Age and sex differences in cause-specific excess mortality and years of life lost associated with COVID-19 infection in the Swedish population

Background Estimating excess mortality and years of life lost (YLL) attributed to coronavirus disease 19 (COVID-19) infection provides a comprehensive picture of the mortality burden on society. We aimed to estimate the impact of the COVID-19 pandemic on age- and sex-specific excess mortality and YLL in Sweden during the first 17 months of the pandemic. Methods In this population-based observational study, we calculated age- and sex-specific excess all-cause mortality and excess YLL during 2020 and the first 5 months of 2021 and cause-specific death [deaths from cardiovascular disease (CVD), cancer, other causes and deaths excluding COVID-19] in 2020 compared with an average baseline for 2017-19 in the whole Swedish population. Results COVID-19 deaths contributed 9.9% of total deaths (98 441 deaths, 960 305 YLL) in 2020, accounting for 75 151 YLL (7.7 YLL/death). There were 2672 (5.7%) and 1408 (3.0%) excess deaths, and 19 141 (3.8%) and 3596 (0.8%) excess YLL in men and women, respectively. Men aged 65-110 years and women aged 75-110 years were the greatest contributors. Fewer deaths and YLL from CVD, cancer and other causes were observed in 2020 compared with the baseline adjusted to the population size in 2020. Conclusions Compared with the baseline, excess mortality and YLL from all causes were experienced in Sweden during 2020, with a higher excess observed in men than in women, indicating that more men died at a younger age while more women died at older ages than expected. A notable reduction in deaths and YLL due to CVD suggests a displacement effect from CVD to COVID-19

Dynamic Modeling of a Solid Oxide Fuel Cell System in Modelica

In this study a dynamic model of a solid oxide fuel cell (SOFC) system has been developed. The work has been conducted in a cooperation between the Department of Energy Sciences, Lund University, and Mode Ion AB using the Modelica language and the Dymola modeling and simulation tool. Modelica is an equation based, object oriented modeling language, which promotes flexibility and reuse of code. The objective of the study is to investigate the suitability of the Modelica language for dynamic fuel cell system modeling. A cell electrolyte model including ohmic, activation and concentration irreversibilities is implemented and verified against simulations and experimental data presented in the open literature. A ID solid oxide fuel cell model is created by integrating the electrolyte model and a ID fuel flow model, which includes dynamic internal steam reforming of methane and water-gas shift reactions. Several cells are then placed with parallel flow paths and connected thermally and electrically in series. By introducing a manifold pressure drop, a stack model is created. The stack model is applied in a complete system including an autothermal reformer, a catalytic afterburner, a steam generator and heat exchangers. Four reactions are modeled in the autothermal reformer; two types of methane steam reforming, the water-gas shift reaction and total combustion of methane. The simulation results have been compared with those in the literature and it can be concluded that the models are accurate and that Dymola and Modelica are tools well suited for simulations of the transient fuel cell system behaviour

Surface microdialysis sampling: a new approach described in a liver ischaemia model.

We recently have shown that samples from microdialysis (MD) probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces. In 13 anesthetized pigs, transient liver ischaemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface and two in parenchyma were perfused with a flow rate of 1 μl per min (n = 13). An identical set-up was used for probes with a flow rate of 2 μl per min (n = 9). Samples were collected for every 15-min period during 60 min of baseline, 45 min of ischaemia and 60 min of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present study. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and those on parenchyma. No significant differences in relative changes in lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischaemia or reperfusion with a flow rate of 1 μl per min. MD sampling applied on the liver surface is a new application area for the MD technique and may be used to monitor liver metabolism during both physiological and pathophysiological conditions