首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2119篇
  免费   169篇
  国内免费   245篇
耳鼻咽喉   9篇
儿科学   19篇
妇产科学   26篇
基础医学   276篇
口腔科学   25篇
临床医学   161篇
内科学   214篇
皮肤病学   26篇
神经病学   122篇
特种医学   63篇
外国民族医学   4篇
外科学   147篇
综合类   630篇
预防医学   22篇
眼科学   64篇
药学   362篇
中国医学   11篇
肿瘤学   352篇
  2023年   15篇
  2022年   25篇
  2021年   48篇
  2020年   29篇
  2019年   27篇
  2018年   20篇
  2017年   20篇
  2016年   17篇
  2015年   18篇
  2014年   46篇
  2013年   165篇
  2012年   65篇
  2011年   96篇
  2010年   71篇
  2009年   86篇
  2008年   111篇
  2007年   159篇
  2006年   225篇
  2005年   218篇
  2004年   192篇
  2003年   191篇
  2002年   154篇
  2001年   138篇
  2000年   117篇
  1999年   87篇
  1998年   53篇
  1997年   44篇
  1996年   37篇
  1995年   27篇
  1994年   15篇
  1993年   5篇
  1992年   5篇
  1991年   4篇
  1990年   1篇
  1988年   2篇
排序方式: 共有2533条查询结果,搜索用时 15 毫秒
1.

Background and aims

Heparin-binding EGF-like growth factor (HB-EGF) is a representative EGF family member that interacts with EGFR under diverse stress environment. Previously, we reported that the HB-EGF-targeting using antisense oligonucleotide (ASO) effectively suppressed an aortic aneurysm in the vessel wall and circulatory lipid levels. In this study, we further examined the effects of the HB-EGF ASO administration on the development of hyperlipidemia-associated atherosclerosis using an atherogenic mouse model.

Methods and results

The male and female LDLR deficient mice under Western diet containing 21% fat and 0.2% cholesterol content were cotreated with control and HB-EGF ASOs for 12 weeks. We observed that the HB-EGF ASO administration effectively downregulated circulatory VLDL- and LDL-associated lipid levels in circulation; concordantly, the HB-EGF targeting effectively suppressed the development of atherosclerosis in the aorta. An EGFR blocker BIBX1382 administration suppressed the hepatic TG secretion rate, suggesting a positive role of the HB-EGF signaling for the hepatic VLDL production. We newly observed that there was a significant improvement of the insulin sensitivity by the HB-EGF ASO administration in a mouse model under the Western diet as demonstrated by the improvement of the glucose and insulin tolerances.

Conclusion

The HB-EGF ASO administration effectively downregulated circulatory lipid levels by suppressing hepatic VLDL production rate, which leads to effective protection against atherosclerosis in the vascular wall.  相似文献   
2.
Introduction: Oligonucleotide therapeutics such as antisense oligonucleotides and siRNA requires chemical modifications and nano-sized carriers to circumvent stability problems in vivo, to reach target tissues, and to overcome tissue and cellular barriers. Hyaluronic acid (HA), already utilized in drug delivery and tissue engineering, possess properties that are useful to solve these problems and achieve full potential of oligonucleotide therapeutics.

Areas covered: Complexes of oligonucleotide therapeutics with HA are discussed in terms of interactions providing the complexes formation and genes targeted by the therapeutics to cure diseases such as cancer, atherosclerosis, liver cirrhosis, and inflammation. The achieved therapeutic effects are rationalized as consequences of biodistribution, cell internalization and endosomal escape provided by HA.

Expert opinion: Design of electrostatic, coordination, and hydrophobic interactions as well as covalent conjugation between oligonucleotide drugs, HA macromolecules and intermediate ligands are crucial for carrier–cargo association and dissociation under different conditions to impart oligonucleotides stability in vivo, their accumulation in diseased organs, cellular uptake, and dissociation in cytoplasm intact. These are the delivery factors that provides eventual complex formation of oligonucleotide therapeutics with their mRNA, microRNA, or protein targets. Elucidation of the impact of structural parameters of oligonucleotide/HA complexes on their therapeutic effect in vivo is important for the future rational design of the delivery agents.  相似文献   

