62 research outputs found

    Improving robustness against electrode shift of high density EMG for myoelectric control through common spatial patterns

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    Background: Most prosthetic myoelectric control studies have concentrated on low density (less than 16 electrodes, LD) electromyography (EMG) signals, due to its better clinical applicability and low computation complexity compared with high density (more than 16 electrodes, HD) EMG signals. Since HD EMG electrodes have been developed more conveniently to wear with respect to the previous versions recently, HD EMG signals become an alternative for myoelectric prostheses. The electrode shift, which may occur during repositioning or donning/doffing of the prosthetic socket, is one of the main reasons for degradation in classification accuracy (CA). Methods: HD EMG signals acquired from the forearm of the subjects were used for pattern recognition-based myoelectric control in this study. Multiclass common spatial patterns (CSP) with two types of schemes, namely one versus one (CSP-OvO) and one versus rest (CSP-OvR), were used for feature extraction to improve the robustness against electrode shift for myoelectric control. Shift transversal (ST1 and ST2) and longitudinal (SL1 and SL2) to the direction of the muscle fibers were taken into consideration. We tested nine intact-limb subjects for eleven hand and wrist motions. The CSP features (CSP-OvO and CSP-OvR) were compared with three commonly used features, namely time-domain (TD) features, time-domain autoregressive (TDAR) features and variogram (Variog) features. Results: Compared with the TD features, the CSP features significantly improved the CA over 10 % in all shift configurations (ST1, ST2, SL1 and SL2). Compared with the TDAR features, a. the CSP-OvO feature significantly improved the average CA over 5 % in all shift configurations; b. the CSP-OvR feature significantly improved the average CA in shift configurations ST1, SL1 and SL2. Compared with the Variog features, the CSP features significantly improved the average CA in longitudinal shift configurations (SL1 and SL2). Conclusion: The results demonstrated that the CSP features significantly improved the robustness against electrode shift for myoelectric control with respect to the commonly used features.National Basic Research Program (973 Program) of China [2011CB013305]; National Natural Science Foundation of China [51375296, 51475292

    Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport

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    【Abstract】The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gasesandliquids underasteady-stateapplied pressure,nearlyeliminate fouling,and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores’ deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles.This work was supported by the National Natural Science Foundation of China (grant no. 21673197), the Young Overseas High-level Talents Introduction Plan, the 111 Project (grant no. B16029). 研究工作得到国家自然科学基金委(项目批准号:21673197)和厦门大学校长基金(项目批准号:20720170050)等资助与支持

    Systematic design of cell membrane coating to improve tumor targeting of nanoparticles

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    Cell membrane (CM) coating technology is increasingly being applied in nanomedicine, but the entire coating procedure including adsorption, rupture, and fusion is not completely understood. Previously, we showed that the majority of biomimetic nanoparticles (NPs) were only partially coated, but the mechanism underlying this partial coating remains unclear, which hinders the further improvement of the coating technique. Here, we show that partial coating is an intermediate state due to the adsorption of CM fragments or CM vesicles, the latter of which could eventually be ruptured under external force. Such partial coating is difficult to self-repair to achieve full coating due to the limited membrane fluidity. Building on our understanding of the detailed coating process, we develop a general approach for fixing the partial CM coating: external phospholipid is introduced as a helper to increase CM fluidity, promoting the final fusion of lipid patches. The NPs coated with this approach have a high ratio of full coating (similar to 23%) and exhibit enhanced tumor targeting ability in comparison to the NPs coated traditionally (full coating ratio of similar to 6%). Our results provide a mechanistic basis for fixing partial CM coating towards enhancing tumor accumulation.Peer reviewe

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Pore development and controllable structural design of graphene sheets

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    Effects of oxygen-containing functional groups on carbon materials in supercapacitors: A review

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    Carbon materials play an indispensable role in supercapacitor devices. However, carbon materials based on the electric double-layer energy storage mechanisms limit the energy density improvement of supercapacitors. The introduction of additional redox pseudocapacitance through oxygen-containing functional groups is a novel strategy to improve the specific capacity of carbon materials. Whereas the influence mechanism of oxygen-containing functional groups on carbon-based electrode materials needs to be explored in-depth. Here, we summarize the types, introductions and characterization methods of oxygen-containing functional groups in carbon materials, and emphatically explain the effect of oxygen-containing functional groups on the structure and physico-chemical properties of carbon-based electrode materials for supercapacitors at the mechanism level, which has not been reported in previous reviews. Different types or content differences of oxygen-containing functional groups can cause changes in the polarity, surface energy, adsorption energy, impedance, energy bands and other aspects of carbon materials, and even lead to defects affecting the structure and physicochemical properties. The mutual constraint relationship between high specific capacity and excellent conductivity caused by the content of oxygen-containing functional groups is also pointed out. Carbon materials with rich oxygen are expected to be developed in lithium/sodium-ion batteries, fuel cells, electrocatalysis, sensor devices, biomedicine and other fields

    Identification of Ground Intrusion in Underground Structures Based on Distributed Structural Vibration Detected by Ultra-Weak FBG Sensing Technology

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    It is challenging for engineers to timely identify illegal ground intrusions in underground systems such as subways. In order to prevent the catastrophic collapse of subway tunnels from intrusion events, this paper investigated the capability of detecting the ground intrusion of underground structures based on dynamic measurement of distributed fiber optic sensing. For an actual subway tunnel monitored by the ultra-weak fiber optic Bragg grating (FBG) sensing fiber with a spatial resolution of five meters, a simulated experiment of the ground intrusion along the selected path was designed and implemented, in which a hydraulic excavator was chosen to exert intrusion perturbations with different strengths and modes at five selected intrusion sites. For each intrusion place, the distributed vibration responses of sensing fibers mounted on the tunnel wall and the track bed were detected to identify the occurrence and characteristics of the intrusion event simulated by the discrete and continuous pulses of the excavator under two loading postures. By checking the on-site records of critical moments in the intrusion process, the proposed detection approach based on distributed structural vibration responses for the ground intrusion can detect the occurrence of intrusion events, locate the intrusion ground area, and distinguish intrusion strength and typical perturbation modes

    Research on the X-ray wavelength division multiplexing technology for blackout region communication

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    After the concept of X-ray communication was proposed, its application in complex electromagnetic environment has received more attention, such as data transmission in re-enter special electro-magnetic condition. In this article, a new type of X-ray source was introduced firstly, which was expected to generate multiple characteristic lines and achieve wavelength division multiplexing technology in X-ray band. Then an experimental platform was built for analyzing transmission characteristics of X-ray photon in various plasma media. Finally, the calculation model for a link power equation was given. Experiment results show that transmittance of 8–18 keV X-ray signal is relatively stable, atomic numbers from 29 to 42 are the most suitable materials for wavelength division multiplexing, the X-ray communication system is expected to realize about 200 kbps data transmission rate in adjacent space
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