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Historical fluxes of metal and metalloids in an aquatic ecosystem affected by land-use change and mining activities in northwestern Mexico

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International Journal of Sediment Research 2023年第5期38卷 724-738页

作者： Ochoa-Contreras Roberto jara-marini martín enrique Ruiz-Fernández Ana Carolina Sanchez-Cabeza Joan Albert Meza-Figueroa Diana Pérez-Bernal Libia Hascibe Posgrado en Ciencias Centro de Investigación en Alimentación y Desarrollo Unidad Hermosillo 2. Centro de Investigación en Alimentación y Desarrollo Unidad Hermosillo Unidad Acad emica Mazatlán Instituto de Ciencias del Mar y Limnología Universidad Nacional Autónoma de M exico Departamento de Geología División de Ciencias Exactas y Naturales Universidad de Sonora Rosales y Encinas

Freshwater reservoirs are essential owing because of their ecological, economic, and social *** are particularly vulnerable to contamination, as of metal and metalloids, derived from anthropogenic activities like mining. The temporal variations in trace element concentrations(arsenic(As),mercury(Hg), chromium(Cr), copper(Cu), nickel(ni), lead(Pb), and zinc(Zn)), enrichment, fluxes, and possible sources were evaluated by studying two sediment cores from the La Angostura(AnG) Reservoir(northwest Mexico), using210Pb geochronology. The enrichment factors showed from null to minor enrichment for most elements, but moderate to severe enrichment of mercury(Hg). Most trace element concentrations had a detrital origin, and notable Hg concentration increases since the past decade were associated with severe drought periods, likely resulting from wildfires. The observed sediment concentrations of As and Hg can cause adverse effects on biota in the ecosystem since they are above the probable effect level(PEL). Development of strategies for metal attenuation in this reservoir is recommended and metals should be controlled until specific ecotoxicological studies are performed.

关键词： Aquatic ecosystems ~(210)Pb geochronology Mining activities Metals Metalloids Enrichment factors

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Rheological and tribological approaches as a tool for the development of sustainable lubricating greases based on nano-montmorillonite and castor oil

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Friction 2021年第2期9卷 415-428页

作者： Jose enrique martÍn-ALFOnSO María Jose martÍn-ALFOnSO Concepción VALEnCIA María Teresa CUBERES Department of Chemical Engineering and Materials Science Campus de“El Carmen”University of HuelvaChemical Product and Process Technology Research Center(Pro2TecS)Huelva 21071Spain Department of Applied Mechanics and Project Engineering University of Castilla-La ManchaAlmadén 13400Spain

This study investigates the development of novel montmorillonite/castor oil blends to formulate sustainable lubricating greases to promote the replacement of petrochemicals industry-derived materials by substances obtained from renewable ***,the effect of the thickener concentration on the rheological,chemical,thermal,tribological properties,and atomic force microscopy(AFM)microstructure of these systems were *** results showed that the C20A nanoclay content could be used to modulate the viscosity values,the linear viscoelastic functions,and tribological properties of these montmorillonite *** general,these gel-like dispersions exhibited remarkable lubricant properties;the samples showed values of the friction coefficient and wear scars similar or lower than those obtained with model bentonite grease.

关键词： lubricating greases nanoclay vegetable oil rheology tribology

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Influence of steel jacket thickness on the RC bridges' seismic vulnerability

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第1期6卷 15-34页

作者： Bertha Olmos José Manuel jara Gerardo Gómez Guillermo martínez Department of Civil Engineering Universidad Michoacana de San Nicolas de Hidalgo

The seismic demands of bridges subjected to strong earthquakes are mostly concentrated on piers. The main objective of this study is to assess the seismic vulnerability of retrofitted bridges with steel jackets. It analyzes the influence of the steel jacket thickness on the seismic capacity and demand of bridges. The bridges in study have two simple supported spans with superstructure composed by AASHTO type girders and a substructure formed with one circular pier over a stiff foundation. They are located on the Pacific coast of Mexico that is a zone of high seismicity. The bridges seismic capacity are evaluated through nonlinear static analyses and the shear force and displacement demands were determined using capacity spectra with a group of 10 real accelerograms from a subduction source. The response spectra were scaled to several peak ground accelerations(PGA) with the aim to estimate four damage scenarios linked each one to a probability of exceedance in a specific period, for return periods in the range of 72-3500 years that represent service level and maximum considered earthquake. Results show that the confining effect provided by the steel jackets substantially improves the seismic performance of the bridges piers. The increase of jacket thickness guides to important increments on columns base shear capacity, and the influence of the steel jacket thickness depends on the limit state and bridge slenderness ratio.

