CO2-responsive smart wormlike micelles based on monomer and “pseudo” gemini surfactant

Xuepeng Wu,Yongping Huang,Sisi Fang,Caili Dai,Hao Li,Zhongliang Xu,Mingwei Zhao 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.60 No.-

CO2-responsive wormlike micelles based on monomer erucic acid 3-(N,N-dimethylamino)propylamide (EADP) with or without sodium salicylate (NaSal) in aqueous solution were studied and compared with “pseudo” gemini system. The “pseudo” gemini system were formed by a mixture of EADP and maleic acid (MA) with molar ratio between 2:1–1:1. Different morphological transformations of microstructures in response to EADP concentrations, additives and CO2 stimuli were further investigated in these systems, the wormlike micelle or vesicles can be obtained. The mechanism of these transitions were further investigated by rheology, cryo-TEM and DFT calculation, the results showed that the mechanism behind this transition involved reversible reaction of CO2 with EADP. The mechanism in this research may give further evidence to the self-assembly of CO2-responsive surfactants.

Characteristic profiles of biofilm, enterotoxins and virulence of Staphylococcus aureus isolates from dairy cows in Xinjiang Province, China

Yehui Wu,Jing Li,Mengfan Qiao,Dan Meng,Qingling Meng,Jun Qiao,Xingxing Zhang,Lixia Wang,Kuojun Cai,Jinsheng Zhang,Zaichao Zhang,Weiwei Yu,Xuepeng Cai 대한수의학회 2019 Journal of Veterinary Science Vol.20 No.6

As an important zoonotic pathogen, Staphylococcus aureus (S. aureus) infection has led to serious mastitis and endometritis in infected dairy cows. HereIn this study, a total of 164 strains of S. aureus were isolated from dairy cows in Xinjiang Province, China, and subjected to assays to determine of drug susceptibility and biofilm (BF) formation ability. The eEnterotoxin-related genes were detected, and then the transcription levels of genes related to BF formation were also determined by using reverse transcription-quantitative polymerase chain reactionPCR. Moreover, the pathogenicity of these isolates with different BF formation abilities was determined via by measuring their hemolysis activity, half lethal dose (LD50) and organ bacterial load, respectively. The results showed that 83.4 % of S. aureus isolates could form BF. Among them, 40.8 % of the strains had weak BF formation ability, and most strains with a strong BF formation ability were ica gene carriers. The S. aureus isolates displayed multidrug resistance and their drug resistance was positively correlated with their BF formation ability. Moreover, 96.3 % of the S. aureus isolates carried enterotoxin genes. Among them, the detection rates of the novel enterotoxin genes were higher than thoseat of conventional enterotoxin genes. Furthermore, the isolates with a strong BF formation ability had higher LD50 but lower hemolysis ability and organ bacterial load than thoseat of the isolates with weak or no BF ability. However, those isolates without BF ability caused produced more severe pathological changes than thoseat of the isolates with strong BF formation ability. These findings suggested that higher frequencies of BF ability and presence of novel enterotoxin genes were are important characteristics of S. aureus isolates from dairy cows in Xinjiang Province, China, and such isolateswhich may posed potential threats to food safety.

Experimental Investigations on the Mechanical Properties of Bamboo Fiber and Fibril

Mingquan Tan,Xuepeng Jiang,Huali Ke,Wenwang Wu,Re Xia 한국섬유공학회 2020 Fibers and polymers Vol.21 No.6

Bamboo based composite materials are widely used for structural components in building and textile industries. The structural hierarchy across different scales could enhance the strength and toughness of bamboo for load-bearingapplications. Firstly, chemical components of bamboo fibril are described, and bamboo fibril specimens are fabricatedthrough chemical solution processing; Secondly, functionally graded mechanical properties of macroscopic bamboo fibersare studied with tensile experiments, and relations between graded mechanical properties and microstructures are explored;Afterwards, hierarchical microstructure characterization of bamboo across different scales are performed using scanningelectron microscopy (SEM), and mechanical properties of bamboo fibrils are tested using homemade in-situ micro-tensionsetup. The results indicate that the elastic modulus, ultimate strain and strength of bamboo fibers are: 5.952 GPa, 0.0136 and81.13 MPa respectively. The Young’s moduli, ultimate strains and fracture strengths of the five fibril samples located in(10.478, 12.285) GPa, (0.0172, 0.0217) and (181.87, 230.50) MPa, respectively. These experimental results suggest that themodulus and ultimate strength of bamboo fibril are higher than that of bamboo fibers which are attributed to several mainfactors including the ages of the bamboo, bamboo species, multi-lamella structures of the fibrils, geometry differences offibrils, etc.

