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synthesis of coral-like structures of Pr-Yb co-doped YIG: structural,optical, magnetic and antimicrobial properties

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Journal of Rare Earths 2024年第3期42卷 543-554,I0004页

作者： A.Fernandez Francisca P.Araujo Y.Guerra s.Castro-Lopes J.Matilla-Arias Idglan s.de Lima Edson C.silva-Filho Josy A.Osajima F.Guerrero R.Pena-Garcia Federal University of Piau Graduate Program in Materials Science and EngineeringTeresinaPIBrazil Federal Rural University of Pernambuco Academic Unit of Cabo de Santo AgostinhoCabo de Santo AgostinhoPEBrazil Federal University of Piaui Department of PhysicTeresinaPBrazil Federal University of Pernambuco Graduate Program in Materials ScienceRecifePEBrazil University of Granma Departmentof Basic Sciences and Applied InformaticsFaculty of Technical SciencesBayamoCuba Federal University of Amazonas Department of PhysicManausAMBrazil Federal University of Pernambuco Department of PhysicRecifePEBrazil

Coral-like structures of the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12),(0.00 ≤ x ≤ 0.04, 0.00 ≤ y ≤ 0.02) compound were synthesized using the sol-gel method. structural investigation certified the YIG cubic crystal structure formation, without any secondary phase. It is shown that, the relatively large ionic radius of the dopant cations results in an expansion of the lattice parameter, variations in the Iona-O-Iondangle, Iona-O,Iond-O and Ionc-O bond distances and decrease in the average crystallite size. Fourier transform infrared(FTIR) and Raman measurements are essential to testify the single-phase formation of YIG crystal structure and are observed changes in the stretching and vibrational modes, respectively. The morphological study, energy dispersive spectroscopy(EDs) spectra and textural properties show corallike structures, peaks associated with Pr^(3+) and Yb^(3+) atoms and the effect of dopants on surface area,diameter, and pore volume, respectively. The optical analysis from diffuse reflectance spectra witnessed an increase in the optical gap band, a decrease in Urbach energy and blue shift in the charge transfer,correlated with the expansion of the unit cell due to the dopant's insertion in the YIG structure. A typical ferrimagnetic behavior is exhibited by the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12)compound. The saturation magnetization(M_(s)), cubic anisotropy constant(K_(1)) and coercive field(H_(c)) increase with the Pr^(3+)cations content, as consequence of their magnetic nature and distribution around of Fe^(3+)ions due to the coexistence with the Yb^(3+). Finally, for the first time, antibacterial tests by mean of the direct contact method were performed for YIG co-doped with Pr^(3+)and Yb^(3+)and it is shown that, relatively high dosages of Pr^(3+) cations favored the activity against s. aureus, therefore, a new biological property for YIG doped with rare earths is presented.

关键词： Yttrium iron garnet(YIG) Coral-like structures Rare earths Band gap energy Magnetic properties Antimicrobial properties

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棒与星系整体恒星形成性质关系的统计研究

天文学进展 2024年第1期42卷 115-127页

作者：穆子豪沈世银 Rafael s.de souza Ana L.Chies-santos 中国科学院上海天文台星系宇宙学重点实验室上海200030 中国科学院大学北京100049 星系和宇宙学半解析研究重点实验室上海200034 赫特福德大学天体物理研究中心英国哈特菲尔德学院巷AL109AB 南里奥格兰德州联邦大学科学研究所巴西阿雷格里港9500

盘状星系中的棒结构特征与星系自身所处环境及整体恒星形成特征之间存在复杂的相互关系。利用细致的星系形态特征测量计划Galaxy Zoo deCaLs中的数据构建了一组目前最大的具有同样恒星质量分布的强棒、弱棒和无棒星系样本。通过引入星... 详细信息

