Recent Advances on Pseudodynamic Hybrid Simulation of Masonry Structures

Hybrid Simulation has been introduced to simulate the seismic response of civil structures. The hybrid model of the emulated system combines numerical and physical subdomains and its dynamic response to a realistic excitation is simulated using a numerical time-stepping response history analysis. In the current practice, lumped parameters structural topologies such as shear type frames or inverted pendulum characterize the physical subdomain and the design of the testing setup is straightforward. Although hybrid simulation has been extensively exploited for testing concrete and steel structures, in the authors' knowledge, there is still a paucity of scientific publications devoted to masonry applications. This is in contrast to the inherent uncertainty carried by masonry failure mechanisms, which hinders any attempt of implementing predictive numerical models. From this perspective, this paper summarizes our recent research achievements aimed at extending hybrid simulation to distributed parameter specimens, such as masonry walls, using the minimum number of actuators. The great potential of reduction bases in driving the substructuring process has been shown in a previous work and here is enhanced to floating physical subdomains

MC^2S: a Mobile Component-based CrowdSensing framework

CrowdSensing often refers to sharing data collected by sensing devices with the aim of measure a phenomena of common interest. Within this thesis we will describe MC^2S, a novel Component-based framework suitable for the easy development of multiple, secure, portable, interopeable and concurrent MCS applications. The framework has been built in collaboration between University of Pisa and Trinity College Dublin, starting from September 2015. It exploits both Apache Felix implementation of OSGi framework specifications to ensure composite applications and Java environment to guarantee portability over an huge range of heterogeneous hardaware. However, even if MC^2S framework already offers several forefront capabilities, a lot of additional features may be introduced during the development of its next versions

Hybrid simulation with dynamic substructuring of masonry structures: A numerical study

Hybrid simulation is used to compute the time history response of an emulated system subject to a dynamic excitation by combining a physical and a numerical substructure. The former is tested in the laboratory by means of servo-controlled actuators whist a real-time computer simulates the latter and solves the coupled equation of motion. Hybrid simulation has been extensively applied for seismic response history analysis of steel and concrete frame structures. For these systems, subdomain partitioning follows storey levels and nodal joints among beam/column-like elements. In the case of planar masonry structures, distributed interfaces characterize system subdomains and, in principle, several actuators should be used to impose the correct boundary conditions to the tested specimen. This paper presents a new substructuring method for planar masonry substructures, which aims to reduce the number of actuators necessary to achieve a predetermined coupling accuracy between physical and numerical subdomains. The numerical validation of this procedure is illustrated for a masonry building facade system

Towards the Seismic Monitoring of a Monumental Structure in Mixed Masonry-RC

The monumental historical heritage is recognized and appreciated worldwide. It is the result of the succession of different cultures that have inevitably influenced and characterized history; therefore, it represents an inestimable value to be preserved for future generations in order to transmit culture and art. In addition, there is a growing engineering interest in the protection of cultural heritage since it is strongly vulnerable. In the present work, the authors present the first attempt of geometric and mechanical modeling (Finite Element Model) and the subsequent sensitivity analysis of the Upper Basilica of the Sanctuary of Oropa (Chiesa Nuova), characterized by a mixed structure in masonry and reinforced concrete. The analysis conducted is placed at the beginning of a path of knowledge which, in subsequent steps, allows the understanding of the static and dynamic behavior of the analyzed structure. The goal of this work is to discriminate and validate which of the elastic parameters characterizing the individual components of the structure have a significant effect on the dynamic response of the structure, to facilitate the subsequent analysis aimed at defining the dynamic monitoring sensing system to be installed on the structure, and to support vulnerability analyses

Assessment of Functional Connectome in End-Stage Organ Disease Patients After Life-Threatening Surgery

