Drag De-Orbit Device: A New Standard Re-Entry Actuator for CubeSats

With the advent of CubeSats, research in Low Earth Orbit (LEO) becomes possible for universities and small research groups. Only a handful of launch sites can be used, due to geographical and political restrictions. As a result, common orbits in LEO are becoming crowded due to the additional launches made possible by low-cost access to space. CubeSat design principles require a maximum of a 25-year orbital lifetime in an effort to reduce the total number of spacecraft in orbit at any time. Additionally, since debris may survive re-entry, it is ideal to de-orbit spacecraft over unpopulated areas to prevent casualties. The Drag Deorbit Device (D3) is a self-contained targeted re-entry subsystem intended for CubeSats. By varying the cross-wind area, the atmospheric drag can be varied in such a way as to produce desired maneuvers. The D3 is intended to be used to remove spacecraft from orbit to reach a desired target interface point. Additionally, attitude stabilization is performed by the D3 prior to deployment and can replace a traditional ADACS on many missions.This paper presents the hardware used in the D3 and operation details. Four stepper-driven, repeatedly retractable booms are used to modify the cross-wind area of the D3 and attached spacecraft. Five magnetorquers (solenoids) over three axes are used to damp rotational velocity. This system is expected to be used to improve mission flexibility and allow additional launches by reducing the orbital lifetime of spacecraft.The D3 can be used to effect a re-entry to any target interface point, with the orbital inclination limiting the maximum latitude. In the chance that the main spacecraft fails, a timer will automatically deploy the booms fully, ensuring the spacecraft will at the minimum reenter the atmosphere in the minimum possible time, although not necessarily at the desired target interface point. Although this does not reduce the risk of casualties, the 25-year lifetime limit is still respected, allowing a reduction of the risk associated with a hardware failure

Decomposition of Molecular Integrals into Atomic Contributions via Becke Partitioning Scheme: a Caveat

Decomposition of molecular integrals into physically meaningful atomic contributions by means of the Becke integration scheme requires some care with respect to the choice of suitable atomic size adjustments. Using a simple illustrative example, it is shown that the adjustment of cell boundaries, as originally proposed by considering Bragg-Slater atomic radii, does not provide reliable results. Alternatively, the positions of the bond critical points of the electron density can be adopted to define heteronuclear cutoff profiles which allow for a more reasonable atomic partition of the molecular electron density. This work is licensed under a Creative Commons Attribution 4.0 International License

Vitamin D deficiency is a risk factor for infections in patients affected by HCV-related liver cirrhosis

Objectives: To evaluate the prevalence of vitamin D deficiency and its impact on infections in HCV-related liver cirrhosis. Methods: We enrolled 291 patients affected by HCV-related liver cirrhosis. Serum vitamin D levels were dosed at enrolment. The presence of infection was assessed at baseline and during follow-up based on physical examination and laboratory analyses. Results: Vitamin D deficiency (15 (p = 0.003), Child-Pugh class B/C vs A (p < 0.001), and active hepatocellular carcinoma (HCC) (p < 0.001). At multivariate analysis, vitamin D deficiency (p < 0.01), HCC (p < 0.05), hospitalization (p < 0.001) and exposure to immunosuppressant agents (p < 0.05) were independent risk factors for infection at baseline. Conclusions: Vitamin D may play a role in the development of infections in patients affected by liver cirrhosis, and preventive strategies with vitamin D supplementation are to be evaluated in randomized controlled trials

Is Pathological Trading an Overlooked Form of Addiction?

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Nurse-Administered Analgesic Treatment in Italian Emergency Medical Services: A Nationwide Survey

Background: Acute pain is common among patients requiring assistance from prehospital emergency medical services (EMS). Nonetheless, the undertreatment of pain in this context remains a frequent phenomenon. Timely and effective analgesia is a crucial feature in emergency medicine. To ensure analgesia provision, prehospital paramedics and nurses can administer analgesics via standard operating protocols or under a physician’s remote supervision. Information about such protocols in Italian EMS is lacking. Objective: Evaluation of the availability of nurse’s standard analgesia protocols in Italy’s prehospital EMS settings. Methods: A cross-sectional online survey involved all 74 Italian emergency medical dispatch centres (EMDCs). Aside from descriptive statistics, we used χ2-analysis and Spearman-rank correlation to look for associations between geographical areas’ dependence upon independent variable categories and their correlations. Results: Of all the 74 Italian EMDCs, 70 (94.6%) completed the survey, covering 100 provinces out of a total of 107 (93.5%). Operating nurses’ prehospital analgesia protocols are available in 46 provinces (46.0%). The availability of prehospital analgesia protocols is more extended in northern Italy EMDCs (n=30, 66.7%) than in central Italy (n=9, 42.8%) and southern Italy and islands (n=7, 20.6%). Morphine (76.1% for medical patients and 95.7% for trauma) and paracetamol (89.1% for both) are the most common drugs included in the prehospital analgesia protocols. Conclusion: Despite international consensus on the necessity, efficacy, and safety of nurses’ prehospital analgesia provision, nurse-administered analgesia protocols are available in less than half of Italian provinces, with substantial differences between northern, central, and southern areas. These results indirectly indicate potential undertreatment of prehospital pain in Italy and yield practice improvements

