Fabrication of Polycrystalline Cubic Boron Nitride/Metal Composite Particles by Surface Metallization Followed by Electroless Deposition Technique.

Polycrystalline cBN/copper composite abrasive particles were prepared by an electroless powder coating process. Ti metallization and tin/silver metallization techniques were used to improve the coating process by depositing an autocatalytic metallic layer on the surface of the cBN particles. Metallized, as well as un-metallized, cBN particles were further coated by copper using electroless deposition.

In vitro selection of DNA aptamers and their integration in a competitive voltammetric biosensor for azlocillin determination in waste water.

The uncontrolled usage of veterinary antibiotics has led to their widespread pollution in waterways and milk products. Potential impact of antibiotic residues on the environment and human health such as increased antibiotic resistance of microorganisms and triggering allergic reactions in humans have been reported. In this work, we developed a highly selective and sensitive voltammetric aptasensor for on-step, sensitive and low cost detection of azlocillin antibiotic, one of the broad spectrum β-lactam antibiotics.

Decomposition of DNA staining agent ethidium bromide by gamma irradiation: Conditions, kinetics, by-products, biological activity, and removal from wastewater.

Ethidium Bromide (Eth-Br) is an intercalating agent commonly used in medical and biological laboratories as a DNA staining dye. Despite its popular use, aqueous solutions containing Eth-Br showed high toxicity, mutagenic capacity, and deactivate DNA transcription. In this study, the removal of Eth-Br from aqueous solutions by gamma irradiation has been fully investigated.

Removal of Antibiotics from Water by Polymer of Intrinsic Microporosity: Isotherms, Kinetics, Thermodynamics, and Adsorption Mechanism.

Traces of antibiotics within domestic and industrial effluents have toxic impact on human health as well as surrounding flora and fauna. Potential increase in antibiotic resistance of microorganisms is likely to rise due to the incomplete removal of antibiotics by traditional wastewater processing, methods such as membrane filtration and biological treatment. In this study, we investigated a novel class of material termed Polymer of Intrinsic Microporosity (PIM) that is based on amorphous microporous organic materials for the application of antibiotic removal form aqueous environments.

Label-Free Fluorescent Aptasensor for Small Targets via Displacement of Groove Bound Curcumin Molecules.

Signal transduction based on fluorescence is one of the most common optical aptasensors for small molecules. Sensors with a number of unique features including high sensitivity, low cost, and simple operation can be constructed easily. However, the label-free fluorescent approach is limited to synthetic dyes that bind strongly to the aptamer sequence and result in a diminished sensor operation with high detection limits.

Effect of Co60 irradiation on the degradation and mineralization of sulfonated aromatic compounds in aqueous solutions.

As sulfonated aromatic compounds are widely used in industry, they have frequently been detected in aquatic environments. This study evaluated the degradation and mineralization of 2,6-naphthalenedisulfonic acid disodium salt (2,6-NS), sodium 2-naphthalenesulfonate (2-NS), benzenesulfonic acid sodium salt (BS), and 4-vinylbenzene sulfonate sodium (4-VBS) by exposing aqueous solutions of these compounds to Co60 irradiation. The radiolytic degradation of these pollutants was found to follow pseudo-first-order kinetics.

Detailed study of water radiolysis-based degradation of chloroorganic pollutants in aqueous solutions.

Water radiolysis-induced destruction, dechlorination and mineralization of harmful chlorophenols, i.e., 2,4,6-trichlorophenol (2,4,6-tCPH), 4-chlorophenol (4-CPH) and 4-chlorocatechol (4-CC), using radioactive Co-60 have been investigated as individual and combination methods (2,4,6-tCPH+4-CPH+4-CC) with an initial concentration of 100 μM of each pollutant.

Gallic acid degradation by electron beam irradiation under various conditions.

In this study, aqueous solutions of gallic acid (GA) were irradiated in an electron beam (EB) accelerator under different experimental conditions (various initial GA concentrations, presence or absence of oxidant and oxygen). For an initial GA concentration of 50 μM, complete GA degradation was achieved with an absorbed dose of 850 Gy in the presence of dissolved oxygen. Both GA removal and mineralization are favored when oxygen is present.

Radiochromic film containing poly(hexa-2,4-diynylene adipate) as a radiation dosimeter.

A radiation-sensitive polymer poly(hexa-2,4-diynylene adipate) (PHDA) was synthesized and incorporated into polyvinyl butyral films for radiation dose measurements in the 0.5 - 60 kGy range. PHDA undergoes crosslinking polymerization upon exposure to γ-rays, which changes its color from very pale yellow to deep orange-yellow.

Colorimetric Aptasensor of Vitamin D3: A Novel Approach to Eliminate Residual Adhesion between Aptamers and Gold Nanoparticles.

Colorimetric aptasensors based on gold nanoparticles (AuNPs) commonly feature ssDNA probes nonspecifically adsorbed to surface gold particles. A major limitation of this versatile method is the incomplete dissociation of the adsorbed nontarget binding segments of the aptamer sequence upon target binding. This results in weak or nonexistent sensor performance by preventing the particles from aggregating when the optimized salt concentration is added.

Removal of antibiotics from water and waste milk by ozonation: kinetics, byproducts, and antimicrobial activity.

The use of antibiotics in the dairy farming for curing and growth promotion results in the production of massive quantities of non-recyclable wastewater by the conventional purification techniques. Additionally, waste milk is produced during the drug withholding periods, which is not suitable for human or animal consumption and cause huge economic loss as well as present serious environmental waste. This study was designed to investigate the decomposition of various antibiotic compounds in un-buffered aqueous solutions and milk samples by ozonation process.

Decomposition byproducts induced by gamma radiation and their toxicity: the case of 2-nitrophenol.

The induced degradation and detoxification of 2-nitrophenol (2-NP) in aqueous media by gamma irradiation were carefully evaluated in this study. Gamma radiation at absorbed doses as low as 20 kGy was able to degrade 2-NP to reach a removal of at least 85% across the investigated range of concentration (50-150 ppm). 2-NP breaks down to aromatic-based compounds with increasing number of byproducts upon increasing the radiation treatment from the absorbed dose of 50% decomposition (D) to the absorbed dose of 90% decomposition (D), after which no byproducts could be detected, indicating the formation of undetectable aliphatic hydrocarbons, insoluble, or volatile byproducts.

Gamma irradiation-induced complete degradation and mineralization of phenol in aqueous solution: Effects of reagent.

This study aims to gain new insight into phenol degradation and mineralization in aqueous solution using ionizing radiation to control its radiolytic elimination under various experimental conditions and to present the different radical reactions involved in water radiolysis. The most obvious finding of this study is that the combination of a reagent, i.e.