60%SiCp/2009铝基复合材料表面等离子体电解氧化膜的生长和表征

在硅酸盐溶液中采用等离子体电解氧化技术在60%SiCP(体积分数)/2009铝基复合材料表面制备陶瓷膜。研究氧化膜的显微组织、成分、润湿性及其耐腐蚀性能,探讨SiC颗粒表面火花放电的产生机理。结果表明,来自硅酸盐溶液的不溶性化合物(SiO_(2))使SiC颗粒表面产生火花放电,Al-Si-O化合物中的缺陷为SiC颗粒表面放电电流的传导提供优先路径。1200s时铝基复合材料表面形成5.5μm厚的均匀膜层,膜层的表面自由能在40s时达到最大值37.10 m J/cm^(2),并在1200 s时下降到25.95 m J/cm^(2)。此外,等离子体电解氧化处理可以显著提高复合材料的耐蚀性。

碳载体空位工程助力原位合成的Pt纳米枝晶促进电催化氧气还原

质子交换膜燃料电池(PEMFCs)因其高能量密度、低操作温度和环保等特性,被视为极具潜力的能量转换系统.目前,碳载铂颗粒(Pt/C)是PEMFCs阴极氧还原反应(ORR)中使用最广泛的催化剂.然而,Pt与碳载体间的电子结构差异导致Pt纳米颗粒(Pt NPs)易从碳载体上脱落,严重降低了ORR的催化活性.此外,Pt的高成本和稀缺性也限制了其广泛应用.相比之下,Pt纳米枝晶(NDs)因具有高利用率的表面活性位点而备受关注.然而,Pt NDs的合成通常需要严格控制反应条件,且其与碳基底间的弱相互作用易导致活性位点损失和性能下降.因此,开发具有强金属载体相互作用的Pt复合碳催化剂对PEMFCs的实际应用至关重要.本文通过原位Cl-介导的生长策略,结合碳本征空位工程,成功制备了分散在富含碳本征空位的中空氮掺杂碳基底上的Pt NDs催化剂(Pt@HNC-V-800).拉曼光谱和电子顺磁共振光谱结果表明,碳本征空位的形成机制源于碳基底结构中氮原子的耗散,该过程引起碳原子的重新排列,进而产生了丰富的本征缺陷位点.X射线吸收光谱和X射线光电子能谱结果表明,与无碳空位的Pt@HNC催化剂相比,富含本征碳空位的样品(Pt@HNC-V-800)表现出较低的Pt-Pt键配位数(8.64)和更强的给电子效应.得益于Pt NDs丰富的活性位点及其与本征碳空位基底之间的强电子效应,Pt@HNC-V-800的ORR半波电位高达0.947 V,质量活性和比表面活性分别为1.55 A mg^(-1) Pt和1.85 mA cm^(-2),是商用Pt/C的8.2和6.8倍(0.191 A mg^(-1)Pt和0.27 mA cm^(-2)).加速耐久性测试结果表明,经20000次电势循环后,Pt@HNC-V-800的活性无明显变化,其活性损失远低于无碳本征空位的Pt@HNC材料和商业Pt/C催化剂.因此,与无碳本征空位的Pt@HNC材料相比,Pt@HNC-V-800的ORR活性和稳定性都有较大提升,进一步证实了碳本征空位工程协同Pt NDs策略的优越性.此外,密度泛函理论计算结果表明,Pt@HNC-V的丰富空位降低了氧中间体过电势,优化了ORR中间体在Pt NDs上的吸附能,进而提高了催化剂的ORR本征活性.同时,富碳本征空位的存在增强了Pt NDs在碳载体上的结合能,使Pt NDs不易在电势循环过程中脱离碳载体,从而增强了稳定性.综上所述,本文通过Pt NDs与碳本征空位工程协同效应策略,精准调控碳负载Pt基催化剂的结构,大幅提升其在酸性条件下的ORR性能,为进一步设计高性能的ORR电催化剂提供了新思路.

