Preventive conservation of paper-based relics with visible light high-transmittance ultraviolet blocking film based on carbon dots.

Paper-based relics is an important carrier for recording and preserving information, however, it faces irreversible UV-induced damage, including photocleavage, oxidation, acidification and discoloration, which seriously affects its value and lifespan. Carbon dots (CDs) possess excellent UV absorption and good chemical stability, making them suitable for UV protection. Herein, we propose a high-security and efficient method utilizing CDs films (CDFs) for preventive protection of paper against UV damage. The CDFs with high tunable UV absorbance and minimal absorbance in the visible light range, effectively shield paper from UV radiation while preserving its visual appeal. Moreover, the UV transmittance of the film can be fine-tuned to the content of CDs and can be easily removed from the paper without residue. Artificial accelerated UV aging experiments demonstrate the deceleration of acidification, oxidation, and photocleavage in the protected bamboo paper and Xuan paper. This research paces a new direction for the protection of paper and paper-based relics and artworks with emerging carbon materials, offering customizable protection effects tailored to specific preservation and exhibition requirements. This research pioneers a novel approach to preventive protection of paper and paper-based relics using emerging carbon dots materials, offering tailored protection for diverse preservation needs.

Green synthesis of sacrificial UV-sensitive core and biobased shell for obtaining optically hollow nanoparticles.

Hollow nanoparticles have been extensively studied in recent years. Obtaining such structures with biobased materials, following greener synthetic routes, is still challenging, especially if accurate particle dimensions are required. This work reports the use of an innovative hybrid silica core (Si@azo) containing UV-sensitive molecule, wrapped in biobased multilayer shell composed of polysaccharides. It is a promising strategy for obtaining optically hollow nanoparticles. Indeed, Si@azo cores have the ability to be partially degraded when irradiated with UV light. Combined with a well-controlled and monodisperse diameter, they provide a good basis for layer-by-layer assembly, leading to a multilayer shell with controlled composition and thickness. Finally, UV irradiation of such a core-shell structure is harmless to the polysaccharide shell, but does impact the hybrid silica core, as revealed by turbidity measurements, among other. Each step, i.e. core synthesis, shell addition, and core-shell irradiation, has been carefully characterized at the macro (Fourier-transform infrared spectroscopy - FTIR, Dynamic Light Scattering - DLS, Zeta-potential measurement, Surface Plasmon Resonance - SPR, turbidity) and microscale (Transmission and Scanning Electron Microscopies). Emphasis is put on how turbidity measurements can be related to the core refractive index (ncore), giving information on the state of core degradation and whether the core-shell particle is optically hollow.

A new method for the rapid identification of external water types in rainwater pipeline networks using UV-Vis absorption spectroscopy.

Ultraviolet-visible (UV-Vis) absorption spectroscopy, due to its high sensitivity and capability for real-time online monitoring, is one of the most promising tools for the rapid identification of external water in rainwater pipe networks. However, difficulties in obtaining actual samples lead to insufficient real samples, and the complex composition of wastewater can affect the accurate traceability analysis of external water in rainwater pipe networks. In this study, a new method for identifying external water in rainwater pipe networks with a small number of samples is proposed. In this method, the Generative Adversarial Network (GAN) algorithm was initially used to generate spectral data from the absorption spectra of water samples; subsequently, the multiplicative scatter correction (MSC) algorithm was applied to process the UV-Vis absorption spectra of different types of water samples; following this, the Variational Mode Decomposition (VMD) algorithm was employed to decompose and recombine the spectra after MSC; and finally, the long short-term memory (LSTM) algorithm was used to establish the identification model between the recombined spectra and the water source types, and to determine the optimal number of decomposed spectra K. The research results show that when the number of decomposed spectra K is 5, the identification accuracy for different sources of domestic sewage, surface water, and industrial wastewater is the highest, with an overall accuracy of 98.81%. Additionally, the performance of this method was validated by mixed water samples (combinations of rainwater and domestic sewage, rainwater and surface water, and rainwater and industrial wastewater). The results indicate that the accuracy of the proposed method in identifying the source of external water in rainwater reaches 98.99%, with detection time within 10 s. Therefore, the proposed method can become a potential approach for rapid identification and traceability analysis of external water in rainwater pipe networks.

