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The Early Pleistocene archeological site of Fuente Nueva-3 (FN3) preserves some of the oldest evidence of hominin presence in Western Europe, including a huge assemblage of Oldowan tools and evidence of butchering and marrow processing of large mammal bones. Moreover, there is also evidence of the regular presence of carnivores at the site, including a small proportion of bones that show tooth marks, the majority of which can be attributed to the giant, short-faced hyena Pachycrocuta brevirostris, and there are 220 coprolites, most of them from the Upper Archeological Level. In order to identify the defecating agent, we analyze here the coprolites and compare them with other specimens from the literature and with scats from zoo spotted hyenas (Crocuta crocuta). The morphology, color, size, and chemical composition of the FN3 coprolites allow us to attribute them to the hyena P. brevirostris, which is also represented at the site by fossil specimens. In addition, we evaluate the origin of the accumulation of coprolites and discuss on the role played by the scavenging hyenas in the accumulation and modification of the bone remains unearthed at the site, which allows evaluating the contribution of the giant hyena to this Early Pleistocene site. Finally, based on the lithology of layer 5 of the Upper Archeological Level, fine sands and clays deposited in a salt-lake environment, we hypothesize that this layer may have acted as a quicksand where large-sized animals like elephants were trapped and their carcasses lured scavenging carnivores.

For this study, 12%Cr–3%C white iron alloys with three titanium contents (1%, 3% and 5%) were tested under the “single scratch” method to analyze the wear behavior. The irons were melted in a vacuum induction furnace and cast into wedge metallic molds to analyze different thicknesses. The alloys were characterized in the as-cast and heat-treated conditions by optical and scanning electron microscopy and X-ray diffraction. Hardness and abrasive wear resistance under single scratch tests were measured. Single scratch tests were carried out with a diamond indenter under a load of 47 N. The scratches were characterized by SEM and by an optical profiler to determine the lost volume. The results show the presence of micro-cracks and plastic deformation along the grooves in the as-cast irons, these were less evident in the heat-treated irons. The heat-treated irons exhibited lower volume losses and particularly the heat-treated iron with 3%Ti showed the least lost volume. The wear resistance is also described in terms of penetration depth of the indenter, which is directly related to the lost volume. SEM micrographs for the experimental alloys in both as-cast (a–c) and heat-treated (d–f) conditions. Carbide volume (a) and Hardness (b) as a function of the thickness for the experimental alloys The volume of material removed as a function of the thickness for the experimental alloys in both as-cast and heat-treated conditions

The development of new modes at x-ray free electron lasers has inspired novel methods for studying fluctuations at different energies and timescales. For closely spaced x-ray pulses that can be varied on ultrafast time scales, we have constructed a pair of advanced instruments to conduct studies targeting quantum materials. We first describe a prototype instrument built to test the proof-of-principle of resonant magnetic scattering using ultrafast pulse pairs. This is followed by a description of a new endstation, the so-called fluctuation–dissipation measurement instrument, which was used to carry out studies with a fast area detector. In addition, we describe various types of diagnostics for single-shot contrast measurements, which can be used to normalize data on a pulse-by-pulse basis and calibrate pulse amplitude ratios, both of which are important for the study of fluctuations in materials. Furthermore, we present some new results using the instrument that demonstrates access to higher momentum resolution.

Las investigaciones arqueológicas en el centro de la provincia de Corrientes han sido escasas y discontinuas. Con el objetivo de revertir este panorama se iniciaron trabajos de campo en el sector sur y sursureste del macrosistema Iberá (Reserva Provincial Iberá y Parque Nacional Iberá). En este trabajo se presentan los resultados de las actividades de prospección y excavación desarrolladas. Como resultado de las mismas, se identificaron 11 áreas en las que los materiales arqueológicos se presentan en densidades variables y asociados a una matriz sedimentaria con alta proporción de conchillas. En líneas generales, estas se caracterizan por la presencia de material cerámico, lítico, restos óseos humanos y faunísticos, ornamentos, entre otros. A esta información, se integran y discuten los antecedentes para el sector, confirmando el alto potencial arqueológico del área. La evaluación de la red de permeabilidad del sector permitió identificar tres formas posibles de desplazamiento práctico entre la totalidad de los sitios hasta ahora identificados (n= 33).

