• Book : ()
• Pub. Date : 2025
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Abstract In recent years, a significant number of oxygen-bearing complex organic molecules (COMs) have been detected in the gas phase of cold dark clouds such as TMC-1. The formation of these COMs cannot be explained by diffusive mechanisms on grains and gas-phase reactions. This study investigates the formation of oxygen-bearing COMs in cold dark clouds using multiphase gas–grain models that incorporate cosmic ray-induced nondiffusive radiation chemistry and nonthermal sputtering desorption mechanisms. Additionally, we present the effects of varying elemental C/O ratio and different sputtering rates. We utilized an accelerated Gillespie algorithm, based on the regular Gillespie algorithm. The results of our models for dimethyl ether (CH3OCH3), methyl formate (HCOOCH3), acetaldehyde (CH3CHO), ethanol (C2H5OH), and methanol (CH3OH) show reasonable agreement with observations toward TMC-1, within a factor of 3. Out of the 94 species compared with observations, 63 show agreement within 1 order of magnitude, accounting for 67.02%. Overall inclusion of nonthermal mechanisms in multiphase models shows notable improvement of modeling on oxygen-bearing COMs in the interstellar medium.

• Book : 277(1)
• Pub. Date : 2025
• Page : pp.8-8
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Hybrid photon counting detectors have significantly advanced synchrotron research. In particular, the introduction of large cadmium telluride-based detectors in 2015 enabled a whole new range of high-energy X-ray measurements. This article describes the specifications of the new PILATUS4 cadmium telluride detector and presents results from prototype testing for high-energy powder X-ray diffraction studies conducted at two synchrotrons. The experiments concern time-resolved in situ solid-state reactions at MAX IV (Sweden) and fast-scanning X-ray diffraction computed tomography of a battery cell at the ESRF (France). The detector's high quantum efficiency up to 100 keV, combined with a maximum frame rate of 4000 Hz, enables fast data collection. This study demonstrates how these capabilities contribute to improved time and spatial resolution in high-energy powder X-ray diffraction studies, facilitating advancements in materials, chemical and energy research.

• Book : 32(2)
• Pub. Date : 2025
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Abstract Background We aimed to validate a low-dose two-volume pulmonary computed tomography (CT) perfusion technique. Methods Five Yorkshire swine (weight 53.6 ± 2.6 kg) underwent 21 independent CT perfusion acquisitions. Intravenous contrast material (370 mg/mL iodine, 0.5 mL/kg) and saline chaser (0.5 mL/kg) were injected at 5 mL/s for each acquisition. Two-volume and multivolume dynamic CT perfusion data were acquired using a 320-slice CT, with multivolume measurements serving as the reference standard. The two-volume CT perfusion involved a low-dose (50 mA) volume scan before contrast injection and a diagnostic (300 mA) volume scan after bolus-tracking in the main pulmonary artery at the peak contrast enhancement. Multivolume CT perfusion included 15–20 volume scans for blood flow measurement. Paired sample t-test, linear regression, and Bland–Altman analysis compared both global and regional two-volume perfusion measurements to the reference standard. The reproducibility of the two-volume CT perfusion was assessed from two independent measurements under the same perfusion condition. Results Two-volume global perfusion measurements (P 2V) were related to reference multivolume (P MV) measurements by P 2V = 0.96 × P MV + 0.45 (r = 0.92), with a root-mean-square error of 1.29 mL/min/g and a root-mean-square deviation of 1.29 mL/min/g. The CT dose index for the two-volume and multivolume CT perfusion measurements were 9.3 mGy and 184.8 mGy, respectively. Conclusion We successfully validated a prospective, two-volume CT perfusion technique in a swine model. The findings affirm the feasibility of accurate and reproducible pulmonary blood flow measurement. Relevance statement This two-volume CT pulmonary perfusion technique, validated in a swine model, demonstrates the feasibility of blood flow measurement with a substantial reduction in radiation exposure. It could allow low-dose regional blood flow measurement in the assessment of pulmonary artery disease in humans. Key Points Lung perfusion can be measured in mL/min/g using a prospective, two-volume CT technique. Flow measurement is achievable in a swine model with a radiation dose as low as 9.3 mGy. CT angiography and perfusion can be acquired following a single contrast injection. Graphical Abstract

