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The investigation results of magnetization, dynamic magnetic susceptibility and microstructure of samples of second generation high-temperature superconducting wires irradiated by Bi ions at room temperature with energy of 670 MeV and fluences of 1011 and 1012 cm–2 are presented. The dependences of the superconducting transition temperature and critical current density on the fluence have been determined. For the sample irradiated to fluence 1011 cm–2, an increase in the critical current density is observed compared to the control nonirradiated sample. The microstructure analysis of irradiated samples demonstrates the presence of amorphous tracks, which can act as effective pinning centers. [ABSTRACT FROM AUTHOR]

Copyright of Eurasian Physical Technical Journal is the property of E.A. Buketov Karaganda University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The electrical conductivity of GMZ grade graphite irradiated by fast neutrons with fluence of 2.22*1019 n/cm² in the temperature range of 298e448 K was studied. It is shown that the more neutrons fluence, than the more the electrical conductivity of the material decreases. [ABSTRACT FROM AUTHOR]

The shelf life of green chillies is very low due to high-water activity (aw = 0.90 ± 0.01). Balancing aw and moisture content is crucial for maintaining freshness, quality and extending shelf life of green chillies. To attain microbial and biochemical stability, the aw should be reduced to 0.6 and 0.3, respectively. Hence, a controlled drying process was introduced. The 0.6 aw (62 ℃/360 min + 35 ℃/60 min) and 0.3 aw (75 ℃/600 min + 40 ℃/240 min) green chillies improved bioactives retention, colour and texture; but could not completely prevent the growth of microorganisms. Therefore, post-drying, a decontamination process i.e., pulsed light (PL) treatment of 0.53 to 2.59 Jcm−2 (1.7–2.1 kV/120–360 s) was employed. Along with microbial decontamination and enzyme inactivation, PL preserved better physicochemical characteristics in 0.6 and 0.3 aw than 0.9 (fresh) green chillies. While, there is 89.8%, 89.0%, 88.8%, and 93.3% retention of phenolics, antioxidants, flavonoids, and capsaicinoids, respectively, in 0.3 aw green chillies at PL fluence of 2.59 J cm−2 fluence. Alongside, ascorbic acid, carotenoids, and chlorophyll showed 30%, 19%, and 26% loss, respectively, in 0.6 aw green chillies at 2.59 J cm−2. Drying followed by PL treatment ensured that the green chillies were safe for consumption, and met regulatory standards while maintaining their quality attributes. Therefore, integrated approach combining drying followed by PL decontamination would be the suitable method for preserving the quality of the green chillies. [ABSTRACT FROM AUTHOR]

Background: The long-term safety and efficacy of repeated applications of subliminal transscleral cyclophotocoagulation (SL-TSCPC) with a focus on cumulative energy was evaluated in glaucoma patients. Methods: In this retrospective, multicentric study the data of a total of 82 eyes with various causes of glaucoma that were treated with a single or multiple applications of SL-TSCPC were collected. Treatments were performed under general or local anesthesia with an 810 nm diode laser. Power was 2000 mW; duty cycle, 31.3%; total treatment duration, 80–320 s; equaling a total energy of 50–200 J per treatment session. Fifty-five eyes (55 patients) presented for all follow-ups, and these eyes were selected for further statistical analysis. The mean age was 60.0 ± 17.1 years, and 22 (40%) of the patients were female. Intraocular pressure (IOP) and dependence on further glaucoma medication were evaluated at 12 months following the initial treatment. Results: Eyes underwent 1 or 2 consecutive SL-TSCPC treatments. Median (min–max) baseline IOP of 34 (13–69) decreased to 21.5 (7–61), 22 (8–68), 20 (9–68), and 19.5 (3–60) mmHg at the 1, 3, 6, and 12-month postoperative timepoints respectively. The mean (± SD) IOP decrease at 12 months was 26 ± 27%, 39 ± 32%, and 49 ± 33% in the low (below 120 J, n = 18), medium (120–200 J, n = 24), and high (above 200 J, n = 13) cumulative energy groups respectively. At the 12-month timepoint, oral carbonic anhydrase use was discontinued in ¾ of the cases. Conclusions: It was found that the repeated application of SL-TSCPC safely and efficiently decreases IOP in a Caucasian population with heterogenous causes of glaucoma, eyes with silicone oil responded to a greater extent. Inclusion of cumulative energy scales may contribute to better addressing repeated procedures in a standardized fashion. [ABSTRACT FROM AUTHOR]

The wettability of polymers is usually inadequate to ensure the appropriate spreading of polar liquids and thus enable the required adhesion of coatings. A standard ecologically benign method for increasing the polymer wettability is a brief treatment with a non-equilibrium plasma rich in reactive oxygen species and predominantly neutral oxygen atoms in the ground electronic state. The evolution of the surface wettability of selected aromatic polymers was investigated by water droplet contact angles deposited immediately after exposing polymer samples to fluxes of oxygen atoms between 3 × 1020 and 1 × 1023 m−2s−1. The treatment time varied between 0.01 and 1000 s. The wettability evolution versus the O-atom fluence for all aromatic polymers followed similar behavior regardless of the flux of O atoms or the type of polymer. In the range of fluences between approximately 5 × 1020 and 5 × 1023 m−2, the water contact angle decreased exponentially with increasing fluence and dropped to 1/e of the initial value after receiving the fluence close to 5 × 1022 m−2. [ABSTRACT FROM AUTHOR]

Cutlery and flatware designs are an everchanging phenomenon of the manufacturing industry. Worldwide hospitality businesses demand perpetual evolution in terms of aesthetics, designs, patterns, colours, and materials due to customers' demands, modernisation, and fierce competition. To thrive in this competitive market, modern fabrication techniques must be flexible, adoptive, fast, and cost effective. For decades, static designs and trademark patterns were achieved through moulds, limiting production to a single cutlery type per mould. However, with the advent of laser engraving and design systems, the whole business of cutlery production has been revolutionised. This study explores the possibility of creating diverse designs for stainless steel 304 flatware sets without changing the entire production process. The research analyses three key laser process parameters, power, scanning speed, and number of passes, and their impacts on the resulting geometry, depth of cut, surface roughness, and material removed. These parameters are comprehensively studied and analysed for steel and zirconia ceramic. The study details the effects of power, scanning speed, number of passages, and fluence on engraved geometry. Fluence (power*number of passages/scanning speed) positively influences outputs and presents a positive trend. Medium power settings and higher scanning speeds with the maximum number of passages produce high-quality, low-roughness optimised cavities with the ideal geometric accuracy for both materials. [ABSTRACT FROM AUTHOR]

