Radon-induced demethylation of Cdk2 CpG island in the rat lung

Cheng Wu,Qiu Chen,Jian Tong,Xin Xie,Fengmei Cui,Yang Jiao,Dandan Qi,Jihua Nie,Tom K. Hei,Qisheng Jiang 한국유전학회 2014 Genes & Genomics Vol.36 No.6

Radon exposure has been linked to lung carcinogenesisin both human and animal studies. The identificationof sequential changes in DNA methylation duringtumour progression and the elucidation of their interplaywith genetic changes will broaden our molecular understandingof this disease. Rats were exposed to 120 or 400working level months (WLM) of radon, lung pathologicalchanges were examined by haematoxylin and eosin staining,lung single cell suspension cell cycles were detected byflow cytometry, lung cell cycle regulated gene (Cdkn2a,P53, Cdk4/2, Mdm4/2 and Rb1 genes) expression wasquantified by real-time PCR and methylation of CpG islandsin the promoters of cell cycle-regulated genes were detectedby bisulfite sequencing PCR. The alveolar walls of rat lungsafter exposured to radon exhibited papillae and the lungbronchial epithelial cells stained positively for proliferatingcell nuclear antigen. The bronchial epithelial cells displayedsome hyperplasia after challenged by 400 WLM of radon. Moreover, G1 arrest decreased; Rb1, Mdm2/4, and Cdk2/4expression decreased and Cdk2 was demethylated at thesecond and sixth CpG loci from base pairs 3092704 to3092953 of chromosome 7. Cdk2 demethylation may beapplicable as a biomarker of early lung damage that wasinduced by radon and other environmental carcinogens.

Potential Serum Markers for Monitoring the Progression of Hepatitis B Virus-Associated Chronic Hepatic Lesions to Liver Cirrhosis

( Cheng Wu ),( Lijie Liu ),( Peng Zhao ),( Dan Tang ),( Dingkang Yao ),( Liang Zhu ),( Zhiqiang Wang ) 대한소화기학회 2015 Gut and Liver Vol.9 No.5

Background/Aims: To screen for serum protein/peptide biomarkers of hepatitis B virus (HBV)-associated chronic hepatic lesions in an attempt to profile the progression of HBV-associated chronic hepatic lesions using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) techniques. Methods: Using SELDI-TOF MS, serum protein/peptide profiles on the CM10 ProteinChip arrays were obtained from a training group including 26 HBV-associated hepatocellular carcinoma patients with liver cirrhosis (LC), 30 HBV-associated LC patients, 85 patients at different stages of liver fibrosis, and 30 asymptomatic HBV carriers. The most valuable SELDI peak for predicting the progression to LC in HBV-infected patients was identified. Results: A SELDI peak of M/Z 5805 with value for predicting LC in HBV-infected patients was found and was identified as a peptide of the C-terminal fraction of the fibrinogen a-chain precursor, isoform 1. Conclusions: The peptide of the C-terminal fraction of the fibrinogen α-chain precursor, isoform 1 with M/Z 5805, may be a serological biomarker for progression to LC in HBV-infected patients. (Gut Liver 2015;9:665-671)

A Competition-based Algorithm for Routing Discovery and Repair in Large-scale VANET

( Cheng Wu ),( Lujie Wang ),( Yiming Wang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.12

Vehicular Ad Hoc Networks (VANET) in the large-scale road section usually have typical characteristics of large number of vehicles and unevenly distribution over geographic spaces. These two inherent characteristics lead to the unsatisfactory performance of VANETs. This poor performance is mainly due to fragile communication link and low dissemination efficiency. We propose a novel routing mechanism to address the issue in the paper, which includes a competition-based routing discovery with priority metrics and a local routing repair strategy. In the routing discovery stage, the algorithm uses adaptive scheme to select a stable route by the priorities of routing metrics, which are the length of each hop, as well as the residual lifetime of each link. Comparisons of different ratios over link length and link stability further show outstanding improvements. In the routing repair process, upstream and downstream nodes also compete for the right to establish repair process and to remain as a member of the active route after repair. Our simulation results confirm the improved performance of the proposed algorithm.

