In this work, new advances concerning the feasibility of extruded cementitious hollow tubes as containing/releasing devices for healing agents and their potential scaling up are presented. Specifically, sodium silicate and potassium silicate were evaluated as healing agents in terms of their ability to diffuse through cracks and of their ability to restore the initial mechanical properties of mortars. Their effect was investigated also in combination with the use of a hydrophobic coating applied to the inner surface of some of the hollow tubes to enhance the release of the healing agents along the crack path. A colorant was added to the sodium/potassium silicate solutions to help highlighting the fracture area covered by the healing agents, thus allowing a qualitative evaluation of the effect of the hydrophobic coating. Finally, image analysis was performed to correlate the mechanical strength/stiffness recovery to the area covered by the healing agent, as well as to the position of the tubes within the samples. On the whole, satisfactory results were obtained as far as restoration of the mechanical properties is concerned: the best performance was displayed when using cementitious hollow tube containing sodium silicate, with maximum values of bending load and stiffness recovery for the system of more than 70% and 50%, respectively.

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COVID-19 infection causes respiratory pathology with severe interstitial pneumonia and extra-pulmonary complications; in particular, it may predispose to thromboembolic disease. The current guidelines recommend the use of thromboprophylaxis in patients with COVID-19, however, the optimal heparin dosage treatment is not well-established. We conducted a multicentre, Italian, retrospective, observational study on COVID-19 patients admitted to ordinary wards, to describe clinical characteristic of patients at admission, bleeding and thrombotic events occurring during hospital stay. The strategies used for thromboprophylaxis and its role on patient outcome were, also, described. 1091 patients hospitalized were included in the START-COVID-19 Register. During hospital stay, 769 (70.7%) patients were treated with antithrombotic drugs: low molecular weight heparin (the great majority enoxaparin), fondaparinux, or unfractioned heparin. These patients were more frequently affected by comorbidities, such as hypertension, atrial fibrillation, previous thromboembolism, neurological disease, and cancer with respect to patients who did not receive thromboprophylaxis. During hospital stay, 1.2% patients had a major bleeding event. All patients were treated with antithrombotic drugs; 5.4%, had venous thromboembolism [30.5% deep vein thrombosis (DVT), 66.1% pulmonary embolism (PE), and 3.4% patients had DVT + PE]. In our cohort the mortality rate was 18.3%. Heparin use was independently associated with survival in patients aged ≥ 59 years at multivariable analysis. We confirmed the high mortality rate of COVID-19 in hospitalized patients in ordinary wards. Treatment with antithrombotic drugs is significantly associated with a reduction of mortality rates especially in patients older than 59 years.

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