Síntesis y caracterización de materiales fotovol-táicos para paneles solares de bajo coste y alta eficiencia

[Abstract] This dissertation studies the use of the hybrid perovskite (CH3)2NH2PbI3 in solid-state dye sensitized solar cells (ssDSSC), which was not previously described in the literature. To that end, thin films of the perovskite were prepared using both the one-step spin-coating and the two-step spin-coating techniques. Those films were characterized by XR powder diffraction and scanning electron microscopy. Furthermore, the UV-Vis spectrum of the compound was obtained, as well as its band gap and structure. The UV-visible absorption spectrum of the (CH3)2NH2PbI3 revealed that it absorbed only in the blue region and the ultraviolet zone, while its band gap was 2.81 eV. Although these optical properties are not adequate for photovoltaic applications, they it make an interesting candidate for use in a blue LED design. The structure of the compound is that of a hexago-nal perovskite, due to the big size of the dimethlyammonium cation. At first, a non-homogenous layer of (CH3)2NH2PbI3 was deposited, with a needle-like structure, and which was due to a large particle size of the precursor solutions. The particle size of the solutions was proved to be in relationship with the amount of organic com-pounds present in the solution, as it was reduced adding MAX or DMAX as additives (me-thyl or dimethlylammonium halides, where X is either Cl- or I-). Also, this memory reports the influence of the additives in the particle size of the colloids and in film morphology on hybrid perovskite CH3NH3PbI3. The obtained results shown that methylammonium chloride employed as additive induces a reduction of particle size of the precursor solutions leading to better, more homogeneous morphologies.[Resumo] This dissertation studies the use of the hybrid perovskite (CH3)2NH2PbI3 in solid-state dye sensitized solar cells (ssDSSC), which was not previously described in the literature. To that end, thin films of the perovskite were prepared using both the one-step spin-coating and the two-step spin-coating techniques. Those films were characterized by XR powder diffraction and scanning electron microscopy. Furthermore, the UV-Vis spectrum of the compound was obtained, as well as its band gap and structure. The UV-visible absorption spectrum of the (CH3)2NH2PbI3 revealed that it absorbed only in the blue region and the ultraviolet zone, while its band gap was 2.81 eV. Although these optical properties are not adequate for photovoltaic applications, they it make an interesting candidate for use in a blue LED design. The structure of the compound is that of a hexago-nal perovskite, due to the big size of the dimethlyammonium cation. At first, a non-homogenous layer of (CH3)2NH2PbI3 was deposited, with a needle-like structure, and which was due to a large particle size of the precursor solutions. The particle size of the solutions was proved to be in relationship with the amount of organic com-pounds present in the solution, as it was reduced adding MAX or DMAX as additives (me-thyl or dimethlylammonium halides, where X is either Cl- or I-). Also, this memory reports the influence of the additives in the particle size of the colloids and in film morphology on hybrid perovskite CH3NH3PbI3. The obtained results shown that methylammonium chloride employed as additive induces a reduction of particle size of the precursor solutions leading to better, more homogeneous morphologies.[resumen] Este traballo estuda o uso da perovskita híbrida (CH3)2NH2PbI3 en células solares sensitivi-zadas por colorantes de estado sólido (ssDSSC), a cal non fora descrito anteriormente na bibliografía. Para ese fin, capas finas da perovskita foron preparadas polos procedementos de spin-coating en un e dous pasos, respectivamente. Esas capas foron caracterizadas por difracción de raios-X en po e por microscopía electrónica de varrido. Ademais, o espectro de UV-Vis foi obtido, así como o seu bandgap e a súa estrutura. O espectro de absorción de UV-visible do (CH3)2NH2PbI3 revelou que este solo absorbía na rexión ultravioleta, mentres que o seu band gap era 2.81 eV. Aínda que estas propiedades non eran adecuadas para aplicacións fotovoltaicas, tamén o fan un candidato interesante para o seu uso nun LED azul. A estrutura cristalina do composta é a dunha perovskita he-xagonal, debido o gran tamaño do catión dimetilamonio. Ao principio depositouse unha capa non homoxénea de (CH3)2NH2PbI3, cunha estrutura en forma de agullas, o calé debido ao gran tamaño de partícula das disolucións precursoras. Demostrouse que o tamaño de partícula das solución precursoras esta relacionado coa can-tidade de compostos orgánicos presentes na disolución, xa que foi reducido ao engadir MAX ou DMAX como aditivos (haluros de metil o dimetil amonio, sendo X ben Cl- ou I-). Esta memoria tamén reporta a influencia dos aditivos nos coloides e na morfoloxía das ca-pas da perovskita híbrida CH3NH3PbI3. Os resultados obtidos mostran que o emprego de cloruro de metilamonio como aditivo induce unha redución do tamaño de partícula das solución precursoras, levando á obtención de morfoloxías mellores e máis homoxéneas.Traballo fin de grao (UDC.CIE). Química. Curso 2014/201

