检索结果-南通市图书馆

Operando electrochemical SERS monitors nanoparticle reactions by capping agent fingerprints

Nano Research 2022年第5期15卷 4517-4524页

作者： Kevin Wonner Steffen Murke Serena RAlfarano Pouya Hosseini Martina Havenith Kristina Tschulik chair of Analytical chemistry Ⅱ Faculty of Chemistry and BiochemistryRuhr University BochumBochum 44801Germany chair of Physical chemistry Ⅱ Faculty of Chemistry and BiochemistryRuhr University BochumBochum 44801Germany

Nanomaterials are frequently employed in daily life goods,including health,textile,and food industry.A comprehensive picture is lacking on the role of the capping agents,added ligand molecules,in case of nanoparticle reactions and degradation in aqueous solutions,like surface waters or ***,we aim to elucidate the capping agent influence on nanoparticle reactivity probing two commonly employed capping agents citrate and polyvinylpyrrolidone(PVP).Their influence on silver nanoparticle(AgNP)transformation is studied,which is particularly important due to its application as an antimicrobial *** induce oxidation and reduction processes of AgNPs in halide solutions and we monitor the associated transformations of particles and capping agents by spectro-electrochemical surface-enhanced Raman spectroscopy(SERS).Raman bands of the capping agents are used here to track chemical changes of the nanoparticles under operando *** sparingly soluble and non-plasmon active silver salts(AgBr and AgCl)are formed under potential *** addition,we spectroscopically observe plasmon-mediated structural changes of citrate to cis-or trans-aconitate,while PVP is *** different behavior of the capping agents implies a change in the physical properties on the surface of AgNPs,in particular with respect to the surface ***,we showcase that reactions of the capping agents induced by different external stimuli,such as applied bias or laser irradiation,can be *** results demonstrate how SERS of capping agents can be exploited to operando track nanoparticle conversions in liquid *** approach is envisaged to provide a more comprehensive understanding of nanoparticle fates in complex liquid environments and varied redox conditions.

关键词： capping agent electrochemical surface-enhanced Raman spectroscopy silver nanoparticle nanoparticle reaction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Crystal Growth of[Ca3Al(OH)6·12H2O]2·(SO4)3·2H2O (Ettringite) Studied Under Microgravity Conditions

引用

Journal of Wuhan University of Technology(Materials Science) 2020年第5期35卷 893-899页

作者： Meier M R LEI L Rinkenburger A Plank J Technische Universitat Miinchen Chair for Construction Chemistry85747 GarchingLichtenbergstrafie 4Germany

On parabolic flights,the growth of ettringite,[Ca3Al(OH)6·12H2O]2·(SO4)3·2H2O,a major reaction product of cement with water which forms instantaneously,was crystallized under microgravity conditions and *** the experiments,Ca(OH)2/Al2(SO4)3 solutions were combined and reacted for 10?s,followed by immediate filtration of the suspension and subsequent quenching with *** the ettringite crystals,the size,aspect ratios,quantity and morphology were determined and the results were compared with those from identical experiments performed under terrestric *** microgravity,generally smaller crystals (l-2.9 μm) precipitated in larger amount than under normal gravity (l-3.5 μm).The aspect ratios of the crystals grown under terrestric or microgravity condition were comparable at about *** is assumed that the reason for the smaller ettringite crystals is the absence of convection leading to more initial nuclei,but slower crystal growth which is diffusion ***,no preference relative to the ion transport to the different faces of the crystals *** results contribute to the understanding of the mineralization of inorganic salts under microgravity conditions for which hitherto only a handful of examples were reported.

关键词： crystallization ettringite microgravity morphology nucleation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Carotenoids: New Applications of “Old” Pigments

引用

Phyton-International Journal of Experimental Botany 2021年第4期90卷 1041-1062页

作者： Stefan M.Kolašinac Zora P.DajićStevanović Sofija N.Kilibarda AleksandarŽ.Kostić Faculty of Agriculture University of BelgradeChair of AgrobotanyBelgrade11080Serbia Faculty of Agriculture University of BelgradeChair of Chemistry and BiochemistryBelgrade11080Serbia

