Search Results (2,859)

The traditional method used in the production of inactivated vaccines is chemical inactivation using beta-propiolactone or formaldehyde. An alternative method is inactivation by irradiation. Virus inactivation is often accompanied by a change in particle shape, which can negatively affect the preservation of antigens and immunogenicity. Therefore, determining the shape and structure of the viral particle after inactivation is an important step in the development of antiviral vaccines. The poliovirus strain Sabin 2 was inactivated with a dose of 30.5 ± 0.5 kGy. in a pulsed linear electron accelerator with a power of 15 kW and electron energy of 10 MeV. Samples inactivated with beta-propiolactone or formaldehyde were used for comparison. All types of inactivation resulted in D-antigen recovery as determined by enzyme-linked immunosorbent assay. There was no statistical difference between D-antigen recovery in irradiated samples and those inactivated chemically. The shape and structure of the inactivated poliovirus particles were studied using atomic force and electron microscopy. After inactivation with beta-propiolactone or formaldehyde, a change in the native icosahedral shape was observed, with many particles appearing flattened. Specific sorption of antibodies showed that the antigen is mainly preserved in intact capsids for all type of inactivation. However, in the case of inactivation with formaldehyde and accelerated electrons, a significant number of fragments measuring 10–20 nm in height were present. Their proportion was 38 ± 2% and 17 ± 2% for inactivation with accelerated electrons and formaldehyde, respectively. The proportion of bound fragments during inactivation with beta-propiolactone was less than 1%. Full article

This study evaluated the effects of low-dose electron beam irradiation (0, 1, 2, and 3 kGy) on storage stability and quality properties of chicken and duck breast meat. Five foodborne pathogens (Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Escherichia coli) were inoculated into the samples and subjected to irradiation under vacuum packaging. The irradiated samples were vacuum-packed and stored at 4 °C. Microbial recovery, lipid and protein oxidation, physicochemical characteristics, and meat color were analyzed over 0, 1, and 2 weeks. A completely randomized design was used with five biological replicates (n = 5) per treatment, and each measurement was performed in triplicate (technical replicates). Electron beam treatment effectively reduced microbial counts, achieving complete inactivation of all pathogens except Bacillus cereus at 3 kGy. Irradiation resulted in significant reductions in pH and water-holding capacity (p < 0.05) while increasing thiobarbituric acid-reactive substances (TBARS) and volatile basic nitrogen (VBN) values, particularly in duck and chicken, respectively. Color parameters such as L* and b* decreased, while a*, chroma, and redness increased, with hue angle showing a decreasing trend. These changes were associated with myoglobin transformation and protein oxidation caused by irradiation-induced reactive oxygen species. Despite minor variations, proximate composition remained unaffected by irradiation. Overall, electron beam irradiation at doses up to 3 kGy effectively enhanced microbial safety without compromising nutritional quality, indicating its potential as a non-thermal preservation method for raw poultry meat products. Full article

The use of artificial oxygenation to counteract the effects of hypoxia and improve living standards in high-altitude, low-oxygen settings is widespread. A recognized consequence of this intervention is that it elevates the risk of fire occurrence. In this study, we simulated a real fire environment with low-pressure oxygen enrichment in a plateau area. A new multi-measuring apparatus was constructed by integrating an electronic control cone heater and a low-pressure oxygen enrichment combustion platform to enable the simultaneous measurement of multiple parameters. The combined effects of varying oxygen concentrations and thermal irradiance on the combustion behavior of wood plastic composites (WPCs) under specific low-pressure conditions were investigated, and alterations in crucial combustion parameters were examined and evaluated. Increasing the oxygen concentration and heat flux significantly reduced the ignition and combustion times. For instance, at 50 kW/m², the ignition time decreased from 75 s to 16 s as the oxygen concentration increased from 21% to 35%. This effect was suppressed by higher heat fluxes. Compared with low oxygen concentrations and low thermal radiation environments, the ignition time of the material under high oxygen concentrations and high thermal radiation conditions was shortened by more than 78%, indicating that its flammability is enhanced under extreme conditions. Higher oxygen concentrations enhanced the heat feedback to the fuel surface, which accelerated pyrolysis and yielded a more compact flame with reduced dimensions and a color transition from blue-yellow to bright yellow. This intensified combustion was further manifested by an increased mass loss rate (MLR), elevated flame temperature, and a decline in residual mass percentage. The combustion of WPCs displayed distinct stage characteristics, exhibiting “double peak” features in both the MLR and flame temperature, which were attributed to the staged pyrolysis of its wood fiber and plastic components. Full article