UV-aging reduces the effects of biodegradable microplastics on soil sulfamethoxazole degradation and sul genes development.

In recent years, the biodegradable plastics has extensively used in industry, agriculture, and daily life. Herein, the effects of two biodegradable microplastics (BMPs), poly(butyleneadipate-co-terephthalate) (PBAT) and polyhydroxyalkanoate (PHA), on soil sulfamethoxazole (SMX) degradation and sul genes development were comparatively studied based on the type, dosage, and state. The addition of virgin BMPs significantly increased soil DOC following a sequential order PBAT > PHA and high dose > low dose. Meanwhile virgin PBAT significantly reduced soil pH. In general, the addition of BMPs not only promoted soil SMX degradation but also increased the abundance of sul genes, with an exception that pH reduction in virgin PBAT inhibited the proliferation of sul genes. The driving effects of BMPs on soil microbial diversity following the same order as that on DOC. Specific bacteria stimulated by BMPs, such as Arthrobacter and two genera affiliated with phylum TM7, accounted for the accelerated degradation of SMX. Intriguingly, UV-aging hindered the release of DOC from BMPs and the reduction in pH, mitigated the stimulation of microbial communities, and ultimately reduced the promotion effect of BMPs on SMX degradation and sul genes proliferation. Our results suggest that more attention should be paid to the proliferation risk of ARGs in the environment affected by BMPs and UV-aging can be employed sometimes to reduce this risk.

A machine vision tool for multi-color H2O2 sensing by MoOx nanoparticles with oxygen vacancies.

Improving the ease of operation and portability of hydrogen peroxide (H2O2) detection in daily production and life holds significant application value. However, it remains a challenge to achieve rapid colorimetric detection of H2O2 and color change quantification. In this study, we achieved rapid and visual detection of H2O2 by MoOx (2 ≤ x ≤ 3) nanoparticles with rich oxygen vacancies using machine vision. As the concentration of H2O2 increases, the detection system exhibited a visible multi-color change from blue to green and then yellow and the absorption peak near 680 nm measured by the UV-visible spectrophotometer gradually decreased. With excellent sensitivity, a wide linear range of 0.1-600 µmol/L, concentrations as low as 0.1 µmol/L can be detected with good selectivity towards H2O2. The sensing mechanism of detecting H2O2 by the change of oxygen vacancies in MoOx was revealed through characterization methods such as XPS, EPR, and DFT. In addition, the Hue, Saturation, Value (HSV) visual analysis system based on MoOx was constructed to assist in the rapid, portable, and sensitive monitoring of H2O2 in practical application scenarios. This work offers an easy-to operate, low cost, and convenience for achieving rapid colorimetric determination of H2O2 and has broad application prospects in daily life and industrial production.

Revisited UV- spectra of chlorohydroxoaurate anions.

The most important ionic precursor of gold, [AuCl4]-, is used in aqueous solution leading to chlorohydroxoaurates species, [AuCl4-x(OH)x]- (x = 1-4) due to partial hydrolysis. Their UV spectral signatures are still relatively unknown though very useful in many domains of application. Individual spectra of each of them are determined for the first time thanks to a thorough experimental investigation comprising the range 200-250 nm, surpringly ignored up to now. New isosbestic points useful for species partition analysis are evidenced. Electronic transition attribution is obtained from quantum chemical calculations based on TD-DFT. The prediction of the experimental blueshifted bands of the [AuCl4-x(OH)x]-1 anions was possible only after applying energy corrections calibrated on the full UV range two-band spectrum of the [AuCl4]- complex.

Lycopene detection in cherry tomatoes with feature enhancement and data fusion.

