Flow-pattern identification around two rectangular cylinders with aspect ratio of 0.5 in tandem arrangement

Yang, Letian,Gu, Zhifu,Zhao, Xuejun,Zhang, Weimin Techno-Press 2013 Wind and Structures, An International Journal (WAS Vol.16 No.2

The flow around two rectangular cylinders with aspect ratio of 0.5 in a tandem arrangement, was investigated using pressure measurements (in a wind tunnel) and flow visualizations (in a water tunnel) in the range of P/h from 0.6 to 4.0. Four flow patterns were identified, and processes of shear layers wrapping around, the shear layer reattachment, vortices wrapping around and vortices impingement, were observed. Mean and rms pressure distributions, flow visualizations and Strouhal numbers were presented and discussed. The paper revealed that the variations of Strouhal numbers were associated with the shear layers or vortex interference around two cylinders.

Genes Associated with Recurrence of Hepatocellular Carcinoma: Integrated Analysis by Gene Expression and Methylation Profiling

Yang, Ju Dong,Seol, So-Young,Leem, Sun-Hee,Kim, Yong Hoon,Sun, Zhifu,Lee, Ju-Seog,Thorgeirsson, Snorri S.,Chu, In-Sun,Roberts, Lewis R.,Kang, Koo Jeong The Korean Academy of Medical Sciences 2011 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.26 No.11

<P>Gene expression is suppressed by DNA methylation. The goal of this study was to identify genes whose CpG site methylation and mRNA expression are associated with recurrence after surgical resection for hepatocellular carcinoma (HCC). Sixty-two HCCs were examined by both whole genome DNA methylation and transcriptome analysis. The Cox model was used to select genes associated with recurrence. A validation was performed in an independent cohort of 66 HCC patients. Among fifty-nine common genes, increased CpG site methylation and decreased mRNA expression were associated with recurrence for 12 genes (Group A), whereas decreased CpG site methylation and increased mRNA expression were associated with recurrence for 25 genes (Group B). The remaining 22 genes were defined as Group C. Complement factor H (<I>CFH</I>) and myosin VIIA and Rab interacting protein (<I>MYRIP</I>) in Group A; proline/serine-rich coiled-coil 1 (<I>PSRC1</I>), meiotic recombination 11 homolog A (<I>MRE11A</I>), and myosin IE (<I>MYO1E</I>) in Group B; and autophagy-related protein LC3 A (<I>MAP1LC3A</I>), and NADH dehydrogenase 1 alpha subcomplex assembly factor 1 (<I>NDUFAF1</I>) in Group C were validated. In conclusion, potential tumor suppressor (<I>CFH</I>, <I>MYRIP</I>) and oncogenes (<I>PSRC1</I>, <I>MRE11A</I>, <I>MYO1E</I>) in HCC are reported. The regulation of individual genes by methylation in hepatocarcinogenesis needs to be validated.</P>

Validation of the Thyrotoxicosis-associated Insomnia Model Induced by Thyroxine through Sympathetic Stimulation: Face, Construct and Predictive Perspectives

Zhifu Ai,Hongwei He,Tingting Wang,Liling Chen,Chunhua Huang,Changlian Chen,Pengfei Xu,Genhua Zhu,Ming Yang,Yonggui Song,Dan Su 한국뇌신경과학회 2021 Experimental Neurobiology Vol.30 No.6

Insomnia has become a common central nervous system disease. At present, the pathogenesis of insomnia is not clear. Animal models can help us understand the pathogenesis of the disease and can be used in transformational medicine. Therefore, it is very necessary to establish an appropriate model of insomnia. Clinical data show that insomnia patients with high levels of thyroxine and often accompanied by cardiovascular problems, a common mechanism underlying all of these physiological disruptions is the sympathetic nervous system. Combined with the characteristics of chronic onset of clinical insomnia, an insomnia model induced by long-term intraperitoneal injection of thyroid hormone has been created in our laboratory. In this paper, the insomnia-like state of the model was evaluated based on three validity criteria. Face validity has been demonstrated in metabolism, the Morris water maze, electrocardiogram (ECG) and electroencephalogram (EEG). Structure validity has been proved by the results of targeted metabolomics. After treatment with diazepam, a commonly used clinical anti-insomnia drug, the above physiological and pathological disorders were reversed. The results of comprehensive analysis show that the established thyrotoxicosis-associated insomnia model meets the validity requirement to establish an appropriate animal model of insomnia. The model presented in this article might help to study pathogenetic mechanisms of clinical insomnia, as well as to test promising methods of insomnia treatment.

