全文获取类型
收费全文 | 91838篇 |
免费 | 8749篇 |
国内免费 | 6774篇 |
专业分类
耳鼻咽喉 | 748篇 |
儿科学 | 978篇 |
妇产科学 | 1084篇 |
基础医学 | 11133篇 |
口腔科学 | 1728篇 |
临床医学 | 12702篇 |
内科学 | 13675篇 |
皮肤病学 | 892篇 |
神经病学 | 4919篇 |
特种医学 | 3328篇 |
外国民族医学 | 66篇 |
外科学 | 8922篇 |
综合类 | 15844篇 |
现状与发展 | 30篇 |
一般理论 | 3篇 |
预防医学 | 5489篇 |
眼科学 | 2601篇 |
药学 | 9712篇 |
93篇 | |
中国医学 | 5166篇 |
肿瘤学 | 8248篇 |
出版年
2024年 | 400篇 |
2023年 | 1839篇 |
2022年 | 4438篇 |
2021年 | 5338篇 |
2020年 | 3964篇 |
2019年 | 3389篇 |
2018年 | 3422篇 |
2017年 | 3144篇 |
2016年 | 2813篇 |
2015年 | 4405篇 |
2014年 | 5255篇 |
2013年 | 4428篇 |
2012年 | 6565篇 |
2011年 | 7348篇 |
2010年 | 4405篇 |
2009年 | 3343篇 |
2008年 | 4276篇 |
2007年 | 4541篇 |
2006年 | 4450篇 |
2005年 | 4571篇 |
2004年 | 2802篇 |
2003年 | 2554篇 |
2002年 | 2223篇 |
2001年 | 1916篇 |
2000年 | 2160篇 |
1999年 | 2506篇 |
1998年 | 1671篇 |
1997年 | 1588篇 |
1996年 | 1216篇 |
1995年 | 1058篇 |
1994年 | 888篇 |
1993年 | 603篇 |
1992年 | 713篇 |
1991年 | 611篇 |
1990年 | 551篇 |
1989年 | 475篇 |
1988年 | 392篇 |
1987年 | 349篇 |
1986年 | 247篇 |
1985年 | 190篇 |
1984年 | 92篇 |
1983年 | 76篇 |
1982年 | 41篇 |
1981年 | 45篇 |
1980年 | 29篇 |
1979年 | 30篇 |
1965年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
新型纳米根管充填材料对成骨细胞生长的影响 总被引:2,自引:0,他引:2
通过体外培养的成骨细胞,采用二甲基噻唑二苯基四唑溴盐比色法和流式细胞术对新型纳米根管充填材料(nHA-PA66)作用下的成骨细胞生长情况的变化进行研究,评价其对成骨细胞生长的影响。以该材料的细胞培养基浸提液作用于实验组细胞,对照组采用培养基本身。实验组和对照组成骨细胞的生长情况和细胞周期无显著性差异,表明该新型纳米材料对成骨细胞的生长和细胞周期无不良影响。提示新型纳米根管充填材料的成骨细胞相容性较好,具有用作根充材料的基础。 相似文献
23.
Two samples of kindergarten children's representation and understanding of written number symbols were examined in two time points in one academic year. About 85% of Chinese five year olds (mean = 5 years 10 months) were able to use conventional number symbols to represent the quantity of 30 or larger. At the end of the kindergarten year, 94% of Chinese six year olds (mean = 6 years 4 months) were able to use conventional number symbols to represent the quantity of 100 or larger. Some Chinese six year olds had problems in representing written addition and subtraction tasks. Children's ability to represent written number symbols, ability to represent written addition and subtraction formula and their performance on written addition and subtraction were closely related. The performance of children in a university-affiliated childcare center was better than that of the center serving working-class families in Time 1, but the performance reversed at the end of the kindergarten year. 相似文献
24.
