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The growth of Staphylococcus aureus and Escherichia coli in low-direct current electric fields

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International Journal of Oral Science 2014年第1期6卷 7-14页

作者： Dunya Zituni Heidi Schtt-Gerowitt Marion Kopp martin Krnke Klaus Addicks Christian hoffmann martin Hellmich franz Faber Wilhelm Niedermeier Department of Prosthetic Dentistry School of Dental and Oral Medicine Cologne University Institute for Medical Microbiology Immunology and HygieneCologne University Institute for Anatomy I Cologne University Institute for Medical Statistics Informatics and Epidemiology Cologne University Department of Pre-Clinical Dentistry School of Dental and Oral Medicine Cologne University

Electrical potentials up to 800 mV can be observed between different metallic dental restorations. These potentials produce fields in the mouth that may interfere with microbial communities. The present study focuses on the impact of different electric field strengths （EFS） on the growth of Staphylococcus aureus （ATCC 25923） and Escherichia coil （ATCC 25922） in vitro. Cultures of S. aureus and E. coil in fluid and gel medium were exposed to different EFS. Effects were determined by calculation of viable counts and measurement of inhibition zones. In gel medium, anodic inhibition zones for S. aureuswere larger than those for E. coliat all field strength levels. In fluid medium, the maximum decrease in the viable count of S. aureus cells was at 10 V.m-1. Field-treated S. aureus cells presented ruptured cell walls and disintegrated cytoplasm. Conclusively, S. aureus is more sensitive to increasing electric field strength than E. coll.

关键词： direct current Escherichia coli electrogaNanism gold electrode Staphylococcus aureus

Formulation of carbon black-ionomer dispersions for thin film formation in fuel cells

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Particuology 2019年第3期17卷 7-21页

作者： Eva hoffmann Su Zhang martin Thoma Cornelia Damm Wolfgang Peukert Institute of Particle Technology (LFG) Friedrich-Alexander-Universitat Erlangen-Niimberg (FAU) CauerstraJSe 4 D-91058 Erlangen Germany

The performance of proton exchange membrane fuel cells (PEMFC) is strongly determined by the structure and composition of the electrode *** interactions between the ionomer,carbon black particles,and solvent affect the suspension properties and thus the layer *** analyze the effect of the ionomer-to-carbon (I/C) weight ratio for two different types of carbon black on the suspension and layer *** branched carbon blacks with a high surface area tend to form less cracked *** less branched carbons can pack together more closely,a smaller pore size results in a larger capillary pressure during drying and thus more *** added ionomer adsorbs on the carbon particles and improves the colloidal stability of the carbon black *** carbon black aggregates are thus smaller,resulting in closer packing and thinner ***,the addition of the ionomer increases the critical coating thickness (CCT) of the layers because drying stresses are dissipated by the deformation of the ionomer,preventing crack *** optimum I/C weight ratio is identified for optimal layer formation and minimized crack formation.

关键词： Perfluorosulfonic acid (PFSA) ionomer Carbon black Layer formation Cracking Porosity

Development and Implementation of a Rotating Nanoimprint Lithography Tool for Orthogonal Imprinting on Edges of Curved Surfaces

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Nanomanufacturing and Metrology 2021年第3期4卷 175-180页

作者： Shraddha Supreeti Ralf Schienbein Patrick FeBer Florian Fern martin hoffmann Stefan Sinzinger Electronics Technology Group Technical University of IlmenauIlmenauGermany Institute for Design and Precision Engineering Technical University of IlmenauIlmenauGermany Technical Optics Group Technical University of IlmenauIlmenauGermany JUMO GmbH&Co.KG FuldaGermany Microsystems Technology Group Ruhr-University BochumBochum.Germany

Uniform molding and demolding of structures on highly curved surfaces through conformal contact is a crucial yet often-overlooked aspect of nanoimprint lithography(NIL).This study describes the development of a NIL tool and its integration into a nanopositioning and nanomeasuring machine to achieve high-precision orthogonal molding and demolding for soft ultraviolet-assisted NIL(soft UV-NIL).The process was implemented primarily on the edges of highly curved plano-convex substrates to demonstrate structure uniformity on the ***-resolution nanostructures of sub-200-nm lateral dimension and microstructures in the range of tens of microns were ***,the nanostructures on the edges of the large,curved substrates were difficult to characterize ***,microstructures were used to measure the structure fidelity and were characterized using profilometry,white light interferometry,and confocal laser scanning *** of the restricted imaging capabilities at high inclinations for high-resolution nanostructures,the scanning electron microscope(SEM)imaging of the structures on top of the lens substrate and at an inclination of 45°was *** micro and nanostructures were successfully imprinted on the edges of the plano-convex lens at angles of 45°,60°,and 90°from the center of rotation of the rotating NIL *** method enables precise imprinting at high inclinations,thereby presenting a different approach to soft UV-NIL on curved surfaces.

