Osteosíntesis con tornillos de Kadar en las fracturas de cuello femoral

Se estudian retrospectivamente 30 pacientes con fractura de cuello femoral, tipo I y II de Garden, tratadas con osteosíntesis a compresión mediante tornillos de esponjosa tipo Kadar. La edad media de los pacientes fue de 70±19 años, siendo el accidente casual la etiología de todas ellas. Se valoró la calidad de la reducción y de la fijación mediante criterios radiográficos, siendo la reducción óptima en el 93 % de los pacientes y la fijación en el 50%. Como complicaciones hubo 2 desplazamientos precoces de la fractura. No ha habido ninguna pseudoartrosis ni necrosis avascular. Valorando los resultados con arreglo a los criterios de Merle d'Aubigné, hemos obtenidos un 84% de buenos resultados. Creemos que el factor pronóstico más importante es la reducción anatómica de la fractura.Thirty patients with Garden's type I and II femoral neck fracture treated by Kadar's spongiosa compressive screws were retrospectively studied. The mean age of patients was 70±9 years. In all cases, the etiology was a casual accident. Fracture reduction and positioning of the osteosynthesis were assessed by radiographic criteria. Satisfactory reduction was achieved in 93 percent of the patients, and the osteosynthesis was accurate in 50 per cent. As for complications, there were 2 early fracture redisplacement. There were neither non-union nor avascular necrosis. When evaluating functional results according to Merle d'Aubigné criteria, satisfactory results were found in 84 per cent of patients. In our opinion, the more important pronostic factor is the anatomic reduction of the fracture

Поверхностные скорости и айсберговый сток ледникового купола Академии Наук на Северной Земле

We have determined the ice-surface velocities of the Academy of Sciences Ice Cap, Severnaya Zemlya, Russian Arctic, during the period November 2016 – November 2017, using intensity offset-tracking of Sentinel-1 synthetic-aperture radar images. We used the average of 54 pairs of weekly velocities (with both images in each pair separated by a12-day period) to estimate the mean annual ice discharge from the ice cap. We got an average ice discharge for 2016–2017 of 1,93±0,12 Gt a−1, which is equivalent to −0,35±0,02 m w.e. a−1 over the whole area of the ice cap. The difference from an estimate of ~1,4 Gt a−1 for 2003–2009 can be attributed to the initiation of ice-stream flow in Basin BC sometime between 2002 and 2016. Since the front position changes between both periods have been negligible, ice discharge is equivalent to calving flux. We compare our results for calving flux with those of previous studies and analyse the possible drivers of the changes observed along the last three decades. Since these changes do not appear to have responded to environmental changes, we conclude that the observed changes are likely driven by the intrinsic characteristics of the ice cap governing tidewater glacier dynamics.По 54 парам космических снимков Sentinel‐1, сделанных с ноября 2016 г. по ноябрь 2017 г., определены скорости движения ледникового купола Академии Наук на Северной Земле. На этой основе оценён среднегодовой расход льда в море этого купола (1,93±0,12 Гт/год), установлены основные пути стока льда, проведено сравнение с прежними оценками

Luxación Traumática de Cadera en el Niño

La luxación traumática de cadera en el niño es una lesión poco frecuente. Los autores presentan un caso de luxación anterior de cadera en un niño de 4 años producida por traumatismo mínimo. La exploración realizada en urgencias mostró impotencia funcional para la deambulación y gran dolor. El seguimiento ha sido de 18 meses tras los cuales el paciente no presenta complicaciones. Exponen su experiencia en el caso y revisión de la bibliografía.Traumatic hip dislocation of the hip is rare in children. The authors report a case of anterior hip dislocation in a 4-year-old boy who received relatively minor trauma. He was unable to walk and was in severe pain when seen in emergency room. He was followed-up for 18 months and no complications have appeared. They report here their experience with one case and review the literature

Drivers for spatial modelling of a critically endangered seabird on a dynamic ocean area: Balearic shearwaters are non-vegetarian

