Equivalent Dose Research Articles

Fractionation dose optimization facilities the implementation of transmission proton FLASH-RT

Objective.The beam switching time and fractional dose influence the FLASH effect. A single-beam-per-fraction (SBPF) scheme using uniform fractional dose (UFD) has been proposed for FLASH- radiotherapy (FLASH-RT) to eliminate the beam switching time. Based on SBPF schemes, a fractionation dose optimization algorithm is proposed to optimize non-UFD plans to maximize the fractionation effect and dose-dependent FLASH effect.Approach.The UFD plan, containing five 236 MeV transmission proton beams, was optimized for 11 patients with peripheral lung cancer, with each beam delivering a uniform dose of 11 Gy to the target. Meanwhile, the non-UFD plan was optimized using fractionation dose optimization. To compare the two plans, the equivalent dose to 2 Gy (EQD2) for the target and normal tissues was calculated with anα/βratio of 10 and 3, respectively. Both UFD and non-UFD plans ensured that the target received an EQD2 of 96.3 Gy. To investigate the overall improvement in normal tissue sparing with the non-UFD plan, the FLASH-enhanced EQD2 was calculated.Main results.The fractional doses in non-UFD plans ranged between 5.0 Gy and 24.2 Gy. No significant differences were found in EQD22%and EQD298%of targets between UFD and non-UFD plans. However, theD95%of the target in non-UFD plans was significantly reduced by 15.1%. The sparing effect in non-UFD plans was significantly improved. The FLASH-enhanced EQD2meanin normal tissue and ipsilateral lung was significantly reduced by 3.5% and 10.4%, respectively, in non-UFD plans. The overall improvement is attributed to both the FLASH and fractionation effects.Significance.The fractionation dose optimization can address the limitation of multiple-beam FLASH-RT and utilize the relationship between fractional dose and FLASH effect. Consequently, the non-UFD scheme results in further improvements in normal tissue sparing compared to the UFD scheme, attributed to enhanced fractionation and FLASH effects.

Space radiation measurements during the Artemis I lunar mission

Space radiation is a notable hazard for long-duration human spaceflight1. Associated risks include cancer, cataracts, degenerative diseases2 and tissue reactions from large, acute exposures3. Space radiation originates from diverse sources, including galactic cosmic rays4, trapped-particle (Van Allen) belts5 and solar-particle events6. Previous radiation data are from the International Space Station and the Space Shuttle in low-Earth orbit protected by heavy shielding and Earth’s magnetic field7,8 and lightly shielded interplanetary robotic probes such as Mars Science Laboratory and Lunar Reconnaissance Orbiter9,10. Limited data from the Apollo missions11–13 and ground measurements with substantial caveats are also available14. Here we report radiation measurements from the heavily shielded Orion spacecraft on the uncrewed Artemis I lunar mission. At differing shielding locations inside the vehicle, a fourfold difference in dose rates was observed during proton-belt passes that are similar to large, reference solar-particle events. Interplanetary cosmic-ray dose equivalent rates in Orion were as much as 60% lower than previous observations9. Furthermore, a change in orientation of the spacecraft during the proton-belt transit resulted in a reduction of radiation dose rates of around 50%. These measurements validate the Orion for future crewed exploration and inform future human spaceflight mission design.

Radiological protection of Young Scientist and Scientific Researcher trainees in controlled areas of the Argonaut reactor installation: analytical approach

Since the increasing use of ionizing radiations in medical and industrial proceedings, recommendations and actions have been necessaries to reduce the individual radiological risks. In the Nuclear Engineering Institute (IEN), there is the Argonauta research nuclear reactor (RARG) used for producing radionuclides, neutrongraphy studies and training young scientists (YST) and scientific researchers (SRT). During their trainings, these trainees are exposed to ionizing radiations meanly during the neutrongraphyc experiments when they need to adjust neutrongraphy plates in front the J9 channel with the RARG in critical condition. At this moment, they are exposed to neutron and gamma radiations in the RARG hall. This paper evaluated the gamma and neutron expositions that YST and SRT are submitted during the neutrongraphy experiments, by using area monitors to measure the ambient dose equivalent rates in two points near to J9 channel. Considering only this experiment, there was found that the annual individual effective dose could reach up to 2.5 mSv, which is more than 150% of the annual dose to member of the public (MP), but below the annual effective dose to occupationally exposed individual (OEI) as a worker. The question is if YST and SRT should be considered an OEI or a MP. This question is answered through an analytical approach of the regulations and recommendations. The conclusion is that YST and SRT shall be controlled as OEI, but must be submitted to MP’ restriction doses.

