检索结果-南通市图书馆

In vivo and in vitro study of resorbable magnesium wires for medical implants:Mg purity,surface quality,Zn alloying and polymer coating

引用

Journal of Magnesium and Alloys 2024年第6期12卷 2472-2488页

作者： K.Tesar J.Luňácková M.Jex M.Žaloudková R.Vrbová M.Bartoš P.Klein L.Vištejnová J.Dušková E.Filová Z.Sucharda M.Steinerová S.Habr K.Balík A.Singh Department of Materials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic Institute of Physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic Institute of Dental Medicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Department of Physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Department of Composites and Carbon Materials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic Institute of Anatomy First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biomedical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Department of Pathological Physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Department of Histology and Embryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Institute of Pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Department of Biomaterials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for Structural Materials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

Magnesium is an excellent material in terms of biocompatibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation limit the potential of Mg-based *** low-alloyed Mg-Zn wires can strongly reduce problems with large H_(2)bubbles and improve the mechanical properties considerably while maintaining excellent long-term *** pickling and a polymer coating can be effectively used to lower the rate of in vivo *** this work,microstructural,mechanical,and in vitro characterization of 250μm and 300μm extruded wires made from ultra-pure Mg,commercially pure Mg,Mg-0.15Zn,Mg-0.4Zn and Mg-1Zn was ***,Mg-0.4Zn wires together with a variant coated with a copolymer of L-lactide andε-caprolactone were tested in vivo on artificially damaged Wistar rat *** on the observed Mg-induced osteogenesis,polymer-coated Mg wires with a small addition of Zn are a perspective material for bone-support applications,such as cerclage and fixation wires.

关键词： Magnesium Resorbable Mg wire Mg-Zn implant degradation Biocompatibility study Zn grain boundary segregation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comparative analysis of microstructure,mechanical,and corrosion properties of biodegradable Mg-3Y alloy prepared by selective laser melting and spark plasma sintering

引用

Journal of Magnesium and Alloys 2024年第4期12卷 1496-1510页

作者： P.Minárik M.Zemková S.Šašek J.Dittrich M.Knapek F.Lukáˇc D.Koutný J.Jaroš R.Král Faculty of Mathematics and Physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic Research Centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of Plasma Physics of the czech Academy of Sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of Machine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of biodegradable magnesium alloy Mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(SPS)and selective laser melting(SLM).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the SLM material and unmeasurably low porosity in the SPS *** main aim of the study was the thorough microstructure characterisation and interrelation between the microstructure and the functional properties,such as mechanical strength,deformability,and corrosion *** materials showed comparable strength of∼110 MPa in tension and compression and relatively good deformability of∼9%and∼21%for the SLM and SPS materials,*** corrosion resistance of the SPS material in 0.1 M NaCl solution was superior to the SLM one and comparable to the conventional extruded *** digital image correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative effect on the functional properties of the SLM *** the other hand,one of the primary outcomes of this study is that the SPS consolidation method is very effective in the preparation of the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might find practical applications.

关键词： Magnesium Yttrium Powder metallurgy Microstructure Mechanical strength Corrosion resistance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Diversity of click beetles in managed nonnative coniferous and native beech stands: Consequences of changes in the structural and species composition of tree stands in Central Europe

引用

Forest Ecosystems 2022年第5期9卷 596-605页

作者： Václav Zumr Oto Nakladal JiríRemes Tereza Brestovanska Váaclav Zumr czech University of Life Sciences Prague Faculty of Forestry and Wood SciencesKamýcka 129Praha 6Suchdol16500Czech Republic The Silva Tarouca Research Institute for Landscape and Ornamental Gardening Kvetnove namestí391Průhonice25243Czech Republic SC*** Czech Republic

The natural composition of forests has undergone significant changes over recent centuries.A closer-to-natural tree species composition has long been perceived as key to a high *** investigated the impact on communities of click beetles(Elateridae)caused by changes in the tree species composition of spruce monocultures compared to reference sites of recently unmanaged natural beech *** collect data,passive interception traps were distributed within managed spruce stands of different age classes and natural beech forests of various developmental *** beetle species richness was slightly but not significantly higher in the beech *** saproxylic species group was significantly more common in the spruce stands,whereas the group of nonsaproxylic species was significantly more abundant in the beech *** the commercial stands,the significantly highest species richness was in the clearings(0–10-year-old stands),and at this forest age class,the vast majority of the beetle species occurred in the spruce *** the developmental stages of the natural forest,a slightly higher beetle richness was found at the disintegration *** study results suggested that different tree species compositions and stand structures affect the communities of click beetles and substantially change their species composition and thus their response to external ***,management of stands using diverse silvicultural systems is recommended for creating diverse ecological niches in forests.

