全文获取类型
收费全文 | 29866篇 |
免费 | 1809篇 |
国内免费 | 148篇 |
专业分类
耳鼻咽喉 | 279篇 |
儿科学 | 880篇 |
妇产科学 | 713篇 |
基础医学 | 4351篇 |
口腔科学 | 1077篇 |
临床医学 | 2761篇 |
内科学 | 6794篇 |
皮肤病学 | 752篇 |
神经病学 | 2741篇 |
特种医学 | 665篇 |
外科学 | 2712篇 |
综合类 | 105篇 |
一般理论 | 15篇 |
预防医学 | 3077篇 |
眼科学 | 527篇 |
药学 | 2021篇 |
中国医学 | 128篇 |
肿瘤学 | 2225篇 |
出版年
2024年 | 37篇 |
2023年 | 291篇 |
2022年 | 668篇 |
2021年 | 1151篇 |
2020年 | 703篇 |
2019年 | 934篇 |
2018年 | 1078篇 |
2017年 | 733篇 |
2016年 | 901篇 |
2015年 | 971篇 |
2014年 | 1298篇 |
2013年 | 1703篇 |
2012年 | 2607篇 |
2011年 | 2758篇 |
2010年 | 1438篇 |
2009年 | 1184篇 |
2008年 | 2006篇 |
2007年 | 1963篇 |
2006年 | 1820篇 |
2005年 | 1708篇 |
2004年 | 1498篇 |
2003年 | 1298篇 |
2002年 | 1168篇 |
2001年 | 155篇 |
2000年 | 89篇 |
1999年 | 127篇 |
1998年 | 180篇 |
1997年 | 143篇 |
1996年 | 133篇 |
1995年 | 101篇 |
1994年 | 82篇 |
1993年 | 94篇 |
1992年 | 60篇 |
1991年 | 50篇 |
1990年 | 48篇 |
1989年 | 52篇 |
1988年 | 40篇 |
1987年 | 28篇 |
1986年 | 39篇 |
1985年 | 32篇 |
1984年 | 48篇 |
1983年 | 38篇 |
1982年 | 48篇 |
1981年 | 37篇 |
1980年 | 23篇 |
1978年 | 18篇 |
1977年 | 26篇 |
1974年 | 18篇 |
1973年 | 17篇 |
1972年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Deitelzweig Steve Luo Xuemei Nguyen Jennifer L. Malhotra Deepa Emir Birol Russ Cristina Li Xiaoyan Lee Theodore C. Ferri Mauricio Wiederkehr Danny Reimbaeva Maya Barnes Geoffrey D. Piazza Gregory 《Journal of thrombosis and thrombolysis》2022,54(4):696-696
Journal of Thrombosis and Thrombolysis - 相似文献
2.
Danielle E Whittier Elizabeth J Samelson Marian T Hannan Lauren A Burt David A Hanley Emmanuel Biver Pawel Szulc Elisabeth Sornay-Rendu Blandine Merle Roland Chapurlat Eric Lespessailles Andy Kin On Wong David Goltzman Sundeep Khosla Serge Ferrari Mary L Bouxsein Douglas P Kiel Steven K Boyd 《Journal of bone and mineral research》2022,37(3):428-439
Prevalence of osteoporosis is more than 50% in older adults, yet current clinical methods for diagnosis that rely on areal bone mineral density (aBMD) fail to detect most individuals who have a fragility fracture. Bone fragility can manifest in different forms, and a “one-size-fits-all” approach to diagnosis and management of osteoporosis may not be suitable. High-resolution peripheral quantitative computed tomography (HR-pQCT) provides additive information by capturing information about volumetric density and microarchitecture, but interpretation is challenging because of the complex interactions between the numerous properties measured. In this study, we propose that there are common combinations of bone properties, referred to as phenotypes, that are predisposed to different levels of fracture risk. Using HR-pQCT data from a multinational cohort (n = 5873, 71% female) between 40 and 96 years of age, we employed fuzzy c-means clustering, an unsupervised machine-learning method, to identify phenotypes of bone microarchitecture. Three clusters were identified, and using partial correlation analysis of HR-pQCT parameters, we characterized the clusters as low density, low volume, and healthy bone phenotypes. Most males were associated with the healthy bone phenotype, whereas females were more often associated with the low volume or low density bone phenotypes. Each phenotype had a significantly different cumulative hazard of major osteoporotic fracture (MOF) and of any incident osteoporotic fracture (p < 0.05). After adjustment for covariates (cohort, sex, and age), the low density followed by the low volume phenotype had the highest association with MOF (hazard ratio = 2.96 and 2.35, respectively), and significant associations were maintained when additionally adjusted for femoral neck aBMD (hazard ratio = 1.69 and 1.90, respectively). Further, within each phenotype, different imaging biomarkers of fracture were identified. These findings suggest that osteoporotic fracture risk is associated with bone phenotypes that capture key features of bone deterioration that are not distinguishable by aBMD. © 2021 American Society for Bone and Mineral Research (ASBMR). 相似文献
3.
