Systems that exhibit phase competition, order parameter coexistence, and emergent order parameter topologies constitute a major part of modern condensed-matter physics. Here, by applying a range of ...characterization techniques, and simulations, we observe that in PbTiO
/SrTiO
superlattices all of these effects can be found. By exploring superlattice period-, temperature- and field-dependent evolution of these structures, we observe several new features. First, it is possible to engineer phase coexistence mediated by a first-order phase transition between an emergent, low-temperature vortex phase with electric toroidal order and a high-temperature ferroelectric a
/a
phase. At room temperature, the coexisting vortex and ferroelectric phases form a mesoscale, fibre-textured hierarchical superstructure. The vortex phase possesses an axial polarization, set by the net polarization of the surrounding ferroelectric domains, such that it possesses a multi-order-parameter state and belongs to a class of gyrotropic electrotoroidal compounds. Finally, application of electric fields to this mixed-phase system permits interconversion between the vortex and the ferroelectric phases concomitant with order-of-magnitude changes in piezoelectric and nonlinear optical responses. Our findings suggest new cross-coupled functionalities.
The performance of ferroelectric devices is intimately entwined with the structure and dynamics of ferroelectric domains. In ultrathin ferroelectrics, ordered nanodomains arise naturally in response ...to the presence of a depolarizing field and give rise to highly inhomogeneous polarization and structural profiles. Ferroelectric superlattices offer a unique way of engineering the desired nanodomain structure by modifying the strength of the electrostatic interactions between different ferroelectric layers. Through a combination of X-ray diffraction, transmission electron microscopy, and first-principles calculations, the electrostatic coupling between ferroelectric layers is studied, revealing the existence of interfacial layers of reduced tetragonality attributed to inhomogeneous strain and polarization profiles associated with the domain structure.
Orbital angular momentum (OAM) and torque transfer play central roles in a wide range of magnetic textures and devices including skyrmions and spin-torque electronics. Analogous topological ...structures are now also being explored in ferroelectrics, including polarization vortex arrays in ferroelectric/dielectric superlattices. Unlike magnetic toroidal order, electric toroidal order does not couple directly to linear external fields. Instead, we find that the presence of an electric toroidal moment in a ferrorotational phase transfers measurable torque and OAM to a localized electron beam in the ballistic limit. We record these torque transfers from a high-energy electron beam using a momentum-resolved detector. This approach provides a high-sensitivity method to detect polarization fields and their more complex order parameters and topologies. In addition to toroidal order, we also demonstrate high-precision measurements of vorticity and chirality for polar vortexlike phases.
The formation of a two-dimensional electron gas at oxide interfaces as a consequence of polar discontinuities has generated an enormous amount of activity due to the variety of interesting effects it ...gives rise to. Here, we study under what circumstances similar processes can also take place underneath ferroelectric thin films. We use a simple Landau model to demonstrate that in the absence of extrinsic screening mechanisms, a monodomain phase can be stabilized in ferroelectric films by means of an electronic reconstruction. Unlike in the LaAlO3/SrTiO3 heterostructure, the emergence with thickness of the free charge at the interface is discontinuous. This prediction is confirmed by performing first-principles simulations of free-standing slabs of PbTiO3. The model is also used to predict the response of the system to an applied electric field, demonstrating that the two-dimensional electron gas can be switched on and off discontinuously and in a nonvolatile fashion. Furthermore, the reversal of the polarization can be used to switch between a two-dimensional electron gas and a two-dimensional hole gas, which should, in principle, have very different transport properties. We discuss the possible formation of polarization domains and how such configuration competes with the spontaneous accumulation of free charge at the interfaces.
