Luminous marine bacteria usually emit bluish-green light with a peak emission wavelength (λ(max) ) at about 490 nm. Some species belonging to the genus Photobacterium are exceptions, producing an accessory blue fluorescent protein (lumazine protein: LumP) that causes a blue shift, from λ(max)  ≈ 490 to λ(max)  ≈ 476 nm. However, the ...

A series of multishelled ZnO hollow microspheres with controlled shell number and inter-shell spacing have been successfully prepared by a simple carbonaceous microsphere templating method, whose large surface area and complex multishelled hollow structure enable them load sufficient dyes and multi-reflect the light for enhancing light harvesting and realize a ...

Blue light triggers carotenogenesis in the non-phototrophic bacterium Myxococcus xanthus by inducing inactivation of an anti-σ factor, CarR, and the consequent liberation of the cognate extracytoplasmic function (ECF) σ, CarQ. CarF, the protein implicated earliest in the response to light, does not resemble any known photoreceptor. It interacts physically with ...

A macrocycle-appended naphthalimide derivative and its Eu(iii) complex show triple luminescence from isolated naphthalimide (blue), aggregated naphthalimide excimers (green) and Eu centres (red) with the balance being sensitive to the degree of aggregation, allowing white light emission to be obtained from a single molecule.

To overcome the drawback of low photocatalytic efficiency brought by electron-hole recombination and narrow photo-response range, a novel Bi2S3/Bi2WO6 composite photocatalyst was designed. The composite possesses a wide photo-absorption till 800 nm, which occupies nearly the whole range of the visible light. Compared with bare Bi2WO6, the Bi2S3/Bi2WO6 composite exhibits ...

ABSTRACT: BACKGROUND: We have studied the impact of carbohydrate-starvation on the acclimation response to high light using Arabidopsis thaliana double mutants strongly impaired in the day- and night path of photoassimilate export from the chloroplast. A complete knock-out mutant of the triose phosphate/phosphate translocator (TPT; tpt-2 mutant) was crossed to ...

Trading up: A bioimaging system that is based on caged D-luciferin/upconversion nanoparticle conjugate has been developed. The nanoparticles upconvert near-infrared light into UV light, which triggers the photorelease of D-luciferin and leads to enhanced fluorescence and bioluminescence signals in vitro and in vivo. The use of near-infrared light enables deep ...

A preferred-handed helical conformation was induced to poly(9,9-dioctylfluoren-2,7-diyl) (PDOF) in a thin film form upon irradiation with single-handed circularly polarized light (CPL) where the induction was reversible.

Monochrome astronomy filters are well suited for use as excitation or suppression filters in fluorescence microscopy. Because of their particular optical design, such filters can be combined with standard halogen light sources for excitation in many fluorescent probes. In this "low energy excitation," photobleaching (fading) or other irritations of native ...

A class of dialkoxyanthracene-containing diblock copolymers is synthesized which possesses visible light-responsivity. These copolymers can self-assemble into a micellar structure in water. Green visible light (540 nm) is able to scissor these anthracene species and cleave the diblock copolymer into two fragments, inducing disassembly of the self-assembled micelles.

Operant discrimination learning has been extensively utilized in the study on the perceptual ability of animals and their higher order brain functions. We tested in this study whether American lobster Homarus americanus, which was previously found to possess ability of operant learning with claw gripping, could be trained to discriminate ...

Signaling photoreceptors mediate diverse organismal adaptations in response to light. As light-gated protein switches, signaling photoreceptors provide the basis for optogenetics, a term that refers to the control of organismal physiology and behavior by light. We establish as novel optogenetic tools the plasmids pDusk and pDawn, which employ blue-light photoreceptors ...

PURPOSE: To investigate at which wavelength melanopsin-containing retinal ganglion cells (mRGCs) depolarize and how they affect pupillary constriction induced by light stimulation in humans. METHODS: The pupil light reflex was evaluated for 30 normal subjects by use of an infrared pupillometer. Blue light stimulation (470 nm) and red light stimulation (635 nm) ...

In this paper, the high performance GaN-based light-emitting diodes (LEDs) with embedded microscale air voids and an SiO(2) nanomask by metal-organic chemical vapor deposition (MOCVD) were demonstrated. Microscale air voids and an SiO(2) nanomask were clearly observed at the interface between GaN nanorods (NRs) and the overgrown GaN layer by ...

The roles of light and temperature in the accumulation of the vegetal impact compound 2-methoxy-3-isobutylpyrazine (MIBP) in grape (Vitis vinifera L.) berries were determined. Individual clusters were exposed to various light intensities using neutral density shade cloth before ripening, during ripening, or throughout the season in three growing seasons. A ...

A cationic polythiophene-porphyrin (PTP) dyad is shown to exhibit efficient light-activated antifungal activity. Higher singlet oxygen ((1) O(2) ) generation efficiency can be attained from PTP upon photoexcitation due to the light-harvesting properties of the polymer backbone and efficient energy transfer from the polythiophene to the porphyrin units. PTP can ...

