Isovitexin Is a Direct Inhibitor of Staphylococcus aureus Coagulase

( Hua Xiang ),( Panpan Yang ),( Li Wang ),( Jiaxin Li ),( Tiedong Wang ),( Junze Xue ),( Dacheng Wang ),( Hongxia Ma ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.10

Staphylococcus aureus (S. aureus) is a major pathogen that causes human pneumonia, leading to significant morbidity and mortality. S. aureus coagulase (Coa) triggers the polymerization of fibrin by activating host prothrombin, which then converts fibrinogen to fibrin and contributes to S. aureus pathogenesis and persistent infection. In our research, we demonstrate that isovitexin, an active traditional Chinese medicine component, can inhibit the coagulase activity of Coa but does not interfere with the growth of S. aureus. Furthermore, we show through thermal shift and fluorescence quenching assays that isovitexin directly binds to Coa. Dynamic simulation and structure-activity relationship analyses suggest that V191 and P268 are key amino acid residues responsible for the binding of isovitexin to Coa. Taken together, these data indicate that isovitexin is a direct Coa inhibitor and a promising candidate for drug development against S. aureus infection.

Influence of Allyl Isothiocyanate on the Soil Microbial Community Structure and Composition during Pepper Cultivation

( Jingxia Gao ),( Hongxia Pei ),( Hua Xie ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.7

Allyl isothiocyanate (AITC), as a fumigant, plays an important role in soil control of nematodes, soil-borne pathogens, and weeds, but its effects on soil microorganisms are unclear. In this study, the effects of AITC on microbial diversity and community composition of Capsicum annuum L. soil were investigated through Illumina high-throughput sequencing. The results showed that microbial diversity and community structure were significantly influenced by AITC. AITC reduced the diversity of soil bacteria, stimulated the diversity of the soil fungal community, and significantly changed the structure of fungal community. AITC decreased the relative abundance of dominant bacteria Planctomycetes, Acinetobacter, Pseudodeganella, and RB41, but increased that of Lysobacter, Sphingomonas, Pseudomonas, Luteimonas, Pseudoxanthomonas, and Bacillus at the genera level, while for fungi, Trichoderma, Neurospora, and Lasiodiplodia decreased significantly and Aspergillus, Cladosporium, Fusarium, Penicillium, and Saccharomyces were higher than the control. The correlation analysis suggested cellulase had a significant correlation with fungal operational taxonomic units and there was a significant correlation between cellulase and fungal diversity, while catalase, cellulose, sucrase, and urease were the major contributors in the shift of the community structure. Our results will provide useful information for the use of AITC in the assessment of environmental and ecological security.

Combined effect of Fe2O3 and Cr2O3 on the structure and properties of glass-ceramics prepared from Baotou steel blast furnace slag

Guangyu Wang,Yongsheng Du,Jie Ma,Hongxia Zhang,Shunli Ouyang,Leibo Deng,Hua Chen,Ming Zhao 한양대학교 세라믹연구소 2021 Journal of Ceramic Processing Research Vol.22 No.6

CaO-MgO-Al2O3-SiO2 glass-ceramics were successfully prepared using Baotou Steel BFS as the raw materials, choosing Fe2O3and Cr2O3 as nucleating agents. This paper focused on analyzing the combined effect of Fe2O3 and Cr2O3 on the structure andproperties of the glass-ceramics. Experimental results showed that the crystallization mechanism of glass-ceramics convertedsurface crystallization into bulk crystallization and the main crystalline phase of glass-ceramics changed gradually from augiteto diopside with the decrease of Fe2O3/Cr2O3 ratios. Therefore, an appropriate ratio of Fe2O3/Cr2O3 can act as nuclei forcrystallization of augite with integrated interlocking crystal structure and the physicochemical properties of glass-ceramic canbe improved. Consequently, the fracture mode of glass-ceramic was changed from intercrystalline to mixed transcrystalline/intercrystalline and therefore the average crack length can be shortened. Glass-ceramic with Fe2O3/Cr2O3 ratio of 1 had a highbending strength of 138.93 MPa, Vickers hardness of 7.51 GPa and acid resistance of 97.75%.

