Mechanism of Catalytic Water Oxidation by the Ruthenium Blue Dimer Catalyst: Comparative Study in D2O versus H2O

Water oxidation is critically important for the development of energy solutions based on the concept of artificial photosynthesis. In order to gain deeper insight into the mechanism of water oxidation, the catalytic cycle for the first designed water oxidation catalyst, cis,cis-[(bpy)2(H2O)RuIIIORuIII(OH2)(bpy)2]4+ (bpy is 2,2-bipyridine) known as the blue dimer (BD), is monitored in D2O by combined application of stopped flow UV-Vis, electron paramagnetic resonance (EPR) and resonance Raman spectroscopy on freeze quenched samples. The results of these studies show that the rate of formation of BD[4,5] by Ce(IV) oxidation of BD[3,4] (numbers in square bracket denote oxidation states of the ruthenium (Ru) centers) in 0.1 M HNO3, as well as further oxidation of BD[4,5] are slower in D2O by 2.1–2.5. Ce(IV) oxidation of BD[4,5] and reaction with H2O result in formation of an intermediate, BD[3,4]′, which builds up in reaction mixtures on the minute time scale. Combined results under the conditions of these experiments at pH 1 indicate that oxidation of BD[3,4]′ is a rate limiting step in water oxidation with the BD catalyst

Errores de medicación en niños que acuden a los servicios de urgencias pediátricas

Errores de medicación; Servicios de urgencias; PediatríaMedication errors; Emergency departments; PediatricsErrors de medicació; Servei d'urgències; PediatriaObjectives: Medication safety represents an important challenge in children. There are limited studies on medication errors in pediatric patients visiting emergency departments. To help bridge this gap, we characterized the medication errors detected in these patients, determining their severity, the stages of the medication process in which they occurred, the drugs involved, and the types and causes associated with the errors. Methods: We conducted a multicenter prospective observational study in the pediatric emergency departments of 8 Spanish public hospitals over a 4-month period. Medication errors detected by emergency pediatricians in patients between 0 and 16 years of age were evaluated by a clinical pharmacist and a pediatrician. Each medication error was analyzed according to the updated Spanish Taxonomy of Medication Errors. Results: In 99,797 visits to pediatric emergency departments, 218 (0.2%) medication errors were detected, of which 74 (33.9%) resulted in harm (adverse drug events). Preschoolers were the age group with the most medication errors (126/218). Errors originated mainly in the prescribing stage (66.1%), and also by self-medication (16.5%) and due to wrong administration of the medication by family members (15.6%). Dosing errors (51.4%) and wrong/improper drugs (46.8%) were the most frequent error types. Anti-infective drugs (63.5%) were the most common drugs implicated in medication errors with harm. Underlying causes associated with a higher proportion of medication errors were "medication knowledge deficit" (63.8%), "deviation from procedures/guidelines" (48.6%) and "lack of patient information" (30.3%). Conclusions: Medication errors presented by children attending emergency departments arise from prescriptions, self-medicationand administration, and lead to patient harm in one third of cases. Developing effective interventions based on the types of errors and the underlying causes identified will improve patient safety.Objetivos La seguridad de medicamentos en pediatría supone un verdadero reto. Se dispone de escasos estudios que hayan analizado los errores de medicación en los pacientes pediátricos que acuden a los servicios de urgencias. El objetivo de este estudio ha sido caracterizar los errores detectados en estos pacientes, determinando su severidad, los procesos afectados, los medicamentos implicados, y los tipos de errores y causas asociados. Métodos Estudio multicéntrico observacional prospectivo realizado en los servicios de urgencias de 8 hospitales públicos españoles durante 4 meses. Los errores de medicación detectados por los pediatras de urgencias en pacientes entre 0 y 16 años fueron evaluados por un farmacéutico y un pediatra. Los errores de medicación fueron analizados utilizando la Taxonomía Española de Errores de Medicación actualizada. Resultados En 99.797 visitas a urgencias se detectaron 218 (0,2%) errores de medicación, de los cuales 74 (33,9%) causaron daños (eventos adversos por medicamentos). Los preescolares fueron el grupo poblacional con mayor número de errores de medicación (126/218). Los errores se originaron mayoritariamente en la prescripción (66,1%), por automedicación (16,5%) y por administración equivocada por parte de familiares (15,6%). Los tipos de errores más frecuentes fueron “dosis incorrectas” (51,4%) y “medicamento inapropiado” (46,8%). Los antiinfecciosos (63,5%) fueron los fármacos más comúnmente implicados en los errores con daño. Las causas subyacentes asociadas a una mayor proporción de errores de medicación fueron: “falta de conocimiento del medicamento” (63,8%), “falta de seguimiento de los procedimientos” (48,6%) y “falta de información del paciente” (30,3%). Conclusiones Los errores de medicación en la población pediátrica que acude a urgencias se producen en la prescripción, por automedicación y en la administración, provocando daños a los pacientes en un tercio de las ocasiones. Desarrollar prácticas seguras basadas en los tipos de errores detectados y sus causas subyacentes, mejorará la seguridad de los pacientes.This study has been carried out with the support of a grant provided by the Spanish Society of Hospital Pharmacists for the period 2015–2016