Synthesis and Stereochemical Characterization of a Novel Chiral α-Tetrazole Binaphthylazepine Organocatalyst

A novel α-tetrazole-substituted 1,1'-binaphthylazepine chiral catalyst has been synthesized and its absolute configuration has been determined by DFT computational analysis of the vibrational circular dichroism (VCD) spectrum of its precursor. The VCD analysis, carried out through the model averaging method, allowed to assign the absolute configuration of a benzylic stereocenter in the presence of a chiral binaphthyl moiety. The 1,1'-binaphthylazepine tetrazole and the nitrile its immediate synthetic precursor, have been preliminarily tested as chiral organocatalysts in the asymmetric intramolecular oxa-Michael cyclization of 2-hydroxy chalcones for the synthesis of chiral flavanones obtaining low enantioselectivity

Anti-HBc positivity was associated with histological cirrhosis in patients with chronic hepatitis C

Introduction. In patients with chronic hepatitis C it is still debated whether previous exposure to the hepatitis B virus, diagnosed from the presence of the anti-HBc antibody, is linked to a greater risk of severe hepatitis. The aim of the study was to evaluate whether the presence of anti-HBc antibodies is associated with cirrhosis in patients with HBsAg-negative chronic hepatitis C. Material and methods. Two hundred twenty-two consecutive HBsAg-negative patients with HCV-related chronic hepatitis were enrolled at their first liver biopsy. Ishak's scoring system was used to grade necroinflammation and fibrosis and the patients with stage 5 or 6 were considered as having histological cirrhosis. Results. Patients with histological cirrhosis had a higher mean age, AST, ALT, a lower platelet count and prothrombin activity compared to those with milder fibrosis. The presence of anti-HBc was identified in 21 (63.6%) of the 33 patients with fibrosis score 5 or 6 and in 56 (29.6%; p < 0.001) of the 189 with score ≤ 4. Patients with cirrhosis had a significantly higher grading than those without cirrhosis (median = 8, IQR 6-11 vs. Median = 6, IQR = 4-8, respectively, p < 0.001). A multivariate logistic regression analysis showed that age, sex and anti-HBc positivity were independent predictors of histological cirrhosis. Conclusion. Our data support the idea that in patients with chronic hepatitis C the presence in serum of anti-HBc is associated with histological cirrhosis and is therefore a marker of clinical value

Daily water demand

This paper develops a model to characterize the demand for domestic water based on its end users' usage habits. The use of individual residential appliances (bathroom sink, toilet, shower, bath, etc.) is interpreted using a probabilistic approach. The paper also applies the model to the distribution network of the municipality of Sparanise, a small city in the province of Caserta, Italy. The results of this application are compared to the real output of the city's actual water reservoir. Flow variability during the day was successfully modelled. A comparison of the simulated and recorded data on a daily level indicates the proper adjustment of the volume distribution; the peak flow rates were also comparable. The model could be a useful tool for analyzing domestic water consumption, especially in the design and management of water distribution networks. Use of the model would particularly aid the Integrated Urban Water Management Operator both in optimizing the operating pressures in the various districts' networks and in predicting domestic water consumption when drafting its water balance documents

Psychological dimensions in alcohol use disorder: comparing active drinkers and abstinent patients

BackgroundAlcohol use disorder (AUD) is a major public health concern due to its various physical, psychological, and social consequences. Despite regulatory differences, abstinence remains the primary treatment objective. Addressing the multifaceted nature of alcohol use disorder requires a comprehensive approach.Methods150 AUD patients (66%male) with a mean age of 54.10 ± 11.3 years were recruited for the study. Depression, impulsivity, alexithymia, and hopelessness were assessed to determine if there were significant differences in these dimensions between abstinent (N=72) and active drinkers (N=78).ResultsThe study found significant differences in the psychological dimensions scores, active drinkers exhibited higher levels of depression, impulsivity, alexithymia, and hopelessness compared to abstinent patients.ConclusionTreatment outcomes for patients with AUD vary between regulatory agencies, but abstinence remains the safest and most preferred objective in managing AUD. Prioritizing abstinence-oriented interventions is crucial for achieving long term recovery and minimizing relapse risk. These results emphasize the intricate relationship between AUD and mental health issues, highlighting the need for comprehensive interventions addressing both alcohol consumption and associated psychological distress. Promoting abstinence (or at least reducing alcohol consumption) not only preserves mental health but also prevents life-threatening consequences such as suicide