全文获取类型
收费全文 | 73505篇 |
免费 | 4597篇 |
国内免费 | 277篇 |
专业分类
耳鼻咽喉 | 1165篇 |
儿科学 | 2104篇 |
妇产科学 | 1385篇 |
基础医学 | 8170篇 |
口腔科学 | 1549篇 |
临床医学 | 7242篇 |
内科学 | 15241篇 |
皮肤病学 | 1131篇 |
神经病学 | 7101篇 |
特种医学 | 2658篇 |
外国民族医学 | 5篇 |
外科学 | 12655篇 |
综合类 | 873篇 |
一般理论 | 95篇 |
预防医学 | 6023篇 |
眼科学 | 1443篇 |
药学 | 4648篇 |
中国医学 | 112篇 |
肿瘤学 | 4779篇 |
出版年
2023年 | 402篇 |
2022年 | 664篇 |
2021年 | 1791篇 |
2020年 | 942篇 |
2019年 | 1572篇 |
2018年 | 1840篇 |
2017年 | 1329篇 |
2016年 | 1364篇 |
2015年 | 1505篇 |
2014年 | 2321篇 |
2013年 | 3273篇 |
2012年 | 4925篇 |
2011年 | 5126篇 |
2010年 | 2806篇 |
2009年 | 2485篇 |
2008年 | 4526篇 |
2007年 | 4808篇 |
2006年 | 4647篇 |
2005年 | 4626篇 |
2004年 | 4368篇 |
2003年 | 4035篇 |
2002年 | 3727篇 |
2001年 | 616篇 |
2000年 | 549篇 |
1999年 | 698篇 |
1998年 | 767篇 |
1997年 | 684篇 |
1996年 | 609篇 |
1995年 | 541篇 |
1994年 | 524篇 |
1993年 | 442篇 |
1992年 | 454篇 |
1991年 | 413篇 |
1990年 | 357篇 |
1989年 | 349篇 |
1988年 | 332篇 |
1987年 | 323篇 |
1986年 | 327篇 |
1985年 | 428篇 |
1984年 | 473篇 |
1983年 | 408篇 |
1982年 | 563篇 |
1981年 | 523篇 |
1980年 | 476篇 |
1979年 | 239篇 |
1978年 | 302篇 |
1977年 | 285篇 |
1976年 | 237篇 |
1975年 | 248篇 |
1974年 | 229篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
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
14.
15.
16.
Naveen B.S. M.T. Mohan J. Tharayil S.T. Joseph 《International journal of oral and maxillofacial surgery》2021,50(8):1003-1008
A local pedicled vascularized bone flap can prevent the morbidity and cost of free bone flap surgery in small segmental bone defects or long cartilaginous defects of the head and neck. Such flaps can also be useful in patients who are high risk for surgery. The periosteal vascularity of the mandible can be used to design islanded facial artery-based bone flaps, which can be utilized to that extent. Two patients with a small segmental mandibulectomy defect and one patient with a long cricotracheal resection defect underwent reconstruction using three different designs of islanded facial artery osteomyomucosal/osseous flap (iFOMM). The patients had a minimum follow-up period of 18 months. All flaps were successful, with satisfactory healing and without any functional deficit or disease at last follow-up. 相似文献
17.
