Influence of Lithium Carbonate and Sodium Carbonate on Physical and Elastic Properties and on Carbonation Resistance of Calcium Sulphoaluminate-Based Mortars

In this study, three different hardening accelerating admixtures (sodium carbonate, lithium carbonate and a blend of sodium and lithium carbonates) were employed to prepare calcium sulphoaluminate cement-based mortars. The workability, setting times, entrapped air, elasto-mechanical properties such as compressive strength and dynamic modulus of elasticity, free shrinkage, water absorption and carbonation rate were measured and mercury intrusion porosimetry were also performed. Experimental results show that a mixture of lithium carbonate and sodium carbonate acts as a hardening accelerating admixture, improving the early-age strength and promoting a remarkable pore structure refinement. Finally, sodium carbonate also reduces the water absorption, the carbonation rate and the shrinkage of mortars without affecting the setting times and the workability

The Role of CT-Angiography in the Acute Gastrointestinal Bleeding: A Pictorial Essay of Active and Obscure Findings

Gastrointestinal bleeding is a potentially life-threatening abdominal emergency that remains a common cause of hospitalisation. Although 80–85% of cases of gastrointestinal bleeding resolve spontaneously, it can result in massive haemorrhage and death. The presentation of gastrointestinal bleeding can range from asymptomatic or mildly ill patients requiring only conservative treatments to severely ill patients requiring immediate intervention. Identifying the source of the bleeding can be difficult due to the wide range of potential causes, the length of the gastrointestinal tract and the intermittent nature of the bleeding. The diagnostic and therapeutic approach is fully dependent on the nature of the bleeding and the patient’s haemodynamic status. Radiologists should be aware of the appropriate uses of computed tomography angiography and other imaging modalities in patients with acute gastrointestinal bleeding, as well as the semiotics of bleeding and diagnostic pitfalls in order to appropriately diagnose and manage these patients. The learning objective of this review is to illustrate the computed tomography angiography technique, including the potential role of dual-energy computed tomography angiography, also highlighting the tips and tricks to identify the most common and uncommon features of acute gastrointestinal bleeding and its obscure form