This study investigated the impact of pulsed light (PL) applied at a fluence of 4–12 J cm−2 (complying with U.S. Food and Drug Administration standards) on fresh‐cut watermelon, focusing on its efficacy in inactivating various food‐borne pathogenic gram‐positive (Escherichia coli and Staphylococcus aureus) and gram‐negative (Listeria monocytogenes and Salmonella) bacteria. The inactivation data were used to fit the log‐linear and Weibull kinetic models. Additionally, the impact of PL on physicochemical properties, lycopene content, total phenolic content, antioxidant activity, and pectin methylesterase (PME) residual activity (RA) was studied. The results demonstrated that the inactivation rate increases with the increase in fluence. Salmonella was most sensitive to PL, resulting in a reduction of 2.55 ± 0.08 log CFU g−1 and a higher kmax, whereas S. aureus was most resistant, with a reduction of 1.87 ± 0.24 log CFU g−1 and a lower kmax. The Weibull model was the best to predict the inactivation kinetics based on standard statistics and information theory criteria. For all assayed food‐borne pathogens, the inactivation curve showed non‐linearity with upward concavity except for L. monocytogenes, which followed a concave downward curve (β >1). Results showed that PL was effective in the retention of color, firmness, pH levels, total soluble solids, and titratable acidity, and also had a positive effect on enhancing the levels of essential components such as lycopene, total phenolic compounds, and antioxidant activity. Additionally, the PME RA significantly decreased with an increase in fluence due to structural modification. Therefore, PL can be explored to enhance fresh‐cut watermelon's safety and quality attributes. Practical Applications: The implementation of this research holds significant potential for practical benefits in the fresh‐cut fruit industry. The findings could revolutionize processing practices, ensuring enhanced microbial safety, enzyme inactivation, and an extended shelf‐life of fresh‐cut watermelon. The study strongly contributes to preserving the desirable texture, color, and overall quality of the product, enhancing the retention of lycopene and other valuable antioxidants by standardizing the pulsed light treatment parameters while adhering to U.S. Food and Drug Administration standards for food application. Moreover, this research will scientifically contribute to addressing the critical challenges of foodborne outbreaks in the fresh‐cut fruit sector while providing consumers with a healthy, convenient food choice. [ABSTRACT FROM AUTHOR]

A comparative analysis of the diffuse reflectance spectra and their changes after irradiation with electrons with an energy of 30 keV of coatings based on polymethylphenylsiloxane resin and pigment powders of two-layer hollow ZnO/SiO2 particles is carried out. The analysis is performed in situ in the range of 250–2500 nm. The samples are irradiated using a Spectrum space-conditions simulator. The radiation resistance of the studied coatings based on two-layer hollow ZnO/SiO2 particles is estimated relative to coatings based on ZnO polycrystals by analyzing the difference diffuse reflectance spectra obtained by subtracting the spectra after irradiation from the spectra of the unirradiated samples. It is found that the intensity of the induced absorption bands in coatings based on hollow ZnO/SiO2 particles is less than in coatings based on ZnO microparticles, and the radiation resistance when estimating changes in the integral absorption coefficient of solar radiation (ΔαS) is twice as high. The increase in the radiation resistance is probably determined by the different nature of defect accumulation: in the case of solid microparticles, defects can accumulate inside grains; in hollow particles, the accumulation of defects can occur only within the thin shell of the sphere. [ABSTRACT FROM AUTHOR]

Microbial contamination of dehydrated onion products is a challenge to the industry. The study focused on opting for a suitable drying condition for minced onion and exploring the decontamination efficacy of pulsed light (PL) treatment conditions for the dehydrated product. The minced onions were hot air dried at 55–75°C for 280 min. The drying condition selected was 195 min at 75°C with a final water activity of 0.5 and moisture content of 7% (wet basis [w.b.]). The weight losses, browning indexes (BI), shrinkage volumes (%), and thiosulfinate content were considered. The dehydrated product was exposed to PL treatment corresponding to an effective fluence range of 0.007–0.731 J/cm2. A fluence of 0.444 J/cm2 (1.8 kV for 150 s) achieved 5.00, 3.14, 2.96, and 2.98 log reduction in total plate count, yeast and mold count, Bacillus cereus 10876, and Escherichia coli ATCC 43888, respectively. The PL‐treated sample (0.444 J/cm2) produced a microbially safe product with no significant difference in the moisture contents (%w.b.) and water activity (aw) from the untreated dehydrated sample. Further, a 30.9% increase in the BI and a 4.25% depletion in thiosulfinate content were observed after PL treatment. An optimum drying combination (75°C for 195 min) of minced onion followed by decontamination using pulsed light treatment at 0.444 J/cm2 fluence satisfies the microbial safety and quality. Practical Application: Dehydrated minced onion can be used for dishes requiring low water content and short cooking time. It is helpful during shortages, high price fluctuations, and famines. [ABSTRACT FROM AUTHOR]

Ready‐to‐drink (RTD) mango beverage enriched with short‐chain fructooligosaccharides (scFOS) was developed to reduce added sugar and incorporate a soluble prebiotic fiber. The impact of pulsed light (PL) technology on microbial inactivation, enzyme activity, and quality attributes in scFOS‐enriched mango RTD beverages was investigated. Effective PL fluence of 0.12–1.2 J/cm2 was employed on mango beverage in order to maximize the retention of nutritional properties along with inactivation of microbial and enzymatic activity. There is complete inactivation of microbial load and enzymatic activity with 72.45, 84.17, 88, 78.79, and 77.63% retention of ascorbic acid, antioxidants, total phenolics, total flavonoids, and total carotenoids in 6% scFOS mango beverage at an effective fluence of 1.2 J/cm2. There is no wide change in TSS, pH, and TA in all the PL treatments. The scFOS increased viscosity, and it also protected bioactives, namely, carotenoids, ascorbic acid, and phenolics, from photoxidation caused by PL. Results showed that scFOS allowed a substantial reduction in added sugar and increased soluble fiber content in the beverage. Sensory score of 3 and 6% scFOS‐enriched beverages were closely comparable with control. The study showcases the potential of scFOS to enhance the nutritional profile of beverages. It also highlights the effectiveness of PL processing in pasteurization fruit beverages, meeting stakeholders' demands for microbial safety, enzymatic stability, and nutrient retention. Practical applications: The practical applications of this research hold significant promise for the food and beverage industry. The innovative formulations of ready‐to‐drink (RTD) mango beverages not only reduce added sugar by up to 52% but also increase fiber content from 0.6 to 6%, meeting consumer demands for healthier options. The integration of pulsed light technology effectively targets microbial and enzyme inactivation, complying with Food and Drug Administration standards and offering a viable processing method. The incorporation of short‐chain fructooligosaccharides enhances the protection of bioactive compounds during pulsed light treatment, ensuring higher retention of antioxidants, vitamins, and other valuable components. This advancement contributes to improved nutritional profiles while maintaining sensory appeal. These findings have the potential to revolutionize RTD beverage production, addressing health‐conscious consumer preferences, and enhancing product quality. [ABSTRACT FROM AUTHOR]

