Retaining the self-released chalcogenate at reconstructed cobalt sites by self-transformed carbonate regulation for boosted oxygen evolution

The in-situ generated oxyanions at electrochemically reconstructed catalysts from metal-based nonoxide compounds have been proven to significantly accelerate oxygen evolution reaction(OER)kinetics.However,it remains a challenge to retain these self-released oxyanions at reconstructed catalysts,hindering its utilization as a tool to develop efficient OER catalysts.Here,we demonstrate a versatile selftransformed carbonate regulation strategy to efficiently retain the self-released chalcogenate at Co oxyhydroxides reconstructed from carbon-incorporated Co selenides under OER conditions.These selftransformed CO_(3)^(2-)can induce electron accumulation and narrow d bond at Co sites to facilitate the Co3d-O 2p orbital hybridization between Co sites and SeO_(x)^(2-)for enhanced SeO_(x)^(2-)retention,which can accelerate the rate-limiting step for^(*)OOH formation during OER.Relative to CoOOH-SeO_(x)^(2-)with limited SeO_(x)^(2-)residues,CoOOH-CO_(3)^(2-)/SeO_(x)^(2-)with elevated SeO_(x)^(2-)retention by CO_(3)^(2-)regulation exhibited a 5.6-fold increase in current density and a remarkable lower Tafel slope towards OER.This strategy paves a rational avenue to design efficient catalysts for electrooxidation reactions through finely regulating self-released oxyanions at reconstructed structures.

Electrical stimulation of the vagus nerve protects against cerebral ischemic injury through an anti-inflammatory mechanism

Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlusion method, and the right vagus nerve was given electrical stimula-tion （constant current of 0.5 mA; pulse width, 0.5 ms; frequency, 20 Hz; duration, 30 seconds; every 5 minutes for a total of 60 minutes） 30 minutes, 12 hours, and 1, 2, 3, 7 and 14 days after surgery. Electrical stimulation of the vagus nerve substantially reduced infarct volume, improved neurological function, and decreased the expression levels of tumor necrosis factor-α and in-terleukin-6 in rats with focal cerebral ischemia. The experimental findings indicate that the neuroprotective effect of vagus nerve stimulation following cerebral ischemia may be associated with the inhibition of tumor necrosis factor-α and interleukin-6 expression.

NiCo-LDH/Ti3C2 MXene hybrid materials for lithium ion battery with high-rate capability and long cycle life

Nickel/cobalt-layered double hydroxides(Ni Co-LDH) have been attracted increasing interest in the applications of anode materials for lithium ion battery(LIB), but the low cycle stability and rate performance are still limited its practice applications. To achieve high performance LIB, the surface-confined strategy has been applied to design and fabricate a new anode material of NiCo-LDH nanosheet anchored on the surface of Ti3C2 MXene(Ni Co-LDH/Ti3C2). The ultra-thin, bended and wrinkled α-phase crystal with an interlayer spacing of 8.1 ? can arrange on the conductive substrates Ti3C2 MXene directly, resulting in high electrolyte diffusion ability and low internal resistance. Furthermore, chemical bond interactions between the highly conductive Ti3C2 MXene and Ni Co-LDH nanosheets can greatly increase the ion and electron transport and reduce the volume expansion of NiCo-LDH during Li ion intercalation. As expected,the discharge capacity of 562 m Ah g-1 at 5.0 A g-1 for 800 cycles without degradation can be achieved,rate capability and cycle performance are better than that of NiCo-LDH(~100 mAh g-1). Furthermore, the density function theory(DFT) calculations were performed to demonstrate that Ni Co-LDH/Ti3C2 system can be used as a highly desirable and promising anode material for lithium ion battery.

TMN4 complex embedded graphene as bifunctional electrocatalysts for high efficiency OER/ORR

Developing highly active bifunctional electrocatalysts for oxygen evolution reaction(OER)and oxygen reduction reaction(ORR)is of great significance in energy conversion and storage technologies.In this study,we systematically investigated the OER/ORR electrocatalytic activity of TMN_(4)@G system by using density functional theory(DFT)calculations.Globally,IrN_(4)@G is a very promising bifunctional catalyst for both OER and ORR with the extremely low overpotentials of 0.30 and 0.26 V,respectively.Such outstanding electrocatalytic performance is mainly attributed to the synergistic effect of Ir and N.More importantly,by constructing 2D activity volcano plots,we obtained the limiting overpotentials of TMN_(4)@G system with the values of 0.26 V for OER and 0.24 V for ORR.These findings open up new opportunities for further exploring graphene-based materials for highly efficient OER/ORR electrocatalysts.

