Antiresonances as precursors of decoherence

We show that, in presence of a complex spectrum, antiresonances act as a precursor for dephasing enabling the crossover to a fully decoherent transport even within a unitary Hamiltonian description. This general scenario is illustrated here by focusing on a quantum dot coupled to a chaotic cavity containing a finite, but large, number of states using a Hamiltonian formulation. For weak coupling to a chaotic cavity with a sufficiently dense spectrum, the ensuing complex structure of resonances and antiresonances leads to phase randomization under coarse graining in energy. Such phase instabilities and coarse graining are the ingredients for a mechanism producing decoherence and thus irreversibility. For the present simple model one finds a conductance that coincides with the one obtained by adding a ficticious voltage probe within the Landauer-Buettiker picture. This sheds new light on how the microscopic mechanisms that produce phase fluctuations induce decoherence.Comment: 7 pages, 2 figures, to appear in Europhys. Let

Contenido de aminoácidos libres en frutos de chirimoyo durante la maduración

El chirimoyo es un fruto tropical que crece en algunos países de América y en una serie de selectivas áreas del sur de España, siendo una fuente rica de aminoácidos libres. Los efectos de las temperaturas después de la postrecolección de este fruto han sido estudiadas. La firmeza del fruto se ha determinado con un medidor de textura y los aminoácidos libres se determinaron por cromatografía en columna de intercambio iónico, utilizando un autoanalizador de aminoácidos. El chirimoyo se caracterizó por un alto contenido en prolina y citrulina. El ácido glutámico y la glutamina estaban también presentes pero en pequeñas cantidades. La citrulina y la prolina se incrementaron durante la maduración; el aumento dependió de la temperatura de almacenamiento

Contenido de aminoácidos libres en frutos de chirimoyo durante la maduración

Cherimoya, a subtropical fruit growing in sorne American countries and restricted areas of the south of Spain, is one of the richest sources of free amino acids. The effects of post-harvest temperatures on the texture and free amino acid profile of this fruit were studied. Fruit firmness was determined with a pressure tester, and free amino acids were measured by ion-exchange colum chromatography using an automatic amino acid analyzer. Cherimoya was characterized by high contents of proline and citrulline. Glutamic acid and glutamine were also present but at lower levels. Citrulline and proline increased during ripening; the increases depended on the temperature of storage.El chirimoyo es un fruto tropical que crece en algunos países de América y en una serie de selectivas áreas del sur de España, siendo una fuente rica de aminoácidos libres. Los efectos de las temperaturas después de la postrecolección de este fruto han sido estudiadas. La firmeza del fruto se ha determinado con un medidor de textura y los aminoácidos libres se determinaron por cromatografía en columna de intercambio iónico, utilizando un autoanalizador de aminoácidos. El chirimoyo se caracterizó por un alto contenido en prolina y citrulina. El ácido glutámico y la glutamina estaban también presentes pero en pequeñas cantidades. La citrulina y la prolina se incrementaron durante la maduración; el aumento dependió de la temperatura de almacenamiento

Efecto de la refinación física sobre la calidad química y sensorial del aceite de coco

The effect of the physical refining stages (degumming, bleaching and deodorization) on some coconut oil quality and sensory parameters was evaluated. The fatty acid profile was within the range reported for this oil. The free fatty acids level (FFA) and the moisture content were significantly reduced (p 0.05) were found in p-anisidine value (AV). The tocopherols content was lower than the reported for this oil (6.57 ppm).The sterol level (899 ppm) was similar to the level reported for this oil. Both tocopherols and sterols content were significantly reduced (p 0.05) en ninguna de las etapas. El contenido de tocoferoles (6.57 ppm) estuvo por debajo de lo reportado para aceite de coco. El nivel de esteroles (899 ppm) determinado correspondió a lo reportado en la bibliografía. Tanto los tocoferoles como los esteroles se redujeron significativamente (p < 0.05) en todas las etapas de la refinación, siendo la etapa de blanqueo donde hubo mayor pérdida de estos compuestos. Se evaluó sensorialmente el aceite de coco usando una prueba con escalas. La calidad sensorial fue mejorada por el proceso de refinación. El aceite de coco desodorizado obtuvo la mejor calificación sensorial

