Aramid Nanofibers Reinforced Polyacrylonitrile Nanocomposite Films with High Transparency and High Mechanical Properties

Xue Bai,Yinghui Zhao,Zhenhu Song,Hui Chen,Sihang Zhang,Yonghui Luo,YingChun Gu,Shijian Tu,Guo Yao,Sheng Chen 한국섬유공학회 2022 Fibers and polymers Vol.23 No.3

The preparation of polymer nanocomposites combined with high strength, toughness, and high transparencyremains a challenge. Aramid fibers are often used as fiber-reinforced materials for their superior mechanical and thermalproperties, but the weak interfacial force between aramid fibers and matrix polymer limits the application in compositematerials. In this work, aramid nanofibers were prepared by a two-step process, which included deprotonation and acidhydrothermal treatment to obtain better dispersions in general solvents. The hydrothermal aramid nanofibers (HANFs) wereused as reinforcing materials and blended with polyacrylonitrile (PAN) to prepare polyacrylonitrile/aramid nanofibers (PAN/HANFs) composite films with different mass fractions of HANFs. The morphologies of HANFs and the thermal, optical, andmechanical properties of composite films were investigated. Interestingly, when the mass fraction of aramid nanofibers wasless than 1.0 %, the composite films were synchronously strengthened and toughened. When the mass fraction of HANFswas 0.5 %, the tensile strength and toughness of the PAN/HANFs composite film reached 62.04 MPa and 22.56 MJ/m3,which were 74.23 % and 162.31 % higher than the pure PAN film, respectively. Besides, its average transmittance in thevisible light region remained 76.34 %. This work may offer a novel and facile strategy for high transparent reinforcedpolymer composites, which have potential applications in high strength fiber or optical film.

Construction of Recombinant Pichia pastoris Carrying a Constitutive AvBD9 Gene and Analysis of Its Activity

( Jian Tu ),( Kezong Qi ),( Ting Xue ),( Haiting Wei ),( Yongzheng Zhang ),( Yanli Wu ),( Xiuhong Zhou ),( Xiaolong Lv ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.12

Avian beta-defensin 9 (AvBD9) is a small cationic peptide consisting of 41 amino acids that plays a crucial rule in innate immunity and acquired immunity in chickens. Owing to its wide antibacterial spectrum, lack of a residue, and failure to induce bacterial drug resistance, AvBD9 is expected to become a substitute for conventional antibiotics in the livestock and poultry industries. Using the preferred codon of Pichia pastoris, the mature AvBD9 peptide was designed and synthesized, based on the sequence from GenBank. The P. pastoris constitutive expression vector pGHKα was used to construct a pGHKα-AvBD9 recombinant plasmid. Restriction enzyme digestion was performed using SacI and BglII to remove the ampicillin resistance gene, and the plasmid was electrotransformed into P. pastoris GS115. High-expression strains with G418 resistance were screened, and the culture supernatant was analyzed by Tricine-SDS-PAGE and western blot assay to identify target bands of about 6 kDa. A concentrate of the supernatant containing AvBD9 was used for determination of antimicrobial activity. The supernatant concentrate was effective against Escherichia coli, Salmonella paratyphi, Salmonella pullorum, Pseudomonas aeruginosa, Enterococcus faecalis, and Enterobacter cloacae. The fermentation product of P. pastoris carrying the recombinant AvBD9 plasmid was adjusted to 1.0 × 108 CFU/ml and added to the drinking water of white feather broilers at different concentrations. The daily average weight gain and immune organ indices in broilers older than 7 days were significantly improved by the AvBD9 treatment.

Susceptibility of Lung Cancer with Polymorphisms of CYP1A1, GSTM1, GSTM3, GSTT1 and GSTP1 Genotypes in the Population of Inner Mongolia Region

Jiang, Xue-Yan,Chang, Fu-Hou,Bai, Tu-Ya,Lv, Xiao-Li,Wang, Min-Jie,Wang, Guang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Background: To study the relationship of susceptibility to lung cancer with the gene polymorphisms of CYP1A1, GSTM1, GSTM3, GSTT1, GSTP1 and smoking status in Han and Mongolian populations of Inner Mongolia, an autonomous region of China. Materials and Methods: PCR-RFLP, allele-specific and multiplex PCR were employed to identify the genotypes of CYP1A1, GSTM1, GSTM3, GSTT1 and GSTP1 in a case-control study of 322 lung cancer patients diagnosed by bronchoscopy and 456 controls free of malignancy. Results: There is a significant difference in genotypic frequency of GSTT1 of healthy Mongolian and Han subjects. A statistically prominent association was found between CYP1A1 Msp1 (vt/vt) (OR=4.055, 95%CI:2.107-7.578, p=0.000), GSTM1 (-) (OR=2.290, 95%CI:1.467-3.573, p=0.000) and lung cancer in Mongolians. Similarly, in the Han population, CYP1A1 Msp1 (vt/vt) (OR=3.194, 95%CI:1.893-5.390, p=0.000) and GSTM1 (-) (OR=1.884, 95%CI:1.284-2.762, p=0.001) carriers also had an elevated risk of lung cancer. The smokers were more susceptible to lung cancer 2.144 fold and 1.631 fold than non-smokers in Mongolian and Han populations, respectively. The smokers who carried with CYP1A1 Msp1 (wt/vt+vt/vt), exon7 (Val/Val+Ile /Val), GSTM1 (-), GSTM3 (AB+BB), and GSTT1 (-) respectively were found all to have a high risk of lung cancer. Conclusions: CYP1A1 Msp1 (vt/vt) and GSTM1 (-) are risk factors of lung cancer in Han and Mongolian population in the Inner Mongolia region. The smokers with CYP1A1 Msp1 (wt/vt+vt/vt), CYP1A1 exon7 (Val/Val+Ile /Val), GSTM1 (-), GSTM3 (AB+BB), and GSTT1 (-) genotypes, respectively, are at elevated risk of lung cancer.

