全文获取类型
收费全文 | 14798篇 |
免费 | 948篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 495篇 |
妇产科学 | 347篇 |
基础医学 | 2146篇 |
口腔科学 | 251篇 |
临床医学 | 1310篇 |
内科学 | 3609篇 |
皮肤病学 | 448篇 |
神经病学 | 1559篇 |
特种医学 | 307篇 |
外科学 | 1307篇 |
综合类 | 41篇 |
一般理论 | 7篇 |
预防医学 | 1257篇 |
眼科学 | 278篇 |
药学 | 1131篇 |
中国医学 | 40篇 |
肿瘤学 | 1184篇 |
出版年
2024年 | 23篇 |
2023年 | 202篇 |
2022年 | 511篇 |
2021年 | 859篇 |
2020年 | 406篇 |
2019年 | 613篇 |
2018年 | 671篇 |
2017年 | 413篇 |
2016年 | 478篇 |
2015年 | 560篇 |
2014年 | 704篇 |
2013年 | 924篇 |
2012年 | 1289篇 |
2011年 | 1280篇 |
2010年 | 764篇 |
2009年 | 590篇 |
2008年 | 914篇 |
2007年 | 894篇 |
2006年 | 791篇 |
2005年 | 718篇 |
2004年 | 585篇 |
2003年 | 514篇 |
2002年 | 474篇 |
2001年 | 63篇 |
2000年 | 38篇 |
1999年 | 68篇 |
1998年 | 85篇 |
1997年 | 77篇 |
1996年 | 42篇 |
1995年 | 31篇 |
1994年 | 32篇 |
1993年 | 22篇 |
1992年 | 21篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 13篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1977年 | 9篇 |
1975年 | 4篇 |
1974年 | 10篇 |
1973年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
Lorenzo Fornaro Gianna Musettini Paola Orlandi Irene Pecora Caterina Vivaldi Marta Banchi Francesca Salani Elisabetta Fini Valentina Massa Silvia Catanese Federico Cucchiara Monica Lencioni Gianluca Masi Enrico Vasile Guido Bocci 《American journal of cancer research》2022,12(7):3347
Ramucirumab plus paclitaxel is considered the standard of care in the second-line treatment of gastric carcinoma (GC). The aim of this study was to evaluate plasma vascular endothelial growth factor-A (VEGF-A), VEGF-D, and circulating soluble VEGF receptor-2 (sVEGFR-2) as possible markers of resistance or response to ramucirumab administered with paclitaxel in pretreated metastatic GC patients. Plasma samples were collected at different time points (on days 1 and 15 of the first 3 cycles, at best radiologic response and at disease progression). VEGF-A, VEGF-D and sVEGFR-2 were analysed by ELISA. Correlations of biomarker baseline levels or dynamic changes with outcome measures were assessed. Progression-free survival (PFS) was the primary endpoint of the study. Forty-one patients were enrolled. VEGF-A and VEGF-D, but not sVEGFR-2, values significantly increased during treatment compared to baseline (P < 0.001). A positive correlation between VEGF-A and sVEGFR-2 at cycle 2 was found (P=0.045). At univariate analysis, higher baseline levels of VEGF-A were associated with worse OS (P=0.015). Early increase of sVEGFR-2 levels after the first treatment cycle was the only factor associated with longer PFS (6.6 vs. 3.6 months, P=0.049) and OS (18.6 vs. 5.2 months, P=0.008). Significance of sVEGFR-2 early increase was retained at multivariate analysis for OS (HR 0.32; 95% CI 0.12-0.91; P=0.032). The reported results confirmed the prognostic role of baseline VEGF-A and, with the limitations of the limited sample size and the lack of a control arm, suggested that the early increase of sVEGFR-2 after 1 cycle of treatment could be a potential predictive biomarker of benefit from second-line ramucirumab plus paclitaxel in GC. 相似文献
142.
143.
144.
In the last 10 years, we have witnessed an extensive development of instrumental techniques in analytical methods for determination of various molecules and ions at very low concentrations. Nevertheless, the presence of interfering components of complex samples hampered the applicability of new analytical strategies. Thus, additional sample pre-treatment steps were proposed to overcome the problem. Solid sorbents were used for clean-up samples but insufficient selectivity of commercial materials limited their utility. Here, the application of molecularly imprinted polymers (MIPs) or ion-imprinted polymers (IIPs) in the separation processes have recently attracted attention due to their many advantages, such as high selectivity, robustness, and low costs of the fabrication process. Bulk or monoliths, microspheres and core-shell materials, magnetically susceptible and stir-bar imprinted materials are applicable to different modes of solid-phase extraction to determine target analytes and ions in a very complex environment such as blood, urine, soil, or food. The capability to perform a specific separation of enantiomers is a substantial advantage in clinical analysis. The ion-imprinted sorbents gained interest in trace analysis of pollutants in environmental samples. In this review, the current synthetic approaches for the preparation of MIPs and IIPs are comprehensively discussed together with a detailed characterization of respective materials. Furthermore, the use of sorbents in environmental, food, and biomedical analyses will be emphasized to point out current limits and highlight the future prospects for further development in the field. 相似文献
145.
146.
147.
148.
149.
Diego Penela Cheryl Teres Juan Fernández-Armenta Luis Aguinaga Luis Tercedor David Soto-Iglesias Beatriz Jauregui Augusto Ordóñez Juan Acosta Felipe Bisbal Marta Aceña Etelvino Silva Alfredo Chauca Francesco De Sensi Radu Vatasescu Pablo Sánchez-Millán Julio Carballo Lluis Mont Antonio Berruezo 《Heart rhythm》2021,18(1):27-33
150.
Legumes have been widely consumed and used to isolate bioactive compounds, mainly proteins. The aim of this study was to review the beneficial actions of different legumes proteins and peptides updating the main findings that correlate legumes consumption and the effects on non-transmissible chronic diseases, specifically metabolic syndrome. An exhaustive revision of five relevant bioactivities (antioxidant, anti-inflammatory, antihypertensive, hypocholesterolemic -all of them linked to metabolic syndrome- and antitumoral) of proteins and peptides from legumes focused on isolation and purification, enzymatic hydrolysis and in vitro gastrointestinal digestion was carried out. The promising potential of bioactive hydrolysates and peptides from pulses has been demonstrated by in vitro tests. However, only a few studies validated these biological activities using animal models. No clinical trials have been carried out yet; so further research is required to elucidate their effective health implications. 相似文献