Red Light Source Research Articles

Organic Two-Photon-Absorbing Photosensitizers Can Overcome Competing Light Absorption in Organic Photocatalysis.

Conventional organic photocatalysis typically relies on ultraviolet and short-wavelength visible photons as the energy source. However, this approach often suffers from competing light absorption by reactants, products, intermediates, and co-catalysts, leading to reduced quantum efficiency and side reactions. To address this issue, we developed novel organic two-photon-absorbing (TPA) photosensitizers capable of functioning under deep red and near-infrared light irradiation. Three model reactions including cyclization, Sonogashira Csp2-Csp cross-coupling, and Csp2-N cross-coupling reactions were selected to compare the performance of the new photosensitizers under both blue (427 nm) and deep red (660 nm) light irradiation. The obtained results unambiguously prove that for reactions involving blue light-absorbing reactants, products, and/or co-catalysts, deep red light source resulted in better performance than blue light when utilizing our TPA photosensitizers. This work highlights the potential of our metal-free TPA photosensitizers as a sustainable and effective solution to mitigate the competing light absorption issue in photocatalysis, not only expanding the scope of organic photocatalysts but also reducing reliance on expensive Ru/Ir/Os-based photosensitizers.

Enhanced hypersensitive (5D0→7F2) transition characteristics of Eu3+ doped β-Ga2O3 microrods

Exploring and realizing the luminescence characteristics of rare earth metal (RE) ions doped gallium oxide (Ga2O3) is crucial for developing optoelectronic device applications. The current research used the solid-state reaction approach to synthesize Ga2O3 microrods doped with various europium (Eu3+) concentrations (0.1, 0.2, 0.3, 0.5, 0.75, and 1 mol). X-ray diffraction (XRD) and Raman spectral analyses confirm the monoclinic structure of β-Ga2O3. The intensity of the Raman phonon modes decreased and a peak shift was observed for Eu:β-Ga2O3. The electron microscopy (SEM, TEM) images depicted a nearly uniform distribution of microrods for undoped and Eu:β-Ga2O3 samples. The interplanar distance (d = 0.290 nm, 0.561 nm, and 0.433 nm), from HR-TEM images, corresponding to (0 0 4), (1 0 0), and (1 0 2) crystallographic orientations confirm the monoclinic structure of β-Ga2O3. The elemental mapping images showed a nearly homogeneous Ga, O, and Eu distribution. The UV–visible diffuse reflectance spectroscopy (UV-DRS) showed a notable reduction in the bandgap as the Eu3+ concentration increased. The emission spectra of Eu: β-Ga2O3 microrods showed a narrow red emission at 612 nm (5D0 → 7F2), which relates to the 5D0 → 7Fj (j = 0, 1, 2, 3) energy level arising from an intra-4f transition of Eu3+ ions upon 394 and 465 nm excitation. The red emission was found to increase with Eu content up to 0.5 mol.%. A quenching of emission due to the multipole–multipole interactions was obtained beyond 0.5 mol.% of Eu. The absolute quantum yield (η) calculated for Eu: β-Ga2O3 (0.5 mol.%) was 3.82 %. The luminescence decay curve using the bi-exponential fit and the average lifetime (τ) of the Eu: β-Ga2O3 (0.5 mol.%) was found to be ∼0.172 ms. CIE chromaticity and correlated color temperature analyses of Eu:β-Ga2O3 microrods yielded a red emission with a superior color purity (93 %). The obtained results suggest that Eu:β-Ga2O3 (0.5 wt.%) microrods could be one of the potential candidates for red light sources.

