Effects of pH and solvent on the fluorescence properties of biomedically important benzamides. Application to determination in drugs and in human urine.

The fluorescence properties of five substituted benzamides, including alizapride, metoclopramide, sulpiride, sultopride and tiapride, were investigated at several pH values and in various solvents (dimethyl sulfoxide, ethanol, ethylene glycol, methanol, propan-2-ol, tetrahydrofuran and water). Except for alizapride, the fluorescence intensities were found to be higher at acidic (1-6) than at alkaline (8-12) pH values. Using the optimum solvent (aqueous solutions) and appropriate pH conditions, linear spectrofluorimetric calibration curves were established over a concentration range of about two orders of magnitude, with correlation coefficients larger than 0.

Quantitative treatment of the effect of solvent on the electronic absorption and fluorescence spectra of substituted coumarins: Evaluation of the first excited singlet-state dipole moments.

The electronic absorption and fluorescence spectra of coumarin and 11 substituted coumarins were measured in several solvents (dioxane, ethyl ether, ethyl acetate, ethanol, dimethylformamide, acetonitrile, and dimethyl sulfoxide). Ground-state dipole moments were determined in dioxane at 298 K. The results were used to obtain the first excited singlet-state dipole moments of the coumarins under study by the solvatochromic shift method (Bakhshiev, Kawski-Chamma-Viallet, McRae, and Suppan correlations).

Ponticles of the atlas: a review and clinical perspective.

The condition of ponticles of the atlas was reviewed in relation to their development, anatomy, incidence and diagnosis with an objective directed toward assessment of their clinical significance. The ponticles are commonly encountered radiographic anomalies characterized by osseous bridging of the posterior margin of the superior articular facet and the posterior arch of the atlas. They are present to a variable degree in about 35% of dissections and a complete osseous ring enclosing the vertebral arteries is identifiable in up to 15% of cases.