检索结果-南通市图书馆

Oligomeric and fibrillar species of β-amyloid(Aβ42) both impair mitochondrial function in P301L tau transgenic mice

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

世界最新医学信息文摘 2015年第A期 8-8页

作者： Anne Eckert Susanne Hauptmann Isabel Scherping Jessica Meinhardt Virginie Rhein stefan dr?se Ulrich Brandt Marcus F?ndrich Walter E.Müller Jürgen G?tz

We recently provided evidence for a mitochondrial dysfunction in P301 l tau transgenic mice, a strain modeling the tau pathology of alzheimer's disease(ad) and frontotemporal dementia(ftd). in addition to tau aggregates, the ad brain is further characterized by Aβ peptide-containing plaques. When we addressed the role of Aβ, this indicated a synergistic action of tau and Aβ pathology on the mitochondria. In the present study, we compared the toxicity of different Aβ42 conformations in light of recent studies suggesting that oligomeric rather than fibrillar Aβ might be the actual toxic species. Interestingly, both oligomeric and fibrillar, but not disaggregated(mainly monomeric) Aβ42 caused a decreased mitochondrial membrane potential in cortical brain cells obtained from FTD P301 L tau transgenic mice. This was not observed with cerebellar preparations indicating selective vulnerability of cortical neurons. Furthermore, we found reductions in state 3 respiration, the respiratory control ratio, and uncoupled respiration when incubating P301 L tau mitochondria either with oligomeric or fibrillar preparations of Aβ42. Finally, we found that aging specifically increased the sensitivity of mitochondria to oligomeric Aβ42 damage indicating that oligomeric and fibrillar Aβ42 are both toxic, but exert different degrees of toxicity.

关键词： Alzheimer’s disease Amyloid aggregates Amyloid β-peptide Amyloid toxicity Fibrils Frontotemporal dementia Globulomer Mitochondria oligomer Protein aggregation respiration tau transgenic mice

Oligomeric and fibrillar species of β-amyloid(A β 42) both impair mitochondrial function in P301L tau transgenic mice

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

世界最新医学信息文摘 2015年第99期 1-1页

作者： Anne Eckert Susanne Hauptmann Isabel Scherping Jessica Meinhardt Virginie Rhein stefan dr?se Ulrich Brandt Marcus F?ndrich Walter E.Müller Jürgen G?tz

We recently provided evidence for a mitochondrial dysfunction in P301L tau transgenic mice, a strain modeling the tau pathology of alzheimer's disease(ad) and frontotemporal dementia(ftd). in addition to tau aggregates, the ad brain is further characterized by Aβ peptide-containing plaques. When we addressed the role of Aβ, this indicated a synergistic action of tau and Aβ pathology on the mitochondria. In the present study, we compared the toxicity of different Aβ42 conformations in light of recent studies suggesting that oligomeric rather than fibrillar Aβ might be the actual toxic species. Interestingly, both oligomeric and fibrillar, but not disaggregated(mainly monomeric) Aβ42 caused a decreased mitochondrial membrane potential in cortical brain cells obtained from FTD P301L tau transgenic mice. This was not observed with cerebellar preparations indicating selective vulnerability of cortical neurons. Furthermore, we found reductions in state 3 respiration, the respiratory control ratio, and uncoupled respiration when incubating P301L tau mitochondria either with oligomeric or fibrillar preparations of Aβ42. Finally, we found that aging specifically increased the sensitivity of mitochondria to oligomeric Aβ42 damage indicating that oligomeric and fibrillar Aβ42 are both toxic, but exert different degrees of toxicity.

Towards greener polymers:Trends in the German chemical industry

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Green Carbon 2024年第1期2卷 33-44页

作者： Adam W.Franz stefan Buchholz Rolf W.Albach Rolf Schmid BASF se Ludwigshafen 67056Germany Evonik Operations GmbH Hanau 63457Germany Association for Chemistry and Economics German Chemical SocietyFrankfurt am Main 60444Germany Stuttgart University and Bio4Business Stuttgart 70569Germany

