Reduced Graphene Oxide-Zinc Sulfide Nanocomposite Decorated with Silver Nanoparticles for Wastewater Treatment by Adsorption, Photocatalysis and Antimicrobial Action.

Reduced graphene oxide nanosheets decorated with ZnS and ZnS-Ag nanoparticles are successfully prepared via a facile one-step chemical approach consisting of reducing the metal precursors on a rGO surface. Prepared rGO-ZnS nanocomposite is employed as an adsorbent material against two model dyes: malachite green (MG) and ethyl violet (EV). The adsorptive behavior of the nanocomposite was tuned by monitoring some parameters, such as the time of contact between the dye and the adsorbent, and the adsorbent dose. Experimental data were also simulated with kinetic models to evaluate the adsorption behavior, and the results confirmed that the adsorption of both dyes followed a pseudo 2nd order kinetic mode. Moreover, the adsorbent was also regenerated in a suitable media for both dyes (HCl for MG and ethanol for EV), without any significant loss in removal efficiency. Ag doped rGO-ZnS nanocomposite was also utilized as a photocatalyst for the degradation of the selected organic contaminant, resorcinol. The complete degradation of the phenolic compound was achieved after 60 min with 200 mg of rGO-ZnS-Ag nanocomposite under natural sunlight irradiation. The photocatalytic activity was studied considering some parameters, such as the initial phenol concentration, the photocatalyst loading, and the pH of the solution. The degradation kinetics of resorcinol was carefully studied and found to follow a linear Langmuir-Hinshelwood model. An additional advantage of rGO-ZnS and rGO-ZnS-Ag nanocomposites was antibacterial activity against Gram-negative bacterium, E. coli, and the results confirmed the significant performance of the nanocomposites in destroying harmful pathogens.

Facile synthesis of graphene oxide-silver nanocomposite for decontamination of water from multiple pollutants by adsorption, catalysis and antibacterial activity.

Here in, we presented a facile one-step method for the synthesis of Graphene oxide-silver (GO-Ag) nanocomposite and its applications as a sorbent for the elimination of some toxic pollutants from aqueous medium, as an efficient catalyst in the individual as well as simultaneous reduction reactions of multiple compounds, and as an antibacterial agent for the destruction of some harmful microorganisms existent in wastewater. GO was prepared using a modified Hummers method and Ag nanoparticles were integrated on GO sheets by chemical reduction of Ag+ ions on the surfaces of GO sheets. The composition and morphology of the nanocomposite was extensively characterized with elemental dispersive X-ray analysis (EDX), Fourier transform infra-red (FT-IR) spectroscopy, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA). The GO-Ag nanocomposite demonstrated remarkable adsorption capacities and recyclability for malachite green (MG) and ethyl violet (EV) dyes. Various experimental parameters affecting adsorptive behavior of nanocomposite like temperature, pH, time of contact between dye and adsorbent, and adsorbent dose were evaluated thoroughly. Experimental data was simulated with different adsorption isotherms and kinetic models to evaluate adsorption behavior of both dyes and results confirmed the adsorption of both the dyes to be followed by pseudo 2nd order kinetic model and Langmuir adsorption model. Moreover, adsorbent was regenerated in suitable media for both dyes without any loss in removal efficiency. The catalytic performance for the 2-nitroaniline (2-NA) reduction was investigated in detail. Most importantly, the prepared nanocomposite was found to have potential to adsorb multiple pollutants all together as well as to catalyze the simultaneous reduction of a mixture of dyes (MG, MO, and EV) and 2-NA. An additional advantage of the GO-Ag nanocomposite was its antibacterial activity acquired to the presence of Ag nanoparticles. Two bacterial strains (Gram-negative bacterium, E. coli and the Gram-positive bacterium, S. aureus) were used to test antibacterial activity of composite and the results confirmed the remarkable performance of the nanocomposite in destroying harmful pathogens.

