Influence of Temperature on the Bacterial Community in Substrate and Extracellular Enzyme Activity of Auricularia cornea

( Xiaoping Zhang ),( Bo Zhang ),( Renyun Miao ),( Jie Zhou ),( Lei Ye ),( Dinghong Jia ),( Weihong Peng ),( Lijuan Yan ),( Xiaoping Zhang ),( Wei Tan ),( Xiaolin Li ) 한국균학회 2018 Mycobiology Vol.46 No.3

Temperature is an important environmental factor that can greatly influence the cultivation of Auricularia cornea. In this study, lignin peroxidase, laccase, manganese peroxidase, and cellulose in A. cornea fruiting bodies were tested under five different temperatures (20℃, 25℃, 30℃, 35℃, and 40℃) in three different culture periods (10 days, 20 days and 30 days). In addition, the V4 region of bacterial 16S rRNA genes in the substrate of A. cornea cultivated for 30 days at different temperatures were sequenced using next-generation sequencing technology to explore the structure and diversity of bacterial communities in the substrate. Temperature and culture days had a significant effect on the activities of the four enzymes, and changes in activity were not synchronized with changes in temperature and culture days. Overall, we obtained 487,694 sequences from 15 samples and assigned them to 16 bacterial phyla. Bacterial community composition and structure in the substrate changed when the temperature was above 35℃. The relative abundances of some bacteria were significantly affected by temperature. A total of 35 genera at five temperatures in the substrate were correlated, and 41 functional pathways were predicted in the study. Bacterial genes associated with the membrane transport pathway had the highest average abundance (16.16%), and this increased at 35℃ and 40℃. Generally, different temperatures had impacts on the physiological activity of A. cornea and the bacterial community in the substrate; therefore, the data presented herein should facilitate cultivation of A. cornea.

Composite of Indium and Polysorbate 20 as Inhibitor for Zinc Corrosion in Alkaline Solution

Xiaoping Li,Man Liang,Hebing Zhou,Qiming Huang,Dongsheng Lv,Weishan Li 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

The combined use of indium and polysorbate 20 (Tween 20) was considered as a new inhibition technique for zinc corrosion. Zn and Zn-In alloy coatings were prepared by electrodeposition and their morphology and composition were characterized by scanning electron microscopy (SEM) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The corrosion inhibition effect of indium and Tween 20 on zinc was investigated by polarization curves and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiencies obtained from Tafel and EIS analyses are well in agreement. Zinc corrosion can be inhibited to some extent by the individual use of indium and Tween 20 and higher corrosion inhibition efficiency can be obtained by the combined use of indium and Tween 20.

Study on optimization of the circumferential and axial wavy geometrical configuration of hydrodynamic journal bearing

Xiaoping Pang,Jin Chen,Sinan H. Hussain 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12

This paper is focused on using GA genetic algorithm to find the optimal performance with respect to shape optimization in three dimensions for the hydrodynamic journal bearing. The mathematical model for film thickness was drawn using Fourier series function and axial waviness value (D) to represent the journal bearing in circumferential and axial direction, respectively. The objective was then to determine the Fourier coefficients and axial waviness value (D) that maximized the load capacity subjected to a given set of constraint. Optimized results show that the presence of cos wave in axial direction, with a positive dimensionless amplitude (+ A) and waviness number m = 0.633 , improves the load capacity by (8-10) % over the cylindrical plain bearing with the same arbitrary shape and size; in general, the increasing order of Fourier series (n), an axial dimensionless amplitude and L/D ratio cause the change in load capacity to become more evident.