Caged non-ionic detergents, comprised of polar oligo(ethylene glycol) and non-polar alkyl chains joined by a photocleavable ortho-nitrobenzyl sulfonate linker have been synthesized and characterized. The light-triggered transformation of such chameleon surfactant from a charge-neutral into a charged form offers great potential to improve 2-D gel electrophoretic separation of complex protein ...

We report a single-step lithographic approach for precisely mapping near field light diffraction in photoresist and fabricating complex subwavelength structures. This method relies on the diffraction of UV light from opaque patterns on a photomask, and utilizes the central diffraction maximum (known as the 'Poisson spot' for an opaque disk) ...

ABSTRACT: BACKGROUND: Solar energy is the ultimate energy source on the Earth. The conversion of solar energy into fuels and energy sources can be an ideal solution to address energy problems. The recent discovery of proteorhodopsin in uncultured marine gamma-proteobacteria has made it possible to construct recombinant Escherichia coli with ...

A periodically aligned submicron ZnO hemispheres array was embedded into a TiO(2) nanoparticulate thin film (thickness; ca. 12 μm) as a photoanode for dye-sensitized solar cells (DSSCs). The ZnO hemisphere array provided light scattering centers that excited more dyes and direct electron pathways to the electrodes, which is beneficial for ...

In this work we show that solution-processed light-emitting electrochemical cells (LECs) based on only an ionic iridium complex and a small amount of ionic liquid exhibit exceptionally good performances when applying a pulsed current: sub-second turn-on times and almost constant high luminances (>600 cd m(-2) ) and power efficiencies over ...

External zeitgebers synchronize the human circadian rhythm of sleep and wakefulness. Humans adapt their chronotype to the day-night cycle, the strongest external zeitgeber. The human circadian rhythm shifts to evening-type orientation when daylight is prolonged into the evening and night hours by artificial light sources. Data from a survey of ...

Extrusive tooth movement has been overlooked in the literature on root resorption. The aims of this study were to quantify the effects of light and heavy controlled extrusive forces on root resorption and to localize the sites of prevalence in premolars. Ten patients (7 girls, 3 boys) who required bilateral ...

TRPM1 is a spontaneously active non-selective cation channel that has recently been shown to play an important role in the depolarizing light responses of ON bipolar cells. Consistent with this role, mutations in the TRPM1 gene have been identified as a principal cause of congenital stationary night blindness. However, previous ...

The effect of triangular air prism (TAP) arrays with different distance-to-width (d/w) ratios on the enhancement of light extraction efficiency (LEE) of InGaN light-emitting diodes (LEDs) is investigated. The TAP arrays embedded at the sapphire/GaN interface act as light reflectors and refractors, and thereby improve the light output power due ...

The mosquito sampling efficiency of light-trap catches and electric motor mosquito catches were compared with that of human biting catches in the Three Gorges Reservoir. There was consistency in the sampling efficiency between light-trap catches and human biting catches for Anopheles sinensis (r = 0.82, P<0.01) and light-trap catches were 1.52 (1.35-1.71) ...

Neuroscience research increasingly relies on optical methods for evoking neuronal activity as well as for measuring it, making bright and stable light sources critical building blocks of modern experimental setups. This paper presents a method to control the brightness of a high-power light emitting diode (LED) light source to an ...

Purpose: To better understand the striking overaccommodation that is triggered at wavelengths below 430 nm (below referred to as OAB). Methods: Fourteen students served as subjects, 6 emmetropic and 8 mildly myopic. They fixated a reading target or a Landolt C at 33-cm distance while the wavelength of light illuminating ...

Nitric oxide (NO) has emerged as a fundamental signal molecule involving in the responses of plant to stress. A role of NO in the regulation of methionine sulfoxide reductase (MSR) mRNA expression and high light acclimation was studied in a green macroalga Ulva fasciata Delile. A transfer from darkness to ...

ADP-glucose pyrophosphorylase (AGP) is a heterotetrameric enzyme comprising two small and two large subunits that catalyze the production of ADP-glucose linked to starch biosynthesis. The current paradigm on leaf starch metabolism assumes that posttranslational redox modification of AGP in response to light is a major determinant of fine regulation of ...

Light-responsive microcapsules constructed by layer-by-layer self-assembly are used as microcarriers to deliver different macromolecules inside cells. The microcapsules carry the macromolecules as cargo in their cavity, while their walls are modified with agglomerated gold nanoparticles. Microcapsules are incorporated by living cells and are then located in lysosomal compartments. Controlled release ...

We report on the changes the photosynthetic apparatus of Chlamydomonas reinhardtii undergoes upon acclimation to different light intensity. When grown in high light, cells had a faster growth rate and higher biomass production with respect to low and control light conditions. However,cells acclimated to low light intensity are indeed able ...

In sighted humans, light intensity, timing, exposure duration, and spectral composition of light are important to entrain the endogenous circadian pacemaker to the 24-h day-night cycle. We tested the impact of two realistic office lighting conditions during the afternoon on subjective sleepiness, hormonal secretion, and cognitive performance in the early ...

