具备限流能力的混合式高压直流断路器拓扑

直流断路器(DCCB)是解决直流系统短路故障的重要手段,针对现有DCCB存在的限流效果差、避雷器使用寿命短和故障隔离速度慢等一系列缺陷,文中提出一种具备限流能力的混合式高压直流断路器拓扑(CLC-HDCCB)方案。CLC-HDCCB载流支路和转移支路采用双桥式结构,具备双向通断能力;限流部分采用限流电阻和限流电感并联限流方式,显著降低了故障电流峰值及上升率;设计泄能电阻在断路过程中将限流电感旁路,减少了避雷器单次开断吸收的能量;对所提CLC-HDCCB方案分断故障电流、正常合闸和分断小电流等直流系统出现的各种工况进行了详细分析,并给出参数选定的方法。最后在PSCAD/EMTDC平台进行仿真验证,结果表明所提CLC-HDCCB方案与现有DCCB方案相比在故障限流、避雷器吸能和故障清除时间等方面具有一定的优势。

静电纺海藻酸钠复合纳米纤维膜制备及其性能

针对现有创伤敷料在促伤口愈合及防粘连方面存在的不足,采用静电纺丝技术,以去离子水为溶剂,选用生物相容性材料海藻酸钠进行制备,通过分析溶液电导率、纤维形态及直径分布,优化溶液配比,成功制得具有良好生物相容性、可降解性和高比表面积的海藻酸钠/聚环氧乙烷/聚乙烯吡咯烷酮复合纳米纤维膜。结果显示:当海藻酸钠与聚环氧乙烷质量比为1∶4,海藻酸钠/聚环氧乙烷总质量分数为4%,聚乙烯吡咯烷酮占溶质总质量的10%时,所得复合纳米纤维膜形貌均匀,纤维直径约为240 nm;经氯化钙质量分数为3.0%的无水乙醇溶液交联处理24 h后,复合纳米纤维膜的吸液倍率达到1050.80%,质量损失率为40.63%,显著提升了其耐水性和结构稳定性,展现了在创伤修复领域的应用潜力。

Mitochondrial transplantation confers protection against the effects of ischemic stroke by repressing microglial pyroptosis and promoting neurogenesis

Transferring healthy and functional mitochondria to the lateral ventricles confers neuroprotection in a rat model of ischemia-reperfusion injury.Autologous mitochondrial transplantation is also beneficial in pediatric patients with cardiac ischemia-reperfusion injury.Thus,transplantation of functional exogenous mitochondria may be a promising therapeutic approach for ischemic disease.To explore the neuroprotective effect of mitochondria transplantation and determine the underlying mechanism in ischemic stroke,in this study we established a photo-thrombosis-induced mouse model of focal ischemia and administered freshly isolated mitochondria via the tail vein or to the injury site(in situ).Animal behavior tests,immunofluorescence staining,2,3,5-triphenyltetrazolium chloride(TTC)staining,mRNA-seq,and western blotting were used to assess mouse anxiety and memory,cortical infarct area,pyroptosis,and neurogenesis,respectively.Using bioinformatics analysis,western blotting,co-immunoprecipitation,and mass spectroscopy,we identified S100 calcium binding protein A9(S100A9)as a potential regulator of mitochondrial function and determined its possible interacting proteins.Interactions between exogenous and endogenous mitochondria,as well as the effect of exogenous mitochondria on recipient microglia,were assessed in vitro.Our data showed that:(1)mitochondrial transplantation markedly reduced mortality and improved emotional and cognitive function,as well as reducing infarct area,inhibiting pyroptosis,and promoting cortical neurogenesis;(2)microglial expression of S100A9 was markedly increased by ischemic injury and regulated mitochondrial function;(3)in vitro,exogenous mitochondria enhanced mitochondrial function,reduced redox stress,and regulated microglial polarization and pyroptosis by fusing with endogenous mitochondria;and(4)S100A9 promoted internalization of exogenous mitochondria by the microglia,thereby amplifying their pro-proliferation and anti-inflammatory effects.Taken together,our findings show that mitochondrial transplantation protects against the deleterious effects of ischemic stroke by suppressing pyroptosis and promoting neurogenesis,and that S100A9 plays a vital role in promoting internalization of exogenous mitochondria.

