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Understanding the corrosion of Mg alloys in in vitro urinary tract conditions: A step forward towards a biodegradable metallic ureteral stent

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Journal of Magnesium and Alloys 2023年第11期11卷 4301-4324页

作者： Margarida Pacheco Ivo M.Aroso Joana M.Silva Sviatlana V.Lamaka jan Bohlen Maria Nienaber Dietmar Letzig Estêvão Lima Alexandre A.Barros Rui L.Reis 3B’s Research Group-Research Institute on Biomaterials Biodegradables and BiomimeticsUniversity of MinhoGuimarãesPortugal ICVS/3B’s-PT Government Associate Laboratory Braga/GuimarãesPortugal Institute of Surface Science Helmholtz-Zentrum hereon GmbHGermany Institute of Material and Process Design Helmholtz-Zentrum hereon GmbHGermany School of Health Sciences Life and Health Sciences Research Institute(ICVS)University of MinhoBragaPortugal

Ureteral stents play a fundamental role in modern time urology. However, following the deployment, stent-related symptoms are frequent and affect patient health and quality of life. Using biodegradable metals as ureteral stent materials have emerged as a promising strategy, mainly due to the improved radial force and slower degradation rate expected. Therefore, this study aimed to characterize different biodegradable metals in urinary tract environment to understand their propensity for future utilization as base materials for ureteral stents. The corrosion of 5 Mg alloys - AZ31, Mg-1Zn, Mg-1Y, pure Mg, and Mg-4Ag - under simulated urinary tract conditions was accessed. The corrosion layer of the different alloys presented common elements, such as Mg(oH)_(2), Mgo, and phosphate-containing products, but slight variations in their chemical compositions were detected. The corrosion rate of the different metals varied, which was expected given the differences in the corrosion layers. on top of this, the findings of this study highlighted the significant differences in the samples' corrosion and corrosion layers when in stagnant and flowing conditions. With the results of this study, we concluded that Mg-1Zn and Mg-4Ag presented a higher propensity for localized corrosion, probably due to a less protective corrosion layer;Mg-4Ag corroded faster than all the other four alloys,and Mg-1Y stood out due to its distinct corrosion pattern, that showed to be more homogeneous than all the other four samples, making this one more attractive for the future studies on biodegradable metals.

关键词： Biodegradable metals Magnesium alloys Localized corrosion Biodegradable metallic ureteral stent

Electrochemical top-down synthesis of C-supported Pt nanoparticles with controllable shape and size:Mechanistic insights and application

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Nano Research 2021年第8期14卷 2762-2769页

作者： Batyr Garlyyev Sebastian Watzele Johannes Fichtner jan Michalicka Alexander Schokel Anatoliy Senyshyn Andrea Perego Dingjie Pan Hany A.El-Sayed jan M.Macak Plamen Atanassov Iryna V.Zenyuk Aliaksandr S.Bandarenka Physics of Energy Conversion and Storage Technical University of MunichJames Franck Strafle 185748 Garching Germany Central European Institute of Technology Brno University of TechnologyPurkynova 12361200 BrnoCzech Republic Deutsches Elektronen Synchrotron(DESY) Notkestr.8522607HamburgGermany Heinz Maier-Leibnitz-Zentrum(MLZ) Technische Universitat MiinchenLichtenbergstr.185748 Garching Germany Department of Chemical Engineering National Fuel Cell Research Center University of CaliforniaIrvine92697-2580 CaliforniaUSA Department of Material Science and Engineering University of CaliforniaIrvine92697-2580 CaliforniaUSA Chair of Technical Electrochemistry Technical University of MunichLichtenbergstrafie 485748 Garching Germany

In this work,we demonstrate the power of a simple top-down electrochemical erosion approach to obtain Pt nanoparticle with controlled shapes and sizes(in the range from-2 to-10 nm).Carbon supported nanoparticles with narrow size distributions have been synthesized by applying an alternating voltage to macroscopic bulk platinum structures,such as disks or *** using any surfactants,the size and shape of the particles can be changed by adjusting simple parameters such as the applied potential,frequency and electrolyte *** instance,application of a sinusoidal AC voltage with lower frequencies results in cubic nanoparticles;whereas higher frequencies lead to predominantly spherical *** the other hand,the amplitude of the,sinusoidal signal was found to affect the particle size;the lower the amplitude of the applied AC signal,the smaller the resulting particle ***/C catalysts prepared by this approach showed 0.76 A/mg mass activity towards the oxygen reduction reaction which is-2 times higher than the state-of-the-art commercial Pt/C catalyst(0.42 A/mg)from *** addition to this,we discussed the mechanistic insights about the nanoparticle formation pathways.