The chemical industry is currently facing the challenge of developing biobased production processes suitable for a more sustainable chemical industry. Acrylic acid produced from monopropylene glycol is a good candidate to become a cost-competitive and sustainable platform chemical. The propylene glycol price is expected to drop due to the expected abundance of propylene glycol as a sugar hydrogenolysis byproduct, which is required to make the conversion to acrylic acid cost-competitive. Two different processes for the conversion of propylene glycol to acrylic acid are evaluated in this work, either by (1) low temperature oxidation of propylene glycol to lactic acid and high temperature dehydration to acrylic acid or by (2) high temperature dehydration of propylene glycol to allyl alcohol and further high temperature oxidation to acrylic acid. Liquid-liquid extraction was found to be a key operation in both production processes. At similar overall yields, the allyl alcohol route appears inherently favored, as a result of the opportunity to integrate the reaction heat available at high temperature. To conclude, the price of propylene glycol has to drop by 45-55% to make the biobased production of acrylic acid from propylene glycol economically feasible.

Understanding magnetic phase transitions from stripe to skyrmion textures provide fundamental scientific insights into the details of the intermediate topologies through which the system evolves. The solitonic nature of spin texture in both stripe and skyrmion phases has been observed in materials with Dzyaloshinskii-Moriya interaction. Here we show that the field evolution in a dipolar interaction mediated Fe/Gd multilayer that exhibits achiral stripe textures behaves similar to a finite-sized chiral soliton lattice. As a function of magnetic field, the stripes exhibit discrete jumps in periodicity indicative of intermediate topologies as the stripes get wound into skyrmions.

Background Thoracic endovascular aortic repair (TEVAR) is widely used for the treatment of blunt traumatic thoracic aortic injuries. Aortic flow dynamics and mechanical implications of this intervention are poorly investigated and may be of particular interest in the long-term follow-up of these mostly young patients. Purpose To assess whether the presence of TEVAR in a cohort of otherwise healthy subjects was related to dilation of the proximal aorta or increase in aortic stiffness and flow alterations. Methods Nineteen patients who underwent TEVAR implantation after a traumatic injury of the thoracic descending aorta (DAo) (10.0±6.1 years from intervention) and 44 healthy volunteers (HV) underwent 4D flow CMR to compute ascending aorta (AAo) pulse wave velocity (PWV), a marker of aortic stiffness, systolic flow reversal ratio (SFRR), quantifying backward flow during systole and in-plane rotational flow (IRF), measuring in-plane strength of helical flow. IRF and SFRR were assessed at 20 planes between the sinotubular junction and the mid thoracic DAo. Aortic diameters were measured using double-oblique cine CMR. Results Patients with TEVAR and HV did not differ in age, sex, body surface area, blood pressure and DAo diameter distal to TEVAR (Table). However, TEVAR patients presented larger diameters at the sinus of Valsalva and AAo, increased AAo PWV and strong flow alterations: IRF was reduced from the distal AAo to the proximal DAo, while SFRR was increased in the whole thoracic aorta (Figure). Conclusions In patients with blunt traumatic thoracic aortic injury treated with TEVAR the aorta proximal to TEVAR is dilated, stiffer and present potentially pathogenic flow conditions. Longitudinal studies are needed to assess whether these alterations have prognostic value and may improve clinical prevention and management of these patients. Figure 1. IRF and SFRR in healthy vs TEVAR Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study has been funded by Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation (PI19/01480). Guala A. received funding from the Spanish Ministry of Science, Innovation and Universities (IJC2018-037349-I).

The lymph node ratio (LNR) is a recent tool, but its predictive value for recurrence is uncertain.To evaluate LNR as a prognostic factor for disease-free survival (DFS) in patients with oral squamous cell carcinoma.Retrospective observational study. Patients with oral squamous cell carcinoma undergoing resection and lymph node dissection. Chi squared, Kaplan-Meier, log rank and Cox regression tests were run; bilateral p ≤ 0.05 determined statistical significance.88 patients were included, 45% (n = 40) men and 54% (n = 48) women, mean age of 60.42 (± 14.28) years. Main tumor location in tongue (75%); 61% in clinical stage I-III and 39% in clinical stage IV. Population was divided into LNR0.06 (58%) and LNR ≥ 0.06 (42%). The median DFS was not reached for both groups (p = 0.018). Predictors of DFS were the LNR (p = 0.024; hazard ratio [HR]: 2.20; confidence interval of 95% [95% CI]: 1.11-4.39) and the clinical stage (p = 0.004; HR: 1.76; 95% CI: 1.19-2.59). In the multivariate analysis, predictors were not maintained (p = 0.227 and 0.191, respectively).Significant differences were observed in the DFS analysis, however, they were not predictive of local recurrence in the multivariate analysis.El cociente ganglionar (LNR) es una herramienta reciente, pero su valor predictivo de recurrencia es incierto.Evaluar el LNR como factor pronóstico de supervivencia libre de enfermedad (SLE) en pacientes con carcinoma oral de células escamosas.Estudio retrospectivo observacional. Pacientes con carcinoma oral de células escamosas sometidos a resección y disección ganglionar. Se aplicaroon las pruebas de ji al cuadrado, Kaplan-Meier, log rank y regresión de Cox; se consideró estadísticamente significativo p ≤ 0.05 bilateral.Fueron incluidos 88 pacientes, el 45% (n = 40) hombres y el 54% (n = 48) mujeres, con una edad media de 60.42 (± 14.28) años. La principal localización tumoral fue la lengua (75%); el 61% en etapa I-III y el 39% en etapa IV. Se dividió en LNR0.06 (58%) y LNR ≥ 0.06 (42%). La mediana de SLE no fue alcanzada para ambos grupos (p = 0.018). Resultaron predictores de SLE el LNR (p = 0.024; hazard ratio [HR]: 2.20; intervalo de confianza del 95% [IC95%]: 1.11-4.39) y la etapa clínica (p = 0.004; HR: 1.76; IC95%: 1.19-2.59). En el análisis multivariado no se mantuvieron predictores (p = 0.227 y p = 0.191, respectivamente).Se observaron diferencias significativas en el análisis de SLE, pero no se mantuvieron como predictoras de recurrencia local en el análisis multivariado.

