Optimal Light Research Articles

Injectable self-assembling peptide hydrogel as a promising vitreous substitute

Vitreoretinal diseases pose significant threats to vision, often requiring vitrectomy and substitution of vitreous humor to restore ocular structure and visual function. However, existing substitutes have limitations that compromise patient outcomes. Supramolecular hydrogels, particularly peptide-based formulations, have emerged as promising alternatives due to their superior optical clarity, biocompatibility, and viscoelasticity. In this study, we designed and evaluated two peptide hydrogels, 3 K-OX and 3E-OX, bearing positive and negative charges, respectively, as potential vitreous substitutes. Our in vitro findings revealed that the physicochemical properties of the negatively charged peptide hydrogel, 3E-OX, closely resembled those of the native vitreous body, exhibiting optimal light transmittance, refractive index, molecular permeability, and biocompatibility. Animal studies further confirmed the safety and biocompatibility of 3E-OX as a promising vitreous substitute. Notably, we introduced optical coherence tomography for retinal microvascular detection in non-pigmented rabbits, presenting a novel approach to evaluate the performance of intraocular tamponade materials. This work not only expands the utility of peptide hydrogels but also provides valuable insights into the design of vitreous substitutes.

Comparison of a Quantum Cascade Laser and an Interband Cascade Laser for the Detection of Stable Carbon Dioxide Isotopes Using Tunable Laser Absorption Spectroscopy.

Quantum cascade lasers (QCLs) and interband cascade lasers (ICLs) are widely used as light sources in tunable laser absorption spectroscopy because they emit in the mid-infrared region where many strong and characteristic absorption bands are present. In this paper, we compare the performance of these lasers emitting at about 2310.1 cm-1 to determine an optimal light source for detecting isotopic ratios of carbon dioxide (CO2). Our results show that the QCL has a higher relative intensity noise of up to 15 dBc/Hz compared to the ICL over the entire measured frequency range. In addition, it has a higher frequency fluctuation. However, the maximum tuning range of the QCL is up to 5.2 cm-1 compared to up to 3.8 cm-1 for the ICL. Both lasers lose more than half of their tuning range when the tuning rate is increased to 10 kHz. When measuring the isotope ratio of CO2, an uncertainty in the value of ‰ was achieved with the ICL and of ‰ with the QCL, both at an integration time of 0.2 s. In summary, the QCL is more appropriate for applications that require a larger spectral tuning range, such as the measurement of a complex gas mixture, while the ICL has an excellent signal-to-noise ratio and is therefore better suited for applications that require higher precision.

Developing Guidelines for Azolla microphylla Production as Compost for Sustainable Agriculture

Azolla is a substitute compost that has the potential to enhance nutrient cycling in agricultural systems for sustainable development. In this study, four experiments were conducted to compare the Department of Agriculture (DOA, Thailand) ‘s methodology for determining the suitable type and rate of animal manure and the optimal light intensity for the growth and yield of Azolla (Azolla microphylla). The results revealed that applying 100% pig manure gave the highest yield of Azolla compared to the other manures. However, there was no discernible (p > 0.05) difference in yield across the various doses (20.16, 30.16, and 40.16 gN m−2) of pig manure treatments, for which the minimal pig manure dosage of 20.16 gN m−2 was chosen. For further experimentation in the optimal light intensity, the 40% shading gave the highest yield of Azolla compared to no shading or 20 and 60% shading (p ≤ 0.01). When compared with the DOA Thailand methodology (1.27 kg m−2 of cow manure and covered with a size 32 mesh net), the findings indicated that the modified method (20.16 gN m−2 of pig manure + 40% shading) gave a 16% greater Azolla yield than that under the DOA Thailand methodology. The current finding method can produce a monthly fresh biomass of A. microphylla of 40.7 t ha−1 year−1 with higher contents of total N (4.92%) and lower C:N ratio (≤10:1) that could release minerals relatively rapidly. Its use can be encouraged by farmers to produce their own ecofriendly biofertilizer or soil amendment for sustainable agriculture.

