Electron Capture Research Articles

High-precision measurements of the atomic mass and electron-capture decay Q value of 95Tc

A direct measurement of the ground-state-to-ground-state electron-capture decay Q value of 95Tc has been performed utilizing the double Penning trap mass spectrometer JYFLTRAP. The Q value was determined to be 1695.92(13) keV by taking advantage of the high resolving power of the phase-imaging ion-cyclotron-resonance technique to resolve the low-lying isomeric state of 95Tc (excitation energy of 38.910(40) keV) from the ground state. The mass excess of 95Tc was measured to be −86015.95(18) keV/c2, exhibiting a precision of about 28 times higher and in agreement with the value from the newest Atomic Mass Evaluation (AME2020). Combined with the nuclear energy-level data for the decay-daughter 95Mo, two potential ultra-low Q-value transitions are identified for future long-term neutrino-mass determination experiments. The atomic self-consistent many-electron Dirac–Hartree–Fock–Slater method and the nuclear shell model have been used to predict the partial half-lives and energy-release distributions for the two transitions. The dominant correction terms related to those processes are considered, including the exchange and overlap corrections, and the shake-up and shake-off effects. The normalized distribution of the released energy in the electron-capture decay of 95Tc to excited states of 95Mo is compared to that of 163Ho currently being used for electron-neutrino-mass determination.

Removal residual, commercial processing factor and risk assessment of four fungicides in orange fruit and various processing by-products

The residual behaviors and processing factors of four fungicides (prochloraz, kasugamycin, oxine-copper and fenaminstrobin) in orange fruit and various processing by-products were evaluated. The residues of kasugamycin, oxine-copper and fenaminstrobin were detected using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with QuEChERS pretreatment method and that of prochloraz was monitored using gas chromatography with an electron capture detector (GC-ECD). The results showed washing processing reduced residues by 8.6%-33.9%. Juicing was an effective process to reduce pesticide residues by 65.6%-98.7% with processing factor (PF) of 0.021-0.339. However, high levels of residual prochloraz, oxine-copper and fenaminstrobin (from 5.777 to 51.533mg/kg) were detected in orange essential oils, with PF of 8.720-14.558. Prochloraz was more easily enriched in wet pomace compared with the other three fungicides. When spraying was conducted in accordance with good agricultural practices and using the recommended highest pesticide application dosage and frequency, the dietary intake exposure risks of the four residual fungicides in orange and its processed juices in China were less than 100% for different age groups and caused no unacceptable risks to human health.

Customizing Bonding Affinity with Multi‐Intermediates via Interfacial Electron Capture to Boost Hydrogen Evolution in Alkaline Water Electrolysis

AbstractDeveloping efficient and earth‐abundant alkaline HER electrocatalysts is pivotal for sustainable energy, but co‐regulating its intricate multi‐step process, encompassing water dissociation, OH− desorption, and hydrogen generation, is still a great challenge. Herein, we tackle these obstacles by fabricating a vertically integrated electrode featuring a nanosheet array with prominent dual‐nitride metallic heterostructures characterized by impeccable lattice matching and excellent conductivity, functioning as a multi‐purpose catalyst to fine‐tune the bonding affinity with alkaline HER intermediates. Detailed structural characterization and theoretical calculation elucidate that charge redistribution at the heterointerface reduces the O p‐W d and H s‐W d interactions vs. single nitride, thereby enhancing OH− transfer and H2 release. As anticipated, the resulting WN‐NiN/CFP catalyst demonstrates a gratifying low overpotential of 36.8 mV at 10 mA/cm2 for alkaline HER, while concurrently maintaining operational stability for 1300 h at 100 mA/cm2 for overall water splitting. This work presents an effective approach to meticulously optimize multiple site‐intermediate interactions in alkaline HER, laying the foundation for efficient energy conversion.

Customizing Bonding Affinity with Multi-Intermediates via Interfacial Electron Capture to Boost Hydrogen Evolution in Alkaline Water Electrolysis.

