RESUMEN
A new cost-effective radiometer has been designed, built, and tested to measure direct normal solar irradiance (DNI). The proposed instrument for solar irradiance measurement is based on an optical fiber as the light beam collector, a semiconductor photodiode to measure the optical power, and a calibration algorithm to convert the optical power into solar irradiance. The proposed radiometer offers the advantage of separating the measurement point, where the optical fiber collects the solar irradiation, from the place where the optical power is measured. A calibration factor is mandatory because the semiconductor photodiode is only spectrally responsive to a limited part of the spectral irradiance. Experimental tests have been conducted under different conditions to evaluate the performance of the proposed device. The measurements confirm that the proposed instrument performs similarly to the expensive high-accuracy pyrheliometer used as a reference.
RESUMEN
This work deals with the application of femtosecond-laser-inscribed fiber Bragg gratings (FsFBGs) for monitoring the internal high-temperature surface distribution (HTSD) in solar receivers of concentrating solar power (CSP) plants. The fiber-optic sensor system is composed of 12 FsFBGs measuring points distributed on an area of 0.4 m2, which leads to obtain the temperature map at the receiver by means of two-dimensional interpolation. An analysis of the FsFBG performance in harsh environment was also conducted. It describes the influence of calibration functions in high-temperature measurements, determines a required 10 nm spectral interval for measuring temperatures in the range from 0 to 700 °C, and reveals wavelength peak tolerances in the FsFBG fabrication process. Results demonstrate the viability and reliability of this measuring technique, with temperature measurements up to 566 °C.
RESUMEN
In this work, data on a temperature-dependent thermic and electrical properties in a novel blend polymer electrolyte membranes based on poly(vinyl alcohol) (PVA) and chitosan (CS) doped with H3PO4 at different concentrations were prepared by solution casting method. Their phase behavior and ionic conductivity were studied by DSC, TGA and IS. These membranes exhibit good proton conductivity of the order of 10-2 Scm-1 at 200 °C and the understanding of the H3PO4 at different concentrations effect in the polymer electrolyte membranes is crucial for possible applications in fuel cells. The data have not been reported nor discussed in the research paper to be submitting.
RESUMEN
Human embryonic and induced pluripotent stem cells (hESCs and hiPSCs) are self-renewing human pluripotent stem cells (hPSCs) that can differentiate to a wide range of specialized cells. Notably, hPSCs enhance their undifferentiated state and self-renewal properties in hypoxia (5% O2). Although thoroughly analyzed, hypoxia implication in hPSCs death is not fully determined. In order to evaluate the effect of chemically mimicked hypoxia on hPSCs cell survival, we analyzed changes in cell viability and several aspects of apoptosis triggered by CoCl2 and dimethyloxalylglycine (DMOG). Mitochondrial function assays revealed a decrease in cell viability at 24 h post-treatments. Moreover, we detected chromatin condensation, DNA fragmentation and CASPASE-9 and 3 cleavages. In this context, we observed that P53, BNIP-3, and NOXA protein expression levels were significantly up-regulated at different time points upon chemical hypoxia induction. However, only siRNA-mediated downregulation of NOXA but not HIF-1α, HIF-2α, BNIP-3, and P53 did significantly affect the extent of cell death triggered by CoCl2 and DMOG in hPSCs. In conclusion, chemically mimicked hypoxia induces hPSCs cell death by a NOXA-mediated HIF-1α and HIF-2α independent mechanism.
Asunto(s)
Apoptosis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Hipoxia de la Célula/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Células Madre Pluripotentes/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/genética , Caspasa 3/genética , Caspasa 9/genética , Muerte Celular/genética , Supervivencia Celular/genética , Fragmentación del ADN , Regulación hacia Abajo/genética , Humanos , Proteínas de la Membrana/genética , Mitocondrias/genética , Transducción de Señal/genética , Proteína p53 Supresora de Tumor/genética , Regulación hacia Arriba/genéticaRESUMEN
INTRODUCCIÓN. La sepsis es un estado de disfunción multisistémica, que se produce por una respuesta desregulada del huésped a la infección. Diversos factores influyen en la gravedad, manifestaciones clínicas y progresión de la sepsis, tales como, heterogeneidad inmunológica y regulación dinámica de las vías de señalización celular. La evolución de los pacientes depende del tratamiento oportuno, las escalas de puntuación clínica permiten saber la mortalidad estimada. OBJETIVO. Evaluar la mortalidad en la unidad de cuidados intensivos; establecer el manejo y la utilidad de aplicar paquetes de medidas o "bundlers" para evitar la progresión a disfunción, fallo multiorgánico y muerte. METODOLOGÍA. Modalidad de investigación tipo revisión sistemática. Se realizó una búsqueda bibliográfica en bases de datos como Google académico, Mendeley, ScienceDirect, Pubmed, revistas como New England Journal Medicine, Critical Care, Journal of the American Medical Association, British Medical Journal. Se obtuvo las guías "Sobreviviendo a la sepsis" actualización 2021, 3 guías internacionales, 10 estudios observacionales, 2 estudios multicéntricos, 5 ensayos aleatorizados, 6 revisiones sistémicas, 5 metaanálisis, 1 reporte de caso clínico, 4 artículos con opiniones de expertos y actualizaciones con el tema mortalidad de la sepsis en UCI con un total de 36 artículos científicos. RESULTADOS. La mortalidad de la sepsis en la unidad de cuidados intensivos, fue menor en el hospital oncológico de Guayaquil, seguido de Australia, Alemania, Quito, Francia, Estados Unidos de Norteamérica y Vietnan, La mortalidad más alta se observa en pacientes con enfermedades del tejido conectivo. DISCUSIÓN. La aplicación de los paquetes de medidas o "bundlers" en la sepsis, se asocia con una mejor supervivencia y menores días de estancia hospitalaria. CONCLUSIÓN. Las escalas SOFA, APACHE II y SAPS II ayudan a predecir la mortalidad de forma eficiente, en la detección y el tratamiento temprano en pacientes con enfermedades agudas y de alto riesgo.
INTRODUCTION. Sepsis is a state of multisystem dysfunction, which is caused by a dysregulated host response to infection. Several factors influence the severity, clinical manifestations and progression of sepsis, such as immunological heterogeneity and dynamic regulation of cell signaling pathways. The evolution of patients depends on timely treatment, clinical scoring scales allow to know the estimated mortality. OBJECTIVE. To evaluate mortality in the intensive care unit; to establish the management and usefulness of applying bundlers to prevent progression to dysfunction, multiorgan failure and death. METHODOLOGY. Systematic review type research modality. A bibliographic search was carried out in databases such as Google Scholar, Mendeley, ScienceDirect, Pubmed, journals such as New England Journal Medicine, Critical Care, Journal of the American Medical Association, British Medical Journal. We obtained the guidelines "Surviving Sepsis" update 2021, 3 international guidelines, 10 observational studies, 2 multicenter studies, 5 randomized trials, 6 systemic reviews, 5 meta-analyses, 1 clinical case report, 4 articles with expert opinions and updates on the subject of sepsis mortality in ICU with a total of 36 scientific articles. RESULTS. The mortality of sepsis in the intensive care unit, was lower in the oncological hospital of Guayaquil, followed by Australia, Germany, Quito, France, United States of America and Vietnam, The highest mortality is observed in patients with connective tissue diseases. DISCUSSION. The application of bundlers in sepsis is associated with better survival and shorter days of hospital stay. CONCLUSIONS. The SOFA, APACHE II and SAPS II scales help to predict mortality efficiently in the early detection and treatment of patients with acute and high-risk disease.