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The potential of starch-chitosan blends with poloxamer for the preparation of microparticles by spray-drying

Particuology 2024年第6期89卷 1-10页

作者： j.an enrique Barranco-García Carolina Caicedo enrique j.vier jim.nez-regalado Carlos Espinoza-González Graciela Morales Rocio Yaneli Aguirre-Loredo Abril Fonseca-García Tecnológico Nacional de México/Instituto Tecnológico de Oaxaca Departamento de Química y BioquímicaAvenida Ing.Víctor Bravo Ahuja No.125Esquina Calzada Tecnológico68030OaxacaMexico Faculty of Engineering Unidad Central del Valle del Cauca(UCEVA)Carrera 17a 48-144763022TuluáColombia Centro de Investigación en Química Aplicada(CIQA) Blvd.Enrique Reyna Hermosillo 14025294SaltilloCoahuilaMexico Investigadoras por México CONAHCYT-CIQA Av.Insurgentes Sur 1562Col.Crédito Constructor03940Alcaldía Benito JuárezCDMXMexico

Using biopolymers as wall materials in spray drying poses challenges,particularly in attaining flowability and thermal stability among their physicochemical *** paper addresses these challenges by preparing microparticles using a blend of starch–chitosan and a poloxamer,commercially named Pluronic®*** aimed to elucidate the effects of varying poloxamer concentrations on the resulting particles through the spray drying *** with a poloxamer concentration of 3%(w/v)demonstrated a notably higher yield,especially when compared to those with 0%and 1%*** with 3%and 5%(w/v)poloxamer displayed a narrower particle size distribution,with the 3%blend showing a superior yield attributed to arrangements of blend components that improve flowability.X-ray diffraction analysis showcased the characteristic peaks of A-type starch form,with shifts suggesting enhanced interactions between *** with increased poloxamer content showed elevated thermal degradation temperatures,with the 3%blend registering a significant rise,opening avenues for encapsulating heat-sensitive *** study primarily focuses on the preparation and basic characterization of *** underscores the potential of blends with optimal poloxamer concentrations in microencapsulation,emphasizing further research to harness their capabilities thoroughly.

关键词： Biopolymer Starch Chitosan Pluronic®F127 Microparticles Spray drying

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Influence of Surfactant and Salt Concentration on the Rheological Properties of Three Different Microstructures of Associative Polyelectrolytes Obtained by Solution Polymerization

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j.urnal of Modern Physics 2014年第14期5卷 1387-1396页

作者： Areli I. Velazquez-Garcia Gregorio Cadenas-Pliego Claudia C. Rivera-Vallej. enrique j. jim.nez-regalado Centro de Investigación en Química Aplicada (CIQA) Saltillo México

The rheological properties of three different microstructures of hydrophobically modified alkalisoluble polymers (telechelic, multisticker and combined) in the presence of various concentrations of anionic surfactant and salt (NaCl) were investigated. Associative polymers containing both ionic sites and small number of hydrophobic groups were obtained, and their thickening properties in aqueous solutions, were investigated. Solution polymerization was used for obtaining the different polymers. Relationships between hydrophobe, sodium dodecyl sulfate (SDS) and NaCl concentration are proposed. Owing to the competition between attractive hydrophobic interaction and repulsive electrostatic interactions, such hydrophobically modified polymers exhibit various rheological behaviors in aqueous solutions, depending on microstructure of polyelectrolyte, SDS and NaCl concentrations.

关键词： Polymerization Associative Polyelectrolyte Rheology Surfactant and Salt Concentration

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Serum levels of chemokines in adolescents with maj.r depression treated with fluoxetine

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World j.urnal of Psychiatry 2020年第8期10卷 175-186页