The Impact of Varying Ratios of Light Quality Emitted by Light-Emitting Diodes (LEDs) on the Butter Lettuce

Light-emitting diodes (LEDs) are considered the optimal artificial light source for plant factories, yet further research is needed to understand the impact of LED light quality on plant growth. This experiment investigated the growth and development of butter lettuce under varying ratios of red and blue light provided by LEDs. The specific effects of different red and blue light quality ratios on butter lettuce growth were systematically tracked and recorded, with comprehensive measurements of growth parameters and photosynthetic characteristics. Empirical findings revealed that a higher red light component compared to blue light led to improved butter lettuce characteristics. These included increased leaf length and width, elevated plant height, higher relative chlorophyll content, and an increased net photosynthetic rate. The study also highlighted that the light quality requirements of lettuce fluctuate across different growth stages, allowing for adaptable modulation of lighting conditions to align with specific growth stage needs.Total fresh weight, total dry weight and dry matter content of lettuce reached the highest values in the R8B2 treatment with 80% red light and 20% blue light, and the percentage differences reached 29.2%, 23.1% and 13.9%, respectively. Additionally, the photosynthetic chlorophyll content and net photosynthetic rate exhibited maximum percentage differences of 22.22% and 14.6%, respectively. In conclusion, the experimental evidence supports that an R8B2 spectral composition (80% red and 20% blue light) in a controlled indoor setting represents the optimal light environment for the accelerated growth and superior quality of butter lettuce.

Exploring the photosensitizing potential of Nanoliposome Loaded Improved Toluidine Blue O (NLITBO) Against Streptococcus mutans: An in-vitro feasibility study.

Streptococcus mutans is a major contributor to dental caries due to its ability to produce acid and survive in biofilms. Microbial resistance towards common antimicrobial agents like chlorhexidine and triclosan has shifted the research towards antimicrobial Photodynamic therapy (PDT). In this context, Toluidine Blue O (TBO) is being explored for its photosensitizing properties against Streptococcus mutans. There is a huge variation in the effective concentration of TBO among the current studies owing to the differences in source of and delivery system TBO as well as the time, power and energy densities of light. The primary objectives of this study are to encapsulate improved Toluidine Blue O (ITBO) in nanoliposomes (NLITBO), characterize it, and evaluate its antibacterial photosensitizing potential against Streptococcus mutans suspensions in vitro. ITBO was synthesised as per Indian patent (number -543908). NLITBO was prepared using the thin-film hydration method. Dynamic light scattering experiment determined the vesicle size, polydispersity index (PDI), and zeta potential. Surface features were characterized by Scanning and Transmission Electron microscopy. ITBO release from NLITBO was assessed using the extrapolation method. The antibacterial activity of the NLITBO was determined by evaluating the zone of inhibition (ZOI) in the Streptococcus mutans culture and comparing with 2% chlorhexidine gluconate. The minimum inhibitory concentration (MIC) of NLITBO as a photosensitizer with red light (wavelength 650nm, power density 0.1 W/cm2, energy density 9-9.1 J/ cm2, 90seconds time) was evaluated against Streptococcus mutans cells by colorimetric method in 96 well plate. Percentage drug loading, loading efficiency, yield percentage, vesicle size, PDI, Zeta potential of NLTBO was reported as 9.3±0.4%, 84.4±7.6%, 73.5%, 123.52 nm, 0.57, -39.54mV respectively. Clusters of uni-lamellar nanovesicles with smooth non-perforated surfaces were observed in SEM and TEM. The size of the vesicle was within 100 nm. At 24 hours, a cumulative 79.81% of ITBO was released from NLITBO. Mean ZOI and MIC of NLITBO (1 μg /ml) were found to be 0.7±0.2 mm, 0.6μg/ml respectively. We have synthesized and encapsulated improved Toluidine Blue O (ITBO) in nanoliposomes (NLITBO) and thoroughly characterized the formulation. The antibacterial efficacy of NLITBO without light was demonstrated by ZOI which is similar to 2% chlorhexidine gluconate. MIC of NLITBO as a photosensitiser along with the optimal light parameter was also proposed in this study. These findings suggested that NLITBO could serve as an effective alternative to conventional antibacterial treatments in managing Streptococcus mutans rich biofilms. It can have potential pharmaceutical application in oral health care.

