Search Results (984)

Experimental and simulation analysis was conducted on the effects of 532 nm nanosecond laser-induced thermal damage on the front-side illuminated CMOS detector. The study examined CMOS detector output images at different stages of damage, including point damage, line damage, and complete failure, and correlated these with microscopic structural changes observed through optical and scanning electron microscopy. A finite element model was used to study the thermal–mechanical coupling effect during laser irradiation. The results indicated that at a laser energy density of 78.9 mJ/cm², localized melting occurs within photosensitive units in the epitaxial layer, manifesting as an irreversible white bright spot appearing in the detector output image (point damage). When the energy density is further increased to 241.9 mJ/cm², metal routings across multiple pixel units melt, resulting in horizontal and vertical black lines in the output image (line damage). Upon reaching 2005.4 mJ/cm², the entire sensor area failed to output any valid image due to thermal stress-induced delamination of the silicon dioxide insulation layer, with cracks propagating to the metal routing and epitaxial layers, ultimately causing structural deformation and device failure (complete failure). Full article

Hydrogen-rich water (HRW) has shown neuroprotective effects in acute brain injury, but its role in chronic radiation-induced brain injury (RIBI) remains unclear. This study investigated the long-term efficacy of HRW in mitigating cognitive impairment and neuronal damage caused by chronic RIBI. Fifty male Sprague Dawley rats were randomly divided into five groups: control, irradiation (IR), IR with memantine, IR with HRW, and IR with combined treatment. All but the control group received 20 Gy whole-brain X-ray irradiation, followed by daily interventions for 60 days. Behavioral assessments, histopathological analyses, oxidative stress measurements, ¹⁸F-FDG PET/CT imaging, transcriptomic sequencing, RT-qPCR, Western blot, and serum ELISA were performed. HRW significantly improved anxiety-like behavior, memory, and learning performance compared to the IR group. Histological results revealed that HRW reduced neuronal swelling, degeneration, and loss and enhanced dendritic spine density and neurogenesis. PET/CT imaging showed increased hippocampal glucose uptake in the IR group, which was alleviated by HRW treatment. Transcriptomic and molecular analyses indicated that HRW modulated key genes and proteins, including CD44, CD74, SPP1, and Wnt1, potentially through the MIF, Wnt, and SPP1 signaling pathways. Serum CD44 levels were also lower in treated rats, suggesting its potential as a biomarker for chronic RIBI. These findings demonstrate that HRW can alleviate chronic RIBI by preserving neuronal structure, reducing inflammation, and enhancing neuroplasticity, supporting its potential as a therapeutic strategy for radiation-induced cognitive impairment. Full article

Progress in establishing environmental risk factors and, consequently, prophylactic measures for glial tumors, particularly for glioblastomas, is of utmost importance, considering the dismal prognosis and limited treatment options. This report surveyed updates on established and recently identified factors that can predispose a patient to glioma formation while highlighting possible mechanistic links and further research directions. In addition to established factors that increase the risk of glioma, i.e., brain irradiation and several genetic syndromes, another group consists of likely factors contributing to such risks, such as the use of tobacco and those yielding ambiguous results (e.g., UV exposure). Oxidative stress is a common denominator for several types of exposure, and a mechanistic background for other factors remains elusive. Nevertheless, the analysis of clinical and basic research strongly suggests that, apart from the effect of environmental stressors on DNA alterations and mutation burden, the impact of modifying the tumor microenvironment should be considered. Identifying the involvement of environmental hazards in gliomagenesis and glial tumor progression would lower overall risk by modifying clinical practice, patient management, and lifestyle choices. Further verifying the environmental hazards in glioma formation and progression would have far-reaching implications for neurologists, neurosurgeons, and patients. Full article

