scholarly journals Visualizing Rayleigh Scattering through UV Photography

2016 ◽  
Vol 97 (9) ◽  
pp. 1561-1564 ◽  
Author(s):  
Anders V. Lindfors ◽  
Lasse Ylianttila
Keyword(s):  
Blue Light ◽  
Uv Radiation ◽  
Rayleigh Scattering ◽  
Fourth Power ◽  
Blue Color ◽  
Wavelength Band ◽  
Scattering Efficiency ◽  
Uv Photography ◽  
Strong Scattering ◽  
Insight Into

Abstract A tailored camera setup has been used to take photographs of the atmosphere and the environment as seen in the ultraviolet (UV) wavelength band. These photographs make visible what the human eye cannot normally perceive—in particular, the effects of the increasingly strong scattering of UV radiation by the molecular atmosphere. This scattering of sunlight by air molecules is commonly known as Rayleigh scattering, and its scattering efficiency is inversely proportional to the fourth power of the wavelength; the shorter the wavelength, the stronger the scattering. The blue color of the cloud-free sky is a well-known consequence of this, while it is also known that radiation in the UV band is even more diffuse than blue light. The UV photographs presented here demonstrate these effects of Rayleigh scattering. They show, for example, how clouds are much harder to distinguish from the background (the sky) in the UV than in the visible band, and how shadows tend to disappear in the UV. Thereby, these photographs provide intuitive insight into the physics of Rayleigh scattering, and help connect the typically abstract and theoretical information of textbooks and scientific articles with a more concrete understanding of the effects of Rayleigh scattering.

scholarly journals Device Modeling of Quantum Dot–Organic Light Emitting Diodes for High Green Color Purity

2021 ◽  
Vol 11 (6) ◽  
pp. 2828
Author(s):  
Byoung-Seong Jeong
Keyword(s):  
Quantum Dot ◽  
Emission Spectrum ◽  
Blue Light ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Color Purity ◽  
Wavelength Band ◽  
Light Emitting ◽  
Green Color ◽  
Organic Light

In this study, the optimal structure for obtaining high green color purity was investigated by modeling quantum dot (QD)–organic light-emitting diodes (OLED). It was found that even if the green quantum dot (G-QD) density in the G-QD layer was 30%, the full width at half maximum (FWHM) in the green wavelength band could be minimized to achieve a sharp emission spectrum, but it was difficult to completely block the blue light leakage with the G-QD layer alone. This blue light leakage problem was solved by stacking a green color filter (G-CF) layer on top of the G-QD layer. When G-CF thickness 5 μm was stacked, blue light leakage was blocked completely, and the FWHM of the emission spectrum in the green wavelength band was minimized, resulting in high green color purity. It is expected that the overall color gamut of QD-OLED can be improved by optimizing the device that shows such excellent green color purity.

scholarly journals Control of microtubule dynamics using an optogenetic microtubule plus end–F-actin cross-linker

2017 ◽  
Vol 217 (2) ◽  
pp. 779-793 ◽  
Author(s):  
Rebecca C. Adikes ◽  
Ryan A. Hallett ◽  
Brian F. Saway ◽  
Brian Kuhlman ◽  
Kevin C. Slep
Keyword(s):  
Blue Light ◽  
Actin Binding ◽  
Cross Linking ◽  
Dependent Manner ◽  
Exclusion Zone ◽  
Actin Networks ◽  
Drosophila Melanogaster S2 Cells ◽  
Actin Binding Domain ◽  
Specific Factors ◽  
Insight Into

We developed a novel optogenetic tool, SxIP–improved light-inducible dimer (iLID), to facilitate the reversible recruitment of factors to microtubule (MT) plus ends in an end-binding protein–dependent manner using blue light. We show that SxIP-iLID can track MT plus ends and recruit tgRFP-SspB upon blue light activation. We used this system to investigate the effects of cross-linking MT plus ends and F-actin in Drosophila melanogaster S2 cells to gain insight into spectraplakin function and mechanism. We show that SxIP-iLID can be used to temporally recruit an F-actin binding domain to MT plus ends and cross-link the MT and F-actin networks. Cross-linking decreases MT growth velocities and generates a peripheral MT exclusion zone. SxIP-iLID facilitates the general recruitment of specific factors to MT plus ends with temporal control enabling researchers to systematically regulate MT plus end dynamics and probe MT plus end function in many biological processes.

scholarly journals Role of Short-wavelength Blue Light in the Formation of Cataract and Expression of Caspase-1, -11 and Gasdermin D in rat Lens Epithelium Cells: Insight into the Novel Pathogenesis of Cataract.