PHOTOINACTIVATION OF CANDIDA ALBICANS BIOFILM WITH GREEN LASER MEDIATED BY THE PAPAYA LEAF EXTRACT CHLOROPHYLL

This study aims to activate the effectiveness of Photodynamic Inactivation (PDI) as an antibacterial agent by using a green laser and papaya leaf chlorophyll extract to prevent Candida albicans cell death. Papaya leaf extract chlorophyll is known to have potential as a photosensitizer (PS) through its antimicrobial properties and ability to absorb optimal light photons at a wavelength range of 405–680 nm. Activation of chlorophyll molecules with appropriate light produces Reactive Oxygen Species (ROS), which are toxic to pathogenic microbes such as Candida albicans. The research method involves using PDI with a green laser light source and chlorophyll extract on Candida albicans biofilms. Four main treatment groups were applied, negative control (C-), positive controls with 10% (C1+) and 15% chlorophyll (C2+), irradiation for 60, 120, 180, 240, and 300 seconds (L1–L5), and combinations of irradiation with chlorophyll (L1F1–L5F2, where F1 for 10% chlorophyll and F2 for 15% chlorophyll), with measurements performed three times for each treatment. Living Candida albicans cells were detected using the XTT assay staining method. The results showed a significant decrease in activity in all treatment groups. Maximum activity was achieved in the L5F1 and L5F2 treatment groups with inactivation of 80% (p<0.05) and 83% (p<0.05), respectively. This study concludes that high papaya leaf extract chlorophyll concentrations combined with a green laser effectively inhibit Candida albicans biofilm.

An Ultrasensitive and Broad-Spectrum MoS2 Photodetector with Extrinsic Response Using Surrounding Homojunction.

As unique building blocks for advancing optoelectronics, 2D semiconducting transition metal dichalcogenides have garnered significant attention. However, most previously reported MoS2 photodetectors respond only to visible light with limited absorption, resulting in a narrow spectral response and low sensitivity. Here, a surrounding homojunction MoS2 photodetector featuring localized p-type nitrogen plasma doping on the surface of n-type MoS2 while preserving a high-mobility underlying channel for rapid carrier transport is engineered. The establishment of p-n homojunction facilitates the efficient separation of photogenerated carriers, thereby boosting the device's intrinsic detection performance. The resulting photoresponsivity is 6.94×104AW-1 and specific detectivity is 1.21×1014 Jones @ 638nm, with an optimal light on/off ratio of ≈107 at VGS = -27V. Notably, the introduction of additional bands within MoS2 bandgap through nitrogen doping leads to an extrinsic broadband response to short-wave infrared. The device exhibits a photoresponsivity of 34AW-1 and a specific detectivity of up to 5.92×1010 Jones @ 1550nm. Furthermore, the high-performance broadband response is further demonstrated through imaging and integration with waveguides, paving the way for next generation of multifunctional imaging systems and high-performance photonic chips.

