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

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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An Architecture for Software Engineering Gamification

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Tsinghua Science and Technology 2020年第6期25卷 776-797页

作者： Oscar Pedreira Felix garcia Mario Piattini Alejandro Cortinas Ana Cerdeira-pena the Universidade da Coruna Centro de Investigacion CITICLaboratorio de Bases de DatosFacultade de InformaticaElvinaA Coruna15071Spain the Universidad de Castilla-La Mancha Grupo AlarcosEscuela Superior de InformaticaPaseo de la Universidad4Ciudad Real13071Spain.

Gamification has been applied in software engineering to improve quality and results by increasing people’s motivation and engagement.A systematic mapping has identified research gaps in the field,one of them being the difficulty of creating an integrated gamified environment comprising all the tools of an organization,since most existing gamified tools are custom developments or *** this paper,we propose a gamification software architecture that allows us to transform the work environment of a software organization into an integrated gamified environment,i.e.,the organization can maintain its tools,and the rewards obtained by the users for their actions in different tools will mount *** developed a gamification engine based on our proposal,and we carried out a case study in which we applied it in a real software development *** case study shows that the gamification engine has allowed the company to create a gamified workplace by integrating custom-developed tools and off-the-shelf tools such as redmine,TestLink,or JUnit,with the gamification *** main advantages can be highlighted:(i)our solution allows the organization to maintain its current tools,and(ii)the rewards for actions in any tool accumulate in a centralized gamified environment.

关键词： gamification software engineering gamification architecture gamification engine

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A review on Genetically Modified Plants Designed to Phytoremediate Polluted Soils： Biochemical responses and International regulation

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Pedosphere 2018年第5期28卷 697-712页

作者： Edgar VAZQUEZ-NUNEZ Julian M. pena-CASTrO Fabian FErNANDEZ-LUQUENO Eduardo CEJUDO Maria G. de la rOSA-ALVArEZ Maria C. garcia-CASTANED Departamento de Ingenierias Quimica Electronica y Biomedica Division de Ciencias e Ingenierlas Universidad de Guanajuato (UG) Campus Leon Loma del Bosque 103 Leon Gto. 37150 (Mexico) Laboratorio de Biotecnologla Vegetal Instituto de Biotecnologia Universidad del Papaloapan Tuxtepec Oaxaca 68333 (Mexico) programa en Sustentabilidad de los recursos Naturales y Eneryla Cinvestav Saltillo Industria Metalurgica 1062 Parque Industrial Saltillo-Ramos-Arizpe Ramos Arizpe Coahuila 25900 (Mexico) CONACYT Unidad de Ciencias del Agua (UCIA) Centro de Investigacion Cientifica de Yucatan A.C. Cancdn Quintana Roo 77500 (Mexico) Center for the Environmental Implications of Nanotechnology University of California at Los Angeles- University of Texas at El Paso 500 W University Ave El Paso 79968 (USA) CONACYT Universidad de Guanajuato Loma del Bosque 103 Leon Guanajuato 37150 (Mexico)

In recent years,there has been an increasing interest in finding sustainable strategies for the efficient removal of contaminants from *** objective of this review is to examine the biochemical principles of specific genetic modifications in plants,their applications in the field for specific contaminants as phytotechnologies,and their international *** addition,the review presents some biological aspects of rhizosphere-related phenomena,the interactions of organic and inorganic pollutants with plants,and the performance of the phytotechnologies across the *** the last few decades,at least eight genera of genetically modified plants(GMPs)have been tested and used for soil remediation with outstanding ***,Nicotiana,and Oryza are the plant genera most widely *** plant genes such as metal transporters,chelators,metallothioneins,phytochelatins,and oxygenases have been transferred to plants to improve the elimination of contaminants in *** discuss some important aspects of gene manipulation and its application for removal of diverse contaminants.A key challenge faced by phytotechnologies is the final disposal of the generated biomass,from a safety *** argue that the commercial success of phytotechnologies depends on the generation of valuable biomass on contaminated land and its use for bioenergy *** use of such technologies would promote a broader understanding of the importance of plants,especially GMPs,in the environment and their contribution to environmental sustainability.

