Burns constitute a significant global public health challenge. The BRICS nations (Brazil, Russia, India, China, South Africa, Saudi Arabia, Egypt, United Arab Emirates, Iran, Ethiopia) represent emerging economies encompassing nearly half the global population. This study analyzes burns incidence trends across BRICS countries from 1990 to 2021, providing evidence to inform prevention and management strategies. Analysis of burns incidence data through age-period-cohort modeling, decomposition analysis, health disparities analysis, frontier analysis, and Bayesian age-period-cohort modeling of future incidence rates. In 2021, BRICS nations collectively reported 5.90 million burn cases, accounting for 2.40 % of all injuries, with a 21.30 % decrease in age-standardized incidence rates (ASIR) from 1990 to 2021. Iran experienced the most significant ASIR reduction (-67.10 %), while China had the smallest decrease (-14.40 %). Health disparities between high- and low-income countries widened over time. Despite high Socio-Demographic Index (SDI) rankings, Russia and Saudi Arabia exhibited elevated burn incidence rates. Linear Age Trends (LAT) for burn reduction varied among countries. In South Africa, burns were primarily caused by fire, heat, and hot substances (60.41 % of cases), while falls accounted for 37.44 % of burns in Saudi Arabia. Projections indicate declining ASIR from 2022 to 2035, with Russia projected to have the highest ASIR (336.76 per 100,000) and Iran the lowest (86.54 per 100,000). Burns pose a major global public health challenge, necessitating action from national policymakers to address the increasing incidence of industrial accidents, household fires, natural disasters, and conflicts. The results of our analysis can help policymakers develop more effective burn prevention strategies.

Background: ¹⁸F-NaF and ^99mTc-MDP are widely used bone imaging tracers, but their comparative uptake in bone versus cartilage is unclear. This study aimed to directly compare these patterns in rats to guide musculoskeletal molecular imaging. Methods: Male Sprague-Dawley rats underwent in vivo and ex vivo radiotracer studies. Tracer uptake (%ID/g) was quantified in bone and cartilage at 30, 60, or 120 min post-injection (¹⁸F-NaF or ^99mTc-MDP), and across different ages. Additional rats received subcutaneous implants of viable or devitalized bone and cartilage; uptake was assessed using PET/CT, autoradiography, and histology. Results: ¹⁸F-NaF showed faster blood/background clearance and higher target-to-background ratios compared to ^99mTc-MDP, especially in weight-bearing joint cartilage. ¹⁸F-NaF uptake in cancellous bone significantly exceeded that of ^99mTc-MDP, whereas ^99mTc-MDP showed higher uptake in knee cartilage. Age-related analysis showed maximal knee cartilage accumulation in aged rats. Histological and cell inactivation studies confirmed that ¹⁸F-NaF uptake reflects both cellular activity and degree of calcification. Conclusions:¹⁸F-NaF demonstrates distinctive, quantifiable uptake in cartilage, dependent on both cellular activity and calcification, and exhibits favorable imaging characteristics versus ^99mTc-MDP for cartilage metabolism. These findings support ¹⁸F-NaF as a promising tool for early diagnosis and therapeutic monitoring of bone and joint disorders, and provide pathophysiological insight into the dynamics of the bone–cartilage interface.