS) can best be explained by prolonged spinal fluid leakage owing to delayed closure of a dural defect. Its incidence after spinal anaesthesia is much lower than after diagnostic lumbar puncture (LP). This difference could be caused by a strand of arachnoid, which might enter the needle with the outflowing cerebrospinal fluid (CSF) during diagnostic LP and upon removal of the needle be threaded back through the dura to produce prolonged CSF leakage. To find a technique that further reduces the incidence of PLPS, this hypothesis was tested by evaluating the effect that reinserting the stylet before removing the needle had on the incidence of PLPS. By reinserting the stylet to the tip of the needle, the hypothesized strand would be pushed out, thereby reducing the frequency of PLPS. Sprotte’s “atraumatic needle” (21 gauge) was used for LP. A total of 600 patients participated in the prospective study. They were randomized into two groups and questioned about their complaints every day for up to 7 days after the LP. All LPs were performed by two experienced neurologists (T.B., M.S.). In 300 patients, the stylet was reinserted to the tip of the needle; in the other 300 it was not reinserted. Whereas 49 of the 300 patients without reinsertion developed PLPS, only 15 of the 300 patients with reinsertion did. This significant difference (16.3 vs 5.0%, P < 0.005, chi square test) supports our hypothesis. On the basis of our results, we recommend reinserting the stylet before removing the needle in order to reduce the incidence of PLPS. Received: 30 September 1997 Received in revised form: 9 March 1998 Accepted: 20 March 1998  相似文献   
33.
A case report is presented in which a patient's initial complaint is of blurred vision after exercise (Uhthoffs symptom). Visual acuity and colour vision were found to be reduced after exercise. Additional neurological signs included homonymous scotomata and delayed visual evoked and somatosensory responses. Magnetic resonance imaging demonstrated multiple abnormal lesions in the brain. The significance of this symptom and its relationship to multiple sclerosis are discussed.  相似文献   
34.
Piribedil is a non-ergot D2/D3 agonist with a significant antagonist action on alpha2A and alpha2C adrenergic receptor subtypes. This double-blind placebo-controlled study was undertaken to confirm the efficacy of 150 mg/day piribedil po in improving motor symptoms of idiopathic Parkinson's disease (PD) in nonfluctuating patients insufficiently controlled by a stable daily dose of levodopa (L-dopa). Efficacy was assessed using the Unified Parkinson's Disease Rating Scale (UPDRS) III score as primary criterion over 4 months. A second comparison was planned at 6 months, after possible adjustment of L-dopa. At 4 months, the rate of response, defined as a 30% decrease from baseline on UPDRS III score, was significantly greater with piribedil compared with placebo (56.4% vs. 37.7%; P = 0.040). At 6 months, the better efficacy of piribedil was maintained (61.8% of responders vs. 39.6% on placebo; P = 0.020). The difference between groups on UPDRS III change from baseline reached statistical significance only at 6 months: -10.0 points in the piribedil group vs. -6.7 points in the placebo group (P = 0.037). Secondary end-points were not significantly different. The most frequently reported adverse events were gastrointestinal symptoms (27 of 61 patients in the piribedil group vs. 13 of 54 patients in the placebo group). In conclusion, a 6-month oral administration of 150 mg/day piribedil in combination with L-dopa is well tolerated, except for minor gastrointestinal symptoms at the beginning of the treatment and significantly improves motor symptoms compared with placebo in PD nonfluctuating patients.  相似文献   
35.
The purpose of this study was to determine the effects of unilateral versus bilateral subthalamic nucleus (STN) stimulation on quantitative measures of walking and reaching in Parkinson's disease (PD). We used kinematic measures and the Unified Parkinson's Disease Rating Scale (UPDRS) motor subscale (subscale III) to evaluate the movement of 6 people with PD who had bilateral STN stimulators implanted for at least 6 months and withheld their anti-parkinson medication for at least 8 hours. Subjects were studied with both stimulators off, one on, and both on. Kinematic data were collected as subjects walked, reached to a target, and were rated using the UPDRS motor subscale. STN stimulation improved walking speed and stride length, with the greatest benefit from bilateral stimulation. Reaching speed was improved by unilateral STN stimulation alone, with no additive effect of bilateral stimulation. UPDRS motor subscale ratings paralleled the kinematic findings. STN stimulation did not restore PD subjects' movements to the level of age-matched controls. Overall, these results provide further evidence that the basal ganglia pathways involved in control of walking and reaching may be distinct. We speculate that basal ganglia may influence walking through bilateral pedunculopontine projections and reaching through ipsilateral thalamocortical projections. Our findings also suggest that maximal improvement of walking requires bilateral rather than unilateral STN stimulation.  相似文献   
36.
