Comparative genomic analysis of Mycoplasma anatis strains

Zhou Qi,Mai Kaijie,Yang Dehong,Liu Junfa,Yan Zhuanqiang,Luo Cuifen,Tan Yangtong,Cao Sheng,Zhou Qingfeng,Chen Li,Chen Feng 한국유전학회 2021 Genes & Genomics Vol.43 No.11

Background The Gram-negative intracellular bacterium Mycoplasma anatis is a pathogen of respiratory infectious diseases in ducks and has caused signifcant economic losses in the poultry industry. Objective This study, as the frst report of the structure and function of the pan-genome of Mycoplasma anatis, may provide a valuable genetic basis for many aspects of future research on the pathogens of waterfowl. Methods We sequenced the whole genomes of 15 Mycoplasma anatis isolated from ducks in China. Draft genome sequencing was carried out and whole-genome sequencing was performed by the sequencers of the PacBio Sequel and an IonTorrent Personal Genome Machine (PGM). Then the common genic elements of protein-coding genes, tRNAs, and rRNAs of Mycoplasma anatis genomes were predicted by using the pipeline Prokka v1.13.7. To investigate homologous protein clusters across Mycoplasma anatis genomes, we adopted Roary v3.13.0 to cluster orthologous genes (OGs) based on the following criteria. Results We obtained one complete genome and 14 genome sketches. Microbial mobile genetic element analysis revealed the distribution of insertion sequences (IS30, IS3, and IS1634), prophage regions, and CRISPR arrays in the genome of Mycoplasma anatis. Comparative genomic analysis decoded the genetic components and functional classifcation of the pan-genome of Mycoplasma anatis that comprised 646 core genes, 231 dispensable genes and among them 110 was strainspecifc. Virulence-related gene profles of Mycoplasma anatis were systematically identifed, and the products of these genes included bacterial ABC transporter systems, iron transport proteins, toxins, and secretion systems. Conclusion A complete virulence-related gene profle of Mycoplasma anatis has been identifed, most of the genes are highly conserved in all strains. Sequencing results are relevant to the molecular mechanisms of drug resistance, adaptive evolution of pathogens, population structure, and vaccine development.

DNMT1 mediates chemosensitivity by reducing methylation of miRNA-20a promoter in glioma cells

Daoyang Zhou,Yingfeng Wan,Dajiang Xie,Yirong Wang,Junhua Wei,Qingfeng Yan,Peng Lu,Lianjie Mo,Jixi Xie,Shuxu Yang,Xuchen Qi 생화학분자생물학회 2015 Experimental and molecular medicine Vol.47 No.-

Although methyltransferase has been recognized as a major element that governs the epigenetic regulation of the genome during temozolomide (TMZ) chemotherapy in glioblastoma multiforme (GBM) patients, its regulatory effect on glioblastoma chemoresistance has not been well defined. This study investigated whether DNA methyltransferase (DNMT) expression was associated with TMZ sensitivity in glioma cells and elucidated the underlying mechanism. DNMT expression was analyzed by western blotting. miR-20a promoter methylation was evaluated by methylation-specific PCR. Cell viability and apoptosis were assessed using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and TdT-mediated dUTP-biotin nick end labeling assays, respectively. The results showed that compared with parental U251 cells, DNMT1 expression was downregulated, miR-20a promoter methylation was attenuated and miR-20a levels were elevated in TMZ-resistant U251 cells. Methyltransferase inhibition by 5-aza-2′-deoxycytidine treatment reduced TMZ sensitivity in U251 cells. In U251/TM cells, DNMT1 expression was negatively correlated with miR-20a expression and positively correlated with TMZ sensitivity and leucine-rich repeats and immunoglobulin-like domains 1 expression; these effects were reversed by changes in miR-20a expression. DNMT1 overexpression induced an increase in U251/TM cell apoptosis that was inhibited by the miR-20a mimic, whereas DNMT1 silencing attenuated U251/TM cell apoptosis in a manner that was abrogated by miR-20a inhibitor treatment. Tumor growth of the U251/TM xenograft was inhibited by pcDNA-DNMT1 pretreatment and boosted by DNMT1-small hairpin RNA pretreatment. In summary, DNMT1 mediated chemosensitivity by reducing methylation of the microRNA-20a promoter in glioma cells.