Xiaoyaosan improves depressive-like behaviors by regulating the NLRP3 signaling pathway in the rat cerebral cortex

Objective:To observe changes in the molecular expression of the NLR Family Pyrin Domain Containing Protein 3(NLRP3)pathway in depressed rats after treatment with Xiaoyaosan,and identify the regulatory mechanism of this compound.Methods:Male SpragueeD awley rats were randomly divided into five groups with 12 rats in each group,including the control group,model group,Fluoxetine group,Xiaoyaosan group,and MCC950 group.A depression model was generated by chronic immobilization stress(induced by 3 h of restraint immobilization every day),and the drugs were administered at the same time in each group for 21 days.The effects of Xiaoyaosan on behavioral changes of depressed rats were observed through macroscopic characterization,body mass,open field experiments,and a sucrose preference test.The m RNA and protein expression of the NLRP3 signaling pathway was examined by fluorescence real-time quantitative PCR and Western blot assays.Results:The Xiaoyaosan group,Fluoxetine group,and MCC950 group rats showed improved depressive behavior and an increased weight of sucrose water consumption.The protein and mRNA expression levels of NLRP3,Caspase-1,and IL-1 b were also decreased in the Fluoxetine,Xiaoyaosan,and MCC950 groups.Conclusion:NLRP3,Caspase-1,and IL-1 b protein and mRNA expression levels were increased in the cortex of depressed rats,while Xiaoyaosan protected cortical tissue in these rats by decreasing NLRP3,Caspase-1,and IL-1 b protein and mRNA expression.

Anchoring Mo on C_(9)N_(4) monolayers as an efficient single atom catalyst for nitrogen fixation

Electrochemical nitrogen fixation via a convenient and sustainable manner,exhibits an intriguing prospect for ammonia generation under ambient conditions.Currently,the design and development of high-efficiency and low-cost electrocatalysts remains the major challenge confronting nitrogen reduction reaction(NRR).Herein,anchoring the single Mo atom on the C_(9)N_(4) substrate(Mo@C_(9)N_(4)) to form an efficient single-atom catalyst(SAC) is proposed for the conversion of N2 to NH3.By employing density functional theory(DFT) calculations,we demonstrated that gas phase N2 can be sufficiently activated and efficiently reduced to NH3 on the surface of Mo@C_(9)N_(4).Meanwhile,we found that the NRR dominantly occurred on the Mo center via a preferred distal pathway with favorable limiting potential of 0.40 V.Importantly,the as-established Mo@C_(9)N_(4) catalyst exhibits an outstanding structural stability and good selectivity toward NRR.These findings provide a promising platform for designing Mo-based SACs for electrochemical N2 fixation.

Differentially Expressed Proteins in Rat Hippocampus after Chronic Immobilization Stress and Intervention Using Xiao Yao San Decoction

Objective To identify differentially expressed proteins in the hippocampus of rats after chronic immobilization stress(CIS)using a proteomics approach,and to study the effect of the Xiao Yao San(XYS)decoction on differentially expressed proteins.Methods Twenty-four Sprague Dawley rats were randomly assigned to one of four groups of equal body weight:control(non-stress),7-day stress,21-day stress and21-day stress+XYS treatment groups.Two-dimensional gel electrophoresis(2-DE)was used to detect differences in protein expression in rat hippocampus.One differentially expressed protein was measured and verified by western blotting.Results Seventeen proteins showed differential expression.Among these,eight could be identified:glial fibrillary acidic protein-2(GFAP-2),tubulin alpha-1c,cytoplasmic muscle actin2,14-3-3protein,β-2a tubulin,phosphatidylethanolamine binding protein,synucleinαsyn3,and a low molecular weight(18kD)protein.Six of these proteins exhibited increased expression,one showed decreased expression,and the other protein,which comprised five subtypes,were either increased or decreased.These proteins are known to be involved in immunity,signal transduction,cell cycle control,apoptosis,regulation of enzyme activity,cytoskeleton structure,and synaptic plasticity.GFAP-2was further analyzed,and its differential expression confirmed by western blotting.Conclusion Some proteins are differentially expressed in the hippocampus of rats under chronic stress.The biological functions of these differentially expressed proteins are varied.Finally,the XYS decoction can significantly up-or down-regulate these protein expression levels.

