Search

Solar‐energy‐driven photocatalytic CO2 reduction by H2O to high‐valuable carbon‐containing chemicals has become one of the greatest concerns in both scientific and industrial communities, due to its potential in solving energy and environmental problems. However, efficiency of photocatalytic CO2 reduction by H2O is still far below the needs of large‐scale applications. The reduction efficiency is closely related to ability of photocatalysts in absorbing visible light which is the main part of sunlight (44 %), separating photogenerated electron‐hole pairs, adsorbing CO2 and producing protons for reducing CO2. Thus, photocatalysts with enhanced visible light absorption, electron‐hole separation, CO2 adsorption and proton production are highly desired. Herein, we aim to provide a picture of recent progresses in improving ability of photocatalysts in visible light absorption, electron‐hole separation, CO2 adsorption and proton production, and give an outlook for future researches associated with photocatalytic CO2 reduction by H2O. [ABSTRACT FROM AUTHOR]

Designing dual oxideand proton-ion-conducting composite electrolytes with enhanced total ionic conductivity is essential for improving the performance of solid oxide fuel cells (SOFCs). Here, we report the impact of relative concentrations between proton and oxygen ion conducting electrolytes on the structure and electrical properties. Barium zirconate (BYZ) and samarium doped ceria (SDC) electrolytes prepared by combustion and co-precipitation method, respectively, were mixed in different ratios (0, 25, 50, 75, and 100 wt%) and sintered at 1400 °C for 6 h. X-ray diffraction studies indicate the co-existence of the perovskite and fluorite structures without the formation additional phases upon sintering. The electrochemical impedance spectra recorded under both reducing and oxidizing conditions demonstrate a reduction in grain boundary resistance of SDC with the increase in BYZ concentration. The composite with 75 % SDC and 25 % BYZ (S75B25) exhibits better conductivity in oxidizing and reducing environments with a maximum power density of 28 mW/cm2 under single-chamber SOFC conditions. The analysis of Wagner polarization results indicates an ionic transport mechanism in S75B25. Our results demonstrate the significance of dual-ion conducting composite electrolytes on improving the performance of single-chamber SOFCs. [ABSTRACT FROM AUTHOR]

The local binding and migration behavior of the proton defect in cubic yttria-stabilized zirconia (YSZ) is studied by first-principles calculations and muon-spin spectroscopy (μSR) measurements. The calculations are based on density-functional theory (DFT) supplemented with a hybrid-functional approach with the proton defect embedded in quasi-random supercells of 10.3 mol% yttria content, where the yttrium–zirconium substitutional defects are charge compensated by oxygen vacancies. Representative migration pathways for the proton comprising both transfer and bond reorientation modes are analysed and linked to the underlying microstructure of the YSZ lattice. The μSR data show the evolution of the diamagnetic fraction corresponding to the muon-isotope analogue with an activation energy of diffusion equal to 0.17 eV. Comparisons between the calculations and the experiment allow an assessment of the character of the short-range migration of the proton particle in cubic YSZ. [ABSTRACT FROM AUTHOR]

Highly intense bunches of protons and ions with energies of several MeV/u can be generated with ultra-short laser pulses focused on solid targets. In the most common interaction regime, target normal sheath acceleration, the spectra of these particles are spread over a wide range following a Maxwellian distribution. We report on the design and testing of a magnetic chicane for the selection of protons within a limited energy window. This consisted of two successive, anti-parallel dipole fields generated by cost-effective permanent C-magnets with customized configuration and longitudinal positions. The chicane was implemented into the target vessel of a petawatt laser facility with constraints on the direction of the incoming laser beam and guidance of the outgoing particles through a vacuum port. The separation of protons and carbon ions within distinct energy intervals was demonstrated and compared to a ray tracing code. Measurements with radiochromic film stacks indicated the selection of protons within [2.4, 6.9] MeV, [5.0, 8.4] MeV, or ≥6.9 MeV depending on the lateral dispersion. A narrow peak at 4.8 MeV was observed with a time-of-flight detector. [ABSTRACT FROM AUTHOR]

Purpose: MedAustron mission is to cure cancer by providing advanced patient care, clinical trials, applied and basic research, and know-how transfer. The facility is constantly striving to improve the therapy method of ion beam therapy, to increase its effectiveness and to make the treatment accessible to more people. Methods: The MedAustron particle therapy accelerator facility is located in Austria and delivers protons in the energy range 60–250 MeV and carbon ions 120–400 MeV/n for tumor treatment to four irradiation rooms. Clinical treatment includes two rooms with fixed beam lines horizontal and horizontal/vertical and a third room with a rotating beam line, the proton gantry. A fourth irradiation room is dedicated to research delivering carbon and helium beams and where proton beams up to 800 MeV are also provided. Results: The facility has been built, the commissioning has been completed and MedAustron is now successfully operating at its full functionality. Since the first patient treatment in December 2016, more than 2,000 patients have been treated at MedAustron. Conclusions: In this paper, we provide an overview of the facility including the world-wide first so-called rotator system used, synchronously with the gantry, to improve the quality of the beam delivered at the patient. Furthermore, we discuss about the ongoing projects for improvement of the facility, the areas of research and potential topics for collaboration. [ABSTRACT FROM AUTHOR]

The local binding and migration behavior of the proton defect in cubic yttria-stabilized zirconia (YSZ) is studied by first-principles calculations and muon-spin spectroscopy (μSR) measurements. The calculations are based on density-functional theory (DFT) supplemented with a hybrid-functional approach with the proton defect embedded in quasi-random supercells of 10.3 mol% yttria content, where the yttrium–zirconium substitutional defects are charge compensated by oxygen vacancies. Representative migration pathways for the proton comprising both transfer and bond reorientation modes are analysed and linked to the underlying microstructure of the YSZ lattice. The μSR data show the evolution of the diamagnetic fraction corresponding to the muon-isotope analogue with an activation energy of diffusion equal to 0.17 eV. Comparisons between the calculations and the experiment allow an assessment of the character of the short-range migration of the proton particle in cubic YSZ.

In this work, the influence of alpha particles, protons and gamma rays on the crystal structure and structural characteristics of n-type silicon (n-Si) single crystals was studied using X-ray diffraction. N-type silicon (KEF-40) was used for the study. The samples were irradiated with protons with a dose of 9×1014 cm-2 with an energy of 600 keV and a current of 1÷1.5 µA, irradiated with alpha particles with a dose of 6×1014 cm-2 with an energy of 800 keV and a current of 0.5÷1 µA and γ− 60Co quanta with a flux intensity of ~ 3.2×1012 quantum/cm2·s. Based on the results of X-ray diffraction analysis, it was established that distortions, vacancies and amorphization of lattice parameters that arose after irradiation lead to an increase in lattice parameters.

Managing safety and supply‐chain risks associated with lithium‐ion batteries (LIBs) is an urgent task for sustainable development. Aqueous proton batteries are attractive alternatives to LIBs because using water and protons addresses these two risks. However, most host materials undergo large volume changes upon H+ intercalation, which induces intraparticle cracking to accelerates parasitic reactions. Herein, we report that Mo3Nb2O14 bronze exhibits reversible H+ intercalation (200 mAh g−1) with a Coulombic efficiency of 99.7 % owing to near‐zero volume change and solid‐solution‐type phase transition. Combination of experimental and theoretical analyses clarifies that rotation and shrinkage of open tunnels, which consist of flexible corner‐sharing Mo/NbOn polyhedra, relieve local structural distortions upon H+ intercalation to suppress intraparticle cracking. The prototype full cell of an aqueous proton battery with a Mo3Nb2O14 anode operates stably over 1000 charge/discharge cycles. This study reveals the importance of implementing distortion‐relieving voids in host materials to reduce volume change upon charge/discharge. [ABSTRACT FROM AUTHOR]