Developing efficient and earth-abundant alkaline HER electrocatalysts is pivotal for sustainable energy, but co-regulating its intricate multi-step process, encompassing water dissociation, OH- desorption, and hydrogen generation, is still a great challenge. Herein, we tackle these obstacles by fabricating a vertically integrated electrode featuring a nanosheet array with prominent dual-nitride metallic heterostructures characterized by impeccable lattice matching and excellent conductivity, functioning as a multi-purpose catalyst to fine-tune the bonding affinity with alkaline HER intermediates. Detailed structural characterization and theoretical calculation elucidate that charge redistribution at the heterointerface reduces the O p-W d and H s-W d interactions vs. single nitride, thereby enhancing OH- transfer and H2 release. As anticipated, the resulting WN-NiN/CFP catalyst demonstrates a gratifying low overpotential of 36.8 mV at 10 mA/cm2 for alkaline HER, while concurrently maintaining operational stability for 1300 h at 100 mA/cm2 for overall water splitting. This work presents an effective approach to meticulously optimize multiple site-intermediate interactions in alkaline HER, laying the foundation for efficient energy conversion.

Theoretical analysis and predictions for the two-neutrino double electron capture of 124Xe

Abstract We provide a complete theoretical description of the two-neutrino electron capture in 124Xe, improving both the nuclear and the atomic structure calculations. We improve the general formalism through the use of the Taylor expansion method, leading to higher-order terms in the decay rate of the process. The nuclear part is treated with pn-QRPA and interacting shell model (ISM) methods. The nuclear matrix elements (NMEs) are calculated with the pn-QRPA method with isospin restoration by fixing the input parameters so that the experimental decay rate is reproduced, resulting in values significantly lower than in previous calculations. The validity of the pn-QRPA NMEs is tested by showing their values to be comparable with the ones for double-beta decay with the emission of two antineutrinos of 128,130Te, which have similar pairing features. Within the ISM, we reproduce the total experimental half-life within a factor of two and predict the capture fraction to the KK channel of about 74%. We also predict the capture fractions to other decay channels and show that for the cumulative decay to the KL1–KO1 channels, a capture fraction of about 24% could be observed experimentally. On the atomic side, calculations are improved by accounting for the Pauli blocking of the decay of innermost nucleon states and by considering all s-wave electrons available for capture, expanding beyond the K and L1 orbitals considered in previous studies. We also provide improved atomic relaxation energies of the final atomic states of 124Te, which may be used as input for background modeling in liquid Xenon experiments.

Empirical formula for electron capture half-lives

Empirical formula for electron capture half-lives

Laser-based approach to verify nuclear excitation by electron capture

Laser-based approach to verify nuclear excitation by electron capture

EEG Infrastructure Within the Veterans Administration: A Survey.

EEG is a vital tool in the diagnosis and management of neurologic conditions prevalent among veterans such as seizures, epilepsy, and brain injuries. This cross-sectional study aimed to assess the state of EEG infrastructure within the Veterans Administration (VA), focusing on availability, utilization, and the potential avenues to addressing gaps in infrastructure. This survey was distributed to 123 VA hospitals using the Research Electronic Data Capture (REDCap) platform, gathering data on EEG equipment, staffing, and service provision from June to December 2023. Of the 123 VA hospitals surveyed, 70 responded (56.9% response rate). Most respondents (88.6%) reported having EEG services, although only 38.7% offering continuous EEG (cEEG). Respondents reported having less EEG technologists, machines, and faculty readers than what they thought would be ideal. Significant correlations were found between the availability of resources (e.g., number of EEG machines) and service capabilities, including remote access and cEEG. The use of alternative EEG technologies such as rapid or quantitative EEG varied greatly. Interest in participating in the VA Tele-EEG program was reported by 59.4% of respondents. There is large variability in EEG infrastructure across the VA. Tele-EEG has the potential to maintain continuity of operations through challenges affecting staffing and to improve EEG service access, especially in resource-limited settings. Expanding access to quantitative, rapid, and tele-EEG services may enhance patient management and may be a potential avenue to explore as the VA continues to invest in and grow its capacity for treating neurologic conditions.

Presolar Grains as Probes of Supernova Nucleosynthesis.