Global plastics production is expected to exceed 400 million tons and reach 600 million tons by *** synthesis currently accounts for approximately 3%of global greenhouse gas *** 60%of all polymers are produced for *** include shopping bags,packaging materials,mulch films,and soluble polymers for cosmetics and other ***,only a portion of single-use plastic is recycled or disposed of in incinerators or *** estimated 20%is not disposed of properly and pollutes the global environment,especially the *** response to these challenges,the United Nations,European Union,and many nation-states are developing regulatory frameworks that encourage the chemical industry to produce plastics with a smaller environmental footprint and often support this through research *** solutions include:(1)the use of green energy,green hydrogen,bio-based feedstocks,or CO_(2) in synthesis;(2)the reuse or recycling of plastics through conversion or pyrolysis;and(3)the production of biodegradable *** German chemical industry contributes approximately one-third of polymer production in the *** is embedded in the EU regulatory and research landscape and anchored in the European Green Deal,which aims for carbon neutrality by *** this paper,we describe how BASF and Evonik,two leading German chemical companies with strong but different polymer portfolios,respond to the call for greener polymers and how technologies are being developed to make polyurethanes,a particularly important and difficult-to-recycle family of elastomers and duromers,renewable and *** the environmental footprint of plastics requires not only innovative materials but also proper governance,regulatory and collection systems,and public willingness to *** an international comparison of these competencies,expressed by the"polymer management index"(PMI),Germany achieved a top position.

关键词： Plastics recycling Biobased plastics Biodegradable plastics Polymer management index European Green Deal

Lensless diffractive imaging with ultra-broadbandtable-top sources: from infrared to extreme-ultravioletwavelengths

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2014年第1期3卷 274-281页

作者： stefan Witte Vasco T Tenner Daniel WE Noom Kjeld se Eikema LaserLaB Amsterdam VU University Amsterdam1081 HV AmsterdamThe Netherlands Present address:Huygens-Kamerlingh Onnes Laboratorium Universiteit Leiden2333 CA LeidenThe Netherlands

Lensless imaging is an approach to microscopy in which a high-resolution image of an object is reconstructed from one or more measured diffraction patterns,providing a solution in situations where the use of imaging optics is not ***,current lensless imaging methods are typically limited by the need for a light source with a narrow,stable and accurately known *** have developed a general approach to lensless imaging without spectral bandwidth limitations or sample *** use two time-delayed coherent light pulses and show that scanning the pulse-to-pulse time delay allows the reconstruction of diffraction-limited images for all the spectral components in the *** addition,we introduce an iterative phase retrieval algorithm that uses these spectrally resolved Fresnel diffraction patterns to obtain high-resolution images of complex extended *** demonstrate this two-pulse imaging method with octave-spanning visible light sources,in both transmission and reflection geometries,and with broadband extreme-ultraviolet radiation from a high-harmonic generation *** approach enables effective use of low-flux ultra-broadband sources,such as table-top high-harmonic generation systems,for high-resolution imaging.

关键词： coherent diffractive imaging extreme ultraviolet Fourier transform spectroscopy high-harmonic generation lensless imaging

Heterocyclization of thiocarbonohydrazides:Facile synthesis of 5-unsubstituted-1,3,4-thiadiazoles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2015年第9期26卷 1183-1186页

作者： Alaa A.Hassan Fathy F.Abdel-Latif Mohamed Abdel Aziz Sara M.Mostafa stefan Brse Martin Nieger Chemistry Department Faculty of ScienceMinia University Department of Medicinal Chemistry Faculty of PharmacyEl-Minia University Institute of Organic Chemistry Karlsruhe Institute of TechnologyFritz-Haber-Weg 676131 KarlsruheGermany Laboratory of Inorganic Chemistry Department of ChemistryUniversity of Helsinki

2-（Hydrazinecarbothioyl）-N-substituted hydrazinecarbothioamides react with 2,3,5,6-tetrachloro-1,4-benzoquinone in high yields in a novel fast and facile method to give 5-unsubstituted-1,3,4-thiadiazole-2-amine *** synthesized compounds were characterized by spectroscopic methods and confirmed by using X-ray crystallography.A rationale for the formation of the products is presented.

关键词： Thiocarbonohydrazides 5-Unsubstituted 1 3 4-thiadiazol-2-amines Tetrachloro-1 4-benzoquinone X-ray crystallography

维普期刊数据库

Neuromorphic devices based on fluorite-structured ferroelectrics

在线全文

学校读者我要写书评

暂无评论

InfoMat 2022年第12期4卷 1-32页

作者： Dong Hyun Lee Geun Hyeong Park se Hyun Kim Ju Yong Park Kun Yang stefan Slesazeck Thomas Mikolajick Min Hyuk Park Department of Materials Science and Engineering&Inter-University semiconductor Research Center College of EngineeringSeoul National UniversitySeoulRepublic of Korea Research Institute of Advanced Materials Seoul National UniversitySeoulRepublic of Korea NaMLab gGmbH DresdenGermany Institute of Engineering Research Seoul National UniversitySeoulRepublic of Korea