Noise Analysis and Structure Optimization for Sleeve Type Regulating Valve Based on CFD

Cheng Wu,Gang Yang,Fabing Tan,Baoren Li 유공압건설기계학회 2015 유공압건설기계학회 학술대회논문집 Vol.2015 No.10

According to the noise problems of sleeve type regulating valve, this paper utilizes the method of Computational Fluid Dynamics(CFD) based on the RNG k-ε turbulence model to analyze flow field characteristics of sleeve type regulating valve, then the window shape and valve core angle is optimized. The analysis shows that the shape of sleeve window has a significant effect on the noise of regulating valve. In the same boundary conditions, the noise of the new valve is 13dB lower than the original valve, and the noise performance of the sleeve type regulating valve gets significant improvement. And its flow characteristic curve is obtained by simulation, which shows that the optimized sleeve flow regulating valve has good linear flow characteristic. The research in this paper can be used for reference for the design of sleeve type regulating valve with low noise and high performance.

Helical gear multi-contact tooth mesh load analysis with flexible bearings and shafts

Chengwu Li,Yulin He,Xianxiong Ning 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.55 No.4

A multi-contact tooth meshing model for helical gear pairs considering bearing and shaft deformations is proposed. First, to easily incorporate into the system model, the complicated Harris’ bearing force-displacement relationship is simplified applying a linear least square curve fit. Then, effects of shaft and bearing flexibilities on the helical gear meshing behavior are implemented through transformation matrices which contain the helical gear orientation and spatial displacement under loads. Finally, true contact lines between conjugated teeth are approximated applying a modified meshing equation that includes the influence of tooth flank displacement on the tooth contact induced by shaft and bearing displacements. Based on the model, the bearing’s force-displacement relation is examined, and the effects of shaft deformation and external load on the multi-contact tooth mesh load distribution are also analyzed. The advantage of this work is, unlike previous works to search true contact lines through time-consuming iterative strategy, to determine true contact lines between conjugated teeth directly with presentation of deformations of bearings and shafts.

Prevalence of Dirofilaria immitis in Dogs in Shenyang, Northeastern China

Chengwu Liu,Na Yang,Jianbin He,Min Yang,Ming Sun 대한기생충학열대의학회 2013 The Korean Journal of Parasitology Vol.51 No.3

PbICl precursor solutions for all solid-state PbS quantum-dot sensitized TiO2 nanorod array solar cells using successive ionic layer adsorption and reaction method

Kai Lv,Chengwu Shi,Zhengguo Zhang,Chengfeng Ma,Qi Wang 한국물리학회 2018 Current Applied Physics Vol.18 No.6

In this work, PbICl precursor solution in N,N-dimethylformamide was successfully applied to deposit PbS quantum-dots on TiO2 nanorod arrays by successive ionic layer adsorption and reaction method (SILAR). The influence of PbI2, PbBr2, PbICl precursor solution on the morphology, crystal size and optical absorption of PbS quantum-dots was investigated and the photovoltaic performance of the corresponding solid-state PbS quantumdot sensitized TiO2 nanorod array solar cells with spiro-OMeTAD was evaluated. The average crystal sizes of PbS quantum-dots were 9.0 nm of PbI2, 8.6 nm of PbBr2 and 8.4 nm of PbICl and the photoelectric conversion efficiency of the corresponding solar cells achieved 2.63%, 3.00%, 3.45%. The result revealed that PbICl precursor solution was superior to PbBr2 and PbI2.

