Characterization of the draping behavior of jute woven fabrics for applications of natural‐fiber/epoxy composites

In this study, we investigated the draping behavior of jute woven fabric to study the feasibility of using natural fabrics in place of synthetic glass‐fiber fabrics. Draping behavior describes the in‐mold deformation of fabrics, which is vital for the end appearance and performance of polymer composites. The draping coefficient was determined with a common drapemeter for fabrics with densities of 228–765 g/m² and thread counts under different humidity and static dynamic conditions. The results were compared to glass‐fiber fabrics with close areal densities. Characterization of the jute fabrics was carried out to fill the knowledge gap about natural‐fiber fabrics and to ease their modeling. The tensile and bending stiffnesses and the shear coupling were also characterized for a plain woven jute fabric with a tensile machine, Shirley bending tester, and picture frame, respectively. As a case study, the draping and resin‐transfer molding of the jute fabric over a complex asymmetric form was performed to measure the geometrical conformance. The adoption of natural fibers as a substitute for synthetic fibers, where the strength requirements are satisfied, would thus require no special considerations for tool design or common practices. However, the use of natural fibers would lead to weight and cost reductions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1453–1465, 2013     

On the Reaction of α,α-Dichlorocarbenium Ions with Isocyanates

Trichlormethanes 4 react with two equivalents of n-alkyl isocyanates R²-NCO in the presence of SbCl₅ to furnish the 2,2-dichloro-5,6-dihydro-6-oxo2H-1,3,5-oxadiazinium salts ( 9 ). The structure of these heterocycles is confirmed by an X-ray analysis of 9d (R¹ = ClC = CCl₂, R² = Et). p-Tolyl isocyanate is Friedel-Crafts alkylated by 4b in the presence of SbCl₅. Subsequent ring closure affords the quinolinium salt 13 , which is hydrolyzed to give inter alia the quinolone 16 .     

Novel Inhibitor for Downstream Targeting of Transforming Growth Factor-β Signaling to Suppress Epithelial to Mesenchymal Transition and Cell Migration

Cancer metastasis accounts for most of the mortality associated with solid tumors. However, antimetastatic drugs are not available on the market. One of the important biological events leading to metastasis is the epithelial to mesenchymal transition (EMT) induced by cytokines, namely transforming growth-factor-β (TGF-β). Although several classes of inhibitors targeting TGF-β and its receptor have been developed, they have shown profound clinical side effects. We focused on our synthetic compound, HPH-15, which has shown anti-fibrotic activity via the blockade of the TGF-β Smad-dependent signaling. In this study, 10 μM of HPH-15 was found to exhibit anti-cell migration and anti-EMT activities in non-small-cell lung cancer (NSCLC) cells. Although higher concentrations are required, the anti-EMT activity of HPH-15 has also been observed in 3D-cultured NSCLC cells. A mechanistic study showed that HPH-15 inhibits downstream TGF-β signaling. This downstream inhibition blocks the expression of cytokines such as TGF-β, leading to the next cycle of Smad-dependent and -independent signaling. HPH-15 has AMPK-activation activity, but a relationship between AMPK activation and anti-EMT/cell migration was not observed. Taken together, HPH-15 may lead to the development of antimetastatic drugs with a new mechanism of action.     

Active packaging gelatin films based on chitosan/Arabic gum/coconut oil Pickering nano emulsions

This investigation intended at fabricating gelatin active packaging films based on nano-sized droplets of coconut oil emulsified by Pickering emulsion (PE) using chitosan/Arabic gum (CH/AG) nanoparticles (NPs) as a stabilizer and in the presence of titanium dioxide NP (TiO₂ NPs) as an extra antimicrobial agent. The developed films were characterized by attenuated total reflectance–Fourier transmittance infrared, X-ray diffraction, and scanning electron microscope. The antimicrobial, antioxidant, water vapor sorption isotherm, and mechanical properties of the prepared films were assessed. The (CH/AG) NPs weight ratios (1:1, 1:2, and 2:1) impact on particle size (PS), zeta potential, wettability, morphology, and in vitro cumulative release was investigated. The (CH/AG) NPs (1:2) exhibits the small PS (246.4 nm). (CH/AG) NPs and PE exhibit spherical and oval morphologies. The CH/AG (1:2) exhibits the higher water contact angle (85.7^o). At the oil volume fraction (α) = 1.0, nearly 81% of the entrapped oil released from the NPs. Gelatin films enriched with P at α = 1.0 exhibits two-fold increasing scavenging activity % (35.69 ± 0.56) compared with control film (14.8 ± 0.25). The films have a considerable antibacterial and antifungal activity for all test microorganism. However, control sample did not show antimicrobial activity against Bacillus cereus and Candida albicans.