关键词： bioenergy contaminants gene manipulation phytotechnology plant-microbe interaction regulatory policy soil pollu-tion soil remediation

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Examination of the profitability of technical analysis based on moving average strategies in BrICS

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Financial Innovation 2018年第1期4卷 44-61页

作者： Matheus JoséSilva de Souza Danilo Guimarães Franco ramos Marina garcia pena Vinicius Amorim Sobreiro Herbert Kimura Department of Economics University of BrasíliaFederal DistrictBrazil Department of Management University of BrasíliaFederal DistrictBrazil.

In this paper,we investigated the profitability of technical analysis as applied to the stock markets of the BrICS member *** addition,we searched for evidence that technical analysis and fundamental analysis can complement each other in these *** implement this research,we created a comprehensive portfolio containing the assets traded in the markets of each BrICS *** developed an automated trading system that simulated transactions in this portfolio using technical analysis *** assessment updated the findings of previous research by including more recent data and adding South Africa,the latest member included in *** results showed that the returns obtained by the automated system,on average,exceeded the value *** were groups of assets from each country that performed well above the portfolio average,surpassing the returns obtained using a buy and hold *** returns from the sample portfolio were very strong in russia and *** also found that technical analysis can help fundamental analysis identify the most dynamic companies in the stock market.

关键词： Technical analysis Moving average strategies Automated trading systems Portfolio analysis BrICS

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rheological Characterization of a Mixed Fruit/Vegetable Puree Feedstock for Hydrogen Production by Dark Fermentation

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Advances in Chemical Engineering and Science 2014年第1期4卷 81-88页

作者： Jacob Gomez-romero Inés garcia-pena Jorge ramirez-Munoz Luis G.Torres Bioprocess and Bioengineering Departments UPIBI-Instituto Politecnico NacionalMexico CityMexico Energy Department Universidad Autónoma Metropolitana-AzcapotzalcoMexico CityMexico

Bio-hydrogen (Bio-H2) production from the organic fraction of solid waste, as fruit and vegetable wastes, constitutes an interesting and feasible technology to obtain clean energy. In spite of the feasibility to produce Bio-H2 from fruit/vegetable wastes (FVW), data about its rheological characterization are scarce. This information is useful to establish the hydrodynamic behavior, which controls the overall mixing process when the feedstock for Bio-H2 production process is a mixture of FVW. In this work, the rheological behavior of a vegetable/fruit waste mixture was characterized. The effect of the solids content (%, w/w), temperature, time (tyxotropy effects) and shear rate over the apparent viscosity of the mixture was evaluated. Most of the mixtures showed non-Newtonian behavior. The curves are typical rheofluidizing fluids. The rheological curves were different at increasing solids contents (80%, 60%, 40% and 30%), independent from the temperature. rheological data were fitted to the power law model. Correlation factors r2 for the different mixtures were 0.991-0.995 for 80%, 0.961 -0.986 for 60%, 0.890 -0.925 for 40%. In the case of 30% of solids, the r2 value was not acceptable, and it was also found that this mixture was very near to the Newtonian behavior. Calculated activation energies (Ea) values were 15.98, 14.89 and 20.96 kJ/mol for the 80%, 60%, 40% mixtures, respectively. FVW purees rheological behavior was well characterized by Carbopol solutions at given concentrations and pH values. This fluid can be used as a model for other studies, e.g. LDA (Laser Doppler Anemometry) and PIV (Particle Image Velocimetry).

关键词： Bio-Hydrogen Mixing rheology rheofluidizing Materials Fruit/Vegetable Waste Mixture

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resistive Cerebral Blood Flow as a Potential Marker of Subclinical Brain Damage in Essential Hypertension

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World Journal of Cardiovascular Diseases 2014年第4期4卷 169-178页

作者： Sergio Gonzalez-garcia Zenaida Hernandez-Diaz Luis Quevedo-Sotolongo Marisol pena-Sanchez Yaima Pino-pena rebeca Fernandez-Carriera Caridad Menendez-Sainz Alina Gonzalez-Quevedo Janis Eells Institute of Neurology and Neurosurgery La HabanaCuba Cira garcia Central Clinic La HabanaCuba College of Health Sciences University of Wisconsin-MilwaukeeMilwaukeeUSA

