Motor network reorganization in stroke patients with dyskinesias during a shoulder-touching task:A fNIRS study

Hemiplegia after stroke has become a major cause of the world's high disabilities,and it is vital to enhance our understanding of post-stroke neuroplasticity to develop e±cient rehabilitation programs.This study aimed to explore the brain activation and network reorganization of the motor cortex(MC)with functional near-infrared spectroscopy(fNIRS).The MC hemodynamic signals were gained from 22 stroke patients and 14 healthy subjects during a shoulder-touching task with the right hand.The MC activation pattern and network attributes analyzed with the graph theory were compared between the two groups.The results revealed that healthy controls presented dominant activation in the left MC while stroke patients exhibited dominant activation in the bilateral hemispheres MC.The MC networks for the two groups had small-world properties.Compared with healthy controls,patients had higher transitivity and lower global e±ciency(GE),mean connectivity,and long connections(LCs)in the left MC.In addition,both MC activation and network attributes were correlated with patient's upper limb motor function.The results showed the stronger compensation of the unaffected motor area,the better recovery of the upper limb motor function for patients.Moreover,the MC network possessed high clustering and relatively sparse inter-regional connections during recovery for patients.Our results promote the understanding of MC reorganization during recovery and indicate that MC activation and network could provide clinical assessment signi¯cance in stroke patients.Given the advantages of fNIRS,it shows great application potential in the assessment and rehabilitation of motor function after stroke.

Glucocorticoid reduces the efficacy of afatinib on the head and neck squamous cell carcinoma

Glucocorticoids(GC)are widely used to counter the adverse events during cancer therapy;nonetheless,previous studies pointed out that GC may reduce the efficacy of chemotherapy on cancer cells,especially in epidermal growth factor receptor(EGFR)-targeted therapy of head and neck squamous cell carcinoma(HNSCC)remaining to be elucidated.The primary aim of the present study was to probe into the GC-induced resistance of EGFR-targeted drug afatinib and the underlying mechanism.HNSCC cell lines(HSC-3,SCC-25,SCC-9,and H-400)and the human oral keratinocyte(HOK)cell lines were assessed for GC receptor(GR)expression.The promoting tumor growth effect of GC was evaluated by the CCK-8 assay and flow cytometry.Levels of signaling pathways participants GR,mTOR,and EGFR were determined by quantitative polymerase chain reaction and western blotting.GC increased the proliferation of HNSCC cells in a GR-dependent manner and promoted AKT/mTOR signaling.But GC failed in counteracting the inhibition of rapamycin in the mTOR signaling pathway.Besides,GC also induced resistance to EGFR-targeted drug afatinib through AKT/mTOR instead of the EGFR/ERK signaling pathway.Thus,GCs reduce the efficacy of afatinib on HNSCC,implicating a cautious use of glucocorticoids in clinical practice.

Ferroptosis molecular inducers:A future direction for malignant tumor chemotherapy

Iron-dependent ferroptosis is a form of cell death dependent on iron levels.Cells that undergo ferroptosis have glutathione(GSH)deficiency,reduced Glutathione peroxidase-4(GPX4)activity and intracellular lipid peroxidation,Mitochondria,lysosomes and many signal pathways are involved in the regulation of ferroptosis.More importantly,many tumor cells resistant to other cell death methods exhibit sensitivity to ferroptosis.Moreover,over recent years,a number of ferroptosis-induced drugs have been recommended for the treatment of malignant tumors.Therefore,the study of ferroptosis is of great significance for future cancer treatments.In this review,we discussed the metabolic process of ferroptosis,the role of different organelles,the typical signaling pathways involved in ferroptosis,as well as natural and synthetic compounds that can induce ferroptosis,aiming to point out new conceptual avenues for utilizing ferroptosis in future cancer treatments.

