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A protective coating is applied on the material surface to enhance the wear resistance, corrosion resistance, and aesthetics and are imperative for the industries, automobiles, and domestic appliances. Recently, researchers are interested in graphene-based nanosheets (GNS) as an additive to coatings owing to their exceptional mechanical, chemical, and catalytic properties, in turn ensuing variety of valuable applications. Here, in the present investigation we have synthesized the graphene oxide (GO) and graphene and blended with our optimized formulation (coating), comprises Alkyd, BUF resin, butyl cellulose, butanol, xylene, para-toluene sulphonic acid, and graphene-based nanosheets. Experiments are carried out by coating the blend on the wood panels and are characterized for various properties such as viscosity, density, surface drying time, tack free drying time, gloss, cross cut, alkaline, and acid test. The experimental results have demonstrated that the desirable properties of coatings are enhanced upon incorporating graphene-based nanosheets. This work implies the potential of the nano thick graphene-based material and its adaptability can be effectively used in numerous technological applications. [ABSTRACT FROM AUTHOR]

Two generations of poly (propylene imine) dendrimer with amino terminated groups (G2- and G5-PPI-NH) were grafted on cotton cellulose fabric using cross linking agents (citric or glutaric acids). Fourier transform infrared (FTIR) spectroscopy identified ester groups which were formed between hydroxyl groups of the cotton fabric and carboxylic groups of the cross linking agents. Also, attenuated total reflectance-FTIR (ATR-FTIR) analysis confirmed formation of amide groups between the carboxylic groups of the cross linking agents and the amino end groups of the dendrimers. Nitrogen content (N-content) analysis revealed the presence of the dendrimers on the cotton fabric even after 5 washing cycles. In order to study the dispersion of the PPI dendrimers on the surface of the cotton fabric, field emission scanning electron microscopy (FE-SEM) was performed. The particle size distribution of the G2- and G5-PPI-NH aqueous solutions was also determined by dynamic light scattering (DLS) analysis. Antimicrobial activity of the PPI dendrimer aqueous solutions and the cotton cellulose fabric grafted with the dendrimers was evaluated both quantitatively and qualitatively against Gram-positive bacterium (Staphylococcus aureus), Gram-negative bacteria ( Pseudomonas aeruginosa and Escherichia coli) and fungus ( Candida albicans). The dendrimer grafted cotton cellulose fabric exhibited a 99 % reduction in bacterial counts against S. aureus, E. coli and C. albicans. The antimicrobial activities of the grafted cotton cellulose fabric with the PPI dendrimers were maintained even after 5 washing cycles. [ABSTRACT FROM AUTHOR]

Abstract: Comet assay under neutral conditions allows detection of DNA double-strand breaks (DSBs), which has consequence to genome instability and carcinogenesis. The present study aims to validate the neutral Comet assay for genotoxicity assessment in Drosophila melanogaster (Oregon R+) with three well known DSBs inducers i.e. cyclophosphamide (CP), bleomycin (BLM), cisplatin (CPT) and subsequently its efficacy in detecting DSBs in the organism exposed to a well known environmental chemical, chromium [Cr(VI)]. Third instar larvae of D. melanogaster were fed different concentrations of BLM, CPT and CP (50.0–200.0μg/ml) or Cr(VI) (5.0–20.0μg/ml) mixed standard Drosophila food for 48h. Neutral Comet assay was performed in cells of mid gut and brain from control and treated larvae. Our results show a dose-dependent increase in the migration of DNA in cells of the exposed organisms. A comparison among DNA lesions per mole number of the test chemical in the exposed groups showed that both BLM and CPT induce more DSBs than CP. Interestingly, Cr(VI) at 20.0μg/ml was found to induce significantly increased (p <0.001) DSBs in the exposed organism as compared to the control. The study while validating neutral Comet assay in D. melanogaster suggests its use for in vivo assessment of environmental chemical induced DSBs. [Copyright &y& Elsevier]

Biological macromolecules such as DNA, proteins, and polysaccharides often display unique absorptive signatures in the THz region, useful in their identification and imaging through Raman and Fourier transform transmission spectroscopy. The optoelectronic properties of nanostructure-DNA complexes immobilized on transparent, semi-rigid substrates such as polymethyl methacrylate (PMMA) have been studied. By chemically modifying the PMMA substrates with amine terminal groups and using suitable linking agents, amine terminated DNA can be localized on these substrates. THz Fourier transform transmission spectroscopy was used to detect low-frequency vibrational modes (10-25 cm-1) within single- and double-stranded DNA molecules immobilized on PMMA attached to TiO2 nanoparticles. Additionally, DNA strands end terminated with TiO2 nanoparticles are used in this study to cleave the DNA at guanine (G) rich sites due to trapping of photo-induced charge carriers from the TiO2 at these sites. Theoretical modeling of charge transport through DNA via polaron transport is discussed in detail. By examining the vibrational modes of DNA, as well as the transport of charge in DNA this study underlies potential applications involving DNA micro-arrays, DNA-based sensors, and DNA-based THz devices. [ABSTRACT FROM PUBLISHER]

Kinetic and thermodynamic studies of the reaction of urea with formaldehyde have led to a technically feasible synthesis of hitherto unknown trialkoxymethyl ureas, particularly trimethoxymethyl urea. Fabrics cured with trimethoxymethyl urea exhibit better resistance to acid hydrolysis than those finished with dimethylol urea. Reactivities, hydrolysis stabilities and other applied properties are described in relation to various reaction parameters.Investigations of the equilibrium states and formation and dissociation constants led to the discovery that, when a monocarboxylic acid amide is reacted with at least two molecules of formaldehyde in highly concentrated solutions, dime thylol compounds can be converted in high yields, by acetalation with alcohols, to the stable N, N-dialkoxymethyl mono carboxylic acid amides. Chlorine-and hydrolysis-resistant, nonwrinkling finishes can be obtained with the N,N-dimethoxy methyl monocarboxylic acid amides just like the dimethylol carbamates.Methylol compounds of 4,5-dihydroxyethylene ureas and of 4-hydroxy (alkoxy)-5, 5-dialkylpropylene ureas occupy a special position, since not only the methylol groups, but also the ring hydroxy or alkoxy groups can be substituted by O- cellulose residues under certain reaction conditions.4,5-Dihydroxy (alkoxy)-ethylene ureas undergo conversion reactions in acid media, particularly at elevated tempera tures, and hydantoin derivatives and strongly colored intermediate products are formed after passing through the 4-hy droxy (alkoxy)-imidazolone stage.While the 4,5-dihydroxy (alkoxy)-ethylene ureas are practically useless for a wrinkle-free finish, and their monomethylol compounds are only conditionally suitable, finishes with good characteristics can be achieved with the monomethylol compounds of 4-hydroxy (alkoxy)-5.5-dialkylpropylene ureas. The kinetics and reaction mechanisms of curing with 4, 5- dihydroxy (alkoxy)-ethylene ureas and with 4-hydroxy (alkoxy)-5,5-dialkylpropylene ureas in relation to various reaction parameters are discussed in detail.Finally, the kinetics and mechanisms of crosslinking with N-methylol compounds are briefly considered. [ABSTRACT FROM PUBLISHER]