检索结果-南通市图书馆

Journal of Environmental Protection 2011年第9期2卷 1143-1148页

作者： Guillermo espinosa Richard Gammage 不详

In this paper we present the results of a survey of indoor radon concentration levels in Mexico. In order to investigate whether differences in climate translate into significant differences in indoor radon concentrations, the country was divided into three climate regions: the northern semi-desert region, the central semitropical region and the southern tropical region. The survey was carried out using nuclear track methodology. The dosimeters employed for the survey were based on the passive closed-end cup device, developed at the Physics Institute of the National Autonomous University of Mexico, and used PADC as detector material. A well-established protocol for chemically etching and reading the detectors was followed. Average annual temperatures differ between regions (from 15℃ to 28℃) but vary relatively little within each region. Atmospheric temperature is one of the most important factors which need to be considered when carrying out a survey of indoor radon concentrations because temperature largely determines building ventilation habits, and ventilation habits are known to have significant effects on indoor radon concentrations. Other factors, including building construction materials, architectural styles, geological and hydrological characteristics, and seismicity, vary from region to region and within each region. In each of the three regions low levels of indoor radon (from 37 to 179 Bq·m-3) were found.

关键词： Radon Indoor Radon Climate Influence Nuclear Tracks Methodology

Integrated Sport： From Theory to Practice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Sports Science 2016年第2期4卷 80-92页

作者： Angela Magnanini Pau espinosa Department of Movement Human and Health Sciences University of "Foro ltalico " Rome 00135 Italy

This paper is articulated in two parts. The first one has a theoretical approach in order to put the basis of an Integrated Sport model, built through Special Education principles. On the second part, the questionnaire which has been developed by the theoretical approach basis analysis tries to highlight Integrated Sport essence, focusing on the participants （athletes with and without disability） of the First European Day of Integrated Sport organized in Rome, from the 22nd to the 24th of May. It will look for clarify the necessity of creating the ＂third way of Sports＂ where people with and without disabilities play together in the same time and context, on the equal opportunities basis and active participation. In the research, 82 people （male n = 53; females n = 29） were selected, of which 50 did not have any kind of disability while the remaining 32 had any disability, from twelve different countries （Italy, Spain, Lithuania, Slovenia, Greece, France, Romania, Turkey, Germany, Portugal, UK and Poland）, taking part in the Sport Day event as athlete, trainer, organizer, familiar or others. The medium age of participants was 31.7 years.

关键词： Integrated Sport integration Special Education disability.

State Variable Model for Considering the Parasitic Inductor Resistance on the Open Loop Performance of DC to DC Converters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Computer and Communications 2014年第13期2卷 41-48页

作者： Carlos Alberto Lozano espinosa Pontificia Universidad Javeriana Santiago de Cali Colombia

This paper shows DC and small-signal circuit models for the PWM DC to DC buck, boost and back/ boost converters with the equivalent series resistance of the inductor. The DC voltage transfer function and the efficiency of the converter are derived from the DC model. Small-signal open-loop characteristics are derived from the small-signal model based on a state variable model. A design example proves the performance of the circuit and verification of the model.

关键词： DC to DC Converter Parasitic Resistance of Inductor Small Signal Analysis Buck Converter Boost Converter Buck-Boost Converter

Diversity, Endemism and Conservation of Ferns(Polypodiales) in the Mexican Mountain Component

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2015年第4期12卷 891-904页

作者： SANGINéS-FRANCO Celia LUNA-VEGA Isolda CONTRERAS-MEDINA Raúl espinosa David TEJERO-DíEZ José Daniel RIVAS Gerardo Laboratorio de Biogeografía y Sistemática Departamento de Biología Evolutiva Facultad de Ciencias Universidad Nacional Autónoma de México (UNAM) Escuela de Ciencias Universidad Autónoma "Benito Juárez" de Oaxaca (UABJO) Av.Universidad s/n Ex Hacienda de Cinco Se?ores Oaxaca de Juárez CP 68120 Oaxaca México Facultad de Estudios Superiores Zaragoza Unidad Multidisciplinaria de Investigación Experimental ZaragozaUniversidad Nacional Autónoma de México (UNAM) Carrera de Biología Facultad de Estudios Superiores Iztacala Universidad Nacional Autónoma de México MéxicoAvenida de los Barrios Número 1 Colonia Los Reyes Iztacala Tlalnepantla CP 54090 Estado de México México Laboratorio de Biogeografía Acuática Departamento de Biología Comparada Facultad de Ciencias Universidad Nacional Autónoma de México (UNAM)

