TCN1 Deficiency Inhibits the Malignancy of Colorectal Cancer Cells by Regulating the ITGB4 Pathway

Zhu Xinqiang,Jiang Xuetong,Zhang Qinglin,Huang Hailong,Shi Xiaohong,Hou Daorong,Xing Chungen 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.3

Background/Aims: This study aimed to investigate the biological function and regulatory mechanism of TCN1 in colorectal cancer (CRC). Methods: We studied the biological function of TCN1 by performing gain-of-function and loss-offunction analyses in HCT116 cell lines; examined the effects of TCN1 on the proliferation, apoptosis, and invasion of CRC cells; and determined potential molecular mechanisms using HCT116 and SW480 CRC lines and mouse xenotransplantation models. Tumor xenograft and colonization assays were performed to detect the tumorigenicity and metastatic foci of cells in vivo. Results: TCN1 knockdown attenuated CRC cell proliferation and invasion and promoted cell apoptosis. Overexpression of TCN1 yielded the opposite effects. In addition, TCN1-knockdown HCT116 cells failed to form metastatic foci in the peritoneum after intravenous injection. Molecular mechanism analyses showed that TCN1 interacted with integrin subunit β4 (ITGB4) to positively regulate the expression of ITGB4. TCN1 knockdown promoted the degradation of ITGB4 and increased the instability of ITGB4 and filamin A. Downregulation of ITGB4 at the protein level resulted in the disassociation of the ITGB4/plectin complex, leading to cytoskeletal damage. Conclusions: TCN1 might play an oncogenic role in CRC by regulating the ITGB4 signaling pathway.

Improving the Electrical Conductivity of PEDOT:PSS Films by Binary Secondary Doping

Zhengyou Zhu,Congcong Liu,Jingkun Xu,Qinglin Jiang,Hui Shi,Endou Liu 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.1

In this work, the electrical conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films was effectively enhanced by binarysecondary doping. Initially, doping with 5 vol.% dimethyl sulfoxide (DMSO)improved the electrical conductivity from 0.3 S cm−1 to 437 S cm−1 and a furtherincrease to 950 S cm−1 was achieved by adding LiClO4. The conductivity value wereport here is one of the highest reported for pretreated PEDOT:PSS films. Theobtained maximum electrical conductivity is almost 3000 times higher than thatshown by pristine PEDOT:PSS films. The increase in the electrical conductivity isascribed to the synergistic effect of the two dopants. Fourier transform infraredspectra indicated the absence of any changes to the chemical structure ofPEDOT:PSS. Atomic force microscopy images demonstrate an increased surfaceroughness and suggest the occurrence of conformational changes of PEDOT chainsfrom the coiled to coil-extended one, which is the key reason for the electricalconductivity enhancement. The pretreatments we propose here are rapid, simple andeffective for the large-scale preparation of high-conductivity PEDOT:PSS films.

Study on Residual Stress Distributions in Press-Braked Stainless Steel Sections

Baofeng Zheng,Gan-Ping Shu,Qinglin Jiang 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.5

The distribution of residual stresses is one of the substantial issues in determining mechanical behaviors of stainless steel structural members. Proper residual stress distribution models are necessary to include the residual stress infl uence in the analysis and design. Currently, the existing residual stress distribution model for press-braked stainless steel sections is either relatively complicated for the application, or only focuses on the longitudinal residual stress. In this study, a simplifi ed residual stress distribution model was proposed based on the analysis of the key mechanisms in the press-braking process that was assumed as two-stage (bending and rebounding) plane strain pure bending process. The stress–strain relationship was represented as a simplifi ed three–stage material model, and all the minor eff ects like the coiling and uncoiling, the material anisotropy, and the shift of neutral axis, etc. were neglected. Compared with test data, the predicted results by the proposed simplifi ed model indicate good agreement for specimens within the commonly used ratio of internal corner radius over the thickness ( r i / t ). Finite element models for the press-braking process were then developed in ABAQUS and validated using the available data from literature. A series of models with varied ratios of r i / t were analyzed. Simulation results indicate that the center of the corner region in the press-braked sections has the largest equivalent plastic strain and residual stresses. From the center to the edge, the equivalent plastic strain and residual stresses declined signifi cantly. As the ratios of r i / t become smaller and smaller, the neutral axis moves towards to the compression side and the proposed simplifi ed model gradually loses its prediction accuracy. Based on the theoretical and fi nite element analysis, the proposed simplifi ed model is applicable for press-braked stainless steel sections with r i / t ratios higher than 2.0.

Research on Local Buckling of Stainless Steel Lipped C-Section Beam Around Strong-Axis

Shenggang Fan,Hang Zhou,Zhixia Ding,Chenxu Li,Qinglin Jiang 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.5

To study the local buckling capacity of stainless steel beams with lipped C-sections under strong axis bending, tensile tests were performed on 12 stainless steel coupons based on S30408 austenitic stainless steel (AISI304) in fl at and corner areas, and mechanical properties and stress–strain curves were obtained. Then, local buckling capacity tests were performed on 6 specimens of stainless steel beams under strong axis bending to determine their mechanical properties and failure mechanism. The failure phenomenon, load–displacement curve, load–strain curve and local buckling capacity were determined. Results show that the failure modes of the specimens are local buckling failure of the fl ange and web at mid-span. Additionally, a refi ned fi nite element analysis model was developed using Python and ABAQUS to simulate and analyse the mechanical performance and local buckling capacity. Then, the analytical results were compared to the test results, and the accuracy of the refi ned model was verifi ed. Then, the refi ned model of the stainless steel C-section beam was simplifi ed including the constraint simplifi cation model, which considered diff erent fl ange constraints and initial imperfections, and the length simplifi cation model, which was based on diff erent length and support constraints. The comparative analysis results showed that the constraint simplifi cation model can simulate the local buckling failure mode more accurately than other models. Additionally, initial imperfections were shown to have little eff ect on the local buckling capacity; however, specimen length and the bearing constraint condition did aff ect the local buckling capacity.

Material Enhancement Model for Austenitic Stainless Steel Sheets Subjected to Pre-stretching

Baofeng Zheng,Gan-Ping Shu,Rui-Hua Lu,Qinglin Jiang 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.5

Austenitic stainless steel has considerable strain hardening property, which can be utilized in the design of cold-formed stainless steel structures to eff ectively reduce project costs. Pre-stretching is a simple and fundamental cold-forming process. Material enhancement model developed for pre-stretching lays a basis for characterizing material properties in more complicated cold-forming process(e.g. cold-rolling and press-braking). In this study, a series of material tensile tests were performed to develop material enhancement models for austenitic stainless steel sheets subjected to pre-stretching. Austenitic stainless steel sheets were tensioned in six diff erent levels to introduce cold working into the sheets. Material properties of the sheets in two directions (i.e. along and perpendicular to the pre-stretching direction) were obtained through coupon tensile tests. To facilitate the development of the material enhancement models, a simplifi ed three-stage material model with six independent parameters was proposed. Enhancement model for each material parameter was developed with the plastic strain experienced in the pre-stretching process as a key factor. Key material parameters and full-range stress–strain curves at diff erent levels of pre-stretching were generated based on the proposed and the available predictive models in literatures. Comparisons of the generated material parameters and the stress–strain curves with the test ones show good agreement.