We report the generation of skyrmions under the combined influence of applied perpendicular magnetic fields and electrical currents in Pt/Co/Os/Pt thin films. Under no electrical current, skyrmions are found to nucleate at specific defect sites distributed throughout the film and remain pinned at these sites for small dc electrical currents $(l0.05\mathrm{MA}/\mathrm{c}{\mathrm{m}}^{2})$ . For larger currents $(l0.05\mathrm{MA}/\mathrm{c}{\mathrm{m}}^{2})$, skyrmions can either move or elongate in the direction of the current flow to form stripe domains. We further observed the current-induced generation of skyrmions through two specific processes: (i) stripe domains depinning from defect sites and collapsing into skyrmions, or (ii) skyrmions breaking off from pinned stripes; the rate of these stripe-to-skyrmion creation phenomena is proportional to the applied current density. Additionally, we observe a sudden increase in the skyrmion population immediately after the applied current is removed----a behavior attributed to stripe domains previously elongated by the electrical current collapsing back into skyrmions.

We have studied the effects of electrical current pulses on skyrmion formation in a series of Co/Ni/Pt-based multilayers. Transmission X-ray microscopy reveals that by applying electrical current pulses of duration and current density on the order of $\tau$=50 $\mu$s and j=1.7x10$^1$$^0$ A/m$^2$, respectively, in an applied magnetic field of $\mu$$_0$Hz=50 mT, stripe-to-skyrmion transformations are attained. The skyrmions remain stable across a wide range of magnetic fields, including zero field. The skyrmions then remain stable across a wide range of magnetic fields, including zero field. We primarily attribute the transformation to current-induced Joule heating on the order of ~125 K. Reducing the magnetic moment and perpendicular anisotropy using thin rare-earth spacers dramatically reduces the pulse duration, current density, and magnetic field necessary to 25 $\mu$s, 2.4x10$^9$ A/m$^2$, and 27 mT, respectively. These findings show that energetic inputs allow for the formation of skyrmion phases in a broad class of materials and that material properties can be tuned to yield more energy-efficient access to skyrmion phases., Comment: 32 pages, 7 figures, 9 supplemental figures

An optical metamaterial is capable of manipulating light in nanometer scale that goes beyond what is possible with conventional materials. Taking advantage of this special property, metamaterial-assisted illumination nanoscopy (MAIN) possesses tremendous potential to extend the resolution far beyond conventional structured illumination microscopy. Among the available MAIN designs, hyperstructured illumination that utilizes strong dispersion of a hyperbolic metamaterial (HMM) is one of the most promising and practical approaches, but it is only theoretically studied. In this paper, we experimentally demonstrate the concept of hyperstructured illumination. A ∼80 nm resolution has been achieved in a well-known Ag/SiO2 multilayer HMM system by using a low numerical aperture objective (NA = 0.5), representing a 6-fold resolution enhancement of the diffraction limit. The resolution can be significantly improved by further material optimization.

The strong galaxy-galaxy lensing produces highly magnified and distorted images of background galaxies in the form of arcs and Einstein rings. Statistically, these effects are quantified, for example, in the number counts of highly luminous sub-millimeter galaxies and of gravitational arcs. Two key quantities to model these statistics are the magnification and the arc cross sections. These are usually computed using either the circular infinitesimal source approximation or ray-tracing simulations for sources of finite size. In this work, we use an analytic solution for gravitational arcs to obtain these cross sections as a function of image magnification and length-to-width ratio in closed form, for finite sources. These analytical solutions provide simple interpretations to the numerical results, can be employed to test the computational codes, and can be used for fast a computation of the abundance of distant sources and arcs. In this paper, the lens is modeled by a Singular Isothermal Sphere, which is an excellent approximation to radial density profile of Early-Type galaxies, and the sources are also axisymmetric. We derive expressions for the geometrical properties of the images, such as the area and several definitions of length and width. We obtain the magnification cross section in exact form and derive a simple analytic approximation covering the arc and Einstein ring regimes. The arc cross section is obtained down to the formation of an Einstein ring and given in terms of elementary functions. Perturbative expansions of these results are worked out, showing explicitly the correction terms for finite sources., Comment: 18 pages, 7 figures. Accepted for publication in MNRAS

