全文获取类型
收费全文 | 56567篇 |
免费 | 4621篇 |
国内免费 | 159篇 |
专业分类
耳鼻咽喉 | 513篇 |
儿科学 | 1548篇 |
妇产科学 | 1087篇 |
基础医学 | 7488篇 |
口腔科学 | 984篇 |
临床医学 | 6254篇 |
内科学 | 10848篇 |
皮肤病学 | 818篇 |
神经病学 | 4845篇 |
特种医学 | 2341篇 |
外科学 | 9388篇 |
综合类 | 792篇 |
一般理论 | 57篇 |
预防医学 | 5583篇 |
眼科学 | 1262篇 |
药学 | 4055篇 |
1篇 | |
中国医学 | 54篇 |
肿瘤学 | 3429篇 |
出版年
2023年 | 291篇 |
2022年 | 372篇 |
2021年 | 1161篇 |
2020年 | 658篇 |
2019年 | 1090篇 |
2018年 | 1309篇 |
2017年 | 953篇 |
2016年 | 1026篇 |
2015年 | 1236篇 |
2014年 | 1813篇 |
2013年 | 2504篇 |
2012年 | 3802篇 |
2011年 | 3893篇 |
2010年 | 2131篇 |
2009年 | 1898篇 |
2008年 | 3411篇 |
2007年 | 3648篇 |
2006年 | 3544篇 |
2005年 | 3444篇 |
2004年 | 3186篇 |
2003年 | 3033篇 |
2002年 | 2854篇 |
2001年 | 887篇 |
2000年 | 845篇 |
1999年 | 847篇 |
1998年 | 668篇 |
1997年 | 554篇 |
1996年 | 531篇 |
1995年 | 543篇 |
1994年 | 455篇 |
1993年 | 436篇 |
1992年 | 544篇 |
1991年 | 488篇 |
1990年 | 514篇 |
1989年 | 476篇 |
1988年 | 441篇 |
1987年 | 394篇 |
1986年 | 405篇 |
1985年 | 437篇 |
1984年 | 377篇 |
1983年 | 305篇 |
1982年 | 273篇 |
1981年 | 237篇 |
1980年 | 218篇 |
1979年 | 243篇 |
1978年 | 234篇 |
1977年 | 194篇 |
1976年 | 190篇 |
1974年 | 210篇 |
1973年 | 194篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
993.
Scott Kizy Ariella M. Altman Schelomo Marmor Jason W. Denbo Eric H. Jensen Todd M. Tuttle Jane Yuet Ching Hui 《Journal of Geriatric Oncology》2019,10(2):322-329
Introduction
The 21-gene recurrence score (RS) (Oncotype Dx, Genomic Health, Redwood City Ca) has not been validated in an older cohort with estrogen receptor (ER)-positive breast cancer. The objective of this study was to evaluate RS validity in a group of older women with ER-positive breast cancer.Methods
Utilizing the Surveillance, Epidemiology, and End Results Program (SEER) database with available RS, we evaluated women with ER-positive breast cancer aged 18–69 and those 70?years of age and older from 2004 to 2014. We utilized multivariable logistic regression models to evaluate factors associated with RS testing as well as a high-risk categorization for those who underwent testing. Survival was analyzed using Kaplan Meier curves and Cox proportional hazard models.Results
We identified 363,876 women aged 18–69?years and 147,107 women aged 70?years and older. A smaller proportion of patients in the older group (8%) underwent RS testing than in the younger group (18%). Of the patients who underwent testing, distribution of RS was similar between groups. High-risk categorization independently predicted a higher likelihood of death for older patients (hazard ratio 1.47, 95% confidence interval 1.15–1.90). Among patients with high-risk RS, chemotherapy was associated with a decreased risk of death in the younger group, but not in the older group.Conclusion
Older women are less likely to receive RS testing, but when tested, older patients have a similar distribution of RS as compared to younger patients. While high-risk categorization in the older cohort was prognostic, chemotherapy was not associated with improved survival. 相似文献994.
995.
996.
