Molecular cloning and characterization under different stress conditions of insulin-like peptide 2 gene (AccILP-2) from Apis cerana cerana

Xuepeng Chi,Wei Wei,Weixing Zhang,HongfangWang,Zhenguo Liu,Baohua Xu 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.2

Insulin-like peptide 2 is an important gene in the insulin/insulin-like signaling pathway. The insulin-like peptide 2 gene (ILP-2) appears to play a key role in metabolism, growth, reproduction, stress resistance and aging. In this study, we isolated and characterized an ILP-2 gene from Apis cerana cerana known as AccILP-2. The full-length AccILP-2 cDNA is 494 bp and contains a 222-bp open reading frame (ORF) encoding a protein of 73 amino acids with a calculated molecular weight of 8.706 kDa and an isoelectric point of 9.02. Multiple sequence alignment revealed that AccILP-2 shares high identity with ILP genes from Apis mellifera, Apis florea, Bombus terrestris, Eufriesea mexicana and Dufourea novaeangliae and contains a typical IlGF-insulin-bombyxin-like domain. Quantitative PCR analysis indicated that the greatest expression of AccILP-2 was observed in the muscles of adult workers. Expression analysis results also indicated that AccILP-2 expression was greatest during the dark-eye developmental period. Furthermore, expression of the AccILP-2 transcript was induced by environmental stressors, including exposure to 4 °C, ultraviolet light, H2O2, heavy metals (HgCl2 and CdCl2) and pesticides (dichlorvos, paraquat and cyhalothrin). However, AccILP-2 expression was downregulated at 44 °C. In conclusion, these results suggested that AccILP-2 might play an important role in the response to abiotic stress. We expect that our study will promote future research on the function of the insulin/insulin-like signaling pathway.

Mechanism of shear deformation, failure and energy dissipation of artificial rock joint in terms of physical and numerical consideration

Xuepeng Zhang,Yujing Jiang,Gang Wang,Jiankang Liu,Dong Wang,Changsheng Wang,Satoshi Sugimoto 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.3

The physical and mechanical change processes of rock are closely related to energy transformation, and its deformation and failure is an instability phenomena driven by energy exchange. This study investigated mechanism of shear deformation, failure and energy dissipation of joint using both physical and numerical direct shear tests under constant normal load (CNL) condition. Three kinds of joint surface were artificially prepared. An acoustic emission system was employed to monitor acoustic emission in physical test, and rupture frequency was recorded in numerical test to represent micro-crack development. By research of numerical micro-crack development accompanied with physical acoustic emission results, mechanism of shear deformation and failure of joints were illustrated schematically. By definition of dissipation energy, captured using the particle flow code (PFC2D), energy releasing and dissipation were discussed with microscopic damage evolution of joints. Results showed that joints under shearing present a dissipation trend of four stages including a slow rise stage, a rapid rise stage, a shock rise stage and a rapid decline stage.

Multi-Epitope Fusion Protein Eg mefAg-1 as a Serodiagnostic Candidate for Cystic Echinococcosis in Sheep

Liu Tianli,Wang Xifeng,Tian Zhenzhong,Wang Lixia,Zhang Xingxing,Qiao Jun,Meng Qingling,Gong Shasha,Chen Ying,Cai Xuepeng 대한기생충학ㆍ열대의학회 2019 The Korean Journal of Parasitology Vol.57 No.1

Cystic echinococcosis (CE) in sheep is a hazardous zoonotic parasitic disease that is caused by Echinococcus granulosus (Eg). At present, serological test is an important diagnostic method for Eg infection in domestic animals. Here, a fusion protein Eg mefAg-1 harboring 8 dominant B-cell epitopes of Eg such as antigen B, tetraspanin 1, tetraspanin 6, reticulon and Eg95 was produced in E. coli and evaluated for CE in sheep by indirect ELISA. Eg mefAg-1 showed in ELI- SA a high sensitivity (93.41%) and specificity (99.31%), with a coincidence rate of 97.02%. Overall, it is suggested that the Eg mefAg-1 could be a potential antigen candidate for CE serodiagnosis in sheep.

