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Biocompatibility and electrochemical evaluation of ZrO_(2) thin films deposited by reactive magnetron sputtering on mgZnCa alloy

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Journal of magnesium and Alloys 2021年第6期9卷 2019-2038页

作者： Benjamín millán-Ramos Daniela morquecho-marín Phaedra silva-Bermudez David Ramírez-Ortega Osmary Depablos-Rivera Julieta García-López mariana Fernández-Lizárraga JoséVictoria-hernández Dietmar Letzig Argelia Almaguer-Flores sandra e.Rodil Instituto de Investigaciones en materiales Universidad Nacional Autónoma de MéxicoCDMX 04510Mexico Posgrado en Ciencia e Ingeniería de materiales Universidad Nacional Autónoma de MéxicoCDMX 04510Mexico Unidad de Ingeniería de Tejidos Terapia Celular y Medicina RegenerativaInstituto Nacional de Rehabilitación Luis Guillermo IbarraCDMX 14389Mexico Posgrado en Ciencias médicas Odontológicas y de la SaludUniversidad Nacional Autónoma de MéxicoCDMX 04510Mexico Instituto de Ciencias Aplicadas y Tecnologia Universidad Nacional Autónoma de MéxicoCDMX 04510Mexico Posgrado de Doctorado en Ciencias en Biomedicina y Biotecnología molecular Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalCDMX 11340Mexico Institute of material and Process Design Helmholtz-Zentrum GeesthachtMax-Planck-Strasse 1Geesthacht 21502Germany magnesium Innovation Centre magIC Helmholtz-Zentrum GeesthachtMax-Planck-Strasse 1Geesthacht 21502Germany Laboratorio de Biointerfases Facultad de OdontologíaDivisión de Estudios de Posgrado e InvestigaciónUniversidad Nacional Autónoma de MéxicoCDMX 04510Mexico

Biodegradable magnesium alloys are promising candidates for temporary fracture fixation devices in orthopedics;nevertheless,its fast degradation rate at the initial stage after implantation remains as one of the main challenges to be ***_(2)-based coatings to reduce the degradation rate of the mg-implants are an attractive solution since they show high biocompatibility and *** this work,the degradation,cytotoxicity,and antibacterial performance of ZrO_(2)thin films deposited by magnetron sputtering on a mg-Zn-Ca alloy was ***-term degradation of ZrO_(2)-coated and uncoated samples was assessed considering electrochemical techniques and H_(2)evolution(gas chromatography).Additionally,long term degradation was assessed by mass-loss *** results showed that a 380 nm ZrO_(2)coating reduces the degradation rate and H_(2)evolution of the alloy during the initial 3 days after immersion but allows the degradation of the bare alloy for the *** ZrO_(2)coating does not compromise the biocompatibility of the alloy and permits better cell adhesion and proliferation of mesenchymal stem cells directly on its surface,in comparison to the bare ***,the ZrO_(2)coating prevents the adhesion and biofilm formation of ***.

关键词： Zirconium dioxide magnetron sputtering short-term degradation H_(2)evolution

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Removing contaminants from tannery wastewater by chemical precipitation using CaO and Ca(OH)2

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Chinese Journal of Chemical engineering 2020年第4期28卷 1107-1111页

作者： Adriana Reyes-serrano Joel eLópez-Alejo manuel Ahernández-Cortázar Ignacio elizalde Instituto Politécnico Nacional Centro Mexicano para la Producción más LimpiaCiudad de México 07340Mexico

