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   11798篇
  免费   1213篇
  国内免费   152篇
耳鼻咽喉   125篇
儿科学   272篇
妇产科学   288篇
基础医学   1045篇
口腔科学   89篇
临床医学   1312篇
内科学   1565篇
皮肤病学   115篇
神经病学   2813篇
特种医学   132篇
外科学   1258篇
综合类   1065篇
现状与发展   1篇
一般理论   1篇
预防医学   1216篇
眼科学   92篇
药学   799篇
  20篇
中国医学   614篇
肿瘤学   341篇
  2024年   42篇
  2023年   264篇
  2022年   333篇
  2021年   622篇
  2020年   704篇
  2019年   639篇
  2018年   551篇
  2017年   572篇
  2016年   558篇
  2015年   493篇
  2014年   771篇
  2013年   1120篇
  2012年   613篇
  2011年   696篇
  2010年   526篇
  2009年   530篇
  2008年   590篇
  2007年   522篇
  2006年   430篇
  2005年   379篇
  2004年   321篇
  2003年   271篇
  2002年   231篇
  2001年   161篇
  2000年   142篇
  1999年   97篇
  1998年   95篇
  1997年   107篇
  1996年   90篇
  1995年   78篇
  1994年   62篇
  1993年   53篇
  1992年   61篇
  1991年   44篇
  1990年   53篇
  1989年   39篇
  1988年   37篇
  1987年   33篇
  1986年   31篇
  1985年   35篇
  1984年   27篇
  1983年   18篇
  1982年   28篇
  1981年   27篇
  1980年   13篇
  1979年   13篇
  1978年   12篇
  1977年   12篇
  1975年   4篇
  1974年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
The intensity dependence of the auditory-evoked potentials (IDAP) is inversely related to serotonergic tone. Depression is frequently observed after stroke, associated with cognitive impairment and increased mortality. Aim of this study was to investigate the serotonergic tone in acute stroke patients by IDAP. Consecutive patients with an acute stroke admitted in our stroke unit were evaluated using clinical and instrumental examinations and compared with healthy controls. The IDAP was calculated as the linear amplitude/stimulus intensity function (ASF) slope, by measuring the peak-to-peak amplitude of Nl-P2 on four blocks of different stimulus intensities. Twenty patients were enrolled; 11 had a right brain infarction; nine had depressive symptoms (DS). The ASF slope of the auditory-evoked potentials was markedly increased in stroke patients compared with controls ( P  = 0.021). Stroke patients with DS had a significant steeper ASF slope than controls ( P  = 0.017). There was no statistical difference in ASF slope between stroke patients without DS and controls. Post-stroke depression pathophysiology is still debated. Our study suggests that in acute stroke patients with DS, there is a direct involvement of the serotonergic system, regardless the degree of disability and the site of the lesion.  相似文献   
42.
Abstract  The purpose of this study is to examine whether there are differences in clinical characteristics between Tourette syndrome (TS) patients with and without 'generalized tics' (GT) which involve the entire body, and/or coprolalia. Subjects were 64 patients (55 males and 9 females, mean age, 17.4 ± 7.2 years) who visited Tokyo University's outpatient clinic of neuropsychiatry from 1974 to 1993 and who met criteria for Tourette's disorder of DSM-III-R. Data on clinical characteristics, including tic symptoms and courses of their development, complications and developmental histories, treatment and severity, were collected by systematic chart review of all subjects. Tourette syndrome patients with 'generalized tics' tended to show multiple complex vocal tics more frequently than TS patients without GT. Tourette syndrome patients with coprolalia tended to show significantly higher rates of copropraxia, echolalia, and 'cleaning/washing' compulsion than did the TS patients without coprolalia. Tourette syndrome patients with both GT and coprolalia were classified as the severest group in terms of tic symptoms and social impairment. Tourette syndrome patients who had neither of these morbidities were classified into the mildest group in all aspects. Generalized tics and coprolalia seemed to indicate the severest end of the TS spectrum and seemed to be related with a need of intensive treatment.  相似文献   
43.
This study investigated whether domperidone could improve gastrointestinal symptoms in patients with Parkinson's disease who were receiving levodopa therapy. A total of 11 patients were studied. Following a baseline gastric emptying test, patients were treated with a starting dose of domperidone 20 mg p.o. q.i.d. A follow-up gastric emptying test was repeated at least 4 months after starting domperidone therapy. At the beginning and at each 3-month follow-up visit, symptoms of nausea, vomiting, anorexia, abdominal bloating, heartburn, regurgitation, dysphagia, and constipation were evaluated and scored on a scale of 0–3. The overall mean follow-up period was 3 years. Compared with their baseline evaluation, patients experienced a significant improvement in all symptoms (p < 0.05) except dysphagia and constipation. Gastric emptying of an isotope-labeled solid meal was significantly faster, with a baseline result of 60.2 ± 6.4% retention of isotope 2 h after the meal compared with 37.0 ± 2.2% retention during domperidone therapy (p < 0.05). Patients' global assessment of Parkinson's disease remained stable or improved. Serum prolactin was elevated in all patients after domperidone therapy (p < 0.05). Domperidone therapy significantly reduces upper gastrointestinal symptoms and accelerates gastric emptying of a solid meal, but does not interfere with response to antiparkinsonism treatment.  相似文献   
44.