Noriyoshi Kurihara Hua Zhou Sakamuri V Reddy Veronica Garcia Palacios Mark A Subler David W Dempster Jolene J Windle G David Roodman 《Journal of bone and mineral research》2006,21(3):446-455
We targeted the MVNP gene to the OCL lineage in transgenic mice. These mice developed abnormal OCLs and bone lesions similar to those found in Paget's patients. These results show that persistent expression of MVNP in OCLs can induce pagetic-like bone lesions in vivo. INTRODUCTION: Paget's disease (PD) of bone is the second most common bone disease. Both genetic and viral factors have been implicated in its pathogenesis, but their exact roles in vivo are unclear. We previously reported that transfection of normal human osteoclast (OCL) precursors with the measles virus nucleocapsid (MVNP) or measles virus (MV) infection of bone marrow cells from transgenic mice expressing a MV receptor results in formation of pagetic-like OCLs. MATERIALS AND METHODS: Based on these in vitro studies, we determined if the MVNP gene from either an Edmonston-related strain of MV or a MVNP gene sequence derived from a patient with PD (P-MVNP), when targeted to cells in the OCL lineage of transgenic mice with the TRACP promoter (TRACP/MVNP mice), induced changes in bone similar to those found in PD. RESULTS: Bone marrow culture studies and histomorphometric analysis of bones from these mice showed that their OCLs displayed many of the features of pagetic OCLs and that they developed bone lesions that were similar to those in patients with PD. Furthermore, IL-6 seemed to be required for the development of the pagetic phenotype in OCLs from TRACP/MVNP mice. CONCLUSIONS: These results show that persistent expression of the MVNP gene in cells of the OCL lineage can induce pagetic-like bone lesions in vivo. 相似文献
25.
X Dong M He X Song B Lu Y Yang S Zhang N Zhao L Zhou Y Li X Zhu R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks. 相似文献
26.
目的 初步建立阴道粘膜上皮细胞体外培养方法,为阴道粘膜上皮研究提供实验模型.方法 取雌性新西兰大白兔阴道粘膜组织小块,胶原酶Ⅳ和胰蛋白酶联合消化分离法收集上皮细胞,接种于角朊细胞无血清培养液中静置培养、传代.动态观察细胞生长增殖情况,扫描和透射电镜观察超微结构,流式细胞仪测定细胞增殖周期,并进行免疫组织化学鉴定.结果 体外培养的阴道粘膜上皮细胞为二倍体细胞,增殖状态良好,细胞间可见桥粒连接,免疫组化角蛋白染色阳性.细胞的超微结构和免疫组化染色均具有上皮细胞特征.结论 在本实验条件下,体外培养的阴道粘膜上皮细胞具有较好的增殖能力,可作为阴道粘膜上皮研究的理想实验模型. 相似文献
27.
28.
支气管结核纤维支气管镜下局部清理、注药与联合微波治疗的疗效比较 总被引:4,自引:0,他引:4
支气管结核患者由于支气管局部的肉芽组织增生、溃疡、干酪性坏死、管腔狭窄阻塞等改变,虽然使用强有力的全身抗痨方案治疗,亦很难将其治愈,常常迁延不愈,局部结构组织破坏明显,引起永久性狭窄、闭塞,导致肺不张、毁损肺等严重的并发症。全身抗痨结合纤维支气管镜清理支气管局部的增生肉芽、坏死组织后注入异烟肼、链霉素的方法可使疗效明显提高。近年来微波技术已逐渐应用于通过纤维支气管镜治疗多种气道疾病。现将我院近5年来确诊的支气管结核用纤支镜局部病灶清理、注抗痨药治疗与同时联合微波热灼治疗的疗效进行分析、报告如下。 相似文献
29.
新疆医科大学为全国第二家中西医合并院校.在新疆进行中西医合校,实属时势所使,事在必行.强弱相合,处于弱势的中医学院只有坚持相对独立,才能保证于合校后发扬中医药特色、办好中医药教育.中西医合校,给原本弱小的新疆高等中医药教育事业的发展带来了诸多可供凭借和利用的积极因素,同时也存在不少负面影响.新疆医科大学在实践中认清了中西医同校的优势与缺憾,采取扶持和爱护中医的策略,不断尝试规避冲突、化解矛盾、趋利祛弊、务期和谐,终喜事业有成,使高等中医药教育得以在新疆生存,并越过低谷,走上健康发展之路. 相似文献
30.
腮腺良性和恶性多形性腺瘤的超声研究 总被引:1,自引:0,他引:1
目的研究腮腺良性和恶性多形性腺瘤的超声特点,为临床医师诊治提供有效依据。方法选取腮腺良性多形性腺瘤患者79例和恶性多形性腺瘤患者15例,对其肿块的大小、硬度、内部回声、彩色多普勒血流显像(CDFI)特点结合病理学诊断进行对照研究。结果恶性多形性腺瘤的声像图特点与良性多形性腺瘤相似,但其肿瘤相对较大,质地更硬,内部回声分布更紊乱。不同性质的肿瘤的大小和质地有显著性差异,(P<0.01)。结论多形性腺瘤的超声诊断主要依据二维图像之特点。当多形性腺瘤大于3.0 cm,硬度较硬,内部回声分布不均多提示恶性。 相似文献