全文获取类型
收费全文 | 182638篇 |
免费 | 17316篇 |
国内免费 | 11811篇 |
专业分类
耳鼻咽喉 | 1632篇 |
儿科学 | 1905篇 |
妇产科学 | 2429篇 |
基础医学 | 21908篇 |
口腔科学 | 3260篇 |
临床医学 | 23929篇 |
内科学 | 26740篇 |
皮肤病学 | 2211篇 |
神经病学 | 9523篇 |
特种医学 | 6481篇 |
外国民族医学 | 97篇 |
外科学 | 18619篇 |
综合类 | 29637篇 |
现状与发展 | 39篇 |
一般理论 | 22篇 |
预防医学 | 12256篇 |
眼科学 | 4779篇 |
药学 | 19743篇 |
192篇 | |
中国医学 | 10988篇 |
肿瘤学 | 15375篇 |
出版年
2024年 | 737篇 |
2023年 | 2988篇 |
2022年 | 7802篇 |
2021年 | 9809篇 |
2020年 | 7376篇 |
2019年 | 6349篇 |
2018年 | 6636篇 |
2017年 | 6088篇 |
2016年 | 5691篇 |
2015年 | 8735篇 |
2014年 | 10599篇 |
2013年 | 9796篇 |
2012年 | 14267篇 |
2011年 | 15424篇 |
2010年 | 9849篇 |
2009年 | 7566篇 |
2008年 | 10058篇 |
2007年 | 9531篇 |
2006年 | 9139篇 |
2005年 | 8877篇 |
2004年 | 5689篇 |
2003年 | 5159篇 |
2002年 | 4273篇 |
2001年 | 3607篇 |
2000年 | 3800篇 |
1999年 | 3854篇 |
1998年 | 2290篇 |
1997年 | 2340篇 |
1996年 | 1782篇 |
1995年 | 1737篇 |
1994年 | 1512篇 |
1993年 | 907篇 |
1992年 | 1280篇 |
1991年 | 1115篇 |
1990年 | 895篇 |
1989年 | 843篇 |
1988年 | 761篇 |
1987年 | 623篇 |
1986年 | 458篇 |
1985年 | 396篇 |
1984年 | 190篇 |
1983年 | 162篇 |
1982年 | 93篇 |
1981年 | 123篇 |
1980年 | 79篇 |
1979年 | 108篇 |
1978年 | 52篇 |
1977年 | 51篇 |
1976年 | 42篇 |
1974年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
We report a case of extragastrointestinal stromal tumor possibly originating from the prostate. The patient underwent radical prostatectomy because of no metastatic evidence. No recurrence and metastasis have been found during 14 months of follow up. To our knowledge, this may be the third such case published in a report in terms of pathological type. 相似文献
32.
Chee-Yueh Angie Ho Chun-Yu Chen Min-Wen Yang Hung-Ping Liu 《European journal of cardio-thoracic surgery》2005,28(1):174-175
Functional separation of the lungs may be accomplished by several methods. Patient with restricted mouth opening has limited options for one-lung ventilation. We report the use of wire-guided endobronchial blockade, a new tool for achieving one-lung ventilation in a patient with restricted mouth opening requiring nasotracheal, fiberoptic intubation for esophagectomy and reconstruction with gastric tube substitution. 相似文献
33.
34.
目的探讨MR检查在颈静脉球瘤诊断中的应用价值。方法对15例病变进行回顾性分析,重点分析其部位、信号及其侵袭性表现等情况。结果15例患者中,右侧病变8个(8/15),左侧7个(7/15);肿瘤形态为类圆形或不规则形,12例较大病变不同程度侵犯颈静脉孔区、乳突、岩骨、岩尖、斜坡等处骨质;肿瘤信号欠均匀,12个(12/15)肿块在MR平扫出现“盐和胡椒征”,以“胡椒”表现最为显著;13个肿块(13/13)均有明显强化,其中10个肿块出现“盐和胡椒征”。9例行MRA检查,颈内动脉和颈内静脉不同程度移位和包绕。结论根据肿瘤的部位、“盐和胡椒征”等MR表现,可在手术前正确诊断颈静脉球瘤。 相似文献
35.