Immunogenicity induced by the use of alternative vaccine platforms to deal with vaccine shortages in a low- to middle-income country: Results of two randomized clinical trials

Background: Shortages of component two of Sputnik V vaccine (rAd5) are delaying the possibility of achieving full immunisation. The immunogenic response associated with the use of alternative schemes to complete the scheme was not explored. Methods: We did two non-inferiority randomized clinical trials with outcomes measures blinded to investigators on adults aged 21–65 years, vaccinated with a single dose of rAd26 ≥ 30 days before screening and no history of SARS-CoV-2. Participants were assigned (1:1:1:1:1) to receive either rAd5; ChAdOx1; rAd26; mRNA-1273 or BBIBP-CorV. The primary endpoint was the geometric mean ratio (GMR) of SARS-CoV-2 anti-spike IgG concentration at 28 days after the second dose, when comparing rAd26/rAd5 with rAd26/ChAdOx1, rAd26/rAd26, rAd26/mRNAmRNA-1273 and rAd26/BBIBP-CorV. Serum neutralizing capacity was evaluated using wild type SARS-CoV-2 reference strain 2019 B.1. The safety outcome was 28-day rate of serious adverse. The primary analysis included all participants who received ≥ 1 dose. The studies were registered with NCT04962906 and NCT05027672. Both trials were conducted in Buenos Aires, Argentina. Findings: Between July 6 and August 3, 2021, 540 individuals (age 56·7 [SD 7·3]; 243 (45%) women) were randomly assigned to received rAd5 (n=150); ChAdOx1 (n=150); rAd26 (N=87); mRNAmRNA-1273 (n=87) or BBIBP-CorV (n=65). 524 participants completed the study. As compared with rAd26/rAd5 (1·00), the GMR (95%CI) at day 28 was 0·65 (0·51–0·84) among those who received ChAdOx1; 0·47 (0·34–0·66) in rAd5; 3·53 (2·68–4·65) in mRNA-1273 and 0·23 (0·16–0·33) in BBIBP-CorV. The geometric mean (IU/ml) from baseline to day 28 within each group increased significantly with ChAdOx1 (4·08 (3·07–5·43)); rAd26 (2·69 (1·76–4·11)); mRNA-1273 (21·98 (15·45–31·08)) but not in BBIBP-CorV (1·22 (0·80–1·87)). Interpretation: Except for mRNA-1273 which proved superior, in all other alternatives non-inferiority was rejected. Antibody concentration increased in all non-replicating viral vector and RNA platforms. Funding: The trials were supported (including funding, material support in the form of vaccines and testing supplies) by the Buenos Aires City Government.Fil: Macchia, Alejandro. No especifíca;Fil: Ferrante, Daniela. No especifíca;Fil: Bouzas, María Belén. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Angeleri, Patricia. No especifíca;Fil: Biscayart, Cristián. No especifíca;Fil: Geffner, Jorge Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Mammana, Lilia. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Zapiola, Inés. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: López, Eduardo Luis. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Gentile, Angela. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Varese, Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Mazzitelli, Ignacio Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Di Diego García, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Sharff, Deborah. No especifíca;Fil: Lucconi, Verónica. No especifíca;Fil: Sujansky, Paula. No especifíca;Fil: Mariani, Javier. No especifíca;Fil: González Bernaldo de Quirós, Fernán. No especifíca

La historia política hoy: sus métodos y las ciencias sociales

En mayo de 2002 se llevó a cabo en la sede de Bogotá de la Universidad Nacional el seminario «La historia política hoy: sus métodos y las ciencias sociales». / Contenido. Preliminares, Capítulo 1 - La emergencia de nuevos temas en la historia en la política; Capítulo 2 - Región e historia política; Capítulo 3 - Historia política en Colombia; Capítulo 4 - Ciencia política, politología e historia política; Capítulo 5 - Proposiciones para la nueva historia política; Anexos

European Journalism Observatory- a platform for training and professional networks in the Faculty of Information Sciences

The launching of a Spanish platform within the Observatory will serve as a training laboratory for undergraduate and graduate students of the Faculty of Information Sciences at the same time as for establishing a professional media network in and outside Spain. The European Journalism Observatory (EJO) is a network of 14 non-profit media research institutes in 11 countries where Spain continue to be the missing element. All researchers in the EJO network actively strive to transfer their knowledge to the media industry as well as interested publics outside the scientific community, as a platform to enable online availability of at least a portion of many publications in several languages

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Experiencias en el aula: tercer encuentro de prácticas pedagógicas innovadoras.

