全文获取类型
收费全文 | 243597篇 |
免费 | 5374篇 |
国内免费 | 268篇 |
专业分类
耳鼻咽喉 | 2223篇 |
儿科学 | 8540篇 |
妇产科学 | 4284篇 |
基础医学 | 24103篇 |
口腔科学 | 2973篇 |
临床医学 | 19130篇 |
内科学 | 44896篇 |
皮肤病学 | 1755篇 |
神经病学 | 23060篇 |
特种医学 | 11295篇 |
外国民族医学 | 5篇 |
外科学 | 40702篇 |
综合类 | 3140篇 |
一般理论 | 94篇 |
预防医学 | 23743篇 |
眼科学 | 4086篇 |
药学 | 13838篇 |
中国医学 | 735篇 |
肿瘤学 | 20637篇 |
出版年
2023年 | 393篇 |
2022年 | 647篇 |
2021年 | 1770篇 |
2020年 | 930篇 |
2019年 | 1560篇 |
2018年 | 23434篇 |
2017年 | 18460篇 |
2016年 | 20612篇 |
2015年 | 2339篇 |
2014年 | 3020篇 |
2013年 | 3913篇 |
2012年 | 11652篇 |
2011年 | 25711篇 |
2010年 | 21285篇 |
2009年 | 13823篇 |
2008年 | 23680篇 |
2007年 | 26098篇 |
2006年 | 5016篇 |
2005年 | 6586篇 |
2004年 | 7543篇 |
2003年 | 8165篇 |
2002年 | 6061篇 |
2001年 | 807篇 |
2000年 | 876篇 |
1999年 | 782篇 |
1998年 | 931篇 |
1997年 | 862篇 |
1996年 | 675篇 |
1995年 | 615篇 |
1994年 | 603篇 |
1993年 | 482篇 |
1992年 | 414篇 |
1991年 | 459篇 |
1990年 | 429篇 |
1989年 | 363篇 |
1988年 | 338篇 |
1987年 | 305篇 |
1986年 | 301篇 |
1985年 | 397篇 |
1984年 | 462篇 |
1983年 | 388篇 |
1982年 | 560篇 |
1981年 | 497篇 |
1980年 | 496篇 |
1979年 | 214篇 |
1978年 | 289篇 |
1977年 | 271篇 |
1976年 | 220篇 |
1975年 | 228篇 |
1974年 | 202篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Boffa Joseph W. Tock Jamie L. Morabito Danielle M. Schmidt Norman B. 《Cognitive therapy and research》2022,46(5):1016-1029
Cognitive Therapy and Research - Despite interest in psychological inflexibility as a marker of suicide risk, no measure of psychological inflexibility specific to SI exists. The present study... 相似文献
2.
3.
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
4.
5.
6.
Whitney S. Brandt Wanpu Yan Jian Zhou Kay See Tan Joseph Montecalvo Bernard J. Park Prasad S. Adusumilli James Huang Matthew J. Bott Valerie W. Rusch Daniela Molena William D. Travis Mark G. Kris Jamie E. Chaft David R. Jones 《The Journal of thoracic and cardiovascular surgery》2019,157(2):743-753.e3
Objective
Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.Methods
Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.Results
In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.Conclusions
Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection. 相似文献7.
Seyed Mehdi BagheriMofidi Majid Pouladian Seyed Behnamedin Jameie Ali Abbaspour Tehrani-Fard 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2016,39(3):717-726
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation. 相似文献
8.
9.