Calibration of the length of a chain of single gold atoms

Using a scanning tunnelling microscope or mechanically controllable break junction it has been shown that it is possible to control the formation of a wire made of single gold atoms. In these experiments an interatomic distance between atoms in the chain of ∼3.6 Å was reported which is not consistent with recent theoretical calculations. Here, using precise calibration procedures for both techniques, we measure the length of the atomic chains. Based on the distance between the peaks observed in the chain length histogram we find the mean value of the interatomic distance before chain rupture to be 2.5±0.2 Å. This value agrees with the theoretical calculations for the bond length. The discrepancy with the previous experimental measurements was due to the presence of He gas, that was used to promote the thermal contact, and which affects the value of the work function that is commonly used to calibrate distances in scanning tunnelling microscopy and mechanically controllable break junctions at low temperatures.

Magnetization reversal of ferromagnetic nanowires studied by magnetic force microscopy

The magnetization reversal of two-dimensional arrays of parallel ferromagnetic Fe nanowires embedded in nanoporous alumina templates has been studied. By combining bulk magnetization measurements (superconducting quantum interference device magnetometry) with field-dependent magnetic force microscopy (MFM), we have been able to decompose the macroscopic hysteresis loop in terms of the irreversible magnetic responses of individual nanowires. The latter are found to behave as monodomain ferromagnetic needles, with hysteresis loops displaced (asymmetric) as a consequence of the strong dipolar interactions between them. The application of field-dependent MFM provides a microscopic method to obtain the hysteresis curve of the array, by simply registering the fraction of up and down magnetized wires as a function of applied field. The observed deviations from the rectangular shape of the macroscopic hysteresis loop of the array can be ascribed to the spatial variation of the dipolar field through the inhomogeneously filled membrane. The system studied proves to be an excellent example of the two-dimensional classical Preisach model, well known from the field of hysteresis modeling and micromagnetism.

Common origin for surface reconstruction and the formation of chains of metal atoms

During the fracture of nanocontacts gold spontaneously forms freely suspended chains of atoms, which is not observed for the isoelectronic noble metals Ag and Cu. Au also differs from Ag and Cu in forming reconstructions at its low-index surfaces. Using mechanically controllable break junctions we show that all the 5d metals that show similar reconstructions (Ir, Pt, and Au) also form chains of atoms, while both properties are absent in the 4d neighbor elements (Rh, Pd, and Ag), indicating a common origin for these two phenomena. A competition between s and d bonding is proposed as an explanation.

Measurement of the conductance of a hydrogen molecule

Recent years have shown steady progress towards molecular electronics, in which molecules form basic components such as switches, diodes and electronic mixers. Often, a scanning tunnelling microscope is used to address an individual molecule, although this arrangement does not provide long-term stability. Therefore, metal–molecule–metal links using break-junction devices have also been explored; however, it is difficult to establish unambiguously that a single molecule forms the contact. Here we show that a single hydrogen molecule can form a stable bridge between platinum electrodes. In contrast to results for organic molecules, the bridge has a nearly perfect conductance of one quantum unit, carried by a single channel. The hydrogen bridge represents a simple test system in which to understand fundamental transport properties of single-molecule devices.

How do primary health care teams learn to integrate intimate partner violence (IPV) management? A realist evaluation protocol

Background: Despite the existence of ample literature dealing, on the one hand, with the integration of innovations within health systems and team learning, and, on the other hand, with different aspects of the detection and management of intimate partner violence (IPV) within healthcare facilities, research that explores how health innovations that go beyond biomedical issues—such as IPV management—get integrated into health systems, and that focuses on healthcare teams’ learning processes is, to the best of our knowledge, very scarce if not absent. This realist evaluation protocol aims to ascertain: why, how, and under what circumstances primary healthcare teams engage (if at all) in a learning process to integrate IPV management in their practices; and why, how, and under what circumstances team learning processes lead to the development of organizational culture and values regarding IPV management, and the delivery of IPV management services. Methods: This study will be conducted in Spain using a multiple-case study design. Data will be collected from selected cases (primary healthcare teams) through different methods: individual and group interviews, routinely collected statistical data, documentary review, and observation. Cases will be purposively selected in order to enable testing the initial middle-range theory (MRT). After in-depth exploration of a limited number of cases, additional cases will be chosen for their ability to contribute to refining the emerging MRT to explain how primary healthcare learn to integrate intimate partner violence management. Discussion: Evaluations of health sector responses to IPV are scarce, and even fewer focus on why, how, and when the healthcare services integrate IPV management. There is a consensus that healthcare professionals and healthcare teams play a key role in this integration, and that training is important in order to realize changes. However, little is known about team learning of IPV management, both in terms of how to trigger such learning and how team learning is connected with changes in organizational culture and values, and in service delivery. This realist evaluation protocol aims to contribute to this knowledge by conducting this project in a country, Spain, where great endeavours have been made towards the integration of IPV management within the health system.

