GAS5 regulates viability and apoptosis in TGF-β1-stimulated bronchial epithelial cells by regulating miR-217/HDAC4 axis

Zhao Sihui,Ning Yunfang,Qin Na,Ping Nan,Yu Yong,Yin Guoyan 한국유전학회 2021 Genes & Genomics Vol.43 No.8

Background Asthma is a serious respiratory disease that afects the physical and mental health of children. Airway epithelial apoptosis concomitantly mediated by transforming growth factor-β1 (TGF-β1) is a crucial component of asthma pathogenesis. LncRNA growth Arrest Specifc 5 (GAS5), microRNA-217 (miR-217) and Histone deacetylase 4 (HDAC4) shown a close relationship with TGF-β1-induced injury of airway epithelial. However, the mechanism underlying TGF-β1-induced injury of airway epithelial in asthma still needs to be investigated. Objective We aimed to investigate the efect and underlying mechanism of GAS5/miR-217/HDAC4 axis in TGF-β1- stimulated bronchial epithelial cells. Methods The levels of were detected by quantitative real-time polymerase chain reaction (RT-qPCR). All protein levels were determined by western blot. Cell viability and apoptosis rate were assessed by Methyl thiazolyl tetrazolium (MTT) and Flow cytometry, respectively. The targeting relationship between miR-217 and GAS5 or HDAC4 was examined with dual-luciferase reporter assay. Results TGF-β1, GAS5, HDAC4 were up-regulated, while miR-217 was down-regulated in bronchial mucosal tissues of asthmatic children and TGF-β1-treated BEAS-2B cells. TGF-β1 could reduce cell viability and induce apoptosis, while these efects could be reversed by downregulation of GAS5 or HDAC4. Mechanically, GAS5 acted as a sponge for miR-217 to regulate the expression of HDAC4. Furthermore, overexpression of HDAC4 rescued the efects of GAS5 knockdown on viability and apoptosis of TGF-β1-induced BEAS-2B cells. GAS5 knockdown induced cell viability and hampered cell apoptosis in TGF-β1-stimulated BEAS-2B cells by regulating the miR-217/HDAC4 axis. Conclusions The lncRNA GAS5/miR-217/HDAC4 axis played an important role in regulating TGF-β1-induced bronchial epithelial cells injury, thus contributing to asthma.

Analysis of queuing mine-cars affecting shaft station radon concentrations in Quzhou uranium mine, eastern China

홍창수,Guoyan Zhao,Xiangyang Li 한국원자력학회 2018 Nuclear Engineering and Technology Vol.50 No.3

Shaft stations of underground uranium mines in China are not only utilized as waiting space forloaded mine-cars queuing to be hoisted but also as the principal channel for fresh air taken to workingplaces. Therefore, assessment of how mine-car queuing processes affect shaft station radon concentrationwas carried out. Queuing network of mine-cars has been analyzed in an underground uraniummine, located in Quzhou, Zhejiang province of Eastern China. On the basis of mathematical analysis ofthe queue network, a MATLAB-based quasi-random number generating program utilizing Monte-Carlomethods was worked out. Extensive simulations were then implemented via MATALB operating on aDELL PC. Thereafter, theoretical calculations and field measurements of shaft station radon concentrationsfor several working conditions were performed. The queuing performance measures of interest,like average queuing length and waiting time, were found to be significantly affected by theutilization rate (positively correlated). However, even with respect to the “worst case”, the shaftstation radon concentration was always lower than 200 Bq/m3. The model predictions were comparedwith the measuring results, and a satisfactory agreement was noted. Under current working conditions,queuing-induced variations of shaft station radon concentration of the study mine are notremarkable.

Experimental and Numerical Study on the Damage Evolution Behaviour of Granitic Rock during Loading and Unloading

Dai Bing,Zhao Guoyan,H. Konietzky,P. L. P. Wasantha 대한토목학회 2018 KSCE Journal of Civil Engineering Vol.22 No.9