SLC4A11 is the most abundant membrane transport protein in corneal endothelial cells. Its functional presence is necessary to support the endothelial fluid pump that draws fluid from the corneal stroma, preventing corneal edema. Several molecular actions have been proposed for SLC4A11 including H2O transport and cell adhesion. One of the most reproduced actions that SLC4A11 mediates is a H+ (or OH-) conductance that is enhanced in the presence of NH4Cl. The mechanism by which this occurs is controversial with some providing evidence in favor of NH3-H+ cotransport and others providing evidence for uncoupled H+ transport that is indirectly stimulated by the effects of NH4Cl upon intracellular pH and membrane potential. In the present study we provide new evidence and revisit previous studies, to support a model in which NH4Cl causes direct allosteric activation of SLC4A11 by means of an acidic shift in the intracellular pK (pKi) that governs the relationship between intracellular pH (pHi) and SLC4A11 H+-conductance. These findings have important implications for the assignment of a physiological role for SLC4A11. [ABSTRACT FROM AUTHOR]

Silicon Photomultipliers (SiPMs) are single photon detectors that gained increasing interest in many applications as an alternative to photomultiplier tubes. In the field of space experiments, where volume, weight and power consumption are a major constraint, their advantages like compactness, ruggedness, and their potential to achieve high quantum efficiency from UV to NIR makes them ideal candidates for spaceborne, low photon flux detectors. During space missions however, SiPMs are usually exposed to high levels of radiation, both ionizing and non-ionizing, which can deteriorate the performance of these detectors over time. The goal of this work is to compare process and layout variation of SiPMs in terms of their radiation damage effects to identify the features that helps reduce the deterioration of the performance and develop the next generation of more radiation-tolerant detectors. To do this, we used protons and X-rays to irradiate several Near Ultraviolet High-Density (NUV-HD) SiPMs with small areas (single microcell, 0.2 × 0.2 mm2 and 1 × 1 mm2) produced at Fondazione Bruno Kessler (FBK), Italy. We performed online current-voltage measurements right after each irradiation step, and a complete functional characterization before and after irradiation. We observed that the main contribution to performance degradation in space applications comes from proton damage in the form of an increase in primary dark count rate (DCR) proportional to the proton fluence and a reduction in activation energy. In this context, small active area devices show a lower DCR before and after irradiation, and we propose light or charge-focusing mechanisms as future developments for high-sensitivity radiation-tolerant detectors. [ABSTRACT FROM AUTHOR]

Background: For proton therapy, a relative biological effectiveness (RBE) of 1.1 is widely applied clinically. However, due to abundant evidence of variable RBE in vitro, and as suggested in studies of patient outcomes, RBE might increase by the end of the proton tracks, as described by several proposed variable RBE models. Typically, the dose averaged linear energy transfer (LETd$\text{LET}_d$) has been used as a radiation quality metric (RQM) for these models. However, the optimal choice of RQM has not been fully explored. Purpose: This study aims to propose novel RQMs that effectively weight protons of different energies, and assess their predictive power for variable RBE in proton therapy. The overall objective is to identify an RQM that better describes the contribution of individual particles to the RBE of proton beams. Methods: High‐throughput experimental set‐ups of in vitro cell survival studies for proton RBE determination are simulated utilizing the SHIELD‐HIT12A Monte Carlo particle transport code. For every data point, the proton energy spectra are simulated, allowing the calculation of novel RQMs by applying different power levels to the spectra of LET or effective Q$Q$ (Qeff$Q_\mathrm{eff}$) values. A phenomenological linear‐quadratic‐based RBE model is then applied to the in vitro data, using various RQMs as input variables, and the model performance is evaluated by root‐mean‐square‐error (RMSE) for the logarithm of cell surviving fractions of each data point. Results: Increasing the power level, that is, putting an even higher weight on higher LET particles when constructing the RQM is generally associated with an increased model performance, with dose averaged LET3$\text{LET}^3$ (i.e., dose averaged cubed LET, cLETd$\mathrm{cLET}_d$) resulting in a RMSE value 0.31, compared to 0.45 for a model based on (linearly weighted) LETd$\text{LET}_d$, with similar trends also observed for track averaged and Qeff$Q_\mathrm{eff}$‐based RQMs. Conclusions: The results indicate that improved proton variable RBE models can be constructed assuming a non‐linear RBE(LET) relationship for individual protons. If similar trends hold also for an in vitro‐environment, variable RBE effects are likely better described by cLETd$\mathrm{cLET}_d$ or tracked averaged cubed LET (cLETt$\mathrm{cLET}_t$), or corresponding Qeff$Q_\mathrm{eff}$‐based RQM, rather than linearly weighted LETd$\text{LET}_d$ or LETt$\text{LET}_t$ which is conventionally applied today. [ABSTRACT FROM AUTHOR]

Simple Summary: Proton therapy has been shown to provide dosimetric benefits in comparison with IMRT when treating prostate cancer with whole pelvis radiation; however, the optimal proton beam arrangement has yet to be established. Twenty-three post-prostatectomy patients were planned using three different beam arrangements: two-field (opposed laterals), three-field (opposed laterals inferiorly matched to a posterior–anterior beam superiorly), and four-field (opposed laterals inferiorly matched to two posterior oblique beams superiorly) arrangements. CTV coverages were similar for all plans, while the four-field plan provided the lowest doses to several metrics for bladder, bowel, sigmoid, rectum, femoral head, bone, penile bulb, and skin. The data presented herein may help inform the future delivery of whole pelvis IMPT for prostate cancer. Background and purpose: Proton therapy has been shown to provide dosimetric benefits in comparison with IMRT when treating prostate cancer with whole pelvis radiation; however, the optimal proton beam arrangement has yet to be established. The aim of this study was to evaluate three different intensity-modulated proton therapy (IMPT) beam arrangements when treating the prostate bed and pelvis in the postoperative setting. Materials and Methods: Twenty-three post-prostatectomy patients were planned using three different beam arrangements: two-field (IMPT2B) (opposed laterals), three-field (IMPT3B) (opposed laterals inferiorly matched to a posterior–anterior beam superiorly), and four-field (IMPT4B) (opposed laterals inferiorly matched to two posterior oblique beams superiorly) arrangements. The prescription was 50 Gy radiobiological equivalent (GyE) to the pelvis and 70 GyE to the prostate bed. Comparisons were made using paired two-sided Wilcoxon signed-rank tests. Results: CTV coverages were met for all IMPT plans, with 99% of CTVs receiving ≥ 100% of prescription doses. All organ at risk (OAR) objectives were met with IMPT3B and IMPT4B plans, while several rectum objectives were exceeded by IMPT2B plans. IMPT4B provided the lowest doses to OARs for the majority of analyzed outcomes, with significantly lower doses than IMPT2B +/− IMPT3B for bladder V30–V50 and mean dose; bowel V15–V45 and mean dose; sigmoid maximum dose; rectum V40–V72.1, maximum dose, and mean dose; femoral head V37–40 and maximum dose; bone V40 and mean dose; penile bulb mean dose; and skin maximum dose. Conclusion: This study is the first to compare proton beam arrangements when treating the prostate bed and pelvis. four-field plans provided better sparing of the bladder, bowel, and rectum than 2- and three-field plans. The data presented herein may help inform the future delivery of whole pelvis IMPT for prostate cancer. [ABSTRACT FROM AUTHOR]

Bragg curves for protons, alpha-particles, and carbon ions in water are calculated using the Geant4 software package. The calculation results, which are of interest for practical applications in proton and ion therapy, are compared with experimental data in terms of the reduced values of χ2. The best result is obtained within the framework of the QBBC-opt_0 physical list, which is not optimized for medical applications. It is concluded that the accuracy of a patient's radiation planning can be improved by developing alternative models of ionization of slow particles in biomaterials. A specific model is proposed, the development of which will help solve this problem. [ABSTRACT FROM AUTHOR]

