Ultraviolet Light Research Articles

Characterization of SLA-printed ceramic composites for dental restorations

This study introduces a novel ceramic-composite resin specifically developed for stereolithography (SLA) 3D printing, aimed at enhancing dental restorations. The integration of advanced digital technologies in dentistry has shifted traditional methods towards more precise and efficient techniques such as computer-aided design/computer-aided manufacturing (CAD/CAM). However, these processes typically involve material waste due to their subtractive nature. Additive manufacturing, or 3D printing, particularly SLA, which uses ultraviolet light to cure photosensitive resins, presents a viable alternative with the potential for creating detailed, custom restorations with minimal waste. Our research focuses on formulating and evaluating a ceramic-composite resin that combines the benefits of light-cured materials with the mechanical robustness required for dental applications. We conducted comprehensive tests to assess the printability, mechanical properties and wear resistance of the developed material. The ceramic-composite resin demonstrated a tensile strength of approximately 73 MPa, significantly higher than the 42 MPa observed for traditional photopolymer resins. Additionally, the ceramic-composite resin showed ability to resist incidental friction and wear. This research could significantly impact the dental prosthetics field by providing a method for producing high-performance, patient-specific restorations efficiently and cost-effectively.

Injectable Hydrogel With Glycyrrhizic Acid and Asiaticoside-Loaded Liposomes for Wound Healing.

Open skin wounds increase the risk of infections and can compromise health. Therefore, applying medications to promote healing at the injury site is crucial. In practice, direct drug delivery is often difficult to maintain for a long time due to rapid absorption or wiping off, which reduces the efficiency of wound healing. Consequently, the development of bioactive materials with both antibacterial and wound-healing properties is highly desirable. This study synthesized liposomes loaded with glycyrrhizic acid (GA) and asiaticoside (AS) by film dispersion-ultrasonication method, which were then incorporated into a GelMA solution and cross-linked by ultraviolet light to form a bioactive composite hydrogel for wound dressings. This hydrogel is conducive to the transport of nutrients and gas exchange. Compared with GelMA hydrogel (swelling rate 69.8% ± 5.7%), the swelling rate of GelMA/Lip@GA@AS is lower, at 52.1% ± 1.0%. GelMA/Lip@GA@AS also has better compression and rheological properties, and the invitro biodegradability is not significantly different from that of the collagenase-treated group. In addition, the hydrogel polymer has a stable drug release rate, good biocompatibility, and an angiogenic promoting effect. Invitro experiments prove that, at concentrations of 0.5, 1, 2, and 3 mg/mL, GelMA/Lip@GA@AS can inhibit the growth of Staphylococcus aureus. We synthesized GelMA/Lip@GA@AS hydrogel and found it possesses advantageous mechanical properties, rheology, and biodegradability. Experimental results invitro showed that the bioactive hydrogel could efficiently release drugs, exhibit biocompatibility, and enhance angiogenesis and antimicrobial effects. These results suggest the promising application of GelMA/Lip@GA@AS hydrogel in wound-dressing materials.

Eco-friendly fabrication of ZnO-TiO2-rGO nanocomposite for efficient adsorption-assisted organic dyes elimination

The growing interest in combining the photocatalytic properties of semiconductors like ZnO and TiO2 with the superior electron conduction capabilities of graphene has resulted in the successful synthesis of in-situ reduced graphene oxide (rGO) supported ZnO-TiO2 nanostructures through a simple microwave-assisted synthesis method. X-ray Diffraction Spectroscopy (XRD), Field Emission Scanning Electron Microscope (FESEM), UV–visible spectroscopy (UV–vis), and Fourier Transform Infrared Spectroscopy (FTIR) were employed to characterize structural, morphological and optical properties as well as surface functional groups of the synthesized products. The XRD measurements of our synthesized samples confirm both structural crystallinity and phase purity, while the FTIR analysis verifies the complete reduction of graphene oxide (GO) to reduced graphene oxide (rGO). The synthesized ternary nanocomposite ZnO-TiO2-rGO exhibited a remarkable 100 % adsorption-assisted removal efficiency for 20 mg/L methylene blue (MB) dye under ultraviolet light illumination within 120 min, along with a 56 % dye adsorption removal efficiency in the same time interval. In comparison, pure ZnO showed 0 % adsorption and only 31 % photocatalytic efficiency at the similar condition. Remarkably, the ZnO-TiO2-rGO nanocomposite exhibited exceptional photocatalytic activity mediated by adsorption, achieving complete degradation of MB dye within 5 min under sunlight irradiation. The photocatalytic efficiency and dye adsorption capacity were found to be significantly lower for the anionic dye methyl orange (MO) compared to the cationic MB dye. The study thoroughly investigated the influence of catalyst dose and initial dye concentration on photodegradation. The proposed mechanism indicates that the extensive surface area and numerous active sites on the rGO promote adsorption, which is then followed by degradation through the metal oxides. Overall, the results unveil that the microwave-assisted synthesis of ZnO-TiO2-rGO nanocomposite is a promising and environmentally friendly approach for efficiently degrading dyes from contaminated wastewater using both UV light and natural sunlight irradiation.