Theoretical and experimental studies have revealed that the damage evolution plays an important role in stability of rock structures. To investigate the damage characteristics of rocks during loading and unloading, a series of conventional triaxial tests and numerical simulations were conducted on granitic rock specimens under different confining pressures. The stress-strain characteristics and fracture patterns of tested specimens were first analyzed. It was found that the failure strain in unloading is smaller than the failure strain in loading. And the difference between the two strains is growing with increasing confining pressure. The failure patterns of specimens displayed two different failure mechanisms: a single distinct failure and a “X” failure. Based on the law of energy conservation, the energy evolution was analyzed. The results indicated that absorbed strain energy converted into elastic strain energy and dissipation energy. For evaluating and predicting damage, two damage degrees were proposed considering increase of dissipation energy and decrease of tangential modulus, respectively. The results show that before the reversal point of volumetric strain, the damage degrees were almost unchanged. During the process of unloading the damage degrees increases fast. For the same strain, lower confining pressure shows more damage. It indicates that the confining pressure has negative effects on increase of the damage degree. Then, the discrete element model based on elastic and unbreakable voronoi blocks was set-up for tri-axial tests. The energy evolution and damage process were simulated. And the ratio of failed contacts was used to simulate the damage degree. It shows that stress-strain behavior as well as micro- and macro-mechanical damage evolution can be reproduced by the DEM model.

Porous WO₃ monolith-based photoanodes for high-efficient photoelectrochemical water splitting

Wang, Yina,Zhang, Fangfang,Zhao, Guoyan,Zhao, Yingao,Ren, Yangyang,Zhang, Huijun,Zhang, Linyu,Du, Jimin,Han, Yumin,Kang, Dae Joon Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.6

<P><B>Abstract</B></P> <P>We report a successful fabrication of low-cost, high-efficient, structurally-rigid, porous WO<SUB>3</SUB> photoelectrochemical (PEC) catalysts using polystyrene as the template by a sol-gel method and a high-temperature annealing treatment. The scanning electron microscopy and Brunauer-Emmett-Teller surface analysis results indicate that such WO<SUB>3</SUB> monoliths possess a porous structure and a large specific surface area, which can supply lots of photogenerated charge transfer pathways as well as more surface PEC active sites. Compared with a commercially available WO<SUB>3</SUB>, our highly porous WO<SUB>3</SUB> PEC catalysts show an excellent PEC water splitting activity. Particularly, the porous WO<SUB>3</SUB> photoanodes calcinated in the presence of oxygen atmosphere at 450 °C for 7 h show the best PEC performance exhibiting the photocurrent density of 0.97 mA/cm<SUP>2</SUP> at 1.23 V versus reversible the hydrogen electrode and the incident photon-to-current conversion efficiency up to 48.9% at 420 nm in 0.5 M Na<SUB>2</SUB>SO<SUB>4</SUB> electrolyte under AM 1.5 G irradiation. Such excellent PEC performance is due to the high porosity of the WO<SUB>3</SUB>, promoting the fast transfer and the separation rate of photogenerated carriers during the PEC water splitting process.</P>

Pyramid-like CdS nanoparticles grown on porous TiO₂ monolith: An advanced photocatalyst for H₂ production

Du, Jimin,Wang, Huiming,Yang, Mengke,Li, Kaidi,Zhao, Lixin,Zhao, Guoyan,Li, Sujuan,Gu, Xiaolei,Zhou, Yalan,Wang, Le,Gao, Yating,Wang, Weimin,Kang, Dae Joon Pergamon Press 2017 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>Efficient production of H<SUB>2</SUB> via solar-light-driven water splitting by a semiconductor-based photocatalyst without noble metals is crucial owing to increasingly severe global energy and environmental issues. However, many challenges, including the low efficiency of H<SUB>2</SUB> evolution, low solar light absorption, excited electron–hole pair recombination, and slow transport of photoexcited carriers, must be resolved to enhance the H<SUB>2</SUB> photoproduction efficiency and photocatalyst stability. Here, a two-step method is used to synthesize advanced H<SUB>2</SUB>-generating photocatalysts consisting of pyramid-like CdS nanoparticles grown on a porous TiO<SUB>2</SUB> monolith, which show promising photocatalytic activity for the hydrogen evolution reaction. Furthermore, the stability of the photocatalysts is examined through long-term tests to verify their good durability. Without noble metals as cocatalysts, the photocatalyst can reach a high H<SUB>2</SUB> production rate of 1048.7μmolh<SUP>−1</SUP> g<SUP>−1</SUP> under UV–vis irradiation when the ratio of the CdS nanoparticles to TiO<SUB>2</SUB> is 5mol%. This unusual photocatalytic activity arises from the wide-region light adsorption due to the narrow band gap of CdS, effective separation of electrons and holes due to conduction band alignment at the CdS–TiO<SUB>2</SUB> interface, and favorable reaction sites resulting from the porous structure.</P>