Artículos investigadores UV

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Taxanes for advanced non-small cell lung cancer (Protocol)
(Cochrane, 2018) Madrid, Eva; Barros Monge, Manuel J; Urrútia, Gerard; Roqué I Figuls, Marta; Pérez Bracchiglione, Javier; Vargas Peirano, Manuel; Loézar Hernández, Cristóbal Nicolás; Bonfill Cosp, Xavier
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effects of taxanes as part of a combined or single‐agent therapy versus other agents or best supportive care as first‐ or second‐line treatment for advanced non‐small cell lung cancer (NSCLC). A secondary objective is to assess different modes or schemes of administration of taxanes in patients with this disease.
Development of Fixed Dose Combination Products Workshop Report: Considerations of Gastrointestinal Physiology and Overall Development Strategy
(Springer, 2019) Hens, Bart; Corsetti, Maura; Bermejo, Marival; Löbenberg, Raimar; González, Pablo M.; Mitra, V; Desai, Divyakant; Murthy Chilukuri, Dakshina; Aceituno, Alexis
The gastrointestinal (GI) tract is one of the most popular and used routes of drug product administration due to the convenience for better patient compliance and reduced costs to the patient compared to other routes. However, its complex nature poses a great challenge for formulation scientists when developing more complex dosage forms such as those combining two or more drugs. Fixed dose combination (FDC) products are two or more single active ingredients combined in a single dosage form. This formulation strategy represents a novel formulation which is as safe and effective compared to every mono-product separately. A complex drug product, to be dosed through a complex route, requires judicious considerations for formulation development. Additionally, it represents a challenge from a regulatory perspective at the time of demonstrating bioequivalence (BE) for generic versions of such drug products. This report gives the reader a summary of a 2-day short course that took place on the third and fourth of November at the Annual Association of Pharmaceutical Scientists (AAPS) meeting in 2018 at Washington, D.C. This manuscript will offer a comprehensive view of the most influential aspects of the GI physiology on the absorption of drugs and current techniques to help understand the fate of orally ingested drug products in the complex environment represented by the GI tract. Through case studies on FDC product development and regulatory issues, this manuscript will provide a great opportunity for readers to explore avenues for successfully developing FDC products and their generic versions.
Inclusión de salud basada en evidencia en carreras de la salud en Chile y el modelo integrado Metodología de la Investigación Científica-Medicina Basada en Evidencia en la Universidad de Valparaíso
(Elsevier, 2019) Papuzinski, Cristian; Loézar, Cristóbal; Carvajal, Natalia; Vargas, Manuel; Borgeat, Marjorie; Madrid, Eva; Pérez-Bracchiglione, Javier; Arancibia, Marcelo
Introducción: La salud basada en evidencia (SBE) integra el uso de la mejor evidencia, la experiencia clínica y los valores y preferencias del paciente para la toma de decisiones. Su incorporación en las carreras sanitarias de Chile es desconocida. Métodos: Se realizó un estudio de corte transversal para evaluar la incorporación de SBE en los programas de las carreras sanitarias en Chile hasta 2019. Se describe la integración del modelo Metodología de la Investigación Científica (MIC)-Medicina Basada en la Evidencia (MBE) en la Escuela de Medicina de la Universidad de Valparaíso. Resultados: Un total de 49 universidades imparten carreras sanitarias. Un 8,13% incorpora SBE como asignatura explícitamente. Todas incorporan asignaturas que potencialmente incluyen contenidos de SBE. Las carreras de Medicina y Enfermería son las que más incorporan SBE, pero solo una carrera de Medicina incluye SBE como asignatura por más de un semestre. El modelo integrado MIC/MBE (4 semestres), orientado en competencias y centrado en el alumno, involucra el diseno ̃ y ejecución de un protocolo de investigación, así como el análisis crítico de la mejor evidencia, integrado con los valores de los pacientes. Conclusión: La incorporación de SBE como asignatura es muy infrecuente en carreras sanitarias chilenas. Se enfatiza su inclusión transdisciplinaria como asignatura individual desde un modelo que integre la ensenanza ̃ de MIC, sobre todo en universidades estatales.
