Interaction between catechol-O-methyltransferase Val/Met polymorphism and cognitive reserve for negative symptoms in schizophrenia

BACKGROUND Cognitive reserve(CR)and the catechol-O-methyltransferase(COMT)Val/Met polymorphism are reportedly linked to negative symptoms in schizophrenia.However,the regulatory effect of the COMT genotype on the relationship between CR and negative symptoms is still unexamined.AIM To investigate whether the relationship between CR and negative symptoms could be regulated by the COMT Val/Met polymorphism.METHODS In a cross-sectional study,54 clinically stable patients with schizophrenia underwent assessments for the COMT genotype,CR,and negative symptoms.CR was estimated using scores in the information and similarities subtests of a short form of the Chinese version of the Wechsler Adult Intelligence Scale.RESULTS COMT Met-carriers exhibited fewer negative symptoms than Val homozygotes.In the total sample,significant negative correlations were found between negative symptoms and information,similarities.Associations between information,similarities and negative symptoms were observed in Val homozygotes only,with information and similarities showing interaction effects with the COMT genotype in relation to negative symptoms(information,β=-0.282,95%CI:-0.552 to-0.011,P=0.042;similarities,β=-0.250,95%CI:-0.495 to-0.004,P=0.046).CONCLUSION This study provides initial evidence that the association between negative symptoms and CR is under the regulation of the COMT genotype in schizophrenia.

Unconventional phase transition of phase-change-memory materials for optical data storage

Recent years, optically controlled phase-change memory draws intensive attention owing to some advanced applications including integrated all-optical nonvolatile memory, in-memory computing, and neuromorphic computing. The light-induced phase transition is the key for this technology. Traditional understanding on the role of light is the heating effect. Generally, the RESET operation of phase-change memory is believed to be a melt-quenching-amorphization process. However, some recent experimental and theoretical investigations have revealed that ultrafast laser can manipulate the structures of phase-change materials by non-thermal effects and induces unconventional phase transitions including solid-to-solid amorphization and order-to-order phase transitions. Compared with the conventional thermal amorphization,these transitions have potential superiors such as faster speed, better endurance, and low power consumption. This article summarizes some recent progress of experimental observations and theoretical analyses on these unconventional phase transitions. The discussions mainly focus on the physical mechanism at atomic scale to provide guidance to control the phase transitions for optical storage. Outlook on some possible applications of the non-thermal phase transition is also presented to develop new types of devices.

Single-crystalline hole-transporting layers for efficient and stable organic light-emitting devices

Efficient charge-carrier injection and transport in organic light-emitting devices(OLEDs)are essential to simultaneously achieving their high efficiency and long-term stability.However,the charge-transporting layers(CTLs)deposited by various vapor or solution processes are usually in amorphous forms,and their low charge-carrier mobilities,defectinduced high trap densities and inhomogeneous thickness with rough surface morphologies have been obstacles towards high-performance devices.Here,organic single-crystalline(SC)films were employed as the hole-transporting layers(HTLs)instead of the conventional amorphous films to fabricate highly efficient and stable OLEDs.The highmobility and ultrasmooth morphology of the SC-HTLs facilitate superior interfacial characteristics of both HTL/electrode and HTL/emissive layer interfaces,resulting in a high Haacke’s figure of merit(FoM)of the ultrathin top electrode and low series-resistance joule-heat loss ratio of the SC-OLEDs.Moreover,the thick and compact SC-HTL can function as a barrier layer against moisture and oxygen permeation.As a result,the SC-OLEDs show much improved efficiency and stability compared to the OLEDs based on amorphous or polycrystalline HTLs,suggesting a new strategy to developing advanced OLEDs with high efficiency and high stability.

