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Nano Research 2019年第4期12卷 767-775页

作者： katharina herkendell Andreas Stemmer Ran Tel-Vered Saumerstrasse 4 Nanotechnology Group D-MAVT ETH Zurich Ruschlikon CH-8803 Switzerland

Enzymatic biofuel cells promise green power generation from a variety of natural resources, yet these systems all suffer from time-dependent degradati on effects, in particular progress! ng inactivation of enzymes, which severely limit the operati on al lifetimes of such power sources. To extend operational lifetimes, we introduce a method to magnetically exchange exhausted enzymes for fresh ones. To this end, anodic and cathodic enzymes or enzyme cascades are immobilized on carbon coated magnetic nanoparticles. Under the action of suitable magnetic field gradie nts, these nano particles are assembled on the respective stati onary electrodes, or released from the electrodes for collection and subsequent excha nge. We dem on strate this method on a fructose/oxygen con suming biofuel cell emplo ying fructose dehydroge nase and bilirubin oxidase as well as on anodic and cathodic cascades employing fructose dehydrogenase/invertase and bilirubin oxidase/catalase, respectively. The en zyme-modified nan oparticles support direct electro n transfer bioelectrocatalytic curre nts by wiring the redox active cofactors to the carbonaceous coating and from there to the electrode surfaces. The facile injection, assembly, and removal of enzyme-modified magnetic nan oparticles along with fuel solutio n provides a promisi ng approach to exte nd the operati on al lifetime of enzymatic biofuel cells without the need for exchanging entire systems including chambers and electrodes.

关键词： direct electron transfer magnetic nanoparticle enzymatic biofuel cell recharge lifetime enzyme cascade

A Time-Space Adaptive Method for the Schrodinger Equation

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Communications in Computational Physics 2016年第6期20卷 60-85页

作者： katharina Kormann Technische Universitat Munchen Zentrum MathematikBoltzmannstr.385747 GarchingGermany

In this paper,we present a discretization of the time-dependent Schrodinger equation based on a Magnus-Lanczos time integrator and high-order Gauss-Lobatto finite elements in space.A truncated Galerkin orthogonality is used to obtain dualitybased a posteriori error estimates that address the temporal and the spatial error *** on this theory,a space-time adaptive solver for the Schrodinger equation is *** efficient matrix-free implementation of the differential operator,suited for spectral elements,is used to enable computations for realistic *** demonstrate the performance of the algorithm for the example of matter-field interaction.

关键词： a posteriori error estimate adaptive mesh refinement finite/spectral elements timedependent Schrodinger equation

MakeHub:Fully Automated Generation of UCSC Genome Browser Assembly Hubs

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Genomics, Proteomics & Bioinformatics 2019年第5期17卷 546-549页

作者： katharina Jasmin Hoff University of Greifswald Institute for Mathematics and Computer Science17489 GreifswaldGermany University of Greifswald Center for Functional Genomics of Microbes17489 GreifswaldGermany

Novel genomes are today often annotated by small consortia or individuals whose background is not from *** audience requires tools that are easy to *** need has been addressed by several genome annotation tools and *** resulting annotation is a crucial step of quality *** UCSC Genome Browser is a powerful and popular genome visualization *** Hubs,which can be hosted on any publicly available web server,allow browsing genomes via UCSC Genome Browser *** steps for creating custom Assembly Hubs are well documented and the required tools are publicly ***,the number of steps for creating a novel Assembly Hub is *** some cases,the format of input files needs to be adapted,which is a difficult task for scientists without programming ***,we describe Make Hub,a novel command line tool that generates Assembly Hubs for the UCSC Genome Browser in a fully automated *** pipeline also allows extending previously created Hubs by additional *** Hub is freely available for downloading at https://***/Gaius-Augustus/Make Hub.

关键词： Genome annotation Annotation visualization RNA-seq Genome browser

Running‑In Behavior of Wet Multi‑plate Clutches:Introduction of a New Test Method for Investigation and Characterization

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Chinese Journal of Mechanical Engineering 2020年第2期33卷 152-160页

作者： katharina Voelkel Hermann Pflaum Karsten Stahl Gear Research Centre(FZG) Technical University of MunichGarchingGermany

Wet multi-plate clutches are relevant components of modern drivetrain applications,not only in terms of function but also safety and *** at the beginning of their lifetime,distinct changes of the friction behavior may occur and make the actuation of the clutch *** transcript describes the typical running-in behavior of wet multi-plate clutches and gives a general definition for running-in of ***,a new test method to systematically investigate the running-in behavior of clutches is *** test method contains a test procedure to characterize the running-in behavior on different load ***,a multi-stage procedure to evaluate and characterize the running-in behavior of clutches with mathematical approaches and new characteristic values is *** quality of the test method is demonstrated on the example of three different tribological systems from dual clutch transmissions(DCT)and automatic transmissions(AT)application using paper friction linings.

