Ultraviolet Irradiation Research Articles

Adsorption and detection of praseodymium ion by ion-imprinted polymer with ultra-low sensitivity.

A novel kind of carbon dot (CD) was prepared by one-step hydrothermal microwave assisted method using L-tryptophan and L-tartaric acid as raw materials. Monodisperse poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres were utilized as the matrix, with praseodymium (Pr) ion (Pr3+) as the template, methacrylic acid as the functional monomer, and 5-amino-8-hydroxyquinoline (5-AHQ) acts as the ligand. A composite microsphere of ion-imprinted polymer (IIP) and CD (noted CD@IIP) was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). For comparison, IIP without CD (Pr-IIP) and non-imprinted polymer (NIP) were also prepared. Through static adsorption experiments, it was determined that the saturated adsorption amount of CD@IIP is 47.19mgg-1, that of Pr-IIP is 54.49mgg-1, while that of NIP is only 24.32mgg-1. Dynamic adsorption experiments showed that the equilibrium of three kinds of materials wasreached within 30min. Particularly, CD@IIP could emit two fluorescence peaks at 325nm and 421nm under ultraviolet irradiation, and exhibited excellent selectivity and fluorescence quenching effect on Pr3+. The fluorescence response of Pr3+ in the range 0-400μmol L-1 was determined by ratiometric fluorescence method, offering a two-stage model and robust linear regression coefficient. These results demonstrated that CD@IIP exhibited selective adsorption ability for Pr3+, and a sensitive, rapid and simple method for detection of Pr3+ was successfully developed.

Synergistic Interactions among Vacuum, Solar Heating, and UV Irradiation Enhance the Lethality of Interplanetary Space

A Planetary Atmospheric Chamber (PAC) was used to create simulations of interplanetary conditions to test the spore survival of three Bacillus spp. exposed to interacting conditions of vacuum (VAC), simulated solar heating (HEAT), and simulated solar ultraviolet irradiation (UV). Synergism was observed among the experimental factors for all three Bacillus spp. tested that suggested the increased lethality of HEAT and UV when concomitantly exposed to VAC. The most aggressive biocidal effects were observed for assays with VAC + HEAT + UV conditions run simultaneously over short time-steps. The results were used to predict the accumulation of extremely rapid Sterility Assurance Levels (SALs; def., −12 logs of bioburden reduction) measured in a few minutes to a few hours for external surfaces of interplanetary spacecraft. Furthermore, the results were extrapolated to predict that approx. 1 × 104 SAL exposures might be accumulated for external surfaces on the Europa Clipper spacecraft during a 3.5-year transit time between Venus (0.7 AU) and Mars (1.5 AU) during a series of Venus–Earth–Earth gravity assists (VEEGA trajectory) to Jovian space. The results are applicable to external spacecraft surfaces exposed to direct solar heating and UV irradiation during transits though the inner solar system.

Hexagonal ZnTiO3 single-crystalline films on α-Al2O3 substrates: Structural and photoelectric properties

Hexagonal ZnTiO3 (h-ZnTiO3) films with stoichiometric were deposited on α-Al2O3 substrates using pulsed laser deposition (PLD) method and post annealing process. The effect of oxygen partial pressure on Zn/Ti atomic ratio, as well as the influence of annealing treatment on the structural and optical properties of the films were investigated in detail. The optimum h-ZnTiO3 film was deposited under 5 Pa oxygen partial pressure and annealed at 800°C, and it exhibited excellent crystalline quality and an optical band gap of 3.72 eV. A photodetector based on the film was fabricated, and its photoresponsivity was approximately 0.18 mA/W under 308 nm ultraviolet light irradiation. This demonstrates that as a wide bandgap semiconductor material, h-ZnTiO3 has potential applications in the field of devices.

