quaternary ammonium compounds (qacs) are employed both as disinfectants for manual processing lines and surfaces in the food industry, and in human medicine area. qacs also cause cell death by protein denaturation . one of the qac is cetyl trimethyl ammonium bromide (ctab) that appears to rapture the cell membrane. the primary site of action of ctab has been suggested to be the lipid components...

PURPOSE To integrate water-fat-resolved spiral gradient-echo imaging with off-resonance correction into a clinical MR scanner and to evaluate its basic feasibility and performance. MATERIALS AND METHODS Three-point chemical shift imaging was implemented with forward and strongly T(2)*-weighted reverse spiral sampling and with off-resonance correction after water-fat separation. It was applied...

Stimulated echoes are formed from three or more radio frequency pulses. Pulse sequences that use stimulated echoes are extremely versatile because of the availability of three pulses for timing variations and for encoding spatial or chemical shift information. This paper concentrates on the uses of stimulated echoes and on techniques for obtaining them reliably and reproducibly. (Through this u...

Hyperpolarized metabolic imaging is a growing field that has provided a new tool for analyzing metabolism, particularly in cancer. Given the short life times of the hyperpolarized signal, fast and effective spectroscopic imaging methods compatible with dynamic metabolic characterizations are necessary. Several approaches have been customized for hyperpolarized (13)C MRI, including CSI with a ce...

nowadays nmr spectroscopy becomes a powerful tool in chemistry because of the nmr chemical shifts. hartree–fock theory and the gauge-including atomic orbital (giao) methods are used in the calculation of 29si nmr chemical shifts of various silicate species in the silicate solution as initial components for zeolite synthesis both in gas and solution phase. calculations have been performed at geo...