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   2441302篇
  免费   176612篇
  国内免费   3927篇
耳鼻咽喉   33013篇
儿科学   78825篇
妇产科学   64906篇
基础医学   361099篇
口腔科学   67247篇
临床医学   219787篇
内科学   477601篇
皮肤病学   54118篇
神经病学   193978篇
特种医学   90138篇
外国民族医学   490篇
外科学   362024篇
综合类   47855篇
现状与发展   12篇
一般理论   886篇
预防医学   192125篇
眼科学   55813篇
药学   181495篇
  11篇
中国医学   4938篇
肿瘤学   135480篇
  2021年   22084篇
  2019年   22140篇
  2018年   30093篇
  2017年   22648篇
  2016年   25448篇
  2015年   28572篇
  2014年   39990篇
  2013年   58998篇
  2012年   82292篇
  2011年   87330篇
  2010年   51391篇
  2009年   48191篇
  2008年   80912篇
  2007年   85815篇
  2006年   86071篇
  2005年   83195篇
  2004年   79203篇
  2003年   76056篇
  2002年   73187篇
  2001年   109177篇
  2000年   111750篇
  1999年   93987篇
  1998年   27655篇
  1997年   24210篇
  1996年   24509篇
  1995年   23095篇
  1994年   21248篇
  1993年   20013篇
  1992年   72228篇
  1991年   70233篇
  1990年   68553篇
  1989年   65805篇
  1988年   60448篇
  1987年   59239篇
  1986年   55354篇
  1985年   53099篇
  1984年   39430篇
  1983年   33502篇
  1982年   19996篇
  1979年   35926篇
  1978年   25718篇
  1977年   21286篇
  1976年   20376篇
  1975年   21851篇
  1974年   26192篇
  1973年   24825篇
  1972年   23219篇
  1971年   22055篇
  1970年   20263篇
  1969年   19333篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
991.
The results of this controlled study of the treatment of 57 patients with Gilles de la Tourette's syndrome suggested that both haloperidol and pimozide were more effective than placebo, but that haloperidol was slightly more effective than pimozide. Adverse effects occurred more frequently with haloperidol vs placebo than with pimozide vs placebo, but the frequency was not significantly different for haloperidol compared with pimozide. Clinically significant cardiac effects did not occur at a maximum dosage of 0.3 mg/kg or 20 mg/d for pimozide and 10 mg/d for haloperidol. However, the QTc interval was prolonged during pimozide treatment compared with that during haloperidol treatment, although the values for both medications were not in an abnormal range.  相似文献   
992.
To date, chronic myopathy has not been reported (to our knowledge) to occur in carnitine palmityltransferase (CPT) deficiency, a disorder of muscle lipid metabolism. We describe two patients with CPT deficiency: a mother, who had a partial CPT deficiency associated with fixed proximal weakness but without rhabdomyolysis, and her son, who had a complete CPT deficiency (95% reduction in enzyme activity) and who suffered from classic attacks of exercise-induced rhabdomyolysis but had normal strength on recovery. Careful examination of family members of patients with complete CPT deficiency is suggested in order to identify clinically affected heterozygotes.  相似文献   
993.
Paracoccidioidomycosis of the central nervous system presents either as meningeal or pseudotumoral lesions. Although occurring more frequently in the brain and meninges, they can occasionally involve the spinal cord. A case of paracoccidioidomycosis in the cervical spinal cord is reported in this paper. Difficulties in establishing the etiologic diagnosis, the importance of radiologic examination of the thorax, and the treatment of the patient are commented. In an extensive review of the literature on the subject, only three other cases have been found, which are also discussed.  相似文献   
994.
To assess the relationship between the DSM-III criteria for attention deficit disorder with hyperactivity (ADDH) and the DSM-III-R criteria for attention-deficit hyperactivity disorder (ADHD), children from an inner city parochial school were evaluated using a 30-item teacher questionnaire consisting of the DMS-III and DSM-III-R criteria for these disorders, the revised Conners Parent and Teacher Questionnaires, and a continuous performance test. Diagnostic groups were established based on teacher ratings of the DSM items and evaluated in relation to the rating scale data and continuous performance test. While children who were identified by teachers as having ADDH almost always satisfied the criteria for ADHD, a new group of children who were hyperactive and impulsive but less clearly inattentive also met the criteria for ADHD. Implications of the change in diagnostic criteria are discussed.  相似文献   
995.
996.
997.
The authors describe a case of retrobulbar optic neuropathy in a patient with type 1 Diabetes mellitus. In spite of good metabolic control, there has been a slow but progressive functional visual decline. Worthy of note is the abnormal precocity of the appearance of the functional damage of the optic nerve compared to the involvement of the peripheral system.  相似文献   
998.
999.
A case of Bonnet syndrome associated with blindness due to bilateral eye disease and a posterior parasagittal meningioma is reported. It is assumed that visual afferent deprivation alone is not enough to produce the syndrome and that, in most instances, a 'cerebral factor' must be operative if hallucinoses are to occur. The distinction between hallucinosis and hallucinations is favored and a common neural circuit for the mediation of hallucinotic imageries in general is suggested. One should not immediately put the blame on obvious eye or visual pathways affections when facing cases of Bonnet syndrome, as they are not likely to explain the complex array of images perceived by any given patient. On the contrary, the possibility of a clinically covert intracranial disease should be always raised and intensively looked for.  相似文献   
1000.
Pharmacological studies suggest that beta-adrenergic receptors (beta AR) in the medial nuclei of the solitary tracts (m-NTS) facilitate presynaptic release of catecholamines and also function at postsynaptic sites. We have localized the antigenic sites for a monoclonal antibody against a peptide corresponding to amino acids 226-239 of beta AR in the m-NTS of rat brain. By light microscopy, immunoperoxidase labeling for this antibody was detected in somata and proximal processes of many small cells that were distributed throughout the rostrocaudal extent of the m-NTS. Electron microscopy confirmed the cytoplasmic localization of beta AR in perikarya and proximal dendrites of neurons. Immunoreactivity occurred as discrete patches associated with cytoplasmic surfaces of plasma membrane and with irregularly-shaped saccules with clear lumen in the immediate vicinity. Select regions of nuclear envelopes, mitochondrial membranes, and rough endoplasmic reticulum were also immunoreactive along their cytoplasmic surfaces. In contrast, the Golgi apparatus was labeled, but infrequently. Immunoreactivity was also detected at numerous post- and occasional presynaptic membrane specializations of select axodendritic junctions. Dual labeling for the beta AR-antibody by the immunoperoxidase method and for a rabbit antiserum against the catecholamine-synthesizing enzyme, tyrosine hydroxylase (TH), by the immunoautoradiographic method within the same sections, further established the precise cellular relations between beta AR and catecholaminergic neurons. Immunoreactivity for beta AR was detected in numerous perikarya and proximal dendrites that did not show detectable levels of TH. However, a few cells were dually labeled for both antigens, as seen by both light and electron microscopy. The TH-labeled terminals formed synapses at junctions both with and without beta AR-like immunoreactivity. These results from the single and dual labeling studies: (1) confirm biochemical predictions that amino acids 226-239 of beta AR protein reside intracellularly; (2) provide the first ultrastructural evidence for beta AR localization within both pre- and postsynaptic membrane specializations of a subset of catecholaminergic synapses; and (3) suggest select intracellular sites that may be involved with synthesis and/or internalization and degradation of the receptor protein.  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