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Background: The most efficient application of ionizing radiation is serving medical purposes and using this radiation has caused people to learn that artificial sources of radiation exposure among these resources can be of highest exposure rate. Obiective: The present study is aimed at initially establishing a baseline for localreference dose level in Mazandaran, Iran in 12 projections of the most conventional x-ray examination. Methods: In this study, 13 public hospitals in Mazandaran province were selected for review and required data collected for ten adult patients with mean weight of 70±10kg in each projection. Then, information of each center was separately analyzed. Next, in order to measure x-ray output tube, the dosimeter RTI model Barracuda calibrated has been applied for measuring air karma within energy rage of 40-150kvp. ESAK and ESD parameters, usually used for monitoring DRL in conventional radiography, were calculated. Results: Mean ESDs in this study has been obtained to 1.47±0.98 for skull (PA/ AP), 1.01±0.79 for skull (LAT), 0.67±0.38 for cervical spine (AP), 0.79±0.37 for cervical (LAT), 0.49±0.38 for chest (PA/AP), 1.06±0.44 for chest (LAT), 2.15±0.73 for thoracic spine (AP), 3±0.87 for thoracic spine (LAT), 2.81 ±0.82 for lumbar spine (AP), 4.28±0.78 for lumbar (LAT), 2.07±1.17 for abdomen and 1.90±0.99 for pelvis, respectively. The ESDs calculated for chest examination in both projections, PA and LAT are more than values recommended by the UK (2000), Brazil and Slovenia. Conclusion: The present study has determined wide variations in radiation dose of x-ray examinations among hospitals in Mazandaran, Iran. In order to reduce skin dose, an optimization procedure should be considered. Application of a reference dose (DRL) could be a practical method for this purpose. The role of optimization of radiography parameters for reducing patient dose is a significant issue. Through optimizing parameters, it would be possible to preserve image quality while reduction of patient dose.

Background: Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective: This study is aimed at evaluating radiation dose to patients from Computed Tomography (CT) examination in Mazandaran hospitals and defining diagnostic reference level (DRL). Methods: Patient-related data on CT protocol for four common CT examinations including brain, sinus, chest and abdomen & pelvic were collected. In each center, Computed Tomography Dose Index (CTDI) measurements were performed using pencil ionization chamber and CT dosimetry phantom according to AAPM report No. 96 for those techniques. Then, Weighted Computed Tomography Dose Index (CTDIW), Volume Computed Tomography Dose Index (CTDI vol) and Dose Length Product (DLP) were calculated. Results: The CTDIw for brain, sinus, chest and abdomen & pelvic ranged (15.6- 73), (3.8-25. 8), (4.5-16.3) and (7-16.3), respectively. Values of DLP had a range of (197.4-981), (41.8-184), (131-342.3) and (283.6-486) for brain, sinus, chest and abdomen & pelvic, respectively. The 3rd quartile of CTDIW, derived from dose distribution for each examination is the proposed quantity for DRL. The DRLs of brain, sinus, chest and abdomen & pelvic are measured 59.5, 17, 7.8 and 11 mGy, respectively. Conclusion: Results of this study demonstrated large scales of dose for the same examination among different centers. For all examinations, our values were lower than international reference doses.