2019 ◽  
Author(s):  
Yamin Wang ◽  
Min Zhang ◽  
Ying Sun ◽  
Xiaohui Wang ◽  
Zhaowei Song ◽  
...  
Keyword(s):  
Blue Light ◽  
Short Wavelength ◽  
Light Exposure ◽  
The Novel ◽  
Blue Led ◽  
Caspase 1 ◽  
Epithelium Cells ◽  
Experimental Group ◽  
Insight Into

Abstract Background Cataracts have been verified to be associated with a number of risk factors. The sun and artificial light sources, including light-emitting diode (LED) and fluorescent light tubes, are the primary sources of short-wavelength blue light. With the increasing popularity of blue-rich LED-backlit display devices, our eyes are now exposed to more short-wavelength blue light than they were in the past. The goal of this study was to evaluate the role of short-wavelength blue light in the formation of cataract. Additionally, the pathogenesis of cataracts after short-wavelength light exposure was investigated.Methods SD rats were randomly divided into 2 main groups: a control group (10 rats each for the 4-, 8-, and 12-week groups) and an experimental group (10 rats each for the 4-, 8-, and 12-week groups). The rats in the experimental group were exposed to a short-wavelength blue LED lamp for 12 hours per day. After exposure to the blue LED lamp, the rats were maintained in total darkness for 12 hours, after which a 12-hour light/dark cycle was resumed. The intensity of the lamp was 3000 lux. At the end of the short-wavelength blue LED lamp exposure (for 4, 8, and 12 weeks), the expression levels of caspase-1, caspase-11 and gasdermin D (GSDMD) in rat epithelium cells (LECs) were examined in rat epithelial cells (LECs) using qRT-PCR and Western blotting analyses. Results After 6 weeks, cataracts had developed in the experimental rats (4/20 eyes). The clarity of the lens then gradually worsened with the duration of exposure. Twelve weeks later, all of the rat eyes had developed cataracts. Then the expression levels of caspase-1, caspase-11 and GSDMD at 4, 8, and 12 weeks were significantly higher in samples from rats exposed to a short-wavelength blue LED lamp than samples from control rat (p˂0.05). Conclusion The data indicate that pyroptosis play a key role of in cataracts induced by short-wavelength blue light exposure, highlighting caspase-1, caspase-11 and GSDMD as possible therapeutic targets for cataract treatment. This study might provide new insight into the novel pathogenesis of cataracts.

Structure and Insight into Blue Light-Induced Changes in the BlrP1 BLUF Domain†,‡

Biochemistry ◽  
2009 ◽  
Vol 48 (12) ◽  
pp. 2620-2629 ◽  
Author(s):  
Qiong Wu ◽  
Kevin H. Gardner
Keyword(s):  
Blue Light ◽  
Bluf Domain ◽  
Induced Changes ◽  
Insight Into

Synthesis and Photophysical Properties of 3-(Trifluoromethyl)-2H-imidazo[5,1-a]isoquinolinium Chloride Derivatives

Synlett ◽  
2017 ◽  
Vol 29 (03) ◽  
pp. 296-300 ◽  
Author(s):  
Ali Darehkordi ◽  
Fariba Rahmani ◽  
Mahin Ramezani ◽  
Alireza Bazmandegan-Shamili
Keyword(s):  
Blue Light ◽  
Uv Radiation ◽  
Photophysical Properties ◽  
Molecular Probes ◽  
Quantum Yields ◽  
Light Emitting ◽  
Fluorescence Studies ◽  
Fluorescence Quantum Yields ◽  
Fluorescent Molecular Probes ◽  
Stokes Shifts

A series of novel blue-light-emitting 2H-imidazo[5,1-a]isoquinolinium chloride derivatives were synthesized by the reaction of isoquinoline with trifluoroacetimidoyl chlorides and isocyanides in dry CH2Cl2 in excellent yields. Fluorescence studies showed that the compounds absorb UV radiation and then emit blue light at about 481 nm with moderate to good fluorescence quantum yields. These compounds also showed high Stokes shifts, and can be used to develop ­ultrasensitive fluorescent molecular probes to study a variety of biological events and processes.

scholarly journals Salate derivatives found in sunscreens block experimental autoimmune encephalomyelitis in mice

