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ilustraciones, fotografías a color Una célula estromal mesenquimal humana (hCEM) es una célula madre adulta caracterizada por su capacidad de autorrenovación y diferenciación. También presentan varias ventajas tales como propiedades inmunomoduladoras que las hacen promisoria fuente en medicina regenerativa. Por lo tanto, el uso de estas células como portadoras de genes ha sido uno de los principales focos de varios estudios. En los últimos años, los vectores no virales todavía presentan algunas limitaciones, siendo la m[as importante las bajas eficiencias de transfección en las CEM. Se ha teorizado que esta baja eficiencia es causada por múltiples factores relacionados con las propiedades de las nanopartículas, incluyendo el tamaño, la carga, la degradación, el escape endosomal y el transporte del cergo al núcleo. Además, se ha demostrado que el tipo de célula y la fase del ciclo celular son una incidencia importante en la entrega de genes. En resumen, la transfección depende directamente de la naturaleza química del material (vector) que cubre el gen y su interacción no específica con todas las vías dentro de la célula. Por lo tanto, en este estudio probamos la hipótesis de que la eficiencia de la transfección génica está limitada principalmente por una barrera física simple: baja concentración de genes (ADN) en la superficie de la célula. Empleamos la centrifugación durante el proceso de transfección como un medio para aumentar más la disponibilidad de ADN en las proximidades de la membrana celular, generando así mayores eficiencias de transfección con el vector dorado no viral: PEI 25kDa. Además, una comprensión más profunda del mecanismo de transfección con este tipo de vectores permitió la estandarización de un nuevo y sencillo protocolo de transfección en el que se evaluaron la relación de peso, diferentes concentraciones de complejo, pH y número de paso para obtener tasas de transfección superiores al 25-30% con un método no viral. Por otro lado, nuestros resultados muestran que el efecto combinado de la centrifugación y la transfección tiene un impacto importante en la actividad metabólica de las MSC y la proliferación celular. (Texto tomado de la fuente) A human mesenchymal stromal cell (hMSC) is an adult stem cell characterized by its self-renoval and differentiation capacity. They also present several advantages such immunomodulatory properties which make them promissory for regenerative medicine. Thus, using these cells as gene carriers has been one of the main focuses of several studies. In recent years, non-viral carriers still exhibit some limitations, namely low transfection efficiencies in MSCs. It has been theorized that this low efficiency is caused by multiple factors regarding nanoparticle properties, including size, charge, degradation, endosomal escape, and transport to the nucleus. Moreover, the cell type and the phase cell cycle have been proven to be an important incidence in the gene delivery. In brief, transfection depends directly on the chemical nature of the material (vector) which covers the gene and its non-specific interaction with all the pathways within the cell. Therefore, in this study we tested the hypothesis that the efficiency of gene transfection is mainly limited by a simple physical barrier: low concentration of gene (DNA) on the surface of the cell. We employed centrifugation during the transfection process as a means to increase more the availability of DNA in the vicinity of the cell membrane, thus generating higher transfection efficiencies with non-viral golden vector: PEI 25kDa. Additionally, a deeper understanding of the transfection mechanism with these types of vectors enabled the standardization of a new and simple transfection protocol in which the weight ratio, different concentrations of complex, pH and passage number were evaluated to obtain transfection rates above 25-30% with a non-viral method. On the other hand, our results show that the combined effect of centrifugation and transfection has an important impact in MSCs metabolic activity and cell proliferation. Maestría Ingeniería de Tejidos

