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There is an urgent need for new, better instrumentation and techniques for detecting and characterizing special nuclear material (SNM), i.e., highly enriched uranium and plutonium. The development of improved instruments and techniques requires experiments performed with the SNM itself, which is of limited availability. This paper describes the findings of experiments performed at the National Criticality Experiments Research Center conducted using new instruments and techniques on unclassified, kg-quantity SNM objects. These experiments, performed in the framework of the Department of Energy, National Nuclear Security Administration Consortium for Monitoring, Technology, and Verification, focused on detecting, characterizing, and localizing SNM samples with masses ranging from 3.3 to 13.8 kg, including plutonium and highly enriched uranium using prototype detectors and techniques. The work demonstrates SNM detection and characterization using recently-developed prototype detection systems. Specifically, we present new results in passive detection and imaging of plutonium and uranium objects using gamma-ray and dual particle (fast neutron and gamma-ray) imaging. We also present a new analysis of the delayed neutron emissions during active interrogation of uranium using a neutron generator.

The ability to distinguish multiple forms of plutonium from one another, such as oxide and metal, is paramount in areas of nuclear nonproliferation and international safeguards. In its metal form, plutonium can be readily used in a nuclear weapon, while oxide forms are associated with nuclear reactor fuel. Oxide-based plutonium forms emit neutrons with an energy spectrum that is significantly different from the fission neutrons that are emitted from plutonium metal. Organic scintillation detectors output pulses that are proportional to the neutron energy deposited, and therefore present a means of distinguishing these plutonium forms based on their energy spectra. In this work, metal and oxide forms of plutonium were measured using a handheld detection system based on an organic glass scintillator. Monte Carlo modeling of these experiments was performed to provide insight into the origin of the features in the observed light output spectra. Through analysis of multiple regions of these spectra, in a matter of minutes we were able to unambiguously discriminate oxide and metal plutonium forms from one another and from a plutonium-beryllium neutron source, which was considered for comparison because these sources are commonly used in industrial applications. The ability to discriminate weapons-usable material from nuclear reactor fuel has applications in nuclear treaty verification and safeguards.

Radiation source localization and characterization are challenging tasks that currently require complex analyses for interpretation. Mixed reality (MR) technologies are at the verge of wide scale adoption and can assist in the visualization of complex data. Herein, we demonstrate real-time visualization of gamma ray and neutron radiation detector data in MR using the Microsoft HoloLens 2 smart glasses, significantly reducing user interpretation burden. Radiation imaging systems typically use double-scatter events of gamma rays or fast neutrons to reconstruct the incidence directional information, thus enabling source localization. The calculated images and estimated ’hot spots’ are then often displayed in 2D angular space projections on screens. By combining a state-of-the-art dual particle imaging system with HoloLens 2, we propose to display the data directly to the user via the head-mounted MR smart glasses, presenting the directional information as an overlay to the user’s 3D visual experience. We describe an open source implementation using efficient data transfer, image calculation, and 3D engine. We thereby demonstrate for the first time a real-time user experience to display fast neutron or gamma ray images from various radioactive sources set around the detector. We also introduce an alternative source search mode for situations of low event rates using a neural network and simulation based training data to provide a fast estimation of the source’s angular direction. Using MR for radiation detection provides a more intuitive perception of radioactivity and can be applied in routine radiation monitoring, education & training, emergency scenarios, or inspections.

Interventional radiology of the male urogenital system includes percutaneous and endovascular procedures, and these last consist mostly of transcatheter arterial embolizations. At the kidney level, arterial embolizations are performed mainly for palliative treatment of parenchymal tumors, for renal traumas and, less frequently, for arteriovenous fistulas and renal aneurysms and pseudoaneurysms. These latter may often require emergency intervention as they can cause renal or peri-renal hematomas or significant hematuria. Transcatheter arterial embolization is also an effective therapy for intractable severe bladder hematuria secondary to a number of neoplastic and inflammatory conditions in the pelvis, including unresectable bladder cancer and radiation-induced or cyclophosphamide-induced hemorrhagic cystitis. Endovascular interventional procedures for the penis are indicated for the treatment of post-traumatic priapism. In this article, we review the main endovascular radiological interventions of the male urogenital system, describing the technical aspects, results, and complications of each procedure at the various anatomical districts.