Continuous serratus anterior plane block for postoperative analgesia following lung transplantation via anterolateral incision: a pilot study.

Unilateral or bilateral anterolateral thoracotomy May lead to severe acute pain in lung transplantation (LTx). Although serratus anterior plane block (SAPB) is apparently effective for pain control after open thoracic surgery, there remains a lack of evidence for the application of SAPB for postoperative analgesia after LTx. In this case series pilot study, we describe the feasibility of continuous SAPB after lung transplantation and provide a preliminary investigation of its safety and efficacy. After chest incisions closure was complete, all patients underwent ultrasound-guided SAPB with catheter insertion. Numerical rating scale (NRS), additional opioid consumption, time to endotracheal tube removal, ICU length of stay, and catheter-related adverse events were followed up and recorded for each patient within 1 week after the procedure. A total of 14 patients who received LTx at this center from August 2023 to November 2023 were included. All patients received anterolateral approaches, and 10 (71.4%) of them underwent bilateral LTx. The duration of catheter placement was 2 (2-3) days, and the Resting NRS during catheter placement was equal to or less than 4. A total of 11 patients (78.6%) were supported by extracorporeal membrane oxygenation (ECMO) in LTx, whereas 8 patients (57.1%) removed the tracheal tube on the first day after LTx. Intensive care unit (ICU) stay was 5 (3-6) days, with tracheal intubation retained for 1 (1-2) days, and only one patient was reintubated. The morphine equivalent dose (MED) in the first week after LTx was 11.95 mg, and no catheter-related adverse events were detected. We did not assess the sensory loss plane due to the retrospective design. In addition, differences in catheter placement time May lead to bias in pain assessment. Although continuous SAPB May be a safe and effective fascial block technique for relieving acute pain after LTx, it should be confirmed by high-quality clinical studies.

The polymyxin-B direct hemoperfusion OPTimal Initiation timing with Catecholamine PMX-OPTIC study: A multicenter retrospective observational study.

Polymyxin-B direct hemoperfusion (PMX-DHP) is an endotoxin adsorption column-based blood purification therapy. Since one of the most potent effects of PMX-DHP is blood pressure elevations, it may be the most effective when it is introduced at the time when the need for vasopressors is the greatest, which, in turn, may reduce mortality. A multicenter retrospective study was conducted at 24 ICUs in Japan. In each ICU, the 20 most recent consecutive cases of septic shock treated with PMX-DHP were analyzed. The duration between the time of the peak vasopressive agent dose, expressed as the noradrenaline equivalent dose (NEq), and the time of PMX initiation was evaluated. The primary outcome was 28-day mortality, and a multivariable analysis was performed to investigate factors associated with mortality. A total of 480 septic shock patients were included in the analysis. Among all patients, the 28-day mortality group was older, more severely ill, and had a higher body mass index. The NEq peak and NEq on PMX-DHP initiation were both higher in deceased patients. Regarding the timing of PMX-DHP initiation from the NEq peak, -4 << 4 h had more survivors (229/304, 75.3%) than ≤-4 h (50/75, 66.7%) and ≥4 h (66/101, 65.4%) (p = 0.085). When -4 << 4 h was assigned as a reference, the timing of PMX-DHP initiation from the NEq peak of ≤-4 h had an odds ratio of 1.96 (1.07-3.58), p = 0.029, while ≥4 h had an odds ratio of 1.64 (0.94-2.87), p = 0.082 for 28-day mortality, in the multivariable regression analysis. A spline curve of the relationship between the probability of death and the timing of PMX-DHP initiation from the NEq peak showed a downward convex curve with a nadir at timing = 0. The odds ratios of the timing of PMX-DHP initiation other than -4 << 4 h were significantly higher in an older age, male sex, lower BMI, more severe illness, and higher oxygenation. The induction of PMX-DHP at the time of the peak vasopressor dose correlated with lower mortality. PMX-DHP is one of the options available for elevating blood pressure in septic shock, and its initiation either too early or late for shock peak may not improve the outcome.

