scholarly journals Compact UV LED Lamp with Low Heat Emissions for Biological Research Applications

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 343 ◽  
Author(s):  
Matija Pirc ◽  
Simon Caserman ◽  
Polonca Ferk ◽  
Marko Topič
Keyword(s):  
Biomedical Research ◽  
Uv Light ◽  
Irradiation Time ◽  
Target Surface ◽  
Ultraviolet B ◽  
Biological Research ◽  
Maximum Deviation ◽  
Light Sources ◽  
Hek 293 ◽  
Average Irradiance

Much biomedical research focuses on the effects of UV light on human cells. UV light sources are a prerequisite for such research. This paper presents the design and achieved performance of a UVA (Ultraviolet A: 320–400 nm) and a UVB (Ultraviolet B: 290–320 nm) LED-based lamp suitable for use in bioassays, as well as inside an incubator. Numerical simulations were used to optimise the number, layout and output power of LEDs to achieve good irradiance homogeneity while maintaining low costs. Design was optimised for the efficient transfer of generated heat away from the irradiated samples through the heatsink at the back of the lamps. The average irradiance of the target surface by the UVA lamp was 70.1 W/m2 with a maximum deviation of 4.9%, and the average irradiance by the UVB lamp was 3.1 W/m2 with a maximum deviation of 4.8%. With the UVA and UVB lamps, the temperature of samples undergoing irradiation in the incubator rises from 37 to 42 °C within 40 and 67 min, respectively. This by far exceeds the required UV irradiation time in most cases. Tests on Jurkat and HEK-293 cell cultures confirmed the suitability of our lamps for biomedical research.

Immobilization of ZnO Suspension on Glass Substrate to Remove Filtration During the Removal of Remazol Red R from Aqueous Solution

2016 ◽  
Vol 12 (6) ◽  
pp. 4127-4133
Author(s):  
Nazmul Kayes ◽  
Jalil Miah ◽  
Md. Obaidullah ◽  
Akter Hossain ◽  
Mufazzal Hossain
Keyword(s):  
Aqueous Solution ◽  
Glass Substrate ◽  
Uv Light ◽  
Aqueous Suspension ◽  
Light Irradiation ◽  
Zno Films ◽  
Light Sources ◽  
Zno Film ◽  
Semiconductor Oxides ◽  
Remazol Red

Photodegradation of textile dyes in the presence of an aqueous suspension of semiconductor oxides has been of growing interest. Although this method of destruction of dyes is efficient, the main obstacle of applying this technique in the industry is the time and cost involving separation of oxides from an aqueous suspension. In this research, an attempted was made to develop ZnO films on a glass substrate by simple immobilization method for the adsorption and photodegradation of a typical dye, Remazol Red R (RRR) from aqueous solution. Adsorption and photodegradation of  RRR were performed in the presence of glass supported ZnO film. Photodegradation of the dye was carried out by varying different parameters such as the catalyst dosage, initial concentrations of RRR, and light sources. The percentage of adsorption as well as photodegradation increased with the amount of ZnO, reaches a maximum and then decreased. Maximum degradation has been found under solar light irradiation as compared to UV-light irradiation. Removal efficiency was also found to be influenced by the pre-sonication of ZnO suspension.

scholarly journals Photocatalytic Performance of ZnO: Al Films under Different Light Sources

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Prashant Pradhan ◽  
Juan Carlos Alonso ◽  
Monserrat Bizarro
Keyword(s):  
White Light ◽  
Irradiation Time ◽  
Zno Films ◽  
Light Sources ◽  
X Ray Diffraction ◽  
Treatment Processes ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Very High ◽  
High Degradation Rate

ZnO and Al doped ZnO films were produced by spray pyrolysis. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy, and photoluminescence. Their photocatalytic activity was evaluated by the decomposition of the methyl orange dye using different light sources: ultraviolet light, artificial white light, and direct sunlight. The films were also tested under darkness for comparison. The ZnO films were able to degrade the test pollutant under UV and sunlight in more than a 60% after 180 min of irradiation and a scarce degradation was obtained using white light. However, the Al doped ZnO films presented a very high degradation rate not only under UV and sunlight (100% degradation), but also under white light (90% degradation after the same irradiation time). An unexpected high degradation was also obtained in the dark, which indicates that a nonphotonic process is taking place parallel to the photocatalytic process. This can be due to the extra electrons—provided by the aluminum atoms—that migrate to the surface and produce radicals favoring the decomposition process even in the dark. The high activity achieved by the ZnO: Al films under natural conditions can be potentially applied to water treatment processes.

scholarly journals Beeporter: a high-throughput tool for non-invasive analysis of honey bee virus infection