Anisotropic thermoelectric transport properties in polycrystalline SnSe_(2)

It is reported that SnSe_(2) consisting of the same elements as SnSe, is a new promising thermoelectric material with advantageous layered structure. In this work, the thermoelectric performance of polycrystalline SnSe_(2) is improved through introducing SnSe phase and electron doping(Cl doped in Se sites). The anisotropic transport properties of SnSe_(2) are investigated. A great reduction of the thermal conductivity is achieved in SnSe_(2) through introducing SnSe phase, which mainly results from the strong SnSe_(2)–SnSe inter-phase scattering. Then the carrier concentration is optimized via Cl doping, leading to a great enhancement of the electrical transport properties, thus an extraordinary power factor of ^5.12 μW·cm^(-1)·K^(-2) is achieved along the direction parallel to the spark plasma sintering(SPS) pressure direction( P). Through the comprehensive consideration on the anisotropic thermoelectric transport properties, an enhanced figure of merit ZT is attained and reaches to ^ 0.6 at 773 K in SnSe_(2)-2% SnSe after 5% Cl doping along the P direction, which is much higher than ^ 0.13 and ^ 0.09 obtained in SnSe_(2)-2% SnSe and pristine SnSe_(2) samples, respectively.

Correlation between knowledge of prevention COVID-19 and depression of residents in Henan province,China

Background:Coronavirus disease 2019(COVID-19) has shown explosive growth in cities in central China in recent days.Residents have the depression due to lack of corresponding prevention knowledge.Methods:A cross-sectional study was investigated 385 residents over 18 years of age.Structured questionnaire and DASS-21 scale used to explore the association between knowledge of prevention COVID-19 and depression among residents.Results:73 respondents (20.3%) suffered varying degrees of depression.The knowledge of the behavior of respondents most concerned (AOR 7.45,95%CI,1.87 ~ 29.77),the main symptoms of the COVID-19 (AOR 9.72,95%CI,1.19 ~ 79.12) and using special ambulances to transport patients or suspected patients (AOR 2.22,95%CI,1.07 ~ 4.62) was found to be significant related to depression.Conclusions:Although residents currently have a lower prevalence of depression,but there is a strong correlation between the knowledge and attitude of prevention COVID-19 and depression.Government agencies need to expand ways to spread the knowledge of prevention COVID-19.

FKF1b controls reproductive transition associated with adaptation to geographical distribution in maize

Maize(Zea mays subspecies mays)is an important commercial crop across the world,and its flowering time is closely related to grain yield,plant cycle and latitude adaptation.FKF1 is an essential clock-regulated blue-light receptor with distinct functions on flowering time in plants,and its function in maize remains unclear.In this study,we identified two FKF1 homologs in the maize genome,named ZmFKF1a and ZmFKF1b,and indicated that ZmFKF1a and ZmFKF1b independently regulate reproductive transition through interacting with ZmCONZ1 and ZmGI1 to increase the transcription levels of ZmCONZ1 and ZCN8.We demonstrated that ZmFKF1b underwent artificial selection during modern breeding in China probably due to its role in geographical adaptation.Furthermore,our data suggested that ZmFKF1bHap_C7 may be an elite allele,which increases the abundance of ZmCONZ1 mRNA more efficiently and adapt to a wider range of temperature zone than that of ZmFKF1bHap_Z58 to promote maize floral transition.It extends our understanding of the genetic diversity of maize flowering.This allele is expected to be introduced into tropical maize germplasm to enrich breeding resources and may improve the adaptability of maize at different climate zones,especially at temperate region.

Four-coordinate disilyl cobalt(Ⅱ)complexes with NHC ligation:Synthesis,characterization,and reactivity