作者： Francisco Rafael de la Peña Carlos Cruz-Fuentes Lino Palacios Manuel Iván Girón-Pérez Emilio Medina-Rivero Maria Dolores Ponce-regalado Samantha Alvarez-Herrera Gilberto Pérez-Sánchez enrique Becerril-Villanueva j.séLuis Maldonado-García María C jim.nez-Martínez Lenin Pavón Adolescent Clinic Clinical ServicesNational Institute of Psychiatry“Ramón de la Fuente”Mexico City 14370Mexico Department of Psychiatric Genetics Clinical Research BranchNational Institute of Psychiatry“Ramón de la Fuente”Mexico City 14370Mexico Universidad Autónoma de Nayarit Laboratorio de InmunotoxicologíaBoulevard Tepic-Xalisco s/nCd de la Cultura Amado NervoTepic 63000Mexico Centro Nayarita de Innovación y Transferencia de Tecnología A.C.Laboratorio Nacional para la Investigación en Inocuidad Alimentaria-Unidad Nayarit Calle Tres s/n.Cd IndustrialTepic 63000NayaritMexico Unidad de Desarrollo e Investigación en Bioprocesos Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalUnidad Profesional Lázaro CárdenasMexico City 11340Mexico Departamento de Ciencias de Salud Centro Universitario de los AltosUniversidad de Guadalajara Av Rafael Casillas Aceves No.1200Tepatitlán de MorelosJalisco47610Mexico Laboratory of Psychoimmunology National Institute of Psychiatry“Ramón de la Fuente”Mexico City 14370Mexico Department of Immunology and Research Unit Institute of Ophthalmology“Conde de Valenciana Foundation”Mexico City 06800Mexico Department of Biochemistry Faculty of MedicineNational Autonomous University of MexicoMexico City 04510Mexico

BACKGROUND Maj.r depressive disorder(MDD)is a global health issue that affects 350 million people of all *** between 2%and 5.6%of affected individuals are adolescents,research on young patients is *** inflammatory response contributes to the onset of depression,and in adult MDD patients,symptom severity has been linked to chemokine *** To determine the differences in circulatory levels of chemokines in healthy volunteers(HVs)and adolescents with MDD,and assess the changes induced by fluoxetine *** The 22 adolescents with MDD were monitored during the first 8 wk of clinical follow-up and clinical psychiatric evaluation was done using the Hamilton depresión rating scale(HDRS).The serum levels of monocyte chemoattractant protein-1(MCP-1),macrophage inflammatory protein(MIP)-1α,MIP-1β,interleukin(IL)-8,interferon gamma-induced protein(IP)-10,and eotaxin were measured in patients and *** In all cases,significant differences were detected in circulating chemokine levels between patients before treatment and HVs(P<0.0001).All chemokines decreased at 4 wk,but only MCP-1 and IL-8 significantly differed(P<0.05)between 0 wk and 4 *** the patients,all chemokines rose to their initial concentrations by 8 wk vs 0 wk,but only IP-10 did so significantly(P<0.05).All patients experienced a significant decrease in HDRS scores at 4 wk(P<0.0001)and 8 wk(P<0.0001)compared with 0 *** Despite the consumption of fluoxetine,patients had significantly higher chemokine levels,even after considering the improvement in HDRS *** high levels of eotaxin,IP-10,and IL-8 partially explain certain aspects that are affected in MDD such as cognition,memory,and learning.

关键词： Adolescents Maj.r depression Chemokine Fluoxetine Interferon gammainduced protein-10

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Parametrization to Improve the Solution Accuracy of Problems Involving the Bi-Dimensional Dirac Delta in the Forcing Function

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j.urnal of Applied Mathematics and Physics 2015年第9期3卷 1168-1177页

作者： enrique j. Chicurel-Uziel Francisco A. Godínez Instituto de Ingeniería Universidad Nacional Autónoma de México México D.F. México

The representation of the Dirac delta, obtained by differentiating the parametric equation of the unit step with a riser, is used to solve two examples referring to problems of a different physical nature, each with the product of two deltas as a forcing function. Each problem was solved by an entirely different procedure. In comparison with non-parametric solutions, the present solutions are both more accurate and truer representations of the physics involved.

关键词： Dirac Delta Partial Differential Equations Parametric Representation

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Parametric Dirac Delta to Simplify the Solution of Linear and Nonlinear Problems with an Impulsive Forcing Function

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j.urnal of Applied Mathematics and Physics 2013年第7期1卷 16-25页

作者： enrique j. Chicurel-Uziel Francisco A. Godínez-Roj.no Instituto de Ingeniería Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de México México D.F. México