Motivation: Clustered DNA-lesions are predominantly induced by ionizing radiation, particularly by high-LET particles, and considered as lethal damage. Quantification of this specific type of damage as a function of radiation parameters such as LET, dose rate, dose, and particle type can be informative for the prediction of biological outcome in radiobiological studies. This study investigated the induction and complexity of clustered DNA damage for three different types of particles at an LET range of 0.5–250 keV/µm. Methods: Nanometric volumes (36.0 nm3) of 15 base-pair DNA with its hydration shell was modeled. Electron, proton, and alpha particles at various energies were simulated to irradiate the nanometric volumes. The number of ionization events, low-energy electron spectra, and chemical yields for the formation of °OH, H°, e a q − , and H2O2 were calculated for each particle as a function of LET. Single- and double-strand breaks (SSB and DSB), base release, and clustered DNA-lesions were computed from the Monte-Carlo based quantification of the reactive species and measured yields of the species responsible for the DNA lesion formation. Results: The total amount of DNA damage depends on particle type and LET. The number of ionization events underestimates the quantity of DNA damage at LETs higher than 10 keV/µm. Minimum LETs of 9.4 and 11.5 keV/µm are required to induce clustered damage by a single track of proton and alpha particles, respectively. For a given radiation dose, an increase in LET reduces the number of particle tracks, leading to more complex clustered DNA damage, but a smaller number of separated clustered damage sites. Conclusions: The dependency of the number and the complexity of clustered DNA damage on LET and fluence suggests that the quantification of this damage can be a useful method for the estimation of the biological effectiveness of radiation. These results also suggest that medium-LET particles are more appropriate for the treatment of bulk targets, whereas high-LET particles can be more effective for small targets. [ABSTRACT FROM AUTHOR]

Laser-induced graphene (LIG) is a three-dimensional graphene structure fabricated through the irradiation of a polymer substrate with laser energy (or fluence, equivalently). This methodology offers a cost-effective and facile means of producing 3D nanostructures, yielding graphene materials characterized by extremely high surface area and superior electrical properties, rendering them advantageous for various electrochemical applications. Nonetheless, it is imperative to acknowledge that the structures and material properties of LIG are subject to substantial variations contingent upon processing parameters, thereby underscoring the necessity for systematic inquiry and systematic comprehension of processing conditions, such as fluence and multi-passing, and resultant outcomes. Herein, we explored the impact of different laser fluence levels on the structural and material properties of LIG. We, especially, focused on how laser fluence affected substrate temperature and found that it caused polyimide (PI) substrate pyrolysis, resulting in changes in 3D structures and material density to LIG properties. We also investigated the effects of a multi-passing process on 3D LIG structures and material qualities, varying fluences, and temperature fluctuations. Lastly, we assessed electrochemical properties using LIGs produced under different conditions as working electrodes, leading to distinct impedance profiles and cyclic voltammetry (CV) curves. These variations were linked to the unique structural and material characteristics of the LIG samples. [ABSTRACT FROM AUTHOR]

Copyright of Acta Oto-Laryngologica is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract—The implantation of aluminum ions into the surface layer of a VT6 titanium alloy and the deposition of an aluminum thin film on the alloy surface by magnetron sputtering with subsequent ion-beam mixing by argon ions are studied. The evolution of the composition of the ion-alloyed layer in the VT6 titanium alloy after aluminum-ion implantation is demonstrated. [ABSTRACT FROM AUTHOR]

Copyright of Eurasian Physical Technical Journal is the property of E.A. Buketov Karaganda University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Laser-based light sources have fostered innovative developments in biomedical and biosensor fields. However, laser-induced damage to optical components is a limitation for designing and implementing highly sensitive biosensors, necessitating the development and characterization of suitable optical components. Microscope glass slides are among the most extensively used optical units in this field. This study investigated the laser-induced damage threshold (LIDT) of high-quality microscope glass slides obtained from three different vendors. An S-on-1 protocol following the ISO 21254 series standards was adopted to ensure a meaningful comparative analysis. Multiple laser pulses at a constant fluence (at the three laser wavelengths most widely used in biosensors) were used for LIDT tests. An automated test bench was developed and employed to minimize the influence of human factors on the test results. The fatigue damage mechanism was observed in all the samples. The findings revealed good consistency among LIDT values within and across batches from the same vendor. However, a notable discrepancy was observed when comparing the results of slides obtained from different vendors, with threshold values differing by up to two-fold. This study emphasizes the need to carefully consider the glass material source when selecting microscope glass slides for laser-sensitive applications. [ABSTRACT FROM AUTHOR]

Pectin methyl esterase (PME) is responsible for the destabilization of clouds in sweet orange juice. The study aims to optimize pulsed light (PL) and ultrasound (US) treatments for the maximum inactivation of PME in sweet orange juice. A central composite design was used for PL treatments (2.5 -2.9 kV for 200–300 s) and US treatments (40- 120 W for 2–10 min). The numerical optimization predicted 98.5% inactivation of PME in the juice after 283 s PL exposure at 2.84 kV (2711 J/cm2). US optimized condition was 108 W for 9 min with 82.5% PME inactivation. The first-order rate constants for PL-induced PME inactivation varied from 0.0033 to 0.0159 s−1, whereas, for the US, the range was 0.00126 to 0.0015 s−1. The impact of PL and US treatments in series on various quality attributes of the juice was assessed. PL exposure at 2.4 kV for 180 s [1278 J/cm2; the highest intensity of PL] followed by US treatment for 360 s at 80 W [1.14 W/mL; the highest intensity of US] resulted in 98.3% PME inactivation, > 5-log reduction in natural microbiota, 5% loss in vitamin C, 1.7% loss in antioxidant capacity, and 99.4% retention in phenolics in the juice. The sequence of PL or US had minimal impact on enzyme inactivation and bioactive degradation in the juice. The PL-optimized processing also led to more than 5.0 log reductions in natural microflora. However, the preliminary sensory acceptance, color difference, and bioactive retention of the sample treated at the highest intensity of PL+US were superior to the PL-optimized juice. [ABSTRACT FROM AUTHOR]

To evaluate corneal stiffening of porcine corneas induced by corneal crosslinking (CXL) with constant irradiance as a function of total fluence. Ninety corneas from freshly enucleated porcine eyes were divided into five groups of 18 eyes. Groups 1–4 underwent epi-off CXL using a dextran-based riboflavin solution and an irradiance of 18 mW/cm2, group 5 served as the control group. Groups 1 to 4 were treated with a total fluence of 20, 15, 10.8, and 5.4 J/cm2, respectively. Thereafter, biomechanical measurements were performed on 5 mm wide and 6 mm long strips using an uniaxial material tester. Pachymetry measurements were performed on each cornea. At 10% strain, the stress was 76, 56, 52, and 31% higher in groups 1–4, respectively compared to the control group. The Young's modulus was 2.85 MPa for group 1, 2.53 MPa for group 2, 2.46 MPa for group 3, 2.12 MPa for group 4, and 1.62 MPa for the control group. The difference between groups 1 to 4 and the control group 5 were statistically significant (p = <0.001; p = <0.001; p = <0.001; p = 0.021). In addition, group 1 showed significantly more stiffening than group 4 (p = <0.001), no other significant differences were found. Pachymetry measurements revealed no statistically significant differences among the five groups. Additional mechanical stiffening can be achieved by increasing the fluence of the CXL. There was no threshold detected up to 20 J/cm2. A higher fluence could compensate the weaker effect of accelerated or epi-on CXL procedures. [ABSTRACT FROM AUTHOR]

