全文获取类型
收费全文 | 24066篇 |
免费 | 2013篇 |
国内免费 | 667篇 |
专业分类
耳鼻咽喉 | 451篇 |
儿科学 | 224篇 |
妇产科学 | 556篇 |
基础医学 | 4269篇 |
口腔科学 | 755篇 |
临床医学 | 3012篇 |
内科学 | 1938篇 |
皮肤病学 | 142篇 |
神经病学 | 8147篇 |
特种医学 | 520篇 |
外科学 | 2032篇 |
综合类 | 1686篇 |
预防医学 | 706篇 |
眼科学 | 291篇 |
药学 | 1340篇 |
3篇 | |
中国医学 | 495篇 |
肿瘤学 | 179篇 |
出版年
2024年 | 60篇 |
2023年 | 485篇 |
2022年 | 717篇 |
2021年 | 1184篇 |
2020年 | 1095篇 |
2019年 | 920篇 |
2018年 | 912篇 |
2017年 | 855篇 |
2016年 | 715篇 |
2015年 | 757篇 |
2014年 | 1366篇 |
2013年 | 1446篇 |
2012年 | 1018篇 |
2011年 | 1245篇 |
2010年 | 1019篇 |
2009年 | 1020篇 |
2008年 | 1109篇 |
2007年 | 1011篇 |
2006年 | 946篇 |
2005年 | 782篇 |
2004年 | 719篇 |
2003年 | 693篇 |
2002年 | 560篇 |
2001年 | 459篇 |
2000年 | 421篇 |
1999年 | 386篇 |
1998年 | 347篇 |
1997年 | 328篇 |
1996年 | 288篇 |
1995年 | 268篇 |
1994年 | 275篇 |
1993年 | 202篇 |
1992年 | 253篇 |
1991年 | 215篇 |
1990年 | 209篇 |
1989年 | 195篇 |
1988年 | 156篇 |
1987年 | 165篇 |
1986年 | 147篇 |
1985年 | 251篇 |
1984年 | 225篇 |
1983年 | 163篇 |
1982年 | 176篇 |
1981年 | 164篇 |
1980年 | 159篇 |
1979年 | 140篇 |
1978年 | 116篇 |
1977年 | 90篇 |
1976年 | 86篇 |
1974年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 718 毫秒
21.
22.
Shafqat R. Chaudhry Ilana S. Lendvai Sajjad Muhammad Philipp Westhofen Johannes Kruppenbacher Lukas Scheef Henning Boecker Dirk Scheele Rene Hurlemann Thomas M. Kinfe 《Brain stimulation》2019,12(3):643-651
Objective
To assay peripheral inter-ictal cytokine serum levels and possible relations with non-invasive vagus nerve stimulation (nVNS) responsiveness in migraineurs.Methods
This double-blinded, sham-controlled study enrolled 48 subjects and measured headache severity, frequency [headache days/month, number of total and mild/moderate/severe classified attacks/month], functional state [sleep, mood, body weight, migraine-associated disability] and serum levels of inflammatory markers [inter-ictal] using enzyme-linked immunoassays at baseline and after 2 months of adjunctive nVNS compared to sham stimulation and suitably matched controls.Results
No significant differences were observed at baseline and after 2 months for headache severity, total attacks/month, headache days/month and functional outcome [sleep, mood, disability] between verum and sham nVNS. However, the number of severe attacks/month significantly decreased in the verum nVNS group and circulating pro-inflammatory IL-1β was elevated significantly in the sham group compared to nVNS. Levels of anti-inflammatory IL-10 were significantly higher at baseline in both groups compared to healthy controls, but not at 2 months follow-up [p?<?0.05]. Concentrations of high-mobility group box-1 (HMGB-1), IL-6, tumor-necrosis factor-α (TNF-α), leptin, adiponectin, ghrelin remained unchanged [p?>?0.05]. No severe device-/stimulation-related adverse events occurred.Conclusion
2 months of adjunctive cervical nVNS significantly declined the number of severe attacks/month. Pro-inflammatory IL-1β plasma levels [inter-ictal] were higher in sham-treated migraine patients compared to verum nVNS. However, pro- [IL-6, HMGB-1, TNF-α, leptin] and anti-inflammatory [IL-10, adiponectin, ghrelin] mediators did not differ statistically. Profiling of neuroinflammatory circuits in migraine to predict nVNS responsiveness remains an experimental approach, which may be biased by pre-analytic variables warranting large-scale biobank-based systematic investigations [omics]. 相似文献23.
24.
《Clinical neurophysiology》2019,130(9):1562-1569
ObjectiveConventional deep brain stimulation (DBS) systems with ring-shaped leads generate spherical electrical fields. In contrast, novel directional leads use segmented electrodes. Aim of this study was to quantify the impedance variations over time in subjects with the directional Cartesia-Boston® system.MethodsImpedance records, programming settings, and clinical data of 11 consecutive Parkinsonian patients implanted with DBS directional leads in two Italian centers (Udine and Vicenza) were retrospectively evaluated. Data were collected before starting stimulation (in the operating room and at days 5 and 40) and after switching stimulation on at the successive follow-up visits (1, 6 and 12 months).ResultsDirectional leads have significantly higher impedance than ring leads. Stimulated contacts had always lower impedance compared to non-stimulated contacts. Before DBS-on, all contacts had higher impedance in the operating room, with an initial decrease five days post-surgery and a subsequent increase at day 40, more evident for directional contacts. The impedance of directional leads increased post-implantation at 1 and 6 months with a plateau at 12 months.ConclusionsThere was a significant difference between the directional and ring leads at baseline (before activation of DBS) and during follow-up (chronic DBS).SignificanceOur study reveals new information about the impedance of segmented electrodes that is useful for patient management during the initial test period, as well as during long-term DBS follow-up. 相似文献
25.
26.
27.
28.
29.
30.
《Brain stimulation》2020,13(5):1159-1167
BackgroundInhibitory control refers to a central cognitive capacity involved in the interruption and correction of actions. Dysfunctions in these cognitive control processes have been identified as major maintaining mechanisms in a range of mental disorders such as ADHD, binge eating disorder, obesity, and addiction. Improving inhibitory control by transcranial direct current stimulation (tDCS) could ameliorate symptoms in a broad range of mental disorders.ObjectiveThe primary aim of this pre-registered meta-analysis was to investigate whether inhibitory control can be improved by tDCS in healthy and clinical samples. Additionally, several moderator variables were investigated.MethodsA comprehensive literature search was performed on PubMed/MEDLINE database, Web of Science, and Scopus. To achieve a homogenous sample, only studies that assessed inhibitory control in the go-/no-go (GNG) or stop-signal task (SST) were included, yielding a total of 75 effect sizes from 45 studies.ResultsResults of the meta-analysis indicate a small but significant overall effect of tDCS on inhibitory control (g = 0.21) which was moderated by target and return electrode placement as well as by the task. The small effect size was further reduced after correction for publication bias.ConclusionBased on the studies included, our meta-analytic approach substantiates previously observed differences between brain regions, i.e., involvement of the right inferior frontal gyrus (rIFG) vs. the right dorsolateral prefrontal cortex (rDLPFC) in inhibitory control. Results indicate a small moderating effect of tDCS on inhibitory control in single-session studies and highlight the relevance of technical and behavioral parameters. 相似文献