The removal of Cr,sulfates and Chemical Oxygen Demand(COD)from industrial tannery wastewater by chemical precipitation was carried out using Calcium oxide(CaO)and Calcium hydroxide(Ca(OH)2).Different doses of alkalis,ranging from deficiency to excess hydroxyl species over the stoichiometric necessary,were used to remove theoretically the 100%of Cr[0.3-3.2 g alkali·(g Cr^3+)^-1].The precipitation was carried out at room temperature,10 min of vigorous stirring,200 r·min^-1 and a settling time of 24 h,followed by separation and characterization of liquid *** result of addition of alkalis,pH underwent increase as did the alkali *** removal of Cr,and sulfates also increased as alkali concentration did,although for first species the changes at higher alkali contents were less *** removal on the other hand,did not follow a unique trend,instead exhibited a *** on our results,selection of a specific dose of alkali was carried out taking as reference the efficiency on total chromium removal,keeping the pH in the range 7 to 9 to ensure Cr precipitation as chromium *** those conditions,jar test was used to produce enough liquid product in order to determine the removal percent of several other *** removal percent of the species was as follows:Cr,sO4^2-,ZnsO4,FesO4,CN^-1,NisO4,Fe2[Fe(CN)6]at 99.8%,66.9%,99.6%,21.4%,70.9%,52.8%and 76.4%with CaO,and 99.8%,61.6%,99.9%,7.1%,84.0%,54.4%and 90.5%with Ca(OH)2,respectively.

关键词： Tannery wastewater Alkali Removal Chromium sulfates synergistic effect

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safety of digoxin in nonagenarian patients with atrial fibrillation:lessons from the spanish multicenter Registry

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Journal of Geriatric Cardiology 2021年第10期18卷 809-815页

作者： Pablo Domínguez-erquicia sergio Raposeiras-Roubín emad Abu-Assi maría Cespón-Fernández David Alonso-Rodríguez santiago jesús Camacho-Freire Naiara Cubelos-Fernández Álvaro López-masjuán Ríos maría melendo-Viu AndrésÍñiguez-Romo Department of Cardiology University HospitalÁlvaro CunqueiroVigoSpain Health Research Institute Galicia sur VigoSpain Department of Cardiology University Hospital of LeónLeónSpain Department of Cardiology University Hospital Juan Ramón JiménezHuelvaSpain

BACKGROUND The association between digoxin and mortality is an unclear *** older patients with atrial fibrillation(AF),where use of digoxin is frequent,the evidence of its safety is *** aim is to assess the safety of digoxin in nonagenarian patients with *** We evaluated data from 795 nonagenarian patients with non-valvular AF from the spanish multicenter *** analyzed the relationship between digoxin and all-cause mortality with the Cox proportional-hazards *** Follow-up was 27.7±18.3 *** age was 92.5±3.8 years,and 71%of nonagenarian patients were *** was not associated with increased risk of mortality[adjusted hazard ratio(aHR)=1.16,95%CI:0.96−1.41,P=0.130].However,we found a significant increase in mortality in the subgroup with estimated glomerular filtration rate(eGFR)mL/min per 1.73 m^(2)(aHR=2.01,95%CI:1.13−3.57,P=0.018),but not in the other subgroups of eGFR(30−59 mL/min per 1.73 m^(2) and≥60 mL/min per 1.73 m^(2)).When exploring the risk of mortality according to sex,male subgroup was associated with an in-crease in mortality(aHR=1.48,95%CI:1.02−2.14,P=0.041).This was not observed in females subgroup(aHR=1.03,95%CI:0.81−1.29,P=0.829).Based on the presence or absence of heart failure,we did not find significant differences(aHR=1.20,95%CI:0.87−1.65,P=0.268 ***=1.15,95%CI:0.90−1.47,P=0.273,respectively).CONCLUsIONs In our large registry of nonagenarian patients with AF,we did not find an association between digoxin and mortality in the total ***,in the subgroup analyses,we found an increase in mortality with the use of digoxin in men and in patients with an eGFRmL/min per 1.73 m^(2).