Bonner sphere measurements of high-energy neutron spectra from a 1 GeV/u 56Fe ion beam on an aluminum target and comparison to spectra obtained by Monte Carlo simulations

The goal of this work is to characterize the secondary neutron spectra produced by 1 GeV/u56Fe beam colliding with a thick cylindric aluminum target and to perform a quantitative comparison with simulated results obtained with Monte Carlo codes. The measurements were performed using extended-range Bonner sphere spectrometers at two positions (15° and 40°) with respect to the beam direction. The secondary radiation field was simulated using four Monte Carlo codes (FLUKA, MCNP6, Geant4 and PHITS) and several physical models of nuclei transport and interaction. Neutron and proton energy distributions were simulated for the experimental measurement positions. The simulated neutron spectra, together with data measured with Bonner sphere spectrometers, after carrying out the correction of the contributions induced by the secondary protons, were used as input for the MAXED spectrum unfolding code to obtain the measured neutron spectra. Unfolded neutron spectra were compared with simulated ones to carry out a quantitative analysis of the performance of the chosen Monte Carlo codes and their corresponding physical models. This comparison showed that, because of experimental uncertainties and physical models, there are no unique solutions for each measurement location, but a range of solutions where the true experimental neutron spectra probably lie. The results showed deviations between 4.23% and 8.42% for some simulated spectra. Regarding the total integral values of neutron fluence and ambient equivalent dose, the unfolded neutron spectra showed deviations lower than 2%.

Study of thermoluminescence characteristics of quartz for high radiation doses (>1kGy): Implications for extending the luminescence dating range

Quartz is an omnipresent abundant natural mineral, used for luminescence dating. Lately, quartz optically stimulated luminescence (OSL) technique is widely used to estimate the equivalent doses (De) for dating geological events (up to 250 Gy, limited by saturation). Some works report thermoluminescence (TL) saturation around ∼ (10–40) kGy. Still dose estimates for such high radiation dose (HRD) range are not achieved. Significant research exists about luminescence response for low dose ranges (<250 Gy) but limited studies are done for HRDs (>1 kGy). This work characterizes the luminescence response of quartz for HRDs (1–21 kGy) to improve existing understanding of luminescence mechanism. Results show that the characteristics of the trap (<200 °C) differ significantly at HRDs than low doses. TL in multi-spectral detection (UV–Visible) band suggest an increase in 340–380 °C peak intensity up to 11 kGy dose. The measurements of saturation dose suggest that it depends on the trapping centres but is independent of recombination centres for the samples used for study. The traps are found bleachable by sunlight, reducing TL signal to residual levels in 1 h. Further, the bleachability is found to be anti-correlated with luminescence emission wavelength. At HRDs luminescence sensitivity is influenced by dose given in previous cycle which is difficult to correct by routine normalization procedures. The work also explores the various normalization methods to find appropriate method for HRD estimation and recommends the use of mass normalization as other normalization methods do not correct the sensitivity changes at HRDs adequately.

Frequent Unrecognized Vertebral Fractures Associated with Increased Body Fat Mass in Children and Adolescents with Duchenne Muscular Dystrophy.

Patients with Duchenne muscular dystrophy (DMD) have an increased risk of vertebral fractures (VFs). Ethnic variations may partly contribute to the fracture risk. This study aimed to demonstrate the VFs and body fat mass in Asian patients with DMD. Demographic data and DMD-related parameters of the enrolled patients were collected. Lateral thoracolumbar spine radiographs were performed for VF assessment. Genant classification was applied for VF severity grading (mild, moderate and severe). Body composition analysis using dual-energy X-ray absorptiometry was performed. Serum calcium, phosphate, intact parathyroid hormone and 25-hydroxyvitamin D concentrations were determined. There were 25 children and adolescents with DMD enrolled. Median (IQR) age was 12.9 (9.6, 19.3) years. Nine patients (36%) had VFs with a total of 31 sites of VFs (mild, N=10; moderate, N=3 and severe, N=18). These VFs had never been recognized prior to this study. Comparing with the non-VF group, the VF group received a significantly greater cumulative prednisolone equivalent dose (1,258 (948, 1,664) vs. 291 (17, 823) mg/kg, p=0.003). Body fat mass, represented by fat mass index and body fat percentage Z-scores was greater in the VF group [2.46 (2.21, 2.51) vs. 1.63 (0.36, 2.07), p=0.011 and 4.4 (3.1, 5.5) vs. 1.8 (0.6, 3.5), p=0.008, respectively]. No differences in serum calciotropic hormones and vitamin D status were demonstrated between patients with and without VFs. VFs were frequent in patients with DMD. Patients with VFs had greater cumulative glucocorticoid dose and body fat mass than those without VFs.

