全文获取类型
收费全文 | 190729篇 |
免费 | 14681篇 |
国内免费 | 5047篇 |
专业分类
耳鼻咽喉 | 1428篇 |
儿科学 | 8886篇 |
妇产科学 | 4612篇 |
基础医学 | 20592篇 |
口腔科学 | 2108篇 |
临床医学 | 23863篇 |
内科学 | 32010篇 |
皮肤病学 | 2742篇 |
神经病学 | 13988篇 |
特种医学 | 5561篇 |
外国民族医学 | 7篇 |
外科学 | 16255篇 |
综合类 | 29893篇 |
现状与发展 | 21篇 |
预防医学 | 11480篇 |
眼科学 | 2930篇 |
药学 | 13234篇 |
129篇 | |
中国医学 | 17357篇 |
肿瘤学 | 3361篇 |
出版年
2024年 | 382篇 |
2023年 | 2998篇 |
2022年 | 4841篇 |
2021年 | 8476篇 |
2020年 | 7780篇 |
2019年 | 6241篇 |
2018年 | 6214篇 |
2017年 | 6496篇 |
2016年 | 6750篇 |
2015年 | 6543篇 |
2014年 | 12582篇 |
2013年 | 13290篇 |
2012年 | 10618篇 |
2011年 | 12018篇 |
2010年 | 9404篇 |
2009年 | 8904篇 |
2008年 | 8822篇 |
2007年 | 9113篇 |
2006年 | 8238篇 |
2005年 | 7074篇 |
2004年 | 6165篇 |
2003年 | 5528篇 |
2002年 | 4232篇 |
2001年 | 3960篇 |
2000年 | 3330篇 |
1999年 | 3033篇 |
1998年 | 2614篇 |
1997年 | 2628篇 |
1996年 | 2311篇 |
1995年 | 2259篇 |
1994年 | 2032篇 |
1993年 | 1688篇 |
1992年 | 1588篇 |
1991年 | 1320篇 |
1990年 | 1134篇 |
1989年 | 1019篇 |
1988年 | 1003篇 |
1987年 | 862篇 |
1986年 | 786篇 |
1985年 | 1077篇 |
1984年 | 893篇 |
1983年 | 559篇 |
1982年 | 768篇 |
1981年 | 634篇 |
1980年 | 535篇 |
1979年 | 415篇 |
1978年 | 302篇 |
1977年 | 265篇 |
1976年 | 233篇 |
1975年 | 114篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
B M Almeida S J Challacombe J W Eveson C G Smith I M Leigh 《The Journal of pathology》1992,166(3):243-253
The murine monoclonal antibody, LH39 was characterized in this study and appeared to bind to a novel basement membrane epitope. This antigen was expressed in the epithelial basement membrane of human tissue derived from all three germ cell layers and in basement membranes surrounding small blood vessels within the stroma of all organs examined. LH39 antigen could be first detected in fetal skin at the dermo-epidermal junction at 7 weeks estimated gestational age but was not present in the dermal vasculature until 16 weeks. When tested against tissue from a range of lower mammalian species, LH39 antigen appeared to be primate-specific. The epithelial basement membrane zone in organotypical cultures, where there is de novo synthesis of basement membrane components, contained abundant LH39 antigen in contrast to other basement membrane components, type IV collagen, laminin, and type VII collagen. Ultrastructural localization of LH39 epitope, using immunogold electron microscopy on unfixed freshly frozen tissue, was to the lamina lucida. No cross-reactivity could be detected between LH39 and laminin, fibronectin, and collagens I, III, IV, and V using the ELISA assay. In vitro studies with a range of proteolytic enzymes suggested that the antigen was non-collagenous in nature. LH39 precipitated a polypeptide with a molecular weight of 185 kD from extracts of metabolically labelled cultured keratinocytes, and polypeptides of 185 and 200 kD from the culture medium. The tissue distribution of LH39 antigen suggested that it may be an epitope within anchoring filaments. Potential applications of this antibody include the study of benign and malignant human vascular disorders, diseases and tumours associated with angiogenesis, epithelial neoplasms, and conditions of tissue regeneration and repair, such as wound healing. 相似文献
994.
