Properties of small molecular drug loading and diffusion in a fluorinated PEG hydrogel studied by ¹H molecular diffusion NMR and ¹⁹F spin diffusion NMR

R_f-PEG (fluoroalkyl double-ended poly(ethylene glycol)) hydrogel is potentially useful as a drug delivery depot due to its advanced properties of sol–gel two-phase coexistence and low surface erosion. In this study, ¹H molecular diffusion nuclear magnetic resonance (NMR) and ¹⁹F spin diffusion NMR were used to probe the drug loading and diffusion properties of the R_f-PEG hydrogel for small anticancer drugs, 5-fluorouracil (FU) and its hydrophobic analog, 1,3-dimethyl-5-fluorouracil (DMFU). It was found that FU has a larger apparent diffusion coefficient than that of DMFU, and the diffusion of the latter was more hindered. The result of ¹⁹F spin diffusion NMR for the corresponding freeze-dried samples indicates that a larger portion of DMFU resided in the R_f core/IPDU intermediate-layer region (where IPDU refers to isophorone diurethane, as a linker to interconnect the R_f group and the PEG chain) than that of FU while the opposite is true in the PEG–water phase. To understand the experimental data, a diffusion model was proposed to include: (1) hindered diffusion of the drug molecules in the R_f core/IPDU-intermediate-layer region; (2) relatively free diffusion of the drug molecules in the PEG-water phase (or region); and (3) diffusive exchange of the probe molecules between the above two regions. This study also shows that molecular diffusion NMR combined with spin diffusion NMR is useful in studying the drug loading and diffusion properties in hydrogels for the purpose of drug delivery applications

Properties of small molecular drug loading and diffusion in a fluorinated PEG hydrogel studied by ^1H molecular diffusion NMR and ^(19)F spin diffusion NMR

R_f-PEG (fluoroalkyl double-ended poly(ethylene glycol)) hydrogel is potentially useful as a drug delivery depot due to its advanced properties of sol–gel two-phase coexistence and low surface erosion. In this study, ^1H molecular diffusion nuclear magnetic resonance (NMR) and ^(19)F spin diffusion NMR were used to probe the drug loading and diffusion properties of the R_f-PEG hydrogel for small anticancer drugs, 5-fluorouracil (FU) and its hydrophobic analog, 1,3-dimethyl-5-fluorouracil (DMFU). It was found that FU has a larger apparent diffusion coefficient than that of DMFU, and the diffusion of the latter was more hindered. The result of ^(19)F spin diffusion NMR for the corresponding freeze-dried samples indicates that a larger portion of DMFU resided in the R_f core/IPDU intermediate-layer region (where IPDU refers to isophorone diurethane, as a linker to interconnect the R_f group and the PEG chain) than that of FU while the opposite is true in the PEG–water phase. To understand the experimental data, a diffusion model was proposed to include: (1) hindered diffusion of the drug molecules in the R_f core/IPDU-intermediate-layer region; (2) relatively free diffusion of the drug molecules in the PEG-water phase (or region); and (3) diffusive exchange of the probe molecules between the above two regions. This study also shows that molecular diffusion NMR combined with spin diffusion NMR is useful in studying the drug loading and diffusion properties in hydrogels for the purpose of drug delivery applications

EFECTO DEL PLOMO EN EL CRECIMIENTO DE PLÁNTULAS DE Acacia macracantha Humb. & Bonpl. ex Willd. “espino” EN CONDICIONES DE LABORATORIO

El Perú posee una gran variedad de especies vegetales adaptadas para vivir en suelos contaminados con altas concentraciones de metales pesados sin alterar su fisiología y crecimiento. Por ello el objetivo del presente trabajo fue determinar el efecto del plomo en el crecimiento de plántulas de Acacia macracantha Humb. & Bonpl. ex Willd. “espino” en condiciones de laboratorio. Se utilizó un diseño experimental de estímulo creciente con cinco tratamientos y tres repeticiones, utilizando 30 plántulas para cada tratamiento (0, 50, 100, 200 y 400 mg Pb/L), en un sistema hidropónico. Los resultados, a los 45 días, indican que el plomo causó efecto en 400 mgPb/L, así mismo se observó una serie de alteraciones morfológicas (clorosis, necrosis) y mayor cantidad de bioacumulaciòn de plomo se encontró en parte aérea (3.904 mgPb/g.).Palabras claves: Acacia macracantha; plántulas; plomo; crecimiento.ABSTRACTPeru has a wide variety of plant species adapted to live in contaminated with high concentrations of heavy metals without altering their physiology and growth soils. The aim of this study was to determine the effect of lead on the growth of seedlings of Acacia macracantha Humb. & Bonpl. ex Willd. "hawthorn" in laboratory conditions. Increasing stimulus experimental design was used with 5 treatments and three replications, 30 seedlings placed in each container, at concentrations of 0, 50, 100, 200 and 400 mgPb / L in a hydroponic system. The results were taken at 45 days, the results indicate that lead caused impact on the T5, in root length 9.06 cm, stem length 9.55 cm, number of secondary roots 10,  sheets 11, fresh weight (0.06 g) and dry (0.04 g) of root fresh weight (1.19 g) and dry (0.21g) of aerial part (leaves and stems), protein content: Following 3,025 mg/g, leaves 3,269 mg/g stalk 5,092 mg/g, chlorophyll a 2.33 mg/ml and carotenes 0.36 ug/ml, also present a series of morphological changes (chlorosis, necrosis). Most bioaccumulation of lead was found in aerial parts of T5, the value of 3,904 mgPb / g.Keywords: Acacia  macracantha; seedlings; lead; growth