Background: Due to causes such as small-scale earthquakes or the increasing amount of heavy rainfall extreme events, many slopes are potentially unstable. Soil bioengineering is an effective tool for treatment of a variety of unstable and/ or eroding sites. Question and hypothesis: Maximum force to breakage of the roots is influenced by diameter. Tensile strength and modulus of elasticity of roots is different between species of the two different ecosystems: Tamaulipan thornscrub and Pine-oak forest. Studied Species: Site 1: Acacia berlandieri, Cordia boissieri, Acacia rigidula, Havardia pallens, and Acacia farnesiana ; Site 2: Quercus rysophylla, Pinus pseudostrobus, Quercus canbyi, Quercus polymorpha, and Arbutus xalapensis . Study area and dates: Tamaulipan thornscrub in Northeastern Mexico (Linares, Nuevo León), from May to July 2016; and Pine-Oak forest in Sierra Madre Oriental, Iturbide, Nuevo Leon, from September to October 2016. Methods: The species considered were selected based on their native characteristics (natural distribution, abundance in the area and widespread existence on slopes). The tests were conducted with the Universal Testing Machine Shimadzu type SLFL-100KN. Results: The relationships between tensile strength (Ts) and diameters of the studied species, and root diameters and modulus of elasticity (Eroot) were negative. The minimum and maximum values of tensile strength varied from 1.86 N / mm2 in C. boissieri to 44.65 N/mm2 in A. rigidula . Conclusions: Acacia berlandieri showed the highest tensile strength among all species of the two ecosystems, in the diametric group I (0.1 to 2.9 mm).

The impact of the use of natural resources associated with anthropogenic activities has increased evidently, mainly through land use changes which have altered hydrophysical properties of soils. We hypothesized that, in the same soil type (Vertisol), four types of land use system (grassland, agricultural, Eucalyptus plantation and thornscrub) and seasonal variation can modify the soil hydrophysical properties. Results showed significant differences between land use systems and seasons for hydraulic conductivity (K), infiltration capacity (fp) and cumulative infiltration (fc). There were no seasonal differences in soil penetration resistance (SPR), bulk density (ρd) and total porosity (φP). Grassland presented higher values for ρd (1.2 g cm⁻³) and SPR (5.3 kg cm⁻²) and lower for K (0.8 × 10⁻⁵ cm s⁻¹) and φP (53%), unlike thornscrub. Agriculture presented lower SPR (0.4 kg cm⁻²), while plantation showed similar values when compared to the thornscrub. Kostiakov infiltration model was fitted to land use infiltration curves, showing differences between land use and season. The values for fp oscillated between 53.6 and 548.8 mm hr⁻¹ and fc ranged from 105.3 to 1,061 mm. The order of the infiltration values goes as follows: agriculture > plantation > thornscrub > grassland. Land use changes in Vertisols induced modification of soil physical properties affecting processes like permeability, soil compaction and water availability.

This research focused on the evaluation of the Fe2O3/TiO2 composite and two industrial wastes, a kaolin (Clay-K) and a blast furnace sludge (BFS), as adsorbents and/or photocatalytic materials to enhance the removal of cyanide from aqueous solutions. Cyanide adsorption tests were conducted in the absence of light. In contrast, cyanide photodegradation tests were conducted under three types of irradiations: visible light, ultraviolet (UV) light, and natural sunlight. For the latter case, two irradiance conditions were evaluated. Cyanide adsorption from aqueous phases was similar for Clay-K and TiO2/Fe2O3 materials, which adsorbed almost twice as much cyanide compared to the BFS sample. The differences observed in cyanide removal were explained in terms of the material’s surface area and chemical composition, and a complexation of cyanide ions with surface metals was suggested as the most feasible adsorption mechanism. The set of cyanide photodegradation experiments promoted, in general, higher cyanide removal from the aqueous solution compared to the adsorption processes. Under the conditions used in this study and when using Clay-K and BFS as promoters, cyanide photodegradation progressively enhanced with the following radiations: visible light < UV light ~ UV+solar ≤ Visible+solar. In the case of the TiO2/Fe2O3 composite, cyanide photodegradation increased in the following order: UV light < visible light < UV+solar ~ Visible+solar. Clearly, solar radiation had a significant effect on promoting cyanide removal. For experiments conducted with natural sunlight, the set with irradiance of 600–800 W/m2 exhibited the highest cyanide removal percentage, and the BFS had the best performance among the three tested samples over a period of 2 h. Results showed the benefit of using industrial wastes to remove cyanide from aqueous solutions and illustrates remediation of industrial effluents is potentially feasible within the framework of a circular economy.

