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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

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

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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

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Tea and depression

Food Science and Human Wellness 2022年第3期11卷 476-482页

作者： Klaus W.Lange Yukiko Nakamura katharina m.Lange Hui Zhao Department of Experimental Psychology University of RegensburgRegensburg 93040Germany Tianjin Key Laboratory of Food and Biotechnology University of CommerceTianjin 300134China

The available evidence,which derives from studies investigating mechanistic effects of tea,research on animal models as well as epidemiological studies and intervention trials in humans,suggests that compounds contained in tea may have the potential to aid in the prevention of depression or in its treatment as an addition to established therapies.A wide range of potentially antidepressive biological activities of tea components have been ***,the mechanisms of tea phytochemicals possibly capable of decreasing the risk of depressive symptoms are complex,multifaceted and not well *** pharmacological effects on circumscribed neurobiological systems may be produced not by individual tea components but rather by the synergistic action of various compounds on multiple pathophysiological mechanisms involved in *** epidemiological studies have generally demonstrated beneficial effects of tea consumption on mood and depressive symptoms,cross-sectional studies are unable to prove a cause-effect *** positive effects on mood could be firmly established,tea drinking could support mental ***,the moderate antidepressive effects observed in healthy people are not necessarily indicative of possible clinical effects in major depressive *** controlled intervention studies are needed to establish a causal relationship between bioactive compounds in tea and depression.

关键词： Depression Tea L-theanine Prevention Treatment

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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

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Divergent foraging behavior in a hybrid zone： Darwin＇s tree finches （Camarhynchus spp.） on Floreana Island

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Current Zoology 2015年第1期61卷 181-190页

作者： katharina J. PETERS Sonia KLEINDORFER School of Biological Sciences Flinders University GPO Box 2100 Adelaide 5001 Australia

Hybrid speciation is increasingly recognized as a mechanism for novel evolutionary trajectories. However, we know very little about the ecology of a contact zone that has arisen in sympatry. This study examines the foraging behavior and fitness of two species of Darwin＇s tree finches （Camarhynchus parvulus, C pauper） and hybrid offspring on Floreana Island. Previous study showed that the percentage of hybrids in the tree finch population increased from 19% in 2005 to 41% in 2010, and their body and beak size increased by -5% （parental phenotype did not change）. In 2005-2006, all three tree finch groups （two paren- tal species and hybrid birds） used the same foraging substrate, technique, and height. By 2010-2013, the small tree finch C. par- vulus had changed its foraging technique and the medium tree finch C. pauper had changed its foraging height. Both parental species had higher body condition when foraging at （divergent） mean foraging heights per species but hybrid birds did not. We discuss the implications of conserving forest to facilitate vertical niche expansion and the role of hybridization for genetic persis- tence [Current Zoology 61 （1）： 181-190, 2015].

关键词： Hybridization Speciation Adaptive radiation Conservation Scalesia Ecological niche

Discrete Vector Calculus and Helmholtz Hodge Decomposition for Classical Finite Difference Summation by Parts Operators

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Communications on Applied mathematics and Computation 2020年第4期2卷 581-611页

作者： Hendrik Ranocha katharina Ostaszewski Philip Heinisch Institute Computational mathematics TU BraunschweigUniversitatsplatz 238106 BrunswickGermany Extreme Computing Research Center(ECRC) Computer Electrical and Mathematical Science and Engineering Division(CEMSE)King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Saudi Arabia Institut für Angewandte Numerische Wissenschaft e.V.(IANW) Bienroder Straae 338110 BrunswickGermany Institut für Geophysik und Extraterrestrische Physik TU BraunschweigMendelssohnstraBe 338106 BrunswickGermany

In this article,discrete variants of several results from vector calculus are studied for clas-sical finite difference summation by parts operators in two and three space *** is shown that existence theorems for scalar/vector potentials of irrotational/solenoidal vector fields cannot hold discretely because of grid oscillations,which are characterised *** results in a non-vanishing remainder associated with grid oscillations in the discrete Helmholtz Hodge ***,iterative numerical methods based on an interpretation of the Helmholtz Hodge decomposition via orthogonal projections are pro-posed and applied *** numerical experiments,the discrete remainder vanishes and the potentials converge with the same order of accuracy as usual in other first-order partial differential *** by the successful application of the Helmholtz Hodge decomposition in theoretical plasma physics,applications to the discrete analysis of magnetohydrodynamic(mHD) wave modes are presented and discussed.

关键词： Summation by parts Vector calculus Helmholtz Hodge decomposition mimetic properties Wave mode analysis

Effect of faade systems on the performance of cooling ceilings: In situ measurements

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Frontiers of Architectural Research 2015年第1期4卷 68-78页

作者： katharina Eder Thomas Bednar Department for Building Physics and Building Acoustic Vienna University of TechnologyAdolf-Blamauer-Gasse 1-31030ViennaAustria

This article presents an innovative faade system designed to increase the thermal comfort inside an office room and to enhance the cooling capacity of the suspended cooling ceiling.A series of measurements is conducted in an existing office building with different faade systems(i.e., a combination of glazing and shading). An innovative faade system is developed based on this intensive set of measurements. The new system enhances the thermal comfort and cooling capacity of the suspended cooling ceiling. The main usage of the new system is the refurbishment and improvement of existing faade systems.

关键词： Office building Innovative fa?ade systems Cooled ceiling Increase in the cooling capacity of cooled ceiling Interaction of building envelope and cooled ceiling Effect on comfort