收费全文 | 81399篇 |
免费 | 7710篇 |
国内免费 | 1678篇 |
耳鼻咽喉 | 620篇 |
儿科学 | 1127篇 |
妇产科学 | 578篇 |
基础医学 | 4950篇 |
口腔科学 | 1157篇 |
临床医学 | 15929篇 |
内科学 | 8514篇 |
皮肤病学 | 453篇 |
神经病学 | 9530篇 |
特种医学 | 23213篇 |
外国民族医学 | 19篇 |
外科学 | 6400篇 |
综合类 | 8572篇 |
现状与发展 | 1篇 |
预防医学 | 1850篇 |
眼科学 | 1289篇 |
药学 | 2567篇 |
61篇 | |
中国医学 | 461篇 |
肿瘤学 | 3496篇 |
2024年 | 232篇 |
2023年 | 1360篇 |
2022年 | 2564篇 |
2021年 | 3694篇 |
2020年 | 3432篇 |
2019年 | 3172篇 |
2018年 | 3071篇 |
2017年 | 3406篇 |
2016年 | 3627篇 |
2015年 | 3511篇 |
2014年 | 6035篇 |
2013年 | 5236篇 |
2012年 | 4964篇 |
2011年 | 5397篇 |
2010年 | 4444篇 |
2009年 | 4536篇 |
2008年 | 4478篇 |
2007年 | 4231篇 |
2006年 | 3733篇 |
2005年 | 3233篇 |
2004年 | 2744篇 |
2003年 | 2075篇 |
2002年 | 1664篇 |
2001年 | 1572篇 |
2000年 | 1309篇 |
1999年 | 1045篇 |
1998年 | 1029篇 |
1997年 | 955篇 |
1996年 | 790篇 |
1995年 | 694篇 |
1994年 | 560篇 |
1993年 | 458篇 |
1992年 | 363篇 |
1991年 | 265篇 |
1990年 | 208篇 |
1989年 | 143篇 |
1988年 | 132篇 |
1987年 | 116篇 |
1986年 | 76篇 |
1985年 | 55篇 |
1984年 | 46篇 |
1983年 | 26篇 |
1982年 | 26篇 |
1981年 | 18篇 |
1980年 | 22篇 |
1979年 | 13篇 |
1978年 | 10篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1973年 | 4篇 |
Background/purpose
Computed tomography (CT) derived Haller Index (HI) remains the standard for quantifying severity in patient with pectus excavatum (PE). Optical scanning described in literature reports optimistic results and new indices that correlate with HI. This study assessed the feasibility of a handheld White Light Scanner (WLS) to obtain 3D measurements and indices of PE deformity.Methods
From April 2015–April 2017, WLS scanning was conducted by orthotists during clinical visits. Included were children with PE up to 18?years. Analysis assessed correlation of a WLS-derived severity index, Hebal-Malas Index (HMI), with physician measured PE Depth (PED), and CT-derived HI.Results
Of 195 participants, 185(94%) patients with PE were scanned and 127(69%) had complete WLS data. For 88 patients undergoing monitoring, HMI correlated with PED (r?=?0.42, p?=?0.004). For 39 patients with pre-operative CT, HMI demonstrated strong correlation with HI (r?=?0.87, p < 0.0001).Conclusions
WLS demonstrated high feasibility of scanning PE. WLS-derived HMI best correlates with HI for patients with severe pectus deformity. Our current data is suggestive that WLS is best applied for severe deformities and yet to be established for milder deformities. Future yearly WLS will provide data on deformity progression and surgical therapy.Level of Evidence
IV.Type of Study
Diagnostic Study. 相似文献Methods: [11C]WAY100635, [18F]altanserin and positron emission tomography were used to compare 5-HT1A and 5-HT2A binding in MDD patients divided into eight past suicide attempters (>4yrs prior to scanning) and eight lifetime non-attempters, and both groups were compared to eight healthy volunteers.
Results: The two receptor types differed in binding pattern across brain regions from each other, but there were no differences in binding between healthy volunteers and the two depressed groups or between depressed suicide attempters and non-attempters. No effects of depression severity or lifetime aggression were observed for either receptor.
Conclusion: Limitations of this study include small sample size and absence of high lethality suicide attempts in the depressed attempter group. No trait-like binding correlations with past suicide attempt or current depression were observed. Given the heterogeneity of nonfatal suicidal behavior, a larger sample study emphasizing higher lethality suicide attempts may find the serotonin biological phenotype seen in suicide decedents. 相似文献