We analyzed the distributional patterns of95 selected species of leptosporangiate ferns inhabiting the Mexican Mountain Component, using grid-cells of one geographical degree as unit areas,applying endemism indices and richness and beta diversity *** data were obtained from several herbaria and specialized *** grid-cells appear to be important for fern species richness, as they contain 35 to 49 *** gridcells are located in the Sierra Madre Oriental(SMO),Trans-Mexican Volcanic Belt(TMVB) and the Sierra Madre del Sur(SMS).Mean richness by latitudinal belts of one degree showed that the belts with highest values are related to the TMVB and SMS.A total of 13grid-cells were recognized as important from theperspective of endemism; most of them are located also in the SMO, TMVB and *** richest gridcells coincided with one of the main centres of endemism for ferns obtained in this study, located in the convergence of the southern part of the SMO, the eastern portion of the TMVB and the northern part of the SMS, reflecting the high humidity existing on the mountain slopes facing the Gulf of *** important grid-cells recognized from richness and endemism analyses coincide with Mexican Natural Protected *** beta diversity analysis showed a low degree of similarity among grid-cells, implying a high species replacement, as the result of environmental heterogeneity occurring in the Mexican mountain *** the other hand, the spatial analysis suggested a pattern of phytogeographical regionalization comprising twomain areas: the Mexican Transition Zone and the Mexican Central *** play an important role in the Mexican biodiversity and contributing to the beta diversity of Mexico.

关键词： Biogeography Distributional patterns Leptosporangiate ferns Mexico

Multi-objective parametrization of interatomic potentials for large deformation pathways and fracture of two-dimensional materials

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 1042-1052页

作者： Xu Zhang Hoang Nguyen Jeffrey T.Paci Subramanian K.R.S.Sankaranarayanan Jose L.Mendoza-Cortes Horacio D.espinosa Theoretical and Applied Mechanics Program Northwestern UniversityEvanstonILUSA Department of Chemistry University of VictoriaVictoriaBCCanada Center for Nanoscale Materials Argonne National LaboratoryLemontILUSA Department of Chemical Engineering&Materials Science Michigan State UniversityEast LansingMIUSA Department of Mechanical Engineering Northwestern UniversityEvanstonILUSA

This investigation presents a generally applicable framework for parameterizing interatomic potentials to accurately capture large deformation *** incorporates a multi-objective genetic algorithm,training and screening property sets,and correlation and principal component *** framework enables iterative definition of properties in the training and screening sets,guided by correlation relationships between properties,aiming to achieve optimal parametrizations for properties of ***,the performance of increasingly complex potentials,Buckingham,Stillinger-Weber,Tersoff,and modified reactive empirical bond-order potentials are *** MoSe_(2)as a case study,we demonstrate good reproducibility of training/screening properties and superior *** MoSe_(2),the best performance is achieved using the Tersoff potential,which is ascribed to its apparent higher flexibility embedded in its functional *** results should facilitate the selection and parametrization of interatomic potentials for exploring mechanical and phononic properties of a large library of two-dimensional and bulk materials.

关键词： materials apparent enable

Helminth parasites of freshwater fishes from Cuatro Ciénegas,Coahuila,in the Chihuahuan Desert of Mexico:inventory and biogeographical implications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2014年第3期9卷 328-339页

作者： Rogelio AGUILAR-AGUILAR Andrés MARTÍNEZ-AQUINO Héctor espinosa-PÉREZ Gerardo PÉREZ-PONCE DE LEÓN Comparative Biology Department National Autonomous University of MexicoMexico CityMexico Laboratory of Helminthology National Autonomous University of MexicoMexico CityMexico Graduate Program in Biological Sciences National Autonomous University of MexicoMexico CityMexico National Collection of Fish National Autonomous University of MexicoMexico CityMexico

As part of an ongoing inventory of the helminth parasites of freshwater fishes in Mexico, 570 individual fish were collected between Apr 2008 and Oct 2011 in 26 localities along the Cuatro Ciénegas region in Coahuila State, northern Mexico. Seventeen species of hosts, mostly corresponding to Nearctic freshwater elements, were studied. A total of 8324 individual worms were collected during this survey, representing 25 species of helminths, of which 9 were digeneans, 3 monogeneans, 3 acanthocephalans, 9 nematodes and 1 cestode. Most of the records in this checklist represent new host or locality records. The information provided in this checklist may be helpful for our understanding of the biodiversity and historical biogeography of this host-parasite system, because in the Cuatro Ciénegas region occur a Nearctic freshwater fish fauna, along with Neotropical and endemic elements, and from a biogeographical point of view, this may represent a transitional area.