The purpose of this work was to investigate the states of water in carbon-epoxy composite under influence of saline solutions using gravimetric analysis and the following spectroscopic techniques: photoluminescence, Raman and UATR/FT-IR. Two sets of samples were prepared after the curing process. The first one was submitted to saline vapor and the other was immersed in the saline solution. All samples were heat-treated at 40, 60 and 80 °C for periods of 7, 14, 21 and 28 days. The dissolved ions in the artificial seawater tend to inhibit the water absorption of the immersed samples that presented similar amounts of water in relation to the samples submitted to saline vapor. The relative intensity decreasing of emission spectra indicated that the nonradiative decay pathways are predominant in relation to the radiative ones due to the increasing of mobility of the polymeric chains. The main changes of the Raman spectra were the decreasing of the relative intensity of the bands at 1610 and 1511 cm −1 attributed to the aromatic rings. This behavior also indicated the enhancement of conformational freedom of the polymeric chains due to the plasticization. The FT-IR band assigned to hydroxyl groups shifted towards lower wavenumbers suggesting interaction of water molecules with OH groups.

The aim of this study was to assess whether angiotensin receptor/neprilysin inhibitor (ARNI) decreases ventricular arrhythmic burden compared to angiotensin-converting enzyme inhibitors or angiotensin receptor antagonist (ACE-I/ARB) treatment in chronic heart failure with reduced ejection fraction (HFrEF) patients. Further, we assessed if ARNI influenced the percentage of biventricular pacing. A systematic review of studies (both RCTs and observational studies) including HFrEF patients and those receiving ARNI after ACE-I/ARB treatment was conducted using Medline and Embase up to February 2023. Initial search found 617 articles. After duplicate removal and text check, 1 RCT and 3 non-RCTs with a total of 8837 patients were included in the final analysis. ARNI was associated with a significative reduction of ventricular arrhythmias both in RCT (RR 0.78 (95% CI 0.63–0.96); p = 0.02) and observational studies (RR 0.62; 95% CI 0.53–0.72; p < 0.001). Furthermore, in non-RCTs, ARNI also reduced sustained (RR 0.36 (95% CI 0.2–0.63); p < 0.001), non-sustained VT (RR 0.67 (95% CI 0.57–0.80; p = 0.007), ICD shock (RR 0.24 (95% CI 0.12–0.48; p < 0.001), and increased biventricular pacing (2.96% (95% CI 2.25–3.67), p < 0.001). In patients with chronic HFrEF, switching from ACE-I/ARB to ARNI treatment was associated with a consistent reduction of ventricular arrhythmic burden. This association could be related to a direct pharmacological effect of ARNI on cardiac remodeling.Trial registration: CRD42021257977.

The detection and characterization of highly enriched uranium (HEU) presents a large challenge in the non-proliferation field. HEU has a low neutron emission rate and most gamma rays are low energy and easily shielded. To address this challenge, an instrument known as the dual-particle imager (DPI) was used with a portable deuterium-tritium (DT) neutron generator to detect neutrons and gamma rays from induced fission in HEU. We evaluated system response using a 13.7-kg HEU sphere in several configurations with no moderation, high-density polyethylene (HDPE) moderation, and tungsten moderation. A hollow tungsten sphere was interrogated to evaluate the response to a possible hoax item. First, localization capabilities were demonstrated by reconstructing neutron and gamma-ray images. Once localized, additional properties such as fast neutron energy spectra and time-dependent neutron count rates were attributed to the items. For the interrogated configurations containing HEU, the reconstructed neutron spectra resembled Watt spectra, which gave confidence that the interrogated items were undergoing induced fission. The time-dependent neutron count rate was also compared for each configuration and shown to be dependent on the neutron multiplication of the item. This result showed that the DPI is a viable tool for localizing and confirming fissile mass and multiplication.