Optimization, imaging and LHE analysis of magnesium oxide nanoparticles synthesized with carambola extract as natural dye sensitizer

This work explores the enhancement of dye-sensitized solar cells (DSSCs) by using magnesium oxide nanoparticles (MgO NPs) that have been green-synthesized, with carambola extract acting as a natural dye sensitizer. Green synthesis minimizes the negative effects of traditional synthesis methods on the environment by providing a sustainable and ecologically friendly way to produce MgO NPs. To increase their effectiveness in DSSC applications, the synthesized nanoparticles underwent optimization. The morphology and size distribution of MgO NPs were characterized by scanning electron microscopy (SEM), which revealed spherical forms with a consistent size distribution. The crystalline nature of the MgO NPs was verified by X-ray diffraction (XRD), which revealed distinctive peaks that correspond to the bulk MgO crystal planes. A band gap of 3.5 eV, appropriate for UV region absorption, was found using UV–visible spectroscopy. FT-IR (Fourier-transform infrared) spectroscopy revealed information about their molecular compositions. Positive electronic characteristics, such as a negative total energy change (ΔE_T) and a high electrophilicity index (ω), which indicates effective charge transfer, were found through computational analysis. The light harvesting efficiency (LHE) value of 0.00459 signifies optimal light absorption capability by the dye molecule. The outcomes show that MgO NPs that have undergone green synthesis have the potential to be efficient and stable sensitizers for DSSCs. In addition to highlighting the significance of green synthesis techniques in nanomaterial research for renewable energy applications, this work advances the development of efficient and sustainable solar energy systems.

Growing Tomato Seedlings Suitable for Mechanical Grafting under Regulated Light Regime

Abstract: The uniformity of growth and mechanical properties of grafted seedlings affect the quality of mechanical grafting operations. The growth uniformity of grafted seedlings in a greenhouse will be poor due to the uneven and unstable light and temperature conditions. Plant factories can cultivate grafted seedlings in the most suitable environment by regulating environmental parameters such as light and temperature. The aim of this study was to investigate the impact of the light conditions on tomato seedlings in plant factory and to develop an optimal cultivation light formula. The effects of light intensity (50, 100, 150, 200, and 250 μmol m−2 s−2) and photoperiod (10, 12, 14, 16, and 18 h a day(h/d)) on the morphological and mechanical properties of tomato seedlings were experimentally investigated. Orthogonal experiments were conducted involving light quality (R:B = 75:25, R:B = 50:50, and R:B = 25:75), light intensity (150 μmol m−2 s−2, 200 μmol m−2 s−2, and 250 μmol m−2 s−2), and photoperiod (14, 16, and 18 h/d) as independent variables to determine the optimal combination. Finally, a comparative grafting experiment was conducted between the seedlings cultivated using the optimal light formula and commercially available seedlings. The result showed that increasing light intensity inhibited hypocotyl length and promoted seedling stem growth, and excessive light intensity decreased seedling mechanical properties. The optimal light intensity for rootstocks is 200 μmol m−2 s−2, and the optimal light intensity for scions is 250 μmol m−2 s−2. Shortening the photoperiod would promote hypocotyl growth and inhibit seedling stem elongation. Different photoperiods had a significant impact on the mechanical properties of tomato seedlings. The most suitable photoperiod for rootstocks was 18 h/d and for scions was 16 h/d. The most suitable light formula was R:B = 50:50, 250 μmol m−2 s−2, 18 h/d. By analyzing the experimental results, the mechanical properties of seedlings grown by the regulated light environment were better than those of commercially available seedlings, and the success rate of mechanical grafting was 7% higher. Overall, in plant factories compared to commercially available tomato seedlings, tomato seedlings cultivated by the regulated light environment were more suitable for mechanical grafting. This research result provides theoretical support for subsequent research on grafting machinery.

