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Microsystems & Nanoengineering 2021年第3期7卷 111-123页

作者： Anton Melnikov Hermann A.G.Schenk Jorge M.Monsalve franziska wall Michael Stolz Andreas Mrosk Sergiu Langa Bert Kaiser Fraunhofer Institute for Photonic Microsystems IPMS Dresden 01109Germany Arioso Systems GmbH Dresden 01109Germany Brandenburg University of Technology Cottbus-Senftenberg Cottbus 03046Germany

Electrostatic micromechanical actuators have numerous applicati ons in scie nee and *** many applications,they are operated in a narrow frequency range close to resonanee and at a drive voltage of low ***,new applications,such as microelectromechanical systems(MEMS)microspeakers(μSpeakers),have emerged that require operation over a wide frequency and dynamic *** the dynamic performance under such circumstances is still highly ***-of-the-art finite element analysis struggles with pull-in instability and does not deliver the necessary in formation about un stable equilibrium states *** lumped-parameter models amenable to direct physical interpretation are *** inhibits the in dispensable in-depth analysis of the dynamic stability of such *** this paper,we take a major step towards mending the *** combining the finite element method(FEM)with an arc-length solver,we obtain the full bifurcation diagram for electrostatic actuators based on prismatic Euler-Bernoulli beams.A subsequent modal analysis then shows that within very narrow error margins,it is exclusively the lowest Euler-Bernoulli eigenmode that dominates the beam physics over the entire relevant drive voltage *** experiment directly recording the deflection profile of a MEMS microbeam is performed and confirms the numerical findings with astonishing *** enables modeling the system using a single spatial degree of freedom.

关键词： bifurcation modal narrow

The push-pull principle:an electrostatic actuator concept for low distortion acoustic transducers

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Microsystems & Nanoengineering 2022年第6期8卷 181-194页

作者： Bert Kaiser Hermann A.G.Schenk Lutz Ehrig franziska wall Jorge M.Monsalve Sergiu Langa Michael Stolz Anton Melnikov Holger Conrad David Schuffenhauer Harald Schenk Fraunhofer Institute for Photonic Microsystems IPMS DresdenGermany Arioso Systems GmbH since Sep.1st 2022:BOSCH Sensortec GmbHDresdenGermany Chair of Micro and Nano Systems Brandenburg University of Technology Cottbus-SenftenbergCottbusGermany

Electrostatic actuators are of particular interest for microsystems(MEMS),and in particular for MEMS audio transducers for use in advanced true wireless *** are attractive because of their typically low electrical capacitance and because they can be fabricated from materials that are compatible with standard complementary metal-oxide semiconductor(CMOS)*** high audio performance and in particular low harmonic distortion(THD)the implementation of the push-pull principle provides strong *** an arrangement of three electrodes in a conjunct moving configuration on a beam,we demonstrate here for the first time a balanced bending actuator incarnating the push-pull principle operating at low *** first design already exhibits a harmonic distortion as low as 1.2%at 79 dB using a signal voltage of only 6 V_(p) and a constant voltage of only±10 V_(dc) in a standard acoustic measurement ***,exceeding our previously reported approach in all three key performance indications at the same *** expect that our novel electrode configurations will stimulate innovative electrostatic actuator developments for a broad range of *** this paper we report the basic theory,the fabrication and the performance of our novel actuator design acting as an audio transducer.

关键词： distortion push electrostatic

Coordination of Schwann cell myelination and node formation at the transcriptional level

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Neural Regeneration Research 2022年第6期17卷 1269-1270页

作者： franziska Fröb Michael Wegner Institut für Biochemie Emil-Fischer-ZentrumFriedrich-Alexander-Universität Erlangen-NürnbergErlangenGermany

Formation of the node of Ranvier as a highly coordinated event:Saltatory conduction ensures that information in the vertebrate nervous system is rapidly transmitted over large distances and efficiently processed in complex *** requires the insulation of axonal segments by myelin and the formation of highly structured nodes of Ranvier that are interspersed at regular intervals between successive myelin sheaths and regenerate the action potential as it propagates along the nerve(Rasband and Peles,2021).

关键词： successive insulation conduction

Impact of alpha-synuclein pathology on adult neurogenesis: evidence for multilayered mechanisms

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Neural Regeneration Research 2022年第7期17卷 1491-1492页

作者： Jana Bonsberger franziska Richter Milos Stanojlovic Department of Pharmacology Toxicology and PharmacyUniversity of Veterinary MedicineHannoverGermany

Parkinson’s disease(PD)is the second most common neurodegenerative disease affecting 8–10 million people ***,PD is the fastest-growing neurodegenerative disease and it is predicted that the number of patients will double in the next thirty ***,PD is characterized by the presence of protein aggregations called Lewy bodies(LB)and by degeneration of dopaminergic neurons in the substantia nigra pars compacta.