Ketanserin降低清醒自发性高血压大鼠血压波动性的机理初探 总被引:2,自引:0,他引:2
应用计算机化清醒大鼠血流动力学测定技术,观察5-HT2受体阻滞剂Ritanserin(Rit)和α1受体阻滞剂哌唑嗪对清醒自发性高血压大鼠(SHR)的血压、血压波动性(BPV)和动脉压力感受性反射血压控制部分(ABR-BP)的效应,旨在初步探讨兼具5-HT2受体和α1受体阻滞作用地新型抗高血压药Ketanserin降低BPV的机制。结果表明:Rit对SHR无降压作用,但侧脑室给药明显提高ABR-B 相似文献
995.
本研究采用中国修订的韦氏儿童智力量表(WISC-CR)、韦氏儿童记忆量表(WMSC-CR),艾森克个性问卷(EPQ)和Achenbach儿童行为量表(ACBC),对39例(未用药组22例,用药组17例)7~14岁Tourette综合征(TS)患儿进行测试,同时采用放射免疫方法测定其血浆催乳素(PRL)含量,并与18例正常对照组比较。结果表明:TS患儿智力测验和记忆测验中的背数、译码和视觉再生分测验量表分低于对照组。其个性测验中的神经质(N)和精神质(P)量表T分高于对照组,掩饰性(L)量表T分低于对照组。其ACBC总分高于对照组。用药组的记忆商(MQ)、理解记忆和累加分测验量表分低于未用药组,TS患儿的血浆催乳素含量高于对照组。相关分析表明血浆催乳素含量与ACBC总分和精神抑制药物如氟哌啶醇和泰必利等因素有关。我们的初步研究提示TS患儿存在不同程度的神经心理缺陷,催乳素可能参与TS发病过程,氟哌啶醇和泰必利等精神抑制药物可能对TS患儿的记忆功能有影响以及可以导致血浆催乳素分泌增加,为TS的防治干预提供了一定的理论依据。 相似文献
996.
Michael Weller Helmut Wilhelm Norbert Sommer Johannes Dichgans Horst Wiethölter 《Journal of neurology》1992,239(4):231-234
Summary Two patients are described with the triad of tonic pupil, hyporeflexia and segmental anhidrosis (Ross syndrome). Only 18 cases of this syndrome have been reported in the literature so far. While tonic pupil and reduced sweating can be attributed to the affection of postganglionic cholinergic parasympathetic and sympathetic fibres projecting to the iris and sweat glands, respectively, the pathogenesis of diminished or lost tendon jerks remains obscure. To identify the characteristic clinical features, the previous cases of Ross syndrome are reviewed. Recent evidence of subclinical disturbances of sweating in most patients with Adie's syndrome, i.e. tonic pupil and areflexia, casts doubt on the nosological concept of Ross syndrome as a distinct clinical entity. 相似文献
997.
Four hundred eighty-three epileptic children attending the Pediatric Epilepsy Clinic at Bai Jerbai Wadia Hospital for Children, Bombay, India were classified according to the International League Against Epilepsy (ILAE) classification of epileptic seizures (1981) and epilepsies and epileptic syndromes (1989). The predominant seizures were partial (53.6), generalized (40.3%), and unclassifiable (6%). In epilepsies and epileptic syndromes, 55.3% were partial, 27% were generalized, 13.5% were undetermined, and 4.1% were special syndromes. Although our results were similar in many respects to those of other reported series, some differences were observed in the incidence of partial and generalized seizures, and partial and generalized epileptic syndromes and their subgroups, such as idiopathic, symptomatic, and cryptogenic partial syndromes, idiopathic generalized syndromes, and symptomatic specific syndromes. These differences are probably due to different age limits, methods of case ascertainment and inclusion criteria, different genetic and environmental factors, variable interpretation of clinical and EEG features, and lack of facilities for investigation in developing countries. Despite various limitations, we were able to classify most cases; the ILAE classification can be used in developing countries so that comparison can be made with other studies. 相似文献
998.
高血糖对急性颅脑伤预后的影响 总被引:25,自引:1,他引:24
对ICU收治的61例急性闭合性颅脑伤患者入院24h血糖水平与急性期格拉斯哥昏迷评分、颅脑伤不同类型及预后进行分析。结果提示:格拉斯哥昏迷评分与血糖水平经回归分析呈显著负相关(r=-0.964,P<0.01);不同类型颅脑伤患者以脑挫裂伤组血糖最高。高血糖组患者病死率明显高于非高血糖组,死亡组患者血糖明显高于恢复不良组及恢复良好组。作者认为,血糖测定有助于了解颅脑伤的严重程度,同时可以估计患者的预后,在颅脑伤的救治过程中加强血糖监测是必要的。 相似文献
999.
1000.