A liquid chromatography-tandem mass spectrometry-based investigation of the lamellar interstitial metabolome in healthy horses and during experimental laminitis induction

Lamellar bioenergetic failure is thought to contribute to laminitis pathogenesis but current knowledge of lamellar bioenergetic physiology is limited. Metabolomic analysis (MA) can systematically profile multiple metabolites. Applied to lamellar microdialysis samples (dialysate), lamellar bioenergetic changes during laminitis (the laminitis metabolome) can be characterised. The objectives of this study were to develop a technique for targeted MA of lamellar and skin dialysates in normal horses, and to compare the lamellar and plasma metabolomic profiles of normal horses with those from horses developing experimentally induced laminitis. Archived lamellar and skin dialysates (n = 7) and tissues (n = 6) from normal horses, and lamellar dialysate and plasma from horses given either 10 g/kg oligofructose (treatment group, OFT; n = 4) or sham (control group, CON; n = 4) were analysed. The concentrations of 44 intermediates of central carbon metabolism (CCM) were determined using liquid chromatography-tandem mass spectrometry. Data were analysed using multivariate (MVA) and univariate (UVA) analysis methods.The plasma metabolome appeared to be more variable than the lamellar metabolome by MVA, driven by malate, pyruvate, aconitate and glycolate. In lamellar dialysate, these metabolites decreased in OFT horses at the later time points. Plasma malate was markedly increased after 6 h in OFT horses. Plasma malate concentrations between OFT and CON at this time point were significantly different by UVA. MA of lamellar CCM was capable of differentiating horses developing experimental laminitis from controls. Lamellar malate, pyruvate, aconitate and glycolate, and plasma malate alone were identified as the source of differentiation between OFT and CON groups. These results highlighted clear discriminators between OFT and CON horses, suggesting that changes in energy metabolism occur locally in the lamellar tissue during laminitis development. The biological significance of these alterations requires further investigation

From favorable atomic configurations to supershell structures: a new interpretation of conductance histograms

Title: From favorable atomic configurations to supershell structures: a new interpretation of conductance histograms Authors: A. Hasmy (IVIC), E. Medina (IVIC), P.A. Serena (CSIC,IVIC) Comments: 7 pages, 3 figures, cond-mat.anwar.10825 Subj-class: Soft Condensed MatterComment: 7 pages, 3 figuresSubject: fput HMS.tex HMS-FIG1.ps HMS-FIG2.ps HMS-FIG3.p

Pathogenic mechanisms of SARS-CoV-2 infection and kidney disease: a clinical and molecular perspective

La infección por SARS-CoV-2 se ha convertido en un problema mundial de salud pública. Su presentación clínica es variada, desde benigna hasta un síndrome de distrés respiratorio agudo, afectación sistémica y fallo multiorgánico. La severidad del cuadro clínico depende de factores biológicos del virus y del huésped y de comorbilidades como la enfermedad renal. Además, la interacción entre el virus, la enzima convertidora de angiotensina 2 y la respuesta inmunológica exacerbada podría conducir al desarrollo de lesión renal aguda. Sin embargo, las implicaciones de la infección por SARSCoV-2 sobre las células renales, las repercusiones pronósticas en los pacientes con enfermedad renal crónica y su efecto a largo plazo sobre la función renal no están del todo claras. El objetivo es revisar el papel del SARSCoV-2 en la enfermedad renal aguda y crónica, y sus posibles mecanismos patogénicos en la afectación renal.The SARS-CoV-2 infection has become as a worldwide public health emergency. It exhibits a variety of clinical presentations, ranging from benign to acute respiratory distress syndrome, systemic involvement, and multiorganic failure. The severity of the clinical picture depends on host and virus biological features and the presence of comorbidities such as chronic kidney disease. In addition, the interaction between the virus, angiotensin-converting enzyme 2, and the exacerbated immune response could lead to the development of acute kidney injury. However, the implications of SARSCoV-2 infection on renal cells, the prognosis of patients with chronic kidney disease, and the long-term behavior of renal function are not entirely understood. This review aims to explore the role of SARS-CoV-2 in acute and chronic kidney disease and the possible pathogenic mechanisms of renal involvement