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The emerging role of tranexamic acid and its principal target,plasminogen,in skeletal health

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Acta Pharmaceutica Sinica B 2024年第7期14卷 2869-2884页

作者： Weixin Xie Antonia Donat Shan Jiang Anke Baranowsky Johannes Keller Department of Trauma and Orthopedic Surgery University Medical Center Hamburg-EppendorfHamburg 20246Germany

The worldwide burden of skeletal diseases such as osteoporosis,degenerative joint disease and impaired fracture healing is steadily *** acid(TXA),a plasminogen inhibitor and anti-fibrinolytic agent,is used to reduce bleeding with high effectiveness and safety in major surgical *** its widespread clinical application,the effects of TXA beyond anti-fibrinolysis have been noticed and prompted renewed interest in its *** clinical trials have characterized the effects of TXA on reducing postoperative infection rates and regulating immune responses in patients undergoing ***,several animal studies suggest potential therapeutic effects of TXA on skeletal diseases such as osteoporosis and fracture *** a direct effect of TXA on the differentiation and function of bone cells in vitro was shown,few mechanisms of action have been ***,we summarize recent findings of the effects of TXA on skeletal diseases and discuss the underlying plasminogen-dependent and-independent mechanisms related to bone metabolism and the immune *** furthermore discuss potential novel indications for TXA application as a treatment strategy for skeletal diseases.

关键词： Tranexamic acid Osteoporosis Osteoarthritis Fracture healing Bone metabolism Inflammation Plasminogen Fibrinolysis

Dielectric and physico-chemical behavior of single thermally thick wood blocks under microwave assisted pyrolysis

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Particuology 2024年第3期86卷 291-303页

作者： Nicole Vorhauer-Huget Jakob Seidenbecher Supriya Bhaskaran Francesca Schenkel Lucas Briest Suresh Gopalkrishna Jan Barowski Andrea Dernbecher Liane Hilfert Ilona Rolfes Alba Dieguez-Alonso Otto von Guericke University Magdeburg Universitatsplatz 239106MagdeburgGermany Ruhr University Bochum Institute of Microwave SystemsUniversitatsstraβe 15044801BochumGermany

Pyrolysis of thermally thick beech wood blocks with a size of around 2.5×8×6 cm^(3)(width×length×height)was carried out in a lab scale microwave reactor with a frequency of 2.45 GHz,operated,both,at 300 W and 600 W under inert conditions,using N_(2) at around 400 mbar absolute *** microwave cavity had a size of 20×20×20 cm^(3).The specific energy supply referred to the untreated wood block was 4-8 W/g,with slight variations depending on the initial water *** mass loss and the reflected microwave power were in-situ monitored during the *** sample surface and chamber temperatures were measured with a pyrometer and a thermocouple,***-chemical and dielectric properties of the produced solids were investigated and compared to those of chars produced under conventional pyrolysis using the same raw *** is shown that the complex dielectric permittivity of the solid products changed drastically during the pyrolysis process,with increasing heating properties as the conversion process *** was easily achieved using 60o W without ***,300 W was not enough to achieve a high conversion degree,independently of the irradiation ***,together with the physico-chemical analyses of the solids,hinted to the importance of the transport kinetics in thermally thick materials,although further investigationis still required.

关键词： Microwave assistedpyrolysis Conventional pyrolysis Dielectric measurements Penetration depth Elemental analysis

Investigating the inflow into a granular bed using a locally resolved method

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Particuology 2024年第2期85卷 89-101页

作者： Maximilian Brommer Maik Scharnowski Enric Illana Mahiques Siegmar Wirtz Viktor Scherer Ruhr University Bochum Institute of Energy Plant TechnologyUniversitätsstraβe 15044780BochumGermany

Discrete Element Method-Computational Fluid Dynamics(DEM/CFD)simulations of industrial-scale granular systems employ spatial averaging(porous media approach)for the fluid-particle interaction in the whole domain,which can lead to poor accuracy,for instance at flow inlets,as local particle bulk morphology is not *** paper presents an approach where the interstitial flow in crucial areas with large gradients can be resolved locally in an otherwise unresolved domain,so that a mixed resolved-unresolved method is *** a generic example to show the feasibility and performance of the new approach,the inflow of ambient air into a flat-bottom hopper through a narrow orifice is *** an experimental setup,the vertical profile of the pressure decay through the inlet and across the packing is chosen for com-parison with respective *** obtained with the conventional porous media method and the locally resolved approach are compared to these experiments for varying volume flow rates and for two different particle *** of different size as well as dodecahedrons are *** is found that although averaging methods already provide good approximations,the locally resolved method can improve the result especially when conventional drag laws are not applicable due to wall effects or if large velocity gradients exist.