• Book : 9(1)
• Pub. Date : 2025
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• Book : 33()
• Pub. Date : 2025
• Page : pp.100306-100306
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It is difficult to measure neutrons and gamma rays coming directly from uranium and plutonium atoms in pyroprocessed ingot, which is of great interest to nuclear safeguards. Most neutrons of the ingot are emitted from 244Cm isotope and gamma rays from its fission products. Therefore, it is necessary to identify spent fuel characteristics such as initial enrichment, burnup and cooling time from measurement and estimate plutonium mass from calibration curve or burnup calculations.In this study, we explored the possibility of characterizing pyroprocessed ingots using neutron and gamma-ray multiplicity counting. We particularly focused on finding the possible correlation between neutron and gammaray multiplicity properties (singles, doubles, and triples) and spent fuel properties for U/TRU/RE preprocessed ingot. We examined neutron and gamma-ray correlation for spent fuel, using the Cascading Gamma-ray Multiplicity with Fission (CGMF) and the Fission Reaction Event Yield Algorithm (FREYA) library in MCNP6.2. Due to high spontaneous fission rate, neutron and gamma-ray multiplicity parameters did not strongly correlate with multiplication factor from the point model but was proportional to 244Cm mass. The results based on the CGMF and FREYA fission library showed the similar trends for neutron and gamma-ray cases. The sum of two multiplicity data yielded best linearity with the 244Cm effective mass. Although total neutron counting (S) alone was sufficient for effectively characterizing spent fuel due to its strong linearity, this feasibility study confirmed that, in principle, it will be more effective to calculate the sum of neutron and gamma-ray multiplicity properties to directly estimate the mass of 244Cm, rather than relying on the conventional method of calculating the multiplication factor.

• Book : 57(3)
• Pub. Date : 2025
• Page : pp.1-6
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Abstract Colorectal cancer (CRC) is the third most commonly diagnosed and leading cause of death worldwide. On the other hand, glioblastoma multiforme (GBM) is the most prevalent and aggressive primary malignant brain tumor in adults. Inherited diseases of DNA mismatch repair (MMR) can cause multiple cancers in the same patient including CRC and GBM. In this study, we report a 59-year-old woman presented with fatigue, constipation, abdominal distention, perianal pain, right-sided arm weakness, and personality changes. After investigations, it was diagnosed that sporadic metastatic CRC and GBM occurred simultaneously in the same patient, which was confirmed by colonoscopy, biopsy, imaging, and molecular testing. As the treatment of two cancers in the same patient is unique and complex, the absence of guidelines for such cases was discussed in a multidisciplinary tumor board including surgeons, medical, and radiation oncologists.

• Book : 2025(2)
• Pub. Date : 2025
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The paper considers the results of experiments on localization of the sources of geoacoustic radiation generated in near-surface sedimentary rocks. Geoacoustic signals from sources were recorded by a spaced sensor system consisting of two combined receivers and a hydrophone. The system was installed near the bottom of a natural water body (Mikizha lake) in Kamchatka. Radiation sources were located by two methods, a triangulation survey and estimation of the signal arrival time difference from spaced receivers. Coordinates for more than 40 sources were measured, and their space distribution was mapped. As the result of the experiment, it was stated that geoacoustic radiation sources are located in bottom rocks at the depths up to 2.20 ± 0.25 m at the distances of up to 8 ± 0.25 m. Localization of geoacoustic radiation sources is topical for projecting a new alarm system for the notification on the possibility of strong earthquake occurrence. The results of the analysis of the frequency of rock AE source generation and accurate estimation of their location will be the basis of this system.

• Book : 25(4)
• Pub. Date : 2025
• Page : pp.1197-1197
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• Pub. Date : 2025
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• Pub. Date : 2025
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