Load-related dynamic behaviors of a helical gear pair with tooth flank errors

Lehao Chang,Xuepeng Cao,Zhaoxia He,Geng Liu 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.4

This study focused on the effects of tooth manufacturing errors (MEs) on the dynamic behaviors of a helical geared system. The composite mesh error is introduced and calculated, which is taken as error excitation in the dynamic model. A combined finite element method (FEM) and analytical contact model is used to investigate the interaction of mesh stiffness and MEs. The dynamic model is developed based on the finite element method and its effectiveness has been verified. By introducing stiffness excitation and error excitation, the effects of mesh stiffness and MEs can be easily distinguished in the total excitation. The influence degrees of these two factors are obtained at different torque levels by simulating the quasi-static and dynamic responses of the system. The results show that the composite mesh error will have great changes under light load conditions, and larger dynamic factors as well as decreased resonance speed will be brought. The excitation produced by manufacturing errors is dominate in the total vibration excitation in a light loading, while the excitation produced by mesh stiffness is becoming the dominating one in a heavy loading.

Molecular Characteristics and Potent Immunomodulatory Activity of Fasciola hepatica Cystatin

Kai Zhang,Yucheng Liu,Guowu Zhang,Xifeng Wang,Zhiyuan Li,Yunxia Shang,Chengcheng Ning,Chunhui Ji,Xuepeng Cai,Xianzhu Xia,Jun Qiao,Qingling Meng 대한기생충학ㆍ열대의학회 2022 The Korean Journal of Parasitology Vol.60 No.2

Cystatin, a cysteine protease inhibitor found in many parasites, plays important roles in immune evasion. This study analyzed the molecular characteristics of a cystatin from Fasciola hepatica (FhCystatin) and expressed recombinant FhCystatin (rFhcystatin) to investigate the immune modulatory effects on lipopolysaccharide-induced proliferation, migration, cytokine secretion, nitric oxide (NO) production, and apoptosis in mouse macrophages. The FhCystatin gene encoded 116 amino acids and contained a conserved cystatin-like domain. rFhCystatin significantly inhibited the activity of cathepsin B. rFhCystatin bound to the surface of mouse RAW264.7 cells, significantly inhibited cell proliferation and promoted apoptosis. Moreover, rFhCystatin inhibited the expression of cellular nitric oxide, interleukin-6, and tumor necrosis factor-α, and promoted the expression of transforming growth factor-β and interleukin-10. These results showed that FhCystatin played an important role in regulating the activity of mouse macrophages. Our findings provide new insights into mechanisms underlying the immune evasion and contribute to the exploration of potential targets for the development of new drug to control F. hepatica infection.

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.

Transcriptomic and proteomic profiling revealed global changes in Streptococcus thermophilus during pH-controlled batch fermentations

Yali Qiao,Cong Leng,Gefei Liu,Yanjiao Zhang,Xuepeng Lv,Hongyu Chen,Jiahui Sun,Zhen Feng 한국미생물학회 2019 The journal of microbiology Vol.57 No.9

Understanding global changes of physiological processes at the molecular level during the growth of Streptococcus thermophilus is essential for the rational design of cultivation media and the optimization of bioprocesses. Transcriptomics and proteomics were combined to investigate the global changes at the transcript and protein level during the growth of S. thermophilus. The expression of 1396 genes (FDR ≤ 0.001) and 876 proteins (P < 0.05) changed significantly over time. The most remarkable growth phase dependent changes occurred in the late-lag phase and were related to heterofermentation, glycolysis, peptidoglycan biosynthesis, conversion between amino acids and stress response. The present results could provide theoretical guidance for high-cell-density culture, help design cultivation media, and help attain a high biomass of S. thermophilus.

Self-Healing Polycarbonate-Based Polyurethane with Shape Memory Behavior

Li Shuai,Zhang Jun,Chen Jianjun,Yao Ming,Liu Xuepeng,Jiang Zhiguo 한국고분자학회 2019 Macromolecular Research Vol.27 No.7

A self-healing polycarbonate-based shape memory polyurethane (PCPU) comprising of polycarbonate diol, 4,4'-diphenylmethane diisocyanate (MDI) and 1,4- Butanediol (1,4-BDO) was synthesized. Through a series of shape memory tests, PCPUs showed 100% shape fixation rate, and a shape recovery rate of over 95% within 15 s. PCPUs exhibit excellent mechanical properties compared to common shape memory polymers, such as a tensile strength of up to 38.10 MPa and elongation at break of 616%. Additionally, after being damaged, polyurethane can self-heal within 60 s at 80 °C without any external force, which makes it applicable in many fields.