全文获取类型
收费全文 | 27098篇 |
免费 | 1884篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 260篇 |
儿科学 | 619篇 |
妇产科学 | 552篇 |
基础医学 | 3932篇 |
口腔科学 | 721篇 |
临床医学 | 2523篇 |
内科学 | 5106篇 |
皮肤病学 | 661篇 |
神经病学 | 2748篇 |
特种医学 | 1345篇 |
外科学 | 3910篇 |
综合类 | 220篇 |
一般理论 | 19篇 |
预防医学 | 1868篇 |
眼科学 | 714篇 |
药学 | 1851篇 |
中国医学 | 31篇 |
肿瘤学 | 1989篇 |
出版年
2023年 | 169篇 |
2022年 | 234篇 |
2021年 | 574篇 |
2020年 | 373篇 |
2019年 | 487篇 |
2018年 | 649篇 |
2017年 | 530篇 |
2016年 | 618篇 |
2015年 | 705篇 |
2014年 | 875篇 |
2013年 | 1119篇 |
2012年 | 1820篇 |
2011年 | 1821篇 |
2010年 | 1026篇 |
2009年 | 943篇 |
2008年 | 1549篇 |
2007年 | 1611篇 |
2006年 | 1450篇 |
2005年 | 1401篇 |
2004年 | 1324篇 |
2003年 | 1169篇 |
2002年 | 1076篇 |
2001年 | 695篇 |
2000年 | 699篇 |
1999年 | 578篇 |
1998年 | 239篇 |
1997年 | 179篇 |
1996年 | 130篇 |
1995年 | 123篇 |
1994年 | 113篇 |
1993年 | 101篇 |
1992年 | 275篇 |
1991年 | 243篇 |
1990年 | 259篇 |
1989年 | 216篇 |
1988年 | 214篇 |
1987年 | 195篇 |
1986年 | 182篇 |
1985年 | 183篇 |
1984年 | 177篇 |
1983年 | 133篇 |
1979年 | 186篇 |
1978年 | 123篇 |
1977年 | 119篇 |
1974年 | 107篇 |
1973年 | 117篇 |
1972年 | 111篇 |
1971年 | 109篇 |
1969年 | 129篇 |
1968年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
Weiyu Ye Anna Olsson-Brown Robert A. Watson Vincent T. F. Cheung Robert D. Morgan Isar Nassiri Rosalin Cooper Chelsea A. Taylor Umair Akbani Oliver Brain Rubeta N. Matin Nicholas Coupe Mark R. Middleton Mark Coles Joseph J. Sacco Miranda J. Payne Benjamin P. Fairfax 《British journal of cancer》2021,124(10):1661
Background Immune checkpoint blockers (ICBs) activate CD8+ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8+ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10−6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8+ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma 相似文献
4.
5.
6.
Stephan Koter Tina U. Cohnert Korbinian B. Hindermayr Jörg Lindenmann Maximilian Brückner Wolfgang K. Oswald Georg Werkgartner Doris Wagner 《Journal of vascular surgery》2019,69(4):1227-1232
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献7.
A typical time series in functional magnetic resonance imaging (fMRI) exhibits autocorrelation, that is, the samples of the time series are dependent. In addition, temporal filtering, one of the crucial steps in preprocessing of functional magnetic resonance images, induces its own autocorrelation. While performing connectivity analysis in fMRI, the impact of the autocorrelation is largely ignored. Recently, autocorrelation has been addressed by variance correction approaches, which are sensitive to the sampling rate. In this article, we aim to investigate the impact of the sampling rate on the variance correction approaches. Toward this end, we first derived a generalized expression for the variance of the sample Pearson correlation coefficient (SPCC) in terms of the sampling rate and the filter cutoff frequency, in addition to the autocorrelation and cross‐covariance functions of the time series. Through simulations, we illustrated the importance of the variance correction for a fixed sampling rate. Using the real resting state fMRI data sets, we demonstrated that the data sets with higher sampling rates were more prone to false positives, in agreement with the existing empirical reports. We further demonstrated with single subject results that for the data sets with higher sampling rates, the variance correction strategy restored the integrity of true connectivity. 相似文献
8.
9.
10.
Oliver Sartor MD Daniel Heinrich MD Neil Mariados MD Maria José Méndez Vidal MD Daniel Keizman MD Camilla Thellenberg Karlsson MD Avivit Peer MD Giuseppe Procopio MD Stephen J. Frank MD Kalevi Pulkkanen MD Eli Rosenbaum MD Stefano Severi MD José Trigo MD Lucia Trandafir MD Volker Wagner MD Rui Li MS Luke T. Nordquist MD 《The Prostate》2019,79(14):1683-1691