Mineralogical evolution of Portland cement blended with silica nanoparticles and its effect on mechanical strength

Mineralogical analysis on pastes of Spanish Portland cement Type I, blended with nanosilica was carried out by conventional and high-resolution thermogravimetric analysis (TG-HRTG) and X-ray diffraction (XRD) in order to determine the quantity of the different mineralogical phases obtained during the hydration process. Simultaneously, mortars with the same materials and replacement ratio were made in order to assess their compressive strength for up to 28 days of curing time. In this paper, the rate and quantity of each one of the main constituent phases of the cement during its hydration process (CSH, portlandite, stratlingite, etc.) were determined. A correlation between the quantity of CSH and the development of compressive strength was established. Additionally, the pozzolanic activity of nanosilica was evaluated by quantifying the fixation of calcium hydroxide and its impact on the development of the compressive strength. © 2012 Elsevier Ltd. All rights reserved.The authors express their thanks to Cementos Argos S.A. and to COLCIENCIAS (Project 20201007768) of Colombia for their financial support in the execution of this research.Tobón, JI.; Paya Bernabeu, JJ.; Borrachero Rosado, MV.; Restrepo Baena, OJ. (2012). Mineralogical evolution of Portland cement blended with silica nanoparticles and its effect on mechanical strength. Construction and Building Materials. 36:736-742. https://doi.org/10.1016/j.conbuildmat.2012.06.043S7367423

Análisis dinámico muscular y de la estructura interna del nervio periférico como biomarcadores para la esclerosis lateral amiotrófica: estudio piloto mediante ecografía

Resumen: Introducción: El objetivo del trabajo fue conocer el comportamiento de los biomarcadores ecográficos de densidad fascicular y fuerza muscular en pacientes con esclerosis lateral amiotrófica (ELA). Métodos: Estudio piloto, observacional y transversal sobre 14 pacientes con ELA (mujeres; 28,6%) y 14 controles. Se tomaron ecografías bilaterales transversales en el abductor corto del pulgar (ACP) y tibial anterior (TA) con registro del grosor muscular (GM) en reposo, en contracción y diferencia de engrosamiento. En los nervios mediano, ciático y peroneo común se analizaron el área de sección transversal (AST), el número de fascículos (NF) y la densidad fascicular (DF). Los análisis se realizaron anidados por lateralidad. Resultados: El acuerdo intra-interobservador en los recuentos de fascículos fue muy bueno con un error mínimo detectable<0,7%. El GM del ACP fue menor en los pacientes con ELA tanto en reposo (p = 0,003; g = 1,03) como en contracción (p = 0,017; g = 0,78) y en el TA en reposo (p = 0,002; g = 0,15) y contracción (p = 0,001; g = 0,46), con una menor capacidad de engrosamiento. En los nervios, se detectó una menor AST, con menor NF y una mayor DF. Se encontraron correlaciones significativas entre el GM del ACP y la Medical Research Council (MRC) (r = 0,34; r2 = 12%; p = 0,011) y con la Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-r) (r = 0,44; r2 = 19%; p < 0,001). La diferencia de engrosamiento del TA se correlacionó con la MRC (r = 0,30; r2 = 15%; p = 0,003) y con la ALSFRS-r (r = 0,26; r2 = 7%; p = 0,049). El NF del nervio ciático mostró una correlación significativa con la MRC (r = 0,35; r2 = 12%; p = 0,008). Conclusión: Las mediciones del GM derivadas de las pruebas dinámicas junto con el NF y DF podrían ser biomarcadores de utilidad para monitorizar pacientes con ELA y su evaluación pronóstica. Abstract: Introduction: The aim of this study was to determine the behaviour of ultrasound biomarkers of fascicle density and muscle strength in patients with amyotrophic lateral sclerosis (ALS). Methods: We conducted an observational, cross-sectional pilot study of 14 patients with ALS (28.6% women) and 14 controls. Bilateral cross-sectional ultrasound scans were performed in the abductor pollicis brevis (APB) and tibialis anterior (TA) muscles, with recording of muscle thickness (MT) at rest and in contraction, and the difference in thickness. In the median, sciatic, and common peroneal nerves, we analysed the cross-sectional area (CSA), number of fascicles (NF) and fascicle density (FD). Analyses were nested by laterality. Results: Intra- and interrater agreement regarding NF was very good, with a minimum detectable error of < 0.7%. In patients with ALS, MT was lower in the APB both at rest (P = .003; g-Hedges = 1.03) and in contraction (P = .017; g-Hedges = 0.78) and in TA at rest (P = .002; g-Hedges = 0.15) and in contraction (P = .001; g-Hedges = 0.46), with lower thickening capacity. In the nerves, patients displayed lower CSA, with lower NF and higher FD. Significant correlations were found between MT of the ABP and Medical Research Council (MRC) scores for muscle strength (r = 0.34; r2 = 12%; P = .011) and with revised ALS Functional Rating Scale scores (r = 0.44; r2 = 19%; P < .001). The difference in TA thickening correlated with MRC scores (r = 0.30; r2 = 15%; P = .003) and with revised ALS Functional Rating Scale scores (r = 0.26; r2 = 7%; P = .049). NF in the sciatic nerve showed a significant correlation with MRC scores (r = 0.35; r2 = 12%; P = .008). Conclusion: MT measurements derived from dynamic testing together with NF and FD may be useful biomarkers for monitoring patients with ALS and establishing a prognosis

