Critical Buckling Load for Lattice Column Elements with Variable Dimensions

Lattice structures are used in a variety of high-value engineering applications; for example, in automobile, aerospace and biomedical applications, due to their light weight, high specific strength, stiffness, heat transfer control and energy absorption. Additive Manufacturing (AM) technologies, such as Selective Laser Melting (SLM), offer radical net-shape manufacturing solutions for metallic structures directly from digital data. The prediction of AM lattice structure mechanical properties prior to manufacture is both cost and time-consuming; particularly as existing models do not readily accommodate the effects of manufacturing defects and lattice node geometry on column buckling. The critical buckling load of columns was algebraically and numerically simulated for a full Design of Experiments (DOE) of independent variables, including column length, column radius, node radius and material type. This simulation data quantifies the effect of independent variables on critical buckling load and demonstrates the limitations of algebraically prediction. This research can be extended to allow the simulation of the load carrying capacity of entire lattice structures; and to accommodate the effect of manufacturing variation on the associated load carrying capacity of AM lattice structures

Global Current Practices of Ventilatory Support Management in COVID-19 Patients: An International Survey

Background: As the global outbreak of COVID-19 continues to ravage the world, it is important to understand how frontline clinicians manage ventilatory support and the various limiting factors. / Methods: An online survey composed of 32 questions was developed and validated by an international expert panel. / Results: Overall, 502 respondents from 40 countries across six continents completed the survey. The mean number (±SD) of ICU beds was 64 ± 84. The most popular initial diagnostic tools used for treatment initiation were arterial blood gas (48%) and clinical presentation (37.5%), while the national COVID-19 guidelines were the most used (61.2%). High flow nasal cannula (HFNC) (53.8%), non-invasive ventilation (NIV) (47%), and invasive mechanical ventilation (IMV) (92%) were mostly used for mild, moderate, and severe COVID-19 cases, respectively. However, only 38.8%, 56.6% and 82.9% of the respondents had standard protocols for HFNC, NIV, and IMV, respectively. The most frequently used modes of IMV and NIV were volume control (VC) (36.1%) and continuous positive airway pressure/pressure support (CPAP/PS) (40.6%). About 54% of the respondents did not adhere to the recommended, regular ventilator check interval. The majority of the respondents (85.7%) used proning with IMV, with 48.4% using it for 12– 16 hours, and 46.2% had tried awake proning in combination with HFNC or NIV. Increased staff workload (45.02%), lack of trained staff (44.22%) and shortage of personal protective equipment (PPE) (42.63%) were the main barriers to COVID-19 management. / Conclusion: Our results show that general clinical practices involving ventilatory support were highly heterogeneous, with limited use of standard protocols and most frontline clinicians depending on isolated and varied management guidelines. We found increased staff workload, lack of trained staff and shortage of PPE to be the main limiting factors affecting global COVID-19 ventilatory support management

Exploring the Impact of Iron Deficiency Anaemia on Glycated Haemoglobin A1c Levels in Pregnant and Non-Pregnant Women: A Systematic Review

Amani M AlQarni,1 Amal A Alghamdi,1 Hussain J Aljubran,2 Omar A Bamalan,2 Abdullah H Abuzaid,2 Mohammed A AlYahya,2 Ahmed M AlAwami,2 Mohammed D Al Shubbar,2 Ghada F Al Yousif1 1Department of Family and Community Medicine, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 2College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi ArabiaCorrespondence: Amani M AlQarni, Family and community medicine department, King Fahd Hospital of the University, Imam Abdulrahman bin Faisal University, Dammam, 34212, Saudi Arabia, Tel +966133333766 ; +966591775751, Email [email protected]: Haemoglobin A1C (HbA1c) is fundamental in monitoring glycaemic control during pregnancy. However, several conditions could affect this test’s accuracy, including iron deficiency anaemia (IDA). Hence, this systematic review delves into the underexplored connection between IDA, iron replacement therapy (IRT), and haemoglobin A1C (HbA1c) during pregnancy. An electronic search of the Cochrane, MEDLINE, and Embase databases was conducted by six authors. From a comprehensive search strategy, 968 records were obtained. After applying the inclusion and exclusion criteria, seven studies were included, comprising 365 women selected for analysis. Six studies indicated a positive correlation between IDA and HbA1c levels, while one found no correlation. The average HbA1c level of the included studies in pregnant women was 5.64%. In comparison, it was found that non-pregnant women had lower HbA1c levels. Among the included studies, the mean HbA1c levels decreased from 5.1% to 4.89% after treating pregnant women with IRT. The review emphasises the complexity of interpreting HbA1c levels in pregnant women with IDA, highlighting the influence of pregnancy-induced physiological changes. In addition, this suggests that HbA1c should not be the sole criterion for diabetes management in pregnant women with IDA. Future research should focus on alternative glycaemic monitoring methods unaffected by IDA.Keywords: iron deficiency anaemia, iron replacement therapy, pregnancy, gestational diabetes, glycated haemoglobin, HbA1

