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Geochemical Studies and Elemental Contaminants in the Bay of the City of Asuncion

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Journal of Chemistry and Chemical Engineering 2013年第11期7卷 1060-1067页

作者： Juan f. facetti-Masulli franklin flores Peter Kump National University of Asunci6n-Hydroconsult Asunci6n 980 Paraguay Jozef Stefan Institute Ljubljana I000 Slovenia

Minor and trace elements composition of bottom sediments from the bay of Asunci6n on the Paraguay River have been investigated by XRf （X-ray fluorescence） techniques to determine their correlation as well as provenance. The analysis of complex spectra was performed by the AXIL software and the quantitative analysis by the QAES （quantitative analysis of environmental samples ） software. Analyzed trace elements were the refractory elements Rb, Sr, Y, Zr, Nb, Ba, La, Ce, Pr, Nd, Zr, Th and others with high field stabilization energy as Cr, Ni, Cu, together with Zn, As, Cd, Pb. Minor elements were Ti, Mn, fe which are often to the above refractories related. According to their normalized spidergrams, two sets of sediments can be differentiated. Those that show LREE （light rare earth elements） enrichment, negative Nb and Ti anomalies and no spike at Zr and those that have spidergrams very alike, with strong negative anomalies at Nb, Nd and Ti whereas a of fe versus the refractory elements except fe-Zr in which correlation seem to be low. positive spike at Zr. In both set, there are strong correlations is negative. Potential hazards of toxic elements in sediments

关键词： Bottom sediments Asuncion Bay XRf LREE Paraguay River.

The body mass index (BMI) as a public health tool to predict metabolic syndrome

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Open Journal of Preventive Medicine 2012年第1期2卷 59-66页

作者： Miguel Murguía-Romero Rafael Jiménez-flores Rafael Villalobos-Molina María Isabel Mendoza-ramos Julia Reyes-Reali Santiago C. Sigrist-flores Adolfo René Méndez-Cruz Carrera de Médico Cirujano FES Iztacala UNAM Tlalnepantla México

Objective: To analyze the body mass index (BMI) as an indicator of metabolic alterations, including the metabolic syndrome (MetS), at both individual level and public health level. Method: We recruited 3683 undergraduate students (17 - 24 years old) from México City identifying metabolic alterations, including the MetS, and comparing its prevalence by BMI ranges. We applied a sensitivity analysis to define BMI optimal cut-off point values. Results: We found 14.6% of MetS prevalence with a BMI average of 24.2%, and 34.5% of overweight prevalence (BMI ≥ 25). A BMI cut-off point value of 22.5 is suggested as an upper limit of a normal weight condition, only for public health purpose;while at individual level the BMI cut-off point of 25 was corroborated as the upper limit for a normal weight condition. A public health tool to estimate the MetS prevalence based on BMI percentages is proposed, and a study case is presented. Conclusion: BMI fails predicting at individual level both, healthy condition or metabolic alterations, when values are lower than 25. At population level, the BMI is a valuable public health tool to estimate MetS prevalence: based on the prevalence of MetS by BMI ranges of a sample of the population.

关键词： BMI Metabolic Syndrome Obesity Public Health Tool

Comparative study on simultaneous removal of calcium and sulfate ions from flotation recycling water by aluminum hydroxide

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Transactions of Nonferrous Metals Society of China 2022年第7期32卷 2379-2390页

作者： Ángel Daniel GUERRERO-flores Martha Araceli ELIZONDO-ÁLVAREZ JoséManuel flores-ÁLVAREZ Alejandro URIBE-SALAS Department of Metallurgical Engineering CINVESTAV-IPNUnidad Saltillo25900Ramos ArizpeCoahuilaMéxico Department of Materials Unidad Académica de Ingeniería IUniversidad Autónoma de Zacatecas“Francisco García Salinas”ZacatecasZacatecasMéxico facultad de Ciencias Químicas Universidad de ColimaCoquimatlánColimaMéxico

