全文获取类型
收费全文 | 2826062篇 |
免费 | 248774篇 |
国内免费 | 15598篇 |
专业分类
耳鼻咽喉 | 39081篇 |
儿科学 | 84837篇 |
妇产科学 | 71140篇 |
基础医学 | 467258篇 |
口腔科学 | 75814篇 |
临床医学 | 249255篇 |
内科学 | 488654篇 |
皮肤病学 | 80764篇 |
神经病学 | 245222篇 |
特种医学 | 110953篇 |
外国民族医学 | 108篇 |
外科学 | 447870篇 |
综合类 | 91425篇 |
现状与发展 | 24篇 |
一般理论 | 2064篇 |
预防医学 | 230299篇 |
眼科学 | 64831篇 |
药学 | 195266篇 |
23篇 | |
中国医学 | 10116篇 |
肿瘤学 | 135430篇 |
出版年
2022年 | 23170篇 |
2021年 | 55136篇 |
2020年 | 35119篇 |
2019年 | 58176篇 |
2018年 | 70054篇 |
2017年 | 53283篇 |
2016年 | 58903篇 |
2015年 | 74026篇 |
2014年 | 108165篇 |
2013年 | 173123篇 |
2012年 | 75212篇 |
2011年 | 71691篇 |
2010年 | 112020篇 |
2009年 | 118036篇 |
2008年 | 58639篇 |
2007年 | 59122篇 |
2006年 | 70718篇 |
2005年 | 65853篇 |
2004年 | 67848篇 |
2003年 | 59347篇 |
2002年 | 49288篇 |
2001年 | 79266篇 |
2000年 | 70826篇 |
1999年 | 75962篇 |
1998年 | 62741篇 |
1997年 | 61125篇 |
1996年 | 58211篇 |
1995年 | 53682篇 |
1994年 | 47775篇 |
1993年 | 44762篇 |
1992年 | 49445篇 |
1991年 | 45964篇 |
1990年 | 42810篇 |
1989年 | 43267篇 |
1988年 | 39969篇 |
1987年 | 38832篇 |
1986年 | 36634篇 |
1985年 | 37355篇 |
1984年 | 37009篇 |
1983年 | 34747篇 |
1982年 | 37593篇 |
1981年 | 35693篇 |
1980年 | 33694篇 |
1979年 | 28114篇 |
1978年 | 27430篇 |
1977年 | 26196篇 |
1976年 | 23263篇 |
1975年 | 21271篇 |
1974年 | 20195篇 |
1973年 | 19242篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Kevin Kyung Ho Choi Santosh Sanagapalli 《World journal of gastrointestinal oncology》2022,14(3):568-586
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations. 相似文献
62.
Triposkiadis Filippos Xanthopoulos Andrew Skoularigis John Starling Randall C. 《Heart failure reviews》2022,27(6):1991-2003
Heart Failure Reviews - The nitric oxide (NO)–guanylate cyclase (GC)–cyclic guanosine monophosphate (cGMP) pathway plays an important role in cardiovascular, pulmonary and renal... 相似文献
63.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献
64.
Two Janus-associated kinase inhibitors (JAKi) (initially ruxolitinib and, more recently, fedratinib) have been approved as treatment options for patients who have intermediate-risk and high-risk myelofibrosis (MF), with pivotal trials demonstrating improvements in spleen volume, disease symptoms, and quality of life. At the same time, however, clinical trial experiences with JAKi agents in MF have demonstrated a high frequency of discontinuations because of adverse events or progressive disease. In addition, overall survival benefits and clinical and molecular predictors of response have not been established in this population, for which the disease burden is high and treatment options are limited. Consistently poor outcomes have been documented after JAKi discontinuation, with survival durations after ruxolitinib ranging from 11 to 16 months across several studies. To address such a high unmet therapeutic need, various non-JAKi agents are being actively explored (in combination with ruxolitinib in first-line or salvage settings and/or as monotherapy in JAKi-pretreated patients) in phase 3 clinical trials, including pelabresib (a bromodomain and extraterminal domain inhibitor), navitoclax (a B-cell lymphoma 2/B-cell lymphoma 2-xL inhibitor), parsaclisib (a phosphoinositide 3-kinase inhibitor), navtemadlin (formerly KRT-232; a murine double-minute chromosome 2 inhibitor), and imetelstat (a telomerase inhibitor). The breadth of data expected from these trials will provide insight into the ability of non-JAKi treatments to modify the natural history of MF. 相似文献
65.
Vilar-Compte Mireya Gaitán-Rossi Pablo Félix-Beltrán Lucía Bustamante Arturo V. 《Journal of immigrant and minority health / Center for Minority Public Health》2022,24(1):65-77
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to... 相似文献
66.
