159 research outputs found
An extended kinetic model-based correction factor equation to account hemodialysis post-treatment hemoconcentration
The hemoconcentration effect for middle weight solutes in hemodialysis is corrected by oversimplified methods based on hematocrit changes or distribution volume variations. Here we implemented a variable volume dual pool kinetic model targeted at obtaining a precise correction factor equation for extracellularly distributed solutes based on relevant kinetic parameters such as the ultrafiltration to dry weight ratio UF/DW, the dialyzer clearance, Kd, the intercompartment mass-transfer coefficient, Kc, and the central compartment to extracellular volume ratio, α. More than 300,000 solutions of the model were computed, performing a sweep among physiological values of the proposed kinetic parameters, resulting in a linear regression denoted by the expression fcorr = 1.0707 - 5.2246 (UF/DW) - 0.0005 Kd - 0.0004 Kc - 0.0007 α, with an excellent coefficient of determination R2 = 0.983. The presented fcorr provides a substantial extension of the currently implemented methods to estimate the hemoconcentration factor for middle and high molecular weight extracellular distributed solutes in hemodialysis
An energy-stable time-integrator for phase-field models
We introduce a provably energy-stable time-integration method for general classes of phase-field models with polynomial potentials. We demonstrate how Taylor series expansions of the nonlinear terms present in the partial differential equations of these models can lead to expressions that guarantee energy-stability implicitly, which are second-order accurate in time. The spatial discretization relies on a mixed finite element formulation and isogeometric analysis. We also propose an adaptive time-stepping discretization that relies on a first-order backward approximation to give an error-estimator. This error estimator is accurate, robust, and does not require the computation of extra solutions to estimate the error. This methodology can be applied to any second-order accurate time-integration scheme. We present numerical examples in two and three spatial dimensions, which confirm the stability and robustness of the method. The implementation of the numerical schemes is done in PetIGA, a high-performance isogeometric analysis framework
Utility of the serum protein electrophoresis in the opportunistic screening for the deficiency of Alpha-1 Antitrypsin
Background: A deficiency in alpha-1 antitrypsin (AAT1) is a rare disorder that represents a significant health threat and early diagnostic priority issue. We investigated the usefulness of the serum protein electrophoresis (SPE) as an opportunistic screening tool for AAT1 deficiency. Methods: For 6 months, all SPE carried out for any reasons were evaluated in our center. In those with less than 3% of alpha-1 globulins, AAT1 concentrations were studied. The SERPINA1 gene was subsequently sequenced in those patients displaying concentrations below 100 mg/dL. Results: Out of the total, 14 patients (0.3%) were identified with low AAT1 concentrations, with 11 of them agreeing to enter the study. Of those, mutations in the SERPINA1 gene were discovered in 10 patients (91%). Heterozygous mutations were detected in seven patients; three had the c.1096G>A mutation (p.Glu366Lys; Pi*Z), two had the c.863A>T mutation (p.Glu288Val; Pi*S), one had the c.221_223delTCT mutation (p.Phe76del; Pi*Malton), and the last one had the c.1066G>A (p.Ala356Thr) mutation, which was not previously described. Finally, one patient had the c.863A>T mutation in homozygosis, whereas two double heterozygous patients c.863A>T/c.1096G>A were detected. Conclusions: An altered result in the concentration of AAT1 anticipates a mutation in the SERPINA1 gene in a manner close to 91%. The relationship between a decrease in the alpha-1 globulin band of the SPE and an alteration in the AAT1 concentration is direct in basal states of health. The SPE is presented as a highly sensitive test for opportunistic screening of AAT1 deficiency
Valoración de la fragilidad en un centro de diálisis. ¿son más frágiles los pacientes con diabetes?
Introducción: El incremento en la inclusión de personas de edad avanzada a los programas de hemodiálisis se relaciona con un aumento de la prevalencia de fragilidad, considerada predictora de discapacidad y asociada a eventos adversos de salud. Dado su carácter reversible, es importante hacer un cribaje para mejorar la práctica clínica.
Objetivo: Evaluar el grado de fragilidad y estado funcional del paciente en nuestra unidad de hemodiálisis y analizar las diferencias entre diabéticos y no diabéticos.
Material y Método: Estudio observacional de corte transversal. La fragilidad se midió utilizando el fenotipo de Fried y la valoración funcional mediante las escalas Barthel, Lawton, Downton y la Short Physical Performance Battery. Se evaluó comorbilidad y riesgo de caídas con las escalas Charlson y Downton respectivamente. Se comparó entre grupos de diabéticos y no diabéticos y se analizó la relación entre la fragilidad y la edad, dependencia, comorbilidad y riesgo de caídas.
Resultados: Se incluyeron 128 pacientes. El 45% tenían Diabetes. Los pacientes con diabetes tenían una edad media mayor que los no diabéticos (74,2±11 vs 67,8±15 años) y mayor comorbilidad (Charlson 8,2±2,2 vs 5,8±2,4). El 25% de los pacientes presentaron fragilidad, observando una tendencia que sugirió mayor fragilidad, peor capacidad funcional y mayor grado de dependencia en los pacientes diabéticos, aunque de forma no significativa.