Pre‐ and postnatal alcohol exposure delays, in female but not in male rats, the extinction of an auditory fear conditioned memory and increases alcohol consumption
(Wiley, 2019) Plaza, Wladimir; Gaschino, Felice; Gutiérrez, Camilo; Santibañez, Nicolás; Estay‐Olmos, Camila; Sotomayor‐Zárate, Ramón; De la Fuente‐Ortega, Erwin; Pautass, Ricardo M.; Haeger, Paola A.
Repeated exposure to alcohol increases retrieval of fear‐conditioned memories, which facilitates, among other factors, the emergence of post‐traumatic stress disorder (PTSD). Individuals with PTSD are more likely to develop alcohol and substance abuse related disorders. We assessed if prenatal and early postnatal alcohol exposure (PAE) increased the susceptibility to retain aversive memories and if this was associated with subsequent heightened alcohol consumption. Pregnant Sprague‐Dawley rats were exposed for 22 hr/day, throughout pregnancy and until postnatal Day 7 to a single bottle of sucralose ‐ sweetened 10% alcohol solution (PAE Group), or to a single bottle of tap water and sucralose (Control Group). Auditory fear conditioning (AFC) was performed in the adolescent offspring at postnatal Day 40. Freezing was measured during acquisition, retention and extinction phases, followed by 3 weeks of free choice alcohol intake. Female, but not male, PAE rats exhibited impaired extinction of the aversive memory, a finding associated with higher levels of 3‐4 Dihidroxyphenylacetic acid (DOPAC) in the nucleus accumbens and heightened alcohol intake, respect to controls. These findings suggest that PAE makes females more vulnerable to long‐term retention of aversive memories, which coexist with heightened alcohol intake. These findings are reminiscent of those of PTSD
Implicaciones Socioeducativas de la Creatividad a partir de la Mediación Pedagógica: Una Revisión Crítica
(Universidad Austral de Chile, 2020) Sandoval-Obando, Eduardo; Toro Arévalo, Sergio; Poblete Gálvez, Carolina; Moreno Doña, Alberto
La institución escolar continúa siendo un espacio rutinario y normativo, desatendiendo notoriamente aspectos socioemocionales, culturales, históricos e incluso políticos del aprendizaje. Creemos que la escuela debe integrar alternativas educativas que minimicen el impacto negativo de los procesos de escolarización. Así, emerge la creatividad como un componente relevante del desarrollo emocional y cognitivo del ser humano. Se presenta la creatividad y sus bases neurobiológicas, describiendo la estrecha conexión que posee con el aprendizaje, presentando pautas de comportamiento y criterios pedagógicos que facilitarían la promoción de este constructo, fundamentadas en las Experiencias de Aprendizaje Mediado. Finalmente, se discute y tensiona la ‘transformación educativa’, dando el salto desde el aprendizaje incidental al intencional, impulsando una pedagogía de la pregunta que posibilite al alumnado descubrir el mundo, más allá de los límites y formas definidas por el mapa escolar.
The Gaia-ESO Survey: Galactic evolution of lithium at high metallicity
(European Southern Observatory, 2020) Bayo, Amelia
Context. Reconstructing the Galactic evolution of lithium (Li) is the main tool used to constrain the source(s) of Li enrichment in the Galaxy. Recent results have suggested a decline in Li at supersolar metallicities, which may indicate reduced production. Aims. We exploit the unique characteristics of the Gaia-ESO Survey open star cluster sample to further investigate this issue and to better constrain the evolution of Li at high metallicity. Methods. We trace the upper envelope of Li abundance versus metallicity evolution using 18 clusters and considering members that should not have suffered any Li depletion. Results. At variance with previous claims, we do not find any evidence of a Li decrease at high metallicity. The most metal-rich clusters in the sample ([Fe/H] = ∼0.3) actually show the highest Li abundances, with A(Li) > 3.4. Our results clearly show that previous findings, which were based on field stars, were affected by selection effects. The metal-rich population in the solar neighbourhood is composed of relatively old and cool stars that have already undergone some Li depletion; hence, their measured Li does not represent the initial interstellar medium abundance, but a lower limit to it.
