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Mechanism of cross-level settlements and void accumulation of wide and conventional sleepers in railway ballast

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Railway Engineering Science 2024年第3期32卷 361-383页

作者： Olga Nabochenko Mykola Sysyn Norman Krumnow Szabolcs fischer Institute of Railway Systems and Public Transport Technical University of DresdenDresdenGermany Rhomberg Sersa Deutschland GmbH BerlinGermany Central Campus Győr Széchenyi István UniversityGyorHungary

The cross-level and twist irregularities are the most dangerous irregularity types that could cause wheel unloading with the risk of derailments and additional maintenance ***,the mechanism of the irregularities initiation and development is *** motivation of the present study was the previous experimental studies on the application of wide sleepers in the ballasted *** long-term track geometry measurements with wide sleepers show an enormous reduction of the vertical longitudinal irregularities compared to the conventional ***,wide sleepers had higher twist and cross-section level *** present paper aims to explain the phenomenon by discrete element method(DEM)modeling the development process of sleeper inhomogeneous support at cross-level depending on the sleeper *** DEM simulations show that the maximal settlement intensity is up to 3.5 times lower for a wide sleeper in comparison with the conventional ***,the cross-level differential settlements are almost the same for both *** particle loading distribution after all loading cycles is concentrated on the smaller area,up to the half sleeper length,with fully unloaded zones under sleeper *** flow limitation under the central part of the sleeper could improve the resilience of wide sleepers to the development of cross-level *** mechanism of initiation of the cross-level irregularity is proposed,which assumes the loss of sleeper support under sleeper *** further growth of inhomogeneous settlements along the sleeper is assumed as a result of the interaction of two processes:ballast flow due to dynamic impact during void closing and on the other side high pressure due to the concentration of the pressure under the middle part of the *** DEM simulation results support the assumption of the mechanism and agree with the experimental studies.

关键词： Wide sleeper Ballasted track Sleeper support inhomogeneity Sleeper foot form Discrete element modeling Void accumulation

A Golden Touch in the Design of Multifunctional Porphyrin Metallacages:Host-Guest Chemistry for Drug-Target Interactions

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CCS Chemistry 2024年第7期6卷 1662-1671页

作者： Tamara Rodríguez-Prieto Darren Wragg Nicole Heiduk Mihyun Park Nicole Strittmatter Roland A.fischer Angela Casini Guillermo Moreno-Alcántar Chair of Medicinal and Bioinorganic Chemistry Department of ChemistrySchool of Natural SciencesTechnical University of Munich85748 Garching b.München Professorship for Analytical Chemistry Department of ChemistrySchool of Natural SciencesTechnical University of Munich85748 Garching b.München Chair of Inorganic and MetalOrganic Chemistry Department of ChemistrySchool of Natural SciencesTechnical University of Munich85748 Garching b.München Munich Data Science Institute(MDSI) Technical University of Munich85748 Garching b.München

The use of three-dimensional self-assembled metallacages(MCgs)as multimodal drug platforms holds great ***,the synthesis of MCgs with increased complexity and functionality is a great challenge since understanding of the interaction of MCgs with biological targets is still *** this context,this work reports on the integration of a gold(III)porphyrin scaffold into a prismatic MCg structure and explores its application for multimodal therapy of cancer in vitro,namely enabling both photodynamic therapy and *** experimental approaches with a state-of-the-art metadynamics theoretical study,we discovered that the gold cage shows unprecedented host-guest interaction-driven selective stabilization of guanine-quadruplex(G4)structures-validated anticancer drug targets-disclosing a new mechanism to pursue in the design of supramolecular drugs.

关键词： gold metallacages porphyrins G4stabili-zation host-guestchemistry anticanceragents

CXCR4 signaling in central nervous system regeneration: friend or foe?

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Neural Regeneration Research 2022年第7期17卷 1481-1483页

作者： Daniel Terheyden-Keighley alexander M.Hilla Dietmar fischer Department of Cell Physiology Ruhr University of BochumUniversitätsstraβe 15044780 BochumGermany

The knockout of the chemokine C-X-C motif chemokine receptor 4(CXCR4)in growthstimulated retinal ganglion cells(RGCs)has a multiplicative effect on optic nerve regeneration.C-X-C motif chemokine ligand 12(CXCL12),the ... 详细信息

关键词： CXCL12 CXCR4 system

Socioecological drivers facilitating biodiversity conservation in traditional farming landscapes

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Ecosystem Health and Sustainability 2015年第9期1卷 8-17页

作者： Ine Dorresteijn Jacqueline Loos Jan Hanspach Joern fischer Faculty of Sustainability Leuphana University LuneburgScharnhorststraße 121335 LuneburgGermany