Improvement of High-Speed Detection Algorithm for Nonwoven Material Defects Based on Machine Vision

Defect detection is vital in the nonwoven material industry,ensuring surface quality before producing finished products.Recently,deep learning and computer vision advancements have revolutionized defect detection,making it a widely adopted approach in various industrial fields.This paper mainly studied the defect detection method for nonwoven materials based on the improved Nano Det-Plus model.Using the constructed samples of defects in nonwoven materials as the research objects,transfer learning experiments were conducted based on the Nano DetPlus object detection framework.Within this framework,the Backbone,path aggregation feature pyramid network(PAFPN)and Head network models were compared and trained through a process of freezing,with the ultimate aim of bolstering the model's feature extraction abilities and elevating detection accuracy.The half-precision quantization method was used to optimize the model after transfer learning experiments,reducing model weights and computational complexity to improve the detection speed.Performance comparisons were conducted between the improved model and the original Nano Det-Plus model,YOLO,SSD and other common industrial defect detection algorithms,validating that the improved methods based on transfer learning and semi-precision quantization enabled the model to meet the practical requirements of industrial production.

P-aminobenzoic acid promotes retinal regeneration through activation of Ascl1a in zebrafish

The retina of zebrafish can regenerate completely after injury.M ultiple studies have demonstrated that metabolic alte rations occur during retinal damage;however to date no study has identified a link between metabolites and retinal regeneration of zebrafish.Here,we performed an unbiased metabolome sequencing in the N-methyl-D-aspartic acid-damaged retinas of zebrafish to demonstrate the metabolomic mechanism of retinal regeneration.Among the differentially-ex pressed metabolites,we found a significant decrease in p-aminobenzoic acid in the N-methyl-D-aspartic acid-damaged retinas of zebrafish.Then,we investigated the role of p-aminobenzoic acid in retinal regeneration in adult zebrafish.Impo rtantly,p-aminobenzoic acid activated Achaetescute complex-like 1a expression,thereby promoting Müller glia reprogramming and division,as well as Müller glia-derived progenitor cell proliferation.Finally,we eliminated folic acid and inflammation as downstream effectors of PABA and demonstrated that PABA had little effect on Müller glia distribution.Taken together,these findings show that PABA contributes to retinal regeneration through activation of Achaetescute complex-like 1a expression in the N-methyl-Daspartic acid-damaged retinas of zebrafish.

老年脑血管疾病的影响因素及防治策略

脑血管疾病是威胁老年人健康的主要疾病之一,其预防和管理对于降低发病率、减轻医疗负担以及提高患者生活质量具有重要意义。随着医学及相关学科的不断发展,脑血管疾病的预防和管理策略也在持续更新与完善。然而,在实际操作中仍存在诸多问题,如预防意识不足、管理体系不完善以及跨学科合作缺乏等。现代医疗技术的发展为提高老年人的生存质量、防止突发事件发生开辟了新途径。本文对相关内容进行综述,提出目前医疗技术在降低老年人脑血管病发病风险方面的成就以及今后的发展趋势。在本章中,将对该系统进行进一步研究,并对其未来发展及可能的变化进行探讨。

Tungsten oxide/nitrogen-doped carbon nanotubes composite catalysts for enhanced redox kinetics in lithium-sulfur batteries

The sluggish redox kinetics of polysulfides in lithium-sulfur(Li-S)batteries are a significant obstacle to their widespread adoption as energy storage devices.However,recent studies have shown that tungsten oxide(WO_(3))can facilitate the conversion kinetics of polysulfides in Li-S batteries.Herein,we fabricated host materials for sulfur using nitrogen-doped carbon nanotubes(N-CNTs)and WO_(3).We used low-cost components and simple procedures to overcome the poor electrical conductivity that is a disadvantage of metal oxides.The composites of WO_(3) and N-CNTs(WO_(3)/N-CNTs)create a stable framework structure,fast ion diffusion channels,and a 3D electron transport network during electrochemical reaction processes.As a result,the WO_(3)/N-CNT-Li2S6 cathode demonstrates high initial capacity(1162 mA·h·g^(-1) at 0.5℃),excellent rate performance(618 mA·h·g^(-1) at 5.5℃),and a low capacity decay rate(0.093%up to 600 cycles at 2℃).This work presents a novel approach for preparing tungsten oxide/carbon composite catalysts that facilitate the redox kinetics of polysulfide conversion.

