A novel approach to phosphopeptide synthesis-preparation of glu-pser-leu

A synthesis of the phosphotripeptide Glu-PSer-Leu is reported via the stepwise incorporation of the protected phosphoamino acid N^α-tert-butoxycarbonyl-o-dibenzylphosphono-L-serine.     

Correlation of the Voice Handicap Index (VHI) and the Voice-Related Quality of Life Measure (V-RQOL)

The purpose of this study was to investigate the correlation between the Voice Handicap Index (VHI) and the Voice-Related Quality of Life Measure (V-RQOL), and to test conversion of scores between the two instruments. Understanding the relationship between instruments will facilitate comparison of voice outcome studies using different measures. A retrospective medical chart review of 140 consecutive patients with a chief complaint related to their voice presenting for speech pathology voice evaluation following laryngology evaluation and diagnosis was adopted. Each patient who filled out the VHI and V-RQOL within a 2-week period with no intervening treatment was included in the study. Correlation analysis for total scores was performed for the patients meeting inclusion criteria (n=132). Correlations were also performed as a function of diagnosis. Calculated VHI score based on measured V-RQOL score was compared to measured VHI score. Pearson correlation between scores on the VHI and V-RQOL was -0.82. There was no significant difference between the mean measured and mean calculated VHI scores. For individual scores, however, regression analysis did reveal a significant difference between calculated and measured VHI. The VHI and V-RQOL are highly correlated; however, this study suggests that the two instruments are not interchangeable for individuals.     

Magnetic resonance studies of dissolving particulate solids

Magnetic resonance methods have been used to elucidate the internal pore structure of particulate solids, in particular detergent tablets. Such information is essential to a comprehensive understanding of the dissolution characteristics of these materials and how this property is related to processing conditions during tablet formation. In particular 3-D images of porosity are produced and 2-D self-diffusion maps are acquired as a function of observation time, which enables pore size to be quantified as a function of position via the extracted surface-to-volume ratio of the pore space. These properties are determined as a function of processing parameters, in particular the compression force used in tablet formation.     

Probing Ganglia Dissolution and Mobilization in a Water-Saturated Porous Medium using MRI

Magnetic resonance imaging (MRI) is used to probe the evolution of geometric characteristics such as the volume, shape, surface area, and cluster size of octanol ganglia trapped in a model porous medium, in this case a packing of spheres, as they dissolve into a mobile aqueous phase. The resulting pore-scale information is used to assess various assumptions used in existing models of the dissolution process. Dissolution of the ganglia was characterized by a reduction in the overall number of ganglia with little effect on the shape and mean of the volume distribution of the ganglia. This apparently anomalous result is explained by dissolution of the ganglia until they reach a critical size, which is dependent on the structure of the pore space, at which point they are mobilized and subsequently removed from the porous medium. The shape of the entrapped ganglia is characterized by a fractal dimension in the range 2.2-2.3, suggesting that models which assume a Euclidean geometry for the entrapped ganglia are appropriate. No significant change in the shape of entrapped ganglia is observed during dissolution. In agreement with the results of earlier workers, most hydrocarbon ganglia exist as singlets within the pore structure. Copyright 2000 Academic Press.     

Vibration of submerged hemi-ellipsoidal domes

Ten thin-walled hemi-ellipsoidal domes were vibrated in air and also underwater. The domes varied in shape from oblate hemi-ellipsoids to prolate ones, and the fundamental eigenmodes were either axisymmetric as asymmetric, depending on the profiles of the domes. A varying meridional curvature annular element was developed for the shell and a similar one for the fluid, except that the latter was of quadrilateral cross-section. For submerged vibration, the two finite elements were coupled together and solution carried out through simultaneous iteration. Theoretical analyses with these structural and fluid finite elements gave satisfactory results compared to the experiments.