全文获取类型
收费全文 | 1587篇 |
免费 | 158篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 4篇 |
妇产科学 | 11篇 |
基础医学 | 212篇 |
口腔科学 | 19篇 |
临床医学 | 135篇 |
内科学 | 305篇 |
皮肤病学 | 8篇 |
神经病学 | 56篇 |
特种医学 | 20篇 |
外国民族医学 | 1篇 |
外科学 | 110篇 |
综合类 | 204篇 |
预防医学 | 68篇 |
眼科学 | 69篇 |
药学 | 385篇 |
3篇 | |
中国医学 | 43篇 |
肿瘤学 | 153篇 |
出版年
2024年 | 1篇 |
2023年 | 57篇 |
2022年 | 87篇 |
2021年 | 145篇 |
2020年 | 129篇 |
2019年 | 104篇 |
2018年 | 54篇 |
2017年 | 47篇 |
2016年 | 45篇 |
2015年 | 60篇 |
2014年 | 103篇 |
2013年 | 87篇 |
2012年 | 70篇 |
2011年 | 81篇 |
2010年 | 60篇 |
2009年 | 55篇 |
2008年 | 57篇 |
2007年 | 44篇 |
2006年 | 41篇 |
2005年 | 46篇 |
2004年 | 35篇 |
2003年 | 38篇 |
2002年 | 28篇 |
2001年 | 25篇 |
2000年 | 14篇 |
1999年 | 9篇 |
1998年 | 14篇 |
1997年 | 22篇 |
1996年 | 19篇 |
1995年 | 9篇 |
1994年 | 22篇 |
1993年 | 15篇 |
1992年 | 14篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 20篇 |
1986年 | 10篇 |
1985年 | 16篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 13篇 |
1981年 | 17篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1978年 | 10篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有1810条查询结果,搜索用时 15 毫秒
2.
作为特殊的非编码RNA,环状RNA(circular RNA,CircRNA)是一种由pre-mRNA通过反式剪接形成的新型闭合环状的RNA分子。随着生物技术的飞速发展和研究的不断深入,对于CircRNA的鉴定和功能已有了新的认识。CircRNA由于缺乏5’帽子结构一直被认为不可翻译成蛋白质,已有证据表明其可通过核糖体内部进入位点(internal ribosomal entry site,IRES)和N6-甲基腺苷(N6-methyladenosine,m6A)诱导的方式编码多肽,在多种恶性肿瘤的生物学行为中扮演重要角色。本文结合国内外研究,回顾CircRNA翻译多肽的可能机制,对其多肽产物在常见的恶性肿瘤中的功能及作用进行综述,探讨其可能存在的问题及潜在临床应用价值。 相似文献
3.
环状RNA(circRNA)是一类重要的调控性非编码RNA,其含量丰富、性质稳定、存在广泛,并且可以通过多种机制调控基因表达,在血管疾病的发生发展中发挥重要调控作用。文章综述了circRNA在多种血管疾病中的研究现状,以期为相关领域的研究人员提供参考。 相似文献
4.
Hao Rong Yanguo Li Shiyun Hu Liuying Gao Tianfei Yi Yangyang Xie Ping Cai Jianjiong Li Xiaoyu Dai Meng Ye Qi Liao 《Molecular carcinogenesis》2022,61(1):59-72
Enhancer RNAs (eRNAs) are a subclass of long noncoding RNAs (lncRNAs) that have a wide effect in human tumors. However, the systematic analysis of potential functions of eRNAs-related genes (eRGs) in colon cancer (CC) remains unexplored. In this study, a total of 8231 eRGs including 6236 protein-coding genes and 1995 lncRNAs were identified in CC based on the multiple resources. These eRGs showed higher expression level and stability compared to other genes. What's more, the functions of these eRGs were closely related to cancer. Then a prognostic prediction model with 12 eRGs signatures were obtained for colon adenocarcinoma (COAD) patients. ROC curves showed the AUCs were 0.81, 0.77, and 0.78 for 1-, 3-, and 5-year survival prediction, respectively. And the prognostic model also manifested good performance in the validation datasets. Besides, the expression levels of two prognostic signatures, TMEM220 and LRRN2, were verified to be significantly lower in CC tissues than in adjacent noncancerous tissues (p < .05). Finally, the distinct molecular features were characterized between the high- and low-risk group through multiomics analysis including DNA mutation and methylation. Our results show eRGs signatures based prognostic model has high accuracy and may provide innovative biomarkers in COAD. 相似文献
5.