Background: Clinical diagnostics, food industries, and biotechnological processes typically use an enzyme called alpha-amylase to metabolize carbohydrates. Objective: The aim of this study is to investigate how low-level laser irradiation (LLLI) affects alpha-amylase activity towards determining the usability of LLLI in non-invasive enzymatic modulation. Methods: Enzyme solutions were irradiated at 10, 20, 30, and 40 J/cm² utilizing 589 nm and 532 nm diode-pumped solid-state lasers. The iodine–starch colorimetric method was used to quantify post-irradiation enzymatic activity, with inverse correlations found between absorbance and activity levels. Modulation was determined by the wavelength and dosage. Results: Enzymatic activity significantly improved when utilizing 589 nm irradiation at lower doses, maximizing at 120% at 20 J/cm² (p < 0.01). Neutral or inhibitory effects were revealed when higher doses were applied. Enzymatic activity showed progressive inhibition when 532 nm irradiation was applied, declining to 75% at 40 J/cm² (p < 0.01). Conclusions: These outcomes indicate that conformational flexibility and catalytic efficiency occur when applying lower-energy photons at 589 nm, whilst oxidative stress and impaired enzymatic function are induced by higher-energy photons at 532 nm. This is consistent with the biphasic dose–response characteristic of photobiomodulation. Full article

Pain following orthodontic treatment is the chief complaint of patients undergoing this form of treatment. Although the use of diode lasers has been suggested for pain reduction, the mechanism of laser-induced analgesic effects remains unclear. Neuropeptides, such as substance P (SP) and calcitonin gene-related peptide (CGRP), contribute to the transmission and maintenance of inflammatory pain. Heat shock protein (HSP) 70 plays a protective role against various stresses, including orthodontic forces. This study aimed to examine the effects of diode laser irradiation on neuropeptides and HSP 70 expression in periodontal tissues induced by experimental tooth movement (ETM). For inducing ETM for 24 h, 50 g of orthodontic force was applied using a nickel–titanium closed-coil spring to the upper left first molar and the incisors of 20 male Sprague Dawley rats (7 weeks old). The right side without ETM treatment was considered the untreated control group. In 10 rats, diode laser irradiation was performed on the buccal and palatal sides of the first molar for 90 s with a total energy of 100.8 J/cm². A near-infrared (NIR) laser with a 808 nm wavelength, 7 W peak power, 560 W average power, and 20 ms pulse width was used for the experiment. We measured the number of facial groomings and vacuous chewing movements (VCMs) in the ETM and ETM + laser groups. Immunohistochemical staining of the periodontal tissue with SP, CGRP, and HSP 70 was performed. The number of facial grooming and VCM periods significantly decreased in the ETM + laser group compared to the ETM group. Moreover, the ETM + laser group demonstrated significant suppression of SP, CGRP, and HSP 70 expression. These results suggest that the diode laser demonstrated analgesic effects on ETM-induced pain by inhibiting SP and CGRP expression, and decreased HSP 70 expression shows alleviation of cell damage. Thus, although further validation is warranted for human applications, an NIR diode laser can be used for reducing pain and neuropeptide markers during orthodontic tooth movement. Full article

This article deals with the effect of Kr¹⁵⁺ ion irradiation on the structure and properties of partially stabilized zirconium dioxide (ZrO₂ + 3 mol. % Y₂O₃) ceramics. Ion irradiation is used to simulate radiation damage typical of operating conditions in nuclear reactors and space technology. It is shown that with an increase in the irradiation fluence, point defects are formed, dislocations accumulate, and the crystal lattice parameters change. At high fluences (>10¹³ ions/cm²), a phase transition of the monoclinic (m-ZrO₂) phase to the tetragonal (t-ZrO₂) and cubic (c-ZrO₂) modifications is observed, which is accompanied by a decrease in the crystallite size and an increase in internal stresses. Changes in the mechanical properties of the material were also observed: at moderate irradiation fluences, strengthening is observed due to the formation of dislocation structures, whereas at high fluences (>10¹⁴ ions/cm²), a decrease in strength and a potential amorphization of the structure begins. The change in the phase composition was confirmed by X-ray phase analysis and Raman spectroscopy. The results obtained allow a deeper understanding of the mechanisms of radiation-induced phase transformations in stabilized ZrO₂ and can be used in the development of ceramic materials with increased radiation resistance. Full article

