For nanoparticle-based technologies, efficient and rapid approaches that yield particles of high purity with a specific shape and size are critical to optimize the nanostructure-dependent optical, electrical, and magnetic properties, and not bias conclusions due to the existence of impurities. Notwithstanding the continual improvement of chemical methods for shaped nanoparticle synthesis, bypro...

The biodegradation of polycyclic aromatic hydrocarbon pollutants is constrained, in part, by their solid physical state and very low water solubility. Searching for ways to overcome these limitations, we isolated from soil a bacterium capable of growing on pyrene as a sole source of carbon and energy. Acid-fast stain, morphology, and fatty acid profile identified it as a Mycobacterium sp. In a ...

In the last years, researches developed with biosurfactants for application in the medical area have been revealing the promising biological activities of these biomolecules. In this work the antimicrobial and anti-adhesive properties of a biosurfactant Rufisan isolated from the yeast Candida lipolytica UCP 0988, growth in a medium supplemented with ground nut refinery residue was determined ag...

We have examined the rate-limiting steps involved in bile acid absorption across the unstirred water layer and lipid cell membrane of the jejunal mucosa. Uptake of the polar bile acid taurocholate is limited solely by the cell membrane since this compound permeates the unstirred water layer more rapidly than the lipid cell membrane and stirring does not enhance uptake. With less polar bile acid...

Micro/nanoparticles could cause adverse effects on cardiovascular system and increase the risk for cardiovascular disease-related events. Nanoparticles prepared from poly(ethylene glycol) (PEG)-b-poly(ε-caprolactone) (PCL), namely PEG-b-PCL, a widely studied biodegradable copolymer, are promising carriers for the drug delivery systems. However, it is unknown whether polymeric PEG-b-PCL nano-mic...

A systematic approach to selection of surfactants for disrupting biological membranes, for solubilizing their components, and for removing the surfactant by dialysis is described. The two relevant surfactant parameters were the critical micelle concentration (CMC) and the hydrophile-lipophile balance (HLB). Rat liver mitochondria were treated with two series of nonionic surfactants and the exte...

Relationships between the molecular structure and the critical micelle concentration (cmc) of anionic surfactants were investigated using a quantitative structure-property relationship approach. Measured cmc values for 119 anionic structures, representing sodium alkyl sulfates and sodium sulfonates with a wide variety of hydrophobic and hydrophilic structures, were considered. The best multiple...

A simple and sensitive method is described for the pre-concentration by cloud point extraction followed by atomic absorption spectrometric determination of copper ion in real samples. At a solution pH of 5.5, 5, 5-diphenylimidazolidine-2, 4-dione (phenytoin) (DFID) and TritonX-114 were used as hydrophobic ligand and non-ionic surfactant. The adopted concentrations for DFID, Triton X-114 and HNO...