Variations of stress and deformation in the straightening process of turnout base plate

Hua Zhai,Yuanhao Wu,Xuepeng Liu,Qi Li,Yushan Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.7

Straightening technology is an important method to manufacture a high-speed railway turnout base plate with positioning blocks after welding. According to the straightening experiment results, the differences in straightening deformation and stress distribution were investigated between the turnout base plate and the counterpart flat plate under different loading conditions. The residual deformation of the counterpart flat plate is much higher than that of the base plate because of the welded positioning blocks. A theoretical model was presented to predict the straightening deformation variation. Finite element simulations were performed to simulate stress variation in the straightening process of the base plate. The stress concentration and residual stress distribution of the base plate were visually observed. The stress concentration factor changes gradually with the interface angle deflection at the welding area of the positioning block. The variation of dynamic stress concentration factor can be calculated and provide a certain theoretical reference to predict the straightening parameters.

Synthesis, surface adsorption and micelle formation of a class of morpholinium gemini surfactants

Caili Dai,Sisi Fang,Mei Hu,Xiaojuan He,Mingwei Zhao,Xuepeng Wu,Shuai Yang,Yining Wua 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-

A series of novel gemini surfactants with morpholinium headgroup, 4, 40-(alkane-4, n-40)bis(4-decyl, dodecyl or tetradecyl morpholinium)bromide (Mm-n-Mm, m = 10, 12, 14, n = 3, 4), were synthesized and characterized using 1H NMR. The surfactants were investigated for their adsorption and micellization in aqueous solutions through surface tension and conductivity methods It was found that the physicochemical properties, such as surface activity and thermodynamic property of the aqueous surfactant system, were dependent on the lengths of both hydrophobic tail chain and spacer. With the increase of the hydrophobic chain length or the decrease of spacer length, the cmc value of the surfactant decreases and the ability to reduce the surface tension is stronger. The calculation result of thermodynamic parameters indicated that the surfactants we synthesized are more inclined to aggregate in solution as compared with traditional m-s-m type gemini surfactants, and the micellization of Mm-n-Mm was an entropy-driven process.

Deficiency of optineurin enhances osteoclast differentiation by attenuating the NRF2-mediated antioxidant response

Xue Peng,Hu Xiangxiang,Chang Emily,Wang Lufei,Chen Minghui,Wu Tai-Hsien,Lee Dong-Joon,Foster Brian L.,Tseng Henry C.,Ko Ching-Chang 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Abnormally increased resorption contributes to bone degenerative diseases such as Paget’s disease of bone (PDB) through unclear mechanisms. Recently, the optineurin (OPTN) gene has been implicated in PDB, and global OPTN knockout mice ( Optn −/− ) were shown to exhibit increased formation of osteoclasts (osteoclastogenesis). Growing evidence, including our own, has demonstrated that intracellular reactive oxygen species (ROS) stimulated by receptor activator of nuclear factor kappa-B ligand (RANKL) can act as signaling molecules to promote osteoclastogenesis. Here, we report that OPTN interacts with nuclear factor erythroid-derived factor 2-related factor 2 (NRF2), the master regulator of the antioxidant response, defining a pathway through which RANKL-induced ROS could be regulated for osteoclastogenesis. In this study, monocytes from Optn −/− and wild-type ( Optn +/+ ) mice were utilized to differentiate into osteoclasts, and both qRT-PCR and tartrate-resistant acid phosphatase (TRAP) staining showed that the Optn −/− monocytes exhibited enhanced osteoclastogenesis compared to the Optn +/+ cells. CellROX ® staining, qRT-PCR, and Western blotting indicated that OPTN deficiency reduced the basal expression of Nrf2 , inhibited the expression of NRF2-responsive antioxidants, and increased basal and RANKL-induced intracellular ROS levels, leading to enhanced osteoclastogenesis. Coimmunoprecipitation (co-IP) showed direct interaction, and immunofluorescence staining showed perinuclear colocalization of the OPTN-NRF2 granular structures during differentiation. Finally, curcumin and the other NRF2 activators attenuated the hyperactive osteoclastogenesis induced by OPTN deficiency. Collectively, our findings reveal a novel OPTN-mediated mechanism for regulating the NRF2-mediated antioxidant response in osteoclasts and extend the therapeutic potential of OPTN in the aging process resulting from ROS-triggered oxidative stress, which is associated with PDB and many other degenerative diseases.