Endothelial Biomarkers in Patients Recovered from COVID-19 One Year after Hospital Discharge: A Cross-Sectional Study.

Background: COVID-19 is characterized by endothelial dysfunction and is presumed to have long-term cardiovascular sequelae. In this cross-sectional study, we aimed to explore the serum levels of endothelial biomarkers in patients who recovered from COVID-19 one year after hospital discharge. Methods: In this clinical follow-up study, 345 COVID-19 survivors from Huanggang, Hubei, and 119 age and gender-matched medical staff as healthy controls were enrolled. A standardized symptom questionnaire was performed, while electrocardiogram and Doppler ultrasound of lower extremities, routine blood tests, biochemical and immunological tests, serum soluble vascular cell adhesion molecule-1(VCAM-1), intercellular cell adhesion molecule-1(ICAM-1), P-selectin, and fractalkine were measured by enzyme-linked immunosorbent assays (ELISA). Results: At one year after discharge, 39% of recovers possessed post-COVID syndromes, while a few had abnormal electrocardiogram manifestations, and no deep vein thrombosis was detected in all screened survivors. There were no significant differences in circulatory inflammatory markers (leukocytes, neutrophils, lymphocytes, C-reactive protein and interleukin-6), alanine aminotransferase, estimated glomerular filtration rate, glucose, triglycerides, total cholesterol and D-dimer observed among healthy controls with previously mild or severe infected. Furthermore, serum levels of VCAM-1, ICAM-1, P-selectin, and fractalkine do not significantly differ between survivors and healthy controls. Conclusions: SARS-CoV-2 infection may not impose a higher risk of developing long-term cardiovascular events, even for those recovering from severe illness.

Neutrophil Counts Help Predict Free Wall Rupture Following St-elevation Myocardial Infarction.

PURPOSE: Free wall rupture (FWR) is a lethal complication after acute myocardial infarction; however, the un-derlying mechanisms of FWR are unclear. This study analyzes the relationship between neutrophil counts and FWR following ST-elevation myocardial infarction (STEMI). METHODS: The case group was STEMI patients with FWR and the control group was STEMI patients without FWR (case-control ratio was 1:4). The demographic data, clinical manifestation and laboratory test results were retrospectively collected and analyzed. RESULTS: Of a total of 6,712 consecutive STEMI patients, 78 patients (1.2%) had FWR. Compared with STEMI patients, patients with FWR were older and more likely to be female with an anterior infarct. White blood cell (WBC) counts were significantly higher in the FWR group. Moreover, we found that the elevated neutrophil counts mainly accounted for the elevated WBC counts. There was also a correlation between the age and neu-trophil counts (P=0.0109); as patient age increased, neutrophil counts decreased (P=0.0387). We also found no correlation between neutrophil counts and the time between myocardial infarction attack and FWR; however, when dividing these patients into FWR ≤48 h after admission to hospital for STEMI and FWR >48 h, there was a significant difference in neutrophil counts (P=0.0196). Furthermore, the results of logistic regression analy-sis showed that increased neutrophil was an independent risk factor for FWR (odds ratio: 2.404, confidence interval: 1.055-5.477). CONCLUSION: Elevated neutrophil counts were found to be the main cause of differences in WBC counts be-tween FWR and STEMI. Elevated neutrophil was an independent risk factor for FWR. This study provided clues for further research and development of therapeutics for the prevention of FWR.

The dynamic tradeoff between safety and efficiency in discretionary lane-changing behavior: A random parameters logit approach with heterogeneity in means and variances.

The discretionary lane-changing behavior is highly associated with crash occurrence. This paper investigates the dynamic tradeoff between safety and efficiency and influencing factors of the decision-making process for the discretionary lane-change. A random parameters logit approach with heterogeneity in means and variances is employed on a microscopic vehicle trajectory dataset. Four vehicles are analyzed as a discretionary lane-changing group, and both the distance-related and speed-related factors are taken into account to examine their dynamic effects. The modeling results indicate that (1) two distance-related variables produce significant random parameters with heterogeneity in means and variances, while there is only one speed-related variable having significant result for heterogeneity in means and variances; (2) the relationship between the speed of lane-changing vehicle and the heterogeneity in mean of vehicle clearance distance between leading vehicle in current lane and lane-changing vehicle quantitatively demonstrates that when the driver decides whether to change lanes, the driver considers the tradeoff between distance (i.e., safety) and speed (i.e., efficiency) at the same time; and (3) the number of significant variables is gradually decreased during the lane-changing decision-making process. It demonstrates that the lane-changing decision is a dynamic process where drivers gradually select more critical factors and pay more attention to them.

Using vehicular trajectory data to explore risky factors and unobserved heterogeneity during lane-changing.

This study aims to investigate contributing factors to potential collision risks during lane-changing processes from the perspective of vehicle groups and explore the unobserved heterogeneity of individual lane-changing maneuvers. Vehicular trajectory data, extracted from the Federal Highway Administration's Next Generation Simulation dataset, are utilized and 579 lane-changing vehicle groups are examined. Stopping distance indexes are developed to evaluate the potential collision risks of lane-changing vehicle groups. Three mixed binary logit models and three mixed logit models with heterogeneity in means and variances are established based on different perception reaction time. Model estimation results show that several variables significantly affect the risk status of lane-changing vehicle groups, including the mean values of clearance distance and speed differences between the leading vehicle in the current lane and the subject vehicle, standard deviations of clearance distance, and speed differences between these two vehicles, as well as standard deviations of the speed difference between the subject vehicle and the following vehicle in the target lane. Interestingly, the influences of the last three variables differ considerably across the observations and the mean of the random parameter for standard deviations of clearance distance between CLV and SV is associated with the mean speed difference between CLV and SV. Since one of the explanations is individual heterogeneity, personalized designs for advanced driver assistance system would be an effective measure to reduce the risk.