Effectiveness of 650 nm red laser photobiomodulation therapy to accelerate wound healing post tooth extraction

After tooth extraction, there can be consequences involving injury to the tissue surrounding the extracted tooth, which may lead to severe problems such as inflammation and infection. The wound healing process comprises inflammation, proliferation, and remodeling phases. Photobiomodulation is a therapy form that utilizes the interaction of a light source with tissue. This interaction can activate an increase in Adenosine Triphosphate (ATP), which subsequently triggers a chain reaction leading to the creation of new blood vessels and an increase in the number of fibroblasts. This study used a red laser light source with a power of 3.32 ± 0.01 mW, delivering a dose of 3.5 J to patients for extraction indications. The parameters observed included Interleukin 1_ (IL-1_), Prostaglandin E2 (PGE2), Human Beta defensin 2 (HBD2), and Gingival Index (GI). The results of testing saliva samples using the enzyme-linked immunosorbent test (ELISA) for the parameters IL-1_, PGE2, and HBD2 show a significant influence between the control and therapy groups. Meanwhile, GI revealed a significant influence of therapy on the wound-healing process. Using the Mann-Whitney U test, on day 1, the p-value was found to be 0.32, indicating no significant deference between the control and therapy groups. However, on the third day after the therapy was administered, the p-value was obtained as 0.01, signifying a significant deference between the control and therapy groups. On day 5, a p-value of 0.034 was obtained, signifying a significant deference between the control and therapy groups. Based on the research results, it can be observed that there is a decrease in the values of IL-1_, PGE2, HBD2, and GI. This indicates that local immune cells, including resident macrophages, are activated by pro-inflammatory mediators released in response to injury, and they play an essential role in accelerating wound healing.

Structural colour in the brown algal genus Sporochnus (Sporochnales, Phaeophyceae)

ABSTRACT The colour produced by an object’s microstructure rather than by pigments is generally called structural colour. Various macroalgae have some mechanisms of structural colouration. The presence of structural colour in the brown algae is well known in the Dictyotales and Fucales but has recently been reported in the Sporochnales where Sporochnus dotyi has structures in the terminal assimilatory filaments (trichothallic hairs) that produce a pronounced green iridescence. Based on observations by light microscopy, the structural colour of this species was caused by iridescent bodies, 10–15 µm in diameter, within the cells of assimilatory filaments. In contrast, another Sporochnus species known as S. radiciformis in Japan (S. radiciformis auct. japon.) also contains iridescent bodies of 6–10 µm diameter in the assimilatory filaments, but no significant structural colour was observed. In epi-illumination observations using red, green and blue LED light sources, iridescent bodies of S. dotyi showed stronger reflection of green compared with red and blue, whereas the reflections were similar among those colours in S. radiciformis. Transmission electron microscopy (TEM) using a rapid freezing method revealed that homogeneous globules 130–160 nm in diameter were tightly packed inside the iridescent bodies of S. dotyi, whereas the sizes of the globules were markedly irregular in iridescent bodies of S. radiciformis. Therefore, we conclude that the structural colouration of S. dotyi is caused by the interference and diffraction of incident light caused by the crystal lattice-like structure of tightly packed and regularly arranged globules of homogeneous size in the iridescent bodies, which is similar to the mechanism causing iridescence in opal. A similar opal-like structure of iridescent bodies causing structural colouration was recently reported in Ericaria selaginoides, but that of S. dotyi lacked the dynamic shift of the globules shown in E. selaginoides that resulted in a change of the wavelength of reflected light.

Hydrothermal Synthesis and Characterization of WSe2 Nanosheets: A Promising Approach for Wearable Photodetector Applications.

