全文获取类型
收费全文 | 49323篇 |
免费 | 3457篇 |
国内免费 | 1044篇 |
专业分类
耳鼻咽喉 | 384篇 |
儿科学 | 1157篇 |
妇产科学 | 1246篇 |
基础医学 | 5356篇 |
口腔科学 | 870篇 |
临床医学 | 4631篇 |
内科学 | 11115篇 |
皮肤病学 | 750篇 |
神经病学 | 4235篇 |
特种医学 | 1801篇 |
外国民族医学 | 6篇 |
外科学 | 6398篇 |
综合类 | 2881篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 2683篇 |
眼科学 | 647篇 |
药学 | 4433篇 |
22篇 | |
中国医学 | 1319篇 |
肿瘤学 | 3887篇 |
出版年
2024年 | 104篇 |
2023年 | 491篇 |
2022年 | 1299篇 |
2021年 | 1865篇 |
2020年 | 1258篇 |
2019年 | 1220篇 |
2018年 | 1363篇 |
2017年 | 1199篇 |
2016年 | 1165篇 |
2015年 | 1551篇 |
2014年 | 2041篇 |
2013年 | 2399篇 |
2012年 | 3122篇 |
2011年 | 3131篇 |
2010年 | 1987篇 |
2009年 | 1772篇 |
2008年 | 2595篇 |
2007年 | 2667篇 |
2006年 | 2468篇 |
2005年 | 2275篇 |
2004年 | 2046篇 |
2003年 | 1777篇 |
2002年 | 1617篇 |
2001年 | 1468篇 |
2000年 | 1390篇 |
1999年 | 1301篇 |
1998年 | 470篇 |
1997年 | 356篇 |
1996年 | 374篇 |
1995年 | 287篇 |
1994年 | 260篇 |
1993年 | 221篇 |
1992年 | 674篇 |
1991年 | 574篇 |
1990年 | 542篇 |
1989年 | 549篇 |
1988年 | 456篇 |
1987年 | 419篇 |
1986年 | 400篇 |
1985年 | 315篇 |
1984年 | 259篇 |
1983年 | 210篇 |
1982年 | 116篇 |
1979年 | 212篇 |
1978年 | 128篇 |
1977年 | 110篇 |
1974年 | 122篇 |
1973年 | 125篇 |
1972年 | 122篇 |
1971年 | 110篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
目的 观察SWIM技术治疗后循环大血管闭塞所致急性缺血性卒中的有效性及安全性。
方法 回顾性分析2017年2月-2018年11月于大连市中心医院采用SWIM技术治疗的后循环大血管闭
塞所致急性缺血性卒中患者的临床资料,评价该技术的疗效和安全性,并分析影响患者预后的因素。
观察指标为术后即刻成功再通(mTICI≥2b)、90 d良好预后(mRS评分≤2分),以及术后24 h任何颅内
出血、90 d全因死亡。
结果 共纳入35例患者,平均年龄66.1±12.1岁,男性26例(74.3%),基线NIHSS评分22(15~34)分。
术后即刻成功再通率为94.3%(33/35),90 d良好预后率为45.7%(16/35),24 h颅内出血率为17.1%
(6/35),90 d全因死亡率为37.1%(13/35)。单因素分析显示,基线NIHSS评分较低(P =0.001)、基
线后循环ASPECTS评分较高(P =0.016)、发病至到院时间较短(P =0.039)、发病至再通时间较短
(P =0.047)、血管成功再通率较高(P =0.036)以及饮酒比例较低(P =0.042)与良好预后相关。
结论 使用SWIM技术治疗后循环急性缺血性卒中相对安全、有效。 相似文献
32.
Gianluca Gambarini Lucila Piasecki Gabriele Miccoli Gianfranco Gaimari Roberto Di Giorgio Dario Di Nardo Adham A Azim Luca Testarelli 《Australian endodontic journal : the journal of the Australian Society of Endodontology Inc》2019,45(2):154-162
This study evaluated the effect of new motions of the motor TriAuto ZX2 on the cyclic fatigue of endodontic instruments. Vortex Blue 35.06 instruments were divided into four groups (n = 10) and tested for fatigue in a curved artificial canal (90° and 2 mm radius) using the following motions: continuous rotation (CR), Optimum Torque Reverse (OTR) set at 180° and the Optimum Glide Path (OGP), which was tested at 90° and 240°. The time to fracture (TTF) and the lengths of the fractured fragments were recorded. The mean TTF was significantly different among the groups (anova , P < 0.05): OGP 90° (213.39 ± 27.45), OTR 180° (121.24 ± 17.03), OGP 240° (45.24 ± 5.61) and CR (8.43 ± 1.27). Weibull analysis confirmed the shortest life expectancy for CR and the longest survival for OGP at 90°. The resistance to fatigue was affected by motions and pre‐set angles. The proprietary movements that are currently available for endodontic instruments were classified according to their kinematics. 相似文献
33.
34.
目的 制备具有天然神经组织结构的支架,构建组织工程化面神经用于修复面神经损伤。方法 取家兔面神经,改良化学萃取法制备脱细胞神经基质,HE染色形态学观察去细胞及脱髓鞘情况,荧光分光光度计测定支架内细胞经Quant-iT PicoGreen工作液染色后的DNA含量。MTT法检测细胞在支架上的相对生长率从而检测支架的细胞毒性。结果 支架移植体呈圆柱形,弹性与正常神经基本一致,组织观察显示细胞结构未见残余完整细胞及细胞碎片残留,未见神经髓鞘及轴突结构,细胞外基质形成纵向排列结构,结构之间可见空隙。兔脱细胞面神经基质支架内残留的DNA含量较正常兔面神经明显下降(P<0.01)。神经基质供体无细胞毒性。结论 改良化学萃取法可有效去除面神经细胞,天然结构保存完好,细胞毒性低,可作为组织工程化面神经的支架。 相似文献
35.