The Gaia-ESO survey: the non-universality of the age–chemical-clocks–metallicity relations in the Galactic disc
(European Southern Observatory, 2020) Bayo, Amelia
Context. In the era of large spectroscopic surveys, massive databases of high-quality spectra coupled with the products of the Gaia satellite provide tools to outline a new picture of our Galaxy. In this framework, an important piece of information is provided by our ability to infer stellar ages, and consequently to sketch a Galactic timeline. Aims. We aim to provide empirical relations between stellar ages and abundance ratios for a sample of stars with very similar stellar parameters to those of the Sun, namely the so-called solar-like stars. We investigate the dependence on metallicity, and we apply our relations to independent samples, that is, the Gaia-ESO samples of open clusters and of field stars. Methods. We analyse high-resolution and high-signal-to-noise-ratio HARPS spectra of a sample of solar-like stars to obtain precise determinations of their atmospheric parameters and abundances for 25 elements and/or ions belonging to the main nucleosynthesis channels through differential spectral analysis, and of their ages through isochrone fitting. Results. We investigate the relations between stellar ages and several abundance ratios. For the abundance ratios with a steeper dependence on age, we perform multivariate linear regressions, in which we include the dependence on metallicity, [Fe/H]. We apply our best relations to a sample of open clusters located from the inner to the outer regions of the Galactic disc. Using our relations, we are able to recover the literature ages only for clusters located at RGC > 7 kpc. The values that we obtain for the ages of the inner-disc clusters are much greater than the literature ones. In these clusters, the content of neutron capture elements, such as Y and Zr, is indeed lower than expected from chemical evolution models, and consequently their [Y/Mg] and [Y/Al] are lower than in clusters of the same age located in the solar neighbourhood. With our chemical evolution model and a set of empirical yields, we suggest that a strong dependence on the star formation history and metallicity-dependent stellar yields of s-process elements can substantially modify the slope of the [s/α]–[Fe/H]–age relation in different regions of the Galaxy. Conclusions. Our results point towards a non-universal relation [s/α]–[Fe/H]–age, indicating the existence of relations with different slopes and intercepts at different Galactocentric distances or for different star formation histories. Therefore, relations between ages and abundance ratios obtained from samples of stars located in a limited region of the Galaxy cannot be translated into general relations valid for the whole disc. A better understanding of the s-process at high metallicity is necessary to fully understand the origin of these variations.
El rol de Chile en la primera globalización del cobre, 1700-1840
(Escuela de Educación en Historia y Geografía de la Universidad Católica Silva Henríquez, 2020) Navarrete-Montalvo, Juan; Llorca-Jaña, Manuel
Este artículo estudia la posición de Chile dentro de las redes mundiales de cobre entre 1700 y la década de 1840. Durante este periodo, los niveles de producción eran bajos, si se los compara con los de 1850-1870 y el siglo XX, debido tanto a las pobres técnicas de extracción y refinado como a los altos costos de transporte. Sin embargo, el cobre chileno fue consumido dentro de Chile, en mercados cercanos como Perú, Bolivia y Argentina, y también se exportó a España, a otros países de Europa, así como a Asia. En esta época, el cobre chileno se había internacionalizado, pero no globalizado. Fue después de la independencia que el cobre chileno comenzó a fluir más libremente a Asia, mientras que los Estados Unidos y Europa continental se convirtieron, también, en mercados claves. Durante este periodo, no solo se exportaba cobre fundido, sino que también regulus y mineral de cobre. Fue solo el arribo de mercantes banqueros británicos a Chile, como Huth & Co., lo que permitió una verdadera globalización del cobre chileno, tal como muestran los archivos de esta compañía.