Resumen Objetivo El uso del dispositivo de rama iliaca (DRI) es una tecnica para evitar complicaciones derivadas de la oclusion de las arterias hipogastricas (AH). Nuestro objetivo es analizar los resultados del uso del DRI a corto y medio plazo en nuestro centro. Material y metodos Estudio descriptivo, 28 AH, 14 pacientes con aneurismas aortoiliacos tratados con DRI entre 2011 y 2015. Catorce (100%) aneurismas iliacos bilaterales, 11 (78,6%) aneurismas aorticos asociados y 4 (14,3%) con aneurisma hipogastrico. De 28 AH, 19 (67,8%) se trataron con DRI (5 bilaterales), 4 (14,3%) fueron cubiertas con endoprotesis, 2 (7,1%) embolizadas, 2 intactas y una con stent cubierto para tratar un aneurisma. En todos los casos quedo al menos una AH permeable. Analizamos mortalidad, permeabilidad del DRI, endofugas, claudicacion glutea, disfuncion erectil e isquemia pelvica. Para realizar el seguimiento se utilizaron angio-TAC y ecodoppler. Resultados El 100% eran varones, con una edad de 74,6 ± 13,6 anos, permeabilidad al mes 94,7%, al ano 80%, a los 2 anos 77,8%, 0% de mortalidad, de endofugas, de claudicacion glutea en el lado permeabilizado, de disfuncion erectil de nueva aparicion y de isquemia pelvica. Hubo dos casos de claudicacion glutea contralateral, un caso de trombosis arterial iliaca contralateral, resuelta mediante bypass femorofemoral, una trombosis del DRI intraoperatoria e isquemia aguda de la extremidad, resuelta mediante trombolisis y embolectomia, e imposibilidad para colocar el DRI por dificultad tecnica en un caso. El seguimiento medio fue de 23,3 meses (rango 1-67), y hubo 2 perdidas en el seguimiento. Conclusion En nuestra experiencia, el DRI es una tecnica eficaz y segura con pocas complicaciones y buena permeabilidad; no obstante, son necesarios estudios a largo plazo.

Resumen Objetivo Comparar la evolucion clinica de las reestenosis > 70% asintomaticas de los stents de arteria femoral superficial (AFS) con tratamiento endovascular vs. tratamiento conservador. Pacientes Estudio descriptivo de cohortes historicas de pacientes con stent femoral con reestenosis del 70-99% asintomatica, desde enero del 2010 a diciembre del 2015. Se formaron 2 grupos de pacientes: manejo conservador vs. tratamiento endovascular. Material y metodos Comparamos: curvas de superviencia libre de amputacion mayor (SLA) y supervivencia libre de isquemia critica o claudicacion limitante ( Resultados y conclusiones Se diagnosticaron un total de 23 reestenosis > 70% en 20 pacientes de 78 anos de edad media (DE 9,6). Seguimiento medio: 30,1 meses. En 12 pacientes (52,2%) se realizo tratamiento medico (AAS y estatinas) + endovascular, y en 11 (47,8%) unicamente tratamiento medico. No hubo diferencias en la SLA (p = 0,967). Observamos que la SLIC fue mayor en el grupo de manejo conservador que en el de tratamiento endovascular (p = 0,031). La permeabilidad primaria fue de 14,2 meses (IC 8,2-20,2), y la permeabilidad primaria asistida de 65,5 meses (IC 57,4-77,5). En nuestra experiencia tratar las lesiones graves asintomaticas de los stents de AFS no disminuye el riesgo de amputacion, isquemia critica o claudicacion limitante respecto a la evolucion natural de las mismas. En pacientes asintomaticos la conducta expectante puede ser una buena opcion, sin que ello suponga un aumento del riesgo de amputacion o isquemia critica a medio plazo.