A continuous exponential rise has been observed in the storage and processing of the data that may not curtail in the foreseeable *** required data processing speed and power consumption are restricted by the buses between the logic and memory devices that are characteristic of the von Neumann computing ***-mimicking neuromorphic computing has garnered considerable academic and industrial interest to resolve these ***,devices based on emerging nonvolatile memories capable of mimicking the behaviors of synapses and neurons,which are the main elements in biological computing systems(brains),are attracting significant interest from the device *** the discovery of ferroelectricity in fluorite-structured oxides,such as HfO2 and ZrO2,which are compatible with the state-of-the-art complementary-metal-oxide-semiconductor processes,ferroelectric devices have rapidly evolved as the main direction of these research and development *** science related to fluorite-structured ferroelectrics has been intensively studied over the last *** present,the focus is gradually moving to practical applications,including neuromorphic computing and advanced classical processing or memory units in the conventional von Neumann ***,despite its rapid development,the wealth of recent progress in neuromorphic computing devices based on fluorite-structured ferroelectrics has not been reviewed and *** progress report comprehensively reviews and systemizes the recent progress in artificial synaptic and spiking neuron devices for neuromorphic computing based on fluorite-structured ferroelectrics.

关键词： ferroelectrics hafnia neuromorphic computing semiconductor devices

Galerkin Spectral Method Applied to the Chemical Master Equation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2009年第5期5卷 871-896页

作者： stefan Engblom Department of Information Technology Uppsala UniversityP.O.Box 337SE-75105 UppsalaSweden

Stochastic well-stirred chemically reacting systems can be accurately modeled by a continuous-time *** corresponding master equation evolves the system’s probability density function in time but can only rarely be explicitly *** investigate a numerical solution strategy in the form of a spectral method with an inherent natural adaptivity and a very favorable choice of basis *** results related to convergence have been developed previously and are briefly summarized while implementation issues,including how to adapt the basis functions to follow the solution they represent,are covered in more detail *** method is first applied to a model problem where the convergence can easily be *** we take on two more realistic systems from molecular biology where stochastic descriptions are often necessary to explain experimental *** conclusion is that,for sufficient accuracy demands and not too high dimensionality,the method indeed provides an alternative to other methods.

关键词： Master equation spectral-Galerkin method high dimensional problem moving basis chemical reactions

Efficient Sampling in Event-driven Algorithms for Reaction-Diffusion Processes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2013年第4期13卷 958-984页

作者： Mohammad Hossein Bani-Hashemian stefan Hellander Per Lotstedt Division of Scientific Computing Department of Information TechnologyUppsala UniversityP.O.Box 337SE-75105 UppsalaSweden

In event-driven algorithms for simulation of diffusing,colliding,and reacting particles,new positions and events are sampled from the cumulative distribution function(CDF)of a probability *** distribution is sampled frequently and it is important for the efficiency of the algorithm that the sampling is *** CDF is known analytically or computed *** formulas are sometimes rather complicated making them difficult to *** CDF may be stored in a table for interpolation or computed directly when it is *** alternatives are compared for chemically reacting molecules moving by Brownian diffusion in two and three *** best strategy depends on the dimension of the problem,the length of the time interval,the density of the particles,and the number of different reactions.

关键词： Event-driven algorithm chemical reactions diffusion efficient sampling

On Diffuse Interface Modeling and Simulation of Surfactants in Two-Phase Fluid Flow

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2013年第9期14卷 879-915页

作者： stefan Engblom Minh Do-Quang Gustav Amberg Anna-Karin Tornberg Division of Scientific Computing Department of Information TechnologyUppsala UniversitySE-75105 UppsalaSweden Linne Flow Centre Department of MechanicsSchool of Engineering ScienceRoyal Institute of TechnologyS-10044 StockholmSweden Linne Flow Centre Department of Numerical AnalysisSchool of Computer Science and CommunicationRoyal Institute of TechnologyS-10044 StockholmSweden

An existing phase-fieldmodel of two immiscible fluids with a single soluble surfactant present is discussed in *** analyze the well-posedness of the model and provide strong evidence that it is mathematically ill-posed for a large set of physically relevant *** a consequence,critical modifications to the model are suggested that substantially increase the domain of *** designed numerical simulations offer informative demonstrations as to the sharpness of our theoretical results and the qualities of the physical model.A fully coupled hydrodynamic test-case demonstrates the potential to capture also non-trivial effects on the overall flow.

关键词： Phase-field model Cahn-Hilliard equation surface active agent Ginzburg-Landau free energy well-posedness