代谢综合征(metabolic syndrome,MS)是包括多种代谢紊乱的一组病理综合征。这些代谢紊乱之间具有密切而复杂的相互关系,是造成包括高血压病、糖尿病、心脑血管疾病在内的一组疾病的基础。MS患病率在世界范围内正以极快的速度增长,预防和治疗MS相关疾病的发生和发展,是目前备受关注的重大社会卫生问题[1]。笔者对119例MS病人进行MS认知程度的调查,分析影响MS病人治疗依从性的因素。1对象和方法1.1对象2003年6月—2005年6月我院内分泌科住院和门诊MS病人119例,均符合中华糖尿病学分会CDS(2004)MS诊断标准[2]。所有病人思维清晰,语言表… 相似文献
36.
Lei Wang Moyi Sun Yuegui Jiang Lianjia Yang Delin Lei Chao Lu Yinghua Zhao Pu Zhang Yaowu Yang Jianhu Li 《Journal of oral and maxillofacial surgery》2006,64(4):636-641
PURPOSE: Perineural invasion is a frequent occurrence in salivary adenoid cystic carcinoma (ACC) and may prevent complete surgical resection. Studies have indicated that nerve growth factor (NGF) and its high-affinity receptor tyrosine kinase A (TrkA) may play a role in perineural invasion in several malignancies in which perineural invasion is observed. The present study was conducted to investigate the expression of NGF and TrkA in salivary ACC and to examine the effects of NGF on adhesion, migration and invasion capacities of a salivary ACC cell line (SACC-83) in vitro. PATIENTS AND METHODS: Expression of NGF and TrkA was explored using immunohistochemistry in paraffin-embedded tissues of 32 cases of salivary ACC. The effects of NGF on in vitro adhesion, migration, and invasion capacities of the SACC-83 cell line were examined using an MTT assay and a modified Boyden chamber assay respectively. RESULTS: In ACC specimens, 31 (96.9%) and 32 (100%) tumors showed immunoreactivity for NGF and TrkA respectively. Significant correlations were found between NGF/TrkA expression levels and perineural invasion (P < .05). In cell adhesion assay, the percent adherences of SACC-83 cells co-cultured with 25 ng/ml NGF at 1.5 hours and 5, 25 ng/ml NGF at 6 hours were significantly higher than that co-cultured with 0 ng/ml NGF (P < .05). However, high concentration of NGF (500 ng/ml) resulted in a significant inhibition of invasion (P < .05). CONCLUSION: Overexpression of NGF and TrkA in human salivary ACC tissues may constitute a reason for perineural invasion in salivary ACC. 相似文献
37.
38.
39.
Calcitonin gene-related peptide (CGRP) causes vasorelaxation in rat aorta involving endothelium/nitric oxide (NO)-dependent elevations of both cAMP and cGMP levels. When endothelium is removed, preincubation with exogenous NO uncovers and potentiates direct (endothelium-independent) cAMP elevations and vasorelaxations caused by CGRP. This enhancing effect of NO potentially involves elevation of cGMP and inhibition of Type III (cGMPinhibitable) phosphodiesterase, causing accumulation of cAMP. However, NO may have other actions. The aim of the present study was to determine if brain natriuretic peptide (BNP), which elevates cGMP levels independent of NO, could enhance cAMP accumulations and vasorelaxations induced by CGRP in rat aortic rings denuded of endothelium. When added separately, neither CGRP (100 nM) nor BNP (10 nM) altered cAMP levels. When added in combination, CGRP (100 nM) and BNP (10 nM) significantly elevated cAMP levels (from control of 0.95 ± 0.08 to 1.53 ± 0.09 pmol/mg protein) at 2 min. BNP (10 nM) elevated cGMP levels 10-fold at 2 min and this response was not altered by co-administration of CGRP (100 nM).Pretreatment with BNP at concentrations as low as 1 nM in endothelium-denuded aortic rings greatly enhanced the direct vasorelaxant effects of CGRP (100 nM) (from control of 0% to 57.6 ± 6.8% relaxation of phenylephrineprecontractions). Our findings indicate that BNP enhances direct (endothelium-independent) cAMP elevations and vasorelaxations caused by CGRP in rat aorta, thus supporting the concept that cGMP inhibits cAMP metabolism and enhances CGRP-induced responses in aortic smooth muscle cells. 相似文献
40.