Introduction: Subclinical brain damage in essential hypertension is more prevalent than cardiovascular or renal impairment;nevertheless, screening for nervous system involvement is difficult due to the low accessibility and high costs of these techniques. Objective: To assess the frequency of silent target organ damage in a cohort of asymptomatic hypertensive patients and to evaluate the potential usefulness of carotid ultrasonographic (US) variables as predictors of subclinical brain damage. Patients and Methods: Thirty four neurologically asymptomatic subjects (mean age 59 years) with essential hypertension were included. Target organ damage was evaluated: degree of hypertensive retinopathy, heart, kidney and brain. Structural and hemodynamical carotid Doppler US parameters were also investigated. results: The brain was the most frequently affected target organ (70.6%), followed by the heart (67.9%) and kidney (58.6%). Carotid US parameters showed no association of intima media thickness with brain MrI results;nevertheless, decreased diastolic flow velocity and increased resistive index pointed to a resistive carotid flow pattern in patients with classical brain MrI lesions and predicted subclinical lesions with a sensitivity of 70% and 74% and a specificity of 72% and 80% respectively. Conclusions: This study supports previous findings that place the brain as the most frequently affected target organ in essential hypertensive patients and sheds more light on the potential usefulness of carotid structure and hemodynamics as imaging biomarkers of subclinical brain lesions.

关键词： Subclinical Brain Damage Essential Hypertension Carotid Doppler

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Highly efficient multi-metal catalysts for carbon dioxide reduction prepared from atomically sequenced metal organic frameworks

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Nano research 2021年第2期14卷 493-500页

作者： Celia Castillo-Blas Consuelo Alvarez-Galvan Ines Puente-Orench Alba garcia-Sanchez Freddy E.Oropeza Enrique Gutirrez-Puebla Angeles Monge Victor A.de la pena-O'hea Felipe Gandara Materials Science Institute of Madrid(CSIC) C/Sor Juana Ines de la Cruz 3Madrid 28049Spain Instituto de Catalisis y Petroleoquimica(CSIC) dM arie Curie 2Madrid 28049Spain Instituto de Ciencia de Materiales de Aragon Pedro Cerbuna 12Zaragoza 50009Spain Institut Laue Langevin 71 Avenue des Martyrs38042 GrenobleFrance Photoactivated Processes Unit IMDEA Energy Institute Mostoles Technology ParkAvenida Ramdn de la Sagra 3MostolesMadrid 28935Spain Department of Inorganic Chemistry University Autonomous of MadridC/Frandsco Tomdsy Valiente 7Madrid 28049Spain

The precise control on the combination of multiple metal atoms in the structure of metal-organic frameworks(MOFs)endowed by reticular chemistry,allows the obtaining of materials with compositions that are programmed for achieving enhanced *** present work illustrates how through the transformation of MOFs with desired arrangements of metal cations,multi-metal spinel oxides with precise compositions can be obtained,and used as catalyst precursor for the reverse water-gas shift *** differences in the spinel initial composition and structure,determined by neutron powder diffraction,influence the overall catalytic activity with changes in the process of in s itu formation of active,metal-oxide supported metal nanoparticles,which have been monitored and characterized with in situ X-ray diffraction and photoelectron spectroscopy studies.

关键词： reticular chemistry multi-metal metal-organic frameworks(MOFs) carbon dioxide reduction heterogeneous catalysis reverse water-gas shift in-situ X-ray photoelectron spectroscopy(XPS)

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Effect of the Nutritional Supplement VIUSlD Vet on the Productivity of Fattening Pigs in a Low-Input Farming System

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Journal of Environmental Science and Engineering(B) 2015年第11期4卷 607-613页

作者： Juan Carlos rodriguez-Fernandez Vicente Mendez-garcia Ibrain Calero-Herrera Kolima pena-Calzada Osdany Martinez-Torres Jorge Gomez-Abdura Department of Veterinary Medicine and Animal Husbandry University of Sancti Spiritus Sancti Spiritus 60100 Cuba Department of Production Swine Farm of Jatibonico Jatibonico 62200 Cuba Veterinary Laboratory Provincial Institute of Veterinary Medicine Sancti Splritus 60100 Cuba

The objective of the study was to evaluate the effect of the nutritional supplement VIUSID vet on the mortality and the productivity behaviour of fattening pigs in a low-input farming system. Two experiments were carried out at a pig farm in the municipality of Jatibonico, Sancti Spiritus province, Cuba. The farm has a low level of specialization, pigs are fed using local resources such as sugarcane （Saccharum officinarum） juice and locally produced concentrated feed. In both studies, the treatment consisted in administering together with the feed 2.0 g of VIUSID vet per Kg of feed. results showed that in low-input rearing conditions, supplying VIUSID vet significantly reduced deaths （17.65%） in the pigs treated, favoured leukocyte and lymphocyte counts, and significantly improved weight gain （16.33%） and feed efficiency （14.41%）.

