Structural evolution, optical gap and thermoelectric properties of CH3NH3SnBr3 hybrid perovskite, prepared by mechanochemistry

Direct bandgap semiconductors of the hybrid-perovskite family CH3NH3PbX3 (X = I, Br, Cl) exhibit outstanding light absorption properties and are the materials of choice for solar energy applications. As an alternative to poisonous Pb, tin-containing perovskites would show a lower effective mass thus exhibiting a higher charge carrier mobility. An auspicious candidate is CH3NH3SnBr3, with an estimated band gap of 1.902 eV, anticipating applications in photovoltaic devices for the visible to ultra-violet wavelength region. We describe that this perovskite can be prepared by ball milling in a straightforward way, yielding specimens with a superior crystallinity. A structural investigation from synchrotron X-ray powder diffraction (SXRD) data was essential to revisit the successive phase transitions this compound experiences down to 120 K, guided by specific heat capacity and DSC measurements. From the cubic structure identified at RT and 270 K, there is a gradual evolution of the patterns, analysed as a phase admixture between the cubic and the low-symmetry phase present at 160 K. This corresponds to an orthorhombic Pmc21 superstructure; this acentric space group enables polarization along the c-axis where there is a twofold screw axis, evidenced in the distribution of Sn-Br distances. Furthermore, there are two conspicuous changes in the orthorhombic framework, yet keeping the Pmc21 space group, which agree with the main calorimetric events (observed at 224 and 147 K). We interpret these changes as an interplay between the tilting of the SnBr6 octahedra of the inorganic framework and the breaking and reconstruction of H-bond interactions with the organic CH3NH+3 unit. The stereochemical effect of the lone electron pair of the Sn2+ ion is clear in the SnBr6 octahedral distortion. Diffuse reflectance UV/Vis spectroscopy yields an optical gap of ∼2.1 eV, in agreement with ab- initio calculations. A Seebeck coefficient of ∼2000 μV K-1 is determined near RT, which is one order of magnitude higher than those reported for other halide perovskites.Fil: Lopez, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentina. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Abia, Carmen. Institut Laue Langevin; Francia. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Gainza, Javier. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Kayser, Paula. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Nemes, Norbert. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Dura, Oscar J.. Universidad de Castilla-La Mancha; EspañaFil: Martinez, Jose L.. Instituto de Ciencia de Materiales de Madrid; EspañaFil: Fernandez Diaz, Maria Teresa. Institut Laue Langevin; FranciaFil: Alvarez Galvan, M. Consuelo. Consejo Superior de Investigaciones Científicas; EspañaFil: Alonso, José Antonio. Instituto de Ciencia de Materiales de Madrid; Españ

Calidad de las elecciones a titular del Ejecutivo en el Centro y Centro-occidente de México

Este libro, que tiene por objetivo analizar la calidad de las elecciones celebradas entre 2006 y 2011 para ocupar la titularidad del Poder Ejecutivo de las 14 entidades federativas de la República Mexicana que conforman las regiones Centro y Centro-occidente de este país, ha sido elaborado por investigadores pertenecientes a la Red Nacional de Investigación sobre la Calidad de la Democracia en México (Renicadem), la cual cuenta con un equipo de investigación en cada una de las entidades federativas del país. A su vez, esta Red constituye una de las cuatro líneas temáticas que componen la red temática del Conacyt “Sociedad civil y calidad de la democracia”. Con todo, la presente obra puede considerarse, en dos sentidos, como el resultado parcial de estudios realizados por investigadores que conforman la mencionada Renicadem. Por un lado, trata sólo de una de las varias dimensiones que esta Red ha establecido como necesarias para analizar la calidad de la democracia: la calidad electoral (otras dimensiones, que se encuentran en proceso de investigación, son calidad de vida, rendición de cuentas y Estado de derecho). También es parcial porque no abarca la totalidad de la República Mexicana, sino únicamente a las 14 entidades indicadas.UAE

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Evaluación de la satisfacción con el tratamiento farmacológico en personas con hipertensión arterial