The implantation of argon ions in a grade 1420 aluminum alloy is studied. The optimum mode allowing the maximum alloy softening is shown to be Е = 36 keV, j = 300 μA/cm2, and Φ = 4.9 × 1017 cm–2 (irradiation time of 7 min). An increase in the ion current density by a factor of 1.5 (up to 450 μA/cm2) causes about a twofold reduction of the irradiation time, while maintaining near the same softening level, namely, σu = 351 MPa, σ0.2 = 161 MPa, and δ = 19.8%, at a lower fluence of 3.7 × 1017 cm–2. [ABSTRACT FROM AUTHOR]

Simple Summary: There are no effective treatments for patients with cancers that induce airway narrowing via extrinsic pressure to the bronchus (i.e., extrinsic malignant central airway obstruction—MCAO). The effects of these cancerous tumors must be quickly alleviated to allow normal breathing and delay disease progression. Currently, stents are used to keep the airway open, but stents do not halt the progression of the cancerous tumor that can crush the stent. We have shown that interstitial photodynamic therapy (I-PDT) can be a safe and beneficial treatment option for patients with extrinsic MCAO. Image-based pre-treatment planning is critical for patient safety and tumor response in I-PDT. Herein, we present and validate novel image-based computer optimization methods for guiding light administration in I-PDT of extrinsic MCAO, based on a rate-based light dose metric. We demonstrate the benefit of our approach in data from representative patients with extrinsic MCAO who were treated with I-PDT. There are no effective treatments for patients with extrinsic malignant central airway obstruction (MCAO). In a recent clinical study, we demonstrated that interstitial photodynamic therapy (I-PDT) is a safe and potentially effective treatment for patients with extrinsic MCAO. In previous preclinical studies, we reported that a minimum light irradiance and fluence should be maintained within a significant volume of the target tumor to obtain an effective PDT response. In this paper, we present a computational approach to personalized treatment planning of light delivery in I-PDT that simultaneously optimizes the delivered irradiance and fluence using finite element method (FEM) solvers of either Comsol Multiphysics® or Dosie™ for light propagation. The FEM simulations were validated with light dosimetry measurements in a solid phantom with tissue-like optical properties. The agreement between the treatment plans generated by two FEMs was tested using typical imaging data from four patients with extrinsic MCAO treated with I-PDT. The concordance correlation coefficient (CCC) and its 95% confidence interval (95% CI) were used to test the agreement between the simulation results and measurements, and between the two FEMs treatment plans. Dosie with CCC = 0.994 (95% CI, 0.953–0.996) and Comsol with CCC = 0.999 (95% CI, 0.985–0.999) showed excellent agreement with light measurements in the phantom. The CCC analysis showed very good agreement between Comsol and Dosie treatment plans for irradiance (95% CI, CCC: 0.996–0.999) and fluence (95% CI, CCC: 0.916–0.987) in using patients' data. In previous preclinical work, we demonstrated that effective I-PDT is associated with a computed light dose of ≥45 J/cm2 when the irradiance is ≥8.6 mW/cm2 (i.e., the effective rate-based light dose). In this paper, we show how to use Comsol and Dosie packages to optimize rate-based light dose, and we present Dosie's newly developed domination sub-maps method to improve the planning of the delivery of the effective rate-based light dose. We conclude that image-based treatment planning using Comsol or Dosie FEM-solvers is a valid approach to guide the light dosimetry in I-PDT of patients with MCAO. [ABSTRACT FROM AUTHOR]

Gold nanoparticles are widely used in laser biomedical applications due to their favorable properties, mainly localized plasmon resonance. However, laser radiation can cause a change in the shape and size of plasmonic nanoparticles, thus resulting in an unwanted reduction of their photothermal and photodynamic efficiency due to a drastic alteration of optical properties. Most previously reported experiments were carried out with bulk colloids where different particles were irradiated by different numbers of laser pulses, thus making it difficult to accurately evaluate the laser power photomodification (PM) threshold. Here, we examine the one-shot nanosecond laser-pulse PM of bare and silica-coated gold nanoparticles moving in a capillary flow. Four types of gold nanoparticles, including nanostars, nanoantennas, nanorods, and SiO2@Au nanoshells, were fabricated for PM experiments. To evaluate the changes in the particle morphology under laser irradiation, we combine measurements of extinction spectra with electron microscopy. A quantitative spectral approach is developed to characterize the laser power PM threshold in terms of normalized extinction parameters. The experimentally determined PM threshold increases in series were as follows: nanorods, nanoantennas, nanoshells, and nanostars. An important observation is that even a thin silica shell significantly increases the photostability of gold nanorods. The developed methods and reported findings can be useful for the optimal design of plasmonic particles and laser irradiation parameters in various biomedical applications of functionalized hybrid nanostructures. [ABSTRACT FROM AUTHOR]

The effect of a fluence of electrons with an energy of 30 keV in the range of (1–7) × 1016 cm–2 on the concentration of color centers in micron-sized hollow particles of aluminum oxide is studied in comparison with bulk Al2O3 microparticles. The analysis is carried out in situ according to diffuse reflection spectra in the range from 250 to 2500 nm. The radiation resistance of the studied microspheres is estimated relative to Al2O3 microparticles from analysis of the difference spectra of diffuse reflection obtained by subtracting the spectra after irradiation from the spectra of nonirradiated samples. Changes in the difference spectra of diffuse reflection of aluminum-oxide microparticles and microspheres show that with an increase in the electron fluence, the induced absorption increases throughout the entire spectrum. It is established that the radiation resistance of aluminum-oxide microspheres to the action of electrons with an energy of 30 keV at a fluence of (1–7) × 1016 cm–2 is greater than the radiation resistance of Al2O3 microparticles. An increase in the radiation resistance of hollow aluminum-oxide particles is due to a low concentration of radiation-induced defects in the anion sublattice. [ABSTRACT FROM AUTHOR]

The shortening of the minority carrier lifetime is the main reason for the degradation of the electrical performance of solar cells; therefore, it is particularly important to evaluate the minority carrier lifetime of inverted metamorphic triple junction (IMM3J) GaInP/GaAs/InGaAs solar cells. We evaluate the minority carrier lifetime of each subcell of IMM3J solar cells before and after 2 MeV proton irradiation by the electroluminescence (EL) method. Before proton irradiation, the minority carrier lifetimes of the GaInP, GaAs, and InGaAs subcells were 6.99 × 10−9 s, 3.09 × 10−8 s, and 2.31 × 10−8 s, respectively. After proton irradiation, the minority carrier lifetime of GaInP, GaAs, and InGaAs subcells degraded significantly. When the proton fluence was 2 × 1012 cm−2, the minority carrier lifetimes of the GaInP, GaAs, and InGaAs subcells degraded to 1.63 × 10−10 s, 1.56 × 10−11 s, and 1.65 × 10−10 s, respectively. These results provide a reference for predicting the degradation of the short-circuit current and open-circuit voltage of each subcell. [ABSTRACT FROM AUTHOR]