We provide an overview of the isotopic signatures of presolar supernova grains, specifically focusing on 44Ti-containing grains with robustly inferred supernova origins and their implications for nucleosynthesis and mixing mechanisms in supernovae. Recent technique advancements have enabled the differentiation between radiogenic (from 44Ti decay) and nonradiogenic 44Ca excesses in presolar grains, made possible by enhanced spatial resolution of Ca-Ti isotope analyses with the Cameca NanoSIMS (Nano-scale Secondary Ion Mass Spectrometer) instrument. Within the context of presolar supernova grain data, we discuss (i) the production of 44Ti in supernovae and the impact of interstellar medium heterogeneities on the galactic chemical evolution of 44Ca/40Ca, (ii) the nucleosynthesis processes of neutron bursts and explosive H-burning in Type II supernovae, and (iii) challenges in identifying the progenitor supernovae for 54Cr-rich presolar nanospinel grains. Drawing on constraints and insights derived from presolar supernova grain data, we also provide an overview of our current understanding of the roles played by various supernova types- including Type II, Type Ia, and electron capture supernovae- in accounting for the diverse array of nucleosynthetic isotopic variations identified in bulk meteorites and meteoritic components. We briefly overview the potential mechanisms that have been proposed to explain these nucleosynthetic variations by describing the transport and distribution of presolar dust carriers in the protoplanetary disk. We highlight existing controversies in the interpretation of presolar grain data and meteoritic nucleosynthetic isotopic variations, while also outlining potential directions for future research.

Automated mapping of electronic data capture fields to SDTM.

The goal of this work is to reduce the amount of manual work required to go from data capture to regulatory submission. It will be shown that the use of Siamese networks will allow for the generation of embeddings that can be used by traditional machine learning classifiers to perform the classification at much higher levels of accuracy than standard approaches. Siamese networks are a method for training data embeddings such that data within the same class are closer with respect to a given distance metric than they are to data points in another class. Because they are designed to learn similarity within pairs of data points, they work well in situations where the number of classes is relatively large compared to the number of training samples. In this work, we will show that embeddings generated via a Siamese network from metadata associated with electronic data capture forms can be used to predict the associated SDTM field. With a relatively simple network coupled with a basic classification algorithm, the proposed method can achieve accuracies greater than 90%, which is significantly higher than what has been achieved with traditional methods, with many of the inaccurate mappings due to a lack of training data. In many cases, there is a 15% increase in accuracy vs. more traditional methods. Leveraging Siamese networks, it is possible to generate embeddings that efficiently represent data fields in a lower dimensional space. This allows the creation of a system that can automatically map between data schemas at high levels of accuracy. Such systems represent the first step in automating one of the many labor-intensive data management tasks associated with clinical trials.

Determination of Fractional Electron Capture Probabilities of 59Ni by Means of Metallic Magnetic Calorimeters

Determination of Fractional Electron Capture Probabilities of 59Ni by Means of Metallic Magnetic Calorimeters

Current Practices for Delivering New Diagnosis Education at Children's Oncology Group Institutions: A Report From the Children's Oncology Group.

The Children's Oncology Group (COG) Nursing Discipline developed expert consensus recommendations and resources to guide the delivery of new diagnosis education across its member institutions. Current new diagnosis education practices across COG member institutions are unknown. To understand current new diagnosis education practices across COG member institutions. We conducted a cross-sectional survey of COG nurses between July and October 2023 to elicit current practices to deliver new diagnosis education to families across COG institutions. Data were collected and managed using REDCap electronic data capture tools. Individual responses from single institutions were averaged as a single institution-level response. Respondents included 146/227 (64.3%) COG institutions across 5 countries. Advanced practice nurses and nurse educators have primary responsibility for new diagnosis education at 28.1% and 26.7% of institutions, respectively. Less than half (42.4%) of institutions have a clearly defined process for delivering new diagnosis patient/family education. Almost all (88.2%) institutions use the COG Family Handbook; 64.7% use the COG New Diagnosis Guide, and 41.9% use the COG KidsCare app to support the delivery of new diagnosis education. More than half (61.5%) of institutions use checklists to facilitate the delivery of new diagnosis education, with 81.6% of large institutions versus 44.1% of small institutions reporting the use of checklists ( P = .004). There is variability in current new diagnosis education practices across COG institutions. These findings highlight opportunities for implementing standardized approaches aligned with expert consensus recommendations for the delivery of new diagnosis education.