关键词： Acanthocephala Cestoda Cuatro Ciénegas Digenea freshwater fish Mexico Monogenea Nematoda

Influence of in vitro capacitation time on structural and functional human sperm parameters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2020年第5期22卷 447-453页

作者： Paula Saez-espinosa Natalia Huerta-Retamal Laura Robles-Gomez Manuel Aviles Jon Aizpurua Irene Velasco Alejandro Romero Maria Jose Gomez-Torres Department of Biotechnology Faculty of ScienceUniversity of AlicanteAlicante 03080Spain FISABI0-University Hospital of San Juan de Alicante Service of Gynecology and ObstetricsSan Juan de Alicante 03550Spain Departm ent of Cell Biology and Histology Faculty of MedicineUniversity of Murcia and IMIB-ArrixacaMurcia 30100Spain IVF Spain Reproductive MedicineAlicante 03540Spain University Hospital of San Juan de Alicante Service of Gynecology and ObstetricsSan Juan de Alicante 03550Spain Human Fertility Cathedra University of AlicanteAlicante 03080Spain.

A cascade of dramatic physiological events is linked to the sperm acrosome reaction and binding to the oocyte's zona pellucida during human sperm ***,structural and functional sperm changes during capacitation currently remain poorly ***,we performed a multibiomarker approach based on the utilization of sperm concentration,motility,viability,morphology,acrosome reaction,tyrosine phosphorylation,DNA fragmentation,and lectin-binding sites to analyze the impact caused by swim-up selection times(uncapacitated,1 h capacitated,and 4 h capacitated)on sperm function and structure in normozoospermic *** found that a 4 h swim-up capacitation increased sperm quality,because a large number of cells with normal morphology and lower DNA fragmentation rates were ***,the long-term capacitation induced a higher percentage of cells with tyrosine phosphorylation of the principal piece as well as a redistribution of lectin-binding ***,the multivariate biomarkers analyzed showed a less variable distribution on spermatozoa recovered after 4 h capacitation than that with the shorter capacitation *** findings stress the importance of capacitation time as a relevant factor in sperm quality with potential biological reproductive implications both for basic research and in assisted reproduction techniques.

关键词： acrosome reaction capacitation DNA fragmentation glycocalyx lectin-binding sites membrane integrity protein phosphorylation sperm selection

Prevalence of refractive errors in school-aged and preadolescent children in Colombia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第12期17卷 2288-2294页

作者： Diana Garcia-Lozada Diana Valeria Rey-Rodríguez Sara Viviana Angulo-Sánchez Jenny Maritza Sánchez-espinosa Universidad El Bosque Facultad de MedicinaPrograma de OptometríaGrupo de investigación Salud visual y ocular UnBosqueBogotáD.C.110110Colombia Fundación Universitaria delÁrea Andina Programa de OptometríaBogotáD.C.110110Colombia

AIM:To describe the distribution of refractive errors by age and sex among schoolchildren in Soacha,***:This was an observational cross-sectional study conducted in five urban public schools in the municipality of Soacha.A total of 1161 school-aged and pre-adolescent children,aged 5-12y were examined during the school year *** included visual acuity and static *** equivalent(SE)was analysed as follows:myopia SE≤-0.50 D and uncorrected visual acuity of 20/25 or worse;high myopia SE≤-6.00 D;hyperopia SE≥+1.00 D(≥7y)or SE≥+2.00 D(5-6y);significant hyperopia SE≥+3.00 *** was defined as a cylinder in at least one eye≥1.00 D(≥7y)or≥1.75 D(5-6y).If at least one eye was ametropic,children were classified according to the refractive error ***:Of the 1139 schoolchildren included,50.6%were male,58.8%were aged between 5 and 9y,and 12.1%were already using optical *** most common refractive error was astigmatism(31.1%),followed by myopia(20.8%)and hyperopia(13.1%).There was no significant relationship between refractive error and *** was a significant increase in astigmatism(P<0.001)and myopia(P<0.0001)with ***:Astigmatism is the most common refractive error in children in an urban area of *** decreased and myopia increased with age.

