Shared and distinct abnormalities of brain magnetization transfer ratio in schizophrenia and major depressive disorder:a comparative voxel-based meta-analysis

Background:Patients with schizophrenia(SCZ)and major depressive disorder(MDD)share significant clinical overlap,although it remains unknown to what extent this overlap reflects shared neural profiles.To identify the shared and specific abnormalities in SCZ and MDD,we performed a whole-brain voxel-based meta-analysis using magnetization transfer imaging,a technique that characterizes the macromolecular structural integrity of brain tissue in terms of the magnetization transfer ratio(MTR).Methods:A systematic search based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted in PubMed,EMBASE,International Scientific Index(ISI)Web of Science,and MEDLINE for relevant studies up to March 2022.Two researchers independently screened the articles.Rigorous scrutiny and data extraction were performed for the studies that met the inclusion criteria.Voxel-wise meta-analyses were conducted using anisotropic effect size-signed differential mapping with a unified template.Meta-regression was used to explore the potential effects of demographic and clinical characteristics.Results:A total of 15 studies with 17 datasets describing 365 SCZ patients,224 MDD patients,and 550 healthy controls(HCs)were identified.The conjunction analysis showed that both disorders shared higher MTR than HC in the left cerebellum(P=0.0006)and left fusiform gyrus(P=0.0004).Additionally,SCZ patients showed disorder-specific lower MTR in the anterior cingulate/paracingulate gyrus,right superior temporal gyrus,and right superior frontal gyrus,and higher MTR in the left thalamus,precuneus/cuneus,posterior cingulate gyrus,and paracentral lobule;and MDD patients showed higher MTR in the left middle occipital region.Meta-regression showed no statistical significance in either group.Conclusions:The results revealed a structural neural basis shared between SCZ and MDD patients,emphasizing the importance of shared neural substrates across psychopathology.Meanwhile,distinct disease-specific characteristics could have implications for future differential diagnosis and targeted treatment.

Brain development in children with developmental delay using amide proton transfer-weighted imaging and magnetization transfer imaging

Importance:The process of brain development in children with developmental delay is not well known.Amide proton transfer-weighted(APTw)imaging is a novel molecular magnetic resonance imaging(MRI)technique that can noninvasively detect cytosolic endogenous mobile proteins and peptides involved in the myelination process,and may be useful for providing insights into brain development.Objective:To assess the contribution of amide proton transfer-weighted(APTw)imaging and magnetization transfer(MT)imaging to the evaluation of children with developmental delay(DD).Methods:Fifty-one patients with DD were recruited to this study.The patients were divided into two groups according to the state of myelination assessed on conventional magnetic resonance imaging(MRI).Thirty patients(10 girls,20 boys;age range:1-8 months;median age:4 months)in group A showed delayed myelination on MRI,while 21 patients(3 girls,18 boys;age range:12-36months;median age:25months)in group B showed normal myelination on MRI.Fifty-one age-and sex-matched children with normal developmental quotient(DQ)and normal MRI appearance were recruited as normal controls.Three-slice APTw/MT axial imaging was performed at the level of the centrum semiovale,the basal ganglia and the pons.Quantitative data of the MT ratio(MTR)and APTw were analyzed for multiple brain regions.Independent-samplet-tests were used to compare differences in APTw and MTR signals between the two DD groups and normal controls.Analysis of Covariance was conducted to correct the statistical results.The level of statistical significance was set toP<0.05.Results:For group A,the MTR values were lower in all regions(P=0.004-0.033)compared with the normal controls,while the APTw values were higher in the pons,middle cerebellar peduncle,corpus callosum,frontal white matter,occipital white matter and centrum semiovale(P=0.004-0.040).For Group B,the MTR values were slightly reduced,and the APTw values were slightly increased compared with the normal controls,but the differences were not statistically significant(P>0.05).Interpretation:For DD patients showing signs of delayed myelination on MRI,MTR and APTw imaging can help to diagnose myelination delay by quantifying semi-solid macromolecules and cytosolic endogenous mobile proteins and peptides at a molecular level,providing a new method for comprehensive evaluation of DD.For DD patients with normal myelination on MRI,the clinical values of MTR and APTw imaging remain to be explored.

Numerical Analysis of Magnetic-Shielding Effectiveness for Magnetic Resonant Wireless Power Transfer System

Magnetic radiation phenomena appear inevitably in the magnetic-resonance wireless power transfer （MR-WPT） system, and regarding this problem the magnetic-shielding scheme is applied to improve the electromagnetic performance in engineering. In this study, the shielding effectiveness of a two-coil MR-WPT system for different material shields is analyzed in theory using Moser＇s formula and Schelkunoff＇s formula. On this basis a candidate magnetic-shielding scheme with a double-layer structure is determined, which has better shielding effectiveness and coils coupling coefficient. Finally, some finite element simulation results validate the correctness of the theoretical analysis, and the shielding effectiveness with the double-layer shield in maximum is 30？dB larger than the one with the single-layer case.

High-Performance Sodium Bose-Einstein Condensate Apparatus with a Hybrid Trap and Long-Distance Magnetic Transfer

We report on the production of large sodium Bose^Einstein condensates in a hybrid of magnetic quadrupole and optical dipole trap. With an optimized spin-flip Zeeman slower, 2 ~ 1010 sodium atoms are captured in the magneto-optical trap （MOT）. A long distance magnetic transfer setup moves the cold atom over 46cm from the MOT chamber to the UHV science chamber, which provides great optical access and long conservative trap lifetime. After evaporative cooling in the hybrid trap, we produce nearly pure condensates of 1 ~ 107 atoms with lifetime of 80 s in the optical dipole trap.