Variability across different calibration laboratories can impact the consistency of ocean color data; this study addresses that challenge through a coordinated comparison of spectral irradiance and radiance calibrations. As part of the Fiducial Reference Measurements for Satellite Ocean Color (FRM4SOC) Phase 2 project, the metrological consistency across six international laboratories was tested in the years 2022–2023. Each participant determined the responsivity for four transfer radiometers using their own SI-traceable radiometric standards and calibration procedures. This was among the first laboratory comparisons for Ocean Color Radiometry (OCR) using hyperspectral radiometers. The main objective was to verify that the instrument manufacturers and research laboratories can fulfill the updated International Ocean Color Coordination Group (IOCCG) protocols to perform SI traceable calibrations with an uncertainty of 1% (k = 1) for irradiance and slightly more for radiance. The comparison revealed biases among participants and provided an overview of the calibration capabilities of OCRs. The differences between the participants varied from ±1 … 2% up to ±5%. Biases due to different measurement conditions were corrected by the Pilot. Furthermore, biases due to traceability and different conditions revealed several data handling errors. However, after uniform data processing, the metrological compatibility between the participants was reached within ±3%. Full article

Background: FLASH radiotherapy delivers ultra-high dose rates with normal tissue sparing, but mechanisms remain unclear. We present a streamlined workflow for establishing a LINAC-based electron FLASH (eFLASH) platform in low-resource settings without requiring vendor-proprietary hardware or software, or vendor-assisted modifications to broaden accessibility for FLASH studies. Methods: A LINAC was converted to eFLASH with pulse control and monitoring. Automatic frequency control (AFC) was optimized to stabilize dose per pulse (DPP). Beam data were measured with EBT-XD films, and a Monte Carlo (MC) model was commissioned for in vivo dose calculation. We demonstrated in vivo dosimetry in planning studies of mouse whole-brain and rat spinal cord (C1–T2) irradiation. We further assessed the impact of AFC optimization on the FLASH spinal cord study. Results: AFC optimization stabilized DPP at ~0.6 Gy/pulse, reducing large fluctuations under the default setting. MC agreed with measurements within 2% for PDDs and profiles. MC planning showed uniform whole-brain irradiation with 6 MeV FLASH, while the spinal cord study exhibited up to 10% dose fall-off within 1 cm along the cord, suggesting potential dose-volume effects confounding FLASH sparing. Following AFC optimization, 50% of the C1–T2 cord reached >133 Gy/s, a 23% increase versus default. Conclusions: We demonstrated a cost-effective eFLASH platform and verified its accuracy for preclinical studies, expanding the accessibility of FLASH research. Full article

Enhancing TiO₂ performance is essential for advancing photocatalysis, environmental remediation, and energy conversion technologies. In this work, nanosized TiO₂ was modified with biochar (BC) derived from red sea algae at different loadings (0, 5, 10, and 15 wt%). Structural analysis confirmed that TiO₂ maintained its crystalline framework while biochar introduced additional amorphous features and modified surface morphology. Optical measurements revealed a redshift in the absorption edge and tunable bandgap values (3.28–3.72 eV), accompanied by increases in refractive index and extinction coefficient, indicating enhanced light–matter interactions. Electrochemical studies demonstrated that the TiO₂/5 wt% BC composite exhibited the lowest charge-transfer resistance and highest peak current, reflecting superior conductivity. Photocatalytic tests showed that TiO₂/5 wt% BC achieved nearly 84% degradation of methylene blue within 150 min under visible-light irradiation, with stable reusability over multiple cycles. These findings demonstrate that moderate biochar incorporation (5 wt%) optimally enhances the physicochemical, electrochemical, and photocatalytic properties of TiO₂, making it a promising candidate for wastewater treatment, solar-driven catalysis, and sustainable energy applications. Full article

