首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   25788篇
  免费   2092篇
  国内免费   100篇
耳鼻咽喉   245篇
儿科学   782篇
妇产科学   534篇
基础医学   3365篇
口腔科学   345篇
临床医学   3254篇
内科学   5775篇
皮肤病学   357篇
神经病学   2011篇
特种医学   813篇
外科学   3506篇
综合类   373篇
一般理论   31篇
预防医学   2314篇
眼科学   861篇
药学   1685篇
中国医学   59篇
肿瘤学   1670篇
  2023年   167篇
  2022年   90篇
  2021年   482篇
  2020年   360篇
  2019年   621篇
  2018年   654篇
  2017年   521篇
  2016年   539篇
  2015年   586篇
  2014年   856篇
  2013年   1230篇
  2012年   1729篇
  2011年   1685篇
  2010年   997篇
  2009年   931篇
  2008年   1563篇
  2007年   1669篇
  2006年   1637篇
  2005年   1599篇
  2004年   1529篇
  2003年   1455篇
  2002年   1288篇
  2001年   361篇
  2000年   327篇
  1999年   302篇
  1998年   280篇
  1997年   238篇
  1996年   162篇
  1995年   233篇
  1994年   191篇
  1993年   163篇
  1992年   219篇
  1991年   181篇
  1990年   179篇
  1989年   166篇
  1988年   184篇
  1987年   166篇
  1986年   149篇
  1985年   130篇
  1984年   140篇
  1983年   141篇
  1982年   144篇
  1981年   126篇
  1980年   122篇
  1979年   100篇
  1978年   103篇
  1977年   111篇
  1976年   82篇
  1975年   61篇
  1974年   69篇
排序方式: 共有10000条查询结果,搜索用时 546 毫秒
1.
2.
ABSTRACT

The lack of stable housing can impair access and continuity of care for patients living with human immunodeficiency virus (HIV). This study investigated the relationship between housing status assessed at multiple time points and several core HIV-related outcomes within the same group of HIV patients experiencing homelessness. Patients with consistently stable housing (CSH) during the year were compared to patients who lacked CSH (non-CSH group). The study outcomes included HIV viral load (VL), CD4 counts, and health care utilization. Multivariable and propensity weighted analyses were used to assess outcomes adjusting for potential group differences. Of 208 patients, 88 (42%) had CSH and 120 (58%) were non-CSH. Patients with CSH had significantly higher proportion of VL suppression and higher mean CD4 counts. The frequency of nurse visits in the CSH group was less than a half of that in the non-CSH group. Patients with CSH were less likely to be admitted to the medical respite facility, and if admitted, their length of stay was about a half of that for the non-CSH group. Our study findings show that patients with CSH had significantly better HIV virologic control and immune status as well as improved health care utilization.  相似文献   
3.
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   
4.
Now is an exciting era of development in immunotherapy checkpoint inhibitors and their effect on the treatment of NPC. While the general prognosis of R/M disease is poor, immunotherapy offers some promise in a malignancy associated with EBV and characterized by a peritumoural immune infiltrate. Our study aims to review past and on-going clinical trials of monoclonal antibody therapies against the checkpoint inhibitors (e.g. PD1 and CTLA-4), in R/M NPC. All randomized and nonrandomized controlled trials involving immune checkpoint inhibitor interventions for treatment of NPC were included in the study. We utilized a validated “risk of bias” tool to assess study quality. Four separate Phase I–II trials report the potential of PD1 inhibitor treatment for patients with NPC. Within the observed groups, camrelizumab combined with chemotherapy achieved an objective response in 91% of patients as first-line treatment for metastatic NPC (PFS 68% at 1-year) but this was associated with a high rate of grade >3 adverse events (87%; CTCAE version 4.03). The remaining three studies focused on recurrent NPC disease in patients who had received at least one line of prior chemotherapy. Within this group, camrelizumab monotherapy achieved an objective response in 34% of patients (PFS 27% at 1-year; range across all three studies 20.5–34%). No NPC trial has yet reported on specific outcomes for non-PD1 checkpoint inhibitors but 11 on-going studies include alternative targets (e.g. PD-L1/CTLA-4) as combination or monotherapy treatments. In considering checkpoint immunotherapies for NPC, initial results show promise for anti-PD1 interventions. Further phase I–III trials are in progress to clarify clinical outcomes, fully determine safety profiles, and optimize drug combinations and administration schedules.  相似文献   
5.
