UV-C Irradiation Research Articles

Air cleaner prototype: Reduction of airborne viruses and effects of UV-C irradiation on virus concentration and RNA copy numbers considering modeled residence times and doses

Air cleaner prototype: Reduction of airborne viruses and effects of UV-C irradiation on virus concentration and RNA copy numbers considering modeled residence times and doses

Effects of UV-A/B/C on flavonoids and related synthetic enzymes in Tetrastigma hemsleyanum

IntroductionTetrastigma hemsleyanum is a folk and rare medicinal plant, and specifically, it is distributed in the south, China. To investigate the cumulative properties of its medicinal components, we examined the effect of UV light on flavonoid content and related enzyme activity changes in T. hemsleyanum.MethodsThe leaves and tubers were treated with UV-A, UV-B and UV-C for 1 h, 1L/23D h, 3 h and 3L/21D h (D represents darkness treatment). High-performance liquid chromatography (HPLC) analysis showed that the content of many flavonoids decreased significantly during UV-A treatment, increased after UV-B and UV-C irradiation and accumulated again after darkness treatment.ResultsIn the root tubers of the UV-A group, naringin content in the 3L/21D h group (0.069 μg/g) was 16.30 times higher than that of 3 h group (0.0042 μg/g). The rutin content was elevated after UV irradiation but was not detected in the CK group. The test results of the enzyme-linked kit indicated that the activities of many enzymes were higher in the UV-A and UV-B irradiation groups than those in the CK group, but the results were reversed in the UV-C treatment. After darkness treatment, the activities of most enzymes were higher than those with UV irradiation alone; F3’5’H activity in the 3L/21D h group (97.25 U/L) was 1.24 times higher than that in the 3 h group (78.12 U/L) in the UV-A-treated group.DiscussionThe study results suggest that appropriate UV-B and UV-C irradiation, as well as darkness supplementation, had a promotive effect on flavonoids in the leaves and root tubers of T. hemsleyanum. Additionally, UV irradiation and darkness treatment enhanced the activity of most enzymes.

Cu-TiO2/Zeolite/PMMA Tablets for Efficient Dye Removal: A Study of Photocatalytic Water Purification

In this study, Cu-doped TiO2 combined with natural zeolite (ZT) was synthesized and applied as a fixed powder layer on poly(methyl methacrylate) (PMMA) tablets. The material’s morphology, structural, and chemical properties were characterized using high-resolution scanning electron microscopy, Raman spectroscopy, and Brunauer–Emmett–Teller analysis. The antioxidant capacity was evaluated by assessing the neutralization of hydroxyl radicals and iron (III) ions. For the first time, tablets with Cu-TiO2 and ZT deposited on PMMA as the carrier were investigated for removing two dyes, methyl orange (MO) and methylene blue (MB), from water under simulated solar (SS) and UVC irradiation. Under SS irradiation, the Cu-TiO2/PMMA and Cu-TiO2/ZT/PMMA tablets achieved about 21% degradation of MB after 240 min. This result is particularly noteworthy because SS radiation provides lower energy compared with UVC, making the process more economically efficient. Furthermore, the photocatalysts are immobilized on a stable carrier, which enhances the method’s cost-effectiveness by reducing material loss and simplifying recovery. In the presence of ZT/PMMA tablets, 69% of MB was removed by adsorption after 240 min. Additionally, we explored the mechanism of degradation, revealing that the enhanced generation of hydroxyl radicals plays a pivotal role in the effective degradation of MB. At the same time, photogenerated holes contribute to the removal of MO. The overall results suggest that the tablets obtained are a promising solution for water purification due to their effectiveness, simplicity, and low processing cost.

Molecular characterization, carbohydrate metabolism and tolerance to abiotic stress of Eremothecium coryli endophytic isolates from fruits of Momordica indica.

