A Customized EKF model for GNSS-based Navigation in the Harsh Space Environment

The extension of the Global Navigation Satellite System (GNSS) Space Service Volume (SSV) is of utmost relevance to afford enhanced autonomy in navigation, guidance, and control of space missions. Pioneering studies have shown the feasibility of using terrestrial GNSS signals in space applications, supporting Orbit Determination and Time Synchronization (ODTS) during Earth-Moon transfer orbits (MTOs) and lunar landings. However, non-terrestrial applications face challenges due to compromised signal availability at high altitudes, thus requiring advanced receiver architectures coupled with external aiding data. This paper presents a customized Bayesian filter, the Trajectory-Aware Extended Kalman Filter (TA-EKF), specifically designed for GNSS navigation along MTOs. The proposed filter architecture integrates aiding information, such as the planned mission orbital trajectory, to speed up filter convergence and achieve highly accurate positioning solutions. The performance of the TA-EKF is evaluated through simulations of MTO mission scenarios supported by Monte Carlo analyses, and it is compared against a standalone EKF

Metabolic disorders across hepatocellular carcinoma in Italy

Background: Metabolic disorders are well-known risk factors for HCC. Conversely, their impact on the natural history of HCC is not established. This study aimed at evaluating the impact of metabolic disorders on clinical features, treatment and survival of HCC patients regardless of its aetiology. Methods: We analysed the ITA.LI.CA database regarding 839 HCC patients prospectively collected. The following metabolic features were analysed: BMI, diabetes, arterial hypertension, hypercholesterolaemia and hypertriglyceridaemia. According to these features, patients were divided into 3 groups: 0-1, 2 and 3-5 metabolic features. Results: As compared with patients with 0-1 metabolic features, patients with 3-5 features showed lower percentage of HCC diagnosis on surveillance (P\ua0=.021), larger tumours (P\ua0=.038), better liver function (higher percentage of Child-Pugh class A [P\ua0=.007] and MELD\ua0<\ua010 [P\ua0=.003]), higher percentage of metastasis (P\ua0=.024) and lower percentage of portal vein thrombosis (P\ua0=.010). The BCLC stage and treatment options were similar among the 3 groups, with the exception of a less frequent access to loco-regional therapies for BCLC stage B patients with 3-5 features (P\ua0=.012). Overall survival and survival according to BCLC stage and/or treatment did not significantly differ among the 3 groups. Only using a probabilistic sensitivity analysis, diabetic patients showed a lower survival (P\ua0=.046). MELD score, HCC morphology, nodule size, BCLC stage, portal vein thrombosis and metastasis were independent predictors of lead-time adjusted survival. Conclusions: Our \u201creal world\u201d study suggests that metabolic disorders shape the clinical presentation of HCC but do not seem to play a major role in setting patient survival