关键词： electrochemical synthesis platinum nanoparticles oxygen reduction reaction

Auto-regulatory feedback by RNA-binding proteins

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Journal of Molecular Cell Biology 2019年第10期11卷 930-939页

作者： Michaela Muller-McNicoll oliver Rossbach Jingyi Hui jan Medenbach Institute of Cell Biology and Neuroscience Goethe University FrankfurtMax-von-Laue-Strasse 13D-60438 Frankfurt am MainGermany Institute of Biochemistry Justus-Liebig-University GiessenHeinrich-Buff-Ring 17D-35392 GiessenGermany State Key Laboratory of Molecular Biology CAS Center for Excellence in Molecular Cell ScienceShanghai Institute of Biochemistry and Cell BiologyChinese Academy of SciencesShanghai 200031China Institute of Biochemistry I University of RegensburgUniversitaetsstrasse 31D-93053 RegensburgGermany

RNA-binding proteins(RBPs)are key regulators in post-transcriptional control of gene *** that alter their activity or abundance have been implicated in numerous diseases such as neurodegenerative disorders and various types of *** highlights the importance of RBP proteostasis and the necessity to tightly control the expression levels and activities of *** many cases,RBPs engage in an auto-regulatory feedback by directly binding to and influencing the fate oftheirown mRNAs,exerting control over their own *** this feedback control,RBPs employ a variety of mechanisms operating at all levels of posttranscriptional regulation of gene *** we review RBP-mediated autogenous feedback regulation that either serves to maintain protein abundance within a physiological range(by negative feedback)or generates binary,genetic on/off switches important for *** fate decisions(by positive feedback).

关键词： autogenous regulation protein homeostasis RNA-binding proteins post-transcriptional regulation of gene expressi on

Inductive effect of Ti-doping in Fe_(2)o_(3)enhances the photoelectrochemical water oxidation

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Science China Chemistry 2023年第7期66卷 2091-2097页

作者： Yumei Lin Yan Wang Hongxia Wang Jingjing Wang Xiaofeng Wu jan P.Hofmann Giulio Gorni Victor A.de la Pena o'Shea Freddy E.oropeza Kelvin H.L.Zhang State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Surface Science Laboratory Department of Materials and Earth SciencesTechnical University of DarmstadtDarmstadt 64287Germany CELLS-ALBA Synchrotron Barcelona 08290Spain Institute of optics(Io-CSIC) c/Serrano 121Madrid 28006Spain Photoactivated Processes Unit IMDEA Energy InstituteMadrid 28935Spain

Hematite(α-Fe_(2)o_(3))is an ideal oxide semiconductor candidate for photoelectrochemical(PEC)water *** of Fe_(2)o_(3)is known to benefit the PEC water oxidation efficiency,but despite extensive research efforts,the underlying mechanism still remains *** this work,we report a comprehensive study on the relationship between the electronic structure,interfacial reaction kinetics and PEC activity of Ti-doped Fe_(2)o_(3)*** results show that the interfacial charge transfer efficiency at the Fe_(2)o_(3)/electrolyte interface is the main factor in the significant increase of the PEC activity of doped Fe_(2)o_(3).Electrochemical impedance spectroscopy reveals that the interfacial charge transfer efficiency is determined by energy overlap between the water oxidation potential and energy distribution of an intermediate surface state that has been identified as Fe^(IV)=o groups on Fe_(2)o_(3)surface generated during PEC ***,the potential energy distribution of this intermediate surface state can be modulated by Ti doping,and a shift towards a more positive potential of the intermediate surface state increases the overlap with the water oxidation potential and thus enhances the kinetics of charge transfer for PEC water *** origin of such potential energy modulation is traced to the inductive effect from Ti-doping on the Fe^(3+)/Fe^(4+)redox transition and the Fe-o bond *** results provide new insight into the mechanism for the doping effect on the PEC water splitting,introducing new strategies to optimize the PEC activity by tuning the redox properties of active metal oxides.

关键词： hematite surface states doping photoelectrochemical water splitting electronic structure

Pancreatic panniculitis and elevated serum lipase in metastasized acinar cell carcinoma of the pancreas: A case report and review of literature

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World Journal of Clinical Cases 2020年第21期8卷 5304-5312页

作者： Rainer Christoph Miksch Tobias S Schiergens Maximilian Weniger Matthias Ilmer Philipp M Kazmierczak Markus o Guba Martin K Angele Jens Werner jan G D'Haese Department of General Visceraland Transplantation SurgeryLudwig-Maximilians-University MunichMunich 81377BavariaGermany Department of General Visceral Transplantat Vasc&Thorac Surg Campus GrosshadernUniversity of MunichMunich 81377Germany Department of General Ludwig Maximilians-University(LMU)Munich 81377Germany Department of Radiology Ludwig-Maximilians-University MunichMunich 81377Germany Department of Surgery University of MunichKlinikum GrosshadernMunich University HospitalMunich 81377Germany Department of General University of MunichKlinikum GrosshadernHospital of the University of MunichMunich 81377Germany Department of General Klinikum Univ MunchenKlin Allgemeine Viszeral Transplantat Gefass&ThStandort GrosshadernLudwig-Maximilians-University(LMU)Munich 81377Germany