Precision tuning of highly efficient Pt-based ternary alloys on nitrogen-doped multi-wall carbon nanotubes for methanol oxidation reaction

The electrochemical methanol oxidation is a crucial reaction in the conversion of renewable energy.To enable the widespread adoption of direct methanol fuel cells(DMFCs),it is essential to create and engineer catalysts that are both highly effective and robust for conducting the methanol oxidation reaction(MOR).In this work,trimetallic PtCoRu electrocatalysts on nitrogen-doped carbon and multi-wall carbon nanotubes(PtCoRu@NC/MWCNTs)were prepared through a two-pot synthetic strategy.The acceleration of CO oxidation to CO_(2) and the blocking of CO reduction on adjacent Pt active sites were attributed to the crucial role played by cobalt atoms in the as-prepared electrocatalysts.The precise control of Co atoms loading was achieved through precursor stoichiometry.Various physicochemical techniques were employed to analyze the morphology,element composition,and electronic state of the catalyst.Electrochemical investigations and theoretical calculations confirmed that the Pt_(1)Co_(3)Ru_(1)@NC/MWCNTs exhibit excellent electrocatalytic performance and durability for the process of MOR.The enhanced MOR activity can be attributed to the synergistic effect between the multiple elements resulting from precisely controlled Co loading content on surface of the electrocatalyst,which facilitates efficient charge transfer.This interaction between the multiple components also modifies the electronic structures of active sites,thereby promoting the conversion of intermediates and accelerating the MOR process.Thus,achieving precise control over Co loading in PtCoRu@NC/MWCNTs would enable the development of high-performance catalysts for DMFCs.

Fast,simple,efficient Agrobacterium rhizogenes-mediated transformation system to non-heading Chinese cabbage with transgenic roots

Non-heading Chinese cabbage, a variety of Brassica campestris, is an important vegetable crop in the Yangtze River Basin of China. However,the immaturity of its stable transformation system and its low transformation efficiency limit gene function research on non-heading Chinese cabbage. Agrobacterium rhizogenes-mediated(ARM) transgenic technology is a rapid and effective transformation method that has not yet been established for non-heading Chinese cabbage plants. Here, we optimized conventional ARM approaches(one-step and two-step transformation methods) suitable for living non-heading Chinese cabbage plants in nonsterile environments. Transgenic roots in composite non-heading Chinese cabbage plants were identified using phenotypic detection, fluorescence observation, and PCR analysis. The transformation efficiency of a two-step method on four five-day-old non-heading Chinese cabbage seedlings(Suzhouqing, Huangmeigui, Wuyueman, and Sijiu Caixin) was 43.33%-51.09%, whereas using the stout hypocotyl resulted in a transformation efficiency of 54.88% for the 30-day-old Sijiu Caixin.The one-step method outperformed the two-step method;the transformation efficiency of different varieties was above 60%, and both methods can be used to obtain transgenic roots for functional studies within one month. Finally, optimized ARM transformation methods can easily,quickly, and effectively produce composite non-heading Chinese cabbage plants with transgenic roots, providing a reliable foundation for gene function research and non-heading Chinese cabbage genetic improvement breeding.

