Blue Light Research Papers - Academia.edu (original) (raw)

The possible effects of blue light during acute hypoxia and the circadian rhythm on several physiological and cognitive parameters were studied. Fifty-seven volunteers were randomly assigned to 2 groups: nocturnal (2200-0230 hours) or... more

The possible effects of blue light during acute hypoxia and the circadian rhythm on several physiological and cognitive parameters were studied. Fifty-seven volunteers were randomly assigned to 2 groups: nocturnal (2200-0230 hours) or diurnal (0900-1330 hours) and exposed to acute hypoxia (4000 m simulated altitude) in a hypobaric chamber. The participants were illuminated by blue LEDs or common artificial light on 2 different days. During each session, arterial oxygen saturation (Spo2), blood pressure, heart rate variability, and cognitive parameters were measured at sea level, after reaching the simulated altitude of 4000 m, and after 3 hours at this altitude. The circadian rhythm caused significant differences in blood pressure and heart rate variability. A 4% to 9% decrease in waking nocturnal Spo2 under acute hypoxia was observed. Acute hypoxia also induced a significant reduction (4%-8%) in systolic pressure, slightly more marked (up to 13%) under blue lighting. Women had significantly increased systolic (4%) and diastolic (12%) pressures under acute hypoxia at night compared with daytime pressure; this was not observed in men. Some tendencies toward better cognitive performance (d2 attention test) were seen under blue illumination, although when considered together with physiological parameters and reaction time, there was no conclusive favorable effect of blue light on cognitive fatigue suppression after 3 hours of acute hypobaric hypoxia. It remains to be seen whether longer exposure to blue light under hypobaric hypoxic conditions would induce favorable effects against fatigue.

ZnS nanoparticles with Mn2+ doping (1–2.5%) have been prepared through a simple soft chemical route, namely the chemical precipitation method. The nanostructures of the prepared undoped ZnS and Mn2+-doped ZnS:Mn nanoparticles have been... more

ZnS nanoparticles with Mn2+ doping (1–2.5%) have been prepared through a simple soft chemical route, namely the chemical precipitation method. The nanostructures of the prepared undoped ZnS and Mn2+-doped ZnS:Mn nanoparticles have been analyzed using X-ray diffraction (XRD), Scanning electron microscope (SEM), transmission electron microscope (TEM) and UV–vis spectrophotometer. The size of the particles is found to be in 2–3nm

We report on the formation of low-resistance and highly transparent indium tin oxide (ITO) ohmic contacts to p-GaN using a Sn–Ag alloy interlayer. Although the as-deposited Sn–Ag(6 nm)/ITO(200 nm) contacts show non-ohmic behaviors, the... more

We report on the formation of low-resistance and highly transparent indium tin oxide (ITO) ohmic contacts to p-GaN using a Sn–Ag alloy interlayer. Although the as-deposited Sn–Ag(6 nm)/ITO(200 nm) contacts show non-ohmic behaviors, the scheme becomes ohmic with specific contact resistance of 4.72×10−4 Ω cm2 and produce transmittance of ∼91% at wavelength of 460 nm when annealed at 530 °C. Blue light-emitting diodes (LEDs) fabricated with the Sn–Ag/ITO contacts give forward-bias voltage of 3.31 V at injection current of 20 mA. LEDs with the Sn–Ag/ITO contacts show the improvement of the output power by 62% (at 20 mA) compared with LEDs with Ni/Au contacts.

This article provides an overview on recent advances in some of the basic signalling mechanisms that par- ticipate in a wide variety of stimulus -response path- ways. The mechanisms include calcium-based signalling,... more

This article provides an overview on recent advances in some of the basic signalling mechanisms that par- ticipate in a wide variety of stimulus -response path- ways. The mechanisms include calcium-based signalling, G-protein-mediated-signalling and signal- ling involving inositol phospholipids, with discussion on the role of protein kinases and phosphatases in- terspersed. As a further defining feature, the article highlights recent

Blue Light Therapy atau Fototerapi merupakan suatu alat yang digunakan untuk terapi mengatasi keadaan hiperbilirubunemia dengan menggunakan sinar biru. Alat ini bekeja dengan cara memancarkan sinar biru dengan lampu khusus. Cahaya Meter... more

Bacteria rely on two-component signaling systems in their adaptive responses to environmental changes. Typically, the two-component system consists of a sensory histidine kinase that signals by transferring a phosphoryl group to a... more

Bacteria rely on two-component signaling systems in their adaptive responses to environmental changes. Typically, the two-component system consists of a sensory histidine kinase that signals by transferring a phosphoryl group to a secondary response regulator that ultimately relays the signal to the cell. Some of these sensors use PAS (Per-Arnt-Sin) domains. A new member of the PAS super family is the LOV (light, oxygen, voltage) domain, a 10-kDa flavoprotein that functions as a light-sensory module in plant, algal, fungal, and bacterial blue-light receptors. Putative LOV domains have been identified in the genomes of many higher and lower eukaryotes, plants, eubacteria, archaebacteria, and particularly in genes coding for histidine kinases (LOV-histidine kinases, LOV-HKs) of plant and animal pathogenic bacteria, including Brucella. We describe here biochemical, photochemical, and biophysical methodology to purify these enzymes and to characterize their light-activation process.