Traditional farming landscapes have evolved as tightly coupled socioecological systems that support high ***,land-use change severely threatens the high biodiversity of these *** nature conservation in such landscapes requires a thorough understanding of the key drivers underpinning *** empirical research on mammals,birds,butterflies,and plants in a traditional cultural landscape in Romania,we revealed seven hypothesized drivers facilitating biodiversity *** proportions of three main land-use types support the landscape species pool,most likely through habitat connectivity and frequent spillover between land-use *** complementation and supplementation provide additional habitat for species outside their core *** of woody vegetation cover and gradients in land-cover heterogeneity provide mosaic landscapes with wide ranges of *** land-use practices underpin landscape heterogeneity,traditional land-use elements such as wood pastures,and human-carnivore ***-down predator control may limit herbivore ***,cultural ties between humans and nature have a central influence on people’s values and sustainable use of natural *** approaches should aim to maintain or restore these socioecological drivers by targeting the heterogeneous character of the forest-farmland mosaic at large scales through"broad and shallow"conservation *** large-scale measures should be complemented with"deep and narrow"conservation measures addressing specific land-use types,threats,or *** both cases,conservation measures should integrate the entire socioecological system,by recognizing and strengthening important links between people and the environment.

关键词： countryside biogeography coupled human and natural systems cultural landscapes human–environment systems landscape ecology resilience Romania Special Feature:Ecosystem Management in Transition in Central and Eastern Europe Transylvania

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微尺度声操控研究及其生物学应用

Engineering 2023年第5期24卷 13-16,I0001页

作者： Zhichao Ma Peer fischer Max Planck Institute for Intelligent Systems Stuttgart 70569Germany Institute of Physical Chemistry University of StuttgartStuttgart 70569Germany School of Biomedical Engineering Shanghai Jiao Tong UniversityShanghai 200030China

Acoustic waves-and ultrasound waves in particular-are biocompatible,with excellent transmission through biological ***,the wavelength and intensity of acoustic waves can be tuned over several orders of *** notably,the commonly used 10–300 MHz frequency range is attractive for biomedical applications,as its wavelength in water(5–150μm)corresponds to the cellular-length scale.

关键词：声操控生物学应用微尺度

碳纳米管/氮化硼混杂填料对尼龙6导热性能的影响及其机理

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高分子材料科学与工程 2019年第3期35卷 42-47页

作者：王亮吴唯邹志强刘江 Andreas fischer Dietmar Drummer 华东理工大学材料科学与工程学院中德先进材料联合研究中心 Institute of Polymer Technology Friedrich-Alexander-Universität Erlangen-Nürnberg(FAU)Erlangen 91054Germany

利用熔融共混工艺,首先制备了尼龙6/氮化硼(PA6/BN)复合材料。根据复合材料的热导率确定BN添加量后,在PA6/BN体系中添加碳纳米管(CNTs)并引入相容剂以改善填料与基体的界面相容性,通过测定材料的热导率,并借助差示扫描量热分析、动态力... 详细信息

利用熔融共混工艺,首先制备了尼龙6/氮化硼(PA6/BN)复合材料。根据复合材料的热导率确定BN添加量后,在PA6/BN体系中添加碳纳米管(CNTs)并引入相容剂以改善填料与基体的界面相容性,通过测定材料的热导率,并借助差示扫描量热分析、动态力学热分析、扫描电镜等手段,探讨CNTs/BN混杂填料对于PA6材料性能的影响,在此基础上建立了相应的三维导热模型来解释体系的导热机理。结果表明,2%CNTs和20.83%BN混杂可显著改善复合材料的导热性能,热导率达0.76 W/(m·K),为纯PA6的2.45倍,同时保持较好的绝缘性;复合材料的动态力学分析结果与扫描电镜图及所搭建导热模型吻合较好。该PA6基导热材料有望应用于LED等电子电气的外壳材料。

关键词：尼龙6 混杂填料热导率三维导热模型

Manufacturing size effect on the structural and mechanical properties of additively manufactured Ti-6Al-4V microbeams

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Journal of Materials Science & Technology 2023年第18期149卷 18-30页

作者： Kaiyang Yin Bo Cao Juraj Todt Florian Gutmann Hasan Furkan Tunçay Antonina Roth Frank fischer Nadira Grübel Aron Pfaff Georg C.Ganzenmüller Jozef Keckes Stefan Hiermaier Christoph Eberl Department of Microsystems Engineering University of FreiburgFreiburgGermany Cluster of Excellence livMatS@FIT-Freiburg Center for Interactive Materials and Bioinspired Technologies University of FreiburgFreiburgGermany Chair of Materials Physics Montanuniversität LeobenLeobenAustria INATECH University of FreiburgFreiburgGermany Fraunhofer Ernst-Mach Institut EMIFreiburgGermany Fraunhofer IWM FreiburgGermany