2021 ◽  
Author(s):  
Jay D. Evans ◽  
Olubukola Banmeke ◽  
Evan C. Palmer-Young ◽  
Yanping Chen ◽  
Eugene V. Ryabov
Keyword(s):  
Virus Infection ◽  
Honey Bee ◽  
High Throughput ◽  
Honey Bees ◽  
High Throughput Screening ◽  
Fluorescent Protein ◽  
Imaging System ◽  
Uv Light ◽  
Light Sources ◽  
Deformed Wing Virus

ABSTRACTHoney bees face numerous pests and pathogens but arguably none are as devastating as Deformed wing virus (DWV). Development of antiviral therapeutics and virus-resistant honey bee lines to control DWV in honey bees is slowed by the lack of a cost-effective high-throughput screening of DWV infection. Currently, analysis of virus infection and screening for antiviral treatments in bees and their colonies is tedious, requiring a well-equipped molecular biology laboratory and the use of hazardous chemicals. Here we utilize a cDNA clone of DWV tagged with green fluorescent protein (GFP) to develop the Beeporter assay, a method for detection and quantification of DWV infection in live honey bees. The assay involves infection of honey bee pupae by injecting a standardized DWV-GFP inoculum, followed by incubation for up to 44 hours. GFP fluorescence is recorded at intervals via commonly available long-wave UV light sources and a smartphone camera or a standard ultraviolet transilluminator gel imaging system. Nonlethal DWV monitoring allows high-throughput screening of antiviral candidates and a direct breeding tool for identifying honey bee parents with increased antivirus resistance. For even more rapid drug screening, we also describe a method for screening bees using 96-well trays and a spectrophotometer.

scholarly journals Visible-Light Photoswitching of G-Quadruplex Ligand Binding Mode Allows Reversible Control of G-Tetrad Structure

2020 ◽  
Author(s):  
Michael O'Hagan ◽  
Javier Ramos Soriano ◽  
Susanta Haldar ◽  
Juan Carlos Morales ◽  
Adrian Mulholland ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Visible Light ◽  
Uv Light ◽  
Binding Mode ◽  
High Energy ◽  
Light Sources ◽  
Biologically Relevant ◽  
G Quadruplex ◽  
Potential Applications ◽  
Robust Regulation

<div><p>Photoresponsive ligands for G-quadruplex oligonucleotides (G4) offer exciting opportunities for the reversible regulation of these assemblies with potential applications in biological chemistry and responsive nanotechnology. However, achieving the robust regulation of G4 ligand activity with low-energy visible light sources that are easily accessible and compatible with biological systems remains a significant challenge to realizing these applications. Herein, we report the G4-binding properties of a photoresponsive dithienylethene (DTE). We demonstrate the first example of G4-specific acceleration of the photoswitching kinetics of a small molecule and the visible-light mediated switching of the G4 ligand binding mode in physiologically-relevant conditions, which in turn allows control over the G4 tetrad structure of telomeric G4 in potassium buffer. The process is fully reversible and avoids the need for high-energy UV light. This affords an efficient, practical and biologically-relevant means of control that may be applied in the generation of new responsive G4/ligand supramolecular systems.</p></div><br>

scholarly journals Researching CdZnS/ZnS (GT) Quantum Dots in Cathodoluminescent Mode

2019 ◽  
Vol 8 (9S2) ◽  
pp. 841-843
Keyword(s):  
Quantum Dots ◽  
Research And Development ◽  
Uv Light ◽  
Spectral Characteristics ◽  
Light Sources ◽  
Application Field ◽  
Medium Pressure

Application field of UV light sources is getting larger at the last decades. Among the most widespread are high and medium pressure vacuum lamps. But there currently is a trend of moving away from using mercury both in household applications and manufacturing. This creates a necessity to conduct research and development for UV sources made and operating without Hg. Cathodoluminescent UV sources are in this category. One of the possible ways to create a viable UV anode phosphor is using quantum dots with needed spectral characteristics.

scholarly journals Effect of light on aggregational behavior of planarian Dugesia tigrina

2017 ◽  
Author(s):  
Jaemin Lee
Keyword(s):  
Defense Mechanisms ◽  
Uv Light ◽  
Infrared Light ◽  
Light Sources ◽  
Initial Exposure ◽  
Dugesia Tigrina ◽  
Wide Range ◽  
Photophobic Response ◽  
Negative Effect ◽  
Effect Of Light