关键词： Clutch Running-in Test method Paper friction lining

Using multispectral landsat and sentinel-2 satellite data to investigate vegetation change at Mount St. Helens since the great volcanic eruption in 1980

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Journal of Mountain Science 2018年第9期15卷 1851-1867页

作者： katharina TELTSCHER Fabian Ewald FASSNACHT Institute of Geography and Geoecology Karlsruhe Institute of Technology

Long-term analyses of vegetation succession after catastrophic events are of high interest for an improved understanding of succession dynamics. However, in many studies such analyses were restricted to plot-based measurements. Contrarily, spatially continuous observations of succession dynamics over extended areas and timeperiods are sparse. Here, we applied a change vector analysis(CVA) to investigate vegetation succession dynamics at Mount St. Helens after the great volcanic eruption in 1980 using Landsat. We additionally applied a supervised random forest classification using Sentinel-2 data to map the currently prevailing vegetation types. Change vector analysis was performed with the normalized difference vegetation index(NDVI) and the urban index(UI) for three subsequent decades after the eruption as well as for the whole observation time between 1984 and 2016. The influence of topography on the current vegetation distribution was examined by comparing altitude, slope angles and aspect values of vegetation classes derived by the random forest classification. WilcoxRank-Sum test was applied to test for significant differences between topographic properties of the vegetation classes inside and outside of the areas affected by the eruption. For the full time period, a total area of 516 km2 was identified as re-vegetated, whereas the area and magnitude of re-growing vegetation decreased during the three decades and migrated closer to the volcanic crater. Vegetation losses were mainly observed in regions unaffected by the eruption and related mostly to timber harvesting. The vegetation type classification reached a high overall accuracy of approximately 90%. 36 years after the eruption, coniferous and deciduous trees have established at formerly devastated areas dominating with a proportion of 66%, whereas shrubs are more abundant in riparian zones. Sparse vegetation dominates at regions very close to the crater. Elevation was found to have a great influence on th

关键词： Mount St. Helens Vegetation change Remote sensing Change vector analysis (CVA) Supervised classification Topography Density-plots

Biomarkers for detection of alcohol consumption in liver transplantation

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World Journal of Gastroenterology 2016年第14期22卷 3725-3734页

作者： katharina Staufer Michel Yegles Division of Transplantation Department of Surgery Medical University of Vienna 1090 Vienna Austria Laboratoire National de Sante Service de Toxicologie medico-legale 1 rue Louis Rech L-3555 Dudelange Luxembourg

Alcoholic liver disease is an established, yet controversial, indication for liver transplantation. Although an abstinence period of up to 6 mo prior to transplantation is mandatory, alcohol relapse after transplantation is a common event. In case of recurrence of heavy drinking, graft survival is significantly impaired. Guidelines on detection and surveillance of alcohol consumption in this patient cohort are lacking. This review summarizes the challenge of patient selection as well as the current knowledge on established and novel alcohol biomarkers with special focus on liver transplant candidates and recipients.

关键词： Ethyl glucuronide Liver cirrhosis Short-term alcohol markers Long-term alcohol markers Psychological support

Metabolomic evidence of independent biotransformation pathways for terpenes in two specialist mammalian herbivores (genus Neotoma)

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Integrative Zoology 2024年第1期19卷 143-155页

作者： katharina SCHRAMM Michele SKOPEC Denise DEARING Department of Biology University of UtahSalt Lake CityUtahUSA Department of Zoology Weber State UniversityOgdenUtahUSA