Efficient and stable PtFe alloy catalyst for electrocatalytic methanol oxidation with high resistance to CO

Direct methanol fuel cells(DMFC) are widely considered to be an ideal green energy conversion device but their widespread applications are limited by the high price of the Pt-based catalysts and the instability in terms of surface CO toxicity in long-term operation.Herein,the PtFe alloy nanoparticles(NPs) with small particle size(~4.12 nm) supported on carbon black catalysts with different Pt/Fe atomic ratios(Pt_(1)Fe_(2)/C,Pt_(3)Fe_(4)/C,Pt_(1)Fe_(1)/C,and Pt_(2)Fe_(1)/C) are successfully prepared for enhanced anti-CO poisoning during methanol oxidation reaction(MOR).The optimal atomic ratio of Pt/Fe for the MOR is 1:2,and the mass activity of Pt_(1)Fe_(2)/C(5.40 A mg_(Pt)^(-1)) is 13.5 times higher than that of conventional commercial Pt/C(Pt/C-JM)(0.40 A mg_(Pt)^(-1)).The introduction of Fe into the Pt lattice forms the PtFe alloy phase,and the electron density of Pt is reduced after forming the PtFe alloy.In-situ Fourier transform infrared results indicate that the addition of oxyphilic metal Fe has reduced the adsorption of reactant molecules on Pt during the MOR.The doping of Fe atoms helps to desorb toxic intermediates and regenerate Pt active sites,promoting the cleavage of C-O bonds with good selectivity of CO_(2)(58.1%).Moreover,the Pt_(1)Fe_(2)/C catalyst exhibits higher CO tolerance,methanol electrooxidation activity,and long-term stability than other Pt_(x)Fe_(y)/C catalysts.

Establishment of NaLuF_(4):15%Tb-based low dose X-PDT agent and its application on efficient antitumor therapy

X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.However,high X-ray irradiation dose caused organ lesions and side effects became the major barrier to X-PDT application.To address this issue,this work employed a classic-al co-precipitation reaction to synthesize NaLuF_(4):15%Tb^(3+)(NLF)with an average particle size of(23.48±0.91)nm,which was then coupled with the photosensitizer merocyanine 540(MC540)to form the X-PDT system NLF-MC540 with high production of singlet oxygen.The system could induce antitumor efficacy to about 24%in relative low dose X-ray irradiation range(0.1-0.3 Gy).In vivo,when NLF-MC540 irradiated by 0.1 Gy X-ray,the tumor inhibition percentage reached 89.5%±5.7%.The therapeutic mechanism of low dose X-PDT was found.A significant increase of neutrophils in serum was found on the third day after X-PDT.By immunohistochemical staining of tumor sections,the Ly6G^(+),CD8^(+),and CD11c^(+)cells infiltrated in the tumor microenvironment were studied.Utilizing the bilat-eral tumor model,the NLF-MC540 with 0.1 Gy X-ray irradiation could inhibit both the primary tumor and the distant tumor growth.De-tected by enzyme linked immunosorbent assay(ELISA),two cytokines IFN-γand TNF-αin serum were upregulated 7 and 6 times than negative control,respectively.Detected by enzyme linked immune spot assay(ELISPOT),the number of immune cells attributable to the IFN-γand TNF-αlevels in the group of low dose X-PDT were 14 and 6 times greater than that in the negative control group,respectively.Thus,it conclude that low dose X-PDT system could successfully upregulate the levels of immune cells,stimulate the secretion of cy-tokines(especially IFN-γand TNF-α),activate antitumor immunity,and finally inhibit colon tumor growth.