BACKGRoUND Pancreatic panniculitis is an extremely rare condition associated with different underlying pancreatic disorders and characterized by subcutaneous fat necrosis induced by elevated serum lipase *** lesions usually affect the lower extremities and may precede abdominal symptoms of pancreatic *** cell carcinoma(ACC)of the pancreas is a rare pancreatic neoplasm,accounting for only 1%-2%of pancreatic tumors in *** present the case of a 72-year-old man with ACC of the pancreatic head and synchronous liver *** the primary tumor and liver metastases were *** lipase was elevated before surgery and decreased to normal *** serum lipase levels at follow-up led to the diagnosis of hepatic *** disease progression was then accompanied by pancreatic panniculitis,with subcutaneous fat necrosis and acute *** the best of our knowledge,only 4 cases have been reported in the literature and each showed a similar association of serum lipase levels with pancreatic panniculitis and progression of *** Clinical symptoms and progression of ACC may correlate with serum lipase levels,suggesting potential usefulness as a follow-up biomarker.

关键词： Pancreatic panniculitis Lipase Acinar cell carcinoma Pancreatic cancer Case report

A rationale for the development of thermally stable nanostructured Ceo_2-Zro_2-containing mixed oxides

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Journal of Rare Earths 2008年第2期26卷 136-140页

作者： Roberta Di Monte jan Kapar Heather Bradshaw Colin Norman Department of Chemistry Sciences Interuniversity Consortium INCA University of Trieste Via L.Giorgieri34127 Trieste Italy MEL Chemicals P.O. Box 6 Clifton Junction SwintonManchester M27 8LS England

Ceo2-Zeo2 solid solutions are extensively used as oxygen storage promoters in the current automotive three-way catalysts. High thermal stability of the textural properties is one of the most important requirements for practical application since temperatures up to 1273 K are easily experienced by these materials under real working conditions. In the present paper, we investigated how hydrothermal treatments applied to cakes of doped and undoped Zro2-rich Ceo2-Zro2 precursors might improve the thermal stability of the final Ceo2-Zro2 solid solution. A rationale was developed that allowed to correlate the morphology of the hydrothermaUy treated cake with the thermal stability at 1273 K of the final product, which did not depend on the composition of the mixed oxides.

关键词： Ceo2-Zro2 mixed oxides Ceo2-Zro2 solid solution Ceo2-Zro2 mixed oxides, thermal stability of three-way catalysts oxygen storage capacity rare earths

Hydrodynamics and suspended particulate matter retention in macrotidal estuaries located in Amazonia-semiarid interface(Northeastern-Brazil)

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International Journal of Sediment Research 2020年第4期35卷 417-429页

作者： Vinicius Henrique Maciel dos Santos Francisco Jose da Silva Dias Audalio Rebelo Torres Romulo Araujo Soares Lais Costa Terto Antonio Carlos Leal de Castro Ricardo Luvizotto Santos Marco Valerio jansen Cutrim Laboratorio de Hidrodinamica Costeira Estuarina e de Aguas Interiores (LHiCEAI) Do Programa de Pos-Graduacao Em Oceanografia (PPGOceano) da Universidade Federal Do Maranhao (UFMA)Cidade Universitaria Dom Delgado Laboratorio de Ictiologia (LabIctio) da Universidade Federal Do Maranhao (UFMA) Cidade Universitaria Dom Delgado Laboratorio de Ecotoxicologia (LabEcotox) Do Programa de Pos-Graduacao Em oceanografia (PPGoceano) da Universidade Federal Do Maranhao (UFMA) Cidade Universitaria Dom Delgado Laboratorio de Ficologia (LabFic) Do Programa de Pos-Graduacao Em oceanografia (PPGoceano) da Universidade Federal Do Maranhao (UFMA) Cidade Universitaria Dom Delgado

