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SYNOPSISA pulse method for the simultaneous determination of thermal diffusivity, a , specific heat capacity, C,, and thermal conductivity, A, are measured for a series of curing of polyester and styrene in the presence of 10,20, and 30% carbon black in the temperature range 300-450 K. The results show a dependence of the above-mentioned properties on temperature and composition. The mechanism of heat transfer through the specimens is also discussed.

Background and Aims: Starting antibiotic therapy at the proper time is the cornerstone of the management of ventilator-associated pneumonia (VAP). However, using antibiotics for a long duration of therapy in intensive care leads to increased bacterial resistance, financial burden and adverse drug reactions. We hypothesised that lung ultrasound may have a role in guiding antibiotic discontinuation in patients with VAP that will help to reduce the antibiotic duration and decrease the resistance. Methods: This was a prospective blinded cohort study from October 2020 to September 2021 in which 62 VAP patients were recruited. Antibiotics were started, procalcitonin (PCT) level and clinical pulmonary infection score were estimated and lung ultrasound (US) was performed on day 1 and repeated on day 7. On day 7, discontinuation of antibiotics was recommended if the PCT level was <0.25 μg/L. A lung reaeration score was recorded. Results: Based on the PCT levels, antibiotics were discontinued in 40 patients. The computed tomography findings of VAP had improved in all. The ultrasound reaeration score showed a highly significant negative correlation with the PCT on day 7 (-0.718, P < 0.001). A cut-off of 5 for the US score showed a sensitivity of 92.5%, specificity of 95.5%, positive predictive value of 97.4% and negative predictive value of 87.5% in detecting a low PCT score on day 7. Conclusion: Lung US is a non-invasive and safe method that can be used to guide antibiotic therapy in VAP.

Purpose Since the declaration of COVID-19 as a pandemic, a wide between-country variation was observed regarding in-hospital mortality and its predictors. Given the scarcity of local research and the need to prioritize the provision of care, this study was conducted aiming to measure the incidence of in-hospital COVID-19 mortality and to develop a simple and clinically applicable model for its prediction. Methods COVID-19-confirmed patients admitted to the designated isolation areas of Ain-Shams University Hospitals (April 2020–February 2021) were included in this retrospective cohort study (n = 3663). Data were retrieved from patients’ records. Kaplan–Meier survival and Cox proportional hazard regression were used. Binary logistic regression was used for creating mortality prediction models. Results Patients were 53.6% males, 4.6% current smokers, and their median age was 58 (IQR 41–68) years. Admission to intensive care units was 41.1% and mortality was 26.5% (972/3663, 95% CI 25.1–28.0%). Independent mortality predictors—with rapid mortality onset—were age ≥ 75 years, patients’ admission in critical condition, and being symptomatic. Current smoking and presence of comorbidities particularly, obesity, malignancy, and chronic haematological disorders predicted mortality too. Some biomarkers were also recognized. Two prediction models exhibited the best performance: a basic model including age, presence/absence of comorbidities, and the severity level of the condition on admission (Area Under Receiver Operating Characteristic Curve (AUC) = 0.832, 95% CI 0.816–0.847) and another model with added International Normalized Ratio (INR) value (AUC = 0.842, 95% CI 0.812–0.873). Conclusion Patients with the identified mortality risk factors are to be prioritized for preventive and rapid treatment measures. With the provided prediction models, clinicians can calculate mortality probability for their patients. Presenting multiple and very generic models can enable clinicians to choose the one containing the parameters available in their specific clinical setting, and also to test the applicability of such models in a non-COVID-19 respiratory infection.

The performance is analysed of different modifications (plane, radial, and Angstrom) of temperature waves techniques used for the simultanous measurement of specific heat (Cp), thermal diffusivity (a), and conductivity coefficient (A) of non-conducting materials in identical experimental conditions. For this purpose, Teflon specimens of adequate forms, are prepared and investigated. The radial modification produce results with the least scattering of the experimental points.Es wird die Leistungsfiihigkeit verschiedener Modifikationen (ebene, radiale und Angstrom) der Temperaturwellenmethode zur gleichzeitigen Messung der spezifischen Wiirme (Cp), des thermischen Diffusionsvermogens (a) und des Leitfiihigkeitskoeffizienten (A) nichtleitender Materialien unter identischen experimentellen Bedingungen getestet. Zu diesem Zweck werden Teflonproben von geeigneter Form priipariert und untersucht. Die radiale Modifikation liefert Egebnisse mit der geringsten Streuung der experimentellen Werte. l ) Nasr City, Cairo, Egypt.

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