2017 ◽  
Vol 114 (32) ◽  
pp. 8528-8531 ◽  
Author(s):  
Yanping Wang ◽  
Steven J. Marling ◽  
Lori A. Plum ◽  
Hector F. DeLuca
Keyword(s):  
Animal Model ◽  
Autoimmune Disease ◽  
Experimental Autoimmune Encephalomyelitis ◽  
Uv Radiation ◽  
Uv Light ◽  
Autoimmune Encephalomyelitis ◽  
Insight Into ◽  
Experimental Autoimmune

UV light suppresses experimental autoimmune encephalomyelitis (EAE), a widely used animal model of MS, in mice and may be responsible for the decreased incidence of MS in equatorial regions. To test this concept further, we applied commercially available sunblock preparations to mice before exposing them to UV radiation. Surprisingly, some of the sunblock preparations blocked EAE without UV radiation. Furthermore, various sunblock preparations had variable ability to suppress EAE. By examining the components of the most effective agents, we identified homosalate and octisalate as the components responsible for suppressing EAE. Thus, salates may be useful in stopping the progression of MS, and may provide new insight into mechanisms of controlling autoimmune disease.

Thermal Conductivity of Single-Crystal and Sintered RBa2Cu3O7 at low Temperatures

1987 ◽  
Vol 99 ◽  
Author(s):  
J. E. Graebner ◽  
L. F. Schneemeyer ◽  
R. J. Cava ◽  
J. V. Waszczak ◽  
E. A. Rietman
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Single Crystals ◽  
Free Path ◽  
Low Temperatures ◽  
Rayleigh Scattering ◽  
Resonant Scattering ◽  
Sintered Sample ◽  
Mean Free Path ◽  
Strong Scattering

ABSTRACTThe thermal conductivity k of micro-twinned single crystals of YBa2Cu3O7 and HoBa2Cu3O7 and a sintered sample of YBa2Cu3O7 has been measured for temperatures 0.03<T<5K. For the single crystals, k is small and varies as T1.8-1.9 This behavior resembles k for glassy insulators except for the lack of a plateau above IK. It is concluded that the thermal carriers are phonons with their mean free path limited by resonant scattering from tunneling entities, as in glasses. Suggestions for the location of tunneling systems are given. For the sinter, k is still smaller but does not follow a power law T-dependence. It is similar to other sintered ceramics with the same particle size, where the phonon mean free path is dominated by Rayleigh scattering from the particles. This strong scattering from the microstructure presumably masks the scattering from TS within each particle.

The nature of seismic noise

1966 ◽  
Vol 290 (1422) ◽  
pp. 290-296 ◽  
Keyword(s):  
Rayleigh Scattering ◽  
Single Scattering ◽  
Phase Shifts ◽  
Body Waves ◽  
Fourth Power ◽  
Frequency Effect ◽  
Power Dependence ◽  
End Effects ◽  
Comparative Efficiency ◽  
Large Phase

When seismic signals from impulsive sources are reflected or refracted by discrete inhomogeneities in the seismic medium, ‘arrivals’ are recorded. If, however, the number of inhomogeneities becomes large and the distance between them becomes small, then interference among the arrivals takes place and source-caused ‘noise ’ is recorded. If the spacing between observatories is large compared with the spacing between and dimensions of the scatterers, the source-caused noise is incoherent. If the number of scatterers is large enough for the problem to be treated statistically, the noise has a random character. The properties of the noise can be computed by averaging statistically over all the signals due to the scattering from the ensemble of scatterers. Single scattering only is treated here. There are ‘local’ or ‘end’ effects corresponding to scattering near the source or the receiver which cannot be taken into account in the calculations. The main problem which has been treated is that of the scattering of body waves of P and S types in an unbounded inhomogeneous medium. The magnitudes of the scattered waves of all types— PP, PS, SP, SS —have been computed. In addition the phase shifts (time delays or advances) in incident P and S can be computed. It is found that body waves of either P or S type convert into scattered S waves with considerably greater ease than into scattered P waves. The comparative efficiency of these processes is about two orders of magnitude. Thus P waves show small phase shifts; S waves show large phase shifts. The waves between P and S are most likely of the character of S . The approximations in the calculations involve the assumptions of wavelength long compared with the dimensions of the scatterer and the dimensions of the scattering region long compared with wavelength. Under these conditions the approximations are those for Rayleigh scattering. Hence, in all the results, the scattering varies as the fourth power of the frequency and the mean square scattered energy is proportional to the linear dimension of the scattering region. At higher frequencies, the scattering changes from a fourth power dependence upon frequency to a second power dependence. This is a result which is obtained only for scattering by elastic media; it is not found in media without shear modulus. Experimental evidence for this high frequency effect has been found.

Sign in / Sign up

Export Citation Format

Share Document