Overexpression of the peroxidase gene ZmPRX1 increases maize seedling drought tolerance by promoting root development and lignification

Drought is a main abiotic stress factor hindering plant growth,development,and crop productivity.Therefore,it is crucial to understand the mechanisms by which plants cope with drought stress.Here,the function of the maize peroxidase gene ZmPRX1 in drought stress tolerance was investigated by measurement of its expression in response to drought treatment both in a ZmPRX1 overexpression line and a mutant line.The higher root lignin accumulation and seedling survival rate of the overexpression line than that of the wild type or mutant support a role for ZmPRX1 in maize drought tolerance by regulating root development and lignification.Additionally,yeast one-hybrid,Dule luciferase and ChIP-qPCR assays showed that ZmPRX1 is negatively regulated by a nuclear-localized ZmWRKY86 transcription factor.The gene could potentially be used for breeding of drought-tolerant cultivars.

Advanced nerve regeneration enabled by neural conformal electronic stimulators enhancing mitochondrial transport

Addressing peripheral nerve defects remains a significant challenge in regenerative neurobiology.Autograftsemerged as the gold-standard management,however,are hindered by limited availability and potential neuromaformation.Numerous recent studies report the potential of wireless electronic system for nerve defects repair.Unfortunately,few has met clinical needs for inadequate electrode precision,poor nerve entrapment andinsufficient bioactivity of the matrix material.Herein,we present an advanced wireless electrical nerve stimulator,based on water-responsive self-curling silk membrane with excellent bioabsorbable and biocompatibleproperties.We constructed a unique bilayer structure with an oriented pre-stretched inner layer and a generalsilk membrane as outer layer.After wetting,the simultaneous contraction of inner layer and expansion of outerlayer achieved controllable super-contraction from 2D flat surface to 3D structural reconfiguration.It enablesshape-adaptive wrapping to cover around nerves,overcomes the technical obstacle of preparing electrodes on theinner wall of the conduit,and prevents electrode breakage caused by material expansion in water.The use of forkcapacitor-like metal interface increases the contact points between the metal and the regenerating nerve,solvingthe challenge of inefficient and rough electrical stimulation methods in the past.Newly developed electronicstimulator is effective in restoring 10 mm rat sciatic nerve defects comparable to autologous grafts.The underlyingmechanism involves that electric stimulation enhances anterograde mitochondrial transport to matchenergy demands.This newly introduced device thereby demonstrated the potential as a viable and efficaciousalternative to autografts for enhancing peripheral nerve repair and functional recovery.

Broadband bidirectional Brillouin–Raman random fiber laser with ultra-narrow linewidth

We present a Brillouin–Raman random fiber laser(BRRFL)with full-open linear cavity structure to generate broadband Brillouin frequency comb(BFC)with double Brillouin-frequency-shift spacing.The incorporation of a regeneration portion consisting of an erbium-doped fiber and a single-mode fiber enables the generation of broadband BFC.The dynamics of broadband BFC generation changing with the pump power(EDF and Raman)and Brillouin pump(BP)wavelength are investigated in detail,respectively.Under suitable conditions,the bidirectional BRRFL proposed can produce a flatamplitude BFC with 40.7-nm bandwidth ranging from 1531 nm to 1571.7 nm,and built-in 242-order Brillouin Stokes lines(BSLs)with double Brillouin-frequency-shift spacing.Moreover,the linewidth of single BSL is experimentally measured to be about 2.5 kHz.The broadband bidirectional narrow-linewidth BRRFL has great potential applications in optical communication,optical sensing,spectral measurement,and so on.

Anti-N-methyl-D-aspartate receptor type autoimmune encephalitis with severe pneumonia:a case report

Autoimmune encephalitis(AE)is a type of encephalitis caused by autoimmune disease.AE was included on a list of the first batch of 121 rare diseases published by the Chinese National Health Commission on 11^(th)May 2018.Currently,patients with AE account for 10%-20% of encephalitis cases,with 54%-80% of those cases classified as the anti-N-methyl-D-aspartate receptor(NMDAR)type,which is the most common type.[1]In 2010,China reported the first case of a patient withanti-NMDARtype AE.