The Laplace transform is a very useful tool for the solution of problems involving an impulsive excitation, usually represented by the Dirac delta, but it does not work in nonlinear problems. In contrast with this, the parametric representation of the Dirac delta presented here works both in linear and nonlinear problems. Furthermore, the parametric representation converts the differential equation of a problem with an impulsive excitation into two equations: the first equation referring to the impulse instant (absent in the conventional solution) and the second equation referring to post-impulse time. The impulse instant equation contains fewer terms than the original equation and the impulse is represented by a constant, j.st as in the Laplace transform, the post-impulse equation is homogeneous. Thus, the solution of the parametric equations is considerably simpler than the solution of the original equation. The parametric solution, involving the equations of both the dependent and independent variables in terms of the parameter, is readily reconverted into the usual equation in terms of the dependent and independent variables only. This parametric representation may be taught at an earlier stage because the principle on which it is based is easily visualized geometrically and because it is only necessary to have a knowledge of elementary calculus to understand it and use it.

关键词： Dirac Delta Parametric Representation Nonlinear Differential Equations Impulsive Problems

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Pyrenetetraone-based covalent organic framework as an effective electrocatalyst for oxygen reduction reaction

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Nano Research 2022年第5期15卷 3907-3912页

作者： Paloma Garcia-Arroyo Emiliano Martinez-Perinan j.rge j.Cabrera-Truj.llo Elena Salagre enrique G.Michel j.se I.Martinez Encarnacion Lorenzo j.se L.Segura Departamento de Quimica Organica I Facultad de CC.QuimicasUniversidad Complutense de Madrid28040 MadridSpain Departamento de Quimica Analitica y Analisis Instrumental Facultad de CienciasUniversidad Autónoma de Madrid28049 MadridSpain Departamento de Fisica de la Materia Condensada Universidad Autónoma de Madrid28049 MadridSpain Condensed Matter Physics Center(IFIMAC) Universidad Autónoma de Madrid28049 MadridSpain Departamento de Nanoestructuras SuperficiesRecubrimientos y Astrofisica MolecularInstituto de Ciencia de Materiales de Madrid(ICMMCSIC)28049 MadridSpain Instituto Madrileno de Estudios Avanzados en Nanociencia(IMDEA-Nanociencia) 28049 MadridSpain Institute for Advanced Research in Chemical Sciences(IAdChem) Universidad Autonoma de Madrid28049 MadridSpain

A novel porous and crystalline two-dimensional(2D)electrochemically active covalent organic framework(COF)based on ortho-quinone units has been prepared as an innovative approach towards the development of organic cathode materials with multiple redox sites as an efficient electrocatalyst for the oxygen reduction reaction(ORR).In contrast with most of the previously reported COFs as electrocatalysts for the ORR,the electrocatalytic application of this material towards ORR has been investigated without adding any metal or conductive supporting material and avoiding any additional carbonization ***,the electrochemical properties of the COF material have been compared with two analogue amorphous frameworks with similar chemical composition,which points out the important role of the enhanced crystallinity and porosity of the COF network in its superior performance as an electrocatalyst towards ORR.

关键词： electrocatalysis oxygen reduction reaction metal free pyrenetetraone covalent organic framework

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Molecular isolation and identification of Mycobacterium avium *** in Didelphis virginiana from Hidalgo,Mexico

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Asian Pacific j.urnal of Tropical Medicine 2020年第3期13卷 131-136页

作者： Nallely Rivero-Perez j.an Ocampo-López Benj.mín Valladares-Carranza Fabián R.Gómez de Anda Francisco j.Pena jim.nez Victor M.Martínez j.árez Armando Peláez Acero j.se I.Olave Leyva Deyanira Oj.da-Ramírez Adrian Zaragoza-Bastida Area Académica de Medicina Veterinaria y Zootecnia Instituto de Ciencias AgropecuariaUniversidad Autónoma del Estado de HidalgoAv.Universidad Km 1Ex-Hda.de AquetzalpaC.P.43600 TulancingoHidalgoMéxico Centro de Investigación y Estudios Avanzados en Salud Animal Facultad de Medicina Veterinaria y ZootecniaUniversidad Autónoma del Estado de MéxicoKm 15.5 Carretera Panamericana Toluca-AtlacomulcoC.P.50200 TolucaEstado de MéxicoMéxico Centro Universitario del Sur/División de Ciencias de la Salud/Departamento de Ciencias Clínicas/Hospital Veterinario CUSUR Universidad de Guadalaj.ra Av.Enrique Arreola Silva No.883colonia centro C.P.49000Ciudad GuzmánJaliscoMéxico