Lycopene, a biologically active phytochemical with health benefits, is a key quality indicator for cherry tomatoes. While ultraviolet/visible/near-infrared (UV/Vis/NIR) spectroscopy holds promise for large-scale online lycopene detection, capturing its characteristic signals is challenging due to the low lycopene concentration in cherry tomatoes. This study improved the prediction accuracy of lycopene by supplementing spectral data with image information through spectral feature enhancement and spectra-image fusion. The feasibility of using UV/Vis/NIR spectra and image features to predict lycopene content was validated. By enhancing spectral bands corresponding to colors correlated with lycopene, the performance of the spectral model was improved. Additionally, direct spectra-image fusion further enhanced the prediction accuracy, achieving RP2, RMSEP, and RPD as 0.95, 8.96 mg/kg, and 4.25, respectively. Overall, this research offers valuable insights into supplementing spectral data with image information to improve the accuracy of non-destructive lycopene detection, providing practical implications for online fruit quality prediction.

Selective microextraction of erythrosine (E127) in foodstuffs using a new generation high-density type-V deep eutectic solvent.

A novel and selective (deep eutectic solvent) DES-based microextraction method was established for the first time, utilizing a synthesized new generation High-Density Type-V DES for monitoring the dye Erythrosine (E127) in various foodstuffs and drugs. Type-V DES was created from acetophenone and diphenylamine at 3:1 M ratio. The pH, DES amount, and vortex time were optimized using Box-Behnken Design (BBD) of Response Surface Methodology (RSM). The quadratic microextraction model with R2 = 0.9982 was obtained. The limit of detection, preconcentration factor and linear dynamic range were determined to be 12 µg/L, 50 and 41-4000 µg/L, respectively. Effects of matrix components were examined. The developed High-Density Type-V Deep Eutectic Solvent Microextraction (HD-V-DES-ME) method was applied to foodstuffs and drugs to monitor their E127 contents and subsequently validated by applying spiked tests to real samples, with recoveries ranging between 94 and 101 %. The indexes of environmental friendliness and practicality for the method were evaluated using the Analytical GREEnness metric approach tool (AGREE) and the Blue Applicability Grade Index tool (BAGI), respectively.

A simple and rapid spectrophotometric method for the determination of trans-chalcone in raw-materialand topical formulation / Método espectrofotométrico simples e rápido paradeterminação de trans-chalcona em matéria-primae em formulação tópica

Trans-chalcone (TC) is a flavonoid precursor characterized by a wide spectrum of action, with anti-inflammatory and antioxidant effects. However, no validated methods are available in official compendia for the analysis of this substance. Thus, the aim of this work was to develop and validate a simple, fast, and reproducible spectrophotometric method for the analysis of TC in raw material, and in topical pharmaceutical formulation containing TC. The established conditions were: methanol as extracting solvent, and detection wavelength of 309 nm by UV spectrophotometer. All tests followed the rules of Resolution RDC 166, 2017. The proposed method was selective. Linearity was demonstrated in the concentration range of 1 to 8 µg/mL (r = 0.999). Repeatability and intermediate precision were confirmed by low relative standard deviation values of 1.53% and 2.70% for TC, and of 1.73% and 2.91% for formulation containing TC. Accuracy, evaluated through recovery test, was adequate, with minimum of 98.24% and maximum of 100.23% of recovery. It was observed that the small deliberate modifications done did not interfere with the results, demonstrating the method is robust. The results showed that the method was considered suitable for the intended purpose, inexpensive, easy to apply, selective, linear, precise, accurate, and robust for the determination TC, and pharmaceutical formulation containing TC. Thus, the method developed satisfies the need for an analytical method for the determination of TC, and topical formulation containing TC, being effective, innovative and able to aid in the development of the pharmaceutical field.