关键词： degeneration pathology Impact

Migration routes and strategies of Grey Plovers (Pluvialis squatarola) on the East Atlantic Flyway as revealed by satellite tracking

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Avian Research 2019年第3期10卷 305-318页

作者： Klaus-Michael Exo franziska Hillig Franz Bairlein Institute of Avian Research Vogelwarte Helgoland

Background:While the general migration routes of most waders are known,details concerning connectivity between breeding grounds, stopover sites and wintering grounds are often *** information is critical from the conservation perspective and necessary for understanding the annual *** are especially needed to identify key stopover sites in remote regions. Using satellite transmitters, we traced spring and autumn migration routes and connectivity of Grey Plovers on the East Atlantic *** findings also revealed the timing,flight speed, and duration of migrations. Methods:We used ARGOS satellite transmitters to track migration routes of 11 Grey Plovers that were captured at the German Wadden Sea where they had stopped during *** were monitored for up to 3 years,***:Monitoring signals indicated breeding grounds in the Taimyr and Yamal regions;important staging sites on the coasts of the southern Pechora Sea and the Kara Sea;and wintering areas that ranged from NW-Ireland to Guinea *** average distance traveled from wintering grounds to breeding grounds was 5534 km. Migration duration varied between 42 and 152 days;during this period birds spent about 95% of the time at staging *** spring most plovers crossed inland Eastern Europe, whereas in autumn most followed the *** all of the birds departed during favorable wind conditions within just 4 days (27-30 May) on northward migration from the Wadden *** spring birds migrated significantly faster between the Wadden Sea and the Arctic than on return migration in autumn (12 vs.37 days),with shorter stopovers during the northward ***:Our study shows that satellite tags can shed considerable light on migration strategies by revealing the use of different regions during the annual cycle and by providing detailed quantitative data on population connectivity and migration timing.

关键词： Annual cycle Long-distance migration Migration speed Migration strategy Migration timing Satellite transmitters Shorebirds Tracking Stopover

Synthesis and electronic properties of expanded 5-(hetero)arylthien-2-yl substituted 3-ethynyl quinoxalines with AIE characteristics

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Science China Chemistry 2018年第8期61卷 909-924页

作者： franziska K.Merkt Thomas J.J.Müller Institute of Organic Chemistry and Macromolecular Chemistry Heinrich Heine University Düsseldorf

Expanded 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes with variable substitution pattern on the peripheral thiophene ring were synthesized in moderate to very good yields by Suzuki and Buchwald-Hartwig coupling of the corresponding brominated 3-ethynyl quinoxalines. Dumbbell-shaped bis(thienyl 3-ethynyl quinoxalines) are also accessible by the Suzuki protocol. The photophysical properties were investigated by UV and fluorescence spectroscopy. Most of the obtained compounds display fluorescence in solution and some of them also in the solid state. Additionally, tuning of the emission color of the quinoxaline based chromophores can be conveniently accomplished by the remote substituent group. The determined absorption and emission maximum as well as the Stokes shifts strongly correlate with Hammett σp+parameters. Besides,photophysical properties of selected derivatives in the solid state, biphasic solutions, and PMMA films, along with their relationships, are comparatively investigated. Moreover, two 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes are aggregation induced emission(AIE) chromophores indicated by restriction of molecular motions. A covalently restricted 3-ethynyl quinoxaline supports that the inhibition of molecular rotation is responsible for the significant enhancement of fluorescence in acetonitrile/water mixtures.

关键词： absorption aggregation induced emission cross-coupling fluorescence heterocycles palladium

Thrombolysis in acute stroke under dual antiplatelet therapy: perspectives arising from translational studies

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Neural Regeneration Research 2021年第1期16卷 113-114页

作者： franziska Lieschke Yi Zheng Christian Foerch Klaus van Leyen Neuroprotection Research Laboratory Massachusetts General HospitalHarvard Medical SchoolCharlestownMAUSA Department of Neurology University Hospital FrankfurtGoethe-UniversityFrankfurt am MainGermany

We have recently established a mouse model of focal stroke under dual antiplatelet therapy(DAPT)to study tissue plasminogen activator(tPA)-associated hemorrhagic *** purpose of this short perspective is to discuss the rationale for establishing the model,highlighting its relevance for addressing unresolved clinical *** conversion of the ischemic stroke remains one of the major liabilities of thrombolytic therapy with tPA,contributing to unfavorable outcomes and failed *** was recognized early on,and the resulting restrictions on tPA usage have led to only a minor percentage of stroke patients receiving any kind of drug treatment to limit ischemic injury.