The two-dimensional (2D) WSe2 nanostructure was successfully synthesized via the hydrothermal method and subjected to comprehensive characterization using various spectroscopic techniques. X-ray diffraction (XRD) analysis confirmed the formation of nanosheets with a hexagonal crystal structure having a space symmetry of P63/mmc. Scanning electron microscopy (SEM) images showed irregular and nonuniform morphology. The size of the 2D nanosheets was determined using transmission electron microscopy (TEM) providing insights intotheir physical characteristics. The optical spectrum analysis yielded a discernible band gap value of 2.1 eV, as determined by the Tauc equation. Photoluminescence (PL) spectra display an emission at a wavelength of 610 nm, showing a broad emission associated with self-trapped excitons. Under excitation at λexc = 360 nm, PL emission spectra displayed a distinct peak at 610 nm, demonstrating the ability of the nanostructure to emit vivid red light. Photometric analysis underscored the potential of this nanostructure as a prominent red-light source for diverse display applications. The optimized photodetection performance of a device showcases a photoresponsivity of approximately 1.25 × 10-3 AW-1 and a detectivity of around 5.19 × 108 Jones at a wavelength of 390 nm. Additionally, the quantum efficiency is reported to be approximately 6.99 × 10-3 at a wavelength of 635 nm. These findings highlight the capability of the device for efficient photoconversion at specified wavelengths, indicating potential applications in sensing, imaging, and optical communication. The combination of structural, morphological, and optical characterizations highlights the suitability of 2D WSe2 nanostructure for practical optoelectronic applications, particularly in display technologies.

Chemical bath deposited CdTe thin film: Optical, electrical, and photoresponse aspects

Owning a narrow bandgap, remarkable optical and electrical properties with notable stability has made cadmium telluride (CdTe) an immensely vital semiconductor to develop cutting-edge optoelectronics. Taking these properties in to account, CdTe thin film is deposited employing the chemical bath deposition (CBD) technique. The X-ray diffraction analysis of the as-deposited thin film unveiled the composite crystalline structure, incorporating cubic, hexagonal, and tetragonal phases. The energy dispersive X-ray analysis and X-ray photoelectron spectroscopy ascertained the chemical composition of CdTe thin film. Distinctive Raman peaks are detected at 141 and 167 cm−1, signifying the presence of Cd-Te bond in the deposited thin film. The comprehensive evaluation of scanning electron micrographs emphasized the firm adhesion of the film to the substrate and displayed a uniform overlay of microstructures resembling rods. The observations from atomic force microscopy unveiled uniform grain structure with topographical features of hills and valleys. The UV-Visible spectroscopic examination elucidated that the as-deposited thin films exhibits a direct optical bandgap value of 1⋅59 eV. Temperature-dependent analysis of d.c. electrical resistivity exhibited a descending pattern, substantiating thin film's semiconducting attributes. The investigation into the photoresponse attributes of the thin film is accomplished by subjecting it to a polychromatic light, green and red monochromatic light source with an intensity of 50 mW/cm² employing three different biasing voltages. The thin film demonstrated maximum photocurrent for red light source than polychromatic and green light with maximum responsivity of 59⋅4 μA/W and detectivity of 17⋅7 × 106 Jones. These findings provide valuable insights on the photoresponse behavior of CBD deposited CdTe thin film in its as-deposited form.

Delayed tunneling of charges to deep traps in a ZnO impurity containing Cr3+ doped Zn2TiO4 inverse spinel.

Herein, the structural, optical and thermoluminescence properties of Cr doped Zn2TiO4 are explored extensively for a possible application in bioimaging. All the samples show prominent luminescence at wavelengths 712 and 716 nm, which correspond to Cr R and N2-lines, respectively. These R and N2 lines correspond to the presence of Cr3+ in undistorted and distorted sites. The excitation spectra of all the samples possess at least five different bands at 616, 440, 388, 330 and 283 nm. The persistent luminescence is observed upon excitation at all these wavelengths, suggesting the existence of both localized and delocalized mechanisms. The charges can be easily stored in deeper traps (trap depth > 1.0 eV) upon localized excitation with green and red light sources. However, upon excitation at wavelengths 254 and 365 nm, these traps were found empty when thermoluminescence glow curves were recorded immediately after excitation. Furthermore, it was observed that the trapping in these deeper traps through the delocalized band is possible when a delay in the thermoluminescence measurement is pursued. We attribute the possible reason for such delayed tunneling to the higher probability of retrapping than the recombination process.

A novel IoT based machine vision system for on-machine diameter measurement and optimization

The use of machine vision systems has been made user-friendly, cost-effective, and flawless by the rapid development in the fields of advanced electro-optical and camera systems, electronics systems, and software systems. One such application of machine vision systems in the field of manufacturing is the inspection of a semi-finished or finished component during an ongoing manufacturing process. In this study, the camera’s intrinsic and extrinsic parameters were maintained constant, while red, green, and blue light sources were employed to measure the component diameter using pixel analysis. A novel approach was used in an IoT-based machine vision system where, on the same image, the smartphone camera was calibrated and the image diameter of the component under study was measured, which was found to be quite accurate. Four different cases were used in the error analysis of image diameter, in which experimental results show that under blue light, the percentage pixel error span is the largest at 0.2624% followed by 0.1422% under green light and 0.0903% under red light. Further, the use of four different cases was followed by the ‘Weighted Sum Model’, which optimized the percentage errors in estimated actual diameter precisely and effectively, where outcome results showed that the approximate percentage errors were determined within 0.8% for blue light, 0.5% for a red light, and 0.1% for a green light. The proposed IoT-based machine vision system was found to be robust and effective for on-machine measurement.

Development of Optical Sensor Technology for Non-Invasive Hemoglobin Measurement

This research focuses on the development of hardware and software required to implement optical sensor technology. The optical sensor used is the MAX30102, equipped with infrared (IR) and red-light sources along with a receiver. The signals generated by the sensor are processed by NodeMCU and displayed on the OLED. The calibration results indicate the relationship between hemoglobin obtained using the invasive method and the output of the MAX30102 sensor, which is in the form of wavelength. It has the equation with an value of 0.9114. This equation is utilized to program the NodeMCU through the Arduino IDE. Validation and clinical trials have been conducted to evaluate its accuracy and applicability in clinical contexts. The results show that the non-invasive device has an average standard deviation of 0.32, indicating consistent measurement values. The non-invasive device demonstrates an average accuracy of 99.24%, signifying high precision and similarity to invasive methods. This suggests that the device holds potential as an innovative solution for Hemoglobin measurement.

Effect of Different Monochromatic LEDs on the Environmental Adaptability of Spathiphyllum floribundum and Chrysanthemum morifolium.

Light-emitting diodes (LEDs) can be programmed to provide specialized light sources and spectra for plant growth. UV-A (397.6 nm), blue (460.6 nm), green (520.7 nm), and red (661.9 nm) LED light sources were used to study the effects of different monochromatic lights on the growth, antioxidant system, and photosynthetic characteristics of Spathiphyllum floribundum 'Tian Jiao' (a shade-loving species) and Chrysanthemum morifolium 'Huang Xiu Qiu' (a sun-loving species). This research revealed that green and blue light could enhance the morphological indicators, Chl a/b, photosynthetic electron transfer chain performance, and photosystem activity of S. floribundum, blue and red light could enhance the solution protein, Chl a, and photosynthetic electron transfer chain performance of C. morifolium, red and UV-A light viewed the highest SOD and CAT activities of S. floribundum (275.56 U·min·g-1; 148.33 U·min·g-1) and C. morifolium (587.03 U·min·g-1; 98.33 U·min·g-1), respectively. Blue and green light were more suitable for the growth and development of the shade-loving plant S. floribundum, while red and blue light were more suitable for the sun-loving plant C. morifolium. UV-A light could be used for their stress research. The research revealed the different adaptation mechanism of different plants to light environmental conditions.