Magnetic skyrmions present interesting physics due to their topological nature and hold significant promise for future information technologies. A key barrier to realizing skyrmion devices has been stabilizing these spin structures under ambient conditions. In this manuscript, we exploit the tunable magnetic properties of amorphous Fe/Gd mulitlayers to realize skyrmion lattices which are stable over a large temperature and magnetic field parameter space, including room temperature and zero magnetic field. These hybrid skyrmions have both Bloch-type and N\'eel-type character and are stabilized by dipolar interactions rather than Dzyaloshinskii-Moriya interactions, which are typically considered required for the generation of skyrmions. Small angle neutron scattering (SANS) was used in combination with soft X-ray microscopy to provide a unique, multi-scale probe of the local and long-range order of these structures. These results identify a pathway to engineer controllable skyrmion phases in thin film geometries which are stable at ambient conditions., Comment: 17 pages, 5 figures

The origin of deterministic macroscopic properties often lies in microscopic stochastic motion. Magnetic fluctuations that manifest as domain avalanches and chaotic magnetization jumps exemplify such stochastic motion and have been studied in great detail. Here we report Fourier space studies of avalanches in a system exhibiting competing magnetic stripe and skyrmion phase using a soft X-ray speckle metrology technique. We demonstrate the existence of phase boundaries and underlying critical points in the stripe and skyrmion phases. We found that distinct scaling and universality classes are associated with these domain topologies. The magnitude and frequency of abrupt magnetic domain jumps observed in the stripe phase are dramatically reduced in the skyrmion phase. Our results provide an incisive way to probe and understand phase stability in systems exhibiting complex spin topologies., Switching of magnetic materials often occurs through discrete random avalanches. Singh et al. observe sharply reduced avalanches in the topologically protected skyrmion phase of a Fe/Gd heterostructure and obtain different critical behaviour in the stripe and skyrmion phases, suggesting distinct universality classes.

Resumen Introduccion Desde hace mas de una decada ha surgido un interes creciente por evaluar la calidad de la atencion sanitaria que prestamos. Los indicadores de calidad son la medida instrumental de esa calidad asistencial. Diferentes sociedades cientificas internacionales estan desarrollando iniciativas para monitorizar sus procesos quirurgicos mas frecuentes. Objetivos El Grupo de Calidad de la Sociedad Espanola de Angiologia Cirugia Vascular considero que seria de interes empezar a desarrollar una estructura basica de indicadores dentro de nuestra sociedad. Para ello se propuso como objetivo seleccionar 4-5 patologias vasculares frecuentes y elaborar 1-2 indicadores de esos procesos, para de esta forma demostrar que esta iniciativa es factible y puede dar lugar a unos resultados utiles para mejorar la calidad de nuestro trabajo diario y poder hacer «benchmarking» europeo. Material y metodos Se seleccionaron 17 Servicios de Cirugia Vascular, 5 de las patologias mas frecuentes y 2 indicadores clave por cada una de ellas: aneurismas de aorta abdominal, patologia arterial periferica, patologia carotidea extracraneal, trombosis venosa profunda y fistulas arteriovenosas para hemodialisis. Para seleccionar los indicadores clave (key performance indicators) se recurrio a las guias de practica clinica, documentos de consenso y estudios publicados de gran relevancia cientifica. Por consenso de expertos se escogieron preferentemente indicadores de proceso y se elaboro una ficha para la recogida uniformada de informacion. Resultados Los resultados mostraron una gran variabilidad entre los centros, siendo alguno de ellos imposible de cuantificar, dada la ausencia de bases de datos informatizadas que permitieran su analisis. Los detalles concretos de cada indicador se describen exhaustivamente en el contenido de este articulo. Conclusiones Este trabajo nos ha permitido mostrar que la elaboracion de indicadores de calidad es factible, util y una oportunidad de mejora valida. Como en otras sociedades cientificas internacionales, y despues de esta positiva experiencia, deberiamos ampliar estos indicadores y crear una base de datos nacional para monitorizarlos.

Resumen Introduccion En todo proceso diagnostico y terapeutico, y mas en tiempo de importantes recortes sanitarios, es imprescindible buscar la maxima eficiencia. El metodo LEAN intenta optimizar todo proceso productivo y proponemos su aplicacion para el estudio ecografico venoso de extremidades inferiores. Material y metodos Se incluyo a pacientes con sintomatologia de insuficiencia venosa, varices visibles y sin intervenciones previas ni afectacion profunda y se les realizo un eco-Doppler estandarizado segun normas del CDVNI. Se valoraron el punto de fuga, el recorrido, el punto de reentrada y el sistema venoso profundo. Se determinaron los puntos minimos de estudio ecografico (puntos LEAN) necesarios para una correcta evaluacion diagnostica y se construyo un algoritmo de decision eficiente. Resultados Entre los anos 2007-2012 se realizo un estudio transversal de 984 ecografias venosas de extremidad inferior. El 96% de los pacientes presentaron un punto de fuga y recorrido correctamente determinados al insonar ingle (LEAN-1) y hueco popliteo (LEAN-2) y, de estos, un 3,6% presentaban un segundo punto de fuga, no detectado en estas localizaciones. Un 4,2% de los pacientes no presento ningun punto de fuga en LEAN-1 o LEAN-2, tratandose de perforantes en muslo (50%), pierna (30%) y Hunter (20%). Conclusiones La exclusiva insonacion de los puntos LEAN-1 y LEAN-2 nos permiten realizar un diagnostico certero y suficiente en el 92,4% de los pacientes, optimizando de esta manera el tiempo y el coste de la exploracion. Siguiendo el algoritmo propuesto, solo un 4,2% de los pacientes precisara una exploracion venosa completa.