A study was undertaken to model the UV-C inactivation kinetics and determine the fluences required for the incremental inactivation of several strains of Cronobacter spp. suspended in clear phosphate-buffered saline (PBS). In total, 13 strains of Cronobacter spp. were individually suspended in PBS and treated with UV-C doses of 0, 2, 4, 6, 8, and 10 mJ cm−2 with a collimated beam device emitting UV-C at 253.7 nm. The log reduction from each treatment was identified using the plate count method and plotted against the UV-C dose and then curve fitted using several mathematical models. The UV-C dose required for incremental inactivation of each isolate was determined using both linear and nonlinear regression. For the 13 strains tested, a UV-C dose of 10 mJ cm−2 inactivated between 3.66 ± 0.101 and 5.04 ± 0.465 log CFU mL−1. The survival behavior of all strains was best fitted to the Weibull+tail model, with correlation coefficients between 97.17 and 99.71%, and was used to determine the fluences required for incremental inactivation. The UV-C fluences needed to inactivate 1 log (D10-value) of Cronobacter spp. in buffer were between 3.53 and 5.50 mJ cm−2, whereas a fluence greater than 6.57 mJ cm−2 was required to achieve a 4-log inactivation. A clear understanding of the UV-C dose-response of several strains of Cronobacter spp. lays the foundation to design effective UV-based disinfection systems. [ABSTRACT FROM AUTHOR]

Background: Intensity-modulated radiation therapy (IMRT) may have too many peaks and valleys, making the treatment plan undeliverable. When there are too many fluency differences between adjacent pixels in the X or Y directions, the X and Y smoothing factors are utilized as weighting factors to penalize this behavior. Generally, a high degree of complexity is accompanied by many monitor units (MUs), large number of segments, small sized segments, and complex segment shapes. The degree of plan delivery uncertainty can all increase with a higher detailed fluence map. Aim: This study aims to evaluate the dosimetric effects of various smoothing levels on the planning target volume (PTV) and organs at risk (OARs) for cervix cancer. Materials and Methods: IMRT treatment plans were re‑optimized by combining several values of the X and Y penalty between 0 and 100. The dose–volume histogram assessed various dosimetric indicators for PTV and OARs. Additionally, gamma passing rates were evaluated and noted as an indicator of the complex treatment plan. Results: At X = 60, Y = 60 fluence map penalty, the conformity index (CI) value reached its highest value of 0.996 ± 0.004. At X = 0, Y = 0, the homogeneity index (HI) was determined to have a maximum value of 0.0628 ± 0.0235. The highest and lowest MU values were 2424.30 ± 471.12 and 1087.80 ± 91.57, respectively, with X = 0, Y = 0 and X = 100, Y = 100. At X = 100, Y = 100, the gamma passing rate reaches its highest value of 99.28% ± 0.44% and minimum value of 85.93% ± 3.87% at X = 0, Y = 0. Conclusion: The CI and HI values showed no discernible fluctuation, and the OAR doses were barely affected as smoothing was increased. When the smoothing factor was raised, the number of MUs sharply dropped, and a decrease in the number of segments and higher gamma passing rates were also seen. [ABSTRACT FROM AUTHOR]

Phenol is a recalcitrant anthropogenic compound whose presence has been reported in both wastewater and drinking water; human exposure to phenolic substances can lead to health problems. The degradation of phenol (measured as COD decrease) through solar heterogeneous photocatalysis with immobilized TiO2 was performed in two different reactors: a flat-plate reactor (FPR) and a compound parabolic collector (CPC). A 23 full factorial experimental design was followed. The variables were the presence of TiO2, H2O2 addition, and the type of reactor. Data were fitted to the pseudo-first-order reaction-rate-kinetics model. The rate constant for photocatalytic phenol degradation with 1 mM of H2O2 was 6.6 × 10−3 min−1 for the FPR and 5.9 × 10−3 min−1 in the CPC. The calculated figures of merit were analyzed with a MANCOVA, with UV fluence as a covariate. An ANCOVA showed that the type of reactor, H2O2 addition, or fluence had no statistically significant effect on the results, but there was for the presence of TiO2. According to the MANCOVA, fluence and TiO2 presence were significant (p < 0.05). The CPC was on average 17.4% more efficient than the FPR when it came to collector area per order (ACO) by heterogeneous photocatalysis and 1 mM H2O2 addition. [ABSTRACT FROM AUTHOR]

Multiple wavelength devices are now available for photobiomodulation (PBM) treatments, but their dosimetry for individual or combinatorial use remains unclear. The present work investigated the effects of 447, 532, 658, 810, 980 and 1064 nm wavelengths on odontoblast differentiation at 10 mW/cm2 using either equal treatment time for conventional fluence (300 seconds for 3 J/cm2) or varying times to adjust for individual wavelength photon fluence (4.6 p.J/cm2). Both 447 and 810 nm significantly increased alkaline phosphatase (ALP) activity, while 1064 nm showed reduced ALP activity at 3 J/cm2. However, ALP induction was significantly improved when equivalent photon fluence dosing was used. Other wavelengths did not show significant changes compared to untreated controls. The data suggest that accounting for wavelength‐specific photon energy transfer during PBM dosing could improve clinical safety and efficacy. [ABSTRACT FROM AUTHOR]

It is shown that the replacement of a part of sulfur atoms with selenium atoms in a TlInS2 single crystal stimulates the formation of a single-phase state with a monoclinic structure (space group C 2 / c) in TlInS x Se 2 − x (x = 1). Irradiation with 2 MeV electrons and a fluence of 2 × 1 0 1 7 electron/cm2 of powder TlInS x Se 2 − x (x = 1) leads to an increase in the crystallite size from 56.5 nm to 65 nm, which is most likely associated with a decrease in the interface. The difference between the surface morphology of the synthesized TlInS x Se 2 − x (x = 1) single crystal and the surface morphology of the TlInS2 single crystal is established, which consists in a decrease in the height and width of the roughness in TlInS x Se 2 − x (x = 1). Irradiation of a TlInS x Se 2 − x (x = 1) single crystal with electrons with a fluence of 2 × 1 0 1 7 electron/cm2 does not lead to a change in the height of the tubercle on its surface, and the average value of its width increases more than ten-fold. The identity of the peaks in the Raman spectra of the TlInS x Se 2 − x (x = 1) single crystal before and after its irradiation with electrons with an energy of 2 MeV and upto a fluence of 2 × 1 0 1 7 electron/cm2, along with the absence of a shift of the peaks, indicates the radiation resistance of the TlInS x Se 2 − x (x = 1) single crystal. [ABSTRACT FROM AUTHOR]