Dan-Dan Shan Qiu-Xian Zheng Jing Wang Zhi Chen 《World journal of gastroenterology : WJG》2022,28(16):1641-1655
Cancer has become the most life-threatening disease in the world. Mutations in and aberrant expression of genes encoding proteins and mutations in noncoding RNAs, especially long noncoding RNAs (lncRNAs), have significant effects in human cancers. LncRNAs have no protein-coding ability but function extensively in numerous physiological and pathological processes. Small nucleolar RNA host gene 3 (SNHG3) is a novel lncRNA and has been reported to be differentially expressed in various tumors, such as liver cancer, gastric cancer, and glioma. However, the interaction mechanisms for the regulation between SNHG3 and tumor progression are poorly understood. In this review, we summarize the results of SNHG3 studies in humans, animal models, and cells to underline the expression and role of SNHG3 in cancer. SNHG3 expression is upregulated in most tumors and is detrimental to patient prognosis. SNHG3 expression in lung adenocarcinoma remains controversial. Concurrently, SNHG3 affects oncogenes and tumor suppressor genes through various mechanisms, including competing endogenous RNA effects. A deeper understanding of the contribution of SNHG3 in clinical applications and tumor development may provide a new target for cancer diagnosis and treatment. 相似文献
6.
7.
8.
《HPB : the official journal of the International Hepato Pancreato Biliary Association》2022,24(10):1780-1788
BackgroundWe assessed whether or not covalently closed circular DNA (cccDNA) levels in the background liver influence the recurrence of hepatocellular carcinoma (HCC) in patients with resolved hepatitis B virus (HBV) infection.MethodsAmong 425 patients who underwent initial hepatectomy for HCC between 2010 and 2018, a retrospective review was performed in 44 with resolved HBV infection. The clinicopathologic characteristics were analyzed for correlation with tumor recurrence. The HBV cccDNA levels were tested via a droplet digital polymerase chain reaction assay.ResultsHBV cccDNA was detected in 27 of 44 patients (61%), and the median level was 1.0 copies/1000 ng (range, 0-931.3 copies/1000 ng). Anti-HBc ≥8.9 S/CO was associated with cccDNA detection (odds ratio, 11.08; 95% confidence interval [95% CI], 2.48-49.46; P = 0.002). Twenty-eight patients (64%) developed HCC recurrence after hepatectomy. The overall 3- and 5-year recurrence-free survival rates were 45.7% and 34.3%, respectively.19 HBV cccDNA levels was not significantly associated with HCC recurrence, while the presence of multiple tumors was an independent risk fact or (hazard ratio, 6.53; 95% CI, 2.48-17.19; P < 0.001.ConclusionHBV cccDNA levels did not influence HCC recurrence after hepatectomy. Anti-HBc levels may be used as a surrogate marker for cccDNA. 相似文献
9.
环状RNA(circular RNA,circRNA)是广泛存在于多物种细胞中结构稳定、高度保守、表达量丰富、可充当微小RNA海绵、具有剪切和转录调控、亲代基因修饰功能的内源性单链闭合circRNA。circRNA主要通过套索驱动的环化、内含子配对驱动的循环、内含子环化方式合成。在胃癌发生和进展过程中,不同种类的circRNA作用不一致。部分circRNA在胃癌组织中表达上调,通过微小RNA/p53/上皮细胞-间充质转化轴等机制促进胃癌细胞增殖、迁移;相反,部分circRNA在胃癌组织中表达下调,通过与miRNA间的海绵作用抑制胃癌细胞增殖和迁移。目前,已在人类唾液、胃液、血浆等成分中检测出胃癌相关的circRNA,提示circRNA具有作为胃癌诊断标志物的潜力。干预circRNA表达提高抗肿瘤药物敏感度,体外合成具有抑癌基因作用的circRNA,或下调具有癌基因作用的circRNA下游信号蛋白是胃癌治疗的有效手段。circRNA为胃癌的诊断和治疗提供了新的思路。 相似文献
10.
长链非编码RNAs(Long noncoding RNAs,lncRNAs)是一类长度在200~100000bp的非编码RNAs,蛋白编码能力缺乏或有限。近几年的研究表明,lncRNAs可通过竞争内源性RNAs(Competing endogenous RNAs,ceRNAs)的机制参与肿瘤细胞增殖、迁移、侵袭和凋亡,在肿瘤的发生发展中发挥重要的调控作用。而肺癌是发病率和死亡率最高的恶性肿瘤之一,严重威胁人类健康和生命安全。因此本文就lncRNAs形成的ceRNAs网络调控机制在肺癌方面的研究进行简要综述,为肺癌的诊断及治疗提供依据。 相似文献