Intelligent Metal Detection and Disposal Automation Equipment Based on Geometric Optimization Driving Algorithm

In order to solve the problem of metal impurities mixed in the production line of wood pulp nonwoven raw materials,intelligent metal detection and disposal automation equipment is designed.Based on the principle of electromagnetic induction,the precise positioning of metal coordinates is realized by initial inspection and multi-directional re-inspection.Based on a geometry optimization driving algorithm,the cutting area is determined by locating the center of the circle that covers the maximum area.This approach aims to minimize the cutting area and maximize the use of materials.Additionally,the method strives to preserve as many fabrics at the edges as possible by employing the farthest edge covering circle algorithm.Based on a speed compensation algorithm,the flexible switching of upper and lower rolls is realized to ensure the maximum production efficiency.Compared with the metal detection device in the existing production line,the designed automation equipment has the advantages of higher detection sensitivity,more accurate metal coordinate positioning,smaller cutting material areas and higher production efficiency,which can make the production process more continuous,automated and intelligent.

Progress in manipulating spin polarization for solar hydrogen production

Photocatalytic and photoelectrochemical water splitting using semiconductor materials are effective approaches for converting solar energy into hydrogen fuel.In the past few years,a series of photocatalysts/photoelectrocatalysts have been developed and optimized to achieve efficient solar hydrogen production.Among various optimization strategies,the regulation of spin polarization can tailor the intrinsic optoelectronic properties for retarding charge recombination and enhancing surface reactions,thus improving the solar-to-hydrogen(STH)efficiency.This review presents recent advances in the regulation of spin polarization to enhance spin polarized-dependent solar hydrogen evolution activity.Specifically,spin polarization manipulation strategies of several typical photocatalysts/photoelectrocatalysts(e.g.,metallic oxides,metallic sulfides,non-metallic semiconductors,ferroelectric materials,and chiral molecules)are described.In the end,the critical challenges and perspectives of spin polarization regulation towards future solar energy conversion are briefly provided.

Systematic investigation of Radix Salviae for treating diabetic peripheral neuropathy disease based on network Pharmacology

BACKGROUND Diabetic peripheral neuropathy(DPN)is a debilitating complication of diabetes mellitus with limited available treatment options.Radix Salviae,a traditional Chinese herb,has shown promise in treating DPN,but its therapeutic mech-anisms have not been systematically investigated.AIM Radix Salviae(Danshen in pinin),a traditional Chinese medicine(TCM),is widely used to treat DPN in China.However,the mechanism through which Radix Salviae treats DPN remains unclear.Therefore,we aimed to explore the mechanism of action of Radix Salviae against DPN using network pharmacology.METHODS The active ingredients and target genes of Radix Salviae were screened using the TCM pharmacology database and analysis platform.The genes associated with DPN were obtained from the Gene Cards and OMIM databases,a drug-com-position-target-disease network was constructed,and a protein–protein inter-action network was subsequently constructed to screen the main targets.Gene Ontology(GO)functional annotation and pathway enrichment analysis were performed via the Kyoto Encyclopedia of Genes and Genomes(KEGG)using Bioconductor.RESULTS A total of 56 effective components,108 targets and 4581 DPN-related target genes of Radix Salviae were screened.Intervention with Radix Salviae for DPN mainly involved 81 target genes.The top 30 major targets were selected for enrichment analysis of GO and KEGG pathways.CONCLUSION These results suggested that Radix Salviae could treat DPN by regulating the AGE-RAGE signaling pathway and the PI3K-Akt signaling pathway.Therefore,Danshen may affect DPN by regulating inflammation and apoptosis.

Clinical intervention effect of Xuefu Zhuyu decoction on chronic heart failure complicated with depression

BACKGROUND The diagnosis and treatment of depression in patients with chronic heart failure(CHF)is challenging,with no ideal treatment at present.AIM To analyze the clinical intervention effect of Xuefu Zhuyu decoction(XFZYD)on CHF complicated with depression.METHODS The study cohort comprised 116 patients with CHF complicated with depression who received treatment from July 2020 to July 2023,of which 55 received Western medicine(control group)and 61 received XFZYD(research group).Data on clinical effectiveness,traditional Chinese medicine(TCM)syndrome score,cardiac function,negative emotions,and serum inflammatory factors,were collected for comparative analyses.RESULTS Compared with the control group,the research group had an evidently higher total effective rate.Furthermore,there were marked reductions in TCM symptom score,left ventricular end-diastolic diameter,left ventricular end-systolic diameter,Self-Rating Depression Scale,Hamilton Depression Scale,high-sensitivity C-reactive protein,monocyte chemoattractant protein-1,and matrix metalloproteinase-9 in the research group after treatment,and these were lower than the corresponding values in the control group.Left ventricular ejection fraction was increased and higher in the research group compared with the control group after treatment.CONCLUSION Our findings conclusively proved that XFZYD was considerably superior to Western medicine for treating CHF complicated with depression because it significantly alleviated patients’symptoms,improved cardiac function,relieved negative emotions,and reduced the levels of serum inflammatory factors.