De novo transcriptomic analysis to reveal insecticide action and detoxification-related genes of the predatory bug, Cyrtorhinus lividipennis

Siyi Liu,David R. Nelson,Jing Zhao,Hongxia Hua,Yueping He 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.2

The mirid bug, Cyrtorhinus lividipennis Reuter, an important predatory natural enemy of rice planthoppers, is widely distributed in rice fields. However, genetic information on C. lividipennis is lacking. Especially, limited data about mechanisms of insecticide selectivity between this piercing-sucking predator (C. lividipennis) and piercing-sucking preys (rice planthoppers), inhibits development of selective insecticides and the integration of chemical and biological control systems to control insect pests of rice. Hence, we performed de novo assembly of a transcriptome from adult and nymph whole bodies of C. lividipennis. A total of> 29 million of reads were generated, and 34,752 transcripts matched known proteins. Then, the genes related to insecticide action and detoxification were manually identified, including 26 carboxylesterases (containing 2 acetylcholinesterases), 57 cytochrome P450s, 19 glutathione S-transferases, 15 nicotinic acetylcholine receptors, 3 GABA-gated ion channels, and 1 glutamate receptor. Comparisons of sequence differences in these genes between C. lividipennis and rice planthoppers, revealed that quite a lot of diversity was found among genes related to insecticide action and detoxification, while a few of these genes share much higher identities between this predator and prey. The present study provides useful information for our understanding of insecticide selectivity between rice planthoppers and the predator mirid bug.

Effect of aggregates of elements induced by rare earth doping on toughening of tailing-derived glass-ceramics

Du Yongsheng,Ma Jie,Zhang Xuefeng,Zhang Hongxia,Chen Hua,Ouyang Shunli,Baowei Li 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.4

Tailings glass-ceramics doped with different proportion of CeO2 were prepared by conventional melts and controllable crystallization. The effect of CeO2 on the microstructure, element distribution characteristics and fracture toughness of glassceramics was studied in this paper. Significant change in microstructure was not observed with the addition of rare earth oxide, but the phenomenon of element aggregates begins to appear in glass-ceramics and the element enrichment of Si, Al, Na and Ce can be observed in the element aggregates. As a result, the integrity of the glass network structure can be improved and the strength of glass phase contributed to the enhancement of fracture toughness. The doping of 3.0% CeO2 achieved a remarkable improvement on fracture toughness that reached 2.86 MPa*m1/2 with a Vickers hardness of 8.49 GPa.

Effect of heat treatment on the crystallization toughening of tailing-derived glass-ceramics

Du Yongsheng,Yang Xiaowei,Zhang Hongxia,Zhang Xuefeng,Zhao Ming,Chen Hua,Ouyang Shunli,Li Baowei 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.12

The effect of heat treatment to a parent glass of the composition CaO-MgO-Al2O3-SiO2 (CMAS) on the course ofcrystallization and properties of the Bayan Obo east mine tailing glass-ceramics is examined. The crystallization behavior,phase composition, morphology and structure of glass-ceramics are characterized. The results indicate that the phases formedin the glass-ceramics are augite and the initial nucleation phases are magnetite, which can be proved by differential scanningcalorimetry (DSC), X-ray diffraction (XRD) and scanning transmission electron microscope (STEM). Heat treatment plays asignificant role in improving the crystallization process, fracture characteristics, modulus and bending strength. All of theseproperties reach a maximum for the fully crystallized glass-ceramic. Scanning electron microscope (SEM) and atomic forcemicroscope (AFM) are used to reveal the topography of the fracture surfaces. The intergranular fracture can be observed onthe fracture surface.

Preparation of decorative slag glass-ceramics and research on the solidification of heavy metals

Yang Tang,Xiaodong Hao,Zhenxiang Fang,Xinyu Bai,Guangyu Wang,Hongxia Zhang,Leibo Deng,Hua Chen,Ming Zhao,Yongsheng Du 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.1

Glass-ceramics with different CuO additions were prepared with Fe2O3 and Cr2O3 as composite nucleating agents, rare earthcontainingblast furnace slag (REBFS) as the main raw material. The existence state and stability of heavy metals Cu, Mn andCr in glass-ceramics were investigated. The results showed that Cr ions contributed to the generation of spinel phase, whileCu ions and Mn ions can enter the spinel crystal and exist stably, which indicated that there was a synergistic solidificationof Cu, Mn and Cr. The depolymerization effect of the copper ions contributed to the transformation of the crystal morphologyfrom dendrites to spherulites. Moreover, the increase in CuO contents promoted glass-ceramics from green to copper red. Based on the leaching experimental data analysis of heavy metals in glass-ceramics, the leaching concentration of heavy metalsCu, Cr and Mn were much lower than the standard leaching toxicity limit of hazardous waste (GB5085.3–2007, China). Theresults showed that the conversion of REBFS into environmentally friendly glass-ceramics can realize solid waste resourceutilization.

