Chemical Imaging

The present work reports the photocurrent response of the MOS sensor to the Hydrogen and ammonia gas moieties. The Au and Pd metals in contact form the gate of the MOS sensor. Depending on the laser excitation regions the photocurrent showed different sensitivity responses to gas exposition that is necessary condition for chemical image gas sensor. The chemical images for hydrogen and ammonia gases, obtained in this work, showed to have different pattern features, which permits the good classification task by using fractal dimension theory.

Near-infrared (NIR) approaches is considered one of the most well-studied process analyzers evolving from the process analytical technology initiatives. The objective of this study was to evaluate NIR spectroscopy and imaging to assess individual components within a novel tenofovir liposomal formulation. By varying stearylamine, as a positive charge imparting agent, five batches were prepared by the thin film method. Each

This article presents recent research on the sedimentary endokarstic infillings in connection with the new contributions of geochemical analysis by autoradiography and X-ray fluorescence (portable analyser, core scanner, micro-XRF, microprobe) in the context of the 'Climanthrope' ANR programme. Coupled with sedimentological analysis (stratigraphy, laser grain size analysis, micromineralogy, and micromorphology), geochemical analysis and imaging refine the study of underground deposits such as carbonated sediments (speleothems), rhythmites, subterranean ice, and prehistoric cave paintings. Formed following a seasonal cycle, stalagmites and rhythmites are likely to provide important data not only on the two main parameters of regional climate, i.e. hydrology and temperature, but also on human impacts (speleothems in urban tunnels) and the rural environment. The microdebris and dusts sampled in subterranean ice record the palaeoenvironment by snow trapping. Parietal paintings c...

Near-infrared (NIR) approaches is considered one of the most well-studied process analyzers evolving from the process analytical technology initiatives. The objective of this study was to evaluate NIR spectroscopy and imaging to assess individual components within a novel tenofovir liposomal formulation. By varying stearylamine, as a positive charge imparting agent, five batches were prepared by the thin film method. Each

The purpose of this study was to utilize near-infrared spectroscopy and chemical imaging to characterize extrusion-spheronized drug beads, lipid-based placebo beads, and modified release tablets prepared from blends of these beads. The tablet drug load (10.5–19.5 mg) of theophylline (2.25 mg increments) and cimetidine (3 mg increments) could easily be differentiated using univariate analyses. To evaluate other tablet attributes (i.e., compression force, crushing force, content uniformity), multivariate analyses were used. Partial least squares (PLS) models were used for prediction and principal component analysis (PCA) was used for classification. The PLS prediction models (R2 > 0.98) for content uniformity of uncoated compacted theophylline and cimetidine beads produced the most robust models. Content uniformity data for tablets with drug content ranging between 10.5 and 19.5 mg showed standard error of calibration (SEC), standard error of cross-validation, and standard error of prediction (SEP) values as 0.31, 0.43, and 0.37 mg, and 0.47, 0.59, and 0.49 mg, for theophylline and cimetidine, respectively, with SEP/SEC ratios less than 1.3. PCA could detect blend segregation during tableting for preparations using different ratios of uncoated cimetidine beads to placebo beads (20:80, 50:50, and 80:20). Using NIR chemical imaging, the 80:20 formulations showed the most pronounced blend segregation during the tableting process. Furthermore, imaging was capable of quantitating the cimetidine bead content among the different blend ratios. Segregation testing (ASTM D6940-04 method) indicated that blends of coated cimetidine beads and placebo beads (50:50 ratio) also tended to segregate.