Growth and characterization of sodium pentaborate [Na(H4B5O10)] single crystals.
The bulk single crystals of sodium pentaborate [Na(H4B5O10)] were grown by slow evaporation solution growth technique using deionized water as solvent. The grown crystal was confirmed by single crystal X-ray diffraction studies. The structural perfection of the grown crystals has been analyzed by high resolution X-ray diffraction (HRXRD) studies by recording rocking curve. The photoluminescence (PL), UV-vis spectral studies were performed and the optical bandgap of the material was calculated. The presence of the functional groups was identified by FT-IR measurement. The factor group analysis was done on Na(H4B5O10) to reveal the vibrational optical modes. The thermal and mechanical properties of the grown crystal were studied by TG-DTA and Vickers microhardness tester, respectively. The dielectric behavior of Na(H4B5O10) was investigated with different frequencies and temperatures.
Polarized IR and Raman spectra of kdy(moo4)2 single crystals, and the 92MO-100MO isotope effect
Abstract Polarized IR and Raman spectra below 4000 cm−1 for single crystals of KDy(MoO4)2 are presented and discussed in relation to molecular and crystal structures. The spectroscopic data indicate additional intermolecular interactions due to pair coupling of the molybdate tetrahedra. This effect, combined with the multilayer crystal structure, is found to restrict the vibrational degrees of freedom, disturbing the selection rules for vibrational transitions. The spectra of first and higher-order transitions are described on the basis of 92Mo/100Mo isotopic-exchange effects and Y/Dy and K/Na substitutions.
Design and Development of an In Vitro Tear Replenishment System
Understanding the cellular and molecular mechanisms of the corneal tissue and translating them into effective therapies requires organotypic culture systems that can better model the physiological conditions of the front of the eye. Human corneal in vitro models currently exist, however, the lack of tear replenishment limits corneal in vitro models’ ability to accurately simulate the physiological environment of the human cornea. The tear replenishment system (TRS), a micro-fluidic device, was developed to mimic the in vivo tear replenishment in the human eye in an in vitro corneal model. The TRS is capable of generating adjustable intermittent flow from 0.1 µL in every cycle. The TRS is a sterilizable device that is designed to fit standard 6-well cell culture plates. Experiments with the corneal models demonstrated that exposure to the TRS did not damage the integrity of the stratified cell culture. Contact lenses “worn” by the in vitro corneal model also remained moist at all times and the cytotoxicity of BAK could also be verified using this model. These in vitro results confirmed that the TRS presents novel avenues to assess lens-solution biocompatibility and drug delivery systems in a physiologically relevant milieu.