Search results for "blue light."
showing 10 items of 12 documents
Protective role of xanthophylls
2010
Xanthophylls, also known as carotenoids are a group of natural fat-soluble pigments that are especially abundant in green and yellow-orange fruits and vegetables. Based on epidemiologic data, it is now evident that carotenoids provide health benefits and particularly in eye diseases. Molecular characterization of retinal carotenoids has shown that there were actually two xanthophylls that are concentrated in macular region, namely lutein and zeaxanthin. Thanks to a strategic position within inner retinal layers, lutein and zeaxanthin are suspected to act as antioxidants in the retina in order to limit oxidative stress that results from metabolism of light. In addition, they are also suppose…
Blue-light imaging compared with high-definition white light for real-time histology prediction of colorectal polyps less than 1 centimeter: a prospe…
2019
Blue-light imaging (BLI) is a new chromoendoscopy technique, potentially useful for differentiating neoplastic from nonneoplastic lesions. The present study was aimed at comparing BLI with high-definition white light (HDWL) in the real-time histology prediction of colon polyps 10 mm.Consecutive outpatients undergoing colonoscopy with the ELUXEO 7000 endoscopy platform and 760 series video colonoscopes (Fujifilm Co, Tokyo, Japan) who had at least 1 polyp 10 mm were randomized to BLI or HDWL for polyp characterization. The accuracy of high-confidence real-time histology prediction (adenoma vs not adenoma) by either BLI or HDWL for polyps 10 mm (primary end-point) and diminutive (≤5 mm) polyps…
Increase in cortisol concentration due to standardized bright and blue light exposure on saliva cortisol in the morning following sleep laboratory
2020
Research studies on LED light exposure and cortisol are inconsistent and not comparable due to different types of light, exposure times, and sample sizes. Therefore, one hour of standardized exposure LED light at different intensities and the spectral composition during the post-awakening phase at 7:30 were compared. A sample of 23 (Study 1) and 26 (Study 2) healthy males were randomly assigned to: 1) bright white light (414 lux) and 2) dim darkened light (2 lux) as well as 3) red light (235 lux) and 4) blue light (201 lux) exposure conditions. Results from repeated measures ANOVA confirm that light exposure affects the cortisol concentration. Study 1 revealed an increase in the saliva cort…
Low-temperature growth of n ++-GaN by metalorganic chemical vapor deposition to achieve low-resistivity tunnel junctions on blue light emitting diodes
2018
We report on low-resistivity GaN tunnel junctions (TJ) on blue light-emitting diodes (LEDs). Si-doped n ++-GaN layers are grown by metalorganic chemical vapor deposition directly on LED epiwafers. Low growth temperature (<800 °C) was used to hinder Mg-passivation by hydrogen in the p ++-GaN top surface. This allows achieving low-resistivity TJs without the need for post-growth Mg activation. TJs are further improved by inserting a 5 nm thick In0.15Ga0.85N interlayer (IL) within the GaN TJ thanks to piezoelectric polarization induced band bending. Eventually, the impact of InGaN IL on the internal quantum efficiency of blue LEDs is discussed.
