The Debye length and anionic transport properties of composite membranes based on supported ionic liquid-like phases (SILLPS).

An analysis of the ionic transport properties of BMIM [NTf2] in supported ionic-liquid-like phase (SILLP)-based membranes has been carried out based on experimental impedance spectroscopy measurements. The direct current (dc)-conductivity was analyzed to determine the temperature and frequency dependence. The fit of the loss tangent curve data with the Cole-Cole approximation of the electrode polarization model provides the conductivity, diffusivity, and density of charge carriers. Among these quantities, a significant increase in conductivity is observed when an ionic liquid is added to the polymeric matrix containing imidazolium fragments. The use of a recent generalization of Eyring's absolute rate theory allowed the elucidation of how the local entropy restrictions, due to the porosity of the polymeric matrix, control the conductive process. The fit of the conductivity data as a function of temperature manifests the behavior of the excess entropy with respect to the temperature. The activation entropy and enthalpy were also determined. Our results correlate the Debye length (LD) with the experimental values of conductivity, electrode polarization relaxation time, and sample relaxation time involved. Our work provides novel insights into the description of ionic transport in membranes as the diffusivity, mobility, and free charge density depend on the LD. Moreover, we discuss the behavior of the polarization relaxation time, the sample relaxation time, and the static permittivity as a function of the temperature.

Rapidly progressive orbital intravascular papillary endothelial hyperplasia in a newborn.

Intravascular papillary endothelial hyperplasia (IPEH), also known as "vegetant intravascular haemangioendothelioma", is a rare benign proliferation of vascular endothelial cells secondary to intravascular thrombosis and thrombus organisation. It can develop from vascular lesions such as haemangiomas, pyogenic granulomas or varicose veins. This vascular tumour of the skin and subcutaneous tissue may exhibit rapid and progressive growth, and is usually located in the neck or head. Ocular presentation is unusual and orbital involvement is even rarer. We report a case of a preterm newborn male with a rapidly growing left orbital mass that was histologically diagnosed as intravascular papillary endothelial hyperplasia. He was successfully managed with total excision of the tumour and propranolol therapy and remains recurrence free after an eight-year follow-up.

Hiperplasia endotelial papilar intravascular orbitaria rápidamente progresiva en un recién nacido / Rapidly progressive orbital intravascular papillary endothelial hyperplasia in a newborn

La hiperplasia endotelial papilar intravascular (IPEH), también conocida como «hemangioendotelioma vegetante intravascular», es una proliferación benigna y rara de células endoteliales vasculares, secundaria a trombosis intravascular u organización del trombo. Puede desarrollarse a partir de lesiones vasculares como hemangiomas, granulomas piógenos o várices. Este tumor vascular de la piel y del tejido subcutáneo puede presentarse como crecimiento rápido y progresivo, y es usualmente localizado en cuello o cabeza. La presentación ocular es inusual y la afectación orbitaria es todavía más rara. Presentamos un caso de un varón recién nacido pretérmino, el cual presentó una masa orbitaria izquierda de crecimiento rápidamente progresivo y se obtuvo el diagnóstico por histología de hiperplasia endotelial papilar intravascular. El paciente fue exitosamente tratado mediante una escisión total del tumor y terapia con propranolol. Actualmente, después de un seguimiento de ocho años, ha permanecido sin recurrencias (AU)

Intravascular papillary endothelial hyperplasia (IPEH), also known as “vegetant intravascular haemangioendothelioma”, is a rare benign proliferation of vascular endothelial cells secondary to intravascular thrombosis and thrombus organisation. It can develop from vascular lesions such as haemangiomas, pyogenic granulomas or varicose veins. This vascular tumour of the skin and subcutaneous tissue may exhibit rapid and progressive growth, and is usually located in the neck or head. Ocular presentation is unusual and orbital involvement is even rarer. We report a case of a preterm newborn male with a rapidly growing left orbital mass that was histologically diagnosed as intravascular papillary endothelial hyperplasia. He was successfully managed with total excision of the tumour and propranolol therapy and remains recurrence free after an eight-year follow-up (AU)

Size and surface-energy dependence of the adsorption/desorption equilibrium in ethanol electro-oxidation by Pd-nanoparticles. Theory and experiment.