Ultrafast laser-induced decomposition for selective activation of GaAs

The manipulation of micro/nanostructures to customise their inherent material characteristics has garnered considerable attention.In this study,we present the selective activation of gallium arsenide(GaAs)via ultrafast laser-induced decomposition,which correlates with the emergence of ripples on the surface.This instigated a pronounced enrichment in the arsenic(As)concentration around the surface while inducing a depletion of gallium(Ga)at the structural depth.Theoretical simulations based on first principles exhibited a robust inclination towards the phase separation of GaAs,with the gasification of As-As pairs proving more facile than that of Ga-Ga pairs,particularly above the melting point of GaAs.As an illustrative application,a metal-semiconductor hybrid surface was confirmed,showing surface chemical bonding and surface-enhanced Raman scattering(SERS)through the reduction of silver ions on the laser-activated pattern.This laser-induced selective activation holds promise for broader applications,including the controlled growth of Pd and the development of Au/Ag alloy-based platforms,and thereby opens innovative avenues for advancements in semiconductors,solar cell technologies,precision sensing,and detection methodologies.

Two-dimensional In_(2)Se_(3):A rising advanced material for ferroelectric data storage

Ferroelectric memory is a promising candidate for next-generation nonvolatile memory owing to its outstanding performance such as low power consump-tion,fast speed,and high endurance.However,the ferroelectricity of conven-tional ferroelectric materials will be eliminated by the depolarization field when the size drops to the nanometer scale.As a result,the miniaturization of ferroelectric devices was hindered,which makes ferroelectric memory unable to keep up with the development of integrated-circuit(IC)miniaturization.Recently,a two-dimensional(2D)In2Se3 was reported to maintain stable ferro-electricity at the ultrathin scale,which is expected to break through the bottle-neck of miniaturization.Soon,devices based on 2D In2Se3,including the ferroelectric field-effect transistor,ferroelectric channel transistor,synaptic fer-roelectric semiconductor junction,and ferroelectric memristor were demon-strated.However,a comprehensive understanding of the structures and the ferroelectric-switching mechanism of 2D In2Se3 is still lacking.Here,the atomic structures of different phases,the dynamic mechanism of ferroelectric switching,and the performance/functions of the latest devices of 2D In2Se3 are reviewed.Furthermore,the correlations among the structures,the properties,and the device performance are analyzed.Finally,several crucial problems or challenges and possible research directions are put forward.We hope that this review paper can provide timely knowledge and help for the research commu-nity to develop 2D In2Se3 based ferroelectric memory and computing technol-ogy for practical industrial applications.

Time-dependent density-functional theory molecular-dynamics study on amorphization of Sc-Sb-Te alloy under optical excitation

Recently,all-optical memory and optical-computation properties of phase-change materials are receiving intensive attention.Because writing/erasing information in these devices is usually achieved by laser pulses,the interaction between the laser and the phase-change materials becomes a key issue for such new applications.In this work,by a time-dependent density-functional theory molecular-dynamics study,the physics underlying the optical excitation induced amorphization of Sc-Sb-Te is revealed,which goes back to superatom-like Sc-centered structural motifs.These motifs are found to be still robust under the excitation.

Excitation to defect-bound band edge states in twodimensional semiconductors and its effect on carrier transport

The ionization of dopants is a crucial process for electronics,yet it can be unexpectedly difficult in two-dimensional materials due to reduced screening and dimensionality.Using first-principles calculations,here we propose a dopant ionization process for twodimensional semiconductors where charge carriers are only excited to a set of defect-bound band edge states,rather than to the true band edge states,as is the case in three-dimensions.These defect-bound states have small enough ionization energies but large enough spatial delocalization.With a modest defect density,carriers can transport through band by such states.

基于光电融合型相变单元的存内计算

In-memory computing based on emerging non-volatile memory arrays holds a great promise to cope with the drastically increased demand for data processing.Phase-change material(PCM)is a leading candidate for in-memory computing,which utilizes the amorphous-crystalline phase transition and the associated changes in electrical resistance or optical transmission for data encoding[1].