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Single-Cell Analysis is a growing field that endeavors to obtain genetic profiles of individual cells. Disruption of cell–cell junctions and digestion of extracellular matrix in tissues requires tissue-specific mechanical and chemical dissociation protocols. Here, a new approach for dissociating tissues into constituent cells is described. Placing a tissue biopsy core within a liquid-filled cavity and applying an electric field between two parallel plate electrodes facilitates rapid dissociation of complex tissues into single cells. Different solution compositions, electric field strengths, and oscillation frequencies are investigated experimentally and with COMSOL Multiphysics. The method is compared with standard chemical and mechanical approaches for tissue dissociation. Treatment of tissue samples at 100 V/cm 1 kHz facilitated dissociation of 95 ± 4% of biopsy tissue sections in as little as 5 min, threefold faster than conventional chemical–mechanical techniques. The approach affords good dissociation of tissues into single cells while preserving cell viability, morphology, and cell cycle progression, suggesting utility for sample preparation of tissue specimens for direct Single-Cell Analysis. [ABSTRACT FROM AUTHOR]

Extensional edge waves propagate along the edges of plates, with low attenuation in the propagation direction and amplitude decreasing rapidly (within one or two wavelengths) in the direction perpendicular to the plate edge. This makes them an ideal candidate for inspecting the edges of plate-like structures. Here, finite-element models and experiments are used to investigate the propagation and scattering of extensional edge waves in composite plates and application to damage detection is demonstrated. Piezoceramic transducers attached to the edge of a 4-mm-thick carbon-fibre-reinforced polymer (CFRP) plate were used to excite 140-kHz edge waves and damage detection demonstrated using two experimental configurations: pitch-catch and two-transducer pulse-echo. Damage due to edge-on impacts of 5 J and 10 J were detected in both configurations. A mass-addition damage model was used to investigate the effect of damage location. Detection was specific to damage within 33 mm (1.5 wavelengths) of the plate edge with propagation unaffected by features beyond that distance. The time of arrival of reflected signals in pulse-echo mode was accurately predicted using the edge-wave group velocity indicating that this configuration can be used for locating damage on edges. The localisation of edge waves means that they can specifically detect damage at the edges of structures, and attenuation measurements indicate that their useful propagation distance is large (5.5 m). [ABSTRACT FROM AUTHOR]

Introduction: While single-cell analysis technology has flourished, obtaining single cells from complex tissues continues to be a challenge. Current methods require multiple steps and several hours of processing. This study investigates chemical and mechanical methods for clinically relevant preparation of single-cell suspension from frozen biopsy cores of complex tissues. The developed protocol can be completed in 15 min. Methods: Frozen bovine liver biopsy cores were normalized by weight, dimension, and calculated cellular composition. Various chemical reagents were tested for their capability to dissociate the tissue via confocal microscopy, hemocytometry and quantitative flow cytometry. Images were processed using ImageJ. Quantitative flow cytometry with gating analysis was also used for the analysis of dissociation. Physical modeling simulations were conducted in COMSOL Multiphysics. Results: A rapid method for tissue dissociation was developed for single-cell analysis techniques. The results of this study show that a combination of 1% type-1 collagenase and pronase or hyaluronidase in 100 U/µL HBSS solution is the most effective at dissociating 2.5 mm thawed bovine liver biopsy cores in 15 min, with dissociation efficiency of 37-42% and viability >90% as verified using live MDA-MB-231 cancer cells. Cellular dissociation is significantly improved by adding a controlled mechanical force during the chemical process, to dissociate 93 ± 8% of the entire tissue into single cells. Conclusions: Understanding cellular dissociation in ex vivo tissues is essential to the development of clinically relevant dissociation workflows. Controlled mechanical force in combination with chemical treatment produces high quality tissue dissociation. This research is relevant to the understanding and assessment of tissue dissociation and the establishment of an automated preparatory workflow for single cell diagnostics. [ABSTRACT FROM AUTHOR]

In recent years, deep convolutional neural networks (DCNNs) have shown promising performance in medical image analysis, including breast lesion classification in 2D ultrasound (US) images. Despite the outstanding performance of DCNN solutions, explaining their decisions remains an open investigation. Yet, the explainability of DCNN models has become essential for healthcare systems to accept and trust the models. This paper presents a novel framework for explaining DCNN classification decisions of lesions in ultrasound images using the saliency maps linking the DCNN decisions to known cancer characteristics in the medical domain. The proposed framework consists of three main phases. First, DCNN models for classification in ultrasound images are built. Next, selected methods for visualization are applied to obtain saliency maps on the input images of the DCNN models. In the final phase, the visualization outputs and domain-known cancer characteristics are mapped. The paper then demonstrates the use of the framework for breast lesion classification from ultrasound images. We first follow the transfer learning approach and build two DCNN models. We then analyze the visualization outputs of the trained DCNN models using the EGrad-CAM and Ablation-CAM methods. We map the DCNN model decisions of benign and malignant lesions through the visualization outputs to the characteristics such as echogenicity, calcification, shape, and margin. A retrospective dataset of 1298 US images collected from different hospitals is used to evaluate the effectiveness of the framework. The test results show that these characteristics contribute differently to the benign and malignant lesions' decisions. Our study provides the foundation for other researchers to explain the DCNN classification decisions of other cancer types. [ABSTRACT FROM AUTHOR]

The need for wireless condition monitoring and control of hydraulic systems in an autonomous and battery‐free manner is attracting increasing attention in an effort to provide improved sensing functionality, monitoring of system health, and to avoid catastrophic failures. The potential to harvest energy from hydraulic pressure ripples and noise is particularly attractive since they inherently have a high energy intensity, which is associated with the hydraulic mean pressure and flow rate. This paper presents a comprehensive overview of the state of the art in hydraulic pressure energy harvesting, which includes the fundamentals of pressure ripples in hydraulic systems, the choice of electroactive materials and device structures, and the influence of the fluid–mechanical interface. In addition, novel approaches for improving the harvested energy and potential applications for the technology are discussed, and future research directions are proposed and outlined. [ABSTRACT FROM AUTHOR]

Device architectures, electroactive materials, energy harvesting, hydraulic pressure ripples Hydraulic Pressure Ripple Energy Harvesting: Structures, Materials, and Applications (Adv. Keywords: device architectures; electroactive materials; energy harvesting; hydraulic pressure ripples EN device architectures electroactive materials energy harvesting hydraulic pressure ripples 1 1 1 03/06/22 20220303 NES 220303 B Hydraulic Pressure Energy b In article number 2103185, Chris R. Bowen and co-workers present a comprehensive overview of the state-of-the-art in hydraulic pressure energy harvesting, which includes the fundamentals of pressure ripples in hydraulic systems, and the selection of electroactive materials and device structures. [Extracted from the article]