Palladium and organocatalysis: an excellent recipe for asymmetric synthesis

The dual activation of simple substrates by the combination of organocatalysis and palladium catalysis has been successfully applied in a variety of different asymmetric transformations. Thus, the asymmetric a-allylation of carbonyl compounds, a-fluorination of acyl derivatives, decarboxylative protonation of β-dicarbonyl compounds, cyclization reactions of alkynyl carbonyl compounds and β-functionalization of aldehydes have been efficiently achieved employing this double-catalytic methodology.

A strongly magnetized pulsar within the grasp of the milky way’s supermassive black hole

The center of our Galaxy hosts a supermassive black hole, Sagittarius (Sgr) A∗. Young, massive stars within 0.5 pc of Sgr A∗ are evidence of an episode of intense star formation near the black hole a few million years ago, which might have left behind a young neutron star traveling deep into Sgr A∗’s gravitational potential. On 2013 April 25, a short X-ray burst was observed from the direction of the Galactic center. With a series of observations with the Chandra and the Swift satellites, we pinpoint the associated magnetar at an angular distance of 2.4±0.3 arcsec from Sgr A∗, and refine the source spin period and its derivative (P = 3.7635537(2) s and ˙ P = 6.61(4) × 10−12 s s−1), confirmed by quasi simultaneous radio observations performed with the Green Bank Telescope and Parkes Radio Telescope, which also constrain a dispersion measure of DM = 1750 ± 50 pc cm−3, the highest ever observed for a radio pulsar. We have found that this X-ray source is a young magnetar at ≈0.07–2 pc from Sgr A∗. Simulations of its possible motion around Sgr A∗ show that it is likely (∼90% probability) in a bound orbit around the black hole. The radiation front produced by the past activity from the magnetar passing through the molecular clouds surrounding the Galactic center region might be responsible for a large fraction of the light echoes observed in the Fe fluorescence features.

Mapping and exploring health systems' response to intimate partner violence in Spain

Background: For a comprehensive health sector response to intimate partner violence (IPV), interventions should target individual and health facility levels, along with the broader health systems level which includes issues of governance, financing, planning, service delivery, monitoring and evaluation, and demand generation. This study aims to map and explore the integration of IPV response in the Spanish national health system. Methods: Information was collected on five key areas based on WHO recommendations: policy environment, protocols, training, monitoring and prevention. A systematic review of public documents was conducted to assess 39 indicators in each of Spain’s 17 regional health systems. In addition, we performed qualitative content analysis of 26 individual interviews with key informants responsible for coordinating the health sector response to IPV in Spain. Results: In 88% of the 17 autonomous regions, the laws concerning IPV included the health sector response, but the integration of IPV in regional health plans was just 41%. Despite the existence of a supportive national structure, responding to IPV still relies strongly on the will of health professionals. All seventeen regions had published comprehensive protocols to guide the health sector response to IPV, but participants recognized that responding to IPV was more complex than merely following the steps of a protocol. Published training plans existed in 43% of the regional health systems, but none had institutionalized IPV training in medical and nursing schools. Only 12% of regional health systems collected information on the quality of the IPV response, and there are many limitations to collecting information on IPV within health services, for example underreporting, fears about confidentiality, and underuse of data for monitoring purposes. Finally, preventive activities that were considered essential were not institutionalized anywhere. Conclusions: Within the Spanish health system, differences exist in terms of achievements both between regions and between the areas assessed. Progress towards integration of IPV has been notable at the level of policy, less outstanding regarding health service delivery, and very limited in terms of preventive actions.

Recent Advances in the Catalytic Enantioselective Reformatsky Reaction

This paper reviews the present state of the catalytic enantioselective Reformatsky reaction. Advancements in asymmetric versions of this reaction have recently led to a considerable extension of its scope and applicability, principally due to the use of highly active chiral ligands and very specific reaction conditions.

