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First-and second-order phase transitions in RE_(6)Co_(2)Ga(RE=ho,Dy or Gd)cryogenic magnetocaloric materials

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Science China Materials 2021年第11期64卷 2846-2857页

作者： Dan Guo luis M.Moreno-Ramírez Carlos Romero-Muñiz Yikun Zhang Jia-Yan Law Victorino Franco Jiang Wang Zhongming Ren State Key Laboratory of Advanced Special Steels Shanghai Key Laboratory of Advanced FerrometallurgySchool of Materials Science and EngineeringShanghai UniversityShanghai 200072China Departamento de Física de la Materia Condensada ICMS-CSICUniversidad de SevillaP.O.Box 1065Sevilla 41080Spain Department of Physical Chemical and Natural SystemsUniversidad Pablo de OlavideSevilla E-41013Spain Departamento de Física Aplicada I Universidad de SevillaSevilla E-41012Spain

Rare-earth(RE)rich intermetallics crystallizing in orthorhombic ho_(6)Co_(2)Ga-type crystal structure exhibit peculiar magnetic properties that are not widely reported for their magnetic ordering,order of magnetic phase transition,and related magnetocaloric *** tuning the type of RE element in RE_(6)Co_(2)Ga(RE=ho,Dy or Gd)compounds,metamagnetic anti-to-paramagnetic(AF to PM)phase transitions could be tuned to ferro-to-paramagnetic(FM to PM)phase ***,the FM ground state for Gd_(6)Co_(2)Ga is confirmed by density functional theory calculations in addition to experimental *** field dependence magnetocaloric and Banerjee’s criteria demonstrate that ho_(6)Co_(2)Ga and Dy_(6)Co_(2)Ga undergo a first-order phase transition in addition to a second-order phase transition,whereas only the latter is observed for Gd_(6)Co_(2)*** two extreme alloys of the series,ho_(6)Co_(2)Ga and Gd_(6)Co_(2)Ga,show maximum isothermal entropy change(|ΔS_(iso)^(max)(5T)|)of 10.1 and 9.1 J kg^(-1)K^(-1)at 26 and 75 K,close to h_(2)and N_(2)liquefaction,*** outstanding magnetocaloric effect performance makes the RE6 Co_(2)Ga series of potential for cryogenic magnetic refrigeration applications.

关键词： RE6Co2Ga compounds magnetic phase transitions magnetocaloric effect rare-earth

Preparation and Characterization of Flexible, Transparent and Thermally Stable Aromatic Co-polyamides

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Chinese Journal of Polymer Science 2019年第2期37卷 136-141页

作者： José Antonio Tec-Sánchez Andrés Iván Oliva Arias Manuel Aguilar-Vega Juan Valerio Cauich-Rodríguez José luis Santiago-García Unidad de Materiales Centro de Investigación Científica de Yucatán A. C. Centro de Investigación y de Estudios Avanzados del IPN Unidad Mérida Departamento de Física Aplicada

Two aromatic co-polyamides were synthesized combining two diacid monomers containing bulky pendant groups, 5-(9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximido)isophthalic acid(DEAIA) and 5-tert-butylisophthalic acid(TERT), with 4,4′-(hexafluoroisopropylidene)dianiline(hFA) or 2,3,5,6-tetramethyl-1,4-phenylenediamine(Durene) by direct polycondensation. The structures of the obtained aromatic co-polyamides were confirmed by FTIR, Raman and 1 h-NMR. The co-copolyamide films, DhTh and DDTD, exhibited rms-roughness values between 0.94 and 1.60 nm, respectively. Moreover, they presented good thermal stability up to300 °C. Young's moduli of the co-polyamide films were between 4.1 and 4.3 GPa. X-ray diffraction results showed that the co-polyamide films were amorphous due to the incorporation of both bulky pendant groups, tert-butyl and dibenzobarrelene. The combination of bulky pendant groups provided intrinsically transparent co-polyamide films with a transmittance higher than 88% in the range of 400-780 *** to these outstanding film and optical properties, they are suggested to be flexible substrates in applications for solar cell and other portable electronic devices.