Post-acute COVID syndrome (long COVID): What should radiographers know and the potential impact for imaging services

This is the final version. Available on open access from Elsevier via the DOI in this recordOBJECTIVES: The COVID-19 pandemic caused an unprecedented health crisis resulting in over 6 million deaths worldwide, a figure, which continues to grow. In addition to the excess mortality, there are individuals who recovered from the acute stages, but suffered long-term changes in their health post COVID-19, commonly referred to as long COVID. It is estimated there are currently 1.8 million long COVID sufferers by May 2022 in the UK alone. The aim of this narrative literature review is to explore the signs, symptoms and diagnosis of long COVID and the potential impact on imaging services. KEY FINDINGS: Long COVID is estimated to occur in 9.5% of those with two doses of vaccination and 14.6% if those with a single dose or no vaccination. Long COVID is defined by ongoing symptoms lasting for 12 or more weeks post acute infection. Symptoms are associated with reductions in the quality of daily life and may involve multisystem manifestations or present as a single symptom. CONCLUSION: The full impact of long COVID on imaging services is yet to be realised, but there is likely to be significant increased demand for imaging, particularly in CT for the assessment of lung disease. Educators will need to include aspects related to long COVID pathophysiology and imaging presentations in curricula, underpinned by the rapidly evolving evidence base. IMPLICATIONS FOR PRACTICE: Symptoms relating to long COVID are likely to become a common reason for imaging, with a particular burden on Computed Tomography services. Planning, education and updating protocols in line with a rapidly emerging evidence base is going to be essential

Effect of Dietary Simulating Solvents on the CAD-CAM Provisional Restorative Materials’ Microhardness and Color Stability Properties: An in vitro Study

Haidar Alalawi,1 Sarah Al-Qanas,2 Sarah Al-Ghamdi,2 Raghad Al-Fuhaid,2 Soban Khan,3 Maram A AlGhamdi,1 Khalid S Almulhim,4 Faisal E Aljofi,5 Zahid A Khan,1 Yousif A Al-Dulaijan1 1Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 2College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 3Department of Dental Education, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 4Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia; 5Department of Preventive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi ArabiaCorrespondence: Yousif A Al-Dulaijan, Department of Substitutive Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia, Tel +966 13 333 1462, Email [email protected]: This in vitro study investigated the effects of dietary solvents on the microhardness and color stability of CAD/CAM provisional restorations compared to conventional materials.Methods: Disc-shaped specimens (n=200) were fabricated from self-cured acrylic resin, two 3D-printing resins (FormLabs, NextDent), and a milled material (TelioCAD). Randomization assigned specimens (n=10/group) to immersion solutions: artificial saliva, citric acid, heptane, coffee, and tea. Microhardness and color stability were evaluated. One-way and three-way ANOVA with Tukey’s post hoc test analyzed the data.Results: Dietary solvents significantly reduced the surface microhardness of all tested materials (p< 0.05). Unpolished surfaces exhibited greater color changes compared to polished ones (p< 0.05) across all materials. Coffee and tea induced the most substantial reductions in hardness and the most significant color alterations (p< 0.05), whereas saliva and citric acid had minimal effects.Conclusion: Milled provisional restorations exhibited superior hardness and color stability. Dietary solvents significantly affected material properties over time, highlighting the importance of material selection for clinical applications.Keywords: 3D-printed, color stability, food, microhardness, milled, self-cure resi