Concomitant Light-Reversible Magnetic Response in Multiferroic Oxide Heterostructures for Multiphysics Applications.

The concept of multiphysics, where materials respond to diverse external stimuli, such as magnetic fields, electric fields, light irradiation, stress, heat, and chemical reactions, plays a fundamental role in the development of innovative devices. Nanomanufacturing, especially in low-dimensional systems, enhances the synergistic interactions taking place on the nanoscale. Light-matter interaction, rather than electric fields, holds great promise for achieving low-power, wireless control over magnetism, solving two major technological problems: the feasibility of electrical contacts at smaller scales and the undesired heating of the devices. Here, we shed light on the remarkable reversible modulation of magnetism using visible light in epitaxial Fe3O4/BaTiO3 heterostructure. This achievement is underpinned by the convergence of two distinct mechanisms. First, the magnetoelastic effect, triggered by ferroelectric domain switching, induces a proportional change in coercivity and remanence upon laser illumination. Second, light-matter interaction induces charged ferroelectric domain walls' electrostatic decompensations, acting intimately on the magnetization of the epitaxial Fe3O4 film by magnetoelectric coupling. Crucially, our experimental results vividly illustrate the capability to manipulate magnetic properties using visible light. This concomitant mechanism provides a promising avenue for low-intensity visible-light manipulation of magnetism, offering potential applications in multiferroic devices.

Reversible optical control of magnetism in engineered artificial multiferroics.

Optical means instead of electric fields may offer a new pathway for low-power and wireless control of magnetism, holding great potential to design next-generation memory and spintronic devices. Artificial multiferroic materials have shown remarkable suitability as platforms towards the optical control of magnetic properties. However, the practical use of magnetic modulation should be both stable and reversible and, particularly, it should occur at room temperature. Here we show an unprecedented reversible modulation of magnetism using low-intensity visible-light in Fe75Al25/BaTiO3 heterostructures, at room temperature. This is enabled by the existence of highly oriented charged domain walls arranged in arrays of alternating in-plane and out-of-plane ferroelectric domains with stripe morphology. Light actuation yields a net anisotropic stress caused by ferroelectric domain switching, which leads to a 90-degree reorientation of the magnetic easy axis. Significant changes in the coercivity and squareness ratio of the hysteresis loops can be light-modulated, encouraging the development of novel low energy-consumption wireless magneto-optical devices.

Photocontrolled Strain in Polycrystalline Ferroelectrics via Domain Engineering Strategy.

The use of photonic concepts to achieve nanoactuation based on light triggering requires complex architectures to obtain the desired effect. In this context, the recent discovery of reversible optical control of the domain configuration in ferroelectrics offers a light-ferroic interplay that can be easily controlled. To date, however, the optical control of ferroelectric domains has been explored in single crystals, although polycrystals are technologically more desirable because they can be manufactured in a scalable and reproducible fashion. Here we report experimental evidence for a large photostrain response in polycrystalline BaTiO3 that is comparable to their electrostrain values. Domains engineering is performed through grain size control, thereby evidencing that charged domain walls appear to be the functional interfaces for the light-driven domain switching. The findings shed light on the design of high-performance photoactuators based on ferroelectric ceramics, providing a feasible alternative to conventional voltage-driven nanoactuators.

Acceso de mujeres en embarazo, parto y post parto a servicios de salud según clase social / Access of women in pregnancy, childbirth and postpartum to health services according to social class