Behavioral response of Nilaparvata lugens (Stål), Cyrtorhinus lividipennis Reuter and Paederus fuscipes Curtis to three synthetic volatile chemical compounds

Khan Muhammad Musa,Huang Qing,Wagan Tufail Ahmed,Hua Hongxia,Cai Wanlun,Zhao Jing 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.2

Plant essential oils (EOs) and a wide range of chemicals affect insect pests in many ways, such as via stimulatory, deterrent, toxic and hormonal effects. Three different compounds ((E)-β-caryophyllene (E-β-C), D-limonene (Dlime) and trans-2-dodecenol (T-2-D)) were tested against Nilaparvata lugens, Cyrtorhinus lividipennis and Paederus fuscipes, and their behavioral response was assessed. The results showed that on average, more N. lugens nymphs were repelled by E-β-C and T-2-D than by D-lime. More C. lividipennis nymphs were attracted to T-2-D and D-lime than to E-β-C. However, P. fuscipes displayed no significant response to the three chemical compounds. The results also demonstrated that T-2-D has exerted significant repellency against N. lugens and a significant attraction for C. lividipennis, while E-β-C and D-lime have no significant effect on any tested insect. T-2-D was selected and tested in a greenhouse under semi-field conditions, where the observations confirmed the results of the laboratory experiments. From the results, it can be concluded that T-2-D at a concentration of 0.06 g/L is an effective synthetic volatile chemical compound and is the strongest repellent of N. lugens and the strongest attractant for C. lividipennis. This synthetic chemical compound can be used as a pest management tool in rice agroecosystems.

Effect of some plant essential oils on the orientation and predation capacity of the predatory spider Pardosa pesudoannulata

Ibrahim Maholidy Farid,Hamada Chakira,Wanlun Cai,Jing Zhao,Hongxia Hua 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.3

Investigating the potential side-effects of plant essential oils to natural enemies is necessary before applying them in the field to control insect pests. In the present laboratory study, the attractancy/repellency of two plant oils to the spider Pardosa pseudoannulata was evaluated using a paired choice method. An individual spider was allowed to choose between the odors of essential oils extracted from Piper nigrum, Litsea cubeba, or their mixture and the control within 10 min. The predation deterrent was evaluated by observing the predation of caged spiders supplied with 20 nymphs or adults of Nephotettix cincticeps pre-treated with essential oils in 24 h. Results revealed that P. nigrum and L. cubeba oil had no significant influence on the orientation of the predator in all tested concentrations. However, the mixture of P. nigrum and L. cubeba triggered significant attraction to P. pseudoannulata at 100 and 1000 ppm. Significant reduction of predation was observed with increasing concentration of the mixture and P. nigrum alone. The predation rate in the L. cubeba assay was not significantly different among the tested concentrations. In all cases, predation was higher on nymphs than on adult stages. We did not observe any interaction effect between the life stages and concentrations. To our knowledge, this is the first study discussing the potential influence of plant essential oils on orientation and predation of P. pseudoannulata. Based on these results, some essential oils and their combinations may influence the orientation of P. pseudoannulata and might affect its predation capacity. Further field studies are needed, but these findings suggest caution regarding the selection and application of plant extracts used for biological control in rice fields.

Influence of In-Plane Simple Shear Strain on the Grain Orientation Regulation and Stretch Formability of Pre-twinned AZ31 Magnesium Alloy Sheet

Liangliang Xue,Lifei Wang,Pengbin Lu,Qiang Zhang,Hua Zhang,Guangsheng Huang,Liwei Lu,Liuwei Zheng,Hanuma Reddy Tiyyagura,Hongxia Wang,Shuyong Jiang,Kwang Seon Shin 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.10

Pre-twin is widely accepted as an efficient method for weakening the basal texture to improve the plasticity of magnesium alloys, particularly for formability. However, the enhancement is limited since the largest Schmid factor (SF) of basal slip cannot be achieved. In-plane simple shear strain is used to control the twin orientation in accordance with Schmid law to further decrease the basal texture and improve the formability of the Mg alloys sheet. Consequently, secondary regulation of initial twin orientation (SRITO) technology, a novel combination procedure, was developed. In this method, the AZ31 Mg alloys sheet is compressed to pre-twins with various volumes (1%, 3%, and 5%), then the twin orientation is regulated by in-plane simple shear strain for the second time. Compared with the as-received sample, the average fracture elongation of the annealed sample with the best properties improves from 15.3 to 28.8%, and the Erichsen value increases from 2.8 to 6.1 mm due to the regulation of twin orientation.