The aim of the current study was to determine the nature of the seasonal variability of the Suspended Particulate Matter(SPM) fluxes from the drainage basin to the estuary in a macrotidal region(Northeastern Brazil),and the estuarine response to a seawater intrusion regarding sediment deposition,which will support the understanding of the global transport of materials at the continent-ocean *** structure data was acquired using a Conductivity,Temperature,and Depth(CTD) probe with a sampling frequency of 4 *** particulate material was measured by gravimetric measurements applied to exact filtered volume *** outflows were measured through the use of an Acoustic Doppler Current Profiler(ADCP) with frequency of 1.5 *** horizontal thermal and saline gradients varied from warmer and less saline waters(2014) to cooler and saline waters(2015).The gradient behavior when linked to volume transport and SPM flows,suggests a minimization of the fluvial flows in 2015,easing the advance of coastal water(CW) towards the inner estuary,leading to an inversion of the baroclinic pressure *** bottom saline front,generated by the entrance of coastal water masses,caused an increase in SPM concentrations due to increased fluid density,resuspension of previously deposited sediment,and erosion of *** concentrations of SPM indicate higher volume transport suggesting a hydraulic barrier due to the change/inversion of the baroclinic pressure gradient,resulting in water and material *** deposition was observed during neap tide,while during spring tide the material is resuspended,increasing the concentration,generating cycles of deposition and erosion during the neap-spring *** sediment in suspension that reach the estuary,even with low fluvial volume,stay in this environment forming new islands because of *** deposition rates or sediment cycling,if generated by the hydraulic barrier,may indicate that the flo

关键词： Brazilian Amazonia Materials discharges Macrotidal estuaries Freshwater percentage Residence time

Milliwatt terahertz harmonic generation from topological insulator metamaterials

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Light(Science & Applications) 2022年第11期11卷 2766-2773页

作者： Klaas-jan Tielrooij Alessandro Principi David Saleta Reig Alexander Block Sebin Varghese Steffen Schreyeck Karl Brunner Grzegorz Karczewski Igor Ilyakov oleksiy Ponomaryov Thales V.A.G.de oliveira Min Chen jan-Christoph Deinert Carmen Gomez Carbonell Sergio o.Valenzuela Laurens W.Molenkamp Tobias Kiessling Georgy V.Astakhov Sergey Kovalev Catalan Institute of Nanoscience and Nanotechnology(ICN2) BIST and CSICCampus UABBellaterraBarcelona 08193Spain Department of Applied Physics TU EindhovenDen Dolech 25612 AZ EindhovenThe Netherlands School of Physics and Astronomy University of ManchesterM139PL ManchesterUK Physikalisches Institut(EP3) Universitat WurzburgAm Hubland97074 WurzburgGermany Institute of Physics Polish Academy of ScienceAl.Lotnikow 32/46PL-02668 WarsawPoland Helmholtz Zentrum Dresden-Rossendorf Bautzner Landstr.40001328 DresdenGermany ICREA Pg.Lluis Companys 2308010 BarcelonaSpain Institute for Topological Insulators Am HublandD-97074 WurzburgGermany

Achieving effcient,high-power harmonic generation in the terahertz spectral domain has technological applications,for example,in sixth generation(6G)communication *** Dirac fermions possess extremely large terahertz nonlinear susceptibilities and harmonic conversion ***,the observed maximum generated harmonic power is limited,because of saturation effects at increasing incident powers,as shown recently for ***,we demonstrate room-temperature terahertz harmonic generation in a Bi_(2)Se_(3) topological insulator and topological-insulator-grating metamaterial structures with surface-selective terahertz field *** obtain a third-harmonic power approaching the miliwatt range for an incident power of 75 mW-an improvement by two orders of magnitude compared to a benchmarked graphene *** establish a framework in which this exceptional performance is the result of thermodynamic harmonic generation by the massless topological surface states,benefiting from ultrafast dissipation of electronic heat via surface-bulk Coulomb *** results are an important step towards on-chip terahertz(opto)electronic applications.

关键词： harmonic insulator incident

Physico-chemical properties of 3-methoxy-2-nitrobenzoates of some rare earth elements(Ⅲ)

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Journal of Rare Earths 2012年第3期30卷 262-268页

作者： Wiesawa Ferenc Beata Cristóvao jan Sarzyński Halina Guchowska Faculty of Chemistry Maria Curie-Skodowska University Institute of Physics Maria Curie-Skodowska University

The complexes of 3-methoxy-2-nitrobenzoates of Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Tb（Ⅲ）, Er（Ⅲ） and Tm（Ⅲ） with the formula： Ln（C8H6No5）3·2H2o, where Ln=lanthanides（Ⅲ）, were synthesized and characterized by elemental analysis, Forier transform irtrared （FTIR） spectroscopy, magnetic and thermogravimetric studies and also by X-ray diffraction （XRD） measurements. The complexes had col- ours typical for Ln（Ⅲ） ions. The carboxylate groups bound as bidentate chelating. on heating to 1173 K in air they decomposed in the same way, at first, dehydrated in one step to anhydrous salts, and then decomposed to the oxides of respective metals with intermediate formation of the oxycarbonates. The enthalpy values of the dehydration process changed from 133.72 to 44.50 kJ/mol. Their solubility in water at 293 K was of the order of 10-4 mol/dm3. The magnetic moments of analysed complexes were determined by Gouy＇s method in the range of 76-303 K.

关键词： 3-methoxy-2-nitrobenzoates thermal stability magnetic properties rare earths