Interacting dark matter and cosmic acceleration
(EDP Sciences, 2020) Cardenas, Victor H.; Lepe, Samuel
We study the effect of an explicit interaction between two scalar fields components describing dark matter in the context of a recent proposal framework for interaction. We find that, even assuming a very small coupling, it is sufficient to explain the observational effects of a cosmological constant, and also overcome the problems of the Λ CDM model without assuming an exotic dark energy.
Microlensing Analysis for the Gravitational Lens Systems SDSS0924+0219, Q1355-2257, and SDSS1029+2623
(The American Astronomical Society, 2020) Rojas, Karina; Motta, Verónica
We use spectroscopic observations of the gravitationally lensed systems SDSS0924+0219(BC), Q1355-2257(AB), and SDSS1029+2623(BC) to analyze microlensing and dust extinction in the observed components. We detect chromatic microlensing effects in the continuum and microlensing in the broad emission line profiles of the systems SDSS0924+0219(BC) and Q1355-2257(AB). Using magnification maps to simulate microlensing and modeling the emitting region as a Gaussian intensity profile with size rs ∝ λp, we obtain the probability density functions for a logarithmic size prior to ‐ Å lrest frame = 3533 . In the case of SDSS0924+0219, we obtain = -  r 4+ M M s 2 3 lt-d (at 1σ), which is larger than the range of other estimates, and p=0.8±0.2 (at 1σ), which is smaller than predicted by the thin disk theory, but still in agreement with previous results. In the case of Q1355- 2257 we obtain (at 1σ) = -  r 3.6+ M M s 1.6 3.0 lt-d, which is also larger than the theoretical prediction, and p=2.0±0.7, which is in agreement with the theory within errors. SDSS1029+2326 spectra show evidence of extinction, probably produced by a galaxy in the vicinity of image C. Fitting an extinction curve to the data we estimate ΔE∼0.2 in agreement with previous results. We found no evidence of microlensing for this system
Uso de cómics para la formación médica en contenidos de migraciones internacionales y salud
(Fundación Educación Médica, 2020) Guerra-Zúñiga, María; Segovia-Chamorro, Jaime
Introducción. El estudio de las migraciones internacionales y sus relaciones con salud-enfermedad-atención en Chile es un foco relevante en la actualidad. El objetivo que se planteó fue analizar cómics efectuados por estudiantes de medicina para conocer los mensajes en ellos sobre salud y migraciones, además de la percepción respecto a su uso educativo. Sujetos y métodos. Estudio cualitativo que considera la descripción y la interpretación de cómics realizados por estudiantes de medicina de la Universidad de Valparaíso para aprobar un curso de interculturalidad y salud siguiendo los principios de análisis fotográfico. Se evalúa la percepción de su uso para el aprendizaje en la asignatura, obtenido de grupos focales, y se realiza posteriormente análisis de contenido. La participación fue anónima y voluntaria. Resultados. Los cómics dan cuenta de una realidad migratoria personificada en población haitiana. La barrera idiomática, el hacinamiento en que viven y las dificultades para encontrar trabajo o atención frente a una enfermedad dentro del sistema de salud son algunas de las características expresadas por los estudiantes. El uso de esta herramienta para la evaluación del curso fue novedoso, aunque encontró resistencia en un inicio. Favorece el trabajo en equipo y la humanización de la medicina. Da cuenta además del aprendizaje de contenidos. Conclusión. El uso de cómics en estudiantes de medicina contribuye al aprendizaje de migraciones internacionales y de salud y a la humanización de la medicina.
