Persistent currents in n-fold twisted Moebius strips

We investigate the influence of the topology on generic features of the persistent current in n-fold twisted Moebius strips formed of quasi one--dimensional mesoscopic rings, both for free electrons and in the weakly disordered regime. We find that there is no generic difference between the persistent current for untwisted rings and for Moebius strips with an arbitrary number of twists.Comment: 7 pages, 2 figure

Towards the understanding of vertical-axis wind turbines in double-rotor configuration

Vertical-axis wind turbines (VAWTs) in double-rotor configuration, meaning two rotors in close proximity, have the ability to enhance the power performance. In this study, we work towards the understanding of vertical-axis wind turbines in double-rotor configuration. Numerical simulations are performed to gain insight in the physics behind the double-rotor concept. Furthermore, a parametric study is performed to explore the effect of the double-rotor lay-out, rotor loading, rotor spacing and wind direction on the flow characteristics and the power generation.</p

Structural Transitions in a Classical Two-Dimensional Molecule System

The ground state of a classical two-dimensional (2D) system with finite number of charged particles, trapped by two positive impurities charges localized at a distance (zo) from the 2D plane and separated from each other by a distance xp are obtained. The impurities are allowed to carry more than one positive charge. This classical system can form a 2D-like classical molecule that exhibits structural transitions and spontaneous symmetry breaking as a function of the separation between the positive charges before it transforms into two independent 2D-like classical atoms. We also observe structural transitions as a function of the dielectric constant of the substrate which supports the charged particles, in addition to broken symmetry states and unbinding of particles.Comment: 9 pages, 7 figure

The Role of Rosmarinic Acid on the Bioproduction of Gold Nanoparticles as Part of a Photothermal Approach for Breast Cancer Treatment.

Breast cancer is a high-burden malignancy for society, whose impact boosts a continuous search for novel diagnostic and therapeutic tools. Among the recent therapeutic approaches, photothermal therapy (PTT), which causes tumor cell death by hyperthermia after being irradiated with a light source, represents a high-potential strategy. Furthermore, the effectiveness of PTT can be improved by combining near infrared (NIR) irradiation with gold nanoparticles (AuNPs) as photothermal enhancers. Herein, an alternative synthetic method using rosmarinic acid (RA) for synthesizing AuNPs is reported. The RA concentration was varied and its impact on the AuNPs physicochemical and optical features was assessed. Results showed that RA concentration plays an active role on AuNPs features, allowing the optimization of mean size and maximum absorbance peak. Moreover, the synthetic method explored here allowed us to obtain negatively charged AuNPs with sizes favoring the local particle accumulation at tumor site and maximum absorbance peaks within the NIR region. In addition, AuNPs were safe both in vitro and in vivo. In conclusion, the synthesized AuNPs present favorable properties to be applied as part of a PTT system combining AuNPs with a NIR laser for the treatment of breast cancer

T-Wave Morphology Changes as Surrogate for Blood Potassium Concentration in Hemodialysis Patients

End-stage renal disease (ESRD) patients undergoing hemodialysis (HD) are at high risk of arrhythmias and sudden cardiac death as a result of blood potassium concentration ([K+ ]) changes. The aim of this study is to investigate if dw, a time-warping-based electrocardiogram (ECG) biomarker of T-wave morphology changes, reflects [K+] evolution in HD patients, facilitating noninvasive [K+] monitoring and avoiding in-hospital blood tests analysis. 48-hour ECGs and a set of hourly-collected blood samples from 12 ESRD patients were acquired and analyzed. dw was calculated between a reference T-wave, measured at the end of the HD session, and the T-waves corresponding to each hour along the whole HD session, when [K+] was measured from blood samples. The values of dw correlated with the relative variations in [K+] with respect to the reference value (end of HD, ¿[K+ ]), with a median (interquartile) correlation coefficient of 0.90 (0.30), evidencing a strong relation between them. Our findings support the use of dw as a surrogate of ¿[K+], suggesting a potential use of dw for non-invasive hyperkalemia monitoring both in hospital and ambulatory settings

Quintessence arising from exponential potentials

We demonstrate how exponential potentials that could arise in the early Universe as a result of Kaluza-Klein type compactifications of string theory, can lead to cosmological solutions which correspond to the currently observed accelerating Universe. The idea is simple, relying solely on the known scaling properties associated with exponential potentials. In particular we show that the existence of stable attractor solutions implies that the results hold for a wide range of coupling constants and initial conditions.Comment: 4 pages, 3 figures, published versio

Caracterización de harinas de tritíceas híbridas

Triticales (x Triticosecale Wittmack) y tricepiros (x Triticosecale Witt. X x Agrotricum A. Camus) se mejoran con la finalidad de obtener cultivares de doble propósito (forraje y grano). Para su utilización en consumo humano, la calidad de las harinas de triticales es frecuentemente evaluada midiendo el diámetro y factor de expansión de las galletitas horneadas. Estos indicadores están fuertemente relacionados al contenido de almidón dañado, proteína y polisacáridos no amiláceos de la harina que determinan sus propiedades de absorción de agua. Se evaluaron 25 líneas experimentales, ocho cultivares de triticale y uno de tricepiro en Santa Rosa, La Pampa, Argentina, durante 2012, mediante análisis de correlación simple y de conglomerados. Se observaron correlaciones positivas entre los valores de la capacidad de retención del solvente agua, carbonato de sodio, ácido láctico y sacarosa, índice de retención de agua alcalina, pentosanos solubles y almidón dañado. La caracterización de las harinas y la separación en grupos según sus propiedades fisicoquímicas permitieron la selección de genotipos con diferentes propiedades funcionales. En el análisis de conglomerados, el cluster 1 agrupó los materiales con mejores características fisicoquímicas de las harinas, lo cual aumenta las posibilidades de su empleo en la alimentación humana.Triticales (x Triticosecale Wittmack) and Tricepiros (x Triticosecale Witt. X x Agrotricum A. Camus) are improved in order to obtain dual-purpose cultivars (forage and grain). In order to use them for human consumption the quality of triticale four is frequently evaluated by measuring the diameter and spread factor of cookies. These indicators are strongly related to the contents of damaged starch, protein and non-starch polysaccharides of four, which determine its water absorption properties. During 2012, twenty-five experimental strains, eight triticale and one tricepiro cultivars were evaluated in Santa Rosa, La Pampa, Argentina by means of simple correlation and cluster analysis. Positive correlations between the values of solvent retention capacity of water, sodium carbonate, lactic acid and sucrose, retention rate of alkaline water, soluble pentosans and damaged starch were observed. The characterization of the tested fours and their differentiation based on their physicochemical properties allowed the selection of genotypes with different functional properties. In the cluster analysis, cluster 1 pooled the materials with the best physicochemical features of four, which increases the possibilities of its use for human consumption.Fil: Castaño, M. N.. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Ferrari, E. D.. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Picca, Aurora Maria Teresita. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Curti, María Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Ribotta, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; Argentina. Universidad Nacional de Córdoba. Secretaría de Ciencia y Tecnología. Instituto Superior de Investigación, Desarrollo y Servicio de Alimentos; ArgentinaFil: Leon, Alberto Edel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Ciencia y Tecnología de Alimentos Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Ciencia y Tecnología de Alimentos Córdoba; ArgentinaFil: Ferreira, V. A.. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Grassi, E. M.. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Di Santo, Hernán Elías. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Castillo, E. A.. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Paccapelo, Hector Antonio. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentin