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Improving contrast and sectioning power in confocal imaging by third harmonic generation in SiOx nanocrystallites

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Chinese Optics Letters 2007年第8期5卷 477-479页

作者： Gilbert boyer Karsten Plamann Laboratoire d'Optique Appliqude Ecole Polytechnique-Ecole Nationale Supérieure de Techniques A vancdes-CNRS UMR 7639 Centre de l'Yvette chemin de la Hunière 91761 Palaiseau cedex France

We present a new optical microscope in which the light transmitted by a sample-scanned transmission confocal microscope is frequency-tripled by SiOx nanocrystallites in lieu of being transmitted by a confocal pinhole. This imaging technique offers an increased contrast and a high scattered light rejection. It is demonstrated that the contrast close to the Sparrow resolution limit is enhanced and the sectioning power are increased with respect to the linear confocal detection mode. An experimental implementation is presented and compared with the conventional linear confocal mode.

关键词： mode Improving contrast and sectioning power in confocal imaging by third harmonic generation in SiO_x nanocrystallites THG

Emerging noble metal-free Mo-based bifunctional catalysts for electrochemical energy conversion

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Nano Research 2022年第12期15卷 10234-10267页

作者： Saswati Santra verena Streibel Ian D.Sharp Walter Schottky Institute and Physics Department Technical University of MunichAm Coulombwall 485748GarchingGermany

The transition from a global economy dependent on fossil fuels to one based on sustainable energy conversion technologies presents the primary challenge of the *** water electrolyzers and metal-air batteries with earth-abundant bifunctional transition metal(TM)catalysts that efficiently catalyse the hydrogen and oxygen evolution reactions(HER and OER)and the oxygen reduction and evolution reactions(ORR and OER),respectively,reduces the cost and system complexity,while also providing prospects for accelerated scaling and sustainable material *** the TMs,earth-abundant molybdenum(Mo)-based multifunctional catalysts are especially promising and have attracted considerable attention in recent *** with a brief introduction to HER,OER,and ORR mechanisms and parameters governing their bifunctionality,this comprehensive review focuses on such Mo-based multifunctional *** review and discuss recent progress achieved through the formation of Mo-based compounds,heterostructures,and nanoscale composites,as well as by doping,defect engineering,and nanoscale sculpting of Mo-based *** systems discussed in detail are based on Mo chalcogenides,carbides,oxides,nitrides,and phosphides,as well as Mo alloys,highlighting specific opportunities afforded by synergistic interactions of Mo with both non-metals and non-noble ***,we discuss the future of Mo-based multifunctional electrocatalysts for HER/OER,ORR/OER,and HER/ORR/OER,analysing emerging trends,new opportunities,and underexplored avenues in this promising materials space.

关键词： molybdenum-based electrocatalysts bifunctional electrocatalysts hydrogen evolution reaction oxygen reduction reaction oxygen evolution reaction

The endoplasmic reticulum: A dynamic and well-connected organelle

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Journal of Integrative Plant Biology 2015年第1期57卷 50-62页

作者： Chris Hawes Petra Kiviniemi verena Kriechbaumer Department of Biological and Medical Sciences Oxford Brookes University

The endoplasmic reticulum forms the first compart- ment in a series of organelles which comprise the secretory pathway, it takes the form of an extremely dynamic and pleomorphic membrane-bounded network of tubules and cisternae which have numerous different cellular functions. In this review, we discuss the nature of endoplasmic reticulum structure and dynamics, its relationship with closely associated organelles, and its possible function as a highway for the distribution and delivery of a diverse range of structures from metabolic complexes to viral particles.

关键词： Actin endomembranes Golgi microtubules myosin

Taking out the garbage:cathepsin D and calcineurin in neurodegeneration

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Neural Regeneration Research 2017年第11期12卷 1776-1779页

作者： Andreas Aufschnaiter verena Kohler Sabrina Büttner Institute of Molecular Biosciences University of GrazHumboldtstraBe 508010 GrazAustria Department of Molecular Biosciences The Wenner-Gren InstituteStockholm UniversitySvante Arrheniusvag 20C106 91 StockholmSweden

Cellular homeostasis requires a tightly controlled balance between protein synthesis, folding and degradation. Especially long-lived, post-mitotic cells such as neurons depend on an efficient proteostasis system to maintain cellular health over decades. Thus, a functional decline of processes contributing to protein degradation such as autophagy and general lysosomal proteolytic capacity is connected to several age-associated neurodegenerative disorders, including Parkinson＇s, Alzheimer＇s and Huntington＇s diseases. These so called proteinopathies are characterized by the accumulation and misfolding of distinct proteins, subsequently driving cellular demise. We recently linked efficient lysosomal protein breakdown via the protease cathep- sin D to the Ca2＋/calmodulin-dependent phosphatase calcineurin. In a yeast model for Parkinson＇s disease, functional calcineurin was required for proper trafficking of cathepsin D to the lysosome and for recycling of its endosomal sorting receptor to allow further rounds of shuttling. Here, we discuss these findings in relation to present knowledge about the involvement of cathepsin D in proteinopathies in general and a possible connection between this protease, calcineurin signalling and endosomal sorting in particular. As dysregulation of Ca2＋ homeostasis as well as lysosomal impairment is connected to a plethora of neurode- generative disorders, this novel interplay might very well impact pathologies beyond Parkinson＇s disease.

