Isochaetomium $A_2$, a new bis(naphthodihydropyran-4-one) with antimicrobial and immunological activities from fungus Chaetomium microcephalum

Xu, Guo-Bo,Yang, Tao,Bao, Jin-Ku,Fang, Dong-Mei,Li, Guo-You 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.5

Isochaetomium $A_2$ (1), a new bis(naphthodihydropyran-4-one), along with chaetochromins A (2) and B (3), was isolated from the solid-state fermented rice culture of Chaetomium microcephalum. The structure of compound 1 was elucidated on the basis of 1D and 2D NMR spectral data, and the relative configuration was confirmed by CD spectrum. Compounds 1-3 possessed significant antimicrobial activity against Escherichia coli 1.044, Staphylococcus aureus 1.252, and Bacillus subtilis 1.079. Moreover, compounds 1-3 showed obvious inhibitory effects on mouse spleen cell proliferation with successive $IC_{50}$ values of 0.52, 0.19, and $0.24{\mu}M$.

Tribological performance of surface treated piston assembly with infiltrated layer

Bo Xu,Bifeng Yin,Dashu Gao,Xijun Hua 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.1

By applying surface treatment on piston assembly and typical samples, an infiltrated layer with the depth of about 30 μm was formed on the treated sample surface. The surface hardness and linear expansion coefficient of treated piston sample decreased, while the hardness of treated ring sample increased. The results of ball-on-disc rotating friction test indicated that the infiltrated layer is helpful for improving the tribological properties of aluminum alloy, reducing friction coefficient under both dry friction and oil lubricated conditions, and improving the anti-friction and wear resistance performance of cast iron. In addition, the reciprocating friction testing results showed that surface treatment technology has stable antifriction effect on piston/liner pair under various working conditions, with the average friction coefficient being reduced by about 10.2-22.1 %; while the anti-friction effect on ring/liner pair is mainly reflected under low-speed heavy-load condition, with the average friction coefficient being reduced by approximately 7.2-9.9 %.

OFPT: OpenFlow based Parallel Transport in Datacenters

( Bo Liu ),( Bo Xu ),( Chao Hu ),( Hui Hu ),( Ming Chen ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.10

Although the dense interconnection datacenter networks (DCNs) (e.g. FatTree) provide multiple paths and high bisection bandwidth for each server pair, the single-path TCP (SPT) and ECMP which are widely used currently neither achieve high bandwidth utilization nor have good load balancing. Due to only one available transmission path, SPT cannot make full use of all available bandwidth, while ECMP`s random hashing results in many collisions. In this paper, we present OFPT, an OpenFlow based Parallel Transport framework, which integrates precise routing and scheduling for better load balancing and higher network throughput. By adopting OpenFlow based centralized control mechanism, OFPT computes the optimal path and bandwidth provision for each flow according to the global network view. To guarantee high throughput, OFPT dynamically schedules flows with Seamless Flow Migration Mechanism (SFMM), which can avoid packet loss in flow rerouting. Finally, we test OFPT on Mininet and implement it in a real testbed. The experimental results show that the average network throughput in OFPT is up to 97.5% of bisection bandwidth, which is higher than ECMP by 36%. Besides, OFPT decreases the average flow completion time (AFCT) and achieves better scalability.

Wallbreaker - Expanding Research on Sculpture Ontology in the Intelligent Era -

Xu Yi Bo 한국동양예술학회 2021 동양예술 Vol.51 No.-

Synthesis and characterization of monodisperse yttrium aluminum garnet (YAG) micro-crystals with rhombic dodecahedron

Xu, Tao,Yuan, Rui,Xu, Peng-Cheng,Pan, Dong-Jie,Yang, Woochul,Guo, Hai-Bo,Shen, Yu-Fang,Hu, Jian-Feng,Zhang, Zhi-Jun,Zhao, Jing-Tai Elsevier 2018 Journal of alloys and compounds Vol.762 No.-

