1,721,105 research outputs found
Stress Echocardiography and myocardial Contrast Echocardiography in Viability Assessment
No full textFibrosis, lipids, and calcium in human atherosclerotic plaque. In vitro differentiation from normal aortic walls by ultrasonic attenuation
No full textFisica, scienze esatte e medicina a servizio dell’uomo: cambiano i tempi e i paradigmi, ma rimane l’eterno anelito!
No full textQuantification of venous blood signal contribution to BOLD functional activation in the auditory cortex at 3 T
Full text linkMost modern techniques for functional magnetic resonance imaging (fMRI) rely on blood-oxygen-level-dependent (BOLD) contrast as the basic principle for detecting neuronal activation. However, the measured BOLD effect depends on a transfer function related to neurophysiological changes accompanying electrical neural activation. The spatial accuracy and extension of the region of interest are determined by vascular effect, which introduces incertitude on real neuronal activation maps. Our efforts have been directed towards the development of a new methodology that is capable of combining morphological, vascular and functional information; obtaining new insight regarding foci of activation; and distinguishing the nature of activation on a pixel-by-pixel basis. Six healthy volunteers were studied in a parametric auditory functional experiment at 3 T; activation maps were overlaid on a high-resolution brain venography obtained through a novel technique. The BOLD signal intensities of vascular and nonvascular activated voxels were analyzed and compared: it was shown that nonvascular active voxels have lower values for signal peak (Pb10−7) and area (Pb10−8) with respect to vascular voxels. The analysis showed how venous blood influenced the measured BOLD signals, supplying a technique to filter possible venous artifacts that potentially can lead to misinterpretation of fMRI results. This methodology, although validated in the auditory cortex activation, maintains a general applicability to any cortical fMRI study, as the basic concepts on which it relies on are not limited to this cortical region. The results obtained in this study can represent the basis for new methodologies and tools that are capable of adding further characterization to the BOLD signal properties
Experimental Investigation and Theoretical Modelling of the Nonlinear Acoustical Behaviour of a Liver Tissue and Comparison with a Tissue Mimicking Hydrogel
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Quick Quality Analysis on Cereals, Pulses and Grains Using Artificial Intelligence
No full textOur purpose is to design a system for Quick Quality analysis of cereals, pulses, and grains using Artificial Intelligence implementing hardware and software technologies, which could swiftly analyze the type and quality of bulk grains without human intervention. Our aim is detecting and image processing to assess the grain's quality, which is also used as food for livestock, that is an important problem since high food quality has a great impact on animal health, overcoming the limitations of prior work in this field. In our methodology, the complete grain is analyzed to determine its quality by placing it in a controlled environment with a 13 Megapixel, 4K Camera Module to perform the initial step for image processing procedures, before implementing a Neural network. Surpassing the hurdles of samples to estimate the quality of the complete grains, we demonstrated a full-grain scan technique, resulting in a unique hardware system that can more efficiently estimate the quality of the entire grains. Furthermore, our technology yields faster results since it captures the moving grains on the conveyor belt using a precise, fast camera module, which is analyzed by expeditious NVidia Jetson Nano. We applied automation in every step of this process by using vacuum tubes to collect the grains, a filter to align them, conveyor belt with a variable notch for optimum grain disposal. In summary, our study describes innovative developments stemming from a system that provides proper analysis of bulk grains, cereals, and pulses as well as automation of the system
CORONARY PRESSURE-FLOW DIAGRAMS DURING MAXIMAL VASODILATION AS ASSESSED BY TRANSESOPHAGEAL DOPPLER OF LEFT CORONARY-ARTERY - A NEW TOOL FOR EVALUATION OF ABSOLUTE CORONARY FLOW RESERVE
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