Experiencias de profesores en su quehacer en los distintos ambientes de aprendizaje presenciales y a distancia.Para el Centro de Excelencia Docente aeiou constituye un honor presentar la publicación del Tercer Encuentro de Prácticas Pedagógicas Innovadoras en el que se destacan cuarenta trabajos de profesores de UNIMINUTO provenientes de diferentes sedes. Con este encuentro son ya tres que bajo la dirección de aeiou los profesores han compartido su quehacer en los distintos ambientes de aprendizaje presenciales y a distancia. Cada año el Centro de Excelencia Docente invita a los profesores a participar en este evento, para el 2108 además de la inscripción voluntaria por parte de cada profesor, se invitó al estudiantado a que postularan a sus profesores que consideraban eran innovadores y creativos en el cumplimiento de su función docente y se obtuvo una respuesta importante por parte de los estudiantes, que para algunos profesores resultó sorpresiva porque quizás no habían considerado que el trabajo que hacían en su ambiente de aprendizaje era diferente, fuera de lo común. Luego de una evaluación de jurados nacionales e internacionales de las prácticas presentadas y de la realización del evento, que tuvo como novedad hacerlo de forma simultánea en cuatro sedes donde UNIMINUTO tiene presencia: Buga, Ibagué, Pereira y Bogotá, se comparte la presente publicación para tener como referencia y evidencia el trabajo que los profesores hacen a diario

Conflictos, poderes e identidades en el Magdalena Medio 1990-201

IP 2206-10-12447Colombia en el cambio de siglo : actores sociales, guerray politica / Mauricio Archila. -- En: Nueva;sociedad. -- No. 182 (nov.-dic. 2002); p.76-89. -- Los clarooscuros de laprotesta social en Colombia,;1975-2002 / Mauricio Archila, Martha Cecila Garcia. -- En:Bajoel volcan.-- Vol. 3, no. 6 (2003). -- p.;93-103. -- La protesta en el campo colombiano de la luchaporlatierra ala defensa de los derechos humanos;LIBRO(S): Conflictos, poderes e identidades en el Magdalena Medio 1990-2001 / Mauricio Archila N. --- [et;al.]. -- Bogotá : Ediciones Antropos, 2006. -- 577 p. ; 24cm.-- ISBN 9586441016 -- ARTICULO(S) EN REVISTA:;1990-2003. -- En: Observatorio social de America Latina. -'- no.11 (mayo 2003); p.53-63. -- CD: Mapas del;conflicto armado en el Magdalena Medio, 1990-2001

User-centered design improves the usability of drug-drug interaction alerts: A validation study in the real scenario

Decision support systems can alert physicians to the existence of drug interactions. The Hospital Italiano de Buenos Aires, Argentina, has an in-house electronic health record with computerized physician order entry and clinical decision support. It includes a drug-drug interaction alert system, initially developed under traditional engineering techniques. As we detected a high alert override rate, we rebuilt the knowledge database and redesigned the alert interface with User-Centered Design techniques. A laboratory crossover study using clinical vignettes showed that new alerts were more usable than traditional ones. This paper aimed to validate these results through a controlled and randomized experimental study with two branches (old vs. new design) in a real setting. We analyzed, quantitatively, every fired alert between April 2015 and September 2016. Finally, we performed user surveys and qualitative interviews to inquire about their satisfaction and perceptions. In real scenarios, user-centered design alerts were more usable, being more effective and satisfactory, but less efficient than traditional alerts. "Safe omission", as a new concept, emerged from our stratified analyses and interviews.Fil: Luna, Daniel R.. Instituto Tecnológico de Buenos Aires; Argentina. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Rizzato Lede, Daniel A.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Rubin, Luciana. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Otero, Carlos M.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Ortiz, Juan M.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: García, Mónica G.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Rapisarda, Romina P.. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: Risk, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; Argentina. Hospital Italiano. Instituto Universitario. Escuela de Medicina; ArgentinaFil: González Bernaldo De Quirós, Fernán. Hospital Italiano. Instituto Universitario. Escuela de Medicina; Argentin