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。

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。

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.

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.

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.

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.

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。

高中历史教学中如何培养“中华民族共同体意识”探析——以“凉州会谈”为例

教育课程改革发展到新阶段,目标已经逐步转型为培养和提高学科核心素养。家国情怀作为中学历史教学中的五大核心素养之一,代表着探究和学习历史应具有的社会责任与人文追求。作为家国情怀重要组成部分的中华民族共同体意识,是国家统一之基、民族团结之本、精神力量之魂。本研究以教育课程改革为背景,藉由高中历史教材中蒙藏“凉州会谈”一事,探讨如何在高中历史教学中培养“中华民族共同体意识”的问题。

体检人群幽门螺杆菌感染与中医体质、糖脂代谢相关性研究

目的探讨体检人群幽门螺杆菌(Helicobacter pylori,Hp)感染与中医体质类型、糖脂代谢的相关性,从中西医结合角度指导Hp感染的防治。方法选取2018年1月至2022年10月在安徽中医药大学第一附属医院体检中心进行一站式体检者506例,根据呼气试验结果分为Hp阳性组和Hp阴性组,对比分析两组的一般资料、中医体质类型、糖脂代谢指标[空腹血糖(fasting blood glucose,FBG)、三酰甘油(triglyceride,TG)、总胆固醇(total cholesterol,TC)、高密度脂蛋白胆固醇(high-density lipoprotein cholesterol,HDL-C)、低密度脂蛋白胆固醇(low-density lipoprotein cholesterol,LDL-C)],并采用Logistic回归分析方法研究中医体质类型、糖脂指标与Hp感染的相关性。结果Hp阳性组湿热质、痰湿质分布比例最高,与Hp阴性组比较,差异有统计学意义(P<0.05);Hp阳性组FBG、TG、TC、LDL-C水平高于Hp阴性组,差异有统计学意义(P<0.05)。Logistic回归分析结果显示,湿热质,痰湿质,FBG、TG、TC、LDL-C水平升高是Hp感染的危险因素。结论体检人群Hp感染与中医体质、糖脂代谢存在关联性,湿热质、痰湿质是Hp的易感体质,Hp感染者FBG和血脂水平更高。

原发性视网膜色素变性的低视力患者配戴琥珀色滤光镜前后视觉功能变化

目的:对比观察原发性视网膜色素变性(RP)的低视力患者在配戴琥珀色滤光镜前后的视觉功能变化。方法:自身前后对照研究。收集2021-08/2022-03就诊于西安市第一医院眼科门诊诊断为原发性RP的低视力患者30例60眼。记录配戴琥珀色滤光镜前后裸眼远视力(UCDVA)、最佳矫正远视力(BCDVA)、裸眼近视力(UCNVA)、最佳矫正近视力(BCNVA)、视野和FM-100色觉,并分别在明室环境、暗室环境和暗室伴眩光环境进行对比敏感度检查并记录,分析配戴前后上述视功能参数的变化。结果:配戴琥珀色滤光镜后UCDVA和BCDVA均优于配戴前(t=-2.32,P<0.001;t=-6.77,P<0.001),而UCNVA和BCNVA在戴镜前后差异无统计学意义。戴镜后的视野指数(VFI)低于配戴前(t=8.62,P<0.001)、视野平均缺损值(MD)大于配戴前(t=7.73,P<0.001),FM100色棋检查显示TES和多个分区PES均高于戴镜前(P<0.001)。配戴后明室环境、暗室伴眩光环境下各频段CS值较配戴前提高(P<0.001),暗室不伴眩光环境下各频段配戴琥珀色滤光镜前后差异无统计学意义。结论:原发性RP的低视力患者配戴琥珀色滤光镜后UCDVA和BCDVA提高,UCNVA和BCNVA无改变,而视野和辨色能力较戴镜前更差。明室环境及暗室伴眩光环境对比敏感度较戴镜前改善,而暗室不伴眩光环境对比敏感度无明显变化。

Impact of the Shrinkage of Arctic Sea Ice on Eurasian Snow Cover Changes in 1979-2021

