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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

Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAD-7) functionalized with D_(2)EHPA

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Journal of rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： P.A.Martínez-Montoya R.G.Sanchez-alvarado D.Y.Medina-Velazquez M.l.Carrera-Jota P.Garnica-Chávez A.de J.Morales-ramirez Higher School of Chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for Research and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/l Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/l)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/l ratio of 10 mg/ml The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/l [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery rare earth solid-liquid extraction XAD-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

A comprehensive review of genetic causes of obesity

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World Journal of Pediatrics 2024年第1期20卷 26-39页

作者： Marcio Jose Concepcion-Zavaleta Juan Eduardo Quiroz-Aldave Maria del Carmen Durand-Vasquez Elman Rolando Gamarra-Osorio Juan del Carmen valencia de la Cruz Claudia Mercedes Barrueto-Callirgos Susan luciana Puelles-leon Elena de Jesus alvarado-leon Frans leiva-Cabrera Francisca Elena Zavaleta-Gutierrez luis Alberto Concepcion-Urteaga Jose Paz-Ibarra Universidad Cientifica del Sur Bolivar 2150 AvenuePueblo Libre15084LimaPeru Division of Medicine Hospital de Apoyo ChepénChepenPeru Division of Family Medicine Hospital de Apoyo ChepénChepenPeru Division of Endocrinology Hospital Victor Lazarte EchegarayTrujilloPeru Division of Pediatrics Hospital de Apoyo ChepenChepenPeru Division of Internal Medicine Hospital de Apoyo ChepenChepenPeru Division of Genetics Universidad Nacional de TrujilloTrujilloPeru Division of Neonatology Hospital Belen de TrujilloTrujilloPeru Division of Internal Medicine Universidad Nacional de TrujilloTrujilloPeru Department of Medicine School of MedicineUniversidad Nacional Mayor de San MarcosLimaPeru

Background Obesity is a multifactorial chronic disease with a high,increasing worldwide *** causes account for 7%of the cases in children with extreme *** sources This narrative review was conducted by searching for papers published in the PubMed/MEDlINE,Embase and SciElO databases and included 161 *** search used the following search terms:"obesity","obesity and genetics","leptin","Prader-Willi syndrome",and"melanocortins".The types of studies included were systematic reviews,clinical trials,prospective cohort studies,cross-sectional and prospective studies,narrative reviews,and case *** The leptin-melanocortin pathway is primarily responsible for the regulation of appetite and body ***,several important aspects of the pathophysiology of obesity remain *** causes of obesity can be grouped into syndromic,monogenic,and polygenic causes and should be assessed in children with extreme obesity before the age of 5 years,hyperphagia,or a family history of extreme obesity.A microarray study,an analysis of the melanocortin type 4 receptor gene mutations and leptin levels should be performed for this *** are three therapeutic levels:lifestyle modifications,pharmacological treatment,and bariatric *** Genetic study technologies are in constant development;however,we are still far from having a personalized approach to genetic causes of obesity.A significant proportion of the affected individuals are associated with genetic causes;however,there are still barriers to its approach,as it continues to be underdiagnosed.

关键词： leptin Melanocortin Obesity Prader-Willi syndrome Precision medicine

From BIM model to 3D construction printing:A framework proposal

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Frontiers of Architectural Research 2024年第4期13卷 912-927页

作者： Rodrigo García-alvarado Pedro Soza Ginnia Moroni Fernando Pedreros Martín Avendaño Pablo Banda Cristian Berríos Depto.Diseño y Teoría de la Arquitectura Universidad Del Bío-BíoConcepciónChile Depto.Arquitectura Universidad de ChileSantiagoChile Facultad de Ingeniería Arquitectura y DiseñoUniversidad San SebastiánConcepciónChile Facultad de Arquitectura Arte y DiseñoUniversidad Diego PortalesSantiagoChile

The growth of 3D construction printing needs appropriate integration into the planning and execution phases of building *** this aim,the Architecture,Engineering,and Construction sector(AEC)has been increasingly adopting building information modeling(BIM)systems to synchronize design and construction *** study proposes a technical workflow to manage 3D construction printing into BIM models,evaluating various procedures according to construction element *** on mature software platforms,the research details the data transfer process using a case study of a single-story *** case delves into design procedures for constructing walls of varied shapes,adjustments in width,joints,openings,textures,fillings,and the insertion of reinforcements and services while also discussing requirements of other building *** steps for managing design information and controlling printing machines are *** study’s outcome presents a comprehensive information flow,encompassing model segmentation,geometric data transfer,adjustments of details,and the generation of printing ***,it is offered a discussion that underlines the importance of a synergistic digital information flow that merges both design and execution phases,promoting construction efficiency and the embrace of innovative *** contribution of the paper focuses on technical design strategies for 3D construction printing,but also on suggesting an integrated process.