Dynamic analysis of muscles and the internal structure of the peripheral nerve as biomarkers of amyotrophic lateral sclerosis: A pilot study with ultrasound imaging

Introduction: The aim of this study was to determine the behaviour of ultrasound biomarkers of fascicle density and muscle strength in patients with amyotrophic lateral sclerosis (ALS). Methods: We conducted an observational, cross-sectional pilot study of 14 patients with ALS (28.6% women) and 14 controls. Bilateral cross-sectional ultrasound scans were performed in the abductor pollicis brevis (APB) and tibialis anterior (TA) muscles, with recording of muscle thickness (MT) at rest and in contraction, and the difference in thickness. In the median, sciatic, and common peroneal nerves, we analysed the cross-sectional area (CSA), number of fascicles (NF) and fascicle density (FD). Analyses were nested by laterality. Results: Intra- and interrater agreement regarding NF was very good, with a minimum detectable error of < 0.7%. In patients with ALS, MT was lower in the APB both at rest (P = .003; g-Hedges = 1.03) and in contraction (P = .017; g-Hedges = 0.78) and in TA at rest (P = .002; g-Hedges = 0.15) and in contraction (P = .001; g-Hedges = 0.46), with lower thickening capacity. In the nerves, patients displayed lower CSA, with lower NF and higher FD. Significant correlations were found between MT of the ABP and Medical Research Council (MRC) scores for muscle strength (r = 0.34; r2 = 12%; P = .011) and with revised ALS Functional Rating Scale scores (r = 0.44; r2 = 19%; P < .001). The difference in TA thickening correlated with MRC scores (r = 0.30; r2 = 15%; P = .003) and with revised ALS Functional Rating Scale scores (r = 0.26; r2 = 7%; P = .049). NF in the sciatic nerve showed a significant correlation with MRC scores (r = 0.35; r2 = 12%; P = .008). Conclusion: MT measurements derived from dynamic testing together with NF and FD may be useful biomarkers for monitoring patients with ALS and establishing a prognosis. Resumen: Introducción: El objetivo del trabajo fue conocer el comportamiento de los biomarcadores ecográficos de densidad fascicular y fuerza muscular en pacientes con ELA. Métodos: Estudio piloto, observacional y transversal sobre 14 pacientes con ELA (mujeres; 28,6%) y 14 controles. Se tomaron ecografías bilaterales transversales en el abductor corto del pulgar (ACP) y tibial anterior (TA) con registro del grosor muscular (GM) en reposo, en contracción y diferencia de engrosamiento. En los nervios mediano, ciático y peroneo común se analizaron el área de sección transversal (AST), el número de fascículos (NF) y la densidad fascicular (DF). Los análisis se realizaron anidados por lateralidad. Resultados: El acuerdo intra-interobservador en los recuentos de fascículos fue muy bueno con un error mínimo detectable <0,7%. El GM del ACP fue menor en los pacientes con ELA tanto en reposo (p = 0,003; g = 1,03) como en contracción (p = 0,017; g = 0,78) y en el TA en reposo (p = 0,002; g = 0,15) y contracción (p = 0,001; g = 0,46), con una menor capacidad de engrosamiento. En los nervios se detectó una menor AST, con menor NF y una mayor DF. Se encontraron correlaciones significativas entre el GM del ACP y la MRC (r = 0,34; r2 = 12%; p = 0,011) y con la ALSFRS-r (r = 0,44; r2 = 19%; p < 0,001). La diferencia de engrosamiento del TA se correlacionó con la MRC (r = 0,30; r2 = 15%; p = 0,003) y con la ALSFRS-r (r = 0,26; r2 = 7%; p=0,049). El NF del nervio ciático mostró una correlación significativa con la MRC r = 0,35; r2 = 12%; p = 0,008). Conclusión: Las mediciones del GM derivadas de las pruebas dinámicas junto con el NF y DF podrían ser biomarcadores de utilidad para monitorizar pacientes con ELA y su evaluación pronóstica

Prediction of long-term outcomes of HIV-infected patients developing non-AIDS events using a multistate approach

Outcomes of people living with HIV (PLWH) developing non-AIDS events (NAEs) remain poorly defined. We aimed to classify NAEs according to severity, and to describe clinical outcomes and prognostic factors after NAE occurrence using data from CoRIS, a large Spanish HIV cohort from 2004 to 2013. Prospective multicenter cohort study. Using a multistate approach we estimated 3 transition probabilities: from alive and NAE-free to alive and NAE-experienced ("NAE development"); from alive and NAE-experienced to death ("Death after NAE"); and from alive and NAE-free to death ("Death without NAE"). We analyzed the effect of different covariates, including demographic, immunologic and virologic data, on death or NAE development, based on estimates of hazard ratios (HR). We focused on the transition "Death after NAE". 8,789 PLWH were followed-up until death, cohort censoring or loss to follow-up. 792 first incident NAEs occurred in 9.01% PLWH (incidence rate 28.76; 95% confidence interval [CI], 26.80-30.84, per 1000 patient-years). 112 (14.14%) NAE-experienced PLWH and 240 (2.73%) NAE-free PLWH died. Adjusted HR for the transition "Death after NAE" was 12.1 (95%CI, 4.90-29.89). There was a graded increase in the adjusted HRs for mortality according to NAE severity category: HR (95%CI), 4.02 (2.45-6.57) for intermediate-severity; and 9.85 (5.45-17.81) for serious NAEs compared to low-severity NAEs. Male sex (HR 2.04; 95% CI, 1.11-3.84), ag