A fluorescent chemical sensor for ethanol determination in alcoholic beverages

A sensor for ethanol is described that is based on the fluorescent probe 5,10,15,20-tetraphenyl porphyrin (TPP). Response is based on the quenching of the fluorescence of TPP by ethanol as a result of electrostatic attraction. The sensor linearly responds to ethanol in the concentration range from 1 to 75 vol.% and was applied to the determination of ethanol in various kinds of wines and whisky.     

Assessment of the anomalous pulmonary circulation by dynamic contrast-enhanced MR angiography in under four seconds

The purpose of this study was to demonstrate the initial results of the dynamic contrast-enhanced MRA in under four seconds in the assessment of anomalous pulmonary circulation. We performed dynamic contrast enhanced MRA on ten patients with a temporal resolution of 2-3 sec for each phase. Five patients had pulmonary vascular anomaly and five patients had reconstructed pulmonary circulation. On nine patients catheter angiography was performed for the correlation. Dynamic contrast-enhanced MRA successfully demonstrated congenital pulmonary vascular anomalies and the pathway of anomalous pulmonary circulation in our series. With the improved temporal and spatial resolution, the dynamic contrast-enhanced MRA can be used in children and infants for the assessment of congenital vascular disease.     

Fluorimetric detection of boron by azomethine-H in micellar solution and sol-gel

Mixtures of boron and azomethine-H in solution result in slow complexation. Addition of sodium dodecyl sulfate (SDS), polyethylene glycol dodecyl ether (Brij-35), 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol (TritonX-100), and cetyltrimethyl ammonium bromide (CTAB) result in considerable decrease in complexation time and enhancement in signal of peak in solution and also sol-gel. The fluorescence of the complex is monitored at an emission wavelength of 486 nm with excitation at 416 nm. The presence of 1x10(-3) mol L(-1) SDS decreased the complexation time up to 10 min in solution and 20 min in sol-gel for above 0.25 microg B mL(-1) and 30 min in solution and 35 min in sol-gel for below 0.25 microg B mL(-1). However, the photostability did not change by adding micelle in both media. The proposed method shows a linear response toward boron in the concentration range of 0.05-10 microg mL(-1) and is selective for boron over a large number of electrolytes and cations. The detection limit was 7 microg L(-1). This method has been used for the detection of boron in environmental water samples and fruit juices with satisfactory results.     

A finite volume implicit time integration method for solving the equations of ideal magnetohydrodynamics for the hyperbolic divergence cleaning approach

A finite volume numerical technique is proposed to solve the compressible ideal MHD equations for steady and unsteady problems based on a quasi-Newton implicit time integration strategy. The solenoidal constraint is handled by a hyperbolic divergence cleaning approach allowing its satisfaction up to machine accuracy. The conservation of the magnetic flux is computed in a consistent way using the numerical flux of the finite volume discretization. For the unsteady problem, the time accuracy is obtained by a Newton subiteration at each physical timestep thereby converging the solenoidal constraint to steady state. We perform extensive numerical experiments to validate and demonstrate the capabilities of the proposed numerical technique.