Functional diversification gave rise to allelic specialization in a rice NLR immune receptor pair

Cooperation between receptors from the nucleotide-binding, leucine-rich repeats (NLR) superfamily is important for intracellular activation of immune responses. NLRs can function in pairs that, upon pathogen recognition, trigger hypersensitive cell death and stop pathogen invasion. Natural selection drives specialization of host immune receptors towards an optimal response, whilst keeping a tight regulation of immunity in the absence of pathogens. However, the molecular basis of co-adaptation and specialization between paired NLRs remains largely unknown. Here, we describe functional specialization in alleles of the rice NLR pair Pik that confers resistance to strains of the blast fungus Magnaporthe oryzae harbouring AVR-Pik effectors. We revealed that matching pairs of allelic Pik NLRs mount effective immune responses, whereas mismatched pairs lead to autoimmune phenotypes, a hallmark of hybrid necrosis in both natural and domesticated plant populations. We further showed that allelic specialization is largely underpinned by a single amino acid polymorphism that determines preferential association between matching pairs of Pik NLRs. These results provide a framework for how functionally linked immune receptors undergo co-adaptation to provide an effective and regulated immune response against pathogens. Understanding the molecular constraints that shape paired NLR evolution has implications beyond plant immunity given that hybrid necrosis can drive reproductive isolation

Splitting CO2 into CO and O2 by a single catalyst

The metal complex [(tpy)(Mebim-py)RuII(S)]2+ (tpy = 2,2′ : 6′,2′′-terpyridine; Mebim-py = 3-methyl-1-pyridylbenzimidazol-2-ylidene; S = solvent) is a robust, reactive electrocatalyst toward both water oxidation to oxygen and carbon dioxide reduction to carbon monoxide. Here we describe its use as a single electrocatalyst for CO2 splitting, CO2 → CO + 1/2 O2, in a two-compartment electrochemical cell

Base-enhanced catalytic water oxidation by a carboxylate–bipyridine Ru(II) complex

Development of rapid, robust water oxidation catalysts remains an essential element in solar water splitting by artificial photosynthesis. We report here dramatic rate enhancements with added buffer bases for a robust Ru(II) polypyridyl catalyst with a calculated half-time for water oxidation of ∼7 μs in 1.0 M phosphate. The results of detailed kinetic studies provide insight into the water oxidation mechanism and an important role for added buffer bases in accelerating water oxidation by concerted atom–proton transfer

Ethics guidelines for the creation and use of registries for biomedical research purposes