Background: Quality assurance (QA) for ultra‐high dose rate (UHDR) irradiation is a crucial aspect in the emerging field of FLASH radiotherapy (FLASH‐RT). This innovative treatment approach delivers radiation at UHDR, demanding careful adoption of QA protocols and procedures. A comprehensive understanding of beam properties and dosimetry consistency is vital to ensure the safe and effective delivery of FLASH‐RT. Purpose: To develop a comprehensive pre‐treatment QA program for cyclotron‐based proton pencil beam scanning (PBS) FLASH‐RT. Establish appropriate tolerances for QA items based on this study's outcomes and TG‐224 recommendations. Methods: A 250 MeV proton spot pattern was designed and implemented using UHDR with a 215nA nozzle beam current. The QA pattern that covers a central uniform field area, various spot spacings, spot delivery modes and scanning directions, and enabling the assessment of absolute, relative and temporal dosimetry QA parameters. A strip ionization chamber array (SICA) and an Advanced Markus chamber were utilized in conjunction with a 2 cm polyethylene slab and a range (R80) verification wedge. The data have been monitored for over 3 months. Results: The relative dosimetries were compliant with TG‐224. The variations of temporal dosimetry for scanning speed, spot dwell time, and spot transition time were within ± 1 mm/ms, ± 0.2 ms, and ± 0.2 ms, respectively. While the beam‐to‐beam absolute output on the same day reached up to 2.14%, the day‐to‐day variation was as high as 9.69%. High correlation between the absolute dose and dose rate fluctuations were identified. The dose rate of the central 5 × 5 cm2 field exhibited variations within 5% of the baseline value (155 Gy/s) during an experimental session. Conclusions: A comprehensive QA program for FLASH‐RT was developed and effectively assesses the performance of a UHDR delivery system. Establishing tolerances to unify standards and offering direction for future advancements in the evolving FLASH‐RT field. [ABSTRACT FROM AUTHOR]

Electromagnetic polarizabilities are fundamental properties of the proton that characterize its response to an external electromagnetic (EM) field. The generalization of the EM polarizabilities to non-zero four-momentum transfer opens up a powerful path to study the internal structure of the proton. They map out the spatial distribution of the polarization densities in the proton, provide access to key dynamical mechanisms that contribute to the electric and magnetic polarizability effects, and allow for the determination of fundamental characteristics of the system, such as the electric and magnetic polarizability radii. This article reviews our knowledge about proton EM generalized polarizabilities (GPs). An introduction is given to the basic concepts and the theoretical framework, which is then followed by a discussion that emphasizes the recent developments and findings of the virtual Compton scattering (VCS) experiments and future perspectives on the topic. [ABSTRACT FROM AUTHOR]

Ultra-high dose-rate 'FLASH' radiotherapy may be a pivotal step forward for cancer treatment, widening the therapeutic window between radiation tumour killing and damage to neighbouring normal tissues. The extent of normal tissue sparing reported in pre-clinical FLASH studies typically corresponds to an increase in isotoxic dose-levels of 5-20%, though gains are larger at higher doses. Conditions currently thought necessary for FLASH normal tissue sparing are a dose-rate =40 Gy s-1, dose-per-fraction =5-10 Gy and irradiation duration =0.2-0.5 s. Cyclotron proton accelerators are the first clinical systems to be adapted to irradiate deepseated tumours at FLASH dose-rates, but even using these machines it is challenging to meet the FLASH conditions. In this review we describe the challenges for delivering FLASH proton beam therapy, the compromises that ensue if these challenges are not addressed, and resulting dosimetric losses. Some of these losses are on the same scale as the gains from FLASH found preclinically. We therefore conclude that for FLASH to succeed clinically the challenges must be systematically overcome rather than accommodated, and we survey physical and pre-clinical routes for achieving this. [ABSTRACT FROM AUTHOR]

Background: This paper presents a Monte Carlo (MC) simulation study estimating Relative Biological Effectiveness at a 10% survival fraction (RBE10) of light ion beams by means of microdosimetric approach. Microdosimetric parameters for estimating Relative Biological Effectiveness (RBE) were determined through the utilisation of the Tool for Particle Simulation (TOPAS) MC simulations. These simulations incorporated a 3D silicon on insulator (SOI) Bridge microdosimeter model. Materials and Methods: The incident 176.8 MeV proton and 176.4 MeV/u helium ion beams were simulated at different depths within a water phantom. The microdosimetric aspects, such as YF and YD at different depths along the fields were predicted from simulations. The RBE10 were derived using simulated microdosimetric spectra as inputs to the modified Microdosimetric Kinetic Model (MKM). Results: Simulated YD distributions for proton and helium ion beams in water were about 4 keV/µm and 4 to 8 keV/µm at the plateau region, respectively and around 7 to 14 keV/µm and 35 to 56 keV/µm at the Bragg peak (BP) region, respectively. In the tail region YD values were increasing from 5 keV/µm to 10 keV/µm and 7 keV/µm to 14 keV/µm at depths of 224 mm to 250 mm, respectively. Conclusion: The RBE10 for protons exhibit a range of 0.99 to 1.22, which differs from the standard practice of using a fixed RBE of 1.1 in the Treatment Planning System (TPS) for proton therapy. The simulation results in this study may be used as an outlook for radiobiological experiments in the NASA Space Radiation Laboratory (NSRL). [ABSTRACT FROM AUTHOR]

Background: Proton Beam Therapy (PBT) provides significantly enhanced dose distribution and dosimetric advantages compared to photon beam radiation therapy. In PBT, the Spread-Out Bragg Peak (SOBP) is crucial for achieving a conformal dose distribution within the target volume. We propose a novel method for creating SOBP by passing the beam through slabs containing varying concentrations of Au nanoparticles (NPs). Materials and Methods: GEANT4.10.6 was used for Monte Carlo tracking of proton beams within the slabs and water phantom. Various arrangements of layers containing AuNPs, with concentrations ranging from 1 to 35 M, were positioned along the path of the proton beams with an energy of 200 MeV. The most suitable arrangement of the slabs was determined based on the width of the SOBP and the dose variation in the SOBP plateau. Results: In the most suitable quintuple and sextuple arrangements of slabs, the width of the Bragg peak increases within the range of 45 to 65 mm. Furthermore, in these arrangements, variations in dose within the SOBP plateau are less than 5%. Conclusion: The arrangement of slabs with different AuNP concentrations is a stationary device placed along the beamline. This setup requires no additional time considerations and can be readily incorporated within the clinical setting. [ABSTRACT FROM AUTHOR]

This paper deals with the observer design for a class of Interconnected Takagi–Sugeno (TS) systems with Immeasurable Premise Variables (IPV). We first investigate the D-stability of Luenberger-like interconnected multiple observers. However, the resulting constraints can be somewhat conservative due to the use of a common Lyapunov matrix. Then, the so-called Finsler's lemma is used to relax the D-stability conditions through the introduction of additional slack variables providing more flexibility and extra degrees of freedom. The designed conditions are expressed as Linear Matrix Inequalities (LMIs). The proposed approaches are applied in simulation to a Proton Exchange Membrane Fuel Cell (PEMFC) system and a four-tank system. [ABSTRACT FROM AUTHOR]

Introduction: Proton beam therapy (PBT) may reduce the number of adverse events in treatment of patients with pediatric cancer. However, it is difficult to evaluate whether the actual therapeutic effect is truly equivalent to that of photon radiotherapy. To compare photon radiotherapy and PBT, a meta-analysis and systematic review were performed. Methods: The meta-analysis used papers from 1990 to 2023 in which postoperative local photon radiotherapy or PBT was performed for pediatric intracranial ependymomas. Fifteen articles (5 PBT, 9 photon radiotherapy, one both) were selected based on administration of radiotherapy as local irradiation. Results: Among the 15 chosen articles, the 1- to 5-year overall survival (OS) rates (photon radiotherapy vs. PBT) were 95.4 % (95 % confidence interval (CI) 92.8–97.1 %) vs. 97.2 % (95.7–98.2 %); 88.3 % (85.0–90.9 %) vs. 93.5 % (91.4–95.1 %); 81.2 % (76.9–84.8 %) vs. 91.1 % (88.4–93.2 %); 76.9 % (71.2–81.6 %) vs. 86.1 % (81.9–89.4 %); and 73.8 % (68.3–78.5 %) vs. 84.7 % (79.9–88.5 %), respectively. The 1- to 5-year local control (LC) rates (photon radiotherapy vs. PBT) were 90.9 % (95 % CI 83.9–94.9 %) vs. 91.0 % (88.7–92.9 %); 81.5 % (68.9–89.4 %) vs. 85.7 % (82.0–88.6 %); 77.3 % (62.8–86.8 %) vs. 82.6 % (79.1–85.5 %); 74.6 % (57.7–85.6 %) vs. 78.3 % (71.6–83.5 %); and 72.6 % (51.4–85.8 %) vs. 79.0 % (73.4–83.5 %), respectively. The meta-regression analysis identified relationships of modality (photon radiotherapy vs. PBT), age at irradiation, pathology (Grade 2 vs. Grade 3), and tumor removal (complete resection vs. none) with significantly better 3-year OS after PBT and better 1- to 5-year LC at a younger age. Conclusion: In postoperative local irradiation of ependymomas in children, proton beam therapy had outcomes comparable to those of photon radiotherapy.