Cdc42EP3对结直肠癌细胞迁移和侵袭的影响

目的:探讨Cdc42EP3在结直肠癌(colorectal cancer,CRC)转移中的作用及相关作用机制。方法:回顾性收集2010年12月至2011年12月于南京医科大学附属淮安第一医院诊治的97例CRC患者的术后病理蜡块,同时收集相关临床病理资料。采用免疫组织化学法检测Cdc42EP3在癌组织与相应正常组织中的表达,随后通过统计学方法分析差异表达,并评估表达水平与临床病理学参数及生存预后之间的相关性。干扰CRC细胞Cdc42EP3的表达后,应用Transwell技术检测Cdc42EP3对CRC细胞的迁移及侵袭能力的影响,并使用Western blot技术检测EMT相关蛋白的表达。通过基因芯片技术及生物信息学分析预测Cdc42EP3的下游靶点STAT1,并通过回复实验验证。结果:Cdc42EP3在癌组织中的表达水平显著高于相应正常组织(P<0.001),并与肿瘤的淋巴结转移(P=0.011)、TNM分期(P=0.008)及患者生存预后(P<0.001)之间呈显著相关性。干扰Cdc42EP3表达后,CRC细胞的迁移及侵袭能力均明显减弱(P<0.01)。预测出Cdc42EP3的下游靶点STAT1。在CRC细胞中,干扰Cdc42EP3表达可提高内源性STAT1蛋白水平,过表达STAT1具有与Cdc42EP3表达下降类似的肿瘤抑制作用,而STAT1表达下降可削弱Cdc42EP3敲低所致的肿瘤抑制作用(P<0.05)。结论:Cdc42EP3在CRC组织中高表达。Cdc42EP3通过调控STAT1的表达促进CRC细胞的迁移及侵袭。

城与园的新构对苏州高新区狮山水质净化厂的解读

文章介绍了九城都市的新作——苏州高新区狮山水质净化厂,将其置于景观都市主义的语境下加以解读,从景观与城市协同共生的视角探析该项目在构建生态网络、植入社会机能、折叠立体基面与协同专业合作等方面的实践策略,论述城市基础设施在高密度建成环境下具有生态修复、功能复合、场所营造与品质提升等方面的潜在价值.文章同时也融入了对目前城市基础设施孤立发展这一状况的批判与反思.

Design principles in MOF-derived electromagnetic wave absorption materials:Review and perspective

At present,metal-organic framework(MOF)-derived nano-micro architectures are actively explored for electromagnetic(EM)wave absorption owing to their flexible composition and structural manipulation that enhance dielectric and magnetic attenuations.However,the basic design principles in MOF-derived microwave absorption materials have not been summarized.This review is devoted to analyzing design principles in MOF-derived microwave absorption materials from the following perspectives:diverse monomers(ligands and ions of MOFs),topologies,chemical states,and physical properties.The derived essential information regarding the EM wave absorption mechanism and the structural-functional dependency is also comprehensively summarized.Finally,a clear insight into the challenges and perspectives of the industrial revolution upgrading in this promising field is proposed.

优化营商环境下的生产建设项目水土保持监督管理工作

通过分析生产建设项目水土保持现状,提出水行政主管部门应加强水土保持监督管理工作思考,可通过建立与规划和自然资源部门的联动协调机制,在土地开发前组织进行水土保持技术评估,提出水土保持评估意见书;制定生产建设项目水土保持评估技术规范;优化水土保持防治指标;完善水土保持监督管理体系;加强水土保持执法体系建设;取消生产建设项目水土保持方案行政审查等一系列改革举措,进一步优化营商环境。

Bottom-up holistic carrier management strategy induced synergistically by multiple chemical bonds to minimize energy losses for efficient and stable perovskite solar cells

The defects from electron transport layer,perovskite layer and their interface would result in carrier nonradiative recombination losses.Poor buried interfacial contact is detrimental to charge extraction and device stability.Here,we report a bottom-up holistic carrier management strategy induced synergistically by multiple chemical bonds to minimize bulk and interfacial energy losses for high-performance perovskite photovoltaics.4-trifluoromethyl-benzamidine hydrochloride(TBHCl)containing–CF_(3),amidine cation and Cl^(-)is in advance incorporated into SnO_(2)colloid solution to realize bottom-up modification.The synergistic effect of multiple functional groups and multiple-bond-induced chemical interaction are revealed theoretically and experimentally.F and Cl^(-)can passivate oxygen vacancy and/or undercoordinated Sn^(4+)defects by coordinating with Sn^(4+).The F can suppress cation migration and modulate crystallization via hydrogen bond with FA^(+),and can passivate lead defects by coordinating with Pb^(2+).The–NH_(2)–C=NH^(+)_(2)and Cl^(-)can passivate cation and anion vacancy defects through ionic bonds with perovskites,respectively.Through TBHCl modification,the suppression of agglomeration of SnO_(2)nanoparticles,bulk and interfacial defect passivation,and release of tensile strains of perovskite films are demonstrated,which resulted in a PCE enhancement from 21.28%to 23.40%and improved stability.With post-treatment,the efficiency is further improved to 23.63%.