The European industries are transitioning from natural gas usage to renewable gases to enhance climate neutrality and energy security—therefore, hydrogen and ammonia gases could be great alternatives to natural gas. Hydrogen can be produced via electrolysis powered by renewable energy or from natural gas with carbon capture. Moreover, ammonia, composed of hydrogen and nitrogen, could also act as an energy carrier and storage medium. This study investigates the combustion process and efficiency of the hydrogen-enriched NH₃ and CH₄ blends using nonthermal plasma assistance. The experiments were performed with a gas burner with a thermal power of 1.30 kW using fully premixed gas blends. The nonthermal plasma was created with a high-voltage and high-frequency generator at 120 kHz and 8.33 kV. Time-resolved chemiluminescence data for OH* and NH₂* were captured using an ICCD camera, an MIR emission spectrometer and a thermal irradiance flux meter. The results indicated that nonthermal plasma enhances the flame stability and increases the infrared radiation intensity. The MIR spectroscopy showed an intensity increase of 13% for ammonia-hydrogen blends under plasma assistance and heat flux measurements showed a 15% increase for the 70% ammonia and 20% hydrogen mixture. These results demonstrate that plasma-assisted combustion can enhance the efficiency and stability of low-carbon fuel blends, facilitating their integration into current infrastructure while reducing greenhouse gas emissions. Full article

This study describes the effect of electron radiation on the macro- and micro-mechanical and tribological properties of composite polypropylene filled with 25% glass fiber. Micro-mechanical and tribological properties were investigated both on the sample surface and at various depths below the surface. Polypropylene was irradiated with radiation doses of 15, 33, 45, 66 and 99 kGy. As the results show, electron radiation has an influence on the change in PP’s structure, in which due to the electron radiation, a crosslinked phase and an increase in crystallinity are formed. These changes in morphology are reflected in an enhancement of micro-mechanical and tribological properties both at the surface and in deeper layers below the surface. More crosslinking and recrystallization occur across the sample’s cross-section up to a depth of 2 mm, where greater micro-mechanical and tribological properties are also measured. The difference between the surface and the center of the material can be up to 32%. The optimum radiation dose appears to be 45 kGy, where the maximum crosslinking, highest crystallinity and best micro-mechanical and tribological properties are found. The difference between non-irradiated and irradiated filled PP is 52% in indentation hardness. In terms of macro-mechanical properties, the tensile modulus increased by 44% (45 kGy). This translates into higher surface wear resistance and the overall stiffness of the part. Higher doses of radiation cause the beginning of degradation processes, which are manifested by a decrease in the degree of embedding, crystallinity and thus micro-mechanical and tribological properties. Full article

Ultraviolet B (UVB) light exerts biological effects beyond the skin; however, its influence on systemic energy metabolism remains unclear. We investigated the effects of chronic, low-dose narrowband UVB irradiation on substrate utilization, circulating metabolites, and thermogenesis of brown adipose tissue (BAT) in mice. Male and female C57BL/6J mice were daily exposed to sub-erythemal UVB (308 nm, 50 or 100 mJ/cm², 3 h) for up to 7 weeks using a custom light-emitting diode-based device. Metabolic outcomes were assessed by indirect calorimetry, locomotor activity monitoring, and infrared thermography. Plasma metabolites were profiled by capillary electrophoresis–time-of-flight mass spectrometry. Gene expression in BAT and skin was measured by reverse transcription quantitative polymerase chain reaction. UVB exposure lowered the respiratory exchange ratio at specific time points, indicating greater lipid utilization, and transiently increased oxygen consumption. Metabolomic profiling revealed reduced succinate levels and enrichment of nicotinate/nicotinamide and propanoate metabolism pathways. Infrared thermography showed elevated surface temperature after irradiation and that prolonged UVB exposure modestly upregulated thermogenic genes in BAT, along with increased cutaneous expression of Cidea. These findings suggested that sub-erythemal UVB exposure modestly modulates systemic metabolism, circulating metabolites, and BAT activity, highlighting UVB as a potential environmental regulator of energy balance. Full article

