Light-emitting Diode Irradiation Research Articles

Comparison of Energy-use Efficiency for Lettuce Plantation under Nutrient Film Technique and Deep-Water Culture Hydroponic Systems

Energy conservation opportunities in closed plant production systems have been widely discussed, however, a comparison of energy-use efficiency (EUE) for different types of hydroponic systems is lacking. This paper compares the EUE of two different hydroponic systems, namely nutrient film technique (NFT) and deep-water culture (DWC), within an aquaponics facility. The energy is monitored in a controlled environment using artificial lighting and its impact on the growth dynamics of the crops is measured, in this case, on a leafy green crop (Lactuca Sativa L. ‘Little Gem’). Offering better efficiency and reliability, light-emitting diode (LED) irradiation is used with a photosynthetic photon flux (PPF) of 140 µmol·s−1 and a photoperiod of 12-hours. The seeds are then placed in growth chambers, kept at an ambient temperature of 18°C for 21 days. These seedlings are then transplanted in rockwool cubes, followed by placement in NFT or DWC systems in equal numbers. Both systems are illuminated with LED irradiation having a PPF of 200 µmol·s−1. Continuous irradiation with a photoperiod of 16-hours is provided to both systems for 5 weeks. Crop growth parameters, such as leaf count and plant height, are measured in both systems resulting in similar numbers obtained, however, shoot fresh weight, leaf area, and root length are significantly different. Furthermore, the NFT system exhibited an EUE of 31.3 g. kWh−1 and outperformed the DWC system with an EUE of 24.53 g. kWh−1; indicating higher growth and better energy savings associated with NFT systems. These results suggest that NFT systems has a higher potential to offer better energy-use efficiency for producing crops in plant factories and aquaponics facilities.

In vitro and in vivo phototoxicity on gastric mucosa induced by methylene blue.

Methylene blue (MB) is used endoscopically to demarcate tumors and as a photosensitizer in photodynamic therapy (PDT). However, there are few in vivo studies about its toxicity in healthy stomach tissue. We performed sequential in vitro and in vivo analyses of MB-induced phototoxicity. We performed in vitro experiments using the AGS human gastric cancer cell line treated with light-emitting diode (LED) irradiation (3.6 J/cm2) and MB. Cytotoxicity was evaluated using terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. In vivo toxicity was evaluated in the stomach of beagles using the same dose of fiber-optic LED via gastroscopy, after spraying 0.1% and 0.5% MB solutions. Stomach tissue was also evaluated using the TUNEL assay. In vitro, increased concentrations of MB led to higher TUNEL scores. However, cell viability was significantly lower after MB plus LED irradiation than after treatment with MB alone (P < 0.001). In vivo, the TUNEL score was highest immediately after treatment with 0.1% or 0.5% MB plus light irradiation, and the score was significantly higher in the LED illumination plus MB group than in the control group (P < 0.05). The elevated TUNEL score was maintained for 3 days in the MB plus light irradiation group but returned to normal levels on day 10. : Endoscopic light application with MB 0.5% concentration to the stomach may be regarded as a safe procedure despite some DNA injuries in the early period.

Repeated irradiation by light-emitting diodes may impede the spontaneous progression of experimental periodontitis: a preclinical study.