4.
5.
6.
Maria Gonzalez-Cao Cristina Carrera Juan Francisco Rodriguez Moreno Pedro Rodríguez-Jiménez Mónica Antoñanzas Basa Rosa Feltes Ochoa Teresa Puertolas Eva Muñoz-Couselo José Luis Manzano Ivan Marquez-Rodas Juan Martín-Liberal Ainara Soria Pilar Lopez Criado Almudena Garcia-Castaño Aram Boada Pablo Ayala de Miguel Susana Puig Guillermo Crespo Alfonso Berrocal 《Journal of the American Academy of Dermatology》2021,84(5):1412-1415
7.
Anastasiia Panfilova Sarah E. Shelton Cristina Caresio Ruud J.G. van Sloun Filippo Molinari Hessel Wijkstra Paul A. Dayton Massimo Mischi 《Ultrasound in medicine & biology》2019,45(2):539-548
Dynamic contrast-enhanced ultrasound (DCE-US) has been proposed as a powerful tool for cancer diagnosis by estimation of perfusion and dispersion parameters reflecting angiogenic vascular changes. This work was aimed at identifying which vascular features are reflected by the estimated perfusion and dispersion parameters through comparison with acoustic angiography (AA). AA is a high-resolution technique that allows quantification of vascular morphology. Three-dimensional AA and 2-D DCE-US bolus acquisitions were used to monitor the growth of fibrosarcoma tumors in nine rats. AA-derived vascular properties were analyzed along with DCE-US perfusion and dispersion to investigate the differences between tumor and control and their evolution in time. AA-derived microvascular density and DCE-US perfusion exhibited good agreement, confirmed by their spatial distributions. No vascular feature was correlated with dispersion. Yet, dispersion provided better cancer classification than perfusion. We therefore hypothesize that dispersion characterizes vessels that are smaller than those visible with AA. 相似文献
8.
9.
Paula Cristina Galati Paula Garcia Chiarello Belinda Pinto Simões 《Nutrition and cancer》2016,68(1):86-93
Changes in resting energy expenditure (REE) of cancer patients vary depending on type of tumor, treatment time point and kind of treatment. Little is known about REE of acute leukemia adult patients after treatment, especially with results related to body weight or fat free mass (FFM). This study aimed to assess changes in REE of acute leukemia adult patients before and after the first remission induction. Evaluation of REE was performed by indirect calorimetry and predicted REE was calculated by Harris-Benedict equation. Weight and height were measured and compared to a control group of healthy individuals. FFM was assessed by bioelectrical impedance for adjusting REE values. We evaluated 18 patients and 26 healthy individuals. At diagnosis, patients presented REE, REE/weight, and REE/FFM higher than the controls. Reductions of REE, REE/weight, and REE/FFM were also observed in patients after the first cycle of chemotherapy. The predicted REE for the patients group showed significant lower value compared with measured REE. Before the first cycle of chemotherapy REE was increased but undergoes a reduction after treatment, reaching values similar to the controls. For predictive Harris-Benedict equation, stress factors should be added to avoid underestimation of REE before and after chemotherapy. 相似文献
10.
Rocco Spagnuolo Alessandro Corea Mariantonietta Blumetti Alessia Giovinazzo Massimiliano Serafino Caterina Pagliuso Raffaele Pagnotta Grazia Curto Cristina Cosco Vincenzo Cosco Rosellina Margherita Mancina Pietro Garieri Anna Papaleo Laura Grande Anna Barilaro Eugenio Garofalo Andrea Bruni Patrizia Doldo 《Journal of advanced nursing》2020,76(11):2993-3002