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Synthesis, characterization,thermal behavior,and antifungal activity of La(Ⅲ) complexes with cinnamates and 4-methoxyphenylacetate

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Journal of Rare Earths 2013年第11期31卷 1106-1113页

作者： Alberto Aragón-Muriel Dorian Polo-cerón Departamento de Química Universidad del Valle Calle 13 No 100-00 CaliColombia 76001000

In this study a series of trivalent lanthanum complexes with 4-（R）-cinnamate （4-Rcinn, R=H（1）, MeO（2）, Cl（3）） and 4-methoxyphenylacetate ligands （4） were prepared and their antifungal activity against Candida albicans, Aspergillus niger and Trichophyton mentagrophytes were examined. Compounds 1-4 were synthesized by a metathesis reaction and fully characterized by elemental analysis, IR, 1H and 13C nMR spectroscopy, fluorescence spectra, thermogravimetry （TG）, derivative thermogravimetry （DTG）, differential scanning calorimetry （DSC） and X-ray diffraction powder patterns. In emission studies, it was observed that lu-minescence intensity was enhanced in the presence of lanthanide ion. The results of X-ray diffraction patterns indicated that all com-plexes studied exhibited crystalline structure. Thermal behavior by TG, DTG, and DSC studies permitted to estimating the hydration degree of the compounds and showed the formation of decomposition products like lanthanum oxide. Determined by antifungal stud-ies, lanthanum complexes 1-4 demonstrated antifungal activity toward all pathogenic fungal strains tested. Compounds 2 and 4 showed significant growth inhibition for A. niger and C. albicans, respectively.

关键词： antifungal activity La(III) complexes cinnamates 4-methoxyphenylacetate infrared spectra excitation emission TG-DTG-DSC Candida albicans Aspergillus niger Trichophyton mentagrophytes rare earths

Estimation of the carbon pool in soil and above-ground biomass within mangrove forests in Southeast Mexico using allometric equations

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Journal of Forestry Research 2014年第1期25卷 129-134页

作者： Jesús Jaime Guerra-Santos Rosa maría cerón-Bretón Julia Griselda cerón-Bretón Diana Lizett Damián-Hernández Reyna Cristina Sánchez-Junco Emma del Carmen Guevara Carrió Centro de Investigación de Ciencias Ambientales-Universidad Autónoma del Carmen Av.Abasolo s/n.Col.Renovación 2da.Sección C.P.24180.Cd.del CarmenCampecheMéxico

We report the results of carbon stored in soil and aboveground biomass from the most important area of mangroves in Mexico, with dominant vegetation of Red mangrove （Rhizophora mangle L.）, Black mangrove （Avicennia germinans L.）, white mangrove （Laguncularia racemosa Gaertn.） and button mangrove （Conocarpus erectus L.）. We sampled soils with high fertility during the dry season in 2009 and 2010 at three sites on Atasta Peninsula, Campeche. We used allometric equations to estimate above ground biomass （AGB） of trees. AGB was higher in C. erectus （253.18±32.17 t？ha-1）, lower in A. germinans （161.93±12.63 t？ha-1）, and intermediate in R. mangle （181.70±16.58 t？ha-1） and L. racemosa （206.07±19.12 t？ha-1）. Of the three studied sites, the highest absolute value for AGB was 279.72 t？ha-1 in button mangrove forest at any single site. Carbon stored in soil at the three sites ranged from 36.80±10.27 to 235.77±66.11 t？ha-1. The Tukey test （p 〈0.05） made for AGB was higher for black mangrove showed significant differences in soil carbon content between black mangrove and button mangrove. C. erectus had higher AGB compared with the other species. A. germinans trees had lower AGB because they grew in hypersaline environments, which reduced their development. C. erectus grew on higher ground where soils were richer in nutrients. AGB tended to be low in areas near the sea and increased with distance from the coast. A. germinans usually grew on recently deposited sediments. We assumed that all sites have the same potential to store carbon in soil, and then we found that there were no significant differences in carbon content between the three samples sites： all sites had potential to store carbon for long periods. Carbon storage at the three sampling sites in the state of Campeche, Mexico, was higher than that reported for other locations.

