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Enhancing electrochemical capacitor performance of N-doped tannin-derived carbons by hydrothermal treatment in ammonia
No full textThis study demonstrates that ammonia concentration when doping carbons using hydrothermal treatment has crucial impact on textural properties. The latter translates into an improvement of the electrochemical performance of carbon materials, when used into electrochemical capacitors, especially at high-rate performance. Nitrogen-doped carbons were synthesized by subjecting tannin to hydrothermal carbonization in ammonia solutions of varying concentrations. After carbonization and CO2 activation, the as-produced activated carbons (ACs) were tested as electrodes for electrochemical capacitors in symmetric configuration using 1 M H2SO4 as aqueous electrolyte. Interestingly, ammonia concentration during the hydrothermal synthesis step did not significantly affect the final N content (ca. 3 and 4 at. %) nor the nitrogen and oxygen functionalities on the surface. However, the use of ammonia had crucial impact on the textural properties developed by CO2 activation, and therefore on the electrochemical performance of the ACs. The best-performing N-doped AC showed specific electrode capacitance values, based on carbon material, of 212 F g−1 at 0.5 A g−1 and outstanding capacitance retention of ca. 71 % at 40 A g−1. It also showed high cycling stability, with capacitance retention of ca. 96 % after 30,000 cycles. Furthermore, this AC outperformed similar reported materials, achieving a specific energy of 4.6 W h kg−1 at 12.1 kW kg−1. © 2024 Elsevier B.V.Agencia Nacional de Investigación y Desarrollo, ANID; European Regional Development Fund, ERDF; Subdirección de Capital Humano; Doctorado, (2019/21190633); ANID-FONDEF, (19I10003); ANID-FONDECYT, (ATE220014, 1220228
Influence of TiO2 nanofiller geometry on the rheological and optical properties of poly(acrylic acid)-based nanocomposite hydrogels
No full textThe properties of macroscopic polymer nanocomposites are highly dependent on the nanoparticle–polymer interfacial region, which varies with the morphology of the nanoparticles. Herein, we used TiO2 nanofillers with very low aspect ratio, the same chemical composition, and surface functions, but different geometries (nanospheres and nanoplates) dispersed in a poly(acrylic acid) matrix to analyze the influence of the nanoparticle geometry on the properties of nanocomposite hydrogels. The geometry was found to affect the swelling and rheological properties of the nanocomposite polymers. Particularly, the yield strain (from 25% to 130%), modulus (from 17,500 to 25,000 Pa), and brittleness of nanoplates based nanocomposite increased more significantly. Finite-difference time-domain simulations demonstrated that nanoplates increased the wavelength of the absorption maxima (224 nm for NS to 240 nm for NP) and charge distribution. The results obtained in this research indicate that the nanofiller shape markedly influences the rheological properties of the nanocomposite polymers, opening the door to further research focused on polymer–nanofiller interactions, and their effect on the macroscopic properties of the nanocomposites. © 2023 Wiley Periodicals LLC.ANID-FONDECYT; ANID‐FONDECYT, (2020R1A2C1006136, 3200379, 3200601, 3200832, 3220108, ANID‐FONDEQUIP EQM140034); NRF-Sout
La noticia sobre ciencia: Sesgo hacia la comunicación de los resultados sobre los procesos de la investigación científica
No full textThe complexity of scientific activity is not reflected in the news. In this paper we propose that aspects related to scientific research processes are scarcely developed in science news. On the contrary, aspects related to the results of scientific research are highly represented. Thirty-five news from the Clarín portal were analyzed between 01-01-2016 and 07-07-2017, using the constructed week methodology. As dimensions related to Processes were considered: epistemological, ethical, political and historical approach. Dimensions linked to Results were: epistemological optimism, utility, progress and spectacularity. It was also analyzed if news were signed by their author. Almost 83% of the news are biased towards Results and 83% of them are editorial. Almost 9 out of 10 news based on Processes are written by other agencies or signed. On the other hand, the opinion or interviews (n = 27), 67% are biased in favor of Processes. We propose that the incorporation into the news of dimensions linked to scientific research Processes favors dialogue, discussion and debate between scientists and publics. The scope of signed news reinforces de idea that a better science communication is possibleLa complejidad de la actividad científica no queda reflejada a través