Heba Hijazi,1,2 Wegdan Baniissa,3 Rabah Al Abdi,4 Nabeel Al-Yateem,3 Amina Almarzouqi,1 Syed Rahman,1 Rayya Alshammari,1 Mohamad Alameddine1 1Department of Health Services Administration, College of Health Sciences, University of Sharjah, Sharjah, United Arab Emirates; 2Department of Health Management and Policy, Faculty of Medicine, Jordan University of Science and Technology, Irbid, Jordan; 3Nursing Department, College of Health Sciences, University of Sharjah, Sharjah, United Arab Emirates; 4Department of Biomedical Engineering, Faculty of Engineering, Jordan University of Science and Technology, Irbid, JordanCorrespondence: Heba Hijazi, Department of Health Services Administration, College of Health Sciences, University of Sharjah, Sharjah, United Arab Emirates, Email hhijazi@sharjah.ac.aeObjective: Frontline healthcare workers experienced high levels of psychological distress and emotional turmoil due to the changes necessitated by the COVID-19 public health emergency. Given that workplace stress can negatively influence both quality of work, and job performance, this study sought to explore the lived experiences of work-related stress among female healthcare workers in United Arab of Emirates during the COVID-19 pandemic.Methods: A qualitative phenomenological investigation was performed using a purposive sampling approach. A total of 26 semi-structured interviews were conducted with female healthcare workers who worked directly with COVID-19 patients. Using Giorgi’s descriptive method, the data were analyzed to identify the main themes.Results: Three main themes emerged from the data analysis, with nine categories under these themes. The first theme was “sources of work-related stress.” The participants reported a high workload, fear of being infected and transmitting the virus to others, and uncertainty and lack of knowledge regarding COVID-19 to be the main sources of their work-related stress. The second theme was “challenges of working during the pandemic.” The participants related being challenged by changes in the organization of care, the need to use personal protective equipment, a work-life imbalance, and witnessing patients’ suffering. The third theme was “coping strategies.” The participants perceived having sources of social support and using self-adjustment skills to be helpful strategies in terms of coping with the stressful situations they experienced.Conclusion: The findings suggest a number of strategies and interventions that could be used at the individual and institutional levels to promote the preparedness and efficacy of healthcare workers during future crises and public health emergencies.Keywords: work-related stress, female healthcare workers, qualitative research, work experiences, healthcare professionals, COVID-19 pandemic, public health emergency

Background Globally, since 1 January 2020 and as of 24 January 2023, there have been over 664 million cases of COVID-19 and over 6.7 million deaths reported to WHO. WHO developed an evidence-based alert system, assessing public health risk on a weekly basis in 237 countries, territories and areas from May 2021 to June 2022. This aimed to facilitate the early identification of situations where healthcare capacity may become overstretched.Methods The process involved a three-stage mixed methods approach. In the first stage, future deaths were predicted from the time series of reported cases and deaths to produce an initial alert level. In the second stage, this alert level was adjusted by incorporating a range of contextual indicators and accounting for the quality of information available using a Bayes classifier. In the third stage, countries with an alert level of ‘High’ or above were added to an operational watchlist and assistance was deployed as needed.Results Since June 2021, the system has supported the release of more than US$27 million from WHO emergency funding, over 450 000 rapid antigen diagnostic testing kits and over 6000 oxygen concentrators. Retrospective evaluation indicated that the first two stages were needed to maximise sensitivity, where 44% (IQR 29%–67%) of weekly watchlist alerts would not have been identified using only reported cases and deaths. The alerts were timely and valid in most cases; however, this could only be assessed on a non-representative sample of countries with hospitalisation data available.Conclusions The system provided a standardised approach to monitor the pandemic at the country level by incorporating all available data on epidemiological analytics and contextual assessments. While this system was developed for COVID-19, a similar system could be used for future outbreaks and emergencies, with necessary adjustments to parameters and indicators.

This research addresses the flow characteristics within a porous medium composed of a monolayer of closely packed spheres, spanning from viscous-dominated to turbulent flow regimes. In the first part of this paper, the turbulent flow characteristics at a 30 MPa pressure drop within the domain are presented. The results are averaged across different cross sections between the inlet and outlet. In the second part of the study, simulations are conducted with pressure drops, ranging from nearly 0 to 100 MPa. The analysis finds distinct flow patterns within the domain and provides estimations for the permeability and the inertial term coefficient. Moreover, the transition from Darcy to non-Darcy and turbulent flow is achieved through the use of different criteria. The specified geometry is suitable for validating and calibrating simplified discrete element method models coupled with computational fluid dynamics. The main goal of this research is to produce a reliable benchmark to figure out the challenge of limited experimental data concerning fluid flow characteristics in densely packed granules specially subjected to high pressure conditions. To do this, representative specimens are designed, accurate simulations are conducted, and precise assessments of the results are carried out. [ABSTRACT FROM AUTHOR]

Considering measurement accuracies, different models used for the prediction of longterm static fatigue for optical fibres under stress were studied. Optical fibres were wound onto an alumina mandrel with various diameters and immersed in hot water at different temperatures. The determination of model parameters was based on the fit of experimental data to model expressions relating time to failure, applied stress and environmental conditions. It is shown that the differences in allowed stress predictions between models become quite close at short times. The time-to-failure depends on the applied stress applied but also and above all on the ageing temperature and the humidity level. Results from tested fibres indicate a clear strength reduction with increasing temperature or applied stress. [ABSTRACT FROM AUTHOR]