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Relativistic charged stellar modeling with a perfect fluid sphere

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Communications in Theoretical Physics 2023年第9期75卷 113-121页

作者： Joaquin Estevez-delgado Joel Arturo Rodríguez Ceballos Jorge Mauricio Paulin-fuentes joséVega Cabrera antonio Rendón Romero Facultad de Ciencias Físico Matemáticas de la Universidad Michoacana de San Nicolás de Hidalgo Edificio BCiudad UniversitariaMorelia MichoacánCP 58040Mexico Facultad de Químico Farmacobiología de la Universidad Michoacana de San Nicolás de Hidalgo Tzintzuntzan No.173Col.MatamorosMorelia MichoacánC.P.58240Mexico División Académica de Ciencias Básicas de la Universidad Juárez Autónoma de Tabasco Carretera Cunduacán-Jalpa Km.1Col.La Esmeralda86690CunduacánTabascoMexico Facultad de Ingenieria Mecanica de la Universidad Michoacana de San Nicolás de Hidalgo Edificio W Ciudad UniversitariaCP 58030Morelia MichoacánMexico

In this report we present the generalization of a solution to Einstein's equations with perfect fluid for the case of Einstein–Maxwell with perfect *** effect of the charge is reflected by a parameter,ν,and its interval is determined by the positivity condition from the pressure in the interior of the *** is shown that the solution is stable according to the Zeldovich criteria as well as in relation to the criteria of the adiabatic *** compactness,u=GM/c^(2)R,of this charged model is greater than it is for the chargeless case as a result of the effect of the presence of the *** allows it to represent stars with a high compactness,in particular a graphic analysis is presented for the star SAX J1808.4-3658 with mass M=1.435M_(⊙)and radius R=7.07 *** these data and employing the solution,we obtain that the total maximum charge for the star is Q=2.4085×10^(20)C.

关键词： general relativity exact solutions charged fluid stars models

Healthcare use among people with diabetes mellitus in Europe:a population-based cross-sectional study

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Family Medicine and Community Health 2022年第4期10卷 16-23页

作者： Álvaro fuentes-Merlos joséantonio Quesada-Rico Raul Reina Domingo Orozco-Beltrán Faculty of Medicine Miguel Hernandez University of ElcheSant Joan D'AlacantSpain department of Sports Sciences Sport Research CentreMiguel Hernandez University of ElcheElcheSpain

Objective This study aimed to determine the association of health determinants,lifestyle and socioeconomic variables on healthcare use in people with diabetes in *** A cross-sectional study was conducted using data from the European Health Interview Survey wave 2(ie,secondary analysis).Setting The sample included data from 25 European *** The sample included 16270 patients with diabetes aged 15 years or older(49.1%men and 50.9%women).Results The survey data showed that 58.2%of respondents had seen their primary care physician in the past month and 22.6%had been admitted to the hospital in the past *** of primary care was associated with being retired(prevalence ratio(PR)1.13,95%CI 1.07 to 1.19)and having very poor self-perceived health(PR 1.80,95%CI 1.51 to 2.15),long-standing health problems(PR 1.14,95%CI 1.04 to 1.24),high blood pressure(PR 1.06,95%CI 1.03 to 1.10)and chronic back pain(PR 1.07,95%CI 1.04 to 1.11).Hospital admission was associated with very poor self-perceived health(PR 3.03,95%CI 2.14 to 4.31),accidents at home(PR 1.54,95%CI 1.40 to 1.69),chronic obstructive pulmonary disease(COPD)(PR 1.34,95%CI 1.22 to 1.47),high blood pressure(PR 1.08,95%CI 1.01 to 1.17),chronic back pain(PR 0.91,95%CI 0.84 to 0.98),moderate difficulty walking(PR 1.33,95%CI 1.21 to 1.45)and severe difficulty walking(PR 1.67,95%CI 1.51 to 1.85).Conclusions In the European diabetic population,the high cumulative incidences of primary care visits and hospital admissions are associated with labour status,alcohol consumption,self-perceived health,long-standing health problems,high blood pressure,chronic back pain,accidents at home,COPD and difficulty walking.