The size effect of Ti-6Al-4V submillimeter structures manufactured by selective laser melting,which is critical for metallic mechanical metamaterials of unique mechanical properties,for example,nega-tive Poisson’s ratio and ultrahigh modulus,which show promise in biomedical,environmental,energy-related applications,has not been systematically *** here are the quantification of the porosities by X-ray microtomography scans,texture analysis,and mechanical characterization of the addi-tively manufactured Ti-6Al-4V *** found linearly decreasing porosities,increasing mechan-ical properties,and increasing texture in the microbeam with increasing diameter from 250 to 500μ*** variation of microstructure in microbeams of different diameters and along the sample height,result-ing from the printing parameters and the thermal conditions,leads to the discrepancy between the be-havior observed in experiments and finite element *** results provide the structure-property-processing correlation to improve the manufacturing and prediction of the mechanical behavior of metal-lic mechanical metamaterials.

关键词： Selected laser melting Porosity Texture Epitaxial growth Finite element modeling Metallic mechanical metamaterials

Effects of immune cells on mesenchymal stem cells during fracture healing

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World Journal of Stem Cells 2021年第11期13卷 1667-1695页

作者： Sabrina Ehnert Borna Relja Katharina Schmidt-Bleek Verena fischer Anita Ignatius Caren Linnemann Helen Rinderknecht Markus Huber-Lang Miriam Kalbitz Tina Histing Andreas K Nussler Siegfried Weller Research Institute at the BG Trauma Center Tübingen Department of Trauma and Reconstructive SurgeryUniversity of TübingenTübingen 72076Germany Experimental Radiology Department of Radiology and Nuclear MedicineOttovon-Guericke UniversityMagdeburg 39120Germany Julius Wolff Institute and Berlin Institute of Health Center of Regenerative Therapies Charité-University Medicine BerlinBerlin 13353Germany Institute of Orthopedic Research and Biomechanics Ulm University Medical CenterUlm 89091Germany Institute for Clinical and Experimental Trauma-Immunology(ITI) University Hospital UlmUlm 89091Germany Department of Trauma and Orthopedic Surgery University Hospital Erlangen Friedrich-Alexander University Erlangen-Nürnberg(FAU)Erlangen 91054Germany

In vertebrates,bone is considered an osteoimmune system which encompasses functions of a locomotive organ,a mineral reservoir,a hormonal organ,a stem cell pool and a cradle for immune *** osteoimmune system is based on cooperatively acting bone and immune cells,cohabitating within the bone *** are highly interdependent,a fact that is confounded by shared progenitors,mediators,and signaling *** fracture healing requires the participation of all the precursors,immune and bone cells found in the osteoimmune *** evidence demonstrated that changes of the immune cell composition and function may negatively influence bone *** this review,first the interplay between different immune cell types and osteoprogenitor cells will be elaborated more *** separate paragraphs focus on the specific cell types,starting with the cells of the innate immune response followed by cells of the adaptive immune response,and the complement system as mediator between ***,a brief overview on the challenges of preclinical testing of immunebased therapeutic strategies to support fracture healing will be given.

关键词： Trauma Bones Immune response Mesenchymal stem cells Fracture healing

腹腔镜与开放肝切除术随机对照试验的系统综述与meta分析摘译

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肝胆外科杂志 2022年第3期30卷 240-240页

作者： Haney CM studier-fischer A Probst P Fan C Muller PC Golriz M 崔笑(摘译) 赵义军(审校) 不详

背景:腹腔镜肝切除技术自Louisville、Morioka和South⁃ampton宣言发表以来,在全世界范围内获得广泛的应用。虽然这些宣言是依据非常严谨的方法学所建立的,但缺乏高级别研究证据。大部分数据支持来自于来自大样本meta分析。该文章旨在通... 详细信息

背景:腹腔镜肝切除技术自Louisville、Morioka和South⁃ampton宣言发表以来,在全世界范围内获得广泛的应用。虽然这些宣言是依据非常严谨的方法学所建立的,但缺乏高级别研究证据。大部分数据支持来自于来自大样本meta分析。该文章旨在通过分析因良性或恶性肝脏疾病行腹腔镜和开放肝切除RCT结果提供可靠的证据结论。方法:本系统综述和荟萃分析按照AMSTAR⁃2标准和PRISMA指南对纳入研究进行了筛选。检索数据库主要包括通过Pubmed检索CENTRAL,Medline以及Web of Science,检索时间截止点为2020年12月30日。包括纳入的研究结果只包括腹腔镜和开放性肝切除治疗良、恶性肝脏肿瘤的RCT研究。检索内容包括英文和中文文献。

关键词： meta分析肝切除术系统综述荟萃分析腹腔镜肝切除肝脏疾病中文文献检索内容