Because some people seek consultations for the removal of unwanted body hair, a permanent, safe, and non-invasive method of hair removal is needed. Laser hair removal has been a popular cosmetic procedure. It is a monthly treatment that may take up to ten sessions for permanent results. However, its efficacy varies due to the patient’s biological skin hair traits, the adjustment of the optimal parameters of the laser, and the protocols. The purpose of this review is to discuss the properties and parameters employed for laser hair removal. Once parameters for laser hair removal have been optimized, this treatment offers an effective and permanent solution for unwanted body hair. [ABSTRACT FROM AUTHOR]

The Y0.95Gd0.05PO4 phosphate with the xenotime structure has been synthesized in powder form and as ceramics. Ceramics with a relative density of ~99% have been produced by spark plasma sintering. The sintering temperature was 1140°C and the sintering time was ~18 min, without isothermal holding. We have assessed the radiation resistance of the ceramics under irradiation with 132Xe26+ ions and investigated the restoration of the obtained metamict phase to a crystalline one via high-temperature heat treatment. No complete amorphization of the samples has been reached at the fluences used in this study. The calculated critical fluence is (9.2 ± 0.1) × 1014 cm–2, and the calculated latent track radius is ~2.8 nm. Hydrolytic tests have shown that the phosphate under study is stable in water under dynamic conditions. The observed Y and Gd leaching rates were Ri = 1.68 × 10–6 and 1.5 × 10–7 g/(cm2 day), respectively. [ABSTRACT FROM AUTHOR]

The development of a painless, non-invasive, and faster way to diabetic wound healing is at the forefront of research. The complexity associated with diabetic wounds makes it a cause for concern amongst diabetic patients and the world at large. Irradiation of cells generates a photobiomodulatory response on cells and tissues, directly causing alteration of cellular processes and inducing diabetic wound repair. Photobiomodulation therapy (PBMT) using red and near-infrared (NIR) wavelengths is being considered as a promising technique for speeding up the rate of diabetic wound healing, eradication of pain and reduction of inflammation through the alteration of diverse cellular and molecular processes. This review presents the extent to which the potential of red and NIR wavelengths have been harnessed in PBMT for diabetic wound healing. Important research challenges and gaps are identified and discussed, and future directions mapped out. This review thus provides useful insights and strategies into improvement of PBMT, including its acceptance within the global medical research community. [ABSTRACT FROM AUTHOR]

Since the first peer-reviewed publication on MicroPulse® Transscleral Laser Therapy (MP-TLT) in 2010, authors worldwide have used a wide range of treatment parameter combinations with varying clinical efficacy in terms of the magnitude of intraocular pressure reduction, success rate, durability, and safety profile. This has made it difficult to determine the proper parameters necessary to optimize efficacy and safety, and has made comparison of results from one investigation to another difficult. The first goal of this paper is to explain and highlight the impact of the choices of exposure time and the number of sweeps per hemisphere in terms of "sweep velocity" on energy delivery to the eye. These treatment parameters are underreported in the literature. The second goal is to introduce fluence as a "dose" metric, that combines all the treatment parameters and constants into a single number. Fluence may be a better light-dose metric and a more reliable indicator of clinical outcomes compared to total energy. [ABSTRACT FROM AUTHOR]

A procedure has been developed for simulating the long-term effect of atomic oxygen (AO) of the Earth's ionosphere on spacecraft polymers in a rarefied plasma flow using Kapton H polyimide as a reference material. The condition for the equivalence of the effect of AO on polymers in the ionosphere and at a test bench is the equality of the mass loss. When Kapton H is bombarded with atomic oxygen ions having energies of 30–80 eV, the mass loss due to chemical etching is two orders of magnitude higher than in the case of kinetic sputtering, and the AO fluence and the acceleration factor of tests on the bench are two orders of magnitude higher than in a 5-eV atomic oxygen beam. [ABSTRACT FROM AUTHOR]

Background: Facial injuries due to flying windscreen glass pieces are common in road accident and require surgical intervention by plastic surgeons to debride, suture, and dress the injuries. Posthealing patients visit dermatologists for further treatment of residual scar tissue. Interestingly, tiny papules or small nodular scars seen on otherwise level background which persists for beyond 3 months (scar modeling time) may actually harbor small fragments of glass. Such lesions can only be treated by fractional CO2 therapy. Methods: Two patients who had papules and small nodular lesions on the accident scarred areas were subjected to fractional CO2 laser (ultraPulse, Lumenis)with moderate fluence and high density, once and observed over a period of 12 weeks. Results: On targeting the papules and small nodules, tiny particles of glass appeared out of the broken lesions. Discussion: Irrespective of the surgery done on accident victims involving windshield glass injuries, fractional CO2 may be considered at a later stage, especially with presence of papules interspersed in the area of facial scars. [ABSTRACT FROM AUTHOR]

Background: The Integral Quality Monitor (IQM®) is an independent online dosimetry device attached to the treatment machine to monitor the accuracy of radiation delivery. Objective: This study investigates the influence of beam segment size and displacement as projected onto the IQM chamber on the signals and determine how individual signals can be added to get a combined segment signal made up of smaller segments. Material and Methods: This is an experimental original research type of study. IQM response maps were generated by irradiating the IQM sensitive area with small elementary segments and measuring their corresponding signals per monitor unit (MU). The output signal/MU was measured for regular and irregular fields and compared with the predicted signal/MU obtained from decomposing the open segment into a set of smaller regular segments and summing their signals from their respective response maps. The dependence of signals on segment size, shape, location and combination was investigated. Results: Predicted signals were calculated within 95-98 % accuracy for regular fields and 90-98% for irregular fields. More uniform fluence contain distribution for larger segments was observed. Response maps were consistent with the geometrical symmetry in the chamber's wedge shape and the symmetry in the linac fluence. Conclusion: The field decomposition method allows the pre-calculation of known segment output signals per MU within 2% error, although the accuracy drops significantly for smaller, irregular fields. A method of correcting predicted signals in smaller segments needs to be laid down to get a better match with measured signals. [ABSTRACT FROM AUTHOR]

Featured Application: This review discusses recent developments in the field of pulsed light processing. Various aspects of recent PL applications are discussed. This review shall form the basis of future research and development in the field. Consumers of the 21st century tend to be more aware and demand safe as well as nutritionally balanced food. Unfortunately, conventional thermal processing makes food safe at the cost of hampering nutritional value. The food industry is trying to develop non-thermal processes for food preservation. Pulsed light (PL) is one such emerging non-thermal food processing method that can decontaminate food products or food contact surfaces using white light. Exposure to intense light pulses (in infrared, visible, and ultraviolet (UV) regions) causes the death of microbial cells, rendering the food safe at room temperature. PL technology is an excellent and rapid method of disinfection of product surfaces and is increasingly being used for food surfaces and packaging decontamination, enabling the minimal processing of food. This paper aims to give an overview of the latest trends in pulsed light research, discuss principles of pulse generation, and review applications of various PL systems for the inactivation of microorganisms in vitro, in various food products, and on food contact surfaces. Effects of PL on food quality, challenges of the process, and its prospects are presented. [ABSTRACT FROM AUTHOR]