One-Step Construction of Ni/Co-Doped C–N Nanotube Composites as Excellent Cathode Catalysts for Neutral Zinc–Air Battery

Liang Yu,Qingfeng Yi,Xiaokun Yang,Xiulin Zhou 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

Development of a neutral Zn–air battery is of much significance due to the high stability of zinc in a neutral electrolyte. Here, Ni/Co-doped C–N nanotube composites (C–N, Ni/C–N, Co/C–N, and Ni–Co/C–N) as efficient oxygen reduction reaction (ORR) electrocatalysts in a neutral medium have been prepared by direct pyrolysis of Ni/Co salt, dicyandiamide (DCD) and glucose. Among the synthesized catalysts, Ni–Co/C–N presents a high ORR current density of 8.5mA · cm -2 in a 0.5 mol · L -1 KNO3 solution. The ORR electron transfer number of the catalyst Ni–Co/C–N is 3.8, indicating that O2 is almost completely reduced to H2O. A neutral zinc–air battery utilizing a 0.5 mol · L -1 KNO3 solution has been assembled by using the prepared composite catalyst coated on carbon paper as an air cathode, and Zn plate as an anode. The battery with the cathode catalyst Ni–Co/C–N delivers the open-circuit voltage of 1.13 V and the maximum power density of 65mW · cm -2. The constant discharge current density of 50mA · cm -2, 100 mA · cm -2 and 150mA · cm -2 can last 202 h, 93 h and 11 h, respectively. A stable voltage plateau appears at various discharge current densities. The neutral zinc–air battery can be repeatedly discharged after replacing the zinc anode. Results indicate that the synthesized Ni–Co/C–N catalyst is an excellent cathode material applied to a neutral zinc–air battery, showing broad application prospects as a mobile power source.

Concurrent Recrystallization and Precipitation for Combination of Superior Precipitation and Grain Boundary Hardening in Co37Cr20Ni37Ti3Al3 High-Entropy Alloy

Linfei Xia,Qingfeng Wu,Kexuan Zhou,Bin Han,Feng He,Zhijun Wang 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.12

According to the precipitation and recrystallization behavior, the precipitation and recrystallization can be concurrently tunedtoward the excellent mechanical property. In this study, a synergistically strengthened Co37Cr20Ni37Ti3Al3 high-entropyalloy was developed through concurrent recrystallization and precipitation (CRP) approach. After the treatment, the highdensityγ' precipitates were introduced in the matrix, while the fully-recrystallized ultrafine grains and annealing twins wereobtained from the recrystallization. Compared with conventional treatment, the CRP-HEA exhibits a superior combinationof ~ 1.62GPa tensile strength and ~ 28% elongation, which is attributed to the synergistic strengthening of precipitation andgrain boundary. In addition, the deformation mechanisms were characterized by TEM. The cutting-through mechanismdominates the deformation behaviors. Moreover, interesting stacking faults in different slip planes prevail during plasticdeformation. The concurrent recrystallization and precipitation for ultra-fine grain structure with nano-precipitates wouldprovide an effective strategy to achieve outstanding combination of strength and ductility.

Carbon Paper-Supported NiCo/C–N Catalysts Synthesized by Directly Pyrolyzing NiCo-Doped Polyaniline for Oxygen Reduction Reaction

Zhongliang Deng,Qingfeng Yi,Yuanyuan Zhang,Huidong Nie,Guang Li,Liang Yu,Xiulin Zhou 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.1

