@article {1558, title = {Measurements of the vapor pressure of cubic ice and their implications for atmospheric ice clouds}, journal = {Geophysical Research Letters}, volume = {33}, number = {17}, year = {2006}, note = {ISI Document Delivery No.: 081QHTimes Cited: 17Cited Reference Count: 38Shilling, J. E. Tolbert, M. A. Toon, O. B. Jensen, E. J. Murray, B. J. Bertram, A. K.}, month = {Sep}, pages = {5}, type = {Article}, abstract = {Under conditions commonly found in Earth{\textquoteright}s atmosphere, water can form two solid phases; hexagonal ice (I-h) and cubic ice (I-c). Recent reports have suggested that Ic may form in the atmosphere under a wider range of conditions than previously believed. In light of these reports, the formation of Ic has been suggested as one contributing factor for in-situ observations of persistent in-cloud supersaturations in cold cirrus. However, an accurate evaluation of the contribution of Ic formation to the observed supersaturations requires knowledge of the saturation vapor pressure of Ic, which has not been measured. In this manuscript, we report direct measurements of the vapor pressure of Ic over the temperature range 180 - 190 K. Over this temperature range, the vapor pressure of the cubic phase is 10.5 +/- 2.5\% higher than that of the hexagonal phase. Field measurements of in-cloud supersaturations made during CRYSTAL-FACE are also re-analyzed and discussed.}, keywords = {AMORPHOUS WATER ICE, ASTROPHYSICAL IMPLICATIONS, CIRRUS CLOUDS, ELECTRON DIFFRACTION, FORMS, GLASSY, HEXAGONAL ICE, LOW-TEMPERATURE, SPECTRA, WATER, X-RAY-DIFFRACTION}, isbn = {0094-8276}, url = {://000240331600005}, author = {Shilling, J. E. and Tolbert, M. A. and Toon, O. B. and Jensen, E. J. and Murray, B. J. and Bertram, A. K.} } @article {1628, title = {On-line content uniformity determination of tablets using low-resolution Raman spectroscopy}, journal = {Applied Spectroscopy}, volume = {60}, number = {6}, year = {2006}, note = {ISI Document Delivery No.: 055FDTimes Cited: 5Cited Reference Count: 31}, month = {Jun}, pages = {672-681}, type = {Article}, abstract = {Analytical techniques for rapid and nondestructive content uniformity determination of pharmaceutical solid dosage forms have been studied for several years in an effort to replace the traditional wet chemistry procedures, which are labor intensive and time consuming. Both Raman spectroscopy and near-infrared spectroscopy have been used for this purpose, and predictability errors are approaching those of the traditional techniques. In this study, a low-resolution Raman spectrometer was utilized to demonstrate the feasibility of both rapid at-line and on-line determination of tablet content uniformity. Additionally, sampling statistics were reviewed in an effort to determine how many tablets should be assayed for specific. batch sizes. A good correlation was observed between assay values determined by high-performance liquid chromatography and Raman analysis. Due. to rapid acquisition times for the Raman data, it was possible to analyze far more samples than with wet chemistry methods, leading to a better statistical description of variation within the batch. For at-line experiments, the sampling volume was increased by rotating the laser beam during the acquisition period. For the on-line experiments, the sampling volume was increased by sampling from a stream of tablets moving underneath the Raman probe on a conveyor system. Finally, an approach is proposed for monitoring content uniformity immediately following the compaction process. In conclusion, Raman spectroscopy has potential as a rapid, nondestructive technique for at- or on-line determination of tablet content uniformity.}, keywords = {ACTIVE-SUBSTANCE, central limit theorem, COATED TABLETS, content uniformity, FORMS, INTACT TABLETS, NEAR-INFRARED SPECTROSCOPY, PARACETAMOL, process analytical technology, Raman spectroscopy, sampling, SPECTRA, STATE, TRANSMITTANCE SPECTROSCOPY}, isbn = {0003-7028}, url = {://000238434500013}, author = {Wikstrom, H. and Romero-Torres, S. and Wongweragiat, S. and Williams, J. A. S. and Grant, E. R. and Taylor, L. S.