音乐数字化对传统音乐产业的影响与转型策略探究

目的:文章探讨音乐数字化对传统音乐产业的深远影响,分析其在产业结构、收入模式、消费者行为和市场竞争等方面的变革,并提出应对这些变化的转型策略,以帮助传统音乐产业在数字化时代保持竞争优势。方法:通过文献综述、案例分析,研究音乐数字化对传统音乐产业各个环节的影响,重点关注技术创新、商业模式革新、版权管理、跨界合作等方面的实践与成效,分析不同策略的实施效果及对行业发展的推动作用。结果:研究表明,数字化已成为音乐产业变革的主要驱动力,促使传统产业结构朝着更加扁平化和灵活化的方向发展。同时,收入模式逐步向流媒体订阅、粉丝经济、版权授权等多元化方式转型,市场竞争也因此变得更加激烈。创新技术手段、参与跨界合作、培养数字化人才等策略,在推动行业变革和开拓新市场方面发挥着关键作用,许多传统音乐企业通过这些策略成功实现了转型。结论:为了在数字化浪潮中持续发展,传统音乐产业必须全面拥抱数字技术,积极加强版权管理,优化商业模式,并注重培养具备数字化技能的人才,提升产业的市场竞争力,为音乐产业开辟新的增长点。

高压脉冲放电在大直径扩底灌注桩中的应用技术研究

本文主要研究了金属丝电爆炸产生的压力冲击波作用在土层孔壁上,在桩底部挤压土体形成扩底桩。建立了金属丝爆炸能量与冲击波压力之间的关系函数与仿真模型,分析了放电参数与冲击波强度的关系;建立了冲击波压力与土体变形之间的关系,计算出粘性土体变形量所需要的压力大小;制作扩底桩、直桩模型,验证金属丝电爆炸荷载作用下土体受力变形特性,并对两种桩型承载力及抗拔力性能进行对比分析。利用高压脉冲扩底技术模型试验中的电学参数及工艺参数,构建国内首根直径0.8 m的高压脉冲扩底桩,完成“灌-扩”一体高压脉冲扩底工法的开发。

PTBP3对食管鳞状细胞癌细胞增殖与迁移的影响及机制研究

目的探讨多嘧啶束结合蛋白3(PTBP3)在食管鳞状细胞癌(ESCC)中的作用及其潜在机制。方法收集2021年1月至2023年5月济宁市第一人民医院的6例ESCC标本及其癌旁正常组织标本,采用实时荧光定量聚合酶链式反应(qRT-PCR)与蛋白质印迹(Western blotting)测定组织及细胞中PTBP3的表达;细胞计数试剂盒(CCK8)测定ESCC细胞活力情况;划痕试验测定ESCC细胞迁移能力。通过检索UALCAN数据库、癌症基因组图谱(TCGA)数据库分析食管癌组织及正常食管组织PTBP3的表达差异及PTBP3与miR29家族的关系。统计学方法采用t检验。结果ESCC组织中PTBP3基因表达量高于正常食管组织(P<0.05)。qRT-PCR结果表明,与对照病毒组相比,3种ESCC细胞(KYSE30、ECA109、KYSE150)的PTBP3敲低组中miR-29a-3p与miR-29c-3p表达水平均下调(t=29.007、7.057、4.844、12.625、15.612、18.861,均P<0.05)。ESCC组织中miR-29a-3p和miR-29c-3p表达量与PTBP3表达量相关。结论PTBP3是ESCC的一个重要分子标志物和潜在治疗靶点,可为ESCC早期诊断及治疗提供新思路和方法。