Development of optimal indoor air disinfection and ventilation protocols for airborne infectious diseases.

Since the COVID-19 pandemic, there has been persistent emphasis on the importance of indoor air disinfection and ventilation in isolation units in the hospital environment. Nevertheless, no optimal and concrete disinfection protocol has been proposed to inactivate the viruses as quickly as possible. In this study, we experimentally evaluated various ventilation and disinfection protocols based on the combination of negative-pressure ventilation, ultraviolet (UV) light illumination, and Hypochlorous acid (HOCl) spray against three active virus species in a 3.5 cubic meters isolation unit. This small-size unit has gained attention during the pandemic due to the high demand for compact mobile laboratory systems capable of rapid disease diagnosis. In accordance with the WHO laboratory biosafety guidance, which states that all enclosed units where diagnostic work is conducted must ensure proper ventilation and disinfection activities, we aim to propose virus removal protocols for units compact enough to be installed within a van or deployed outdoor. The results confirmed the superiority (in terms of virus removal rate and time required) of the virus removal methods in the order of UV light, ventilation, and HOCl spray. Ultimately, we propose two optimal protocols: (i) UV light alone for three minutes, and (ii) UV light with ventilation for three minutes, followed by one-minute ventilation only. The time span of three minutes in the latter protocol is based on the clinical practice such that the medical staffs have a sufficient time to process the samples taken in transition to next patient to care.

Enhanced photo-oxidation of hormones in water using biomass waste-derived hydrochar composites as photocatalysts

This study introduces a green chemistry approach to enhance the catalytic efficiency of metal oxides in photocatalytic reactions using agro-industrial waste. Specifically, rice husks and spent coffee grounds were utilized as carbon sources to produce hydrochars, which served as sustainable supports for ZnO and ZnFe₂O₄ oxides. This method promotes waste minimization and circularity by repurposing agricultural byproducts, reducing the environmental impact of traditional catalyst production. The hydrochars were synthesized through mild hydrothermal carbonization (250 °C for 4 h) and characterized by various physicochemical analyses. Their photocatalytic performance was evaluated using a 20 mg L−1 solution of conjugated estrogens under ultraviolet light (120 W cm−2) for 30 min. Composites with ZnO exhibited a significant increase in oxidation reaction rates due to enhanced porosity and an oxygen-rich structure. Reactive oxygen species (ROS) analysis revealed hydroxyl radicals (OH) as the primary agents, with photocatalytic efficiencies exceeding 83 % after eleven cycles. In toxicity tests, 4 mL of treated solution was applied to 20 Lactuca sativa (lettuce) seeds, kept in the dark at 25 °C for 7 days. Seeds exposed to treated solutions showed improved radicle elongation and germination rates compared to controls, except for those with coffee hydrochar and ZnO. This indicates effective degradation of toxic estrogens without harmful by-products. Overall, this work highlights the advantages of integrating green chemistry principles and circular economy practices, transforming waste into valuable materials to enhance environmental sustainability and catalytic performance.

