全文获取类型
收费全文 | 251126篇 |
免费 | 24317篇 |
国内免费 | 16794篇 |
专业分类
耳鼻咽喉 | 2010篇 |
儿科学 | 2846篇 |
妇产科学 | 2661篇 |
基础医学 | 33992篇 |
口腔科学 | 4335篇 |
临床医学 | 31838篇 |
内科学 | 35792篇 |
皮肤病学 | 2702篇 |
神经病学 | 12660篇 |
特种医学 | 8924篇 |
外国民族医学 | 136篇 |
外科学 | 24685篇 |
综合类 | 42841篇 |
现状与发展 | 59篇 |
一般理论 | 18篇 |
预防医学 | 17497篇 |
眼科学 | 6584篇 |
药学 | 27870篇 |
209篇 | |
中国医学 | 14522篇 |
肿瘤学 | 20056篇 |
出版年
2024年 | 945篇 |
2023年 | 3931篇 |
2022年 | 10174篇 |
2021年 | 12868篇 |
2020年 | 9523篇 |
2019年 | 8225篇 |
2018年 | 8673篇 |
2017年 | 7930篇 |
2016年 | 7569篇 |
2015年 | 11187篇 |
2014年 | 13852篇 |
2013年 | 12924篇 |
2012年 | 18435篇 |
2011年 | 19921篇 |
2010年 | 13398篇 |
2009年 | 10753篇 |
2008年 | 13335篇 |
2007年 | 13268篇 |
2006年 | 12438篇 |
2005年 | 11863篇 |
2004年 | 8538篇 |
2003年 | 8078篇 |
2002年 | 6938篇 |
2001年 | 5979篇 |
2000年 | 5620篇 |
1999年 | 5481篇 |
1998年 | 3566篇 |
1997年 | 3710篇 |
1996年 | 2722篇 |
1995年 | 2582篇 |
1994年 | 2282篇 |
1993年 | 1519篇 |
1992年 | 1915篇 |
1991年 | 1645篇 |
1990年 | 1430篇 |
1989年 | 1324篇 |
1988年 | 1148篇 |
1987年 | 987篇 |
1986年 | 908篇 |
1985年 | 704篇 |
1984年 | 499篇 |
1983年 | 415篇 |
1982年 | 330篇 |
1981年 | 297篇 |
1980年 | 242篇 |
1979年 | 250篇 |
1978年 | 192篇 |
1977年 | 211篇 |
1976年 | 191篇 |
1974年 | 157篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Chien-Hua Tseng Ben-Jei Tsuang Chun-Ju Chiang Kai-Chen Ku Jeng-Sen Tseng Tsung-Ying Yang Kuo-Hsuan Hsu Kun-Chieh Chen Sung-Liang Yu Wen-Chung Lee Tsang-Wu Liu Chang-Chuan Chan Gee-Chen Chang 《Journal of thoracic oncology》2019,14(5):784-792
Introduction
For never-smokers (smoked <100 lifetime cigarettes), lung cancer (LC) has emerged as an important issue. We aimed to investigate the effects of prevalence changes in tobacco smoking and particulate matter (PM) 2.5 (PM2.5) levels on LC in Taiwan, in relation to contrasting PM2.5 levels, between Northern Taiwan (NT) and Southern Taiwan (ST).Methods
We reviewed 371,084 patients with LC to assess smoking prevalence and correlations between the incidence of adenocarcinoma lung cancer (AdLC) and non-AdLC. Two subsets were selected to assess different AdLC stage trends and the effect of PM2.5 on survival of patients with AdLC.Results
From 1995 to 2015, the proportion of male adult ever-smokers decreased from 59.4% to 29.9% whereas the female smoking rate remained low (3.2% to 5.3%). AdLC incidence in males and females increased from 9.06 to 23.25 and 7.05 to 24.22 per 100,000 population, respectively. Since 1993, atmospheric visibility in NT improved (from 7.6 to 11.5 km), but deteriorated in ST (from 16.3 to 4.2 km). The annual percent change in AdLC stages IB to IV was 0.3% since 2009 (95% confidence interval [CI]: -1.9%–2.6%) in NT, and 4.6% since 2007 (95% CI: 3.3%–5.8%) in ST; 53% patients with LC had never smoked. Five-year survival rates for never-smokers, those with EGFR wild-type genes, and female patients with AdLC were 12.6% in NT and 4.5% in ST (hazard ratio: 0.79, 95% CI: 0.70–0.90).Conclusions
In Taiwan, greater than 50% of patients with LC had never smoked. PM2.5 level changes can affect AdLC incidence and patient survival. 相似文献93.