We investigated whether repeated irradiation with light-emitting diodes (LEDs) at a combination of 470 nm and 525 nm could suppress the progression of experimental periodontitis. A experimental periodontitis model was established in the second, third, and fourth premolars of the mandible in beagle dogs for 2 months. The spontaneous progression of periodontitis was monitored under the specified treatment regimen for 3 months. During this period, the animals were subjected to treatments of either plaque control only (control) or plaque control with LED application (test) at 2-week intervals. The clinical parameters included the probing pocket depth (PPD), gingival recession (GR), and the clinical attachment level (CAL). Histomorphometric analysis was performed using measurements of the length of the junctional epithelium, connective tissue (CT) zone, and total soft tissue (ST). There were significant differences in PPD between the control and test groups at baseline and 12 weeks. When the change in PPD was stratified based on time intervals, it was shown that greater differences occurred in the test group, with statistical significance for baseline to 12 weeks, 6 to 12 weeks, and baseline to 6 weeks. There was no significant difference in GR between the control and test groups at any time points. Likewise, no statistically significant differences were found in GR at any time intervals. CAL showed a statistically significant difference between the control and test groups at baseline only, although significant differences in CAL were observed between baseline and 12 weeks and between 6 and 12 weeks. The proportion of CT to ST was smaller for both buccal and lingual areas in the control group than in the test group. Repeated LED irradiation with a combination of 470-nm and 525-nm wavelengths may help suppress the progression of periodontal disease.

Superior photo-induced antibacterial/antibiofilm activities of ZnPcs/TiO2 and computational simulation studies.

Bacteria can form biofilms on any surface, which causes biofilm-associated infections and bacterial resistance to antibiotics. Thus, it is important to design new-generation non-chemotherapeutic nanoagents for effective antibacterial and antibiofilm strategies. Herein, the effects of the anchoring groups, which are imidazole and carboxylic acid, of zinc phthalocyanines (ZnPcs) sensitized TiO2 on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated under light-emitting diode (LED) irradiation. The photocatalytic antibacterial activities of ZnPc-1/TiO2 and ZnPc-2/TiO2 on the bacterial strains were examined by monitoring the optical density value at 600 nm (OD600 nm). Glutathione (GSH) oxidation assay was used to measure the reactive oxygen species (ROS) generation activity of the compounds. Bacterial damages were imaged by scanning electron microscopy (SEM). According to our photocatalytic antibacterial mechanism, photogenerated electrons are transferred from Pcs to TiO2 and then react with O2, thus creating ROS, which causes damage to bacterial membrane, protein and biofilm destruction as well. Further, computational simulation analysis was used to show the interaction patterns of ZnPc-1 and ZnPc-2 with penicillin binding protein 2a (PBP2a) of S. aureus and FimH lectin protein (PDB:4XO8) of E. coli to elucidate the dark molecular antibacterial mechanism of the compounds. The obtained results from computational studies showed that ZnPc-2 binds firmly through bonds with the 1MWT protein from S. aureus. On the other hand, ZnPc-1 binds firmly through bonds with the 4XO8 protein from E. coli. From combining experimental and computational results, we can conclude that this strategy can be applied to different types of bacterial infections.

Susceptibility of enveloped and non-enveloped viruses to ultraviolet light-emitting diode (UV-LED) irradiation and implications for virus inactivation mechanisms

UV-LED treatment at 265 nm was more efficient than UV-LED treatment at 280 nm in inactivating both enveloped and non-enveloped viruses. Capsid damage is not important in virus inactivation by UV-LEDs for both enveloped and non-enveloped viruses.

Practical photocatalytic and sonophotocatalytic reduction of nitroarenes in water under blue LED irradiation using β-CD modified TiO2 as a green nest photocatalyst.

Photocatalysis using natural photosynthesis is a green technology that is gaining popularity in a number of industries due to its potential for environmental applications and the use of solar energy. Focus is being placed on using inexpensive materials and light-emitting diodes (LEDs) of various wavelengths in photocatalytic reactions in order to improve the performance of solar-driven photocatalysts at a lower cost. In this study, a scalable, highly efficient photocatalytic and sonophotocatalytic method was investigated for the reduction of nitro-compounds by a water/titania/β-cyclodextrin system under sunlight and blue LED irradiation, using sodium sulfide as a sacrificial electron donor. β-Cyclodextrin, chemically bound to TiO2 nanoparticles as an encapsulating agent, hosted nitro compounds in aqueous media and formed an inclusion complex. In addition, this method was used to successfully carry out one-pot reduction-amidation of nitroarene compounds in the presence of acetic anhydride. Interestingly, it was found that ultrasound has a synergistic effect on photocatalytic reduction and considerably reduces the duration time. In this regard, a fast, practical sonophotocatalytic reduction of nitroarenes was carried out in an ultrasound bath.