Recent research has shown that snow cover induces extreme wintertime cooling and has detrimental impacts.Although the dramatic loss of Arctic sea ice certainly has contributed to a more extreme climate,the mechanism connecting sea-ice loss to extensive snow cover is still up for debate.In this study,a significant relationship between sea ice concentration(SIC)in the Barents-Kara(B-K)seas in November and snow cover extent over Eurasia in winter(November-January)has been found based in observational datasets and through numerical experiments.The reduction in B-K sea ice gives rise to a negative phase of Arctic Oscillation(AO),a deepened East Asia trough,and a shallow trough over Europe.These circulation anomalies lead to colder-than-normal Eurasian mid-latitude temperatures,providing favorable conditions for snowfall.In addition,two prominent cyclonic anomalies near Europe and Lake Baikal affect moisture transport and its divergence,which results in increased precipitation due to moisture advection and wind convergence.Furthermore,anomalous E-P flux shows that amplified upward propagating waves associated with the low SIC could contribute to the weakening of the polar vortex and southward breakouts of cold air.This work may be helpful for further understanding and predicting the snowfall conditions in the middle latitudes.

A gap-free reference genome reveals structural variations associated with flowering time in rapeseed(Brassica napus)

Allopolyploid oilseed rape(Brassica napus)is an important oil crop and vegetable.However,the latest version of its reference genome,with collapsed duplications,gaps,and other issues,prevents comprehensive genomic analysis.Herein,we report a gap-free assembly of the rapeseed cv.Xiang5A genome using a combination of ONT(Oxford Nanopore Technologies)ultra-long reads,PacBio high-fidelity reads,and Hi-C datasets.It includes gap-free assemblies of all 19 chromosomes and telomere-to-telomere assemblies of eight chromosomes.Compared with previously published genomes of B.napus,our gap-free genome,with a contig N50 length of 50.70 Mb,has complete assemblies of 9 of 19 chromosomes without manual intervention,and greatly improves contiguity and completeness,thereby representing the highest quality genome assembly to date.Our results revealed that B.napus Xiang5A underwent nearly complete triplication and allotetraploidy relative to Arabidopsis thaliana.Using the gap-free assembly,we found that 917 flowering-related genes were affected by structural variation,including BnaA03.VERNALIZATION INSENSITIVE 3 and BnaC04.HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 1.These genes may play crucial roles in regulating flowering time and facilitating the adaptation of Xiang5A in the Yangtze River Basin of China.This reference genome provides a valuable genetic resource for rapeseed functional genomic studies and breeding.

郑州国际文化交流中心结构设计

郑州国际文化交流中心项目建筑造型新颖,为规则性超限的复杂高层建筑。其主入口部分含大跨拱支结构,内部为数层大跨楼面结构,与相邻结构单元通过大跨连接体相连,主体采用了钢框架-中心支撑结构体系。主要介绍了结构方案选型、超限结构设计措施,重点论述了主入口的巨拱及相连的观景平台、空中连接体的结构设计要点。采用相应的结构分析软件对结构进行了不同水准地震作用分析、抗震性能化分析、巨拱稳定分析及关键节点分析。分析结果表明,结构体系传力明确,整体结构安全可靠,经济合理。

郑州国际文化交流中心酒店结构设计

郑州国际文化交流中心酒店地上9层,地下2层,地上分为A区、B区两个结构单元,均为复杂超限高层建筑。主体结构均采用钢筋混凝土框架-剪力墙体系,关键部位采用型钢混凝土或全钢结构。A区有跨度为23.7~25.3m的弧形转换,采用弧形型钢混凝土转换梁;B区在3层~屋面有11.3m的超长悬挑,采用双层斜拉杆体系。分析了结构整体性能,明确了结构关键部位,选取并验证了中震、大震下的性能化目标,采用大震弹塑性时程分析揭示了结构薄弱部位并采取了针对性措施。专项分析了弧形转换梁的抗扭能力和应力分布,超长悬挑区的楼板作用、节点应力、抗连续倒塌能力,并提出了加强措施。分析结果表明,结构设计满足规范要求,并具有良好的抗震性能。