关键词： admitted sectional difficulty

A charged star with geometric Karmarkar condition

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Communications in Theoretical Physics 2023年第8期75卷 139-149页

作者： Gabino Estevez-delgado Joaquin Estevez-delgado Rafael Soto-Espitia antonio Rendón Romero Jorge Mauricio Paulin-fuentes Facultad de Químico Farmacobiología de la Universidad Michoacana de San Nicolás de Hidalgo Facultad de Ciencias Físico Matemáticas de la Universidad Michoacana de San Nicolás de Hidalgo Edificio BCiudad Universitaria Facultad de Ingeniería Civil de la Universidad Michoacana de San Nicolás de Hidalgo Edificio A Ciudad Universitaria Facultad de Ingeniería Mecánica de la Universidad Michoacana de San Nicolás de Hidalgo Edificio W Ciudad Universitaria División Académica de Ciencias Básicas de la Universidad Juárez Autónoma de Tabasco

In this paper,we analyse an analytical solution of the Einstein–Maxwell field equations that considers matter with anisotropic pressures in a static and spherically symmetric *** report the manner in which we obtained the solution,which is by means of the Karmarkar *** the model,we assume a state equation that describes the interaction of matter from quarks P=(c^(2)ρ-4B_(g))/3 and we consider the presence of electric charge,which can generate that the radial and tangential pressures are not *** a graphic manner,we analyse the physical properties of the model,taking as the observational data those of mass 1M⊙and radius7.69 km which were reported for the star Her *** charge values are found between 5.57×10^(18)C≤Q≤1.31×10^(20)C and the interval of the Bag constant Bg∈[118.7,122.13]MeV/fm^(3).Also,we show the stability of the configuration by means of the static stability criteria of Harrison–Zeldovich–Novikov((?M)/?ρc>0),as well as in regards to infinitesimal radial adiabatic perturbation,since the adiabatic indexγ>3.3 which guarantees the stability of the solution.

关键词： general relativity exact solutions anisotropic fluid Karmarkar condition

Cities and Methods from Complexity Science

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Journal of Systems Science & Complexity 2016年第5期29卷 1177-1186页

作者： BALMACEDA Beatriz fuentes Miguel CIdeS Corpotraining Av. Providencia 2370 Santiago Chile Santa Fe Institute 1399 Hyde Park Road Santa Fe New Mexico 87501 USA IIF-Sadaf/CONICET Bulnes 642 Buenos Aires 1176 Argentina Facultad de Ingenieria y Tecnologla Universidad San Sebastidn Lota 2465 Santiago 7510157 Chile

The dynamics of human society is now been studying in the context of the artificial environment created by cities. In this work, the authors describe some of the formal methods used in complexity science to study urban systems. The authors discuss some of the important quantitative approaches on cities paying attention to some of the deepest controversies in present scientific *** authors will stress the importance of a transdisciplinary approach when studying this type of cooperative social environments.

关键词： Cities complexity environment.

Atmospheric-pressure dielectric barrier discharge generation by a full-bridge flying capacitor multilevel inverter

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Plasma Science and Technology 2017年第7期19卷 40-49页

作者： Rosendo PE?A-EGUILUZ josé A LóPEZ-FERNáNdeZ antonio MERCADO-CABRERA Bethsabet JARAMILLO-SIERRA Régulo LóPEZ-CALLEJAS Benjamín RODRíGUEZ-MéNdeZ Raúl VALENCIA-ALVARADO Allan A FLORES-fuentes Arturo E MU?OZ-CASTRO Plasma Physics Laboratory Instituto Nacional de Investigaciones Nucleares Tecnológico de Estudios Superiores de Tianguistenco Universidad Autónoma del Estado de México

A new configuration of a resonant full-bridge flying capacitor multicell inverter has been designed and constructed with the aim of achieving an extended output voltage frequency range with low harmonic distortion and reduced semiconductor commutation losses. This configuration was tested as a power supply for two different coaxial dielectric barrier discharge reactors, one of them employed for electric characterization and the other one for inorganic compound elimination in an aqueous solution. Two different gas mixtures, 90% Ar-10% 02 and 80% Ar-20% 02, were individually supplied during the experiments; the results showed a high- efficiency removal of meta-cresol （m-cresol） to the order of 98%, which was obtained by adding more oxygen to the plasma gas mixture.