Abstract Thirty-nine patients with schizophrenia, diagnosed according to DSM-III-R, who were under 15 years of age, were studied in two groups; 16 subjects with obsessive-compulsive symptoms during the prodromal phase, and 23 with no obsessive-compulsive disorders. The group with obsessive-compulsive symptoms during the prodromal phase was characterized by a higher ratio of males, higher incidences of perinatal and brain computed tomography (CT) abnormalities, fewer hereditary factors, longer duration of the prodromal phase, and a higher incidence of insidious onset and negative symptoms compared with the group without such prodromal symptoms. Schizophrenic patients with obsessive-compulsive symptoms during the prodromal phase were clinically distinct from those without, which suggests the possibility of subtype categorization.  相似文献   
45.
In the 19th century, investigators recognized that addiction to opiates involves tolerance and dependence. In the United States, the National Academy of Sciences and the Public Health Service initiated systematic investigations into opiate addiction in 1929. Tolerance and dependence to morphine, the prototype for opiate drugs, were the emphasis of human studies for the next fifty years. This presentation highlights salient features of tolerance and dependence learned in these studies and relates these findings to clinical use in treating pain.  相似文献   
46.
47.
The relationship of skin reactivity and serum immunoglobulin E (IgE) levels to the prevalence of chronic respiratory symptoms and to ventilatory capacity is examined in workers exposed to different organic aerosols. The results from group of control workers similarly tested are also presented. Workers exposed to occupational allergens had positive skin tests more frequently than did controls, except for soy bean workers. Workers with positive skin tests to occupational allergens had a higher prevalence of almost all symptoms than those with negative skin tests although the differences did not always reach statistical significance. Workers with positive skin reactions in general had significantly higher serum IgE levels than did workers with negative skin reactions. There were across-shift reductions of ventilatory capacity in all groups of exposed workers, varying for forced vital capacity from 1.7% to 13.3%, for forced expiratory volume from 0.4%–21.9%, for maximum flow rates at 50% from 1.5% to 16.1% and for maximum flow rates at the last 25% of control vital capacity from 0% to 24.9%. There was, however, no correlation between acute and chronic lung function changes and skin reactivity or IgE values. Our data suggest that although exposure to organic aerosols may be associated with frequent immunologic reactions, these findings do not predict objective respiratory impairment.The research was supported in part by grant no. JBP 733 from the National Institutes of Health, Bethesda, Md., USA, and by grant no. RO1 OHO-2593-04 from the National Institutes of Occupational Safety and Health, Centers for Disease Control, Atlanta, Ga., USA  相似文献   
48.
The study presents results from a five-year follow-up on abdominal symptoms in an age and sex stratified random sample of 4,581 Danes. Abdominal pain occurred significantly more often among women (prevalence: 49%, incidence: 21%) compared to men (prevalence: 38%, incidence: 15%). Five years later the pain had disappeared in 43% of the men and 31% of the women (p=0.003). Distension, borborygmi, and altering consistency of stools occurred with a prevalence of approximately 50% and an incidence of approximately 30%, significantly more often among women compared to men. Five years later these symptoms had disappeared in about 20%. Prevalence of both heartburn and acid regurgitation were significantly higher among men (38%) than women (30%), whereas no sex difference was observed regarding incidence of these symptoms (16%). Approximately 30% of subjects who had experienced heartburn or acid regurgitation did not do so five years later. In conclusion, abdominal symptoms occur frequently and recurrently in the general population. This information is of importance to doctors when they evaluate patients with abdominal complaints, but no obvious organic etiology.  相似文献   
49.
The aetiology of Klinefelter's Syndrome is not known. The causative factor(s) must explain the hypogonadism, low androgen levels, the disordered carbohydrate metabolism and the commonly associated psychiatric conditions. A biotin deficient/dependent state can account for the above. A biotin deficient Klinefelter's Syndrome patients with the above is described. The possible role of biotin in the primary, secondary and tertiary prevention of Klinefelter's Syndrome needs further research.  相似文献   
50.
We examined the discriminant ability and responsiveness of the General Well-Being Adjustment Scale in patients enrolled in a randomized clinical trial of antihypertensive therapy. We also tried to translate the effects of physical symptoms on general well-being. This secondary analysis used demographic, clinical, physical symptom, and general well-being data for 545 white, male hypertensive patients. General well-being was measured by the General Well-Being Adjustment Scale (GWB) collected on 2 occasions over 8 weeks of treatment. Patients with any one of 14 physical symptoms or problems, compared to those without symptoms, had lower GWB scores (p < 0.003 to p < 0.0001). Decreases of 2.83–8.76 points in GWB scores were observed in patients developing physical symptoms over the 8 week study period (p < 0.05 to p < 0.0001). These effects were demonstrated in patients developing cold sensitivity, sexual problems, chest pain, shortness of breath, loss of taste, nausea, hot or cold spells, numbness and tingling, dry mouth, blurred vision, and dizziness. We conclude that the GWB is responsive to clinically meaningful changes in symptoms and may provide a more complete evaluation of the effects of medical treatment. The GWB is a valid and responsive measure of health status outcomes in the evaluation of antihypertensive treatment.  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