Reforço sísmico da fachada de um palácio do Séc. XII

Neste estudo foi efectuada uma análise da fachada do palácio Podestà, situado em Foligno, Itália, através de um modelo não linear de elementos finitos. Com base na geometria e no modelo mecânico, foi desenvolvida a análise da estrutura em três fases. Numa primeira fase, foi efectuada uma análise da estrutura para as cargas permanentes do edifício (análise estática com o peso próprio da estrutura e de elementos não estruturais, considerando os impulsos transmitidos pelas abóbadas). Numa segunda fase foi avaliado o comportamento da estrutura sujeita às cargas permanentes combinadas com a acção sísmica. Finalmente, foi avaliada numericamente a eficiência de uma solução de reforço baseada na aplicação de fibras de carbono. São comparados os resultados de cada análise tendo em consideração os deslocamentos e as tensões na fachada. Estas modulações permitiram compreender os mecanismos potenciais de dano e de colapso da fachada do edifício para cada análise efectuada, bem como estudar a eficiência de uma solução de reforço

Bis maltolato oxovanadium (BMOV) and ischemia/reperfusion-induced acute kidney injury in rats

The aim of the present study was to test the potential protective effects of the organic vanadium salt bis (maltolato) oxovanadium (BMOV; 15 mg/kg) in the context of renal ischemia/reperfusion (30 min of ischemia) and its effects on renal oxygenation and renal function in the acute phase of reperfusion (up to 90 min post-ischemia). Ischemia was established in anesthetized and mechanically ventilated male Wistar rats by renal artery clamping. Renal microvascular and venous oxygenation were measured using phosphorimetry. Creatinine clearance rate, sodium reabsorption, and renal oxygen handling efficiency were considered markers for renal function. The main findings were that BMOV did not affect the systemic and renal hemodynamic and oxygenation variables and partially protected renal sodium reabsorption. Pretreatment with the organic vanadium compound BMOV did not protect the kidney from I/R injur

Blood transfusion in the critically ill: does storage age matter?

Morphologic and biochemical changes occur during red cell storage prior to product expiry, and these changes may hinder erythrocyte viability and function following transfusion. Despite a relatively large body of literature detailing the metabolic and structural deterioration that occurs during red cell storage, evidence for a significant detrimental clinical effect related to the transfusion of older blood is relatively less conclusive, limited primarily to observations in retrospective studies. Nonetheless, the implication that the transfusion of old, but not outdated blood may have negative clinical consequences demands attention. In this report, the current understanding of the biochemical and structural changes that occur during storage, known collectively as the storage lesion, is described, and the clinical evidence concerning the detrimental consequences associated with the transfusion of relatively older red cells is critically reviewed. Although the growing body of literature demonstrating the deleterious effects of relatively old blood is compelling, it is notable that all of these reports have been retrospective, and most of these studies have evaluated patients who received a mixture of red cell units of varying storage age. Until prospective studies have been completed and produce confirmative results, it would be premature to recommend any modification of current transfusion practice regarding storage age

Effects of Fluids on the Macro- and Microcirculations.

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2018. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2018. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901

Evaluation of multi-exponential curve fitting analysis of oxygen-quenched phosphorescence decay traces for recovering microvascular oxygen tension histograms

Although it is generally accepted that oxygen-quenched phosphorescence decay traces can be analyzed using the exponential series method (ESM), its application until now has been limited to a few (patho)physiological studies, probably because the reliability of the recovered oxygen tension (pO2) histograms has never been extensively evaluated and lacks documentation. The aim of this study was, therefore, to evaluate the use of the ESM to adequately determine pO2 histograms from phosphorescence decay traces. For this purpose we simulated decay traces corresponding to uni- and bimodal pO2 distributions and recovered the pO2 histograms at different signal-to-noise ratios (SNRs). Ultimately, we recovered microvascular pO2 histograms measured in the rat kidney in a model of endotoxemic shock and fluid resuscitation and showed that the mean microvascular oxygen tension, 〈pO2〉, decreased after induction of endotoxemia and that after 2 h of fluid resuscitation, 〈pO2〉 remained low, but the hypoxic peak that had arisen during endotoxemia was reduced. This finding illustrates the importance of recovering pO2 histograms under (patho)physiological conditions. In conclusion, this study has characterized how noise affects the recovery of pO2 histograms using the ESM and documented the reliability of the ESM for recovering both low- and high-pO2 distributions for SNRs typically found in experiments. This study might therefore serve as a frame of reference for investigations focused on oxygen (re)distribution during health and disease and encourage researchers to (re-)analyze data obtained in (earlier) studies possibly revealing new insights into complex disease states and treatment strategies