Flexible Three-Dimensional Force Tactile Sensor Based on Velostat Piezoresistive Films.

The development of a high-performance, low-cost, and simply fabricated flexible three-dimensional (3D) force sensor is essential for the future development of electronic skins suitable for the detection of normal and shear forces for several human motions. In this study, a sandwich-structured flexible 3D force tactile sensor based on a polyethylene-carbon composite material (velostat) is presented. The sensor has a large measuring range, namely, 0-12 N in the direction of the normal force and 0-2.6 N in the direction of the shear force. For normal forces, the sensitivity is 0.775 N-1 at 0-1 N, 0.107 N-1 between 1 and 3 N, and 0.003 N-1 at 3 N and above. For shear forces, the measured sensitivity is 0.122 and 0.12 N-1 in x- and y-directions, respectively. Additionally, the sensor exhibits good repeatability and stability after 2500 cycles of loading and releasing. The response and recovery times of the sensor are as fast as 40 and 80 ms, respectively. Furthermore, we prepared a glove-like sensor array. When grasping the object using the tactile glove, the information about the force applied to the sensing unit can be transmitted through a wireless system in real-time and displayed on a personal computer (PC). The prepared flexible 3D force sensor shows broad application prospects in the field of smart wearable devices.

PDC-Net: parallel dilated convolutional network with channel attention mechanism for pituitary adenoma segmentation.

Accurate segmentation of the medical image is the basis and premise of intelligent diagnosis and treatment, which has a wide range of clinical application value. However, the robustness and effectiveness of medical image segmentation algorithms remains a challenging subject due to the unbalanced categories, blurred boundaries, highly variable anatomical structures and lack of training samples. For this reason, we present a parallel dilated convolutional network (PDC-Net) to address the pituitary adenoma segmentation in magnetic resonance imaging images. Firstly, the standard convolution block in U-Net is replaced by a basic convolution operation and a parallel dilated convolutional module (PDCM), to extract the multi-level feature information of different dilations. Furthermore, the channel attention mechanism (CAM) is integrated to enhance the ability of the network to distinguish between lesions and non-lesions in pituitary adenoma. Then, we introduce residual connections at each layer of the encoder-decoder, which can solve the problem of gradient disappearance and network performance degradation caused by network deepening. Finally, we employ the dice loss to deal with the class imbalance problem in samples. By testing on the self-established patient dataset from Quzhou People's Hospital, the experiment achieves 90.92% of Sensitivity, 99.68% of Specificity, 88.45% of Dice value and 79.43% of Intersection over Union (IoU).

Highly sensitive electrochemical determination of rutin based on the synergistic effect of 3D porous carbon and cobalt tungstate nanosheets.

Rutin, a flavonoid found in fruits and vegetables, is a potential anticancer compound with strong anticancer activity. Therefore, electrochemical sensor was developed for the detection of rutin. In this study, CoWO4 nanosheets were synthesized via a hydrothermal method, and porous carbon (PC) was prepared via high-temperature pyrolysis. Successful preparation of the materials was confirmed, and characterization was performed by transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. A mixture of PC and CoWO4 nanosheets was used as an electrode modifier to fabricate the electrochemical sensor for the electrochemical determination of rutin. The 3D CoWO4 nanosheets exhibited high electrocatalytic activity and good stability. PC has a high surface-to-volume ratio and superior conductivity. Moreover, the hydrophobicity of PC allows large amounts of rutin to be adsorbed, thereby increasing the concentration of rutin at the electrode surface. Owing to the synergistic effect of the 3D CoWO4 nanosheets and PC, the developed electrochemical sensor was employed to quantitively determine rutin with high stability and sensitivity. The sensor showed a good linear range (5-5000 ng/mL) with a detection limit of 0.45 ng/mL. The developed sensor was successfully applied to the determination of rutin in crushed tablets and human serum samples.

Highly sensitive electrochemical determination of rutin based on the synergistic effect of 3D porous carbon and cobalt tungstate nanosheets / 药物分析学报

Rutin,a flavonoid found in fruits and vegetables,is a potential anticancer compound with strong anti-cancer activity.Therefore,electrochemical sensor was developed for the detection of rutin.In this study,CoWO4 nanosheets were synthesized via a hydrothermal method,and porous carbon(PC)was prepared via high-temperature pyrolysis.Successful preparation of the materials was confirmed,and character-ization was performed by transmission electron microscopy,scanning electron microscopy,and X-ray photoelectron spectroscopy.A mixture of PC and CoWO4 nanosheets was used as an electrode modifier to fabricate the electrochemical sensor for the electrochemical determination of rutin.The 3D CoWO4 nanosheets exhibited high electrocatalytic activity and good stability.PC has a high surface-to-volume ratio and superior conductivity.Moreover,the hydrophobicity of PC allows large amounts of rutin to be adsorbed,thereby increasing the concentration of rutin at the electrode surface.Owing to the syn-ergistic effect of the 3D CoWO4 nanosheets and PC,the developed electrochemical sensor was employed to quantitively determine rutin with high stability and sensitivity.The sensor showed a good linear range(5-5000 ng/mL)with a detection limit of O.45 ng/mL.The developed sensor was successfully applied to the determination of rutin in crushed tablets and human serum samples.

Determination of miRNA derived from exosomes of prostate cancer via toehold-aided cyclic amplification combined with HRP enzyme catalysis and magnetic nanoparticles.

MicroRNAs (miRNAs) play a significant role in tumorigenesis and tumor development. Exosomal microRNA-141 (miRNA-141, miR-141) has been reported to be overexpressed in prostate cancer (PCa) and has become a potential biomarker for the diagnosis of PCa. Herein, a novel fluorescent biosensor based on toehold-aided cyclic amplification combined with horseradish peroxidase (HRP) enzyme catalysis and magnetic nanoparticles (MNPs) was designed for determination of the exosomes-derived microRNA-141 (miRNA-141, miR-141). The synergy of HRP enzyme catalysis and toehold mediated strand display reaction (TSDR) increase the sensitivity of the method, and the good separation ability of MNPs ensures the specificity of the method. Therefore, under the optimized experimental conditions, the highly sensitive and specific detection of miRNA-141 can be realized, and the detection limit is as low as 10 fM. More importantly, the biosensor successfully determinates the exosomal miR-141 in the plasma of patients with PCa.