USE OF THE PHOTRONIC CELL AND SPECTROPHOTOMETER FOR MEASURING TRANSLUCENCY OF WHITEWARE*

A method has been developed for measuring the translucency of whiteware by means of the photronic cell, and a modified formula has been derived to express the relationship between translucency and thickness of ware. Bodies containing mixtures of feldspar and lepidolite were translucent over a greater range of temperatures than those which contained feldspar or lepidolite alone, although the translucency of the feldspar bodies was greater than that of the lepidolite bodies having equivalent absorptions. The spec-trophotometer gives a more complete record of the translucency of porcelain because it may be used to measure the transmittance of ultraviolet, visible, and infrared light.     

Mice Lacking Gpr179 with Complete Congenital Stationary Night Blindness Are a Good Model for Myopia

Mutations in GPR179 are one of the most common causes of autosomal recessive complete congenital stationary night blindness (cCSNB). This retinal disease is characterized in patients by impaired dim and night vision, associated with other ocular symptoms, including high myopia. cCSNB is caused by a complete loss of signal transmission from photoreceptors to ON-bipolar cells. In this study, we hypothesized that the lack of Gpr179 and the subsequent impaired ON-pathway could lead to myopic features in a mouse model of cCSNB. Using ultra performance liquid chromatography, we show that adult Gpr179^−/− mice have a significant decrease in both retinal dopamine and 3,4-dihydroxyphenylacetic acid, compared to Gpr179^+/+ mice. This alteration of the dopaminergic system is thought to be correlated with an increased susceptibility to lens-induced myopia but does not affect the natural refractive development. Altogether, our data added a novel myopia model, which could be used to identify therapeutic interventions.     

Hyaluronic Acid Scaffolds for Loco-Regional Therapy in Nervous System Related Disorders

Hyaluronic acid (HA) is a Glycosaminoglycan made of disaccharide units containing N-acetyl-D-glucosamine and glucuronic acid. Its molecular mass can reach 10 MDa and its physiological properties depend on its polymeric property, polyelectrolyte feature and viscous nature. HA is a ubiquitous compound found in almost all biological tissues and fluids. So far, HA grades are produced by biotechnology processes, while in the human organism it is a major component of the extracellular matrix (ECM) in brain tissue, synovial fluid, vitreous humor, cartilage and skin. Indeed, HA is capable of forming hydrogels, polymer crosslinked networks that are very hygroscopic. Based on these considerations, we propose an overview of HA-based scaffolds developed for brain cancer treatment, central and peripheral nervous systems, discuss their relevance and identify the most successful developed systems.     

An improved critical angle equation for channeling

Lindhard proposed his classical equation for the critical channeling angle from consideration of conservation of transverse energy. We generalize those ideas via consideration of conservation of transverse momentum, and propose an improved equation. A dimensional analysis of the problem is also presented, and that analysis puts our arguments and results on a firm footing.     

THE EFFECT OF PREPARATION AND CALCINATION TREATMENT ON THE PROPERTIES OF THE KAOLIN-ALUMINA MIXTURES A1203. SiO2*

Calcined mixtures of kaolin and alumina were prepared by grinding for different lengths of time and firing the several grinds at different temperatures ranging from slightly above dehydration temperature of clay to 1700°C. The X-ray diffraction patterns revealed several interesting points relative to the degree of combination of the oxides present.     

The Thermal-Chemical Damage in Biological Material under Laser Irradiation

A mathematical model for thermal-chemical damage to biological materials excited by laser irradiation is described. The chemical rate equations for protein denaturization are used to predict radii of damage for cases where the input-laser-energy distribution results in the uniform heating of a small sphere or a disk. These rate equations are limited to a single-hit process. Experimental checks on this model are presented for ruby-laser irradiation of small carbon particles in egg albumin and for CO2?laser surface heating of egg albumin.