Trans-chalcona (TC) é um precursor de flavonoides caracterizado por um amplo espectro de ação, como efeitos anti-inflamatórios e antioxidantes. No entanto, não há método validado disponível em compêndio oficial para análise deste composto. Então, o objetivo deste trabalho foi desenvolver e validar um método espectrofotométrico, simples, rápido e reprodutível para análise de TC em matéria-prima, e em formulação farmacêutica tópica contendo TC. As condições estabelecidas foram: metanol como o solvente de extração, e detecção no comprimento de onda de 309 nm por espectrofotometria no UV. Todos os testes seguiram as normas da RDC 166, 2017. O método proposto foi seletivo. A linearidade foi demonstrada na faixa de concentração de 1 a 8 µg/mL (r = 0.999). A repetibilidade e a precisão intermediária foram confirmadas pelos valores baixos de desvio padrão relativo de 1,53% e 2,70% para a TC, e de 1,73% e 2,91% para a formulação contendo TC. A exatidão, avaliada por meio de testes de recuperação, foi adequada, com mínimo de 98,24% e máximo de 100,04% de recuperação. Observou-se que pequenas modificações no método não interferiram nos resultados, demonstrando que o método é robusto. Os resultados demonstraram que o método foi adequado para a finalidade pretendida, barato, de fácil aplicação, seletivo, linear, preciso, exato e robusto para determinação de TC, e de formulação contendo TC. Então o método desenvolvido satisfaz as necessidades de um método analítico para determinação de TC, e de formulação tópica contendo TC, e é eficaz, inovador e pode contribuir para o desenvolvimento da área farmacêutica.

Real-time monitoring of aqueous total N-nitrosamines by UV photolysis and chemiluminescence.

N-nitrosamines such as N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosopiperidine (NPIP), and N-nitrosopyrrolidine (NPYR) have been established as potent carcinogens that can induce diverse types of cancer. Several studies have extensively investigated the accurate quantification of total N-nitrosamines (TONO) and the intricate nature of the matrix in which they are detected. The potential for the formation of N-nitrosamines in post-combustion CO2 capture (PCCC) and water treatment has raised concerns. This study outlines a unique method for the quantification of TONO in aqueous matrices using UV photolysis and the subsequent detection of NO by chemiluminescence. This method offers benefits such as operation in the continuous mode and handling of high sample flow rates to achieve a low limit of detection (LOD) and a low limit of quantification (LOQ). The observed LODs for the individual N-nitrosamines of NDMA, N-nitrosomorpholine (NMOR), N-nitrosodibutylamine (NDBA), and NPIP range between 0.06 and 0.2 µM at a sample flow rate of 0.25 mL/min, while the LOD range is reduced to between 0.02 and 0.06 µM at 0.75 mL/min. Linear responses for the NO produced from specific N-nitrosamines are observed between 0.5 and 10 µM. The developed method is resistant to interfering chemicals (i.e., nitrite, amines, and carbonyls) and exhibits high specificity.

An ingenious chemiluminescence sensing strategy for recalcitrant triphenyl phosphate based on oxidant-free UV-activated MIL-100(Fe) gel system.

BACKGROUND: Organophosphate flame retardants (OPFRs) are notorious emerging contaminants threatening the environment and human health. Triphenyl phosphate (TPHP), which has an extremely serious biotoxicity, is a typical harmful OPFR. Due to its wide use, TPHP has been discovered in various environmental mediums. Moreover, it is pretty recalcitrant to the removal process, resulting in the need for a technique to understand it better. Hence, accurate and quick discrimination of TPHP in the environment is critical to further evaluate its potential effect on ecosystems and human health. RESULTS: An ingenious oxidant-free chemiluminescence (CL) sensor based on the oxidant-free UV/MIL-100(Fe) gel system was established for TPHP detection. The oxidation of luminol in the UV-activated MIL-100(Fe) gel has resulted in remarkable CL emission, which is contributed by reactive oxygen species (ROS) generated by it. Notably, the CL intensity was inhibited significantly after introducing TPHP. An investigation into the mechanism underlying the effect of CL suppression demonstrated that TPHP competed with luminol to consume ROS from UV-activated MIL-100(Fe) gel, contributing to CL inhibition. The subsequent sensing performance experiments demonstrated the advantages of environmentally friendly, economic efficiency, user-friendly operation, rapid determination, potential for compact size, high selectivity, and sensitivity. Additionally, these investigations confirmed the low limit of detection (210 ng L-1) and wide linear range (10-1000 µg L-1). SIGNIFICANCE: In this paper, a green, economical, and oxidant-free CL sensing strategy for TPHP has been established. It has the advantage of being rapid, having the potential for compact size, high selectivity, and sensitivity. This ingenious method has promising applications in real-time and online environmental monitoring, and it paves the way for the rapid and environmentally friendly identification of emerging contaminants that are structurally stable and recalcitrant to remove.

