Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances:a 3-month longitudinal study

Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 infections.Previous studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019(COVID-19).However,neuroimaging studies on sleep disturbances caused by COVID-19 are scarce,and existing studies have primarily focused on the long-term effects of the virus,with minimal acute phase data.As a result,little is known about the pathophysiology of sleep disturbances in the acute phase of COVID-19.To address this issue,we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection,and verified the results using 3-month follow-up data.A total of 26 COVID-19 patients with sleep disturbances(aged 51.5±13.57 years,8 women and 18 men),27 COVID-19 patients without sleep disturbances(aged 47.33±15.98 years,9 women and 18 men),and 31 age-and gender-matched healthy controls(aged 49.19±17.51 years,9 women and 22 men)were included in this study.Eleven COVID-19 patients with sleep disturbances were included in a longitudinal analysis.We found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain lobes.The cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index scores.Additionally,we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy controls.The 3-month follow-up data revealed indices of altered cerebral structure(cortical thickness,cortical grey matter volume,and cortical surface area)in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep disturbances.Our findings indicate that the sleep disturbances patients had altered morphology in the cortical and hippocampal structures during the acute phase of infection and persistent changes in cortical regions at 3 months post-infection.These data improve our understanding of the pathophysiology of sleep disturbances caused by COVID-19.

Piezotronic neuromorphic devices:principle,manufacture,and applications

With the arrival of the era of artificial intelligence(AI)and big data,the explosive growth of data has raised higher demands on computer hardware and systems.Neuromorphic techniques inspired by biological nervous systems are expected to be one of the approaches to breaking the von Neumann bottleneck.Piezotronic neuromorphic devices modulate electrical transport characteristics by piezopotential and directly associate external mechanical motion with electrical output signals in an active manner,with the capability to sense/store/process information of external stimuli.In this review,we have presented the piezotronic neuromorphic devices(which are classified into strain-gated piezotronic transistors and piezoelectric nanogenerator-gated field effect transistors based on device structure)and discussed their operating mechanisms and related manufacture techniques.Secondly,we summarized the research progress of piezotronic neuromorphic devices in recent years and provided a detailed discussion on multifunctional applications,including bionic sensing,information storage,logic computing,and electrical/optical artificial synapses.Finally,in the context of future development,challenges,and perspectives,we have discussed how to modulate novel neuromorphic devices with piezotronic effects more effectively.It is believed that the piezotronic neuromorphic devices have great potential for the next generation of interactive sensation/memory/computation to facilitate the development of the Internet of Things,AI,biomedical engineering,etc.

Fiber-Shaped Triboiontronic Electrochemical Transistor

Contact electrification-activated triboelectric potential offers an efficient route to tuning the transport properties in semiconductor devices through electrolyte dielectrics,i.e.,triboiontronics.Organic electrochemical transistors(OECTs)make more effective use of ion injection in the electrolyte dielectrics by changing the doping state of the semiconductor channel.However,the mainstream flexible/wearable electronics and OECT-based devices are usually modulated by electrical signals and constructed in conventional geometry,which lack direct and efficient interaction between the external environment and functional electronic devices.Here,we demonstrate a fiber-shaped triboiontronic electrochemical transistor with good electrical performances,including a current on/off ratio as high as≈1286 with off-current at~nA level,the average threshold displacements(D_(th))of 0.3 mm,the subthreshold swing corresponding to displacement(SS_(D))at 1.6 mm/dec,and excellent flexibility and durability.The proposed triboiontronic electrochemical transistor has great potential to be used in flexible,functional,and smart self-powered electronic textile.

Ambipolar tribotronic transistor of MoTe_(2)

Two-dimensional(2D)tribotronic devices have been successfully involved in electromechanical modulation for channel conductance and applied in intelligent sensing system,touch screen,and logic gates.Ambipolar transistors and corresponding complementary inverters based on one type of semiconductors are highly promising due to the facile fabrication process and readily tunable polarity.Here,we demonstrate an ambipolar tribotronic transistor of molybdenum ditelluride(MoTe_(2)),which shows typical ambipolar transport properties modulated by triboelectric potential.It is comprised of a MoTe_(2)transistor and a lateral sliding triboelectric nanogenerator(TENG).The induced triboelectric potential by Maxwell’s displacement current(a driving force for TENG)can readily modulate the transport properties of both electrons and holes in MoTe_(2)channel and effectively drive the transistor.High performance tribotronic properties have been achieved,including low cutoff current below 1 pA·μm^(−1)and high current on/off ratio of~103 for holes and electrons dominated transports.The working mechanism on how to achieve tribotronic ambipolarity is discussed in detail.A complementary tribotronic inverter based on single flake of MoTe_(2)is also demonstrated with low power consumption and high stability.This work presents an active approach to efficiently modulate semiconductor devices and logic circuits based on 2D materials through external mechanical signal,which has great potential in human–machine interaction,intelligent sensor,and other wearable devices.