Background: Oncologic surgical resection is the standard of care for extremity and truncal soft tissue sarcoma (STS), often accompanied by the addition of pre- or postoperative radiation therapy (RT). Preoperative RT may decrease the risk of joint stiffness and fibrosis at the cost of higher rates of wound complications. Hypofractionated, preoperative RT has been shown to provide acceptable outcomes in prospective trials. Proton beam therapy (PBT) provides the means to decrease dose to surrounding organs at risk, such as the skin, bone, soft tissues, and adjacent joint(s), and has not yet been studied in patients with extremity and truncal sarcoma. Methods: Our study titled "PROspective phase II trial of preoperative hypofractionated protoN therapy for extremity and Truncal soft tissue sarcOma (PRONTO)" is a non-randomized, prospective phase II trial evaluating the safety and efficacy of preoperative, hypofractionated PBT for patients with STS of the extremity and trunk planned for surgical resection. Adult patients with Eastern Cooperative Group Performance Status ≤ 2 with resectable extremity and truncal STS will be included, with the aim to accrue 40 patients. Treatment will consist of 30 Gy radiobiological equivalent of PBT in 5 fractions delivered every other day, followed by surgical resection 2–12 weeks later. The primary outcome is rate of major wound complications as defined according to the National Cancer Institute of Canada Sarcoma2 (NCIC-SR2) Multicenter Trial. Secondary objectives include rate of late grade ≥ 2 toxicity, local recurrence-free survival and distant metastasis-free survival at 1- and 2-years, functional outcomes, quality of life, and pathologic response. Discussion: PRONTO represents the first trial evaluating the use of hypofractionated PBT for STS. We aim to prove the safety and efficacy of this approach and to compare our results to historical outcomes established by previous trials. Given the low number of proton centers and limited availability, the short course of PBT may provide the opportunity to treat patients who would otherwise be limited when treating with daily RT over several weeks. We hope that this trial will lead to increased referral patterns, offer benefits towards patient convenience and clinic workflow efficiency, and provide evidence supporting the use of PBT in this setting. Trial registration: NCT05917301 (registered 23/6/2023). [ABSTRACT FROM AUTHOR]

We report our early clinical experience with image-guided, pencil beam scanning proton beam therapy (PBS-PBT) for residual and recurrent craniopharyngioma. Between September 2019 and January 2023, 19 consecutive patients with residual or recurrent craniopharyngioma, suitable for radiotherapy and treated with image-guided PBS-PBT were analyzed. We documented detailed dosimetric data, acute toxicities, early outcomes, and imaging response on follow-up magnetic resonance imaging scans. A total of 19 patients (11 males and 8 females) with residual or recurrent craniopharyngioma were treated during the study period. The median age of the cohort was 14 years (range, 3–33 years). The histology of most lesions was the adamantinomatous subtype (95%). The most common clinical presentation (before PBT) and most common endocrine deficit was visual disturbance (79%) and hypocortisolism (74%), respectively. Of the 19 patients, 13 had recurrent craniopharyngioma, and 5 had undergone radiotherapy previously. Five patients (26%) had undergone surgery ≥3 times before proton therapy. The median dose delivered was 54 GyE. The most common acute toxicity was grade 1 alopecia (63%). No patient experienced grade ≥3 acute toxicity. With a median follow-up of 18 months (range, 3–40 months), 12 patients showed shrinkage of the residual tumor and/or cyst, and 4 showed a dramatic cyst reduction at 3–9 months of follow-up. Two patients experienced a reduction in both solid and cystic components, with the remaining experiencing a reduction in the cystic component only. The remaining 8 patients had stable disease on magnetic resonance imaging, with 100% disease control and overall survival. Visual function remained stable after treatment. Our preliminary experience with modern PBS-PBT and image guidance for craniopharyngioma is encouraging. Proton therapy in our cohort was well tolerated, resulting in limited toxicity and promising early outcomes. [ABSTRACT FROM AUTHOR]

In this work, the influence of alpha particles, protons and gamma rays on the crystal structure and structural characteristics of n-type silicon (n-Si) single crystals was studied using X-ray diffraction. N-type silicon (KEF-40) was used for the study. The samples were irradiated with protons with a dose of 9×1014 cm-2 with an energy of 600 keV and a current of 1÷1.5 μA, irradiated with alpha particles with a dose of 6×1014 cm-2 with an energy of 800 keV and a current of 0.5÷1 μA and γ-60Co quanta with a flux intensity of ~ 3.2×1012 quantum/cm2·s. Based on the results of X-ray diffraction analysis, it was established that distortions, vacancies and amorphization of lattice parameters that arose after irradiation lead to an increase in lattice parameters. [ABSTRACT FROM AUTHOR]

Introduction: Chondrosarcoma is a rare malignant bone tumor. Particle beam therapy (PT) can concentrate doses to targets while reducing adverse events. A meta-analysis based on a literature review was performed to examine the efficacy of PT and photon radiotherapy for skull base chondrosarcoma. Methods: The meta-analysis was conducted using 21 articles published from 1990 to 2022. Results: After PT, the 3- and 5-year overall survival (OS) rates were 94.1% (95% confidence interval [CI]: 91.0-96.2%) and 93.9% (95% CI: 90.6-96.1%), respectively, and the 3- and 5-year local control rates were 95.4% (95% CI: 92.0-97.4%) and 90.1% (95% CI: 76.8-96.0%), respectively. Meta-regression analysis revealed a significant association of PT with a superior 5-year OS rate compared to three-dimensional conformal radiotherapy (p < 0.001). In the studies used in the meta-analysis, the major adverse event of grade 2 or higher was temporal lobe necrosis (incidence 1-18%, median 7%). Conclusion: PT for skull base chondrosarcoma had a good outcome and may be a valuable option among radiotherapy modalities. However, high-dose postoperative irradiation of skull base chondrosarcoma can cause adverse events such as temporal lobe necrosis. [ABSTRACT FROM AUTHOR]

This work explains that the Coulomb elastic process on the nucleus is a major source of single-event effects (SEE) for protons within the energy range of 1–10 MeV. The infinite range of Coulomb interactions implies an exceptionally high recoil probability. This research seeks to extend the investigations under which the elastic process becomes significant in the energy deposition process by providing a simplified methodology to evaluate the elastic contribution impact on the reliability of electronics. The goal is to derive a method to provide a simple way to calculate and predict the SEE cross-section. At very low energy, we observe a significant increase in the proton differential cross-section. The use of a direct Monte Carlo approach would mainly trigger low energy recoiling ions, and a very long calculation time would be necessary to observe the tail of the spectrum. In this sense, this work provides a simple methodology to calculate the SEE cross-section. The single-event upset (SEU) cross-section results demonstrate a good agreement with the experimental data in terms of shape and order of magnitude for different technological nodes. [ABSTRACT FROM AUTHOR]

