Faraday rotation and transmittance as markers of topological phase transitions in 2D materials

We analyze the magneto-optical conductivity (and related magnitudes like transmittance and Faraday rotation of the irradiated polarized light) of some elemental twodimensional Dirac materials of group IV (graphene analogues, buckled honeycomb lattices, like silicene, germanene, stannane, etc.), group V (phosphorene), and zincblende heterostructures (like HgTe/CdTe quantum wells) near the Dirac and gamma points, under out-of-plane magnetic and electric fields, to characterize topological-band insulator phase transitions and their critical points. We provide plots of the Faraday angle and transmittance as a function of the polarized light frequency, for different external electric and magnetic fields, chemical potential, HgTe layer thickness and temperature, to tune the material magneto-optical properties. We have shown that absortance/transmittance acquires extremal values at the critical point, where the Faraday angle changes sign, thus providing fine markers of the topological phase transition. In the case of non-topological materials as phosphorene, a minimum of the transmittance is also observed due to the energy gap closing by an external electric field.Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (through Organization: Consejería de Economía Innovación Ciencia y Empleo)Ministerio de Ciencia e InnovaciónUniversidad Nacional Autónoma de México / National Autonomous University of Mexico [UNAM

Avances en el diagnóstico y tratamiento de las arritmias cardíacas

The era of catheter ablation for the treatment of arrhythmias began in 1981 when Dr Scheinman performed the first atrioventricular junction ablation using direct current shocks in a patient with drug refractory atrial fibrillation and an uncontrolled ventricular rate. With the progress of radiofrequency catheter ablation, the range of arrhythmias amenable to catheter ablation and the number of patients that could be treated safely by this procedure expanded enormously. Lastly, although still in an evolutionary phase, catheter ablation to eliminate atrial fibrillation has been demostrated in the past years to be feasible and clinically useful. On the other hand, innovations in technology and pharmacology, and better preventive and diagnostic tools, have provided our patients with an important improvement in their prognosis. The new developments in molecular genetics and biology are likely to change the way we approach a cardiac patient in the future. The diseases are now being deciphered at the most basic level, and the information obtained opens new possibilities not only for better therapeutic and diagnostic measures but also for prevention of the disease

Prevalencia del síndrome metabólico en población laboral española: registro MESYAS

Introducción y objetivos. Estudiar la prevalencia del síndrome metabólico (SM) en la población laboral activa española y analizar sus diferencias según las categorías laborales. Sujetos y método. Se recogieron los datos de 7.256 trabajadores activos (un 82,4% varones), con una edad media de 45,4 ± 9,8 años, empleados en una factoría de coches y unos grandes almacenes. El diagnóstico del SM se realizó mediante los criterios modificados del ATP-III (se utilizó el índice de masa corporal en lugar del perímetro abdominal). Resultados. La prevalencia bruta del SM fue del 10,2%. Ajustada por edad y sexo en una población plana (20-60 años) fue del 5,8% (intervalo de confianza [IC] del 95%, 4,1-7,6%), significativamente más alta en varones que en mujeres (el 8,7%; IC del 95%, 7,3-10,0 frente al 3,0%; IC del 95%, 0,8-5,1). Todos los componentes del SM fueron significativamente más prevalentes en varones, excepto las concentraciones de lipoproteínas de alta densidad, que fueron más bajas. La prevalencia aumentó con la edad y el sexo masculino (odds ratio [OR] = 1,7), la obesidad (OR = 9,6), la hipertensión (OR = 3,4) y la diabetes (OR = 15,4). Los trabajadores manuales presentaron la mayor prevalencia de SM (11,8%), seguidos por EPIDEMIOLOGÍA Y PREVENCIÓN Prevalencia del síndrome metabólico en población laboral española: registro MESYAS Eduardo Alegríaa, Alberto Corderoa, Martín Laclaustrab, Alberto Grimac, Montserrat Leónb, José A. Casasnovasb, Emilio Luengod, Alfonso del Ríob e Ignacio Ferreirab, en representación de los investigadores del registro MESYAS* aDepartamento de Cardiología. Clínica Universitaria de Navarra. Pamplona. Navarra. España. bUnidad de Investigación Cardiovascular. Hospital Clínico Universitario. Zaragoza. España. cServicio de Cardiología Preventiva. Asepeyo. Valencia. España. dServicio de Cardiología. Hospital Militar. Zaragoza. España. *Al final del artículo se relacionan los miembros del equipo de investigación MESYAS. Martín Laclaustra está contratado como investigador en el Instituto Aragonés de Ciencias de la Salud dentro del programa de ayudas a contratos para investigadores que han finalizado su formación médica especializada del Instituto de Salud Carlos III. El registro MESYAS cuenta con una beca de la Sociedad Española de Cardiología (Sevilla, 2003) y la Sección de Cardiología Preventiva y Rehabilitadora. Correspondencia: Dr. E. Alegría Ezquerra. Departamento de Cardiología. Clínica Universitaria de Navarra. Avda. Pío XII, 36. 31008 Pamplona. Navarra. España. Correo electrónico: [email protected] Recibido el 5 de octubre de 2004. Aceptado para su publicación el 18 de marzo de 2005. los trabajadores de oficina (9,3%) y los directivos (7,7%) (gradiente social inverso). Los trabajadores manuales tienen un riesgo superior de presentar SM, con independencia de la edad y el sexo (OR = 1,3); este efecto parece depender de las concentraciones de triglicéridos. Conclusiones. Uno de cada 10 trabajadores activos tiene SM; la prevalencia aumenta con la edad y el sexo masculino. La obesidad y la diabetes suponen gran incremento de la prevalencia. Los trabajadores manuales son el colectivo con mayor prevalencia