Novel SHAL base derived cobalt containing organic semiconducting metallogel thin film for self-powered high-performance photodetector application

The development of new materials with facile synthesis and better semiconducting and photonic properties is crucial for the fabrication of durable thin film-based semiconductor devices. In this study, an organic semiconducting and photo-conducting metallogel has been obtained by deprotonation of the ligand SHAL using LiOH followed by treatment with Co(II) acetate in dimethylformamide (DMF) under ambient conditions. Various characterization techniques are used to analyze the mechanical, morphological, and optical properties. This analyses reveal the formation of a organic semiconducting Co(II)-metallogel with a nanofibrous architecture. Furthermore, a comprehensive analysis of this material in thin film form demonstrates its n-type organic semiconducting nature with a good rectification ratio in the Schottky diode configuration, among the best-known values of all these materials. The Co(II)-metallogel is analyzed based on its semiconducting properties as a self-powered (in absence of external bias voltage) photodetectors (PDs) in an ITO/Co(II)-metalogel/Au configuration, for the first time. The measured photocurrent demonstrates responsivity, R(λ), of 2.77 x 103, 0.27 x 103, and 0.025 × 103 mA/W, external quantum efficiency (EQE) of 73.4 x 104, 63.1 x 103, and 25 x 103, and detectivity (D) of 5.28 x 1012, 5.2 x 1011, 4.7 x 109 Jones, with on/off ratio of 16 080, 1580, and 150 at 0 V under the illumination of 470-nm (blue), 530-nm (green), and 630-nm (red) light sources, respectively. The high performance of the PDs is attributed to the UV–vis spectrum of the thin film, morphology, and metal-semiconductor energy band schematic outcomes. Overall, this study presents considerable potential for novel applications of Co(II)metallogels in technologically challenging electronic and optoelectronic devices.

Preparation and photosensitization analysis of warm red emanating Europium (III) complexes with heterocyclic ligands for material in display devices

A series of the six novel europium complexes containing five ternary and one binary complex were characterised via different techniques such as photoluminescent (PL) spectroscopy in powdered as well as liquid phase, percentage color purity (%CP), CIE color coordinate, corelated color temperature (CCT), UV-vis absorbance, diffuse reflectance spectra (DR) were recorded to investigate the optical behaviour of the complexes. Colorimetric parameters unlocked the applicability of complexes as warm crimson red-light source and J-O parameters competently summarized the coordinating surrounding around the metal ion. Spectroscopic techniques Inferred (IR), proton nuclear magnetic resonance (1HNMR), carbon nuclear magnetic resonance (13CNMR), energy dispersive X-ray spectroscopy was done by the authors. Thermal stability of all complexes were describe by the thermogravimetry analysis. The energy gap between HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) were estimated experimentally and computationally with the help of DFT calculation. The authors studied precisely the transfer phenomenon of absorbed ligand energy to Eu3+ metal ion. Urbach energy optical energy and lasing properties were also calculated by using linear and gaussian fitting respectively.

Using a Diffraction Grid to Measure the Wavelength of a POF Laser

The research has been carried out to determine the wavelength of the POF laser using a diffraction grating. The diffraction grating used consists of three kinds of grid constants, namely 100 lines/mm, 300 lines/mm, and 600 lines/mm. Furthermore, the variation of the distance between the grid and the screen with a length of 40 cm, 60 cm, and 90 cm is carried out. The results showed that the wavelength of the POF laser light was between 664.07 nm-728.31 nm and the red monochromatic light source obtained the interference pattern of light on the screen as well as red monochromatic light. Based on the results of the research, it can be proven that the wavelength obtained from the use of a diffraction grating to measure the wavelength of the red laser is close to the wavelength value of 664.07 nm.

Design of a Low-Cost Diffuse Optical Mammography System for Biomedical Image Processing in Breast Cancer Diagnosis.