Utilization of Ultraviolet C Light-Emitting Diodes for the Deactivation of SARS-CoV-2 in Human Breath

Ultraviolet light has a long track record when it comes to use for deactivating harmful microorganisms. With recent developments in LED technology in terms of generating electromagnetic waves from this specific spectral range, new applications have emerged. In this study, the possibility of constructing an effective miniature UV barrier for deactivating the SARS-CoV-2 virus in both exhaled and inhaled air is investigated. Our findings demonstrate that utilizing commonly available UVC diodes operating at the wavelength of 275 nm makes it possible to attain an adequate level of deactivation that fulfills the standards specified for commercial devices. Full Text: PDF References N.G. Reed, "The History of Ultraviolet Germicidal Irradiation for Air Disinfection", Public Health Rep. 125(1), 15 (2010) CrossRef S. Oliveira De Souza, A. Cardoso, A. Sales, C. Sarmento, F. D'errico, "Effectiveness of a UVC air disinfection system for the HVAC of an ICU", Eur. Phys. J. Plus 137, 37 (2022), CrossRef N. Trivellin et al., "UV-Based Technologies for SARS-CoV2 Inactivation: Status and Perspectives", Electronics 10, 4 (2021), CrossRef R. S. Bergman, "Germicidal UV Sources and Systems", Photochem. Photobiol. 97(3), 466 (2021), CrossRef M. Shatalov, R. Jain, T. Saxena, A. Dobrinsky, M. Shur, "Chapter Two - Development of Deep UV LEDs and Current Problems in Material and Device Technology", Semiconductors and Semimetals 96, 45 (2017). CrossRef W. Kowalski, Ultraviolet Germicidal Irradiation Handbook UVGI for Air and Surface Disinfection, 1 (2009), CrossRef P. Sobotka, M. Przychodzki, K. Uściło, T.R. Woliński, M. Staniszewska, "Effect of Ultraviolet Light C (UV-C) Radiation Generated by Semiconductor Light Sources on Human Beta-Coronaviruses’ Inactivation", Materials 15(6), 2302 (2022), CrossRef Y. Gerchman, H. Mamane, N. Friedman, M. Mandelboim, "UV-LED disinfection of Coronavirus: Wavelength effect", J. Photochem. Photobiol. B Biol. 212, 112044 (2020), CrossRef R.M. Mariita, J.W. Peterson, "Not all wavelengths are created equal: disinfection of SARS-CoV-2 using UVC radiation is wavelength-dependent", Access Microbiology 3(11), 1 (2021), CrossRef Polio laboratory manual, 4th ed., World Health Organization 2004. DirectLink J.V. Maizel, D.O. White, M.D. Scharff, "The polypeptides of adenovirus: I. Evidence for multiple protein components in the virion and a comparison of types 2, 7A, and 12", Virology 36(1), 115 (1968), CrossRef H. Inagaki, A. Saito, H. Sugiyama, T. Okabayashi, S. Fujimoto, "Rapid inactivation of SARS-CoV-2 with deep-UV LED irradiation", Emerging Microbes and Infections 9(1), 1744 (2020), CrossRef

A dual emission ratiometric fluorescent probe constructed based on MOF-embedded dye for sequential detection of Al3+ and PPA

The ratiometric fluorescence probe has a self-calibration system that greatly reduces interference from the external environment, it has high sensitivity and accuracy in qualitative and quantitative experiments. In this work, a novel ratio fluorescence probe (RhB@1) was constructed by enclosing Rhodamine B (RhB) in the channel of [Cd2(H2L)2(1,4-bib)2]•DMA (H2L=2-hydroxyterephthalic acid, 1,4-bib=1, 4-bis (imidazol-1-ylmethyl) benzene). The probe can display dual emission characteristics under a single excitation. Al3+ ion was detected by RhB@1. The results showed that the fluorescence of 1 in RhB@1 was increased, the fluorescence of RhB is unchanged, and limit of detection (LOD) of Al3+ is as low as 20.9nM. Interestingly, when PPA (phenylpyruvic acid) is added to the mixture of RhB@1 and Al3+, PPA competes with RhB@1 for Al3+ result in achieving continuous ratio sensing of Al3+ and PPA, and LOD of PPA is 3.21nM. More importantly, the response of RhB@1 to Al3+ in tap water and PPA in artificial urine was quantitatively determined by label recovery method. The results showed that the recovery rate were 97.706%-99.060% (Al3+) and 94.732%-98.100% (PPA). In addition, we prepared a portable test paper modified with carboxymethyl cellulose. This test paper has obvious color change when detecting Al3+ under ultraviolet light, which is easy to detect Al3+ by naked eye.

