Pseudospin-dependent Zitterbewegung in monolayer graphene

We propose a spintronic device based on a narrow nanoribbon patterned from a monolayer graphene (MLG) sheet, embedded between a film of hexagonal boron nitride and a SiO2 substrate, all comprised under a three top-gated structure, to explore spin-dependent quantum transport of Dirac fermions. We developed a theoretical procedure for describing the pseudospin-related effects and the dynamics of Dirac fermions represented by a one-dimensional Gaussian wave packet (1DGWP), which is electrostatically confined in the device. The free-space 1DGWP time evolution follows expected features. Meanwhile, due to the weak breakdown of the real-spin degeneracy, the 1DGWP barely splits inside the under-barrier region governed by the extrinsic Rashba spin–orbit interaction (SOI-R). Most importantly, departing from the pristine MLG, we have found evidence of trembling antiphase oscillations in the probability density time-distribution for each sublattice state, which we have called the pseudospinorial Zitterbewegung effect (PZBE). The PZBE appears modulated with robust transient character and with a decay time in the femtosecond scale. Interestingly, several features of the PZBE become tunable, even its complete disappearance at the vicinity of the Dirac points or at a symmetric pseudospin configuration. For the proposed quasi-1D MLG device, we have captured evidence of the familiar Klein tunneling and the unusual anti-Klein tunneling, whose interplay for 2D MLG under tunable SOI-R was reported recently

Enhancement of Fano-resonance response in bilayer graphene single and double barriers induced by bandgap opening

Fano resonances in bilayer graphene arise due to the coupling between extended and discrete electrons states, and represent an exotic phenomenon in graphene akin to Klein and anti-Klein tunneling, atomic collapse and negative refraction to mention a few. The hallmark of these resonances is identifiable in the conductance curves of bilayer graphene barrier structures. Furthermore, the Fano line-shape can be presented in the conductance by reducing the angular range in the computation of the transport properties. In this work, we explore the possible consequences that bandgap opening in the band structure of bilayer graphene can have over Fano resonances. We have used a four-band Hamiltonian to taking into account the mentioned band structure modifications. The hybrid matrix method and the Landauer–Büttiker formalism have been implemented to obtain the transmittance and the conductance, respectively. We find that the signatures of the Fano resonances on the conductance are enhanced by the opening of the bandgap. In fact, the Fano profile is manifested in the conductance without the need of reducing the angular range. This enhancement results from the improvement of the chirality matching between extended and discrete states induced by the bandgap opening. The main characteristics of the impact of the bandgap opening on the transmission and transport properties of single and double barriers are presented. So, the bandgap opening far from hamper the Fano resonance response promotes it and can be used as modulation parameter to prove the exotic phenomenon of Fano resonances in bilayer graphene barrier structures

Tunneling times in a taut string

The mathematical analogy of classical and matter waves can help to teach the elusive subject of tunneling times in undergraduate physics courses. The tunneling of mechanical energy through a taut string is revisited in this paper in order to study tunneling times for this classical system. General properties of the group delay, the dwell time and the interference time are described. Moreover, we explain how to build string arrays with piecewise constitutive parameters that behave like quantum mechanical heterostructures with alternating well and barrier layers. The paradoxical Hartman effect is also analyzed

Naturaleza, libertad y persona: Reflexiones sobre la paradoja humana

The present paper discusses the openness of man from a legalized nature. It analyses the conflict between law, physis and freedom We wonder why nature is understood as incompatible with free will, and why the law seems to be contradictory with this opening. Does being free mean being away from any attachment to the law and nature? The text begins with a presentation of nature and the notion of legality, as well as its relation to freedom, and it offers a definition of person, based on the understanding about dignity and self, as an explanation of the meaning of openness in the social dimension of human beings.Se analiza la apertura del hombre a partir de su naturaleza legalizada. Ante el conflicto entre ley, physis y libertad, nos preguntamos: ¿por qué se considera la naturaleza incompatible con la libertad?, ¿por qué la legalidad parece contradecir a la apertura?, ¿ser libre significa estar lejos de cualquier atadura a la ley y a la naturaleza? El texto inicia con una exposición de las nociones de naturaleza y legalidad y de su relación con la libertad, ofrece una definición de la persona basada en su comprensión yoica y su dignidad y una explicación del sentido de la apertura en la dimensión social del ser humano. &nbsp

Lattice Green's function approach to the solution of the spectrum of an array of quantum dots and its linear conductance

