全文获取类型
收费全文 | 58884篇 |
免费 | 5175篇 |
国内免费 | 4159篇 |
专业分类
耳鼻咽喉 | 382篇 |
儿科学 | 1666篇 |
妇产科学 | 744篇 |
基础医学 | 11188篇 |
口腔科学 | 1228篇 |
临床医学 | 5236篇 |
内科学 | 8788篇 |
皮肤病学 | 882篇 |
神经病学 | 3762篇 |
特种医学 | 1253篇 |
外国民族医学 | 29篇 |
外科学 | 3112篇 |
综合类 | 12770篇 |
现状与发展 | 22篇 |
一般理论 | 1篇 |
预防医学 | 3045篇 |
眼科学 | 1068篇 |
药学 | 4174篇 |
4篇 | |
中国医学 | 1368篇 |
肿瘤学 | 7496篇 |
出版年
2024年 | 44篇 |
2023年 | 580篇 |
2022年 | 924篇 |
2021年 | 1678篇 |
2020年 | 1609篇 |
2019年 | 1547篇 |
2018年 | 1451篇 |
2017年 | 1640篇 |
2016年 | 1917篇 |
2015年 | 1975篇 |
2014年 | 2953篇 |
2013年 | 3961篇 |
2012年 | 3227篇 |
2011年 | 3964篇 |
2010年 | 3256篇 |
2009年 | 3295篇 |
2008年 | 3582篇 |
2007年 | 3895篇 |
2006年 | 3732篇 |
2005年 | 3514篇 |
2004年 | 3169篇 |
2003年 | 2760篇 |
2002年 | 2417篇 |
2001年 | 2206篇 |
2000年 | 1843篇 |
1999年 | 1478篇 |
1998年 | 1197篇 |
1997年 | 963篇 |
1996年 | 675篇 |
1995年 | 691篇 |
1994年 | 525篇 |
1993年 | 348篇 |
1992年 | 265篇 |
1991年 | 207篇 |
1990年 | 177篇 |
1989年 | 117篇 |
1988年 | 87篇 |
1987年 | 64篇 |
1986年 | 51篇 |
1985年 | 69篇 |
1984年 | 40篇 |
1983年 | 22篇 |
1982年 | 31篇 |
1981年 | 26篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
91.
Rosa Della Monica Mariella Cuomo Roberta Visconti Annabella di Mauro Michela Buonaiuto Davide Costabile Giulia De Riso Teodolinda Di Risi Elia Guadagno Roberto Tafuto Sabrina Lamia Alessandro Ottaiano Paolo Cappabianca Maria Laura Del Basso de Caro Fabiana Tatangelo Juergen Hench Stephan Frank Salvatore Tafuto Lorenzo Chiariotti 《Oncology research》2020,28(9):837-845
Unresectable neuroendocrine neoplasms (NENs) often poorly respond to standard therapeutic approaches.
Alkylating agents, in particular temozolomide, commonly used to treat high-grade brain tumors including glioblastomas, have recently been tested in advanced or metastatic NENs, where they showed promising response
rates. In glioblastomas, prediction of response to temozolomide is based on the assessment of the methylation
status of the MGMT gene, as its product, O6
-methylguanine-DNA methyltransferase, may counteract the damaging effects of the alkylating agent. However, in NENs, such a biomarker has not been validated yet. Thus, we
have investigated MGMT methylation in 42 NENs of different grades and from various sites of origin by two
different approaches: in contrast to methylation-specific PCR (MSP), which is commonly used in glioblastoma
management, amplicon bisulfite sequencing (ABS) is based on high-resolution, next-generation sequencing
and interrogates several additional CpG sites compared to those covered by MSP. Overall, we found MGMT
methylation in 74% (31/42) of the NENs investigated. A higher methylation degree was observed in welldifferentiated tumors and in tumors originating in the gastrointestinal tract. Comparing MSP and ABS results,
we demonstrate that the region analyzed by the MSP test is sufficiently informative of the MGMT methylation
status in NENs, suggesting that this predictive parameter could routinely be interrogated also in NENs. 相似文献
92.
目的:利用慢病毒介导的RNA干扰(RNAi)技术,构建稳定敲降NF-YB基因的HeLa细胞系。方法:设计shRNA-NF-YB引物,利用分子克隆技术构建H1/GFP-Puro-shRNA-NF-YB质粒,转染293T后收集病毒感染HeLa细胞;用嘌呤霉素筛选细胞得到稳定敲降细胞株;利用Western blot和实时荧光定量PCR对细胞系进行鉴定。结果:构建的质粒经测序后与设计的引物对比序列一致,Western blot和实时荧光定量PCR结果表明构建细胞的NF-YB蛋白和mRNA表达抑制效果明显。结论:本实验成功构建了NF-YB-shRNA-HeLa细胞系,获得了特异性NF-YB基因敲降的HeLa细胞。 相似文献
94.
95.
ABSTRACTAlthough exclusive breastfeeding has been linked to lower rates of postnatal HIV transmission compared to nonexclusive breastfeeding, mechanisms underlying this are unclear. Across a longitudinally sampled cohort of South African infants, we showed that exclusively breastfed (EBF) infants had altered gut bacterial communities when compared to nonexclusively breastfed (NEBF) infants, as well as reduced peripheral CD4 + T cell activation and lowered chemokine and chemokine receptor expression in the oral mucosa. We further demonstrated that the relative abundance of key taxa was correlated with peripheral CD4 + T cell activation. Here, we supplement those findings by using compositional data analyses to identify shifts in the abundance of several Bifidobacteria strains relative to select strains of Escherichia, Bacteroides, and others that are associated with the transition to NEBF. We illustrate that the abundance ratio of these taxa is tightly correlated with feeding modality and is a strong predictor of peripheral T cell activation. More broadly, we discuss our study in the context of novel developments and explore future directions for the field. 相似文献
96.
《Vaccine》2020,38(39):6141-6152
Influenza vaccination is considered the most valuable means to prevent and control seasonal influenza infections, which causes various clinical symptoms, ranging from mild cough and fever to even death. Among various influenza vaccine types, the inactivated subunit type is known to provide improved safety with reduced reactogenicity. However, there are some drawbacks associated with inactivated subunit type vaccines, with the main ones being its low immunogenicity and the induction of Th2-biased immune responses. In this study, we investigated the role of a single-stranded RNA (ssRNA) derived from the intergenic region in the internal ribosome entry site of the Cricket paralysis virus as an adjuvant rather than the universal vaccine for a seasonal inactivated subunit influenza vaccine. The ssRNA adjuvant stimulated not only well-balanced cellular (indicated by IgG2a, IFN-γ, IL-2, and TNF-α) and humoral (indicated by IgG1 and IL-4) immune responses but also a mucosal immune response (indicated by IgA), a key protector against respiratory virus infections. It also increases the HI titer, the surrogate marker of influenza vaccine efficacy. Furthermore, ssRNA adjuvant confers cross-protective immune responses against heterologous influenza virus infection while promoting enhanced viral clearance. Moreover, ssRNA adjuvant increases the number of memory CD4+ and CD8+ T cells, which can be expected to induce long-term immune responses. Therefore, this ssRNA-adjuvanted seasonal inactivated subunit influenza vaccine might be the best influenza vaccine generating robust humoral and cellular immune responses and conferring cross-protective and long-term immunity. 相似文献
98.
99.