Dissecting the Strong-lensing Galaxy Cluster MS 0440.5+0204. I. The Mass Density Profile
(The American Astronomical Society, 2020) Foëx, Gael; Motta, Verónica
We present a parametric strong-lensing modeling of the galaxy cluster MS 0440.5+0204 (located at z = 0.19). We have performed a strong-lensing mass reconstruction of the cluster using three different models. The first model uses the image positions of four multiply imaged systems (providing 26 constraints). The second one combines strong-lensing constraints with dynamical information (velocity dispersion) of the cluster. The third one uses the mass calculated from weak lensing as an additional constraint. Our three models reproduce equally well the image positions of the arcs, with an rms image equal to ≈0farcs5. However, in the third model, the inclusion of the velocity dispersion and the weak-lensing mass allows us to obtain better constraints in the scale radius and the line-of-sight velocity dispersion of the mass profile. For this model, we obtain rs = ${132}_{-32}^{+30}$ kpc, ${\sigma }_{s}={1203}_{-47}^{+46}$ km s−1, M200 = ${3.1}_{-0.6}^{+0.6}$ ×1014 ${M}_{\odot }$, and a high concentration c200 = ${9.9}_{-1.4}^{+2.2}$. Finally, we used our derived mass profile to calculate the mass up to 1.5 Mpc. We compare it with X-ray estimates previously reported, finding a good agreement.
Evaluation of the Implementation of Li-Fi in the Communes of Santiago
(Springer Nature, 2020) González, Alvaro; Castillo, Juan C.; Carrasco, Raúl; Lagos, Carolina; Viera, Eduardo; Banguera, Leonardo; Astudillo, Gabriel
This work seeks to implement the functioning of a network communication system, this is done through visible light in the urban sectors of the metropolitan region. While it should be known that, Li-Fi (Light Fidelity) is a wireless communication system that uses visible light as a means of data propagation, becoming an alternative to wireless radio frequency systems. The multicriteria method called Elimination et Choix Traduisant la R´ealit´e (ELECTRE). An extended version of ELECTRE I method will be used to obtain a reliable result, since it is possible to obtain a decision with several alternatives, deriving a single solution from the analysis. It must be taken into account that the election process is about the correct place to implement Li-Fi connections, taking into account as a dependent variable places with a better standard of living in the Metropolitan Region, and random variables will be about areas of interest such as; physical, climatological, among others. Likewise, it must be borne in mind that the advantages, disadvantages and hierarchy are evaluated in order of preference.
Respuesta a la prueba de caminata de seis minutos en niños con riesgo cardiovascular
(Sociedad Chilena de Pediatría, 2020) Ciudad A., Daniel; Arellano, Ester; Díaz, Patricia; Donoso, Rubén; Rival, Yocelin; Rojas, Valentina; Sánchez, Nicolás; Cano-Cappellacci, Marcelo
El riesgo cardiovascular (RCV) se define como la posibilidad que tiene un sujeto de sufrir una enfermedad cardiovascular dentro de un determinado plazo de tiempo. Si bien la patología se hace sintomatica en etapa adulta, los cambios fisiopatológicos comienzan a desarrollarse en edades tempranas. Objetivo: Establecer la relación entre capacidad cardiorrespiratoria, estimada a través de la prueba de caminata de seis minutos (PC6M), y el RCV en niños con síndrome metabólico. Pacientes y Método: se analizaron 42 niños, edad 5 a 15 años, que asistieron a la Unidad de Cardiología Infantil del Hospital Carlos Van Buren entre los años 2015 y 2017. Cada participante se categorizó de acuerdo al puntaje de RCV de Alustiza, que define 3 niveles de riesgo: bajo (0 a 6 puntos), medio (7 a 8 puntos) y alto (9 o más puntos), lo que se traduciría en una mayor probabilidad de desarrollar una enfermedad cardiovascular, y realizó concomitantemente la PC6M. Resultados: La edad media del grupo de niños fue de 10,9 ± 2,7 años, con un Índice de Masa Corporal (IMC) = 31,0 ± 4,6 kg/m2 (z-score 3,2 ± 0,7). Los niños recorren 75,2 ± 8,9 por ciento de la distancia teórica, con un porcentaje de frecuencia cardíaca de reserva (FCR) = 31,0 ± 9,4. No se observaron relaciones estadísticamente significativas entre RCV y PC6M. Conclusiones: No se encuentra relación entre la capacidad cardiorrespiratoria y RCV. Se cuestiona la utilidad de la PC6M para valorar el RCV en la población de estudio.