In this paper we derive general relations for the band-structure of an array of quantum dots and compute its transport properties when connected to two perfect leads. The exact lattice Green's functions for the perfect array and with an attached adatom are derived. The expressions for the linear conductance for the perfect array as well as for the array with a defect are presented. The calculations are illustrated for a dot made of three atoms. The results derived here are also the starting point to include the effect of electron-electron and electron-phonon interactions on the transport properties of quantum dot arrays. Different derivations of the exact lattice Green's functions are discussed

Adenocarcinoma de la próstata Gleason 6

This is a 69 year old patient with a medical history of ischemic heart disease, hypertension and type 2 diabetes mellitus who was admitted twice in the "Arnaldo Milián Castro" Surgical Hospital of the City of Santa Clara, Province Villa Clara, by decay and weight loss, abdominal tumors of four and 5cm respectively on the right flank and left hemiparesis with neurological symptoms, physical examination was found to further enlargement of the thyroid. He had a long evolution in living and he performed various add -abdominal and thyroid ultrasound, chest  X-ray and computed tomography of the skul, which showed an increase in nodular thyroid volume and a parahilum left pulmonary inflammatory process, not reached a definitive clinical diagnosis and died 55 days after admission.Se trata de un paciente de 69 años de edad con antecedentes personales patológicos de cardiopatía isquémica, hipertensión arterial y diabetes mellitus tipo 2 que fue ingresado en dos oportunidades en el Hospital Clínico Quirúrgico “Arnaldo Milián Castro” de la Ciudad de Santa Clara, Provincia de Villa Clara, por decaimiento y pérdida de peso, tumoraciones abdominales de cuatro y 5cm respectivamente en el flanco derecho y cuadro neurológico con hemiparesia izquierda; se constató al examen físico, además, aumento de volumen de la tiroides. Tuvo una evolución prolongada en sala y se le realizaron diversos complementarios -ultrasonido abdominal y de tiroides, rayos X de tórax y tomografía axial computadorizada de cráneo- que arrojaron un aumento de volumen nodular de la tiroides y un proceso inflamatorio pulmonar izquierdo parahiliar; no se llegó a un diagnóstico clínico definitivo y falleció 55 días después de su ingreso.

Genetic landscape of 6089 inherited retinal dystrophies affected cases in Spain and their therapeutic and extended epidemiological implications

ESRETNET Study Group, The ERDC Study Group, The Associated Clinical Study Group.Inherited retinal diseases (IRDs), defined by dysfunction or progressive loss of photoreceptors, are disorders characterized by elevated heterogeneity, both at the clinical and genetic levels. Our main goal was to address the genetic landscape of IRD in the largest cohort of Spanish patients reported to date. A retrospective hospital-based cross-sectional study was carried out on 6089 IRD affected individuals (from 4403 unrelated families), referred for genetic testing from all the Spanish autonomous communities. Clinical, demographic and familiar data were collected from each patient, including family pedigree, age of appearance of visual symptoms, presence of any systemic findings and geographical origin. Genetic studies were performed to the 3951 families with available DNA using different molecular techniques. Overall, 53.2% (2100/3951) of the studied families were genetically characterized, and 1549 different likely causative variants in 142 genes were identified. The most common phenotype encountered is retinitis pigmentosa (RP) (55.6% of families, 2447/4403). The most recurrently mutated genes were PRPH2, ABCA4 and RS1 in autosomal dominant (AD), autosomal recessive (AR) and X-linked (XL) NON-RP cases, respectively; RHO, USH2A and RPGR in AD, AR and XL for non-syndromic RP; and USH2A and MYO7A in syndromic IRD. Pathogenic variants c.3386G > T (p.Arg1129Leu) in ABCA4 and c.2276G > T (p.Cys759Phe) in USH2A were the most frequent variants identified. Our study provides the general landscape for IRD in Spain, reporting the largest cohort ever presented. Our results have important implications for genetic diagnosis, counselling and new therapeutic strategies to both the Spanish population and other related populations.This work was supported by the Instituto de Salud Carlos III (ISCIII) of the Spanish Ministry of Health (FIS; PI16/00425 and PI19/00321), Centro de Investigación Biomédica en Red Enfermedades Raras (CIBERER, 06/07/0036), IIS-FJD BioBank (PT13/0010/0012), Comunidad de Madrid (CAM, RAREGenomics Project, B2017/BMD-3721), European Regional Development Fund (FEDER), the Organización Nacional de Ciegos Españoles (ONCE), Fundación Ramón Areces, Fundación Conchita Rábago and the University Chair UAM-IIS-FJD of Genomic Medicine. Irene Perea-Romero is supported by a PhD fellowship from the predoctoral Program from ISCIII (FI17/00192). Ionut F. Iancu is supported by a grant from the Comunidad de Madrid (CAM, PEJ-2017-AI/BMD7256). Marta del Pozo-Valero is supported by a PhD grant from the Fundación Conchita Rábago. Berta Almoguera is supported by a Juan Rodes program from ISCIII (JR17/00020). Pablo Minguez is supported by a Miguel Servet program from ISCIII (CP16/00116). Marta Corton is supported by a Miguel Servet program from ISCIII (CPII17/00006)