Yeasts are unicellular fungi that occur in a wide range of ecological niches, where they perform numerous functions. Furthermore, these microorganisms are used in industrial processes, food production, and bioremediation. Understanding the physiological and adaptive characteristics of yeasts is of great importance from ecological, biotechnological, and industrial perspectives. In this context, we evaluated the abilities to assimilate and ferment different carbon sources, to produce extracellular hydrolytic enzymes, and to tolerate salt stress, heavy metal stress, and UV-C radiation of two isolates of Eremothecium coryli, isolated from Momordica indica fruits. The two isolates were molecularly identified based on sequencing of the 18S-ITS1-5.8S-ITS2 region. Our isolates were able to assimilate nine carbon sources (dextrose, galactose, mannose, cellobiose, lactose, maltose, sucrose, melezitose, and pectin) and ferment three (glucose, maltose, and sucrose). The highest values of cellular dry weight were observed in the sugars maltose, sucrose, and melezitose. We observed the presence of hyphae and pseudohyphae in all assimilated carbon sources. The two isolates were also capable of producing amylase, catalase, pectinase, and proteases, with the highest values of enzymatic activity found in amylase. Furthermore, the two isolates were able to grow in media supplemented with copper, iron, manganese, nickel, and zinc and to tolerate saline stress in media supplemented with 5% NaCl. However, we observed a decrease in CFU at higher concentrations of these metals and NaCl. We also observed morphological changes in the presence of metals, which include changes in cell shape and cellular dimorphisms. The isolates were sensitive to UV-C radiation in the shortest exposure time (1min). Our findings reinforce the importance of endophytic yeasts for biotechnological and industrial applications and also help to understand how these microorganisms respond to environmental variations caused by human activities.

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 4.0kJ m-2) on the quality and antioxidant capacity of peach fruit were examined. Results showed that irradiation at 2.0kJ m-2 led to higher firmness and total soluble solids, as well as lower weight loss and decay index. Additionally, peach fruits irradiated with 2.0kJ 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 2.0kJ 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.

Structural, Morphological, Optical and Vibrational Properties of a Novel Coral-Like Fibrous CuO Nanostructure Synthesized via Dropwise Precipitation for UV-light Induced Photocatalytic Wastewater Remediation on Aqueous R6G Dye

CuO is a well-known monoclinic structure with unique properties that is extensively investigated for sensor, energy storage, and optoelectronic applications. In this work, the CuO nanostructure was synthesized through facile precipitation by mixing the aqueous copper (II) sulfate pentahydrate with sodium hydroxide. The as-synthesized CuO was characterized by scanning electron microscopy (SEM), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and UV–visible spectroscopy. A homogeneous growth of a narrow, fine coral-like fibrous morphology was observed on CuO under SEM imaging. The FTIR spectra reveal the existence of some dominant sharp bands in the lower wavenumber region that represent the Cu-O bonds. The high solubility of CuO in water confirms the formation of particles with nanoscale dimensions. CuO exhibits a strong optical absorption peak at 510 nm, and the band gap determined by Tauc's relation is 2.11 eV. CuO is capable of inducing photocatalytic degradation on R6G dye solutions under low-intensity UVC irradiation, which can serve as a future photocatalyst for wastewater treatment.

Decontamination of Fused-Silica Surfaces by UVC Irradiation as Potential Application on Touchscreens.

The contamination of surfaces by antibiotic-resistant pathogens presents an escalating challenge, especially on touchscreens in public settings such as hospitals, airports, and means of transport. Traditional chemical cleaning agents are often ineffective and leave behind harmful residues. Thus, the application of optical radiation is gaining relevance as a rapid, effective, and environmentally friendly disinfection method. This study examines the contamination of publicly accessible touchscreens and the efficacy of an irradiation approach for the radiation disinfection of microorganisms on quartz surfaces with UVC LEDs. In this setup, the LED radiation is laterally coupled into a quartz plate that serves as cover glass of a simplified touchscreen model. The process allows for the irradiation of microorganisms on the surface, without the user being exposed to hazardous radiation. To assess the efficacy of the disinfection process, a range of bacteria, mostly ESKAPE surrogates, such as Staphylococcus carnosus, Acinetobacter kookii, Escherichia coli, Enterococcus mundtii, and additionally Micrococcus luteus, were spread over a quartz plate with a homebuilt nebulization system. After operating the side-mounted LEDs for 30 s, a reduction in all bacteria except M. luteus by more than three orders of magnitude was observed. In the case of M. luteus, a significant reduction was achieved after 60 s (p < 0.05). This result demonstrates the potential of side-mounted UVC LEDs for rapid disinfection of touchscreens between two users and thus for reducing the spread of pathogens without irradiating humans.