Highly stable β-Bi2O3/Ag decorated nanosilica as an efficient Schottky heterojunction for ciprofloxacin photodegradation in wastewater under LED illumination

A novel mesopours SiO2/β-Bi2O3/Ag plasmonic heterojunction was first fabricated by a simple multi-step approach. The fabricated heterojunction was applied for ciprofloxacin (CIP) degradation in wastewater. The ternary SiO2/β-Bi2O3/Ag photocatalyst exhibited a wide absorption in the visible region (400–700 nm) with the assistance of the surface plasmonic resonance (SPR) behavior of Ag0 metal. Furthermore, the experimental results indicated that 96% of CIP was degraded with a TOC removal efficiency of 65% in 105 min under 140 W of light-emitting diode (LED) irradiation. The kinetics studies showed that the degradation rate of SiO2/β-Bi2O3/Ag is 0.02651 min−1, which is 3.17, 2.62, and 1.99 times higher than that of pure β-Bi2O3, SiO2/β-Bi2O3, and β-Bi2O3/Ag, respectively. The impacts of operational parameters like solution pH, CIP concentration, and SiO2/β-Bi2O3/Ag dosage were also assessed. The trapping experiments suggested that the main reactive species is the •OH radical, which can be easily generated on the valence band of β-Bi2O3. The Schottky heterojunction between β-Bi2O3 and Ag nanoparticles was well depicted based on trapping tests and characterization techniques. The stability experiments suggested that the SiO2/β-Bi2O3/Ag nanocomposite possessed high stability in five consecutive cycles and could be applied for CIP removal with acceptable photodegradation performance. Finally, it can be concluded that the nanosilica exhibited an efficient support structure, which can significantly improve the surface properties of SiO2/β-Bi2O3/Ag by inhibiting the agglomeration effects of β-Bi2O3/Ag nanoparticles as well as enhance the adsorption and stability of nanocomposite.

Effect of substituents on 1,3,5-triphenylpyrazoline as light-emitting diode-sensitive initiators in photopolymerization

By introducing different substituents at the N1 position, a series of 1,3,5-triphenylpyrazolines were designed and synthesized as photoinitiators (PIs) for cationic and free radical photopolymerization processes. As evaluated through ultraviolet–visible (UV–vis) spectroscopy, fluorescence spectroscopy, theoretical calculations, electrochemistry, and electron spin resonance–spin trapping tests, all PIs show good photoinitiating properties under light-emitting diode (LED) irradiation at 365–425 nm. Their light absorption within the UV–vis range (λmax = 352–390 nm; εmax = 26 000–40 700 M−1 cm−1) is strongly influenced by the substituents on the N1 phenyl ring. Remarkably, the introduction of the carbonyl group redshifts the maximum absorption spectra from 375 nm to 390 nm, which could well match the emission of LEDs in the range of 365–425 nm. The pyrazolines, together with iodonium salt and N-methyldiethanolamine, can generate acid and free radicals under LED irradiation and conduct high-performance LED-induced cationic and free radical photopolymerization processes under 365–425 nm irradiation. Cationic polymerization is enhanced by the introduction of an electron-pushing group, and free radical polymerization is promoted by the introduction of a carbonyl group at the N1 position. These pyrazoline-based photoinitiating systems have promising applications in LED-induced photopolymerization.

Incorporating Ni-Polyoxometalate into the S-Scheme Heterojunction to Accelerate Charge Separation and Resist Photocorrosion for Promoting Photocatalytic Activity and Stability.