Resumen Objetivo: comprender el acceso que tienen las mujeres en situación de embarazo, parto y post parto a los servicios de salud según la clase social en Bogotá (Colombia). Métodos: estudio cualitativo. Perspectiva hermenéutica crítica. Método etnografía crítica. Muestreo teórico. Análisis por triangulación en Atlas Ti. Participaron 9 mujeres y 8 profesionales de la salud. Se realizaron 38 entrevistas a profundidad durante 13 meses y 62 acompañamientos a las maternas en las actividades de control prenatal, vacunación, trabajo de parto, consulta post parto, exámenes de seguimiento, curso Psicoprofiláctico, hospitalización y sala de espera, tanto en servicios públicos como privados. Resultados: existen desigualdades según la clase social en el acceso que tienen las mujeres a los servicios de salud en los siguientes aspectos: acceso a servicio a especialistas, hacer la fila para esperar la atención, la disponibilidad de citas y agenda para programar la cita, perder la cita habiendo llegado al servicio, la prioridad que le dan las instituciones a las maternas, madrugar para conseguir atención, pedir la cita, las condiciones de la espera y elegir la clínica o el personal. Conclusiones: los anteriores aspectos se intensifican en clases sociales con menos ventajas. Se requiere disminuir las desigualdades sociales para disminuir las inequidades en salud.

Abstract Objective: to understand the access that women in pregnancy, childbirth and postpartum have to health services according to social class in Bogotá (Colombia). Methods: qualitative study. Critical hermeneutical perspective. Critical ethnography method. Theoretical sampling. Analysis by triangulation in Atlas Ti. 9 women and 8 health professionals participated. 38 in-depth interviews were carried out during 13 months and 62 accompaniments to the maternal in the activities of prenatal control, vaccination, labor, postpartum consultation, follow-up examinations, Psychoprophylactic course, hospitalization and waiting room, both in public services as private. Results: there are inequalities according to social class in the access that women have to health services in the following aspects: access to specialist services, queuing to wait for care, availability of appointments and schedule to schedule the appointment, Missing the appointment having arrived at the service, the priority that institutions give to maternal mothers, getting up early to get care, requesting an appointment, waiting conditions and choosing the clinic or staff. Conclusions: the previous aspects are intensified in social classes with less advantages. Reducing social inequalities is required to decrease health inequities.

[Women in pregnancy, delivery, and postpartum: a look from the feminist point of view]. / Mujeres en embarazo, parto, y posparto: una mirada desde el pensamiento feminista.

This essay analyzes the contributions of the gender approach of feminist thinking to understand the relationship of women in pregnancy, childbirth, and postpartum with health service personnel. Origi nal qualitative design research was analyzed, were the relationship of women with health personnel is visualized. It is concluded that the gender approach of feminist thinking is a useful approximation to understand the problem of women's relations with health service personnel in aspects such as obstetric violence, care and the intersection of gender with other categories, in the framework of the health system.

Este ensayo analiza los aportes del enfoque de género del pensamiento feminista para comprender la relación de las mujeres en el embarazo, parto, y posparto con el personal de los servicios de salud. Se analizaron investigaciones originales de diseño cualitativo en las cuales se visualiza la relación de las mujeres con el personal de salud. Se concluye que el enfoque de género del pensamiento feminista es una aproximación útil para comprender la problemática de las relaciones de las mujeres con el personal de los servicios de salud en aspectos como la violencia obstétrica, el cuidado y la intersección del género con otras categorías, en el marco del sistema de salud.

Relations established by women during pregnancy, delivery and postpartum with health personnel according to social class in Bogotá: qualitative study. / Relaciones que establecen las mujeres durante el embarazo, parto y posparto con el personal de salud según clase social en Bogotá: estudio cualitativo.

OBJECTIVE: To understand the relationship established between women in a situation of pregnancy, childbirth and postpartum with the health services personnel according to social class in Bogotá (Colombia). MATERIALS AND METHODS: Qualitative study. Critical hermeneutical perspective and critical ethnography. Theoretical sampling. Analysis by triangulation in Atlas.ti. 9 women and 8 health professionals participated. 38 in-depth interviews were conducted for 13 months and 62 accompaniments to the maternal in the activities of prenatal control, vaccination, labor, postpartum consultation, follow up exams, prophylactic pisco course, hospitalization and waiting room, both in public services as private. RESULTS: There are inequalities according to social class in which the relationship between women and staff is configured in the following aspects: permeability to the needs of women, recognition of psychosocial aspects, having different points of view against a medical recommendation and right to complain or demand to improve. CONCLUSIONS: The situation described above intensifies gender issues in women with a less advantageous social class. It is necessary to develop interventions in educational and health institutions that consider aspects where human resources are sensitized on social issues related to the theoretical proposals of research and the democratization of medical information. It is unfair that the condition of social class and gender affects the quality of care and economically stratifies people's rights.