Crosslinking of Ly6a metabolically reprograms CD8 T cells for cancer immunotherapy

T cell inhibitory mechanisms prevent autoimmune reactions, while cancer immunotherapy aims to remove these inhibitory signals. Chronic ultraviolet (UV) exposure attenuates autoimmunity through promotion of poorly understood immune-suppressive mechanisms. Here we show that mice with subcutaneous melanoma are not responsive to anti-PD1 immunotherapy following chronic UV irradiation, given prior to tumor injection, due to the suppression of T cell killing ability in skin-draining lymph nodes. Using mass cytometry and single-cell RNA-sequencing analyzes, we discover that skin-specific, UV-induced suppression of T-cells killing activity is mediated by upregulation of a Ly6ahigh T-cell subpopulation. Independently of the UV effect, Ly6ahigh T cells are induced by chronic type-1 interferon in the tumor microenvironment. Treatment with an anti-Ly6a antibody enhances the anti-tumoral cytotoxic activity of T cells and reprograms their mitochondrial metabolism via the Erk/cMyc axis. Treatment with an anti-Ly6a antibody inhibits tumor growth in mice resistant to anti-PD1 therapy. Applying our findings in humans could lead to an immunotherapy treatment for patients with resistance to existing treatments.

Investigation of the Nonradiative Photoprocesses of Unnatural DNA Base: 7-(2-Thienyl)-imidazo[4,5-b]pyridine (Ds)─A Computational Study.

7-(2-Thienyl)-imidazo[4,5-b]pyridine (Ds) is an unnatural nucleic acid that forms a stable pair with pyrrole-2-carbaldehyde (Pa) in DNA. This Ds-Pa pair gets stabilized via van der Waals interaction and shape fitting. In our previous study [Ghosh, P. J. Phys. Chem. A 2021, 125, 5556-5561], we investigated the nonradiative photoprocesses of the unnatural DNA base Pa, and also there are some studies on its stability and reactivity in the ground state. But, to consider it as a good unnatural base pair, one has to understand its stability not only in the ground state but also in the excited states after absorbing ultraviolet (UV) radiation. Therefore, in this study, the excited-state photoprocesses of Ds on UV irradiation and its nonradiative decay channels have been investigated using state-of-the-art multireference methods, and this investigation finally leads the molecule to access the minimum energy crossing point (MECP) via a downhill pathway.

A novel Zn(II) coordination polymer based on viologen: Photochromism, photocontrolled luminescence, ammonia vapor sensing, and luminescent sensing

A novel Zn(II) coordination polymer, {[Zn4(BTEC)3][(3-BCBPY)2]·5H2O}n (compound 1), was synthesized based on viologen ligand (3-BCBPY·2Cl = 1,1′-bis(3-cyanobenzyl)-4,4′-bipyridinium chloride), benzoic acid (H4BTEC = 1,2,4,5-benzenetetracarboxylic acid) and ZnCl2. Single crystal X-ray diffraction analysis revealed that the Zn(II) ions are bridged by BTEC4− anions, giving rise to a 3D structure, with the 3-BCBPY2+ cations occupying the pores within the channels of compound 1. This compound displays photoactivity, undergoing significant color transformations under ultraviolet light irradiation. Furthermore, to gain a deeper theoretical understanding of the color-changing behavior of compound 1, time-dependent density functional theory (TDDFT) was employed. Additionally, compound 1 demonstrates ammonia vapor sensing capabilities, along with intriguing light-modulated luminescence properties. Notably, it also exhibits significant sensing abilities for Fe3+ and Cr2O72− ions, even at low concentrations (10−5 M). This compound not only showcases its applications in the realms of photochromism, but also explores its potential in ammonia vapor detection and ion sensing.