关键词： Steel jacket Piers’retrofit Subduction earthquakes RC piers’vulnerability

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Would behavioral thermoregulation enable pregnant viviparous tropical lizards to cope with a warmer world?

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Integrative Zoology 2017年第5期12卷 379-395页

作者： Saúl LÓPEZ-ALCAIDE Miguel nAKAMURA Eric n.SMITH enrique martÍnEZ-MEYER Departament of Zoology Institute of BiologyNational Autonomous University of MexicoMexico CityMexico Center for Research in Mathematics GuanajuatoMexico Amphibian and Reptile Diversity Research Center and Department of Biology University of Texas at ArlingtonArlingtonTexasUSA

Sceloporus lizards depend on external heat to achieve their preferred temperature(Tsel)for performing physiological *** both in the field and laboratory indicates that pregnant females of this Genus select body temperatures(Tb)lower than 34℃ as higher temperatures may be lethal to ***,thermoregulation is crucial for successful embryo *** the increase in global air temperature,it is expected that the first compensatory response of species that inhabit tropical climates will be behavioral *** tested whether viviparous Sceloporus formosus group lizards in the wild exhibited differences in thermoregulatory behavior to achieve the known Tsel for developing embryos regardless of local thermal *** quantified field active body temperature,thermoregulatory behavior mechanisms(time of sighting,microhabitat used and basking time)and available microhabitat thermal conditions(*** temperature)for 10 lizard species during gestation,distributed along an altitudinal *** applied both conventional and phylogenic analyses to explore whether Tb or behavioral thermoregulation could be regulated in response to different thermal *** species showed no significant differences in field Tb during gestation regardless of local thermal *** contrast,they exhibited significant differences in their behavioral thermoregulation associated with local environmental *** on these observations,the differences in thermoregulatory behavior identified are interpreted as compensatory adjustments to local thermal *** conclude that these species may deal with higher temperatures predicted for the tropics by modulating their thermoregulatory behavior.

关键词： altitudinal gradient behavior global warming Sceloporus formosus thermal stress

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A VSC-based Model for Power Flow Assessment of Multi-terminal VSC-HVDC Transmission Systems

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Journal of Modern Power Systems and Clean Energy 2021年第6期9卷 1363-1374页

作者： Ricardo martínez-Parrales Claudio R.Fuerte-Esquivel Boris A.Alcaide-Moreno enrique Acha Faculty of Electrical Engineering Universidad Michoacana de San Nicolás de Hidalgo(UMSNH) national Center for Energy Control Secretary of Energy Department of Electrical Engineering Tampere University(TU)

This paper puts forward a new practical voltage source converter(VSC)based AC-DC converter model suitable for conducting power flow assessment of multi-terminal VSCbased high-voltage direct current(VSC-MTDC)*** model uses an advanced method to handle the operational limits and control modes of VSCs into the power flow *** new model is incorporated into a unified framework encompassing AC and DC power grids and is solved by using the newton-Raphson method to enable quadratically convergent iterative *** use of complementarity constraints,together with the Fischer-Burmeister function,is proposed to enable the seamless incorporation of operational control modes of VSC and automatic enforcement of any converter’s operational limits that become violated during the iterative solution ***,a dedicated process for checking limits is no longer ***,all existing relationships between the VSC control laws and their operational limits are considered directly during the solution of the power flow *** applicability of the new model is demonstrated with numerical examples using various multi-terminal AC-DC transmission networks,one of which is a utility-sized power system.

关键词： Complementarity constraint current limit high-voltage direct current(HVDC) voltage source converter(VSC) multi-terminal VSC-HVDC(VSC-MTDC)system power flow

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nature and evolution of the lower crust under central Spain:Inferences from granulite xenoliths(Calatrava Volcanic Field-Spanish central system)

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Geoscience Frontiers 2023年第3期14卷 10-32页

作者： David Orejana Carlos Villaseca Marlina A.Elburg enrique Merino-martínez Javier García Serrano Departamento de Mineralogía y Petrología Universidad Complutense de MadridSpain Departamento de Dinámica Terrestre y Observación de la Tierra Instituto de Geociencias IGEO(UCMCSIC)MadridSpain Department of Geology University of JohannesburgSouth Africa Instituto Geológico y Minero de España–Consejo Superior de Investigaciones Científicas CN IGME–CSIC