Cross-National Analysis of Opioid Prescribing Patterns: Enhancements and Insights from the OralOpioids R Package in Canada and the United States

Background: The opioid crisis remains a significant public health challenge in North America, highlighted by the substantial need for tools to analyze and understand opioid potency and prescription patterns. Methods: The OralOpioids package automates the retrieval, processing, and analysis of opioid data from Health Canada’s Drug Product Database (DPD) and the U.S. Food and Drug Administration’s (FDA) National Drug Code (NDC) database. It includes functions such as load_Opioid_Table, which integrates country-specific data processing and Morphine Equivalent Dose (MED) calculations, providing a comprehensive dataset for analysis. The package facilitates a comprehensive examination of opioid prescriptions, allowing researchers to identify high-risk opioids and patterns that could inform policy and healthcare practices. Results: The integration of MED calculations with Canadian and U.S. data provides a robust tool for assessing opioid potency and prescribing practices. The OralOpioids R package is an essential tool for public health researchers, enabling a detailed analysis of North American opioid prescriptions. Conclusions: By providing easy access to opioid potency data and supporting cross-national studies, the package plays a critical role in addressing the opioid crisis. It suggests a model for similar tools that could be adapted for global use, enhancing our capacity to manage and mitigate opioid misuse effectively.

Pembrolizumab or placebo with chemoradiotherapy followed by pembrolizumab or placebo for newly diagnosed, high-risk, locally advanced cervical cancer (ENGOT-cx11/GOG-3047/KEYNOTE-A18): overall survival results from a randomised, double-blind, placebo-controlled, phase 3 trial

At the first interim analysis of the phase 3 ENGOT-cx11/GOG-3047/KEYNOTE-A18 study, the addition of pembrolizumab to chemoradiotherapy provided a statistically significant and clinically meaningful improvement in progression-free survival in patients with locally advanced cervical cancer. We report the overall survival results from the second interim analysis of this study. Eligible patients with newly diagnosed, high-risk (FIGO 2014 stage IB2-IIB with node-positive disease or stage III-IVA regardless of nodal status), locally advanced, histologically confirmed, squamous cell carcinoma, adenocarcinoma, or adenosquamous cervical cancer were randomly assigned 1:1 to receive five cycles of pembrolizumab (200 mg) or placebo every 3 weeks with concurrent chemoradiotherapy, followed by 15 cycles of pembrolizumab (400 mg) or placebo every 6 weeks. Pembrolizumab or placebo and cisplatin were administered intravenously. Patients were stratified at randomisation by planned external beam radiotherapy type (intensity-modulated radiotherapy [IMRT] or volumetric-modulated arc therapy [VMAT] vs non-IMRT or non-VMAT), cervical cancer stage at screening (FIGO 2014 stage IB2-IIB node positive vs III-IVA), and planned total radiotherapy (external beam radiotherapy plus brachytherapy) dose (<70 Gy vs ≥70 Gy [equivalent dose of 2 Gy]). Primary endpoints were progression-free survival per RECIST 1.1 by investigator or by histopathological confirmation of suspected disease progression and overall survival defined as the time from randomisation to death due to any cause. Safety was a secondary endpoint. Between June 9, 2020, and Dec 15, 2022, 1060 patients at 176 sites in 30 countries across Asia, Australia, Europe, North America, and South America were randomly assigned to treatment, with 529 patients in the pembrolizumab-chemoradiotherapy group and 531 patients in the placebo-chemoradiotherapy group. At the protocol-specified second interim analysis (data cutoff Jan 8, 2024), median follow-up was 29·9 months (IQR 23·3-34·3). Median overall survival was not reached in either group; 36-month overall survival was 82·6% (95% CI 78·4-86·1) in the pembrolizumab-chemoradiotherapy group and 74·8% (70·1-78·8) in the placebo-chemoradiotherapy group. The hazard ratio for death was 0·67 (95% CI 0·50-0·90; p=0·0040), meeting the protocol-specified primary objective. 413 (78%) of 528 patients in the pembrolizumab-chemoradiotherapy group and 371 (70%) of 530 in the placebo-chemoradiotherapy group had a grade 3 or higher adverse event, with anaemia, white blood cell count decreased, and neutrophil count decreased being the most common adverse events. Potentially immune-mediated adverse events occurred in 206 (39%) of 528 patients in the pembrolizumab-chemoradiotherapy group and 90 (17%) of 530 patients in the placebo-chemoradiotherapy group. This study is registered with ClinicalTrials.gov, NCT04221945. Pembrolizumab plus chemoradiotherapy significantly improved overall survival in patients with locally advanced cervical cancer These data, together with results from the first interim analysis, support this immuno-chemoradiotherapy strategy as a new standard of care for this population. Merck Sharp & Dohme, a subsidiary of Merck & Co.