Numeric and experimental study of generalized geometrical design of a hydrodynamic journal bearing based on the general film thickness equation

Xiaoping Pang,Jin Chen,Sinan H. Hussain 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.10

This paper deals with multi-objective shape optimization related to the geometrical design of a hydrodynamic journal bearing. The aim proposed here is to show that optimum shape design with better performance could surpass the limitations of existing bearing profiles. Attempting to remove the difficulty of selecting the weighting factor in multi-objective journal bearing optimization problems, a modified non-dominant sort in genetic algorithm was used as an optimization tool with a penalty to those solutions that violate constraints. Three kinds of optimized shapes were manufactured and taken as experimental objects. Experimental apparatus was described and some experimental data was presented. The comparison was made for the optimized bearings between numeric values and experimental data. The results show that the new method for shape optimization of hydrodynamic journal bearings based on the general film thickness equation is feasible.

Absolute Molecular Weight Determination of Sodium Salt of Methacrylic Acid/Acrylic Acid-2-Isooctyl Ester/2-Acrylamido-2-Methylpropanesulfonic Acid Terpolymer by GPC/MALLS

Xiaoping Chang,Zequan Liu,Qiang Zhang 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.12

The samples of sodium salt of methacrylic acid/acrylic acid-2-isooctyl ester/2-acrylamido-2-methylpropanesulfonic acid terpolymer (SSMAA) were synthesized by free radical solution polymerization. The absolute weight-average molar mass (Mw) and polydispersity (Mw /Mn ) of the polymers were successfully determined using aqueous-based gel permeation chromatography coupled with multiangle laser light scattering. The results show that mixed solutions of highly concentrated buffered salt (NaNO3 or NaCl and NaH2PO4 ) and organic solvent modifier (methanol) are needed to eliminate the undesirable interactions between polymer and polymer, and between polymer and stationary phase. Dynamic light scattering was first used to investigate the aggregation behavior of SSMAA in a variety of potential mobile phase compositions and screen the optimum compositions. The Mw and Mw /Mn values of the three samples prepared with different amount of initiator are 13500, 5820, and 2490 g/mol and 1.52, 1.45, and 1.47, respectively.

Preparation and Characterization of Polyimide/Alumina Composite Films as Improved Solid Dielectrics

Xiaoping Cui,Guangming Zhu,Wenyuan Liu 한국고분자학회 2016 폴리머 Vol.40 No.4

Polyimide/alumina (PI/Al₂O₃) nanocomposite films were prepared by incorporating different nano-sized Al₂O₃ contents into PI which derived from pyromellitic dianhydride (PMDA) and a flexible diamine 4,4-bis(3-aminophenoxy) biphenyl (4,3-BAPOBP). The micromorphology, chemical structure, dielectric, mechanical properties and glass transition temperatures (Tg) of prepared films were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), LCR metry, electronic tensile testing and differential scanning calorimetry (DSC). SEM images show uniform distribution of Al₂O₃ nanoparticles in matrix. FTIR spectra indicate that Al₂O₃ nanoparticles are functionalized with γ-aminopropyl triethoxysilane (γ-APS) and the imidization was complete. XRD patterns reveal the peaks of PI/Al₂O₃ composite films were similar to those of Al₂O₃, indicating that the crystal structure of Al₂O₃ remains unchanged and stable after being doped into PI matrix. Meanwhile, the effects of additives on the dielectric and mechanical properties of composite films were also studied. The results show the dielectric constant and dielectric loss of hybrid materials increase with the addition of Al₂O₃ nanoparticles. The electrical breakdown strength and tensile strength of PI/Al₂O₃ can be markedly improved by the addition of appropriate amounts of Al₂O₃ to the PI matrix.

The Faceted Discrete Growth and Phase Differentiation During the Directional Solidification of 20SiMnMo5 Steel

Xiaoping Ma,Dianzhong Li 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.4

The microstructures, segregation and cooling curve were investigated in the directional Solidification of 20SiMnMo5 steel. The typical characteristic of faceted growth is identifi ed. The microstructures within the single cellular and within the singledendritic arm, together with the contradictive segregation distribution against the cooling curve, verify the discrete crystalgrowth in multi-scales. Not only the single cellular/dendritic arm but also the single martensite zone within the single cellular/dendritic arm is produced by the discrete growth. In the viewpoint of segregation, the basic domain following continuousgrowth has not been revealed. Along with the multi-scale faceted discrete growth, the phase Differentiation happens forboth the solid and liquid. The Differentiated liquid phases appear and evolve with Different sizes, positions, compositionsand durations. The physical mechanism for the faceted discrete growth is qualitatively established based on the nucleationof new faceted steps induced by the composition gradient and temperature gradient.