<P><B>Abstract</B></P> <P>Uniform, monodisperse yttrium aluminum garnet (YAG) rhombic dodecahedron micro-crystals were synthesized using coprecipitation and hydrothermal methods. The Na<SUB>2</SUB>SO<SUB>4</SUB> as a surfactant was helpful in improving the dispersity of the crystallites and forming well-faceted, micro-sized dodecahedral YAG crystallites. The effect of the reaction time and the solvent has also been studied. The crystal growth mechanism called dissolution/crystallization was determined by analyzing the experimental and simulated results. And the specific well-developed crystal facets in the {110} family have been demonstrated by the theoretical calculation. A higher integrated emission intensity can be achieved for the YAG:Ce crystallites by improving the phase purity, morphology with better developed dodecahedrons, and dispersion. Furthermore, a rather high luminous efficacy (LE = 104.14 lm/W) for the white LED fabricated using the YAG:Ce<SUP>3+</SUP> phosphor prepared in this work was realized. The correlation between the crystal growth, morphology and luminescence properties of YAG crystallites has been established, which exhibits a great importance for the synthesis and application of mono-dispersed YAG crystallites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Uniform and monodisperse YAG rhombic dodecahedron micro-crystals were synthesized. </LI> <LI> The growth mechanism of YAG rhombic dodecahedron was studied through experimental and computational simulation. </LI> <LI> The correlation between the crystal growth, morphology and luminescence of YAG crystallites was established. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

SIMULATION OF MIXED GAS FORMATION FOR A SPRAY-WALL COMPLEX GUIDED LPG DIRECT INJECTION ENGINE

Bo-yan Xu,Xiang-long Liu,Long-long Jiang,Juan Xu 한국자동차공학회 2017 International journal of automotive technology Vol.18 No.3

To obtain an ultralean air-fuel ratio and to reduce engine-out NOX and HC emissions induced by the richer mixture near the spark plug, a spray and wall complex guided combustion system has been developed by utilizing the fuel characteristics of LPG. The new combustion system configuration is optimized by using a commercial CFD code, FIRE V2013, and the reliability of the system has been experimentally demonstrated by Plane Laser-Induced Fluorescence (PLIF). The mixture formation in the new combustion system under part load (2,000 rpm) is numerically simulated. With an injection timing of 40°CA BTDC, the LPG spray which is injected from two upper holes, reaches the ignition point, and the other part of the LPG spray which is injected from the bottom hole, is directed to the ignition point through the vertical vortices at the same time. At the ignition timing of about 20°CA BTDC, the two-part mixtures have been shown to form a stable and richer stratified mixture around the ignition point, and the maximum global air-fuel ratio reaches to 60 : 1.

Three‑dimensional magnetic field analytical model‑based electromagnetic environment assessment of WPT systems

Bo Wang,Ping-an Tan,Xu Shangguan,Guang Tan,Xining Xu,Yanming Wu 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.2

Electromagnetic environment assessment is an important step in the design process of a wireless power transfer (WPT) system to ensure that it complies with electromagnetic radiation standards. Electromagnetic environment assessment usually requires an effective magnetic field analytical model. However, the traditional magnetic field analytical model does not consider the impact of shielding media on the external electromagnetic environment of the WPT system. Therefore, based on subdomain analysis technology in the Cartesian coordinate system, this paper establishes a three-dimensional magnetic field analytical model that comprehensively considers coil parameters, passive shielding media, and active shielding coils. To solve the problem of re-dividing various regions when migrating, a misalignment parameter was introduced in the modeling analysis. In addition, an efficient active shielding coil modeling method is proposed based on electromagnetic theory, which reduces the analytical calculation time of the model. Finally, a 200 W WPT system electromagnetic environment assessment platform that includes both active and passive shielding is built. Under different misalignment and transmission distance conditions, the maximum error of the model calculation and finite element analysis (FEA) is less than 3%, and the maximum error of the model calculation and measurement values is less than 8%. Research results verify the accuracy of the proposed three-dimensional magnetic field analytical model and the effectiveness of the shielding measures. This paper lays a theoretical foundation for the electromagnetic environment assessment of WPT systems and the pre-design of shielding measures.