Gamma-ray spectroscopy is an effective technique for radioactive material characterization, routine inventory verification, nuclear safeguards, health physics, and source search scenarios. Gamma-ray spectrometers typically cannot be operated in the immediate vicinity of nuclear reactors due to their high flux fields and their resulting inability to resolve individual pulses. Low-power reactor facilities offer the possibility to study reactor gamma-ray fields, a domain of experiments hitherto poorly explored. In this work, we present gamma-ray spectroscopy experiments performed with various detectors in two reactors: The EPFL zero-power research reactor CROCUS, and the neutron beam facility at the Ohio State University Research Reactor (OSURR). We employed inorganic scintillators (CeBr3), organic scintillators (trans-stilbene and organic glass), and high-purity germanium semiconductors (HPGe) to cover a range of typical—and new—instruments used in gamma-ray spectroscopy. The aim of this study is to provide a guideline for reactor users regarding detector performance, observed responses, and therefore available information in the reactor photon fields up to 2 MeV. The results indicate several future prospects, such as the online (at criticality) monitoring of fission products (like Xe, I, and La), dual-particle sensitive experiments, and code validation opportunities.

Sodium-glucose cotransoporter-2 inhibitors (SGLT-2Is) improve prognosis in heart failure (HF) patients both with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). However, these drugs can have some side effects. To estimate the relative risk of side effects in HF patients treated with SGLT-2Is irrespective from left ventricular EF and setting (chronic and non-chronic HF). Five randomized controlled trials (RCTs) enrolling patients with HFrEF, 4 RCTs enrolling non-chronic HF, and 3 RCTs enrolling HFpEF were included. Among side effects, urinary infection, genital infection, acute kidney injury, diabetic ketoacidosis, hypoglycemia, hyperkalemia, hypokalemia, bone fractures, and amputations were considered in the analysis. Overall, 24,055 patients were included in the analysis: 9020 (38%) patients with HFrEF, 12,562 (52%) with HFpEF, and 2473 (10%) with non-chronic HF. There were no differences between SGLT-2Is and placebo in the risk to develop diabetic ketoacidosis, hypoglycemia, hyperkalemia, hypokalemia, bone fractures, and amputations. HFrEF patients treated with SGLT-2Is had a significant reduction of acute kidney injury (RR = 0.54 (95% CI 0.33–0.87), p = 0.011), whereas no differences have been reported in the HFpEF group (RR = 0.94 (95% CI 0.83–1.07), p = 0.348) and non-chronic HF setting (RR = 0.79 (95% CI 0.55–1.15), p = 0.214). A higher risk to develop genital infection (overall 2.57 (95% CI 1.82–3.63), p < 0.001) was found among patients treated with SGLT-2Is irrespective from EF (HFrEF: RR = 1.96 (95% CI 1.17–3.29), p = 0.011; HFpEF: RR = 3.04 (95% CI 1.88–4.90), p < 0.001). The risk to develop urinary infections was increased among SGLT-2I users in the overall population (RR = 1.13 (95% CI 1.00–1.28), p = 0.046) and in the HFpEF setting (RR = 1.19 (95% CI 1.02–1.38), p = 0.029), whereas no differences have been reported in HFrEF (RR = 1.05 (95% CI 0.81–1.36), p = 0.725) and in non-chronic HF setting (RR = 1.04 (95% CI 0.75–1.46), p = 0.806). SGLT-2Is increase the risk of urinary and genital infections in HF patients. In HFpEF patients, the treatment increases the risk of urinary infections compared to placebo, whereas SGLT-2Is reduce the risk of acute kidney disease in patients with HFrEF.

The ability to localize and image radiation sources has found use in various applications for nuclear nonproliferation practices, specifically in treaty verification, nuclear safeguards, and homeland security. Technologies that are capable of angular radiation imaging have been prevalent for years and, recently, 3D imaging technologies making use of emerging media like mixed reality have been rapidly developing and gaining popularity. Modern imaging techniques typically use a Compton camera to record coincident events and reconstruct the incident directional information of a gamma ray-emitting radiation source. However, Compton cameras are limited as they cannot obtain accurate source depth information when used for simple back projection imaging. Neutron scatter cameras are a complementary imaging technique that use double elastic scatters but also have their own limitations. This work presents a framework for multiple scatter-based particle imagers to construct 3D images and to localize a radiation source using gamma rays or fast neutrons. Specifically, localization is achieved by accounting for the position of the imagers. The imaging algorithm was validated using experimental data, measuring a 252Cf source. A three-dimensional representation of the imaging data provides a more intuitive and informative depiction of source positions and can aid in scenarios with complex environmental geometries such as when sources are in containers.