Long-Term Outcomes After Cyberknife Radiosurgery for Nonfunctioning Pituitary Adenomas.

Stereotactic radiosurgery (SRS) has been widely adopted as an important adjunctive treatment modality for managing nonfunctioning pituitary adenomas (NFPAs). However, current studies on the long-term effects of SRS on pituitary adenomas have been largely limited by small sample sizes and short follow-up periods. The aim of this study was to evaluate the long-term outcomes of SRS for NFPAs. We conducted a retrospective review of 178 patients with NFPAs who received Cyberknife radiosurgery at a single institution between February 2008 and July 2021. Long-term outcomes of tumor control, new-onset hypopituitarism, and new visual disorders were assessed. During a median radiological follow-up of 49.7 months (range, 2.5-158.1 months), only 11 (7.0%) patients experienced tumor progression. The progression-free survival at 3, 5, and 10 years was 97.47%, 95.57%, and 93.04%, respectively. New-onset hypopituitarism was diagnosed in 27 (16.9%) patients with a median clinical follow-up duration of 71.2 months (range, 11.5-175.4 months). The median time from SRS to new-onset hypopituitarism was 28.3 months (range, 2.8-101.7 months). The cumulative incidence of new-onset hypopituitarism at 3, 5, and 10 years was 8.47%, 12.43%, and 15.25%, respectively. Biological effective dose >140 Gy and single fraction equivalent dose >16.0 Gy were significant risk factors for new-onset hypopituitarism (P = .046). Other adverse events were experienced by 15 (8.4%) patients, 9 (5.1%) of whom presented with new visual disorders. Development of new visual disorders was associated with a pretreatment tumor volume of >2.5 mL (P = .044). SRS is an effective and relatively safe means of managing both primary and residual/recurrent NFPAs.

The impact of chiropractic care on prescription opioid use for non-cancer spine pain: protocol for a systematic review and meta-analysis

BackgroundIn recent studies, receipt of chiropractic care has been associated with lower odds of receiving prescription opioids and, among those already prescribed, reduced doses of opioids among patients with non-cancer spine pain. These findings suggest that access to chiropractic services may reduce reliance on opioids for musculoskeletal pain.ObjectiveTo assess the impact of chiropractic care on initiation, or continued use, of prescription opioids among patients with non-cancer spine pain.MethodsWe will search for eligible randomized controlled trials (RCTs) and observational studies indexed in MEDLINE, Embase, AMED, CINAHL, Web of Science, and the Index to Chiropractic Literature from database inception to June 2024. Article screening, data extraction, and risk-of-bias assessment will be conducted independently by pairs of reviewers. We will conduct separate analyses for RCTs and observational studies and pool binary outcomes (e.g. prescribed opioid receipt, long-term opioid use, and higher versus lower opioid dose) as odds ratios (ORs) with associated 95% confidence intervals (CIs). When studies provide hazard ratios (HRs) or relative risks (RRs) for time-to-event data (e.g. time-to-first opioid prescription) or incidence rates (number of opioid prescriptions over time), we will first convert them to an OR before pooling. Continuous outcomes such as pain intensity, sleep quality, or morphine equivalent dose will be pooled as weighted mean differences with associated 95% CIs. We will conduct meta-analyses using random-effects models and explore sources of heterogeneity using subgroup analyses and meta-regression. We will evaluate the certainty of evidence of all outcomes using the GRADE approach and the credibility of all subgroup effects with ICEMAN criteria. Our systematic review will follow the PRISMA statement and MOOSE guidelines.DiscussionOur review will establish the current evidence informing the impact of chiropractic care on new or continued prescription opioid use for non-cancer spine pain. We will disseminate our results through peer-reviewed publication and conference presentations. The findings of our review will be of interest to patients, health care providers, and policy-makers.Trial registrationSystematic review registration: PROSPERO CRD42023432277.

