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   36364篇
  免费   1932篇
  国内免费   198篇
耳鼻咽喉   522篇
儿科学   718篇
妇产科学   429篇
基础医学   4575篇
口腔科学   821篇
临床医学   2484篇
内科学   9287篇
皮肤病学   786篇
神经病学   2403篇
特种医学   1413篇
外国民族医学   1篇
外科学   6453篇
综合类   191篇
一般理论   2篇
预防医学   911篇
眼科学   470篇
药学   2646篇
中国医学   94篇
肿瘤学   4288篇
  2023年   185篇
  2022年   333篇
  2021年   718篇
  2020年   432篇
  2019年   557篇
  2018年   679篇
  2017年   572篇
  2016年   686篇
  2015年   709篇
  2014年   952篇
  2013年   1108篇
  2012年   1814篇
  2011年   1940篇
  2010年   1098篇
  2009年   1008篇
  2008年   1654篇
  2007年   1866篇
  2006年   1795篇
  2005年   1891篇
  2004年   1786篇
  2003年   1656篇
  2002年   1625篇
  2001年   1177篇
  2000年   1100篇
  1999年   1063篇
  1998年   423篇
  1997年   304篇
  1996年   326篇
  1995年   265篇
  1994年   243篇
  1993年   258篇
  1992年   704篇
  1991年   643篇
  1990年   596篇
  1989年   604篇
  1988年   589篇
  1987年   532篇
  1986年   499篇
  1985年   456篇
  1984年   342篇
  1983年   290篇
  1982年   172篇
  1979年   275篇
  1977年   189篇
  1973年   187篇
  1972年   192篇
  1971年   205篇
  1970年   178篇
  1969年   200篇
  1968年   176篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
We evaluated the effects of various intravenously administered drugs, which had been shown to influence bladder function in anesthetized and/or conscious rats, on the cystometrogram in conscious restrained-denervated rats (produced by transection of the hypogastric nerve) placed in a restraining cage in comparison to those in conscious restrained-intact rats (with the hypogastric nerve intact) placed in a restraining cage. The bladder capacity in the restrained-denervated rats was smaller than that in restrained-intact rats and did not change when they were transferred to a wide cage, but the bladder capacity of the restrained-intact rats decreased following transfer to the wide cage. Therefore, the activity of the hypogastric nerve in conscious rats appears to be stimulated by restraint. Atropine suppressed the amplitude of the micturition contraction (time to micturition in the cystometrogram). In the restrained-denervated rats, thiopental and indomethacin increased the bladder capacity at almost the same doses as those in restrained-intact rats, but it took a higher dose of morphine to increase the bladder capacity than in restrained-intact rats. These findings suggest that cystometrography in restrained-denervated rats is a useful method for evaluating the effect of a newly developed agent on bladder function without any influence from the hypogastric nerve.  相似文献   
72.
73.
Background :
The aim of this study was to investigate the influence of osteoarthritis of lumbar vertebrae on serum bone formation and resorption marker levels of patients with benign prostatic hypertrophy (BPH).
Methods :
Serum levels of carboxyterminal propeptide of type I procollagen (PICP), alkaline phosphatase (ALP), carboxyterminaltelopeptide of type I collagen (ICTP), and prostate-specific antigen (PSA) were examined in 40 patients with BPH, and the presence of osteoarthritis at the lumbar vertebrae of the patients was evaluated by plain x-ray-p.
Results :
Findings of osteoarthritis were observed in 23 of the 40 patients (58%), and 10 of the patients had severe osteoarthritis (involving at least 2 lumbar vertebral bodies). The serum levels of PICP, ALP, ICTP, and PSA of the patients without osteoarthritis findings were not different from those of the patients with osteoarthritis or severe osteoarthritis.
Conclusion :
The influence of osteoarthritis on serum bone formation and resorption marker levels of patients with BPH appears to be rather slight, if there is any influence at all.  相似文献   
74.
To examine whether prostacyclin has an attenuating effect on nonspecific bronchial responsiveness in asthma, we measured provocative concentration of methacholine producing a 20% fall in forced expiratory volume in 1 second (PC20-FEV1) before and after oral administration of a chemically stable prostacyclin analog (OP-41483) (200 μg 4 times a day for 4 days) in 8 patients with stable asthma. Neither baseline pulmonary function nor PC20-FEV1 significantly improved after the treatment. These results suggest that prostacyclin may have no direct effect on bronchial responsiveness in asthmatics. Further studies using more potent and long-lasting prostacyclin mimetic will be needed to confirm the conclusion.  相似文献   
75.
