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Catalytic recombination of dissociated atmospheric oxygen and nitrogen is a major heat source for re-entry vehicles beyond Mach 10. Present thermal protection systems are designed to the extreme assumption of full catalycity. However mass, performance, and cost considerations of future reusable launch vehicles require that their thermal protection system is designed to the more realistic assumption of partial catalycity. With this in mind, the authors of this paper have studied the catalytic behavior of a coated C/C material as it was used for the heat shield of the OREX re-entry capsule. In this presentation. we will report on the laboratory measurements of the atomic oxygen recombination coefficient and its associated coefficient for thermal accommodation. The recombination coefficient was determined in plasma test chambers by actinometry and in plasmatron at 200 and 2000 Pa, respectively. The results show an effective recombination coefficient of the order of 1% (600 K - 1900 K). Unlike Stewart and the Bruno models, we did not observe a strong temperature dependency of the effective recombination coefficient, neither in the laboratory data nor in the flight data. The observed behaviour can be explained by the Cacciatore model on silica. [ABSTRACT FROM AUTHOR]

What Is Known on the Subject: Peer research methodologies and methods are increasingly used in research, particularly to benefit from lived experiences. The experiences of peer researchers with severe mental illness are less common, including the impact on them of conducting peer-led research., What the Paper Adds to Existing Knowledge: This paper shares the experience of peer research and suggests in the context of food insecurity, that it is not well understood by some healthcare professionals., What Are the Implications for Practice: Implications include considerations around trauma-informed care and the need for screening for food insecurity in mental healthcare settings. Research implications include providing training for peer research and needing to consider longevity of peer researcher relationships., Abstract: Introduction Food insecurity means that a person does not have access to sufficient nutritious food for normal growth and health. This can lead to health problems such as obesity, heart disease, diabetes and other long term chronic health conditions. People living with a severe mental illness are more likely to experience food insecurity than people without a severe mental illness. Aim The aim of this paper is to present a lived experience narrative of two peer researchers. Peer researchers conducted interviews with adults with severe mental illness from Northern England as part of a funded research project. These interviews discussed experiences of food insecurity and strategies to tackle it and were conducted between March and December 2022. Thesis The following paper does not discuss the results of the interviews themselves. Rather the narrative begins with an overview of peer research, before sharing the experiences of the two peer researchers in undertaking this project. Implications for Practice This includes healthcare professionals understanding food insecurity, what it is and what it is not, thinking about trauma-informed care, and screening for food insecurity. Peer research implications centre on adequate support and training, considerations to longevity of peer research relationships and reducing unnecessary research burden for peer researchers., (© 2024 The Authors. Journal of Psychiatric and Mental Health Nursing published by John Wiley & Sons Ltd.)

We report 5 cases of vascular Q fever complicated by polymicrobial superinfection in patients who had no risk factors for acute Q fever. Q fever was diagnosed by serologic and molecular assays for Coxiella burnetii. We confirmed additional infections using conventional graft cultures.

Background: Augmented renal clearance (ARC) is recognized as a leading cause of β-lactam subexposure when conventional dosing regimens are used. The main objective was to compare the clinical outcome of ARC patients treated by conventional or increased β-lactam dosing regimens for a first episode of hospital or ventilator-acquired pneumonia (HAP-VAP)., Methods: In this single-center, retrospective study, every ARC patient treated by β-lactam for a first episode of HAP-VAP was included during two 15-month periods, before (Control period) and after (Treatment period) the modification of a local antibiotic therapy protocol. ARC was defined by a 24-h measured creatinine clearance ≥ 150 ml/min. The primary endpoint was defined as a therapeutic failure of the antimicrobial therapy or a HAP-VAP relapse within 28 days. Inverse probability of treatment weight (IPTW) was derived from a propensity score model. Cox proportional hazard models were used to evaluate the association between treatment period and clinical outcome., Results: During the study period, 177 patients were included (control period, N = 88; treatment period, N = 89). Therapeutic failure or HAP-VAP relapse was significantly lower in the treatment period (10 vs. 23%, p = 0.019). The IPTW-adjusted hazard ratio of poor clinical outcome in the treatment period was 0.35 (95% CI 0.15-0.81), p = 0.014. No antibiotic side effect was reported during the treatment period., Conclusions: Higher than licensed dosing regimens of β-lactams may be safe and effective in reducing the rate of therapeutic failure and HAP-VAP recurrence in critically ill augmented renal clearance (ARC) patients.

