Nanoporous Amorphous Carbon with Exceptional Ultra-High Strength.

Nanoporous materials show a promising combination of mechanical properties in terms of their relative density; while there are numerous studies based on metallic nanoporous materials, here we focus on amorphous carbon with a bicontinuous nanoporous structure as an alternative to control the mechanical properties for the function of filament composition.Using atomistic simulations, we study the mechanical response of nanoporous amorphous carbon with 50% porosity, with sp3 content ranging from 10% to 50%. Our results show an unusually high strength between 10 and 20 GPa as a function of the %sp3 content. We present an analytical analysis derived from the Gibson-Ashby model for porous solids, and from the He and Thorpe theory for covalent solids to describe Young's modulus and yield strength scaling laws extremely well, revealing also that the high strength is mainly due to the presence of sp3 bonding. Alternatively, we also find two distinct fracture modes: for low %sp3 samples, we observe a ductile-type behavior, while high %sp3 leads to brittle-type behavior due to high high shear strain clusters driving the carbon bond breaking that finally promotes the filament fracture. All in all, nanoporous amorphous carbon with bicontinuous structure is presented as a lightweight material with a tunable elasto-plastic response in terms of porosity and sp3 bonding, resulting in a material with a broad range of possible combinations of mechanical properties.

Neurological Complications in Systemic Inflammatory Diseases.

Systemic inflammatory diseases could produce neurologic complications, and they are frequently incorporated in the differential diagnosis of neurological symptoms. There are wellestablished criteria to meet the diagnosis of neurologic manifestations of these systemic diseases. Methods: However, the range of clinical presentations varies in each condition, and the prevalence of these complications differs between studies. Hence, in many cases, an etiological relationship is not clearly defined. Results and Conclusion: For these reasons, it is challenging to make an accurate diagnosis. We analyzed the spectrum of neurological manifestations in a cohort of patients with systemic lupus erythematosus, rheumatoid arthritis, Behçet disease and sarcoidosis in order to improve our current knowledge of these complications.

Probing the Mechanical Properties of Porous Nanoshells by Nanoindentation.

In this contribution, we present a study of the mechanical properties of porous nanoshells measured with a nanoindentation technique. Porous nanoshells with hollow designs can present attractive mechanical properties, as observed in hollow nanoshells, but coupled with the unique mechanical behavior of porous materials. Porous nanoshells display mechanical properties that are dependent on shell porosity. Our results show that, under smaller porosity values, deformation is closely related to the one observed for polycrystalline and single-crystalline nanoshells involving dislocation activity. When porosity in the nanoparticle is increased, plastic deformation was mediated by grain boundary sliding instead of dislocation activity. Additionally, porosity suppresses dislocation activity and decreases nanoparticle strength, but allows for significant strain hardening under strains as high as 0.4. On the other hand, Young's modulus decreases with the increase in nanoshell porosity, in agreement with the established theories of porous materials. However, we found no quantitative agreement between conventional models applied to obtain the Young's modulus of porous materials.

Nanoparticle Shape Influence over Poly(lactic acid) Barrier Properties by Molecular Dynamics Simulations.

Climate change is leading us to search for new materials that allow a more sustainable environmental situation in the long term. Poly(lactic acid) (PLA) has been proposed as a substitute for traditional plastics due to its high biodegradability. Various components have been added to improve their mechanical, thermal, and barrier properties. The modification of the PLA barrier properties by introducing nanoparticles with different shapes is an important aspect to control the molecular diffusion of oxygen and other gas compounds. In this work, we have described changes in oxygen diffusion by introducing nanoparticles of different shapes through molecular dynamics simulations. Our model illustrates that the existence of curved surfaces and the deposition of PLA around them by short chains generate small holes where oxygen accumulates, forming clusters and reducing their mobility. From the several considered shapes, the sphere is the most suitable structure to improve the barrier properties of the PLA.