Due to the environmental policies and economic reasons,the water used in some flotation operations of complex sulfide ores is recirculated,causing the ion concentration of some species to increase over time,affecting the flotation of the minerals of *** this work,an experimental and thermodynamic analysis of the synthetic solutions was presented with a high content of calcium and sulfate *** study focused on evaluating the use of two aluminum compounds for the precipitation of Ca^(2+)and SO_(4)^(2−)in the form of *** amorphous aluminum hydroxide was found to be more efficient than the crystalline one,giving rise to 83%calcium and 91%sulfate *** XRD analysis of the solids showed the main reaction product of ettringite,accompanied by small amounts of calcite,due to the absorption of atmospheric carbon *** final solution after the chemical treatment showed residual calcium and sulfate concentrations below 200 mg/***,the kinetics of calcium removal appeared to correspond to a second order reaction with respect to calcium concentration,with an apparent activation energy of 53.48 kJ/mol,which may suggest that the ettringite precipitation process is governed by the chemical reaction.

关键词： ettringite ion removal aluminum hydroxide calcium sulfate

Role of vitamin B_(12) on methylmalonyl-CoA mutase activity

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第6期13卷 423-437页

作者： Tóshiko TAKAHASHI-IIGUEZ Enrique GARCíA-HERNANDEZ Roberto ARREGUíN-ESPINOSA María Elena flores Department of Molecular Biology and Biotechnology Institute of Biomedical ResearchNational Autonomous University of MexicoD.F.04510Mexico Department of Chemistry of Biomacromolecules Institute of ChemistryNational Autonomous University of MexicoD.F.04510Mexico

Vitamin B 12 is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes,which have been grouped into three subfamilies depending on their *** them,methylmalonyl-CoA mutase (MCM) has been extensively *** enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the *** crystal structure of MCM determined in Propionibacterium freudenreichii *** has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme,coenzyme,and *** existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in *** recent crystallization of the human MCM has shown that despite being similar to the bacterial protein,there are significant differences in the structural organization of the two *** studies have identified the involvement of an accessory protein called MMAA,which interacts with MCM to prevent MCM's inactivation or acts as a chaperone to promote regeneration of inactivated *** interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase,the impact of mutations at a functional level and their repercussion in the development and progression of MMA in *** is still necessary to study the mechanisms involved in more detail using new methods.

关键词： Vitamin B 12 Methylmalonyl-CoA mutase (MCM) MMAA MeaB Methylmalonic academia (MMA) Protectase Reactivase

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

Particulate matter geochemistry of a highly industrialized region in the Caribbean:Basis for future toxicological studies

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Geoscience frontiers 2022年第1期13卷 376-387页

作者： Luis f.O.Silva Ismael L.Schneider Paulo Artaxo Yuleisy Núñez-Blanco Diana Pinto Érico M.M.flores Leandro Gómez-Plata Omar Ramírez Guilherme L.Dotto Department of Civil and Environmental Universidad de la CostaCUCCalle 58#55–66BarranquillaAtlánticoColombia Department of Applied Physics Institute of PhysicsUniversity of São PauloBrazil Department of Chemistry Universidade Federal de Santa MariaRSBrazil Universidad Militar Nueva Granada(UMNG) Faculty of EngineeringEnvironmental EngineeringKm 2 Cajicá-ZipaquiráColombia Chemical Engineering Department Federal University of Santa Maria-UFSM1000Roraima Avenue97105-900 Santa MariaRSBrazil

