全文获取类型
收费全文 | 10443篇 |
免费 | 1658篇 |
国内免费 | 129篇 |
专业分类
耳鼻咽喉 | 84篇 |
儿科学 | 368篇 |
妇产科学 | 184篇 |
基础医学 | 1547篇 |
口腔科学 | 214篇 |
临床医学 | 1342篇 |
内科学 | 2324篇 |
皮肤病学 | 120篇 |
神经病学 | 1600篇 |
特种医学 | 1053篇 |
外科学 | 831篇 |
综合类 | 666篇 |
一般理论 | 1篇 |
预防医学 | 795篇 |
眼科学 | 111篇 |
药学 | 458篇 |
12篇 | |
中国医学 | 128篇 |
肿瘤学 | 392篇 |
出版年
2024年 | 5篇 |
2023年 | 171篇 |
2022年 | 199篇 |
2021年 | 389篇 |
2020年 | 542篇 |
2019年 | 633篇 |
2018年 | 557篇 |
2017年 | 594篇 |
2016年 | 531篇 |
2015年 | 541篇 |
2014年 | 716篇 |
2013年 | 752篇 |
2012年 | 580篇 |
2011年 | 547篇 |
2010年 | 468篇 |
2009年 | 459篇 |
2008年 | 485篇 |
2007年 | 385篇 |
2006年 | 386篇 |
2005年 | 331篇 |
2004年 | 324篇 |
2003年 | 313篇 |
2002年 | 326篇 |
2001年 | 281篇 |
2000年 | 217篇 |
1999年 | 163篇 |
1998年 | 145篇 |
1997年 | 138篇 |
1996年 | 90篇 |
1995年 | 117篇 |
1994年 | 109篇 |
1993年 | 100篇 |
1992年 | 73篇 |
1991年 | 80篇 |
1990年 | 74篇 |
1989年 | 45篇 |
1988年 | 44篇 |
1987年 | 41篇 |
1986年 | 43篇 |
1985年 | 46篇 |
1984年 | 48篇 |
1983年 | 35篇 |
1982年 | 17篇 |
1981年 | 33篇 |
1980年 | 18篇 |
1979年 | 15篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
1.
2.
3.
《Clinical neurophysiology》2021,132(7):1416-1432
ObjectiveNeuromonitoring of primary motor regions allows preservation of motor strength and is frequently employed during cranial procedures. Less is known about protection of sensory function and ability to modulate movements, both of which rely on integrity of thalamocortical afferents (TCA) to fronto-parietal regions. We describe our experience with TCA monitoring and their cortical relays during brain tumor surgery.MethodologyTo study its feasibility and usefulness, continuous somatosensory evoked potentials (SSEP) recording via a subdural electrode was attempted in 32 consecutive patients.ResultsMedian and posterior tibial SSEP were successfully monitored in 31 and 17 patients respectively. SSEP improved lesion localization and prevented unnecessary cortical stimulation in 9 and 16 cases respectively. A threshold of ≥30% SSEP amplitude decrease influenced management in 10 patients while a decrement of ≥50 % had a sensitivity of 0.89 and specificity of 1 in detecting worsening of sensory function. Simultaneous motor evoked potentials (MEP) and SSEP monitoring were performed in 10 cases, 9 of which showed short-lived fluctuations of the former.ConclusionDirect cortical SSEP monitoring is feasible, informs management and predicts outcome.SignificanceEarly intervention prevents sensory deficit. Concomitant MEP fluctuations may reflect modulation of motor activity by TCA. 相似文献
4.
ObjectivesDespite its use in determining nigrostriatal degeneration, the lack of a consistent interpretation of nigrosome 1 susceptibility map-weighted imaging (SMwI) limits its generalized applicability. To implement and evaluate a diagnostic algorithm based on convolutional neural networks for interpreting nigrosome 1 SMwI for determining nigrostriatal degeneration in idiopathic Parkinson's disease (IPD).MethodsIn this retrospective study, we enrolled 267 IPD patients and 160 control subjects (125 patients with drug-induced parkinsonism and 35 healthy subjects) at our institute, and 24 IPD patients and 27 control subjects at three other institutes on approval of the local institutional review boards. Dopamine transporter imaging served as the reference standard for the presence or absence of abnormalities of nigrosome 1 on SMwI. Diagnostic performance was compared between visual assessment by an experienced neuroradiologist and the developed deep learning-based diagnostic algorithm in both internal and external datasets using a bootstrapping method with 10000 re-samples by the “pROC” package of R (version 1.16.2).ResultsThe area under the receiver operating characteristics curve (AUC) (95% confidence interval [CI]) per participant by the bootstrap method was not significantly different between visual assessment and the deep learning-based algorithm (internal validation, .9622 [0.8912–1.0000] versus 0.9534 [0.8779-0.9956], P = .1511; external validation, 0.9367 [0.8843-0.9802] versus 0.9208 [0.8634-0.9693], P = .6267), indicative of a comparable performance to visual assessment.ConclusionsOur deep learning-based algorithm for assessing abnormalities of nigrosome 1 on SMwI was found to have a comparable performance to that of an experienced neuroradiologist. 相似文献
5.
