Orbital stability analysis and photometric characterization of the second Earth Trojan asteroid 2020 XL5

Trojan asteroids are small bodies orbiting around the L₄ or L₅ Lagrangian points of a Sun-planet system. Due to their peculiar orbits, they provide key constraints to the Solar System evolution models. Despite numerous dedicated observational efforts in the last decade, asteroid 2010 TK₇ has been the only known Earth Trojan thus far. Here we confirm that the recently discovered 2020 XL₅ is the second transient Earth Trojan known. To study its orbit, we used archival data from 2012 to 2019 and observed the object in 2021 from three ground-based observatories. Our study of its orbital stability shows that 2020 XL₅ will remain in L₄ for at least 4 000 years. With a photometric analysis we estimate its absolute magnitude to be [Formula: see text], and color indices suggestive of a C-complex taxonomy. Assuming an albedo of 0.06 ± 0.03, we obtain a diameter of 1.18 ± 0.08 km, larger than the first known Earth Trojan asteroid.

Venous Thromboembolism Risk and Adherence to Pharmacological Thromboprophylaxis in Hospitalized Patients in Uruguay: First Nationwide Study

INTRODUCTION

Venous thromboembolism (VTE) is a serious, frequent, and preventable medical complication in hospitalized patients. Although the efficacy of prophylaxis (pharmacological and/or mechanical) has been demonstrated, compliance with prophylaxis is poor at international and national levels.

AIM

To determine the indication and use of pharmacological thromboprophylaxis in hospitalized patients in Uruguay.

METHODS

An observational, descriptive, cross-sectional, multicentre study involving 31 nationwide healthcare facilities was conducted. Baseline characteristics associated with hospital admission, the percentage of the population with an indication for thromboprophylaxis, and the percentage of patients receiving pharmacological thromboprophylaxis were assessed. The VTE risk was determined using the Padua score for medical patients; the Caprini score for surgical patients; the Royal College of Obstetricians and Gynaecologists (RCOG) guidelines for pregnant-postpartum patients.

RESULTS

1925 patients were included, representing 26% of hospitalized patients in Uruguay. 71.9% of all patients were at risk of VTE. Of all patients at risk of VTE, 58.6% received pharmacological thromboprophylaxis. The reasons for not receiving thromboprophylaxis were prescribing omissions in 16.1% of cases, contraindication in 15.9% and 9.4% of patients were already anticoagulated for other reasons. Overall, just 68% of patients were "protected" against VTE. Recommendations of major thromboprophylaxis guidelines were followed in 70.1% of patients at risk.

CONCLUSIONS

Despite the progress made in adherence to thromboprophylaxis indications, nonadherence remains a problem, affecting one in six patients at risk of VTE in Uruguay.