The relation between current and voltage in the electro-oxidation of ethanol by metal nanoparticles depends on experimental parameters like the applied potential, peak potential, temperature, the electron-transfer coefficient, and the number of molecules adsorbed at active sites on the nanoparticle surface. In this form, the oxidation current depends on the ability of the nanoparticles to adsorb the ethanol molecules. Though the Laviron model well describes this phenomenology, few studies focus on the dependence of the oxidation current on the size and surface properties of the metal nanoparticles. Here, we present an experimental and theoretical study that comprises the synthesis of palladium-based nanoparticles and the generalization of the Laviron model that allows determining the dependence of the oxidation current on the size, surface energy, and adsorption-desorption properties of the nanoparticles for the ethanol oxidation. The determination of the adsorption-desorption equilibrium and the electro-oxidation current dependence with the physicochemical properties of the materials was carried out by electrochemical characterization.

Spine stabilization exercises are not superior to flexion exercises for ultrasound-detected muscle thickness changes in patients with chronic low back pain and lumbar spondylolisthesis.

INTRODUCTION: exercise programs can reduce pain and improve functionality in patients with degenerative spondylolisthesis and chronic low back pain. However, there is still no consensus surrounding the superiority of any specific routine for exercise-induced trophic changes of lumbar muscles. The aim was to compare the changes in the primary lumbar stabilizing muscle thickness after spine stabilization exercises and flexion exercises in patients with spondylolisthesis and chronic low back pain. MATERIAL AND METHODS: prospective, longitudinal and comparative study was carried out. Twenty-one treatment-naive patients with a diagnosis of both chronic low back pain and degenerative spondylolisthesis over the age of 50 were included. A physical therapist taught participants either spine stabilization exercises or flexion exercises to execute daily at home. The thickness of the primary lumbar muscles was measured through ultrasound (at rest and contraction) at baseline and three months. A Mann-Whitney U test and Wilcoxon signed-rank test were performed for comparisons, and Spearman's rank correlation coefficients were calculated for associations. RESULTS: we did not find statistically between the exercise programs: all patients presented significant changes in the thickness of the multifidus muscle but in none of the other evaluated muscles. CONCLUSION: there is no difference between spine stabilization exercises and flexion exercises after three months in terms of the changes in muscle thickness evaluated by ultrasound.

INTRODUCCIÓN: el ejercicio reduce el dolor y mejora la funcionalidad en pacientes con dolor crónico lumbar y espondilolistesis degenerativa. Sin embargo, no existe a la fecha un consenso sobre la superioridad de algún programa de ejercicio para inducir cambios tróficos de los músculos estabilizadores lumbares, por lo que el objetivo fue comparar el trofismo de estos músculos mediante ultrasonido, con dos programas de ejercicio distintos: estabilización vertebral versus ejercicios flexores. MATERIAL Y MÉTODOS: estudio prospectivo, longitudinal y comparativo, en veintiún pacientes mayores de 50 años, con dolor crónico lumbar y espondilolistesis degenerativa. Se entrenó a los pacientes para la ejecución diaria de ejercicio: estabilización lumbar o ejercicios flexores, los cuales fueron asignados por aleatorización como parte de un ECA en desarrollo. El trofismo muscular fue evaluado mediante ultrasonido al inicio y a tres meses. Las pruebas de U de Mann-Whitney y prueba de Wilcoxon se usaron para comparaciones entre grupos y para correlaciones se usaron los coeficientes de correlación de Spearman. RESULTADOS: todos los pacientes presentaron ganancia en el trofismo de los músculos multífidos a tres meses, pero sin diferencias entre grupos de tratamiento. No se detectaron cambios significativos en el resto de los músculos evaluados. CONCLUSIÓN: no encontramos diferencia significativa entre los ejercicios de estabilización lumbar y los ejercicios flexores, a tres meses de seguimiento, en términos de los cambios tróficos medidos por ultrasonido de los músculos estabilizadores lumbares.

