Correction: Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance.

Correction for 'Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance' by Alejandra Gomez-España et al., Dalton Trans., 2023, 52, 6722-6729, https://doi.org/10.1039/d3dt00744h.

Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance.

The iridium(III) complexes [Ir(H)(Cl)(κ2-NSitBu2)(κ2-bipyMe2)] (2) and [Ir(H)(OTf)(κ2-NSitBu2)(κ2-bipyMe2)] (3) (NSitBu2 = {4-methylpyridine-2-yloxy}ditertbutylsilyl) have been synthesized and characterized including X-ray studies of 3. A comparative study of the catalytic activity of complexes 2, 3, [Ir(H)(OTf)(κ2-NSitBu2)(coe)] (4), and [Ir(H)(OTf)(κ2-NSitBu2)(PCy3)] (5) (0.1 mol%) as catalysts precursors for the solventless formic acid dehydrogenation (FADH) in the presence of Et3N (40 mol%) at 353 K has been performed. The highest activity (TOF5 min ≈ 3260 h-1) has been obtained with 3 at 373 K. However, at that temperature the FTIR spectra show traces of CO together with the desired products (H2 and CO2). Thus, the best performance was achieved at 353 K (TOF5 min ≈ 1210 h-1 and no observable CO). Kinetic studies at variable temperature show that the activation energy of the 3-catalyzed FADH process is 16.76 kcal mol-1. Kinetic isotopic effect (5 min) values of 1.6, 4.5, and 4.2 were obtained for the 3-catalyzed dehydrogenation of HCOOD, DCOOH, and DCOOD, respectively, at 353 K. The strong KIE found for DCOOH and DCOOD evidenced that the hydride transfer from the C-H bond of formic acid to the metal is the rate-determining step of the process.

Correction: Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance.

Correction for 'Iridium-(κ2-NSi) catalyzed dehydrogenation of formic acid: effect of auxiliary ligands on the catalytic performance' by Alejandra Gomez-España et al., Dalton Trans., 2023, https://doi.org/10.1039/d3dt00744h.

Estudios de casos con la utilización del enfoque de “matriz de riesgos” para prevenir accidentes en tratamientos de radioterapia / Case studies on the use of the "risk matrix" approach for accident prevention in radiotherapy

RESUMEN La radioterapia de haces externos es la única práctica en la cual los seres humanos son colocados directamente en un haz de radiación con la intención de administrar altas dosis. Los accidentes que han ocurrido en el mundo en esta práctica muestran la necesidad de hacer análisis de seguridad capaces de identificar medidas preventivas para minimizar las consecuencias de las exposiciones accidentales. El enfoque de la matriz de riesgo es un método semicuantitativo para evaluar la probabilidad de ocurrencia del accidente y la severidad de sus consecuencias mediante escalas, y definir criterios de aceptabilidad en base al riesgo. Para cada secuencia accidental que es identificada nos preguntamos: cuán frecuente es, cuán severa son sus consecuencias y cuáles medidas de seguridad existen para evitar dicha secuencia. A partir de las respuestas a estas preguntas se puede obtener el riesgo resultante haciendo uso de la tabla de la “Matriz de Riesgo”. En esta investigación se aplicó el método para realizar el estudio de tres casos (departamentos de radioterapia reales). El estudio de caso permitió identificar las debilidades más importantes de los servicios de radioterapia y proponer medidas para reducir el riesgo de accidentes. El método tiene valor práctico y es asequible a nivel de hospitales. Este enfoque permite a los reguladores perfeccionar la calidad de sus inspecciones y el rigor de las evaluaciones que se realizan para otorgar la licencia de operación de las entidades que realizan la práctica de la radioterapia.

ABSTRACT External beam radiotherapy is the only practice during which humans are directly exposed to a radiation beam to receive high doses. Accidental exposures have occurred throughout the world, thus showing the need for systematic safety assessments, capable to identify preventive measures and to minimize consequences of accidental exposure. The ‘risk matrix’ approach is a semi quantitative method to evaluate the likelihood and the severity of events by means of a scale, and defines acceptability criteria on the basis of the risk. For each accident sequence identified, the following questions come up: how often is it?, how severe are the consequences? and, what safety measures should be taken to prevent it?. From these answers we can obtain the resulting risk by using the "Risk Matrix" table. In this study we have used this method to conduct the study in 3 cases (real radiotherapy departments). The case study identified the major weaknesses in radiotherapy service and proposed measures to reduce the risk of accidents. The method is practical and it could be applied in hospitals. This approach allows regulators to improve the quality of their inspections and the rigor of the assessments made to grant the operating license to the entities working with radiotherapy.

Management of pediatric maxillary fractures.

BACKGROUND: Maxillary trauma in pediatric patients is a challenge to health care professionals. The successful treatment and extended care of pediatric maxillary fractures requires multiple considerations. METHODS: This review of the current literature investigates all components of management to provide optimal outcome. Specifically, pediatric management distinctions are discussed for both facial reconstruction and rehabilitation. The current etiology, incidence, classification of injury, and methods to diagnose and treat these patients is outlined. CONCLUSIONS: Pediatric maxillofacial fractures remain a challenging problem. The management of this patient population includes comprehensive knowledge of pediatric maxillofacial growth and development, available reduction techniques, biocompatible materials, and duration of the selected therapy.