Carotenoids represent a large group of mainly red,orange,and yellow natural metabolites mainly involved in regulation of many metabolic *** are beneficial for human *** study describes the importance,chemical composition and functioning of *** is well known that carotenoids support pigments acting in light absorbance mechanisms during photosynthesis,and are known to protect the chlorophyll molecules from oxidative stress and reactive oxygen species(ROS)*** are involved in signaling processes in plants,responses to environmental stresses,pollination,germination and reproduction,and development *** nutrients of strong antioxidant activity that is primarily linked to their polyene molecular structure,the carotenoids are reported as immune-enhancement and anticancer agents,which are also involved in prevention of eye-,gastric and neurocognitive disorders,and in regulation of obesity and *** the wide prospective applications of carotenoids as pharmaceuticals and nutraceuticals,there are some critical aspects associated with carotenoids’bioavailability and challenges in their *** mostly refers to the needs for identification and cloning of genes responsible for carotenoid biosynthesis and transformation and related development of transgenic carotenoid-rich *** the recent years,technologies of micro-and nanoencapsulation have addressed the needs of carotenoid entrapping to enhance their bioavailability,solubility and chemical stability,and to ensure the target delivery and manifestation of their strong antioxidant and other biological *** standard and some advanced analytic tools for carotenoid determination(e.g.,High performance liquid chromatography-HPLC,Liquid chromatography–mass spectrometry-LC-MS,Ultra high performance liquid chromatography-UHPLC,High-performance thin-layer chromatography-HPTLC and others),the vibrational spectroscopy techniques,primaril

关键词： Antioxidant and biological activity biosynthesis of carotenoids encapsulation raman spectroscopy role in plants

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The role of polysulfide-saturation in electrolytes for high power applications of real world Li-S pouch cells

引用

Nano Research 2023年第6期16卷 8313-8320页

作者： Tom Boenke Sebastian Kirchhoff Florian SReuter Florian Schmidt Christine Weller Susanne Dörfler Kai Schwedtmann Paul Härtel Thomas Abendroth Holger Althues Jan J.Weig Stefan Kaskel Technische Universität Dresden Chair of Inorganic Chemistry IBergstr.6601069 DresdenGermany Fraunhofer Institute for Material and Beam Technology(IWS) Winterbergstr.2801277 DresdenGermany Technische Universität Dresden Chair of Inorganic Molecular ChemistryMommsenstraße 401069 DresdenGermany

The lithium-sulfur(Li-S)technology is the most promising candidate for next-generation batteries due to its high theoretical specific energy and steady progress for applications requiring lightweight batteries such as aviation or heavy electric *** these applications,however,the rate capability of Li-S cells requires significant *** electrolyte formulations in Li-S batteries enable new pathways for cell development and adjustment of all ***,their rate capability at pouch cell level is often neither evaluated nor compared to state of the art(SOTA)LiTFSI/dimethoxyethane/dioxolane(LITFSI:lithium-bis(trifluoromethylsulfonyl)imide)***,the combination of the sparingly polysulfide(PS)solvating hexylmethylether/1,2-dimethoxyethane(HME/DME)electrolyte and highly conductive carbon nanotube Buckypaper(CNT-BP)with low porosity was evaluated in both coin and pouch cells and compared to dimethoxyethane/dioxolane reference *** advanced sulfur transfer melt infiltration was employed for cathode production with *** Li+ion coordination in the HME/DME electrolyte was investigated by nuclear magnetic resonance(NMR)and Raman ***,ionic conductivity and viscosity was investigated for the pristine electrolyte and a polysulfide-statured *** electrolytes,DME/DOL-1/1(DOL:1,3-dioxolane)and HME/DME-8/2,are then combined with CNT-BP and transferred to multi-layered pouch *** study reveals that the ionic conductivity of the electrolyte increases drastically over state of(dis)charge especially for DME/DOL electrolyte and lean electrolyte regime leading to a better rate capability for the sparingly polysulfide solvating *** evaluation in prototype cells is an important step towards bespoke adaption of Li-S batteries for practical applications.