Drivers who collide with a vehicle that is parked on the hard shoulder of a motorway or dual-carriageway sometimes claim not to have seen it before the collision. Previous research into vehicle conspicuity has taken such... more

Drivers who collide with a vehicle that is parked on the hard shoulder of a motorway or dual-carriageway sometimes claim not to have seen it before the collision. Previous research into vehicle conspicuity has taken such 'looked but failed to see' claims at face value, and concentrated on attempting to remedy the problem by making vehicles more conspicuous in sensory terms. However, the present study describes investigations into accidents of this kind which have involved stationary police cars, vehicles which are objectively highly conspicuous. Two laboratory studies showed that experienced drivers viewing a film of dual-carriageway driving were slower to respond to a parked police car as a 'hazard' if it was parked directly in the direction of travel than if it was parked at an angle; this effect was more pronounced when the driver's attention was distracted with a secondary reasoning task. Taken together with the accident reports, these results suggest that 'looked but failed to see' accidents may arise not because the parked vehicle is difficult to see, but for more cognitive reasons, such as vigilance failure, or possession by the driver of a 'false hypothesis' about the road conditions ahead. An emergency vehicle parked in the direction of travel, with only its blue lights flashing, may encourage drivers to believe that the vehicle is moving rather than stationary. Parking at an angle in the road, and avoiding the use of blue lights alone while parked, are two steps that drivers of parked emergency vehicles should consider taking in order to alert approaching drivers to the fact that a stationary vehicle is ahead.

Biomass productivity and fatty acid methyl esters (FAME) derived from intracellular lipid of a Nannochloropsis sp. isolated from Singapore’s coastal waters were studied under different light wavelengths and intensities. Nannochloropsis... more

Biomass productivity and fatty acid methyl esters (FAME) derived from intracellular lipid of a Nannochloropsis sp. isolated from Singapore’s coastal waters were studied under different light wavelengths and intensities. Nannochloropsis sp., was grown in both phototrophic and mixotrophic (glycerol as the carbon source) culture conditions in three primary monochromatic light wavelengths, i.e., red, green and blue LEDs, and also in white LED. The maximum specific growth rate (μ) for LEDs was blue > white > green > red. Nannochloropsis sp. achieved a μ of 0.64 and 0.66 d−1 in phototrophic and mixotrophic cultures under blue lighting, respectively. The intracellular fatty acid composition of Nannochloropsis sp. varied between cultures exposed to different wavelengths, although the absolute fatty acid content did differ significantly. Maximum FAME yield from Nannochloropsis sp. was 20.45% and 15.11% of dry biomass weight equivalent under photo- and mixotrophic culture conditions respectively for cultures exposed to green LED (550 nm). However, maximum volumetric FAME yield was achieved for phototrophic and mixotrophic cultures (i.e., 55.13 and 111.96 mg/l, respectively) upon cell exposure to blue LED (470 nm) due to highest biomass productivity. It was calculated that incremental exposure of light intensity over the cell growth cycle saves almost 20% of the energy input relative to continuous illumination for a given light intensity.

Blue Light Therapy atau Fototerapi merupakan suatu alat yang digunakan untuk terapi mengatasi keadaan hiperbilirubunemia dengan menggunakan sinar biru. Alat ini bekeja dengan cara memancarkan sinar biru dengan lampu khusus. Cahaya Meter... more

A gadget included in the modern gadget which has a boon for the entire human race and almost all of them have an important and integral part in their daily routine, that thing is the smartphone. While on one hand it remains a boon for... more

A gadget included in the modern gadget which has a boon for the entire human race and almost all of them have an important and integral part in their daily routine, that thing is the smartphone. While on one hand it remains a boon for humans, and the other hand it causes serious health problem due to its increasing misuse. And it's making people sick. Radiations emanating from the phone are absorbed by the skin, although it is tolerable. But its prolonged exposure can cause various types of complications. If the smartphone is used for too long of the night, the circadian rhythm is disturbed. It leads to insomnia as well as its glossy blue light brings change in photoreceptor cell in eyes. Most people carry or keep smartphone near the waist and in the pockets of paint, by doing so, it adversely affects reproductive organs and brings infertility. Radio-frequency electromagnetic radiation ( RFEMR) which is emitted from smartphone causes damage of gonad. These radiation decreases sperm motility and development. In females radiation exert adverse effect on ovary and endometrial tissue. The study also revealed that cancer and tumor is also possible due to misuse and excessive of smartphone.

This study describes a preclinical investigation with laser-activated bleaching agent for discolored teeth. Bleaching techniques involve a broad-spectrum approach utilizing hydrogen peroxide (3-38%) with or without heat or laser,... more

This study describes a preclinical investigation with laser-activated bleaching agent for discolored teeth. Bleaching techniques involve a broad-spectrum approach utilizing hydrogen peroxide (3-38%) with or without heat or laser, carbamide peroxide (10-30%), or a mixture of sodium perborate and hydrogen peroxide. Extracted human maxillary central incisors were selected. In the bleaching experiment, 38% hydrogen peroxide was used. Two different laser