关键词： Nanoimprint lithography Rotating NIL tool Curved surface Imprinting Nanopositioning

A force-compensated compliant MEMS-amplifier with electrostatic anti-springs

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微系统与纳米工程(英文) 2023年第3期9卷 235-244页

作者： Philip Schmitt martin hoffmann Microsystems Technology Ruhr-Universität BochumUniversitätsstr.15044801 BochumGermany

In this paper,an electrostatic compliant mechanical amplifier intended for force-compensated displacement amplification in MEMS sensor applications is ***,mechanical transformers that enhance a small input displacement into a large output displacement generate large forces at the input of the *** microsystem proposed here allows for the reduction and compensation of the input stiffness of the amplifier and any mechanical components connected to it while providing a constant amplification ratio at the same *** amplifying mechanism features bidirectional electrostatic anti-springs enabling the control of the stiffness by applying a constant DC *** electrode design of the anti-springs and its influence on the force-displacement characteristic,the side instability and the maximal displacement are studied through analytical approaches and supported by FEA and by *** on the derived models,a compliant electromechanical amplifier is developed,featuring an amplification ratio of *** this amplifier the initial input stiffness of 422 N/m could be reduced to 6.8 N/m by applying a voltage of 100 *** an additional application,we show how the amplifier can be used as a mechanical force sensor with tuneable sensitivity,where the forces at the input are transformed into large output *** experiments,we show how the sensitivity can be adjusted and increased by a factor of 25 by applying a voltage at the anti-springs.

关键词： amplifier electrostatic spring

CD2 deficiency partially prevents small bowel inflammation and improves parasite control in murine Toxoplasma gondii infection

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World Journal of Gastroenterology 2007年第31期13卷 4207-4213页

作者： Nina N Pawlowski Daniela Struck Katja Grollich Anja A Kühl martin Zeitz Oliver Liesenfeld Jrg C hoffmann Medizinische Klinik I Charité-Universittsmedizin Berlin Campus Benjamin Franklin D12200 Berlin Germany Institut für Mikrobiologie und Hygiene Charité-Universittsmedizin Berlin Campus Benjamin Franklin D12203 Berlin Germany

To investigate whether bowel inflammation and/or parasite control is altered in the absence of the T cell adhesion molecule CD2.

关键词： CD2 IL-6 Ileitis Inflammatory bowel dis-ease Interferon-T Toxoplasma gondii

No evidence for increased cell entry or antibody evasion by Delta sublineage AY.4.2

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Cellular & Molecular Immunology 2022年第3期19卷 449-452页

作者： Prerna Arora Amy Kempf Inga Nehlmeier Luise Graichen martin S.Winkler martin Lier Sebastian Schulz Hans-martin Jäck Stefan Pöhlmann Markus hoffmann Infection Biology Unit German Primate CenterKellnerweg 437077GöttingenGermany Faculty of Biology and Psychology Georg-August-University GöttingenWilhelmsplatz 137073GöttingenGermany Department of Anesthesiology University of Göttingen Medical CenterGeorg-August University GöttingenRobert-Koch-Straße 4037075GöttingenGermany Division of Molecular Immunology Department of Internal Medicine 3Friedrich-Alexander University Erlangen-NürnbergGlückstraße 691054ErlangenGermany

Since the beginning of the COVID-19 pandemic,multiple SARS-CoV-2 variants have *** some variants spread only locally,others,referred to as variants of concern,disseminated globally and became drivers of the *** SARS-CoV-2 variants harbor mutations relative to the virus circulating early in the pandemic,and mutations in the viral spike(S)protein are considered of particular relevance since the S protein mediates host cell entry and constitutes the key target of the neutralizing antibody *** a consequence,mutations in the S protein may increase SARS-CoV-2 infectivity and enable its evasion of neutralizing ***,mutations in the S protein can modulate viral transmissibility and pathogenicity.