To assess the performance of a knowledge-based planning (KBP) model for generating intensity-modulated proton therapy (IMPT) treatment plans as part of an adaptive radiotherapy (ART) strategy for patients with high-risk prostate cancer. A knowledge-based planning (KBP) model for proton adaptive treatment plan generation was developed based on thirty patient treatment plans utilizing RapidPlanTM PT (Varian Medical Systems, Palo Alto, CA). The model was subsequently validated using an additional eleven patient cases. All patients in the study were administered a prescribed dose of 70.2 Gy to the prostate and seminal vesicle (CTV70.2), along with 46.8 Gy to the pelvic lymph nodes (CTV46.8) through simultaneous integrated boost (SIB) technique. To assess the quality of the validation knowledge-based proton plans (KBPPs), target coverage and organ-at-risk (OAR) dose-volume constraints were compared against those of clinically used expert plans using paired t -tests. The KBP model training statistics (R2) (mean ± SD, 0.763 ± 0.167, range, 0.406 to 0.907) and χ² values (1.162 ± 0.0867, 1.039-1.253) indicate acceptable model training quality. Moreover, the average total treatment planning optimization and calculation time for adaptive plan generation is approximately 10 minutes. The CTV70.2 D 98% for the KBPPs (mean ± SD, 69.1 ± 0.08 Gy) and expert plans (69.9 ± 0.04 Gy) shows a significant difference (p < 0.05) but are both within 1.1 Gy of the prescribed dose which is clinically acceptable. While the maximum dose for some organs-at-risk (OARs) such as the bladder and rectum is generally higher in the KBPPs, the doses still fall within clinical constraints. Among all the OARs, most of them received comparable results to the expert plan, except the cauda equina D max , which shows statistical significance and was lower in the KBPPs than in expert plans (48.5 ± 0.06 Gy vs 49.3 ± 0.05 Gy). The generated KBPPs were clinically comparable to manually crafted plans by expert treatment planners. The adaptive plan generation process was completed within an acceptable timeframe, offering a quick same-day adaptive treatment option. Our study supports the integration of KBP as a crucial component of an ART strategy, including maintaining plan consistency, improving quality, and enhancing efficiency. This advancement in speed and adaptability promises more precise treatment in proton ART. [ABSTRACT FROM AUTHOR]

With the extraction of surface minerals and the depletion of their reserves, the exploration of deeper deposits has become a pressing consideration. Among the geophysical techniques available for such exploration, magnetometry stands out. Proton magnetometers, the prevailing instruments in terrestrial magnetometry, are characterized by their high cost, high weight, and large size. Moreover, their low sampling rate necessitates prolonged and consequently costly field operations. However, the advancement of Micro Electro Mechanical System (MEMS) sensors, which are both lightweight and cost-effective and possess high sampling rates and satisfactory sensitivity, has garnered significant interest. In this research, one such MEMS sensor was deployed and employed in the examination of a small iron deposit located in Western Iran. Then, the findings from these measurements were compared to those obtained using a proton magnetometer. The comparison reveals a substantial difference in efficiency. Magnetometry with MEMS sensors over the selected deposit took approximately 8.5 hours, whereas the survey with the proton magnetometer on the same profiles spanned around 44 hours. In addition to the time savings, the application of MEMS sensors led to a remarkable reduction in operating costs, by up to fivefold. On the other hand, due to the small size of this magnetometer, by placing it in a handbag or backpack of the operator, it is possible to carry out the magnetometer survey without any problem of dealing with the opponents and to prevent the postponement of the field magnetometer operation. [ABSTRACT FROM AUTHOR]

SLC4A11 is the most abundant membrane transport protein in corneal endothelial cells. Its functional presence is necessary to support the endothelial fluid pump that draws fluid from the corneal stroma, preventing corneal edema. Several molecular actions have been proposed for SLC4A11 including H2O transport and cell adhesion. One of the most reproduced actions that SLC4A11 mediates is a H+ (or OH−) conductance that is enhanced in the presence of NH4Cl. The mechanism by which this occurs is controversial with some providing evidence in favor of NH3-H+ cotransport and others providing evidence for uncoupled H+ transport that is indirectly stimulated by the effects of NH4Cl upon intracellular pH and membrane potential. In the present study we provide new evidence and revisit previous studies, to support a model in which NH4Cl causes direct allosteric activation of SLC4A11 by means of an acidic shift in the intracellular pK (pKi) that governs the relationship between intracellular pH (pHi) and SLC4A11 H+-conductance. These findings have important implications for the assignment of a physiological role for SLC4A11.

Electromagnetic polarizabilities are fundamental properties of the proton that characterize its response to an external electromagnetic (EM) field. The generalization of the EM polarizabilities to non-zero four-momentum transfer opens up a powerful path to study the internal structure of the proton. They map out the spatial distribution of the polarization densities in the proton, provide access to key dynamical mechanisms that contribute to the electric and magnetic polarizability effects, and allow for the determination of fundamental characteristics of the system, such as the electric and magnetic polarizability radii. This article reviews our knowledge about proton EM generalized polarizabilities (GPs). An introduction is given to the basic concepts and the theoretical framework, which is then followed by a discussion that emphasizes the recent developments and findings of the virtual Compton scattering (VCS) experiments and future perspectives on the topic.

Ultra-high dose-rate ‘FLASH’ radiotherapy may be a pivotal step forward for cancer treatment, widening the therapeutic window between radiation tumour killing and damage to neighbouring normal tissues. The extent of normal tissue sparing reported in pre-clinical FLASH studies typically corresponds to an increase in isotoxic dose-levels of 5–20%, though gains are larger at higher doses. Conditions currently thought necessary for FLASH normal tissue sparing are a dose-rate ≥40 Gy s-1, dose-per-fraction ≥5–10 Gy and irradiation duration ≤0.2–0.5 s. Cyclotron proton accelerators are the first clinical systems to be adapted to irradiate deep-seated tumours at FLASH dose-rates, but even using these machines it is challenging to meet the FLASH conditions. In this review we describe the challenges for delivering FLASH proton beam therapy, the compromises that ensue if these challenges are not addressed, and resulting dosimetric losses. Some of these losses are on the same scale as the gains from FLASH found pre-clinically. We therefore conclude that for FLASH to succeed clinically the challenges must be systematically overcome rather than accommodated, and we survey physical and pre-clinical routes for achieving this.

This work explains that the Coulomb elastic process on the nucleus is a major source of single-event effects (SEE) for protons within the energy range of 1–10 MeV. The infinite range of Coulomb interactions implies an exceptionally high recoil probability. This research seeks to extend the investigations under which the elastic process becomes significant in the energy deposition process by providing a simplified methodology to evaluate the elastic contribution impact on the reliability of electronics. The goal is to derive a method to provide a simple way to calculate and predict the SEE cross-section. At very low energy, we observe a significant increase in the proton differential cross-section. The use of a direct Monte Carlo approach would mainly trigger low energy recoiling ions, and a very long calculation time would be necessary to observe the tail of the spectrum. In this sense, this work provides a simple methodology to calculate the SEE cross-section. The single-event upset (SEU) cross-section results demonstrate a good agreement with the experimental data in terms of shape and order of magnitude for different technological nodes.

Accurate determination of cross-sections for residual radionuclide products (spallation fragments) resulting from proton spallation reactions is imperative for the detection of primary and secondary particles etc. Experimental measurement of these cross-sections faces challenges due to the complexities associated with target preparation and detection of spallation fragments. Monte Carlo simulations have emerged as a potent tool for estimation of spallation fragments yield. This research, with introducing an innovative formulation method based on spallation yield, focuses on calculating the cross-section for the detection of primary and secondary particles in particle interaction with matter. Investigations indicate that the introduced method achieves remarkable agreement, ranging from 85.4% to 95.15%, with experimental outcomes at MeV energies. Consequently, this method can confidently be utilized for calculating the spallation cross-section fragments. In a case study, the spallation fragment cross-section was calculated for proton beam interaction with 222Rn in the range of 10 MeV to 60 MeV for the application of 222Rn detection. Among the 28 common spallation products of radon with the proton interaction in the energy range of 10 MeV to 60 MeV, elements 106Mo, 109Tc, 118Cd, 112Ru, 110Pd, and 114Rh exhibit dominant spallation cross-sections, emphasizing their exceptional significance.

