3,963 research outputs found
Metastable states influence on the magnetic behavior of the triangular lattice: Application to the spin-chain compound Ca3Co2O6
It is known that the spin-chain compound Ca3Co2O6 exhibits very interesting
plateaus in the magnetization as a function of the magnetic field at low
temperatures. The origin of them is still controversial. In this paper we study
the thermal behavior of this compound with a single-flip Monte Carlo simulation
on a triangular lattice and demonstrate the decisive influence of metastable
states in the splitting of the ferrimagnetic 1/3 plateau below 10 K. We
consider the [Co2O6]n chains as giant magnetic moments described by large Ising
spins on planar clusters with open boundary conditions. With this simple
frozen-moment model we obtain stepped magnetization curves which agree quite
well with the experimental results for different sweeping rates. We describe
particularly the out-of-equilibrium states that split the low-temperature 1/3
plateau into three steps. They relax thermally to the 1/3 plateau, which has
long-range order at the equilibrium. Such states are further analyzed with
snapshots unveiling a domain-wall structure that is responsible for the
observed behavior of the 1/3 plateau. A comparison is also given of the exact
results in small triangular clusters with our Monte Carlo results, providing
further support for our thermal description of this compound.Comment: 8 pages, 11 figures, submitted to PR
Datos estructurales sobre el anticlinal de "San Emiliano-Valgrande" y unidades periféricas (Cordillera Cantábrica)
Se mencionan algunos datos estructurales sobre el anticlinal mecanizado que se extiende, desde las proximidades de San Emiliano (León) hasta el nacimiento del río Valgrande (Asturias), el cual, resulta ser una muy destacada estructura de replegamiento de la Unidad Cabalgante de Pajares. Se citan algunas otras observaciones sobre el carácter, en estazona, de la Unidad Cabalgante de Villamanín, que se le superpone, adquiriendo aquí una notable complejidad en la zona frontal, definiendo una serie de escamas y, conjuntamente, una semiventana tectónica de cierta importancia
Reconocimiento de señales de deformación en pudingas de la Cuenca Carbonífera Central de Asturias
Se describe la existencia de señales de deformación (impresiones cóncavas, torsiones y fracturas) de nexo tectónico en cantos de pudingas cuarcíticas del Carbonífero (Westfaliense C-D, probablemente) de la Cuenca Central de Asturias (España)
Nota sobre las características estructurales de la zona de "Cueto Negro" (Cordillera Cantábrica)
Se citan algunos datos estructurales respecto a la zona comprendida entre los puertos Pajares y La Cubilla (Cordillera Cantábrica). Se destaca la presencia de una ventana tectónica, en la zona de Cueto negro, relacionada con la unidad cabalgante de Bodón, ampliamente replegada. Estos elementos se integran dentro del haz de estructuras que caracterizan el "arco medio" de la Rodilla Astúrica (Cordillera Cantábrica, España)
Extended hildebrand solubility approach in the solubility estimation of the sunscreen ethylhexyl triazone in ethyl acetate + ethanol mixtures
Ethylhexyl triazone (EHT) is a sunscreen agent widely used in the formulation of skin care
products, whose physicochemical properties have not been thoroughly studied. In this work the Extended
Hildebrand Solubility Approach (EHSA) was applied to evaluate the solubility of EHT in ethyl acetate +
ethanol mixtures at 298.15 K. A good correlative capacity of EHSA was found using a regular polynomial
model in order five (overall deviation lower than 1.2 %), when the W interaction parameter is related to
the solubility parameter of the mixtures. Besides, the deviations obtained in the estimated solubility with
respect to experimental solubility were lower compared with those obtained directly by means of an empiric
regression of the experimental solubility as a function of the mixtures' solubility parameters.Colegio de Farmacéuticos de la Provincia de Buenos Aire
Extended hildebrand solubility approach in the solubility estimation of the sunscreen ethylhexyl triazone in ethyl acetate + ethanol mixtures
Ethylhexyl triazone (EHT) is a sunscreen agent widely used in the formulation of skin care
products, whose physicochemical properties have not been thoroughly studied. In this work the Extended
Hildebrand Solubility Approach (EHSA) was applied to evaluate the solubility of EHT in ethyl acetate +
ethanol mixtures at 298.15 K. A good correlative capacity of EHSA was found using a regular polynomial
model in order five (overall deviation lower than 1.2 %), when the W interaction parameter is related to
the solubility parameter of the mixtures. Besides, the deviations obtained in the estimated solubility with
respect to experimental solubility were lower compared with those obtained directly by means of an empiric
regression of the experimental solubility as a function of the mixtures' solubility parameters.Colegio de Farmacéuticos de la Provincia de Buenos Aire
On the Moat-Penumbra Relation
Proper motions in a sunspot group with a delta-configuration and close to the
solar disc center have been studied by employing local correlation tracking
techniques. The analysis is based on more than one hour time series of G-band
images. Radial outflows with a mean speed of 0.67 km s^{-1} have been detected
around the spots, the well-known sunspots moats. However, these outflows are
not found in those umbral core sides without penumbra. Moreover, moat flows are
only found in those sides of penumbrae located in the direction marked by the
penumbral filaments. Penumbral sides perpendicular to them show no moat flow.