关键词： 3D construction printing Additive manufacturing Architectural design BIM

Effects of Phytoremediation on Soil Contaminated with Pb and Cd in Tolerant Bacterial Populations

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Journal of Environmental Science and Engineering(A) 2024年第4期13卷 122-127页

作者： Alejandra Vásquez María Montes Melissa Cervantes María alvarado Pedro García Victor Aguilar Department of Environmental Engineering Institute for EngineeringUniversity of VeracruzBoca del RioVer.94294Mexico Department Chemical Engineering Faculty of Chemical SciencesUniversity of VeracruzBoca del RíoVer.94294Mexico Faculty of Environmental Engineering Popular Autonomous University of the State of PueblaBarrio de Santiago 72410PueblaPueMexico Department of Administration Open Education SystemUniversity of VeracruzBoca del RioVer.94294Mexico

Bacterial populations isolated from treated soil,artificially contaminated with lead(Pb)and cadmium(Cd)and undergoing a phytoremediation process were studied to determine their potential application in soil *** physicochemical parameters evaluated in the soil varied *** bacterial strains were selected from each polluted soil to test tolerance and growth in contaminated *** concentrations of heavy metals tested were 1,000 ppm for lead and 850 ppm for *** strains were morphologically identified through Gram *** strains showing the most significant growth in both contaminants were then selected to verify their tolerance to different concentrations of heavy *** results demonstrated that the selected bacteria have high tolerance to Pb,resisting inhibition up to 2,000 *** contrast,strains exposed to cadmium tended to slow their growth as the concentration increased.

关键词： lead cadmium soil bacteria remediation

Evaluation of Clinical Characteristics and Plasma Cortisol Concentrations in Individuals with COVID-19 and Post-COVID Syndrome

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Case Reports in Clinical Medicine 2024年第1期13卷 12-24页

作者： David Alejandro García lópez Stephania ramos Hernández Yamile lópez-Hernández María Argelia lópez luna Elena Donaji ramírez alvarado Rosa María ramírez Santoyo Sergio Hugo Sánchez Rodríguez laboratorio de Biología Celular y Neurobiología Universidad Autónoma de Zacatecas México Zacatecas Unidad Académica de Ciencias Químicas Universidad Autónoma de Zacatecas México Zacatecas laboratorio de Metabolómica y Proteómica Universidad Autónoma de Zacatecas México Zacatecas laboratorio de Bacterias y Hongos filamentosos Universidad Autónoma de Zacatecas México Zacatecas

COVID-19 generates systematic alterations in humans both in active stages of infection and over time, called post-COVID syndrome. Cortisol is a hormone that is overexpressed in inflammation and cellular stress processes. Its main function is to return to physiological homeostasis, so its evaluation together with other clinical parameters can allow us to determine the degree of systemic affectation by COVID-19. Objective: To evaluate changes in clinical parameters and plasma cortisol concentrations in patients with active COVID-19 and post-COVID syndrome. Material and Methods: Healthy patients, in stages of mild infection, critical and with post-COVID syndrome, were recruited, obtaining, through clinical diagnoses and interviews, their main clinical characteristics, in addition to plasma, in which cortisol concentrations were determined using competitive ElISA. Results: The critical stage group had higher frequencies of comorbidities, clinical symptoms, as well as more altered laboratory parameters compared to the other subgroups. In the post-COVID syndrome group after the initial infection, most laboratory parameters recovered, however, several clinical symptoms remained latent over time. The determination of cortisol showed an increase in its concentration, being higher in patients in critical stage and with post-COVID syndrome. Conclusion: COVID-19 disease generates clinical alterations that trigger an increase in plasma cortisol. These alterations increase as the stages of infection become more severe and some of them remain altered in patients with post-COVID syndrome.

关键词： COVID-19 Cortisol Post-COVID Syndrome

Sensorial Evaluation and Physical Chemical Characterization of a Beverage Based on Whey and β-Glucans as a Potential Prevention of Nonalcoholic Steatohepatitis

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Food and Nutrition Sciences 2024年第8期15卷 770-789页

作者： Adriana Hernandez Santana Andrea Jimena Valdés alvarado Sandra Karina Espinoza Stephany Bernardeth lanza Aguilar Food Science Department Zamorano Pan-American Agricultural School Tegucigalpa Honduras

Whey and B-glucans are functional food ingredients that contribute to the prevention of non-communicable diseases. The objective of the study was to develop a functional beverage based on whey, B-glucans, and blackberry concentrate for the prevention of nonalcoholic steatohepatitis, determining its sensory, physicochemical, and nutritional qualities. The following phases were developed: 1) formulation with 75%, 85%, and 90% whey and 25%, 15%, and 10% blackberry concentrate, with a fixed amount of 0.243 g β-glucans in 100 ml;2) microbiological analysis to ensure the safety of the beverage;3) sensory analysis with untrained panelists to assess the degree of preference (appearance, color, odor, flavor, viscosity, acidity, sweetness), and general acceptance, with a seven-point hedonic scale to rate the level of acceptability;4) physicochemical and nutritional characterization of the beverage with the highest acceptance. An experimental design using complete random blocks was employed. Data analysis was performed with variance (ANDEVA) and mean DUNCAN separation at a 95% confidence level, using SAS®. A correlation study was conducted on acceptance analysis. A nutritional label was developed for the control beverage and the treatment with the highest acceptance. The formulation with 75% whey, 25% blackberry concentrate, and 0.243 g of β-glucan obtained the highest acceptance, with flavor and sweetness being the attributes that contributed to its acceptance. Nutritionally, the beverage with 80 cal, would be considered fortified with fiber (2 g), free of cholesterol, sodium, and saturated fat, according to the Central American Technical Regulation on Nutritional labeling (Version 67.01.60:10). It is recommended that the effect of this beverage be measured to determine the benefits.