Ultraviolet radiation inhibits mitochondrial bioenergetics activity.

Mitochondria play an important role in cellular function, not only as a major site of adenosine triphosphate (ATP) production but also by regulating energy expenditure, apoptosis signaling, control of the cell cycle, cellular growth, cell differentiation, transportation of metabolites, and production of reactive oxygen species. Interaction with electromagnetic waves can lead to dysregulation or alterations in the patterns of energy activities in the mitochondria. Ultraviolet light (UV) can be found in sunlight and artificial sources, such as lamps. UV radiation can cause damage to DNA, proteins, and lipids. Besides that, UV radiation is largely used in microorganism disinfection. To establish possible alterations in mitochondrial bioenergetics, this study proposes to investigate the UV (at two distinct intervals) effects on isolated mitochondria from mice liver to obtain direct responses and selective permeability of the internal membrane information. UVA-371 and UVC-255 nm lamps were used to irradiate, at different doses varying from 22.5 to 756 mJ/cm2, isolated mitochondria samples. Mitochondrial respiration pathways were investigated by high-resolution respirometry, and possible mitochondrial membrane damages were evaluated by mitochondrial swelling by spectrophotometer analysis. UVC irradiation results (in the higher dose) indicate decrease in 75% of mitochondrial bioenergetics capacity, such as limitation of oxidative phosphorylation in 60% and increased energy dissipation in 30%. Mitochondrial swelling experiments (spectrophotometer) indicated inner membrane damage, and consequently a loss of selective permeability. Direct correlation between irradiation and effect responses was observed, mitochondrial bioenergetics is severely affected by UVC radiation, but (UVA) radiation did not present bioenergetic alterations. These alterations can contribute to improving the knowledge behind the cell death mechanism in disinfection UV light and UV therapy such as phototherapy.

Photoprotective Effects of Yeast Pulcherrimin.

Sunscreen products can protect the skin against the harmful effects of UV radiation, including reddening, aging, and cancer. The aim of this research was to evaluate the photoprotective effects of yeast pulcherrimin, an iron-chelating dipeptide. We first investigated the cytotoxicity of pulcherrimin produced by Metschnikowia pulcherrima yeast on the human keratinocyte HaCaT cell line, using the PrestoBlue assay. We assessed the ability of pulcherrimin to induce DNA repair after the exposure of HaCaT cells to oxidative stress. We also evaluated its protective activity against UVC radiation. The sun protective factor (SPF) was calculated using the Mansur equation. The UVA/UVB ratio values for pure pulcherrimin were evaluated using the Boots Star Rating system. The critical wavelength was determined by calculating the integrated optical density curve area. Based on the results, pulcherrimin shows strong cytoprotective effects through antioxidant and photoprotective activities on the HaCaT cell line. The calculated SPFs were 20 and 15 at pH = 7 and pH = 10, respectively. The critical wavelength above 370 nm and the UVA/UVB ratio R > 1 suggest that yeast pulcherrimin-a cyclic dipeptide containing iron-may be considered a promising photoprotective agent.