Herbivory is common in mammals,yet our understanding of detoxification processes used by mammals to biotrans-form plant secondary compounds(PSCs)is *** herbivores are thought to have evolved detoxifica-tion mechanisms that rely more heavily on energetically cheap Phase I biotransformation reactions to process high levels of PSCs in their *** explored this hypothesis by comparing the urinary metabolite patterns of two spe-cialist herbivores(genus Neotoma).Neotoma stephensi is an obligate specialist on one-seeded juniper(Juniperus monosperma).Neotoma lepida is a generalist forager across its range,yet populations in the Great Basin specialize on Utah juniper(***).While both juniper species have high levels of terpenes,the terpene profiles and quantities differ between the *** from both woodrat species were fed diets of each juniper in a cross-over ***,collected over a 24-h period,was extracted and analyzed in an untargeted metabolomics approach using both GC-MS and HPLC-MS/*** obligate specialist *** excreted a unique pattern of Phase I metabolites when fed its native juniper,while *** excreted a unique pattern of Phase II metabolites when fed its native *** woodrat species utilized the Phase II metabolic pathway of glucuronidation more heavily when consuming the more chemically diverse ***,and *** utilized less glucuronida-tion than *** when consuming *** results are consistent with the hypothesis that obligate specialists may have evolved unique and efficient biotransformation mechanisms for dealing with PSCs in their diet.

关键词： dietary specialization herbivory juniper metabolomics Neotoma

Locus coeruleus-norepinephrine: basic functions and insights into Parkinson’s disease

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Neural Regeneration Research 2020年第6期15卷 1006-1013页

作者： Bilal Abdul Bari Varun Chokshi katharina Schmidt The Solomon H.Snyder Department of Neuroscience Brain Science InstituteKavli Neuroscience Discovery InstituteThe Johns Hopkins University School of MedicineBaltimoreMDUSA Department of Physiology The Johns Hopkins University School of MedicineBaltimoreMDUSA

The locus coeruleus is a pontine nucleus that produces much of the brain's *** its small size,the locus coeruleus is critical for a myriad of functions and is involved in many neurodegenerative and neuropsychiatric *** this review,we discuss the physiology and anatomy of the locus coeruleus system and focus on norepinephrine's role in synaptic *** highlight Parkinson's disease as a disorder with motor and neuropsychiatric symptoms that may be understood as aberrations in the normal functions of locus coeruleus.

关键词： catecholamines copper neurodegenerative diseases neuromodulation neuronal circuits neuropsychiatric symptoms noradrenaline synaptic plasticity

Ray tracing particle image velocimetry-Challenges in the application to a packed bed

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Particuology 2024年第1期84卷 194-208页

作者： Christin Velten Mirko Ebert Christian Lessig katharina Zahringer Lehrstuhl für Strömungsmechanik und Strömungstechnik Otto-von-Guericke-Universität Magdeburg39106MagdeburgGermany Institut für Simulation und Graphik Otto-von-Guericke-Universität Magdeburg39106MagdeburgGermany

Ray tracing Particle Image Velocimetry(RT-PIV)is an optical technique for high resolution velocity measurements in challenging optical systems,such as transparent packed beds,that uses ray tracing to correct for distortions introduced by transparent geometries in the light *** ray tracing based correction is a post processing step applied to the raw PIV particle images before classical PIV *** this study,RT-PIV is performed in the top layer of a body centred cubic(bcc)sphere packing with gaseous flow,where optical access is obtained by the use of transparent N-BK7 glass balls with a diameter of d=40 ***-PIV introduces new experimental and numerical challenges,for example a limited field of view,illumination difficulties,a very large required depth of field and high sensitivity to geometric parameters used in the ray tracing *** challenges and their implications are the main scope and discussed in the present ***,the validation of the ray tracing reconstruction step is presented and examples for the obtained corrected vector fields in a packed bed are *** results show the strength of the method in reconstructing velocity fields behind transparent spheres that would not have been accessible by optical measurement techniques without the ray tracing correction.

关键词： Ray tracing particle image velocimetry(RT-PIV) Transparent spherical particles Packed bed Distortion correction Gas flow

Iron catalyzed Michael addition: Chloroferrate ionic liquids as efficient catalysts under microwave conditions

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Science China Chemistry 2012年第8期55卷 1614-1619页

作者： VASILOIU Maria GAERTNER Peter BICA katharina Institute of Applied Synthetic Chemistry Vienna University of Technology Vienna A-1060 Austria

The iron containing ionic liquid 1-butyl-3-methylimidazolium tetrachloroferrate （[C4mim]C1/FeCl3; Z = 0.5） proved to be an efficient catalyst for the solvent-free metal catalyzed Michael addition of β-keto esters and enones. Due to the ionic structure of the catalyst, a significant acceleration of the reaction rate was observed under microwave conditions. Furthermore, recycling of the ionic liquid catalyst could be performed after simply distilling off the products.

关键词： ionic liquids iron catalysis michael addition lewis acid microwave chemistry