Optimized blue light generation in optically contacted walk-off compensated RbTiOAsO4 and KTiOP1−yAsyO4
1999
Abstract We study type II 1.32 μm second harmonic generation (SHG) in a RbTiOAsO 4 optically contacted walk-off compensated device. The reduction of the effective walk-off angle by a factor of 3.7 with respect to KTiOPO 4 for the same interaction leads to an enhancement by a factor of 10 of the conversion efficiency. A model is proposed for both type I and type II SHG in such a structure. The angular tuning curve is a multi-peaked one, as predicted by the model. The enhancement of the SHG conversion efficiency allows us to optimize the generation of blue laser light at 440 nm: a specially designed KTiOP 0.98 As 0.02 O 4 solid solution crystal achieves angular non-critical phase matching at …
Zilo gaismu bloķējošo lēcu ietekme uz kontrastjutību
2018
Bakalaura darbs ir 21 lappaspusi garš, satur 9. attēlus, 1. tabulu un 39. literatūras atsauces. Darba mērķis ir novērtēt zilo gaismu bloķējošo lēcu ietekmi uz kontrastjutību. Mērījumi tika veikti, izmantojot Pelli-Robsona testu, kurš tika rādīts iPad telefonā. Mērījumā piedalījās 55 dalībnieki. Mērījumi tika veikti ar briļļu lēcām, kurām bija zilo gaismu bloķējošais klājums, kā arī ar lēcām, kurām bija tradicionālais pretatspīdumu klājums. Kontrastjutība bija labāka ar zilo gaismu bloķējošām lēcām nekā ar lēcām, kurām bija tradicionālais pretatspīdumu klājums (p<0.001). Dalībniekiem ar sūdzībām par žilbšanu kontrastjutības uzlabojums ar zilo gaismu bloķējošām lēcām bija lielāks nekā dalībni…
Effects of UV and Blue Light on the Bipotential Changes in Etiolated Hypocotyl Hooks of Dwarf Beans
1980
One of the most complex topics to study in biology is the ability of organism to perceive, code, transmit, and integrate environmental information, which is used to direct the cellular metabolism and developmental processes occurring. The detection of different wavelengths of light by specific mechanism plays a key role in plant development. Although great progress has been made in the study of plant photoreceptor pigments, some pigment systems are understood better than others.
Zilās gaismas draudu kumulatīvā analīze
2022
Maģistra darbs uzrakstīts angļu valodā uz 42 lappusēm. Tas satur 15 attēlus, 4 vienadojumi, 8 tabulas un 64 atsauces. Cilvēki katru dienu ir pakļauti zilajai gaismai. Zilā gaisma ir bīstama, ja tā pārsniedz 100 J / (cm2-sr) uz 106 ≤ t. Pirmsreceptoru makulas pigmenti, luteīns un zeaksantīns kopā ar lēcas kristālu absorbē zilo gaismu. Zilās gaismas svērtais spožums dažādos ekspozīcijas ilgumos tika modelēts ar doto datu bāzi, kas ņemta no f. fluxometrs dažādiem zilās gaismas avotiem. Rezultāti parādīja, ka gaismai, ko izstaro saules gaisma, īpaši saulainās dienās, ir visaugstākās zilās gaismas spožuma vērtības un tā tiek uzskatīta par kaitīgu, bet tomēr nepārsniedz vērtības, kas pierāda bīst…
Combined Analysis of the Effects of Exposure to Blue Light in Ducks Reveals a Reduction in Cholesterol Accumulation Through Changes in Methionine Met…
2021
Monochromatic light is widely used in industry, medical treatment, and animal husbandry. Green-blue light has been found to stimulate the proliferation of satellite cells and the results of studies on the effects of blue light on poultry vary widely. It would be worthwhile to study the effect of blue light on poultry growth and how exposure to blue light affects metabolism and the intestinal microbiota. In this study, we irradiated Cherry Valley ducks with 460 nm wavelength light (blue light) for 3 weeks to explore the effects of blue light in comparison to those of white light (combined wavelength light) on animal growth and development. Our results showed that, under exposure to blue ligh…
The influence of blue light on the Dionaea muscipula cultivation
2018
Rośliny wykorzystują światło jako źródło energii do fotosyntezy, reagują na jego intensywność, długość fali świetlnej i kierunek światła. Jest ono także swoistym sygnałem środowiskowym. Światło jest odbierane przez fotoreceptory roślin, takie jak: kryptochromy, fototropiny oraz fitochromy, a rośliny generują szeroki zakres specyficznych odpowiedzi fizjologicznych przez te receptory. Do badań wykorzystano dwie hodowle roślinne składające się z dwóch odmian muchołówki amerykańskiej - Dionaea muscipula: Regular form oraz Red green. Jedną z hodowli poddano oddziaływaniu światła niebieskiego, a drugą - kontrolną prowadzono w warunkach oddziaływania światła słonecznego. Prowadzono pomiary morfolo…