Vegetables Treated before Drying with Natural Antioxidants plus UV-C Improve Colour and Bioactive Compounds

The quality of minimally processed fruits and vegetables is essential for consumers’ health and effective marketing. This study investigates the effects of UV-C irradiation, applied alone and combined with various natural antioxidants, on the preservation of bioactive compounds and the colour of dehydrated fruits and vegetables. To achieve this, red peppers, yellow peppers, tomatoes, zucchini, eggplants, and melons were subjected to pre-treatments with natural antioxidants and UV-C before processing using low-temperature airflow (50 °C). The drying kinetics showed typical curves of hygroscopic materials, while the drying time was high due to the low temperature applied. The higher drying rate was found for eggplant, due to its porosity, thus allowing a faster moisture removal. The application of antioxidants and UV-C treatments effectively preserved the colour parameters L*, a*, and b*, while in the case of untreated dried vegetables, a significant worsening of colour parameters was noted. However, most applied pre-treatments had positive effects on bioactive compound losses. The best results were obtained using a combination of UV-C with one antioxidant mix that was composed of vanillin, rosemary, and citrus extracts, and combined with a mixture of olive, onion, garlic, and citric acid extracts, which was highly effective in preserving the colour and bioactive compounds of most dried vegetables.

The histone demethylase JMJ27 acts during the UV-induced modulation of H3K9me2 landscape and facilitates photodamage repair.

Plants have evolved sophisticated DNA repair mechanisms to cope with the deleterious effects of ultraviolet (UV)-induced DNA damage. Indeed, DNA repair pathways cooperate with epigenetic-related processes to efficiently maintain genome integrity. However, it remains to be deciphered how photodamages are recognized within different chromatin landscapes, especially in compacted genomic regions such as constitutive heterochromatin. Here we combined cytogenetics and epigenomics to identify that UV-C irradiation induces modulation of the main epigenetic mark found in constitutive heterochromatin, H3K9me2. We demonstrated that the histone demethylase, Jumonji27 (JMJ27), contributes to the UV-induced reduction of H3K9me2 content at chromocentres. In addition, we identified that JMJ27 forms a complex with the photodamage recognition factor, DNA Damage Binding protein 2 (DDB2), and that the fine-tuning of H3K9me2 contents orchestrates DDB2 dynamics on chromatin in response to UV-C exposure. Hence, this study uncovers the unexpected existence of an interplay between photodamage repair and H3K9me2 homeostasis.

Effect of UV-C Irradiation on Growth, Photosynthetic Pigments, and Lipid Profile of Chlorella sorokiniana.

Chlorella sorokiniana holds significant industrial relevance owing to its lipid profile. Consequently, the objective of this investigation was to enhance growth, lipid content, and photosynthetic pigment production through the application of UV-C irradiation. The growth parameters of microalgae demonstrated an increase in response to concentration. After 35days of incubation, cells exposed to UV-C for 8min produced the most biomass at 2.2g/l. Additionally, the chlorophyll content demonstrated a comparable pattern, with the highest concentrations of chlorophyll a (4.99mg/l), chlorophyll b (6.22mg/l), and total chlorophyll (11.21mg/l) observed in cells incubated for 35days and exposed to UV-C for 8min. The lipid profile, nevertheless, demonstrated minor fluctuations. Specifically, the relative abundance of frequently occurring lipid compounds was found to be greater in cells treated with UV-C compared to the control group, and the most significant increase was obtained in 15-day culture exposed to UV-C for 8min. However, after 35days of incubation, this abundance decreased in cells exposed to UV-C for more than 4min. Additionally, the observation of specific lipid compounds presented solely in cells obtained from algal cultures treated with UV-C was made. Consequently, drawing from the results obtained in the current investigation, it is possible to deduce that UV-C can be utilised to augment the overall development and yield of significant metabolites in microalgae. Furthermore, these microalgae can be converted into single-cell bioreactors to facilitate the production of lipids utilised in a variety of applications, a process that could be refined to cater to industrial demands.