关键词： lithium-sulfur pouch cell polysulfide solubility electrolyte characterization high power

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Endophytic fungi harbored in Cannabis sativa L.:diversity and potential as biocontrol agents against host plant-specific phytopathogens

引用

Fungal Diversity 2013年第3期60卷 137-151页

作者： Parijat Kusari Souvik Kusari Michael Spiteller Oliver Kayser Department of Biochemical and Chemical Engineering Chair of Technical BiochemistryTU DortmundEmil-Figge-Str.6644227 DortmundGermany Institute of Environmental Research(INFU)of the Faculty of chemistry Chair of Environmental Chemistry and Analytical ChemistryTU DortmundOtto-Hahn-Str.644221 DortmundGermany

The objective of the present work was isolation,phylogenetic characterization,and assessment of biocontrol potential of endophytic fungi harbored in various tissues(leaves,twigs,and apical and lateral buds)of the medicinal plant,Cannabis sativa L.A total of 30 different fungal endophytes were isolated from all the plant tissues which were authenticated by molecular identification based on rDNA ITS sequence analysis(ITS1,5.8S and ITS2 regions).The Menhinick’s index revealed that the buds were immensely rich in fungal species,and Camargo’s index showed the highest tissue-specific fungal dominance for the *** most dominant species was Penicillium copticola that could be isolated from the twigs,leaves,and apical and lateral buds.A detailed calculation of Fisher’s log series index,Shannon diversity index,Simpson’s index,Simpson’s diversity index,and Margalef’s richness revealed moderate overall biodiversity of *** endophytes distributed among its *** fungal endophytes were challenged by two host phytopathogens,Botrytis cinerea and Trichothecium roseum,devising a dual culture antagonistic assay on five different *** observed 11 distinct types of pathogen inhibition encompassing a variable degree of antagonism(%)on changing the *** revealed the potential chemodiversity of the isolated fungal endophytes not only as promising resources of biocontrol agents against the known and emerging phytopathogens of Cannabis plants,but also as sustainable resources of biologically active and defensive secondary metabolites.

关键词： Cannabis sativa Endophytic fungi Fungal diversity Antagonism Botrytis cinerea Trichothecium roseum

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nanodispersed Oxides-Plasma-Chemical Synthesis and Properties

引用

Plasma Science and Technology 2007年第5期9卷 603-610页

作者： Gheorghi VISSOKOV Katerina ZAHARIEVA Institute of Catalysis Bulgarian Academy of SciencesSofia 1113Bulgaria chemistry chair St.Ivan Rilski University of Mining and GeologySofia 1700Bulgaria

We discuss the plasma-chemical synthesis and the properties of transition metals oxides, Al2O3, SiO2, rare-earth oxides, oxides for ceramics and metal-ceramics, and oxides used as catalysts. Bearing in mind the indisputable advantages of using plasma-chemically synthesized nanodispersed oxides for the needs of various industrial fields, we set out to review the articles published in the past few years devoted to the problems of plasma-chemical synthesis and characterization of nanodispersed oxides.

关键词： plasma synthesis nanodispersed oxides properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Preparation of composite tubular grafts for vascular repair via electrospinning

引用

Progress in Natural Science:Materials International 2012年第2期22卷 108-114页

作者： Salem S.Al-Deyab Mohamed El-Newehy Petrochemical Research chair Department of ChemistryCollege of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia Department of chemistry Faculty of ScienceTanta UniversityTanta 31527Egypt

A novel type of composite vascular graft was developed via electrospinning in the present *** and chitosan were blended to form the inner and outer ***(l-lactide-co-caprolactone)(P(LLA-CL))was selected as a material for the middle layer of composite vascular *** morphology and diameter of the composite grafts were studied by Scanning Electron Microscope(SEM).The results of mechanical tests showed that the composite scaffolds provided the whole grafts with better strength and flexibility compared with blended grafts,mainly due to the fact that the middle layer was P(LLA-CL).Cell viability studies with endothelial cells suggested a prompt adhesion and proliferation duo to the fact that the outer layer was collagen and *** microscopy demonstrated that a monolayer of endothelial cells could be formed after 7 days of *** above results indicated that the composite fibrous scaffolds could be a good candidate for blood vessel repair by electrospinning method.

关键词： Electrospinning Composite Vascular graft Endothelial cell Nanofiber

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Age-dependent peculiarities modulation of activity of aldehyde scavenger enzymes in mitochondria of rat thigh muscle during stress

引用

Frontiers in Biology 2016年第1期11卷 28-31页

作者： Vadim V. Davydov Evgenya R. Grabovetskaya Amjad Hamdallah chair of Biochemistry State Academican LP.Pavlov Medical University Ryazan 390026 Russia chair of Medical chemistry Kharkov National Medical University Kharkov 61022 Ukraine chair of Biochemistry EN. Karazin Kharkov National University Kharkov 61077 Ukraine