Air pollution has become an important issue,especially in Caribbean urban areas,and,particulate matter(PM)emitted by different natural and anthropogenic sources causes environmental and health *** this work,we studied the concentrations of PM_(10) and PM_(2.5) sources in an industrial and port urban area in the Caribbean region of *** samples were collected within 48-h periods between April and October 2018 by using a Partisol 2000 i-D *** geochemical characterization was performed by X-ray fluorescence(XRf)***,ionic species and black carbon(BC)were quantified by ion chromatography and reflectance spectroscopy,*** the Positive Matrix factorization(PMf)receptor model,the contributions of PM sources were *** average concentration of PM_(10) was 46.6±16.2μg/m^(3),with high concentrations of Cl and *** PM_(2.5),the average concentration was 12.0±3.2μg/m^(3),and the most abundant components were BC,S,and *** receptor model identified five sources for PM_(10) and PM_(2.5).for both fractions,the contributions of marine sea spray,re-suspended soil,and vehicular traffic were *** addition,PM_(2.5) included two mixed sources were found to be fuel oil combustion with fertilizer industry emissions,and secondary aerosol sources with building construction ***,PM_(10) was found to also include building construction emissions with re-suspended soil,and metallurgical industry *** obtained geochemical atmospheric results are important for the implementation of strategies for the continuous improvement of the air quality of the Caribbean region.

关键词： Urban air pollution Particulate matter Geochemical composition Aerosol source apportionment Receptor models PMf

Cytogenetical Changes among Polyembryonic(PEm)and Non-PEm Maize Plants

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Phyton-International Journal of Experimental Botany 2021年第1期90卷 87-97页

作者： A.A.Román-Calzoncit f.Ramírez-Godina J.Sánchez-Laureano A.C.flores-Gallegos J.Espinoza-Velázquez R.Rodríguez-Herrera School of Chemistry Universidad Autónoma de Coahuila.Blvd.V.Carranza e Ing.JoséCárdenas V.s/n.Col.República Ote.C.P.25280.SaltilloCoahuilaMéxico Plant Breeding Department Universidad Autónoma Agraria Antonio NarroBlvd.Antonio Narro 1923BuenavistaSaltilloMéxico

Polyembryony in maize(PEm)contributes to improving the nutritional properties of the grain,as well as an increase in yield,since it generates multiple plants per seed,opening the possibility of developing new ***,it is unknown whether polyembryony in maize is the product of chromosomal *** on the above,in this research a cytogenetic study was proposed to verify if chromosomal abnormalities are related to the maize *** a meiotic study,maize genotypes with variable proportions of polyembryony(PEm),from the UA-IMM-BAP population and non-PEm(monoembryonic)maize were used,while for a mitosis analysis,30 families of maternal half-siblings(MHS)from two different populations with high polyembryony,denominated as BHP(brachytic,high polyembryony)and NHP(normal height,high polyembryony)were *** these genotypes were planted in the Buenavista Agricultural Experimental Station-UAAAN at Saltillo,Coahuila,*** frequency of PEm was estimated in all *** was found that the polyembryony occurs at frequencies from 34 to 66%in the D-02,BHP group,and from 13 to 21%in the segregating groups of the G3-0202 and *** squash technique was used for both cytogenetic *** meiotic irregularities in maize chromosomes were detected,such as irregular association of 10%of chromosomes in metaphase 1,and agglomeration of chromatin in 100%of the *** addition,pollen viability was estimated by the staining technique with 1%acetocarmine dye,and it was found that the polyembryonic ones have pollen viability of 100%.In meiosis in prophase,I sub-phase diakinesis,ten pairs of bivalents were confirmed,confirming 2n=20,both in non-PEm and PEm maize,corroborating mating,and balanced segregation,without the presence of univalent or *** the chromosomal count carried out in cells in mitosis,only in the BHP-200 polyembryonic family was registered two out of twenty triploid *** condition of ploidy is atypical in

关键词： Zea mays irregular meiosis mitosis chromosomes chromatin polyploidy

Volcanic emissions and atmospheric pollution:A study of nanoparticles

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Geoscience frontiers 2021年第2期12卷 746-755页

作者： Erika M.Trejos Luis f.O.Silva James C.Hower Eriko M.M.flores Carlos Mario González Jorge E.Pachón Beatriz H.Aristizábal Hydraulic Engineering and Environmental Research Group Universidad Nacional de Colombia Sede ManizalesManizalesColombia Department of Civil and Environmental Universidad de la CostaCalle 58#55-66Barranquilla 080002Colombia University of Kentucky Center for Applied Energy Research2540 Research Park DriveLexingtonKY 40511USA Department of Earth&Environmental Sciences University of KentuckyLexingtonKY 40506USA Universidade federal de Santa Maria Santa MariaBrazil Centro Lasallista de Investigación y Modelación Ambiental–CLIMA Universidad de La SalleBogotáColombia