Luminescent iron phthalocyanine organic polymer nanosheets with space-separated dual-active sites for the detection and photocatalytic reduction of Cr(Ⅵ) from wastewater

Cr(Ⅵ) residues in livestock and poultry wastewater are a rising concern for human health and biotic environments. For the removal of Cr(Ⅵ), its simultaneous reduction and adsorption represents a sustainable and efficient strategy. Herein, iron nodes on covalently bonded two-dimensional phthalocyanine organic polymer (PcOP-Fe) nanosheets with space-separated dual-active sites are developed for the simultaneous detection and removal of Cr(VI) from wastewater. In the FeN4 structure of PcOP-Fe nanosheets, Fe acts as an electron capture center, effectively facilitating the accumulation of photogenerated electrons and transferring them to Cr(VI), thereby achieving its photocatalytic reduction. Meanwhile, pyrrolic nitrogen provides excellent adsorption sites, enabling the adsorption of Cr(III) or Cr(0). Fe accumulates the photogenerated electrons from pyrrole N and transfer them to Cr(Ⅵ). The formation of N-Cr(Ⅲ) bonds causes a space-separation between Cr(Ⅵ) and Cr(III). In addition, PcOP-Fe can be used for a Cr(Ⅵ) detection agent. The photoluminescence intensity decreases linearly with increasing Cr(Ⅵ) concentration from 80 μM to 2 mM, with a limit of detection of 0.18 μM. The PcOP-Fe nanosheets exhibit good Cr(Ⅵ) detection and reduction performance in livestock and poultry wastewater, suggesting their suitability for practical sensing applications. Thus, the PcOP-Fe nanosheets with space-separated dual-active sites are promising for the simultaneous detection and removal of Cr(Ⅵ) in water treatment processes.

Interatomic Coulombic electron capture beyond the virtual photon approximation.

Via the interatomic Coulombic electron capture (ICEC) process, an electron can be captured by an atom or a molecule, while the binding and excess energy is transferred, via a long-range Coulomb interaction, to a neighboring atom or molecule. The transferred energy can be used to ionize or electronically excite the neighboring species. When the two species are asymptotically far apart, an analytical formula for the ICEC cross sections can be derived. The latter can then be estimated using only the energies and the photoionization cross sections of each species. In this work, we develop an analytical model that allows us to predict the ICEC cross sections when the size of the involved species is comparable to the distance between the two entities. Using abinitio R-matrix results for various systems, we show that the new model reduces the error of the asymptotic formula by two orders of magnitude on average while only using parameters that can be taken from the properties of each species.

Spin polarization effect on linear polarization of photon emission following resonant electron capture of lithiumlike ions

Spin polarization effect on linear polarization of photon emission following resonant electron capture of lithiumlike ions

A highly-efficient peroxymonosulfate activator using a sewage sludge derived biochar supported cobalt oxide: Mechanism and characteristics

The application of biochar derived from sewage sludge (BS) in Fenton-like reactions for contaminant removal has attracted considerable attention. Herein, a BS-supported Co3O4 (BS-Co3O4) catalyst was synthesized using a simple two-step hydrothermal-calcination process to achieve highly efficient activation of peroxymonosulfate (PMS). The introduction of biochar effectively inhibited the aggregation of Co3O4 and reduced cobalt leaching. Compared to Co3O4, the mesoporous BS-Co3O4 exhibited an 8-fold increase in specific surface area (SSA) to 111.92 m2∙g−1, and a 46 %-66.4 % reduction in crystal plane size. The interaction between biochar and cobalt oxide resulted in several notable enhancements in the BS-Co3O4 composite. Specifically, there was an increase in sp2 carbon content, a 42.69 % rise in capacitance, and a 79.99 % reduction in charge transfer resistance. These improvements contributed to enhanced PMS activation performance. The BS-Co3O4 also contained a higher content of Co(II), sp2 carbon, and oxygen vacancies (OV). Co(II) played a crucial role in the redox reaction, accelerating the formation of SO4•− and 1O2 during the PMS activation process. Additionally, OV acted as electron capture centers, further promoting the generation of 1O2. Evidence from reactive species investigations and electron paramagnetic resonance (EPR) tests indicated that SO4•− and 1O2 were the main reactive radicals for eliminating tetracycline (TC). Based on the identification of TC intermediates, two potential degradation pathways were proposed, and a reduction in intermediate toxicity was observed. Experiments involving interference and repetition demonstrated that the BS-Co3O4 catalyst was stable and reusable. This work provides a solution with low metal leaching, high recycling performance, and safety for antibiotic wastewater treatment.

Management of Post-transplant Infections in Collaborating Hospitals (MATCH) Programme: a prospective cohort of all transplant recipients at Copenhagen University Hospital—Rigshospitalet, Denmark

PurposeThe Management of Post-transplant Infections in Collaborating Hospitals (MATCH) programme, initiated in 2011 and still ongoing, was created to 1) optimise the implementation of existing preventive strategies against viral infections...