So far,the nature and evolution of the lower crust under central Spain have been constrained mainly on the basis of a heterogeneous suite of granulite xenoliths from the Spanish Central System(SCS).In recent years,ultramafic volcanics from the Calatrava Volcanic Field(CVF)have also provided deep-seated crustal xenoliths which have not been studied in *** data,combining mineral,whole-rock and isotopic geochemistry with U–Pb–Hf isotope ratios in zircons from the CVF and SCS xenoliths,highlight the felsic composition of the lower crust under central Iberia.A number of the Calatrava xenoliths represents Variscan igneous protoliths,which are a minor population in the SCS,and were likely formed by crystallisation of intermediate and felsic melts in the lower crust during the Variscan orogeny(leucodiorite protolith age of 314±3 Ma and leucogranite protolith age of 308±2.5 Ma).U–Pb data of metamorphic zircons show that granulite-facies metamorphism mainly occurred from 299 to 285 Ma in both *** ages are slightly younger than those of granitic intrusions that could be genetically related to the granulitic residue,which points to a main role of U–Pb isotope resetting in lower crustal zircons during HT or UHT *** zircon U–Pb–Hf isotopic ratios support the idea that the lower crust in central Iberia consists mainly of Ordovician–neoproterozoic metaigneous and metasedimentary rocks associated with the Cadomian continental arc of northern *** rocks provide evidence of mixing between juvenile magmas and an enriched crustal component,ultimately extracted from an Eburnean *** more evolved components present in detrital zircons are likely related to recycling of Archean crust derived from north Africa cratonic terranes.

关键词： Granulite xenoliths U-Pb geochronology Lu-Hf isotopes Calatrava Volcanic Field Spanish central system

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new insights into the pathophysiology of achalasia and implications for future treatment

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World Journal of Gastroenterology 2016年第35期22卷 7892-7907页

作者： Janette Furuzawa-Carballeda Samuel Torres-Landa Miguel ángel Valdovinos enrique Coss-Adame Luis A martín del Campo Gonzalo Torres-Villalobos Department of Immunology and Rheumatology Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán Department of Experimental Surgery Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán Department of Gastroenterology Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán

Idiopathic achalasia is an archetype esophageal motor disorder, causing significant impairment of eating ability and reducing quality of life. The pathophysiological underpinnings of this condition are loss of esophageal peristalsis and insufficient relaxation of the lower esophageal sphincter(LES). The clinical manifestations include dysphagia for both solids and liquids, regurgitation of esophageal contents, retrosternal chest pain, cough, aspiration, weight loss and heartburn. Even though idiopathic achalasia was first described more than 300 years ago, researchers are only now beginning to unravel its complex etiology and molecular pathology. The most recent findings indicate an autoimmune component, as suggested by the presence of circulating anti-myenteric plexus autoantibodies, and a genetic predisposition, as suggested by observed correlations with other well-defined genetic syndromes such as Allgrove syndrome and multiple endocrine neoplasia type 2 B syndrome. Viral agents(herpes, varicella zoster) have also been proposed as causative and promoting factors. Unfortunately, the therapeutic approaches available today do not resolve the causes of the disease, and only target the consequential changes to the involved tissues, such as destruction of the LES, rather than restoring or modifying the underlying pathology. new therapies should aim to stop the disease at early stages, thereby preventing the consequential changes from developing and inhibiting permanent damage. This review focuses on the known characteristics of idiopathic achalasia that will help promote understanding its pathogenesis and improve therapeutic management to positively impact the patient's quality of life.

关键词： Achalasia Treatment Autoimmune disease Pathophysiology

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Frozen ground and periglacial processes relationship in temperate high mountains: a case study at Monte Perdido-Tucarroya area(The Pyrenees, Spain)

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Journal of Mountain Science 2020年第5期17卷 1013-1031页

作者： SERRAnO enrique LóPEZ-MOREnO Juan Ignacio GóMEZ-LEnDE Manuel PISABARRO Alfonso martín-MOREnO Raúl RICO Ibai ALOnSO-GOnZáLEZ Esteban Dept of GeographyUniversity of ValladolidValladolid 47011Spain Dept of Geoenvironmental Processes and Global ChangePyrenean Institute of EcologyZaragoza 50.080Spain Dept.Specific Didactics.Autonom University of Madrid.Madrid 28049Spain Dept of GeographyPrehistory and ArcheologyUniversity of the Basque CountryVitoria 01006Spain

Seasonally frozen ground,mountain permafrost and cryogenic geomorphological processes are important components of the Pyrenean high *** work presents the results of a study on the distribution of frozen ground in a marginal and paraglacial environment of temperate *** inventory was made of landforms and indicators of frozen ground,and frozen ground was mapped *** 2014 and 2016 ground temperatures and thermal regimes were monitored,basal temperatures of snow-cover(BTS)were measured and a thermal map was *** thermal behaviours were detected among different elevations and slope *** processes are the most widespread,in which frost weathering and nivation,together with gelifluction and cryoturbation,are the most efficient processes;the latter two are generally linked to the presence of frozen *** fall in air and ground temperatures with altitude,slope orientations,and snowpack thickness and evolution determine ground thermal *** the study area,three types of thermal regimes were established:climate-controlled,snowcover-controlled,and frozen *** frozen ground occurs across a broad range of elevation between 2650 and 3075 m asl,whereas possible permafrost only occurs above 2750 m asl.