This study assessed whether augmented renal clearance (ARC) impacts negatively on antibiotic concentrations and clinical outcomes in patients treated by high-dose β-lactams administered continuously. Over a 9-month period, all critically ill patients without renal impairment treated by one of the monitored β-lactams for a documented infection were eligible. During the first 3 days of antibiotic therapy, every patient underwent 24-h CL Cr measurements and therapeutic drug monitoring. The main outcome was the rate of β-lactam underdosing, defined as a free drug concentration <4 × MIC of the known pathogen. Secondary outcomes were rates of subexposure for β-lactams and therapeutic failure. The performance of CL Cr in predicting underdosing was assessed by a ROC curve, and multivariable logistic regression was performed to determine risk factors for subexposure and therapeutic failure. A total of 79 patients were included and 235 samples were analysed. The rate of underdosing <4×MIC was 12%, with a significant association with CL Cr (P <0.0001). A threshold of CL Cr  ≥ 170 mL/min had a sensitivity and specificity of 0.93 (95% CI 0.77-0.99) and 0.65 (95% CI 0.58-0.71) for predicting β-lactam underdosing <4×MIC . Mean CL Cr values ≥170 mL/min were significantly associated with subexposure <4xMIC [OR = 10.1 (2.4-41.6); P = 0.001]. Patients with subexposure <4×MIC presented higher rates of therapeutic failure [OR = 6.3 (1.2-33.2); P = 0.03]. Mean CL Cr values ≥170 mL/min remain a risk factor for subexposure to β-lactams despite high doses of β-lactams administered continuously. β-Lactam subexposure was associated with higher rates of therapeutic failure in septic critically ill patients., (Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.)

Objective: We propose a non-invasive method for diagnosing post-capillary pulmonary hypertension (PH group 2). We evaluated pulmonary capillary wedge pressure (PCWP) by studying the left atrium (LA) on thoracic ECG-gated CT compared with right heart catheterisation (RHC)., Methods: We retrospectively studied 54 patients with suspected PH or followed for PH who underwent thoracic ECG-gated CT and RHC within 15 days. The diagnostic accuracy of CT morphological and functional data of the LA for the detection of PCWP >15 mmHg, evaluated by two independent readers, was assessed using correlation and receiver-operating characteristic (ROC) analysis., Results: Interobserver agreement was high (r = 0.97-0.99). Correlations were found between PCWP and the morphological criteria of the LA such as anteroposterior diameter at 0 % of the R-R interval (r = 0.70, P ≤ 0.001) as well as at 40 % (r = 0.69, P ≤ 0.001). ROC curves constructed with a threshold value of PCWP > 15 mmHg showed an area under the curve between 0.88 and 0.91. Significant correlations were found between PCWP and functional criteria of the LA, including distensibility (r = -0.49, P ≤ 0.001) and ejection fraction (r = -0.58, P ≤ 0.001)., Conclusion: Thoracic ECG-gated CT in a PH workup helps distinguish between pre- and post-capillary PH., Key Points: • Computed tomography may help differentiate the various types of pulmonary hypertension (PH). • Post-capillary PH group 2 is due to left heart disease. • Right heart catheterisation is used to separate pre- and post-capillary PH. • Left atrium anteroposterior diameter measured on CT is of value. • ECG-gated CT helps clinicians to assess patients with PH non-invasively.