Worldwide, breast cancer is the most common type of cancer that mainly affects women. Several diagnosis techniques based on optical instrumentation and image analysis have been developed, and these are commonly used in conjunction with conventional diagnostic devices such as mammographs, ultrasound, and magnetic resonance imaging of the breast. The cost of using these instruments is increasing, and developing countries, whose deaths indices due to breast cancer are high, cannot access conventional diagnostic methods and have even less access to newer techniques. Other studies, based on the analysis of images acquired by traditional methods, require high resolutions and knowledge of the origin of the captures in order to avoid errors. For this reason, the design of a low-cost diffuse optical mammography system for biomedical image processing in breast cancer diagnosis is presented. The system combines the acquisition of breast tissue photographs, diffuse optical reflectance (as a biophotonics technique), and the processing of digital images for the study and diagnosis of breast cancer. The system was developed in the form of a medical examination table with a 638 nm red-light source, using light-emitted diode technology (LED) and a low-cost web camera for the acquisition of breast tissue images. The system is automatic, and its control, through a graphical user interface (GUI), saves costs and allows for the subsequent analysis of images using a digital image-processing algorithm. The results obtained allow for the possibility of planning in vivo measurements. In addition, the acquisition of images every 30° around the breast tissue could be used in future research in order to perform a three-dimensional (3D) reconstruction and an analysis of the captures through deep learning techniques. These could be combined with virtual, augmented, or mixed reality environments to predict the position of tumors, increase the likelihood of a correct medical diagnosis, and develop a training system for specialists. Furthermore, the system allows for the possibility to develop analysis of optical characterization for new phantom studies in breast cancer diagnosis through bioimaging techniques.

Self-regulation of light emission of an AlGaInP quantum well diode.

When an AlGaInP quantum well (QW) diode is biased with a forward voltage and illuminated with an external shorter-wavelength light beam, the diode is in a superposition state of both light emission and detection. The two different states take place simultaneously, and both the injected current and the generated photocurrent begin to mix. Here, we make use of this intriguing effect and integrate an AlGaInP QW diode with a programmed circuit. The AlGaInP QW diode with the dominant emission peak wavelength centered around 629.5 nm is excited by a 620-nm red-light source. The photocurrent is then extracted as a feedback signal to regulate the light emission of the QW diode in real time without an external or monolithically integrated photodetector, paving a feasible way to autonomously adjust the brightness of the QW diode for intelligent illumination in response to changes in the environmental light condition.

Red and blue light-specific metabolic changes in soybean seedlings.

Red and blue artificial light sources are commonly used as photosynthetic lighting in smart farm facilities, and they can affect the metabolisms of various primary and secondary metabolites. Although the soybean plant contains major flavonoids such as isoflavone and flavonol, using light factors to produce specific flavonoids from this plant remains difficult because the regulation of light-responded flavonoids is poorly understood. In this study, metabolic profiling of soybean seedlings in response to red and blue lights was evaluated, and the isoflavone-flavonol regulatory mechanism under different light irradiation periods was elucidated. Profiling of metabolites, including flavonoids, phenolic acids, amino acids, organic acids, free sugars, alcohol sugars, and sugar acids, revealed that specific flavonol, isoflavone, and phenolic acid showed irradiation time-dependent accumulation. Therefore, the metabolic gene expression level and accumulation of isoflavone and flavonol were further investigated. The light irradiation period regulated kaempferol glycoside, the predominant flavonol in soybeans, with longer light irradiation resulting in higher kaempferol glycoside content, regardless of photosynthetic lights. Notably, blue light stimulated kaempferol-3-O-(2,6-dirhamnosyl)-galactoside accumulation more than red light. Meanwhile, isoflavones were controlled differently based on isoflavone types. Malonyl daidzin and malonyl genistin, the predominant isoflavones in soybeans, were significantly increased by short-term red light irradiation (12 and 36h) with higher expressions of flavonoid biosynthetic genes, which contributed to the increased total isoflavone level. Although most isoflavones increased in response to red and blue lights, daidzein increased in response only to red light. In addition, prolonged red light irradiation downregulated the accumulation of glycitin types, suggesting that isoflavone's structural specificity results in different accumulation in response to light. Overall, these findings suggest that the application of specific wavelength and irradiation periods of light factors enables the regulation and acquisition of specialized metabolites from soybean seedlings.