3.
Long non-coding RNAs (lncRNAs) have been identified as crucial regulators in the tumorigenesis and progression of hepatocellular carcinoma (HCC). Recently, long intergenic non-protein coding RNA 205 (LINC00205) has been identified as a prognostic biomarker in HCC. However, the biological role of LINC0205 and its potential molecular mechanism are poorly investigated. Here, we found that the expression of LINC00205 was dramatically up-regulated in HCC tissues compared to adjacent nontumor tissues. Furthermore, the level of LINC00205 in both Hep3B and Huh7 cells was prominently higher than that in normal hepatic cell line LO2. Notably, the high expression of LINC00205 was strongly correlated with tumor size ≥5 cm, venous infiltration and advanced tumor stages. Functionally, LINC00205 knockdown obviously repressed the proliferation, migration and invasion of Hep3B and Huh7 cells in vitro. An inverse correlation between LINC00205 and miR-122-5p was detected in HCC tissues. Interestingly, LINC00205 knockdown increased the level of miR-122-5p in both Hep3B and Huh7 cells. Mechanistically, luciferase reporter assay demonstrated LINC00205 acted as a competing endogenous RNA (ceRNA) by directly interacting with miR-122-5p. More importantly, miR-122-5p overexpression significantly restrained the proliferation, migration and invasion of HCC cells. Collectively, our study provides solid evidence to support the oncogenic role of LINC00205 in HCC, which may be benefit for the improvement of HCC therapy.  相似文献   
4.
MicroRNAs (miRNAs) have been found to be aberrantly expressed and exert essential roles in the tumorigenesis and progression of gastric cancer (GC). miR-301b-3p has been recognized as a cancer-related miRNA in lung cancer, bladder cancer and hepatocellular carcinoma. However, the function of miR-301b-3p in GC progression and its underlying mechanism have not been studied yet. In this study, we found that miR-301b-3p expression was up-regulated in GC tissues compared to adjacent noncancerous tissues. Furthermore, the elevated levels of miR-301b-3p were detected in GC cell lines (SGC-7901, AGS, MKN-45 and MGC-803) as compared with GES-1 cells. Interestingly, GC tissues from patients with tumor size ≥ 5 cm and advanced tumor stages showed obvious higher levels of miR-301b-3p compared to matched controls. Functionally, miR-301b-3p knockdown prominently inhibited cell proliferation, and induced cell cycle arrest at G1 phase and apoptosis in MGC-803 cells. Meanwhile, ectopic expression of miR-301b-3p conversely regulated these biological behaviors of MKN-45 cells. Next, we found that miR-301b-3p knockdown increased, whereas miR-301b-3p overexpression reduced the expression of zinc finger and BTB domain containing 4 (ZBTB4) in GC cells. Accordingly, luciferase reporter assay identified ZBTB4 as a direct target of miR-301b-3p. ZBTB4 overexpression markedly restrained the growth of MGC-803 cells. More importantly, ZBTB4 silencing partially reversed miR-301b-3p knockdown-induced tumor suppressive effects on MGC-803 cells. In conclusion, we firstly revealed that miR-301-3p was highly expressed in GC and contributed to tumor progression via attenuating ZBTB4, which might provide a novel molecular-targeted strategy for GC treatment.  相似文献   
5.
MicroRNAs (miRNAs) can act not only as tumor suppressor genes but also as oncogenes. Oncogenic miRNAs (oncomiRs) could therefore provide opportunities for the treatment of human malignancies. Here, we aimed to identify oncomiRs present in oral squamous cell carcinoma (OSCC) and addressed whether targeting these miRNAs might be useful in treatment for cancer. Functional screening for oncomiRs in a human OSCC cell line (GFP‐SAS) was carried out using the miRCURY LNA microRNA Knockdown Library – Human version 12.0. We identified a locked nucleic acid (LNA)/DNA antisense oligonucleotide against miR‐361‐3p (LNA‐miR‐361‐3p) which showed the largest degree of growth inhibition of GFP‐SAS cells. Transfection with a synthetic mimic of mature miR‐361‐3p resulted in an approximately 20% increase in the growth of GFP‐SAS cells. We identified odd‐skipped related 2 (OSR2) as a miR‐361‐3p target gene. Transfection of GFP‐SAS cells with LNA‐miR‐361‐3p caused a significant increase in the expression levels of OSR2. Cotransfection of a OSR2 3′‐UTR luciferase reporter plasmid and LNA‐miR‐361‐3p into GFP‐SAS cells produced higher levels of luciferase activity than in cells cotransfected with the LNA‐nontarget. We assessed the effect of LNA‐miR‐361‐3p on the in vivo growth of GFP‐SAS cells. We found that LNA‐miR‐361‐3p significantly reduced the size of s.c. xenografted GFP‐SAS tumors, compared to the control group treated with LNA‐NT. Finally, we observed that miR‐361‐3p is overexpressed in OSCC tissues. These results suggest that miR‐361‐3p supports the growth of human OSCC cells both in vitro and in vivo and that targeting miR‐361‐3p could be a useful therapeutic approach for patients with OSCC.  相似文献   
6.
7.
Introduction: A spectrum of disorders, ranging from rare severe cases of homozygous null lipoprotein lipase deficiency (LPLD)–familial chylomicronemia syndrome (FCS) to heterozygous missense LPLD or polygenic causes, result in hypertriglyceridemia and pancreatitis. The effects of mutations are exacerbated by environmental factors such as diet, pregnancy, and insulin resistance.