Carbon dioxide (CO₂) emissions due to human activities are responsible for approximately 80% of the drivers of global warming, resulting in a 1.1 °C increase above pre-industrial temperatures. This study quantified the CO₂ assimilation and productivity of the brown macroalgae Lessonia spicata in the central Pacific coast of Chile, across seasonal and daily cycles, under different environmental stressors, such as temperature and solar irradiance. Measurements were performed using an infra-red gas analysis (IRGA) instrument which had a chamber allowing for precise quantification of CO₂ concentrations; additional photophysiological and biochemical responses were also measured. CO₂ assimilation, along with the productivity and biosynthesis of proteins and lipids, increased during the spring, coinciding with moderate temperatures (~14 °C) and high photosynthetically active radiation (PAR). Furthermore, the increased production of photoprotective and antioxidant compounds, including phenolic compounds, and carotenoids, along with the enhancement of non-photochemical quenching (NPQ), contribute to the effective photoacclimation strategies of L. spicata. Principal component analysis (PCA) revealed seasonal associations between productivity, reactive oxygen species (ROSs), and biochemical indicators, particularly during the spring and summer. These associations, further supported by Pearson correlation analyses, suggest a high but seasonally constrained photoacclimation capacity. In contrast, the reduced productivity and photoprotection observed in the summer suggest increased physiological vulnerability to heat and light stress. Overall, our findings position L. spicata as a promising nature-based solution for climate change mitigation. Full article

FeCrAl exhibits excellent resistance to high temperatures, corrosion, and irradiation, making it a prime candidate material for accident-tolerant fuel (ATF) cladding. This study investigates the high-temperature creep behavior of FeCrAl alloys with grain sizes of 12.0 μm and 9.9 μm under temperatures ranging from 450 °C to 650 °C and applied stresses between 75 and 200 MPa. The texture, grain morphology, grain orientation, and dislocation density of FeCrAl were characterized by electron backscatter diffraction (EBSD). The results indicate that temperature, applied stress, and grain size are the primary factors governing high-temperature creep behavior. The material texture showed no significant difference before and after creep. Large grains tend to engulf smaller ones during the creep process at lower temperatures and stresses, reducing the proportion of low-angle grain boundaries (LAGBs). In contrast, at higher temperatures or under higher stress, dislocations proliferate within grains, leading to a significant increase in the number of LAGBs. As the applied stress increases, the dominant creep mechanism tends to convert from grain boundary sliding to dislocation motion. Moreover, higher temperatures or smaller grain sizes lower the critical stress required to activate dislocation motion and significantly increase dislocation density, severely degrading the creep resistance. Full article

Elucidating the mechanisms of radioresistance in highly radiotolerant organisms can provide valuable insights into the adaptation and evolution of organisms. However, research has been limited on many naturally occurring radioresistant organisms due to a lack of information regarding their genetic and biochemical characteristics and the difficulty of handling them experimentally. To address this, we conducted an experiment on adaptive evolution using gamma radiation as the selection pressure to generate evolved Escherichia coli with gamma radiation resistance approximately one order of magnitude greater than that of wild-type E. coli. Gene expressions in all wild-type and evolved radioresistant E. coli in the presence or absence of gamma irradiation were analyzed and compared using RNA sequencing. Under steady-state conditions, the genes involved in survival, cell recovery, DNA repair, and response following stress exposure were upregulated in evolved E. coli compared with those in wild-type E. coli. Furthermore, the evolved E. coli induced these genes more efficiently following gamma irradiation and greater DNA repair activity than that in the wild-type E. coli. Our results indicate that an increased steady-state expression of various anti-stress genes, including DNA repair-related genes, and their highly efficient induction under irradiation are responsible for the remarkable radioresistance of evolved E. coli. Full article