关键词： SARS-CoV-2 AY.4.2 Delta Host cell entry Antibody evasion

Noninvasive Detection of Coronary Artery Stenosis Using 16-slice Spiral CT: a Comparison with Selective X-ray Coronary Angiography

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Journal of Huazhong University of Science and Technology(Medical Sciences) 2006年第3期26卷 338-340页

作者：史河水韩萍孔祥泉冯敢生 martin HK hoffmann Department of Radiology Union hospital Tongji medical college Huazhong University of Science and Technology Wuhan 430022 China Department of Radiology Ulm University Ulm 89075 Germany

The role of 16-slice spiral CT was selective X-ray coronary angiography （SCA） who were suspected of having coronary heart evaluated in the diagnosis of coronary stenosis, with serving as the reference standard. Sixty-five patients disease, without percutaneous transluminal coronary angioplasty or coronary bypass-grafting, were investigated using 16-slice CT. Eight patients with pre-scan heart rate of more than 80 beats/min were given β-blockers. After the retrospectively ECG-gated axial imaging reconstruction, volume redering （VR）, multi-planar reconstruction （MPR）, curved MPR and maximum intensity projection （MIP） were used to reconstruct. Every segment of coronary artery with a diameter ≥1.5 mm was assessed, and the presence on CT with a stenosis exceeding 50 % diameter reduction was compared with that on SCA. The reasons which lead to some segments unevaluable were analysed. Compared with SCA, 93 % coronary segments and 94 % main branches were evaluable. Residual cardiac motion artifacts, severe calcification and poor opacification made 58 %, 28 % and 14 % of the remaining 60 segments unevaluable respectively. Without routine administration of β-blockers, good coronary imaging quality can be acquired using 16-slice spiral CT. It is a reliable noninvasive method for detection of obstructive coronary artery disease.

关键词： tomography, X-ray computed angiography coronary artery stenosis

Tracking of Flat Belts

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Journal of Mechanics Engineering and Automation 2012年第1期2卷 27-36页

作者： martin Egger Klaus hoffmann Mechanical Engineering FH-OOE Wels 4600 Austria Engineering Design and Logistics Engineering TU- Vienna Wien 1060 Austria

When applying fiat belts, correct tracking of the belt through the installation has to be assured. Since flat belts are commonly used for conveying and transmission purposes, tracking systems have been well developed, but the ultimate tracking behaviour of the belt can be greatly enhanced by taking special care in the creation of an adequate tracking mechanism. To obtain long-life operation and full value from the equipment, the correct tracking technique plays an important role. This paper deals with two tracking techniques： The skewed and the angled pulley axis. Numerical simulation results are compared with both measurements and an analytical approach. The advantages of numerical simulation compared to experimental tests are ease, convenience and the absence of any safety risk. Compared to analytical approaches the simulation is used for systems for which simple closed form analytic solutions are not possible.

关键词： Flat belt belt tracking angled pulley axis skewed pulley axis.

Efficient antibody evasion but reduced ACE2 binding by the emerging SARS-CoV-2 variant B.1.640.2

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Cellular & Molecular Immunology 2022年第9期19卷 1067-1069页

作者： Prerna Arora Amy Kempf Inga Nehlmeier Luise Graichen Sebastian Schulz Anne Cossmann Alexandra Dopfer-Jablonka martin S.Winkler Hans-martin Jäck Georg M.N.Behrens Stefan Pöhlmann Markus hoffmann Infection Biology Unit German Primate CenterKellnerweg 437077GöttingenGermany Faculty of Biology and Psychology Georg-August-University GöttingenWilhelmsplatz 137073GöttingenGermany Division of Molecular Immunology Department of Internal Medicine 3Friedrich-Alexander University of Erlangen-NürnbergGlückstraße 691054ErlangenGermany Department for Rheumatology and Immunology Hannover Medical SchoolCarl-Neuberg-Straße 130625HannoverGermany German Centre for Infection Research(DZIF) Partner Site Hannover-BraunschweigHannoverGermany Centre for Individualised Infection Medicine(CiiM) HannoverGermany Department of Anesthesiology University of Göttingen Medical CenterGöttingenGeorg-August University of GöttingenRobert-Koch-Straße 4037075GöttingenGermany

The SARS-CoV-2 spike(S)protein engages ACE2 for cell entry,and the S protein/ACE2 interface is an important target for neutralizing *** the course of the COVID-19 pandemic,SARS-CoV-2 variants have emerged that harbor mutations in the S protein,which confer neutralization resistance and allow viral spread in immunologically nonnaive *** most prominent example is the highly mutated Omicron variant,which infects convalescent or vaccinated individuals with unprecedented efficiency[1,2].

关键词： ACE2 harbor neutral