盘状星系中的棒结构特征与星系自身所处环境及整体恒星形成特征之间存在复杂的相互关系。利用细致的星系形态特征测量计划Galaxy Zoo deCaLs中的数据构建了一组目前最大的具有同样恒星质量分布的强棒、弱棒和无棒星系样本。通过引入星系所处暗晕质量及相空间特征来控制星系所处的环境效应之后,进一步对比研究强棒、弱棒和无棒星系的恒星形成特征。研究表明,有棒星系中的恒星形成熄灭的比例系统地高于无棒星系,且强棒的效应更为明显。但是,对于仍处于恒星形成主序上的星系来说,强棒、弱棒和无棒星系的恒星形成特征并没有显著差别。以上结果表明,星系中的棒特征在其存在的时标中可能使部分星系迅速地从恒星形成转入熄灭状态。

关键词：棒旋星系恒星形成环境

A tribo-chemical view on astringency of plant-based food substances

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Friction 2024年第7期12卷 1392-1407页

作者： samuel s.GAMANIEL Paloma s.DUEÑAs ROBLEs Hans TROMP Els H.A.de HOOG sissi de BEER Emile van der HEIde Laboratory for surface Technology and Tribology Faculty of Engineering TechnologyUniversity of TwenteEnschede 7522 LWthe Netherlands NIZO Food Research B.V. Ede6710 BAthe Netherlands department of Molecules and Materials MEsA+Institute for Nanotechnology University of TwenteEnschede 7500 AEthe Netherlands

Consumption of plant-based food products having high composition of polyphenols leads to the sensation of *** sliding oral surfaces,friction is an essential property during the oral perception of roughness and dryness which are attributes associated with *** factors including the chemical composition of interacting layers,structure and operation of interfaces have an effect on the astringency development *** manner of interactions occurring at oral interfaces suggest there is a system dependence of astringency and highlights the importance of adopting a tribosystems *** measurement techniques have shown an existing relationship between salivary protein-polyphenol interaction and an astringent ***,the tribo-chemistry involved in this multifaceted sensation remains largely unexplored in a comprehensive *** this review the underlying tribo-chemical processes useful in understanding the mechanism of astringency are highlighted and discussed cons.dering current techniques employed to investigate astringency *** of lubrication on oral surfaces owing to the tribo-chemical interactions involving saliva and astringent plant proteins requires subsequent deformations of oral tissues which are significant enough to induce strains at mechanoreceptor locations,leading to the sensation of *** is proposed that micro-scale contact modelling on the interaction of food particles/aggregates,boundary layers and oral surfaces shows potential in addressing the knowledge gap between tribo-chemical measurement techniques and panel tests,making it possible to attain a predictor for astringency.

关键词： oral lubrication astringency tribo-chemistry tribology

Recurrent evolution of seaweed body plan complexity among photosynthetic eukaryotes

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Molecular Plant 2024年第7期17卷 999-1001页

作者： Elisa s.Goldbecker Iker Irisarri Jan de Vries department of Applied Bioinformatics Institute for Microbiology and GeneticsUniversity of GottingenGoldschmidtstr.137077 GottingenGermany section Phylogenomics Center for Molecular Biodiversity ResearchLeibniz Institute for the Analysis of Biodiversity Change(LIB)Museum of Nature HamburgMartin-Luther-King-Platz 320146 HamburgGermany department of Applied Bioinformatics Campus Institute Data Science(CIDAS)University of GottingenGoldschmidtstr.137077 GottingenGermany department of Applied Bioinformatics Gottingen Center for Molecular Biosciences(GZMB)University of GottingenGoldschmidtstr.137077 GottingenGermany

The evolutionary origin of multicellularity is an age-old question in biological *** studies have delved into the evolutionary processes that led to the evolution of multicellular life forms from unicellular *** beauty and the challenge about this topic are that evolution has brought forth various forms of multicellular life,multiple times independently,scattered across the evolutionary tree of *** to the challenge,multicellular organisms exist in a diversity of forms and complexities,and the mechanisms by which multicellularity emerged are also likely different between animals,algae,or fungi(Niklas and Newman,2020).Recently,Nelson et al.(2024)presented a large-scale comparative genomics study focused on particularly intricate multicellular organisms:macroalgae(seaweeds),which emerged independently in three distinct eukaryotic lineages-green algae(Chlorophyta),red algae(Rhodophyta),and brown algae(Phaeophyceae).