Jiawei Xionggui Decoction promotes meningeal lymphatic vessels clearance of β-amyloid by inhibiting arachidonic acid pathway

BackgroundAlzheimer's disease (AD) is an aging-associated form of dementia characterized by the pathological deposition of toxic misfolded proteins in the central nervous system (CNS), which is closely related to the clearance impairment of meningeal lymphatic vessels (mLVs). Thus, enhancement dural meningeal lymphatic drainage to remove amyloid-β (Aβ) is usually considered as a potential therapeutic target for AD. PurposeThis study aimed to investigate the mechanisms of Jiawei Xionggui Decoction (JWXG) to attenuate cognitive dificits in APP/PS1 mice with impaired meningeal lymphatic drainage. MethodsLigation of deep cervical lymph nodes (dcLNs) was performed to establish the mice model of the impaired meningeal lymphatic drainage in APP/PS1 mice. Cognitve behaviors and pathological morphology of mice were assessed. Cerebral blood flow (CBF) of mice was determined using Laser speckle contrast imaging analysis. Serum non-targeted metabolomics analysis was applied to decipher the mechanisms of JWXG in rescuing the impairment of mLVs, and C8-D1A cells were employed to validate in vitro. ResultsDisruption of mLVs in APP/PS1 mice deteriorated cognitive dysfunction, accelerated Aβ burden and glia activation, accompanied by more severe neuropathological damage, CBF reduction and neuroinflammation exacerbation. Serum non-targeted metabolomics analysis indicates the increase of arachidonic acid (AA) metabolic pathway was the key contributor to the neuropathological exacerbation of dcLNs ligation APP/PS1 mice. Interestingly, clinically equivalent dose of JWXG was sufficient to restore mLVs drainage and rescue cognitive performance by inhibiting neuroinflammation depended by AA metabolic pathway in dcLNs ligation APP/PS1 mice. ConclusionOur findings establish a novel mechanism that rescue mLVs by inhibiting AA metabolic pathway to clear brain Aβ, and support JWXG as a feasible treatment strategy for AD by suppressing AA metabolic pathway to improve mLVs drainage efficiency.

Ghost age components in detrital thermochronology

Thermochronological dating of detrital samples is an important tool for understanding the thermal history of basins and their source regions. Detrital thermochronology data are often complex with apparent ages ranging over hundreds of million years due to variations in source-rock cooling age and rate, and the influence of post-depositional burial. A common strategy to interpret such data is to split a dataset into several age components by finite-mixture modeling. Herein, we describe for the first time a remarkable pattern of age components in some thermochronological datasets: two or more components showing ages that are approximately multiples of each other. We apply finite-mixture modeling to a log-normal age distribution (a random effects model) and show that these “ghost age components” are artifacts of inappropriately fitting discrete components to continuous age ranges. The striking pattern of the age components is a direct consequence of the underlying age distribution. For a continuous log-normal age distribution, the ghost components have approximately similar age ratios that depend on the overdispersion and the number of components. Due to their artifactual nature, ghost components appear in a range of dating methods, including fission-track, UPb and (UTh)/He dating, and in equivalent doses of luminescence dating. As they are not geologically meaningful, their occurrence hampers the geological interpretation of thermochronological data. We thus propose to carefully decide for the number of fitted components based on grain properties and additional geological information and to screen modeling results for the constant age ratios that are characteristic of ghost components.

Structural, thermal, and radiation shielding properties of B2O3-TeO2-Bi2O3-CdO-Tm2O3 glasses: The role of Tm2O3

This study presents a detailed investigation into the structural, thermal, and radiation shielding properties of a new glass composition, labeled as (50-x)B2O3 + 30TeO2 + 10Bi2O3 + 10CdO + x Tm2O3 (where x = 0, 1, 2, 3, 4, 5 mol %). Various radiation shielding parameters such as mass attenuation coefficient, linear attenuation coefficient, half-value layer, mean free path, effective atomic number, and absorbed equivalent dose rates for neutrons were determined through experimental measurements. The study also employed theoretical calculations to assess the exposure buildup factor and effective removal cross-section for neutrons. Additionally, the SRIM program was utilized to investigate mass stopping power and projected range for proton and alpha particles. The structural characteristics of the glasses were analyzed using XRD and FT-IR, while thermal properties were examined through Differential Thermal Analysis (DTA). FTIR analysis revealed distinctive bands corresponding to Bi—O, B—O—B, and Te—O bonds. Glass transition temperatures (Tg) increased with Tm2O3 content, ranging from 422 °C to 444 °C. The radiation shielding properties of bismuth boro-tellurite glasses showed that a dose of 1.2025 μSv/h emitted from a fast neutron source was absorbed by 35.1574 % in pure glass and 40.0391 % in glass doped with 5 mol% Tm2O3. Incorporating Tm2O3 into the glass matrix significantly improved the shielding and thermal properties, thus enhancing their potential for advanced high-energy radiation absorption. This investigation contributes to a deeper understanding of how Tm2O3 enhances the structural and thermal attributes of these glasses, positioning them as promising materials for radiation shielding applications.