Efficient control of antibiotic resistance in wastewater by UV/peracetic acid treatment: Unveiling distinct mechanisms behind the elimination of various contaminants

The abuse of antibiotics has led to an increase in contamination by antibiotics, antibiotic-resistant bacteria (ARB), and antibiotic resistance genes (ARGs) in the environment, especially in wastewater treatment plants, which are the main treatment sites for antibiotic contaminants. In this study, we demonstrated that the combined ultraviolet (UV)/peracetic acid (PAA) process effectively removes coexisting antibiotics, ARB, and ARGs simultaneously by removing 96 % of ampicillin (AMP, with an initial concentration of 10 μM) in 8 min and completely inactivating super-resistant Escherichia coli (E. coli) NDM-1 (i.e., achieving 7.44-log reduction) in just 3 min (PBS, pH=7.0). These bacteria did not proliferate during the 86-h bacterial regrowth test. The analysis of radical quenching and electron paramagnetic resonance revealed that reactive species, such as hydroxyl radicals (·OH) and carbon-centered organic radicals (R-C·), played dominant roles in AMP removal, whereas UV irradiation was crucial for ARB inactivation. Furthermore, the ARGs fragments were efficiently damaged, as demonstrated by gel electrophoresis analysis, leaving few intact sequences. This strategy effectively reduced the horizontal transfer frequency of ARGs. Subsequent evaluations of the stability and efficiency of UV/PAA for pollutant removal in real wastewater further affirmed the broad applicability of the UV/PAA process. This study revealed that UV/PAA system has the potential to alleviate the burden of antibiotic resistance and contribute to a better comprehension and application for novel technology to control antibiotic resistance spread.

Ultrasonic-Assisted Conversion of Micrometer-Sized BiI3 into BiOI Nanoflakes for Photocatalytic Applications

This work describes a novel method for converting bismuth triiodide (BiI3) microplates into bismuth oxyiodide (BiOI) nanoflakes under ultrasonic irradiation. To produce BiOI nanoflakes with a high yield and high purity, the conversion process was carefully adjusted. Rapid reaction kinetics and increased mass transfer are benefits of the ultrasonic-assisted approach that result in well-defined converted BiOI nanostructures with superior characteristics. The produced BiOI nanoflakes were examined utilizing a range of analytical methods, such as Transmission Electron Microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The progress in the ultrasonic conversion process with time was monitored through diffuse reflectance spectroscopy (DRS). The outcomes demonstrated the effective conversion of BiI3 microplates into crystalline, homogeneous, high-surface-area BiOI nanoflakes. Additionally, the degradation of organic dyes (methylene blue) under ultraviolet (UV) light irradiation was used to assess the photocatalytic efficacy of the produced BiOI nanoflakes. Because of their distinct morphology and electrical structure, the BiOI nanoflakes remarkably demonstrated remarkable photocatalytic activity, outperforming traditional photocatalysts. The ability of BiOI nanoflakes to effectively separate and utilize visible light photons makes them a viable option for environmental remediation applications. This work not only shows the promise of BiOI nanoflakes for sustainable photocatalytic applications but also demonstrates a simple and scalable approach to their manufacturing. The knowledge gathered from this work opens up new avenues for investigating ultrasonic-assisted techniques for creating sophisticated nanomaterials with customized characteristics for a range of technological uses.

Investigation of Persistent Photoconductivity of Gallium Nitride Semiconductor and Differentiation of Primary Neural Stem Cells.

A gallium nitride (GaN) semiconductor is one of the most promising materials integrated into biomedical devices to play the roles of connecting, monitoring, and manipulating the activity of biological components, due to its excellent photoelectric properties, chemical stability, and biocompatibility. In this work, it was found that the photogenerated free charge carriers of the GaN substrate, as an exogenous stimulus, served to promote neural stem cells (NSCs) to differentiate into neurons. This was observed through the systematic investigation of the effect of the persistent photoconductivity (PPC) of GaN on the differentiation of primary NSCs from the embryonic rat cerebral cortex. NSCs were directly cultured on the GaN surface with and without ultraviolet (UV) irradiation, with a control sample consisting of tissue culture polystyrene (TCPS) in the presence of fetal bovine serum (FBS) medium. Through optical microscopy, the morphology showed a greater number of neurons with the branching structures of axons and dendrites on GaN with UV irradiation. The immunocytochemical results demonstrated that GaN with UV irradiation could promote the NSCs to differentiate into neurons. Western blot analysis showed that GaN with UV irradiation significantly upregulated the expression of two neuron-related markers, βIII-tubulin (Tuj-1) and microtubule-associated protein 2 (MAP-2), suggesting that neurite formation and the proliferation of NSCs during differentiation were enhanced by GaN with UV irradiation. Finally, the results of the Kelvin probe force microscope (KPFM) experiments showed that the NSCs cultured on GaN with UV irradiation displayed about 50 mV higher potential than those cultured on GaN without irradiation. The increase in cell membrane potential may have been due to the larger number of photogenerated free charges on the GaN surface with UV irradiation. These results could benefit topical research and the application of GaN as a biomedical material integrated into neural interface systems or other bioelectronic devices.