关键词： carbon storage Rhizophora mangle Laguncularia racemosa,Avicennia germinans tree biomass

Potential Effects on Human Health of Hydrogen Sulfide Exposure in a Place in Southeast of Mexico

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Open Journal of Ecology 2016年第1期6卷 47-54页

作者： Manuel Muriel-García Rosa maría cerón-Bretón Julia Griselda cerón-Bretón Instituto Mexicano del Petróleo Ciudad del Carmen México Facultad de Quimica Universidad Autónoma del Carmen Ciudad del Carmen México

Ambient concentrations of H2S were determined by modeling the H2S emissions dispersion for three sites located in the surroundings of oil and gas maritime terminal at the southeast of Mexico. Hazard quotient is reported for different age groups. Paraiso City in Tabasco State reported the highest values for over 19 years old group (0.49). It was concluded that there was no threat to human health due to H2S emissions derived from the maritime terminal for the studied sites.

关键词： Risk assessment H2S Air Pollution Southeast of Mexico

An artificial neuronal network coupled with a genetic algorithm to optimise the production of unsaturated fatty acids in Parachlorella kessleri

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Artificial Intelligence in Agriculture 2024年第3期13卷 32-44页

作者： Pablo Fernández Izquierdo Leslie cerón Delagado Fedra Ortiz Benavides Department of Biology University of NariñoPastoColombia School of Basic Sciences Technology and EngineeringNational Open and Distance UniversityColombia

In this study,an Artificial neural network-Genetic Algorithm(Ann-GA)approachwas successfully applied to optimise the physicochemical factors influencing the synthesis of unsaturated fatty acids(UFAs)in the microalgae *** UCM *** optimized model recommended specific cultivation conditions,including glucose at 29 g/L,nanO_(3)at 2.4 g/L,K_(2)HPO_(4)at 0.4 g/L,red LED light,an intensity of 1000 lx,and an 8:16-h light-dark *** Ann-GA optimisation,a remarkable 66.79%increase in UFAs production in *** UCM 001 was achieved,compared to previous *** underscores the potential of this technology for enhancing valuable lipid *** variations in the application of physicochemical factors during microalgae culture under mixotrophic conditions,as optimized by Ann-GA,induced alterations in UFAs production and composition in *** UCM *** suggests the feasibility of tailoring the lipid profile of microalgae to obtain specific lipids for diverse industrial *** isolated froma high-mountain lake in Colombia,highlighting their adaptation to extreme *** underscores their potential for sustainable lipid and biomaterial *** study demonstrates the effectiveness of using Ann-GA technology to optimise UFAs production in microalgae,offering a promising avenue for obtaining valuable ***'s unique origin in a high-mountain environment in Colombia emphasises the importance of exploring and harnessing microbial resources in distinctive geographical regions for biotechnological applications.

关键词： Artificial neural network(Ann) Genetic algorithm(GA) Microalgae Unsaturated fatty acids(UFAs) Mixotrophy

Air Pollution in the Gulf of Mexico

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Open Journal of Ecology 2016年第1期6卷 32-46页

作者： Manuel Muriel-García Rosa maría cerón-Bretón Julia G. cerón-Bretón Instituto Mexicano del Petróleo Ciudad del Carmen México Facultad de Química Universidad Autónoma del Carmen Ciudad del Carmen México

An integral analysis of Air Pollution in the Gulf of Mexico was made considering pollutants emissions assessment and diagnosis;air pollution monitoring;and modeling of air pollution dispersion. Combustion sources considered in this work were: thermoelectric power plants and open flares;and pollutants considered were sulfur dioxide, nitrogen dioxides, particulate matter (PM10 and PM2.5), Total suspended particles (TSP) and carbon monoxide (CO). This study made evident a lack of more recent information and a homogenization in emissions factors in order to know the conditions of air pollution in the Gulf of Mexico in a more reliable way.

