Homophilic Interaction of CD147 Promotes IL-6-Mediated Cholangiocarcinoma Invasion via the NF-κB-Dependent Pathway

Cholangiocarcinoma (CCA), an aggressive cancer of bile ducts, is a well-known chronic inflammation-related disease. The major impediment in CCA treatment is limited treatment options for advanced disease; hence, an alternative is urgently required. The role of CD147 on cytokine production has been observed in inflammation-related diseases, but not in CCA. Therefore, this study was focused on CD147-promoting proinflammatory cytokine production and functions. Proinflammatory cytokine profiles were compared between CD147 expressing CCA cells and CD147 knockout cells (CD147 KO). Three cytokines, namely interleukin (IL)-6, IL-8, and granulocyte–monocyte colony-stimulating factor (GM-CSF), were dramatically diminished in CD147 KO clones. The involvement of the CD147-related cytokines in CCA invasion was established. CD147-promoted IL-6, IL-8, and GM-CSF secretions were regulated by NF-κB nuclear translocation, Akt activation, and p38 phosphorylation. CD147-fostering IL-6 production was dependent on soluble CD147, CD147 homophilic interaction, and NF-κB function. The overexpression of specific genes in CCA tissues compared to normal counterparts emphasized the clinical importance of these molecules. Altogether, CD147-potentiated proinflammatory cytokine production leading to CCA cell invasion is shown for the first time in the current study. This suggests that modulation of CD147-related inflammation might be a promising choice for advanced CCA treatment.     

Preparation and characterization of novel polyimide with chiral side chain for twist nematic liquid crystal display

The synthesis of novel polyimide (PI) films containing chirals in side chain was investigated for utilizing in twist nematic (TN) liquid crystal display (LCD). The polyimide with amine side groups (PI4 a.m.) was prepared by two steps copolymerization of 4,4′‐hexafluoroisopropylidene diphthalic anhydride (6FDA), 4,4′‐oxydianiline (ODA), and 3,3′‐diaminobezidine (4 a.m.) in N‐methyl‐2‐ pyrrolidinone (NMP). In the first step, the oligomer of 6FDA and ODA with mole ratio 4 : 3 was synthesized. In the second step, the oligomer was reacted with 4 a.m. by gradually dropping the oligomer into 4 a.m. solution with the mole ratio 4 : 5. By reacting chiral compounds, mandelic acid, menthyl chloroformate, and menthyl glyoxylate hydrate using condensation reaction with amine groups along polyimide molecules, the novel polyimides can be synthesized. Their chemical structures were confirmed by fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy (¹H‐NMR). The coated glass slides pairs were coated with PI4 a.m. and with each Polyimide/chiral. The liquid crystals (LCs) were inserted between two coated glass slides at above the nematic temperature under the polarized light microscope to observe the alignment of LCs. The results showed the alignment of LCs in some certain direction under Polyimide/chiral pair, regardless of the type of the chiral molecule. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Stress intensity factor solutions for estimation of fatigue lives of laser welds in lap-shear specimens

Fatigue behavior of laser welds in lap-shear specimens of high strength low alloy (HSLA) steel is investigated based on experimental observations and two fatigue life estimation models. Fatigue experiments of laser welded lap-shear specimens are first reviewed. Analytical stress intensity factor solutions for laser welded lap-shear specimens based on the beam bending theory are derived and compared with the analytical solutions for two semi-infinite solids with connection. Finite element analyses of laser welded lap-shear specimens with different weld widths were also conducted to obtain the stress intensity factor solutions. Approximate closed-form stress intensity factor solutions based on the results of the finite element analyses in combination with the analytical solutions based on the beam bending theory and Westergaard stress function for a full range of the normalized weld widths are developed for future engineering applications. Next, finite element analyses for laser welded lap-shear specimens with three weld widths were conducted to obtain the local stress intensity factor solutions for kinked cracks as functions of the kink length. The computational results indicate that the kinked cracks are under dominant mode I loading conditions and the normalized local stress intensity factor solutions can be used in combination with the global stress intensity factor solutions to estimate fatigue lives of laser welds with the weld width as small as the sheet thickness. The global stress intensity factor solutions and the local stress intensity factor solutions for vanishing and finite kinked cracks are then adopted in a fatigue crack growth model to estimate the fatigue lives of the laser welds. Also, a structural stress model based on the beam bending theory is adopted to estimate the fatigue lives of the welds. The fatigue life estimations based on the kinked fatigue crack growth model agree well with the experimental results whereas the fatigue life estimations based on the structural stress model agree with the experimental results under larger load ranges but are higher than the experimental results under smaller load ranges.