关键词： neurodegeneration Parkinson’s disease α-synuclein cathepsin D calcineurin retromer yeast lysosome endosomal sorting

Integrated Disaster Risk Management(IDRM):Elements to Advance Its Study and Assessment

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International Journal of Disaster Risk Science 2023年第3期14卷 343-356页

作者： Vicente Sandoval Martin Voss verena Florchinger Stephan Lorenz Parisa Jafari Disaster Research Unit Freie Universitat Berlin12165 BerlinGermany

This study analyzed the international key literature on integrated disaster risk management(IDRM),considering it a dynamic sociocultural process subjected to the historical process of social formation,offering a closer look at the concept while exploring conceptual elements and ideas to advance IDRM in both national and international ***,the study adopted a literature review strategy,following the Preferred Reporting Items for Systematic Reviews and MetaAnalyses(PRISMA)approach,combined with qualitative content *** article examines the history of IDRM,discusses current challenges for implementation,looks at some experiences,and proposes avenues for further *** findings point out the lack of an overarching IDRM approach,which is characterized by a rather disperse set of ideas and experiences concerning what IDRM is and how it should be operationalized,thereby revealing the need for a more comprehensive theory and methodologies to further advance *** findings highlight that IDRM encompasses different kinds and levels of"integrations"that go from internal(that is,disaster risk reduction and management domains)to external(that is,all societal processes such as sustainable development),including temporal and spatial ***,we are talking about a multidimensional integration of disaster risk *** this regard,the article proposes four dimensions for integration:sectoral,spatial/hierarchical,temporal,and externally with other cross-cutting societal challenges,especially climate change and sustainable *** dimensions cover 29 ideas for indicators or"proto-indicators"to guide the discussion,exploration,and analysis of IDRM in specific contexts.

关键词： Integrated disaster risk management Literature review Proto-indicators Sustainable development

Particle-size-dependent upconversion luminescence of NaYF4:Yb,Er nanoparticles in organic solvents and water at different excitation power densities

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Nano Research 2018年第12期11卷 6360-6374页

作者： Marco Kraft Christian Würth verena Muhr Thomas Hirsch Ute Resch-Genger Federal Institute for Matefiab Research and Testing (BAM) Division1.2BiophotonicsRichard-Willstaetter-Str.1112489BerlinGermany Institute of Analytical Chemistry Chemo-and BiosensorsUniversity of Regensburg93040RegensburgGermany

A systematic study of the luminescence properties of monodisperse β-NaYF4: 20% Yb3+, 2% Er3+ upconversion nanoparticles (UCNPs) with sizes ranging from 12-43 nm is presented utilizing steady-state and time-resolved fluorometry. Special emphasis was dedicated to the absolute quantification of size- and environment-induced quenching of upconversion luminescence (UCL) by high-energy O-H and C-H vibrations from solvent and ligand molecules at different excitation power densities (P). In this context, the still-debated population pathways of the 4F9/2 energy level of Er3+ were examined. Our results highlight the potential of particle size and P value for color tuning based on the pronounced near-infrared emission of 12 nm UCNPs, which outweighs the red Er3+ emission under “strongly quenched” conditions and accounts for over 50% of total UCL in water. Because current rate equation models do not include such emissions, the suitability of these models for accurately simulating all (de)population pathways of small UCNPs must be critically assessed. Furthermore, we postulate population pathways for the 4F9/2 energy level of Er3+, which correlate with the size-, environment-, and P-dependent quenching states of the higher Er3+ energy levels.

关键词： upconversion nanoparticle quenching diameter water cyclohexane

Manufacturing of Long Products Made of Innovative Lightweight Materials

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Acta Metallurgica Sinica(English Letters) 2015年第12期28卷 1496-1502页

作者： Karsten Richter Roland Müller Andreas Kunke verena Kr? usel Dirk Landgrebe Fraunhofer Institute for Machine Tools and Forming Technology (IWU) Professorship Forming and Joining (UFF) Technische Universit?t Chemnitz

The processing of innovative lightweight materials to sheet metal components and assemblies with globally or locally defined properties is the object of this work. It takes a load-dependent design of components and assemblies, for example, based on the composition of different construction materials or a targeted setting of component areas with specified characteristics to fully exploit the lightweight potential when substituting conventionally used materials. Different process chains for the manufacturing of roll-formed long products made of magnesium alloys and high-strength steels with locally defined properties will be presented in this paper. Depending on the kind of material to be formed and the desired product characteristics, different temperature managements are needed for capable processes. Due to limited formability at room temperature, magnesium alloys require a heating of the forming zones above 200–225 °C throughout the bending process in order to activate additional gliding planes and to avoid any failures in the radii. The realization of local hardening effects requires at least one process-integrated heat treatment when roll forming manganese–boron steels. For both processes, it is imperative to realize a heating and cooling down or quenching appropriate for the manufacturing of long products with the required quality. Additionally, proper line speeds that allow a continuously operated economical production have to be considered. Research results including design, FEA, realization and experimentation of the mentioned process chains and strategies will be described in detail.