1. Spatial modelling is an important research tool to improve our knowledge about the distribution of wildlife in the ocean. Using different modelling techniques (MaxEnt and a generalized linear mixed model), a predictive habitat suitability model was developed for one of the most threatened seabirds in the world: the Balearic shearwater, Puffinus mauretanicus. 2. Models were developed using a 10-year dataset from the Gulf of Cádiz (on the south-western Iberian Peninsula), a key foraging area for Balearic shearwaters during migration and the non-breeding season. 3. Predictive habitat maps strongly matched the observed distribution patterns, pointing to bathymetric features as the main modelling drivers. The species was concentrated on shallow areas (up to approximately 100 m in depth) of the continental shelf, very close to the mouth of the Guadalquivir River. In contrast with previous studies, Balearic shearwater distribution in the highly dynamic Gulf of Cádiz was not correlated with areas of high chlorophyll a concentration. 4. This lack of spatial correlation probably arises from the delay between the phytoplankton bloom and the response of the zooplankton and small fish that are preyed upon by Balearic shearwaters, which may result in important displacements of this trophic chain across the Gulf of Cádiz. 5. The analysis presented contributes to a better understanding of the spatial distribution and ecology of the critically endangered top predator in the Gulf of Cádiz and offers important information to improve management plans.Versión del editor1,92

Practical Characterization of Cell-Electrode Electrical Models in Bio-Impedance Assays

This paper presents the fitting process followed to adjust the parameters of the electrical model associated to a cell-electrode system in Electrical Cell-substrate Impedance Spectroscopy (ECIS) technique, to the experimental results from cell-culture assays. A new parameter matching procedure is proposed, under the basis of both, mismatching between electrodes and time-evolution observed in the system response, as consequence of electrode fabrication processes and electrochemical performance of electrode-solution interface, respectively. The obtained results agree with experimental performance, and enable the evaluation of the cell number in a culture, by using the electrical measurements observed at the oscillation parameters in the test circuits employed.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

Surface emergence of glacial plumes determined by fjord stratification

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in De Andres, E., Slater, D. A., Otero, J., Das, S., Navarro, F., & Straneo, F. Surface emergence of glacial plumes determined by fjord stratification. Cryosphere, 14(6), (2020): 1951-1969, doi:10.5194/tc-14-1951-2020.Meltwater and sediment-laden plumes at tidewater glaciers, resulting from the localized subglacial discharge of surface melt, influence submarine melting of the glacier and the delivery of nutrients to the fjord's surface waters. It is usually assumed that increased subglacial discharge will promote the surfacing of these plumes. Here, at a western Greenland tidewater glacier, we investigate the counterintuitive observation of a non-surfacing plume in July 2012 (a year of record surface melting) compared to the surfacing of the plume in July 2013 (an average melt year). We combine oceanographic observations, subglacial discharge estimates and an idealized plume model to explain the observed plumes' behavior and evaluate the relative impact of fjord stratification and subglacial discharge on plume dynamics. We find that increased fjord stratification prevented the plume from surfacing in 2012, show that the fjord was more stratified in 2012 due to increased freshwater content and speculate that this arose from an accumulation of ice sheet surface meltwater in the fjord in this record melt year. By developing theoretical scalings, we show that fjord stratification in general exerts a dominant control on plume vertical extent (and thus surface expression), so that studies using plume surface expression as a means of diagnosing variability in glacial processes should account for possible changes in stratification. We introduce the idea that, despite projections of increased surface melting over Greenland, the appearance of plumes at the fjord surface could in the future become less common if the increased freshwater acts to stratify fjords around the Greenland ice sheet. We discuss the implications of our findings for nutrient fluxes, trapping of atmospheric CO2 and the properties of water exported from Greenland's fjords.This research has been supported by the Ministerio de Educación, Cultura y Deporte (grant no. FPU14/04109), the National Science Foundation (grant no. 1418256), the Ministerio de Economía, Industria y Competitividad, Gobierno de España (grant no. CTM2017-84441-R), and the Horizon 2020 Research and Innovation Programme (grant no. 727890)

Host-pathogen evolutionary signatures reveal dynamics and future invasions of vampire bat rabies

