Search results for "Color"
showing 10 items of 2721 documents
Effect of sport-tinted contact lenses for contrast enhancement on retinal straylight measurements
2008
PURPOSE: To investigate the effect of two tinted contact lenses (CL) designed for outdoor sports activity on the psychometric determination of retinal straylight using the compensation comparison method. METHODS: Thirteen emmetropic subjects were randomly fitted with two different tinted Nike Maxsight (Bausch & Lomb, Rochester, NY, USA) CL in one eye, while the contralateral eye was fitted with a clear lens made of the same material (Optima 38, Bausch & Lomb). Three valid straylight measurements were taken on each eye before and a few minutes after lens insertion, when lens stabilization had occurred. RESULTS: The subjects' mean straylight values were 0.90 +/- 0.09 at baseline and 0.95 +/- …
Genetic colour variation visible for predators and conspecifics is concealed from humans in a polymorphic moth
2022
The definition of colour polymorphism is intuitive: genetic variants express discretely coloured phenotypes. This classification is, however, elusive as humans form subjective categories or ignore differences that cannot be seen by human eyes. We demonstrate an example of a 'cryptic morph' in a polymorphic wood tiger moth (Arctia plantaginis), a phenomenon that may be common among well-studied species. We used pedigree data from nearly 20,000 individuals to infer the inheritance of hindwing colouration. The evidence supports a single Mendelian locus with two alleles in males: WW and Wy produce the white and yy the yellow hindwing colour. The inheritance could not be resolved in females as t…
Color memory matching in normal and red-green anomalous trichromat subjects
2001
The methods of simultaneous and successive color matching have been studied for a set of seven color reference samples by 15 protanomalous and 21 deuteranomalous trichromat subjects. From comparison between both populations and a group of 25 trichromat normal ones, investigated previously under similar experimental conditions [J. Perez–Carpinell et al. Color memory matching: time effect and other factors. Color Res Appl 1998;23:234–247], we can deduce the following. (a) For anomalous trichromat populations, as with a normal one, we find significant differences between simultaneous and successive color matching, p < 0.05. (b) If we consider the average of all the colors, we find that, while …
Effect of PCL/PEG-Based Membranes on Actinorhodin Production in Streptomyces coelicolor Cultivations
2015
The actinomycetes, Gram-positive filamentous bacteria, are the most prolific source of natural occurring antibiotics. At an industrial level, antibiotics from actinomycete strains are produced by means of submerged fermentations, where one of the major factors negatively affecting bioproductivity is the pellet-shaped biomass growth. The immobilization of microorganisms on properly chosen supports prevents cell-cell aggregation resulting in improving the biosynthetic capability. Thus, novel porous biopolymer-based devices are developed by combining melt mixing and particulate leaching. In particular, polycaprolactone (PCL), polyethylene glycol (PEG), and sodium chloride (NaCl) with different…
The evaluation of surface sealants effect on the color stability of Nano-hybrid composite after polishing with One-Step system (in-vitro)
2018
Background The clinical use of composite resins has increased substantially over the past few years due to increased esthetic demands by patients, improvements in formulation, and simplification of bonding procedures. An alternative for preventing or reducing composite discoloration is using of composite surface sealant. The purpose of this study was to determine the effect of surface sealant on color-stability of Nano-hybrid composites after polishing with one-step system. Material and Methods 56 disk-shaped specimens (10*2 mm) of a Nano-hybrid composite resin (VOCO,Cuxhaven,Germany) were prepared. The specimens were randomly divided in to 2 groups of 28 specimens each. The surfaces of spe…
Effect of finishing and polishing systems on the surface roughness and color change of composite resins
2020
Background This study is to examine the surface roughness and color changes occurring on composite resins following the application of different finishing and polishing systems. Material and Methods In our study, a total of 200 samples were prepared from composites resin (6×2 mm) containing supra-nano, submicron hybrid, nanohybrid, nano-ceramic and microhybrid filler. They were polished with diamond, aluminum oxide, silicon carbide finishing and polishing systems. The initial color values of composite samples were measured with a spectrophotometer and surface roughness values with a profilometer. After that, samples were immersed of coffee solution and color measurements were repeated on th…
Effect of water-jet flossing on surface roughness and color stability of dental resin-based composites.
2019
Background The purpose of this in vitro study was to investigate the effects of water-jet flossing on the color stability and surface roughness of five resin-based composites. Material and methods Five commercially available composite resins were studied. Nine disc-shaped specimens (6x2mm) were fabricated from each composite. The specimens were randomly allocated into three groups and three different treatments were performed on each group: storage in water (control group), water-jet flossing using 50 Psi water pressure, and water-jet flossing using 100 Psi water pressure. The water-jet flossing was performed in a standardized manner using a Waterpik® Aquarius® water flosser. Color and roug…
Hackmanite—The Natural Glow-in-the-Dark Material
2020
“Glow-in-the-dark” materials are known to practically everyone who has ever traveled by airplane or cruise ship, since they are commonly used for self-lit emergency exit signs. The green afterglow, persistent luminescence (PeL), is obtained from divalent europium doped to a synthetic strontium aluminate, but there are also some natural minerals capable of afterglow. One such mineral is hackmanite, the afterglow of which has never been thoroughly investigated, even if its synthetic versions can compete with some of the best commercially available synthetic PeL materials. Here we combine experimental and computational data to show that the white PeL of natural hackmanite is generated and cont…
The effect of combining laser and nanohydroxy-apatite on the surface properties of enamel with initial defects
2017
Background The aim of this study was to evaluate the effect of combining fractional CO2 LASER and nanohydroxy apatite on surface microhardness and color of enamel with initial defects. Material and Methods Two types of nano hydroxylapatite (nHAP) was prepared; Pure hydroxyapatite (nHA) and Fluoro hydroxyapatite (nFHA), Sixty extracted premolar teeth without visible caries or structural defects on enamel surface were used, immersed in 10 ml of a demineralizing solution for 2 weeks to create artificial white spot lesions, they were randomly allocated into two groups; Group 1: nHA, Group 2: nFHA, each group is then subdivided into 2 subgroups (A and B) where two different in vitroremineralizat…
Polychromatic, continuous-wave mirrorless lasing from monochromatic pumping of cesium vapor
2019
We report on studies of simultaneous continuous-wave mirrorless lasing on multiple optical transitions, realized by pumping hot cesium vapor with laser light resonant with the 6$S_{1/2}\rightarrow 8$P$_{3/2}$ transition. The multiplicity of decay paths for the excited atoms to their ground state is responsible for the emergence of lasing in a number of transitions, observed here in at least seven wavelengths in the infrared (IR), and at two wavelengths in the blue. We study the properties of the fields generated in the cesium vapor, such as optical power, directionality and optical linewidth.