An interesting phenomenon is that some light-demanding plants fold their leaves when exposed to high light. Since high light could induce selective photodamage to photosystem II (PSII), we suggest that the leaves fold themselves to diminish the absorption of light energy and remedy the deficiency of physiological photoprotection for PSII. ...

Firefly luciferase-catalyzed light emission from D-luciferin is widely used as a reporter of gene expression and enzymatic activity both in vitro and in vivo. Despite the power of bioluminescence for imaging and drug discovery, light emission from firefly luciferase is fundamentally limited by the physical properties of the D-luciferin substrate. We and ...

Ionic transition-metal complex (iTMCs)-based electro-luminescent nanofibers (TELFs) are developed by using co-electrospinning. A single TELF consists of a Galistan liquid metal core (cathode), an iTMC-based polymer shell, and an ITO thin film coating (anode). Lights emitted from the TELFs can be detected by a CCD camera at 4.2 V and ...

Low-voltage-operating organic electrochemical light-emitting cells (LECs) and transistors (OECTs) can be realized in robust device architectures, thus enabling easy manufacturing of light sources using printing tools. In an LEC, the p-n junction, located within the organic semiconductor channel, constitutes the active light-emitting element. It is established and fixated through electrochemical ...

Context:Light exposure, particularly at the short-wavelength range, triggers several nonvisual responses in humans. However, the extent to which the melatonin-suppressing and alerting effect of light differs among individuals remains unknown.Objective:Here we investigated whether blue-enriched polychromatic light impacts differentially on melatonin and subjective and objective alertness in healthy participants genotyped for ...

We propose a microscopic theory of light-induced deformation of azobenzene elastomers bearing photosensitive azo-moieties in their strands. The theory is based on the orientation approach (V.Toshchevikov, et al. J. Phys. Chem. B 2009, 113, 5032), in which the light-induced mechanical stress originates from reorientation of chromophores with respect to the ...

Based on combined microsensor measurements of irradiance, temperature and O(2) , we compared light energy budgets in photosynthetic microbial mats, with a special focus on the efficiency of light energy conservation by photosynthesis. The euphotic zones in the three studied mats differed in their phototrophic community structure, pigment concentrations and ...

OBJECTIVES: Since photoinitiator systems for dental resins based on camphorquinone (CQ) present color disadvantages, trimethylbenzoyl-diphenyl-phosphine oxide (TPO) has been proposed as an alternative. However, there are remaining considerations about its curing efficiency. The aims of the present investigation were: to characterize the relationship between the photoinitiator absorption spectra and the ...

Photodynamic therapy (PDT) or photothermal therapy (PTT) using nanomaterials has shown great prospect for cancer treatment. Phycocyanin (PC) is a photoharvesting pigment and is also an attractive candidate for PDT. The multiwalled carbon nanotube (MWNT) is a potent candidate for PTT due to its extraordinary photo-to-thermal energy conversion efficiency upon ...

Micelle-to-vesicle morphological transition has been achieved by light-induced rapid hydrophilic arm detachment from a star polymer. This provides a remote and clean method to control morphology transition of polymeric assemblies.

The purpose of the present study was to elucidate the effect of posterior capsule opacification (PCO) on the straylight domain of visual function. PCO is heterogeneous with regard to morphology and severity; both aspects contribute to its functional effect. The isolated impact of capsule areas with specific morphology and severity ...

We built a differential optical absorption spectroscopy system to measure near-surface CO₂ absorption in the atmosphere using a nanosecond white light continuum. The white light laser can cover wavelengths ranging from 420 to 2400 nm, where the CO₂ and H₂O absorption lines are located. At an optical path length of ...

The bright and glossy appearance of the flowers of Ranunculus repens was investigated spectroscopically and the optical results were correlated with the layered anatomy of the petal. The highly directional reflected light arises from the partially transparent, pigment-bearing epidermal layer, while a more diffused yellow colour is the result of ...

Purpose:Time spent outdoors reduces the likelihood that children will develop myopia, possibly because light levels are much higher outdoors than indoors. To test this hypothesis, we investigated the effects of high ambient lighting on vision-induced myopia in monkeys.Methods:Monocular form deprivation was imposed on 8 infant rhesus monkeys. Throughout the rearing ...

Aim:  Various light emitting diode (LED) phototherapy devices have been trialled on the assumption of a more effective spectral distribution of the light emitted. We reviewed the current literature to determine whether LED is more effective than other types of phototherapy. Methods:  Eligible studies were randomized controlled trials of LED ...

A new phototransistor based on the mechanically-exfoliated single-layer MoS2 nanosheet is fabricated and its light-induced electric properties are investigated in details. Photocurrent generated from the phototransistor is solely determined by the illuminated optical power at a constant drain or gate voltage. The switching behavior of photocurrent generation and annihilation can ...

Photofermentation by the photosynthetic bacterium Rhodopseudomonas palustris has been used to convert the crude glycerol fraction from biodiesel production to hydrogen as a means of converting this large resource to useful energy. In the present study response surface methodology was applied to investigate the interactive effects among several important process ...