Evaluating the influence of a high-fidelity generator model on the gearbox dynamic responses of wind turbines

Yunpeng Zhou,Chengwu Lee 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.12

This study evaluates the influence of a high-fidelity generator model on the dynamic responses of the gears and bearings of a 1 MW wind turbine. Fully coupled aeroelasticservo-control numerical models with simplified and high-fidelity generators of the wind turbine are established. The numerical models are then verified through comparisons with another software in terms of natural characteristics and dynamic responses in the time domain. Dynamic analyses of the numerical models of the wind turbine are conducted under several environmental conditions. The external dynamic load excitation and internal load effects of the gearbox of the wind turbine numerical models with the simplified and high-fidelity generators are compared. The long-term fatigue damage of the gears and bearings of the two numerical models is also calculated and compared. Results show that the high-fidelity generator model increases the gearbox’s external and internal load fluctuations due to power grid and generator control effects. The high-fidelity generator model results in higher fatigue damage of the gears and bearings in the gearbox in comparison with the fatigue damage in the simplified generator model. This study provides a crucial basis for the design and dynamic analysis of wind turbine gearboxes.

Selective Detection of Trace Metronidazole by Using a Magnetic Molecularly Imprinted Polymer-based Fluorescent Probe

Nai-Di Tan,Chengwu Lan,Jian-Hang Yin,Lei Meng,Na Xu 대한화학회 2020 Bulletin of the Korean Chemical Society Vol.41 No.1

A magnetic molecularly imprinted polymer-based fluorescent (MIP-FL) probe has been synthesized by embedding glutathione-stabilized gold nanoclusters (GSH-AuNCs) and Fe3O4 nanoparticles (Fe3O4NPs) into silica composites. The Fe3O4NPs/AuNCs@MIPs are characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and UV?Vis absorption spectroscopy. The results show that the spherical Fe3O4NPs/AuNCs@MIPs contain a core-shell structure with GSH-AuNCs anchored on the surface of silica-protected Fe3O4NPs. As a fluorescence probe (excitation: 360?nm, emission: 615?nm), Fe3O4NPs/AuNCs@MIPs can selectively detect metronidazole (MNZ) among other nitroimidazoles (ronidazole, ornidazole, and tinidazole). During the detection, the fluorescence intensity of the MIP-FL probe drops gradually with increasing MNZ concentration. The sensitive linear range of the fluorescence probe is from 0 to 5 ?M, and the limit of detection is 4.2 nM. After the recognition sites interact with the template, the occurrence of charge transfer from the GSH-AuNCs to MNZ results in fluorescence quenching. Finally, a real sample test has been performed in spiked milk. Satisfactory recoveries spanning from 96% to 102% indicate that Fe3O4NPs/AuNCs@MIPs enable highly sensitive detection of MNZ based on fluorescence signal output, while the MIPs also have enrichment potential for the target from complex samples due to the magnetic properties.

Change in Photosynthesis, Proline Content, and Osmotic Potential of Corn Seedling under High-Saline Condition

Byeong Sung Yoon,Chengwu Jin,Park Sang Un,Dong Ha Cho 韓國作物學會 2005 Korean journal of crop science Vol.50 No.1

To identify salt-tolerance characteristics of corn seedling was treated in solution of 0, 50 and 100 mM NaCl of hydroponic cultivation. In photosynthesis of corn seedling, there was no large difference between 50mM and 0 mM NaCl solution, however, in 100 mM NaCl solution, the tolerance gradually decreased to 76~%,~;49~%,~;and~;31~% after one day, four days, and seven days, respectively, in comparison to 0 mM NaCl solution. Osmotic potential of corn in seedling period was significantly decreased with increasing saline level, however, free proline content in the plant on the ground was significantly increased with increasing saline level and with the lapse of time. In terms of correlation among major characteristics, there was a highly significant positive difference between osmotic pressure potential and photosynthesis, However, highly negative correlation was found between osmotic pressure potential and free proline content. In addition, it was expected that young seedling of corn with saline tolerance may be utilized in the transplantation in salt-accumulated land. Based on above-shown result, in terms of saline tolerance of Chalok-2 variety, growth suppression was serious with 100mM NaCl solution. However, growth was expected that seedling growth would be favorable under 50 mM NaCl solution.