Two-Terminal Lithium-Mediated Artificial Synapses with Enhanced Weight Modulation for Feasible Hardware Neural Networks

Recently,artificial synapses involving an electrochemical reaction of Li-ion have been attributed to have remarkable synaptic properties.Three-terminal synaptic transistors utilizing Li-ion intercalation exhibits reliable synaptic characteristics by exploiting the advantage of nondistributed weight updates owing to stable ion migrations.However,the three-terminal configurations with large and complex structures impede the crossbar array implementation required for hardware neuromorphic systems.Meanwhile,achieving adequate synaptic performances through effective Li-ion intercalation in vertical two-terminal synaptic devices for array integration remains challenging.Here,two-terminal Au/LixCoO_(2)/Pt artificial synapses are proposed with the potential for practical implementation of hardware neural networks.The Au/LixCoO_(2)/Pt devices demonstrated extraordinary neuromorphic behaviors based on a progressive dearth of Li in LixCoO_(2)films.The intercalation and deintercalation of Li-ion inside the films are precisely controlled over the weight control spike,resulting in improved weight control functionality.Various types of synaptic plasticity were imitated and assessed in terms of key factors such as nonlinearity,symmetricity,and dynamic range.Notably,the LixCoO_(2)-based neuromorphic system outperformed three-terminal synaptic transistors in simulations of convolutional neural networks and multilayer perceptrons due to the high linearity and low programming error.These impressive performances suggest the vertical two-terminal Au/LixCoO_(2)/Pt artificial synapses as promising candidates for hardware neural networks.

Rationally designed graphene channels for real-time sodium ion detection for electronic tongue

Monitoring taste-inducing ions and molecules continuously in liquids or solutions is of great considerable matter for the realization of the electronic tongue(E-tongue).Particularly from the five major tastes,the highly selective,sensitive detection of Na^(+)in real-time is prioritized.Prioritization is due to the saltiness of food is the key ingredient in most meals.Nevertheless,existing Na^(+)detecting devices have relatively low performances of selectivity,sensitivity,and lack of on–off functions.Additionally,conventional devices significantly deteriorate in capac-ity due to repetitive usage or lifetime shortage by degradation of the sensing mate-rial.Herein,a graphene-based channel was rationally designed by the facile decoration of Calix[4]arene and Nafion to address this issue.They act as a receptor and a molecular sieve,respectively,to enhance selectivity and sensitivity and elon-gate the life expectancy of the device.This device was merged with a microfluidic channel to control the injection and withdrawal of solutions to fulfill dynamic on–off functions.The fabricated device has highly selective,sensitive Na^(+)detection properties compared to other 10 molecule/ionic species.Dynamic on–off functions of the device were available,also possesses a long lifespan of at least 220 days.Additionally,it can precisely discriminate real beverages containing Na^(+),which can be observed by principal component analysis plot.These features offer the possibility of ascending to a platform for E-tongues in near future.

Unexpected positive cultures including isolation of Propionibacterium acnes in revision shoulder arthroplasty

Objective Little information is available to guide treatment strategies regarding patients with unexpected positive cultures （UPC）,including Propionibacterium acnes （PA）,without overt signs of infection in revision shoulder arthroplasty （RSA）.The purpose of our study was to analyze the prevalence,clinical meaning,treatment and prognosis of UPC in RSA.Data sources and study selection We performed a systematic review of the literature between 1950 and 2013 for all studies reporting on UPC for PA.Studies with the prevalence and prognosis of patients with UPC in RSA were analyzed.Results Six studies meeting our inclusion criteria yielded data for 1 402 patients who underwent a total of 1405 RSA.Based on the available data,following RSA 235 shoulders had UPCs with a pooled percentage of 16.7％ （235/1405）.The most commonly isolated bacteria from shoulders following RSA with UPCs was PA with pooled percentages of 63.4％ （149/235）.Occurrence of true infection from UPCs after RSA was seen in 24 shoulders （24/235,10.2％）.Antibiotic use did not influence the rate of the occurrence of true infection from UPCs （P=0.498）.Conclusions Our study showed a low risk of having a true infection from UPCs after RSA without clinical signs of preoperative infection at the time of the surgery.Therefore,prolonged antibiotic therapy may not be necessary in these patients.