In this study, we report the findings that the C–N composites containing Ni and Co (Ni1Co1/C–N, Ni3Co1/C–N, Ni6Co1/C–N, Ni9Co1/C–N, Ni10Co0/C–N and Ni0Co10/C–N) can be produced by direct pyrolysis of the NiCo-doped polyaniline (PANI) precursors in N2 atmosphere at 800 ℃ and show efficient electroactivity for oxygen reduction reaction (ORR) in alkaline media. Distribution and compositions of the catalysts were characterized by SEM, TEM, EDS and XRD techniques. The catalysts were loaded on carbon paper to prepare gas diffusion electrodes, in which electrocatalytic activity for ORR in alkaline media was investigated by voltammetric techniques. The ORR current density on these carbon paper-supported NiCo/C–N catalysts exhibits a linear increase with the negative shift of ORR potential. The ORR onset potential is around 0.2 V (versus Ag/AgCl) in alkaline media. Among the prepared catalysts, the catalyst Ni6Co1/C–N presents the largest ORR current density, which is 68.5 mA cm -2@-0.8 V (versus Ag/AgCl) in alkaline media. Moreover, Ni6Co1/C–N catalyst also presents good electrocatalytic activity stability for ORR.

Preparation and characterization of Ag2O/SWNTs photocatalysts and its photodegradation on tetracycline

Huiqin Wang,Pengwei Huo,Jinze Li,Mingjun Zhou,Qingfeng Guan,Ziyang Lu,Yongsheng Yan 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.30 No.-

The Ag2O/SWNTs photocatalysts were prepared by precipitated method, the photocatalysts werecharacterized by XRD, SEM, TEM, EDS, BET, UV–vis DRS, XPS, PL and Raman. The photocatalytic activitieswere evaluated by degradation of tetracycline. The results showed that the composited photocatalystswere successfully prepared, the responded light was enhanced with increasing the supported dosage ofAg2O, and the photocatalytic activity was also improved. The enhanced photocatalytic activity wasattributed to the synergy effect of SWNTs and Ag2O, the recycled degradation of tetracycline exhibitedstability of Ag2O/SWNTs composited photocatalysts. Finally, the possible mechanism for transferredprocesses of photoelectrons and photoholes were proposed.

High photocatalytic degradation of tetracycline under visible light with Ag/AgCl/activated carbon composite plasmonic photocatalyst

Huiqin Wang,Xiaoqing Yang,Jinzhao Zi,Mingjun Zhou,Zhefei Ye,Jinze Li,Qingfeng Guan,Peng Lv,Pengwei Huo,Yongsheng Yan 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.35 No.-

Ag/AgCl/activated carbon (AC) plasmonic photocatalysts were prepared by precipitation and photoreduc-tion method. The as-prepared plasmonic photocatalysts were characterized by XRD, SEM, BET, EDS, UV–visDRS, XPS and PL. The results show the composite photocatalysts are successfully obtained and obviouslyexhibit surface plasmon resonance and effectively enhance the separation of h+/e . The photocatalyticdegradation rate of tetracycline (TC) could reach 97.3% in 60 min under visible light irradiation and cycledexperiments show stably photocatalytic activities. The active species analysis displays holes andsuperoxide radicals are the main reactive species. Photocatalytic kinetic indicates that the degradationprocesses obey pseudo first order kinetic equation.

Research on Action Strategies and Simulations of DRL and MCTS-based Intelligent Round Game

Yuxiang Sun,Bo Yuan,Yongliang Zhang,Wanwen Zheng,Qingfeng Xia,Bojian Tang,Xianzhong Zhou 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.9

The reinforcement learning problem of complex action control in multiplayer online battlefield games has brought considerable interest in the deep learning field. This problem involves more complex states and action spaces than traditional confrontation games, making it difficult to search for any strategy with human-level performance. This paper presents a deep reinforcement learning model to solve this problem from the perspective of game simulations and algorithm implementation. A reverse reinforcement-learning model based on high-level player training data is established to support downstream algorithms. With less training data, the proposed model is converged quicker, and more consistent with the action strategies of high-level players’ decision-making. Then an intelligent deduction algorithm based on DDQN is developed to achieve a better generalization ability under the guidance of a given reward function. At the game simulation level, this paper constructs Monte Carlo Tree SearchIntelligent Decision Model for turn-based antagonistic deduction games to generate next-step actions. Furthermore, a prototype game simulator that combines offline with online functions is implemented to verify the performance of proposed model and algorithm. The experiments show that our proposed approach not only has a better reference value to the antagonistic environment using incomplete information, but also accurate and effective in predicting the return value. Moreover, our work provides a theoretical validation platform and testbed for related research on game AI for deductive games.