Gradient carbonyl-iron/carbon-fiber reinforced composite metamaterial for ultra-broadband electromagnetic wave absorption by multi-scale integrated design

The demand of high-end electromagnetic wave absorbing materials puts forward higher requirements on comprehensive performances of small thickness,lightweight,broadband,and strong absorption.Herein,a novel multi-layer stepped metamaterial absorber with gradient electromagnetic properties is proposed.The complex permittivity and permeability of each layer are tailored via the proportion of carbonyliron and carbon-fiber dispersing into the epoxy resin.The proposed metamaterial is further optimized via adjusting the electromagnetic parameters and geometric sizes of each layer.Comparing with the four-layer composite with gradient electromagnetic properties which could only realize reflection loss(RL)of less than−6 dB in 2.0-40 GHz,the optimized stepped metamaterial with the same thickness and electromagnetic properties realizes less than−10 dB in the relevant frequency range.Additionally,the RL of less than−15 dB is achieved in the frequency range of 11.2-21.4 GHz and 28.5-40 GHz.The multiple electromagnetic wave absorption mechanism is discussed based on the experimental and simulation results,which is believed to be attributed to the synergy effect induced by multi-scale structures of the metamaterial.Therefore,combining multi-layer structures and periodic stepped structures into a novel gradient absorbing metamaterial would give new insights into designing microwave absorption devices for broadband electromagnetic protections.

Unraveling abnormal buried interface anion defect passivation mechanisms depending on cation-induced steric hindrance for efficient and stable perovskite solar cells

Although ionic liquids(ILs)have been widely employed to heal the defects in perovskite solar cells(PSCs),the corresponding defect passivation mechanisms are not thoroughly understood up to now.Herein,we first reveal an abnormal buried interface anion defect passivation mechanism depending on cationinduced steric hindrance.The IL molecules containing the same anion([BF4]^(-))and different sizes of imidazolium cations induced by substituent size are used to manipulate buried interface.It was revealed what passivated interfacial defects is mainly anions instead of cations.Theoretical and experimental results demonstrate that the large-sized cations can weaken the ionic bond strength between anions and cations,and facilitate the interaction between anions and SnO2as well as perovskites,which is conducive to interfacial defect passivation and ameliorating interfacial contact.It can be concluded that interfacial chemical interaction strength and defect passivation effect are positively correlated with the size of cations.The discovery breaks conventional thinking that large-sized modification molecules would weaken their chemical interaction with perovskite.Compared with the control device(21.54%),the device based on 1,3-Bis(1-adamantyl)-imidazolium tetrafluoroborate(BAIMBF4)with maximum size cations achieves a significantly enhanced efficiency of 23.61%along with much increased moisture,thermal and light stabilities.

HPLC法测定佐米曲普坦片有关物质及质量评价研究

目的对国家抽验品种佐米曲普坦片的质量现状进行评价,建立佐米曲普坦片有关物质测定的HPLC法,完善质量标准,为药品监管提供技术支持。方法Supelco Ascentis Express90 Phenyl-Hexy色谱柱(10 cm×3.0 mm,2.7μm),流动相为含己烷磺酸钠的磷酸盐缓冲液(pH 2.0)-乙腈,梯度洗脱,检测波长为220 nm,流速为0.8mL·min^(-1),柱温为40℃,进样量为10μL。采用该方法对从全国范围内抽取的40批佐米曲普坦片样品及收集的原料进行检测。结果佐米曲普坦在0.840~1.260μg·mL^(-1)浓度范围内线性关系良好(r=0.9999),检出限为1 ng;杂质1~5的检出限分别为0.11,0.52,10.91,1.04,2.18 ng。结论所建立的方法专属性强,采用该方法对市售佐米曲普坦片进行质量评价,发现该品种生产工艺的关键控制点及包衣工艺对产品质量的影响,并建议将产品的储存条件规定为“凉暗处”。