Clinical Presentation and Outcomes of Kawasaki Disease in Children from Latin America: A Multicenter Observational Study from the REKAMLATINA Network

Objetivos: Describir la presentación clínica, el manejo y los resultados de la enfermedad de Kawasaki (EK) en Latinoamérica y evaluar los indicadores pronósticos tempranos de aneurisma de la arteria coronaria (AAC). Diseño del estudio: Se realizó un estudio observacional basado en el registro de la EK en 64 centros pediátricos participantes de 19 países latinoamericanos de forma retrospectiva entre el 1 de enero de 2009 y el 31 de diciembre de 2013, y de forma prospectiva desde el 1 de junio de 2014 hasta el 31 de mayo de 2017. Se recopilaron datos demográficos, clínicos y de laboratorio iniciales. Se utilizó una regresión logística que incorporaba factores clínicos y la puntuación z máxima de la arteria coronaria en la presentación inicial (entre 10 días antes y 5 días después de la inmunoglobulina intravenosa [IGIV]) para desarrollar un modelo pronóstico de AAC durante el seguimiento (>5 días después de la IGIV). Resultados: De 1853 pacientes con EK, el ingreso tardío (>10 días tras el inicio de la fiebre) se produjo en el 16%, el 25% tuvo EK incompleta y el 11% fue resistente a la IGIV. Entre los 671 sujetos con puntuación z de la arteria coronaria notificada durante el seguimiento (mediana: 79 días; IQR: 36, 186), el 21% presentaba AAC, incluido un 4% con aneurismas gigantes. Un modelo pronóstico simple que utilizaba sólo una puntuación z de la arteria coronaria máxima ≥2,5 en la presentación inicial fue óptimo para predecir la AAC durante el seguimiento (área bajo la curva: 0,84; IC del 95%: 0,80, 0,88). Conclusiones: De nuestra población latinoamericana, la puntuación z de la arteria coronaria ≥2,5 en la presentación inicial fue el factor pronóstico más importante que precedió a la AAC durante el seguimiento. Estos resultados resaltan la importancia de la ecocardiografía temprana durante la presentación inicial de la EK. © 2023 Los autoresObjectives: To describe the clinical presentation, management, and outcomes of Kawasaki disease (KD) in Latin America and to evaluate early prognostic indicators of coronary artery aneurysm (CAA). Study design: An observational KD registry-based study was conducted in 64 participating pediatric centers across 19 Latin American countries retrospectively between January 1, 2009, and December 31, 2013, and prospectively from June 1, 2014, to May 31, 2017. Demographic and initial clinical and laboratory data were collected. Logistic regression incorporating clinical factors and maximum coronary artery z-score at initial presentation (between 10 days before and 5 days after intravenous immunoglobulin [IVIG]) was used to develop a prognostic model for CAA during follow-up (>5 days after IVIG). Results: Of 1853 patients with KD, delayed admission (>10 days after fever onset) occurred in 16%, 25% had incomplete KD, and 11% were resistant to IVIG. Among 671 subjects with reported coronary artery z-score during follow-up (median: 79 days; IQR: 36, 186), 21% had CAA, including 4% with giant aneurysms. A simple prognostic model utilizing only a maximum coronary artery z-score ≥2.5 at initial presentation was optimal to predict CAA during follow-up (area under the curve: 0.84; 95% CI: 0.80, 0.88). Conclusion: From our Latin American population, coronary artery z-score ≥2.5 at initial presentation was the most important prognostic factor preceding CAA during follow-up. These results highlight the importance of early echocardiography during the initial presentation of KD. © 2023 The Author(s

Eligibility criteria for Menopausal Hormone Therapy (MHT): a position statement from a consortium of scientific societies for the use of MHT in women with medical conditions. MHT Eligibility Criteria Group