This paper presents a reconfigurable switching circuit and control methodology for mitigating power losses in photovoltaic (PV) systems under partial shading. The proposed hardware uses a simplified network of power MOSFETs and diodes to enable dynamic reconfiguration between series and parallel connections, improving energy yield with minimal conduction losses. Unlike conventional approaches that require irradiance measurements or extensive sensing, the control algorithm uses only per-module voltage and a single-current measurement to detect shading events in real time. A novel switching strategy reduces the number of actively controlled transistors, simplifying the control circuitry and reducing power dissipation. Both simulation and experimental results validate the method. Simulations of a 4-module PV system showed maximum power point (MPP) increases from 900 W to over 1100 W and from 460 W to 900 W, with full recovery to 1500 W after shading removal. Experimental verification on a 3-module setup under controlled shading yielded similar improvements: MPP increased from 38.4 W to 45.6 W and from 38.4 W to 45.8 W. These results demonstrate rapid adaptability, effective mismatch loss reduction, and maximisation of available power, making the proposed design a practical and low-overhead solution for commercial PV systems with non-uniform irradiance. Full article

Energy-intensive sectors in emerging nations have the simultaneous difficulties of trying to diminish greenhouse gas emissions while maintaining a stable and cost-effective energy supply. Rooftop solar photovoltaic (PV) systems offer a viable solution, especially in tropical areas like Indonesia that have elevated solar irradiance. This study employs a comprehensive methodology to evaluate the structural, economic, and safety viability of rooftop photovoltaic adoption in the Fast-Moving Consumer Goods (FMCG) sector. Structural analysis utilizing the PMM Ratio verified that industrial rooftops can support a 599 kWp photovoltaic system with minimal reinforcements. The economic assessment revealed substantial feasibility, featuring a Levelized Cost of Energy (LCOE) of Rp 261.40/kWh (about USD 0.016/kWh), yearly savings of Rp 1.36 billion (approximately USD 89,000), a Return on Investment (ROI) of 570%, and a payback duration of 3.73 years. The safety evaluation utilizing the Hazard Identification and Risk evaluation (HIRA) technique found significant hazards—working at height, electrical faults, and fire risks—and recommended mitigation measures in accordance with IEC and Indonesian standards. The findings establish a replicable paradigm for assessing rooftop photovoltaic systems in energy-intensive sectors and furnish actionable recommendations for policymakers and industry executives to expedite the adoption of renewable energy in tropical emerging economies. Full article

Removing orthodontic brackets often presents clinical challenges, as it may cause patient discomfort, bracket fracture, or enamel damage resulting from strong adhesive bonds. Various techniques have been proposed to facilitate safer and more efficient debonding. Among them, laser-assisted methods have gained attention for their potential to minimize mechanical stress and improve patient comfort. The main objective of this study was to evaluate the effect of an erbium-doped yttrium–aluminum–garnet (Er:YAG) laser as an alternative to traditional mechanical methods for removing metal and ceramic orthodontic brackets. Materials and Methods: Thirty-six extracted premolars were prepared for bonding metal or ceramic brackets using a light-cure adhesive system. The control group consisted of six ceramic and six metal brackets removed with conventional orthodontic pliers. In the experimental groups, brackets were debonded using the Er:YAG laser (2940 nm, 0.6 mm spot size, 150 mJ; 15 Hz; (2.25 W) with an H14 handpiece. Irradiation time was recorded for each method, and teeth were rescanned to measure the surface area and volume of the crowns before and after bracket removal. Data were analyzed using one-way ANOVA and Tukey’s HSD test (p < 0.05). Scanning electron microscopy (SEM) was used for surface analysis. Results: A significant difference in debonding time (p = 0.001) was observed between the laser and traditional methods. The laser group took 52.5 s for metal and 56.25 s for ceramic brackets, compared to 1.05 s (metal) and 0.64 s (ceramic) in the traditional group. A significant difference in remaining cement volume was noted (p = 0.0002), but no differences were found between metal and ceramic brackets with laser removal. Conclusions: Er:YAG laser-assisted debonding is safe and minimally invasive but more time-consuming and costly than conventional methods, showing no improvement in clinical efficiency under current parameters. Full article