Resultados comparativos de la implementación en práctica diaria de un checklist de evaluación para pacientes con espondiloartritis axial y artritis psoriásica / Comparative results of the implementation in daily practice of an evaluation checklist for patients with axial spondyloarthritis and psoriatic arthritis

Objetivo: Analizar y comparar los cambios en la recogida de variables clínicas tras la implementación en la práctica diaria de un checklist de evaluación para pacientes con espondiloartritis axial (EspAax) y artritis psoriásica (APs). Métodos: Se realizó un estudio observacional. Mediante revisión de historias médicas, se recogieron el número y el tipo de variables del checklist de evaluación que figuraban en las mismas. La primera revisión se realizó antes de la implementación del checklist, y la segunda, 6meses después de la implementación (pacientes diferentes) para poder comparar los cambios producidos con la misma. Se realizó un análisis descriptivo y bivariado. Resultados: Participaron 6 hospitales y 11 reumatólogos. Se revisaron un total de 83 y 68 historias médicas pre- y post-implementación del checklist. Tras la implementación, en la EspAax aumentó significativamente el registro en la historia clínica del consumo de alcohol, diarrea o enfermedad inflamatoria intestinal (EII) y la uretritis, diabetes mellitus, hiperlipidemia, depresión, obesidad o la gota/hiperuricemia, peso, talla, presión arterial, VGM, VGP, BASDAI y DAS28. Y en la APs el consumo de alcohol, HTA, diabetes mellitus, hiperlipidemia, enfermedad, gota/hiperuricemia, expansión torácica, rotación cervical, peso, talla, presión arterial, VGM, VGP, ASDAS, BASDAI y BASFI. Tanto pre- como post-implantación en general existe una tendencia a un mayor porcentaje de recogida de variables en pacientes con EspAax que en pacientes con APs. Conclusiones: La implementación de un checklist específico en la práctica diaria mejora la evaluación de los pacientes con EspAax y APs. Se debe seguir trabajando en la mejoría de la evaluación de los pacientes con EspA, pero especialmente en la APs.(AU)

Objective: To analyse and compare changes in the collection of clinical variables after the implementation in daily practice of an evaluation checklist for patients with axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA). Methods: An observational study was performed based on medical records review. The number and type of variables of the evaluation checklist in the medical records were collected. The first review was made before the implementation of the checklist, and the second one 6months after the implementation (in different patients). A descriptive and bivariate analysis was carried out. Results: Six hospitals and 11 rheumatologists participated. A total of 83 and 68 medical records were reviewed before and after the implementation of the checklist. After the implementation, in the axSpA patients, a significant increase was recorded in alcohol consumption, diarrhoea or IBD and urethritis, diabetes mellitus, hyperlipidaemia, depression, obesity or gout/hyperuricaemia, weight, height, blood pressure, patient and physician global assessments of disease activity, BASDAI and DAS28. And, in the PsA patients, alcohol consumption, hypertension, diabetes mellitus, hyperlipidaemia, disease, gout/hyperuricaemia, thoracic expansion, cervical rotation, weight, height, blood pressure, patient and physician global assessments of disease, ASDAS, BASDAI, and BASFI were recorded. In general, there was a trend towards greater recording in axSpA compared with PsA. Conclusions: The implementation of a specific checklist in daily practice improves the evaluation of patients with axSpA and PsA. More efforts are necessary to continue improving the evaluation of patients with axSpA, but especially of those with PsA.(AU)

Comparative results of the implementation in daily practice of an evaluation checklist for patients with axial spondyloarthritis and psoriatic arthritis.

