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.

Life Assessment of Hydrogen Reformer Furnace Tube in Terms of Microstructure Evaluation and Damage Mechanics Approach

Tu Shan Tung,Yoon Kee Bong,Gong Jian Ming 대한기계학회 1998 대한기계학회 춘추학술대회 Vol.- No.-

Microstructure and mechanical properties of carbon graphite composites reinforced by carbon nanofibers

Chen Yixing,Tu Chuanjun,Liu Yanli,Liu Ping,Gong Pei,Wu Guangning,Huang Xia,Chen Jian,Liu Tianhua,Jiang Jizhou 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Renewed interest in the reinforced carbon graphite composites has intrigued the community in the advanced materials fields. In this work, we present a simple carbon nanofibers reinforced carbon graphite composites synthetic method by incorporating mixture of coal tar pitch, synthetic graphite, pitch coke and the dispersion liquid of carbon nanofibers via liquid-phase mixing process. The impact of carbon nanofiber utilization on the microstructures and mechanical properties of carbon graphite composites are studied systematically. The covalent surface modification of carbon nanofibers effectively improves its microstructure and thereby promotes the carbon graphite composites’ dispersion behavior. We propose that a small amount of carbon nanofibers could promote the carbonization process of carbon graphite composites, facilitating the densification of carbon graphite composites and reducing the undesired open porosity. The amount of 0.7 wt % of carbon nanofiber concentration allows the enhancement of bend and compressive strength of carbon graphite composites up to 36.50 MPa and 60.46 MPa, increased by 167.9% and 146.9% compared with the pure carbon graphite composite, respectively. Our findings can be rationalized due to the improvement in the mechanical strength of carbon graphite composites could be attributed due to pull-out of carbon nanofibers from the matrix and bridging effect across the crack pores within the matrix.

Effects of habitat fragmentation on the functional diversity of insects in Thousand Island Lake, China

Tian‐Hao Tu,Ji-Rui WANG,Jian-Qiang GU,Tian-Qi LI,Kun LV,Guo-Xin ZHOU,Zhi-Hong XU 한국곤충학회 2019 Entomological Research Vol.49 No.2

Due to habitat fragmentation, the loss of species diversity has been extensively studied. On the contrary, the effects of habitat fragmentation on functional diversity is still poorly understood. In the Thousand Island Lake, we conducted studies of insect functional diversity on a set of 29 isolated islands. We used 10 functional diversity indices from three aspects (functional richness, functional evenness and functional divergence) to respectively describe functional diversity of insects on sample islands. We found the following results: (i) The functional indices selected could reflect the functional diversity of sample islands and it is further proved that in general, three components of functional diversity were independent of each other; (ii) Sample islands could be divided into two categories, island JSD and the remaining islands; (iii) Functional richness increased with island area and shape index, but had no significant correlation with isolation. Likewise, both functional evenness and functional divergence had no significant correlation with island attributes. The conclusion to emphasize from our research is that: (i) habitat fragmentation reduced the biological functional diversity to some extent, further demonstrating the importance of habitat continuity in biodiversity protection; and (ii) for functional diversity protection of insects in a fragmented landscape, an island which has high approximate shape index values of at least hundred hectare magnitude order has a critical promoting effect.

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.

Effect of Ultrasonic Surface Rolling on Dry Sliding Tribological Behavior of Ductile Iron Under Different Normal Loads

Xiaoshuang Luo,Haitao Duan,Jian Li,Shengpeng Zhan,Dan Jia,Jiesong Tu,Yinhua Li,Yaping Chen 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.4

This study emphasizes the effect of ultrasonic surface rolling (USR) on the surface roughness, hardness, and tribologicalproperties of ductile iron under different normal loads. Results revealed that surface roughness was reduced by 96% andsurface hardness increased by 37.8% after USR treatment. By increasing normal load, the average friction coefficient of theUSR-treated specimens decreased, but the wear rate of both USR-treated and untreated specimens increased, mainly becausethe dominant wear mechanism changed. The average friction coefficient of the untreated specimen (~ 0.32) was much higherthan the USR-treated specimen (~ 0.24) when the normal load was 30 N. However, the wear rate of the USR-treated specimenwas larger than that of the untreated specimen when the normal load was greater than 20 N because the higher hardnessabrasive particles on the worn surface of the USR-treated specimen not only accelerated abrasive particle wear, but alsocaused more severe adhesive wear.

Subgrain Effect on Grain Scale Plasticity of NiTi Shape Memory Alloy Under Canning Compression: A Crystal Plasticity Finite Element Analysis

Li Hu,Shuyong Jiang,Jian Tu,Zhiming Zhou 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.2

The subgrain effect of NiTi shape memory alloy during canning compression at 400 °C is investigated through electronback-scattered diffraction (EBSD) experiment, transmission electron microscope (TEM) experiment and crystal plasticityfinite element (CPFE) simulation in explicit consideration of subgrain within each grain. Experimental investigations basedon TEM and EBSD measurements confirm that the formation of subgrain actually results from the dislocation motion duringcanning compression. Numerical simulations based on the constructed polycrystalline models with various subgrains areused to investigate the subgrain effect during canning compression from a different point of view. In terms of texture evolution,subgrain effect does not change the tendency of texture evolution, but it contributes to the dispersed distribution withrespect to the deformed grain/subgrain orientations. As for accumulative shear strain, subgrain effect contributes to sustaininglarger plastic strain inside each grain, and it also results in the strain concentration near grain boundaries. With respectto von Mises stress, the subgrain effect facilitates the ease of stress concentration near grain boundaries and it contributesto possessing a homogeneous stress distribution within the inner part of each grain.