Assessment of organochlorine pesticide contamination in Astyanax altiparanae from the Alagados Dam, Southern Brazil

Organochlorine pesticides (OCPs) are persistent pollutants previously used in agriculture, known for their ability to bioaccumulate and pose health risks. This study analyzed samples of roe, viscera, and muscle from Astyanax altiparanae fish collected from the Alagados reservoir in Paraná, Brazil. Samples were prepared through extraction and purification, then analyzed using gas chromatography with an electron capture detector (GC/ECD), chosen for its sensitivity in detecting OCPs. The method was validated for precision, accuracy, and detection limits. Detected OCPs included Aldrin (17.1 to 50.6 ng/g in roe), α-endosulfan (3.4 to 23.5 ng/g), p, p’-DDE (4.2 to 134.7 ng/g), Dieldrin (84.7 to 183.1 ng/g), β-endosulfan (6.0 to 51.6 ng/g), and p, p’-DDT (56.6 to 286.8 ng/g). In viscera, concentrations ranged from Aldrin (19.8 to 93.3 ng/g) to p, p’-DDT (52.3 to 89.2 ng/g). Muscle samples showed similar trends. Principal component analysis indicated a link between higher OCP concentrations and increased abdominal width of the fish. While OCP levels were below FAO and WHO limits, risk quotient calculations suggest potential health risks from consuming these fish.

A JWST Medium-resolution MIRI Spectrum and Models of the Type Ia Supernova 2021aefx at +415 days

We present a JWST MIRI medium-resolution spectrometer spectrum (5–27 μm) of the Type Ia supernova (SN Ia) SN 2021aefx at +415 days past B-band maximum. The spectrum, which was obtained during the iron-dominated nebular phase, has been analyzed in combination with previous JWST observations of SN 2021aefx to provide the first JWST time series analysis of an SN Ia. We find that the temporal evolution of the [Co iii] 11.888 μm feature directly traces the decay of 56Co. The spectra, line profiles, and their evolution are analyzed with off-center delayed-detonation models. Best fits were obtained with white dwarf (WD) central densities of ρ c = 0.9−1.1 × 109 g cm−3, a WD mass of M WD = 1.33–1.35 M ⊙, a WD magnetic field of ≈106 G, and an off-center deflagration-to-detonation transition at ≈0.5 M ⊙ seen opposite to the line of sight of the observer (−30°). The inner electron capture core is dominated by energy deposition from γ-rays, whereas a broader region is dominated by positron deposition, placing SN 2021aefx at +415 days in the transitional phase of the evolution to the positron-dominated regime. The formerly “flat-tilted” profile at 9 μm now has a significant contribution from [Ni iv], [Fe ii], and [Fe iii] and less from [Ar iii], which alters the shape of the feature as positrons mostly excite the low-velocity Ar. Overall, the strength of the stable Ni features in the spectrum is dominated by positron transport rather than the Ni mass. Based on multidimensional models, our analysis is consistent with a single-spot, close-to-central ignition with an indication of a preexisting turbulent velocity field and excludes a multiple-spot, off-center ignition.

The role of electronic data capture systems in clinical trials: Streamlining data integrity and improving compliance with FDA and ICH/GCP guidelines

This study investigates the transformative role of Electronic Data Capture (EDC) systems in clinical trials, emphasizing their impact on data integrity, compliance with regulatory standards, and the efficiency of trial processes. The purpose of the research was to critically analyze how EDC systems align with FDA and ICH/GCP guidelines, addressing the complexities of modern clinical trials. By conducting a detailed literature review, the study explores the benefits, challenges, and technological advancements associated with EDC systems. Key findings highlight the significant advantages of EDC systems in enhancing data accuracy, real-time monitoring, and facilitating regulatory compliance through secure data management and audit trails. The study also identifies several challenges, including high implementation costs, data privacy concerns, and integration issues with other digital trial technologies. Technological advancements, such as artificial intelligence, blockchain, and decentralized trial models, are explored as promising solutions to these limitations, offering new avenues for optimizing clinical trial management. The study concludes that EDC systems have revolutionized clinical trials, streamlining data collection and analysis while ensuring compliance with stringent regulatory requirements. It recommends continued investment in EDC technologies, enhanced training for trial staff, and the integration of cutting-edge innovations to ensure future clinical trials' success.