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A new semi-quantitative Surface-Enhanced Raman Spectroscopy (SERS) method for detection of maleimide (2,5-pyrroledione) with potential application to astrobiology

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Geoscience Frontiers 2021年第5期12卷 421-426页

作者： j.Aramendia L.gomez-Nubla M.L.Tuite K.H.Williford K.Castro j.M.Madariaga jet Propulsion Laboratory California Institute of Technology4800 Oak Grove DrPasadenaCA 91109United States Department of Analytical Chemistry University of the Basque Country UPV/EHUP.O.Box 64448080 BilbaoSpain

Nitrogen-containing heterocyclic compounds are fundamental biochemical components of all life on Earth and,presumably,life elsewhere in our solar *** and characterization of these compounds by traditional solvent extraction,chromatographic separation,and GC-MS analysis require more sample mass than will be available from samples returned to Earth from *** its small sample mass requirement,Surface Enhanced Raman Spectroscopy could be an appropriate technique for analysis of returned *** have developed a SERS method for the detection of maleimide(2,5-pyrroledione),an N-containing heterocycle with a structure that is widespread in *** semi-quantitative methodology accurately determines maleimide concentration in the range from 60 mg/mL to 120 mg/*** present a maleimide SERS standard spectrum which will be useful as a reference for future *** present work demonstrates an easy,accurate,and effective method for the non-destructive qualitative and semi-quantitative study of maleimide as a first step toward developing a method for analysis of related compounds.

关键词： Maleimide Surface-Enhanced Raman Spectroscopy Astrobiology Biosignature Extraterrestrial life

Hydrogen storage in a rare-earth perovskite-type oxide La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_3 for battery applications

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Rare Metals 2018年第12期37卷 1003-1013页

作者： john Henao Oscar Sotelo Maura Casales-Diaz Lorenzo Martinez-gomez CONACYT-CIATEQ A.C. Av. Manantiales 23-AParque Industrial Bernardo Quintana Instituto de Ciencias Fisicas (ICF) Universidad Nacional Autonoma de Mexico (UNAM)-Campus Morelos

Recently, rare-earth perovskite-type oxides with the general formula ABO(A rare earth element, B transition metal, O oxygen) are regarded as promising materials for Ni/oxide batteries due to their hydrogen storage ability. In the present study, the hydrogen storage properties of the rare-earth perovskite-type oxide LaSrCoFeOwere evaluated in alkaline solution and at various temperatures. The hydrogen storage properties were investigated electrochemically by applying galvanostatic charge/discharge currents. Electrochemical pressurecomposition-temperature isotherms were constructed using the Nernst equation. The exchange current density and proton hydrogen diffusion coefficient were calculated using linear polarization measurements and the potential-step method, respectively. Interestingly, the maximum hydrogen absorption capacity, re-calculated from the electrochemical capacity, is 1.72 wt% at 333 K and 6 mol·LKOH. In addition, the hysteresis value, calculated from pressure-composition-temperature isotherms, was429 j·molat 333 K,while the self-discharge rate was about 25% after 24-h storage at open circuit and at 333 K.

关键词： Hydrogen storage Rare earths Perovskites Ni/oxide batteries

High-throughput study of the anomalous Hall effect

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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

Postural control quantification in minimally and moderately impaired persons with multiple sclerosis:The reliability of a posturographic test and its relationships with functional ability

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journal of Sport and Health Science 2020年第6期9卷 677-684页

作者： David Barbado Ramon gomez-Illan Pedro Moreno-Navarro Gregori Valero-Conesa Raul Reina Francisco j.Vera-Garcia Department of Sport Sciences Sports Research CentreMiguel Hern_andez University of ElcheElche(Alicante)03202Spain

Background:Postural control has been associated with the functional impairment in persons with multiple sclerosis(pwMS).However,there is a need for reliable methods to assess postural control in early stages of the disease,when subtle changes can be difficult to *** aims of this study were to assess the absolute and relative reliability of a standing and a sitting posturographic protocol in minimally(Expanded Disability Status Scale≤2)and moderately(2.5≤Expanded Disability Status Scale≤4)impaired pwMS,and to analyze relationships among postural control and functional mobility and gait ***:To assess postural control in an upright stance,14 minimally and 16 moderately impaired pwMS performed six 70 s trials in tandem stance,3 with their weaker leg behind(TSWL)and 3 with their stronger leg behind(TSSL).Additionally,participants completed five 70 s trials using an unstable sitting protocol(US)to assess trunk *** mean radial errors of TSWL,TSSL,and US trials were calculated as postural control ***,participants performed the Timed Up and Go test(TUG)and the Timed 25-foot Walk test(T25FW)to measure their functional mobility and gait speed,*** was evaluated using the intraclass correlation coefficient(ICC3,1)and the standard error of measurement(SEM).Analyses of variances were carried out to assess between-group ***’g index(dg)was used to estimate the effect size of *** correlation analyses(r)were performed to examine the relationships among the postural control and the functional ***:Posturographic tests showed a high reliability in both minimally(0.87≤ICC≤0.92;9.32%≤SEM≤11.76%)and moderately(0.80≤ICC≤0.92;10.33%≤SEM≤15.33%)impaired ***,T25FW and TUG displayed a high consistency in minimally(0.89≤ICC≤0.94;3.43%≤SEM≤5.17%)and moderately(0.85≤ICC≤0.93;5.57%≤SEM≤6.56%)impaired *** impaired pwMS showed a better performance on the TUG,T25FW