Investigating and correlating the photocatalytic activity of synthesised strontium titanate nanopowder with calcination temperature

In this study, SrTiO3 nanoparticles were synthesised in high yield using a simple and low-cost method, followed by calcination. The effect of the calcination temperature in the range from 700 to 1100 °C on the morphology, phase structure, crystallite size, and photocatalytic activity of SrTiO3 nanoparticles was investigated. Analysis of the morphology and structure of the synthesised samples revealed an increase in the average particle size from 70.4 to 361.72 nm as well as crystallite growth with increasing calcination temperature (from 800 to 1100 °C), likely due to the fusion of smaller crystallites into larger ones. A possible pathway for the growth mechanism of strontium titanate grains was also proposed. The SrTiO3 sample calcined at 800 °C exhibited the highest methylene blue (MB) photodegradation efficiency, achieving 100 % degradation within 30 min of irradiation. The pseudo-first-order reaction rate constant k for this sample was determined to be 0.156 min−1, which is almost 1.8 and 14.19 times higher compared to those of commercial P25 and SrTiO3, respectively. The analysis indicated that the high photoactivity of this sample was due to its high crystallinity, relatively small particle size, and optimal light absorption, which enhanced the separation and transport of the photogenerated charges and increased the number of active sites, thereby positively affecting the photocatalytic properties. Additionally, the effects of the initial dye concentration and amount of photocatalyst loaded on the photodegradation efficiency were investigated.

Illuminating Cannabis sativa L.: The Power of Light in Enhancing C. sativa Growth and Secondary Metabolite Production.

Light is crucial for higher plants, driving photosynthesis and serving as a powerful sensory signal that profoundly modulates growth, development, physiological functions, hormone activation, and biochemical pathways. Various light parameters-quality, intensity, composition, and photoperiod-exert a tremendous influence on plant growth and development, particularly in industrial hemp (Cannabis sativa L.). C. sativa, a crop of historical significance and unparalleled versatility, holds immense value in the food, fiber, and medicinal industries. The cultivation of medicinal cannabis is burgeoning in controlled environments due to evolving healthcare regulations. Optimal light conditions significantly enhance both yield and harvest quality, notably increasing the density of apical inflorescences and the ratio of inflorescence to total aboveground biomass. C. sativa metabolites, especially phenolic and terpene compounds and Phytocannabinoids like CBD (cannabidiol), THC (tetrahydrocannabinol), and CBG (cannabigerol), possess immense medicinal value. Secondary metabolites in C. sativa predominantly accumulate in the trichomes of female flowers and surrounding sugar leaves, underscoring the critical need to boost inflorescence weight and metabolite concentrations while ensuring product consistency. Different light parameters distinctly impact C. sativa's metabolic profile, providing a robust foundation for understanding the optimal conditions for synthesizing specific secondary metabolites. While the effects of light measurement on various crops are well-established, scientific evidence specifically relating to light quality effects on C. sativa morphology and secondary metabolite accumulation remains scarce. In this review, we critically summarized how different light properties can alter cannabis growth (vegetative and reproductive), physiology and metabolism. Furthermore, the mechanisms by which specific wavelengths influence growth, development, and secondary metabolite biosynthesis in C. sativa are not fully elucidated, which could be a prospective task for future researchers. Our review paves the way for a profound understanding of light's influence on C. sativa growth and advancements in greenhouse settings to maximize metabolite production for commercial use.

Role of Polyhouse Technology in Mitigating Climate Risks for Floriculture

Climate change poses significant challenges to agricultural productivity, particularly in sectors like floriculture that rely heavily on favorable environmental conditions. In this context, polyhouse technology emerges as a promising solution for mitigating climate risks faced by floriculture farmers. Polyhouses provide a controlled environment that shields crops from extreme weather events, temperature fluctuations, and excessive rainfall, thereby reducing the vulnerability of floriculture production to climate variability. This paper reviews the role of polyhouse technology in climate risk mitigation for floriculture farmers. It examines how polyhouses help in maintaining optimal growing conditions, including temperature, humidity, and light intensity, throughout the year. By regulating these environmental factors, polyhouses enable year-round cultivation of high-value flower crops, offering farmers a stable income stream despite external climate fluctuations. Furthermore, the study explores the economic and environmental benefits associated with polyhouse-based floriculture systems. It analyses the cost-effectiveness of polyhouse construction and operation, considering factors such as energy consumption, water usage, and crop yield. Additionally, the environmental sustainability of polyhouse technology, including its potential to reduce pesticide and fertilizer usage, is discussed. The paper also highlights the challenges and limitations of adopting polyhouse technology in floriculture farming, including initial investment costs, technical expertise requirements, and market access issues. Strategies for overcoming these barriers, such as government subsidies, capacity building programs, and market linkages, are proposed. The polyhouse technology can play a climate-resilient solution for floriculture farmers, offering opportunities for increased productivity, income stability, and environmental sustainability in the face of climate change.