关键词： patients digoxin fibrillation

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effects of the partial replacement of La by m(m=Ce,Ca and sr) in La_(2-x)m_xCuO_4 perovskites on catalysis of the water-gas shift reaction

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Journal of Natural Gas Chemistry 2010年第6期19卷 567-574页

作者： s.s.maluf e.m.Assaf Institute de Química de so Carlos Universidade de So PauloAv.Trabalhador Socarlense400 So CarlosSP 13560-970Brazil

The performance of La2-x m x CuO4 perovskites （where m=Ce,Ca or sr） as catalysts for the water-gas shift reaction was investigated at 290℃ and 360℃.The catalysts were characterized by eDs,XRD,N2 adsorption-desorption,XPs and *** XRD results showed that all the perovskites exhibited a single phase （the presence of perovskite structure）,suggesting the incorporation of metals in the perovskite *** XPs and XANes results showed the presence of Cu2＋ on the *** perovskites that exhibited the best catalytic performance were La 2 x Ce x CuO 4 perovskites,with CO conversions of 85% 90%.moreover,these perovskites have higher surface areas and larger amounts of Cu on the *** Ce has a higher filled energy level than the other metals,increasing the energy of the valence band of Ce and providing more electrons for the ***,the La1.80Ca0.20CuO4 perovskite showed a good catalytic performance.

关键词： perovskites water-gas shift reaction lanthanum copper calcium cerium strontium

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The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-mercado Aranza I.Torrado-Tapias Iris K.salgado Jose m.santiago samuel e.Ocasio Rivera Dina P.Bracho-rincon Luis H.Pagan Rivera Jorge D.miranda Department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of Health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain eAAT-1/GLAsT eAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma

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effects of Tillage and Crop Residue management on maize Yields and Net Returns in the Central mexican Highlands Under Drought Conditions

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Pedosphere 2014年第4期24卷 476-486页

作者： R.ROmeRO-PeReZGROVAs N.VeRHULsT D.De LA ROsA V.hernández m.mAeRTeNs J.DeCKeRs B.GOVAeRTs International maize and Wheat Improvement Center(CImmYT) P.O.Box 6-641Mexico D.F.06600(Mexico) Department of earth and environmental sciences University of LeuvenCelestijnenlaan 200 ELeuven 3001(Belgium) mathematics Research Center(CImAT) Jalisco S/NValencianaGuanajuatoMexico CP 36240(Mexico)

In the subtropical highlands of Central mexico, where the main crop is maize （Zea mays）, the conventional practice （CP） involves tillage, monoculture and residue removal, leading to soil degradation and unsustainable use of natural resources and agricultural inputs. Conservation agriculture （CA） has been proposed as a viable alternative in the region, based on reduction in tillage, retention of adequate levels of crop residues and soil surface cover and use of crop rotation. This study began in 2009 when the highlands of Central mexico suffered from a prolonged drought during vegetative maize growth in July-August, providing an opportunity for the on-farm comparison of CA with CP under severe drought conditions which 21 climate change models projected to become more frequent. Under dry conditions, CA resulted in higher yields and net returns per hectare as early as the first and second years after adoption by farmers. As an average of 27 plots under farmers＇ management in 2009, the maize yields were 26% higher under CA （6.3 t ha-1） than under CP （5.0 t ha-l）. 2010 was close to a normal year in terms of rainfall so yields were higher than in 2009 for both practices; in addition, the yield difference between the practices was reduced to 19% （6.8 t ha-1 for CA vs. 5.7 t ha-1 for CP）. When all the 2009 and 2010 observations were analyzed in a modified stability analysis, CA had an overall positive effect of 3 838 mexican Pesos ha-1 （320 $Us ha-1） on net return and 1.3 t ha-1 on yield. After only one to two years of adoption by farmers on their fields, CA had higher yields and net returns under dry conditions that were even drier than those predicted by the analyzed 21 climate change models under a climate change scenario, emission scenario A2.