Timothy J. Cordingley Mark A.G. Wilson Kathryn M. Weston 《Health & social care in the community》2022,30(1):353-359
Vaccination is a vital health care initiative to prevent individual and population infection. To increase vaccination rates the federal government implemented the ‘No Jab, No Pay’ policy, where eligibility for several government benefits required children to be fully vaccinated by removing ‘conscientious objections’ and expanding the age range of children whose families receive benefits. This study assesses the impact of this policy at a local area within a single medical practice community in NSW, Australia. A retrospective clinical audit was performed between 2012 and 2017 on a single general practice's vaccination records for children ≤19 years. Catch-up vaccinations were assessed based on age at vaccination. Incidence of catch-up vaccinations was assessed for each of four years before and two years after the implementation of the ‘No Jab, No Pay’ policy in January 2016, along with the age of children and vaccination(s) given. Catch-up vaccinations were assessed temporally either side of implementation of ‘No Jab, No Pay’. Comparing the average annual vaccination catch-up incidence rate of 6.2% pre-implementation (2012–2015), there was an increase to 9.2% in 2016 (p < .001) and 7.8% in 2017 (p = .027). Secondary outcome measurement of catch-up vaccination incidence rates before (2012–2015) and after (2016–2017) ‘No Jab, No Pay’ implementation showed statistically significant increases for children aged 8–11 years (3.2%–5.6%, p = .038), 12–15 years (7.5%–14.7%, p < .001) and 16–19 years (3.3%–10.2%, p < .001) along with a statistically significant reduction in children aged 1–3 years (11.4%–6.2%, p = .015). Also, catch-up rates for DTPa significantly increased after program implementation. This study demonstrates that the Australian federal government vaccination policy ‘No Jab, No Pay’ was coincident with an increase in catch-up vaccinations within a rural NSW community served by one medical practice, especially for older children. 相似文献
67.
Raymond J. Chan RN PhD Vivienne E. Milch MBBS MHPol Fiona Crawford-Williams PhD Oluwaseyifunmi Andi Agbejule BRadTherapy Ria Joseph MNutrDiet Jolyn Johal BND Narayanee Dick BSc Matthew P. Wallen PhD Julie Ratcliffe PhD Anupriya Agarwal MBBS Larissa Nekhlyudov MD Matthew Tieu PhD Manaf Al-Momani BPharm Scott Turnbull PhD Rahul Sathiaraj MPH Dorothy Keefe MBBS MD Nicolas H. Hart PhD 《CA: a cancer journal for clinicians》2023,73(6):565-589
Patient navigation is a strategy for overcoming barriers to reduce disparities and to improve access and outcomes. The aim of this umbrella review was to identify, critically appraise, synthesize, and present the best available evidence to inform policy and planning regarding patient navigation across the cancer continuum. Systematic reviews examining navigation in cancer care were identified in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase, Cumulative Index of Nursing and Allied Health (CINAHL), Epistemonikos, and Prospective Register of Systematic Reviews (PROSPERO) databases and in the gray literature from January 1, 2012, to April 19, 2022. Data were screened, extracted, and appraised independently by two authors. The JBI Critical Appraisal Checklist for Systematic Review and Research Syntheses was used for quality appraisal. Emerging literature up to May 25, 2022, was also explored to capture primary research published beyond the coverage of included systematic reviews. Of the 2062 unique records identified, 61 systematic reviews were included. Fifty-four reviews were quantitative or mixed-methods reviews, reporting on the effectiveness of cancer patient navigation, including 12 reviews reporting costs or cost-effectiveness outcomes. Seven qualitative reviews explored navigation needs, barriers, and experiences. In addition, 53 primary studies published since 2021 were included. Patient navigation is effective in improving participation in cancer screening and reducing the time from screening to diagnosis and from diagnosis to treatment initiation. Emerging evidence suggests that patient navigation improves quality of life and patient satisfaction with care in the survivorship phase and reduces hospital readmission in the active treatment and survivorship care phases. Palliative care data were extremely limited. Economic evaluations from the United States suggest the potential cost-effectiveness of navigation in screening programs. 相似文献
68.
69.
Janitz Amanda E. Schraw Jeremy M. Xu Chao Lupo Philip J. 《Cancer causes & control : CCC》2022,33(3):483-488
Cancer Causes & Control - Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among... 相似文献
70.
A Coupled FEM-BEM Approach for the Solution of the Free-Boundary Axi-Symmetric Plasma Equilibrium Problem
下载免费PDF全文
![点击此处可从《Communications In Computational Physics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. Bonotto D. Abate P. Bettini & F. Villone 《Communications In Computational Physics》2022,31(1):27-59
In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric
plasma equilibrium problem. The proposed method, obtained from an improvement
of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium
problem in unbounded domains by discretizing only the plasma region; the external
conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear
Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high
resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github.
om/matteobonotto/
FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against
experimental data from RFX-mod device, and numerical equilibria of an ITER-like device. 相似文献