关键词： Fatty Acids Fatty liver Glucans Whey

Academic Stress Assessment Using Virtual Reality as an Educational Tool in Spine Surgery

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Open Journal of Modern Neurosurgery 2024年第2期14卷 114-123页

作者： Diana Chávez lizárraga Jesús Alberto Pérez Contreras Fernando alvarado Gómez Evelyn Quintero Medina Emmanuel Cantú Chávez Iván Ulises Sámano lópez Ana Sofía Peña Blesa Department of Neurosurgery ángeles Pedregal Ciudad de México México Department of Traumatology and Orthopedics Hospital Santa Fe Bogotá Colombia

Introduction: The evaluation of academic stress in medical students and residents is a topic of significant interest, given the considerable challenges they face during their learning process with traditional teaching methods. The use of technologies like virtual reality presents an opportunity to enhance their skills through simulations and training. The main objective of this study is to qualitatively assess the stress levels experienced by medical students and residents by integrating virtual reality into their current learning methods, aiming to improve their ability to manage stressors in their practice. Material and Methods: A questionnaire was conducted with 12 medical students and 12 Traumatology and orthopedics residents. The purpose of the questionnaire was to evaluate the levels of academic stress using the SISCO inventory. The stress levels were calculated by transforming average values into percentages, and the following criteria were assigned: 0 to 33% for Mild Stress, 34 to 66% for Moderate Stress, and 67 to 100% for Deep Stress. Then, a virtual reality class focused on spine surgery was provided. Both medical students and residents were trained using the Non Nocere SharpSurgeon software platform and Oculus Quest 2 virtual reality glasses. At the end of the session, a second questionnaire related to the practice with virtual reality was conducted with the same evaluation criteria and a comparative analysis was carried out. Results: 12 undergraduate students from Hospital Angeles Mexico, CDMX and 12 traumatology and orthopedics residents at Hospital Santa Fe, Bogota were evaluated. The students in CDMX reported an average qualitative stress of 28.50% during habitual practices, which decreased to an average of 14.67% after virtual reality practice. Residents in Bogotá experienced an average qualitative stress of 30.50% with their current learning methods but this reduced to an average of 13.92% after using virtual reality. These findings indicate that t

关键词： Virtual Reality Academic Stress learning Strategies Spine Surgery Training

Evaluation of Mandibular Deprogramming Using TENS (Transcutaneous Electrical Nerve Stimulation) in Patients at the Specialty Clinic of the Juarez Autonomous University of Tabasco from 2022 to 2024

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Journal of Biosciences and Medicines 2024年第7期12卷 245-251页

作者： Christian C. Aguilar-Caamal landy V. limonchi-Palacio Crystell G. Guzmán-Priego Jeannette ramírez-Mendoza José M. lehmann-Mendoza Miguel A. lópez-alvarado Xavier E. Moreno-Enriquez Jorda A. Albarrán-Melzer Academic Division of Health Sciences Juarez Autonomous University of Tabasco Villahermosa Tabasco Mxico Cardiometabolism laboratory Academic Division of Health Sciences Juarez Autonomous University of Tabasco Villahermosa Tabasco Mxico

Temporomandibular disorders (TMD) negatively affect quality of life, causing pain and restricted jaw movements. This study evaluates the effectiveness of Transcutaneous Electrical Nerve Stimulation (TENS) on TMD patients before orthodontic treatment at the Juarez Autonomous University of Tabasco. A quantitative, quasi-experimental study was conducted with 30 patients who met the inclusion criteria: aged 18 to 65 years, with TMJ pain symptoms, diagnosed with temporomandibular disorders using the Helkimo index, and who had provided informed consent for the study. The range of mandibular movement and the Visual Analog Scale (VAS) were measured to record values before therapy. The electrodes of the TENS therapy were positioned on both sides of the jaw in the preauricular area and the masseter muscle, the therapy was administered for 40 minutes, utilizing a frequency of 2 - 4 Hz and a pulse duration of 300 microseconds. Following this, the range of mandibular movement and the VAS were reassessed to evaluate the outcomes., significantly improved maximum mouth opening (37.7 ± 6.4 mm to 44.6 ± 5.88 mm), right laterality (3.86 ± 1.57 mm to 5.43 ± 1.21 mm), left laterality (3.13 ± 1.63 mm to 4.53 ± 1.61 mm), protrusion (4.01 ± 1.7 mm to 5.36 ± 1.32 mm), and pain perception (4.56 ± 2.045 to 2.03 ± 1.5) (P rapy enhances mandibular movement and reduces pain, making it a well-tolerated, non-invasive complementary treatment for TMD.

关键词： TENS Opening Deprogramming Electrostimulation TMJ (Temporomandibular Joint)