Areas covered: In this review, authors discuss chronic treatment of FCS by ultra-low fat diets allied with the use of fibrates, omega-3 fatty acids, niacin, statins, and insulin-sensitizing therapies depending on the extent of residual lipoprotein lipase (LPL) activity; novel therapies in development target triglyceride (TG)-rich lipoprotein particle clearance. Previously, a gene therapy approach to LPL-alipogene tiparvovec showed that direct targeting of LPL function reduced pancreatitis events. An antisense oligonucleotide to apolipoprotein-C3, volanesorsen has been shown to decrease TGs by 70–80% and possibly to reduce rates of pancreatitis admissions. Studies are underway to validate its long-term efficacy and safety. Other approaches investigating the role of LPL modulating proteins such as angiopoietin-like petide-3 (ANGPTL3) are under consideration.

Expert opinion: Current therapeutic options are not sufficient for management of many cases of FCS. The availability of antisense anti-apoC3 therapies and, in the future, ANGPTL3 therapies may remedy this.  相似文献   

8.
目的 :观察牙本质基质蛋白 1(dentalmatrixprotein ,DMP1)基因反义寡核苷酸 (AS -ODN)对成牙本质细胞系MDPC -2 3细胞碱性磷酸酶 (ALPase)活性和矿化能力的影响 ,深入研究成牙本质细胞的分化和牙本质形成的机制。方法 :以稳定表达DMP1的MDPC -2 3细胞为靶细胞、不同浓度DMP1反义核酸为阻断剂 ,观察不同作用时间对MDPC -2 3细胞ALPase活性的影响。用Westernblot法检测 10 μmol/LAS -ODN不同作用时间细胞DMP1表达情况 ,并观察连续作用 10d对该细胞矿化能力的影响。结果 :与正常组和S -ODN组比较 ,不同浓度的AS -ODN能够降低MDPC -2 3细胞ALPase活性 ,其中 10 μmol/LAS -ODN降低ALPase活性最为显著 (作用 5d时OD值最低 ,为 0 .3 3 78± 2 .0E)。Westernblot法检测到DMP1在MDPC -2 3细胞的表达在 10 μmol/LAS -ODN加入 12h后减弱 ,2 4h后完全阻断。此浓度AS -ODN连续作用细胞 10d后 ,vonKossa染色显示细胞中出现明显的钙盐沉积 ,矿化结节的数量和大小明显少于对照组。结论 :DMP1反义核酸能够降低MDPC -2 3细胞AL Pase活性和矿化能力 ,提示DMP1参与调节成牙本质细胞矿化过程 ,可能具有启动牙本质矿化的作用。  相似文献   
9.
目的:探讨乙酰肝素酶(Hpa)反义寡脱氧核苷酸对人肝癌细胞株Hpa mRNA和蛋白表达的影响。方法:设计合成互补于Hpa mRNA起始密码区的硫代反义寡脱氧核苷酸AS-ODN及相应的无义对照寡脱氧核苷酸NS-ODN,以阳离子脂质体Oligofectamine~(TM) Reagent包埋后转染SMMC-7721、BEL-7402细胞,以RT-PCR和Western-blot检测转染前后细胞Hpa mRNA以及蛋白表达的变化。结果:与正常对照组和NS-ODN相应浓度组相比,转染AS-ODN组肝癌细胞Hp amRNA和蛋白的表达均下降。结论:Hpa反义寡脱氧核苷酸下调Hpa mRNA和蛋白的表达,可能抑制肝癌的侵袭转移。  相似文献   
10.
目的 探讨N6-甲基腺苷(m6A)识别蛋白人类抗原R(HuR)调控长链非编码RNA T细胞受体γ位点反义RNA 1(lncRNA TRG-AS1)对结直肠癌(CRC)生长的影响。方法 比色法检测CRC患者的癌组织、癌旁组织及正常结肠上皮细胞NCM460及CRC细胞HCT116、SW480、LOVO中m6A含量;实时荧光定量PCR(qPCR)检测TRG-AS1表达;Western blot检测HuR蛋白表达。将HCT116细胞分为Ct组、OE-NC组、OE-HuR组、si-NC组、si-HuR组、siHuR+pcDNA组、si-HuR+pcDNA-TRG-AS1组,CCK-8法检测细胞增殖;平板克隆实验检测细胞克隆形成能力;流式细胞术检测细胞凋亡率;划痕愈合实验检测细胞迁移;Transwell检测细胞侵袭;裸鼠体内移植瘤实验观察肿瘤生长情况;采用甲基化RNA免疫共沉淀(MeRIP)检测TRG-AS1上是否存在m6A位点;RNA pull-down实验和RNA免疫共沉淀(RIP)检测TRG-AS1与HuR蛋白的相互作用。结果 在CRC组织和细胞中,HuR蛋白、TRG-AS1高表达,m6A含...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号