OBJECTIVE: To analyse and compare changes in the collection of clinical variables after the implementation in daily practice of an evaluation checklist for patients with axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA). METHODS: An observational study was performed based on medical records review. The number and type of variables of the evaluation checklist in the medical records were collected. The first review was made before the implementation of the checklist, and the second one 6 months after the implementation (in different patients). A descriptive and bivariate analysis was carried out. RESULTS: Six hospitals and 11 rheumatologists participated. A total of 83 and 68 medical records were reviewed before and after the implementation of the checklist. After the implementation, in the axSpA patients, a significant increase was recorded in alcohol consumption, diarrhoea or IBD and urethritis, diabetes mellitus, hyperlipidaemia, depression, obesity or gout/hyperuricaemia, weight, height, blood pressure, patient and physician global assessments of disease activity, BASDAI and DAS28. And, in the PsA patients, alcohol consumption, hypertension, diabetes mellitus, hyperlipidaemia, disease, gout/hyperuricaemia, thoracic expansion, cervical rotation, weight, height, blood pressure, patient and physician global assessments of disease, ASDAS, BASDAI, and BASFI were recorded. In general, there was a trend towards greater recording in axSpA compared with PsA. CONCLUSIONS: The implementation of a specific checklist in daily practice improves the evaluation of patients with axSpA and PsA. More efforts are necessary to continue improving the evaluation of patients with axSpA, but especially of those with PsA.

Hollow Gold Nanoparticles Produced by Femtosecond Laser Irradiation.

Metallic hollow nanoparticles exhibit interesting optical properties that can be controlled by geometrical parameters. Irradiation with femtosecond laser pulses has emerged recently as a valuable tool for reshaping and size modification of plasmonic metal nanoparticles, thereby enabling the synthesis of nanostructures with unique morphologies. In this Letter, we use classical molecular dynamics simulations to investigate the solid-to-hollow conversion of gold nanoparticles upon femtosecond laser irradiation. Here, we suggest an efficient method for producing hollow nanoparticles under certain specific conditions, namely that the particles should be heated to a maximum temperature between 2500 and 3500 K, followed by a fast quenching to room temperature, with cooling rates lower than 120 ps. Therefore, we describe the experimental conditions for efficiently producing hollow nanoparticles, opening a broad range of possibilities for applications in key areas, such as energy storage and catalysis.

Formation of Hollow Gold Nanocrystals by Nanosecond Laser Irradiation.

The irradiation of spherical gold nanoparticles (AuNPs) with nanosecond laser pulses induces shape transformations yielding nanocrystals with an inner cavity. The concentration of the stabilizing surfactant, the use of moderate pulse fluences, and the size of the irradiated AuNPs determine the efficiency of the process and the nature of the void. Hollow nanocrystals are obtained when molecules from the surrounding medium (e.g., water and organic matter derived from the surfactant) are trapped during laser pulse irradiation. These experimental observations suggest the existence of a subtle balance between the heating and cooling processes experienced by the nanocrystals, which induce their expansion and subsequent recrystallization keeping exogenous matter inside. The described approach provides valuable insight into the mechanism of interaction of a pulsed nanosecond laser with AuNPs, along with interesting prospects for the development of hollow plasmonic nanoparticles with potential applications related to gas and liquid storage at the nanoscale.

Implementation of an assessment checklist for patients with spondyloarthritis in daily practice.

OBJECTIVES: To analyse the feasibility and changes in the collection of clinical measures after the implementation in daily practice of a checklist designed for an optimal evaluation and monitoring of patients with spondyloarthritis (SpA). METHODS: An observational prospective study was performed. The feasibility of the assessment checklist (paper/on-line format) for patients with SpA was tested (time to complete the checklist, simplicity, amenity clarity, usefulness). Through a medical files review, changes in the number of the checklist variables collected were analysed previous to the implementation of the checklist and 6 months later. A descriptive and bivariate analysis was performed. RESULTS: A total 6 hospitals and 11 rheumatologists participated. The median time to checklist completion was 15 (12-20) minutes, and the mean scores for the rest of variables of the feasibility test were in general positives. A total of 83 and 68 medical files pre-implementation and post-implementation were reviewed respectively. We observed a significant increase in the collection of many of the checklist variables after the implementation. The record of BASDAI increased from 46.2% to 73.1% (p=0.001), physical activity from 48.2% to 88.2% (p<0.0001), physician global (VAS) from 28.0% to 73.5% (p<0.0001), patient global (VAS) from 48.8% to 85.3% (p<0.0001), morning stiffness from 62.8% to 84.8% (p=0.003), ASDAS from 12.2% to 32.8% (p=0.002), BASFI from 43.7% to 65.7% (p=0.008), or DAS28 from 24.7% to 46.3% (p=0.006). These changes were observed irrespectively of SpA classification. CONCLUSIONS: The implementation of an assessment checklist in daily practice is feasible and improves the assessment of SpA patients.