La respuesta sanitaria a la violencia de género. ¿Adaptar el sistema o medicalizar la violencia? estudio cualitativo

Antecedentes/Objetivos: El sistema sanitario puede jugar un papel clave en la prevención y atención de la violencia de género (VG), debido a las consecuencias para la salud de la violencia y al hecho de que las mujeres afectadas acceden a los servicios de salud con mayor frecuencia que a otros servicios públicos. El objetivo de este estudio es analizar cómo entienden los profesionales encargados de la coordinación de los programas de VG en los servicios regionales de salud la integración de la respuesta sanitaria a este problema en el Sistema Nacional de Salud español. Métodos: Estudio cualitativo en el que se realizaron 26 entrevistas individuales a informantes clave del nivel gerencial, 23 de las 17 comunidades autónomas y 3 del nivel nacional, entre julio de 2012 a marzo de 2013. Las transcripciones se importaron al software informático Atlas.ti-5 y se analizaron de acuerdo al método de la Teoría Fundamentada. Resultados: Se desarrolló un modelo conceptual que explica los esfuerzos y retos cuando se intenta integrar la respuesta a la VG en el sistema sanitario, que permanece fuertemente biomedicalizado. Emergieron una categoría central: Integrando respuestas a problemas no biomédicos en sistemas de salud biomédicos, el caso de la VG; y 4 categorías relacionadas con la central: La VG es un problema complejo que genera resistencia o activismo; El mandato para integrar una respuesta sanitaria a la violencia: una prioridad no siempre priorizada; El sistema sanitario español, respetuoso con la autonomía de los profesionales, biomédico y familiarista; y Desarrollando respuestas a la integración de la violencia: adaptar el sistema de salud o medicalizar la violencia. Conclusiones: Integrar el abordaje de la VG en un sistema de salud biomédico es un reto. Los hallazgos sugieren que la motivación individual puede compensar las deficiencias en el sistema existente, en términos de ser más centrada en la persona y, por lo tanto, fomentar una fuerte relación de confianza. Sin embargo, la sostenibilidad de los procesos dependientes en la motivación e interés individual es difícil si no hay una estructura organizativa que los respalde.

Estudio cualitativo sobre la sostenibilidad de los programas de violencia de género en el sistema sanitario español durante la crisis

Antecedentes/Objetivos: La Ley 1/2004 de atención a la integral a la violencia de género institucionaliza la respuesta sanitaria a este problema. En la actualidad, los servicios sanitarios se están viendo afectados por las políticas de austeridad del gobierno como respuesta a la crisis financiera, lo que puede afectar negativamente a la atención de la violencia de género. El objetivo de este estudio es explorar las percepciones de profesionales sanitarios del nivel gerencial sobre el impacto de la crisis económica en la respuesta sanitaria a la violencia de género en España. Métodos: Estudio cualitativo con 26 entrevistas individuales a informantes clave del nivel gerencial, 23 de las 17 Comunidades Autónomas y 3 del nivel nacional, entre julio de 2012 a marzo de 2013. Las transcripciones se importaron al software informático Atlas.ti-5 y se realizó un análisis de contenido cualitativo. Resultados: Se identificaron 4 categorías que explican las consecuencias de las políticas de austeridad en la atención sanitaria de la violencia de género. Tres de ellas hacen referencia a los efectos negativos: Desmotivación y pesimismo para avanzar en la integración de la respuesta a la violencia; Un sistema desbordado por los recortes y presión asistencial; y Necesidad de una mayor implicación por parte del personal sanitario para suplir las carencias del sistema. Una cuarta categoría concibe la crisis como oportunidad: El desafío es mantener y no desmantelar, una visión optimista de la crisis como un reto para afianzar lo que hay. Las personas implicadas luchan para mantener el abordaje de la violencia en las agendas, movidas por su motivación personal, pero sienten que es luchar contra un muro o ir contracorriente porque no se ha producido una integración oficial en la práctica sino sólo en la teoría, a raíz de la ley 1/2004 y las políticas de igualdad impulsadas por el anterior gobierno. Todo ello se ve dificultado por la desaparición de las subvenciones estatales para la formación y sensibilización, implantación de protocolos o creación de sistemas de información, junto a que no está en la cartera de servicios de las comunidades. Conclusiones: Continuar con la integración del abordaje de la violencia de género en el sistema de salud en época de crisis no es una prioridad. Los hallazgos sugieren que la motivación individual trata de compensar las deficiencias en el sistema existente, pero que el voluntarismo de las personas individuales no es suficiente sin estructuras organizativas que les respalden, lo que se ve especialmente dificultado en tiempos de crisis.