关键词： algae seaweed evolution

Tribologically induced nanostructural evolution of carbon materials: A new perspective

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Friction 2024年第1期12卷 144-163页

作者： Guilherme Oliveira NEVEs Nicolás ARAYA Diego Berti sALVARO Thiago de souza LAMIM Renan Oss GIACOMELLI Cristiano BINdeR Aloisio Nelmo KLEIN JoséDaniel Biasoli de MELLO Laboratório de Materiais Universidade Federal de Santa CatarinaSanta Catarina 88040-900Brazil departamento de Ingeniería Mecánica Facultad de IngenieríaUniversidad del Bío-BíoConcepcion 4070-386Chile Universidad de Concepción Concepcion 4070-386Chile sENAI Innovation Institute for Laser Processing Santa Catarina 89218-153Brazil Universidade Federal de Uberlândia Minas Gerais 38408-100Brazil

Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes *** the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem *** a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon *** addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application *** of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects.density until a specific saturation limit in the same order of magnitude for all the materials tested.

关键词： carbon nanostructures tribology Raman spectroscopy defects quantification tribolayer solid lubrication

Kentish Plover(Charadrius alexandrinus) and Little Tern(sternula albifrons) prefer shells for nesting:A field experiment

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Avian Research 2024年第1期15卷 55-59页

作者： Macarena Castro Andrés.de la Cruz Nuria Martin-sanjuan Alejandro Pérez-Hurtado Instituto Universitario de Investigacion Marina(INMAR) Campus de Excelencia Internacional del Mar(CEIMAR)Departamento de BiologíaUniversidad de CadizPuerto RealSpain servicios centrales.de Investigacion salinas.de la Esperanza Universidad de CadizPuerto RealSpain

shorebird populations are declining worldwide,mainly due to human disturbances and loss of coastal ***,supratidal habitats as saltpans could play a role in buffering human *** have shown to be important as feeding or breeding sites of some shorebird species.A potential conservation strategy to increase shorebird populations in saltpans is to manipulate the cues that birds use to select optimal breeding *** it is hypothesized that shorebirds are attracted to bivalve shells due to the advantages they *** this hypothesis,we supplemented a restored saltpan in 2019 and 2021 with bivalve shells,expecting an increase in the number of breeding birds’ *** than 75% of Kentish Plover(Charadrius alexandrinus) and Little Tern(sternula albifrons) nests were found in patches with shells in both *** best model for both species indicates that the presence of shells is the factor that most correlates with the location of *** probability of choosing one place over another to settle their nest increases in areas with an abundance of shells,double in the case of the Kentish Plover and triple in the case of the Little *** result of this study may constitute a valuable tool for attracting birds to restored saltpans and could contribute to the success of expensive restoration projects where time is usually a constraint.

关键词： Habitat management Nest site selection saltpan restoration shell supplementation shorebirds

Interplay of RNA-binding proteins controls germ cell development in zebrafish

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Journal of Genetics and Genomics 2024年第9期51卷 889-899页

作者： de-Li shi Laboratory of developmental Biology CNRS-UMR7622Institut de Biologie Paris-Seine(IBPS)Sorbonne University75005 ParisFrance

The specification of germ cells in zebrafish mostly relies on an inherited mechanism by which localized maternal determinants,called germ plasm,confer germline fate in the early *** studies have partially allowed the identification of key regulators governing germ plasm formation and subsequent germ cell ***-binding proteins,acting in concert with other germ plasm components,play essential roles in the organization of the germ plasm and the specification,migration,maintenance,and differentiation of primordial germ *** loss of their functions impairs germ cell formation and causes sterility or sexual *** is emerging that they instruct germline development through differential regulation of mRNA fates in somatic and germ ***,the challenge remains to decipher the complex interplay of maternal germ plasm components in germ plasm compartmentalization and germ cell *** failure to control the developmental outcome of germ cells disrupts the formation of gametes,it is important to gain a complete picture of regulatory mechanisms operating in the germ cell *** review sheds light on the contributions of RNA-binding proteins to germ cell development in zebrafish and highlights intriguing questions that remain open for future investigation.