HPLC法同时测定固本益肠片中5种成分含量

目的:建立HPLC同时测定固本益肠片中儿茶素、表儿茶素、芍药苷、补骨脂素及异补骨脂素含量的方法并为监测该药风险成分提供参考。方法:色谱柱采用依利特Hypersil ODS2柱(4.6 mm×300 mm,5μm);流动相:乙腈(B)-水(A),梯度洗脱,检测波长:240 nm;流速:1.0 mL·min^(-1);柱温:30℃。结果:5种成分均能达到基线分离,且在相应范围内线性关系良好;儿茶素、表儿茶素、芍药苷、补骨脂素及异补骨脂素的平均加样回收率分别为98.22%、96.93%、101.46%、98.60%和100.24%,RSD分别为1.5%、2.1%、2.0%、1.4%和1.0%(n=6)。结论:经方法学验证,本法可为进一步完善固本益肠片质量控制标准,并为监测该药风险成分提供参考。

Exploring the mechanism of action of DHI on myeloproliferative neoplasms based on network pharmacology

Objective:The aim of this study is to explore the active ingredients and mechanism of action of danhong injection(DHI)in treating myeloproliferative neoplasms using network pharmacology.Methods:The TCMSP platform and relevant literature were used to search for the active ingredients and targets of Radix Salviae and Carthami Flos in DHI.Disease targets related to myeloproliferative neoplasms were obtained from the GEO database,GeneCards,and DisGeNET database.The queried component targets were normalized using the UniProt database.Potential targets were identified by constructing protein-protein interactions networks using STRING 11.5 and visualized and analyzed using Cytoscape 3.9.1.GO and KEGG analysis were performed using the Metascape platform,and visualization was done using the built-in plug-in CluoGO or SangerBox platforms with Cytoscape 3.9.1.Results:The active ingredients of DHI for treating myeloproliferative neoplasms mainly consist of flavonoids and o-benzoquinones,including quercetin,luteolin,kaempferol,stigmasterol,tanshinone iia,cryptotanshinone,beta-carotene,2-isopropyl-8-methylphenanthrene-3,4-dione,and neocryptotanshinone ii.The potential targets are JUN,TP53,STAT3,AKT1,MAPK1,RELA,TNF,MAPK14,IL6,and FOS.The relevant signaling pathways involved are mainly TNFαsignaling pathway,PI3K-Akt signaling pathway,apoptosis,IL-17 signaling pathway,cellular senescence,MAPK signaling pathway,p53 signaling pathway,JAK-STAT signaling pathway,and NF-kappa B signaling.Conclusions:DHI acts mainly through flavonoids and o-benzoquinones to treat myeloproliferative neoplasms in a multi-targeted and multi-pathway manner.

Deciphering the potential mechanism of Radix Rehmanniae Praeparata for treating cancer-related anemia based on network pharmacology and molecular docking technology