Performance of tube-in-tube membrane microreactor in E2/EE2 degradation via UV/H2O2/TiO2 process

The tube-in-tube membrane microreactor is an advanced system designed for the continuous removal of contaminants of emerging concerns (CECs) from urban and industrial wastewater. Despite its high removal efficiency, critical questions remain regarding the impact of various operational parameter: (i) flow rate of contaminants, (ii) oxidant dosage, (iii) concentration of the H2O2 stock solution, and (iv) pH of the H2O2 stock solution. This study addresses these questions, with particular focus on the previously unexplored effects of H2O2 concentration and pH. We investigated the degradation of estrogens 17β-Estradiol (E2) and 17α-Ethinylestradiol (EE2) using a UV/H2O2/TiO2 process using a membrane tube-in-tube reactor assembled with an inner glass fiber microfiltration membrane, coated with the catalyst TiO2-P25, and an outer quartz tube. Synthetic contaminated solution [E2/EE2]inlet = 500μgL-1 was fed in the reactor annulus and the H2O2 stock solution with different pHs (2, 3, 4, 5, 6.8, 8) and concentrations ([H2O2]stock solution = 3000, 6000, 9000 and 12000mgL-1) was fed through the membrane pores (radial permeation) or injected upstream the reactor inlet with different dosages ([H2O2]inlet = 0, 5, 10, 15, 20mgL-1) by means of a syringe pump. Experiments were performed under UVC irradiation and dark conditions. The highest observed removal rate was, approximately, 2.9µM/min for both estrogens, achieved after 7min of reactor operation, highlighting the reactor’s potential for effective CEC degradation under optimized conditions.

Persistence luminescence and thermoluminescence of 260 nm UVC irradiated mixed-phase (BaAl2O4 - BaAl12O19) barium aluminate

Persistence luminescence (PerL) and thermoluminescence (TL) of BaAl2O4 - BaAl12O19 mixed phase compound under 260 nm UVC irradiation are studied. The sample shows PerL for more than 1 hour post irradiation. TL glow curves of the sample recorded at 1 oC/s following irradiation to UVC radiation shows a composite glow peak between 30 and 230 oC. The TL intensity is found to be affected by thermal quenching. The activation energy for thermal quenching is estimated to be W=0.85±0.12 eV. A Tm-Tstop analysis reveals that the TL glow peak is composed of multiple first order components. The activation energy associated with the electron traps are found to vary from 0.66 to 1.70 eV. The density of traps is high between 0.60 and 1.20 eV. Due to presence of continuous distribution of electron traps, there is an excellent scope of developing colour tuneable persistence luminescence phosphor using mixed phase barium aluminate.

Influence of Sulfur Addition on The Physical and Photocatalytic Properties Biosynthesized Se-doped ZnO Nanoparticles

Abstract The objective of this study was to investigate the influence of Sulfur (S) addition to selenium-doped zinc oxide (Se-ZnO) nanoparticles on their physical properties and photocatalytic activity. S,Se-ZnO sample was prepared by adding 1wt% sulfur onto 4%Se-ZnO nanoparticles. In the synthesis procedure, microwave irradiation was used as heating power and matoa leaf extract was used as a bioreductor. The nanoparticles were characterized using UV-Vis Spectroscopy, X-ray diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM). The calculated band gap energies of Se-ZnO and 1% S,Se-ZnO are 2.38 eV and 2.62 eV, respectively. Both samples exhibit a hexagonal wurtzite structure. FESEM image of addition S reveals flower petal flake formations and decrease particle size of 187 nm. The photocatalytic activity of nanoparticles was evaluated through 4-nitrophenol (4-NP) degradation under UV-C irradiation. 1% S,Se-ZnO exhibits high photocatalytic efficiency compared to Se-ZnO, with a degradation percentage of 85.09% after 60 min and a reaction rate of -0.0315 min−1. Based on these results, the addition of S on Se-ZnO biosynthesized shows improve physical properties and efficient photocatalytic materials for pollutant removal.

Can UVC radiation be useful in prolonging the shelf life of mangoes?

Can UVC radiation be useful in prolonging the shelf life of mangoes?