Towards adjustable tri-response thermochromic fluorescent materials for information encryption via SO2CF3 terminal bis-tolane luminescent liquid crystals

A series of novel bis-tolane luminescence liquid crystals (LLCs) with SO2CF3 as terminal were first time achieved. These SO2CF3-based LLCs act as thermally responsive emission sources combined with a series of thermosensitive long-chain carboxylic acids with self-crystallization properties to obtain adjustable tri-response thermochromic fluorescent materials (TFMs). Notably, TFMs of (CH3)2N-2F-SO2CF3 exhibit excellent temperature sensitivity and tri-response thermochromic fluorescent character, which display outstanding thermochromic properties from 45 °C to 165 °C. These TFMs displayed an intuitively evident orange under ultraviolet (UV) irradiation then changed to orange-yellow color after adding long-chain carboxylic acids. Notably, it changed to yellow-green when heated to the long-chain carboxylic acids melting point of these phase change materials, further emitting a blue color at the mesophases transition when increasing temperature at 165 °C of (CH3)2N-2F-SO2CF3. Interestingly, the various thermochromic abilities and stimuli-responsive fluorescence of these TFMs could be regulated by substituents of LLCs and long-chain carboxylic acids. Therefore, such tri-response and high-contrasted thermochromic fluorescent character of TFMs are different from previous reports which promise candidates for information encryption.

Langerhans cells orchestrate apoptosis of DNA-damaged keratinocytes upon high-dose UVB skin exposure.

Ultraviolet (UV) irradiation of the skin causes mutations that can promote the development of melanoma and nonmelanoma skin cancer. High-dose UVB exposure triggers a vigorous skin reaction characterized by inflammation resulting in acute sunburn. This response includes the formation of sunburn cells and keratinocytes (KC) undergoing programmed cell death (apoptosis) when repair mechanisms of DNA damage are inadequate. The primary objective of this research was to clarify the involvement of Langerhans cells (LC) in the development of acute sunburn following intense UVB skin irradiation. To address this, we subjected the dorsal skin of mice to a single high-dose UVB exposure and analyzed the immediate immune response occurring within the skin tissue. Acute sunburn triggered an activation of LC, coinciding with a rapid influx of neutrophils that produced TNF-α. Furthermore, our investigation unveiled a marked increase in DNA-damaged KC and the subsequent induction of apoptosis in these cells. Importantly, we demonstrate a crucial link between the inflammatory cascade, the initiation of apoptosis in DNA-damaged KC, and the presence of LC in the skin. LC were observed to modulate the chemokine response in the skin following exposure to UVB, thereby affecting the trafficking of neutrophils. Skin lacking LC revealed diminished inflammation, contained fewer TNF-α-producing neutrophils, and due to the prevention of apoptosis induction, a lingering population of DNA-damaged KC, presumably carrying the risk of enduring genomic alterations. In summary, our results underscore the pivotal role of LC in preserving the homeostasis of UVB-irradiated skin. These findings contribute to a deeper understanding of the intricate mechanisms underlying acute sunburn responses and their implications for UV-induced skin cancer.

Curcumin-Loaded Liposomes in Gel Protect the Skin of Mice against Oxidative Stress from Photodamage Induced by UV Irradiation.