OBJETIVO: Comprender la relación que se establece entre las mujeres en situación de embarazo, parto y posparto con el personal de los servicios de salud según la clase social en Bogotá (Colombia). MATERIALES Y MÉTODOS: Estudio cualitativo, perspectiva hermenéutica crítica y etnografía crítica con muestreo teórico. Análisis por triangulación en Atlas.ti. Participaron nueve mujeres y ocho profesionales de la salud. Se realizaron 38 entrevistas a profundidad durante 13 meses y 62 acompañamientos a las mujeres en las actividades de control prenatal, vacunación, trabajo de parto, consulta posparto, exámenes de seguimiento, curso psicoprofiláctico, hospitalización y sala de espera, tanto en servicios públicos como privados. RESULTADOS: Existen desigualdades según la clase social en la forma en que se configura la relación entre las mujeres y el personal en los siguientes aspectos: permeabilidad a las necesidades de la mujer, reconocimiento de aspectos psicosociales, tener diferentes puntos de vista frente a una recomendación médica y derecho a quejarse o exigir para mejorar la atención de los servicios de salud. CONCLUSIONES: Lo anterior intensifica las problemáticas relacionadas con el género en las mujeres con una clase social menos aventajada. Es necesario el desarrollo de intervenciones en las instituciones educativas y de salud que tengan en cuenta aspectos donde se sensibilice el recurso humano en temas sociales relacionados con las propuestas teóricas de la investigación y la democratización de la información médica. Es injusto que la condición de clase social y de género afecte la calidad en la atención y estratifique económicamente los derechos de las personas.

Relaciones que establecen las mujeres durante el embarazo, parto y posparto con el personal de salud según clase social en Bogotá: estudio cualitativo / Relations established by women during pregnancy, delivery and postpartum with health personnel according to social class in Bogotá: qualitative study

RESUMEN Objetivo: Comprender la relación que se establece entre las mujeres en situación de embarazo, parto y posparto con el personal de los servicios de salud según la clase social en Bogotá (Colombia). Materiales y métodos: Estudio cualitativo, perspectiva hermenéutica crítica y etnografía crítica con muestreo teórico. Análisis por triangulación en Atlas.ti. Participaron nueve mujeres y ocho profesionales de la salud. Se realizaron 38 entrevistas a profundidad durante 13 meses y 62 acompañamientos a las mujeres en las actividades de control prenatal, vacunación, trabajo de parto, consulta posparto, exámenes de seguimiento, curso psicoprofiláctico, hospitalización y sala de espera, tanto en servicios públicos como privados. Resultados: Existen desigualdades según la clase social en la forma en que se configura la relación entre las mujeres y el personal en los siguientes aspectos: permeabilidad a las necesidades de la mujer, reconocimiento de aspectos psicosociales, tener diferentes puntos de vista frente a una recomendación médica y derecho a quejarse o exigir para mejorar la atención de los servicios de salud. Conclusiones: Lo anterior intensifica las problemáticas relacionadas con el género en las mujeres con una clase social menos aventajada. Es necesario el desarrollo de intervenciones en las instituciones educativas y de salud que tengan en cuenta aspectos donde se sensibilice el recurso humano en temas sociales relacionados con las propuestas teóricas de la investigación y la democratización de la información médica. Es injusto que la condición de clase social y de género afecte la calidad en la atención y estratifique económicamente los derechos de las personas.

