全文获取类型
收费全文 | 440519篇 |
免费 | 32420篇 |
国内免费 | 1781篇 |
专业分类
耳鼻咽喉 | 4875篇 |
儿科学 | 11545篇 |
妇产科学 | 8587篇 |
基础医学 | 57555篇 |
口腔科学 | 8833篇 |
临床医学 | 43436篇 |
内科学 | 93145篇 |
皮肤病学 | 5911篇 |
神经病学 | 42589篇 |
特种医学 | 14619篇 |
外国民族医学 | 24篇 |
外科学 | 67910篇 |
综合类 | 6681篇 |
现状与发展 | 2篇 |
一般理论 | 592篇 |
预防医学 | 39023篇 |
眼科学 | 10529篇 |
药学 | 30011篇 |
6篇 | |
中国医学 | 718篇 |
肿瘤学 | 28129篇 |
出版年
2023年 | 1867篇 |
2022年 | 3075篇 |
2021年 | 8495篇 |
2020年 | 5086篇 |
2019年 | 8244篇 |
2018年 | 9454篇 |
2017年 | 7300篇 |
2016年 | 7951篇 |
2015年 | 9423篇 |
2014年 | 14009篇 |
2013年 | 19812篇 |
2012年 | 29613篇 |
2011年 | 31525篇 |
2010年 | 17829篇 |
2009年 | 16045篇 |
2008年 | 28797篇 |
2007年 | 30374篇 |
2006年 | 29714篇 |
2005年 | 30139篇 |
2004年 | 28512篇 |
2003年 | 26686篇 |
2002年 | 25208篇 |
2001年 | 3896篇 |
2000年 | 3010篇 |
1999年 | 4246篇 |
1998年 | 5614篇 |
1997年 | 4760篇 |
1996年 | 4199篇 |
1995年 | 3868篇 |
1994年 | 3355篇 |
1993年 | 3095篇 |
1992年 | 2407篇 |
1991年 | 2244篇 |
1990年 | 2027篇 |
1989年 | 1897篇 |
1988年 | 1952篇 |
1987年 | 1936篇 |
1986年 | 1917篇 |
1985年 | 2026篇 |
1984年 | 2611篇 |
1983年 | 2511篇 |
1982年 | 3063篇 |
1981年 | 2844篇 |
1980年 | 2622篇 |
1979年 | 1500篇 |
1978年 | 1668篇 |
1977年 | 1535篇 |
1976年 | 1392篇 |
1975年 | 1140篇 |
1974年 | 1108篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
31.
Xin Yi Wong Andrew Qi Jun Lim Qianyu Shen John Whay Kuang Chia Min Hoe Chew Wah Siew Tan 《Current medical research and opinion》2020,36(10):1677-1686
Abstract
Objective
Ras wild-type metastatic colorectal cancers (mCRC) may be treated with anti-vascular endothelial growth factor (VEGF) or anti-epidermal growth factor receptor (EGFR) agents. We aim to estimate patients’ preferences for mCRC treatment and relative importance of cost, efficacy improvement, avoidance of side effects and therapy convenience, and relative uptake between profiles that resemble Bevacizumab (anti-VEGF) and Cetuximab (anti-EGFR), two commonly prescribed mCRC targeted therapies. 相似文献32.
33.
34.
Krishna Pillai Javid Akhter Terence C. Chua Mena Shehata Nayef Alzahrani Issan Al-Alem David L. Morris 《Medicine》2015,94(9)
Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices.With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored.With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres.Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected.Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5.MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. 相似文献
35.
36.
37.
Katja T. Turunen Vasiliki Pletsa Panagiotis Georgiadis John K. Triantafillidis Dimitrios Karamanolis 《Nutrition and cancer》2016,68(4):560-567
The aim of the study was to determine the effect of β-glucan on the cytotoxicity and genotoxicity of polypectomized patient's fecal water (FW). Polypectomized volunteers (n = 69) were randomly assigned to consume bread with or without β-glucan, for 3 months. FW was collected at the beginning (t = 0), the 30th and 90th day and 2 wk after the intervention. Cytotoxicity and genotoxicity were estimated on Caco-2 cells, using trypan blue exclusion test and comet assay, respectively. Gastrointestinal symptoms were recorded and subjects kept a 3-day food diary at baseline and after completion. Trypan blue exclusion test revealed cell survival of approximately 87% after incubation with FW. The FW samples showed 49% genotoxicity at the baseline. Genotoxicity in the intervention group decreased during the trial reaching statistical significance on the 90th day compared to control. An increase was noticed 2 wk after the trial, but it still remained significantly lower compared to control. Group-specific analysis for β-glucan also revealed significant decrease in the genotoxicity on the 90th day compared to baseline. β-glucan ingestion in polypectomized patients significantly decreased the genotoxicity of their FW. Our findings suggest that β-glucan consumption could possibly provide protection against colon cancer development. 相似文献
38.
The present narrative review examines the scientific evidence of the biological mechanisms that may link periodontitis and diabetes, as a source of comorbidity. Publications regarding periodontitis and diabetes, in human, animals, and in vitro were screened for their relevance. Periodontal microbiome studies indicate a possible association between altered glucose metabolism in prediabetes and diabetes and changes in the periodontal microbiome. Coinciding with this, hyperglycemia enhances expression of pathogen receptors, which enhance host response to the dysbiotic microbiome. Hyperglycemia also promotes pro-inflammatory response independently or via the advanced glycation end product/receptor for advanced glycation end product pathway. These processes excite cellular tissue destruction functions, which further enhance pro-inflammatory cytokines expression and alteration in the RANKL/osteoprotegerin ratio, promoting formation and activation of osteoclasts. The evidence supports the role of several pathogenic mechanisms in the path of true causal comorbidity between poorly controlled diabetes and periodontitis. However, further research is needed to better understand these mechanisms and to explore other mechanisms. 相似文献
39.
Rebecca L. King Albert C. Yan Debora R. Sekiguchi John K. Choi 《Journal of cutaneous pathology》2015,42(12):1012-1017
Reactive lymphoid infiltrates of the skin composed predominantly of gamma‐delta (γδ) T cells are not well described in the literature. Herein we report a case of an otherwise healthy 4‐year‐old male who presented with a waxing and waning papular rash characterized by small, discrete crusted papules spread across his trunk, face and extremities. Clinical evaluation revealed no evidence of systemic disease. Microscopic examination revealed a dermal, perivascular infiltrate of highly atypical lymphocytes with a γδ T cell phenotype, worrisome for primary cutaneous γδ T cell lymphoma. The clinical course, however, was that of a reactive condition and prompted consideration of a diagnosis of pityriasis lichenoides et varioliformis acuta (PLEVA) and lymphomatoid papulosis (LyP). In many ways, this case defies current classification schemes and seems to expand the spectrum of reactive γδ T cell infiltrates of the skin. 相似文献
40.