关键词： Air Pollution Dispersion Models Air Pollution Monitoring Gulf of Mexico

The Influence of Meteorology and Atmospheric Transport Patterns on the Sulfate Levels in Raiwater in Orizaba Valley, Veracruz, Mexico

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Journal of Environmental Protection 2019年第6期10卷 821-837页

作者： Rosa maría cerón Bretón Jonathan Kahl Julia Griselda cerón Bretón José Angel Solís Canul Chemistry Faculty Autonomous University of Carmen Ciudad del Carmen Mexico Department of Mathematical Sciences University of Wisconsin-Milwaukee Milwaukee WI USA

This work assessed the relationship between synoptic circulation patterns, meteorological conditions and sulfate levels in rainwater in Orizaba Valley, Veracruz, Mexico during 2015. Samples were collected by using an automatic deposition sampler considering three climatic periods: Cold fronts or nortes, Dry and Rainy seasons. Sulfate in rainwater was determined by turbidimetry (nMX-AA-SCFI-074-1981). A backward trajectory model (HYSPLIT) was used to characterize the potential source regions and transport pathways for air parcels arriving to Orizaba Valley;trajectories extended five days during 2015 were calculated. Mean concentrations of sulfate were 105.33, 37.5, and 52.5 μEq·l-1, for Cold Fronts, Dry and Rainy seasons, respectively. An evident dilution pattern was observed with lower concentration levels when rainfall increased. Mean values for sulfate concentration exceeded the background hemispheric value reported by Galloway et al. (1982) for remote sites (10 μEq·l-1), exceeding almost 10, 3.7 and 5.2 times, during the nortes, Rainy and Dry seasons, respectively. From the obtained results, it was concluded that the high sulfate levels in the rainwater measured in Orizaba Valley had their origin in different upwind regional sources as a result of long-range transport during Rainy and nortes seasons.

关键词： Atmospheric Transport Rainwater Sulfate

Study of Trace Ions in Wet Deposition of an Industrial Site in Monterrey’s Metropolitan Area, Mexico

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Open Journal of Ecology 2016年第1期6卷 1-12页

作者： Evangelina Ramírez-Lara Rosa maría cerón-Bretón Julia Griselda cerón-Bretón Ulrico López-Chuken Jonathan Kahl Facultad de Ciencias Químicas Universidad Autónoma de Nuevo León San Nicolás de los Garza México Facultad de Química Universidad Autónoma del Carmen Ciudad del Carmen México Department of Mathematical Science University of Wisconsin-Milwaukee Milwaukee USA

The chemistry of rainwater has been subject to numerous investigations during the last two decades due to the increase of environmental problems caused by the acid deposition. The present study focuses on one aspect of air pollution, the chemical composition of wet deposition of an industrial zone. The sampling period was from march to December 2009. The station was located on the roof of the Chemistry School at the University of nuevo León, an area in the north of Monterrey where the majority of pollution is generated. Twenty-five wet precipitation samples were collected with an automatic sampler and analyzed for pH, ions (, , Cl-, Ca2+, Mg2+, na+, K+) and conductivity. The results show that the average pH is higher than 5.6;the characteristics of the rainwater studied are of alkaline nature due to the values of pH found;there is an evident anthropogenic source contributing to the alkaline of rain water. In order to find possible association between ions and consequently the possible sources of pollutants correlation study was applied using the program SPSS v.12. Good correlations were found between ions and along with Ca2+ and Mg2+. The local extraction industry and surrounding aerosols might be causing of alkaline rain which may be due to the neutralization effect of particulate matter. This study represents a continuation of the studies of rainwater chemistry in the northeast of Mexico.