ABSTRACT Objective: To understand the relationship established between women in a situation of pregnancy, childbirth and postpartum with the health services personnel according to social class in Bogotá (Colombia). Materials and methods: Qualitative study. Critical hermeneutical perspective and critical ethnography. Theoretical sampling. Analysis by triangulation in Atlas.ti. 9 women and 8 health professionals participated. 38 in-depth interviews were conducted for 13 months and 62 accompaniments to the maternal in the activities of prenatal control, vaccination, labor, postpartum consultation, follow up exams, prophylactic pisco course, hospitalization and waiting room, both in public services as private. Results: There are inequalities according to social class in which the relationship between women and staff is configured in the following aspects: permeability to the needs of women, recognition of psychosocial aspects, having different points of view against a medical recommendation and right to complain or demand to improve. Conclusions: The situation described above intensifies gender issues in women with a less advantageous social class. It is necessary to develop interventions in educational and health institutions that consider aspects where human resources are sensitized on social issues related to the theoretical proposals of research and the democratization of medical information. It is unfair that the condition of social class and gender affects the quality of care and economically stratifies people's rights.

Mujeres en embarazo, parto, y posparto: una mirada desde el pensamiento feminista* / Women in pregnancy, delivery, and postpartum: a look from the feminist point of view

RESUMEN Este ensayo analiza los aportes del enfoque de género del pensamiento feminista para comprender la relación de las mujeres en el embarazo, parto, y posparto con el personal de los servicios de salud. Se analizaron investigaciones originales de diseño cualitativo en las cuales se visualiza la relación de las mujeres con el personal de salud. Se concluye que el enfoque de género del pensamiento feminista es una aproximación útil para comprender la problemática de las relaciones de las mujeres con el personal de los servicios de salud en aspectos como la violencia obstétrica, el cuidado y la intersección del género con otras categorías, en el marco del sistema de salud.

ABSTRACT This essay analyzes the contributions of the gender approach of feminist thinking to understand the relationship of women in pregnancy, childbirth, and postpartum with health service personnel. Origi nal qualitative design research was analyzed, were the relationship of women with health personnel is visualized. It is concluded that the gender approach of feminist thinking is a useful approximation to understand the problem of women's relations with health service personnel in aspects such as obstetric violence, care and the intersection of gender with other categories, in the framework of the health system.

The generalized Vogel-Fulcher-Tamman equation for describing the dynamics of relaxor ferroelectrics.

Relaxor ferroelectrics (RF) are outstanding materials owing to their extraordinary dielectric, electromechanical, and electro-optical properties. Although their massive applications, they remain to be one of the most puzzling solid-state materials because understanding their structural local order and relaxation dynamics is being a long-term challenge in materials science. The so-called Vogel-Fulcher-Tamman (VFT) relation has been extensively used to parameterize the relaxation dynamics in RF, although no microscopic description has been firmly established for such empirical relation. Here, we show that VFT equation is not always a proper approach for describing the dielectric relaxation in RF. Based on the Adam-Gibbs model and the Grüneisen temperature index, a more general equation to disentangle the relaxation kinetic is proposed. This approach allows to a new formulation for the configurational entropy leading to a local structural heterogeneity related order parameter for RF. A new pathway to disentangle relaxation phenomena in other relaxor ferroics could have opened.

Photo-Controlled Ferroelectric-Based Nanoactuators.

Finding a feasible principle for a future generation of nano-optomechanical systems is a matter of intensive research, because it may provide new device prospects for optoelectronics and nanomanipulation techniques. Here we show that the strain of a ferroelectric crystal can be manipulated to achieve macroscopic, stable, and reproducible dimensional changes using illumination with photon energy below the material bandgap. The photoresponse can be activated without direct light incidence on the actuation area, because the cooperative nature of the phenomenon extends the photoinduced strain to the whole material. These results may be useful for developing the next generation of high-efficiency photocontrolled ferroelectric devices.

Light-Induced Capacitance Tunability in Ferroelectric Crystals.