Prolonged exposure to ultraviolet (UV) irradiation can cause oxidative stress in the skin, accompanied by rapid immunosuppressive effects, resulting in a peroxidation reaction throughout the body. Curcumin (Cur), as the bioactive compound of turmeric, is a natural polyphenol with potent antioxidant properties but is often overlooked due to its poor solubility and low bioavailability. In this study, curcumin-loaded liposomes in a sodium alginate gel complex preparation were designed to improve the bioavailability of curcumin and to study its preventive effect on photodamage. Cur-loaded liposomes (Cur-L), Cur-loaded gel (Cur-G) based on an alginate matrix, and curcumin-loaded liposomes in gel (Cur-LG) were prepared, and their antioxidant effects and drug diffusion abilities were evaluated. The antioxidant capacity of Cur, Cur-L, Cur-G, and Cur-LG was also studied in a mouse model of photodamage. Cur had the highest antioxidant activity at about 4 mg/mL. Cur-LG at this concentration showed antioxidant effects during 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH) and H2O2 experiments. During the UV light damage test, Cur-LG demonstrated the ability to effectively neutralize free radicals generated as a result of lipid peroxidation in the skin, serum, and liver, thereby enhancing the overall activity of superoxide dismutase (SOD). In conclusion, using Cur-LG may protect against epidermal and cellular abnormalities induced by UV irradiation.

Three birds with one stone: ZIF-8@g-C3N4 nanosheets simultaneously enhance barrier property, active protection and UV aging resistance of epoxy coatings

In order to address the challenge of the epoxy coating’s limited ability to mitigate electrochemical reactions following metal corrosion as well as its susceptibility to degradation and aging under ultraviolet irradiation, ZIF-8 (ZIF=Zeolitic Imidazolate Framework) was modified on the surface of Graphite-like carbon nitride (g-C3N4) nanosheets by in-situ loading method to construct ZIF-8@g-C3N4 (ZCN) smart nanoparticles which exhibited an acidic pH response with releasing Zn2+ cations and imidazole molecules to achieve an 87.2 % corrosion inhibition efficiency on carbon steel within 5 h. Modified by ZCN, epoxy coating (ZCN/EP) retained high barrier property even after a 40-day immersion in a 3.5 wt% NaCl solution. Meanwhile, ZCN responded to pH changes from localized corrosion, releasing inhibitors and forming zinc oxide/zinc hydroxide and Fe-Im chelate to further impede corrosion progression. Furthermore, combining the ability to absorb and reflect/scatter UV radiation, ZCN provided excellent UV resistance for ZCN/EP coatings to maintain exceptional anti-corrosion after 300 h of UV exposure, as well as good surface characteristics and thermal–mechanical properties. This work provides a novel concept for developing long-lasting coatings with multifunctionality.

Modelling of radiation and flow fields in in-duct ultraviolet germicidal irradiation systems with and without ribs

In-duct ultraviolet germicidal irradiation systems (ID-UVs) is a promising technology for the development of biosecure buildings. This study explored the Computational Fluid Dynamics (CFD) method for accurately predicting the inactivation efficiency of ID-UVs. The results showed that the setting of ‘Divisions’ is crucial to the accuracy of radiation field modelling, and 15 × 15 was considered to be a reasonable value in this study. In addition, residence time and deposition ratio are two crucial parameters determining the average UV dose (AD) received by microbial particles, thereby influencing the inactivation efficiency. For ID-UVs without ribs, the Renormalization Group (RNG) [Formula: see text] model largely overestimated these two parameters, while the Reynolds Stress Model (RSM) with correcting fluctuation velocity improved the predictive accuracy of AD by 10.0%. For ID-UVs with ribs, the RNG [Formula: see text] model overestimated the eddy size and AD by 28.6% and 12.0%, respectively. The RSM model provided results closer to the Large Eddy Simulation. Adding 0.10 H (H: duct height) ribs increased the inactivation efficiency for MS2 Bacteriophage by 19.0%–64.3%, with an additional pressure drop of only 3.3 Pa. These findings contributed to a reliable CFD framework and provided novel ideas for improving inactivation efficiency.