Research on the Improved Way of RED Algorithm S-RED

ZHAO Yu-hong,ZHENG Xue-feng,TU Xu-yan 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.2

In order to improve sensitivity of parameter and network load, an improved random early detect ion (RED) mechanism orienting to stability, which is named extended stability of random early detection ( S-RED) , was proposed. This algorithm sectionally calculates the probability of packet loss by using the quadratic function to make its variability smoother, meanwhil ,and simplify the calculation formula ofprobability by decreasing the number of parameters in the calculation to properly weaken the performance influence due to parameter settings. We tested our proposed algorithm using the Network Simulator version 2 (ns-2) and found that it shows better stable performance than other typical RED variants and close throughput.

Performance-based Analysis of Elastoplastic Rotational Behavior of Multi-cell Shaped Concrete-filled Steel Tubular Connection

Xi Chen,Jian-yang Xue,Hechao Li,Guangxu Tu,Xin Lu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

Experimental and theoretical research on the rotational behavior of Multi-cell shaped concrete-filled steel tubular (MCFST) connection under low-period cyclic load is performed. The experimental results showed that the design parameters had significant effects on the elastic rotational stiffness of the connection, and affected the sequence and position of the plastic hinges appearance at the column and beam ends. Furthermore, the damage mechanism of the plastic hinge lines is obtained, and the simultaneous yielding for the plastic hinges results in the rapid increase of the beam end rotation. In order to handle the problem with irregular geometry boundary and uneven distribution of tightening-ring stresses a differential element of an unified material is proposed considering the effective tightening-ring stresses of special-shaped steel tube on confined concrete, which can be used to analyse the whole mechanical and damage performance of the connection. Combining unified design theory and experimental results, the calculation for the elastic bending rigidity of the connection is obtained. Finally, the moment-rotation relation model of the connection is proposed by regression analysis on experimental results, and the theoretical results are observed to agree well with the experimental results.

Esophageal Motility in the Supine and Upright Positions for Liquid and Solid Swallows Through High-resolution Manometry

( Xiu Jing Zhang ),( Xue Lian Xiang ),( Lei Tu ),( Xiao Ping Xie ),( Xiao Hua Hou ) 대한소화기기능성질환·운동학회 2013 Journal of Neurogastroenterology and Motility (JNM Vol.19 No.4

Background/Aims Most recent studies using high-resolution manometry were based on supine liquid swallows. This study was to evaluate the differences in esophageal motility for liquid and solid swallows in the upright and supine positions, and to determine the percentages of motility abnormalities in different states. Methods Twenty-four asymptomatic volunteers and 26 patients with gastroesophageal reflux disease underwent high-resolution manometry using a 36-channel manometry catheter. The peristalses of 10 water and 10 steamed bread swallows were recorded in both supine and upright positions. Integrated relaxation pressure, contractile front velocity, distal latency (DL) and the distal contractile integral (DCI) were investigated and comparisons between postures and boluses were analyzed. Abnormal peristalsis of patients was assessed applying the corresponding normative values. Results In total, 829 swallows from healthy volunteers and 959 swallows from patients were included. (1) The upright position provided lower integrated relaxation pressure, shorter DL and weaker DCI than the supine position. (2) In the comparison of liquid swallows, the mean for contractile front velocity was obviously reduced while DL and DCI were increased in solid swallows. (3) The supine position detected more hypotensive peristalsis than the upright position. The upright position provided more rapid and premature contraction than the supine position but there was no statistically significant difference. Conclusions Supine solid swallows occur with more hypotensive peristalsis. Analysis should be based on normative values from the corresponding posture and bolus. (J Neurogastroenterol Motil 2013;19:467-472)