F Sebastiano G Di Gennaro V Esposito A Picardi R Morace A Sparano A Mascia C Colonnese G Cantore P P Quarato 《Clinical neurophysiology》2006,117(2):341-347
OBJECTIVES: To evaluate a novel method for localization of subdural electrodes in presurgical assessment of patients with drug-resistant focal epilepsy. METHODS: We studied eight consecutive patients with posterior epilepsy in whom subdural electrodes were implanted for presurgical evaluation. Electrodes were detected on post-implantation brain CT scans through a semiautomated procedure based on a MATLAB routine. Then, post-implantation CT scans were fused with pre-implantation MRI to localize the electrodes in relation to the underlying cortical structures. The reliability of this procedure was tested by comparing 3D-rendered MR images of the electrodes with electrode position as determined by intraoperative digital photography. RESULTS: In each patient, all electrodes could be correctly localized and visualized in a stereotactic space, thus allowing optimal surgery planning. The agreement between the procedure-generated images and the digital photographs was good according to two independent raters. The mean mismatch between the 3D images and the photographs was 2 mm. CONCLUSIONS: While our findings need confirmation on larger samples including patients with anterior epilepsy, this procedure allowed to localize subdural electrodes and to establish the spatial relationship of each electrode to the underlying brain structure, either normal or damaged, on brain convessity, basal and medial cortex. SIGNIFICANCE: Being simple, rapid, unexpensive, and reliable, this procedure holds promise to be useful to optimize epilepsy surgery planning. 相似文献
36.
BACKGROUND/PURPOSE: Sensitive skin is a condition associated with reduced tolerance to environmental factors and/or the application of topical products, such as cosmetics. Its pathophysiology has not been fully elucidated and few data are available on its prevalence. The aim of this study was to investigate possible correlation between objective sensitivity and skin surface microrelief. METHODS: During an epidemiological survey conducted for a campaign promoted by International Society of Plastic Dermatology in Italy, 243 adult healthy subjects of both sexes with no evident dermatological disorder but positive to the lactic acid stinging test, were submitted to cyanoacrylate stratum corneum stripping from the volar forearm for the determination of the irregularity of the skin surface microrelief (irregularity skin index (ISI)). RESULTS: A significant correlation was found between intensity of symptoms in stingers and ISI (r(s)=-0.47; P<0.001). CONCLUSION: Sensitive skin is common in the healthy population. ISI can contribute towards the identification of subjects with sensitive skin and the development of more specific skin treatments for this prevalent condition. 相似文献
37.
Daniela Brizzolara Anna Chilosi Paola Cipriani Gloria Di Filippo Filippo Gasperini Sara Mazzotti Chiara Pecini Pierluigi Zoccolotti 《Cognitive and behavioral neurology》2006,19(3):141-149
OBJECTIVE: The study aims to verify whether phonologic and rapid automatized naming (RAN) deficits are present and associated in Italian dyslexic children and whether they differentially affect dyslexics with and without a history of previous language delay (LD). BACKGROUND: According to the phonologic core deficit hypothesis, dyslexia may stem from impairment of the representation and manipulation of phonemes and may be closely associated with oral language deficits. However, deficits in tasks not requiring fine-grained phonologic representations, such as RAN, have also been described in dyslexic children. METHODS: Thirty-seven children were selected on the basis of a reading deficit and were assigned to 2 groups according to whether or not they had a history of early LD as determined retrospectively by parental report. A battery of reading and writing, verbal working memory, metaphonologic, RAN, and visual search tests were administered. RESULTS: RAN deficits were shared by most dyslexics (with and without a history of LD), whereas phonologic deficits were mainly associated with a previous LD. This last condition did not result in a more profound impairment of reading and writing decoding skills. CONCLUSION: In a shallow orthography such as Italian, RAN, not phonologic deficits, may represent the main cognitive marker of developmental dyslexia. 相似文献
38.
39.
从先进教育理念及模式的运用、不同教学方法的应用等方面对国内外手术室临床护理教学方法进行分析、归纳和探讨,为手术室临床护理教学管理提供方向和指导。 相似文献
40.
Caterina Proto Daniela Romualdi Rosa Maria Cento Rosario S Spada Giuseppina Di Mento Raffaele Ferri Antonio Lanzone 《Gynecological endocrinology》2006,22(4):213-218
BACKGROUND: In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimer's disease (AD). Indeed, previous studies have documented that glucagon-like peptide 1 (GLP-1) possesses neurotropic properties and can reduce amyloid-beta peptide levels in the brain in vivo. Moreover, the concentrations of neuropeptide Y (NPY) seem to be altered in the cerebrospinal fluid of patients with AD and in subjects with major depression. Finally, among the modifications induced by aging, a dysregulation of the ghrelin-growth hormone (GH) system has been reported. METHODS: We investigated the plasma concentrations of these neuropeptides in 14 subjects with AD. Data obtained from these patients were compared with data from an age- and weight-matched healthy group. RESULTS: No significant differences were found between the two groups in relation to plasma levels of GLP-1, NPY, ghrelin and GH. Peripheral NPY concentrations were positively correlated with ghrelin levels in both groups, and with plasma GLP-1 concentration only in controls. CONCLUSION: On the basis of our results, peripheral levels of these neuropeptides seem not to serve as biochemical markers of AD. 相似文献