Three-dimensional/one-dimensional perovskite heterostructures for stable tri-state synaptic memristors

Memristors have great potential in neural network computation.Perovskite memristors exhibit excellent resistive-switching(RS)properties between high resistance state(HRS)and low resistance state(LRS)state under applied voltage due to the extraordinary ion migration and superior charge transfer.However,the stability issue of traditional three-dimensional(3D)perovskites is still challenging.Here,one-dimensional(1D)(CH_(3))_(3)SPbI_(3)perovskite passivation layer was in-situ formed on 3D perovskite film,which was further applied in stable synaptic memristor.The memristor was provided with three resistance states due to the heterojunction electric field coupled with ion migration.The on/off ratio of memristors was obviously improved from 10 to over 60.The RS characteristics of 3D/1D perovskite memristor remained unchanged after 10^(3)s read and 300 switching cycles.The 3D/1D perovskite memristor effectively exhibited versatile synaptic plasticity behaviors including long-term potentiation,long-term depression and paired-pulse facilitation by controlling the input voltages.Notably,the novel device provides a new candidate for next-generation neuromorphic computing.

Targeting p53 pathways:mechanisms,structures,and advances in therapy

The TP53 tumor suppressor is the most frequently altered gene in human cancers,and has been a major focus of oncology research.The p53 protein is a transcription factor that can activate the expression of multiple target genes and plays critical roles in regulating cell cycle,apoptosis,and genomic stability,and is widely regarded as the“guardian of the genome”.Accumulating evidence has shown that p53 also regulates cell metabolism,ferroptosis,tumor microenvironment,autophagy and so on,all of which contribute to tumor suppression.Mutations in TP53 not only impair its tumor suppressor function,but also confer oncogenic properties to p53 mutants.Since p53 is mutated and inactivated in most malignant tumors,it has been a very attractive target for developing new anti-cancer drugs.However,until recently,p53 was considered an“undruggable”target and little progress has been made with p53-targeted therapies.Here,we provide a systematic review of the diverse molecular mechanisms of the p53 signaling pathway and how TP53 mutations impact tumor progression.We also discuss key structural features of the p53 protein and its inactivation by oncogenic mutations.In addition,we review the efforts that have been made in p53-targeted therapies,and discuss the challenges that have been encountered in clinical development.