Changes in the amplitude of low-frequency fluctuations in specific frequency bands in major depressive disorder after electroconvulsive therapy

BACKGROUND Major depressive disorder(MDD)tends to have a high incidence and high suicide risk.Electroconvulsive therapy(ECT)is currently a relatively effective treatment for MDD.However,the mechanism of efficacy of ECT is still unclear.AIM To investigate the changes in the amplitude of low-frequency fluctuations in specific frequency bands in patients with MDD after ECT.METHODS Twenty-two MDD patients and fifteen healthy controls(HCs)were recruited to this study.MDD patients received 8 ECT sessions with bitemporal placement.Resting-state functional magnetic resonance imaging was adopted to examine regional cerebellar blood flow in both the MDD patients and HCs.The MDD patients were scanned twice(before the first ECT session and after the eighth ECT session)to acquire data.Then,the amplitude of low-frequency fluctuations(ALFF)was computed to characterize the intrinsic neural oscillations in different bands(typical frequency,slow-5,and slow-4 bands).RESULTS Compared to before ECT(pre-ECT),we found that MDD patients after the eighth ECT(post-ECT)session had a higher ALFF in the typical band in the right middle frontal gyrus,posterior cingulate,right supramarginal gyrus,left superior frontal gyrus,and left angular gyrus.There was a lower ALFF in the right superior temporal gyrus.Compared to pre-ECT values,the ALFF in the slow-5 band was significantly increased in the right limbic lobe,cerebellum posterior lobe,right middle orbitofrontal gyrus,and frontal lobe in post-ECT patients,whereas the ALFF in the slow-5 band in the left sublobar region,right angular gyrus,and right frontal lobe was lower.In contrast,significantly higher ALFF in the slow-4 band was observed in the frontal lobe,superior frontal gyrus,parietal lobe,right inferior parietal lobule,and left angular gyrus.CONCLUSION Our results suggest that the abnormal ALFF in pre-and post-ECT MDD patients may be associated with specific frequency bands.

Current progress in neuroimaging research for the treatment of major depression with electroconvulsive therapy

Electroconvulsive therapy(ECT)uses a certain amount of electric current to pass through the head of the patient,causing convulsions throughout the body,to relieve the symptoms of the disease and achieve the purpose of treatment.ECT can effectively improve the clinical symptoms of patients with major depression,but its therapeutic mechanism is still unclear.With the rapid development of neuroimaging technology,it is necessary to explore the neurobiological mechanism of major depression from the aspects of brain structure,brain function and brain metabolism,and to find that ECT can improve the brain function,metabolism and even brain structure of patients to a certain extent.Currently,an increasing number of neuroimaging studies adopt various neuroimaging techniques including functional magnetic resonance imaging(MRI),positron emission tomography,magnetic resonance spectroscopy,structural MRI,and diffusion tensor imaging to reveal the neural effects of ECT.This article reviews the recent progress in neuroimaging research on ECT for major depression.The results suggest that the neurobiological mechanism of ECT may be to modulate the functional activity and connectivity or neural structural plasticity in specific brain regions to the normal level,to achieve the therapeutic effect.

Generation of microwave photon perfect W states of three coupled superconducting resonators

We propose an efficient method for the generation of perfect W states on three microwave superconducting resonators,of which the two nearest neighbors are coupled by a symmetric direct current superconducting quantum interference device(dc-SQUID).With suitable external magnetic fluxes applied to the dc-SQUID symmetry loops,on-chip tunable interactions between neighboring resonators can be realized,and different perfect W states can be deterministically created on-demand in one step.Numerical simulations show that high-fidelity target states can be generated and our scheme is robust against imperfect parameter tuning and environment-induced decoherence.The present work may have potential applications for implementing quantum computation and quantum information processing based on microwave photons.

Global influenza surveillance with Laplacian multidimensional scaling

The Global Influenza Surveillance Network is crucial for monitoring epidemic risk in participating countries. However, at present, the network has notable gaps in the developing world, principally in Africa and Asia where laboratory capabilities are limited. Moreover, for the last few years, various influenza viruses have been continuously emerging in the resource-limited countries, making these surveillance gaps a more imminent challenge.We present a spatial-transmission model to estimate epidemic risks in the countries where only partial or even no surveillance data are available. Motivated by the observation that countries in the same influenza transmission zone divided by the World Health Organization had similar transmission patterns, we propose to estimate the influenza epidemic risk of an unmonitored country by incorporating the surveillance data reported by countries of the same transmission zone. Experiments show that the risk estimates are highly correlated with the actual influenza morbidity trends for African and Asian countries. The proposed method may provide the much-needed capability to detect, assess, and notify potential influenza epidemics to the developing world.

Synergistic enhancement of spin-phonon interaction in a hybrid system

An investigation to significantly enhance coupling to nitrogen-vacancy(NV)centers at a single-quanta level is of great interest to further explore its applications in quantum information processing(QIP).This study explores a joint scheme to further enhance NV-phonon coherent coupling with two methods working together in hybrid optomechanical systems.Both methods are mechanics-induced mode field coupling(MFC)that lead,respectively,to the modification of the spatial distribution of the optical field and the mechanical parametric amplification(MPA)realized by modulating the mechanical spring constant in time.With the joint assistance of MFC and MPA,the coherent coupling between the NV spin and one supermode of the mechanical resonators(MRs)can be further significantly enhanced with the rate∝n_(cav)e^(r).Several potential applications are also discussed in this work.With the ultimate goal to enhance the coupling to NV spin at a single-quanta level,this attempt may provide a promising spin-phonon platform to implement more active control.