Preparation of superhydrophobic polyurethane sponge with photodegradation function and study on its oil-water separation performance

The surface of tetrapod-shaped zinc oxide whiskers (T-ZnOw) was hydrophobized by the sol-gel method, and then loaded onto the surface of polyurethane sponge by dip-curing method to prepare a superhydrophobic polyurethane sponge with photodegradation function. When the mass ratio of superhydrophobic tetrapod-shaped zinc oxide whiskers (ST-ZnOw) and polydimethylsiloxane (PDMS) was 0.5:1, the water contact angle of the sponge was 157.5°. After being soaked in acid and alkali corrosion solution, rubbed with sandpaper and heat treated, the sponge can still maintain excellent hydrophobic properties. The adsorption capacity for different oils and organic solvents is 12 to 35 times of its own mass. After repeated extrusion-oil absorption experiments, it can still maintain its good adsorption capacity and high hydrophobicity, showing excellent reusability. The continuous oil-water separation efficiency of the material for different oils and organic solvents is above 95%, and the separation efficiency for the emulsion prepared with span80 content of 0.1wt% is 99.84%. At the same time, the prepared material can degrade the organic dye methylene blue under ultraviolet light, with a degradation rate of 99.35%, showing excellent potential for degrading organic pollutants.

A novel sandwich ELISA method for quantifying CHI3L1 in blood serum and cerebrospinal fluid multiple sclerosis patients using sustainable photo-irradiated zero-valence gold nanoparticles

The widespread occurrence of chronic demyelinating MS presents a significant challenge for ongoing research aimed at comprehending its progression, diagnosis, and treatment. In our research, we have devised a novel approach to quantify CHI3L1 (Chitinase-3-like protein 1), which has emerged as a valuable biomarker in MS because of its involvement in inflammation, tissue remodeling, and immune response—crucial factors in regulating damaged nerve cells and preventing their accumulation in the brain, utilizing sandwich ELISA technology. This innovative method primarily depends on gold nanoparticles synthesized through a novel process of photo-irradiation with ultraviolet light. The crystal structure and particle size of sustainable zero-valent gold nanoparticles were measured using X-ray diffraction (XRD), which proved the cubic shape, with a cubic unit cell edge length of 4.0095 Å. The transmission electron microscopy (TEM) and field emission scanning electron microscope (FE-SEM) demonstrated that the distribution of Au NPs is uniform, with an average diameter of 22 nm. The UV–Vis spectrum, displaying a pronounced absorbance peak at a wavelength of 548 nm, suggests the presence of Au NPs. The optimal conditions for the formation of the Au-biotinylated antibody-HRP complex were studied. The optimum pH was 7, the dilution ratio of AuNPs with biotinylated antibody-HRP was 1:3, and the concentration of nanogold was (1 × 10−3 mg/ml) to avoid increasing it. Then a standard curve was drawn for this method and compared to the traditional method, and it was found to be twice as sensitive as the traditional method, with a high accuracy of CV% (3–6 %) as well as a rapid color generation for measurement. This method, based on gold nanoparticles that are considered a carrier for biotinylated antibody-HRP, was applied for the first time to measure CHI3L1 in the sera and cerebrospinal fluid of patients with multiple sclerosis, and the results demonstrated the accuracy and sensitivity of the method. The method has the potential to be an excellent tool for evaluating CHI3L1 and may have applications in other diseases for rapid diagnosis and timely treatment.

Enhanced scintillating performance in Tb3+ doped oxyfluoride glass for high-resolution X-ray imaging

Scintillators that exhibit excellent scintillation performance coupled with superior radiation resistance are anticipated to cater the growing demand of X-ray detection across various fields including medicine and scientific research. Oxyfluoride glasses, which combine the benefits of both fluorine and oxide glasses, show significant potential as scintillator candidates. Here, highly transparent Tb3+ doped oxyfluoride glasses with splendid radioluminescence were successfully synthesized by melt quenching method with the aid of a two-step component tuning strategy. The luminescence excited by X-ray and ultraviolet light are significantly enhanced by boosting the effective atomic number of glass components and optimizing the B2O3/Al2O3 ratio. The integrated X-ray excited luminescence intensity of representative specimen reaches 219% of that of BGO. Exceptional anti-irradiation recoverability and thermal stability of 93% @ 573 K are conferred in the resultant glass. Moreover, X-ray imaging with a spatial resolution of up to 20 lp mm−1 was triumphantly achieved. These properties testify that the prepared oxyfluoride glass owns an enormous application foreground in X-ray imaging.