Obj.ctive:To isolate and identify the exact species of the genus Mycobacterium from Didelphis(D.)virginiana,and the direct implications of this bacterium to public health and veterinary ***:Thirty-one *** were captured and necropsied in Hidalgo,*** samples were collected to culture mycobacteria present and examine individual specimens’*** identification was obtained through the application of amplification and sequencing of 16S rDNA ***:Three strains were isolated and identified as Mycobacterium(M.)avium *** by utilizing *** complexspecific *** lesions were observed in the subpleural zone(granuloma gradeⅡ)and bronchial(granuloma gradeⅠ)of the lungs of *** with positive ***:Three strains of *** ***,from lung tissue samples of *** were *** subspecies of *** has important implications in public health and veterinary medicine.

关键词： Didelphis virginiana Mycobacterium avium complex Mycobacterium avium subsp.hominissuis Public health

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Extraction of Carotenoids and Fatty Acids from Microalgae Using Supercritical Technology

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American j.urnal of Analytical Chemistry 2012年第12期3卷 877-883页

作者： Lourdes Casas Cardoso Casimiro Mantell Serrano Miguel Rodríguez Rodríguez enrique j. Martínez de la Ossa Luis M. Lubián Department of Chemical Engineering and Food Technology Faculty of Science University of Cadiz International Agri-Food Campus of Excellence Cadiz Spain Institute for Marine Science of Andalucia (CSIC) Cadiz Spain

The work described here is based on a comparative study of carotenoids and fatty acids extracted from Synechococcus sp. with (1) pure supercritical CO2, (2) CO2 with 5% (v/v) ethanol as cosolvent and (3) ultrasound-assisted extraction using N, N-dimethylformamide (DMF). The effects of extraction conditions on supercritical CO2 extraction with and within cosolvent were analyzed at different temperatures (40℃, 50℃ and 60℃) and pressures (200, 300 and 400 bars). SFE with CO2 proved to be the most selective method for the extraction of β-carotene, but under these conditions the contents of zeaxanthin and fatty acids were only comparable to or lower than those obtained with techniques that use SFE cosolvent. The SFE technique with CO2 and ethanol simultaneously extracted β-carotene and zeaxanthin and not only increased the concentrations of fatty acids obtained, but also helped to remove fatty acids (palmitoleic and linolenic acid) that were not obtained with pure CO2. Comparison of the supercritical technology with the ultrasound-assisted extraction (UAE) shows that the former technique is the most appropriate due to the fact that ethanol is generally regarded as a safe solvent in comparison to DMF.

关键词： Carotenoids Fatty Acids Synechococcus sp. Supercritical Technology Ultrasound-Assisted Extraction

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Modelling fuel loads of understorey vegetation and forest floor components in pine stands in NW Spain

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Forest Ecosystems 2022年第6期9卷 775-789页

作者： j.se A.Vega Stefano Arellano-Perez j.an Gabriel Alvarez-Gonzalez Cristina Fernandez enrique jim.nez Pedro Cuinas j.se María Fernandez-Alonso Daniel j.Vega-Nieva Fernando Castedo-Dorado Cecilia Alonso-Rego Teresa Fontúrbel Ana Daría Ruiz-Gonzalez Centro de Investigacion Forestal de Lourizan PO Box 12736080PontevedraSpain Unidad de Gestion Ambiental y Forestal Sostenible(UXAFORES) Departamento de Ingeniería AgroforestalEscuela Politecnica Superior de IngenieríaUniversidad de Santiago de CompostelaCampus Universitario s/n27002LugoSpain Facultad de Ciencias Forestales Universidad Juarez del Estado de DurangoRío Papaloapan y Blvd.Durango s/nCol.Valle del Sur34120DurangoMexico Departamento de Ingeniería y Ciencias Agrarias Universidad de LeonCampus de Ponferrada24401PonferradaSpain