Dual-State Red-Emitting Zinc-Based MOF Accompanied by Dual-Mode and Dual-State Detection: Color Tonality Visual Mode for the Detection of Tetracycline.

Red-emitting metal-organic frameworks (MOFs) are still mostly based on the use of lanthanides or functionalization with red fluorophores. However, production of transition-metal-based MOFs with red-emitting is scarce. This work reports on the synthesis of a novel dual-state red-emitting Zn-based MOF (denoted as UoZ-7) with the capability to detect target molecules in dual state, in solution, and as solid on paper. UoZ-7 gives strong red emission when excited in the solution and in the solid state with 365 nm ultraviolet (UV) lamp irradiation. Coordination-induced emission is the mechanism for the red emission enhancement in the MOF as a restriction of intramolecular rotation occurred to the ligand within the framework structure. UoZ-7 was successfully used for tetracycline (TC) using dual-mode detection, fluorescence-based ratiometry, and color tonality, in the dual state, in solution, and on the paper. TC molecules adsorb on the red-emitting UoZ-7 surface, and a yellow-greenish color emerges due to aggregation-induced emission between TC and UoZ-7. Concurrently, the inner filter effect diminishes the red emission of UoZ-7. The dual-mode or dual-state detection platform provides a simple and reliable fast method for the detection of TC on-site in various environmental and biomedical applications. Moreover, red-emitting UoZ-7 will have further luminescence-based biomedical applications.

Plastic film from the source of anaerobic digestion: Surface degradation, biofilm and UV response characteristics

This study simulates a major environmental scenario involving “organic fertilizer source” plastics, by exploring the key factors influencing the changes in plastic-films during anaerobic digestion (AD), as well as the responses of the anaerobically digested plastics to ultraviolet (UV) radiation exposure. The results demonstrate that the degradation effect of AD on plastics is reflected by their yellowish and ruptured appearance, slightly worn surfaces, hardening and opacity, and fragmentation. AD significantly increases the content of oxygen-containing functional groups and the degree of unsaturation in plastic films, with thermophilic temperature processes proving more effective than those conducted at mesophilic temperatures. Exposure to UV light has been found to amplify the degradative effects, suggesting the potential cumulative impact of AD and UV. Both AD and UV irradiation reduced the hydrophilicity of plastics. In particular, the hydrophobicity of polylactic acid films was completely disrupted under overlay-exposure. Furthermore, microbial populations on plastic surfaces were mainly bacterial. These bacterial populations were primarily influenced by temperature, and moderately by the plastic types. In contrast, archaea were predominantly affected by both temperature and digested substrate. This study offers a theoretical foundation for strategies aimed at preventing and controlling plastic pollution derived from organic fertilizers.

Applications of robot-assisted UV disinfection in dentistry.

Maintaining a microbial-free environment in healthcare facilities is more widely recognized as an essential component of therapies to minimize transmission of viruses associated with healthcare sector. The global spread of COVID-19 and recent outbreaks have presented humanity with previously unheard-of challenges. The development of autonomous disinfection robots seems to be necessary given the urgent need for constant sterilization in the face of a labor shortage. Due to their automated and perceived cost advantages by eliminating cleaning staff, these robots are being advertised more and more as an easy solution to immediately disinfect rooms and operating areas. The use of these services lowers the danger of infection, and expense of traditional cleaning and, most significantly, builds trust and security in medical facilities. Currently, routine (manual) cleaning is not replaced by disinfection robots; rather, they may support it. Additional hospital and device design alterations are necessary to address the overshadowing (visibility) issue allowing Ultraviolet disinfectant (UV-D) robots move freely in the medical environment. More technical developments and clinical studies in a variety of hospitals are needed to overcome the current challenges and find ways to integrate this unique technology into hospitals now and in the future. Thus, we present a review that includes detailing all elements required for it to function, as well as both its advantages and disadvantages. To the best of our knowledge, very limited studies have collected an in- depth data on the sterilization effect using a disinfection robot in the field of dentistry. We believe that this data will work as a foundation in more advanced uses at diverse sites that require disinfection and will highlight unsolved challenges and potential research avenues for UV robot operational concerns in dental hospitals. The goal of this work is to offer a comprehensive manual for UV-D robots covering pertinent information on traditional Ultraviolet germicidal irradiation (UVGI) system along with advancements in UV-D robots and thereby focusing on in-depth application in medical and dental facilities.