Proton radiotherapy may be a compelling technical option for the treatment of breast cancer due to its unique physical property known as the "Bragg peak." This feature offers distinct advantages, promising superior dose conformity within the tumor area and reduced radiation exposure to surrounding healthy tissues, enhancing the potential for better treatment outcomes. However, proton therapy is accompanied by inherent challenges, primarily higher costs and limited accessibility when compared to well-developed photon irradiation. Thus, in clinical practice, it is important for radiation oncologists to carefully select patients before recommendation of proton therapy to ensure the transformation of dosimetric benefits into tangible clinical benefits. Yet, the optimal indications for proton therapy in breast cancer patients remain uncertain. While there is no widely recognized methodology for patient selection, numerous attempts have been made in this direction. In this review, we intended to present an inspiring summarization and discussion about the current practices and exploration on the approaches of this treatment decision-making process in terms of treatment-related side-effects, tumor control, and cost-efficiency, including the normal tissue complication probability (NTCP) model, the tumor control probability (TCP) model, genomic biomarkers, cost-effectiveness analyses (CEAs), and so on. Additionally, we conducted an evaluation of the eligibility criteria in ongoing randomized controlled trials and analyzed their reference value in patient selection. We evaluated the pros and cons of various potential patient selection approaches and proposed possible directions for further optimization and exploration. In summary, while proton therapy holds significant promise in breast cancer treatment, its integration into clinical practice calls for a thoughtful, evidence-driven strategy. By continuously refining the patient selection criteria, we can harness the full potential of proton radiotherapy while ensuring maximum benefit for breast cancer patients. [ABSTRACT FROM AUTHOR]

In the pursuit of enhancing the technological maturity of innovative magnetic sensing techniques, opportunities presented by in-orbit platforms (IOD/IOV experiments) provide a means to evaluate their in-flight capabilities. The Magnetic Experiments for the Laser Interferometer Space Antenna (MELISA) represent a set of in-flight demonstrators designed to characterize the low-frequency noise performance of a magnetic measurement system within a challenging space environment. In Low Earth Orbit (LEO) satellites, electronic circuits are exposed to high levels of radiation coming from energetic particles trapped by the Earth's magnetic field, solar flares, and galactic cosmic rays. A significant effect is the accidental bit-flipping in memory registers. This work presents an analysis of memory data redundancy resources using auxiliary second flash memory and exposes recovery options to retain critical data utilizing a duplicated data structure. A new and lightweight technique, CCM (Cross-Checking and Mirroring), is proposed to verify the proper performance of these techniques. Four alternative algorithms included in the original version of the MELISA software (Version v0.0) are presented. All the versions have been validated and evaluated according to various merit indicators. The evaluations showed similar performances for the proposed techniques, and they are valid for situations in which the flash memory suffers from more than one bit-flip. The overhead due to the introduction of additional instructions to the main code is negligible, even in the target experiment based on an 8-bit microcontroller. [ABSTRACT FROM AUTHOR]

Simple Summary: Around 30% of the patients receiving intracranial particle therapy develop radiogenic reactions of the brain. There are a wide range of symptoms, ranging from asymptomatic blood–brain barrier disorders to life-threatening brain necrosis. The aim of our retrospective study is to assess the patterns of occurrence in patients treated for skull base chordoma and chondrosarcoma with protons or carbon ions. Furthermore, we aimed to develop a prognostic model for the prediction of radiation reactions. Background: The current study aims to evaluate the occurrence of temporal lobe reactions and identify possible risk factors for patients who underwent particle therapy of the skull base. Methods: 244 patients treated for skull base chordoma (n = 144) or chondrosarcoma (n = 100) at the Heidelberg Ion Beam Therapy Center (HIT) using a raster scan technique, were analyzed. Follow-up MRI-scans were matched with the initial planning images. Radiogenic reactions were contoured and analyzed based on volume and dose of treatment. Results: 51 patients with chordoma (35.4%) and 30 patients (30%) with chondrosarcoma experienced at least one temporal lobe reaction within the follow-up period (median 49 months for chondrosarcoma, 62 months for chordoma). Age, irradiated volume, and dose values were significant risk factors for the development of temporal lobe reactions with the highest significance for the value of DMax-7 being defined as the dose maximum in the temporal lobe minus the 7cc with the highest dose (p = 0.000000000019; OR 1.087). Conclusion: Temporal lobe reactions are a common side effect after particle therapy of the skull base. We were able to develop a multivariate model, which predicted radiation reactions with a specificity of 99% and a sensitivity of 52.2%. [ABSTRACT FROM AUTHOR]

The compound semiconductor gallium nitride offers enormous potential for facilitating economic expansion in the silicon-based semiconductor industry, which is currently seeing decreasing performance returns compared to investment costs. Its high electron mobility and electric field strength at the material level have already demonstrated enormous potential for photonics and high-frequency communications applications. However, its application in devices used in the radiation-prone environment is hindered by degradation and failure caused by the radiation. In this paper, the effect of proton radiation on the electrical properties of InGaN light emitting diodes (LEDs) for the fluence range of 1×1014 cm-2 to 3×1014 cm-2 is performed. On comparing the results before and after radiation, it is found that radiation mainly affected the reverse IV characteristics of the device with little or no effect on forward IV or CV characteristics. Apart from the electric properties, the optical properties of the LEDs show improvement after radiation as the light intensity increases post-irradiation. [ABSTRACT FROM AUTHOR]

Background: Surface‐guided radiation therapy (SGRT) systems have been widely installed and utilized on linear accelerators. However, the use of SGRT with proton therapy is still a newly developing field, and published reports are currently very limited. Purpose: To assess the clinical application and alignment agreement of SGRT with CT‐on‐rails (CTOR) and kV‐2D image‐guided radiation therapy (IGRT) for breast treatment using proton therapy. Methods: Four patients receiving breast or chest wall treatment with proton therapy were the subjects of this study. Patient #1′s IGRT modalities were a combination of kV‐2D and CTOR. CTOR was the only imaging modality for patients #2 and #3, and kV‐2D was the only imaging modality for patient #4. The patients' respiratory motions were assessed using a 2‐min surface position recorded by the SGRT system during treatment. SGRT offsets reported after IGRT shifts were recorded for each fraction of treatment. The agreement between SGRT and either kV‐2D or CTOR was evaluated. Results: The respiratory motion amplitude was <4 mm in translation and <2.0° in rotation for all patients. The mean and maximum amplitude of SGRT offsets after application of IGRT shifts were ≤(2.6 mm, 1.6°) and (6.8 mm, 4.5°) relative to kV‐2D‐based IGRT; ≤(3.0 mm, 2.6°) and (5.0 mm, 4.7°) relative to CTOR‐based IGRT without breast tissue inflammation. For patient #3, breast inflammation was observed for the last three fractions of treatment, and the maximum SGRT offsets post CTOR shifts were up to (14.0 mm, 5.2°). Conclusions: Due to the overall agreement between SGRT and IGRT within reasonable tolerance, SGRT has the potential to serve as a valuable auxiliary IGRT tool for proton breast treatment and may improve the efficiency of proton breast treatment. [ABSTRACT FROM AUTHOR]

The low ionic conductivity of proton conductor electrolytes at low temperatures was one of the key issues that restrict the reduction of operating temperature in ceramic fuel cells. The traditional Y-doped BaCeO 3 proton conductor (BCY) has an ionic conductivity of only a few tens of mS·cm−1 at 500 °C, which cannot meet the needs of high-performance low-temperature ceramic fuel cells. In this paper, we found that the ionic conductivity of the composite electrolyte made by adding 20 % Li 2 O to BCY at 550 °C was 0.526 S cm−1, which was 40 times that of the dense BCY electrolyte sintered at 1550 °C. The maximum power density of a ceramic fuel cell using a BCY- Li 2 O composite material with a thickness of 1 mm as the electrolyte and porous Ag as the symmetrical electrode was 129 mW cm−2 in H 2 at 550 °C. The characterization results of XRD, EPR, and FTIR showed that there may be a region with a large number of oxygen vacancies and lithium vacancies created at the interface of the BCY and Li 2 O–LiOH composite electrolyte formed in the BCY-Li 2 O composite electrolyte during the testing conditions for fuel cell performance due to the migration of Li+. The formation of this region should be the main reason for the extremely high conductivity of the BCY-Li 2 O–LiOH composite electrolytes formed in the cell at low temperatures. [ABSTRACT FROM AUTHOR]