Silyl cobalt species are putative intermediates in cobalt-catalyzed transformations of hydrosilanes.However,their reactivity has remained poorly understood.Reported here is the investigation on four-coordinate disilyl Co(Ⅱ)complexes with N-hetereocyclic carbene ligation.The reactions of[(ICy)_(2)Co(vtms)](ICy=1,3-dicyclohexylimidazol-2-ylidene,vtms=vinyltrimethylsilane)with primary and secondary hydrosilanes(3 equiv.)furnish the four-coordinate disilyl complexes[trans-(ICy)_(2)Co(SiHRR')_(2)](SiHRR'=SiH_(2)Mes,1;SiH_(2)Ph,2;SiH_(2)Cy,3;SiHPh_(2),4;SiHEt_(2),5)in moderate to good yields.The structures of 1,2 and 4 were established by single-crystal X-ray diffraction.Solution magnetic susceptibility measurement and EPR spectroscopy indicate their low-spin nature(S=1/2).Reactivity studies on 4 led to the establishment of the conversions of 4 to the disilyl dihydride Co(Ⅲ)complex[K(THF)][(ICy)_(2)Co(H)_(2)(SiHPh_(2))_(2)]_n(6)and the fluorosilyl Co(Ⅱ)complex[(ICy)_(2)Co(THF)(SiFPh_(2))][BF_(4)](7)when 4 was treated with excess amount of K and AgBF_(4),respectively,in THF.These conversions hint at the high activity of low-valent and high-valent disilyl cobalt species[trans-(ICy)_(2)Co(SiHPh_(2))_(2)]^(1-)and[trans-(ICy)_(2)Co(SiHPh_(2))_(2)]^(2+).Complex 4 is reactive toward terminal alkynes,but inert toward alkenes and internal alkynes.The reactions of 4 with terminal alkynes CyC≡CH and Me_(3)SiC≡CH(3 equiv.)yield the Co(Ⅱ)complexes[(ICy)_(2)Co(C≡CCy)_(2)](8)and[(ICy)_(2)Co(C≡CSiMe_(3))((SiMe_(3))C=CH_(2))](9),respectively,along with H_(2)SiPh_(2)and alkynylsilanes RC≡CSiHPh_(2)(R=Cy,SiMe_(3)),whereas the reaction with 4-CF_(3)C_(6)H_(4)C≡CH(3 equiv.)produce[(ICy)_(2)Co(C≡CAr)((Ar)C=CH(SiHPh_(2))C=CHAr)](Ar=4-CF_(3)C_(6)H_(4))(10)and H_(2)SiPh_(2).These reactions are proposed to involveσ-bond metathesis reactions between alkyne C(sp)-H bonds and Co-Si bonds in 4.Complexes 6–10 have been characterized by NMR spectroscopy,X-ray diffraction study,and elemental analysis.

Asymmetric frequency multiplexing topological devices based on a floating edge band

Topological photonics provides a platform for robust energy transport regardless of sharp corners and defects.Recently,the frequency multiplexing topological devices have attracted much attention due to the ability to separate optical signals by wavelength and hence the potential application in optical communication systems.Existing frequency multiplexing topological devices are generally based on the slow light effect.However,the resulting static local spatial mode or finely tuned flat band has zero-group velocity,making it difficult for both experimental excitation and channel out-coupling.Here,we propose and experimentally demonstrate an alternative prototype of asymmetric frequency multiplexing devices including a topological rainbow and frequency router based on floating topological edge mode(instead of localized ones);hence the multiple wavelength channels can be collectively excited with a point source and efficiently routed to separate output ports.The channel separation in our design is achieved by gradually tuning the band gap truncation on a topological edge band over a wide range of frequencies.A crucial feature lies in that the topological edge band is detached from bulk states and floating within the upper and lower photonic band gaps.More interestingly,due to the sandwiched morphology of the edge band,the top and bottom band gaps will each truncate into transport channels that support topological propagation towards opposite directions,and the asymmetrical transportation is realized for the frequency multiplexing topological devices.

Electromagnetic anisotropic homogeneous model for eddy-current field in single-phase wound core

The analysis of the eddy-current field in the wound core widely used in the field of transformer energy conservation is taken as the theme.Adopting the homogenisation idea to consider the unique geometry of the wound core and features of its equivalent multi-stage circular cross-section magnetic boundary,a homogeneous model consisting of a columnar material with continuous homogeneous electromagnetic anisotropy is established by deriving the Maxwell equations of the magnetic quasi-static field in the columnar coordinate system.Finally,a homogeneous fine element model for the eddycurrent field in the wound core is established and the accuracy of the model has been verified by the test platform.The result shows that the homogeneous model can be effectively used for the analysis of the eddy-current field in the wound core,and the error of calculating the eddy-current loss under different excitation conditions is less than 6%under the premise of extremely saving the engineering calculation cost,which will help improve the operational performance of the wound core and contribute to the energysaving goal of the high-voltage equipment.

