A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral

Introduction: To date, little is known about the clinical features of pediatric COVID-19 patients admitted to intensive care units (ICUs). Objective: Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes of Iranian pediatric COVID-19 patients admitted to ICU versus those in non-ICU settings. Methods: This multicenter investigation involved 15 general and pediatrics hospitals and included cases with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on positive real-time reverse transcription polymerase chain reaction (RT-PCR) admitted to these centers between March and May 2020, during the initial peak of the COVID-19 pandemic in Iran. Results: Overall, 166 patients were included, 61 (36.7%) of whom required ICU admission. The highest number of admitted cases to ICU were in the age group of 1–5 years old. Malignancy and heart diseases were the most frequent underlying conditions. Dyspnea was the major symptom for ICU-admitted patients. There were significant decreases in PH, HCO3 and base excess, as well as increases in creatinine, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and potassium levels between ICU-admitted and non-ICU patients. Acute respiratory distress syndrome (ARDS), shock, and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate in the ICU-admitted patients was substantially higher than non-ICU cases (45.9% vs. 1.9%, respectively; p<0.001). Conclusions: Underlying diseases were the major risk factors for the increased ICU admissions and mortality rates in pediatric COVID-19 patients. There were few paraclinical parameters that could differentiate between pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with underlying medical conditions

In vitro corrosion and biocompatibility behavior of CoCrMo alloy manufactured by laser powder bed fusion parallel and perpendicular to the build direction

Biomedical cobalt-chromium-molybdenum alloys (CoCrMo) are frequently used for orthopedic implant and dental materials exposed to mechanical stressors, such as wear and cyclic load. Due to the high demand for customizable implant shapes, these alloys are increasingly manufactured by additive manufacturing methods such as laser powder bed fusion (LPBF). LPBF results in different microstructures and surface roughness as a function of the building direction. This study investigated the corrosion resistance, bioactivity, biocompatibility, and microstructure of LPBF CoCrMo (low carbon content, heat-treated) in the XY (perpendicular) and XZ (parallel) plane of the building direction for as-printed (as-received) and abraded surfaces. A distinct microstructure and different surface roughness were found for the XY and XZ planes. The as-received XY surface showed the lowest corrosion resistance but was still passive in phosphate-buffered saline (PBS, pH 7.4). As-received surfaces were less corrosion-resistant than abraded surfaces. All specimens exhibited lower corrosion resistance in PBS containing citric acid at pH 7.4 than in PBS and citric acid alone. As-received surfaces showed better hydroxyapatite precipitation and cell viability; however, all surfaces had satisfactory biocompatibility and bioactivity. This study showed that the building direction had a minor effect on the corrosion of LPBF CoCrMo