Accurate determination of cross-sections for residual radionuclide products (spallation fragments) resulting from proton spallation reactions is imperative for the detection of primary and secondary particles etc. Experimental measurement of these cross-sections faces challenges due to the complexities associated with target preparation and detection of spallation fragments. Monte Carlo simulations have emerged as a potent tool for estimation of spallation fragments yield. This research, with introducing an innovative formulation method based on spallation yield, focuses on calculating the cross-section for the detection of primary and secondary particles in particle interaction with matter. Investigations indicate that the introduced method achieves remarkable agreement, ranging from 85.4% to 95.15%, with experimental outcomes at MeV energies. Consequently, this method can confidently be utilized for calculating the spallation cross-section fragments. In a case study, the spallation fragment cross-section was calculated for proton beam interaction with 222Rn in the range of 10 MeV to 60 MeV for the application of 222Rn detection. Among the 28 common spallation products of radon with the proton interaction in the energy range of 10 MeV to 60 MeV, elements 106Mo, 109Tc, 118Cd, 112Ru, 110Pd, and 114Rh exhibit dominant spallation cross-sections, emphasizing their exceptional significance. [ABSTRACT FROM AUTHOR]

Simple Summary: Ultra-high dose rate (UHDR) irradiation in proton therapy has mostly been performed using a cyclotron system so far. In this study, we present our approach to achieve an ultra-high dose rate for a clinical synchrotron proton therapy system and its dosimetric specifications. We demonstrated that it is feasible to adapt an existing clinical synchrotron-based proton therapy system and reach ~100 nA nozzle beam. UHDR dose rate (>40 Gy/s) was reached with the tested spot scanning patterns. The maximum dose per spill depends on the field size and is limited by the maximum charge extraction per spill. A beam monitoring ion chamber is currently being incorporated into the beam control system to improve system reproducibility and expand the irradiation area. Background: This study aims to present the feasibility of developing a synchrotron-based proton ultra-high dose rate (UHDR) pencil beam scanning (PBS) system. Methods: The RF extraction power in the synchrotron system was increased to generate 142.4 MeV pulsed proton beams for UHDR irradiation at ~100 nA beam current. The charge per spill was measured using a Faraday cup. The spill length and microscopic time structure of each spill was measured with a 2D strip transmission ion chamber. The measured UHDR beam fluence was used to derive the spot dwell time for pencil beam scanning. Absolute dose distributions at various depths and spot spacings were measured using Gafchromic films in a solid-water phantom. Results: For proton UHDR beams at 142.4 MeV, the maximum charge per spill is 4.96 ± 0.10 nC with a maximum spill length of 50 ms. This translates to an average beam current of approximately 100 nA during each spill. Using a 2 × 2 spot delivery pattern, the delivered dose per spill at 5 cm and 13.5 cm depth is 36.3 Gy (726.3 Gy/s) and 56.2 Gy (1124.0 Gy/s), respectively. Conclusions: The synchrotron-based proton therapy system has the capability to deliver pulsed proton UHDR PBS beams. The maximum deliverable dose and field size per pulse are limited by the spill length and extraction charge. [ABSTRACT FROM AUTHOR]

In this paper, we have analyzed the proton form factor data by using a number of phenomenological parametrizations (models) and extracting the proton electric and magnetic radii. To this end, we performed a global fit to all available form factor data, with the virtual photon momentum squared Q 2 from 0. 0 0 0 2 to nearly 10 GeV2 for electric form factor and from 0. 0 1 5 to 31 GeV2 for magnetic one. Special attention was given to the small structure shown by the form factor data near Q 2 = 0. 2 GeV2. It was found that different models yield different structures with different numbers of minimum at this kinematics. Since the slope of form factor in the limit of Q 2 → 0 is influenced by this structure, the extracted proton radii are consequently different for different models. Our finding recommends that future experiments should focus on this kinematics instead of low Q 2 . Experimental data with accuracies comparable to those of the latest data at low Q 2 would clearly help to clarify the effect of this structure on the proton charge radius. Interestingly, most of the extracted proton charge radii were found to be closer to the value obtained from the muonic hydrogen atom spectroscopy. [ABSTRACT FROM AUTHOR]

A systematic directionality coherent control of total proton momentum distributions in the dissociative‐ionization of H2+ subjected to a strong field of six‐cycle laser pulses in a full range of carrier‐envelope phase ϑ is studied by solving a non‐Born‐Oppenheimer time‐dependent Schrödinger equation numerically. The trend of distributions involves insightful investigation into the spatial‐temporal overlap between nuclear wave packets evolving on the coupled field‐dressed electronic potentials of H2+ associated with the n‐photon potential crossings. This leads to new quantum images for the nonlinear nonperturbative interaction of H2+ with a strong field. It turns out that the symmetry of the ϑ‐dependent momentum distribution begins to break after undergoing interaction with one‐photon field‐dressed potentials. At this point, the most probable proton momentum distribution tends to move in a forward direction indicating also that the three‐photon field‐dressed potentials strongly govern the dissociative‐ionization pathway. [ABSTRACT FROM AUTHOR]

Based on the concept of the proton hydrate-anion complex [H(H2O)n]+A−, equations are proposed that characterize the catalytic activity of the proton in aqueous solutions of three acids: sulfuric, hydrochloric, and chloric. The equations are based on the linear dependence of the value of "excessive acidity" on the logarithm of the relative stoichiometric concentration of water Х = f(log C*w) in acid solutions with a predominance of water (Н2О/НА > 1). Using the directly proportional dependence of the Hammett function (–H0) on the sum of parameters (log C*H+ + mX), two-parameter equations were obtained for calculating the complex function of acidity –Hw0 = log C*H+ + Blog C*w (standard state—pure water, C0w). The equations make it possible to calculate the function Hw0 at a given acid concentration, having only data on the concentrations of the proton CH+ and water Hw0, i.e. avoiding the use of the ratio of the activity coefficients of the components included in parameter X. The function Hw0 collectively reflects the participation of proton and water in the acidity of the medium, practically reproduces the experimental values of H0 obtained by different authors in the concentration range from pure water to 68 wt % (H2SO4), 40% (HCl), 70% (HClO4), combines the pH and H0 scales. It is concluded that the Blog Hw0 contribution, which characterizes the participation of water in the hydration shells of ions, is determined by their nature and plays no less important role in characterizing the acidity of the medium than the proton itself. The final tables of the concentration dependence of the values Hw0 for each of the acids are given. The paper represents a methodological review, since it is based on a critical analysis of experimental literature data. [ABSTRACT FROM AUTHOR]

The electron emission yields from silicon carbide ceramics and silicon surfaces induced by protons in the energy range of 50～250 keV were measured on the 320 kV electron cyclotron resonance ion source(ECRIS) platform of the Institute of Modern Physics, Chinese Academy of Science(IMP, CAS) in Lanzhou. The experimental results show that the variation trend of electron emission yield with proton incident energy of the two kinds of semiconductor targets is similar to the variation trend of electronic energy loss with proton incident energy during the action process. By analyzing the energy source of electron emission, it is found that the electron emission is mainly contributed by the kinetic electron emission, and the potential electron emission can be ignored. The electron emission yield of the two targets is approximately proportional to the electronic energy loss in the process of proton incident on the target, and the proportionality coefficient B varies slightly with the incident energy. The results will provide important reference data for the study of electron emission in the process of ion and semiconductor target interaction and the characteristics of new semiconductor materials. [ABSTRACT FROM AUTHOR]