Introduction. Planarians are renowned for their regenerative ability due to pluripotent stem cells, as well as their peculiar photophobic response. However, few facts are known about their aggregational behavior. This study aims to reveal the effect of light on aggregational behavior. Reynierse (1966) suggested that light has a negative effect on the formation of aggregations. However, one of his objectives for aggregational behavior was inappropriate. This study reevaluated the effect of existence of light on aggregational behavior, as well as ascertained the effect of wavelength on the formation of aggregations. Methods. In this study, the ratio of individuals participating in aggregations was measured as a criterion to determine aggregational behavior. Aggregational behavior was measured after two hours from the initial exposure to different light sources. The behaviors under white LED light and under shade were compared, as well as the behaviors under five different light sources: infrared lamp, red, green, blue LED, and ultraviolet lamp. Results. The existence of light interfered the formation of aggregations (t-test, p < 0.0001), which supports the former study of Reynierse. Also, aggregational behavior differed under different wavelengths (ANOVA, p < 0.0001). Except for the infrared light which emitted a wide range of wavelengths, the behavior showed hierarchy: decreasing aggregational behavior in accordance with decreasing wavelength. UV light has the most significant negative effect on the formation of aggregations. Discussion. Exposure to light caused negative effects on performing aggregational behavior. Participation in aggregations appears to be influenced by photophobic response, especially under lights of short wavelength. Disintegrating aggregations under exposure to lights can potentially bring evolutionary benefit. This behavior possibly makes the aggregating planarians altogether exposed to a higher risk or predation, considering that they lack defense mechanisms. Planarians can lower the risk and continue the populations by disintegrating the aggregational behavior under the existence of UV and lights of higher wavelength, which are indicatives of daytime. Understanding aggregational behavior of animals of a lower order would give better insight on general herding behavior, and potentially help interpreting more complex behaviors of higher animals.

scholarly journals TIPS-Naphthalene for Efficient Visible-to-UV Photon Upconversion under Sunlight and Room Light

2020 ◽  
Author(s):  
Naoyuki Harada ◽  
Yoichi Sasaki ◽  
Masanori Hosoyamada ◽  
Nobuo Kimizuka ◽  
Nobuhiro Yanai
Keyword(s):  
High Performance ◽  
Uv Light ◽  
Light Sources ◽  
Solar Simulator ◽  
Visible Absorption ◽  
Excitation Light ◽  
Uv Emission ◽  
Threshold Excitation ◽  
Weak Light ◽  
Optimized Conditions

Until now, the efficiency of triplet-triplet annihilation-based photon upconversion (TTA-UC) from visible to ultraviolet (UV) light has been limited to ca. 10% due to the absence of high-performance acceptors (emitters). Here, we present the first example of visible-to-UV TTA-UC internal efficiency <i>η</i><sub>UC</sub> beyond 20% by developing a novel UV emitter, 1,4-bis((triisopropylsilyl)ethynyl)naphthalene (TIPS-Nph), and sensitizing its triplet by a donor Ir(C6)<sub>2</sub>(acac) with strong visible absorption and weak UV absorption. Under optimized conditions, 97% of the excitation light is absorbed, the threshold excitation intensity (<i>I</i><sub>th</sub> = 1.1 mW cm<sup>−2</sup>) is lower than the solar irradiance (1.4 mW cm<sup>−2</sup> for 445 ± 5 nm), and significantly, the highest external UC efficiency <i>η</i><sub>UC,ext</sub> of 17.4% for vis-to-UV TTA-UC is achieved. Upconverted UV emission can also be obtained with weak light sources such as an AM 1.5 solar simulator and room LEDs, paving the way for a variety of solar and indoor applications.

Performance of the light emitting diodes versus conventional light sources in the UV light cured formulations

2007 ◽  
Vol 105 (2) ◽  
pp. 803-808 ◽  
Author(s):  
Kelechi C. Anyaogu ◽  
Andrey A. Ermoshkin ◽  
Douglas C. Neckers ◽  
Alex Mejiritski ◽  
Oleg Grinevich ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Uv Light ◽  
Light Sources ◽  
Light Emitting

Intense Photoluminescence and Photoluminescence Enhancement of Silicon Nanocrystals by Ultraviolet Irradiation

2007 ◽  
Vol 31 ◽  
pp. 74-76 ◽  
Author(s):  
P.T. Huy ◽  
P.H. Duong
Keyword(s):  
Silicon Nanocrystals ◽  
Room Temperature ◽  
Laser Excitation ◽  
Uv Light ◽  
Irradiation Time ◽  
Excitation Wavelength ◽  
Nonradiative Recombination ◽  
Emission Yield ◽  
Recombination Centers ◽  
Pl Intensity

Photoluminescence (PL) from silicon nanocrystals deposited on top of silica-glass template and from silicon nanocrystals in nc_Si/SiO2 multilayer films were studied as a function of ultraviolet (UV) laser irradiation time in vacuum. Both the films exhibit intense visible PL at room temperature under laser excitation. It was found that upon prolong irradiation time using a He-Cd laser (325 nm) the PL intensity of the films was spectacularly enhanced. The process is reversible and does not happen with excitation wavelength longer than 400 nm. Upon introducing air into the measurement chamber, a rapid decrease of the PL intensity was recorded. This observation suggests that the UV light may lead to modification of nonradiative recombination centers in the films and thus improves the emission yield of silicon nanocrystals.

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