关键词： DEM/CFD Packed bed Pressure drop

Characterization of the tribologically relevant cover layers formed on copper in oxygen and oxygen-free conditions

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Friction 2023年第8期11卷 1505-1521页

作者： Selina RAUMEL Khemais BARIENTI Hoang-Thien LUU Nina MERKERT Folke DENCKER Florian NÜRNBERGER Hans Jürgen MAIER Marc Christopher WURZ Institute of Micro Production Technology Leibniz Universität HannoverGarbsen 30823Germany Institut für Werkstoffkunde(Materials Science) Leibniz Universität HannoverGarbsen 30823Germany Institute of Applied Mechanics Clausthal University of TechnologyClausthal-Zellerfeld 38678Germany

Engineering in vacuum or under a protective atmosphere permits the production of materials, wherever the absence of oxygen is an essential demand for a successful processing. However, very few studies have provided quantitative evidence of the effect of oxidized surfaces to tribological properties. In the current study on 99.99% pure copper, it is revealed that tribo-oxidation and the resulting increased abrasive wear can be suppressed by processing in an extreme high vacuum (XHV) adequate environment. The XHV adequate atmosphere was realized by using a silane-doped shielding gas (1.5 vol% SiH4 in argon). To analyse the influence of the ambient atmosphere on the tribological and mechanical properties, a ball–disk tribometer and a nanoindenter were used in air, argon, and silane-doped argon atmosphere for temperatures up to 800 ℃. Resistance measurements of the resulting coatings were carried out. To characterize the microstructures and the chemical compositions of the samples, the scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) were used. The investigations have revealed a formation of η-Cu3Si in silane-doped atmosphere at 300 ℃, as well as various intermediate stages of copper silicides. At temperatures above 300 ℃, the formation of γ-Cu5Si were detected. The formation was linked to an increase in hardness from 1.95 to 5.44 GPa, while the Young’s modulus increased by 46% to 178 GPa, with the significant reduction of the wear volume by a factor of 4.5 and the suppression of further oxidation and susceptibility of chemical wear. In addition, the relevant diffusion processes were identified using molecular dynamics (MD) simulations.

关键词： wear behavior tribochemical reaction oxidation behavior surface analysis molecular dynamics(MD)simulation

CFD–DEM simulation of fine particles in a spouted bed apparatus with a Wurster tube

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Particuology 2019年第1期17卷 114-125页

作者： Paul Breuninger Dominik Weis Isabell Behrendt Philipp Grohn Fabian Krull Sergiy Antonyuk Institute of Particle Process Engineering University of KaiserslauternGottlieb Daimler Str.. KaiserslauternGermany

In this work, a coupled computational fluid dynamics–discrete element method (CFD–DEM) approach was employed to evaluate the spouting behavior of fine, cohesive powders in a cylindrical spouted bed with a conical base and equipped with a Wurster tube. The particle and gas dynamics inside the apparatus were simulated with 1.7 million spherical ZrO2 particles with a particle size of 100 μm. For an accurate prediction of the interactions of cohesive particles in the spouted bed, the adhesion forces according to JKR theory were included in the Hertz–Tsuji contact model. The surface energy of the particles was varied over a wide range to determine the effect of the adhesion on the spouting (the fountain shape and maximum height as well as the distribution of the concentrations and velocities of particles in different zones of the apparatus). A detailed analysis of the collision dynamics was conducted. The spouting behavior of a spouted bed with the same dimensions, particles, and processing parameters was recorded with a high-speed camera. The CFD–DEM simulations showed good agreement with the experimentally captured spouting behavior.

关键词： CFD–DEM Spouted bed Wurster tube Cohesive powder

Aromatic self-assembled monolayers with pentafluoro-λ^(6)-sulfanyl(−SF_(5))termination:Molecular organization and charge transport properties

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Nano research 2023年第5期16卷 7991-8002页

作者： Yangbiao Liu Marc Zeplichal Sonja Katzbach Adrian Wiesner Saunak Das reas Terfort Michael Zharnikov Angewandte Physikalische Chemie Universität HeidelbergIm Neuenheimer Feld 253D-69120 HeidelbergGermany Institut für Anorganische und Analytische Chemie Johann Wolfgang Goethe Universität FrankfurtMax-von-Laue-Straße 7D-60438 Frankfurt am MainGermany

A series of molecules with oligophenylene backbone,thiolate anchoring group,pentafluoro-λ^(6)-sulfanyl(−SF_(5))tail group was synthesized and used as precursors to form self-assembled monolayers(SAMs)on Au(111)*** resulting SAMs feature dense molecular packing,upright molecular orientation,chemically homogeneous SAM-ambient interface,comprised entirely of the−SF_(5)*** SAMs exhibit exceptional wetting and electrostatic properties,showing advancing water contact angles up to 103°and work function values up to 5.96 eV—probably the highest values reported for any aromatic monolayers on *** also feature a comparably low value of the tunnelling decay coefficient(0.38±0.07Å^(−1)),typical of oligophenylene backbone,which is not affected by the introduction of the−SF_(5)*** latter also hardly affects the current densities at a specific bias compared to analogous monolayers with other electronegative tail *** superior electrostatic and good charge transport properties of the designed,SF_(5)-terminated SAMs make them potentially useful for interface engineering in organic electronics and photovoltaics.

