全文获取类型
收费全文 | 1907954篇 |
免费 | 161576篇 |
国内免费 | 25058篇 |
专业分类
耳鼻咽喉 | 24508篇 |
儿科学 | 56180篇 |
妇产科学 | 50952篇 |
基础医学 | 265362篇 |
口腔科学 | 52480篇 |
临床医学 | 184695篇 |
内科学 | 360966篇 |
皮肤病学 | 36986篇 |
神经病学 | 147375篇 |
特种医学 | 76217篇 |
外国民族医学 | 687篇 |
外科学 | 274976篇 |
综合类 | 88927篇 |
现状与发展 | 79篇 |
一般理论 | 563篇 |
预防医学 | 141410篇 |
眼科学 | 45717篇 |
药学 | 152688篇 |
337篇 | |
中国医学 | 20288篇 |
肿瘤学 | 113195篇 |
出版年
2022年 | 16429篇 |
2021年 | 26094篇 |
2020年 | 18080篇 |
2019年 | 21068篇 |
2018年 | 25841篇 |
2017年 | 21321篇 |
2016年 | 21981篇 |
2015年 | 29014篇 |
2014年 | 37968篇 |
2013年 | 46182篇 |
2012年 | 64506篇 |
2011年 | 69717篇 |
2010年 | 41755篇 |
2009年 | 37136篇 |
2008年 | 59327篇 |
2007年 | 61577篇 |
2006年 | 62447篇 |
2005年 | 60870篇 |
2004年 | 54233篇 |
2003年 | 51569篇 |
2002年 | 49342篇 |
2001年 | 82200篇 |
2000年 | 85703篇 |
1999年 | 74642篇 |
1998年 | 22961篇 |
1997年 | 21643篇 |
1996年 | 20496篇 |
1995年 | 19839篇 |
1994年 | 18181篇 |
1992年 | 57926篇 |
1991年 | 55898篇 |
1990年 | 54450篇 |
1989年 | 52505篇 |
1988年 | 48610篇 |
1987年 | 47693篇 |
1986年 | 45229篇 |
1985年 | 43624篇 |
1984年 | 32475篇 |
1983年 | 27876篇 |
1982年 | 16344篇 |
1979年 | 30631篇 |
1978年 | 21114篇 |
1977年 | 17829篇 |
1976年 | 16744篇 |
1975年 | 17622篇 |
1974年 | 21564篇 |
1973年 | 20732篇 |
1972年 | 18910篇 |
1971年 | 17809篇 |
1970年 | 16330篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
131.
Feasibility and Diagnostic Potential of Pulmonary Transit Time Measurement by Contrast Echocardiography: A Pilot Study
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
132.
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
133.
134.
135.
Qiaojie Wang Karan Goswami Noam Shohat Arash Aalirezaie Jorge Manrique Javad Parvizi 《The Journal of arthroplasty》2019,34(5):947-953
Background
Whether prolonged operative time is an independent risk factor for subsequent surgical site infection (SSI) and periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant and underexplored issue. The aim of this study is to investigate the association between operative time and the risk of subsequent SSI and PJI in patients undergoing primary TJA.Methods
We retrospectively reviewed 17,342 primary unilateral total knee arthroplasty and total hip arthroplasty performed at a single institution between 2005 and 2016, with a minimum follow-up of 1 year. A multivariate logistic regression model was conducted to identify the association between operative time and the development of SSI within 90 days and PJI within 1 year.Results
Overall, the incidence of 90-day SSI and 1-year PJI was 1.2% and 0.8%, respectively. Patients with an operative time of >90 minutes had a significantly higher incidence of SSI and PJI (2.1% and 1.4%, respectively) compared to cases lasting between 60 and 90 minutes (1.1% and 0.7%), and those lasting ≤60 minutes (0.9% and 0.7%, P < .01). In the multivariate model, the risk for infection increased by an odds ratio of 1.346 (95% confidential interval 1.114-1.627) for 90-day SSI and 1.253 (95% confidential interval 1.060-1.481) for 1-year PJI for each 20-minute increase in operative time.Conclusion
In patients undergoing primary TJA, each 20-minute increase in operative time was associated with nearly a 25% increased risk of subsequent PJI. We advocate that surgeons pay close attention to this underappreciated risk factor while maintaining safe operative practices, which minimize unnecessary steps and wasted time in the operating room. 相似文献136.
137.
138.
139.
Chih-Wei Hsu Sheng-Yu Lee Yao-Hsu Yang Liang-Jen Wang 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2020,23(10):653
BackgroundGeneric antidepressants are approved on the market based on evidence of bioequivalence to their brand-name versions. We aimed to assess whether generic antidepressants exert equal effectiveness as their brand-name counterparts for treating patients with depressive disorders.MethodsIn a nationwide, population-based cohort in Taiwan from 1997 through 2013, patients with a diagnosis of a depressive disorder aged between 18 and 65 years who were new users of antidepressant drugs were classified into either the brand-name group or the generic group. All patients were followed up until medication discontinuation or the end of the study period. We assessed the risk for hospitalization as a primary outcome and augmentation therapy, daily dose, medication discontinuation, or switching to another antidepressant as secondary outcomes.ResultsA total of 277 651 brand-name users (35.8% male; mean age: 41.2 years) and 270 583 generic users (35.8% male; mean age: 41.0 years) were divided into 10 different antidepressant groups (fluoxetine, sertraline, paroxetine, escitalopram, citalopram, venlafaxine, mirtazapine, moclobemide, imipramine, and bupropion). We found that patients treated with the generic form of sertraline, paroxetine, escitalopram, venlafaxine, mirtazapine, and bupropion demonstrated significantly higher risks of psychiatric hospitalization (adjusted hazard ratios ranged from 1.20–2.34), compared to their brand-name counterparts. The differences between brand-name antidepressants and their generic counterparts in secondary outcomes varied across different drugs.ConclusionsCompared to most generic antidepressants, brand-name drugs exhibited more protective effects on psychiatric hospitalization for depressive patients. These findings could serve as an important reference for clinicians when encountering patients with depressive disorder. 相似文献
140.
Richard Kim Elaine Tan Emily Wang Amit Mahipal Dung-Tsa Chen Biwei Cao Fadzai Masawi Cindy Machado James Yu Dae Won Kim 《The oncologist》2020,25(12):e1893-e1899
Lessons Learned
- The combination of trametinib and sorafenib has an acceptable safety profile, albeit at doses lower than approved for monotherapy.
- Maximum tolerated dose is trametinib 1.5 mg daily and sorafenib 200 mg twice daily.
- The limited anticancer activity observed in this unselected patient population does not support further exploration of trametinib plus sorafenib in patients with hepatocellular carcinoma.