The influence of emissions of an active volcano on the composition of nanoparticles and ultrafine road dust was identified in an urban area of the *** many cities are close to active volcanoes,few studies have evaluated their influence in road dust *** quality in urban areas is significantly affected by nonexhaust emissions(*** dust,brake wear,tire wear),however,natural sources such as volcanoes also impact the chemical composition of the *** this study,elements from volcanic emissions such as Si>Al>fe>Ca>K>Mg,and Si-Al with K were identified as complex ***,As,Hg,Cd,Pb,As,H,Cd,Pb,V,and salammoniac were observed in nanoparticles and ultrafine *** composition was detected in the order of quartz>mullite>calcite>kaolinite>illite>goethite>magnetite>zircon>monazite,in addition to salammoniac,a tracer of volcanic *** foregoing analysis reflects the importance of carrying out more studies relating the influence of volcanic emissions in road dust in order to protect human *** road dust load(RD_(10))ranged between 0.8 and 26.8 mg m^(−2)in the city.

关键词： Nanoparticles Amorphous phases Potential hazardous elements Road dust Volcano zone

Control Alternatives for Damping-Off in Tomato Seedling Production

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Phyton-International Journal of Experimental Botany 2019年第3期88卷 325-333页

作者： A.C.Michel-Aceves J.f.Díaz-Nájera R.Ariza-flores M.A.Otero-Sánchez R.Escobar-Martínez C.H.Avendaño-Arrazate Centro de Estudios Profesionales del Colegio Superior Agropecuario del Estado de Guerrero Av.Vicente Guerrero No.81Colonia CentroIgualaGuerreroC.P.40000México Instituto Nacional de Investigaciones forestales Agrícolas y Pecuarias(INIFAP)Campo Experimental IgualaCarr.Iguala-TuxpanKm.2.5 IgualaGuerreroMéxico INIfAP-Campo Experimental Rosario Izapa.Carr.Tapachula-Cacahoatán Tuxtla chicoChiapasC.P.30870México

In two tomato genotypes,we assessed control alternatives for damping-off with combinations of chemical fungicides and native/commercial strains of biological *** treatments consisting of 19 levels of mixing products,chemical fungicides,native strains and commercial products from biological control agents,and untreated treatment were used onto Ramsés and Toro *** were distributed on an incomplete block design in divided plots arrangement,where genotypes constitute the larger ones and the 8-repetition mixed products,the smaller *** 180 mL of fungal complexes,made of spores and mycellium fusarium-solani(2×106 UfC),Rhizoctonia-solani(1×106 UfC),Phytophthora-capsici(1×105 UfC)and Sclerotium-rolfsii(mycellium-sclerotia)on each seedling trays,made inoculation *** mixtures of(Bacillus spp.+Streptomyces spp.+Trichoderma spp.)+(Propamocarb+fosetyl);(Bacillus spp.+Streptomyces spp.+Trichoderma spp.)+(Metalaxyl+Chlorothalonil);Pseudomonas fluorescens+Streptomyces+Micromonospore+Sporideamium+Aminoacidos,Péptidos,Carbohidratos)+(Propamocarb+fosetyl);the native strain of Trichoderma asperellum+(Propamocarb+fosetil)and the native strains Trichoderma asperellum+Bacillus subtilis,diminished damping-off,prevented its appearance and had most significant agronomic *** contrast to this,combination of(Mancozeb)+(free iodine)+(Metalaxyl+Chlorothalonil)+(Methyl thiophanate)produced some toxicity in the *** addition,Ramsés presented the best agronomic parameters,while Toro had the utmost fresh and dry weight in root.

关键词： Trichoderma harzianum T.lignorum biological control