Robust, intelligent photochromic cotton fabrics with superamphiphobicity and expedient UV detection ability.

Multifunctional photochromic cotton fabrics have enormous application potential in our daily lives, but still suffer from poor durability, slow coloration, tedious fabrication process, and short service life. The hydrophilic and polysaccharide characteristics of cotton fabrics make them vulnerable to bacteria adhesion and proliferation. Herein, intelligent photochromic cotton fabrics featured with durable superamphiphobicity are fabricated by in situ growth of ZIF-8 nanoparticles encapsulating spirooxazine (SP) photochromic dyes on the fabric surface, followed by low surface energy treatment using a fluorocarbon resin (FR) via a dip-coating method. The resultant SP@ZIF-8/FR cotton fabrics exhibit superamphiphobicity with contact angles of over 150° to both water and oils (surface tension ≥30 mN/m). When exposed to UV light, the fabric rapidly changes its color from white to blue within 10 s and fades in 2 min under visible room light. The developed SP@ZIF-8/FR coating is durable against numerous damages in daily usage, such as machine laundry, abrasion and UV irradiation, without losing photochromic and superamphiphobic properties. The high durability and excellent reversible color response allow the coated fabric to intuitively and quantitatively monitor outdoor UV intensity. Owing to the presence of ZIF-8, the treated fabrics also show excellent antibacterial property with antibacterial rates of over 99 % against both E. coli and S. aureus. The developed fabric coating can be engineered to visually assess the UV intensity in the outdoor environment.

Impact of UV annealing on the hole effective mobility in SnO pFET.

Using ultraviolet (UV) annealing through wide energy bandgap HfO2/SiO2 gate dielectric, nanosheet SnO pFET achieved hole effective mobility (µeff) from 55 cm2/V-s at low hole density (Qh) to 13.38 cm2/V-s at 5 × 1012 cm-2 Qh, compared to that of 9.03 cm2/V-s at 5 × 1012 cm-2 Qh for SnO device without UV annealing. This is the highest µeff among oxide semiconductor pFETs at high Qh, which is required to realize low-power high-density monolithic 3D CMOS logic. This requires excellent surface roughness, good uniformity and free-from grain boundaries that is beyond the thermally-annealed poly-Si. Excellent on-current/off-current (ION/IOFF) value of 1.05 × 105 were measured simultaneously in the UV-annealed SnO pFET, which is due to the ultra-thin 8 nm thick SnO nanosheet channel to pinch off the channel leakage. From X-ray photoelectron spectroscopy (XPS) analysis, the 48% µeff improvement by UV irradiation is due to increased Sn2+ and decreased Sn0. Such high µeff at high Qh, large ION/IOFF, smooth surface, good uniformity and low thermal budget process are the enabling technologies for monolithic 3D CMOS.

Direct colour printing on zirconia using 222 nm UV-C photons.

OBJECTIVES: To proof the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C through investigating the degree and durability of the colour changes, and testifying whether surface, mechanical and biological properties are influenced by the treatment. METHODS: 222 nm UV-C light (Irradiance: 1.870 mW/cm2) was used to treat 3Y-TZP for durations from 15 min to 24 h. ΔE*, TP, crystalline structure, surface morphology, Sa, BFS and biological activities were investigated before and after irradiation. SPSS 28.0 was used for statistical analysis (α = 0.05). RESULTS: 222 nm UV-C irradiation was capable to shade white 3Y-TZP into tooth colours. With the increase of ΔE*, TP decreased, such that the longer the irradiation time, the higher the ΔE* (logarithmic relationship) and lower the TP. Despite the induced optical changes being prone to fade, the process can be predicted by inversely proportional relationships between ΔE*, TP and the testing points. The treated surface exhibited enhanced hydrophilicity, while the recovery phenomenon was observed. Other properties were not altered by the treatment. SIGNIFICANCE: This is the seminal study demonstrating the feasibility of direct colour printing on 3Y-TZP using 222 nm UV-C. The new relationship between the colour centre and Eg of 3Y-TZP was established, whereas the induced optical changes were stabilised after a certain period and were highly predictable by controlling the irradiation periods. The irradiation was only correlated to the electron excitation and oxygen vacancies, and would not lead to any changes of other properties. A simple, safe and promising approach to achieve satisfactory colours on 3Y-TZP in clinical practice can be developed.