During switching, the microstructure of a ferroelectric normally adapts to align internal dipoles with external electric fields. Favorably oriented dipolar regions (domains) grow at the expense of ...those in unfavorable orientations and this is manifested in a predictable field‐induced motion of the walls that separate one domain from the next. Here, the discovery that specific charged 90°domain walls in copper–chlorine boracite move in the opposite direction to that expected, increasing the size of the domain in which polarization is anti‐aligned with the applied field, is reported. Polarization–field (P–E) hysteresis loops, inferred from optical imaging, show negative gradients and non‐transient negative capacitance, throughout the P–E cycle. Switching currents (generated by the relative motion between domain walls and sensing electrodes) confirm this, insofar as their signs are opposite to those expected conventionally. For any given bias, the integrated switching charge due to this anomalous wall motion is directly proportional to time, indicating that the magnitude of the negative capacitance component should be inversely related to frequency. This passes Jonscher's test for the misinterpretation of positive inductance and gives confidence that field‐induced motion of these specific charged domain walls generates a measurable negative capacitance contribution to the overall dielectric response.
During switching, specific charged 90° domain walls in copper–chlorine boracite are seen to move in the opposite direction to that expected, increasing the size of the domain in which polarization is anti‐aligned with the applied electric field. Polarization–field hysteresis loops show negative gradients and measured switching currents confirm the negative‐capacitance contribution to the overall dielectric response.
Several studies support the hypothesis that scabies is on the rise in Spain. There are also concerns about the possible development of resistance to treatment and an increase in atypical ...presentations. The aims of this study were to describe the demographic and clinical characteristics of patients with scabies seen by dermatologists in Spain, to identify the possible emergence of atypical forms of scabies, and to explore the frequency of treatment failures and associated risk factors.
We conducted an observational, cross-sectional, multicenter study of data collected prospectively in April and May 2023 using the CLINI-AEDVp platform created by the Spanish Academy of Dermatology and Venereology (AEDV).
Participating dermatologists from 31 hospitals in 15 of Spain's autonomous communities recorded 186 cases of active scabies (51% in women) during the study period. A diagnostic certainty level of A, B or C as per the International Alliance for the Control of Scabies Consensus Criteria was required for diagnosis. Overall, 92% of patients had clinical features of classic scabies and 66% had already been treated with a scabicide for the current episode. Of the treated patients, only 36% had received and completed adequate treatment (including the simultaneous treatment of all household members) and 50% had not received clear written recommendations.
In a high proportion of scabies cases, the patient has already received treatment. In those cases, we observe several remediable shortcomings that could explain why some of these treatments fail. Remedying these deficiencies should lead to better control of scabies and an improved assessment of the actual effectiveness of currently available scabicides.
Several studies support the hypothesis that scabies is on the rise in Spain. There are also concerns about the possible development of resistance to treatment and an increase in atypical ...presentations. The aims of this study were to describe the demographic and clinical characteristics of patients with scabies seen by dermatologists in Spain, to identify the possible emergence of atypical forms of scabies, and to explore the frequency of treatment failures and associated risk factors.
We conducted an observational, cross-sectional, multicenter study of data collected prospectively in April and May 2023 using the CLINI-AEDVp platform created by the Spanish Academy of Dermatology and Venereology (AEDV).
Participating dermatologists from 31 hospitals in 15 of Spain's autonomous communities recorded 186 cases of active scabies (51% in women) during the study period. A diagnostic certainty level of A, B or C as per the International Alliance for the Control of Scabies Consensus Criteria was required for diagnosis. Overall, 92% of patients had typical scabies and 66% had already been treated with a scabicide for the current episode. Of the treated patients, only 36% had received and completed adequate treatment (including the simultaneous treatment of all household members) and 50% had not received clear written recommendations.
In a high proportion of the cases of scabies studied, the patient had already received treatment. In those cases, we observed several remediable shortcomings that could explain why some of these treatments had failed. Remedying these deficiencies should lead to better control of scabies and an improved assessment of the actual effectiveness of currently available scabicides.
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Diversos trabajos apoyan la hipótesis de que en España se está produciendo un aumento de incidencia de la escabiosis, y existen dudas sobre el posible desarrollo de resistencias y el ...incremento de formas clínicas atípicas. Los objetivos de este estudio fueron caracterizar el perfil demográfico y clínico de los pacientes de escabiosis atendidos por dermatólogos en España, identificar la posible aparición de escabiosis atípicas, así como describir la frecuencia y los posibles factores de riesgo de los fracasos terapéuticos previos.
