scholarly journals Visible blue light inhibits infection and replication of SARS-CoV-2 at doses that are well-tolerated by human respiratory tissue

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathan Stasko ◽  
Jacob F. Kocher ◽  
Abigail Annas ◽  
Ibrahim Henson ◽  
Theresa S. Seitz ◽  
...  
Keyword(s):  
Visible Light ◽  
Blue Light ◽  
Light Exposure ◽  
Light Emitting Diode ◽  
Spectral Band ◽  
Dependent Manner ◽  
Light Emitting ◽  
Biological Surfaces ◽  
Visible Wavelengths ◽  
High Doses

AbstractThe delivery of safe, visible wavelengths of light can be an effective, pathogen-agnostic, countermeasure that would expand the current portfolio of SARS-CoV-2 intervention strategies beyond the conventional approaches of vaccine, antibody, and antiviral therapeutics. Employing custom biological light units, that incorporate optically engineered light-emitting diode (LED) arrays, we harnessed monochromatic wavelengths of light for uniform delivery across biological surfaces. We demonstrated that primary 3D human tracheal/bronchial-derived epithelial tissues tolerated high doses of a narrow spectral band of visible light centered at a peak wavelength of 425 nm. We extended these studies to Vero E6 cells to understand how light may influence the viability of a mammalian cell line conventionally used for assaying SARS-CoV-2. The exposure of single-cell monolayers of Vero E6 cells to similar doses of 425 nm blue light resulted in viabilities that were dependent on dose and cell density. Doses of 425 nm blue light that are well-tolerated by Vero E6 cells also inhibited infection and replication of cell-associated SARS-CoV-2 by > 99% 24 h post-infection after a single five-minute light exposure. Moreover, the 425 nm blue light inactivated cell-free betacoronaviruses including SARS-CoV-1, MERS-CoV, and SARS-CoV-2 up to 99.99% in a dose-dependent manner. Importantly, clinically applicable doses of 425 nm blue light dramatically inhibited SARS-CoV-2 infection and replication in primary human 3D tracheal/bronchial tissue. Safe doses of visible light should be considered part of the strategic portfolio for the development of SARS-CoV-2 therapeutic countermeasures to mitigate coronavirus disease 2019 (COVID-19).

scholarly journals Refrigeration temperature enhanced synergistic interaction of curcumin and 460 nm light emitting diode against Staphylococcus saprophyticus at neutral pH

2020 ◽  
Author(s):  
Ziyuan Wang ◽  
Lin Han ◽  
Jie Liu ◽  
Mingfei Yao
Keyword(s):  
Blue Light ◽  
Light Emitting Diode ◽  
Combined Treatment ◽  
Light Dose ◽  
Synergistic Interaction ◽  
Dependent Manner ◽  
Light Emitting ◽  
Neutral Ph ◽  
Staphylococcus Saprophyticus ◽  
Significant Difference

Abstract As considered highly resistant to antibiotics like mecillinam, the rise of Staphylococcus saprophyticus contamination of fresh foods and food processing environments necessitates the development of new antimicrobial approach for food safety control. This study aimed to investigate the synergistic effect of food grade curcumin (CUR) and blue light emitting diode (LED) on S. saprophyticus under different pH (pH 2.2-7.2) and temperatures (4 and 25 °C). The influence of other parameters, including CUR concentration, light dose and incubation time on the inactivation of S. saprophyticus were characterized. Results indicated that the combined treatment of CUR and blue light irradiation significantly (P < 0.05) reduced bacterial counts and the antimicrobial effect was in a CUR concentration and light dose-dependent manner. Moreover, refrigeration temperature (4 °C) significantly (P < 0.05) enhanced the antibacterial effect at neutral pH condition (6.2-7.2), resulting in approximately 6.0 log reductions. Under acidic condition (pH 2.2-5.2), there was no significant difference in bacterial population reduction between treatments at both temperatures. These finding proposed that synergistic interaction of curcumin and 460 nm LED under refrigerated temperature could enhance the inactivation of S. saprophyticus at neutral pH condition.

Ultra-high-speed single red–green–blue light-emitting diode-based visible light communication system utilizing advanced modulation formats

2014 ◽  
Vol 12 (1) ◽  
pp. 010605-10608 ◽  
Author(s):  
Nan Chi Nan Chi ◽  
Yuanquan Wang Yuanquan Wang ◽  
Yiguang Wang Yiguang Wang ◽  
Xingxing Huang Xingxing Huang ◽  
Xiaoyuan Lu Xiaoyuan Lu
Keyword(s):  
Visible Light ◽  
Blue Light ◽  
Communication System ◽  
High Speed ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Modulation Formats ◽  
Light Emitting ◽  
Ultra High Speed ◽  
Advanced Modulation Formats

Acute Effect of Blue Light Exposition on Well-being and Melatonin Secretion in Humans

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
L. Franke ◽  
D. Sülflow ◽  
K. Stark ◽  
H. Piazena ◽  
R. Uebelhack
Keyword(s):  
Blue Light ◽  
Light Exposure ◽  
Light Emitting Diode ◽  
Well Being ◽  
Acute Effect ◽  
Menstrual Phase ◽  
Melatonin Secretion ◽  
Light Emitting ◽  
Post Test ◽  
Dim Light