Joseph F. Levy Rahul Khairnar Alexander V. Louie Timothy N. Showalter C. Daniel Mullins Mark V. Mishra 《Practical radiation oncology》2019,9(2):e172-e179
Purpose
A hydrogel rectal spacer (HRS) is a medical device that is approved by the U.S. Food and Drug Administration to increase the separation between the prostate and rectum. We conducted a cost-effectiveness analysis of HRS use for reduction in radiation therapy (RT) toxicities in patients with prostate cancer (PC) undergoing external beam RT (EBRT).Methods and Materials
A multistate Markov model was constructed from the U.S. payer perspective to examine the cost-effectiveness of HRS in men with localized PC receiving EBRT (EBRT alone vs EBRT + HRS). The subgroups analyzed included site of HRS placement (hospital outpatient, physician office, ambulatory surgery center) and proportion of patients with good baseline erectile function (EF). Data on EF, gastrointestinal and genitourinary toxicities incidence, and potential risks associated with HRS implantation were obtained from a recently published randomized clinical trial. Health utilities and costs were derived from the literature and the 2018 Physician Fee Schedule and were discounted 3% annually. Quality-adjusted life years (QALYs) and costs were modeled for a 5-year period from receipt of RT. Probabilistic sensitivity analysis and value-based threshold analyses were conducted.Results
The per-patient 5-year incremental cost for spacers administered in a hospital outpatient setting was $3578, and the incremental effectiveness was 0.0371 QALYs. The incremental cost-effectiveness ratio was $96,440/QALY for patients with PC undergoing HRS insertion in a hospital and $39,286/QALY for patients undergoing HRS insertion in an ambulatory facility. For men with good baseline EF, the incremental cost-effectiveness ratio was $35,548/QALY and $9627/QALY in hospital outpatient and ambulatory facility settings, respectively.Conclusions
Based on the current Medicare Physician Fee Schedule, HRS is cost-effective at a willingness to pay threshold of $100,000. These results contain substantial uncertainty, suggesting more evidence is needed to refine future decision-making. 相似文献18.
Rian M. Hasson Kayla A. Fay Joseph D. Phillips Timothy M. Millington David J. Finley 《American journal of surgery》2021,221(4):725-730
BackgroundRural populations face many health disadvantages compared to urban areas. There is a critical need to better understand the current lung cancer screening landscape in these communities to identify targeted areas to improve the impact of this proven tool.MethodsData from the County Health Rankings of New Hampshire and Vermont was reviewed for population density, distribution of adult smokers, and level of education compared to the distribution of Lung Cancer Screening Facilities throughout these two states.ResultsScreening programs in southern counties of Vermont with lower levels of education have decreased access. In New Hampshire, there are no programs within 30 miles of the areas with the largest distribution of smokers, and decreased access in some areas with the lowest levels of education.ConclusionsImproving equitable access to high-quality screening services in rural regions and the creation of targeted interventions to address decreased access in areas of high tobacco use and low education is vital to decreasing the incidence of latestage presentations of lung cancer within these populations. 相似文献
19.
Joseph Wheatley Zhengyang Liu Joel Loth Mark P. Plummer Jahan C. Penny-Dimri Reny Segal Julian Smith Luke A. Perry 《Acta anaesthesiologica Scandinavica》2023,67(2):131-141
Background
Patients undergoing cardiac surgery are at significant risk of developing postoperative acute kidney injury (AKI). Neutrophil–lymphocyte ratio (NLR) is a widely available inflammatory biomarker which may be of prognostic value in this setting.Methods
We conducted a systematic review and meta-analysis of studies reporting associations between perioperative NLR with postoperative AKI. We searched Medline, Embase and the Cochrane Library, without language restriction, from inception to May 2022 for relevant studies. We meta-analysed the reported odds ratios (ORs) with 95% confidence intervals (CIs) for both elevated preoperative and postoperative NLR with risk of postoperative AKI and need for renal replacement therapy (RRT). We conducted a meta-regression to explore inter-study statistical heterogeneity.Results
Twelve studies involving 10,724 participants undergoing cardiac surgery were included, with eight studies being deemed at high risk of bias using PROBAST modelling. We found statistically significant associations between elevated preoperative NLR and postoperative AKI (OR 1.45, 95% CI 1.18–1.77), as well as postoperative need for RRT (OR 2.37, 95% CI 1.50–3.72). Postoperative NLR measurements were not of prognostic significance.Conclusions
Elevated preoperative NLR is a reliable inflammatory biomarker for predicting AKI following cardiac surgery. 相似文献20.
Marie V. Plaisime PhD MPH Marie Jipguep-Akhtar PhD Joseph J. Locascio PhD Harolyn M. E. Belcher MD MHS Rachel R. Hardeman PhD MPH Katherine Picho-Kiroga PhD Sylvia P. Perry PhD Sean M. Phelan PhD MPH Michelle van Ryn PhD LMFT MPH John F. Dovidio PhD 《Health services research》2023,58(Z2):229-237