Magnetic skyrmions are topologically protected spin textures with promising prospects for applications in data storage. They can form a lattice state due to competing magnetic interactions and are commonly found in a small region of the temperature—magnetic field phase diagram. Recent work has demonstrated that these magnetic quasi-particles fluctuate at the μeV energy scale. Here, we use a coherent x-ray correlation method at an x-ray free-electron laser to investigate these fluctuations in a magnetic phase coexistence region near a first-order transition boundary where fluctuations are not expected to play a major role. Surprisingly, we find that the relaxation of the intermediate scattering function at this transition differs significantly compared to that deep in the skyrmion lattice phase. The observation of a compressed exponential behavior suggests solid-like dynamics, often associated with jamming. We assign this behavior to disorder and the phase coexistence observed in a narrow field-window near the transition, which can cause fluctuations that lead to glassy behavior.

We demonstrate deterministic control of dipole-field-stabilized skyrmions by means of spin-orbit torques arising from heavy transition-metal seed layers. Experiments are performed on amorphous Fe/Gd multilayers that are patterned into wires and exhibit stripe domains and dipole skyrmions at room temperature. We show that while the domain walls and skyrmions are achiral on average due to lack of Dzyaloshinskii-Moriya interactions, the N\'eel-like closure domain walls at each surface are chiral and can couple to spin-orbit torques. The current-induced domain evolutions are reported for different magnetic phases, including disordered stripe domains, coexisting stripes and dipole skyrmions and a closed packed dipole skyrmion lattice. The magnetic textures exhibit motion under current excitations with a current density ~10^8 A/m2. By comparing the motion resulting from magnetic spin textures in Fe/Gd films with different heavy transition-metal interfaces, we confirm spin currents can be used to manipulate achiral dipole skyrmions via spin-orbit torques., Comment: 23 pages, 8 figures

Resumen Introduccion Los signos y sintomas de la trombosis venosa profunda (TVP) en las extremidades suelen ser inespecificos y a menudo influidos por la comorbilidad del paciente. Objetivo Analisis de variables clinicas de los pacientes con sospecha clinica de un primer episodio de TVP en Atencion Primaria. Material y metodos Estudio observacional transversal y analitico de pacientes ambulatorios con sospecha de un primer episodio de TVP en extremidades inferiores. Se correlacionan los factores de riesgo y comorbilidades con la confirmacion diagnostica de TVP mediante ecografia-doppler. Resultados Se estudio a 116 pacientes, de los cuales en 22 (18,9%) se confirmo el diagnostico. Las comorbilidades mas frecuentes fueron la hipertension, la hipercolesterolemia y la diabetes tipo 2. Solo la presencia de un diagnostico alternativo probable y la inmovilizacion prolongada se asociaron con la exclusion o el diagnostico final de TVP, respectivamente. Las enfermedades del aparato locomotor conllevaron una mayor probabilidad de falsa sospecha de TVP y el unico signo clinico que se correlaciono con el diagnostico fue la tumefaccion de la extremidad afecta. Conclusiones En la practica clinica, la tumefaccion o el antecedente de paralisis de la extremidad nos ha de hacer sospechar firmemente una TVP. Sin embargo, la presencia de un posible diagnostico alternativo practicamente descartara dicha enfermedad.

Time-resolved magneto-optical imaging reveals that the dynamics of the helicity-dependent all-optical switching (HD-AOS) of Co/Pt ferromagnetic multilayers occurs on the time scales from nanoseconds to seconds. We find HD-AOS proceeds by two stages. First, for an optimized laser fluence, the ultrashort laser pulse demagnetizes the film to 25% of the initial magnetization. Subsequent laser pulses aids nucleation of small reversed domains. The observed nucleation is stochastic and independent of the helicity of laser light. At the second stage circularly polarized light breaks the degeneracy between the magnetic domains promoting a preferred direction of domain wall motion. One circular polarization results in a collapse of the reversed magnetic domains. The other polarization causes the growth of reversed magnetic domain from the nucleation sites, via deterministic displacement of the domain wall resulting in magnetization reversal. This mechanism is supported by further imaging studies of deterministic laser-induced displacement of the domain walls when excited by circularly polarized optical pulses.