Anthocyanin accumulation enhanced in Lc-transgenic cotton under light and increased resistance to bollworm

Xiaoping Fan,Bohong Fan,Yuxiang Wang,Weicai Yang 한국식물생명공학회 2016 Plant biotechnology reports Vol.10 No.1

Breeding of naturally colored cotton fiber has been hampered by the limited germplasm, an alternative way is to use transgenic approach to create more germplasm for breeding. Here, we report our effort to engineer anthocyanin production in cotton. The maize Lc gene, under the control of the constitutive 35S promoter, was introduced into cotton through genetic transformation. Our data showed that the expression of the Lc gene alone is sufficient to trigger the accumulation of anthocyanin in a variety of cell types including fiber cells in cotton. However, the accumulation of colored anthocyanin in cotton fibers requires the participation of light signaling. These data indicate that it is feasible to engineer colored fibers through transgenic approach in cotton. Furthermore, we showed that the Lc-transgenic cotton plants are resistant to cotton bollworm. These transgenic plants are, therefore, potentially useful for cotton breeding against cotton bollworm.

Pyrazinone derivatives from the coral-derived Aspergillus ochraceus LCJ11-102 under high iodide salt

Xiaoping Peng,Yi Wang,Tonghan Zhu,Wei-Ming Zhu 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.2

Five new pyrazin-2(1H)-one derivatives, ochramidesA–D (1–4) and ochralate A (5), as well as threeknown analogues (6–8) were isolated from the fermentationbroth of the marine coral-derived halotolerant Aspergillusochraceus LCJ11-102 in a nutrient-limited mediumcontaining 10% NaI. Their chemical structures weredetermined by analyzing NMR and X-ray diffraction data. Compounds 2, 5 and 6 showed antimicrobial activitiesagainst Enterobacter aerogenes with the MIC values of40.0, 18.9, and 20.1 lM, respectively.

Mechano-Chemical Modification of Waste Rubber Powder with 2-Mercatobenzothiozole and 3-Aminopropyltriethoxysilane

Xiaoping Wang,Jianghua Du,Xin Zhang,Deming Jia 한국고분자학회 2018 Macromolecular Research Vol.26 No.5

A mechano-chemical modification process for waste rubber powder (WRP) was investigated in this paper. 2-Mercatobenzothiozole (accelerator M) was introduced as a peptizer to improve plasticity of WRP, and 3-aminopropyltriethoxysilane (silane coupling agent KH550) was used as a surfactant to further modify the surface of plasticized rubber powder (PRP) to improve interfacial bonding with epoxidized natural rubber (ENR). Infrared spectrums showed that the WRP generated more oxygen-containing groups by mechanical forces in the presence of accelerator M and then grafted amino groups with KH550. The mechano-chemical process with accelerator M changed the structure of WRP obviously shown by sol fraction and microstructure of PRP, which increased the mechanical properties and crosslink density of full rubber powder vulcanizates. After further modified by KH550, the modified rubber powder (MRP) had a positive chemical interfacial bonding with ENR, changing the fracture surface and improving the mechanical properties of vulcanizates. The cure characteristics of the vulcanizates also illustrated that accelerator M and KH550 participated in the vulcanization process increasing the curing efficiency. The best mechanical properties of ENR/MRP vulcanizates were better than the neat ENR vulcanizates. It indicated that the mechano-chemical process with accelerator M and KH550 will be a potential method to reclaim WRP.