Correction: Temperature dependence of anomalous protonic and superprotonic transport properties in mixed salts based on CsH2PO4.

Correction for 'Temperature dependence of anomalous protonic and superprotonic transport properties in mixed salts based on CsH2PO4' by Andreu Andrio et al., Phys. Chem. Chem. Phys., 2019, 21, 12948-12960, DOI: 10.1039/C8CP07472K.

Entropic restrictions control the electric conductance of superprotonic ionic solids.

The crystallographic structure of solid electrolytes and other materials determines the protonic conductivity in devices such as fuel cells, ionic-conductors, and supercapacitors. Experiments show that a rise of the temperature in a narrow interval may lead to a sudden increase of several orders of magnitude of the conductivity of some materials, a process called a superprotonic transition. Here, we use a novel macro-transport theory for irregular domains to show that the change of entropic restrictions associated with solid-solid phase or structural transitions controls the sudden change of the ionic conductivity when the superprotonic transition takes place. Specifically, we deduce a general formula for the temperature dependence on the ionic conductivity that fits remarkably well experimental data of superprotonic transitions in doped cesium phosphates and other materials reported in the literature.

Temperature dependence of anomalous protonic and superprotonic transport properties in mixed salts based on CsH2PO4.

We present an experimental study and a theoretical interpretation of the temperature dependence of the transport properties of doped CsH2PO4 salts in both protonic and superprotonic phases. Cesium phosphate based solid electrolytes are technologically relevant because their operational temperature range is about 100 to 300 °C in which a superprotonic transition may manifest depending on its mixed composition. The experimental study was carried out using impedance spectroscopy at the temperature range of 150-230 °C, and the protonic and superprotonic transport properties and proton concentrations were calculated and analyzed by using the electrode polarization, and the Debye and Cole-Cole models for the dielectric constant. We have shown that the transport properties predicted by the Cole-Cole model are consistent with the conductivity measurements whereas the Debye model shows some inconsistencies. We attribute this to the fact that the Cole-Cole model incorporates the effects of interactions among charge carriers better than the more commonly used Debye model. In this way, our work shows a more consistent approach to determine the transport properties of solid electrolytes and, therefore, provides a more reliable tool to analyze the transport properties of heterogeneous solid electrolytes that can be used in electrochemical devices, including fuel cells and supercapacitors.

Relation between the porosity and tortuosity of a membrane formed by disconnected irregular pores and the spatial diffusion coefficient of the Fick-Jacobs model.

In this work, we provide a theoretical relationship between the spatial-dependent diffusion coefficient derived in the Fick-Jacobs (FJ) approximation and the macroscopic diffusion coefficient of a membrane that depends on the porosity, tortuosity, and the constriction factors. Based on simple mass conservation arguments under equilibrium as well as in nonequilibrium conditions, we generalize previous expressions for the effective diffusion coefficient of an irregular pore, originally obtained by Festa and d'Agliano for horizontal and periodic pores, and then extended by Bradley for tortuous periodic pores, to the case of pores with arbitrary geometry. Through a formal definition of the constrictivity factor in terms of the geometry of the pore, our results provide very clear physical interpretation of experimental measurements since they link the local properties of the flow with macroscopic quantities of experimental relevance in the design and optimization of porous materials. The macroscopic diffusion coefficient as well as the spatiotemporal evolution of the concentration profiles inside a pore have been recently measured by using pulse field gradient NMR techniques. The advantage of using the FJ approach is that the spatiotemporal concentration profile inside a pore of irregular geometry is directly related to the pore's shape and, therefore, that the macroscopic diffusion coefficient can be obtained by comparing the spatiotemporal concentration profiles from such experiments with those of the theoretical model. Hence, the present study is relevant for the understanding of the transport properties of porous materials where the shape and arrangement of pores can be controlled at will.