Tree diversity and species identity effects on soil fungi, protists and animals are context dependent

Plant species richness and the presence of certain influential species (sampling effect) drive the stability and functionality of ecosystems as well as primary production and biomass of consumers. However, little is known about these floristic effects on richness and community composition of soil biota in forest habitats owing to methodological constraints. We developed a DNA metabarcoding approach to identify the major eukaryote groups directly from soil with roughly species-level resolution. Using this method, we examined the effects of tree diversity and individual tree species on soil microbial biomass and taxonomic richness of soil biota in two experimental study systems in Finland and Estonia and accounted for edaphic variables and spatial autocorrelation. Our analyses revealed that the effects of tree diversity and individual species on soil biota are largely context dependent. Multiple regression and structural equation modelling suggested that biomass, soil pH, nutrients and tree species directly affect richness of different taxonomic groups. The community composition of most soil organisms was strongly correlated due to similar response to environmental predictors rather than causal relationships. On a local scale, soil resources and tree species have stronger effect on diversity of soil biota than tree species richness per se

Doctorado en educación: temas y conceptos

1 documento en PDF de 11 páginas.Los escritos reunidos aquí presentan varios rasgos comunes, que les dan derecho a formar parte de la primera publicación del Doctorado en Educación. El primero de ellos, el rigor documental y argumentativo. Sus autores muestran un sólido manejo de los temas que enfrental, se percibe su reflexión y apropiación crítica, lo que les permite exponerlos de forma sistemática y profunda, desde una perspectiva propia, a veces retadora y siempre propositiva. Otro rasgo es la apertura, en el sentido de que los autores no pretenden dar la última palabra, sino aportar al campo del saber educativo; abrir nuevas puertas a la investigación, al diálogo y a la reflexión académica. También salta a la vista la trans- e interdisciplinariedad de los contenidos, sino en los modos y perspectivas desde donde abordan sus objetos de estudio. El último rasgo que quiero destacar es la actualidad de los asuntos tratados, actualidad que proviene de la relevancia de los temas, de su íntima relación con elementos esenciales de la educación: su finalidad, sus agentes, sus instituciones y sus procesos, lo cual explica su permanencia en la investigación educativa.Presentación, Ciro Hernando Parra Moreno La formación doctoral en Colombia, Marina Camargo Abello Naturaleza de las instituciones educativas, Rafael Alvira Domínguez Finalidad de la Universidad: reflexión necesaria, Javier Bermúdez Aponte La Universidad, escuela al servicio de la verdad, Luz Yolanda Sandoval Estupiñán, Alfredo Rodríguez Sedano La vida y el reto contemporáneo de educar para la paz, María Elvira Martínez A. Teorías sociales contemporáneas en educación, Marta Ardila Debates en torno a la educación familiar desde una perspectiva pedagógica, Aurora Bernal Martínez de Soria, Sandra Patricia Varela Londoño Alfabetización y construcción de subjetividad, Rosa Julia Guzmán Rodríguez Educomunicación en entornos digitales: mirada desde la comunicación no verbal, Andrés Chiappe, Hugo Rozo, Eduardo Menjivar, María Alejandra Corchuelo, Maite Alarcón Retos para la formación del tutor en modalidad virtual, Cristina Hennig Manzuoli Juego serio: modelo teórico para su diseño y producción, Oscar Boude Figueredo, Edgar Andrés Sosa"Presentación, Ciro Hernando Parra Moreno La formación doctoral en Colombia, Marina Camargo Abello Naturaleza de las instituciones educativas, Rafael Alvira Domínguez Finalidad de la Universidad: reflexión necesaria, Javier Bermúdez Aponte La Universidad, escuela al servicio de la verdad, Luz Yolanda Sandoval Estupiñán, Alfredo Rodríguez Sedano La vida y el reto contemporáneo de educar para la paz, María Elvira Martínez A. Teorías sociales contemporáneas en educación, Marta Ardila Debates en torno a la educación familiar desde una perspectiva pedagógica, Aurora Bernal Martínez de Soria, Sandra Patricia Varela Londoño Alfabetización y construcción de subjetividad, Rosa Julia Guzmán Rodríguez Educomunicación en entornos digitales: mirada desde la comunicación no verbal, Andrés Chiappe, Hugo Rozo, Eduardo Menjivar, María Alejandra Corchuelo, Maite Alarcón Retos para la formación del tutor en modalidad virtual, Cristina Hennig Manzuoli Juego serio: modelo teórico para su diseño y producción, Oscar Boude Figueredo, Edgar Andrés Sosa

A call for standardised age-disaggregated health data.

The 2030 Sustainable Development Goals agenda calls for health data to be disaggregated by age. However, age groupings used to record and report health data vary greatly, hindering the harmonisation, comparability, and usefulness of these data, within and across countries. This variability has become especially evident during the COVID-19 pandemic, when there was an urgent need for rapid cross-country analyses of epidemiological patterns by age to direct public health action, but such analyses were limited by the lack of standard age categories. In this Personal View, we propose a recommended set of age groupings to address this issue. These groupings are informed by age-specific patterns of morbidity, mortality, and health risks, and by opportunities for prevention and disease intervention. We recommend age groupings of 5 years for all health data, except for those younger than 5 years, during which time there are rapid biological and physiological changes that justify a finer disaggregation. Although the focus of this Personal View is on the standardisation of the analysis and display of age groups, we also outline the challenges faced in collecting data on exact age, especially for health facilities and surveillance data. The proposed age disaggregation should facilitate targeted, age-specific policies and actions for health care and disease management

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Executive experience : a multiparadigmatic analysis of the work experience of a selected group of senior executives.

EducationDoctor of Education (Ed.D.