Improvement of Pristinamycin Production by Genome Shuffling and Medium Optimization for Streptomyces Pristinaespiralis

Bo Xu,Zhihua Jin,Qingchao Jin,Ninghui Li,Peilin Cen 한국생물공학회 2009 Biotechnology and Bioprocess Engineering Vol.14 No.2

To isolate an improved pristinamycin producing strain of Streptomyces pristinaespiralis, the technique of Genome shuffling was used which resulted in a high-yield recombinant G 3-56 strain. Strain G 3-56 yielded 322 ± 17 mg/L of pristinamycin which was 11.4-fold higher than that of the initial strain and 3.7-fold higher than strain UN-78 which previously had the highest yield of pristinamycin. The genetic characteristics of the recombinant G 3-56 strain was stable as revealed by our subculture experiments. The optimal production medium was determined using the orthogonal matrix method. Under the optimal medium conditions, the maximum yield of pristinamycin was 412 mg/L with about 1.24-fold higher than the original medium. To isolate an improved pristinamycin producing strain of Streptomyces pristinaespiralis, the technique of Genome shuffling was used which resulted in a high-yield recombinant G 3-56 strain. Strain G 3-56 yielded 322 ± 17 mg/L of pristinamycin which was 11.4-fold higher than that of the initial strain and 3.7-fold higher than strain UN-78 which previously had the highest yield of pristinamycin. The genetic characteristics of the recombinant G 3-56 strain was stable as revealed by our subculture experiments. The optimal production medium was determined using the orthogonal matrix method. Under the optimal medium conditions, the maximum yield of pristinamycin was 412 mg/L with about 1.24-fold higher than the original medium.

A Novel Monoclonal Antibody Induces Cancer Cell Apoptosis and Enhances the Activity of Chemotherapeutic Drugs

Xu, Heng,Tian, Yan-Na,Dun, Bo-Ying,Liu, Hai-Tao,Dong, Guang-Kuo,Wang, Jin-Hua,Lu, Shang-Su,Chen, Bo,She, Jin-Xiong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

A novel monoclonal antibody (mAb), known as AC10364, was identified from an antibody library generated by immunization of mice with human carcinoma cells. The mAb recognized proteins in lysates from multiple carcinoma cell lines. Cell cytotoxicity assays showed that AC10364 significantly inhibited cell growth and induced apoptosis in multiple carcinoma cell lines, including Bel/fu, KATO-III and A2780. Compared with mAb AC10364 or chemotherapeutic drugs alone, the combination of mAb AC10364 with chemotherapeutic drugs demonstrated enhanced growth inhibitory effects on carcinoma cells. These results suggest that mAb AC10364 is a promising candidate for cancer therapy.

Transcriptional profiling reveals the molecular bases of immune regulation in Apis mellifera in response to Ascosphaera apis infection

Bo Xu,Yingzhe WANG,Shixin ZHU,Haizhu ZHOU,Changlong GOU,Wenlong DONG,Yu Wang,Yunhang GAO,Hongxia MA 한국곤충학회 2019 Entomological Research Vol.49 No.1

Chalkbrood, which results from Ascosphaera apis infection, is one of the bee diseases that causes serious damage to the bee colony. Understanding the molecular bases underlying immune response to chalkbrood disease would facilitate the genetic breeding of bees by selecting races with superior chalkbrood resistance. In this study, transcriptome sequencing was performed to identify genes and pathways involved in the immune response to As. apis infection in A. mellifera larvae. In total, 2,890 differentially expressed genes (DEGs) (FDR < 0.001) were identified between the healthy and As. apis infected bee larvae, including 2,214 up‐regulated and 676 down‐regulated unigenes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway classification of the DEGs revealed association with development, energy metabolism, signal transduction, disease, and immune response. Among the immune‐related genes, p38, toll‐like receptors (TLRs), integrin, and antimicrobial peptides were up‐regulated under As. apis infection. This study provides valuable gene transcriptional information towards the investigation of molecular mechanisms related to chalkbrood immune response and host pathogenesis in A. mellifera.