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

Design and Characterisation of a Low-Photon Flux UV-Radiance Standard for the Calibration of Radioluminescence Detection Systems

Abstract For the calibration of the radioluminescence detection systems developed within 19ENV02 RemoteALPHA EMPIR project, two purely optical radiation-based devices, which accurately simulate the radioluminescence induced in air nitrogen by an alpha-particle emitted from a planar radionuclide-based sample, were designed, manufactured, and characterized. The variable low-photon flux radiance sources are based on a combination of two integrating spheres and LEDs as UV-A and UV-C radiation sources. The calibrated maximum integrated photon radiances are 7.5·1011 s−1·m−2·sr−1 for the UV-A (CWL = 337 nm, FWHM = 10 nm) and 3.0·1010 s−1·m−2·sr−1 for the UV-C (CWL = 260 nm, FWHM = 20 nm) spectral range with relative standard uncertainties (k=1) from 5 % (UV-A) to 8 % (UV-C).

Enhancing Shelf-life and Quality of Tomatoes (Lycopersicum esculentum L.) Using UV-C Radiation and Natural Preservatives

AbThe influence of UV-C radiation and garlic extract on the shelf life and storage of tomatoes (Lycopersicum esculentum L. cv. Arka Rakshak) was investigated in this study. Fresh tomatoes were subjected to four treatments: control (untreated), UV-C (1.2 kJ/m²), garlic (10% w/v aqueous extract), and UV-C (1.2 kJ/m²) + garlic (10% w/v aqueous extract). The treated tomatoes were preserved at 4°C for 14 days, and their physical, chemical, and microbial properties were analyzed at 0, 3, 7, and 14 days. The combination of UV-C and garlic treatments lowered the loss of firmness, maintained color, and minimized weight loss. The UV-C treatment enhanced the initial lycopene and total phenolic content, while the combination treatment showed the best retention of these bioactive compounds during storage. The garlic treatment contributed to the antimicrobial activity, and the combination treatment significantly (p &lt; 0.05) reduced the total plate count and yeast and mold count compared to the control. Pathogenic bacteria were not detected in the samples throughout the storage period. The results demonstrate the potential of UV-C radiation and garlic extract as natural preservatives for improving the shelf life. The combination treatment can be an effective approach to reduce post-harvest losses and ensure the safety and nutritional value of the produce.stract

Finite element analysis of non-ultraviolet and ultraviolet-irradiated titanium implants.

The purpose of this study is to calculate von Mises stresses, von Mises strains, deformation, principal stresses and principal elastic strains of non-UV and UV-irradiated hybrid SLA (sandblasted, large-grit, acid-etched)-coated titanium implants. A cross-sectional analytical study was conducted at the Institute of Dentistry, CMH Lahore Medical College. Cone beam computed tomography (CBCT) data of One Hundred and Thirty Eight Dio Hybrid sandblasted and acid-etched implants of identical dimensions (10mm in length and 4.5mm in diameter) were allocated in the three groups. Control group A samples were not given UV irradiation, while groups B and C were given UVA (382nm, 25 mWcm-2) and UVC (260nm, 15 mWcm-2) irradiation, respectively. The CBCT data were analyzed using FEA (ANSYS software). CBCT images were taken before functional loading (8thweek) and after functional loading (26thweek). A 3-way ANOVA test was employed to see the difference between the three groups. Tukey test was utilized for multiple comparisons. p ≤ 0.05 was considered significant. The control group exhibited the highest average values for maximum von Mises stress, von Mises strain, deformation, principal stress, and principal elastic strain in both the maxilla and mandible compared to the UV-irradiated groups. Additionally, these measures consistently displayed higher averages in the maxilla across all groups compared to the mandible. Particularly, the UVC-irradiated group demonstrated the lowest von Mises stresses around the implants compared to the UVA group. Insignificant differences were observed between UVA- and UVC-irradiated implants in terms of principal stress, deformation, von Mises strain, and principal elastic strain. The only notable distinction was in von Mises stress, where the UVC-irradiated group exhibited lower von Mises stress around SLA-coated titanium implants.