关键词： Wet Deposition Air Quality Monterrey Air Pollution

Species delimitation based on diagnosis and monophyly, and its importance for advancing mammalian taxonomy

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Zoological Research 2018年第5期39卷 301-308页

作者： Eliécer E.Gutiérrez Guilherme S.T.Garbino Pós-Graduacao em Biodiversidade Animal Departamento de Ecologia e Evolucao Centro de Ciências Naturais e Exatas Universidade Federal de Santa Maria Santa Maria RS 97105-900 Brazil Division of Mammals National Museum of Natural History Smithsonian Institution Washington DC 20013-7012 USA Pós-graduacao Departamento de Zoologia Instituto de Ciências Biológicas Universidade Federal de Minas Gerais Belo Horizonte Minas Gerais 31270-901 Brazil

A recently proposed taxonomic classification of extant ungulates sparked a series of publications that criticize the Phylogenetic Species Concept （PSC） claiming it to be a particularly poor species *** opinions reiteratively stated that （1） the two fundamental elements of the ＂PSC＂,i.e.,monophyly and diagnosability,do not offer objective criteria as to where the line between species should be drawn;and （2） that extirpation of populations can lead to artificial diagnosability and spurious recognitions of *** sudden eruption of criticism against the PSC is *** attributed to the PSC are common to most approaches and concepts that modern systematists employ to establish species *** controversial taxonomic propositions that sparked criticism against the PSC are indeed highly problematic,not because of the species concept upon which they are based,but because no evidence （whatsoever） has become public to support a substantial portion of the proposed *** herein discuss these topics using examples from *** areas of biological research rest upon taxonomic accuracy （including conservation biology and biomedical research）;hence,it is necessary to clarify what are （and what are not）the real sources of taxonomic inaccuracy.

关键词： Alpha taxonomy Phylogenetic SpeciesConcept Species concepts Taxonomic inertia Taxonomic inflation

Dichloro-Diphenyl-Trichloroethane (DDT) and Endosulfan in Sediments of Sabancuy Lagoon, Campeche, Mexico

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Open Journal of Ecology 2016年第1期6卷 22-31页

作者： Miguel Angel Ramírez-Elías Atl Victor Córdova-Quiroz Julia Griselda cerón-Bretón Rosa maría cerón-Bretón Jaime Rendón-von Osten Javier Hipólito Cortés-Simón Facultad de Química Universidad Autónoma del Carmen Ciudad del Carmen México Centro de Ecología Pesquerías y Oceanografía del Golfo de México (EPOMEX) Universidad Autónoma de Campeche Campeche México Secretaria de marina V Zona Naval Estación de Investigación Oceanográfica Cd del Carmen Campeche México

DDT and Endosulfan are persistent organic compounds which have been prohibited and their use has been limited in agricultural activities due to their toxicity, persistence and bioaccumulation potential. The use of DDT in fumigation campaigns against endemic diseases transmitted by vectors of malaria and dengue was prohibited in Carmen Island, Campeche, Mexico since 1995. In the surroundings of Sabancuy Lagoon, many and diverse agricultural activities are carried out and it is a common practice to use organ-chlorine pesticides as endosulfan. In order to know the levels of these compounds in this area, a sediment sampling campaign was carried out in ten sampling points randomly located within the Sabancuy Lagoon, Campeche and considering one reference sampling point located 2 km away from Sabancuy Lagoon within the Mexican Gulf. Three metabolites were identified in sediments samples belonging to DDT’s family: (4,4’-DDD;4,4’-DDE;4,4’- DDT) and Endosulfan’s family (Endosulfan I, Endosulfan II y Endosulfan sulfate). Higher concentrations in DDT’s family were found for 4,4’-DDD, followed by 4,4’-DDE and 4,4’-DDT. Endosulfan’s family, showed the following order for concentrations: Endosulfan II > Endosulfan I > Endosulfan sulfate. Mean concentration for S-DDT and S-Endosulfan in Sabancuy Lagoon sediments was twice higher than those found in other studies carried out in Términos Lagoon, Campeche, Mexico in 2002.

关键词： Organochlorine Pesticides Pollution Sabancuy Coastal Lagoons