Validación de la versión española del cuestionario Physician Readiness To Manage Intimate Partner Violence Survey (PREMIS)

Fundamentos: El Physician Readiness to Manage Intimate Partner Violence Survey (PREMIS) es uno de los cuestionarios más completos en el contexto internacional para la valoración de la capacidad de respuesta frente a la violencia del compañero íntimo por los profesionales de Atención Primaria de Salud. El objetivo de este estudio fue determinar la fiabilidad, consistencia interna y validez de constructo de la versión española de este cuestionario. Métodos: Tras la traducción, retrotraducción y valoración de la validez de contenido del cuestionario, se distribuyeron en una muestra de 200 profesionales de medicina y enfermería de 15 centros de atención primaria de 4 Comunidades Autónomas en 2013 (Comunidad Valenciana, Castilla León, Murcia y Cantabria). Se calcularon los coeficientes alfa de Cronbach, los de correlación intraclase y rho de Spearman (test-retest). Resultados: la versión española del PREMIS incluyó 64 ítems. El coeficiente α de Cronbach fue superior a 0,7 o muy cercano a ese valor en la mayoría de los índices. Se obtuvo un coeficiente de correlación intraclase de 0,87 y un coeficiente de Spearman de 0,67 que muestran una fiabilidad alta. Todas las correlaciones observadas para la escala de opiniones, la única tratada como estructura factorial en el cuestionario PREMIS, fueron superiores a 0,30. Conclusiones: el PREMIS en español obtuvo una buena validez interna, alta fiabilidad y capacidad predictiva de las prácticas auto-referidas por médicos(as) y enfermeros(as) frente a casos de violencia del compañero íntimo en centros de atención primaria.

Applying the WHO recommendations on health-sector response to violence against women to assess the Spanish health system. A mixed methods approach

This methodological note describes the development and application of a mixed-methods protocol to assess the responsiveness of Spanish health systems to violence against women in Spain, based on the World Health Organization (WHO) recommendations. Five areas for exploration were identified based on the WHO recommendations: policy environment, protocols, training, accountability/monitoring, and prevention/promotion. Two data collection instruments were developed to assess the situation of 17 Spanish regional health systems (RHS) with respect to these areas: 1) a set of indicators to guide a systematic review of secondary sources, and 2) an interview guide to be used with 26 key informants at the regional and national levels. We found differences between RHSs in the five areas assessed. The progress of RHSs on the WHO recommendations was notable at the level of policies, moderate in terms of health service delivery, and very limited in terms of preventive actions. Using a mixed-methods approach was useful for triangulation and complementarity during instrument design, data collection and interpretation.

Developing a programme theory to explain how primary health care teams learn to respond to intimate partner violence: a realist case-study

Background: Despite the progress made on policies and programmes to strengthen primary health care teams’ response to Intimate Partner Violence, the literature shows that encounters between women exposed to IPV and health-care providers are not always satisfactory, and a number of barriers that prevent individual health-care providers from responding to IPV have been identified. We carried out a realist case study, for which we developed and tested a programme theory that seeks to explain how, why and under which circumstances a primary health care team in Spain learned to respond to IPV. Methods: A realist case study design was chosen to allow for an in-depth exploration of the linkages between context, intervention, mechanisms and outcomes as they happen in their natural setting. The first author collected data at the primary health care center La Virgen (pseudonym) through the review of documents, observation and interviews with health systems’ managers, team members, women patients, and members of external services. The quality of the IPV case management was assessed with the PREMIS tool. Results: This study found that the health care team at La Virgen has managed 1) to engage a number of staff members in actively responding to IPV, 2) to establish good coordination, mutual support and continuous learning processes related to IPV, 3) to establish adequate internal referrals within La Virgen, and 4) to establish good coordination and referral systems with other services. Team and individual level factors have triggered the capacity and interest in creating spaces for team leaning, team work and therapeutic responses to IPV in La Virgen, although individual motivation strongly affected this mechanism. Regional interventions did not trigger individual and/ or team responses but legitimated the workings of motivated professionals. Conclusions: The primary health care team of La Virgen is involved in a continuous learning process, even as participation in the process varies between professionals. This process has been supported, but not caused, by a favourable policy for integration of a health care response to IPV. Specific contextual factors of La Virgen facilitated the uptake of the policy. To some extent, the performance of La Virgen has the potential to shape the IPV learning processes of other primary health care teams in Murcia.

Quantum spin Hall phase in multilayer graphene

The so-called quantum spin Hall phase is a topologically nontrivial insulating phase that is predicted to appear in graphene and graphenelike systems. In this paper we address the question of whether this topological property persists in multilayered systems. We consider two situations: purely multilayer graphene and heterostructures where graphene is encapsulated by trivial insulators with a strong spin-orbit coupling. We use a four-orbital tight-binding model that includes full atomic spin-orbit coupling and we calculate the Z2 topological invariant of the bulk states as well as the edge states of semi-infinite crystals with armchair termination. For homogeneous multilayers we find that even when the spin-orbit interaction opens a gap for all possible stackings, only those with an odd number of layers host gapless edge states while those with an even number of layers are trivial insulators. For heterostructures where graphene is encapsulated by trivial insulators, it turns out that interlayer coupling is able to induce a topological gap whose size is controlled by the spin-orbit coupling of the encapsulating materials, indicating that the quantum spin Hall phase can be induced by proximity to trivial insulators.