Ribosomal RNAs (rRNAs) have long been known to carry chemical modifications, including 2'O-methylation, pseudouridylation, N

Slags, sludges, and dust from steelmaking industries have been probed as adsorbents for Pb(II) removal from synthetic water solutions, and these residues have showed good potential in the treatment of industrial effluents contaminated with this heavy metal. Adsorption and precipitation of Pb(II) have been postulated as the main mechanisms to remove Pb(II) from aqueous solutions by using steelmaking residues. The significant effect of pH on Pb(II) removal has been well studied but few studies explicitly address the effect of chemical and mineralogical composition of steelmaking residues and a better understanding of this key parameter is still needed for full elucidation and optimization of the Pb(II) removal process. In this study, samples obtained from different sections of a dust collector system (BFD) in a steelmaking factory, were used to evaluate the effect of BFD sample’s chemical composition on the removal of Pb(II) from synthetic aqueous solution. BFD samples were characterized to determine their chemical composition, particle size distribution and isoionic point. Equilibrium and transient experiments of Pb(II) removal from aqueous solutions were conducted a 25 °C and initial pH = 5.0. Results showed that CaO and MgO, as well as metallic Fe and FeO had a positive linear effect BDF samples Pb(II) adsorption capacity. Pb(II) removal process may take place by ion exchange with CaO and MgO, and by precipitation on the surface of metallic Fe and FeO. MgO and FeO promoted the Pb(II) removal in lesser extend that CaO and metallic Fe, respectively, because the surface ion exchange with MgO and FeO are less thermodynamic favourable and their lower composition in the sample. Bimolecular ion exchange process between Pb(II) ions and Ca and Fe species was supported by results from equilibrium and transient adsorption studies. Results of this work clearly showed that removal of Pb(II) from aqueous solutions is a strong function of the chemical composition of BFD samples and it provided further insight to promote the valorisation and optimization of steelmaking residues as heavy-metal adsorbents.

Fil: Sanchez Castillo, Juan Andres. Instituto Universitario de Ciencias de la Salud. Fundación Barceló; Argentina. El modelo chileno de donación, procuramiento y trasplante de órganos tiene como uno de los pilares organizativos y de gestión la participación de las/os licenciadas/os en enfermería como coordinadores locales de procuramiento (CLP), sin embargo, la formación de pregrado no entrega las herramientas para el desarrollo de estas funciones, lo que impacta negativamente en la tasa de donantes a nivel nacional.

Adamantinoma of long bones is a slow-growing, low-grade primary malignant bone tumor. It is a rare entity and accounts for less than 1% of all primary bone tumors, and in most cases, it occurs in the mid-axis of the tibia of adolescents and young adults. In this report, we describe the case of a 53-year-old woman with a diagnosis of adamantinoma of the left tibia who was initially treated surgically in 2004. Two years later, she presented with local relapse, for which she underwent new surgical management. The patient was referred to our practice 16 years after the initial diagnosis, and she presented with recurrence characterized by ipsilateral inguinal lymph node metastasis. The histological findings and immunohistochemistry were compatible with metastatic adamantinoma with high-grade differentiation, which ultimately required surgical salvage management.

The RNA N(6)-methyladenosine (m(6)A) methylation is installed by the METTL3-METTL14 methyltransferase complex. This modification has critical regulatory roles in various biological processes. Here, we report that deletion of Mettl14 dramatically reduces mRNA m(6)A methylation in developing B cells and severely blocks B cell development in mice. Deletion of Mettl14 impairs interleukin-7 (IL-7)-induced pro-B cell proliferation and the large-pre-B-to-small-pre-B transition and causes dramatic abnormalities in gene expression programs important for B cell development. Suppression of a group of transcripts by cytoplasmic m(6)A reader YTHDF2 is critical to the IL-7-induced pro-B cell proliferation. In contrast, the block in the large-pre-B-to-small-pre-B transition is independent of YTHDF1 or YTHDF2 but is associated with a failure to properly upregulate key transcription factors regulating this transition. Our data highlight the important regulatory roles of the RNA m(6)A methylation and its reader proteins in early B cell development.

