Boosting redox activity on MXene-induced multifunctional collaborative interface in high Li2S loading cathode for high-energy Li-S and metallic Li-free rechargeable batteries

Use of metallic Li anode raises serious concerns on the safety and operational performance of Li-S batteries due to uncontrolled hazard of Li dendrite formation, which is difficultly eliminated as long as the metallic Li exists in the cells. Pairing lithium sulfide (Li2S) cathode with currently available metallic Lifree high-capacity anodes offers an alternative solution to this challenge. However, the performance of Li2S cathode is primarily restricted by high activation barrier upon initial charge, low active mass utilization and sluggish redox kinetics. Herein, a MXene-induced multifunctional collaborative interface is proposed to afford superb activity towards redox solid-liquid/liquid-liquid phase transformation, strong chemisorption, high conductivity and fast ionic/charge transport in high Li2S loading cathode. Applying collaborative interface effectively reduces initial voltage barrier of Li2S activation and regulates the kinetic behavior of redox polysulfide conversion. Therefore, stable operation of additive-free Li2S cathode with high areal capacities at high Li2S loading up to 9 mg cm^-2 can be achieved with less sacrifice of high capacity and rate capability in Li-S batteries. Rechargeable metallic Li-free batteries are successfully constructed by pairing this high-performance Li2S cathode with high-capacity metal oxide anodes, which delivers superior energy density to current Li-ion batteries.

Network-pharmacology and molecular docking-based investigation of mechanism of Sophora flavescens on cancer and inflammation

Objective:In order to explore the systematical regulatory mechanism of Kushen(Sophora flavescens,SF)on inflammation and cancer,we analyzed inter-molecular interactions between herbal ingredients of SF and human inflammation and cancer through network-pharmacology and molecular docking-based approaches.Methods:Firstly,ingredients and potential targets were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform,GeneCards database,Therapeutic Targets Database and Online Mendelian Inheritance in Man database.Then,protein-protein interaction network and medicine-ingredient-target-disease network were established and analyzed via STRING and Cytoscape.Surflex-dock was performed by SybylX-2.0.Finally,functional enrichment and pathway enrichment were achieved by Gene Ontology database and Kyoto Encyclopedia of Genes and Genomes database.Results:The results showed that 113 components of SF and 53 potential targets were related in the study.SF exerts anti-inflammatory and anti-cancer mechanism through key targets located in nucleus,such as JUN,MYC,RELA,NCOA,PPARG which may trigger the NF-κB pathway,the Bcl-2/Bax pathway and other pathways to effect DNA transcriptional activity.Conclusions:The study predicted the mechanism of SF on cancer and inflammation.According to the results,we suggest that the ingredients of SF effect on DNA bingding and transcription in nuclear receptors-like JUN,MYC,RELA,NCOA,PPARG.the receptors trigger several pathways including NF-κB pathway,the Bcl-2/Bax pathway and others.Eventually,it regulats inflammatory factors and cell proliferation,senescence and apoptosis.

Rh(Ⅱ)-catalyzed intermolecular carboamination of pyridines via double Csp^(2)-H bond activations

We disclose the development of the Rh-catalyzed amine-directed remote 5,6-carboamination protocol of pyridines via dual Csp^(2)-H functionalizations.A variety of readily available 2-aminopyridines and 1,2,3-triazoles are allowed for coupling cyclization to access polyfunctionalized azaindoles.Mechanistic studies including DFT calculations unveil that relay carbenoidelectrophilic addition to pyridines and the sequential pyridyl Csp^(2)-H amination are involved in this transformation.The postsynthetic utility of this methodology is showcased by versatile and site-selective modification of azaindoles.

A nanonewton-scale biomimetic mechanosensor

Biomimetic mechanosensors have profound implications for various areas,including health care,prosthetics,human‒machine interfaces,and robotics.As one of the most important parameters,the sensitivity of mechanosensors is intrinsically determined by the detection resolution to mechanical force.In this manuscript,we expand the force detection resolution of current biomimetic mechanosensors from the micronewton to nanonewton scale.We develop a nanocrack-based electronic whisker-type mechanosensor that has a detection resolution of 72.2 nN.We achieve the perception of subtle mechanical stimuli,such as tiny objects and airflow,and the recognition of surface morphology down to a 30 nm height,which is the finest resolution ever reported in biomimetic mechanosensors.More importantly,we explore the use of this mechanosensor in wearable devices for sensing gravity field orientation with respect to the body,which has not been previously achieved by these types of sensors.We develop a wearable smart system for sensing the body’s posture and movements,which can be used for remote monitoring of falls in elderly people.In summary,the proposed device offers great advantages for not only improving sensing ability but also expanding functions and thus can be used in many fields not currently served by mechanosensors.

Sacrificial layer-assisted nanoscale transfer printing

Transfer printing is an emerging assembly technique for flexible and stretchable electronics.Although a variety of transfer printing methods have been developed,transferring patterns with nanometer resolution remains challenging.We report a sacrificial layer-assisted nanoscale transfer printing method.A sacrificial layer is deposited on a donor substrate,and ink is prepared on and transferred with the sacrificial layer.Introducing the sacrificial layer into the transfer printing process eliminates the effect of the contact area on the energy release rate(ERR)and ensures that the ERR for the stamp/ink-sacrificial layer interface is greater than that for the sacrificial layer/donor interface even at a slow peel speed(5mm s−1).Hence,large-area nanoscale patterns can be successfully transferred with a yield of 100%,such as Au nanoline arrays(100 nm thick,4 mm long and 47 nm wide)fabricated by photolithography techniques and PZT nanowires(10mm long and 63nm wide)fabricated by electrohydrodynamic jet printing,using only a blank stamp and without the assistance of any interfacial chemistries.Moreover,the presence of the sacrificial layer also enables the ink to move close to the mechanical neutral plane of the multilayer peel-off sheet,remarkably decreasing the bending stress and obviating cracks or fractures in the ink during transfer printing.