The emerging polyoxometalate (POM) nanomaterials are transition metal oxygen anion clusters with d0 electronic configurations, which could be attractive and potential photocatalysts. Hence, a nickel (Ni)-substituted polyoxometalate K6Na4[Ni4(H2O)2(PW9O34)2]·32H2O (Ni4POM)-incorporating step (S)-scheme heterojunction was developed to promote photocatalytic activity and stability in H2 and H2O2 production. The multielectron transfer through variable valence metal centers in Ni4POM would facilitate the recombination of invalid charges through the S-scheme pathway. Moreover, incorporating Ni4POM into the S-scheme heterojunction can broaden the light absorption range and meanwhile lead to resistance to photocorrosion to promote the optical and chemical stability of Cd0.5Zn0.5S (CZS). The optimized CZSNi-70 exhibited a H2 evolution rate of 42.32 mmol g-1 h-1 under visible-light irradiation with an apparent quantum yield of 32.27% at 420 nm and a H2O2 production rate of 295.4 μmol L-1 h-1 under 420 nm light-emitting diode irradiation. This work can provide a new view for the development of transition metal-substituted POM-based stable and efficient S-scheme photocatalysts.

The physiochemical and photodynamic inactivation properties of corn starch/erythrosine B composite film and its application on pork preservation

This study explored the effect of erythrosine B (EB) as a photosensitizer in corn starch (CS) film and its physicochemical properties and photodynamic bacteriostatic ability against Staphylococcus aureus, Escherichia coli, and Salmonella both in vitro and inoculated on pork under the irradiation of D65 light-emitting diode (LED) (400-800 nm). The study revealed that the physiochemical properties of CS films: moisture content, water solubility, and water vapor transmission were improved with the addition of EB. In addition, the elasticity and the thermal stability of the film were enhanced. The results showed that the CS-EB films stimulated a maximum of 26.36 μg/mL hydrogen peroxide and 74.5 μg/g hydroxyl radical under irradiation. The CS composite films with a 5 % concentration of EB inhibited the bacterial growth by 4.7 Log CFU/mL in vitro after 30 min of illumination, and 2.4 Log CFU/mL on the pork samples under the same experimental condition. Moreover, the antibacterial ability was enhanced with the increase in EB concentration. Overall, the CS-EB composite films can inhibit the growth of bacteria through photodynamic inactivation and has the potential to become a new type of environmentally friendly packaging material.

Study of banana preservation extension by UVC radiation in precise monitoring LED irradiation cavity.

Ultraviolet C (UVC) radiation has been considered a possible option to alleviate the seriousness of black spots on bananas during preservation which help increase economic efficiency. In this study, using 275nm UVC light-emitting diodes (LEDs), a preliminary cavity with dimensions of 30 × 30 × 30cm was designed and fabricated to aid in reducing black spots on bananas with the aim of application in the factory conveyor belts. The UVC irradiance distribution was thoroughly monitored for many sections at different box heights in both simulation and measurement, with a dominant range of 6-9W/m2 in the middle. Afterward, trials were conducted in vitro and in vivo at different selected UVC doses. The results in vitro revealed that a dose of over 0.36kJ/m2 has an excellent effect on inhibiting the colonial germination of fungal Colletotrichum musae, a common species of fungi causing black spot disease on bananas. In vivo conditions, with a short exposure time of around 5s, the black spots on UVC-irradiated banana peel significantly reduced with minimal sensory damage compared to a control banana via observation after seven days from treatment. Finally, the optimal UVC dose is proposed from 0.030 to 0.045kJ/m2 for the one-time treatment when considering the upper surface of the banana. With flexibility advantage and short exposure time, the fabricated cavity (box) promises to bring a lot of application potential to aid banana preservation in factories and households.

590 nm LED Irradiation Improved Erythema through Inhibiting Angiogenesis of Human Microvascular Endothelial Cells and Ameliorated Pigmentation in Melasma.