关键词： Balance Consistency of the assessment Core stability Functional mobility

A mathematical model of circadian rhythms synchronization using fractional differential equations system of coupled van der Pol oscillators

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International journal of Biomathematics 2018年第1期11卷 313-336页

作者： j. E. Escalante-Martfnez j. F. gomez-Aguilar C. Calderon-Ramon A. Aguilar-Melendez P. Padilla-Longoria Facultad de Ingenieria Mecdnica y Eldctrica Universidad Veracruzana Av. Venustiano Carranza S/N Col. Revolucidn C. P. 93390 Poza Riea Veracruz Mdxico CONACyT-TecnolSgico Nacional de Mexico/CENIDET Interior Internado Palmira S/N Col. Palmira C. P. 62490 Cuernavaca Morelos Mexico Facultad de Ingenier~a Mecdnica y Eldctrica Universidad Veracruzana Av. Venustiano Carranza S/ZN Col. Revolucidn C. P. 93390 Poza Rica Veracruz Mexico Facul$ad de Ingenierd Civil Universidad Veracruzana Av. Venustiano Carranza S/N Col. Revolucion C. P. 93390 Poza Rica Veracruz Mexico Instituto de Investigaciones en Matemdticas Aplicadas ySistemas (IIMAS) UNAM Circuito Escolar Cd. Universitaria Del. Coyoacan Mdxico D. F. C. P. 04510 Mexico

This paper presents an alternative representation of a system of differential equations qualitatively showing the behavior of the biological rhythm of a crayfish during their transition from juvenile to adult stages. The model focuses on the interaction of four cellular oscillators coupled by diffusion of a hormone, a parameter μ is used to simu- late the quality of communication among the oscillators, in biological terms, it mea- sures developmental maturity of the crayfish. Since some quorum-sensing mechanism is assumed to be responsible for the synchronization of the biological oscillators, it is nat- ural to investigate the possibility that the underlying diffusion process is not standard, i.e. it may be a so-called anomalous diffusion. In this case, it is well understood that diffusion equations with fractional derivatives describe these processes in a more realis- tic way. The alternative formulation of these equations contains fractional operators of Liouville-Caputo and Caputo-Fabrizio type. The numerical simulations of the equations reflect synchronization of ultradian rhythms leading to a circadian rhythm. The classical behavior is recovered when the order of the fractional derivative is V = 1. We discuss possible biological implications.

关键词： Circadian rhythm van der Pol oscillators Liouville-Caputo fractional oper-ator Caput^Fabrizio fractional operator Adams Bashforth Moulton method syn-chronicity.

Li2SiO3 fast microwave-assisted hydrothermal synthesis and evaluation of its water vapor and C02 absorption properties

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Particuology 2016年第1期14卷 129-137页

作者： j. Ortiz-Landeros R. Lopez-juarez I.C, Romero-Ibarra H. Pfeiffer H. Balmori-Ramirez C. gomez-Yanez Department of MetaUurgical and Materials Engineering National Polytechnic Institute ESIQIE-IPN UPALM Campus Instituto Politecnico NacionalAvenue 07738 Mexico City Mexico Materials Research Institute Morelia Campus National Autonomous University of Mexico Old Pdtzcuaro road 8701 58190 Morelia Michoacdn Mexico Department of Chemistry Metropolitan Autonomous University Iztapalapa Campus San Rafael Atlixco Avenue 186 09340 Mexico City Mexico Materials Research Institute National Autonomous University of Mexico Cd Universitaria Campus 04510 Mexico City Mexico

A series of lithium metasilicate （Li2SiO3） powder materials has been successfully synthesized by the microwave-assisted hydrothermal route using lithium hydroxide and tetraethyl-orthosilicate-derived sol precursors. Ceramic powders were obtained under hydrothermal conditions of autogenous pressure in the presence of a nonionic surfactant. The production of pure and well-crystallized Li2 SiO3 using very short reaction times at low temperatures was shown by X-ray diffraction, scanning electron microscopy, and N2 adsorption-desorption analyses. Synthesized Li2SiO3 particles were nanocrystalline and exhibited different morphologies and specific surface areas depending on the synthesis conditions. Additionally, the capability of selected Li2SiO3 samples to absorb H20 and CO2 was evaluated via thermogravimet- ric analyses by varying the temperature, carrier gas, and water vapor concentration. Li2SiO3 particles exhibited interesting textural and morphological characteristics that make them suitable for use as a CO2 absorbent and which suggest that they also have the potential to be used in other applications.