关键词： Species richness Forest management Saproxylic beetles Nonsaproxylic beetles Dead wood Elateridae Canopy openness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Individual effect of Y and Nd on the microstructure formation of Mg-Y-Nd alloys processed by severe plastic deformation and their effect on the subsequent mechanical and corrosion properties

引用

Journal of Magnesium and Alloys 2023年第2期11卷 509-521页

作者： Maria Zemkova Peter Minarik Jan Dittrich Jan Bohlen Robert Kral Charles University Department of Physics of MaterialsKe Karlovu 512116PragueCzechia University of Zilina Research CentreUniverzitna8215/1Zilina01026Slovakia Institute of Material and Process Design Helmholtz-Zentrum Hereon21502GeesthachtGermany

This work investigated the effect of sole yttrium and neodymium alloying on the microstructure formation during severe plastic deformation by equal channel angular pressing(ECAP) and an impact on the mechanical strength and corrosion resistance of binary Mg-3Y and Mg-3Nd *** results are compared with a ternary Mg-4Y-3Nd alloy,which represents a simplified version of the commercially successful WE43 *** extensive study comprises a thorough microstructural analysis performed by scanning and transmission electron microscopy,including electron backscatter diffraction and texture analysis performed by X-ray *** is shown that the presence of Nd primarily caused precipitation during the processing of the Mg-3Nd alloy,while Y remained dissolved in the magnesium matrix in the Mg-3Y *** difference resulted in a significantly smaller average grain size in the Mg-3Y alloy(~0.77 nm) than in the Mg-3Nd alloy(~1.3 μm) after the final step of the processing and formation of a slightly different ***,the composition and the processing affected the mechanical and corrosion properties of the investigated materials,measured by compression deformation tests,microhardness measurement,and electrochemical impedance *** study shows that the ECAP-processed W3 sample exhibits a surprisingly good combination of ultrafine-grain structure,weak crystallographic texture,high strength,and high corrosion resistance compared with the other investigated *** attributes make this material very interesting for utilisation in the industry and/or medicine.

关键词： Magnesium Rare earth elements Microstructure Texture Mechanical strength Corrosion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Same place, different time, head up: Multiple antipredator responses to a recolonizing apex predator

引用

Current Zoology 2023年第6期69卷 703-717页

作者： Bruno Esattore Agnese Carlotta Rossi Francesco Bazzoni Chiara Riggio Raquel Oliveira Ivan Leggiero Francesco Ferretti Department of Ethology Institute of Animal SciencePratelstvi 81510400UhrinevesPragueCzech Republic Department of Ethology and Companion Animal Science Faculty of AgrobiologyFood and Natural ResourcesCzech University of Life SciencesKamycka 12916500SuchdolPragueCzech Republic Department of Life Sciences Research Unit of Behavioral EcologyEthology and Wildlife ManagementUniversity of SienaVia Pier Andrea Mattioli 453100SienaItaly NBFC National Biodiversity Future CenterPalermo 90133Italy

Prey adjust their antipredator behavioral tactics to minimize the risk of an encounter with *** responses of prey to pred-ators have been reported,but the nature of antipredator response is not ubiquitous and it is the object of increasing interest,especially consid-ering the recent recovery of large carnivores in Europe,and the potential for behavioral antipredator responses to elicit consequences at the ecosystem *** have tested multiple antipredator responses by fallow deer Dama dama to wolf Canis lupus in a Mediterranean protected area recently recolonized by this apex *** intensive camera trapping,we tested for temporal and spatial association between predator and prey,and we have also studied deer vigilance in forest habitats where focal observations are usually *** detection rates were spatially associated with those of fallow ***,no evidence was found for fallow deer avoiding sites with higher predator detection *** activity patterns were significantly different between the 2 species,with the wolf being mainly nocturnal whereas fallow deer was active especially during daylight.A comparison with a preliminary study strongly suggests an increase in the diurnal activity of fallow deer along with the stabilization of wolf presence in the *** the rate and the duration of vigilance of female fallow deer increased with the local frequency of wolf *** suggest an antipredator response based on temporalrather than spatialavoidance,as well as increasedvigilance.