In this study,310 destructively sampled plots were used to develop two equation systems for the three main pine species in NW Spain(***;*** and ***):one for estimating loads of understorey fuel components by size and condition(live and dead)and another one for forest floor *** systems of equations were simultaneously fitted for estimating fuel loads using overstorey,understorey and forest floor variables as *** systems of equations included both the effect of pine species and the effect of understorey compositions dominated by ferns-brambles or by woody species,due to their obvious structural and physiological *** general,the goodness-of-fit statistics indicated that the estimates were reasonably robust and accurate for all of the fuel *** best results were obtained for total understorey vegetation,total forest floor and raw humus fuel loads,with more than 76%of the observed variability explained,whereas the poorest results were obtained for coarse fuel loads of understory vegetation with a 53%of observed variability *** reduce the overall costs associated with the field inventories necessary for operational use of the models,the additive systems were fitted again using only overstorey variables as potential *** relationships for fine(<6 mm)and total understorey vegetation and total forest floor fuel loads were obtained,indicating the complexity of the forest overstorey-understorey and overstorey-forest floor ***,these models explained around 52%of the observed ***,equations estimating the total understorey vegetation and the total forest floor fuel loads based only on canopy cover were *** models explained only 26%-32%of the observed variability;however,their main advantage is that although understorey vegetation in forested landscapes is largely invisible to remote sensing,canopy cover can be estimated with moderate accuracy,allowin

关键词： Area-based approach Additive equation systems Live and dead fine fuel Pinus pinaster Pinus radiata Pinus sylvestris

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Impact of liver enzymes on SARS-CoV-2 infection and the severity of clinical course of COVID-19

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Liver Research 2021年第1期5卷 21-27页

作者： Fátima Higuera-de la Tij.ra Alfredo Servín-Caamaño Daniel Reyes-Herrera Argelia Flores-López enrique j.A.Robiou-Vivero Felipe Martínez-Rivera Victor Galindo-Hernández Oscar Chapa-Azuela Alfonso Chávez-Morales Victor H.Rosales-Salyano Multidisciplinary Team for the Attention and Care of Patients with COVID-19 Hospital General de México Dr.Eduardo LiceagaMexico CityMexico Gastroenterology and Hepatology Department Hospital General de México Dr.Eduardo LiceagaMexico CityMexico Internal Medicine Department Hospital General de México Dr.Eduardo LiceagaMexico CityMexico Hepatobiliary and Pancreatology Clinic Surgery DepartmentHospital General de México Dr.Eduardo LiceagaMexico CityMexico Intensive Care Unit Hospital General de México Dr.Eduardo LiceagaMexico CityMexico

Background and aim Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the virus responsible for the current pandemic,can have multi-organ *** studies show that liver inj.ry could be a manifestation of the disease,and that liver disease could also be related to a worse *** aim was to compare the characteristics of patients with severe coronavirus disease 2019(COVID-19)due to SARS-CoV-2 who required intubation versus stable hospitalized patients to identify the early biochemical predictive factors of a severe course of COVID-19 and subsequent requirement for intubation,specifically in *** This was an observational case-control study nested in a cohort *** medical records of patients admitted for confirmed COVID-19 at a tertiary level center in Mexico City were *** and biochemical data were collected,and the characteristics of patients who required invasive mechanical ventilation(IMV)(cases)were compared with stable hospitalized patients without ventilation(controls).Results We evaluated 166 patients with COVID-19 due to SARS-CoV-2 infection;114(68.7%)were men,the mean age was 50.6±13.3 years,and 27(16.3%)required *** comparative analysis between cases and controls showed(respectively)significantly lower blood oxygen saturation(SpO_(2))(73.5±12.0%vs.83.0±6.8%,P<0.0001)and elevated alanine aminotransferase(ALT)(128(14–1123)IU/L vs.33(8–453)IU/L,P=0.003),aspartate aminotransferase(AST)(214(17–1247)vs.44(12–498)IU/L,P=0.001),lactic dehydrogenase(LDH)(764.6±401.9 IU/L vs.461.0±185.6 IU/L,P=0.001),and D-dimer(3463(524–34,227)ng/mL vs.829(152–41,923)ng/mL,P=0.003)*** in the cases group were older(58.6±12.7 years vs.49.1±12.8 years,P=0.001).Multivariate analysis showed that important factors at admission predicting the requirement for IMV during hospitalization for COVID-19 were AST≥250 IU/L(odds ratio(OR)=64.8,95%confidence interval(CI)7.5–560.3,P<0.0001)and D-dimer≥3500 ng/mL(OR=4.1,95

关键词： Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) Coronavirus disease 2019(COVID-19) Liver enzymes D-dimer Disease severity Invasive mechanical ventilation(IMV) Multi-organ failure

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