Hydrogel electrodes with conductive and substrate-adhesive layers for noninvasive long-term EEG acquisition

Noninvasive brain–computer interfaces (BCIs) show great potential in applications including sleep monitoring, fatigue alerts, neurofeedback training, etc. While noninvasive BCIs do not impose any procedural risk to users (as opposed to invasive BCIs), the acquisition of high-quality electroencephalograms (EEGs) in the long term has been challenging due to the limitations of current electrodes. Herein, we developed a semidry double-layer hydrogel electrode that not only records EEG signals at a resolution comparable to that of wet electrodes but is also able to withstand up to 12 h of continuous EEG acquisition. The electrode comprises dual hydrogel layers: a conductive layer that features high conductivity, low skin-contact impedance, and high robustness;and an adhesive layer that can bond to glass or plastic substrates to reduce motion artifacts in wearing conditions. Water retention in the hydrogel is stable, and the measured skin-contact impedance of the hydrogel electrode is comparable to that of wet electrodes (conductive paste) and drastically lower than that of dry electrodes (metal pin). Cytotoxicity and skin irritation tests show that the hydrogel electrode has excellent biocompatibility. Finally, the developed hydrogel electrode was evaluated in both N170 and P300 event-related potential (ERP) tests on human volunteers. The hydrogel electrode captured the expected ERP waveforms in both the N170 and P300 tests, showing similarities in the waveforms generated by wet electrodes. In contrast, dry electrodes fail to detect the triggered potential due to low signal quality. In addition, our hydrogel electrode can acquire EEG for up to 12 h and is ready for recycled use (7-day tests). Altogether, the results suggest that our semidry double-layer hydrogel electrodes are able to detect ERPs in the long term in an easy-to-use fashion, potentially opening up numerous applications in real-life scenarios for noninvasive BCI.

Transient thermal network model for train-induced wind cooling dry-type on-board traction transformer in electric multiple units

Thermal characteristic is one of the key performances of dry-type on-board traction transformer(D-OBTT),which directly affects the operation safety of the new generation electric multiple units.However,due to the particularity of train-induced wind cooling mode of D-OBTT,the existing efficient thermal modelling methods cannot be used under fluctuating air velocity and load.A time-saving transient thermal model for D-OBTT is proposed.First,the framework of the transient thermal network model(TTNM)is proposed considering the coexistence of non-fully and fully developed state of the train-induced wind and the addition heat flow in the solid domain.Then,a novel formula for calculating the length of non-fully developed section considering the geometric dimensions and heat flux density is proposed based on computational fluid dynamics(CFD)parametric sweeps for the first time.The accuracy of TTNM is validated by a D-OBTT experimental setup,and the time consumption is significantly reduced compared with CFD.

Advances in Transition-Metal-Catalyzed Hydrogermylation of Alkenes and Alkynes

Hydrogermylation of alkenes and alkynes provides a straightforward synthetic route to organogermanium compounds that have been found applications in organic synthesis,medicinal chemistry,and material science.This paper reviews the advances in transition-metal-catalyzed hydrogermylation of unsaturated carbon-carbon bonds,including alkenes,alkynes,dienes,and allenes,with the objective of providing readers with the status of the field.Progress,problems,and perspectives in this field are discussed.

Experimental realization of chiral Landau levels in two-dimensional Dirac cone systems with inhomogeneous effective mass

Chiral zeroth Landau levels are topologically protected bulk states.In particle physics and condensed matter physics,the chiral zeroth Landau level plays a significant role in breaking chiral symmetry and gives rise to the chiral anomaly.Previous experimental works on such chiral Landau levels are mainly based on three-dimensional Weyl degeneracies coupled with axial magnetic fields.Their realizations using two-dimensional Dirac point systems,being more promising for future applications,were never experimentally realized before.Here we propose an experimental scheme for realizing chiral Landau levels in a two-dimensional photonic system.By introducing an inhomogeneous effective mass through breaking local parity-inversion symmetries,a synthetic in-plane magnetic field is generated and coupled with the Dirac quasi-particles.Consequently,the zeroth-order chiral Landau levels can be induced,and the one-way propagation characteristics are experimentally observed.In addition,the robust transport of the chiral zeroth mode against defects in the system is also experimentally tested.Our system provides a new pathway for the realization of chiral Landau levels in two-dimensional Dirac cone systems,and may potentially be applied in device designs utilizing the chiral response and transport robustness.

