Arterial Distension Monitoring Scheme Using FPGA-Based Inference Machine in Ultrasound Scanner Circuit System.

This paper presents an arterial distension monitoring scheme using a field-programmable gate array (FPGA)-based inference machine in an ultrasound scanner circuit system. An arterial distension monitoring requires a precise positioning of an ultrasound probe on an artery as a prerequisite. The proposed arterial distension monitoring scheme is based on a finite state machine that incorporates sequential support vector machines (SVMs) to assist in both coarse and fine adjustments of probe position. The SVMs sequentially perform recognitions of ultrasonic A-mode echo pattern for a human carotid artery. By employing sequential SVMs in combination with convolution and average pooling, the number of features for the inference machine is significantly reduced, resulting in less utilization of hardware resources in FPGA. The proposed arterial distension monitoring scheme was implemented in an FPGA (Artix7) with a resource utilization percentage less than 9.3%. To demonstrate the proposed scheme, we implemented a customized ultrasound scanner consisting of a single-element transducer, an FPGA, and analog interface circuits with discrete chips. In measurements, we set virtual coordinates on a human neck for 9 human subjects. The achieved accuracy of probe positioning inference is 88%, and the Pearson coefficient (r) of arterial distension estimation is 0.838.

Dual-signal optical detection of Lead(II) ions (Pb2+) using galloyl group-functionalized polydiacetylene.

In this study, we developed a novel galloyl group-functionalized polydiacetylene (Galloyl-PDA) sensor for colorimetric and fluorescent detection of Pb2+. Among three types of Galloyl-PDA vesicles prepared by changing the ratio of newly synthesized galloyl group-conjugated 10,12-pentacosadiynoic acid (Galloyl-PCDA) and matrix 10,12-tricosadinoic acid (TCDA), the blue Galloyl-PDA vesicles with 1:9 molar ratio of Galloyl-PCDA:TCDA showed the most dramatic color transitions to red with colorimetric response (CR) value of 46.66 ± 1.373% within 5 min upon addition of 50 µM Pb2+. However, they didn't exhibit any color change upon interaction with other heavy metals. Since the terminal galloyl moieties of the Galloyl-PDA vesicles could form coordination bonds with Pb2+, the Galloyl-PDA vesicles were stressed and showed obvious blue-to-red chromatic transitions. Besides, because the Galloyl-PDA vesicles exhibited nonfluorescent-to-fluorescent transitions, a linear response in colorimetric and fluorescent signals was observed in the range of 0-10 µM and 0.025-1 µM, respectively. From the colorimetric and fluorescent results, the limit of detection (LOD) was determined to be 1.329 µM and 0.068 µM, which is 8-fold and 12-fold better sensitivity than those of previously reported methods, respectively. Furthermore, the capability of our PDA sensor for detection of Pb2+ in tap water, river water, and human serum was validated with excellent precision and recovery rates of 97.14-100.0%, 99.05-103.3%, and 100.7-106.7%, respectively. As our PDA dual-signal sensor for Pb2+ is rapid, sensitive, specific, and detectable by the naked eye, this approach holds great promise for application in point-of-care testing (POCT).

Antioxidant and anti-aging carbon quantum dots using tannic acid.

Overexpression of collagenase, elastase, and tyrosinase is caused by external factors such as ultraviolet (UV) radiation and stress, resulting in wrinkle formation and freckles through the loss of skin elasticity and skin pigmentation. In this study, we developed novel carbon quantum dots (CQDs) with antioxidant and anti-aging properties using tannic acid as a carbon source through a simple microwave-assisted pyrolysis method. The synthesized tannic acid-derived CQDs (T-CQDs) showed bright blue fluorescence (QY = 28.2 ± 4.0%), exhibiting maximum emission at 430 nm under 350 nm excitation. Even though small amount of the T-CQDs (3µg ml-1) was used, they exhibited excellent free radical scavenging ability (82.8 ± 4.3%). Also, the T-CQDs (10µg ml-1) revealed remarkable inhibitory activity against skin aging-related collagenase (77.6 ± 4.8%), elastase (52.6 ± 1.0%), and tyrosinase (44.2 ± 1.3%), demonstrating their antioxidant and anti-aging effects. Furthermore, their antioxidant and anti-aging properties were superior to those of tannic acid, L-ascorbic acid, and quercetin used as positive controls. Finally, the T-CQDs effectively suppressed UV-induced reactive oxygen species generation by 30% at the cellular levels and showed high cell viability (99.7 ± 0.8%) even at 500µg ml-1. These results demonstrate that the T-CQDs with superior antioxidant, anti-aging properties, and low cytotoxicity can be utilized as novel anti-aging materials in cosmetic and nanomedicine fields.