关键词： climate change conservation agriculture conventional practice emission scenario modified stability analysis

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Kinetics of the H＋-ATPase from Dry and 5-Hours- Imbibed maize embryos in Its Native, solubilized, and Reconstituted Forms

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molecular Plant 2011年第3期4卷 505-515页

作者： sobeida sanchez-Nieto Consuelo enriquez-Arredondo Fernando Guzmbn-Chavez Rolando hern&ndez-munoz Jorge Ramirez m.rina Gavilanes-Ruiz Departamento de Bioquimica Facultad de Quimica Conjunto E. Universidad Nacional Autonoma de Mexico Cd Universitaria 04360 Mexico DF Mexico Instituto de Fisiologfa Celular Universidad Nacional Autonoma de Mexico Cd Universitaria 04360 Mexico DF Mexico

membranes undergo recovery upon rehydration in seed germination. Previous work has described that the plasma membrane H＋-ATPase from maize embryos adopts two different forms at 0 and 5 h of imbibition. We investigated how the kinetics of these two forms could be affected by alterations in the plasma membrane （Pm）. In comparison to the O-h, Pms from the 5-h imbibed embryos showed changes in glycerophospholipid composition, decrease in leakage, and increase in fluidity. Kinetics of the Pm H^-ATPase from 0 and 5-h imbibed embryos showed negative cooperativity, With the removal of the membrane environment, the activity of the enzymes shifted to a more complex kinetics, displaying two enzyme components. Lipid reconstitution produced one component with positive cooperativity. In all cases, enzymes from 0 and 5-h imbibed embryos presented similar kinetics with some quantitative differences. These results indicate that the two enzyme forms have the potential ability to respond to changes in the membrane enyiror^rpent, but the fact that they do not show differences in the native membranes at 0 or 5 h implies that modifications in the membrane are not drastic enough to alter their kinetics, or that they are able to preserve their boundary lipids or associated proteins and thus retain the same kinetic behavior.

关键词： ATPase activity H^-ATPase maize germination plasma membrane H+-ATPase plasma membrane Zea mays.

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Numerical study of the Distribution of Temperatures and Relative Humidity in a Ventilated Room Located in Warm Weather

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Computer modeling in engineering & sciences 2020年第5期123卷 571-602页

作者： J.serrano-Arellano J.m.Belman-Flores I.hernández-Pérez K.m.Aguilar-Castro e.V.macías-melo F.elizalde-Blancas J.m.Riesco-Ávila F.J.García-Rodríguez Instituto Tecnológico superior de Huichapan El SaucilloHuichapan42411México Universidad de Guanajuato Palo BlancoSalamanca36885México Universidad Juárez Autónoma de Tabasco CunduacánTabasco86690México Instituto Tecnológico de Celaya Col.FovisssteCelaya38010México

In the present study,an analysis of the heat and mass transfer in a ventilated cavity in a warm climate zone was carried out to analyze,among others,the temperatures and percentage of relative humidity(RH).The governing equations of the mathematical model were solved through the finite volume *** used the k-εturbulence mode to find the results of the variables of interest in seven climate records on a given *** velocity of the inlet flow of the air-H2O mixture was varied through the Reynolds number(Re)from 500 to *** outdoor weather conditions considered were solar radiation,ambient temperature,and *** was found that at low velocities,flow recirculation was formed inside the cavity which increased the temperature and concentration of *** Re=5000 the flow is predominantly forced,which tends to set the values of temperature and RH as 20°C and 20%*** values of the RH increase in the afternoon hours when the solar radiation decreases to the value of ***,the mass transfer through the values of sh is maintained with similar values in the seven weather *** was concluded that when air conditioning supplies air at speeds higher than 0.26 m/s at low temperatures it produces cooling with low RH,this causes discomfort,illness and/or discomfort to the users.