Aim:The aim of this study was to investigate the efficacy of blue light emitting diode units in suppression of melatonin secretion and to evaluate whether a single exposure can improve well being in healthy males and females (20/30) and in 15 women with premenstrual syndrome.Methods:All study participants were of morning-type with a regular sleep schedule. On control day 1, the subjects were kept under dim illumination (< 10 lx) from 19:00 to 22:30. On day 2, after 1.5h in dim light, the subjects were exposed for 60 min to blue light (12.15 μM/cm², TurboLite, Germany) following by 30 min dim light. Blood samples were collected every 30 min for melatonin assay. Zerssen's complaints scale was used to assess mental und physical well-being at 19:00 (pre-test) and at 22:30 (post-test) after dim illumination or blue light exposure. In addition a visual analogue scale (VAS) for sleepiness was applied.Results:Overall, blue light improved significantly mental and physical complaints from pre-test to post-test (reduction in sum score of the Zerssen's complaints scale by in average 30%) and reduced sleepiness, as measured by the VAS. There were gender-related differences, as well as differences related to the menstrual phase in females. Blue light reduced but not suppressed the gradual increase of melatonin in plasma with time mostly pronounced in the follicular phase.Conclusion:A single exposition with blue light of low radiant flux density, as applied in our study, seems to be helpful in reducing mental and physical distress.

The Intellectual Lighting And Data Transmission System based On RGBW Light Emitting Diodes

2021 ◽  
pp. 63-68
Author(s):  
Daniil S. Shiryaev ◽  
Olga A. Kozyreva ◽  
Ivan S. Polukhin ◽  
Sergey A. Shcheglov ◽  
Svetlana A. Degtiareva ◽  
...  
Keyword(s):  
Visible Light ◽  
Data Transmission ◽  
Light Transmission ◽  
Transmission Rate ◽  
Light Emitting Diode ◽  
Spectral Characteristics ◽  
System Component ◽  
Transmission Channel ◽  
Error Vector Magnitude ◽  
Light Emitting

The system of intellectual lighting data transmission via visible light is developed and manufactured. Spectral characteristics of a downlink which uses the red crystal of a RGBW light emitting diode for data transfer were studied. The DALI protocol-based radiation chromaticity control system which allows us to set different lighting scenarios with constant data transmission rate was developed. The radiation chromaticity range covers almost the entire colour gamut in the colour space. The system of high-frequency matching of system component impedances was developed and frequency characteristics of the suggested scheme were studied for development of the system. Optimal parameters of the signal for visual light communication such as carrier frequency, modulation type and band were determined. Observation of the constellation diagram which represents different values of the complex amplitude of the keyed signal in the form of a complex number on a quadrature plane (cosine and sine components of the carrying signal) and of fixation of the amplitude of the error vector magnitude (EVM) was selected as a method of study of the transmission channel quality. The value of EVM in the visible light transmission channel was significantly lower for signals with amplitude modulation than for phase-manipulated signals. When implementing different lighting change scenarios, radiation of other crystals of the light emitting diode crystals not used for transmission did not lead to increase of EVM by more than one percent.

scholarly journals In vitro and in vivo Efficacy of New Blue Light Emitting Diode Phototherapy Compared to Conventional Halogen Quartz Phototherapy for Neonatal Jaundice

2005 ◽  
Vol 20 (1) ◽  
pp. 61 ◽  
Author(s):  
Yun Sil Chang ◽  
Jong Hee Hwang ◽  
Hyuk Nam Kwon ◽  
Chang Won Choi ◽  
Sun Young Ko ◽  
...  
Keyword(s):  
Blue Light ◽  
Neonatal Jaundice ◽  
Light Emitting Diode ◽  
In Vivo Efficacy ◽  
Light Emitting

scholarly journals Operando direct observation of spin-states and charge-trappings of blue light-emitting-diode materials in thin-film devices

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fumiya Osawa ◽  
Kazuhiro Marumoto
Keyword(s):  
Blue Light ◽  
High Performance ◽  
Density Functional ◽  
Light Emitting Diode ◽  
Green Light ◽  
Spin States ◽  
Light Emitting ◽  
Full Color ◽  
Color Displays ◽  
Materials Used

Abstract Spin-states and charge-trappings in blue organic light-emitting diodes (OLEDs) are important issues for developing high-device-performance application such as full-color displays and white illumination. However, they have not yet been completely clarified because of the lack of a study from a microscopic viewpoint. Here, we report operando electron spin resonance (ESR) spectroscopy to investigate the spin-states and charge-trappings in organic semiconductor materials used for blue OLEDs such as a blue light-emitting material 1-bis(2-naphthyl)anthracene (ADN) using metal–insulator–semiconductor (MIS) diodes, hole or electron only devices, and blue OLEDs from the microscopic viewpoint. We have clarified spin-states of electrically accumulated holes and electrons and their charge-trappings in the MIS diodes at the molecular level by directly observing their electrically-induced ESR signals; the spin-states are well reproduced by density functional theory. In contrast to a green light-emitting material, the ADN radical anions largely accumulate in the film, which will cause the large degradation of the molecule and devices. The result will give deeper understanding of blue OLEDs and be useful for developing high-performance and durable devices.

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