Background: Medication satisfaction is a patientcentered measure that helps predict the continuity of treatment, correct use and therapeutic compliance. The objective has been to evaluate the satisfaction with the treatment (ST) of subjects with arterial hypertension (HT) and find out if the type of treatment, the state of health and the personal characteristics are related to the satisfaction. Methods: Observational cross-sectional study conducted in the community pharmacy field. A total of 484 users of antihypertensive medication were evaluated (response rate: 81.6%). The ST was evaluated through the Treatment Satisfaction with Medicines. In the statistical analysis, means comparison and correlation tests were used to verify the existence of associations between the ST level and the different variables, considering a significance level of p<0.05. Likewise, a multiple linear regression model was constructed to identify the associated variables avoiding possible confounding factors. Results: In a range of 0-100 the mean ST value was 79.9 (SD=12.9, 95% CI= 78.8-81.0). A weak correlation was observed between perceived health score and ST (r= 0.145, p=0.001). ST was higher in subjects with controlled BP (82.1 ±12.1 SD vs 77.5 ±13.3 SD, p<0.001), in treated subjects over 5 years (83.5 ±12.8 SD vs 78.5 ±12.6 SD; p<0.001), in subjects without adverse effects (82.5 ±11.6 SD vs 68.7 ±11.9 SD; p<0.001) and in lower social classes (81.2 ±12.8 SD vs 78.5 ±12.8 SD, p=0.02). It was lower in the non-compliers with the treatment (73.2 ±12.9 vs 82.1 ±12.1, p<0.001). Conclusions: The ST level is acceptable, despite insufficient BP control and the high rate of noncompliance. Satisfaction is conditioned both by effectiveness and by therapeutic adherence, although health status, treatment and personal characteristics also intervene.Fundamentos: La satisfacción con la medicación constituye una medida centrada en el paciente que ayuda a predecir la continuidad del tratamiento, su uso correcto y el cumplimiento terapéutico. El objetivo de este estudio fue evaluar la satisfacción con el tratamiento (ST) de sujetos con hipertensión arterial (HTA), así como averiguar si el tipo de tratamiento, el estado de salud y las características personales guardan relación con el nivel de satisfacción. Sujetos y métodos: Se elaboró un estudio observacional de carácter transversal, realizado en el ámbito de la farmacia comunitaria. Fueron evaluados 484 consumidores de medicación antihipertensiva (tasa de respuesta del 81,6%). La ST fue evaluada mediante el Treatment Satisfaction with Medicines Questionnaire. Otras variables fueron la presión arterial (PA), los fármacos antihipertensivos, los efectos adversos, otros medicamentos, la comorbilidad, la salud autopercibida, el cumplimiento y las características personales. En el análisis estadístico se utilizaron pruebas de comparación de medias y de correlación para comprobar asociaciones entre el nivel de ST y las diferentes variables, considerando un nivel de significación de p<0,05. Así mismo, se construyó un modelo de regresión lineal múltiple para identificar las variables asociadas, evitando posibles factores de confusión. Resultados: En un rango entre 0 y 100, el valor medio de ST fue de 79,9 (DE=12,9; IC 95%=78,8-81,0). Se observó una débil correlación entre la puntuación en salud percibida y la ST (r=0,145; p=0,001). La ST fue superior en los sujetos con PA controlada (82,1 ±12,1 DE frente a 77,5 ±13,3 DE; p<0,001), en los tratados durante más de 5 años (83,5 ±12,8 DE frente a 78,5 ±12,6 DE; p<0,001), en los sujetos sin efectos adversos (82,5 ±11,6 DE frente a 68,7 ±11,9 DE; p<0,001) y en las clases sociales inferiores (81,2 ±12,8 DE frente a 78,5 ±12,8 DE; p=0,02). Fue inferior en los incumplidores con el tratamiento (73,2 ±12,9 frente a 82,1 ±12,1; p<0,001). Conclusiones: El nivel de ST es aceptable, a pesar del insuficiente control de las cifras de PA y a la elevada proporción de incumplimiento. La satisfacción está condicionada tanto por la efectividad como por la adherencia terapéutica, aunque también intervienen el estado de salud, el tratamiento y las características personales

Adaptacion transcultural al espanol y validez de contenido de 3 escalas de riesgo nutricional

Introduction: There are various scales designed to determine the risk of malnutrition at hospital admission in children. However, most of these instruments are developed and published in English. Their cross-cultural adaptation and validation being mandatory in order to be used in our country. Objectives: Cross-culturally adapt three scales designed to determine the risk of malnutrition linked to the disease and determine the validity of their content. Material and methods: Cross-cultural adaptation using the translation-back-translation met-hod in accordance with the recommendations of the International Test Commission Guidelines for Translating and Adapting Tests. Content validity was measured by a panel of experts (under seven basic selection criteria adapted from the Fehring model) who evaluated each item of the scales by measuring 4 criteria: ambiguity, simplicity, clarity and relevance. With the extracted score, Aiken's V statistic was obtained for each item and for the complete scales. Results: Starting from three independent translations per scale, 3 definitive versions in Spanish of the PNRS, STRONGkids and STAMP scales were obtained semantically equivalent to their original versions. The PNRS and STRONGkids scales presented an Aiken's V greater than 0.75 in all their items, while the STAMP scale presented a value less than 0.75 for the item "weight and height". Conclusion: This study provides the transculturally adapted Spanish versions of the PNRS, STRONGkids and STAMP scales. The PNRS and STRONGkids scales present valid content to be applied in the state hospital context. STAMP requires the adaptation of its item "weight and height" to consider its use in a Spanish child population adequate. (c) 2021 Asociacion Espanola de Pediatr?? acute accent a. Published by Elsevier Espana, S.L.U. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/)