全文获取类型
收费全文 | 1747057篇 |
免费 | 126449篇 |
国内免费 | 4816篇 |
专业分类
耳鼻咽喉 | 22661篇 |
儿科学 | 56985篇 |
妇产科学 | 47588篇 |
基础医学 | 264172篇 |
口腔科学 | 48142篇 |
临床医学 | 164815篇 |
内科学 | 331767篇 |
皮肤病学 | 36375篇 |
神经病学 | 140707篇 |
特种医学 | 63279篇 |
外国民族医学 | 423篇 |
外科学 | 247258篇 |
综合类 | 36088篇 |
现状与发展 | 1篇 |
一般理论 | 569篇 |
预防医学 | 145690篇 |
眼科学 | 39181篇 |
药学 | 131093篇 |
6篇 | |
中国医学 | 3989篇 |
肿瘤学 | 97533篇 |
出版年
2019年 | 14249篇 |
2018年 | 19883篇 |
2017年 | 15016篇 |
2016年 | 16344篇 |
2015年 | 18618篇 |
2014年 | 25558篇 |
2013年 | 39577篇 |
2012年 | 54169篇 |
2011年 | 57833篇 |
2010年 | 33673篇 |
2009年 | 31039篇 |
2008年 | 53478篇 |
2007年 | 56608篇 |
2006年 | 57037篇 |
2005年 | 54939篇 |
2004年 | 52729篇 |
2003年 | 50179篇 |
2002年 | 48813篇 |
2001年 | 79377篇 |
2000年 | 81913篇 |
1999年 | 68353篇 |
1998年 | 18976篇 |
1997年 | 17069篇 |
1996年 | 17154篇 |
1995年 | 16201篇 |
1994年 | 15108篇 |
1993年 | 14253篇 |
1992年 | 53972篇 |
1991年 | 53554篇 |
1990年 | 52414篇 |
1989年 | 49954篇 |
1988年 | 46275篇 |
1987年 | 45255篇 |
1986年 | 43096篇 |
1985年 | 41148篇 |
1984年 | 30859篇 |
1983年 | 26271篇 |
1982年 | 15471篇 |
1979年 | 28501篇 |
1978年 | 20413篇 |
1977年 | 16797篇 |
1976年 | 16450篇 |
1975年 | 17355篇 |
1974年 | 21054篇 |
1973年 | 20350篇 |
1972年 | 19193篇 |
1971年 | 18060篇 |
1970年 | 16683篇 |
1969年 | 15431篇 |
1968年 | 14626篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
J H Newcorn J M Halperin J M Healey J D O'Brien D M Pascualvaca L E Wolf A Morganstein V Sharma J G Young 《Journal of the American Academy of Child and Adolescent Psychiatry》1989,28(5):734-738
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
994.
M M Pedrotti A L Basso 《Metabolic, pediatric, and systemic ophthalmology (New York, N.Y. : 1985)》1986,9(2-4):94-97
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
995.
Dissociation of GFAP intermediate filaments in EAE: observations in the lumbar spinal cord 总被引:1,自引:0,他引:1
Acute experimental allergic encephalomyelitis (EAE) in the Lewis rat is a cell-mediated autoimmune disease of central nervous system myelin. The lesion has been characterized by breakdown of the blood-brain barrier, edema, and periventricular infiltration of macrophages and lymphocytes. At the early stage of the disease, the astrocytes show a marked increase in immunostaining for glial fibrillary acidic protein (GFAP). A corresponding increase in GFAP content, however, cannot be demonstrated. Electron microscopic examination of the early lesion shows a typical reactive astrocytic response expressed by an enlarged watery cytoplasm, particularly at the level of the processes surrounding neurons and blood vessels and in the neuropil itself. The astroglial processes contain numerous glycogen particles (aggregates and single particles). Glial filaments are also conspicuous and are arranged in small bundles or loose thin filaments adjacent to the bundles. The glial filaments that normally appear as tight bundles have expanded and appear less dense. We suggest that the increase in GFAP immunostaining of the astrocytes in the early lesion is due in part to edema, which causes dissociation of the filaments and thereby exposes more antigenic sites to the antibodies. 相似文献
996.
S. Tsagarakis Feng Ge L. H. Rees G. M. Besser A. Grossman 《Journal of neuroendocrinology》1989,1(2):129-133
While extensive evidence suggests that adrenoceptors play an important role in the control of growth hormone in the rat, there are few studies involving the direct measurement of growth hormone-releasing hormone (GHRH). We have therefore developed a radioimmunoassay for rat GHRH, and used it to investigate the modulation of GHRH release by noradrenaline from incubated rat hypothalamus in vitro. The GHRH radioimmunoassay had no significant cross-reactivity with other hypothalamic or GHRH-related peptides, and was sensitive to 4 pg/tube; intra- and interassay coefficients of variation were 6% and 12% respectively. Single incubated rat hypothalami produced a stable and readily measurable output of GHRH in successive 20 min incubations after an initial 60 min preincubation; the release of GHRH was increased in the presence of 56 mM KCI, but did not respond to KCI-depolarization when calcium was excluded from the medium. Stimulated GHRH release was identical to synthetic rat GHRH(1–43) on high-performance liquid chromatography and Sephadex G-75 chromatography.
Noradrenaline stimulated GHRH secretion in a dose-dependent manner in the concentration range 10−10 — 10−6 M, with a plateau in response at 10−7 M. Stimulation with noradrenaline 10−7 M was blocked by idazoxan 10−5 M and attenuated by thymoxamine 10−5 M, but was unaffected by timolol 10−5 M. Both the α2 -adrenoceptor agonist guanfacine, and the α1 -adrenoceptor agonist methoxamine, specifically stimulated GHRH secretion.
It is concluded that noradrenaline stimulates the release of GHRH at both α1 and α2 -adrenoceptors. 相似文献
Noradrenaline stimulated GHRH secretion in a dose-dependent manner in the concentration range 10
It is concluded that noradrenaline stimulates the release of GHRH at both α
997.
C L Grady A M Grimes N Patronas T Sunderland N L Foster S I Rapoport 《Archives of neurology》1989,46(3):317-320
To determine if impaired dichotic performance in patients with dementia of the Alzheimer type is due to the inability to divide attention or the inability to perceive degraded auditory stimuli, we measured performance on tasks of both dichotic and degraded monotic speech materials. We also examined whether perception of degraded speech stimuli presented monaurally is related to abnormalities of temporal lobe anatomy and physiology, as we have shown for dichotic performance. Although the patients were impaired on both dichotic and monotic tests, significantly greater impairment was seen on the dichotic test. Our earlier finding of a significant relation between dichotic performance and measures of anterior temporal lobe atrophy and reduced glucose metabolism was replicated, but no significant relation was found between monotic tests and measures to temporal lobe integrity. We conclude that the inability to divide attention, rather than abnormal processing of degraded stimuli per se, is reflected in poor dichotic performance in patients with dementia of the Alzheimer type, and that dichotic performance, unlike degraded monotic perception, depends directly on the integrity of temporal cortex in these patients. 相似文献
998.
The results of clinical trials of ditrastic, an agent manufactured by Orion, Finland, are analyzed. The drug contains 1.5 or 3% of ditranol. Of the 59 patients treated with this drug complete resolution of clinical eruptions was achieved in 43, the condition of 10 patients considerably improved, a partial effect was observed in 4, and no effect in 2 patients. Therefore ditrastic has proved to be a highly effective agent for the treatment of psoriasis, convenient for outpatient therapy. 相似文献
999.
This study examined longitudinal health and intelligence data to determine whether sensory or motor deficits account for some of the age-related intellectual changes that are commonly seen from midlife onward. Although sensory and motor functioning did not account for the age-related decrements in performance on speeded, visual perceptual tasks found for this sample in previous work, we did find that hearing deficits added error variance to performance estimates on two verbal subtests of the Wechsler scales. 相似文献
1000.
C E Paniak D L Shore B P Rourke 《Journal of clinical and experimental neuropsychology》1989,11(5):631-644
This study examined selective reminding and recognition memory performance of 21 severe closed-head injured patients tested within 6 months of regaining consciousness and then again after at least 1 year. Performances on selective reminding parameters were highly correlated and patients performed significantly worse at both testings than did hospitalized controls matched for age, education, and sex. Patients improved from testing 1 to testing 2 on only four of six memory variables. Average Impairment Rating at testing 1 was a marginally better predictor of memory performance at testing 2 than was length of coma. Results are discussed in terms of (a) utility of selective reminding parameters and predictors of outcome and (b) dissociations in recovery of memory parameters. 相似文献