Femtosecond laser reshaping yields gold nanorods with ultranarrow surface plasmon resonances.

The irradiation of gold nanorod colloids with a femtosecond laser can be tuned to induce controlled nanorod reshaping, yielding colloids with exceptionally narrow localized surface plasmon resonance bands. The process relies on a regime characterized by a gentle multishot reduction of the aspect ratio, whereas the rod shape and volume are barely affected. Successful reshaping can only occur within a narrow window of the heat dissipation rate: Low cooling rates lead to drastic morphological changes, and fast cooling has nearly no effect. Hence, a delicate balance must be achieved between irradiation fluence and surface density of the surfactant on the nanorods. This perfection process is appealing because it provides a simple, fast, reproducible, and scalable route toward gold nanorods with an optical response of exceptional quality, near the theoretical limit.

Permanent modifications in silica produced by ion-induced high electronic excitation: experiments and atomistic simulations.

The irradiation of silica with ions of specific energy larger than ~0.1 MeV/u produces very high electronic excitations that induce permanent changes in the physical, chemical and structural properties and give rise to defects (colour centres), responsible for the loss of sample transparency at specific bands. This type of irradiation leads to the generation of nanometer-sized tracks around the ion trajectory. In situ optical reflection measurements during systematic irradiation of silica samples allowed us to monitor the irradiation-induced compaction, whereas ex situ optical absorption measurements provide information on colour centre generation. In order to analyse the results, we have developed and validated an atomistic model able to quantitatively explain the experimental results. Thus, we are able to provide a consistent explanation for the size of the nanotracks, the velocity and thresholding effects for track formation, as well as, the colour centre yield per ion and the colour centre saturation density. In this work we will discuss the different processes involved in the permanent modification of silica: collective atomic motion, bond breaking, pressure-driven atom rearrangement and ultra-fast cooling. Despite the sudden lattice energy rise is the triggering and dominant step, all these processes are important for the final atomic configuration.

Understanding the ion-induced elongation of silver nanoparticles embedded in silica.

In this work we have studied the elongation of silver nanoparticles irradiated with 40 MeV Bromine ions by means of in situ optical measurements, transmission electron microscopy and molecular dynamics simulations. The localized surface plasmon resonance of silver nanoparticles has a strong dependence on the particle shape and size, which allowed us to obtain the geometrical parameters with remarkable accuracy by means of a fit of the optical spectra. Optical results have been compared with transmission electron microscopy images and molecular dynamics simulations and the agreement is excellent in both cases. An important advantage of in situ measurements is that they yield an extremely detailed information of the full elongation kinetics. Final nanoparticle elongation depends on a complex competition between single-ion deformation, Ostwald ripening and dissolution. Building and validating theoretical models with the data reported in this work should be easier than with the information previously available, due to the unprecedented level of kinetic details obtained from the in situ measurements.

Transporte de residuos sólidos urbanos por ferrocarril

Aborda la problemática del transporte de residuos sólidos por ferrocarril, describiendo la caracterización del sistema, recolección y transferencia. Remarca la evaluación del proyecto y el análisis costo-beneficio

Transporte de residuos sólidos urbanos por ferrocarril

Aborda la problemática del transporte de residuos sólidos por ferrocarril, describiendo la caracterización del sistema, recolección y transferencia. Remarca la evaluación del proyecto y el análisis costo-beneficio