Evaluation on Dry Sliding Wear Behavior of (TiB+TiC)/Ti- 6Al-4V Matrix Composite

Zi-Run Yang,Hai-Xiang Huan,Cui-Feng Jiang,Wen-Min Li,Xue-Ran Liu,류성기 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.8

The dry sliding wear tests were performed for 10 vol.% (TiB+TiC)/Ti-6Al-4V matrix composites at various test conditions. The morphology and phases of worn surfaces and cross-sectional surfaces were investigated by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The wear loss of composites with the increase of load, but the wear behavior got more complex when the sliding speed and ambient temperature got higher. Low wear loss was achieved at lower sliding speed with higher temperature or higher sliding speed with lower temperature. A tribo-layer was always formed on worn surface during testing. It possessed different features and thus presented different effects during sliding wear. Meanwhile, the TiB and TiC particulates strengthened the Ti-6Al- 4V matrix, which increased the thermal stability of composites and postponed the occurrence of severe plastic deformation. In the mild wear region, those particulates could directly resist wear by reducing adhesive wear. In the steady stage, fractured TiB and TiC particulates participated in forming the tribo-layer together with wear debris, which effectively hindered the plastic deformation and thermal softening of the matrix. Experiment results suggest that the existence of different characteristic tribo-layers would result in the variation of wear behavior.

Selected microRNA-192 mutant indicates association with several function genes in bovine cells

Chen Zi,Dexin Zeng,Jiyong Zhou,Jianjun Dai,Luyan Jiang,Feng Xue,Yuan Jiang,Baoguang Li 한국유전학회 2018 Genes & Genomics Vol.40 No.4

MicroRNAs are implicated in many cellular processes such as cell differentiation and development, tumorigenesis, and immune regulation. In this study, miR192 was detected using quantitative real-time polymerase chain reaction (qRT-PCR) when MDBK cells were exposed to Escherichia coli. Cells with malfunction of bta-miR-192 were established using transcription activator-like effector nuclease (TALEN) technology. Finally, bta-miR-192 mutant cells were screened for differentially expressed genes using RNA-sequencing (RNA-seq). The results showed that miR192 significantly decreased in cells exposed to E. coli F18ac and E. coli K88ac. The RNA-seq results showed that 1673 differentially expressed transcripts were identified; 890 genes were upregulated and 775 genes were downregulated. With the gene ontology enrichment analysis, 431 differentially expressed genes (DEGs) were classified into 937 gene ontology terms. The pathway enrichment analysis showed that 535 genes were involved in 254 pathway terms. Interestingly, most of these DEGs were associated with the pathways in cancers or infectious diseases. When the selected DEGs (n = 162) in these pathways were intersected with 120 differential transcripts, 11 DEGs were identified. Subsequently, several genes associated with regulation, cancers, or viral infections, such as LEF1, AXIN2, MX1, and FCGR2B, were identified among the DEGs using functional analysis. Furthermore, associations between bta-miR-192 and DEGs were detected by intersecting the bta-miR-192’s target genes with the DEGs, indicating that three genes including CBL, DICER1 and TRERF1 were involved in this relationship. These findings provided useful guidance for investigating the role played by bta-miR-192 in cellular functionality in bovine cells.

Cloning and expression pattern of odorant receptor 11 in Asian honeybee drones, Apis cerana (Hymenoptera, Apidae)

Jun Feng Liu,Le Yang,Mang Li,Xu Jiang He,Zi-long Wang,Zhijiang Zeng 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.1

Odorant receptors play a crucial role in the special recognition of scent molecules in the honeybee olfaction system. The odorant receptor 11 (AmOR11) in western honeybee drones (Apis mellifera) has been demonstrated to specifically bind to 9-oxo-2-decenoic acid (9-ODA) of queens. However, little is known regarding the functions of OR11 Asian honeybee drones (Apis cerana) in the context of their mating activities. In this study, the odorant receptor 11 gene (AcOr11) from A. cerana was cloned, and its expression profiles were examined during two developmental stages (immature and sexually mature) and different physiological statuses (flying and crawling). The cDNA sequence of AcOr11 was highly similar to that of AmOr11, and encoded a membrane-coupled protein of 384 amino acids. The results of qRT-PCR indicated that AcOr11 was expressed at higher levels in drone antennae compared to brains, and the expression was significantly up-regulated in sexually mature drone brains compared to immature brains. Interestingly, AcOr11 expression in brains of mature flying drones was dramatically higher than those of mature crawling drones. To our knowledge, this study demonstrate a link between AcOr11 gene expression in the brain of honeybee drones and behavior associated with sexual maturity and mating flight.