Biodegradable Zn-0.5Li alloy rib plate:Processing procedure development and in vitro performance evaluation

Trauma kills more than four million people worldwide each year,with chest trauma accounting for 25%of these deaths.Rib fractures are the main manifestation of chest trauma.Biodegradable Zn alloys offer a new option to overcome clinical problems caused by permanent rib fracture internal fixation mate-rials,e.g.,long-term stress masking and secondary surgery.In this study,the fabrication procedure of biodegradable Zn-0.5Li alloy rib plates is successfully developed,which consists of casting,hot-warm rolling,cutting,and pressing sequentially.Biomechanical three-point bending performance of the Zn al-loy rib plates is comparable to that of commercial pure Ti rib plates,much higher than that of pure Zn rib plates.In addition,the Zn alloy exhibits the best antibacterial ability against E.coli and S.aureus among the three materials.Although the Zn alloy exhibits a weaker MC3T3 cytocompatibility than pure Ti,it is better than pure Zn.This study provides a foundation for the future development of various biodegrad-able Zn alloy rib plates.

300 MPa grade highly ductile biodegradable Zn-2Cu-(0.2-0.8)Li alloys with novel ternary phases

Although a few high-strength biodegradable Zn alloys with yield strengths(YSs)over 300 MPa in rolled state have been developed,their elongations(ELs)are generally less than 30%.This study developed rolled Zn-2Cu-x Li(x=0.2 wt.%,0.5 wt.%,0.8 wt.%)alloys with YSs of 316-335 MPa and ELs of 44%-61%.Three-dimensional atom probe(3DAP)and time of flight secondary ion mass spectrometry(TOF-SIMS)were employed to characterize Li distribution.Three kinds of Zn-Cu-Li ternary phases are identified,which are blockyε′-(Cu_(0.5),Li_(0.5))Zn 4,blockyβ′-(Li_(0.9),Cu_(0.1))Zn 4,and small roundγparticles with high Li content in the annealed state.Other identified phases are Zn,β-LiZn 4,andε-CuZn 4 phases.With the increase of Li content in the alloys,ε′phase with 6.50 at.%Cu transforms intoβ′phase with 2.12 at.%Cu,i.e.,the average level in the alloys.Withinε′phase,there exist nano-scale Li clusters andεphase,resulting inε′/εstructure.Dense Zn laths precipitate fromβ′phase,resulting inβ′/Zn lamellar structure.The lamel-lar structure is the matrix of Zn-2Cu-0.8Li and leads to near-isotropic plasticity.Electrochemistry tests show that degradation rates fall in the range of 153-196μm/year,which decrease with Li content.All the alloys exert positive effects on the growth of MC3T3-E1 cells with 10%extract.This research reveals how microstructure evolves in Zn-2Cu-x Li alloys,which lays the foundation for their future applications.

Few-shot node classification via local adaptive discriminant structure learning

Node classification has a wide range of application scenarios such as citation analysis and social network analysis.In many real-world attributed networks,a large portion of classes only contain limited labeled nodes.Most of the existing node classification methods cannot be used for few-shot node classification.To train the model effectively and improve the robustness and reliability of the model with scarce labeled samples,in this paper,we propose a local adaptive discriminant structure learning(LADSL)method for few-shot node classification.LADSL aims to properly represent the nodes in the attributed graphs and learn a metric space with a strong discriminating power by reducing the intra-class variations and enlargingginter-classdifferences.Extensiveexperiments conducted on various attributed networks datasets demonstrate that LADSL is superior to the other methods on few-shot node classification task.

Controlling the strength of Zr(10 1 2) grain boundary by nonmetallic impurities doping: A DFT study

Impurity segregation even small amounts,can drastically change the cohesive properties of the grain boundaries(GB),eventually leading to intergranular embrittlement and failure of the materials,thereby effectively controlling the types and the concentrations of the impurity is very important.In this work,the nonmetallic impurities(C,H,O,N) segregation and their effects on the strength of Zr(10 1 2) GB were thoroughly investigated using first-principles calculations based on density functional theory.A comprehensive analysis of the interstitial configurations and the relative site energies indicating that C,N and O overwhelmingly prefer the octahedral sites,only H,prefers to reside in the tetrahedral sites.Moreover,the strengthening/embrittlement potency of impurity atoms on the GB was estimated using both the Rice-Wang model and first-principles tensile test calculations.The results show that all impurities,exhibit a strong segregation tendency near the GB region.The segregation of C,N and O has a remarkable strengthening effect on strength of the GB,whereas the presence of impurity H weaken the GB.Most importantly,the underlying mechanism of the strength change of the GBs due to the segregation of impurities was profoundly discussed by charge density and the bond lengths analyses,revealing that the strengthening effect especially for C-doped GB,mainly comes from an enhancement of the charge density across the GB plane.In the end,we expect that our results will be certainly useful for future theoretical and experimental investigations on Zr and its alloys.