Anticipating how epidemics will spread across landscapes requires understanding host dispersal events that are notoriously difficult to measure. Here, we contrast host and virus genetic signatures to resolve the spatiotemporal dynamics underlying geographic expansions of vampire bat rabies virus (VBRV) in Peru. Phylogenetic analysis revealed recent viral spread between populations that, according to extreme geographic structure in maternally inherited host mitochondrial DNA, appeared completely isolated. In contrast, greater population connectivity in biparentally inherited nuclear microsatellites explained the historical limits of invasions, suggesting that dispersing male bats spread VBRV between genetically isolated female populations. Host nuclear DNA further indicated unanticipated gene flow through the Andes mountains connecting the VBRV-free Pacific coast to the VBRV-endemic Amazon rainforest. By combining Bayesian phylogeography with landscape resistance models, we projected invasion routes through northern Peru that were validated by real-time livestock rabies mortality data. The first outbreaks of VBRV on the Pacific coast of South America could occur by June 2020, which would have serious implications for agriculture, wildlife conservation, and human health. Our results show that combining host and pathogen genetic data can identify sex biases in pathogen spatial spread, which may be a widespread but underappreciated phenomenon, and demonstrate that genetic forecasting can aid preparedness for impending viral invasions

Reversible Interlayer Sliding and Conductivity Changes in Adaptive Tetrathiafulvalene-Based Covalent Organic Frameworks.

Ordered interlayer stacking is intrinsic in two-dimensional covalent organic frameworks (2D COFs) and has strong implications on COF's optoelectronic properties. Reversible interlayer sliding, corresponding to shearing of 2D layers along their basal plane, is an appealing dynamic control of both structures and properties, yet it remains unexplored in the 2D COF field. Herein, we demonstrate that the reversible interlayer sliding can be realized in an imine-linked tetrathiafulvalene (TTF)-based COF TTF-DMTA. The solvent treatment induces crystalline phase changes between the proposed staircase-like sql net structure and a slightly slipped eclipsed sql net structure. The solvation-induced crystallinity changes correlate well with reversible spectroscopic and electrical conductivity changes as demonstrated in oriented COF thin films. In contrast, no reversible switching is observed in a related TTF-TA COF, which differs from TTF-DMTA in terms of the absence of methoxy groups on the phenylene linkers. This work represents the first 2D COF example of which eclipsed and staircase-like aggregated states are interchangeably accessed via interlayer sliding, an uncharted structural feature that may enable applications such as chemiresistive sensors

Meisenheimer complexes as hidden intermediates in the aza-S_NAr mechanism

In this work we report a computational study about the aza-S_NAr mechanism in fluorine- and chlorine-containing azines with the aim to unravel the physical factors that determine the reactivity patterns in these heterocycles towards propylamine. The nature of the reaction intermediate was analyzed in terms of its electronic structure based on a topological analysis framework in some non-stationary points along the reaction coordinate. The mechanistic dichotomy of a concerted or a stepwise pathway is interpreted in terms of the qualitative Diabatic Model of Intermediate Stabilization (DMIS) approach, providing a general mechanistic picture for the S_NAr process involving both activated benzenes and nitrogen-containing heterocycles. With the information collected, a unified vision of the Meisenheimer complexes as transition state, hidden intermediate or real intermediate was proposed

Meisenheimer complexes as hidden intermediates in the aza-S_NAr mechanism

In this work we report a computational study about the aza-S_NAr mechanism in fluorine- and chlorine-containing azines with the aim to unravel the physical factors that determine the reactivity patterns in these heterocycles towards propylamine. The nature of the reaction intermediate was analyzed in terms of its electronic structure based on a topological analysis framework in some non-stationary points along the reaction coordinate. The mechanistic dichotomy of a concerted or a stepwise pathway is interpreted in terms of the qualitative Diabatic Model of Intermediate Stabilization (DMIS) approach, providing a general mechanistic picture for the S_NAr process involving both activated benzenes and nitrogen-containing heterocycles. With the information collected, a unified vision of the Meisenheimer complexes as transition state, hidden intermediate or real intermediate was proposed