关键词： Co-polyamides Flexible films Transmittance Thermal stability Polycondensation

Fractions of a chloroform extract of ajenjo leaves (Artemisiamendozana DC. var. mendozana) inhibit the proliferation,viability and clonogenicity of B16-F0 melanoma cells

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BIOCELL 2020年第3期44卷 293-299页

作者： MARÍA ELISA MILLÁN MARÍA FERNANDA MARRA LEONARDO ANDRÉS SALVARREDI EMILIO FERNANDO LIZARRAGA luis ALBERTO LOPEZ Universidad Nacional de Cuyo MendozaArgentina Comisión Nacional de Energía Atómica Buenos AiresArgentina Fundación Escuela de Medicina Nuclear MendozaArgentina Fundación Miguel Lillo y Universidad Nacional de Tucumán San Miguel de TucumánArgentina

The ajenjo,Artemisia mendozana ***(Asteraceae),grows in the Andean foothills of Mendoza and San Juan,Argentina,and is used as a medicinal plant for its antispasmodic and antifungal *** aim of this work was to obtain fractions of a chloroform extract of ajenjo leaves and to evaluate the in vitro effects on proliferation,viability and clonogenicity of B16-F0 melanoma *** a silica gel chromatography column,120 fractions were collected and grouped according to the chromatographic profile in 9 main fractions(F1–F9).Their major compounds identified were:terpenes(F1),terpenes and sesquiterpene lactones(F2–F3),sesquiterpenes(F4–F6)and phenols and sesquiterpenes(F7-9).B16-F0 cells were incubated for 72 h with DMSO(vehicle)or 0.1 mg/ml F1–*** 72 h of culture,F1 decreased both the growing index(GI)and cell viability.F2 and F3 both decreased GI and only F3 decreased clonogenic activity.F4 and F5 both decreased *** F5 decreased cell viability and F4 decreased ***,fractions F6–F8 did not affect any of the cell parameters assayed,while F9 decreased cell viability and inhibited clonogenicity.

关键词： Terpenes Sesquiterpene lactones Sesquiterpenes Phenols

Kinetics for Describing the Creaming of Protein-Stabilized O/W Emulsions by Multiple Light Scattering

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Journal of Food Science and Engineering 2014年第5期4卷 236-243页

作者： luis Alberto Panizzolo luis Eduardo Mussio María Cristina Anon Departamento de Ciencia y Tecnologia de Alimentos Facultad de Quimica Universidad de la Republica Av. Gral. Flores 2124Montevideo 11800 Uruguay International Organization of Legal Metrology 11 Rue Turgot Paris 75009 France Centro de Investigación y Desarrollo en Criotecnologia de Alimentos (CIDCA) CONICET Facultad de Ciencias ExactasUniversidad Nacional de La Plata Calle 47 y 116 La Plata 1900 Argentina

In the present work, new kinetics to describe the creaming stability of oil-in-water emulsions determined by backscattering measurements （BS） is proposed. The emulsions assayed exhibited a different backscattering profiles regarding creaming destabilization hyperbolic and sigmoid one. hyperbolic behavior can be described by a second order kinetics, where k_h could be equaled to a rate constant that describes the creaming process and its values would indicate the stability of emulsions. While for the sigmoid BS pattern, kinetics with two terms, is adequate to describe the creaming process in contrast to kinetics previously reported in the literature. The kh value has the same meaning as before, and ks indicates the delaying effect on the creaming rate.

关键词： Emulsion proteins creaming kinetic multiple light scattering.

The biosynthesis and wall-binding of hemicelluloses in cellulose-deficient maize cells:An example of metabolic plasticity

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Journal of Integrative Plant Biology 2015年第4期57卷 373-387页

作者： María de Castro Janice G.Miller José luis Acebes Antonio Encina Penélope García-Angulo Stephen C.Fry The Edinburgh Cell Wall Group Institute of Molecular Plant SciencesSchool of Biological SciencesDaniel Rutherford BuildingThe King's Buildings Laboratory of Plant Physiology Faculty of Biological and Environmental SciencesUniversity of Léon

