19 research outputs found

    A new approach for alkali incorporation in Cu2ZnSnS4 solar cells

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    The addition of alkali elements has become mandatory for boosting solar cell performance in chalcogenide thin films based on kesterites (Cu2ZnSnS4, CZTS). A novel doping process is presented here, that consists in the incorporation of sodium or lithium during the deposition of the CdS buffer layer, followed by a post-deposition annealing (PDA). As the doping route leads to more efficient devices in comparison with the undoped reference sample, the influence of PDA temperature was also investigated. Compositional profiling techniques, time-of-flight secondary ion mass spectrometry (TOF-SIMS) and glow discharge optical mission spectroscopy (GDOES), revealed a dependence of the alkaline distribution in kesterites with the PDA temperature. Although the doping process is effective in that it increases the alkaline concentration compared to the undoped sample, the compositional profiles indicate that a significant proportion of Li and Na remains ‘trapped’ within the CdS layer. In the 200 °C-300 °C range the alkali profiles registered the higher concentration inside the kesterite. Despite this, an additional alkali accumulation close to the molybdenum/fluorine doped tin oxide substrate was found for all the samples, which is frequently related to alkali segregation at interfaces. The addition of both, lithium and sodium, improves the photovoltaic response compared to the undoped reference device. This is mainly explained by a substantial improvement in the open-circuit potential (V oc) of the cells, with best devices achieving efficiencies of 4.5% and 3% for lithium and sodium, respectively. Scanning-electron microscopy images depicted a ‘bilayer structure’ with larger grains at the top and small grains at the bottom in all samples. Moreover, the calculated bandgap energies of the CZTS films account for changes in the crystallographic order-disorder of the kesterites, more related to the PDA treatment rather than alkali incorporation. Even if further optimization of the absorber synthesis and doping process will be required, this investigation allowed the evaluation of a novel strategy for alkali incorporation in kesterite based solar cells.Fil: Valdes, Matias Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Hernandez, A.. Catalonia Institute For Energy Research Irec; EspañaFil: Sánchez, Y.. Catalonia Institute For Energy Research Irec; EspañaFil: Fonoll, R.. Catalonia Institute For Energy Research Irec; EspañaFil: Placidi, M.. Universidad Politécnica de Catalunya; España. Catalonia Institute For Energy Research Irec; EspañaFil: Izquierdo, V.. Catalonia Institute For Energy Research Irec; EspañaFil: Cabas Vidani, A.. Swiss Federal Laboratories for Materials Science and Technology; SuizaFil: Valentini, M.. Enea Centro Ricerche Casaccia; ItaliaFil: Mittiga, A.. Enea Centro Ricerche Casaccia; ItaliaFil: Pistor, P.. Universidad Pablo de Olavide; EspañaFil: Malerba, C.. Enea Centro Ricerche Casaccia; ItaliaFil: Saucedo, E.. Universidad Politécnica de Catalunya; Españ

    Alternative splicing: the pledge, the turn, and the prestige

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    Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

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    Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life

    {'en_US': 'Relationship between complications and the quality of life of the patient on hemodialysis', 'es_ES': 'Relación entre las complicaciones y la calidad de vida del paciente en hemodiálisis'}

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    Introducción: Los pacientes con Enfermedad Renal Crónica (ERC) son tratados con terapias de diálisis. Dentro de este tipo de tratamiento se encuentran la Diálisis Peritoneal (DP) y Hemodiálisis (HD). Los pacientes sometidos a HD tienen una evolución imprevisible por las complicaciones del tratamiento y/o complicaciones propias de la ERC. Estas aumentan el número de hospitalizaciones y deterioran la calidad de vida (CV). Objetivos: Evaluar la calidad de vida de pacientes en hemodiálisis y determinar la asociación entre las complicaciones y la CV. Material y Método: Estudio transversal analítico en 157 pacientes en HD (75 hombres, 82 mujeres), mayores de 18 años y con más de 3 meses en tratamiento. La CV se evaluó con el instrumento KDQOL-36, el cual, mide 5 dimensiones en escala del 0 al 100. Se realizó un análisis bivariado, ANOVA y regresión múltiple para evaluar la relación de cada una de las dimensiones con edad, sexo, ocupación, estado civil, escolaridad, tipo de acceso venoso, tiempo con la ERC, con la HD y complicaciones de la ERC y la HD. Resultados: La edad promedio fue de 50.9 años. El 77% de los participantes presentaron complicaciones, 69.4% por HD, 5% por evolución de la ERC y 25.6% ambas complicaciones. En el análisis multivariado se encontró que la presencia de ambas complicaciones deteriora más la calidad de vida que las ocasionadas únicamente por el tratamiento de HD. Conclusión: Las complicaciones del tratamiento de hemodiálisis aunadas a las de la ERC deterioran  la calidad de vida del paciente

    Recombinant Adenovirus Delivery of Calreticulin-ESAT-6 Produces an Antigen-Specific Immune Response but no Protection Against a Mycobacterium Tuberculosis Challenge

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    Bacillus CalmetteGuerin (BCG) has failed to efficaciously control the worldwide spread of the disease. New vaccine development targets virulence antigens of Mycobacterium tuberculosis that are deleted in Mycobacterium bovis BCG. Immunization with ESAT-6 and CFP10 provides protection against M. tuberculosis in a murine infection model. Further, previous studies have shown that calreticulin increases the cell-mediated immune responses to antigens. Therefore, to test whether calreticulin enhances the immune response against M. tuberculosis antigens, we fused ESAT-6 to calreticulin and constructed a recombinant replication-deficient adenovirus to express the resulting fusion protein (AdCRTESAT-6). The adjuvant effect of calreticulin was assayed by measuring cytokine responses specific to ESAT-6. Recombinant adenovirus expressing the fusion protein produced higher levels of interferon-gamma and tumour necrosis factor-a in response to ESAT-6. This immune response was not improved by the addition of CFP-10 to the CRT-ESAT-6 fusion protein (AdCRTESAT-6CFP10). Mice immunized with these recombinant adenoviruses did not decrease the mycobacterial burden after low-dose aerosol infection with M. tuberculosis. We conclude that calreticulin can be used as an adjuvant to enhance the immune response against mycobacterial antigens, but it is not enough to protect against tuberculosis
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