Santiago sí es Chile: ¿cómo es el avance de la pandemia de COVID19 en regiones?
(Ciper, 2020) Guerrero, Camilo; Fuster, Nicolás; Gaete, José Manuel; Cabrera, Rodrigo; Hevia, Álvaro; Bassa, Jaime
Tacna y Arica: visualizaciones, plebiscito y nueva Frontera en La Unión de Valparaíso, 1922
(Universidad de Tarapacá, 2020) Aravena, Pablo; Cobos, Eduardo
La presente investigación tiene como propósito indagar ciertos aspectos relacionados con el discurso nacional de principios del siglo XX, centrando nuestra atención en un amplio reportaje acerca de Arica y Tacna publicado por entregas en el diario La Unión de Valparaíso en diciembre de 1922, momento de tensión diplomática entre Perú y Chile cuyo entorno era una posible definición plebiscitaria de los límites de la nueva frontera norte. Este tipo de reportajes –que basaban su efectividad en la conjunción entre imágenes fotográficas y textos– fueron utilizados como una postura periodística que se correspondía con la alianza practicada entre las políticas de chilenización del Estado y las empresas editoriales para crear y fomentar un imaginario nacionalista postguerra del Pacífico. En este sentido, la intencionalidad estratégica del reportaje de La Unión consistió en replicar una idea general preconcebida, estereotipada, que daba a entender la conveniencia de que los territorios ocupados y aún en disputa continuaran bajo el dominio de Chile, debido a que el país era el más apto para ejercer el progreso y la modernización. Estos intereses se habían tornado esenciales para la elite porteña, que fue la tribuna hacia donde apuntó en especial el diario.
Candidiasis of the tongue in cannabis users: a report of 2 cases
(Academy of General Dentistry, 2020) Ferrada, Luis Valentín; Cordero, Karina
Cannabis, a psychoactive drug widely used for medicinal, recreational, and religious purposes, can have detrimental effects on several body systems, including the respiratory, cardiovascular, and central nervous systems. The use of cannabis in cigarette form can produce a series of oral alterations, including periodontitis, caries, xerostomia, a decreased salivary pH, and an increase in the density of Candida albicans. However, the occurrence of oral candidal lesions related to cannabis use is little reported in the literature. This article reports 2 cases of oral candidiasis associated with cannabis use. The adult male patients, both of whom were systemically healthy, had white and red spots consistent with oral candidiasis on the dorsal surface of the tongue. One of the patients also had a red lesion on an area of the hard palate that was in contact with the affected area of the tongue. Neither patient was currently undergoing antibiotic or corticosteroid treatment, and both reported frequent smoking of cannabis. One patient was initially treated with an oral suspension of nystatin without clinical improvement. Miconazole gel therapy was then prescribed, and clinical improvement was observed after 2 weeks. The patient did not stop smoking cannabis, and a recurrence of oral candidiasis was observed 6 months posttreatment. Treatment with miconazole gel was repeated, resulting in resolution of the infection. The second patient declined treatment. The reported cases demonstrate that, although it is infrequently reported, oral candidiasis may occur in cannabis smokers.