Cory P. Daignault Edwin L. Palmer James A. Scott John S. Swan Gilbert H. Daniels 《Nuclear Medicine and Molecular Imaging》2015,49(3):217-222
A Schmorl’s node is a common incidental finding encountered during radiologic imaging. Despite the vertebral body being a common site of metastatic disease, a lytic lesion adjacent to an endplate with typical imaging features can often confidently be called a Schmorl’s node. This is a case report of a patient with a single well-defined FDG-avid papillary thyroid carcinoma metastasis to the spine that had imaging findings characteristic of a Schmorl’s node on CT and MRI. This case is important to consider as it demonstrates that the imaging characteristics of metastatic disease and Schmorl’s nodes can overlap. 相似文献
997.
998.
Chan-Kyung Jane Cho Katherine Sunderland Tom Pickles Francois Bachand Kim N. Chi Scott Tyldesley 《Practical radiation oncology》2019,9(3):e274-e282
PurposeIncreasing the survival of patients with metastatic prostate cancer (PCa) may affect the demand for palliative radiation to bone (PRTB). Our aim was to characterize the use of PRTB in patients who died of PCa in British Columbia between 2003 and 2015.Methods and MaterialsAll patients with a diagnosis of PCa who died during the study period (n = 23,260) were identified from a population-based provincial registry. Patient and treatment characteristics were analyzed. PRTB utilization rate was calculated by year and location. Survival was calculated from the first and the last course of PRTB.ResultsA total of 5701 patients died of PCa, with a median survival from diagnosis of 5.2 years. The overall PRTB utilization rate was 38.6%, with an increasing trend over time. Multiple courses of PRTB were frequent, with 51% of patients receiving ≥2 courses of PRTB. Of the patients who died of PCa (15.2% of the PRTB cohort), 5.4% received PRTB within the last 4 weeks of life, 60% of whom received multiple fractions. Rural areas had a lower referral rate and lower use of PRTB. Patients with longer survival tended to receive multiple courses of treatment. The median survival after the first course of PRTB increased from 8.2 months in 2003 to 2004 to 9.4 months in 2013 to 2014 (P = .04).ConclusionsPRTB is only used in a minority of patients dying of PCa. The majority who die of PCa after PRTB do so within a year of their first course. The use of multifractionation was common in the last 4 weeks of life. Survival after first PRTB increased minimally over time, and additional research is required to identify its association with recent changes in practice. The referral rate and PRTB utilization rate differ between rural and nonrural locations, underlying the importance of accessibility and referral for utilization of PRTB. Investigating other barriers and ensuring equitable access to radiation are needed. 相似文献
999.
1000.
Donald R. Dengel Aaron S. Kelly Lei Zhang Qi Wang James S. Hodges Julia Steinberger K. Scott Baker 《Biology of blood and marrow transplantation》2019,25(1):151-156
This study examined the effects of hematopoietic cell transplantation (HCT) and associated preparative regimens on vascular structure and function. Measures of carotid artery stiffness and brachial artery endothelial-dependent dilation were obtained in patients who had survived ≥ 2 years after HCT for hematologic malignancy and were diagnosed at ≤21 years. HCT survivors (n?=?108) were examined: 66 received total body irradiation (TBI) alone or with a low-dose cranial radiation boost (TBI±LD-CRT), 19 received TBI plus high-dose cranial radiation (TBI+HD-CRT), and 23 received a chemotherapy-only preparative regimen (CHEMO). Siblings (n?=?83) were invited to participate as control subjects. Although endothelial-dependent dilation did not differ between siblings and HCT survivors, carotid cross-sectional compliance, cross-sectional distensibility, diameter compliance, and diameter distensibility were greater in siblings than HCT survivors. Comparing the HCT preparative regimens, carotid cross-sectional compliance, cross-sectional distensibility, diameter compliance, diameter distensibility, and incremental elastic modulus were significantly lower in the TBI+HD-CRT group compared with siblings or with TBI±LD-CRT and CHEMO treatment groups. Cross-sectional distensibility and diameter compliance were significantly lower in the TBI±LD-CRT group compared with siblings. TBI±LD-CRT and CHEMO groups did not differ from each other in these vascular measures. HCT preparative regimens containing TBI+HD-CRT resulted in greater arterial decrements, indicating increased risk for cardiovascular disease. 相似文献