Molecular identification and characterization of haptoglobin in teleosts revealed an important role on fish viral infections

Haptoglobin (Hp) molecule has been cloned and characterized in two marine teleosts (gilthead seabream and European sea bass), obtaining putative proteins of 319 residues encoded by an ORF of 960 bp in both species. However, the matrix of similarity revealed low identities among bony fish species 78.9% (seabream-sea bass), 43% (seabream/seabass-zebrafish) and lower than 20% with sharks and human. The protein sequences showed a signal peptide from the position 1 to 23, a trypsin domain from 47 to 297, and several predicted disulfide bridges and glycosylation sites. The expression of hp transcript levels during ontogeny showed a progressive increase of expression in seabream whilst remained almost unaltered in sea bass. By tissues, this gene was found constitutively expressed with the highest levels on liver in both species. The main results on hp transcript levels showed the up-regulation in gilthead seabream suffering from naturally occurring lymphocystis disease; and the down-regulation and up-regulation after nodavirus infection in the resistant gilthead seabream and the susceptible European sea bass, respectively. These findings demonstrate for the first time an important role of haptoglobin against viral infections, operating differently in two of the most important marine farmed fish species.Postprint3,26

Geometrical dynamics of Born-Infeld objects

We present a geometrical inspired study of the dynamics of $Dp$-branes. We focus on the usual nonpolynomial Dirac-Born-Infeld action for the worldvolume swept out by the brane in its evolution in general background spacetimes. We emphasize the form of the resulting equations of motion which are quite simple and resemble Newton's second law, complemented with a conservation law for a worldvolume bicurrent. We take a closer look at the classical Hamiltonian analysis which is supported by the ADM framework of general relativity. The constraints and their algebra are identified as well as the geometrical role they play in phase space. In order to illustrate our results, we review the dynamics of a $D1$-brane immersed in a $AdS_3 \times S^3$ background spacetime. We exhibit the mechanical properties of Born-Infeld objects paving the way to a consistent quantum formulation.Comment: LaTex, 20 pages, no figure

Natural iminosugar (+)-lentiginosine inhibits ATPase and chaperone activity of Hsp90

Heat shock protein 90 (Hsp90) is a significant target in the development of rational cancer therapy due to its role at the crossroads of multiple signaling pathways associated with cell proliferation and cell viability. The relevance of Hsp90 as a therapeutic target for numerous diseases states has prompted the identification and optimization of novel Hsp90 inhibitors as an emerging therapeutic strategy. We performed a screening aimed to identify novel Hsp90 inhibitors among several natural compounds and we focused on the iminosugar (+)-lentiginosine, a natural amyloglucosidases inhibitor, for its peculiar bioactivity profile. Characterization of Hsp90 inhibition was performed using a panel of chemical and biological approaches, including limited proteolysis, biochemical and cellular assays. Our result suggested that the middle domain of Hsp90, as opposed to its ATP-binding pocket, is a promising binding site for new classes of Hsp90 inhibitors with multi-target anti-cancer potential

Utilidad de los Beta-bloqueantes en el tratamiento de la insuficiencia cardiaca crónica

Heart failure has become a major public health problem. About 2-3% of people over 65 years suffer from Heart Failure. A huge amount of money is spent every year treating problems connected with this syndrome. In this paper we analyse randomised prospective trials which support the use of beta-blockers in these patients. We also analyse the benefits of this treatment and some special considerations concerning the use of these drugs

Persistent extreme ultraviolet irradiance in Antarctica despite the ozone recovery onset

Attributable to the Montreal Protocol, the most successful environmental treaty ever, human-made ozone-depleting substances are declining and the stratospheric Antarctic ozone layer is recovering. However, the Antarctic ozone hole continues to occur every year, with the severity of ozone loss strongly modulated by meteorological conditions. In late November and early December 2020, we measured at the northern tip of the Antarctic Peninsula the highest ultraviolet (UV) irradiances recorded in the Antarctic continent in more than two decades.The support of INACH (RT_69-20 & RT_70-18), ANID (ANILLO ACT210046, FONDECYT 1191932 & 1221122, DFG190004 and REDES180158), CORFO (19BP-117358 & 18BPE-93920) is gratefully acknowledged

Modified geodetic brane cosmology

We explore the cosmological implications provided by the geodetic brane gravity action corrected by an extrinsic curvature brane term, describing a codimension-1 brane embedded in a 5D fixed Minkowski spacetime. In the geodetic brane gravity action, we accommodate the correction term through a linear term in the extrinsic curvature swept out by the brane. We study the resulting geodetic-type equation of motion. Within a Friedmann-Robertson-Walker metric, we obtain a generalized Friedmann equation describing the associated cosmological evolution. We observe that, when the radiation-like energy contribution from the extra dimension is vanishing, this effective model leads to a self-(non-self)-accelerated expansion of the brane-like universe in dependence on the nature of the concomitant \beta-parameter associated with the correction, which resembles an analogous behaviour in the DGP brane cosmology. Several possibilities in the description for the cosmic evolution of this model are embodied and characterized by the involved density parameters related in turn to the cosmological constant, the geometry characterizing the model, the introduced \beta-parameter as well as the dark like-energy and the matter content on the brane.Comment: 15 pages, 3 figures. New version corresponds to the one published in CQ