全文获取类型
收费全文 | 1393125篇 |
免费 | 89423篇 |
国内免费 | 1785篇 |
专业分类
耳鼻咽喉 | 18825篇 |
儿科学 | 39321篇 |
妇产科学 | 34507篇 |
基础医学 | 212045篇 |
口腔科学 | 39211篇 |
临床医学 | 122555篇 |
内科学 | 265513篇 |
皮肤病学 | 29724篇 |
神经病学 | 101844篇 |
特种医学 | 54241篇 |
外国民族医学 | 130篇 |
外科学 | 220348篇 |
综合类 | 24834篇 |
现状与发展 | 2篇 |
一般理论 | 332篇 |
预防医学 | 95816篇 |
眼科学 | 31836篇 |
药学 | 108083篇 |
4篇 | |
中国医学 | 3136篇 |
肿瘤学 | 82026篇 |
出版年
2018年 | 13803篇 |
2017年 | 10455篇 |
2016年 | 11804篇 |
2015年 | 13333篇 |
2014年 | 18118篇 |
2013年 | 26645篇 |
2012年 | 37479篇 |
2011年 | 40082篇 |
2010年 | 23505篇 |
2009年 | 21940篇 |
2008年 | 38218篇 |
2007年 | 40822篇 |
2006年 | 41166篇 |
2005年 | 39452篇 |
2004年 | 38311篇 |
2003年 | 36887篇 |
2002年 | 36009篇 |
2001年 | 73273篇 |
2000年 | 75591篇 |
1999年 | 62778篇 |
1998年 | 15242篇 |
1997年 | 13254篇 |
1996年 | 13333篇 |
1995年 | 12476篇 |
1994年 | 11394篇 |
1993年 | 10679篇 |
1992年 | 47700篇 |
1991年 | 47358篇 |
1990年 | 46325篇 |
1989年 | 45219篇 |
1988年 | 41334篇 |
1987年 | 40545篇 |
1986年 | 37729篇 |
1985年 | 36109篇 |
1984年 | 26051篇 |
1983年 | 22151篇 |
1982年 | 11439篇 |
1979年 | 23697篇 |
1978年 | 16242篇 |
1977年 | 13602篇 |
1976年 | 12774篇 |
1975年 | 14605篇 |
1974年 | 17157篇 |
1973年 | 16282篇 |
1972年 | 15337篇 |
1971年 | 14595篇 |
1970年 | 13807篇 |
1969年 | 12904篇 |
1968年 | 11950篇 |
1967年 | 10726篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
981.
Out of 24 patients with laryngeal papillomatosis 6 (5 female, 1 male) suffered from repeated relapses and underwent long-term treatment with alpha-IFN-therapy. Age at onset of the disease: 1 5/12-16 2/12 years. Duration of illness: 1-7 years, with several relapses were treated surgically and with laser-coagulation. Three out of 6 patients had a tracheal cannula and were cauterized by podophylline at 2-4 week intervals. IFN was given in dosages of 5-20 X 10(4) U/kg 2 or 3 times a week. IFN-dosage for each patient was determined using the induction kinetics of (2'-5')-oligo(A)synthetase (OAS) in the mononuclear cells of the circulating blood of patients with laryngeal papillomatosis. A continuous effect could be achieved by the dose of IFN determined in the described way always before OAS activity decreased to its initial level. All 6 patients responded favorably to the alpha-IFN-therapy. Two patients treated only with IFN showed remission without relapses. In 2 cases IFN was successfully used to prevent relapses after surgical treatment and laser-coagulation. In 2 patients with papillomatosis extending into the main bronchi the disease could only be brought to a standstill, i.e. it was not necessary to remove the papillomas. Two out of 3 patients with laryngeal papillomatosis could be decannulated. Long-term therapy following the above described principles is efficient and without significant side-effects. Three patients are in treatment for more than 3 10/12 years. 相似文献
982.
983.
984.
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
985.
986.
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
987.
988.
Endoscopic pictures of the bronchi were studied in 509 new cases of pulmonary tuberculosis. Tuberculosis of the bronchi and its aftereffects such as cicatricial lesions were detected in 31.1 per cent of the children and adolescents, 7.9 per cent of the adults at the age of 18 to 29 years, 9.0 per cent of the adults at the age of 30 to 55 years and 14.7 per cent of the adults at the age of 56 to 75 years. Nonspecific endobronchitis was diagnosed in 27.9 per cent of the children and adolescents, 44.9 per cent of the adults at the age of 18 to 29 years, 46.3 per cent at the age of 30 to 55 years and 44.1 per cent at the age of 56 to 75 years. The incidence and nature of tuberculosis of the bronchi and nonspecific endobronchitis were not related to the patients' age. 相似文献
989.
Treatment of primary hypogonadism in men by the transdermal administration of testosterone 总被引:2,自引:0,他引:2
J C Findlay V Place P J Snyder 《The Journal of clinical endocrinology and metabolism》1989,68(2):369-373
We tested the efficacy of a thin flexible testosterone-impregnated membrane applied to the scrotum for the long term treatment of male hypogonadism. Ten men with primary hypogonadism were treated for 3 months (2 men) or 13 months (8 men). Serum testosterone concentrations increased in all 10 men, to within the normal range in 8. Serum dihydrotestosterone concentrations increased to supranormal values in all of the men, decreased to the normal range in 6, indicating the biological effectiveness of the testosterone in those subjects. Two men whose serum LH concentrations did not fall to normal had small or distorted scrotal surfaces. Seven of the 8 men whose serum testosterone concentrations became normal said that their hypogonadal symptoms were corrected by this treatment. We conclude that the transdermal administration of testosterone is an effective means of treating the majority of hypogonadal men who have a normal scrotum. 相似文献
990.
A case of Ewing's tumour of rib presenting as chest mass is reported. The role of computed tomography and chest ultrasound in evaluating such patients is discussed along with a brief review of literature. 相似文献