关键词： Heat transfer mass transfer solar radiation turbulence

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BaTiO_(3)solid solutions co-doped with Gd^(3+)and eu^(3+):synthesis,structural evolution and dielectric properties

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Journal of Rare earths 2024年第10期42卷 1920-1926页

作者： R.martínez-López m.Pérez-Labra J.A.Romero-serrano F.R.Barrientos-hernández m.Reyes-Pérez m.I.Valenzuela-Carrillo G.Urbano-Reyes V.e.Reyes-Cruz G.I.Dávila-Pulido Academic Area of earth sciences and materials Autonomous University of Hidalgo StateRoad Pachuca-Tulancingo Km 4.5 Mineral de La Reforma.Hidalgo42184Mexico metallurgy and materials Department ESIQIE-IPNUPALMZacatencoCiudad de Mexico07738Mexico Autonomous University of Coahuila Boulevard Adolfo López Mateos S/nNueva RositaCoahuila26800Mexico

In this paper,the synthesis,structural evolution,and dielectric properties of BaTiO_(3)solid solutions codoped with rare earth elements(Gd^(3+)and eu^(3+))prepared using the solid-state reaction method are *** pure precursor powders of BaCl_3,TiO_(2),Gd_(2)O_(3),and eu_(2)O_(3)were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 mPa and sintered at 1300℃in air atmosphere for 6 h to obtain Ba_(1-3x)Gd_(2x)Ti_(1-3x)eu_(4x)O_(3)(x=0,0.0015,0.01 and0.1).X-ray diffraction(XRD)and Rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO_(3)for the samples with x=0,0.0015 and 0.01,as well as a consistent increment in the lattice parameters caused by the *** solubility limit of Gd^(3+)and eu^(3+)in the BaTiO_(3)structure is reached for the sample with x>0.01,and the orthorhombic eu_2TiO_(5)and monoclinic BaTi_(2)O_(5)secondary phases were *** Raman results show the characteristic peaks of ferroelectric tetragonal BaTiO_(3)around 716 cm^(-1)(LO of A1 symmetry),515 cm^(-1)(TO of A1 symmetry),and 305 cm^(-1)(B1).The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,Gd,and eu homogeneously distributed in the BaTiO_(3)*** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO_(3) Doping Gadolinium europium synthesis Rare earths

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Host-parasite interactions in perpetual darkness:macroparasite diversity in the cavefish Astyanax mexicanus

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Zoological Research 2023年第4期44卷 782-792页

作者： Ana santacruz David hernández-mena Ramses miranda-Gamboa Gerardo Pérez-Ponce De León Claudia Patricia Ornelas-García Departamento de Zoología Instituto de BiologíaUniversidad Nacional Autónoma de MéxicoMéxico City CP 04510México Departamento de sistemas y Procesos Naturales Escuela Nacional de Estudios Superiores Unidad MéridaUcúYucatán CP 97357México Instituto de energías Renovables Universidad Nacional Autónoma de MéxicoTemixcoMorelos CP 62580México Colección Nacional de Peces Departamento de ZoologíaInstituto de BiologíaUniversidad Nacional Autónoma de MéxicoMéxico City CP 04510México stowers Institute for medical Research Kansas CityMO 64110USA

Astyanax mexicanus has repeatedly colonized cave environments,displaying evolutionary parallelisms in many troglobitic *** being a model system for the study of adaptation to life in perpetual darkness,the parasites that infect cavefish are practically *** this study,we investigated the macroparasite communities in 18 cavefish populations from independent lineages and compared them with the parasite diversity found in their sister surface fish populations,with the aim of better understanding the role that parasites play in the colonization of new *** the cavefish populations,we identified 13 parasite taxa,including a subset of 10 of the 27 parasite taxa known for the surface *** infecting the cavefish belong to five taxonomic groups,including trematodes,monogeneans,nematodes,copepods,and *** are the most dominant group,found in 14 *** macroparasites include species with direct life cycles and trophic transmission,including invasive ***,paired comparisons indicate higher parasite richness in the cavefish than in the surface *** variation in parasite composition across the caves suggests historical and geographical contingencies in the host-parasite colonization process and potential evolution of local *** base-line data on parasite diversity in cavefish populations of *** provides a foundation to explore the role of divergent parasite infections under contrasting ecological pressures(cave *** environments)in the evolution of cave adaptive traits.

关键词： Adaptation metazoan parasites Niche change Parasite assemblage Prevalence

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