Optimizing damage resistance and structural evolution in CaO-modified Li2O-Al2O3-B2O3-TiO2-P2O5 glass-ceramics

Aluminoborate glass, recognized for its remarkable crack resistance, presents significant potential as a cover material for portable electronic devices. Nevertheless, its relatively low hardness has been a limiting factor. This study synthesized a series of 11 Li2O-30 Al2O3-(55-x) B2O3-2 TiO2-2 P2O5-xCaO (wt%), with x varying from 0 to 10, employing the melt-cast method. The resultant glass-ceramics were produced via heat treatment at 590 °C for 2 h, followed by a systematic examination of their structural and mechanical properties. The investigation demonstrated that an increase in CaO content diminishes crystallization and induces a morphological transition in the crystalline phases from granular and short rod-like structures to lath-like formations, which subsequently impacts the coordination environment of Al and B atoms. With a CaO content of 2 %, the GC2 sample precipitated Li(Al7B4O17) and Li2AlB5O10 phases, achieving a compressive strength (CR) value of 15.0 N, a hardness of 7.51 GPa, and a fracture toughness of 1.50 MPa m0.5. This glass-ceramic exhibited optimal scratch resistance and visible light transmittance exceeding 85 %, underscoring its considerable promise for application as smartphone cover glass due to its impressive overall damage resistance.

Exposure dose, light distribution and wavelength affect the fate of introduced bacterial biological control agents in the phyllosphere of greenhouse grown tomato

Societal Impact StatementThe use of chemical plant protection products must be reduced to promote sustainability in food production. One possible alternative is biological control agents (BCAs), but their efficacy under commercial conditions does not always reach the standard of chemical control agents. Previously, light has been found to induce mechanisms in bacterial BCAs that can affect their distribution and establishment. This could promote BCA efficacy. We looked into how monochromatic and polychromatic (which is what growers use) light treatments affected the occurrence of three BCAs post‐application. By combining two non‐chemical methods: a biological (BCA) and a cultural (light) control method, this offers a new integrated pest control strategy.Summary The dynamics and functionality of beneficial and non‐beneficial, non‐phototrophic bacteria can be influenced by light quality. We investigated if light could aid the survival of three bacterial biological control agents (BCAs; Bacillus amyloliquefaciens DSM7, Pseudomonas chlororaphis 50083 and Streptomyces griseoviridis CBS904.68) in the canopy of greenhouse‐grown tomatoes at four light treatments. Tomato plants were exposed to 50 μmol m−2 s−1 of either polychromatic light (white) or monochromatic light (blue: 420 nm, green: 530 nm and red: 660 nm) using DYNA LED lamps for a total of 48 h post foliar application of the BCAs. Leaves were harvested from two levels in the canopy at the top and middle of each plant at 0, 2, 4, 8, 12, 24 and 48 h post inoculation. The occurrences of the BCAs were quantified by plate count and droplet digital PCR (ddPCR). S. griseoviridis persisted under most treatments, whereas P. chlororaphis and B. amyloliquefaciens preferred the polychromatic and green light treatments as depicted by the viable count analyses. Significant differences between the DNA and cDNA concentrations were only noted for P. chlororaphis, with prominent wavelength effects. Light exposure dose, placement in the canopy and wavelength were found to be decisive factors for BCA re‐isolation, indicating that they have different optimal light environments.