Exposure to ionizing radiation of medical staff performing vascular and interventional radiology procedures.

Vascular and interventional radiology procedures are characterized by high exposure of personnel to ionizing radiation. This study assessed the exposure of medical personnel to ionizing radiation during vascular radiology and mechanical thrombectomy procedures. During vascular radiology procedures, the exposure of 4 groups of workers participating in the procedures was analyzed, i.e., the main operating physician, an assistant physician, a sterile nurse, and a nurse. Measurements of exposure to ionizing radiation were performed using thermoluminescent dosimetry. The registered effective dose during 1 treatment in individual groups is, respectively: mean (M) ± standard deviation (SD) 75±15 μSv, 24±5 μSv, 13±3 μSv, and 8±2 μSv. During mechanical thrombectomy, the operating physician receives an effective dose of M±SD 9±2 μSv. The equivalent doses for the lenses for the operating physician and the doctor assisting during vascular radiology procedures are M±SD 1419±285 μSv and 987±198 μSv, respectively, and for the hands, including the left and right hands, M±SD 4605±930 μSv, 1420±284 μSv, 1898±380 μSv, 1371±274 μSv. If the principles of optimizing radiological protection are not applied during vascular radiology procedures, the permissible dose limits and operational limits equivalent to doses to lenses and hands may be exceeded. Exposure during vascular radiology procedures is comparable to exposure during nuclear medicine procedures in terms of the use of glucose labeled with radioactive fluorine. Int J Occup Med Environ Health. 2024;37(4).

Concurrent Opioid and Psychotropic Drug Use During Pregnancy: Descriptive Study from Two Canadian Provinces

ObjectivesThis study aims to describe the patterns of concurrent opioid and psychotropic drug use (CU) during pregnancy and the characteristics of the mothers dispensed these drugs. MethodsPregnancies between 2000-2020 were identified using administrative data from Manitoba and British Columbia, Canada. Prenatal opioid and psychotropic drug dispensations were assessed, and exposure groups created based on the number of dispensations within each drug category. Descriptive statistics are reported. ResultsApproximately 1.4% of 1,040,021 pregnancies involved CU. Odds of CU were greater for 2+ opioid pregnancies compared to pregnancies with only 1 opioid (OR=4.05). Among CU pregnancies, it was more likely for 2+ types of psychotropics to be dispensed for those involving 2+ opioids compared to 1 (OR=2.23). Percent of CU pregnancies did not change over time, while opioid pregnancies decreased, and psychotropic pregnancies increased. Average morphine equivalent dose of opioids/pregnancy was higher in CU than opioid only pregnancies. Compared to mothers without exposure, CU exposed mothers were of similar age, more likely to live rurally, in lower income areas, and have lower care continuity. ConclusionCU pregnancies remained stable over time. It was more likely for mothers dispensed 2+ opioids to be CU than mothers dispensed only 1 opioid, and more likely for CU mothers dispensed 2+ opioids to be dispensed 2+ psychotropic types. Overall strength of opioids was higher for CU mothers compared to opioid only exposed mothers. ImplicationsStudies measuring the impact of CU on maternal and child outcomes should be conducted to inform safe prescribing practices.

Design and Implementation of an Opioid Scorecard for Hospital System-Wide Peer Comparison of Opioid Prescribing Habits: Observational Study.

