Radiation Dose and Fluoroscopy Time of Diagnostic Angiography in Patients with Spinal Dural Arteriovenous Fistula

Purpose Spinal dural arteriovenous fistulas (SDAVFs) represent the most common indication for a spinal angiography. The diagnostic reference level (DRL) for this specific endovascular procedure is still to be determined. This single-center study provides detailed dosimetrics of diagnostic spinal angiography performed in patients with SDAVFs. Methods Retrospective analysis of all diagnostic spinal angiographies between December 2011 and January 2021. Only patients with an SDAVF who had baseline magnetic resonance angiography (MRA), diagnostic digital subtraction angiography (DSA), treatment and follow-up at this institution were included. Dose area product (DAP, Gy cm2) and fluoroscopy time were compared between preoperative and postoperative angiographies, according to SDAVF locations (common versus uncommon), MRA results at baseline (positive versus negative) and DSA protocols (low-dose, mixed-dose, normal-dose). The 75th percentile of the DAP distribution was used to define the local DRL. Results A total of 62 spinal angiographies were performed in 25 patients with SDAVF. Preoperative angiographies (30/62, 48%) yielded a significantly higher DAP and longer fluoroscopy time when compared to postoperative angiographies (32/62, 53%) (p < 0.01). The local DRL was 329.41 Gy cm2 for a nonspecific (n = 62), 395.59 Gy cm2 for a preoperative and 138.6 Gy cm2 for a postoperative spinal angiography. Preoperative angiography of uncommonly located SDAVFs yielded a significantly longer fluoroscopy time (p = 0.02). The MRA-based fistula detection had no significant impact on dosimetrics (p > 0.05). A low-dose protocol yielded a 61% reduction of DAP. Conclusion The results of the present study suggest novel DRLs for spinal angiography in patients with SDAVF. Dedicated low-dose protocols enable radiation dose optimization in these procedures.

Intraoral and dental panoramic imaging: A diagnostic reference level study comparing radiation dose using two dosimeters in Saudi Arabia

The purpose of this study was to determine local diagnostic reference levels (DRLs) for patients undergoing intraoral and panoramic dental examinations at the intraoral radiology units of the public hospitals in Najran, Saudi Arabia. DRLs were determined based on measurements of dose area product (DAP) at intraoral and dental panoramic radiology units. This study has covered over 47% of the public hospitals in Najran with the intention to establish the local DRLs for all the possible intraoral and panoramic X-ray examinations for children and adults. For intraoral, the values for the estimated DAP ranged from 6 to 70 mGy.cm2 (average: 27.6, 29.8, 39.9 and 39.6 mGy.cm2 for incisive, both premolar and canine, molar upper and lower jaw, respectively). For panoramic, the mean value of DAP is 61.5 and 89.8 mGy.cm2 for paediatric and adult patients, respectively. DRLs were established at the 3rd quartile for incisive, both premolar and canine, molar upper and lower jaw protocols are 29.2, 37.1, 50.2 and 50.1 mGy.cm2, respectively. Furthermore, DRLs for panoramic radiography for paediatric and adult patients are 72.7 and 92.3 mGy.cm2, respectively. The proposed DRLs were comparable to those previously reported in other countries, such as UK and India.

First Steps towards a National Approach for Radon Survey in Romanian Schools

Schools are a category of public buildings with a high radon exposure risk, due to their high occupancy factor. In Romania, the elaboration of a methodology for radon measurements in schools is a necessity imposed both by the European legislation and by the relatively high percentage (about 10%) of the mapped territory with a potential increased risk of exposure to the action of ionizing radiation emitted by radon. In order to optimize the design of a national survey aimed to evaluate radon exposure of children in Romanian schools, we conducted a pilot study in two schools in Cluj-Napoca, following the screening measurements carried out in 109 schools and kindergartens from five counties. The specific steps that must be followed were described, taking into account the international protocols and particularities of Romanian territory. The proposed approach could act as a guide for other large buildings and is implicit for the implementation of National Radon Action Plan, approved by HG no. 526/12 July 2018 in accordance with Council Directive 2013/59/EURATOM. The obtained results indicate that a high probability of annual radon concentration above the national reference level is to be expected in schools.