Effect of gamma and ultraviolet irradiation on the optical properties of copper oxide nanostructured thin films by chemical spray pyrolysis

Nanostructured copper oxide thin films were grown by the chemical spray pyrolysis (CSP) technique. Utilizing a homemade spray pyrolysis method, thin films are created. This work investigates the role of gamma ray and ultraviolet ray irradiation on the optical properties of copper oxide thin films(CuO) prepared. In this framework, used different substrate temperatures 300 °C, 350 °C, and 400 °C for the layers were grown on glass for the prepared CuO thin films. UV–visible spectrometer, field emission scanning electron microscopy (FE-SEM) and X-ray diffraction patterns(XRD) measurements were all used to characterize the samples. The UV–visible spectroscopy showed a decrease in the absorbance and the optical band gap of CuO thin films with the increase in the higher substrate temperatures before irradiation. Additionally, surface plasmon resonance peaks (λSPR) were observed at 329 nm. FE-SEM images revealed spherical-like shapes with an average diameter range of 48 nm,56 nm and 62 nm for 300 °C, 350 °C, and 400 °C, respectively. An analysis of X-rays revealed that CuO thin films contained the crystallographic planes of a monoclinic and an orthorhombic crystal system. Also, when samples were exposed to gamma and UVC radiation, the absorbance intensity of CuO thin films increased, but the optical band gap decreased.

Effect of Silica Nanoparticle Treatment on Adhesion between Tissue-like Substrates and In Vivo Skin Wound Sealing.

Silica nanoparticles are innovative solutions of surgical glue that can readily adhere to various tissue-like substrates without the need for time-consuming chemical reactions or ultraviolet irradiation. Herein, 10 nm-sized silica nanoparticle (SiNP10) treatment exhibited maximum adhesion strength in the porcine heart tissue model, which was approximately 7.15 times higher than that of the control group of non-treatment. We assessed the effects of silica nanoparticle treatment on in vivo skin wounds by scoring tissue adhesion and inflammation using histological images. Compared to the commercial cyanoacrylate skin adhesive (Dermabond), suppression of inflammatory cytokine levels in the incision wound skin was observed. We further quantified the expression of angiogenic growth factors and connective tissue formation-related proteins. On day 5 after wound closing treatment, the expression levels of PDGF-BB growth factor were significantly higher in SiNP10 treatment (0.64 ± 0.03) compared to Dermabond (0.07 ± 0.05). This stimulated angiogenesis and connective tissue formation in the skin of the incision wound may be associated with the promoting effects of SiNP10 treatment on wound closure and tissue adhesion.

Shedding the Light on Powdery Mildew: The Use of Optical Irradiation in Management of the Disease.

Ultraviolet (UV) irradiation below 300 nm may control powdery mildew in numerous crops. Depending on disease pressure, wavelength, and crop growth stage, one to three applications of 100-200 J/m2 per week at night are as effective or better than the best fungicides. Higher doses may harm the plants and reduce yields. Although red light alone or in combination with UV has a suppressive effect on powdery mildew, concomitant or subsequent exposure to blue light or UV-A strongly reduces the efficacy of UV treatments. To be effective, direct exposure of the pathogen/infection sites to UV/red light is important, but there are clear indications for the involvement of induced resistance in the host. Other pathogens and pests are susceptible to UV, but the effective dose may be phytotoxic. Although there are certain limitations, this technology is gradually becoming more used in both protected and open-field commercial production systems.