Degree of polymerisation estimation for insulation paper immersed in silicone oil using frequency domain dielectric spectroscopy

Frequency domain dielectric spectroscopy(FDS)is an effective method reflecting the changes of ageing status of silicone oil‐immersed insulation paper.For better evaluating the ageing status of silicone oil‐immersed insulation paper,an evaluation method was studied by analysing the ageing kinetic model and results of FDS.First,the method to separate the different polarization losses and conductivity loss from the results of FDS was studied.Then,based on the idea of ageing correction translation coefficient and timevarying pre exponential factor,the zero order ageing dynamic model was modified,which combines the ageing kinetic model with the results of FDS.Finally,the evaluation method for the degree of polymerisation(DP)of silicone oil‐immersed paper was proposed,and experiments were conducted to obtain the parameters in the modified model and then to verify the proposed method.The results show that the proposed method can be used to evaluate the DP effectively.

Surface-ligand protected reduction on plasmonic tuning of one-dimensional MoO_(3−x)nanobelts for solar steam generation

Sub-stoichiometric MoO_(3−x)nanostructures with plasmonic absorption via creating oxygen vacancies have attracted extensive attentions for many intriguing applications.However,the synthesis of one-dimensional(1D)plasmonic MoO_(3−x)nanostructures with widely tunable plasmonic absorption has remained a significant challenge because of their serious morphological destruction and phase change with increasing the concentration of oxygen vacancies.Here we demonstrate a surface-ligand protected reduction strategy for the synthesis of 1D MoO_(3−x)nanobelts with tunable plasmonic absorption in a wide wavelength range from 200 to 2,500 nm.Polyethylene glycol(PEG-400)is used as both the reductant to produce oxygen vacancies and the surface protected ligands to maintain 1D morphology during the formation process of MoO_(3−x)nanobelts,enabling the widely tunable plasmonic absorption.Owing to their broad plasmonic absorption and unique 1D nanostructure,we further demonstrate the application of 1D MoO_(3−x)nanobelts as photothermal film for interfacial solar evaporator.The surface-ligand protected reduction strategy provides a new avenue for the developing plasmonic semiconductor oxides with maintained particle morphology and thus enriching their wide applications.

具有超低热导率的一维铋硒卤族化合物

本征低热导率材料的研究具有重要的科学意义,已引起广泛关注.本工作报道了一类具有简单一维晶体结构的超低热导率材料:铋硒卤族化合物(BiSeX,X=Br,I).研究发现,BiSeI的热导率在573K仅为~0.27Wm^-1K^-1,达到了最低本征热导率的理论极限值.本研究采用第一性原理计算结合粉末中子衍射和变温球差扫描透射电子显微镜表征,深入探究了其超低热导率的机制.研究表明,BiSeX的一维结构赋予了材料低热导特性:弱的成键特性、低的声子速度、声学支和光学支的强非简谐性以及Bi和卤族元素较大的偏移效应,从而有效阻碍了声子输运,使得BiSeX具有超低的热导率.本研究提出了在具有一维结构的材料中寻找低传导特性的新思路,该研究思路在热电材料和热障涂层材料等低热传导需求领域中具有广阔的应用前景.

在低载流子浓度的n型层状SnS晶体中实现高的面内热电性能

硫化锡(SnS)作为一种简单的二元化合物,具有优异的电子和声子输运特性,加上其成本低、地球储量丰富、环境友好等优点,在热电材料领域显示出巨大的竞争力.为了促进低成本热电器件的发展和应用,我们采用溴(Br)掺杂生长SnS晶体实现其从本征p型向n型的转变.此外,得益于低的载流子浓度,我们报道了n型SnS优异的面内载流子迁移率和较大的塞贝克系数,从而导致一个高的功率因子PF~28μW cm^(-1)K^(-2).弹性性能计算表明, SnS中的低晶格热导率与其强非简谐性密切相关.结合其优良的热电输运性能,在室温下ZT值达到了~0.4, 823 K时其理论热电转化效率达到~5%.

