Preliminary study of a millimeter wave FMCW InSAR for UAS indoor navigation.

Small autonomous unmanned aerial systems (UAS) could be used for indoor inspection in emergency missions, such as damage assessment or the search for survivors in dangerous environments, e.g., power plants, underground railways, mines and industrial warehouses. Two basic functions are required to carry out these tasks, that is autonomous GPS-denied navigation with obstacle detection and high-resolution 3Dmapping with moving target detection. State-of-the-art sensors for UAS are very sensitive to environmental conditions and often fail in the case of poor visibility caused by dust, fog, smoke, flames or other factors that are met as nominal mission scenarios when operating indoors. This paper is a preliminary study concerning an innovative radar sensor based on the interferometric Synthetic Aperture Radar (SAR) principle, which has the potential to satisfy stringent requirements set by indoor autonomous operation. An architectural solution based on a frequency-modulated continuous wave (FMCW) scheme is proposed after a detailed analysis of existing compact and lightweight SAR. A preliminary system design is obtained, and the main imaging peculiarities of the novel sensor are discussed, demonstrating that high-resolution, high-quality observation of an assigned control volume can be achieved.

Acute kidney injury after composite valve-graft replacement for ascending aorta aneurysms.

Acute kidney injury (AKI) following cardiac surgery is a continuing source of morbidity and mortality. Although several studies have attempted to determine its etiology and prophylactic measures, limited data exist after thoracic aortic surgery. The aim of this study was to evaluate the incidence and predictors of AKI in patients undergoing aortic root replacement (ARR) with valve conduit for ascending aorta aneurysms. A multi-center observational study of 414 patients undergoing ARR with a valve conduit was conducted, focusing on clinical outcome and AKI defined by consensus RIFLE (risk, injury, failure, loss of function, end-stage renal disease) criteria. Mean age was 62.5 years (range: 21-82 years) with 327 males (79%). Emergent operations were performed in 5% of the cases, while concomitant surgical procedures were performed in 24.9%. Postoperative AKI (all RIFLE classes) occurred in 69 (16.7%) patients, while eight (1.9%) required dialysis. Independent AKI predictors were packed red blood cells (pRBCs) >4 units (OR 2.28; 95% CI 1.20-4.30), cardiopulmonary bypass (CPB) time longer than 180 min (OR, 2.08; 95% CI, 1.16-3.73), and concomitant surgical procedures (OR, 1.85; 95% CI, 1.04-3.29). The severity of RIFLE class was associated with longer ICU stay, hospitalization, and higher hospital mortality (p < 0.001 for each variable). AKI after ARR operations with valve conduit for ascending aorta aneurysms increases utilization of health resources and is associated with adverse events. Concomitant surgical procedures, prolonged CPB-time, and pRBCs >4 units as independent AKI predictors merit further researches enhancing possible preventive strategies.

Tako-tsubo cardiomyopathy complicated by ventricular septal perforation and septal dissection.

Tako-tsubo cardiomyopathy is a form of reversible left ventricular dysfunction, with a clinical and electrocardiographic picture of acute myocardial infarction in the absence of significant coronary disease. The precise clinical features and etiologic basis of this syndrome remain unclear, although an association with emotional or stressful triggers has been recognized. We describe the first case of this syndrome complicated with a ventricular septal perforation and dissection.