Fabrication of novel MoOx / PVA hydrogel nanocomposite for photochromic smart window

Photochromic smart windows allow for simple manufacturing without the need for additional energy input for adaptive control of sunlight, which will have a huge impact on the comfort of daylight and the development of smart windows. Among them, although molybdenum-based materials have advantages such as low cost and stable coloring, the lack of fast transmission switching capability and liquid phase color changing environment limit its implementation in the field of smart windows. Here, we report a low-cost method to fabricate a novel photochromic hydrogel (MoOx/PVA) by combining molybdenum oxide nanosheets (MoOx, 2≤x≤3) with polyvinyl alcohol (PVA) gel. Under ultraviolet light (UV=360∼400 nm) irradiation, the hydrogel achieves rapid color change visible to the naked eye within 10 s, with an exponential decrease in transmittance, reversible switching of transparency between 70% and 5%, and retains about 95% transmittance after 14 cycles. Due to the good biocompatibility of molybdenum oxide, hydrogel can also be used for personal wearable, which can achieve 1.4°C of cooling when exposed to sunlight for 3 min. Moreover, the photochromic and recovery properties of the large-sized (29.7 cm×21 cm) MoOx/PVA hydrogel demonstrate its broad prospects for production applications in smart windows. It is believed that this study will open new opportunities for both fabrication and application in photochromic smart windows and intelligent devices.

Cu-doped NaNbO3 nanorods: Enhanced photocatalytic activity for RhB dye removal and antibacterial activity against E. coli

Sodium niobate (NaNbO3) nanorods with Cu (0.00, 0.01, 0.02 and 0.04 mmol) insertion were prepared by the microwave-assisted hydrothermal method and the photocatalytic and antibacterial activity was explored for the first time. X-ray diffraction confirms the coexistence of two orthorhombic phases (P21ma and Pbma) for all samples, with the percentage of each phase being strongly influenced by doping. The micrographs reveal that doping did not alter the shape or size of the grains (nanorods, with a diameter of ∼200 nm and a length of tens micrometers). The samples of pure NaNbO3 and those with 0.01 and 0.02 mmol of Cu showed an average band gap value of 3.08 eV. However, the sample containing 0.04 mmol of Cu exhibited a slight redshift. The photocatalytic activity of the samples was assessed by the removal of Rhodamine B dye (RhB), under ultraviolet light. All doped samples exhibited superior performance, with the sample containing 0.02 mmol of Cu showing the best photocatalytic activity, achieving 100 % RhB removal in 50 min. This was attributed to a lower rate of recombination of photogenerated charges, as evaluated through photoluminescence analysis. Additionally, the photocatalyst demonstrated excellent recyclability over three cycles. Pure NaNbO3 nanorods showed no antibacterial activity, but doping with 0.04 mmol of Cu reduced the growth of Escherichia coli.

Properties of Thin Film Composites of rGO–SnO2 and Modeling of Ultraviolet Laser‐Induced Conductivity Decay

AbstractReduced graphene oxide (rGO) and tin dioxide (SnO2) form composites in a wide range of SnO2/rGO proportions, which are deposited as thin films on borosilicate glass and silica substrates. The rGO proportion affects the SnO2 optical properties and the sample surface, as observed by optical transmittance and confocal and scanning electron microscopies images, mainly for high proportion of rGO. For low proportion, the presence of small surface islands may contribute to optical confinement. The evaluated bandgap is basically from the SnO2 matrix unless the presence of rGO affects the optical absorption edge. Monochromatic ultraviolet light from a He–Cd laser (325 nm) irradiating on the composite film increases the conductivity, giving rise to the phenomenon of persistent photoconductivity (PPC), even very close to room temperature. Modeling by considering mainly the SnO2/rGO interface barrier for electron transport, yield an interface energy barrier of 250 meV. The strong response to ultraviolet light and the phenomenon of PPC indicates potential application in amplifiers, which could be adjusted by doping with rare‐earth ions, such as Er3+ in the SnO2 matrix.

In-situ preparation of lanthanide luminescent MOF hydrogel for aldehyde detection☆

Metal-organic frameworks (MOFs) usually exist in the state of powder or crystal. When they are exposed to hydrophilic solvents, their structure will change and become unstable. Therefore, it is a challenge to construct MOF materials with tunable mechanical properties. Herein, we report in-situ growth lanthanide metal-organic framework (LnMOF) in sodium alginate (SA) and polyvinyl alcohol (PVA) hydrogel matrix. The prepared composite hydrogel not only displays characteristic lanthanide narrow-band emission under ultraviolet light, but also demonstrates excellent mechanical properties. The addition of LnMOF significantly enhances the compressive strength of the hydrogel (from 0.75 to 7.32 MPa). Furthermore, the composite hydrogel shows highly selective recognition of glutaraldehyde and gaseous formaldehyde at room temperature. The detection limits (LOD) of SP-EuMOF for glutaraldehyde and formaldehyde are 0.27 and 0.22 ppm, respectively. Based on these results, the LnMOF composite hydrogel is deemed to have significant potential as a fluorescent sensor for both glutaraldehyde and formaldehyde detection.