Over the last three decades, the Malaysian government has undertaken a number of steps to ensure the competitiveness of its automotive industry and to stay up with worldwide advances in this sector. This study investigates the factors influencing consumer purchase behavior towards locally manufactured vehicles, specifically on Malaysians who own national cars, namely Proton and Perodua. Based on a causal research design, this study employed descriptive statistics and Partial Least Squares-Structural Equation Modelling (PLS-SEM) method. Findings from a survey of 281 respondents from different states in Malaysia showed partial support for the effect of country-of-origin, price-quality association, and value consciousness on attitude towards products and behavioral behavior. The findings suggest that it is crucial for practitioners to understand the impact of country-of-origin, price-quality association, value consciousness, and attitude towards products on behavioral intention, in the context of Malaysian perceptions towards Proton and Perodua cars. Thus, the outcome of this study helps to expand current knowledge on consumers purchase towards Proton and Perodua cars, and contributively effect of country-of-origin effects, price-quality association, and value consciousness on attitude towards products and purchase intention towards Proton and Perodua cars. [ABSTRACT FROM AUTHOR]

The inspiration for writing this editorial came from a recent visit to the European Organization for Nuclear Research (CERN, Conseil Européen pour la Recherche Nucléaire) in Geneva. There I had the opportunity to take a closer look at the technology of proton production and acceleration in cyclotrons. I was impressed by this direct insight into physical findings that have an impact on many other scientific fields. I learned how these scientific discoveries are used in medicine, especially in oncology, and how this interdisciplinary approach can improve patients' lives. This experience gave me a new perspective and encouraged me to research and write about this important and innovative field. In the following, we will explore how proton therapy has changed the way and success of treatments in oncology and how the interdisciplinary collaboration between physics and medicine has contributed to this progress. In addition, I have focused on the relevance of this technology to veterinary medicine and the potential it offers for improving cancer treatment in our pets. Interdisciplinarni pristopi k onkološkim zdravljenjem: Protonska terapija na presečišču fizike in medicine Navdih za pisanje tega uredniškega članka je nastal z nedavnim obiskom Evropske organizacije za jedrske raziskave (CERN, Conseil Européen pour la Recherche Nucléaire) v Ženevi. Tam sem imela priložnost pobliže spoznati tehnologijo pridobivanja protonov in njihovega pospeševanja v ciklotronih. Ta neposreden vpogled v fizikalno znanje, ki seva v mnoga druga znanstvena področja, me je navdušil. Spoznala sem, kako se ta znanstvena odkritja uporabljajo v medicini, zlasti v onkologiji, in kako lahko ta interdisciplinarni pristop izboljša življenja bolnikov. Ta izkušnja mi je dala novo perspektivo in me spodbudila k raziskovanju in pisanju o tem pomembnem in inovativnem področju. V nadaljevanju bomo raziskali, kako je protonska terapija preoblikovala način in uspešnost zdravljenj v onkologiji in kako je interdisciplinarno sodelovanje med fiziko in medicino prispevalo k temu napredku. Pri tem sem se osredotočila o pomenu te tehnologije za veterinarsko medicino in kakšen potencial predstavlja pri izboljšanju zdravljenja raka pri naših ljubljenčkih.

PurposePediatric brain tumor patients are vulnerable to radiotherapy (RT) sequelae including endocrinopathies. We compared post-RT neuroendocrine outcomes between pediatric brain tumor patients receiving photons (XRT) versus protons (PRT).MethodsUsing a prospectively maintained single-institution database, we analyzed 112 pediatric primary brain tumor patients (80 XRT, 32 PRT) from 1996 to 2019. Patient/treatment characteristics and endocrinopathy diagnoses (growth hormone deficiency [GHD], sex hormone deficiency [SHD], hypothyroidism, and requirement of hormone replacement [HRT]) were obtained via chart review. Univariable/multivariable logistic regression identified neuroendocrine outcome predictors. Time-adjusted propensity score models accounted for treatment type. Craniospinal irradiation (CSI) patients were evaluated as a sub-cohort.ResultsMedian follow-up was 6.3 and 4.4 years for XRT and PRT patients respectively. Medulloblastoma was the most common histology (38%). Half of patients (44% in XRT, 60% in PRT) received CSI. Common endocrinopathies were GHD (26% XRT, 38% PRT) and hypothyroidism (29% XRT, 19% PRT). CSI cohort PRT patients had lower odds of hypothyroidism (OR 0.16, 95% CI[0.02-0.87], p = 0.045) on multivariable regression and propensity score analyses. There were no significant differences in endocrinopathies in the overall cohort and in the odds of GHD or HRT within the CSI cohort. SHD developed in 17.1% of the XRT CSI group but did not occur in the PRT CSI group.ConclusionEndocrinopathies were common among pediatric brain tumor survivors. Among CSI patients, PRT was associated with lower risk of hypothyroidism, and potentially associated with lower incidence of SHD. Future studies should involve collaborative registries to explore the survivorship benefits of PRT.

Purpose: Obtaining prior authorization (PA) before treatment is becoming increasingly burdensome in oncology, especially in radiation oncology. Here, we describe the impact of a strategic novel operational PA redesign to shorten authorization time and to improve patient access to cancer care at a large United States academic proton therapy center. We ask whether such a redesign may be replicable and adoptable across oncology centers. Materials and Methods: Our PA redesign strategy was based on a 3-tiered approach. Specifically, we (1) held payors accountable to legally backed timelines, (2) leveraged expertise on insurance policies and practices, and (3) updated the submission, appeal writing, and planning procedures for PA. Metrics were compared at the following 3 time points: 6 months before, at phase-in, and at 6 months after intervention. Results: In analyzing the impact of improving PA access to care, the percentage of approvals for commercial proton beam therapy improved by an absolute 30.6% postintervention (P < .001). The proportion of commercially insured patients treated with proton beam therapy also increased by 6.2%, and the number of new starts rose by 11.7 patients/mo. Overall patient census increased by 13 patients/d. Median authorization time was 1 week, and 90% of surveyed providers reported reduced PA burden and improved patient care. Conclusion: This is the first validated, comprehensive operational strategy to improve access to cancer therapy while reducing the burden of PA. This novel approach may be helpful for addressing barriers to PA in medical and surgical oncology because the redesign is predicated on laws that regulate PA across disciplines.

Silicon Photomultipliers (SiPMs) are single photon detectors that gained increasing interest in many applications as an alternative to photomultiplier tubes. In the field of space experiments, where volume, weight and power consumption are a major constraint, their advantages like compactness, ruggedness, and their potential to achieve high quantum efficiency from UV to NIR makes them ideal candidates for spaceborne, low photon flux detectors. During space missions however, SiPMs are usually exposed to high levels of radiation, both ionizing and non-ionizing, which can deteriorate the performance of these detectors over time. The goal of this work is to compare process and layout variation of SiPMs in terms of their radiation damage effects to identify the features that helps reduce the deterioration of the performance and develop the next generation of more radiation-tolerant detectors. To do this, we used protons and X-rays to irradiate several Near Ultraviolet High-Density (NUV-HD) SiPMs with small areas (single microcell, 0.2 × 0.2 mm2 and 1 × 1 mm2) produced at Fondazione Bruno Kessler (FBK), Italy. We performed online current-voltage measurements right after each irradiation step, and a complete functional characterization before and after irradiation. We observed that the main contribution to performance degradation in space applications comes from proton damage in the form of an increase in primary dark count rate (DCR) proportional to the proton fluence and a reduction in activation energy. In this context, small active area devices show a lower DCR before and after irradiation, and we propose light or charge-focusing mechanisms as future developments for high-sensitivity radiation-tolerant detectors.

Highly intense bunches of protons and ions with energies of several MeV/u can be generated with ultra-short laser pulses focused on solid targets. In the most common interaction regime, target normal sheath acceleration, the spectra of these particles are spread over a wide range following a Maxwellian distribution. We report on the design and testing of a magnetic chicane for the selection of protons within a limited energy window. This consisted of two successive, anti-parallel dipole fields generated by cost-effective permanent C-magnets with customized configuration and longitudinal positions. The chicane was implemented into the target vessel of a petawatt laser facility with constraints on the direction of the incoming laser beam and guidance of the outgoing particles through a vacuum port. The separation of protons and carbon ions within distinct energy intervals was demonstrated and compared to a ray tracing code. Measurements with radiochromic film stacks indicated the selection of protons within [2.4, 6.9] MeV, [5.0, 8.4] MeV, or ≥6.9 MeV depending on the lateral dispersion. A narrow peak at 4.8 MeV was observed with a time-of-flight detector.