Cell-suspension cultures（Zea mays L.,Black Mexican sweet corn） habituated to 2,6-dichlorobenzonitrile（DCB） survive with reduced cellulose owing to hemicellulose network modification. We aimed to de fine the hemicellulose metabolism modifications in DCB-habituated maize cells showing a mild reduction in cellulose at different stages in the culture cycle. Using pulse-chase radiolabeling, we fed habituated and non-habituated cultures with [3h]arabinose,and traced the distribution of 3h-pentose residues between xylans, xyloglucans and other polymers in several cellular compartments for 5 h. habituated cells were slower taking up exogenous [3h]arabinose. Tritium was incorporated into polysaccharide-bound arabinose and xylose residues, but habituated cells diverted a higher proportion of their new [3h]xylose residues into（hetero） xylans at the expense of xyloglucan synthesis. During logarithmic growth, habituated cells showed slower vesicular traf ficking of polymers,especially xylans. Moreover, habituated cells showed a decrease in the strong wall-binding of all pentose-containing polysaccharides studied; correspondingly, especially in log phase cultures, habituation increased the proportion of 3h-hemicelluloses（[3h]xylans and [3h]xyloglucan） sloughed into the medium. These findings could be related to the cel walls’ cellulose-deficiency, and consequent reduction in binding sites for hemicelluloses; the data could also re fl ect the habituated cells’ reduced capacity to integrate arabinox ylans by extra-protoplasmic phenolic cross-linking, as well as xyloglucans, during wall assembly.

关键词： Arabinoxylan cell wall cross-linking 2,6-dichlorobenzonitrile hemicellulose biosynthesis xyloglucan

Early life investment in antlers and body growth reflects adult performance in roe deer population under supplementary feeding conditions

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Integrative Zoology 2022年第3期17卷 396-407页

作者： Marta PELÁEZ Isabel SANUY Juan Carlos PERAL JoséluisÁlvarez ESTEBAN Santiago LAVÍN Emmanuel SERRANO Ramón PEREA Departamento de Sistemas y Recursos Naturales Universidad Politécnica de MadridMadridSpain Wildlife Ecology&health group(WE&h)and Servei d’Ecopatologia de Fauna Salvatge(SEFaS).Facultat de Veterinària Universitat Autònoma de Barcelona(UAB)BarcelonaSpain Centro Cinegético I+D de Valsemana Junta de Castilla y LeónLa ErcinaLeónSpain

Recent research has challenged the idea that cervid antlers are such costly traits,supporting the assertion early-life antler investment is an honest signal of adult phenotypic ***,inferences were made based on antler measurements while growing(velvet)and thus,studies on fully-formed clean antlers are needed to avoid possible bias caused by the inter-individual variation in antler growth *** studied a semi-captive population of European roe deer inhabiting a sub-Mediterranean area(Valsemana research station)and living under optimal conditions(ad libitum food supply and veterinary care).Based on repeated measurements taken from 146 individuals,we assessed whether allocation to secondary sexual traits during early life affected body mass or antler development during ***,we evaluated which body measurements better predicted future male ***,using 488 individuals,we described age-class-specific variation in male body measurements and assessed the decline in antler size between adult and senescent stages(*** of senescence).Results agree with the assertion that there is no negative effect of a high investment in antler during early life on adult antler size or body mass,but we suggest the use of clean antlers as a more robust and reliable *** variables that better predicted body mass during adulthood were yearling body mass and body size at 6 *** score between 10 and 18 months resulted in the best indicator of adult antler ***,we support the idea that the magnitude of senescence in antler size is smaller in environments with higher resource availability during winter.

关键词： antler size body mass early-life investment Mediterranean environments secondary sexual traits and senescence trade-offs

Optimization of Micromechanical Cleavage Technique of Natural Graphite by Chemical Treatment

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Graphene 2014年第1期3卷 1-5页

作者： luis Torres luis Gomez Armas Antonio Carlos Seabra Centro de Ciências Naturais e humanas Universidade Federal do ABC Sao Paulo Brazil Grupo de óptica Micro e Nanofabricao de Dispositivos (GOMNDI) Universidade Federal do Pampa Rio Grande do Sul Brazil Laboratório de Sistemas Integráveis do Departamento de Engenharia de Sistemas Eletronicos da Escola Politécnica da USP (LSI-PSI/EPUSP) Sao Paulo Brazil

In this work,we report a method to improve the efficiency of the micromechanical cleavage technique to obtain few-layers graphene samples, from natural graphite flakes, which were previously submitted to two chemical treatment times with h2SO4(17 and 25 hours). After the chemical treatment times, Raman spectroscopy reveals a hydrogenation of the few-layer graphene samples, which were obtained from the treated graphite flakes. To analyze the hydrogenation of the samples, the G and 2D bands of the Raman spectra of the treated and un-treated samples were analyzed and compared, as well as the I(2D)/I(G) ratio, revealing a p-doping on the treated samples when compared with the untreated samples. Our studies could be of great importance to obtain larger and greater amount of few-layer graphene samples.