The Classic Security Application in M2M: the Authentication Scheme of Mobile Payment

( Liang Hu ),( Ling Chi ),( Hong-tu Li ),( Wei Yuan ),( Yu Yu Sun ),( Jian-feng Chu ) 한국인터넷정보학회 2012 KSII Transactions on Internet and Information Syst Vol.6 No.1

As one of the four basic technologies of IOT (Internet of Things), M2M technology whose advance could influence on the technology of Internet of Things has a rapid development. Mobile Payment is one of the most widespread applications in M2M. Due to applying wireless network in Mobile Payment, the security issues based on wireless network have to be solved. The technologies applied in solutions generally include two sorts, encryption mechanism and authentication mechanism, the focus in this paper is the authentication mechanism of Mobile Payment. In this paper, we consider that there are four vital things in the authentication mechanism of Mobile Payment: two-way authentication, re-authentication, roaming authentication and inside authentication. Two-way authentication is to make the mobile device and the center system trust each other, and two-way authentication is the foundation of the other three. Re-authentication is to re-establish the active communication after the mobile subscriber changes his point of attachment to the network. Inside authentication is to prevent the attacker from obtaining the privacy via attacking the mobile device if the attacker captures the mobile device. Roaming authentication is to prove the mobile subscriber`s legitimate identity to the foreign agency when he roams into a foreign place, and roaming authentication can be regarded as the integration of the above three. After making a simulation of our proposed authentication mechanism and analyzing the existed schemes, we summarize that the authentication mechanism based on the mentioned above in this paper and the encryption mechanism establish the integrate security framework of Mobile Payment together. This makes the parties of Mobile Payment apply the services which Mobile Payment provides credibly.

Comparisons of Curative and Side Effects of Chemoradiotherapy among Xinjiang Han, Uigur and Kazakh Esophageal Carcinoma Patients

Zhang, Li,Ma, Li-Li,Zhang, Jian-Qing,Yang, Mei,Xun, Tu-Er,Li, Ai Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Objective: This study aimed to explore the differences in the curative and side effects of chemoradiotherapy on esophageal cancer (EC) among Xinjiang Han, Uigur and Kazakh patients. Methods: 170 patients with IIA stage-IV of esophageal squamous cell carcinoma were analyzed retrospectively. Based on different nationalities, they were divided into the Han, Uigur and Kazakh groups. The 1-, 2- and 3-year survival rates, incidence of the side effects (including hematological toxicities, radioactive esophagitis and percutaneous reactions) and application of antibiotics and harmonics were compared among the groups. There was no significant difference in the short-term curative effects among the Han, Uigur and Kazakh groups. The 1- 2- and 3-year survival rates of the three groups were 84%, 40%, 26%; 78%, 27%, 18%; and 60%, 21%, 12% ($x^2$=14.497, P<0.05). The incidence rate of hamatological toxicity ${\geq}$Grade 2 in the Kazakh group was significantly lower than that in the Han or Uigur group. Results: The incidence rates of radioactive esophagitis and percutaneous reactions Grade 2 in the Han group were significantly higher than those in the Uigur or Kazakh group. There was no significant difference in the types of applied antibiotics among the groups, but there were significant differences in the days of antibiotic application and proportion of patients receiving harmonics between the Hans and either of other groups. Conclusion: Chemoradiotherapy shows a better effect in the long-term survival rate among Han EC patients compared with Uigur or Kazakh EC patients. Uigur and Kazakh patients show a better tolerance to the side effects of chemoradiotherapy compared with Hans.

An Auto-inducible Expression System Based on the RhlI-RhlR Quorum-sensing Regulon for Recombinant Protein Production in E. coli

Rao Ben,Fan Jiying,Sun Jian’an,Truong Ngoc Tu,Sun Jing,Zhou Jingsong,Qiuyi,Shen Yaling 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

An artificial network which can accomplish recombinant protein synthesis guided by cell population in E. coli was constructed. The successful functioning of this network requires two plasmids, pWNB and pET. pWNB is responsible for production of T7 RNA polymerase, which controls pET; pET, in turn, regulates the production of target proteins. Several model proteins were tested and the results show that this E. coli system can be used to efficiently express various recombinant proteins. Since system contains T7 RNA polymerase production elements, it is transferable and applicable to well-characterized E. coli strains. Compared to the IPTG-induced system, an equal or greater amount of target protein can be obtained using this auto-inducible expression system in flasks and bioreactors. Our results suggest that it is a competitive alternative to other expression systems used in labs or for industrial applications.