} } @article {1530, title = {Raman spectroscopy for tablet coating thickness quantification and coating characterization in the presence of strong fluorescent interference}, journal = {Journal of Pharmaceutical and Biomedical Analysis}, volume = {41}, number = {3}, year = {2006}, note = {ISI Document Delivery No.: 051CCTimes Cited: 22Cited Reference Count: 27}, month = {Jun}, pages = {811-819}, type = {Article}, abstract = {We report a novel approach to the measurement of colored tablet coating thickness, which employs Raman spectroscopy with univariate and multivariate data analysis. Our results suggest that Raman sensing can serve as a viable non-invasive means to quantify tablet coating thickness in the presence of a fluorescent ingredient in the coating formulation (food colorant Alphazurine FG or D\&C Blue No. 4). This study comparatively tests the advantage of several data transformation approaches, including mean centering, standard normal variate, and Savitzky-Golay smoothed second derivative as means of improving predictive models in the presence of fluorescence. By application of the partial least squares (PLS) calibration algorithm to establish optimum covariance between transformed spectral data and measured tablet coating thicknesses, we have been able to create predictive models with calibration errors as small as 4 mu m for a training set that spans colored coating thicknesses from 50 to 151 mu m. (c) 2006 Elsevier B.V. All rights reserved.}, keywords = {film coating, FLUORESCENCE, FORMS, INDUCED BREAKDOWN SPECTROSCOPY, near infrared spectroscopy, QUANTITATIVE-ANALYSIS, Raman spectroscopy, REFLECTANCE, SPECTRA, SPECTROMETRY}, isbn = {0731-7085}, url = {://000238137100019}, author = {Romero-Torres, S. and Perez-Ramos, J. D. and Morris, K. R. and Grant, E. R.} } @article {3114, title = {IN-VIVO INHIBITION OF BETA-GLUCOSIDASE AND BETA-MANNOSIDASE ACTIVITY IN RATS BY 2-DEOXY-2-FLUORO-BETA-GLYCOSYL FLUORIDES AND RECOVERY OF ACTIVITY IN-VIVO AND IN-VITRO}, journal = {Biochemical Journal}, volume = {301}, year = {1994}, note = {ISI Document Delivery No.: PA559Times Cited: 12Cited Reference Count: 25Part 2}, month = {Jul}, pages = {343-348}, type = {Article}, abstract = {2-Deoxy-2-fluoro-beta-glucosyl and -beta-mannosyl fluorides administered to rats in a single dose(10 mg/kg) inhibited beta-glucosidase and beta-mannosidase activity respectively after 1 h in brain, spleen, liver and kidney tissues. This inhibition, presumably caused by accumulation of 2-deoxy-2-fluoroglycosyl-enzyme intermediates, indicates that intact 2-deoxy-2-fluoroglycosyl fluorides are distributed to these organs and, in the case of brain, that they cross the blood/brain barrier. beta-Glucosidase activity recovered completely or partially in brain, spleen, liver and kidney by 20-48 h. beta-Mannosidase activity partially recovered in all tissues by 48 h. beta-Galactosidase activity in brain and kidney was not significantly affected by administration of either the gluco or manno compounds at this dosage, indicating that these inhibitors are directed towards specific glycosidases. Observation of similar relatively rapid rates of beta-glycosidase re-activation in vivo and in tissue homogenates in vitro at 37 degrees C suggests that hydrolysis or transglycosylation of 2-deoxy-2-fluoroglycosyl-enzymes, not protein synthesis, are the primary mechanisms involved in the recovery of glycosidase activity inhibited by this class of compounds in vivo.}, keywords = {DEFICIENCY, ENZYME INTERMEDIATE, FORMS, GLUCOCEREBROSIDASE, GLYCOSIDASES, INACTIVATION, LIVER, MICE}, isbn = {0264-6021}, url = {://A1994PA55900006}, author = {McCarter, J. D. and Adam,Michael J. and Hartman, N. G. and Withers, S. G.} }