We report the observation of room-temperature magnetic skyrmions in Pt/Co/Os/Pt thin-film heterostructures and their response to electric currents. The magnetic properties are extremely sensitive to inserting thin Os layers between the Co-Pt interface resulting in reduced saturation magnetization, magnetic anisotropy and Curie temperature. The observed skyrmions exist in a narrow temperature, applied-field and layer-thickness range near the spin-reorientation transition from perpendicular to in-plane magnetic anisotropy. The skyrmions have an average diameter of 2.3{\mu}m and transport measurements demonstrate these features can be displaced with current densities as low as J = 2x10^4 A/cm^2 and display a skyrmion Hall effect., Comment: 17 pages, 5 figures

We report an x-ray photon correlation spectroscopy method that exploits the recent development of the two-pulse mode at the Linac Coherent Light Source. By using coherent resonant x-ray magnetic scattering, we studied spontaneous fluctuations on nanosecond time scales in thin films of multilayered Fe/Gd that exhibit ordered stripe and Skyrmion lattice phases. The correlation time of the fluctuations was found to differ between the Skyrmion phase and near the stripe-Skyrmion boundary. This technique will enable a significant new area of research on the study of equilibrium fluctuations in condensed matter.

ResumenObjetivoReportar el caso de una complicación poscolonoscopia de tratamiento complejo.Caso clínicoPresentamos el caso de una mujer de 82 años, a quien se practicó una colonoscopia total por sangrado rectal, reportando úlcera anal. Dos días después presentó dolor abdominal y distensión abdominal. En las imágenes se encontró gran neumoperitoneo; se realizó laparotomía exploradora sin encontrar lesión en el colon. Presentó buena evolución postoperatoria. Se hace una revisión de la literatura respectiva.AbstractAimTo report a case of one of the most complex complication post-colonoscopy and is treatment.Case reportWe report the case of a 82 years old woman, who was taken to complete colonoscopy for rectal bleeding, then reporting an anal ulcer. Two days later, she has abdominal pain and bloating. In images she has a great pneumoperitoneum. At laparotomy it was not found any injury to the colon. She has a good post-operative evolution. Respective literature review is done.

The dynamic response of dipole skyrmions in Fe/Gd multilayer films is investigated by ferromagnetic resonance measurements and compared to micromagnetic simulations. We detail thickness and temperature dependent studies of the observed modes as well as the effects of magnetic field history on the resonant spectra. Correlation between the modes and the magnetic phase maps constructed from real-space imaging and scattering patterns allows us to conclude the resonant modes arise from local topological features such as dipole skyrmions but does not depend on the collective response of a closed packed lattice of these chiral textures. Using, micromagnetic modeling, we are able to quantitatively reproduce our experimental observations which suggests the existence of localized spin-wave modes that are dependent on the helicity of the dipole skyrmion. We identify four localized spin wave excitations for the skyrmions that are excited under either in-plane or out-of-plane r.f. fields. Lastly we show that dipole skyrmions and non-chiral bubble domains exhibit qualitatively different localized spin wave modes., 38 pages, 17 figures

El perfeccionamiento de habilidades de comprensión lectora es fundamental para aquellos estudiantes decididos a extender sus estudios a nivel universitario. Este estudio de métodos mixtos secuencial-explicativo pretendió medir el impacto que una evaluación de competencias de comprensión lectora en inglés tiene en el rendimiento de 96 colegiales, quienes recibieron 15 horas de instrucción, facilitadas por tecnologías sobre técnicas de evaluación lectora. Los datos fueron colectados mediante exámenes de comprensión lectora y entrevistas semi-estructuradas, y analizados mediante una prueba-t para muestras pareadas y un enfoque fenomenológico. Los alumnos mostraron mejores resultados mediante la técnica de evaluación “relacionar características”. Existen avances significativos de involucramiento crítico con el texto, aunque sus marcas bajas infieren un conocimiento deficiente del lenguaje para el nivel evaluado.Palabras clave: Evaluación, lectura, tecnologías, rendimiento académicoASSESSMENT TECHNIQUES OF ENGLISH READING COMPREHENSION MEDIATED BY TECHNOLOGIES TO IMPROVE COLLEGE STUDENT’S ACHIEVEMENT. AbstractImproving reading comprehension skills is fundamental to those students willing to enroll in undergraduate studies. This sequential-explanatory mixed methods research design attempted to measure the impact that English reading comprehension assessment had on 96 college students’ school performance after receiving a 15-hour instruction on reading evaluating techniques in technological-enriched environments. The data was collected through reading comprehension pre/post-tests and a semi-structured interview. A paired samples t-test and phenomenological approach were used to analyze the data. The students showed better results in reading when assessed through the "relate characteristics" technique. Although remarkable progress of critical engagement with the text was shown, it was inferred that students had some language knowledge deficiencies according to the evaluated level. Keywords: Evaluation, reading, technology, academic achievemen