The progressive degeneration of the brain seen in dementia is often accompanied by behavioural disturbances. Aggressive behaviour is one of the most serious of these disturbances and is a common cause for psychiatric referral, admission to hospital and drug treatment. In this article, we discuss the conceptual issues associated with defining aggressive behaviour in cognitively impaired patients. We then review the aetiology, epidemiology, methods of assessment, and management of aggressive behaviour in elderly people with dementia.  相似文献   
37.
目的 探讨晕可宁颗粒的主要药效学 ,为临床提供药效学资料及治疗学基础。方法 采用三氯甲烷破坏豚鼠一侧膜迷路感受器模型 ,探讨受试药对眼震颤、摆头及旋转的影响 ;采用内淋巴囊和内淋巴管阻塞手术复制豚鼠膜迷路实验性膜迷路积水模型 ,研究内耳组织平均中阶面积 (SMA)增加率及形态学的变化。结果 抑眩宁阳性对照组、晕可宁颗粒 (8、16g/kg)模型给药组豚鼠眼球震颤次数减少 ,差异有显著意义 (P <0 .0 5 )。成功复制了不同程度膜迷路积水豚鼠模型 ,表现为前庭膜重度膨出 ,前庭阶缩小 ,膜蜗管增大 ,SMA增加率变大 ,差异有显著意义 (P <0 .0 1) ;晕可宁颗粒灌胃后可减轻豚鼠实验性膜迷路积水的程度 ,差异有显著意义 (P <0 .0 1) ;但与空白对照组比较SMA增加率差异无显著意义 (P >0 .0 5 )。结论 晕可宁颗粒可以减轻内淋巴囊积水程度 ,对梅尼埃病症状有对抗治疗作用。  相似文献   
38.
There have been a few studies and inconsistent results regarding the coincidence of Parkinson's disease (PD) and atherosclerotic diseases, such as cerebrovascular disease. Carotid intima-media thickness (IMT) is a known marker for subclinical atherosclerosis. The aim of this study was to investigate the carotid IMT between PD patients and controls. We studied 43 patients with PD and 86 matched controls. The carotid IMT in PD patients was significantly smaller than in controls (0.796 +/- 0.179 mm vs. 0.913 +/- 0.237 mm, P < 0.05). In multivariate analysis, the carotid IMT was inversely associated with the duration of levodopa medication and the severity of PD. These results suggest that PD patients have a lower risk of atherosclerosis.  相似文献   
39.
40.
The subthalamic nucleus (STN) is a major target for treatment of advanced Parkinson's disease patients undergoing deep brain stimulation surgery. Microelectrode recording (MER) is used in many cases to identify the target nucleus. A real-time procedure for identifying the entry and exit points of the STN would improve the outcome of this targeting procedure. We used the normalized root mean square (NRMS) of a short (5 seconds) MER sampled signal and the estimated anatomical distance to target (EDT) as the basis for this procedure. Electrode tip location was defined intraoperatively by an expert neurophysiologist to be before, within, or after the STN. Data from 46 trajectories of 27 patients were used to calculate the Bayesian posterior probability of being in each of these locations, given RMS-EDT pair values. We tested our predictions on each trajectory using a bootstrapping technique, with the rest of the trajectories serving as a training set and found the error in predicting the STN entry to be (mean +/- SD) 0.18 +/- 0.84, and 0.50 +/- 0.59 mm for STN exit point, which yields a 0.30 +/- 0.28 mm deviation from the expert's target center. The simplicity and computational ease of RMS calculation, its spike sorting-independent nature and tolerance to electrode parameters of this Bayesian predictor, can lead directly to the development of a fully automated intraoperative physiological procedure for the refinement of imaging estimates of STN borders.  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