Study of Natural Daylighting Houses in Coastal Area (Case Study: Pasar Bengkulu Village)

Abstract Sunlight is an important thing that humans need to see, recognize and learn certain things in their environment. Sunlight helps humans carry out daily activities indoors. The aim of this research is to examine the intensity of natural lighting in houses in the coastal area of the case study RT 3, Pasar Bengkulu Village. This research is quantitative research by obtaining data from observations and Dialux software simulations. The measurement data will be compared with the lighting standards set out in SNI No. 03-2396-2001. From the simulation results, it was found that there were several rooms that had not reached natural lighting standards, namely, there were 3 rooms in house A, 2 rooms in house B and 3 rooms in house C. Simulation of the optimal light intensity value in house A in room 1 was 508 lux, room 2 is 217 lux and room 3 is 235 lux. At house BThe average value is 220 lux in room 1, the value is 230 lux in room 2, 229 lux in room 3, 235 lux in room 4 and room 5 gets a value of 213 lux. Meanwhile, in house C there is room 1 with a value of 141 lux, room 2 with a value of 197 lux, room 3 with a value of 163 lux, room 4 with a value of 292 lux and room 5 with a value of 242 lux.

Harvesting the tuning mechanism of strategic polychrome and white light emission in NapH dye based on excited state intermolecular proton transfer

Organic white light emitting (WLE) materials have sparked a research boom due to their promising applications in display devices, artificial lighting, and molecular sensors. However, the complex luminescence mechanism of full-spectra emitting materials has limited the development of white light materials with high stability and reproducibility. In this study, building on the full-spectra luminescent naphthimide dye (NapH) introduced by Xu et al., (Chin. Chem. Lett. 35(2024), 108348), we report the solvent-sensitive excited state proton transfer (ESPT) properties and white light emission mechanism in NapH. Our theoretical research results show that the ESPT process of NapH molecule is hindered in the low-polar solvent tetrahydrofuran (THF), so only the blue fluorescence from the Enol* is observed in the experiment. In contrast, in polar solvents such as water (H2O) and methanol (MeOH), the formation of strong intermolecular hydrogen bonds successfully initiates the ESPT process, leading to the dual fluorescence observed in experiments, with blue emission from the Enol* and red emission from the Nap anion. In essence, different solvent environments can adjust several emission colors. Furthermore, we theoretically verify that the optimal white light emission can be achieved when the mixed solvent ratio of dimethyl sulfoxide (DMSO) and dioxane (DIOX) is 5:5, which aligns well with experimental results. More importantly, we elucidate the specific WLE mechanism from multiple perspectives, including potential energy curves and electron spectra. Our work not only displays the interaction models of NapH molecule in various solvents, but also reveals the underlying luminescence mechanism, thus providing a valuable theoretical reference for the development and advancement of new white light materials.

Impact of environmental conditions on the early growth of the endangered Korean fir (Abies koreana E.H.Wilson): insights for conservation and restoration strategies

Environmental factors are crucial elements that significantly influence the growth and development of plants. This study investigated the impact of environmental conditions (light, air temperature, air humidity, etc.) on the early growth of juvenile Korean fir (Abies koreana E.H.Wilson). Using random forest models and scatterplot matrix analyses, we examined the complex relationships between juvenile Korean fir early survival and various environmental factors. Specifically, a one-way ANOVA was conducted to assess the impact of light regulation in shading experiments on the growth of Korean fir seedlings. Additionally, a t-test was performed to compare the growth differences of Korean fir seedlings in two restoration sites with different canopy coverages. The results confirmed that light conditions significantly affect the growth of Korean fir seedlings, with better early growth observed in shaded conditions compared to full sunlight. Furthermore, field restoration site surveys indicated that the growth of height and root collar diameter of restored Korean fir seedlings was better in areas where the canopy coverage of the existing forest was between 60% and 75%. These findings suggest that the prerequisite for the restoration of the endangered Korean fir seedlings is the achievement of optimal light conditions during the early establishment phase.