This study developed phospholipid-based liposomes loaded with extract from wild thyme (Thymus serpyllum L.) tea processing residues to enhance polyphenol stability and delivery. Liposomes were prepared with phospholipids alone or combined with 10–30 mol% cholesterol or β-sitosterol. The effect of different lipid compositions on encapsulation efficiency (EE), particle size, polydispersity index (PDI), zeta potential, stability, thermal properties, diffusion coefficient, and diffusion resistance of the liposomes was investigated. Liposomes with 10 mol% sterols (either cholesterol or β-sitosterol) exhibited the highest EE of polyphenols, while increasing sterol content to 30 mol% resulted in decreased EE. Particle size and PDI increased with sterol content, while liposomes prepared without sterols showed the smallest vesicle size. Encapsulation of the extract led to smaller liposomal diameters and slight increases in PDI values. Zeta potential measurements revealed that sterol incorporation enhanced the surface charge and stability of liposomes, with β-sitosterol showing the most pronounced effect. Stability testing demonstrated minimal changes in size, PDI, and zeta potential during storage. UV irradiation and lyophilization processes did not cause significant polyphenol leakage, although lyophilization slightly increased particle size and PDI. Differential scanning calorimetry revealed that polyphenols and sterols modified the lipid membrane transitions, indicating interactions between extract components and the liposomal bilayer. FT-IR spectra confirmed successful integration of the extract into the liposomes, while UV exposure did not significantly alter the spectral features. Thiobarbituric acid reactive substances (TBARS) assay demonstrated the extract’s efficacy in mitigating lipid peroxidation under UV-induced oxidative stress. In contrast, liposomes enriched with sterols showed enhanced peroxidation. Polyphenol diffusion studies showed that encapsulation significantly delayed release, particularly in sterol-containing liposomes. Release assays in simulated gastric and intestinal fluids confirmed controlled, pH-dependent polyphenol delivery, with slightly better retention in β-sitosterol-enriched systems. These findings support the use of β-sitosterol- and cholesterol-enriched liposomes as stable carriers for polyphenolic compounds from wild thyme extract, as bioactive antioxidants, for food and nutraceutical applications. Full article

The laser damage resistance of optical films holds significant practical importance, as it largely determines both the maximum power output of laser systems and the overall stability of the entire optical assembly. A comprehensive investigation was conducted to examine the influence of both single additives—acetylacetone (ACAC) and diethanolamine (DEA)—and dual-additive systems, specifically ACAC combined with polyethylene glycol 200 (PEG 200) and DEA combined with PEG 200, on TiO₂ film properties and their laser-induced damage behavior under 1064 nm irradiation. It demonstrated that the films fabricated using ACAC exhibited smoother surfaces. Nevertheless, the sol prepared with DEA was more stable, resulting in films with superior optical properties and an enhanced laser-induced damage threshold (LIDT). The incorporation of dual additives further improved the films’ LIDT. Specifically, the film with DEA and PEG 200 achieved the highest LIDT, reaching 21.5 J/cm². Moreover, all films exhibited defect-induced damage, yet distinct damage morphologies were observed across different samples. The single-additive films predominantly displayed stress-type damage patterns, whereas the dual-additive films manifested melting-type damage characteristics. Furthermore, through a combination of experiments and calculations, it was revealed that the reasons why the film with DEA and PEG 200 achieved the highest LIDT were twofold: first, the high thermal conductivity of DEA reduced the maximum temperature at the defect center within the film; second, the long molecular chains of PEG 200 created a looser film structure that better mitigated damage caused by stress and expansion during laser irradiation. This study presents a promising approach to enhancing the LIDT through the strategic selection of additives with high thermal conductivity while simultaneously incorporating organic compounds with long molecular chains to develop effective dual-additive films. Full article

Ultraviolet B (UVB) irradiation drives skin photodamage, prompting exploration of natural therapeutics. This study investigated the reparative effects and mechanisms of crude Gastrodia elata polysaccharides (GP) on UVB-induced acute skin damage. GP was extracted from fresh G. elata via water extraction and alcohol precipitation. It is a homogeneous polysaccharide with a weight-average molecular weight of 808.863 kDa, comprising Ara, Glc, Fru, and GalA. Histopathological analysis revealed that topical application of GP on the dorsal skin of mice effectively restored normal physiological structure, suppressing epidermal hyperplasia and collagen degradation. Biochemical assays showed that GP significantly reduced the activities of MPO and MDA following UVB exposure while restoring the enzymatic activities of SOD and GSH, thereby mitigating oxidative stress. Moreover, GP treatment markedly upregulated the anti-inflammatory cytokines TGF-β and IL-10 and downregulated the pro-inflammatory mediators IL-6, IL-1β, and TNF-α, suggesting robust anti-inflammatory effects. Transcriptomics revealed dual-phase mechanisms: Early repair (day 5) involved GP-mediated suppression of hyper inflammation and accelerated necrotic tissue clearance via pathway network modulation. Late phase (day 18) featured enhanced anti-inflammatory, antioxidant, and tissue regeneration processes through energy-sufficient, low-inflammatory pathway networks. Through a synergistic response involving antioxidation, anti-inflammation, promotion of collagen synthesis, and acceleration of skin barrier repair, GP achieves comprehensive repair of UVB-induced acute skin damage. Our findings not only establish GP as a potent natural alternative to synthetic photoprotective agents but also reveal novel pathway network interactions governing polysaccharide-mediated skin regeneration. Full article