关键词： CO2 capture Lithium metasilicate Hydrothermal synthesis Thermal analysis

Plasmonics for solid-state lighting: enhanced excitation and directional emission of highly efficient light sources

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Light(Science & Applications) 2013年第1期2卷 163-169页

作者： Gabriel Lozano Davy j Louwers Said RK Rodrı´guez Shunsuke Murai Olaf TA jansen Marc A Verschuuren jaime gomez Rivas Center for Nanophotonics FOM Institute AMOLFc/o Philips Research LaboratoriesEindhovenThe Netherlands Philips Research Laboratories EindhovenThe Netherlands Department of Material Chemistry Graduate School of EngineeringKyoto UniversityKyotoJapan COBRA Research Institute Eindhoven University of TechnologyEindhovenThe Netherlands

Light sources based on reliable and energy-efficient light-emitting diodes (LEDs) are instrumental in the development of solid-statelighting (SSL). Most research efforts in SSL have focused on improving both the intrinsic quantum efficiency (QE) and the stability oflight emitters. For this reason, it is broadly accepted that with the advent of highly efficient (QE close to 1) and stable emitters, thefundamental research phase of SSL is coming to an end. In this study, we demonstrate a very large improvement in SSL emission (above70-fold directional enhancement for p-polarized emission and 60-fold enhancement for unpolarized emission) using nanophotonicstructures. This is attained by coupling emitters with very high QE to collective plasmonic resonances in periodic arrays of aluminumnanoantennas. Our results open a new path for fundamental and applied research in SSL in which plasmonic nanostructures are able tomold the spectral and angular distribution of the emission with unprecedented precision.

关键词： diffraction fluorescence LED nanophotonics plasmonics

Tunable nano-engineered anisotropic surface for enhanced mechanotransduction and soft-tissue integration

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Nano Research 2023年第5期16卷 7293-7303页

作者： Pingping Han Tianqi Guo Anjana jayasree Guillermo A.gomez Karan Gulati Sašo Ivanovski The University of Queensland School of DentistryEpigenetics nanodiagnostic and therapeutic groupCenter for Oral-facial RegenerationRehabilitation and Reconstruction(COR3)BrisbaneQueensland 4006Australia The University of Queensland School of DentistryBrisbaneQueensland 4006Australia The University of Queensland School of DentistryGroup for Anodized Therapies for OsseointegrationRegeneration and StimulationCenter for Oral-facial RegenerationRehabilitation and Reconstruction(COR3)BrisbaneQueensland 4006Australia Centre for Cancer Biology South Australia Pathology and the University of South AustraliaAdelaideSouth Australia 5001Australia

Electrochemically engineered titania(TiO_(2))nanopores enable tailored cellular function;however,the cellular mechanosensing mechanisms dictating the cell response and soft tissue integration are yet to be ***,we report the fabrication of anisotropic TiO_(2)nanopores with diameters of 46 and 66 nm on microrough titanium(Ti)via electrochemical anodization,towards short-and long-term guidance of human primary gingival fibroblasts(hGFs).Cells on tissue culture plates and bare Ti substrates were used as ***,we show that nanopores with a diameter of 66 nm induced more mature focal adhesions of vinculin and paxillin at the membrane,encouraged the development of actin fibers at focal adhesion sites,led to elongated cell and nuclear *** topographical-driven changes were attributed to the Ras-related C3 botulinum toxin substrate 1(Rac 1)GTPase pathway and nuclear localisation of LAMIN A/C and yes-associated protein(YAP)and associated with increased ligament differentiation with elevated expression of the ligament marker Mohawk homeobox(MKX).Study findings reveal that minor tuning of nanopore diameter is a powerful tool to explore intracellular and nuclear mechanotransduction and gain insight into the relationships between nanomaterials and mechanoresponsive cellular elements.

关键词： titanium nanopores nanotopography fibroblast mechanosensing mechanotransduction ligament differentiation

Arabinan Metabolism during Seed Development and Germination in Arabidopsis

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Molecular Plant 2009年第5期2卷 966-976页

作者： Leonardo D. gomez Clare G. Steele-King Louise jones jonathan M. Foster Supachai Vuttipongchaikij Simon j. McQueen-Mason CNAP Department of Biology University of York Heslington York YO10 5YW United Kingdom

Arabinans are found in the pectic network of many cell walls, where, along with galactan, they are present as side chains of Rhamnogalacturonan I. Whilst arabinans have been reported to be abundant polymers in the cell walls of seeds from a range of plant species, their proposed role as a storage reserve has not been thoroughly investigated. In the cell walls of Arabidopsis seeds, arabinose accounts for approximately 40% of the monosaccharide composition of non- cellulosic polysaccharides of embryos. Arabinose levels decline to -15% during seedling establishment, indicating that cell wall arabinans may be mobilized during germination. Immunolocalization of arabinan in embryos, seeds, and seedlings reveals that arabinans accumulate in developing and mature embryos, but disappear during germination and seedling establishment. Experiments using 14C-arabinose show that it is readily incorporated and metabolized in growing seedlings, indicating an active catabolic pathway for this sugar. We found that depleting arabinans in seeds using a fungal arabinanase causes delayed seedling growth, lending support to the hypothesis that these polymers may help fuel early seedling growth.

关键词： Cell walls development embryogenesis and seed development Arabidopsis arabinan arabinose carbohydrate metabolism physiology of plant growth.