The purpose of this study is to describe a subset of atypical hepatic hemangiomas that enhance rapidly and diffusely and to determine whether heavily T2-weighted images could distinguish between atypically enhancing liver hemangiomas and hypervascular malignancies. A retrospective search of MR records identified seven patients with liver hemangiomas that demonstrated diffuse early enhancement and 23 patients with biopsy-proven malignant liver lesions that were hypervascular on dynamic gadolinium-enhanced MR images. Quantitative analysis of signal intensity measurements was performed on the T2-weighted images, heavily T2-weighted (TE < 140), and dynamic gadolinium-enhanced images. Blinded reader comparison of the T2-weighted images and gadolinium-enhanced images was performed. Hypervascular hemangiomas enhanced to a greater degree than hypervascular malignant liver lesions on the early phase gadolinium-enhanced images. Perilesional parenchymal enhancement was demonstrated in five cases of rapidly enhancing hemangiomas. Signal intensity and contrast-to-noise ratios on the heavily T2-weighted images of the hemangiomas were significantly greater than that of the hypervascular malignant lesions (P < .05). Hemangiomas were differentiated from the hypervascular malignant liver lesions with high accuracy (97–100%) by three blinded readers based on the T2-weighted images. A subset of hemangiomas have atypical rapid diffuse enhancement on dynamic gadolinium-enhanced images. These atypical hemangiomas can be distinguished from hypervascular malignant liver lesions on T2-weighted MR images.  相似文献   
76.
Classifications based on clinical and radiographic criteria have proved to be inadequate predictors of the course of cerebral ischemia or its response to therapy. In this study the cerebrovascular reserve capacity (CRC) of 46 patients with symptomatic cerebrovascular ischemia was studied by stable xenon-enhanced CT (Xe-CT) combined with the acetazolamide test. Fifteen patients had internal carotid artery (ICA) occlusion, 10 had ICA stenosis, 10 had middle cerebral artery (MCA) occlusion, and 11 had MCA stenosis. In the patients with chronic cerebral ischemia due to occlusive lesions of the ICA and MCA, the CRC was reduced most in those with MCA occlusion, followed, in descending order, by those with ICA stenosis, MCA stenosis, and ICA occlusion. Our results indicate that measurement of the CRC elucidates cerebral hemodynamic factors that cannot be detected by angiography in patients with chronic cerebral ischemia and that Xe-CT combined with the acetazolamide test is useful for this purpose.  相似文献   
77.
The results of experiments with Acanthopanax giraldii polysaccharide (AGP) demonstrated that it inhibited the growth of solid Sarcoma 180 and prolonged the survival time significantly. In tumor-bearing mice, AGP enhanced the phagocytosis and chemiluminescence of macrophages. By the immunofluorescent method, binding of the third component of complement (C3) cleavage product to macrophages and proportion of C3 positive cells were increased. In crossed immunoelectrophoresis, human serum C3 was converted by AGP and appeared as the 3rd peak. The height of the 3rd peak was directly proportional to doses of AGP. The residual CH50 units of human serum decreased dose-dependently. These results suggest that the antitumor activity of AGP is related to the enhancement of immune responses.  相似文献   
78.
A 52-year-old woman who developed acute transverse myelopathy following systemic lupus erythematosus (SLE) was reported. At the age of 46, she was diagnosed as having atypical psychosis. Neurological examination revealed mild depressive state, paraparesis, diffuse hyperreflexia, hypesthesia below the breasts, and urinary disturbance. Gait was slightly ataxic and Romberg sign was positive. Laboratory study disclosed lymphocytopenia, positive antinuclear antigen, false positive Venereal Disease Research Laboratories flocculation test and prolonged activated partial thromboplastin time. IgG anticardiolipin antibody (aCLA) was positive, whereas IgM aCLA was negative. Cerebrospinal fluid was normal except the elevation of %IgG. Nerve conduction studies were normal and no abnormality was detected in the brain and spinal cord by MRI and CT. We treated her by two series of steroid pulse therapy, which resulted in marked improvement of symptoms and disappearance of aCLA. Before and after the pulse therapy, symptoms were fluctuated in parallel with the levels of aCLA. These findings suggest the relation of aCLA to the transverse myelopathy in SLE. This is the first case report of a good prognosis of myelopathy in a SLE patient who was treated by steroid pulse therapy with the aim of disappearance of aCLA.  相似文献   
79.
80.
In order to find useful information for the establishment of new treatment method to alcohol dependence, we investigated the change of the body image of patients with alcohol dependence before and after the treatment. HABIT (Haga Body Image Test), a questionnaire about body image developed in department of psychiatry in Kyoto Prefectural University of Medicine, was used to examine the change of body image between pre- and post-3-month conventional treatment program in 46 patients with alcohol dependence hospitalized into special institutions for treatment of the disease in Kyoto. Patients with poor outcome of the treatment showed improvement of body image on visceral function, feeling of appetite and outward appearance, while patients with good outcome indicated no significant change in these aspects. This finding likely suggests that the treatment would result in good outcome in patients having stable feeling of physical health, and the cognitive treatment approach about these aspects of body image should be performed on the patients with poor treatment outcome. On the other hand, the body image about motor function showed significantly higher score in the patients approach for the patients with poor outcome to become aware of their physical activity would be effective.  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