Background:Rehmanniae Radix Praeparata(RRP,Shu Dihuang in Cinese)is a traditional Chinese herb with multiple pharmacological effects and is commonly used to treat blood deficiency syndrome,such as cancer-related anemia(CRA),alone or in combination with other herbs.However,its main active ingredients and mechanisms of action in treating CRA remain unknown.This study aims to elucidate RRP’s potential mechanism and main active components in treating CRA by using network pharmacology and molecular docking technology system.Methods:The main components of RRP were obtained by the TCMSP database and literature search,and active components and potential targets were obtained by the SwissADME and SwissTargetPridiction databases.CRA targets were collected through GeneCards,DisGeNET,and DrugBank databases.Protein-protein interaction networks of potential targets were constructed via STRING 11.5 and analyzed visually with Cytoscape 3.9.1.The Metascape platform was used for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis,which were subsequently visualized with Cytoscape 3.9.1 or SangerBox platform.Moreover,Autodock Vina was used for the molecular docking of potential targets and main active ingredients that were visualized with PyMOL software.Results:In this study,31 main active ingredients of PPR were screened,and 155 related targets related to CRA were unearthed.Protein-protein interaction results showed that PPR’s core proteins for CRA intervention correlate to STAT3,SRC,MAPK3,MAPK1,PIK3R1,PIK3CA,and AKT.Multiple signaling pathways were closely related to the treatment of CRA intervened by PPR,including the PI3K-Akt signaling pathway,HIF-1 signaling pathway,JAK-STAT3 signaling pathway,TNF-αsignaling,cytokine signaling pathway and NF-kappB signaling pathway,which are closely involved in the proliferation and differentiation of hematopoietic stem cell and inflammatory response.Molecular docking results showed that these potential targets had good conformation with the core active components of RRP for treating CRA.Conclusion:This study revealed RRP’s main active components and potential molecular mechanisms in treating CRA,providing a reference for subsequent basic research.

循环肿瘤细胞在肺癌精准医疗中的研究进展

肺癌是最常见的恶性肿瘤,也是癌症死亡的主要原因。循环肿瘤细胞(circulating tumor cells,CTCs)是从原发病灶或转移病灶脱落到外周血的肿瘤细胞,可在远处播散并引发肿瘤转移。现CTCs的研究已逐渐深入分子层面,CTCs携带的潜在临床信息也进一步被开发,在指导治疗、揭示转移机制、评估程序性细胞凋亡配体1(programmed cell death-ligand 1,PD-L1)表达等方面有巨大的潜在临床价值。本文就CTCs在肺癌精准医疗中的研究进展进行综述,并探讨CTCs与循环游离DNA(circulating free DNA,cfDNA)检测在肺癌中的互补意义,以期为肺癌的临床检测及个体化治疗提供新思路。

经动脉化疗栓塞术对肝癌乙肝病毒再激活的影响及抗病毒药物的治疗作用

经动脉化疗栓塞(transarterial chemoembolization,TACE)是治疗不能切除肝细胞癌(hepatocellularcarcinoma, HCC)的首选治疗方法,被证实能延长不能切除HCC患者的存活时间.然而,近期研究发现:TACE可能诱发HCC的乙肝病毒(hepatitis B virus,HBV)再激活, HBV-DNA大量复制,从而诱发HBV相关肝炎,甚至肝衰竭,导致HCC病人死亡,而术前应用抗病毒药物则可能降低术后HBV的再激活,改善病人的存活.本文将TACE对HCC-HBV再激活的影响及抗病毒药物对HBV再激活的抑制作用以及术后存活的影响进行综述.

非线性和复杂动态供应网络研究:系统文献综述

此综述的目的是探究复杂性理论在供应网络中的应用,及其对供应链管理发展的影响。文章采用了可重现的、科学和透明的系统文献综述(Systematic LiteratureReview)方法,对Scopus、BusinessSource Complete(EBSCO)和ABI/INFORMComplete(ProQuest)三个数据库中2001—2021年间的51篇样本文献进行了描述性和专题分析。在综述过程中,归纳了四个供应网络复杂性的驱动因素和两个基本特征,同时总结了两种用于测量复杂性的常见模型。与此前研究不同的是,此综述认为并非所有供应网络复杂性的来源都是坏事。未来的研究可以对不同维度的复杂性以及它们之间的关系进一步调查,建立起供应网络应用中的新思维,以应对供应网络复杂性新常态中的挑战。

晚期非小细胞肺癌维持治疗的研究进展

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