Plasma-based technology is an alternative to produce universal polymer coatings with the appropriate requirements of robustness and stability for antibacterial applications. Here, we proposed a sequential two-step alternative to synthesize antibacterial polymer coatings. A non-isothermal plasma reactor, operated at atmospheric pressure (Patm) and room temperature (Troom), was used to induce free radical polymerization of 4-vinyl pyridine (4VP) on high-density polyethylene (PE). In a subsequent step, the poly-4VP (P4VP) films were treated with a bromoethane/He gas stream to produce quaternized P4VP (P4VPQ) films. Chemical structure of polymer films was validated by infrared and UV–visible spectroscopy, and morphology was evaluated by optical and atomic force microscopy; scanning electron microscopy was used to determine films thickness, which was then used to estimate the surface charge density. The bactericidal capacity was determined with a standard test by using Escherichia coli. Both types of films had an estimated charge density in the order of 1016 positive charges per cm2; P4VP films removed about 95–99% of bacteria, whereas 4PVPQ films eliminated 100%. The methodology proposed for the synthesis of antibacterial polymer coatings is simpler, faster, and more environmentally friendly than other plasma-based methods; operation at Troom and Patm may also have a significant effect on the economics and the ease of implementation of the process at commercial scale. The suggested approach may facilitate the development of new universal coatings, and operating plasma conditions could be extrapolated for engineering antibacterial coatings in industrial areas where bacterial attachment is of concern.

Correction for ‘Expanding plastics recycling technologies: chemical aspects, technology status and challenges’ by Houqian Li et al., Green Chem., 2022, 24, 8899–9002, https://doi.org/10.1039/D2GC02588D.

Las TIC han generado revolución en todas las dimensiones del ser humano, para el tema específico de la educación, su accionar ha reconfigurado la relación docente-estudiante y con ello la dinámica de los procesos de enseñanza-aprendizaje. El presente manuscrito da a conocer los resultados de un proceso de investigación cuantitativo sobre la incorporación de estas herramientas a las dinámicas académicas de la Universidad de la Amazonia, desde la percepción docente. La presentación de los hallazgos se estructuró a través de tres capítulos: formación docente, la incorporación de las TIC y el desarrollo de procesos mediados por estas herramientas, encontrado entonces una sentida necesidad de generar políticas institucionales sobre el tema, mayores niveles de inversión para garantizar el acceso a estos recursos, así como la necesidad de motivar y cautivar a los maestros para los procesos de transformación de la institución en una cultura mediadas por estas tecnologías.

El presente trabajo de investigación Desempeño Docente y Aprendizaje de estudiantes de Agronomía Universidad San Pedro de Chimbote en el año 2018, tuvo como propósito establecer la relación entre la variable desempeño docente y la variable aprendizaje de los estudiantes. La metodología empleada, se hizo a través del tipo de investigación correlacional, diseño de investigación transversal, en la que se analiza una muestra probabilística seleccionados por el método aleatorio simple de los estudiantes de Agronomía del sexto al décimo ciclo los cuales han sido seleccionados para este estudio. Con respecto a los resultados obtenidos, en lo concerniente a Desempeño Docente se obtuvo el 59% en el nivel alto, en los otros niveles se obtuvo el 35% en el nivel medio y el 6% en el nivel bajo, considerándose que para esta variable el nivel fue alto. En lo que se refiere a la variable Aprendizaje, se obtuvo el 44% en el nivel medio, 32% en el nivel bajo y 24% en el nivel alto, considerándose que para esta variable el nivel fue medio. En el presente trabajo se obtuvo una correlación de 0.199 (rho de Spearman), lo que significa que existe una relación baja entre las variables, por lo que se acepta la hipótesis nula, comprobándose que existe una relación baja entre el desempeño docente y aprendizaje de los estudiantes de Agronomía de la Universidad San Pedro de Chimbote. Tesis