These results strongly suggest a relation between the moat flow and the
well-known, filament aligned, Evershed flow. The standard picture of a moat
flow originated from a blocking of the upward propagation of heat is commented
in some detail.Comment: 4 pages, 4 figures, To appear in ApJ Letter
Development and validation of a new methodological platform to measure behavioral, cognitive, and physiological responses to food interventions in real time
To fully understand the causes and mechanisms involved in overeating and obesity, measures of both cognitive and physiological determinants of eating behavior need to be integrated. Effectively synchronizing behavioral measures such as meal micro-structure (e.g., eating speed), cognitive processing of sensory stimuli, and metabolic parameters, can be complex. However, this step is central to understanding the impact of food interventions on body weight. In this paper, we provide an overview of the existing gaps in eating behavior research and describe the development and validation of a new methodological platform to address some of these issues. As part of a controlled trial, 76 men and women self-served and consumed food from a buffet, using a portion-control plate with visual stimuli for appropriate amounts of main food groups, or a conventional plate, on two different days, in a random order. In both sessions participants completed behavioral and cognitive tests using a novel methodological platform that measured gaze movement (as a proxy for visual attention), eating rate and bite size, memory for portion sizes, subjective appetite and portion-size perceptions. In a sub-sample of women, hormonal secretion in response to the meal was also measured. The novel platform showed a significant improvement in meal micro-structure measures from published data (13 vs. 33% failure rate) and high comparability between an automated gaze mapping protocol vs. manual coding for eye-tracking studies involving an eating test (ICC between methods 0.85; 90% CI 0.74, 0.92). This trial was registered at Clinical Trials.gov with Identifier NCT03610776. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.3758/s13428-021-01745-9
Cumplimiento, conocimiento y automedicación como factores asociados a los resultados clínicos negativos de la farmacoterapia
The patient plays a fundamental role in the attainment of good results in pharmacotherapy. Noncompliance,self-medication, or insufficient knowledge of the therapy being employed may provide asource for the causes of these negative clinical outcomes, otherwise known as medicine related problems(MRP). he Dader method was used in the evaluation, identification and classification of MRP. Theassociation of variables was established through the statistical Chi square test. Patient knowledge of themedicine, degree of compliance to therapy and self-medication were studied as causes of the negativeoutcomes encountered. 2556 patients were interviewed throughout the year that the study took place,giving a total of 2261 of valid cases. 33% presented an MRP as the cause of his/her visit to the hospitalemergency ward. Knowledge of the medicine, compliance and self-medication were only studied in thepopulation that presented an MRP and in this work it is demonstrated that these are aspects that areassociated with different dimensions of MRP. It is not possible to establish an association between theexistence or not of negative clinical outcomes in patients with the factors of knowledge of medication,compliance and self-medication. This is due to the fact that these variables are not attributable to thepatient himself, but rather are associated with the characteristics of each medicine.El paciente juega un papel primordial en la consecución de los resultados terapéuticos. El incumplimiento,la automedicación, o la falta de conocimiento del la farmacoterapia pueden ser causas de esosresultados clínicos negativos, denominados en ocasiones problemas relacionados con medicamentos(PRM). El método Dáder se utilizó para la evaluación, identificación y clasificación de PRM. Laasociación de variables se estableció mediante el estadístico chi cuadrado. El conocimiento de la medicación,el cumplimiento y la automedicación fueron estudiados como causa de estos resultados negativosde la medicación. Fueron entrevistados 2556 pacientes durante el año de estudio, resultando 2261 casosválidos. El 33 % presentaron un PRM como causa de visita a urgencias. El conocimiento de la medicación,el cumplimiento y la automedicación fueron estudiados solo en la población que presentó unPRM y se demuestra que son aspectos asociados a las distintas dimensiones de PRM. No es posibleestablecer asociación entre la existencia o no de resultados clínicos negativos en los pacientes con elconocimiento de la medicación, el cumplimiento y la automedicación, debido a que estas variables noson atributos del paciente sino que están asociadas a cada medicamento
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