关键词： antipredator responses deer interspecific interactions temporal patterns vigilance

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Domestication-related changes in seed dispersal and pigmentation:Visual selection and functional trait?

引用

Molecular Plant 2023年第8期16卷 1240-1242页

作者： Petr Smykal Travis Parker Department of Botany Palacky University in Olomouc77900 OlomoucCzech Republic Department of Plant Sciences University of CaliforniaDavisDavisCA 95616USA

The development of agriculture is one of the most transformative changes in the history of *** the most common changes occurring during plant domestication are reductions in seed dispersal and changes in *** there are archaeological records of these processes,the advancement of genomics offers a tool to achieve greater insight into the process of converting wild plants into crops(Smýkal et al.,2018).This involved and resulted in a set of specific phenotypic changes referred to collectively as the domestication ***,less obvious domestication-related modifications have also been identified,including changes in plant *** processes are often *** example,among visible changes,selection for visual appearance such as pigmentation is governed by modulation of specific metabolic *** genomic tools,the improvement of analytical methods provides the opportunity to reveal metabolomic changes involved in plant domestication.

关键词： Visual collective crops

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High-throughput study of the anomalous Hall effect

引用

npj Computational Materials 2023年第1期9卷 767-774页

作者： JakubŽelezný Yuta Yahagi Carles Gomez-Olivella Yang Zhang Yan Sun Institute of Physics Czech Academy of SciencesCukrovarnická1016200 Praha 6Czech Republic Department of Applied Physics Tohoku UniversitySendaiMiyagiJapan Department of Physics and Astronomy University of Tennessee KnoxvilleKnoxvilleTN 37996USA Min H.Kao Department of Electrical Engineering and Computer Science University of TennesseeKnoxvilleTN 37996USA Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Despite its long history,the anomalous Hall continues to attract attention due to its complex origins,its connection to topology,and its use as a probe of magnetic *** this work we investigate the anomalous Hall effect in 2871 ferromagnetic materials using an automatic high-throughput calculation *** analyze general properties of the effect,such as its reliance on spin-orbit coupling strength and *** materials with the largest anomalous Hall effect,we find that symmetry-protected band degeneracies in the non-relativistic electronic structure,such as mirror symmetry-protected nodal lines,are typically responsible for the large ***,we examine the dependence of the anomalous Hall effect on magnetization direction and demonstrate deviations from the commonly assumed expression j^(AHE)~M×E.

关键词： effect symmetry protected

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Association of Psb28 and Psb27 Proteins with PSII-PSI Supercomplexes upon Exposure of Synechocystis sp. PCC 6803 to High Light

引用

Molecular Plant 2017年第1期10卷 62-72页

作者： Martina Beckova Zdenko Gardian Jianfeng Yu Peter Konik Peter J. Nixon Josef Komenda Institute of Microbiology Center Algatech Opatovicky mlyn37981 Trebon Czech Republic Faculty of Science University of South Bohemia Branisovska 1760 37005 Ceske Budejovice Czech Republic Institute of Plant Molecular Biology Biology Centre Academy of Sciences Branisovska 3137005 Ceske Budejovice Czech Republic Sir Ernst Chain Building-Wolfson Laboratories Department of Life Sciences Imperial College London South Kensington Campus London SW7 2AZ UK