关键词： Graphene Micromechanical Cleavage Raman Spectroscopy Chemical Treatment

Movement behaviors and their association with depressive symptoms in Brazilian adolescents:A cross-sectional study

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Journal of Sport and health Science 2022年第2期11卷 252-259页

作者： Bruno Goncalves Galdino da Costa Jean-Philippe Chaput Marcus Vinicius Veber Lopes luis Eduardo Argenta Malheiros Kelly Samara Silva Research Centre in Physical Activity and health Federal University of Santa CatarinaFlorianopolis88040-900Brazil healthy Active Living and Obesity Research Group Children’s Hospital of Eastern Ontario Research InstituteOttawaON K1H 8L1Canada

Background:Physical activity,sleep,and sedentary behaviors compose 24-h movement behaviors and have been independently associated with depressive ***,it is not clear whether it is the movement behavior itself or other contextual factors that are related to depressive *** objective of the present study was to examine the associations between self-reported and accelerometer-measured movement behaviors and depressive symptoms in ***:Cross-sectional data from 610 adolescents(14-18 years old)were *** answered questions from the Center for Epidemiological Studies Depression scale and reported time spent watching videos,playing videogames,using social media,time spent in various physical activities,and daytime ***-worn accelerometers were used to measure sleep duration,sleep efficiency,sedentary time,and physical ***-effects logistic regressions were ***:Almost half of the adolescents(48%)were classified as being at high risk for depression(score≥20).No significant associations were found between depressive symptoms and accelerometer-measured movement behaviors,self-reported non-sport physical activity,watching videos,and playing ***,higher levels of self-reported total physical activity(odd ratio(OR)=0.92,95%confidence interval(95%CI):0.86-0.98)and volume of sports(OR=0.88,95%CI:0.79-0.97),in minutes,were associated with a lower risk of depression,while using social media for either 2.0-3.9 h/day(OR=1.77,95%CI:1.58-2.70)or>3.9 h/day(OR=1.67,95%CI:1.10-2.54),as well as higher levels of daytime sleepiness(OR=1.17,95%CI:1.12-1.22),were associated with a higher risk of ***:What adolescents do when they are active or sedentary may be more important than the time spent in the movement behaviors because it relates to depressive *** daytime sleepiness,promoting sports,and limiting social media use may benefit adolescents.

关键词： Accelerometry Depression Physical activity Sedentary behavior Sleep

LiMnPO<SUB>4</SUB>: Review on Synthesis and Electrochemical Properties

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Journal of Materials Science and Chemical Engineering 2015年第5期3卷 54-64页

作者： Joel O. herrera héctor Camacho-Montes luis E. Fuentes Lorena álvarez-Contreras Universidad Autónoma de Ciudad Juárez Cd. Juárez México Centro de Investigación en Materiales Avanzados Chihuahua México

The olivine structured mixed lithium-transition metal phosphates LiMPO4 (M = Fe, Mn, Co) have attracted tremendous attention of many research teams worldwide as a promising cathode material for lithium batteries and for studying their magnetic and electrical properties. high energy density is required for mind- to large-scale batteries because the mounting spaces are quite small for vehicles and other energy storage applications. This constraint necessitates synthesis to yield high volumetric energy density and reliable battery performance. Development of eco-friendly, low cost and high energy density, LiMnPO4 cathode material became attractive due to its high operating voltage, which can be located inside of the electrochemical stability window of conventional electrolyte solutions and it offers more safety features due to the presence of a strong P-O covalent bond. This review is an overview of current research activities on LiMnPO4 cathodes and its carbon coating synthesized by various synthetic techniques.

关键词： Synthesis Properties LiMnPO4