Perpendicular magnetic tunnel junction and its application in magnetic random access memory

Recent progresses in magnetic tunnel junctions with perpendicular magnetic anisotropy （PMA） are reviewed and summarized. At first, the concept and source of perpendicular magnetic anisotropy （PMA） are introduced. Next, a historical overview of PMA materials as magnetic electrodes, such as the RE-TM alloys TbFeCo and GdFeCo, novel tetragonal manganese alloys Mn-Ga, L10-ordered （Co, Fe）/Pt alloy, multilayer film [Co, Fe, CoFe/Pt, Pd, Ni, AU]N, and ultra-thin magnetic metal/oxidized barrier is offered. The other part of the article focuses on the optimization and fabrication of CoFeB/MgO/CoFeB p-MTJs, which is thought to have high potential to meet the main demands for non-volatile magnetic random access memory.

On the Line Formation in Stellar Magnetized Atmospheres

The line formation process in stellar magnetized atmospheres is studied by observing the wavelength- dependence of Stokes contribution functions. The influence of magnetic field on the escape line photon distribution and line absorption is obtained by comparing with the null magnetic field case. Two models airs adopted. One assumes limited distributions of both the line absorption and magnetic field where a hypothetical magneto-sensitive line is formed. The other is a model atmosphere of sunspot umbra in which MgI 5172.7 forms. It is found that the magnetic field influences the formation region of Stokes I at wavelengths sufficient close to the Zeeman splitting points ±△ H. The formation regions at wavelengths far away from the Zeeman splitting points generally show a non-magnetic behaviour. Further, if the line core is split by the Zeeman effect, the line formation core introduced in the previous paper disappears. On the other hand, Stokes Q, U, V at each wavelength within the line form in the same layers where both the line absorption and magnetic field are present in the models accepted for the lines used. When the line absorption and magnetic field ubiquitously exist, the formation regions of the T peaks or valleys of Stokes Q, U and those of σ of Stokes V generally cover the widest depth range. It is pointed out that such a study is instructive in the explanation of solar polarized filtergrams. It can tell us at each observation point where the received line photons of wavelengths within the bandpass come from and where their polarization states are formed or give us the distributions of these photons as well as their polarization intensities. Thus a three-dimensional image can be constructed for a morphologic study of the observed area from serial filtergrams.

Some issues in diagnostics of solar chromospheric magnetic fields with the Mg b_2 line

Up to now, exact measurements of chromospheric magnetic fields have not been as successful as those done in the photosphere. We are currently engaging in diagnostics of chromospheric magnetic fields with the Mg b2 line by employing the Multi-Channel Solar Telescope at Huairou Solar Observing Station. Therefore, how to improve accuracy in the measurement is the main issue of our present study. To this end, we first study linear calibration coefficients for longitudinal and transverse components of chromospheric fields, which vary with wavelength, in the case of a weak field assumption. Then the polarization crosstalk introduced by instruments is analyzed in detail with two numerical simulation methods. Comparisons of the po- larization signals between cases with and without correction are presented. The result indicates that polarization accuracy is greatly improved after crosstalk correction.

Probing Lanthanide Ions Binding on tRNA^(Phe) by ~1H NMR

The structure of phenylalanine transfer ribonucleic acid(tRNA Phe ) in solution was explored by 1 H NMR spectroscopy to evaluate the effect of lanthanide ion on the structural and conformational change. It was found that La 3+ ions possess specific effects on the imino proton region of the 1 H NMR spectra for yeast tRNA Phe . The dependence of the imino proton spectra of yeast tRNA Phe as a function of La 3+ concentration was examined, and the results suggest that the tertiary base pair G 15 ·C 48 , which is located in the terminal in the augmented dihydrouridine helix(D helix), was markedly affected by La 3+ (shifted to downfield by as much as 0 35). Base pair U 8·A 14 in yeast tRNA Phe , which are stacked on G 15 ·C 48 , was also affected by added La 3+ when 1～2 Mg 2+ were also present. Another imino proton that may be affected by La 3+ in yeast tRNA Phe is that of the tertiary base pair G 19 ·C 56 . The assignment of this resonance in yeast tRNA Phe is tentative since it is located in the region of highly overlapping resonances beween 12 6 and 12 2. This base pair helps to anchor the D loop to the TΨC loop. The binding of La 3+ caused conformational change of tRNA, which is responsible for shifts to upfield or downfield in 1 H NMR spectra.

Local heat transfer properties in co- and counter-current G-L-S magnetically stabilized fluidized beds

Heat transfer coefficients were measured by immersed probes in co- and counter-current G-L-S magnetically stabilized fluidized beds （MSFBs） using air, water and nickel-alloy particles as the gas, liquid and solid phases. Influences of major factors, including magnetic field intensity, superficial gas and liquid velocities, liquid viscosity and surface tension, on heat-transfer properties were studied experimentally, indicating that both co- and counter-current G-L-S MSFB can provide relatively uniform radial distribution of heat transfer coefficients under appropriate operation conditions, thus controlling operation temperature for highly exothermic multi-phase reaction systems. Two correlations were provided to estimate accurately heat transfer properties in both co- and counter-current G-L-S MSFB systems, with an average error of less than 10%.