We investigated whether the threshold concentration for polychlorinated biphenyl (PCB) dechlorination may be lower in biosurfactant-amended sediments compared with biosurfactant-free samples. At PCB concentrations of 40, 60, and 120 ppm, the surfactant amendment enhanced the PCB dechlorination rate at all concentrations and the rate was also faster at higher concentrations. On a congener group ...

We study the effect of adsorbed surfactant on drop deformation in linear flows by means of analytical solutions for small perturbations of the drop shape and surfactant distribution, and by numerical simulations for large distortions. We consider a drop with the same viscosity as the suspending fluid. Under these conditions, the problem simplifies because the disturbance flow field results sole...

To explain enhanced retention of water insoluble gases and water insoluble particulate matter (tar)when smoke is inhaled we propose that these compounds interact physically with phospholipids forming the mono-molecular layer of surfactant lining the alveolar epithelium. This would account for the alteration in surface tension lowering properties of surfactant when exposed to whole smoke but not...

Two sensitive and selective stability-indicating methods were developed for the determination of sertaconazole nitrate (Ser-NO3), in the presence of its acid, alkaline and oxidative degradation products. The first method was based on measuring the fluorescence intensity of the drug at λex/λem = 231 nm/312 nm. The influence of micelle medium on the fluorescence emission was studied. The nonionic...

The photoluminescence (PL) quantum yield of single-walled carbon nanotubes (SWNTs) is relatively low, with various quenching effects by metallic species reported in the literature. Here, we report the first case of metal enhanced fluorescence (MEF) of surfactant-coated carbon nanotubes on nanostructured gold substrates. The photoluminescence quantum yield of SWNTs is observed to be enhanced mor...

We propose models for the first-order unbinding transition of lyotropic lamellae in surfactant solutions. The coupling between the surfactant volume fraction and the elastic degree of freedom is considered so that the net attractive interaction between the surfactant molecules is enhanced. The elastic degree of freedom can be either (i) a membrane elastic degree of freedom or (ii) a bulk elasti...

OBJECTIVES Biologically variable ventilation improves lung function in acute respiratory distress models. If enhanced recruitment is responsible for these results, then biologically variable ventilation might promote distribution of exogenous surfactant to nonaerated areas. Our objectives were to confirm model predictions of enhanced recruitment with biologically variable ventilation using comp...

The effect of uncharged surfactant additives on the oppositely charged polyion/ionic surfactant complexation is usually described as a direct equilibrium association between the polyelectrolyte molecules and free mixed micelles analogous to the polyion/colloidal particle interactions. This approach predicts that the binding of the ionic surfactant to the polyelectrolyte molecules can be complet...

A new analytical approach was developed involving magnetic solid–phase extraction and spectrofluorimetric determination of carvedilol in human plasma samples. A plasma sample was prepared and adjusted to pH 8.2–10, then carvedilol was quickly extracted using iron oxide magnetic nanoparticles modified by the surfactant cetyltrimethylammonium bromide and determined to apply spectrofluorimetry...

The supersaturatable self-emulsifying drug delivery system (S-SEDDS) represents a new thermodynamically stable formulation approach wherein it is designed to contain a reduced amount of a surfactant and a water-soluble cellulosic polymer (or other polymers) to prevent precipitation of the drug by generating and maintaining a supersaturated state in vivo. The S-SEDDS formulations can result in e...