Conclusiones: Una cuarta parte de la población estudiada presenta fragilidad, con una tendencia más acusada a padecerla los pacientes diabéticos, que podría estar relacionada con mayor edad, mayor comorbilidad y menor capacidad funcional que los no diabéticos
Enhanced superconductivity in atomically thin TaS2
The ability to exfoliate layered materials down to the single layer limit has presented the opportunity to understand how a gradual reduction in dimensionality affects the properties of bulk materials. Here we use this top-down approach to address the problem of superconductivity in the two-dimensional limit. The transport properties of electronic devices based on 2H tantalum disulfide flakes of different thicknesses are presented. We observe that superconductivity persists down to the thinnest layer investigated (3.5 nm), and interestingly, we find a pronounced enhancement in the critical temperature from 0.5 to 2.2 K as the layers are thinned down. In addition, we propose a tight-binding model, which allows us to attribute this phenomenon to an enhancement of the effective electron-phonon coupling constant. This work provides evidence that reducing the dimensionality can strengthen superconductivity as opposed to the weakening effect that has been reported in other 2D materials so far
Efectos en la salud asociados a la ingesta de frutas cítricas en infantes de 6 a 24 meses de edad: Protocolo de una revisión sistemática
Introduction: In Latin America, the recommendations about the introduction of citrus in the complementary feeding are heterogeneous. Food restriction during the first years of life can increase the risk of nutritional deficiencies. The objective of the review is to identify the health effects associated with the citrus intake in infants from 6 to 24 months of age.Material and Methods: We will include studies with preterm infants, without diseases or surgical interventions that require dietary modification. Citrus are considered as Orange, Camu Camu, Tangelo, Lemon, Mandarin, Lime, Cider, Grapefruit, and Clementine, consumed in the natural form or in juices or extracts, or in combination with other foods. All health effects associated with the intake of citrus will be reported. The databases of MEDLINE (through PubMed), Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), Epistemonikos, LILACS, and SciELO will be searched.Also, grey literature will be searched in international thesis repositories. Observational studies, randomized and non-randomized clinical trials will be included. Study selection, data extraction and risk of bias assessment will be done independently, in duplicate and with blinding. At the end of each stage, blinding will be lifted to resolve conflicts between reviewers through consensus. A narrative synthesis of the results of the primary studies and the risk of bias will be conducted.Ethics and Dissemination: The protocol is registered in PROSPERO: CRD42021230561.Introducción: En América Latina, las recomendaciones sobre la introducción de frutas cítricas en la alimentación complementaria son heterogéneas. La restricción de alimentos durante los primeros años de vida puede incrementar el riesgo de tener deficiencias nutricionales. El objetivo de la revisión es identificar los efectos en la salud asociados a la ingesta de frutas cítricas en infantes de 6 a 24 meses de edad.
Metodología: Se incluirán a estudios que tengan como población a infantes nacidos pretérmino, sin enfermedades o intervenciones quirúrgicas que demanden de la modificación de la dieta. Se considera como frutas cítricas a la Naranja, Camu Camu, Tangelo, Limón, Mandarina, Lima, Sidra, Pomelo y Clementina, consumidas en su forma natural o en jugos o extractos, o en combinación con otros alimentos. Se reportarán todos los efectos en la salud asociados a la ingesta de frutas cítricas. Se realizarán búsquedas en MEDLINE (a través de PubMed), SCOPUS, LILACS, SciELo, Epistemonikos, y CENTRAL. También, se realizarán búsquedas de literatura gris en repositorios de tesis internacionales. Se incluirán a estudios observacionales, ensayos clínicos aleatorizados y no aleatorizados. La selección de estudios, extracción de datos y evaluación de riesgo de sesgo se realizará de forma independiente, por duplicado y con cegamiento. Al culminar cada etapa, se levantará el cegamiento para resolver los conflictos entre los revisores mediante el consenso. Se realizará una síntesis narrativa de los resultados de los estudios primarios y el riesgo de sesgo.
Ética y diseminación: El protocolo está registrado en PROSPERO: CRD42021230561
O Mapa Geográfico de América Meridional, de Juan de la Cruz Cano y Olmedilla
This essay examines the history of the construction of the Mapa Geográfico de América Meridional (Map of South America) by Juan de la Cruz Cano y Olmedilla, how its various editions were engraved, as well as its circulation and reception during the second half of the 18th century in the light of the ongoing dispute between Portugal and Spain over the boundaries of Brazil
Clinical forms of Trypanosoma cruzi infected individuals in the chronic phase of Chagas disease in Puebla, Mexico
Plant chemicals and the sexual behavior of male tephritid fruit flies
Plant compounds affect insects in many different ways. In addition to being a food source, plants also contain secondary metabolites that may have positive and negative impacts on insects. The influence of these compounds on sexual behavior, in particular, has been the focus of many recent studies. Here, we review the existing literature on the effects of plant compounds on the sexual behavior of tephritid fruit fly males. We put special focus on polyphagous species whose males congregate in leks, where females exert strong mate selection. We first summarize the main findings related to plant compounds that increase male signaling behavior and attraction of females and consequently increase mating frequency, a phenomenon that has been recorded mainly for species of Anastrepha and Ceratitis. In other tephritid species, males are attracted to phenylpropanoids produced by plants (such as methyl eugenol or raspberry ketone) that, upon encounter, are consumed and sequestered by males. These compounds, or metabolic derivatives, which normally have negligible nutritional value, are included in the pheromone and also confer advantages in a sexual context: enhanced female attraction and improved male mating success. These phenomena have been reported for several Bactrocera species as well as for Zeugodacus cucurbitae. Because many tephritid species are serious pests, the effect of plant compounds on male behavior has been explored for potential incorporation into control strategies such as the sterile insect technique (SIT). We conclude noting several factors, such as age and nutrition during larval and adult stage, that modulate the effect of plant compounds on male mating behavior as well as some prominent gaps that preclude a thorough understanding of the plant-mediated enhancement of male sexual performance and hence limit our ability to effectively utilize phytochemicals in pest control strategies.Instituto de GenéticaFil: Segura, Diego Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Belliard, Silvina A. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vera, María Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Bachmann, Guillermo Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruiz, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Jofre-Barud, Flavia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lopez, M. Liza. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shelly, Todd E. United States Department of Agriculture. Animal and Plant Health Inspection Service; Estados Unido
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