Realizing ranged performance in SnTe through integrating bands convergence and DOS distortion

As a typical IV-VI compound,SnTe has aroused widely attentions in the thermoelectric community due its similar crystal and band structures with PbTe.However,both the large number of inherent Sn vacancies and high thermal conductivity result in inferior thermoelectric performance in intrinsic SnTe over a broad temperature.In this work,we successfully improved those disadvantages of SnTe via stepwisely Pb heavily alloying and then In doping.A significantly wide fraction of Pb into SnTe(0-50%)achieves multiple effects:(a)the carrier concentration of SnTe is reduced through decreasing Sn vacancies via alloying high solution Pb atoms in the matrix;(b)the band structure is optimized through promoting the convergence of the two valence bands,simultaneously enhancing the Seebeck coefficient;(c)HAADF-STEM coupled with EDS results illustrate that guest Pb atoms randomly and uniformly occupied Sn atomic sites in the matrix,concurrently strengthening the phonon scattering.Furthermore,we introduced indium into Sn_(0.6)Pb_(0.4)Te system to create resonant states further enlarging the power factors at low-medium temperature.The integration of bands convergence and DOS distortion achieves a considerably high ZT_(ave) of~0.67 over the wide temperature range of 300-823 K in(Sn_(0.6)Pb_(0.4))_(0.995)In_(0.005)Te sample.

Experimental study on ageing characteristics of electric locomotive ethylene propylene rubber cable under mechanical-thermal combined action

The train-mounted ethylene propylene rubber(EPR)cables of electric locomotive are partly restricted by the body structure and spatial layout and are in a combined envi-ronment of strong mechanical bending and thermal ageing.The degradation character-istics of the insulation layer have not yet received sufficient attention.In order to study the ageing characteristics of EPR cables of electric locomotive under the combined action of machine and thermal,this paper designs a bending-thermal combined ageing test platform for cables with a temperature of 135°C,bending diameter of 393.52 mm,590.28 mm and unbending cables,and tests after ageing.The product has been tested by infrared spectroscopy,scanning electron microscopy,elongation at break and broadband dielectric spectroscopy.The research results show that the bending outer part of the train-mounted EPR cable is a pain point.Under the combined action of bending and thermal,whether it is microstructure or macro performance,the degradation rate and degree of the bending of outer insulation layer are greater than the value under a single thermal ageing condition.Mechanical bending has an accelerating effect on the ageing of the EPR insulation layer.The research results can provide a reference for the ageing characteristics of the train-mounted EPR cable under the bending-thermal synergy and the evaluation of operating state of the train-mounted EPR cable under bending-thermal operating conditions.

Enhancing the thermoelectric performance of Bi2S3: A promising earth-abundant thermoelectric material

Recently, bismuth sulfide (Bi2S3) has attracted much attention in the thermoelectric community owing to its abundance, low cost, and advanced properties. However, its poor electrical transport properties have prevented Bi2S3 devices from realizing high thermoelectric performance. In this work, our motivation is to decrease the large electrical resistivity, which is recognized as the origin of the low ZT value in undoped Bi2S3. We combined melting and spark plasma sintering (SPS) in a continuous fabrication process to produce Bi2S3–xSex (x = 0, 0.09, 0.15, 0.21) and Bi2S2.85–ySe0.15Cly (y = 0.0015, 0.0045, 0.0075, 0.015, 0.03) samples. Our results show that Se alloying at S sites can narrow the band gap and activate intrinsic electron conduction, leading to a high power factor of ~2.0 μW·cm–1·K–2 at room temperature in Bi2S2.85S0.15, about 100 times higher than that of undoped Bi2S3. Moreover, our further introduction of Cl atoms into the S sites resulted in a second-stage optimization of carrier concentration and simultaneously reduced the lattice thermal conductivity, which contributed to a high ZT value of ~0.6 at 723 K for Bi2S2.835Se0.15Cl0.015. Our results indicate that high thermoelectric performance could be realized in Bi2S3 with earth-abundant and low-cost elements.