Purpose The purpose of this study was to assess the organization of intrinsic functional brain networks (functional connectome) in neurologically asymptomatic patients with end-stage organ disease who had undergone major surgery for life-threating conditions and compare it to a control group. Materials and Methods Resting-state functional magnetic resonance imaging (rest-fMRI) was performed in 10 adult, post-operative patients with end-stage organ disease. The patients (7 men, 3 women, mean age 57.9 ± 7.4 years) had undergone: n=4 coronary artery bypass graft for heart failure, n=2 orthotopic liver transplantation for non-alcoholic cirrhotic liver failure, n=3 mitral valve repair for heart failure, n=1 pancreaticoduodenectomy for pancreatic papillary tumor. Rest-fMRI was acquired within 48 hours after intensive care unit discharge. Structural brain MR imaging was acquired with T1-weighted, T2-weighted, diffusion weighted imaging, and susceptibility weighted imaging along with 3D isotropic T1-weighted MR images. MR examinations were performed on a 3T MR scanner (Discovery 750w, General Electric Healthcare, Milwaukee, WI, USA). Ten age- and sex-matched healthy controls were studied with the same protocol. Brain functional networks were analyzed by calculating the interregional correlation of low-frequency fluctuations in spontaneous brain activity. Weighted graph-based models were employed to topologically recognize reproducibly determined large-scale functional networks, including default mode, salience, dorsal attention, sensorimotor, visual and language networks using a seed-based approach with Functional Connectivity Toolbox (CONN) (https://web.conn-toolbox.org/) running under MatLab (The MathWorks Inc., Natick, MA, USA). A p-uncorrected < 0.0025 was used to threshold connectomes for voxel-wise paired statistical analysis to take in account the lateralization effect. Network comparisons were thresholded using a false discovery rate (FDR) cluster-level correction approach in patients and controls using the MatLab function “mafdr” for p-uncorrected <0.0025 obtaining the p-FDR < 0.077. Results Functional connectivity in patients and controls was successfully assessed for the default mode, salience, dorsal attention, sensorimotor, visual, and language networks of the brain. There was statistically significant (p <0.05) reduced connectivity between seeds in the default mode, salience, sensorimotor, and language networks in patients compared to controls (Fig. 1). No acute structural lesions were observed in patients at MR imaging. Conclusion Assessment of functional connectome in end-stage organ disease patients is feasible in routine clinical setting. Rest-fMRI can demonstrate reduced connectivity of several intrinsic functional networks in critically ill, post-operative patients and it may be a useful prognostic indicator of early and long-term clinical outcome. References Ma X, et al. Aberrant functional connectome in neurologically asymptomatic patients with end-stage renal disease. PloS One 2015;10:e0121085. Lariviere S, et al. Disrupted functional network integrity and flexibility after stroke: Relation to motor impairments. NeuroImage. Clinical 2018;19:883–891. Cheng Y, et al. Longitudinal Intrinsic Brain Activity Changes in Cirrhotic Patients before and One Month after Liver Transplantation. Korean Journal of Radiology, 2017;18,370–377. Zhang XD, et al. Long-and short-range functional connectivity density alteration in non-alcoholic cirrhotic patients one month after liver transplantation: A resting-state fMRI study. Brain Research, 2015;1620:177–187. Whitfield-Gabrieli S, Nieto-Castanon A. Conn: a functional connectivity toolbox for correlated and anticorrelated brain networks. Brain Connect. 2012; 2:125-141. Additional Video Material: https://youtu.be/15lzif0MOO

Assessment of cerebral microbleeds by susceptibility-weighted imaging at 3T in patients with end-stage organ failure

Purpose: Cerebral microbleeds (CMBs) are small rounded lesions representing cerebral hemosiderin deposits surrounded by macrophages that results from previous microhemorrhages. The aim of this study was to review the distribution of cerebral microbleeds in patients with end-stage organ failure and their association with specific end-stage organ failure risk factors. Materials and methods: Between August 2015 and June 2017, we evaluated 15 patients, 9 males, and 6 females, (mean age 65.5 years). Patients population was subdivided into three groups according to the organ failure: (a) chronic kidney failure (n = 8), (b) restrictive cardiomyopathy undergoing heart transplantation (n = 1), and (c) end-stage liver failure undergoing liver transplantation (n = 6). The MR exams were performed on a 3T MR unit and the SWI sequence was used for the detection of CMBs. CMBs were subdivided in supratentorial lobar distributed, supratentorial non-lobar distributed, and infratentorial distributed. Results: A total of 91 microbleeds were observed in 15 patients. Fifty-nine CMBs lesions (64.8%) had supratentorial lobar distribution, 17 CMBs lesions (18.8%) had supratentorial non-lobar distribution and the remaining 15 CMBs lesions (16.4%) were infratentorial distributed. An overall predominance of supratentorial multiple lobar localizations was found in all types of end-stage organ failure. The presence of CMBs was significantly correlated with age, hypertension, and specific end-stage organ failure risk factors (p < 0.001). Conclusions: CMBs are mostly founded in supratentorial lobar localization in end-stage organ failure. The improved detection of CMBs with SWI sequences may contribute to a more accurate identification of patients with cerebral risk factors to prevent complications during or after the organ transplantation

Neumonía por COVID-19 en niños: De su etiología a su manejo

El COVID-19 es menos serio en niños que en adultos. Sin embargo, las afecciones respiratorias dominan el cuadro clínico de pacientes hospitalizados por COVID-19, aun en niños. En algunas series de casos, el deterioro del estado clínico, donde la disnea, la cianosis y el inicio del síndrome de dificultad respiratoria aguda (SDRA) emergieron ∼8–10 días después del inicio de la infección por SARS-CoV-2, pudo progresar rápidamente hasta la falla multiorgánica y la muerte. Esta revisión tiene como objetivo evaluar las características de la neumonía por COVID-19 en poblaciones pediátricas, comenzando con su etiología y sus mecanismos patológicos, para cerrar con su manejo clínico

Brain-core temperature of patients before and after orthotopic liver transplantation assessed by DWI thermometry

To assess brain-core temperature of end-stage liver disease patients undergoing orthotopic liver transplantation (OLT) using a temperature measurement technique based on the apparent diffusion coefficient of the cerebrospinal fluid in the lateral ventricles

Upper airway involvement in pediatric COVID-19

The clinical spectrum of SARS-CoV-2 infection is mixed. It ranges from asymptomatic cases, medium-intensity forms with mild to moderate symptoms, to severe ones with bilateral lung involvement and respiratory distress, which can require transfer to ICUs and intubation. In most cases, the clinical picture is characterized by a persistent fever, cough, dyspnoea, expectoration, myalgias, arthralgias, headache, gastrointestinal symptoms, nasal congestion, and pharyngodynia. The spread of COVID-19 in Europe has highlighted an atypical presentation of disease involving upper airways and, above all, dysfunction of olfactory and gustatory senses. There is ample evidence that COVID-19 is significantly less severe in children than in adults. However, due to difficulties in assessing the disorder in children, especially among very young patients, the olfaction and gustatory dysfunctions remain open issues. This article sheds light on the upper airway involvement in pediatric COVID-19 subjects