The remote controlling of ferroic properties with light is nowadays a hot and highly appealing topic in materials science. Here, we shed light on some of the unresolved issues surrounding light-matter coupling in ferroelectrics. Our findings show that the capacitance and, consequently, its related intrinsic material property, i.e., the dielectric constant, can be reversibly adjusted through the light power control. High photodielectric performance is exhibited across a wide range of the visible light wavelength because of the wavelength-independence of the phenomenon. We have verified that this counterintuitive behavior can be strongly ascribed to the existence of "locally free charges" at domain wall.

Sobre nubes y relojes: aproximación al problema de la racionalidad y libertad del hombre / About clouds and clocks: approach to the problem of rationality and human freedom

La presente reseña tiene como propósito discutir el texto ''Sobre Nubes y Relojes'' de Karl Popper, en el cual el autor expone sus planteamientos en torno al problema del determinismo y el indeterminismo. En primer lugar, se presenta la discusión sobre el determinismo y el indeterminismo a partir de tres categorías de análisis: lo ontológico, lo metodológico y lo ético; seguidamente se analiza la propuesta evolucionista de Popper con relación al problema del determinismo y, finalmente, se plantean algunas consecuencias epistemológicas y éticas del determinismo en el campo de la salud.

This review discusses the text ''On clouds and Clocks'' by Karl Popper, in which the author presents his views on the issue of determinism and indeterminism. First, a discussion on determinism and indeterminism is presented from three analysis categories: ontological, methodological and ethical. Then, Popper's evolutionist approach regarding the issue of determinism is analyzed. Finally, some of the epistemological and ethical consequences of determinism on the field of health are presented.

Determinismo/indeterminismo y determinación: implicaciones en el campo de la salud píblica / Determinism/indeterminism and determination: implications in the field of public health

El objetivo es analizar las categorías de determinismo e indeterminismo en el campo de la salud píblica y plantear las diferencias de estas categorías con la de determinación social propuesta en el contexto de la salud píblica latinoamericana. Se plantea que tanto el determinismo como el indeterminismo resultan insuficientes para dar cuenta de la complejidad de la salud y de la vida, no solo en el plano epistémico, sino también en el marco del análisis ético; en su lugar, la noción de determinación se presenta como una categoría compleja que permite abordar los problemas relacionados con la salud y la vida a partir de sus relaciones dialécticas con las condiciones sociales, políticas, culturales y económicas. Finalmente, se exponen algunas de las principales diferencias entre el enfoque de determinantes sociales de la salud propuesto por la OMS y el enfoque de determinación social de la salud y la vida de la salud píblica latinoamericana.

The purpose of this paper is to analyze the categories of determinism and indeterminism in the Public Health field and to establish the differences between these categories and that of the social determination proposed in the context of Latin American Public Health. It is suggested that both determinism and indeterminism are insufficient terms to explain the complexity of health and life, not only in the epistemic map but also in the framework of ethical analysis. Instead, the notion of determination is presented as a complex category that makes it possible to approach the problems related to health and life from their dialectic relationships with social, politic, cultural and economic conditions. Finally, some of the main differences between the Social determinants of health approach proposed by the who and the Social determination of health and life approach proposed by the Latin American Public Health are presented.

Optimization of elastic nonlinear behavior measurements of ceramic piezoelectric resonators with burst excitation.

A system of nonlinear measurement and nonlinear elastic characterization of resonators is presented, which increases the possibilities and characteristics of the other classic nonlinear characterization methods. This characterization has been necessary due to the use of resonators in power devices, where their behavior departs from the linear characteristics. The use of burst signals and a system of acquisition and data processing is proposed instead of impedance analyzers, thus avoiding the thermal effects associated with the high-signal measures, which are necessary for this characterization. The measures are repeated for different amplitudes and at the same frequency near the resonance by a single amplitude sweep, which is simpler and faster to carry out than the multiple frequency sweepings used in other methods. As a last resort, a variation on the proposed method, closer to the classical measures, is put forward, in which the resonance is ensured in all the measures. Special emphasis is placed on obtaining nonlinear characterization of the piezoceramic material in order to increase its optimization in the transducers in terms of both its use and its composition and structure.