Delayed improvements in visual memory task performance among chronic schizophrenia patients after high-frequency repetitive transcranial magnetic stimulation

BACKGROUND Cognitive impairments are core characteristics of schizophrenia,but are largely resistant to current treatments.Several recent studies have shown that highfrequency repetitive transcranial magnetic stimulation(rTMS)of the left dorsolateral prefrontal cortex(DLPFC)can reduce negative symptoms and improve certain cognitive deficits in schizophrenia patients.However,results are inconsistent across studies.AIM To examine if high-frequency rTMS of the DLPFC can improve visual memory deficits in patients with schizophrenia.METHODS Forty-seven chronic schizophrenia patients with severe negative symptoms on stable treatment regimens were randomly assigned to receive active rTMS to the DLPFC(n=25)or sham stimulation(n=22)on weekdays for four consecutive weeks.Patients performed the pattern recognition memory(PRM)task from the Cambridge Neuropsychological Test Automated Battery at baseline,at the end of rTMS treatment(week 4),and 4 wk after rTMS treatment(week 8).Clinical symptoms were also measured at these same time points using the Scale for the Assessment of Negative Symptoms(SANS)and the Positive and Negative Syndrome Scale(PANSS).RESULTS There were no significant differences in PRM performance metrics,SANS total score,SANS subscores,PANSS total score,and PANSS subscores between active and sham rTMS groups at the end of the 4-wk treatment period,but PRM performance metrics(percent correct and number correct)and changes in these metrics from baseline were significantly greater in the active rTMS group at week 8 compared to the sham group(all P<0.05).Active rTMS treatment also significantly reduced SANS score at week 8 compared to sham treatment.Moreover,the improvement in visual memory was correlated with the reduction in negative symptoms at week 8.In contrast,there were no between-group differences in PANSS total score and subscale scores at either week 4 or week 8(all P>0.05).CONCLUSION High-frequency transcranial magnetic stimulation improves visual memory and reduces negative symptoms in schizophrenia,but these effects are delayed,potentially due to the requirement for extensive neuroplastic changes within DLPFC networks.

Antiferromagnetic insulating state in quasi-one-dimensional K_(2)Cr_(3)As_(3)H

Quasi-one-dimensional(Q1D) Cr-based pnictide K_(2)Cr_(3)As_(3)exhibits superconductivity probably with spin-triplet pairing. It is of fundamental importance to explore the parent compound from which superconductivity emerges. Here we report the synthesis,crystal structure, physical properties, and density functional theory(DFT) calculations of(nearly) fully hydrogenized K_(2)Cr_(3)As_(3)H.It is found that the intercalation of hydrogen in K_(2)Cr_(3)As_(3)leads to absence of metallicity as well as superconductivity. An antiferromagnetic transition nearby room temperature is evidenced from the measurements of magnetic susceptibility and heat capacity.The antiferromagnetic insulating state can be reproduced by the DFT calculations, which show a novel non-collinear co-planar magnetic order. Our result sheds light on the mechanism of unconventional superconductivity in Q1D Cr-based superconductors.

Superconductivity in kagome metal ThRu_(3)Si_(2)

We report the physical properties of ThRu_(3)Si_(2)featured with distorted Ru kagome lattice.The combined experiments of resistivity,magnetization and specific heat reveal bulk superconductivity with T_(c)=3.8 K.The specific heat jump and calculated electron–phonon coupling indicate a moderate coupled BCS superconductor.In comparison with LaRu_(3)Si_(2),the calculated electronic structure in ThRu_(3)Si_(2)shows an electron-doping effect with electron filling lifted from 100 meV below flat bands to 300 meV above it.This explains the lower superconducting transition temperature and weaker electron correlations observed in ThRu_(3)Si_(2).Our work suggests the Tc and electronic correlations in the kagome superconductor could have an intimate connection with the flat bands.

BaTh2Fe4As4(N0.7O0.3)2:块层间电荷转移稳定化铁基超导体（英文）

本文基于结构设计、采用高温固相反应,首次合成了电子掺杂"12442"型超导体BaTh2(N0.7O0.3)2.研究发现,"BaFe2As2"和"ThFeAsN0.7O0.3"块层间的电荷转移是稳定该目标化合物的必要条件.霍尔测量证实该化合物主要为电子型导电.电阻、直流磁化率和比热测量的综合结果表明,样品在22 K呈现体超导电性.

Synthesis,Structure and Properties of Layered Phosphide Nitrides AkTh_(2)Mn_(4)P_(4)N_(2)(Ak=Rb,Cs)

Main observation and conclusion We report the design,synthesis,structure,and properties of two complex layered phosphide nitrides,AkTh_(2)Mn_(4)P_(4)N_(2)(Ak=Rb,Cs),which contain anti-fluorite-type[Mn_(2)P_(2)]bilayers separated by fluorite-type[Th_(2)N_(2)]layers as a result of the intergrowth between AkMn2P2 and ThMnPN.The new compounds are featured with an intrinsic hole doping associated with the interlayer charge transfer and a built-in chemical pressure from the[Th_(2)N_(2)]layers,both of which are reflected by the changes in the lattice and the atomic position of phosphorus.The measurements of magnetic susceptibility,electrical resistivity,and specific heat indicate existence of local moments as well as itinerant electrons in relation with d-p hybridizations.The expected dominant antiferromagnetic interactions with enhanced d-p hybridizations were demonstrated by the first-principles calculations only when additional Coulomb repulsions are included.The density of states at the Fermi level derived from the specific-heat analysis are 3.5 and 7.5 times of the calculated ones for Ak=Rb and Cs,respectively,suggesting strong electron correlations in the title compounds.