Automated prediction of phosphorus concentration in soils using reflectance spectroscopy and machine learning algorithms.

A method is presented for predicting total phosphorus concentration in soils from Santander de Quilichao, Colombia, using a UV-VIS V-750 Spectrophotometer and machine learning techniques. A total of 152 soil samples, prepared with varying proportions of P2O5 fertilizer and soil, were analyzed, obtaining reflectance spectra in the 200 to 900 nm range with 3501 wavelengths. Additionally, 152 laboratory results of total phosphorus concentration were used to train the prediction model. The spectra were filtered using a Savitzky-Golay filter. Key wavelengths were identified using Variable Importance in Projection - Partial Least Squares (VIP-PLS) and Random Forest (RF), reducing the spectral bands to 1085. Principal Component Analysis (PCA) further reduced data dimensionality. A feedforward artificial neural network was then trained to predict phosphorus concentration. This method is faster than traditional lab tests by leveraging advanced data analysis and machine learning, offering results in less time. While sample preparation remains consistent with standard spectroscopic analysis, the value added by the proposed method lies in its data processing and interpretation. Currently applied to a single soil type, future improvements will include more soil types and other macronutrients, enhancing nutrient management in agriculture. Accurate macronutrient measurements aid in better fertilizer uses planning. • Filtering spectra and determining relevant wavelengths using VIP-PLS and RF. • Dimensionality reduction with PCA. • Training feedforward artificial neural networks.

Leaf Photosynthetic and Photoprotective Acclimation in the Ultraviolet-A1 and Blue Light Regions Follow a Continuous, Shallow Gradient.

Although blue light is known to produce leaves with high photosynthetic capacity, the role of the blue-adjacent UV-A1 (350-400 nm) in driving leaf photosynthetic acclimation is less studied. Tomato plants were grown under hybrid red and blue (RB; 95/5 µmol m-2 s-1), as well as four treatments in which RB was supplemented with 50 µmol m-2 s-1 peaking at 365, 385, 410 and 450 nm, respectively. Acclimation to 365-450 nm led to a shallow gradient increase in trait values (i.e., photosynthetic capacity, pigmentation and dry mass content) as the peak wavelength increased. Furthermore, both UV-A1 and blue light grown leaves showed efficient photoprotection under high light intensity. When treated plants were transferred to fluctuating light for 5 days, leaves from all treatments showed increases in photosynthetic capacity, which were strongest in RB, followed by additional UV-A1 treatments; RB grown leaves showed reductions in maximum quantum yield of photosystem II, while UV-A1 grown leaves showed increases. We conclude that both UV-A1 and blue light effectively trigger photosynthetic and photoprotective acclimation, the extent of acclimation becoming stronger the longer the peak wavelength is. Acclimatory responses to UV-A1 and blue light are thus not distinct from one another, but follow a continuous gradient.

UV-induced reactive oxygen species and transcriptional control of 3-deoxyanthocyanidin biosynthesis in black sorghum pericarp.

Black pericarp sorghum has notable value due to the biosynthesis of 3-deoxyanthocyanidins (3-DOAs), a rare class of bioactive polyphenols valued as antioxidant food additives and as bioactive compounds with cytotoxicity to human cancer cells. A metabolic and transcriptomic study was conducted to ascertain the cellular events leading to the activation of 3-DOA biosynthesis in black sorghum pericarp. Prolonged exposure of pericarp during grain maturation to high-fluence ultraviolet (UV) light resulted in elevated levels of reactive oxygen species (ROS) and the activation of 3-DOA biosynthesis in pericarp tissues. In conjunction with 3-DOA biosynthesis was the transcriptional activation of specific family members of early and late flavonoid biosynthesis pathway genes as well as the downstream activation of defense-related pathways. Promoter analysis of genes highly correlated with 3-DOA biosynthesis in black pericarp were enriched in MYB and HHO5/ARR-B motifs. Light microscopy studies of black pericarp tissues suggest that 3-DOAs are predominantly localized in the epicarp and are associated with the cell wall. A working model of UV-induced 3-DOA biosynthesis in black pericarp is proposed that shares features of plant immunity associated with pathogen attack or mechanical wounding. The present model depicts ROS accumulation, the transcriptional activation of receptor kinases and transcription factors (TFs) including NAC, WRKY, bHLH, AP2, and C2H2 Zinc finger domain. This study identified key biosynthetic and regulatory genes of 3-DOA accumulation in black pericarp and provided a deeper understanding of the gene networks and cellular events controlling this tissue-and genotype-specific trait.