Plants are continuously exposed to multiple environmental stressors throughout their lifecycle. Understanding their integrated physiological, biochemical, and anatomical responses under combined stress conditions is crucial for developing effective approaches to improve stress tolerance and maintain crop productivity. This study aimed to investigate the physiological, biochemical, and anatomical changes in photomorphogenic Micro-Tom plants exposed to high irradiance and water deficit—an abiotic stress combination that commonly co-occurs in natural environments but remains poorly understood in light-sensitive genotypes. We hypothesized that the high pigment 1 (hp1) mutant, due to its enhanced light responsiveness, would display improved stress acclimation compared to the wild-type when exposed to combined stress factors. This study was conducted in a controlled plant growth chamber, using a randomized block design with five replicates. Two Micro-Tom genotypes (wt and hp1) were exposed to control (soil at field capacity (FC) + 450 μmol m⁻² s⁻¹ PPFD) and combined stress (40% FC + 1800 μmol m⁻² s⁻¹ PPFD) conditions. Despite the higher concentration of chloroplast pigments in hp1, its photosynthetic performance under combined stress was not significantly improved, and its defense mechanisms did not effectively mitigate the stress impacts. Anatomically, wt exhibited greater structural adjustment, observed by adaptations in the spongy parenchyma and mesophyll. Overall, the wt genotype showed stronger defense mechanisms, while hp1 was more susceptible to combined abiotic stress. Full article

Plant triterpenoids are structurally diverse specialized metabolites with significant ecological, medicinal, and agricultural importance. Oxidosqualene cyclases (OSCs) catalyze the crucial cyclization step in triterpenoid biosynthesis, generating the fundamental carbon skeletons that determine their structural diversity and biological functions. Genome-wide identification of OSC genes was performed using bioinformatics tools, including HMMER and BLASTP, followed by phylogenetic analysis, gene structure analysis, conserved domain and motifs identification, cis-regulatory element prediction, protein–protein interaction analysis, and expression profiling using publicly available transcriptome data from UV-B treated A. annua six-week-old seedlings. We identified 24 AaOSC genes, classified into CAS, LAS, LUS, and unknown subfamilies. Phylogenetic analysis revealed evolutionary relationships with OSCs from other plant species. Gene structure analysis showed variations in exon–intron organization. Promoter analysis identified cis-regulatory elements related to light responsiveness, plant growth and development, hormone signaling, and stress response. Expression profiling revealed differential expression patterns of AaOSC genes under UV-B irradiation. This genome-wide characterization provides insights into the evolution and functional diversification of the OSC gene family in A. annua. The identified AaOSC genes and their regulatory elements lay the foundation for future studies aimed at manipulating triterpenoid biosynthesis for medicinal and biotechnological applications, particularly focusing on enhancing stress tolerance and artemisinin production. Full article

The thermal stability of carbon fiber-reinforced plastic (CFRP) materials is constrained by the low thermal conductivity of its polymer matrix, resulting in inefficient heat dissipation, local overheating, and accelerated degradation during thermal loads. To overcome these limitations, composite materials can be modified with buckypapers—thin, densely interconnected layers of carbon nanotubes (CNTs). In this study, sixteen 8552/IM7 prepreg plies were processed with up to nine buckypapers and strategically placed at various positions. The resulting nanocomposites were evaluated for manufacturability, material properties, and thermal resistance. The findings reveal that prepreg plies provide only limited matrix material for buckypaper infiltration. Nonetheless, up to five buckypapers, corresponding to 8 wt.% CNTs, can be incorporated into the material without inducing matrix depletion defects. This integration significantly enhances the material’s thermal properties while maintaining its mechanical integrity. The nanotubes embedded in the matrix achieve an effective thermal conductivity of up to 7 W/(m·K) based on theoretical modeling. As a result, under one-sided thermal irradiation at 50 kW/m², thermo-induced damage and strength loss can be delayed by up to 20%. Therefore, thermal resistance is primarily determined by the nanotube concentration, whereas the arrangement of the buckypapers affects the material quality. Since this innovative approach enables the targeted integration of high particle fractions, it offers substantial potential for improving the safety and reliability of CFRP under thermal stress. Full article