关键词： plasma applications water pollution plasma sources power supply circuits electricdischarges

Potential seed germination-enhancing plant growth-promoting rhizobacteria for restoration of Pinus chiapensis ecosystems

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Journal of Forestry Research 2021年第5期32卷 2143-2153页

作者： Cristina Domínguez-Castillo Julia María Alatorre-Cruz Dolores Castañeda-antonio jose antonio Munive Xianwu Guo Jesús Francisco López-Olguín Luis Ernesto fuentes-Ramírez Ricardo Carreño-López Centro de Investigaciones en Ciencias Microbiológicas Instituto de CienciasBenemérita Universidad Autónoma de PueblaPueblaMéxico Universidad Autónoma de Querétaro QuerétaroMéxico Centro de Biotecnología Genómica Instituto Politécnico NacionalReynosaTamaulipasMéxico

Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting *** isolates that showed promise were identified to five genera Dyella,Luteimonas,Euterobacter,Paraburkholderia and Bacillus based on the sequences of16 S rRNA *** the strains were isolated from nondisturbed *** bacteria significantly decreased germination time and increased sprout *** acetic acid and gibberellin production and phosphate solubilisation were *** indicate that these biochemicals could be essential for *** distribution and suggest the possibility that PGPR inoculation on *** seeds prior to planting could improve germination and possibly seedling development.

关键词： Pinus chiapensis Plant growth-promoting rhizobacteria Dyella Luteimonas Enterobacter

Acceptance of living liver donation among medical students: A multicenter stratified study from Spain

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World Journal of Gastroenterology 2016年第25期22卷 5800-5813页

作者： antonio Ríos Ana Isabel López-Navas Ana Isabel López-López Francisco Javier Gómez Jorge Iriarte Rafael Herruzo Gerardo Blanco Francisco Javier Llorca Angel Asunsolo Pilar Sánchez-Gallegos Pedro Ramón Gutiérrez Ana Fernández María Teresa de Jesús Laura Martínez-Alarcón Alberto Lana Lorena fuentes Juan Ramón Hernández Julio Virseda josé Yelamos josé antonio Bondía antonio Miguel Hernández Marco antonio Ayala Pablo Ramírez Pascual Parrilla International Collaborative Donor Project ('Proyecto Colaborativo Internacional Donante' 30007 Casillas Murcia Spain department of Surgery Paediatrics Obstetrics and Gynaecology University of Murcia Avenida de las Fuerzas Armadas 30800 Espinardo Murcia Spain Transplant Unit Surgery Service IMIB - Virgen de la Arrixaca University Hospital Carretera Madrid-Cartagena s/n 30120 El Palmar Murcia Spain Regional Transplant Centre Consejeria de Sanidad y Consumo de la Region de Murcia 30008 Ronda de Levante Murcia Spain Hospital Clinico Universitario Virgen de la Arrixaca Departamento de Cirugia General y del Aparato Digestivo Unidad de Trasplantes 30007 Casillas Murcia Spain department of Psychology Universidad Catolica San Antonio (UCAM) Avenida de los Jeronimos 30107 Guadalupe Murcia Spain department of Urology San Juan University Hospital of Alicante 03010 Calle Pintor Baeza Alicante Spain Universidad de Granada Avenida del Hospicio s/n 18010 Granada Spain Universidad de Navarra Campus Universitario 31080 Pamplona Navarra Spain Universidad Autonoma de Madrid Ciudad Universitaria de cantoblanco 28049 Madrid Spain Servicio de Cirugia HBP y Trasplante Hepatico Complejo Hospitalario Universitario de Badajoz Hospital Infanta Cristina Avenida Elvas s/n 06006 Badajoz Spain Universidad de Cantabria Avenida los Castros s/n 39005 Santander Cantabria Spain departamento de Cirugia Ciencias Medicas y Sociales Facultad de Medicina y Ciencias de la Salud Universidad de Alcala Campus Cientifico-Tecnologico Plaza de San Diego s/n 28801 Alcala de Henares Madrid Spain Facultad de Medicina Universidad de Malaga 29071 Avenida de Cervantes Malaga Spain Servicio de Urologia (Complejo Hospitalario Universitario de Canarias CHUC) y Departamento de Cirugia (Universidad de La Laguna ULL) Calle Molinos de Agua s/n 38207 San Cristobal de La Laguna Santa Cruz de Tenerife Spain departamento de Ciencias Biomedicas Basicas Facultad de Ciencias Biomedicas Universidad Europea de