Formation of the multi-subunit oxygen-evolving photosystem II （PSII） complex involves a number of auxiliary protein factors. In this study we compared the localization and possible function of two homolo- gous PSU assembly factors, Psb28-1 and Psb28-2, from the cyanobacterium Synechocystis sp. PCC 6803. We demonstrate that FLAG-tagged Psb28-2 is present in both the monomeric PSII core complex and a PSII core complex lacking the inner antenna CP43 （RC47）, whereas Psb28-1 preferentially binds to RC47. When cells are exposed to increased irradiance, both tagged Psb28 proteins additionally associate with oligo- meric forms of PSII and with PSII-PSI supercomplexes composed of trimeric photosystem I （PSI） and two PSII monomers as deduced from electron microscopy. The presence of the Psb27 accessory protein in these complexes suggests the involvement of PSI in PSII biogenesis, possibly by photoprotecting PSII through energy spillover. Under standard culture conditions, the distribution of PSII complexes is similar in the wild type and in each of the single psb28 null mutants except for loss of RC47 in the absence of Psb28-1. In comparison with the wild type, growth of mutants lacking Psb28-1 and Psb27, but not Psb28-2, was retarded under high-light conditions and, especially, intermittent high-light/dark conditions, emphasizing the physiological importance of PSII assembly factors for light acclimation.

关键词： Psb28 proteins photosystem I and II Synechocystis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rheology of Poly(vinyl butyral)Solution Containing Fumed Silica in Correlation with Electrospinning

引用

Chinese Journal of Polymer Science 2018年第6期36卷 742-748页

作者： Petra Peer Martina Polaskova Pavol Suly Institute of Hydrodynamics of the czech Academy of Sciences Pod Patankou 5166 12 Prague 6Czech Republic Centre of Polymer Systems Tomas Bata University in Zlintrida Tomase Bati 5678760 O1 ZlinCzech Republic Department of Polymer Engineering Faculty of TechnologyTomas Bata University in ZlinVavreckova 27576001 ZlinCzech Republic

The rheological properties in question are influenced by many factors, ranging from the characteristics of the given polymer or solvent to the flowing conditions. The primary focus of this study is to analyse the rheological behaviour of poly（vinyl butyral）—Mowital B 60 H—（PVB） solutions dissolved in methanol and a blend of these with fumed silica nanoparticles. The preparation of the nanofibrous web and the quality of nanofibres were correlated with the rheology of the polymer solution. It was discerned that drastically intensifying shear viscosity and the elasticity of the solution exerted a negligible effect on the formation of fibres, a finding which has rarely been discussed in the literature. The morphologies and structures of the PVB/silica nanofibrous membranes were investigated by scanning electron microscopy, thermogravimetric analysis and Fourier transform infrared spectroscopy.

关键词： Electrospinning Nanofibres Poly(vinyl butyral) Fumed silica Rheology

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Grain Size Distribution of Soils within the Cordillera Blanca, Peru: An Indicator of Basic Mechanical Properties for Slope Stability Evaluation

引用

Journal of Mountain Science 2014年第3期11卷 563-577页

作者： Jan NOVOTNY Jan KLIME ARCADIS CZ a.s. Institute of Hydrogeology Engineering Geology and Applied Geophysics Charles University in Prague Albertov Department of Engineering Geology Institute of Rock Structure and Mechanics Academy of Sciences of the Czech Republic v.v.i

This paper presents results of a study on the mechanical properties of sandy and gravely soils within the Cordillera Blanca, Peru. The soils were divided into groups according to their origin(glacial, fluvial, or debris flow). The grain size distribution of forty three soil samples was used to classify the soils according to the scheme of the Unified Soil Classification System(USCS). These distributions have then been used to estimate shear strength and hydraulic properties of the soils. There are clear differences between the soils which reflect their divergent origins. The glacial soils normally fit within one of two distinctive groups according to the proportion of fines(Group A, 7%-21.5%; Group B, 21%-65%). The estimation of shear strength at constant volume friction angle and peak shear strength of the glacial sediments with low content of fines was made using published data relating to the measured shear strength characteristics of soils with similar origins and grain size distributions. The estimated values were supported by measurements of the angle of repose taken from fourteen samples from two moraines and by shear tests on samples from one locality. The results of the grain size distribution werealso used to estimate the average hydraulic conductivity using the empirical Hazen formula which results were verified by field infiltration tests at two localities.

关键词：土壤分布粒度分布力学性能边坡稳定性评价秘鲁冰川沉积物剪切强度水力传导率

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：