The purpose of this study was a comparative investigation of activity of aldehyde scavenger enzymes in mitochondrial fraction of a thigh muscle in intact and immobilized rats of different ages. It has been shown that 12- month-old （adult） rats have high basal levels of aldehyde dehydrogenase, aldehyde reductase and glutathione transferase activity in mitochondrial fraction of thigh muscle. Aldehyde dehydrogenase activity increases during immobilization stress in adult rats. This change promote to enhance the effectiveness of utilization of carbonyl products of free radical oxidation in mitochondria of skeletal muscle of 12-month-old rats during stress. Immobilization of old and pubertal rats is accompanied by metabolic preconditions leading to accumulation of endogenous aldehydes in mitochondria, and, as a result, to the injury of muscular fibers and intensification of sarcopenia manifestations.

关键词： aldehydes mitochondria muscle immobilization stress aging

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Vinylene-Linked Two-Dimensional Covalent Organic Frameworks:Synthesis and Functions

引用

Accounts of Materials Research 2021年第4期2卷 252-265页

作者： Shunqi Xu Marcus Richter Xinliang Feng Technische Universität Dresden Center for Advancing Electronics Dresden(cfaed)and Faculty of Chemistry and Food ChemistryChair of Molecular Functional Materials01069 DresdenGermany

Two-dimensional covalent organic frameworks(2D COFs)with covalently bonded repeat units and crystalline,porous framework backbones have attracted immense attention since the first 2D COFs were reported by Yaghi’s group in *** extended single-layer structures of 2D COFs are also generally considered to be the 2D *** precise incorporation of molecular building blocks into ordered frameworks enables the synthesis of novel organic materials with designable and predictable properties for specific applications,such as in optoelectronics,energy storage,and *** particular,the 2Dπ-conjugated COFs(2D-c-COFs)represent a unique class of 2D conjugated polymers that have 2D molecular-periodic structures with extended in-planeπ-*** the 2D-c-COFs,the conjugated skeletons andπ−πstacking interactions can provide the pathways for electron transport,while the porous channel can enable the loading of active sites for catalysis and *** far,the synthesis of 2D-c-COFs has been mostly limited to Schiff base chemistry based on the condensation reaction between amine and aldehyde/ketone monomers because the construction of 2D COFs as thermodynamically controlled products generally requires a highly reversible reaction for error-correction ***,the high reversibility of imine linkages would conversely endow moderateπ-electron delocalization due to the polarized carbon−nitrogen bonds and poor stability against strong acids/*** achieve robust and highly conjugated 2D-c-COFs,a series of synthesis strategies have been developed,including a one-step reversible reaction with a bond-forming−bond braking−bond reforming function,a quasi-reversible reaction combing reversible and irreversible processes,and postmodifications converting labile bonds to a robust *** all of the reported 2D-c-COFs,vinylene-linked(also sp^(2)-carbon-linked)2D covalent organic frameworks(V-2D-COFs)with high in-planeπ-conjugation have attracted increasing

关键词： conjugated bonds reversible

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Gadolinium doped tin dioxide nanoparticles: an efficient visible light active photocatalyst

引用

Journal of Rare Earths 2015年第12期33卷 1275-1283页

作者： Abdullah M Al-Hamdi Mika Sillanp?? Joydeep Dutta Laboratory of Green chemistry Lappeenranta University of Technology chair in Nanotechnology Water Research Center Sultan Qaboos University Functional Materials Division School of Information and Communication Technology KTH Royal Institute of Technology

Photocatalytic degradation of phenol with sol-gel prepared rare earth doped tin dioxide （SnO2） nanoparticles was reported. Gadolinium doped tin dioxide （SnO2：Gd） nanoparticles were found to absorb higher visible light compared to lanthanum, neodymium and cerium doped materials that were studied in detail. Photocatalytic degradation of phenol under artificial white light and sunlight in the presence of SnO2：Gd nanoparticles was studied with high performance liquid chromatography （HPLC）, capillary electrophoresis （CE）, total organic carbon （TOC） measurements and the determination of chemical oxygen demand （COD）. Clear correlations be- tween the results obtained from these multiple measurements were found, and a kinetic pathway for the degradation process was pro- posed. Within 150 min of solar irradiation, the TOC of a 10 ppm phenol solution in water was reduced by 95%-99%, thus demon- strating that SnO2：Gd nanoparticles are efficient visible light photocatalysts.

关键词： rare earth dopants solar irradiation phenol photo-degradation tin dioxide nanoparticles organic by-products

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：