Development of UV light-emitting diodes based AlGaN/GaN heterojunction utilizing thermal oxidation annealing

Ultraviolet (UV) irradiation has a significant impact on enhancing the performance of sensors. Currently, there is still an urgent need for devices that are simple and easy to fabricate. In this work, a cost-effective and convenient method was employed to fabricate a UV light emitting diode. A four-inch silicon based AlGaN/GaN heterojunction substrate was used. The Ni/Au (20/20 nm) layer was deposited on the AlGaN barrier layer, followed by thermal oxidation to prepare the UV diode. The diode annealed in oxygen can emit UV light at a wavelength of 365 nm and is visible, and no light is emitted from the device in nitrogen annealing. The I–V and C–V characteristics of the device are tested to explore the mechanism. Transmission electron microscopy and technology computer aided design simulation methods were used to analyze the device luminescence mechanism.

Electronic and optical properties of Cr-Mn co-doped in monolayer MoS2: A first-principles study

The effects of Cr-Mn co-doping of neighboring and spacer sites on the electronic and optical properties of monolayer molybdenum disulfide (ML-MoS2) are investigated using a first-principles plane-wave pseudopotential method based on density-functional theory (DFT). The results show that the band structure (BS) and the bandgap of pristine ML-MoS2 are in good agreement with the available experimental and theoretical data. Electronic analysis implies that the bandgap of Cr-Mn co-doped ML-MoS2 is smaller than that of the pristine ML-MoS2 and the bandgap of Cr-Mn co-doped ML-MoS2 at spacer sites is the smallest. Moreover, the ML-MoS2 changes from a direct bandgap to an indirect bandgap semiconductor, which facilitates electron-hole pair transfer. In addition, pristine ML-MoS₂ has no magnetism, while Cr-Mn co-doped ML-MoS2 at neighboring and spacer sites present ferromagnetism. Studies of optical properties have shown that doped ML-MoS2 systems, especially Cr-Mn co-doped at spacer sites, exhibit higher sensitivity to visible and ultraviolet (UV) light along the x-axis as well as to UV light along the z-axis. This suggests the possibility of applications in photodetectors, solar cells, and photocatalysis. It is noteworthy that Cr-Mn co-doping at the spacer sites significantly improves the photovoltaic performance and light utilization efficiency of ML-MoS2 by increasing the dielectric tensor, absorption coefficient, and photoconductivity while decreasing the extinction coefficient compared with pristine ML-MoS2.

Metabolic responses of sea anemone and jellyfish to temperature and UV bleaching: Insights into stress adaptation using LCMS-based metabolomics, molecular networking and chemometrics

IntroductionClimate change poses various threats to marine life, particularly in shallow tropical waters. Objective: The impact of increased temperature and ultraviolet (UV) exposure on two photosymbiotic Cnidarians, a common bubble-tip anemone and an upside-down jellyfish, was investigated. MethodsTo illustrate the response of aquatic organisms, the metabolomes of unstressed Entacmaea quadricolor and Cassiopea andromeda were compared for detailed metabolite profiling. UHPLC-MS coupled with chemometrics and GNPS molecular networking was employed for sample classification and identification of markers unique to stress responses in each organism. ResultsSeveral compounds with bioactive functions, including peptides and terpenoids, were reported for the first time in both organisms, viz. cyclic tetraglutamate, campestriene, and ceramide aminoethyl phosphonate (CEAP d18:2/16:0). Both anemone and jellyfish were subjected to either elevated UV-B light intensity up to 6.6 KJ m−2 or increased temperatures (28 °C, 30 °C, 32 °C, and 34 °C) over 4 days. Phospholipids, steroids, and ceramides emerged as chief markers of both types of stress, as revealed by the multivariate data analysis. Lysophosphatidylcholine (LPC 16:0), LPC (18:0/0:0), and echinoclasterol sulfate appeared as markers in both UV and thermal stress models of the anemone, whereas methyl/propyl cholestane-hexa-ol were discriminatory in the UV stress model only. In the case of jellyfish, nonpolar glycosyl ceramide GlcCer (d14:1/28:6) served as a marker for UV stress, whereas polar peptides were elevated in the thermal stress model. Interestingly, both models of jellyfish share a phospholipid, lysophosphatidylethanolamine (LPE 20:4), as a distinctive marker for stress, reported to be associated indirectly with the activity of innate immune response within other photosymbiotic Cnidaria such as corals and appears to be a fundamental stress response in marine organisms. ConclusionThis study presents several bioinformatic tools for the first time in two cnidarian organisms to provide not only a broader coverage of their metabolome but also broader insights into cnidarian bleaching in response to different stressors, i.e., heat and UV light, by comparing their effects in anemone versus jellyfish.