关键词： Germplasm Primordialgerm cell Germlinestem cell Gametogenesis Zebrafish RNA-binding protein Posttranscriptional gene expression Translational activation and repression

Correcting distortions of thin-walled machined parts by machine hammer peening

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Chinese Journal of Aeronautics 2024年第6期37卷 439-453页

作者： Aitor MADARIAGA Mikel CUEsTA Gorka ORTIZ-de-ZARATE Eneko sAENZ-de-ARGANDONA denis sORIANO Michael B.PRIME Pedro Jose ARRAZOLA department of Materials University of ManchesterOxford RoadManchester M139PLUnited Kingdom Mechanical and Industrial Production department Faculty of EngineeringMondragon UnibertsitateaArrasate 20500Spain Los Alamos National Laboratory Los AlamosNew MexicoUSA

Thin-walled aerostructural components frequently get distorted after the machining *** to correct distortions or eventually rejecting parts significantly increases the *** paper proposes a new approach to correct distortions in thin-walled components by strategically applying hammer peening on target surfaces of a machined *** alloy 7475-T7351 was chosen for this *** study was divided in two ***,the residual stresses(Rs)induced by four different pneumatic hammer peening conditions(modifying the stepover distance and initial offset)were characterised in a test coupon,and one of the conditions was selected for the next *** the second stage,a FEM model was used to predict distortions caused by machining in a representative ***,the Rs induced by hammer peening were included in an FEM model to define two hammer peening strategies(varying the coverage area)to analyse the capability to reduce *** workpieces were machined and then treated with the simulated hammer peening strategies for experimental *** in the test coupon showed that pneumatic hammer peening can generate high compressive Rs(-50 to350 MPa)up to 800 lm depth,with their magnitude increasing with a reduced stepover *** of hammer peening over 4% of the surface of the representative workpiece reduced the machininginduced distortions by 37%,and a coverage area of 100% led to and overcorrection by a factor of *** confirms that hammer peening can be strategically applied(in target areas and changing the percentage of coverage)to correct low or severe distortions.

关键词： Aeronautics Machining,Hammer Peening Aluminium alloy Distortions Residual stress

stereotactic body radiotherapy in pancreatic adenocarcinoma

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Hepatobiliary & Pancreatic Diseases International 2024年第1期23卷 14-19页

作者： Carolina de la Pinta Radiation Oncology department Ramón y Cajal University HospitalIRYCISAlcaláUniversity28034 MadridSpain

Background:stereotactic body radiotherapy(sBRT)in pancreatic cancer allows high delivery of radiation doses on tumors without affecting surrounding *** review aimed at the sBRT application in the treatment of pancreatic *** sources:We retrieved articles published in MEDLINE/PubMed from January 2017 to december *** used in the search included:“pancreatic adenocarcinoma”OR“pancreatic cancer”AND“stereotactic ablative radiotherapy(sABR)”OR“stereotactic body radiotherapy(sBRT)”OR“chemoradiotherapy(CRT)”.English language articles with information on technical characteristics,doses and fractionation,indications,recurrence patterns,local control and toxicities of sBRT in pancreatic tumors were *** articles were assessed for validity and relevant ***:Optimal doses and fractionation have not yet been ***,sBRT could be the standard treatment in patients with pancreatic adenocarcinoma in addition to ***,the combination of sBRT with chemotherapy may have additive or synergic effect on pancreatic ***:sBRT is an effective modality for patients with pancreatic cancer,supported by clinical practice guidelines as it has.demonstrated good tolerance and good disease *** opens a possibility of improving outcomes for these patients,both in neoadjuvant treatment and with radical intent.

关键词： Chemoradiotherapy Pancreatic adenocarcinoma Radiotherapy stereotactic body radiotherapy stereotactic ablative radiotherapy