A novel synthesis of ditrimethylolpropane biphosphoramide diethyleneamine as flame retardant and antistatic textiles

Wei Jiang,Jin-Feng Li,Zi-Yuan Li,Xiao-Yan Zhang,Fan-Long Jin,박수진 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.4

A novel phosphorous- and nitrogen-containing flame retardant, ditrimethylolpropane biphosphoramide diethyleneamine (DBD), was synthesized. Its chemical structure is characterized by Fourier-transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. The effect of DBD on the physical, mechanical, and antistatic properties, thermal stability, and flame retardancy of wool fabric was systematically investigated. Thermogravimetric analysis showed that the initial decomposition temperature of DBD was 165 oC and 243 oC under nitrogen and air atmosphere, respectively. Furthermore, after 30 washes, the treated wool fabric exhibited excellent wash durability and good antistatic properties. Vertical burning tests indicated that both the burning time and char length of the treated wool fabric were lower than those of the flame-retardant standard, leading to a B1 flame retardant rating for the treated wool fabric. Compared to untreated wool fabric, the limiting oxygen index value of treated wool fabric increased significantly from 25.7% to 34.7%.

DFT and TD-DFT study on structure and properties of organic dye sensitizer TA-St-CA

Cai-Rong Zhang,Zi-Jiang Liu,Yu-Hong Chen,Hong-Shan Chen,You-Zhi Wu,WangJun Feng,Dao-Bin Wang 한국물리학회 2010 Current Applied Physics Vol.10 No.1

The geometry, electronic structure, polarizability and hyperpolarizability of organic dye sensitizer TA-St-CA, which contains a π-conjugated oligo-phenylenevinylene unit with an electron donor.acceptor moiety, was studied using density functional theory (DFT), and the electronic absorption spectrum was investigated via time-dependent DFT (TD-DFT) with several hybrid functionals. The calculated geometry indicates that the strong conjugated effects are formed in the dye. The TD-DFT results show that the hybrid functional PBE1PBE and MPW1PW91 are more suitable than B3LYP for calculating electronic absorption spectra. The features of electronic absorption spectra were assigned on account of the qualitative agreement between the experiment and the calculations. The absorption bands in visible and near-UV region are related to photoinduced electron transfer processes, and the diphenylaniline group is major chromophore that contributed to the sensitization, and the interfacial electron transfer are electron injection processes from the excited dyes to the semiconductor conduction band. Compared with the similar dye D5, the good performance of TA-St-CA in dye-sensitized solar cells may be resulted from the higher energy level of the lowest unoccupied molecular orbital and the larger oscillator strengths for the most excited states with intramolecular electron transfer character.

A DNA-Based Approach Assigns Species Identity to Extreme Sexual Dimorphism: A Case Study of Fig Wasps (Hymenoptera, Chalcidoidea, Agaonidae)

Da-Wei Huang,Zi-Feng Jiang,Chao-Dong Zhu 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05

Silencing of long noncoding RNA PVT1 inhibits podocyte damage and apoptosis in diabetic nephropathy by upregulating FOXA1

Dong-Wei Liu,Jia-Hui Zhang,Feng-Xun Liu,Xu-Tong Wang,Shao-Kang Pan,Deng-Ke Jiang,Zi-Hao Zhao,Zhang-Suo Liu 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

The number of patients with diabetic nephropathy (DN) is still on the rise worldwide, and this requires the development of new therapeutic strategies. Recent reports have highlighted genetic factors in the treatment of DN. Herein, we aimed to study the roles of long noncoding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) and histone 3 lysine 27 trimethylation (H3K27me3) in DN. A model of DN was established by inducing diabetes in mice with streptozotocin. Mouse podocyte clone 5 (MPC5) podocytes and primary podocytes were cultured in normal and high glucose media to observe cell morphology and to quantify PVT1 expression. The roles of PVT1 and enhancer of zeste homolog 2 (EZH2) were validated via loss-of-function and gain-of-function in vitro experiments to identify the interactions among PVT1, EZH2, and forkhead box A1 (FOXA1). The podocyte damage and apoptosis due to PVT1 and FOXA1 were verified with in vivo experiments. PVT1 was highly expressed in MPC5 and primary podocytes in DN patients and in cultures grown in high glucose medium. A large number of CpG (C-phosphate-G) island sites were predicted at the FOXA1 promoter region, where PVT1 recruited EZH2 to promote the recruitment of H3K27me3. The silencing of PVT1 or the overexpression of FOXA1 relieved the damage and inhibited the apoptosis of podocytes in DN, as was evidenced by the upregulated expression of synaptopodin and podocin, higher expression of Bcl-2, and lower expression of Bax and cleaved caspase-3. The key findings of this study collectively indicate that the suppression of lncRNA PVT1 exerts inhibitory effects on podocyte damage and apoptosis via FOXA1 in DN, which is of clinical significance.