关键词： Geomorphology Periglacial Seasonally frozen ground Mountain permafrost Pyrenees

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Antifungal Activity of Crude Extracts of Tectona grandis L.f. against Wood DecayFungi

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Phyton-International Journal of Experimental Botany 2022年第8期91卷 1795-1808页

作者： enrique Cárcamo-Ibarra Mauro Manuel martínez-Pacheco Abril Munro-Rojas Jorge enrique Ambriz-Parra Crisanto Velázquez-Becerra Facultad de Ingeniería en Tecnología de la Madera Universidad Michoacana de San Nicolás de HidalgoMorelia58030México Instituto de Investigaciones Químico-Biológicas Universidad Michoacana de San Nicolás de HidalgoMorelia58030México

Wood is mainly made up of cellulose, hemicelluloses, lignin polymers and other organic and inorganic substances, making it susceptible to deteriorate by various biological agents. Tectona grandis L.f. (Teak) is a timberspecies with high resistance to biological deterioration, valued for its durability, beauty, and mechanical *** purpose of this work was to evaluate the antifungal activity of crude extracts from teak on various fungi thatcause wood deterioration. For this, Teak heartwood was obtained, then fragmented and pulverized until obtaininga flour which was used for compounds extraction using the Soxhlet technique coupled to a rotary evaporatorthrough solvents of increasing polarity (hexane, dichloromethane, tetrahydrofuran, and acetone). The extractsobtained were tested against fungal organisms collected in the field, and the LC50 was determined using teak crudeextracts on Artemia salina as a biological model. The results obtained showed that a high flour yield was obtainedwith hexane (0.951 g), followed by tetrahydrofuran (0.446 g), dichloromethane (0.348 g), and acetone (0.152 g). Byusing nine fungal organisms that predominantly correspond to the genus Aspergillus, the extractable compoundswere tested, inhibiting 25% of mycelial growth with tetrahydrofuran (T. versicolor), and 40.9% with dichloromethane(G. trabeum). Likewise, the biological model of A. salina showed an LC50 of 84.9 μg/mL with hexane, 43.3 μg/mLwith dichloromethane, 59.6 μg/mL with tetrahydrofuran, and 54.7 μg/mL with acetone. For this reason, it is concluded that Teak wood contains many extractable compounds in relation to its weight, besides having antimicrobialactivity when extracted through polar compounds such as dichloromethane and tetrahydrofuran.

关键词： Tectona grandis wood deterioration naphthoquinone antifungal activity wood protection

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Evidences supporting the vascular etiology of post-double balloon enteroscopy pancreatitis: Study in porcine model

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World Journal of Gastroenterology 2017年第34期23卷 6201-6211页

作者： Rafael Latorre Octavio López-Albors Federico Soria Esther Morcillo Pilar Esteban enrique Pérez-Cuadrado-Robles enrique Pérez-Cuadrado-martínez Department of Anatomy and Comparative Pathology University of Murcia Minimally Invasive Surgery Centre Jesús Usón Department of Gastroenterology Small Bowel UnitMorales Meseguer Hospital

Double balloon enteroscopy(DBE) is an endoscopic technique broadly used to diagnose and treat small bowel diseases. Among the associated complications of the oral DBE, post-procedure pancreatitis has taken the most attention due to its gravity and the thought that it might be associated to the technique itself and anatomical features of the pancreas. However, as the etiology has not been clarified yet, this paper aims to review the published literature and adds new results from a porcine animal model. Biochemical markers, histological sections and the vascular perfusion of the pancreas were monitored in the pig during DBE practice. A reduced perfusion of the pancreas and bowel, the presence of defined hypoxic areas and disseminated necrotic zones were found in the pancreatic tissue of pigs. All these evidences contribute to support a vascular distress as the most likely etiology of the post-DBE pancreatitis.

关键词： Double balloon enteroscopy Pancreas Animal model Pancreatitis Pig

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