No abstract available.
Light

The purpose of this study was the evaluation of spectral transmission of the commercial three shade guides and the relationship of hue, value, and chroma according to the transmission rate. The spectral transmittance of three shade guides - Vita Lumin Shade Guide, Vintage and Unibond Shade Guide, and Vitapan 3D-Master Shade Guide - were measured. For direct transmission measurements, each shade tabs were placed at the entrance port of the 1mm diameter intergrating sphere. The intensity of the light source passing through the shade tabs to the right angle was continuously recorded for wavelength from 400 to 700 nm. A transmission spectrum and digital data were obtained for each measurement and they were evaluated using Microcal Origin program. The obtained results of this study were as follows 1. In Vita Lumin Shade Guide, sum of the transmission rate of the shade tabs at the wavelength 400-700nm was decreased in agreement with the arrangement order at each A, B, C, D group, except D4 shade tab. However, there were no relationships between the transmission rate of the shade tabs and the value-oriented. 2. In Vintage and Unibond Shade Guide, sum of the total transmission rate of the shade tabs was decreased in agreement with the arrangement order at each A, B, C, D group. When all shade tabs arranged in value-oriented, transmission rate was accord with the order, except D4 shade tab. 3. When shade tabs of the Vitapan 3D-Master Shade Guide have the same value and hue, sum of their total transmission rate decreased in accordance with the chroma-oriented. When the shade tabs have the same value and chroma, there were no differences from the order of the transmission rate to the various hue type. However, in the "R" tabs of reddish hue type, the transmission rate increased at the long wavelength range area. In conclusion, we need the quantitative analyzing instruments in transmission determination. Vitapan 3D-Master Shade Guide covers the tooth color space taking into account the parameters of the systematic value, chroma, hue oriented, and the transmission rate relatively accorded with that sequence.
Light* ; Tooth

No abstract available.
Light ; Rhinophyma

No abstract available.
Gout ; Light

No abstract available.
Gout ; Light

The fungal bioluminescence pathway (FBP) is a metabolic pathway responsible for the generation of bioluminescence derived from fungi. This pathway utilizes caffeic acid as the substrate, generating a high-energy intermediate, and the decomposition of which yields green fluorescence with a wavelength of approximately 520 nm. The FBP is evolutionally conserved in luminescent fungal groups. Unlike other bioluminescent systems, the FBP is particularly suitable for engineering applications in eukaryotic organisms, especially in plants. Currently, metabolically engineered luminescent plants are able to emit visible light to illuminate its surroundings, which can be visualized clearly in the dark. The fungal bioluminescent system could be explored in various applications in molecular biology, biosensors and glowing ornamental plants, and even green lighting along city streets.
Luminescence ; Light ; Fluorescence ; Eukaryota ; Green Light

The objective of this study was to evaluate the effect of color measuring instrument by measuring the color of dental composite resins. Nine shade light cured composite resin disks were prepared (diameter : 15 mm, thickness : 4 mm). CIE L*a*b* color scale of each disk was measured with 3 different types of spectrophotometer [MiniScan XE plus (Model 4000S, Hunter Lab, USA), CM-3500d (Minolta, Japan) and Specbos 2100 Miniature VIS Reflection spectrometer (Serial No: 319416, JETI Technishe VIS Instrumentic GmbH, Germany)]. Miniscan XE Plus and CM-3500d using identical measuring geometry with different size of viewing aperture. But Specbos 2100 using different measuring geometry. Within the limitation of this study, there were color difference (DeltaE*) from 2.4 to 7.8 between Miniscan XE Plus and CM-3500d, but L*, a*, b* values showed the high correlation. However, there were great color difference (DeltaE*) in the extent of about 20 between instruments with the different measuring geometry. Therefore, color scale measured by color measuring instrument should be used as a relative value rather than an absolute value in the field of dentistry.
Dentistry ; Light ; Pyridines ; Thiazoles

PURPOSE: The purpose of this study was to compare the accuracy of the implant master cast according to the type (pick-up, transfer) and the length (long, short) of the impression copings. MATERIALS AND METHODS: The metal master cast was fabricated with three internal connection type implant analogs (Osstem GS III analog), embedded parallel and with 10degrees of mesial angulation to the center analog. Four types of impression coping were prepared with different combinations of types (transfer, pick-up) and lengths (long, short) of the coping. The impressions were made using vinyl polysiloxane (one step, heavy + light body) with an individual tray, and 10 impressions were made for each group. Eventually, 40 experimental casts were produced. Then, the difference in the distance between the master cast and the experimental cast were measured, and the error rate was determined. The analysis of variance was performed using the SPSS (v 12.0) program (alpha = .05), and the statistical significance was set at P < .05. RESULTS: The ANOVA showed that the pick-up type impression coping exhibited a significantly lower error rate than the transfer type. However, no significant difference was observed with respect to the length of the impression coping. Additionally, no significant difference was observed between the parallel and mesial angulated groups. CONCLUSION: Within the limitations of this study, the pick-up type impression coping exhibited a more accurate implant master cast than the transfer type in parallel group. The accuracy of the implant master cast did not differ for different lengths of impression coping of at least 11 mm. Additionally, the accuracy of the implant cast was not different for the parallel and 10degrees mesial angulated groups.
Light ; Polyvinyls ; Siloxanes

PURPOSE: This study compared the accuracy of an abutment-framework (A-F) taken with open tray impression technique combining cementon crown abutments, a metal framework and resin cement to closed tray and resin-splinted open tray impression techniques for the 3-implant definitive casts. The effect of angulation on the accuracy of these 3 techniques was also evaluated. MATERIAL AND METHODS: Three definitive casts, each with 3 linearly positioned implant analogs at relative angulations 0, 30, and 40 degrees, were fabricated with passively fitted corresponding reference frameworks. Ten impressions were made and poured, using each of the 3 techniques on each of the 3 definitive casts. To record the vertical gap between reference frameworks and analogs in duplicate casts, a light microscope with image processing was used. Data were analyzed by two-way analysis of variance and the Tukey test. RESULTS: The open tray techniques showed significantly smaller vertical gaps compare to closed tray technique (P < .05). The closed tray and the resin-splinted open tray technique showed significantly different vertical gaps according to the angulation of implant (P < .05), but the A-F impression technique did not (P > .05). CONCLUSION: The accuracy of the A-F impression technique was superior to that of conventional techniques, and was not affected by the angulation of the implants.
Crowns ; Light ; Resin Cements

Photodynamic therapy (PDT) is a promising new modality that utilizes the combination of a photosensitizing chemical and visible light for the management of various solid malignancies, including gastrointestinal (GI) cancer. PDT has some advantages over chemotherapy in terms of its greater safety and lower toxicity in the treatment of malignant lesions. However, PDT has not been used widely for treating upper GI cancer due to its relatively low cost-effectiveness and anatomical characteristics of the GI system. Nevertheless, PDT may be an effective alternative therapy for early upper-GI cancer patients who are at a high risk of curative surgical resection or systemic chemotherapy. In some clinical studies, PDT for various upper GI cancer showed positiveresults. To improve the efficacy of PDT for upper GI cancer, development of photosensitezer and light delivery system is needed.
Humans ; Light ; Photochemotherapy ; Triazenes