19F NMR-Based Fragment Screening for 14 Different Biologically Active RNAs and 10 DNA and Protein Counter-Screens

We report here the nuclear magnetic resonance ¹⁹F screening of 14 RNA targets with different secondary and tertiary structure to systematically assess the druggability of RNAs. Our RNA targets include representative bacterial riboswitches that naturally bind with nanomolar affinity and high specificity to cellular metabolites of low molecular weight. Based on counter-screens against five DNAs and five proteins, we can show that RNA can be specifically targeted. To demonstrate the quality of the initial fragment library that has been designed for easy follow-up chemistry, we further show how to increase binding affinity from an initial fragment hit by chemistry that links the identified fragment to the intercalator acridine. Thus, we achieve low-micromolar binding affinity without losing binding specificity between two different terminator structures.     

Enterprise social media and cyber-slacking: A Kahn’s model perspective

This study investigates the associations between enterprise social media (ESM) use, psychological conditions, and cyber-slacking in the workplace and examines the mediating role of psychological conditions between ESM use and cyber-slacking. The study utilizes Kahn’s framework to develop a research model and investigate various associations, and it employs a cross-sectional design, testing the developed research model with 277 ESM users from Chinese enterprises. The study results suggest that ESM use stimulates various psychological conditions that discourage cyber-slacking behaviors and significantly mediate the associations between ESM use and cyber-slacking.     

Preparation and characterization of genistein containing poly(ethylene glycol) microparticles

The purpose of this study was to prepare, characterize, and evaluate genistein‐containing microparticles with enhanced dissolution profile using poly(ethylene glycol) (PEG) as polymer matrix. Genistein loaded microparticles were prepared by a solvent evaporation process and their surface, thermal, chemical, and dissolution properties were analyzed by microscopy, differential scanning calorimetry, ATR‐FTIR spectroscopy, and USP dissolution apparatus II, respectively. The wettability index was also determined. Genistein exhibited an elongated crystal habit. However, the drug containing PEG microparticles were discrete and quasispherical. The ATR‐FTIR studies performed on the formulation suggested hydrogen bonding between the drug and the polymer matrix. Thermal analysis indicated a conversion of the crystalline form of the drug to an amorphous form. Genistein, exhibiting low solubility and high permeability, is a Class II drug of the Biopharmaceutical Classification Scheme. However, there was a ～9‐fold increase in the rate of dissolution of genistein in the case of all formulations as compared to native genistein. This study showed that genistein could be effectively encapsulated into PEG microparticles using an emulsion‐solvent evaporation technique, therefore avoiding the potential disadvantages of other solid dispersion techniques. This approach provided a significant enhancement in the drug dissolution profile. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2070–2078, 2006     

Graft copolymerization of methyl methacrylate onto wool by use of ferrous ion–peroxodiphosphate

Polymethyl methacrylate has been graft copolymerized onto wool using a ferrous ion–peroxodiphosphate initiator system in an aqueous methanol medium. Graft copolymerization was carried out at 20°C, 30°C, 40°C, and 50°C. The rate of grafting was found to be dependent on the concentrations of monomer (MMA), ferrous ion (Fe²⁺), peroxodisphosphate (PP), wool (w), and reaction temperature. [Acid], solvent composition and ionic strenghth were also varied to study their effect on grafting. Based on the experimental results, a suitable kinetic scheme was proposed. Rate and thermodynamic parameters were also varied to study their effect on grafting. Based on the experimental results, a suitable kinetic scheme was proposed. Rate and thermodynamic parameters were also evaluated.     

Quantification of oxytocin residues in dairy milk from Sindh,Pakistan

In this study, a total of 84 milk samples (60 nonbranded and 24 branded) were analysed for occurrence of oxytocin (OT) residues by ELISA. OT level was detected in the range of 39.29–456.55 pg mL^?1 with mean value of 138.53 ng L^?1. In branded milk samples, OT residues were minimal as compared to nonbranded milk samples. Nonbranded milk samples had higher prevalence of OT residues; 16.67% had OT level in the range of ≤500 ng L^?1. The average daily intake of OT was found 0.087 μg day^?1 per person. It was concluded that the OT concentration was relatively higher in samples obtained from dairy farm, dairy shop and milk man than that in ultra‐high temperature (UHT) and powder milk samples. In addition, there are no reports subjected to standardising a permissible OT level in dairy milk category, although OT is considered detrimental to both human and animal life.     

Determination of Cadmium and Lead in Water and Food by Organic Drop Microextraction and Flame Atomic Absorption Spectrometry

Single-solidified floating organic drop microextraction was used for the preconcentration and determination of Cd(II) and Pb(II). The procedure employed 1-(2-pyridylazo)-2-naphthol as a chelating agent, 1-undecanol as the extractant solvent, and methanol as the dispersive solvent. Factors influencing the recovery of Cd(II) and Pb(II) such as the pH, volume of extractant, volume of ligand, volume of dispersant, and stirring time were optimized by Plackett Burman design. In order to complete the optimization, a central 2³ +star orthogonal composite design was applied. The limits of detection for Cd(II) and Pb(II) were 0.15 and 0.52 μg L^?1. The validation of the procedure was evaluated by the analysis of TMDA 70 Fortified Water and NCSDC–73349 Bush Branches certified reference materials. The determined values were in good agreement with the certified values. The single-solidified floating organic drop microextraction method was employed for the determination of cadmium and lead in water, vegetables, and fruit.     

Variation in accumulation of heavy metals in different verities of sunflower seed oil with the aid of multivariate technique

In this work, three heavy metals (HMs) cadmium, lead, and zinc were determined in 16 newly breaded varieties of sunflower seed oil, using atomic absorption spectrometry, prior to use of microwave-assisted acid digestion method (MWD). The accuracy of the proposed method was studied by standard addition method and values obtained by conventional wet acid digestion methods (CAM) on same samples. The detection limit obtained from the standard addition curve was 0.327, 3.38, 10.0 ng/ml for Cd, Pb, and Zn, respectively, with high percentage recoveries. Multivariate statistical techniques (cluster and principal component analysis) were applied to modeling classes of different varieties of sunflower seed oils grown in same agricultural plot, on the basis of the analytical data of HMs. The results obtained providing sufficient information on tolerable limit of all three HMs by different varieties of sunflower oil to grow safely.