Joint pricing and ordering decisions for a loss-averse retailer with quantity-oriented reference point effect and demand uncertainty: a distribution-free approach

PurposeThis work examines the joint pricing and ordering (JPO) decisions for a loss-averse retailer with quantity-oriented reference point (RP) effect under demand uncertainty.Design/methodology/approachThe demand is assumed to be uncertain with the mean and variance as the only known information. The prospect theory is used to model the retailer's expected utility. An expected utility maximization model in the distribution-free approach (DFA) is then developed. Using duality theory, the expected utility under the worst-case distribution is transformed into tractable piece-wise functions. To examine the effectiveness of the DFA in coping with the demand uncertainty, a stochastic programming model is developed and its solutions are used as benchmarks.FindingsThe proposed model and solution approach can effectively hedge against the demand uncertainty. The JPO decisions are significantly influenced by the LA coefficient and the reference level. The LA has a stronger influence than the reference level does on the expected utility. An excessive LA is detrimental while an appropriate reference level is beneficial to the retailer.Practical implicationsThe results of this work are applicable to loss-averse retailers with the quantity-oriented RP when making JPO decisions with difficulty in predicting the demands.Originality/valueThe demand is assumed to be uncertain in this work, but a certain demand distribution is usually assumed in the existing literature. The DFA is used to study JPO decisions for the loss-averse retailer with quantity-oriented RP effect under the uncertain demand.

The multiple sclerosis patient’s journey model in Poland – future tasks

Improvement of the diagnostic and therapeutic processes and optimal use of resources in the context of health care system specificity accelerate the diagnosis and treatment onset, as well as improve the quality of life of patients with multiple sclerosis. International experience and data from clinical practice in Poland gave rise to a number of guidelines for the needed measures, from increasing the awareness about multiple sclerosis among the society and doctors in general, through expanding outpatient medical care, to proposing a model network of healthcare centres dedicated to patients with multiple sclerosis. It was pointed out that there is a need for a network of clinics specialised in the diagnosis and treatment of multiple sclerosis (MS clinics) and centres for comprehensive diagnosis and treatment, with a higher reference level and all the competences of an MS clinic, and, at the same time, providing both consultations in difficult clinical cases and access to the most advanced diagnostic and therapeutic methods. Attention was also drawn to the need to use modern e-health tools, which should improve the diagnostic and therapeutic process, as well as tighten the coordination of care by enabling an effective exchange of information between the patient and the entire interdisciplinary team involved in the therapeutic process.

Modified Predictive Control System of the DC-DC Boost Converter

Nowadays, predictive control systems are becoming more and more popular, which significantly reduce the cost of setting up converters. However, DC-DC converter control problem persists. In this work, a modified model of the predictive control system (MPCS) for step-up DC-DC converters is presented. For its implementation, a nonlinear model of a converter with discrete time switching was derived, which describe a continuous conduction mode of operation. The synthesis of the controller was achieved by formulating the objective function that should be minimized considering the dynamic model of the converter. The proposed predictive control strategy, used as a voltage control system, allows keeping the output voltage at the reference level. The modified system for calculating the objective function makes it possible to significantly reduce the required computing power and expand the prediction horizon. The results of modeling have been presented that demonstrate the advantages of the proposed control method: a fast transient response and a high degree of robustness.