关键词： backbone charge electrostatic

MULTIDIMENSIONAL RELAXATION APPROXIMATIONS FOR HYPERBOLIC SYSTEMS OF CONSERVATION LAWS

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Journal of Computational Mathematics 2007年第4期25卷 440-457页

作者： Mohammed Seaid UniversitSt Kaiserslautern Fachbereich Mathematik 67663 Kaiserslautern Germany

We construct and implement a non-oscillatory relaxation scheme for multidimensional hyperbolic systems of conservation laws. The method transforms the nonlinear hyperbolic system to a semilinear model with a relaxation source term and linear characteristics which can be solved numerically without using either Riemann solver or linear iterations. To discretize the relaxation system we consider a high-resolution reconstruction in space and a TVD Runge-Kutta time integration. Detailed formulation of the scheme is given for problems in three space dimensions and numerical experiments are implemented in both scalar and system cases to show the effectiveness of the method.

关键词： Multidimensional hyperbolic systems Relaxation methods Non-oscillatory reconstructions Asymptotic-preserving schemes.

Multidimensional separation due to selective spherical agglomeration—Evidence of shape separation via X-ray microtomography

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Particuology 2021年第5期19卷 316-323页

作者： Julia Schreier Ulrich Brockel University of Applied Sciences Trier Institute for Micro-Process-Engineering and Particle Technology(IMiP)Umwelt-Campus BirkenfeldP.O.Box 1380D-55761 BirkenfeldGermany

Objective of this work was to develop a novel method for characterizing real 3D shapes of particles smaller than 20μm by X-ray microtomography(X-RMT).Multidimensional separation of heterogenous solids through agglomeration in suspension will improve recycling processes as the particle shape and the agglomerate size are used for shape-selective *** the present paper we discuss the fundamentals of X-ray tomography and the experimental setup for selective spherical agglomeration in suspension.A specific preparation method of the particulate sample for X-RMT followed by 3D image processing,are essential for the shape analysis expressed as *** also discuss the limitation of this method due to the so-called Partial Volume Effect and particle clusters in the order of magnitude of X-RMT *** proof of concept,we used a mixture of graphite platelets and spheronized graphite particles for a shape selective-agglomeration in *** remaining fines were analyzed and showed more platelets than in the *** indicates that spheronized particles are preferably bound in the *** findings show that,based on the discussed sample preparation and a 3D image analysis in connection with X-RMT,particle shapes of micronized particles can be discriminated.

关键词： Multidimensional separation X-ray microtomography Selective agglomeration Particle shape Graphite

Tetranuclear yttrium and gadolinium 2-acetylcyclopentanoate clusters：Synthesis and their use as spin-coating precursors for metal oxide film formation for field-effect transistor fabrication

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Journal of Rare Earths 2018年第10期36卷 1098-1105页

作者： Elaheh Pousaneh Andrea Preuβ Khaybar Assim Tobias Rüffer Marcus Korb Jana Tittmann-Otto Sascha Hermann Stefan E.Schulz Heinrich Lang Technische Universitat Chemnitz Faculty of Natural Sciences Institute of Chemistry Inorganic Chemistry D-09107 Chemnitz Germany Technische Universitiat Chemnitz Center for Mierotechnologies D-09107 Chemnitz Germany Fraunhofer Institute for Electronic Nano Systems ENAS Technologie-Campus 3 D-09126 Chemnitz Germany

Lanthanide clusters [Ln4（μ3-OH）2（η2-accp）4（（μ-O）-η2-accp）6]（Ln = Y（4）,Gd（5）; accp = 2-acetylcyclopentanoate） are accessible by treatment of [M（NO33·6 H2 O]（M = Y（1）,Gd（2）） with 3 equiv. of Haccp（3） in presence of NaOH. The molecular structures of 4 and 5） in the solid-state are discussed. The thermal behavior of 4 and 5 was studied by TG under Ar and O2, showing multistep decomposition processes. Additionally, DSC studies were carried out under an atmosphere of O2. PXRD measurements of the TG residues confirm the formation of Ln2 ***-coating experiments were carried out with 4 and 5 for Ln2 O3 film deposition on silicon substrates. The layers are smooth, close and are of thicknesses of 18.87±1.13 nm and 25.59 ± 4.55 nm for Ln = Y and Gd, which was evidenced by SEM and EDX studies. Field-effect transistors were successfully fabricated by deposition of carbon nanotubes on top of the Y2 O3 films and formation of palladium contacts by a lift-off procedure. An on/off ratio of more than 4 orders of magnitude is achieved without considerable leakage currents. These results demonstrate the potential use of spin-coated Y2 O3 as a gate dielectric in electronic devices.

关键词： β-Diketonates Yttrium Gadolinium Thermal analysis Spin coating CNT transistor