A yellow-green-emitting phosphor K3LaSi2O7:Eu2+ with superior thermal stability for solid-state lighting

Yellow-green-emitting phosphors with good thermal stability when excited by ultraviolet (UV) light are relatively less common compared to blue and red phosphors. In this study, a serial of K3LaSi2O7:xEu2+ (KLSO: xEu2+) phosphors with hexagonal structure (P63/mcm space group) were successfully synthesized. Under 360 nm excitation, KLSO: xEu2+ exhibits yellow-green luminescence peaked at 540 nm. Additionally, sharp emission peaks at 592 and 614 nm are observed when excited at 390 nm, indicating a small amount of Eu3+ ions still exist. The Eu2+ ions are found to occupy both La3+ and K+ sites in the KLSO host, resulting in two luminescent centers at 535 and 592 nm based on Gaussian fitting of the emission spectrum. The optimal Eu2+-doping concentration is verified at KLSO:0.05Eu2+. The thermal stability tests indicate that its luminescence intensity at 150 °C maintains 90.01 % of that at room-temperature. Meanwhile, the component substitution of Na+ ions for K+ ones is beneficial for the enhancement of luminescence, achieving a quantum efficiency of 40.62 %. Finally, this phosphor is applied to white LED, which shows a correlated color temperature (CCT) of 4164 K, a color rendering index (CRI) of 86.6, and CIE color coordinate of (0.3604,0.3174). It indicates that K3LaSi2O7:xEu2+ is a promising candidate for solid-state lighting.

Quantification of Synergistic Two-Color Covalent Bond Formation.

The emergence of highly wavelength resolved reactivity information for complex photochemical reaction processes allows the establishment of multi-color reaction modes. One particularly powerful mode is the synergistic two-color reaction, where two colors of light have to be present in the same volume element to either enable or enhance photochemical reactivity that leads to a specific photoproduct. Herein, we introduce a two-color synergistic photochemical reaction system based on a diaryl indenone epoxide (DIO) photoswitch and the cis-to-trans isomerization of a bridged ring-strained azobenzene (SA), which respond to ultraviolet (365 nm) and visible light (430 nm), respectively, with different rates, forming a well-defined heterocyclic photoadduct, DIOSA, that we structurally confirm via single crystal x-ray diffraction (SXRD). To quantitatively capture the effectiveness of the dual-color irradiation as a function of the reaction conditions such as light intensity and starting material ratio as a function of product yield, we introduce a parameter, the photochemical synergistic ratio. A reduced synergistic ratio- that extrapolates to conditions of infinitesimal conversions - allows to compare the efficiency of the synergistic photochemistry at varying reaction conditions.

Modeling and application of array light sources in ultraviolet communication systems

Reliable communication over long distances using ultraviolet (UV) light is challenging due to the strong scattering and atmospheric absorption of UV light. However, with advancements in UV LED technology, the performance of transmitters can be significantly enhanced by employing an array of light sources, which improves the overall quality of communication. Despite these advancements, the impact of various array configurations—such as shape, quantities, and other parameters—on light intensity distribution and UV optical communication remains largely unexplored. In this work, we first modeled the light intensity distribution of arrayed light sources with varying shapes, quantities, and other parameters. We improved the traditional Monte Carlo method to better accommodate these distributions, enabling more accurate simulations. Subsequently, we obtained simulation results for different array configurations. Building on these findings, we developed a UV LED array communication system that achieved a bit error rate (BER) of 10−6 for information transmission over a distance of 500 meters. This research provides valuable insights into the long-distance transmission capabilities of UV light using arrayed light sources.