关键词： Colombia prevalence refractive errors myopia hyperopia astigmatism children

Manipulating the Gut Microbiome to Alleviate Steatotic Liver Disease:Current Progress and Challenges

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2024年第9期40卷 51-60页

作者： Ernesto Saenz Nathally espinosa Montagut Baohong Wang Christoph Stein-Thöringer Kaicen Wang Honglei Weng Matthias Ebert Kai Markus Schneider Lanjuan Li Andreas Teufel Division of Hepatology Division of Clinical BioinformaticsDepartment of Medicine ⅡMedical Faculty MannheimHeidelberg UniversityMannheim 68167Germany Clinical Cooperation Unit Healthy Metabolism Center for Preventive Medicine and Digital HealthMedical Faculty MannheimHeidelberg UniversityMannheim 68167Germany School of Medicine Universidad de Los AndesBogotá111711Colombia State Key Laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Center for Infectious DiseasesCollaborative Innovation Center for Diagnosis and Treatment of Infectious DiseasesThe First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Internal MedicineⅠ University Clinic Tuebingen&CoE CMFI(Controlling Microbes to Fight Infections)Tuebingen 72074Germany Department of MedicineⅡ Medical Faculty MannheimHeidelberg UniversityMannheim 68167Germany DKFZ Hector Cancer Institute at the University Medical Center Mannheim 69120Germany Molecular Medicine Partnership Unit European Molecular Biology LaboratoryHeidelberg 69117Germany Department of MedicineⅢ University Hospital RWTH AachenAachen 52074Germany

The prevalence of metabolic-dysfunction-associated steatotic liver disease(MASLD)is alarmingly high;it is estimated to affect up to a quarter of the global population,making it the most common liver disorder *** is characterized by excessive hepatic fat accumulation and is commonly associated with comorbidities such as obesity,dyslipidemia,and insulin resistance;however,it can also manifest in lean ***,it is crucial to develop effective therapies for this complex ***,there are no approved medications for MASLD treatment,so there is a pressing need to investigate alternative *** research has characterized MASLD as a multifaceted disease,frequently linked to metabolic disorders that stem from dietary *** suggests that changes in the gut microbiome play a fundamental role in the development and progression of MASLD from simple steatosis to steatohepatitis and even hepatocellular carcinoma(HCC).In this review,we critically examine the literature on the emerging field of gut-microbiota-based therapies for MASLD and metabolicdysfunction-associated steatohepatitis(MASH),including interventions such as fecal microbiota transplantation(FMT),probiotics,prebiotics,short-chain fatty acids,antibiotics,metabolic pathway targeting,and immune checkpoint kinase blockade.

关键词： Microbiome Fecal microbiota transplantation Metabolic-dysfunction-associated steatotic liver disease Fatty liver

Tumor invasion front in oral squamous cell carcinoma

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第28期10卷 10387-10390页

作者： Juan Carlos Cuevas-González Maria Veronica Cuevas-González Leon Francisco espinosa-Cristobal Alejandro Donohue Cornejo Institute of Biomedical Sciences Universidad Autonoma de Ciudad JuarezJuarez 32320ChihuahuaMexico Faculty of Health Sciences Valle de las Palmas Universidad Autonoma de Baja CaliforniaTijuana 21480Baja CaliforniaMexico

Oral squamous cell carcinoma is a neoplasm that originates from the epithelial *** is usually more frequent between the fifth and sixth decades of life,and more than 90% of carcinomas of the oral cavity are squamous cell *** is an invasive neoplasia with a significant recurrence rate;40% of patients present with metastases in the cervical lymph nodes at the time of *** tumor invasion front is a characteristic of tumor growth,which can be infiltrative or *** histopathological parameters examined include the number of mitoses,depth of the tumor,invasion pattern,degree of keratinization,and nuclear *** the pathologist,these parameters are routinely evaluated but are not reported to the treating physician in all cases,which we consider to be useful information when determining the therapeutic route.

关键词： Oral squamous cell carcinoma Invasive neoplasia Therapeutic route Life Tumor growth Pleomorphism