The UK has low breastfeeding rates, with socioeconomic disparities. The Assets‐based feeding help Before and After birth (ABA) intervention was designed to be inclusive and improve infant feeding behaviours. ABA is underpinned by the behaviour change wheel and offers an assets‐based approach focusing on positive capabilities of individuals and communities, including use of a Genogram. This study aimed to investigate feasibility of intervention delivery within a randomised controlled trial (RCT). Nulliparous women ≥16 years, (n = 103) from two English sites were recruited and randomised to either intervention or usual care. The intervention – delivered through face‐to‐face, telephone and text message by trained Infant Feeding Helpers (IFHs) – ran from 30‐weeks' gestation until 5‐months postnatal. Outcomes included recruitment rates and follow‐up at 3‐days, 8‐weeks and 6‐months postnatal, with collection of future full trial outcomes via questionnaires. A mixed‐methods process evaluation included qualitative interviews with 30 women, 13 IFHs and 17 maternity providers; IFH contact logs; and fidelity checking of antenatal contact recordings. This study successfully recruited women, including teenagers, from socioeconomically disadvantaged areas; postnatal follow‐up rates were 68.0%, 85.4% and 80.6% at 3‐days, 8‐weeks and 6‐months respectively. Breastfeeding at 8‐weeks was obtained for 95.1% using routine data for non‐responders. It was possible to recruit and train peer supporters to deliver the intervention with adequate fidelity. The ABA intervention was acceptable to women, IFHs and maternity services. There was minimal contamination and no evidence of intervention‐related harm. In conclusion, the intervention is feasible to deliver within an RCT, and a definitive trial required.  相似文献   
6.
Women with breast cancer are increasingly being cured of the disease but fatigue remains the most frequently reported symptom. The aims of our study were to identify distinct trajectories in four fatigue dimensions during 2 years after breast cancer surgery and to explore the demographic, clinical and personality characteristics associated with these profiles. We included women from the prospective longitudinal multicenter FATSEIN cohort in France. They completed the Multidimensional Fatigue Inventory for nine follow-ups over 24 months after surgery. A group-based trajectory model identified distinct trajectories in each fatigue dimension. Multinomial logistic regression determined the factors associated with each profile. From the 459 women followed, 3–5 fatigue trajectories were revealed in each fatigue dimension, from its absence to its severest degree. In our multivariate analysis, the risk of severe fatigue was decreased in all dimensions by a high quality of life before surgery (measured by the European Organization for Research and Treatment of Cancer 30-item QoL questionnaire; e.g., for general and physical fatigue: OR = 0.93, 95% CI 0.91, 0.96), especially a high physical and emotional functions for general and physical fatigue, and a high cognitive function for mental fatigue. Both severe mental fatigue and severely reduced motivation worsened with low optimism before surgery (e.g., for mental fatigue: OR = 0.93, 95% CI 0.89, 0.97). Severely reduced activities increased by having chemotherapy (OR = 9.41, 95% CI 2.28, 38.79). Targeting women at risk for severe fatigue can provide early preventive and curative treatment and appropriate psychological support.  相似文献   
7.
We present a patient with both dynamic left ventricular outflow tract obstruction and valvular aortic stenosis. The aortic valve was calcified, and velocities and gradients measured by continuous‐wave Doppler met standard criteria for severe aortic stenosis. The increased subvalvular velocities invalidated assumptions of the simplified Bernoulli equation; correction using the longer form of the Bernoulli equation suggested a lower but still significant gradient. The complex shape of the subvalvular spectral Doppler envelope indicated supranormal systolic function and dynamic left ventricular outflow obstruction. Left heart catheterization with an end‐hole catheter was required to determine the subvalvular and valvular components of the obstruction.  相似文献   
8.
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号