To optimize the design of silicon carbide (SiC) devices for applications in space and nuclear environments, this work introduces varying degrees of lattice damage into SiC through controlled irradiation conditions, with Raman spectroscopy revealing its damage evolution behavior and quantitatively characterizing the increasing trend of disorder with irradiation fluences. Fine analysis of the A₁(LO) phonon mode demonstrates that proliferation of irradiation-induced acceptor centers and accumulation of scattering defects lead to significant attenuation of carrier concentration and mobility (cross-verified by Hall effect measurements), thereby causing degradation in electrical conductivity of SiC. Subsequent electrical testing confirms an orders-of-magnitude reduction in conductivity, establishing a quantitative correlation model with total disorder quantified by the DI/DS model. The non-destructive Raman technique enables simultaneous acquisition of material damage characteristics and quantitative electrical performance degradation, providing a predictive framework for the evolution of electrical behavior for SiC under irradiation damage, with significant implications for optimizing irradiation-hardened device designs. Full article

Chinese shale reservoirs are typically deep, clay-rich, and highly water-sensitive, which severely limits the effectiveness of conventional hydraulic fracturing. To address this challenge, we propose a microwave-assisted waterless fracturing method and investigate its feasibility through laboratory experiments on core samples from the Gulong shale and tight sandstone formations in the Daqing Oilfield. A coupled model integrating microwave power dissipation, pore water heating, and thermal stress evolution is developed to interpret the underlying mechanisms. Experimental results show that, under microwave irradiation (200 W, 40 s) and initial pore water content of 2.1–6%, fracturing is successfully induced without external fluid injection. The tensile failure of the rock coincides with the peak internal pore pressure generated by rapid vaporization and thermal expansion of pore water, as confirmed by a modified tensile strength measurement method. Fracture patterns observed in SEM and post-treatment imaging align with model predictions, demonstrating that microwave energy absorption by pore water is the primary driver of rock failure. The technique eliminates water-related formation damage and is inherently suitable for deep, water-sensitive reservoirs. This study provides experimental evidence and mechanistic insight supporting microwave-based waterless fracturing as a viable approach for challenging shale formations. Full article

In systemic diseases, controlling oral bacteria and cancer is an important issue. As biomaterials, recently, carbon dots (DSs) are the focus of a variety of studies owing to their extensive applicability in life sciences. In this study, the effectiveness of carbon dots (CDs) for the elimination of both oral bacteria and oral cancer in vitro was assessed using a dental light-curing unit (LCU) as a light source. CDs were synthesized using an amino acid. The absorbance of CDs and the emission spectrum of the LCU were measured. The production of reactive oxygen species (ROS) was evaluated spectroscopically. Changes in glutathione (GSH) content were evaluated. Using oral bacteria and cancer cells, in vitro antibacterial and antitumor capabilities of CDs were evaluated under light irradiation. Confocal microscopy was used to observe live/dead cells and intracellular lipid peroxidation (LPO). The emission spectrum of the LCU fully matched the absorbance of CDs. After CD treatment, the initial peak absorbances of the p-nitrosodimethylaniline-imidazole (for singlet oxygen assay) and nitroblue tetrazolium (for superoxide oxide assay) solutions changed under light irradiation. The initial peak absorbance of the GSH assay solution decreased during and after light irradiation. Both CD-treated oral bacteria and oral cancer cells were near totally eliminated at 50 and 200 μg/mL concentrations, respectively, after light irradiation. In the live/dead cell and C11-BODIPY^581/591 dye assays, red and green fluorescent spots were, respectively, observed in the CD-treated and light-irradiated cells. Accordingly, CDs effectively eliminated both oral bacteria and cancer cells in vitro in conjunction with dental LCU with less damage to normal cells through ROS-induced or ROS-initiated GSH depletion-induced intracellular LPO. Dental LCU plays a crucial role in ROS production through CD photoexcitation. Dental LUC has the potential to be used as a light source in dentistry for the treatment of oral bacteria and cancer cells. Full article