The ability to engineer metamaterials with tunable nonlinear optical properties is crucial for nonlinear optics. Traditionally, metals have been employed to enhance nonlinear optical interactions through field localization. Here, inspired by the electronic properties of materials, we introduce and demonstrate experimentally an asymmetric metal-semiconductor-metal (MSM) metamaterial that exhibits a large and electronically tunable effective second-order optical susceptibility (\c{hi}(2)). The induced \c{hi}(2) originates from the interaction between the third-order optical susceptibility of the semiconductor (\c{hi}(3)) with the engineered internal electric field resulting from the two metals with dissimilar work function at its interfaces. We demonstrate a five times larger second-harmonic intensity from the MSM metamaterial, compared to contributions from its constituents with electrically tunable nonlinear coefficient ranging from 2.8 to 15.6 pm/V., 12 pages, 4 figures, 1 table

When engineered on scales much smaller than the operating wavelength, metal-semiconductor nanostructures exhibit properties unobtainable in nature. Namely, a uniaxial optical metamaterial described by a hyperbolic dispersion relation can simultaneously behave as a reflective metal and an absorptive or emissive semiconductor for electromagnetic waves with orthogonal linear polarization states. Using an unconventional multilayer architecture, we demonstrate luminescent hyperbolic metasurfaces, wherein distributed semiconducting quantum wells display extreme absorption and emission polarization anisotropy. Through normally incident micro-photoluminescence measurements, we observe absorption anisotropies greater than a factor of 10 and degree-of-linear polarization of emission >0.9. We observe the modification of emission spectra and, by incorporating wavelength-scale gratings, show a controlled reduction of polarization anisotropy. We verify hyperbolic dispersion with numerical simulations that model the metasurface as a composite nanoscale structure and according to the effective medium approximation. Finally, we experimentally demonstrate >350% emission intensity enhancement relative to the bare semiconducting quantum wells., Here, Smalley et al. demonstrate luminescent hyperbolic metasurfaces wherein quantum heterostructures simultaneously function as the emission source and constituent dielectric. The design enables extreme polarization anisotropy of photoluminescence and efficient extraction of in-plane surface modes.

We report the demonstration of luminescent hyperbolic metasurfaces (LuHMS) fabricated from deeply subwavelength multilayer metal-semiconductor nanostructures. The LuHMS exhibit extreme polarization anisotropy of absorption and emission, modified emission spectra, and enhanced emission intensity.

The origin of deterministic macroscopic properties often lies in microscopic stochastic motion. Magnetic fluctuations that manifest as domain avalanches and chaotic magnetization jumps exemplify such stochastic motion and have been studied in great detail. Here we report Fourier space studies of avalanches in a system exhibiting competing magnetic stripe and skyrmion phase using a soft X-ray speckle metrology technique. We demonstrate the existence of phase boundaries and underlying critical points in the stripe and skyrmion phases. We found that distinct scaling and universality classes are associated with these domain topologies. The magnitude and frequency of abrupt magnetic domain jumps observed in the stripe phase are dramatically reduced in the skyrmion phase. Our results provide an incisive way to probe and understand phase stability in systems exhibiting complex spin topologies.

We propose modification to gain spectra of semiconductor quantum heterostructures by incorporation of nanostructured metal, paving the way for tailor made “meta-gain” media. We show that the wavelength dependence of the principal direction of energy propagation in media with hyperbolic dispersion leads to blue-shifting of peak photoluminescence (PL), and thereby optical gain, relative to emission from the bare semiconductor. Additionally we show that emission spectra from metal-semiconductor hyperbolic metasurfaces depends strongly upon the polarization of an external optical pump. The simultaneous co-optimization of pump properties and optical and electronic densities of states provides a platform for not only compensating losses in metallic metamaterials, but also designing emission spectra beyond that provided by the constituent quantum heterostructures.

© 2017 Elsevier B.V. Recently, Lorentz transmission electron microscopy (LTEM) has helped researchers advance the emerging field of magnetic skyrmions. These magnetic quasi-particles, composed of topologically non-trivial magnetization textures, have a large potential for application as information carriers in low-power memory and logic devices. LTEM is one of a very few techniques for direct, real-space imaging of magnetic features at the nanoscale. For Fresnel-contrast LTEM, the transport of intensity equation (TIE) is the tool of choice for quantitative reconstruction of the local magnetic induction through the sample thickness. Typically, this analysis requires collection of at least three images. Here, we show that for uniform, thin, magnetic films, which includes many skyrmionic samples, the magnetic induction can be quantitatively determined from a single defocused image using a simplified TIE approach.