Shake-table testing of a stone masonry building aggregate: overview of blind prediction study

City centres of Europe are often composed of unreinforced masonry structural aggregates, whose seismic response is challenging to predict. To advance the state of the art on the seismic response of these aggregates, the Adjacent Interacting Masonry Structures (AIMS) subproject from Horizon 2020 project Seismology and Earthquake Engineering Research Infrastructure Alliance for Europe (SERA) provides shake-table test data of a two-unit, double-leaf stone masonry aggregate subjected to two horizontal components of dynamic excitation. A blind prediction was organized with participants from academia and industry to test modelling approaches and assumptions and to learn about the extent of uncertainty in modelling for such masonry aggregates. The participants were provided with the full set of material and geometrical data, construction details and original seismic input and asked to predict prior to the test the expected seismic response in terms of damage mechanisms, base-shear forces, and roof displacements. The modelling approaches used differ significantly in the level of detail and the modelling assumptions. This paper provides an overview of the adopted modelling approaches and their subsequent predictions. It further discusses the range of assumptions made when modelling masonry walls, floors and connections, and aims at discovering how the common solutions regarding modelling masonry in general, and masonry aggregates in particular, affect the results. The results are evaluated both in terms of damage mechanisms, base shear forces, displacements and interface openings in both directions, and then compared with the experimental results. The modelling approaches featuring Discrete Element Method (DEM) led to the best predictions in terms of displacements, while a submission using rigid block limit analysis led to the best prediction in terms of damage mechanisms. Large coefficients of variation of predicted displacements and general underestimation of displacements in comparison with experimental results, except for DEM models, highlight the need for further consensus building on suitable modelling assumptions for such masonry aggregates

Deferasirox, an oral chelator in the treatment of iron overload

BACKGROUND Deferasirox is a once-daily oral iron chelator developed for treating iron overload complicating long-term transfusion therapy in patients with diseases such as beta-thalassemia and myelodysplastic syndromes. Iron overload can damage the liver, pancreas and the heart. Deferoxamine, the only other drug approved for iron chelation, can prevent these effects but requires parenteral administration. Deferasirox has been approved after a one-year, open-label trial in patients ≥ 2 years old with beta-thalassemia and transfusional emosiderosis randomized to once-daily oral 5, 10, 20, 30 mg/kg/day in comparison of subcutaneous deferoxamine 20-60 mg/mg/kg/day x 5/week. CONCLUSIONS Deferasirox 20-30 mg/kg/day produced reductions in liver iron concentration (LIC) similar to those with deferoxamine. Adverse effect of deferasirox (increases of serum creatinine and aminotransferases), including the gastrointestinal ones, are similar but more frequent than those occurring with deferoxamine. Information is lacking on the effects of deferasirox on cardiac iron and cardiac dysfunction which is the most serious complication of transfusional iron overload

The aquaretics in the treatment of hyponatremia

BACKGROUND Severe hyponatremia is the most common in-hospital electrolyte disorder and is a predictor of death among patients with chronic heart failure (CHF) and cirrhosis; it develops spontaneously or following diuretic therapy. Even mild hyponatremia is associated with worse outcomes when it complicates these conditions. Increased arginine-vasopressin (AVP) secretion is primarily involved, through decreased free water excretion, in causing dilutional hyponatremia. At present the therapy of hyponatremia is often ineffective and poorly tolerated. AIM OF THE STUDY At examining the activity of a new class of medications known as AVP receptor V2 selective antagonists – or aquaretics – as therapy of hyponatremia due to edema-forming states such as CHF, cirrhosis and syndrome on inappropriate antidiuretic hormone secretion (SIADH). METHODS We reviewed clinical trial data on the non-peptide AVP antagonists recently approved for marketing or in late development. RESULTS Aquaretics are effective at increasing free water excretion without natriuresis or kaliuresis – an effect termed aquaresis – and significantly and rapidly increase serum sodium concentration without significant changes in blood pressure or serum creatinine levels. Treatments were conducted even in outpatient setting and for a maximum of 7 weeks period. After discontinuation of aquaretic treatment, hyponatremia recurred. Side effects were thirst and dry mouth; higher doses produced significant dehydratation and will require close monitoring. CONCLUSIONS The aquaretics are promising drugs for the management of hyponatremia. The utility of these agents for the long-term management of hyponatremia and in preventing the development of hyponatremia associated with diuretic usage remains to be determined

Polymyalgia rheumatica and seronegative rheumatoid arthritis: some considerations based on a northern Italian population

To report some considerations on polymyalgia rheumatica and seronegative rheumatoid arthritis based on a northern Italian populatio

Polymyalgia rheumatica

To report a population-based study in which we confirmed the presence of a subset of polymyalgia patients with normal ESR