Nanosecond laser pulses (1064 nm, 8 ns and 10 Hz) were employed to ablate a Cu target immersed in deionized water (DI) and ethylene glycol (EG). The ablation process was carried out for 60 min for two different laser fluences, i.e., 27 J / cm 2 and 80 J / cm 2 , which resulted in the formation of Cu/CuO nanoparticles (NPs) in both the media. The effects of laser fluence and solvents on the morphology of NPs were investigated using structural and optical characterization techniques (such as TEM, HRTEM, XRD, UV–visible and PL spectroscopy). The colloidal solution synthesized at the low fluence of 27 J / cm 2 in DI illustrated the presence of hollow structured CuO NPs and has been attributed to the Kirkendall effect. At the high fluence of 80 J / cm 2 , porous NPs were seen which has been attributed to the dissolution of H 2 molecules. In EG, no signature of hollow or porous NPs was seen and this has been accredited to its oxygen deficiency and viscous nature. Additionally, the growth kinematics involved in the transformation of morphology are elaborately discussed. [ABSTRACT FROM AUTHOR]

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The influence exerted by the carrier concentration in the range (1–50) × 1014 cm–3 in n-4H-SiC chemical-vapor deposited (CVD) epitaxial layers on the spectral characteristics of UV photodetectors with Cr Schottky barriers in the range of 200–400 nm is revealed and explained in terms of the photoconductivity theory. Schottky barriers with a Cr film thickness of 20 nm and diameter of 8 mm are formed by thermal evaporation in vacuum through masks. A noticeable effect of the carrier concentration in the CVD epitaxial layers on the spectral characteristics of photodetectors upon heating to 200°C is also observed and accounted for by a difference between the generation-recombination processes. The irradiation of photodetectors with 15-MeV protons at a fluence of 4 × 1012 cm–2 and a temperature of 200°C leads to an increase in the quantum efficiency as compared to samples irradiated in similar modes at 25°C. This is indicative of an increase in the radiation hardness and service life of 4H-SiC devices at elevated temperatures. [ABSTRACT FROM AUTHOR]

Solar Proton Events (SPEs) are of great importance and significance for the study of Space Weather and Heliophysics. These populations of protons are accelerated at high energies ranging from a few MeVs to hundreds of MeVs and can pose a significant hazard both to equipment on board spacecrafts as well as astronauts as they are ionizing radiation. The ongoing study of SPEs can help to understand their characteristics, relative underlying physical mechanisms, and help in the design of forecasting and nowcasting systems which provide warnings and predictions. In this work, we present a study on the relationships between the Peak Flux and Fluence spectra of SPEs. This study builds upon existing work and provides further insights into the characteristics and the relationships of SPE Peak flux and Fluence spectra. Moreover it is shown how these relationships can be quantified in a sound manner and exploited in a simple methodology with which the Fluence spectrum of an SPE can be well predicted from its given Peak spectrum across two orders of magnitude of proton energies, from 5 MeV to 200 MeV. Finally it is discussed how the methodology in this work can be easily applied to forecasting and nowcasting systems. [ABSTRACT FROM AUTHOR]

The availability of high power ultrafast lasers for material processing enables new applications such as deep hole drilling. To reach high ablation rates and high aspect ratios, fluences in the order of magnitude of 100 J/cm² are required. As this range has rarely been described in literature, a detailed study of the ablation rate for stainless steel is presented here. At a mean fluence of ~1.3 J/cm² a molten phase is observed in the center of the hole which then extends over the entire ablated area for increasing fluences. Due to the onset of a melt layer a melt supported ablation superimposes the anticipated second ablation regime and hence no logarithmic dependence of the ablation depth is visible for higher fluences. For fluences of 10 J/cm² and higher the entire area is subject to a melt supported ablation. In addition, in this fluence range only the deposition of a few pulses at a higher repetition rate can boost the ablation rate up to a factor of 10 due to heat accumulation. [ABSTRACT FROM AUTHOR]

The quality of micro-features in various technologies is mostly affected by the choice of the micro-fabrication technique, which in turn results in several limitations with regard to materials, productivity, and cost. Laser beam micro-machining has a distinct edge over other non-traditional methods in terms of material choices, precision, shape complexity, and surface integrity. This study investigates the effect of laser fluence and pulse overlap while developing microchannels in alumina ceramic using an neodymium-doped yttrium aluminum garnet (Nd:YAG) laser. Microchannels 200 µm wide with different depths were machined using different laser peak fluence and pulse overlap (percentage of overlap between successive laser pulses) values. It was found that high pulse overlaps and fluences should be avoided as they give rise to V-shaped microchannels i.e., 100% bottom width errors. The optimal peak fluence range was found to be around 125–130 J/cm2 corresponding to 3–5 µm depth per scan. In addition, channels fabricated with moderate pulse overlap were found to be of good quality compared to low pulse overlaps. [ABSTRACT FROM AUTHOR]

The features of defect formation in the surface and near-surface silicon layers under the influence of irradiation with beams of high-energy ions of gases of various masses are investigated and the prospects of using such ion beams are shown for the technology of radiation doping of semiconductors. It has been established that the degree of Si damage both in the ion path region and in the braking region of ions rises and becomes more complex with an increase in the energy and mass of the ions. The greatest structural damages were observed in the ion braking region, where the concentration of defects was maximal. It was revealed that the structure of the path range after irradiation with protons did not change significantly, in contrast to the heavily damaged structure after irradiation with alpha particles. More orderly and narrower lines of stress associated with defects were observed in Si irradiated with protons, and their number and location relative to the braking line depended on the ion beam intensity. It was established for Si irradiated with alpha particles that the area of their braking consists of the voids with various sizes and shapes etched as a continuous layer and in the form of individual clusters, accompanied by dislocation loops that were formed. It was found that complex structure of the deuteron braking band in Si is due to the presence of dislocations in the initial Si, their movement and interaction with radiation defects at irradiation. The definitive picture of the formation and ordering of defects is determined by the interaction of growth and radiation defects and temperature at irradiation. Changes in the width of the etched braking band in the range from 20 to 200 μm, depending on the mass of ions, are revealed. The minimal width of the braking band for all types of radiation was obtained at the edge of irradiated area, where the sample temperature was lower due to cooling, and the maximal one was obtained in the center of irradiated area. [ABSTRACT FROM AUTHOR]