Development of a breast reconstruction satisfaction questionnaire (BRECON-31): principal components analysis and clinimetric properties.

BACKGROUND: A reliable, valid questionnaire is essential to assess patient satisfaction with breast reconstruction. METHODS: A 105-item pilot BRECON questionnaire was previously developed. One hundred eighty-one women with breast reconstruction were mailed the pilot BRECON, BREAST-Q, and EQ-5D questionnaires. Fifty women were re-mailed the BRECON. Based on the responses, the BRECON was refined using statistical means and principal components analysis (PCA). Reliability was assessed using the intraclass correlation coefficient (ICC) and Cronbach's alpha. Validity was assessed by comparing subscales of the BRECON to the BREAST-Q and comparing a summary score of the BRECON-31 to the EQ-5D using the Pearson's correlation coefficient (PCC). RESULTS: A total of 71% (128/181) of women completed the three questionnaires, and 86% (43/50) of women responded to the re-mailed BRECON. Statistical methods and PCA maintained 31 items covering eight components including self-image, arm concerns, intimacy, satisfaction, recovery, self-consciousness, expectations, and breast appearance. A 4-item "nipple" subscale and a 10-item "abdominal" subscale were developed for use where applicable. Measures of reliability and validity were high: Cronbach's alpha ranged from 0.67 to 0.91, ICC ranged from 0.55 to 0.85, and PCC ranged from 0.42 to 0.76. CONCLUSIONS: A reliable, valid 31-item breast reconstruction satisfaction questionnaire was developed.

Biochemical analysis of arginine methylation in transcription.

Protein arginine methylation has emerged as an important mechanism for regulating the functions of proteins involved in diverse aspects of gene regulation such as transcriptional activation and repression, mRNA processing and nuclear-cytoplasmic shuttling. This modification is catalyzed by the PRMT family of enzymes which utilize intracellular S-adenosyl methionine as a cofactor to dimethylate-specific arginines found within many target proteins.The establishment of in vitro biochemical assays as well as the development of modification-specific antibodies, and more recently mass spectrometry, have increased our understanding of the mechanism of catalysis of the PRMT family of enzymes. In the following discussion, we present some of the more commonly used in vivo and in vitro techniques which can be utilized to study the mechanism of arginine methylation and its role in transcription.

The activity and stability of the transcriptional coactivator p/CIP/SRC-3 are regulated by CARM1-dependent methylation.

The transcriptional coactivator p/CIP(SRC-3/AIB1/ACTR/RAC3) binds liganded nuclear hormone receptors and facilitates transcription by directly recruiting accessory factors such as acetyltransferase CBP/p300 and the coactivator arginine methyltransferase CARM1. In the present study, we have established that recombinant p/CIP (p300/CBP interacting protein) is robustly methylated by CARM1 in vitro but not by other protein arginine methyltransferase family members. Metabolic labeling of MCF-7 breast cancer cells with S-adenosyl-L-[methyl-(3)H]methionine and immunoblotting using dimethyl arginine-specific antibodies demonstrated that p/CIP is specifically methylated in intact cells. In addition, methylation of full-length p/CIP is not supported by extracts derived from CARM1(-/-) mouse embryo fibroblasts, indicating that CARM1 is required for p/CIP methylation. Using mass spectrometry, we have identified three CARM1-dependent methylation sites located in a glutamine-rich region within the carboxy terminus of p/CIP which are conserved among all steroid receptor coactivator proteins. These results were confirmed by in vitro methylation of p/CIP using carboxy-terminal truncation mutants and synthetic peptides as substrates for CARM1. Analysis of methylation site mutants revealed that arginine methylation causes an increase in full-length p/CIP turnover as a result of enhanced degradation. Additionally, methylation negatively impacts transcription via a second mechanism by impairing the ability of p/CIP to associate with CBP. Collectively, our data highlight coactivator methylation as an important regulatory mechanism in hormonal signaling.