Analysis of the application of the generalized monod kinetics model to describe the human corneal oxygen-consumption rate during soft contact lens wear.

This work is an analysis of the application of the generalized Monod kinetics model describing human corneal oxygen consumption during soft contact lens wear to models previously used by Chhabra et al. (J Biomed Mater Res B Appl Biomater, 2009a;90:202-209, Optom Vis Sci 2009b;86:454-466) and Larrea and Büchler (Invest Ophthalmol Vis Sci 2009;50:1076-1080). We use oxygen tension from in vivo estimations provided by Bonanno [Bonanno et al., Invest Ophthalmol Vis Sci 2002;43:371-376, and Bonanno et al 2009]. We consider four hydrogel and six silicone hydrogel lenses. The cornea is considered a single homogeneous layer, with constant oxygen permeability regardless of the type of lens worn. Our calculations yield different values for the maximum oxygen consumption rate Qc,max , whith differents oxygen tensions (high and low pc ) at the cornea-tears interface. Surprisingly, for both models, we observe an increase in oxygen consumption near an oxygen tension of 105 mmHg until a maximum is reached, then decreasing for higher levels of oxygen pressure. That is, when lowering the pressure of oxygen, the parameter Qc,max initially increases depending on the intensity of the change in pressure. Which, it could be related with the variation of the pH. Furthermore, it is also noted that to greater reductions in pressure, this parameter decreases, possibly due to changes in the concentration of glucose related to the anaerobic respiration. The averaged in vivo human corneal oxygen consumption rate of 1.47 × 10-4 cm3 of O2 /cm3 tissue s, with Monod kinetics model, considering all the lenses studied, is smaller than the average oxygen consumption rate value obtained using the Larrea and Büchler model. The impact that these calculations have on the oxygen partial pressure available at different depths in the corneal tissue is presented and discussed, taking into consideration previous models used in this study. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2269-2281, 2017.

Efectos del láser de baja potencia en el tratamiento de la parálisis facial periférica aguda / Effects of low power laser in the treatment of acute peripheral facial paralysis

Introducción. La parálisis facial periférica es una afección altamente incidente, que puede generar complicaciones discapacitantes. No existe un tratamiento único para la misma. El láser infrarrojo es efectivo en la recuperación de la estructura y función de los nervios periféricos, aunque hay pocos estudios que exploren su utilidad clínica en la parálisis facial periférica. Material y métodos Se realizó un ensayo clínico aleatorizado doble ciego controlado. Se incluyeron pacientes mayores de 18 años con diagnóstico de parálisis facial periférica idiopática de menos de 7 días de evolución, sin tratamiento previo. Fueron distribuidos aleatoriamente en 2 grupos, uno con tratamiento rehabilitador convencional más placebo y otro con láser de GaAsAl de λ 830nm a dosis de 20J/cm2 en la emergencia del nervio facial. Se evaluó de forma ciega la fuerza muscular, la presencia de disacusia, disgeusia y epífora a los 0, 15, 30 y 60 días. Resultados. Se incluyeron 21 pacientes, 10 en el grupo control y 11 en el experimental. Ambos grupos tuvieron mejoría significativa en la fuerza muscular antes y después (p<0,001). Al compararlos entre ellos, el grupo de láser alcanzó una recuperación del 94,84% y el grupo control del 87,83% (p=0,24), en cuanto a la disgeusia, disacusia y epífora ambos grupos mostraron mejoría del 100%. Conclusión. El láser de baja potencia resultó exento de riesgo y con un efecto clínico moderado respecto a la recuperación de la fuerza muscular, no así respecto a la epífora, disgeusia y disacusia (AU)