The effect of laser fluence and nature of ambient environments on the sputtering yield, surface modifications, crater depth, UV-visible absorption spectra, chemical composition, and micro hardness of Zr has been investigated. Nd: YAG laser (532 nm, 10 Hz, 6 ns) at different fluences varying from 16 to 60.8 Jcm−2 was employed as an irradiation source. All measurements are performed under two ambient environments of Ar and O2 at a constant pressure of 10 Torr. Quartz crystal microbalance has been employed for the measurement of sputtering yield of laser irradiated Zr. It is revealed that sputtering yield increases monotonically with increasing fluence under both environments however, it is higher in Ar as compared to O2 environment. Scanning electron microscope (SEM) has been used to explore the surface morphology. SEM analysis exhibits the formation of cones, ridges, and cracks at the central ablated areas whereas, laser-induced periodic surface structures, periodic ridges and sharp cones are observed at inner boundaries in both environments of Ar and O2. Sharp spikes are observed in both environments, however, their height and distinctness are more pronounced in Ar as compared to O2. Cones are characteristic features in Ar, whereas, cavities and channels are dominant features in O2 environment at outer boundaries. The formation and growth of surface structures are dependent upon laser fluence and ambient gas nature. The depth profilometry has been used to measure the crater depth of irradiated Zr target by using an optical microscope. UV visible spectroscopy and energy-dispersive X-ray analyses reveal the oxide formation in the case of Zr irradiation in O2 environment. The Vicker Micro-hardness tester has been employed to measure the hardness. The higher observed values of sputtering yield, crater depth and hardness of laser ablated Zr in Ar as compared to O2 are well correlated with distinct surface structures. [ABSTRACT FROM AUTHOR]

Background: Recent investigations demonstrate a strong potential for cobalt-60 (Co-60)-based teletherapy. The influence of the lower energy and penetration of a cobalt-60 beam compared with linear accelerator beams is negligible for intensity-modulated radiotherapy. Purpose: The aim of this research is to investigate source head fluence modulation in cobalt-60 teletherapy by using a three-dimensional (3D) physical compensator and secondary collimator jaw motion. Materials and methods: The Oncentra treatment planning system was used to develop three hypothetical plans by secondary collimator jaw motion. A clinical MDS Nordion Equinox 80 cobalt-60 teletherapy unit was used to acquire conventional water phantom beam characteristics. Fluence modulation experiments were executed at 5·0 cm depth in a PTW universal intensity-modulated radiation therapy (IMRT) verification phantom using calibrated Gafchromic external beam therapy 2 (EBT2) and RTQA2-1010 film batches. Gafchromic EBT2 film was used to sample intensity maps generated by secondary collimator jaw motion, yet Gafchromic RTQA2-1010 film sampled maps from the 3D physical compensator. The solid-state drives used were 75·0 and 74·3 cm for the Gafchromic EBT2 and Gafchromic RTQA2-1010 film measurements. Results: A 2D gamma index analysis was coded to compare EBT2 film measurements with Digital Imaging and Communications in Medicine data. This analysis was also used to verify film measurements versus Monte-Carlo simulations. Conclusion: Lateral beam profiles generated from water phantom measurements were used to establish source head fluence modulation on the film measurements. The source head fluence of a cobalt-60 teletherapy beam could be modulated by secondary collimator jaw motion and using a 3D physical compensator. [ABSTRACT FROM AUTHOR]

Low power lasers have been used successfully for treatment of many diseases in soft and bone tissues. Basic and clinical researches have developed quickly being the scientific basis to therapeutic protocols based on these lasers. However, there are difficulties to compare experimental and clinical results obtained from different researchers because a complicated and intricate list of physical and biological parameters should be checked before the irradiation procedures as well as part of these parameters are omitted or inaccurately reported. This review focuses on the physical and biological parameters proposed to make experimental and clinical protocols accurate and reproducible as well as suggests dose parameters based on biological effects induced by low power lasers. A variety of parameters are reported by different authors and the number of parameter suggested could overcome three dozens. Thus, laser dose and laser dose equivalent are defined based on laser-induced biological effects and suggested as simplified dose parameters for low power lasers. These parameters could simplify and be useful to researchers and clinicians, permitting comparisons and decreasing mistakes and inaccuracies when laser-induced effects are evaluated and compared with those obtained in previous studies. The laser dose and laser dose equivalent could contribute significantly to improve accuracy, effectiveness, and safety of clinical protocols based on low power lasers. [ABSTRACT FROM AUTHOR]

Solar energetic particle events and galactic cosmic rays are important aspects of space weather. Investigating them requires consistent measurements of electrons and ions over long time periods, that is, over more than a solar cycle. The Electron Proton Helium INstrument onboard the SOlar and Heliospheric Observatory is operational since 1995 and was designed to measure electrons in the energy range of 0.3 to 10 MeV as well as protons and helium ions in the energy range from 4 to 50 MeV per nucleon in four different coincidence channels with 1‐min resolution. Early in the mission and in 2017 two of six detectors became noisy and had to be switched of reducing the number of coincidence channels from 4 to 2, and thereby significantly reducing the energy resolution of the instrument. In order to restore the original count rate channels we present here a new data analysis applying the so called dE/dx − dE/dx method. A data set with different temporal resolutions from 1 min to a day has been generated for the whole ongoing SOlar and Heliospheric Observatory mission from 1995 to 2018. The resulting data sets are successfully validated against measurements from instruments close to Earth. Studies with regard to long‐term variation of the measured flux with special emphasis on the contribution of individual solar energetic particle events to the fluence observed over more than two solar cycles are presented here. Key Points: A new data product of SOHO/EPHIN with consistent data quality over more than two solar cycles is providedThe fluence of protons and helium particles in the energy range from 5 to 50 MeV per nucleon is dominated by individual SEP events [ABSTRACT FROM AUTHOR]

Introduction: It is essential that Quality Assurance (QA) need to be in line with progresses in HDR brachytherapy treatment planning and delivery to ensure an appropriate level of dosimetric accuracy and quality. Aim: To verify radiation fluence using stack films in HDR brachytherapy with heterogeneity algorithm. Materials and Methods: Gafchromic EBT2 films were stacked in different experimental setup and each film acted as dosimeter to validate AcurosTMBV algorithm in HDR brachytherapy. These films were read using Epson expression 10000 XL flatbed scanner, calibrated against the standard value and analysed with Film QA Pro 2015 software. Different criterion were set for gamma analysis which include Dose Difference (DD)/Distance-To-Agreement (DTA); 2%/1 mm, 5%/1 mm, 10%/1 mm. Results: In order to validate the point doses calculated using model based dose calculation algorithm (AcurosTM BV), a virtual phantom created in the TPS, which agreed with MC based calculation mostly within 2%. The results of each plane were analysed in all the experimental setup. In the gamma pass criteria of 2% and 1 mm, 92% passed, in 5% and 1 mm criteria 96% passed and with 10% and 1 mm criteria, almost 100% passing rate was achieved. Conclusion: Methods provide a comprehensive verification for commissioning the MBDCA-AcurosTM BV and are recommended to use stack film for QA program in HDR brachytherapy. [ABSTRACT FROM AUTHOR]