de la noticia. Se propone aquí que aspectos vinculados a los procesos de investigación científica están escasamente desarrollados en las noticias sobre ciencia. Por el contrario,aspectos vinculados a los resultados de la investigación científica están altamente representados. Se analizaron 35 noticias del portal Clarín (Argentina), formato digital entre los días 01-01-2016 al 1-07-2017, mediante metodología de semana construida. Como dimensiones vinculadas a procesos se consideraron: abordaje epistemológico, ético, político e histórico. Como dimensiones vinculadas a resultados: optimismo epistemológico, utilidad, progreso y espectacularidad. Se analizó también si las notas estaban firmadas por su autor. El 82% de las noticias tienen sesgo hacia resultados y de ellas 83%son de agencias o redacción (no firmadas). El 85% de las notas basadas en procesos están redactadas por otros medios o firmadas. Se analizaron también notas de opinión (n=27). El 44% presenta un sesgo a favor de procesos. Proponemos quela incorporación en las noticias de dimensiones vinculadas a procesos de la investigación científica favorece el diálogo, la discusión y el debate entre expertos científicos y públicos. El perfil de las noticias firmadas refuerza la idea que una mejor comunicación de la ciencia en medios es posible
La aplicación del derecho internacional por los tribunales nacionales. Reseña del libro de Díaz Fuenzalida, Juan Pablo: Principales tratados internacionales sobre derechos humanos de la ONU aplicables en los tribunales de justicia En Chile. Concordancias con las garantías constitucionales chilenas y jurisprudencia relevante de los máximos tribunales. Santiago, Ediciones Jurídicas de Santiago, 2019, 341 pp.
No full textEl sistema universal de protección de los derechos humanos en el ámbito del derecho internacional convencional se compone por nueve tratados que han sido identificados como principales (“The Core International Human Rights Instruments”). Este libro significa un aporte para la implementación de estos en el ordenamiento jurídico chileno, ya que Chile es parte de este sistema y ha ratificado y puesto en vigencia todos ellos, por tanto se encuentra en la obligación de darles cumplimiento de buena fe (principio pacta sunt servanda reconocido en el artículo 26 de la Convención de Viena sobre el Derecho de los Tratados) y todos los órganos del Estado, incluyendo el Poder Judicial, deben adecuar sus actuaciones a lo prescrito en tal plexo normativo internacional
Do the associations of daily steps with mortality and incident cardiovascular disease differ by sedentary time levels? A device-based cohort study
No full textObjectives This study aims to examine the associations of daily step count with all-cause mortality and incident cardiovascular disease (CVD) by sedentary time levels and to determine if the minimal and optimal number of daily steps is modified by high sedentary time. Methods Using data from the UK Biobank, this was a prospective dose–response analysis of total daily steps across low (<10.5 hours/day) and high (≥10.5 hours/day) sedentary time (as defined by the inflection point of the adjusted absolute risk of sedentary time with the two outcomes). Mortality and incident CVD was ascertained through 31 October 2021. Results Among 72 174 participants (age=61.1±7.8 years), 1633 deaths and 6190 CVD events occurred over 6.9 (±0.8) years of follow-up. Compared with the referent 2200 steps/day (5th percentile), the optimal dose (nadir of the curve) for all-cause mortality ranged between 9000 and 10 500 steps/day for high (HR (95% CI)=0.61 (0.51 to 0.73)) and low (0.69 (0.52 to 0.92)) sedentary time. For incident CVD, there was a subtle gradient of association by sedentary time level with the lowest risk observed at approximately 9700 steps/day for high (0.79 (0.72 to 0.86)) and low (0.71 (0.61 to 0.83)) sedentary time. The minimal dose (steps/day associated with 50% of the optimal dose) of daily steps was between 4000 and 4500 steps/day across sedentary time groups for all-cause mortality and incident CVD. Conclusions Any amount of daily steps above the referent 2200 steps/day was associated with lower mortality and incident CVD risk, for low and high sedentary time. Accruing 9000–10 500 steps/day was associated with the lowest mortality risk independent of sedentary time. For a roughly equivalent number of steps/ day, the risk of incident CVD was lower for low sedentary time compared with high sedentary time. © Author(s) (or their employer(s)) 2024.National Health and Medical Research Council, NHMRC, (APP 1194510); National Health and Medical Research Council, NHMRC; National Heart Foundation of Australia, (APP 107158, EMRGIA 2020/00158); National Heart Foundation of AustraliaUniversidad Autónoma de Chil