The Role of Forests in Climate Change Mitigation: The EU Context

The European Union (EU) aims at reaching carbon neutrality by 2050. Within the land use, land-use change, and forestry (LULUCF) sector, forestry will contribute to this target with CO2 sink, harvested wood products (HWP), and use of wood for material or energy substitution. Despite the fact that the forest sink currently offsets about 9% of the total EU GHG emissions, evaluating its future mitigation potential is challenging because of the complex interactions between human and natural impacts on forest growth and carbon accumulation. The Regulation (EU) 2018/841 has improved robustness, accuracy, and credibility of the accounting of GHG emissions and removals in the LULUCF sector. For the forest sector, the accounting is based on the Forest Reference Level (FRL), i.e., a projected country-specific value of GHG emissions and removals against which the actual GHG emissions and removals will be compared. The resulting difference will count toward the EU GHG target for the period 2021–2030. Here, we provide an overview of the contribution of forests and HWP to the EU carbon sink for the period 2021–2025 (proposed FRLs) and focus on the contribution of mountain forests to the EU carbon sink, through exploring co-benefits and adverse side effects between climate regulation and other ecosystem services.

Centromere-Specific Retrotransposons and Very-Long-Chain Fatty Acid Biosynthesis in the Genome of Yellowhorn (Xanthoceras sorbifolium, Sapindaceae), an Oil-Producing Tree With Significant Drought Resistance

In-depth genome characterization is still lacking for most of biofuel crops, especially for centromeres, which play a fundamental role during nuclear division and in the maintenance of genome stability. This study applied long-read sequencing technologies to assemble a highly contiguous genome for yellowhorn (Xanthoceras sorbifolium), an oil-producing tree, and conducted extensive comparative analyses to understand centromere structure and evolution, and fatty acid biosynthesis. We produced a reference-level genome of yellowhorn, ∼470 Mb in length with ∼95% of contigs anchored onto 15 chromosomes. Genome annotation identified 22,049 protein-coding genes and 65.7% of the genome sequence as repetitive elements. Long terminal repeat retrotransposons (LTR-RTs) account for ∼30% of the yellowhorn genome, which is maintained by a moderate birth rate and a low removal rate. We identified the centromeric regions on each chromosome and found enrichment of centromere-specific retrotransposons of LINE1 and Gypsy in these regions, which have evolved recently (∼0.7 MYA). We compared the genomes of three cultivars and found frequent inversions. We analyzed the transcriptomes from different tissues and identified the candidate genes involved in very-long-chain fatty acid biosynthesis and their expression profiles. Collinear block analysis showed that yellowhorn shared the gamma (γ) hexaploidy event with Vitis vinifera but did not undergo any further whole-genome duplication. This study provides excellent genomic resources for understanding centromere structure and evolution and for functional studies in this important oil-producing plant.

Mean Glandular Dose Measurement in Three Mammography Centers in Kashan: An approach to Provide a Local DRL

Purpose: Mammography is the most important diagnostic modality for early detection of breast cancer, however, concerns related to the side effects induced by ionizing radiation are still present. In the current study, the Mean Glandular Dose (MGD) values for mammography examinations as well as a local Diagnostic Reference Level (DRL) were obtained for mammography centers in Kashan, Iran. Materials and Methods: Three mammography devices from three radiology centers were selected to obtain the MGD values of mammography examinations. To assess the MGD values, the technical parameters for patients’ imaging at these three radiology centers were extracted. Then, the incident air kerma (in mGy) value received by each patient was measured by a UNIDOS E electrometer (PTW, Germany) along with a SFD mammography ionization chamber (PTW, Germany). Finally, the incident air kerma values were converted to the MGD values by specific conversion factors. Based on the obtained MGD values, a local DRL was also established for mammography examinations. Results: Mean MGD values per exposure were obtained 2.39 ± 1.46 mGy for Right Craniocaudal (RCC), 2.64 ± 1.67 mGy for Left Craniocaudal (LCC), 2.82 ± 1.89 mGy for Right Mediolateral Oblique (RMLO), and 3.09 ± 1.90 mGy for left mediolateral oblique views. Moreover, a local DRL obtained from mammography examinations, which was established as the overall median of MGD value, was 1.72 mGy (1.91 mGy for digital and 1.32 mGy for analog mammography). Conclusion: The MGD values for different views obtained in this study are in the range of previously reported values. Considering the European guidelines for quality assurance in breast cancer screening and diagnosis, it can be mentioned that the obtained DRL was less than the recommended dose level (2.0 mGy).