Assessment of quality and antioxidant capacity of peach in response to different UV-C dose irradiation.

The effects of different doses of UV-C irradiation (0, 0.5, 1.0, 2.0, and 4.0 kJ m-2) on the quality and antioxidant capacity of peach fruit were examined. Results showed that irradiation at 2.0 kJ m-2 led to higher firmness and total soluble solids, as well as lower weight loss and decay index. Additionally, peach fruits irradiated with 2.0 kJ m-2 UV-C exhibited increased production of reactive oxygen species, which in turn stimulated the synthesis of total phenolics and total flavonoids and enhanced the activities of superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. Overall, the best abiotic stress effect was observed with 2.0 kJ m-2 UV-C irradiation, resulting in improved shelf quality and increased antioxidant capacity of peach fruits during storage. PRACTICAL APPLICATION: This study provides a theoretical basis for the application of UV-C irradiation in peach fruit preservation.

The Role of Carnosic Acid in the UV-B Stress Resistance Signalling Pathway in Arabidopsis thaliana.

Carnosic acid (CA) is recognized as an antioxidant that confers protection to plants against various forms of oxidative stress, including UV-B stress. However, limited research has been conducted to elucidate the molecular mechanisms underlying its defence against UV-B stress. In this study, we demonstrated that CA exhibits more efficacy compared to other antioxidants in UV-B resistance. Moreover, CA was found to enhance the accumulation of secondary metabolites in Arabidopsis leaves. Through the analysis of differentially expressed genes in response to UV-B stress with or without CA treatment, we uncovered that the exogenous application of CA effectively activates the flavonoid biosynthesis pathway in Arabidopsis to improve resistance of Arabidopsis to UV-B stress.

Photocurable Thiol-Ene/Nanocellulose Elastomeric Composites for Bioinspired and Fluorine-Free Superhydrophobic Surfaces.

Artificially prepared superhydrophobic surfaces toward a self-cleaning "lotus effect" and anticontamination performance have become critically important in the past few years. However, most approaches to create the required topology with a hierarchical roughness comprise several manufacturing steps of varying practicality. Moreover, the desired low surface energy is in most cases achieved with fluorinated moieties that are currently criticized due to biological and environmental hazards. In this work, rapidly photocuring but weak thiol-ene resins were reinforced with cellulose nanofibrils (CNFs) to replicate lotus leaves via one-step UV nanoimprint lithography. The CNFs were surface-modified using countercation exchange of carboxyl groups and grafting of thiol and methacrylate functionalities. The formulation methodology resulted in free-flowing, shear-thinning composite resins without surfactants or dispersants. The rheological and photo-cross-linking behavior of the resins, the thermal stability, the mechanical performance, and the hydrophobicity of the cured composites were characterized. Notably, the surface modifications increased the as received fibril diameter (1.9 ± 0.6 nm) by 1.6-2.3 nm and raised the fibril-resin compatibility. The resins underwent rapid polymerization and the high thermal stability of thiol-enes was retained. The methacrylated nanofibrils (10 vol %) significantly strengthened the rubbery network, outperforming the neat thiol-ene polymer in terms of hardness (3.4×), reduced modulus (5.8×), and wear resistance (>100×). Moreover, the surface of lotus-texturized composites was superhydrophobic with a water contact angle of 155°, higher than that of the neat polymer (147°), and was self-cleaning. These CNF composite resins are compatible with fast-cure processes such as 3D printing and roll-to-roll processing, are exempt of fluorine or any other hydrophobization treatment, and are extremely wear-resistant.