Melasma is a common refractory acquired pigmentary skin disease that mainly affects middle-aged women. The pathogenesis of melasma is still uncertain, while abnormal vascular endothelial cells may play a role. We previously demonstrated the yellow light of light-emitting diodes (LED) could inhibit melanogenesis through the photobiomodulation (PBM) of melanocytes and keratinocytes. In the current study, we investigated the effect of 590 nm LED on the function of human microvascular endothelial cells (HMEC-1). We revealed 0-40 J/cm2 590 nm LED had no toxic effect on HMEC-1 in vitro. 590 nm LED irradiation significantly reduced cell migration, tube formation, as well as the expression of vascular endothelial growth factor (VEGF) and stem cell factor (SCF), a pro-melanogenic factor. Moreover, we illustrated that 590 nm LED inhibited the phosphorylation of the AKT/PI3K/mTOR signaling pathway, and the inhibitory effect on HMEC-1 could be partially reversed by insulin-like growth factor 1 (IGF-1), an AKT/PI3K/mTOR pathway agonist. Besides, we conducted a pilot clinical study and observed a marked improvement on facial erythema and pigmentation in melasma patients after amber LED phototherapy. Taken together, 590 nm LED inhibited HMEC-1 migration, tube formation and the secretion of VEGF and SCF, predominantly through the inhibition of the AKT/PI3K/mTOR pathway, which may serve as a novel therapeutic option for melasma.

Effect of Interchanging Red and Blue LED Irradiation Sequence on Growth of Lettuce

Light-emitting diode (LED) is commonly employed as supplementary light sources to enhance plant growth and quality. Nowadays, a combination of red (R) and blue (B) LED sources is mainly used since it can boost plant photosynthesis rate and biomass. Generally, both light sources are continuously irradiated for 16–18 hours for plant photoperiod, which may result in high electricity costs. Therefore, interchanging use of red and blue LED irradiation is introduced to reduce the use of electricity, thus minimising the operating cost. In this study, a growth chamber with red and blue LED was constructed and its intensity and power distribution were assessed. The effect of blue and red LED irradiation sequence on plant growth parameters and chlorophyll content was examined. Three light treatments over a period of 16 hours (RB16 - 16 hours constant simultaneous (R) and (B) light, R4/B4 - 4 hours interval interchanging R and B light and R8/B8 - 8 hours interval interchanging R- and B-light) were exposed to lettuce under controlled room temperature. Results revealed that the different light treatments influence lettuce plant morphology such as plant height, leaf width and leaf number. However, the results are similar for fresh and dry mass, and chlorophyll concentration. It is found that, both plant height and leaf width were the highest under R4/B4 and RB16, respectively. Such findings would be extremely valuable information on the use of interchanging LED irradiation in plant development for commercial production, resulting in optimized power consumption.

Effect of diode low level laser and red light emitting diode irradiation on cell proliferation and osteogenic/odontogenic differentiation of stem cells from the apical papilla

BackgroundThis experimental study aimed to assess the effect of irradiation of red light-emitting diode (LED) and Diode low-level laser (LLL) on osteogenic/odontogenic differentiation of stem cells from the apical papilla (SCAPs).Materials and methodsSCAPs were isolated from the human tooth root. The experimental groups were subjected to 4 J/cm2 diode low level laser and red LED irradiation in osteogenic medium. The control group did not receive any irradiation. Cell viability/proliferation of SCAPs was assessed by the methyl thiazolyl tetrazolium (MTT) assay on days 1 and 2 (n = 9). Osteogenic differentiation was evaluated by alizarin red staining (ARS) (n = 3), and expression of osteogenic genes by real-time polymerase chain reaction (RT-PCR) (n = 12) on days 1 and 2. SPSS version 18 was used for data evaluation. The Kruskal-Wallis and Mann-Whitney tests were used to compare the groups at each time point.ResultsThe MTT assay showed no significant difference in cell viability/proliferation of SCAPs in the low level laser, red LED, and control groups at 24 or 48 h (P < 0.001). The ARS assessment showed that low level laser and red LED irradiation enhanced osteogenic differentiation of SCAPs. low level laser and red LED irradiation both induced over-expression of osteogenic/dentinogenic genes including alkaline phosphatase (ALP), dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP-1), and bone sialoprotein (BSP) in SCAPs. Up-regulation of genes was significantly greater in low level laser irradiation group than red LED group (P < 0.001).ConclusionDiode low level laser irradiation with 4 J/cm2 energy density and red LED irradiation enhanced osteogenic differentiation of SCAPs without adversely affecting cell viability.