Realizamos un estudio observacional, transversal, multicéntrico con recogida de datos prospectiva, en abril y mayo de 2023 dentro de la plataforma CLINI-AEDVp de la Academia Española de Dermatología y Venereología.
Se reclutaron 186 casos de escabiosis activa (51% mujeres) en 31 centros participantes de 15 comunidades autónomas. Se requirió un nivel A, B o C de los criterios de consenso de la International Alliance for the Control of Scabies (IACS) para el diagnóstico. El 92% de los pacientes presentaron formas clínicas típicas de escabiosis y un 66% había recibido tratamiento escabicida previo para el episodio en curso. De los pacientes previamente tratados, solo un 36% había recibido y cumplimentado una pauta terapéutica adecuada que incluyera el tratamiento simultáneo de convivientes, y un 50% careció de un documento escrito y claro con las recomendaciones.
Una elevada proporción de los casos de escabiosis atendidos actualmente ha recibido tratamiento previo. En estos se observan defectos corregibles que pueden justificar parte de los fracasos terapéuticos. Trabajar en la mejora de las deficiencias encontradas ayudará a un mejor control de la enfermedad y a evaluar la efectividad actual de los escabicidas disponibles.
Several studies support the hypothesis that scabies is on the rise in Spain. There are also concerns about the possible development of resistance to treatment and an increase in atypical presentations. The aims of this study were to describe the demographic and clinical characteristics of patients with scabies seen by dermatologists in Spain, to identify the possible emergence of atypical forms of scabies, and to explore the frequency of treatment failures and associated risk factors.
We conducted an observational, cross-sectional, multicenter study of data collected prospectively in April and May 2023 using the CLINI-AEDVp platform created by the Spanish Academy of Dermatology and Venereology (AEDV).
Participating dermatologists from 31 hospitals in 15 of Spain's autonomous communities recorded 186 cases of active scabies (51% in women) during the study period. A diagnostic certainty level of A, B or C as per the International Alliance for the Control of Scabies Consensus Criteria was required for diagnosis. Overall, 92% of patients had typical scabies and 66% had already been treated with a scabicide for the current episode. Of the treated patients, only 36% had received and completed adequate treatment (including the simultaneous treatment of all household members) and 50% had not received clear written recommendations.
In a high proportion of the cases of scabies studied, the patient had already received treatment. In those cases, we observed several remediable shortcomings that could explain why some of these treatments had failed. Remedying these deficiencies should lead to better control of scabies and an improved assessment of the actual effectiveness of currently available scabicides.
Introduction: Collecting duct carcinomas (CDC), also known as Bellini’s tumors, are a rare and aggressive subtype of renal cell carcinoma. Therefore, there are very few data about their management, ...and there is no standard therapy for this malignancy. We report the outcome of CDC patients treated on institutions belonging to the ‘Grupo Centro’ of Genitourinary Tumors, a novel networking cooperative group in Spain. Material and Methods: Patients with CDC diagnosed between 1995 and 2015 were included. They had to have an appropriate follow-up, as well as available tissue for further correlative studies. Demographic baseline features and therapy outcomes were collected in a retrospective fashion. Approval for this data collection was obtained from a central ethical committee. Results: A total of 43 patients were analysed, with a median overall survival (OS) of 14 months (95% CI: 9.2–18.8 months). 29 of them (67.4%) were diagnosed as localized disease, and 14 (32.6%) as metastatic disease. For the subgroup of patients diagnosed without metastases, median relapse-free survival (RFS) is 22 months (95% CI: 12.4–35.6 months), and median OS, 53 months (95% CI: 35.5–84.3 months). For the subgroup of patients with metastatic disease, median OS is 6 months (95% CI: 4.1–7.8 months). 16 patients (55.2%) with stage IV disease received systemic therapy, mainly platinum-based chemotherapy, with a response rate of 12.5% and a median progression-free survival (PFS) of 2 months. Conclusions: CDC of the kidney is a malignancy with poor prognosis and few responses to therapy. Median OS of our group in the metastatic setting is similar to what has been observed in previous series. There is a clear need to improve the armamentarium we have for the systemic approach of patients with advanced CDC.