目的:建立大黄特征化学成分和抗氧化活性相关联的二维指纹图谱,研究大黄抗氧化活性物质。方法:利用高效液相多检测器联用的抗氧化活性成分在线检测体系,对大黄中化学成分进行检测,共鉴定出大黄中化学成分15种;其中8种具有抗氧化活性;然后采用清除效率为指标对各活性成分的抗氧化活性进行评价。结果:结果发现化合物葡萄糖紫丁香酸、腺嘌呤、没食子酸、儿茶素或表儿茶素、双花母草素、2-O-桂皮酰-没食子酰葡萄糖等具有较强的清除ABTS·+的活性,而蒽醌类成分对ABTS·+的清除作用较弱。结论:采用HPLC-ABTS-DAD-Q-TOF/MS对大黄中的抗氧化活性成分进行快速分析鉴定,初步阐明大黄在抗氧化环节起作用的效应物质。 相似文献
94.
95.
96.
Photobiomodulation (PBM) therapy is based on the exposure of biological tissues to low‐level laser light (coherent light) or light‐emitting diodes (LEDs; noncoherent light), leading to the modulation of cellular functions, such as proliferation and migration, which result in tissue regeneration. PBM therapy has important clinical applications in regenerative medicine. Vitiligo is an acquired depigmentary disorder resulting from disappearance of functional melanocytes in the involved skin. Vitiligo repigmentation depends on available melanocytes derived from (a) melanocyte stem cells located in the bulge area of hair follicles and (b) the epidermis at the lesional borders, which contains a pool of functional melanocytes. Since follicular melanoblasts (MBs) are derived from the melanocyte stem cells residing at the bulge area of hair follicle, the process of vitiligo repigmentation presents a research model for studying the regenerative effect of PBM therapy. Previous reports have shown favourable response for treatment of vitiligo with a low‐energy helium‐neon (He‐Ne) laser. This review focuses on the molecular events that took place during the repigmentation process of vitiligo triggered by He‐Ne laser (632.8 nm, red light). Monochromatic radiation in the visible and infrared A (IRA) range sustains matrix metalloproteinase (MMP), improves mitochondrial function, and increases adenosine triphosphate (ATP) synthesis and O2 consumption, which lead to cellular regenerative pathways. Cytochrome c oxidase in the mitochondria was reported to be the photoacceptor upon which He‐Ne laser exerts its effects. Mitochondrial retrograde signalling is responsible for the cellular events by red light. This review shows that He‐Ne laser initiated mitochondrial retrograde signalling via a Ca2+‐dependent cascade. The impact on cytochrome c oxidase within the mitochondria, an event that results in activation of CREB (cyclic‐AMP response element binding protein)‐related cascade, is responsible for the He‐Ne laser promoting functional development at different stages of MBs and boosting functional melanocytes. He‐Ne laser irradiation induced (a) melanocyte stem cell differentiation; (b) immature outer root sheath MB migration; (c) differentiated outer root sheath MB melanogenesis and migration; and (d) perilesional melanocyte migration and proliferation. These photobiomodulation effects result in perifollocular and marginal repigmentation in vitiligo. 相似文献
97.
98.
99.
100.