AIM: To analyze the attitude of Spanish medical students toward living liver donation (LLD) and to establish which factors have an influence on this ***: Study type: A sociological, interdisciplinary, multicenter and observational study. Study population: Medical students enrolled in Spain (n = 34000) in the university academic year 2010-2011. Sample size: A sample of 9598 students stratified by geographical area and academic year. Instrument used to measure attitude: A validated questionnaire (PCID-DVH RIOS) was self-administered and completed anonymously. Data collection procedure: Randomly selected medical schools. The questionnaire was applied to each academic year at compulsory sessions. Statistical analysis: Student´s t test, χ2 test and logistic regression ***: The completion rate was 95.7% (n = 9275). 89% (n = 8258) were in favor of related LLD, and 32% (n = 2937) supported unrelated LLD. The following variables were associated with having a more favorable attitude: (1) age (P = 0.008); (2) sex (P demic year (P de toward deceased donation (P de toward living kidney donation (P ded (P dents have a favorable attitude toward LLD.

关键词： Attitude Living liver donation Medical students Transplantation Organ donation Psychosocial variables Spain

New semi-analytical approach for ice lens heaving during artificial freezing of fine-grained material

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第11期15卷 2994-3009页

作者： K.Niggemann R.fuentes Institute of Geomechanics and Underground Technology RWTH Aachen UniversityAachenGermany

The calculation of frost heaving with ice lens formation is still not standard for construction projects using artificial ground freezing(AGF).In fine-grained material,ice lenses may initiate and lead to significant heaving at the ground surface,which should be considered in ***,the complex processes during ice lens formation are still not fully understood and difficult to capture in a simple *** the past,the semi-analytical approach of Konrad and Morgenstern used one soil constant,the“segregation potential(SP)”.It has been mainly and most successfully applied to the heave calculation of natural-induced soil freezing in cold *** application to AGF has been so far *** solve this,a new semi-analytical approach is presented in this *** includes AGF conditions such as bottom-up freezing,temperature gradients to reach great freezing velocities,and a distinction between two freezing *** is the freezing-up state until a certain frost body thickness is reached(thermal transient state),and the other is a holding phase where the frost body thickness is kept constant(thermal quasi-steady state).To test its ability,the results are applied to another freezing direction,the top-down *** new approach is validated using two different frost-susceptible soils and,in total,50 frost heave *** the thermal transient region,where the SP is applicable,the two semi-analytical approaches are compared,showing improved performance of the current method by about 15%.

关键词： Semi-analytical approach Ice lens formation Frost heaving Bottom freezing Segregation potential Frost-susceptible soil

Evaluation of patient visual comfort and repeatability of refractive values in non-presbyopic healthy eyes

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International Journal of Ophthalmology(English edition) 2015年第5期8卷 1031-1036页

作者： Francisco Segura Ana Sanchez-Cano Carmen Lopez de la Fuente Lorena fuentes-Broto Isabel Pinilla department of Surgery Gynaecology and ObstetricsUniversity of Zaragoza Aragon Health Sciences Institute University of Zaragoza department of Applied Physics University of Zaragoza department of Physiology and Pharmacology University of Zaragoza department of Ophthalmology Lozano Blesa University Hospital

AIMTo evaluate the intra-operator repeatability in healthy subjects using the WAM-5500 auto-kerato/refractometer and the iTrace aberrometer, to compare the refractive values and the subjective refraction obtained with both devices and to determine which of these three spherocylindrical corrections allows the subject to achieve the best visual ***-two non-presbyopic healthy eyes of 42 subjects were enrolled in this prospective study. Refractive values were compared, evaluating the repeatability, the relationship between the methods and the best visual comfort ***, cylinder and axis results showed good intraclass correlation coefficients (ICC); the highest ICC was obtained using the spherical refraction with the autorefractometer and the aberrometer, achieving levels of 0.999 and 0.998, respectively. The power vector (PV) was calculated for each refraction method, and the results indicated that there were no statistically significant differences between them (P>0.05). Direct comparison of PV measurements using the three methods showed that aberrometer refraction gave the highest values, followed by the subjective values; the autorefractometer gave the lowest values. The subjective method correction was most frequently chosen as the first selection. Equal values were found for the autorefractometer and the aberrometer as the second *** iTrace aberrometer and the WAM-5500 auto-kerato/refractometer showed high levels of repeatability in healthy eyes. Refractive corrections with the aberrometer, the autorefractometer and subjective methods presented similar results, but spherocylindrical subjective correction was the most frequently selected option. These technologies can be used as complements in refractive evaluation, but they should not replace subjective refraction.

关键词： repeatability optical correction aberrometer autorefractometer subjective refraction