The efficacy of LED microneedle patch on hair growth in mice.

Light penetration depth in the scalp is a key limitation of low-level light therapy for the treatment of androgenetic alopecia (AGA). A novel light emitting diode (LED) microneedle patch was designed to achieve greater efficacy by enhancing the percutaneous light delivery. The study aimed to investigate the efficacy and safety of this device on hair growth in mice. Thirty-five male C57BL/6 mice which their dorsal skin was split into upper and lower parts to receive either LED irradiation alone or LED irradiation with a microneedle patch. Red (629nm), green (513nm), and blue light (465nm) at an energy dose of 0.2J/cm2 were applied once daily for 28days. Outcomes were evaluated weekly using digital photographs. Histopathological findings were assessed using a 6mm punch biopsy. A significant increase in hair growth was observed in the green light, moderate in the red light, and the lowest in the blue light group. The addition of the microneedle patch to LED irradiation enhanced greater and faster anagen entry in all the groups. Histopathology showed an apparent increase in the number of hair follicles, collagen bundles in the dermis, angiogenesis, and mononuclear cell infiltration after treatment with the green-light LED microneedle patches. No serious adverse effects were observed during the experiment. Our study provides evidence that the newly developed green-light LED microneedle patch caused the optimal telogen-to-anagen transition and could lead to new approaches for AGA. Microneedle stimulation may aid percutaneous light delivery to the target hair follicle stem cells.

Fabrication of a dual pH-responsive and photothermal microcapsule pesticide delivery system for controlled release of pesticides.

The development of stimulus-responsive and photothermally controlled-release microcapsule pesticide delivery systems is a promising solution to enhance the effective utilization and minimize the excessive use of pesticides in agriculture. In this study, an AVM@CS@TA-Fe microcapsule pesticide delivery system was developed using avermectin as the model drug, chitosan and tannic acid as the wall materials, and tannic acid-Fe complex layer as the photothermal agent. The optical microscope, scanning electron microscope, transmission electron microscope, and Fourier-transform infrared spectroscope were used to characterize the prepared microcapsule. The slow-release, UV-shielding, photothermal performance, and nematicidal activity of the microcapsule were systematically investigated. The results showed that the system exhibited excellent pH-responsive and photothermal-sensitive performances. In addition, the UV-shielding performance of the delivery system was improved. The photothermal conversion efficiency (η) of the system under the irradiation of near-infrared (NIR) light was determined to be 14.18%. Moreover, the nematicidal activities of the system against pine wood nematode and Aphelenchoides besseyi were greatly increased under the irradiation of light-emitting diode (LED) simulated sunlight. The release of the pesticide-active substances in such a pesticide delivery system could be effectively regulated with the irradiation of NIR light or LED-simulated sunlight. Thus, the developed pesticide delivery system may have broad application prospects in modern agriculture fields. © 2022 Society of Chemical Industry.

Effects of green light-emitting diode irradiation on neural differentiation of human umbilical cord matrix-derived mesenchymal cells; Involvement of MAPK pathway