El Modelo Dual-Incremental de Regionalización en Chile: Intendentes Electos Y Gobernadores Delegados
No full textEl artículo analiza la pugna por el moderado proceso de descentralización regional que impulsa el Gobierno chileno, replicando lo que se puede llamar la experien- cia francesa de los 1980s: La Nueva Mayoría gobernante (partidos y ministros/ agencias públicas claves) articuló un modelo dual de poder para las regiones, permitiendo la elección de Intendentes junto a una delegación central fuerte a través de gobernadores delegados que coordinarán la nutrida red de agencias estatales desconcentradas. Dicho proceso se complementa con un acotado pro- ceso de traspaso de competencias que tomará una década tras pilotajes, donde se incluyeron sólo algunos de los servicios con las competencias esenciales a los entes regionales de los países de la OECD. Se complementa con una propuesta de aumento de los pequeños impuestos a actividades vinculadas a recursos na- turales y puertos. Todo ello explica tanto el avance de los sectores reformistas/ centralista como la con la racionalidad centralista/iluminista que predomina en la elite chilena. La ley de elección de intendentes con fuerte delegación central y de traspaso de competencias limitado se contrasta con el enfoque más autonomista de las propuestas de la Comisión Asesora Presidencial para la Descentralización y el Desarrollo Regional que reunió a 33 expertos en el año 2014
Una nueva institucionalidad para la protección de los derechos de las personas migrantes en Chile
No full textEl estudio tiene por objeto explicar, en base a normativa del Derecho Internacional de los Derechos Humanos, el porqué es necesario en Chile una renovada institucionalidad para proteger los derechos de las personas migrantes
Urinary Tract Development
No full textThe urinary tract includes the kidneys, ureters, bladder and urethra. In the evolution of vertebrates, including humans, has been differentiated three types of kidneys, each of which is an improvement over the previous. This review focuses on some topics concerning the embryological development of the kidney and urinary tract, as well as molecules associated with its development and finally the phylogeny of the kidney in vertebrates
Dropout From Exercise Interventions in Adults With Fibromyalgia: A Systematic Review and Meta-analysis
No full textObjective: To meta-analyze the prevalence and predictors of dropout rates among adults with fibromyalgia participating in exercise randomized controlled trials (RCTs). Data Sources: Two authors searched Embase, CINAHL, PsycARTICLES, and Medline up to 01/21/2023. Study Selection: We included RCTs of exercise interventions in people with fibromyalgia that reported dropout rates. Data Extraction: Dropout rates from exercise and control conditions and exerciser/participant, provider, and design/implementation related predictors. Data Synthesis: A random effects meta-analysis and meta-regression were conducted. In total, 89 RCTs involving 122 exercise arms in 3.702 people with fibromyalgia were included. The trim-and-fill-adjusted prevalence of dropout across all RCTs was 19.2% (95% CI=16.9%-21.8%), which is comparable with the dropout observed in control conditions with the trim-and-fill-adjusted odds ratio being 0.31 (95% CI=0.92-1.86, P=.44). Body mass index (R2=0.16, P=.03) and higher effect of illness (R2=0.20, P=.02) predicted higher dropout. The lowest dropout was observed in exergaming, compared with other exercise types (P=.014), and in lower-intensity exercises, compared with high intensity exercise (P=.03). No differences in dropout were observed for the frequency or duration of the exercise intervention. Continuous supervision by an exercise expert (eg, physiotherapist) resulted in the lowest dropout rates (P<.001). Conclusions: Exercise dropout in RCTs is comparable with control conditions, suggesting that exercise is a feasible and accepted treatment modality; however, interventions are ideally supervised by an expert (eg, physiotherapist) to minimize the risk of dropout. Experts should consider a high BMI and the effect of the illness as risk factors for dropout. © 2023 American Congress of Rehabilitation Medicin
Use of Occlusal Splints in Patients with Deep Bite and Bruxism
No full textThe occlusal splints are most commonly used devices for the treatment of temporomandibular disorders and bruxism. A case report of a male patient with deep bite and bruxism, indicating two flat occlusal splints presents full coverage made up of rigid acrylic and permanent use for five months is described. Using both intraoral devices allowed restoring lost vertical dimension and protect teeth attrition, deprogram the musculature and establish a new mandibular positioning prior to treatment of oral rehabilitation