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1.
Materials (Basel) ; 14(6)2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33804054

RESUMEN

Deriving mesoporous ZnO from calcinated, molecular layer deposited (MLD) metal-organic hybrid thin films offers various advantages, e.g., tunable crystallinity and porosity, as well as great film conformality and thickness control. However, such methods have barely been investigated. In this contribution, zinc-organic hybrid layers were for the first time formed via a three-step MLD sequence, using diethylzinc, ethanolamine, and maleic anhydride. These zinc-organic hybrid films were then calcinated with the aim of enhancing the porosity of the obtained ZnO films. The saturation curves for the three-step MLD process were measured, showing a growth rate of 4.4 ± 0.2 Å/cycle. After initial degradation, the zinc-organic layers were found to be stable in ambient air. The transformation behavior of the zinc-organic layers, i.e., the evolution of the film thickness and refractive index as well as the pore formation upon heating to 400, 500, and 600 °C were investigated with the help of spectroscopic ellipsometry and ellipsometric porosimetry. The calculated pore size distribution showed open porosity values of 25%, for the sample calcinated at 400 °C. The corresponding expectation value for the pore radius obtained from this distribution was 2.8 nm.

2.
Circ Heart Fail ; 9(9)2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27609832

RESUMEN

BACKGROUND: A greater understanding of the different underlying mechanisms between patients with heart failure with reduced (HFrEF) and with preserved (HFpEF) ejection fraction is urgently needed to better direct future treatment. However, although skeletal muscle impairments, potentially mediated by inflammatory cytokines, are common in both HFrEF and HFpEF, the underlying cellular and molecular alterations that exist between groups are yet to be systematically evaluated. The present study, therefore, used established animal models to compare whether alterations in skeletal muscle (limb and respiratory) were different between HFrEF and HFpEF, while further characterizing inflammatory cytokines. METHODS AND RESULTS: Rats were assigned to (1) HFrEF (ligation of the left coronary artery; n=8); (2) HFpEF (high-salt diet; n=10); (3) control (con: no intervention; n=7). Heart failure was confirmed by echocardiography and invasive measures. Soleus tissue in HFrEF, but not in HFpEF, showed a significant increase in markers of (1) muscle atrophy (ie, MuRF1, calpain, and ubiquitin proteasome); (2) oxidative stress (ie, higher nicotinamide adenine dinucleotide phosphate oxidase but lower antioxidative enzyme activities); (3) mitochondrial impairments (ie, a lower succinate dehydrogenase/lactate dehydrogenase ratio and peroxisome proliferator-activated receptor-γ coactivator-1α expression). The diaphragm remained largely unaffected between groups. Plasma concentrations of circulating cytokines were significantly increased in HFrEF for tumor necrosis factor-α, whereas interleukin-1ß and interleukin-12 were higher in HFpEF. CONCLUSIONS: Our findings suggest, for the first time, that skeletal muscle alterations are exacerbated in HFrEF compared with HFpEF, which predominantly reside in limb, rather than in respiratory, muscle. This disparity may be mediated, in part, by the different circulating inflammatory cytokines that were elevated between HFpEF and HFrEF.


Asunto(s)
Citocinas/sangre , Insuficiencia Cardíaca/sangre , Mediadores de Inflamación/sangre , Músculo Esquelético/metabolismo , Volumen Sistólico , Función Ventricular Izquierda , Animales , Diafragma/metabolismo , Modelos Animales de Enfermedad , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/fisiopatología , Interleucina-12/sangre , Interleucina-1beta/sangre , Mitocondrias Musculares/metabolismo , Músculo Esquelético/enzimología , Músculo Esquelético/patología , Atrofia Muscular/sangre , Atrofia Muscular/patología , Estrés Oxidativo , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Factor de Necrosis Tumoral alfa/sangre , Regulación hacia Arriba
3.
IEEE Trans Vis Comput Graph ; 20(10): 1379-91, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26357385

RESUMEN

Data-driven methods have received increasing attention in recent years in order to meet real-time requirements in computationally intensive tasks. In our current work we examine the application of such approaches in soft-tissue simulation. The core idea is to split deformations into a coarse approximation and a differential part that contains the details. We employ the data-driven stamping approach to enrich a fast simulation surface with details that have been extracted from a set of example deformations obtained in offline computations. In this paper we detail our technique, and suggest further extensions over our previous work. First, we propose an improved method for correlating the current coarse approximation to the examples in the database. The new correlation metric combines Euclidean distances with cosine similarity. It allows for better example discrimination, resulting in a well-conditioned linear system. This also enables us to use a non-negative least squares solver that leads to a better regression and guarantees positive stamp blending weights. Second, we suggest a frequency-space stamp compression scheme that saves memory and, in most instances, is faster, since many operations can be done in the compressed space. Third, cutting is included by employing a physically-inspired influence map that allows for proper handling of material discontinuities that were not present in the original examples. We thoroughly evaluate our method and demonstrate its practical application in a surgical simulator prototype.


Asunto(s)
Artroscopía/educación , Instrucción por Computador/métodos , Imagenología Tridimensional/métodos , Meniscos Tibiales/patología , Meniscos Tibiales/cirugía , Modelos Biológicos , Simulación por Computador , Módulo de Elasticidad/fisiología , Humanos , Aumento de la Imagen/métodos , Interpretación de Imagen Asistida por Computador/métodos , Meniscos Tibiales/fisiopatología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Interfaz Usuario-Computador
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