关键词： VIUSID pigs additive Glycyrrhiza glabra.

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Determining a Diagnostic Cut-Off on Fluorescence Polarization Assay(FPA)for Bovine Brucellosis in Carchi,Ecuador

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Open Journal of Animal Sciences 2017年第4期7卷 425-432页

作者： Ibarra Marcelo Benavides Hernan Salgado ruth Gutierrez Milena garcia Judith pena Julio Herrera David Mina Jorge Campos Martin Puga Byron Agricultural Career Carchi State Polytechnic UniversityTulcánEcuador School of Veterinary Medicine and Animal Science Central University of EcuadorQuitoEcuador

Serology is the foundation of any brucellosis control and eradication program worldwide, thus it is important to define accuracy diagnostics assays and cut-off of those assays, due to variations from country to country and even among specific areas in the country. The variation of cutoff values depended on: prevalence of disease, vaccination status, animal management, and control and eradication programs. Therefore, a cut-off for the diagnosis of bovine brucellosis through fluorescence polarization assay (FPA) in Carchi—Ecuador was determined. The survey has been carried out in Carchi province of Ecuador, who is considered a province of high prevalence of brucellosis and the vaccination status is unknown due to the lack of registers. Sera samples (n = 200) were obtained from individual cows from randomly selected herds. Blood sera were tested through Fluoresce Polarization Assay (FPA) and competitive enzyme-linked inmunosorbent assay (cELISA) as confirmatory test, and then receiver operating characteristic (rOC) analysis was done. The sensitivity and specificity values of FPA were 88.7% and 92.50% respectively using a cut-off of 89.90 mP. Moreover, the area under the curve showed that 92.2% is the probability accuracy of the test. The advantage of the FPA is that it is a test with good characteristics of sensitivity and specificity as well as a simple and quick test.

关键词： Brucella Diagnosis Fluorescence Polarization Sensitivity Specificity

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Temperature Inversions,Meteorological Variables and Air Pollutants and Their Influence on Acute respiratory Disease in the Guadalajara Metropolitan Zone,Jalisco,Mexico

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Journal of Environmental Protection 2013年第8期4卷 142-153页

作者： Hermes U.ramirez-Sanchez Mario E.García-Guadalupe Hector H.Ulloa-Godinez Angel r.Meulenert-pena Omar garcia-Concepcion Jaime Alcala Gutierrez Sarahi J.Lizarraga Brito Department of Physics Institute of Astronomy and MeteorologyUniversity Center of Exact Sciences and Engineering(CUCEI)University of GuadalajaraGuadalajaraMexico

The presence of temperature inversions (TI), concentration of air pollutants (AP) and meteorological variables (MV) affect the welfare of the population, creating public health problems (acute respiratory diseases ArDs, among others). The Guadalajara Metropolitan Zone (GMZ) experiences high levels of air pollution, which associated with the presence of temperature inversions and meteorological variations is conducive to the incidence of ArDs in children. The aim of this work is to evaluate the TI, MV, AP and their influence on the ArDs in children under five years in the GMZ from 2003 to 2007. In this period, the moderate and strong TI are the most frequent presenting from November to May. The AP shows a variable behavior during the year and between years, with the highest concentration of particles less than 10 microns (PM10), followed by ozone (O3), nitrogen dioxide (NO2), nitrogen oxides (NOX), carbon monoxide (CO) and sulfur dioxide (SO2), the most affected areas are the southeast of the GMZ. Annual arithmetic mean is 213,510 ± 41,209 ArDs consultations. The most important diseases are acute respiratory infections (98.0%), followed by pneumonia and bronchopneumonia (1.1%), asthma and status asthmaticus (0.5%) and streptococcal pharyngitis and tonsillitis (0.4%). Months with most inquiries were from October to March, mainly in the southeast, south and center of the city, coinciding with high levels of AP. Statistical analysis shows that the TI have significant correlation with ArDs in three years, temperature (Temp) in two, relative humidity (rH) in two, wind speed (WS) in three, wind direction (WD) in two, while that air pollutants NOX and NO2 showed significant correlation with ArDs throughout the period. CO and SO2 showed significance in two years, while the PM10 and O3 in one.

关键词： Temperature Inversions Meteorological Variables Air Pollutants Acute respiratory Diseases

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