Yicheng Chen Ozan Genc Clare B. Poynton Suchandrima Banerjee Christopher P. Hess Janine M. Lupo 《NMR in biomedicine》2022,35(5):e4666
Quantitative susceptibility mapping (QSM) has the potential for being a biomarker for various diseases because of its ability to measure tissue susceptibility related to iron deposition, myelin, and hemorrhage from the phase signal of a T2*-weighted MRI. Despite its promise as a quantitative marker, QSM is faced with many challenges, including its dependence on preprocessing of the raw phase data, the relatively weak tissue signal, and the inherently ill posed relationship between the magnetic dipole and measured phase. The goal of this study was to evaluate the effects of background field removal and dipole inversion algorithms on noise characteristics, image uniformity, and structural contrast for cerebral microbleed (CMB) quantification at both 3T and 7T. We selected four widely used background phase removal and five dipole field inversion algorithms for QSM and applied them to volunteers and patients with CMBs, who were scanned at two different field strengths, with ground truth QSM reference calculated using multiple orientation scans. 7T MRI provided QSM images with lower noise than did 3T MRI. QSIP and VSHARP + iLSQR achieved the highest white matter homogeneity and vein contrast, with QSIP also providing the highest CMB contrast. Compared with ground truth COSMOS QSM images, overall good correlations between susceptibility values of dipole inversion algorithms and the COSMOS reference were observed in basal ganglia regions, with VSHARP + iLSQR achieving the susceptibility values most similar to COSMOS across all regions. This study can provide guidance for selecting the most appropriate QSM processing pipeline based on the application of interest and scanner field strength. 相似文献
6.
Kelly H. M. Cooijmans Roseriet Beijers Bonnie E. Brett Carolina de Weerth 《Maternal & child nutrition》2022,18(1):e13241
This randomized controlled trial evaluated the effect of a 5-week daily skin-to-skin contact (SSC) intervention between mothers and their full-term infants, compared with care-as-usual, on exclusive and continued breastfeeding duration during the first post-natal year. Healthy pregnant women (n = 116) from a community sample were enrolled and randomly allocated to the SSC or care-as-usual condition. SSC mothers were requested to provide one daily hour of SSC for the first five post-natal weeks. Twelve months post-partum, mothers indicated the number of exclusive and continued breastfeeding months. Multiple regression analyses were conducted using intention-to-treat, per-protocol and exploratory dose–response frameworks. In intention-to-treat analyses, exclusive and continued breastfeeding duration was not different between groups (exclusive: 3.61 ± 1.99 vs. 3.16 ± 1.77 months; adjusted mean difference 0.28, 95% confidence interval [CI] ?0.33 to 0.89; p = 0.36; continued: 7.98 ± 4.20 vs. 6.75 ± 4.06 months; adjusted mean difference 0.81, 95% CI ?0.46 to 2.08; p = 0.21). In per-protocol analyses, exclusive and continued breastfeeding duration was longer for SSC than care-as-usual dyads (exclusive: 4.89 ± 1.26 vs. 3.25 ± 1.80 months; adjusted mean difference 1.28, 95% CI 0.31–2.24; p = 0.01; continued: 10.81 ± 1.97 vs. 6.98 ± 4.08 months; adjusted mean difference 2.33, 95% CI 0.13–4.54; p = 0.04). Exploratory dose–response effects indicated that more SSC hours predicted longer exclusive and continued breastfeeding duration. This study demonstrates that for the total group, the 5-week daily SSC intervention did not extend exclusive and continued breastfeeding duration. However, for mothers performing a regular daily hour of SSC, this simple and accessible intervention may extend exclusive and continued breastfeeding duration by months. Future studies are required to confirm these promising findings. Trial registration: Netherlands Trial Register (NTR5697). 相似文献
7.
目的 分析国内婴儿哭声研究领域的现状,探索该领域国内研究热点,旨在为婴儿哭声领域科研工作提供一定思路和依据。方法 检索CNKI建库至2021年12月期间所收录的婴儿哭声相关研究文献,运用CiteSpace软件对纳入文献从发文量、作者、机构、关键词、突现5个方面进行可视化分析。结果 共纳入190篇文献,1980—2021年间该领域发文量整体呈上升趋势;研究作者较少,作者间合作网络尚未形成;研究机构之间交互性差,发文量最多的是杭州医学院及其附属医院;“护理干预”、“哭声信息识别”、“深度学习”为该领域研究热点;“护理”、“新生儿”、“婴儿哭声”、“深度学习”为该领域研究前沿;研究趋势由新生儿病理性哭声研究转向婴儿哭声针对性干预、深度学习。结论 国内婴儿哭声领域受到更多重视,未来应强化作者和机构间的合作交流,融合多学科发展,扩大研究范围,可从婴儿情感需求分析、智能医学与监护、新型护理干预方法等方面着手,加速国内婴儿哭声研究进程。 相似文献
8.
9.
10.