Illumination optimization strategies to enhance hydrogen productivity and light conversion efficiency for photo-fermentation by Rhodobacter sphaeroides KKU-PS1 using a concentrated multi-substrate feedstock

With the use of biotechnology, hydrogen can be produced from wastewater rich in short-chain fatty acids. A previous study revealed the ability of Rhodobacter sphaeroides KKU-PS1 to produce biohydrogen from substrates mimicking succinate fermentation effluent. However, the process still requires optimization. Before illumination optimization, due to high concentration of the effluent, various effluent dilution factors ranging from 10 to 100 were compared, and the optimal dilution factor was determined to be 50. Light-emitting diode (LED) setups consisting of bands and tubes were compared, and various illuminated surface-to-volume ratios (S/V) were obtained. LED tubes were subsequently used for light intensity optimization in the range of 5–23 klux, revealing optimum light intensity at 15 klux, yielding 2202 mL H2/L and 13.8 mL H2/L/h as the cumulative hydrogen and maximum output rate, respectively. The lighting protocol at 15 klux and with a 6h–6h light-dark cycle improved the total light conversion efficiency by up to 3.1%. The study successfully optimized the process, with results rivalling those of a previous study using malate.

Optimal Light Intensity for Lettuce Growth, Quality, and Photosynthesis in Plant Factories.

In agriculture, one of the most crucial elements for sustained plant production is light. Artificial lighting can meet the specific light requirements of various plants. However, it is a challenge to find optimal lighting schemes that can facilitate a balance of plant growth and nutritional qualities. In this study, we experimented with the light intensity required for plant growth and nutrient elements. We designed three light intensity treatments, 180 μmol m-2 s-1 (L1), 210 μmol m-2 s-1 (L2), and 240 μmol m-2 s-1 (L3), to investigate the effect of light intensity on lettuce growth and quality. It can be clearly seen from the radar charts that L2 significantly affected the plant height, fresh weight, dry weight, and leaf area. L3 mainly affected the canopy diameter and root shoot ratio. The effect of L1 on lettuce phenotype was not significant compared with that of the others. The total soluble sugar, vitamin C, nitrate, and free amino acid in lettuce showed more significant increases under the L2 treatment than under the other treatments. In addition, the transpiration rate and stomatal conductance were opposite to each other. The comprehensive evaluation of the membership function value method and heatmap analysis showed that lettuce had the highest membership function value in L2 light intensity conditions, indicating that the lettuce grown under this light intensity could obtain higher yield and better quality. This study provides a new insight into finding the best environmental factors to balance plant nutrition and growth.

Toward Enhanced Biomimetic Artificial Visual Systems Based on Organic Heterojunction Optoelectronic Synaptic Transistors

AbstractArtificial visual systems, inspired by the human eye, hold significant potential in artificial intelligence. Optoelectronic synapses, integrating image perception, processing, and memory in a single device, offer promising solutions. The human eye exhibits different recognition accuracies for objects under varying light conditions. Therefore, a more biomimetic visual system is needed to better fit actual application scenarios. Here, an organic heterojunction‐based optoelectronic synaptic transistor (OHOST) is proposed to enhance biomimetic artificial visual systems. By utilizing the excellent carrier capture ability of core‐multi‐shell quantum dots (QDs) and the high exciton dissociation efficiency of heterojunction interfaces, the device achieves a recognition capability under different light intensities closely resembling that of the human eye. Under optimal light intensity, the recognition accuracy for the modified national institute of standards and technology (MNIST) dataset can reach 91.52%. Nevertheless, under both low and high light intensities, the accuracy drops to a low level. This work pushes the development of artificial visual systems toward higher levels of biomimicry.