Effect of nano-SiO2 on performances of KBaYSi2O7: Eu3+ red phosphor for NUV-pumped LEDs

KBaY0.9Si2−xSixO7: 0.1Eu3+ phosphors were prepared by traditional high temperature solid state reaction method at 1050 ℃ with nano and micron SiO2 as raw materials. The particle size of nano-SiO2 is 15, 30 and 50 nm. The crystal structure, morphology, luminescence intensity and thermal stability of the samples were characterized by XRD, SEM, photoluminescence spectra and temperature-dependent fluorescence spectra, respectively. The results show that the phosphor is a single matrix, and the mixing of nano-SiO2 increases the particle size and improves crystallization of the phosphor. KBaY0.9Si0.4Si1.6O7: 0.1Eu3+ mixed by nano-SiO2 with particle size of 15 nm has the improved performance of luminescence intensity enhanced by 13.7 % and thermal stability enhanced by 11 %. CIE coordinates are (0.670, 0.330) and close to the standard redlight source. Therefore, KBaY0.9Si0.4Si1.6O7: 0.1Eu3+ has a broad prospect in red phosphors for NUV excited LEDs.

Multi-color luminescence and anticounterfeiting application of upconversion nanoparticle.

Multi-color luminescence materials are important in the illumination, solid-state three-dimensional display, information storage, biological labelling and anticounterfeiting fields. Herein, we designed a novel core-shell structure upconversion nanoparticle (UCNP) material (NaYF4) with lanthanide ion doping to achieve multi-color luminescence under a single NIR excitation laser. Different from the typical single-sensitizer materials, the core-shell structure utilizes Nd3+, Yb3+, Tm3+ and Er3+ ions to obtain tuning of the color and brightness. The doping of Nd3+ ions enhances the weak color (red) light source to maintain the light color balance. Benefiting from the color adjustment of the sensitizers and the change of the core-shell coating, bright-white emission and flexible color emission from red to green, cyan and blue can be achieved via the diverse doped rare earth ions in a single UCNP under continuous-wave laser excitation (980 nm). Simultaneously, the emission color of the UCNPs can change with the intensity of the excitation light source and the wavelength. The bright-white emission can be used for lighting displays, and the flexible full-color emission can be applied in the anticounterfeiting and information storage fields.

Effect of Different Light Qualities and Intensities on the Yield and Quality of Facility-Grown Pleurotus eryngii.

Proper light is essential for the formation and development of macrofungi fruiting bodies. Currently, there are unclear treatment conditions, such as light quality and light intensity, in the production of Pleurotus eryngii in intensive cultivation facilities, which is not helpful to the formation and implementation of standardized production programs. The research discussed in this paper investigated the effects of different light quality and intensity conditions on the yield and quality of P. eryngii. The results showed that the yield and nutritional quality of the red light treatment samples were higher than those of the white light control, the commercial properties were good, and the energy consumption of the red LED light source was the lowest under the same light intensity. The results of this experiment further provide a reference for the energy-saving and high-quality cultivation of P. eryngii.

Color preference of Sergentomyia minuta (Diptera: Phlebotominae) determined using Flebocollect Do It Yourself light traps based on LED technology

Whether phlebotomine sand flies show a preference for different light colors remains controversial. As light-capture methods are widely used to study sand flies, knowing the visual stimuli they respond to could help the design of novel control tools to prevent their attraction to hosts. We have detected a significant preference of male Sergentomyia minuta for green and red light sources. Accordingly, male S. minuta were 2.16 and 2.01 times more likely to be lured by Flebocollect model traps with green and red diode-lights, respectively, than the commercial CDC traps. Flebocollect traps are homemade light traps developed through citizen science. Dipterans are widely considered unable to distinguish the color red so this finding was unexpected. To our knowledge, this is the first description of a color preference in a species of the genus Sergentomyia. Our research also confirms the great potential of Flebocollect light traps for use in medical entomology studies.