The role of environment on quenching|, star formation and AGN activity
(Cambridge University Press, 2020) Poggianti, Bianca M.; Bellhouse, Callum; Deb, Tirna; Franchetto; Fritz, Jacopo; George, Koshy; Gullieuszik, Marco; Jaffé, Yara; Moretti, Alessia; Mueller, Ancla; Radovich, Mario; Ramatsok, Pati; Vulcani, Benedetta
Galaxies undergoing ram pressure stripping in clusters are an excellent opportunity to study the effects of environment on both the AGN and the star formation activity. We report here on the most recent results from the GASP survey. We discuss the AGN-ram pressure stripping connection and some evidence for AGN feedback in stripped galaxies. We then focus on the star formation activity, both in the disks and the tails of these galaxies, and conclude drawing a picture of the relation between multi-phase gas and star formation.
People living with HIV/AIDS: appraisal on dental care in Salta, Argentina
(Universidad de Antioquia, 2020) Cordero, Karina
Introduction: many patients living with HIV-AIDS (PLHIV) feel discriminated due to their disease, both socially and in health centers, including dental care. However, no current studies are available in Argentina regarding the preferences of these patients when visiting a dentist, the places where they prefer to be treated, or if they disclose their HIV(+) status, among other situations. Objective: to determine PLHIV’s appraisal on dental care in Salta, Argentina. Methods: descriptive, cross-sectional study. The study population were subjects who attended the HIV/STIs Program in the Salta Province in the period June-September 2015. Sociodemographic data, underlying disease, and dental care were collected in a survey created for this purpose. Results: 200 PLHIV were surveyed. 54% were male aged 37 years in average (IQR 29.2-45), with a median period of disease evolution of 78 months (IQR 30-126). 78% of respondents consulted a dentist in the last two years and 60% did so in public institutions. 70% perceived that their dentist has some knowledge on HIV. 50.5% disclosed their serological status to the treating professional. 87% reported that there were no prejudices during the service provided. Of the 49.6% who did not disclose their diagnosis, 55% claimed fear of discrimination. Conclusion: although PLHIV’s appraisal of dental care was positive, with no prejudices in most cases, fear of discrimination is the main reason for not informing the dentist of their diagnosis. Interdisciplinary work would help PLHIV in comprehensive care, thus avoiding one more reason for non-adherence to treatment.
Electrochemically Assisted Growth of CsPbBr3-Based Solar Cells Without Selective Contacts
(European Chemical Societies Publishing, 2020) Ramírez, Daniel; Riveros, Gonzalo; Díaz, Patricia; Verdugo, Javier; Núñez, Gerard; Lizama, Susy; Lazo, Pamela; Contreras-Bernal, Lidia; Riquelme, Antonio; Idigoras, Jesús; Dalchiele, Enrique A.; Gau, Daniel L.; Marotti, Ricardo E.; Anta, Juan A.
In this work we report a simple and cost-effective CsPbBr3- based solar cell without ordinary selective contacts. To do so we follow an electrochemical approach consisting of three successive steps: (1) electrodeposition of PbO2 directly on top of FTO substrates, (2) heterogeneous phase reaction with gaseous HBr and (3) spin-coating of methanolic CsBr solutions followed by annealing. This method is more adequate for large- scale environmentally friendly production as it reduces chemical waste, particularly toxic lead. The resulting films were structurally and optically characterized showing good coverage of the FTO substrates, absence of defects such as pinholes and orthorhombic structure. Photovoltaic and impedance characterization was carried out by pressing a carbon coated metal spring onto the CsPbBr3 film until obtaining maximized opencircuit potential (Voc) and short-circuit photocurrent density (jsc) under simulated sunlight. The stabilized current at fixed voltage (SCFV) technique gave a maximum PCE value of 2.70% close to devices with similar configuration. Impedance measurements demonstrated analogous behavior to that of state-of-art CsPbBr3 based solar cells, comprising a recombination arc at midhigh frequencies, geometrical capacitance and ideality factors closed to 2, typical of SRH recombination in the perovskite bulk.

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