This project aims to develop eligibility criteria for menopausal hormone therapy (MHT). The tool should be similar to those already established for contraception A consortium of scientific societies coordinated by the Spanish Menopause Society met to formulate recommendations for the use of MHT by women with medical conditions based on the best available evidence. The project was developed in two phases. As a first step, we conducted 14 systematic reviews and 32 metanalyses on the safety of MHT (in nine areas: age, time of menopause onset, treatment duration, women with thrombotic risk, women with a personal history of cardiovascular disease, women with metabolic syndrome, women with gastrointestinal diseases, survivors of breast cancer or of other cancers, and women who smoke) and on the most relevant pharmacological interactions with MHT. These systematic reviews and metanalyses helped inform a structured process in which a panel of experts defined the eligibility criteria according to a specific framework, which facilitated the discussion and development process. To unify the proposal, the following eligibility criteria have been defined in accordance with the WHO international nomenclature for the different alternatives for MHT (category 1, no restriction on the use of MHT; category 2, the benefits outweigh the risks; category 3, the risks generally outweigh the benefits; category 4, MHT should not be used). Quality was classified as high, moderate, low or very low, based on several factors (including risk of bias, inaccuracy, inconsistency, lack of directionality and publication bias). When no direct evidence was identified, but plausibility, clinical experience or indirect evidence were available, "Expert opinion" was categorized. For the first time, a set of eligibility criteria, based on clinical evidence and developed according to the most rigorous methodological tools, has been defined. This will provide health professionals with a powerful decision-making tool that can be used to manage menopausal symptoms

Genetic landscape of 6089 inherited retinal dystrophies affected cases in Spain and their therapeutic and extended epidemiological implications

Inherited retinal diseases (IRDs), defined by dysfunction or progressive loss of photoreceptors, are disorders characterized by elevated heterogeneity, both at the clinical and genetic levels. Our main goal was to address the genetic landscape of IRD in the largest cohort of Spanish patients reported to date. A retrospective hospital-based cross-sectional study was carried out on 6089 IRD affected individuals (from 4403 unrelated families), referred for genetic testing from all the Spanish autonomous communities. Clinical, demographic and familiar data were collected from each patient, including family pedigree, age of appearance of visual symptoms, presence of any systemic findings and geographical origin. Genetic studies were performed to the 3951 families with available DNA using different molecular techniques. Overall, 53.2% (2100/3951) of the studied families were genetically characterized, and 1549 different likely causative variants in 142 genes were identified. The most common phenotype encountered is retinitis pigmentosa (RP) (55.6% of families, 2447/4403). The most recurrently mutated genes were PRPH2, ABCA4 and RS1 in autosomal dominant (AD), autosomal recessive (AR) and X-linked (XL) NON-RP cases, respectively; RHO, USH2A and RPGR in AD, AR and XL for non-syndromic RP; and USH2A and MYO7A in syndromic IRD. Pathogenic variants c.3386G > T (p.Arg1129Leu) in ABCA4 and c.2276G > T (p.Cys759Phe) in USH2A were the most frequent variants identified. Our study provides the general landscape for IRD in Spain, reporting the largest cohort ever presented. Our results have important implications for genetic diagnosis, counselling and new therapeutic strategies to both the Spanish population and other related populations.This work was supported by the Instituto de Salud Carlos III (ISCIII) of the Spanish Ministry of Health (FIS; PI16/00425 and PI19/00321), Centro de Investigación Biomédica en Red Enfermedades Raras (CIBERER, 06/07/0036), IIS-FJD BioBank (PT13/0010/0012), Comunidad de Madrid (CAM, RAREGenomics Project, B2017/BMD-3721), European Regional Development Fund (FEDER), the Organización Nacional de Ciegos Españoles (ONCE), Fundación Ramón Areces, Fundación Conchita Rábago and the University Chair UAM-IIS-FJD of Genomic Medicine. Irene Perea-Romero is supported by a PhD fellowship from the predoctoral Program from ISCIII (FI17/00192). Ionut F. Iancu is supported by a grant from the Comunidad de Madrid (CAM, PEJ-2017-AI/BMD7256). Marta del Pozo-Valero is supported by a PhD grant from the Fundación Conchita Rábago. Berta Almoguera is supported by a Juan Rodes program from ISCIII (JR17/00020). Pablo Minguez is supported by a Miguel Servet program from ISCIII (CP16/00116). Marta Corton is supported by a Miguel Servet program from ISCIII (CPII17/00006). The funders played no role in study design, data collection, data analysis, manuscript preparation and/or publication decisions