Alteration of the proliferation rate and differentiation of mesenchymal stem cells (MSCs) into various lineages, including neural cells, by light emitting diodes (LEDs) irradiation has received considerable attention in recent years. Human umbilical cord matrix-derived mesenchymal cells (hUCMs) are an accessible source of adult stem cells with appropriate characteristics that make them ideal tools for stem cell researches, cell therapy procedures and regenerative medicine. The aim of the present study was to investigate the effects of green LED irradiation, retinoic acid (RA) and their combination on the differentiation of hUCMs into neural lineage as well as the mechanisms involved. Exposure of hUCMs to green LED (530 nm, 1.59 J/cm2) with or without retinoic acid (RA) treatment, significantly increased the expression of specific genes including nestin, β-tubulin III, MAP2 and Olig2. In addition, immunohistochemical analysis confirmed expression of specific neural-related proteins including MAP2, GFAP and Olig2 in irradiated cells. ROS generation significantly increased following green light irradiation which in turn has activated the MAPK signaling pathway, resulting in the differentiation of hUCMs into neurons and glial cells, confirmed by western blot analysis of MAPK-related pathway. Taken together, our results suggest that the green LED irradiation, alone and in combination with RA, via ERK 1/2, JNK and p38 phosphorylation improves differentiation of hUCMs into neural lineage. Other mechanisms and inducers to enhance differentiation phenomena in vitro and in vivo should be investigated to determine the most appropriate strategy for therapeutic purposes.

Osmotic-Enhanced-Photoelectrochemical Hydrogen Production Based on Nanofluidics

Osmotic-Enhanced-Photoelectrochemical Hydrogen Production Based on Nanofluidics

Suitable light combinations enhance cadmium accumulation in Bidens pilosa L. by regulating the soil microbial communities

Light is one of the natural resources greatly influencing plant growth, and light regulation has been recently considered one of the effective means of enhancing phytoremediation. In this study, monochromatic (red, blue, green), bichromatic (red and blue light combinations at different ratios), and trichromatic (red, blue, and green light combinations at different ratios) lights were applied at the same intensity (100 ± 5 μmol m−2 s−1) to enhance cadmium (Cd) accumulation in Bidens pilosa L. Compared with the control (fluorescent light), the translocation factor (TF), bioconcentration factor (BCF), and total metal extraction (TE) values of the plant were increased by 13.47–99.24%, 5.33–39.64%, and 20.51–109.62%, respectively, under light-emitting diode (LED) irradiation. The highest BCF and TE values were observed in plants under R20B70G10 (20% red, 70% blue, and 10% green light) irradiation, whereas a higher TF value was detected in plants under the condition of R50B50 (50% red and 50% blue light) and R20B70G10. Hierarchical clustering and heatmap analysis showed that trichromatic light influenced plant growth, photosynthesis, antioxidant enzyme activity, and soluble protein contents more than bichromatic and monochromatic lights. Additionally, the abundances of rhizosphere microbes and plant growth-promoting rhizobacteria, such as Lysobacter and Ramlibacter, were significantly higher under LED irradiation, along with enhanced soil enzyme activity. Our findings suggested that the R20B70G10 trichromatic light efficiently induces plant Cd extraction and can significantly improve the phytoremediation of Cd-contaminated soils by Bidens pilosa L.

Effect of Narrowband UV-B Irradiation on the Growth Performance of House Crickets.

Indoor co-cultivation systems can answer to the need for sustainable and resilient food production systems. Rearing organisms under light-emitting diodes (LEDs) irradiation provides the possibility to control and shape the emitted light spectra. UV-B-irradiation (280-315 nm) can positively affect the nutritional composition of different plants and other organisms, whereas information on edible insects is scarce. To evaluate the potential effect of the photosynthetically active radiation (PAR) and LED-emitting LEDs on the rearing and nutritional quality of edible insects, house crickets (Acheta domesticus) were reared from the age of 21 days under controlled LED spectra, with an additional UV-B (0.08 W/m2) dose of 1.15 KJm2 d-1 (illuminated over a period for 4 h per day) for 34 days. UV-B exposure showed no harm to the weight of the crickets and significantly increased their survival by ca. 10% under narrowband UV-B treatment. The nutritional composition including proteins, fat and chitin contents of the insects was not affected by the UV-B light and reached values of 60.03 ± 10.41, 22.38 ± 2.12 and 9.33 ± 1.21%, respectively, under the LED irradiation. Therefore, house crickets can grow under LED irradiation with a positive effect of narrowband UV-B application on their survival.