Introduction. Peripheral facial paralysis is a very pathological condition that may generate disabling complications. There is no unique treatment for it. Infrared low power laser is effective in recovering the structure and function of peripheral nerves, although few studies have been conducted on its clinical use in peripheral facial paralysis. Material and methods. We performed a randomized double-blind controlled trial. Inclusion criteria were patients older than 18 years with a diagnosis of idiopathic peripheral facial paralysis of less than 7 days duration, with no previous treatment. The patients were randomized into two groups, one with conventional rehabilitation treatment plus placebo and another with GaAsAl of λ 830nm laser at doses of 20 joules/cm2 in the emergence of the facial nerve. Muscle strength, disacusia, dysgeusia and epiphora were evaluated in a blinded way at 0, 15, 30 and 60 days. Results. Twenty-one patients were included, 10 in the control group and 11 in the experimental one. Both groups showed significant improvement in muscle strength before and after treatment (P<.001). When a comparison was made between the groups, the laser group achieved recovery of 94.84% vs 87.83% in the control group (P=.24). Regarding dysgeusia, disacusia and epiphora, both groups showed 100% improvement. Conclusion. Low-power laser was safe and had a moderate clinical effect on the recovery of muscle strength, but not for the epiphora, dysgeusia and disacusia (AU)

Effect of polymerized-type I collagen in knee osteoarthritis. II. In vivo study.

BACKGROUND: Polymerized-Type I Collagen (Polymerized-Collagen) is an anti-inflammatory and a tissue regenerator biodrug. The aim of the study was to evaluate the efficacy and safety of intra-articular injections of Polymerized-Collagen in patients with knee osteoarthritis (OA). METHODS AND DESIGN: Patients (n=53) were treated with 12 intra-articular injections of 2 mL of Polymerized-Collagen (n=27) or 2 mL of placebo (n=26) during 6 months. Follow up period was 6 months. The primary endpoints included Western Ontario and McMaster University Osteoarthritis Index, Lequesne index, and pain intensity on a visual analogue scale (VAS). Secondary outcomes were patient global score, investigator global score and drug evaluation. Clinical improvement was determined if the decrease in pain exceeds 20 mm on a VAS and patients achieved at least 20% of improvement from baseline. Urinary levels of C-terminal crosslinking telopeptide of collagen type II (CTXII) and serum high-sensitivity C-reactive protein (hsCRP) were determined by enzyme immunoassays. Statistical analysis was performed by intention to treat. RESULTS: Polymerized-Collagen was safe and well tolerated. Patients had a statistically significant improvement (P<0.05) from baseline vs. Polymerized-Collagen and vs. placebo at 6 months in: Lequesne Index (13.1+/-0.5 vs. 7.1+/-0.7 vs. 9.6+/-0.8; P=0.027), WOMAC (9.0+/-0.5 vs. 4.0+/-0.6 vs. 5.80+/-0.8; P=0.032), patient VAS (60.0+/-2.6 vs. 20.6+/-2.4 vs. 36.1+/-4.5; P=0.003), physician VAS (49.8+/-1.9 vs. 16.8+/-2.9 vs. 29.8+/-2.9; P=0.002), patient global score (1.08+/-0.1 vs. 2.7+/-0.1 vs. 1.9+/-0.2; P=0.028) and analgesic usage (30.1+/-9.4 vs. 11.0+/-3.4 vs. 17.9+/-4.9; P=0.001). This improvement was persistent during the follow up. A threefold increase in CTXII was determined in placebo group. No differences were found on hs CRP and incidence of adverse events between groups. CONCLUSION: Polymerized-Collagen is safe and effective in the treatment of knee OA.

Generalized hydrodynamics of a dilute suspension of finite-sized particles: dynamic viscosity.

We present a mesoscopic hydrodynamic description of the dynamics of colloidal suspensions. We consider the system as a gas of Brownian particles suspended in a Newtonian heat bath subjected to stationary nonequilibrium conditions imposed by a velocity field. By means of a generalized Fokker-Planck equation, we obtain a set of coupled differential equations for the local diffusion current and the evolution of the total stress tensor. We find that the dynamic shear viscosity of the system contains contributions arising from the finite size of the particles.