关键词： DAPT hemorrhagic establishing

Rangeland degradation assessment in Kyrgyzstan:vegetation and soils as indicators of grazing pressure in Naryn Oblast

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Journal of Mountain Science 2016年第9期13卷 1567-1583页

作者： HOPPE franziska ZHUSUI KYZY Taalaigul USUPBAEV Adilet SCHICKHOFF Udo CEN Center for Earth System Research and Sustainability Institute of Geography Laboratory of "Flora" Institute for Biology and Pedology National Academy of Sciences of the Kyrgyz Republic

Rangelands occupy more than 80% of the agricultural land in Kyrgyzstan. At least 30% of Kyrgyz pasture areas are considered to be subject to vegetation and soil degradation. Since animal husbandry is the economic basis to sustain people＇s livelihoods, rangeland degradation presents a threat for the majority of the population. We present for the first time an ecological assessment of different pasture types in a remote area of the Naryn Oblast, using vegetation and softs as indicators of rangeland conditions. We analysed the current degree of utilization （grazing pressure）, the amount of biomass, soil samples, and vegetation data, using cluster analysis as well as ordination techniques. Winter pastures （kyshtoo） are characterized by higher pH values （average of 7.27） and lower organic matter contents （average of 12.83%） compared to summer pastures （dzailoo） with average pH values of 6.03 and average organic matter contents of 21.05%. Additionally, summer pastures show higher above- ground biomass, and higher species richness and diversity. Our results support the hypothesis that winter pastures, which are located near settlements, suffer from over-utilisation, while the more distant summer pastures are subjected to much lower grazing pressure,

关键词： Alpine meadows Alpine steppes Animalhusbandry Classification Grazing management Montane pastures Ordination Plant communities

Hepatospheres:Three dimensional cell cultures resemble physiological conditions of the liver

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World Journal of Hepatology 2010年第1期2卷 1-7页

作者： franziska van Zijl Wolfgang Mikulits Department of Medicine I Institute of Cancer ResearchMedical University of Vienna

Studying physiological and pathophysiological mechanisms in the liver on a molecular basis is a challenging *** two dimensional(2D) culture conditions hepatocytes dedifferentiate rapidly by losing metabolic functions and structural ***,inappropriate 2D hepatocellular models hamper studies on the xenobiotic metabolism of the liver which strongly influences drug ***,the lack of effective therapies against hepatocellular carcinoma shows the urgent need for robust models to investigate liver functions in a defined hepatic ***,we summarize and discuss three-dimensional cultures of hepatocytes,herein referred to as hepatospheres,which provide versatile tools to investigate hepatic metabolism,stemness and cancer development.

关键词： Hepatosphere Hepatocyte Tissue engineering 3D culture Microenvironment

Enhancement of hydroxyapatite dissolution through structure modification by Krypton ion irradiation

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Journal of Materials Science & Technology 2020年第3期38卷 148-158页

作者： Hui Zhu Dagang Guo Hang Zang Dorian AHHanaor Sen Yu franziska Schmidt Kewei Xu State Key Laboratory for Mechanical Behavior of Materials School of Material Science and EngineeringXi’an Jiaotong UniversityXi’an710049China School of Nuclear Science and Technology Xi’an Jiaotong UniversityXi’an710049China Fachgebiet Keramische Werkstoffe/Chair of Advanced Ceramic Materials Institut für Werkstoffwissenschaften und-TechnologienTechnische Universit?t BerlinHardenbergstra?e 4010623BerlinGermany Shaanxi Key Laboratory of biomedical metal materials Northwest Institute for Non-ferrous Metal ResearchXi’an710016China

Hydroxyapatite(HA)synthesized by a wet chemical route was subjected to heavy ion irradiation,using4 Me V Krypton ion(Kr17+)with ion fluence ranging from 1×1013 to 1×1015 ions/*** incidence X-ray diffraction(GIXRD)results confirmed the phase purity of irradiated HA with a moderate contraction in lattice parameters,and further indicated the irradiation-induced structural disorder,evidenced by broadening of the diffraction ***-resolution transmission electron microscopy(HRTEM)observations indicated that the applied Kr irradiation induced significant damage in the hydroxyapatite ***,cavities were observed with their diameter and density varying with the irradiation fluences,while a radiation-induced crystalline-to-amorphous transition with increasing ion dose was *** and X-ray photoelectron spectroscopy(XPS)analysis further indicated the presence of irradiationinduced *** release from pristine and irradiated materials following immersion in Tris(p H 7.4,37?)buffer showed that dissolution in vitro was enhanced by irradiation,reaching a peak at 0.1 *** examined the effects of irradiation on the early stages of the mouse osteoblast-like cells(MC3 T3-E)response.A cell counting kit-8 assay(CCK-8 test)was carried out to investigate the cytotoxicity of samples,and viable cells can be observed on the irradiated materials.

关键词： High energy heavy ion irradiation Hydroxyapatite HRTEM Crystal defects In vitro dissolution Cell compatibility