Flow-pattern identification around two rectangular cylinders with aspect ratio of 0.5 in tandem arrangement

Letian Yang,Zhifu Gu,Xuejun Zhao,Weimin Zhang 한국풍공학회 2013 Wind and Structures, An International Journal (WAS Vol.16 No.2

The flow around two rectangular cylinders with aspect ratio of 0.5 in a tandem arrangement, was investigated using pressure measurements (in a wind tunnel) and flow visualizations (in a water tunnel) in the range of P/h from 0.6 to 4.0. Four flow patterns were identified, and processes of shear layers wrapping around, the shear layer reattachment, vortices wrapping around and vortices impingement, were observed. Mean and rms pressure distributions, flow visualizations and Strouhal numbers were presented and discussed. The paper revealed that the variations of Strouhal numbers were associated with the shear layers or vortex interference around two cylinders.

Triptolide inhibits ovarian cancer cell invasion by repression of matrix metalloproteinase 7 and 19 and upregulation of E-cadherin

Hongxi Zhao,Zhifu Yang,Xiaohong Wang,Xianzhi Zhang,Meng Wang,Yukun Wang,Qibing Mei,Zhipeng Wang 생화학분자생물학회 2012 Experimental and molecular medicine Vol.44 No.11

Triptolide, a compound extracted from the traditional Chinese medicine preparation of Tripterygium wilfordii Hook F., has been reported to have anti-inflammatory and anti-cancer activities. However, its effect on ovarian cancer invasion is unknown. We observed that MMP7 and MMP19 expression increased in ovarian cancer tissue. Triptolide treatment inhibited the migration and invasion of ovarian cancer cells SKOV3 and A2780 at the concentration of 15 nM. We also observed that triptolide suppressed MMP7 and MMP19 promoter activity in a dose-dependent manner,down-regulating the expressions of these promoters on mRNA and protein level. Moreover, triptolide enhanced E-cadherin expression in ovarian cancer cells. In vivo, triptolide inhibited tumor formation and metastasis in nude mice, and suppressed MMP7 and MMP19 expression; it also enhanced E-cadherin expression in tumor in a dose-dependent manner. Over expression of MMP7 and MMP19, or suppression of E-cadherin expression partially abolished the inhibitory effect of triptolide on invasion of ovarian cancer cells. To summarize, triptolide significantly inhibited the migration and invasion of ovarian cancer cells by suppression of MMP7 and MMP19 and up-regulation of E-cadherin expression. This study shows that triptolide is a good candidate for the treatment of ovarian cancer and reduction of metastasis.

Inactivation of LLC1 gene in nonsmall cell lung cancer

Hong, Kyeong-Man,Yang, Sei-Hoon,Chowdhuri, Sinchita Roy,Player, Audrey,Hames, Megan,Fukuoka, Junya,Meerzaman, Daoud,Dracheva, Tatiana,Sun, Zhifu,Yang, Ping,Jen, Jin Alan R. Liss, Inc 2007 International journal of cancer Vol.120 No.11

<P>Serial analysis of gene expression studies led us to identify a previously unknown gene, c20orf85, that is present in the normal lung epithelium but absent or downregulated in most primary nonsmall cell lung cancers and lung cancer cell lines. We named this gene LLC1 for Low in Lung Cancer 1. LLC1 is located on chromosome 20q13.3 and has a 70% GC content in the promoter region. It has 4 exons and encodes a protein containing 137 amino acids. By in situ hybridization, we observed that LLC1 message is localized in normal lung bronchial epithelial cells but absent in 13 of 14 lung adenocarcinoma and 9 out of 10 lung squamous carcinoma samples. Methylation at CpG sites of the LLC1 promoter was frequently observed in lung cancer cell lines and in a fraction of primary lung cancer tissues. Treatment with 5-aza deoxycytidine resulted in a reduced methylation of the LLC1 promoter concomitant with the increase of LLC1 expression. These results suggest that inactivation of LLC1 by means of promoter methylation is a frequent event in nonsmall cell lung cancer and may play a role in lung tumorigenesis. © 2007 Wiley-Liss, Inc.</P>

Low Cost and Simple PMMA Nozzle Fabrication by Laser Cutting and PDMS Curing Bonding

E. Cheng,Xue Yang,Zhifu Yin,Wei Hu,Lu Li 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.1

Electrohydrodynamic (EHD) printing can rapidly fabricate micro- or nano-scale lines without employment of any mask, which is suitable for small volume production in industrial applications. However, it is required that the nozzles should be disposable since they can easily be blocked by the un-cleaned ink. CO 2 laser is an excellent tool for fabrication of microtrenches in most of polymers with low-cost and high-speed. This paper presented a low-cost PMMA (Polymethyl methacrylate) nozzle fabrication method based on laser cutting and PDMS (Polydimethylsiloxane) curing bonding. The influence of thickness on the maximum stress and deformation rate of PMMA substrate was investigated to decrease the deformation of PMMA nozzle after laser cutting. To avoid stress concentration in PMMA nozzle after thermal bonding, PDMS curing bonding method was proposed. The effect of spin-coating speed on PDMS thickness was studied. The O 2 plasma conditions were optimized based on contact angle to improve the bonding strength of PMMA nozzle. The EHD printing experiments demonstrated the practicability of proposed nozzle fabrication method.