Effects of Rad51 on Survival of A549 Cells

Yu, Sha-Sha,Tu, Yi,Xu, Lin-Lin,Tao, Xue-Qin,Xu, Shan,Wang, Shan-Shan,Xiong, Yi-Feng,Mei, Jin-Hong Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.1

Rad51, a key factor in the homologous recombination pathway for the DNA double-strand break repair, plays a vital role in genesis of non-small-cell lung cancer (NSCLC). In recent years, more and more studies indicate that high expression of Rad51 is of great relevance to resistance of NSCLC to chemotherapeutic agents and ionizing radiation. However, the underlying molecular mechanisms are poorly understood. In this study, we investigated the role of single Rad51 on cell viability in vitro. Our results show that depletion of endogenous Rad51 is sufficient to inhibit the growth of the A549 lung cancer cell line, by accumulating cells in G1 phase and inducing cell death. We conclude that independent Rad51 expression is critical to the survival of A549 cells and can be an independent prognostic factor in NSCLC patients.

Cloning and Biochemical Characterization of a Hyaluronate Lyase from Bacillus sp. CQMU-D

Wang Lu,Liu Qianqian,Gong Xue,Jian Wenwen,Cui Yihong,Jia Qianying,Zhang Jibei,Zhang Yi,Guo Yanan,Lu He,Tu Zeng 한국미생물·생명공학회 2023 Journal of microbiology and biotechnology Vol.33 No.2

Hyaluronidase (HAase) can enhance drug diffusion and dissipate edema by degrading hyaluronic acid (HA) in the extracellular matrix into unsaturated HA oligosaccharides in mammalian tissues. Microorganisms are recognized as valuable sources of HAase. In this study, a new hyaluronate lyase (HAaseD) from Bacillus sp. CQMU-D was expressed in Escherichia coli BL21, purified, and characterized. The results showed that HAaseD belonged to the polysaccharide lyase (PL) 8 family and had a molecular weight of 123 kDa. HAaseD could degrade chondroitin sulfate (CS) -A, CS-B, CSC, and HA, with the highest activity toward HA. The optimum temperature and pH value of HAaseD were 40°C and 7.0, respectively. In addition, HAaseD retained stability in an alkaline environment and displayed higher activity with appropriate concentrations of metal ions. Moreover, HAaseD was an endolytic hyaluronate lyase that could degrade HA to produce unsaturated HA oligosaccharides. Together, our findings indicate that HAaseD from Bacillus sp. CQMU-D is a new hyaluronate lyase and with excellent potential for application in industrial production.

Application of Membrane Filtration Method to Isolate Uninuclei Conidium in Aspergillus oryzae Transformation System Based on the pyrG Marker

Yanwei Ji,Yang Xu,Yanping Li,Zhui Tu,Zhibing Huang,Xue Liu,Da Lei 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.1

The purpose of this study was to develop a membrane filtration method to isolate uninuclei conidium of Aspergillus oryzae, then the method was adopted to develop a transformation system of A. oryzae. A. oryzae 3.951 contained 1–4 nuclei in each conidium. The percentages of uninucleate and binucleate conidia were approximately 16.15 and 74.22%, respectively. Conidia suspension was filtrated with a 5-μm membrane to overcome the bottleneck caused by multinucleate conidia and to remove excess multinucleate conidia before UV mutagenesis. Uninucleate conidia of 5-fluoroorotic acid (5-FOA)-resistant strains were enriched by filtration with a 3-μm membrane. The pyrG mutant strain AS11 was obtained and GFP-pyrG was successfully transformed into AS11.

A Novel High Performance SOI LDMOS with Buried Stepped Gate Field Plate

Hongchao Hu,Hongli Dai,Luoxin Wang,Haitao Lyu,Yuming Xue,Tu Qian 한국전기전자재료학회 2023 Transactions on Electrical and Electronic Material Vol.24 No.6

With the continuous development of science and technology, the power semiconductor devices are becoming more and more extensive. A novel silicon-on-insulator (SOI) lateral double-diffused metal–oxide–semiconductor (LDMOS) has been proposed in this paper. The new device is mainly characterized by introducing a stepped gate field plate in the low-K dielectric buried layer (SGFP-LK). On the one hand, the stepped gate field plate introduces extra lateral electric field peaks, which makes the distribution of potential lines more uniform and improves the breakdown voltage (BV). Moreover, the stepped gate fi eld plate decreases the specific on-resistance ( R on,sp ) by a promoted depletion. On the other hand, different from the traditional buried oxygen layer, the low-K dielectric layer strengthens the vertical electric field and signifi cantly increases BV. Ultimately, compared with the conventional device (C-SOI LDMOS), the BV of the SGFP-LK LDMOS is dramatically enhanced by 107% and the R on,sp is reduced by 24.8%. Furthermore, the figure of merit is enhanced by 472%. In addition, the maximum lattice temperature of the SGFP-LK LDMOS is dropped by 23.1 K, which relieves self-heating effects to some extent.