Reductions in opioid prescribing by health care providers can lead to a decreased risk of opioid dependence in patients. Peer comparison has been demonstrated to impact providers' prescribing habits, though its effect on opioid prescribing has predominantly been studied in the emergency department setting. The purpose of this study is to describe the development of an enterprise-wide opioid scorecard, the architecture of its implementation, and plans for future research on its effects. Using data generated by the author's enterprise vendor-based electronic health record, the enterprise analytics software, and expertise from a dedicated group of informaticists, physicians, and analysts, the authors developed an opioid scorecard that was released on a quarterly basis via email to all opioid prescribers at our institution. These scorecards compare providers' opioid prescribing habits on the basis of established metrics to those of their peers within their specialty throughout the enterprise. At the time of this study's completion, 2034 providers have received at least 1 scorecard over a 5-quarter period ending in September 2021. Poisson regression demonstrated a 1.6% quarterly reduction in opioid prescribing, and chi-square analysis demonstrated pre-post reductions in the proportion of prescriptions longer than 5 days' duration and a morphine equivalent daily dose of >50. To our knowledge, this is the first peer comparison effort with high-quality evidence-based metrics of this scale published in the literature. By sharing this process for designing the metrics and the process of distribution, the authors hope to influence other health systems to attempt to curb the opioid pandemic through peer comparison. Future research examining the effects of this intervention could demonstrate significant reductions in opioid prescribing, thus potentially reducing the progression of individual patients to opioid use disorder and the associated increased risk of morbidity and mortality.

Potentiation of growth suppression and modulation of multidrug resistance by gamma and beta interferons in MDA-MB-231 breast cancer cell line.

Multi-drug resistance (MDR) might be acquired by the cancer cells during chemotherapy, and ATP-binding cassette (ABC) transporters play a significant role in MDR. Interferon-γ (IFN-γ) and IFN-β can inhibit cancer cell proliferation; however, the effects and mechanism of these cytokines on the growth and MDR are still unclear. To investigate the effects of IFN-γ and IFN-β, alone or in combination, on viability, resistance, and the expression of ABC transporters of the MDA-MB-231 breast cancer cell line. Using the MDA-MB-231 cell line, we assessed the effects of 20, 100, and 500 IU/ml of IFN-γ and IFN-β, alone or in combination, on cell viability by methyl thiazolyl tetrazolium(MTT) assay; and then we performed the Uptake and Efflux experiment to evaluate the effect of these IFNs on the cell resistance. Then, using quantitative real-time PCR, we evaluated changes in the expression of ABCB1, ABCC1, and ABCG2 mRNA levels. We discovered that IFN-γ and IFN-β might both reduce viability, either alone or in combination. The combination of IFNs also displayed synergistic responses, particularly when utilizing equivalent dosages of 500 or 100 IU/ml. The combination of IFN-γ and IFN-β resulted in a significant increase in Doxorubicin accumulation and down-regulation of the ABCC1 gene at the mRNA level. Our study suggested that equal doses of IFN-γ and IFN-β in combination might result in potentiated responses against cancer, especially, along with chemotherapy agents.

New chronology evidence of prehistoric human activities indicated by pottery luminescence dating in the humid subtropical mountains of South China

The age of prehistoric human sites serves as a fundamental basis for studying the relationship between human activities and landscape changes in the humid subtropical mountains of South China. The presence of pottery in these archaeological sites is widespread and offers a valuable resource for precise dating purposes. The Longtoushan (LTS) site, located in the northern mountains of Fujian Province, contains a rich variety of pottery types from various periods, representing a rare multi-period stratigraphic overlap in this area and playing a crucial role in constructing the cultural sequence and lineage of prehistoric and ancient times in this region. In this study, we employed thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques to establish the age of pottery samples collected from the LTS site situated in the upper Minjiang River region of southeast China for the first time, while also comparing our findings with other dating methods to construct a chronological framework for the site. The results showed that: (1) The samples analyzed in this study can be classified according to the peak strength of 325 °C TL signal at natural and regenerative doses of quartz. Samples with weak TL signal at 325 °C (type II samples) showed high recuperation and equivalent dose underestimation at a low preheat temperature (220 °C) in OSL test. (2) Conventional SAR procedures employed for type I samples are not suitable for type II samples. Type II samples require additional OSL stimulation towards the end of the cycle and an extended stimulation duration. (3) The application of various dating methods has revealed that the LTS site represents a long-term settlement in the humid subtropical mountains of South China, commencing around 4.6–4.4 thousand years ago (ka). Specifically, the dating of pottery pieces from kiln sites and tombs in the late Neolithic period provides a specific temporal reference for further understanding of prehistoric human culture and production behavior in the humid mountains of Fujian.