关键词： Roll forming Heat treatment Lightweight component Light metals Manganese steels AZ31 magnesium alloy

Nitrogen further promotes a dominant salt marsh plant in an increasingly saline environment

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Journal of Plant Ecology 2012年第4期5卷 429-441页

作者： Amelia Byrd Ryan Katharyn E.boyer Romberg Tiburon Center for Environmental Studies San Francisco State University3152 Paradise DriveTiburonCA 94920USA Department of Biology San Francisco State University1600 Holloway AvenueSan FranciscoCA 94132 USA

Aims Human alterations of the environment are combining in unprecedented ways,making predictions of alterations to natural communities a difficult and pressing *** systems have been subject to a high degree of modification,including increased nitrogen(N)inputs and altered salinity,factors important in shaping estuarine plant *** human populations increase and the climate changes,both N and salinity levels are likely to increase in these coastal *** objective was to evaluate the interactive effects of N and salinity on USWest Coast salt marsh species;in particular,the performance of the dominant species Sarcocornia pacifica(pickleweed)alone and in mixed species *** expected increased salinity to favor *** but that N enrichment could help maintain greater species richness through use of N in salinity tolerance *** We crossed treatments of N(added or not)and salinity(salt added or not)in a field experiment at a salt marsh in the San Francisco Estuary,California,USA,in each of three habitats:(i)monotypic pickleweed on the marsh plain,(ii)monotypic pickleweed along channels and(iii)mixed assemblages along *** a greenhouse experiment,we crossed treatments of N(added or not)and salinity(at three levels to simulate brackish to saline conditions)in(i)pots of pickleweed only and(ii)the same species mix as in the *** Findings Naddition doubled *** biomass and branching in both channel and marsh plain habitats regardless of salinity and greatly increased its dominance over Distichlis spicata and Jaumea carnosa in mixed assemblages along *** the greenhouse,*** biomass increased 6-to 10-fold with N addition over the range of salinities,while *** and *** biomass increased with N addition only at lower salinity ***,while localized management could influence outcomes,expected overall increases in both N and salinity with human population growth and climat

关键词： Distichlis eutrophication Jaumea salinity Sarcocornia

Two-Photon Direct Laser Writing Beyond the Diffraction Limit Using the Nanopositioning and Nanomeasuring Machine

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Nanomanufacturing and Metrology 2021年第3期4卷 149-155页

作者： Laura Mohr-Weidenfeller Annika-verena Hacker Carsten Reinhardt Eberhard Manske Microsystems Technology Group Ilmenau University of TechnologyMax-Planck-Ring 12IlmenauGermany Institute for Process Measurement and Sensor Technology Ilmenau University of TechnologyGustav-Kirchhoff-Str.1IlmenauGermany Bremen University of Applied Science Neustadtswall 30BremenGermany

Since the first realization of two-photon direct laser writing(DLW)in Maruo et al.(Opt Lett 22:132-134,1997),the manufacturing using direct laser writing techniques spread out in many laboratories all over the *** materials with different material properties open a new field for micro-and *** achievable structuring resolution using this technique is reported to be sub-100 nm(Paz et *** *** Appl.24:042004,2012),while a smallest linewidth of 25 nm could be shown in Tan et al.(Appl Phys Lett 90:071106,2007).In our approach,the combination of DLW with the nanopositioning and nanomeasuring machine NMM-1 offers an improvement of the technique from the engineering side regarding the ultra-precise positioning(Weidenfeller et *** Adv Fabr Technol Micro/Nano Opt Photon Ⅺ 10544:105440E,2018).One big benefit besides the high positioning resolution of 0.1 nm is offered by the positioning range of 25 mm×25 mm×5 mm(Jager et *** Technisches Messen 67:319-323,2000;Manske et *** Meas Sci Technol 18:520-527,2007).Thus,a trans-scale fabrication without any stitching or combination of different positioning systems is *** immense synergy between the highly precise positioning and the DLW is demonstrated by the realization of resist lines and trenches whose center-to-center distance undergoes the modified diffraction limit for two-photon *** precise positioning accuracy enables a defined distance between illuminated ***,with a comparable huge width of the trenches of 1.655|im due to a low effective numerical aperture of 0.16,a resist line of 30 nm between two written trenches could be *** the interrelationships for achieving such narrow trenches have not yet been clarified,much smaller resist lines and trench widths are possible with this approach in the near future.

关键词： Direct laser writing Nanopositioning and nanomeasuring machine Two-photon absorption Laser power controlling