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   4468篇
  免费   441篇
  国内免费   241篇
  2024年   1篇
  2023年   41篇
  2022年   58篇
  2021年   202篇
  2020年   147篇
  2019年   206篇
  2018年   211篇
  2017年   141篇
  2016年   186篇
  2015年   295篇
  2014年   300篇
  2013年   377篇
  2012年   378篇
  2011年   357篇
  2010年   216篇
  2009年   182篇
  2008年   249篇
  2007年   212篇
  2006年   170篇
  2005年   174篇
  2004年   118篇
  2003年   124篇
  2002年   98篇
  2001年   98篇
  2000年   74篇
  1999年   81篇
  1998年   60篇
  1997年   43篇
  1996年   56篇
  1995年   54篇
  1994年   31篇
  1993年   33篇
  1992年   33篇
  1991年   28篇
  1990年   20篇
  1989年   21篇
  1988年   13篇
  1987年   16篇
  1986年   8篇
  1985年   9篇
  1984年   9篇
  1983年   5篇
  1982年   1篇
  1981年   2篇
  1980年   5篇
  1979年   1篇
  1978年   3篇
  1976年   1篇
  1974年   1篇
  1959年   1篇
排序方式: 共有5150条查询结果,搜索用时 31 毫秒
1.
A cancer microenvironment generates strong hydrogen bond network system by the positive feedback loops supporting cancer complexity and robustness. Such network functions through the AKT locus generating high entropic energy supporting cancer metastatic robustness. Charged lepton particle muon follows the rule of Bragg effect during a collision with hydrogen network in cancer cells. Muon beam dismantles hydrogen bond network in cancer by the muon-catalyzed fusion, leading to apoptosis of cancer cells. Muon induces cumulative energy appearance on the hydrogen bond network in a cancer cell with its fast decay to an electron and two neutrinos. Thus, muon beam, muonic atom, muon neutrino shower, and electrons simultaneously cause fast neutralization of the AKT hydrogen bond network by the conversion of hydrogen into deuterium or helium, inactivating the hydrogen bond networks and inducing failure of cancer complexity and robustness with the disappearance of a malignant phenotype.  相似文献   
2.
BackgroundPeripheral artery disease (PAD), which is caused by atherosclerosis, results in progressive narrowing and occlusion of the peripheral arteries and inhibits blood flow to the lower extremities. Therapeutic angiogenesis is a promising strategy for treating ischemia caused by PAD. Nitric oxide (NO) has been shown to be a key mediator of angiogenesis. It has been demonstrated that β-cyclodextrincan stimulate vessel growth in rabbit corneas. In this study, we assessed the mechanism of action and therapeutic potential of a new angiogenic molecule, (2-hydroxypropyl)-β-cyclodextrin (2HP-β-CD).ConclusionsTherapeutic angiogenesis by 2HP-β-CD may be beneficial to patients with PAD.  相似文献   
3.
4.
5.
A case of chromomycosis in which hyperthermia proved effective is reported. The patient was a 56-year-old male bean curd maker who, without any previous history of minor trauma, developed on the extensor side of the left upper arm an eczematous lesion that underwent gradual radial expansion. The lesion showed a well-defined, 7×10 cm infiltrated erythematous plaque with the central area healed and, at the upper and lower borders, adherent scales and crusts on the surface. Histological examination revealed granulomatous changes in the dermis, as well as sclerotic cells within giant cells and microabscesses. On culturing,Fonsecaea pedrosoi was isolated. The patient was treated with disposable chemical pocket warmers, which were secured over the lesion with a rather tight elastic bandage, so that they kept the affected area warm for 24 hours a day. After a month of such hyperthermic treatment, the erythema and infiltration had decreased considerably, and microscopic examination and culture of the crusts both yielded negative results. Examination of biopsy specimens of the lesion after the third month showed that it had cicatrized. The treatment was stopped after 4 months, and no relapse occurred. We also summarize the published results of local hyperthermic treatment of chromomycosis in Japan.  相似文献   
6.
Heart failure (HF) remains a common complication after acute ST-segment elevation myocardial infarction (STEMI). Here, we aim to identify critical genes related to the developed HF in patients with STEMI using bioinformatics analysis. The microarray data of GSE59867, including peripheral blood samples from nine patients with post-infarct HF and eight patients without post-infarct HF, were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between HF and non-HF groups were screened by LIMMA package. Functional enrichment analyses of DEGs were conducted, followed by construction of a protein-protein interaction (PPI) network. The dynamic messenger RNA (mRNA) level of the hub genes during the follow-up was analyzed to further elucidate their role in HF development. A total of 58 upregulated and 75 downregulated DEGs were screen out. They were mainly enriched in biological processes about inflammatory response, extracellular matrix organization, response to cAMP, immune response, and positive regulation of cytosolic calcium ion concentration. Pathway analysis revealed that the DEGs were also involved in hematopoietic cell lineage, pathways in cancer, and extracellular matrix-receptor interaction. In the PPI network consisting of 58 nodes and 72 interactions, CXCL8 (degree = 15), THBS1 (degree = 8), FOS (degree = 7), and ITGA2B (degree = 6) were identified as the hub genes. In the comparison of patients with and without post-infarct HF, the mRNA level of these hub genes were all higher within 30 days but reached similar at 6 months after STEMI. In conclusion, CXCL8, THBS1, FOS, and ITGA2B may play important roles in the development of HF after acute STEMI.  相似文献   
7.
CA9 is a member of the carbonic anhydrases’ family, that is often expressed in cancer cells under hypoxic condition. However, the role of CA9 in the molecular mechanisms of tongue squamous cell carcinoma (TSCC) pathogenesis remains unclear. CA9 expression was analysed using the TCGA database, and its influence on survival was performed using Kaplan-Meier, LASSO and COX regression analyses. The correlation between CA9 and immune infiltration was investigated by CIBERSORT and ESTIMATE. Moreover, the relationship between CA9 expression and downstream molecular regulation pathways was analysed by GSEA, GO and WGCNA. CA9 expression correlated with clinical prognosis and tumour grade in TSCC. Moreover, CA9 expression potentially contributes to the regulation of cancer cell differentiation and mediates tumour-associated genes and signalling pathways, including apoptosis, hypoxia, G2M checkpoint, PI3K/AKR/mTOR signalling and TGF-beta signalling pathways. However, the follicular helper T cells, regulatory T cells, immune and stromal scores showed no significance between high and low CA9 expression groups. These findings suggested that CA9 plays a critical role of TSCC prognosis and tumour grade. CA9 expression significantly correlated with the regulation of cell differentiation, various oncogenes and cancer-associated pathways.  相似文献   
8.
9.
10.
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