The clinical information stored in registries and records of different types is a fundamental tool for biomedical research. Up until just a few years ago, hardly any limitations existed on the creation and use of epidemiological registries or the use of information from pre-existing records for research purposes. This situation has changed substantially due mainly to the growing importance current laws place upon the safeguarding of the privacy and confidentiality of personal data. Although the legal framework is already quite explicit, a certain degree of leeway exists for ethical debate and prudence advice for the purpose of conducting valid, useful research with this information which will also respect the rights of the subjects and the laws in force. These guidelines deal with those aspects which have been considered relevant from an ethical standpoint in the handling of records and registries for research-related purposes, including not only the use but also the creation proper of the registries. A total of twenty-four recommendations are provided, grouped into ten sections: warranting of the creation of registry, organization and definition of responsibilities, scientific validity of the research project, ethical requirements of the collections of anonymous and anonymized data, ethical requirements of the registries including personal data, uses of medical records for research purposes, use of historical records of deceased individuals, contact with the research subjects, notification of results and review by a Research Ethics Committee. La información clínica almacenada en registros de diverso tipo constituye una herramienta fundamental para la investigación biomédica. Hasta hace pocos años la creación y uso de registros epidemiológicos, o la utilización de información procedente de registros pre-existentes con fines de investigación, apenas tenía limitaciones. Esta situación ha cambiado de modo sustancial debido básicamente a la creciente importancia que las leyes actuales conceden a la protección de la intimidad, la privacidad y la confidencialidad de los datos de carácter personal. Aunque el marco legal es ya muy explícito, hay un cierto espacio para la deliberación ética y el consejo prudente, al objeto de realizar con dicha información una investigación válida y útil y que, al mismo tiempo, respete los derechos de los sujetos y la legalidad vigente. En las presentes directrices se abordan aquellos aspectos que se han considerado relevantes desde un punto de vista ético en el manejo de registros con fines de investigación, incluyendo no sólo el uso sino la creación misma del registro. Se proporcionan 24 recomendaciones agrupadas en 10 apartados: justificación de la creación de un registro, organización y definición de responsabilidades, validez científica del proyecto de investigación, requisitos éticos de las colecciones de datos anónimos y de los registros anonimizados, requisitos éticos de los registros que contienen datos de carácter personal, usos de la historia clínica con fines de investigación, uso de registros históricos y de personas fallecidas, contacto con los sujetos de investigación, comunicación de resultados y revisión por un Comité de Ética de la Investigación

A Customized Pigmentation SNP Array Identifies a Novel SNP Associated with Melanoma Predisposition in the SLC45A2 Gene

As the incidence of Malignant Melanoma (MM) reflects an interaction between skin colour and UV exposure, variations in genes implicated in pigmentation and tanning response to UV may be associated with susceptibility to MM. In this study, 363 SNPs in 65 gene regions belonging to the pigmentation pathway have been successfully genotyped using a SNP array. Five hundred and ninety MM cases and 507 controls were analyzed in a discovery phase I. Ten candidate SNPs based on a p-value threshold of 0.01 were identified. Two of them, rs35414 (SLC45A2) and rs2069398 (SILV/CKD2), were statistically significant after conservative Bonferroni correction. The best six SNPs were further tested in an independent Spanish series (624 MM cases and 789 controls). A novel SNP located on the SLC45A2 gene (rs35414) was found to be significantly associated with melanoma in both phase I and phase II (P<0.0001). None of the other five SNPs were replicated in this second phase of the study. However, three SNPs in TYR, SILV/CDK2 and ADAMTS20 genes (rs17793678, rs2069398 and rs1510521 respectively) had an overall p-value<0.05 when considering the whole DNA collection (1214 MM cases and 1296 controls). Both the SLC45A2 and the SILV/CDK2 variants behave as protective alleles, while the TYR and ADAMTS20 variants seem to function as risk alleles. Cumulative effects were detected when these four variants were considered together. Furthermore, individuals carrying two or more mutations in MC1R, a well-known low penetrance melanoma-predisposing gene, had a decreased MM risk if concurrently bearing the SLC45A2 protective variant. To our knowledge, this is the largest study on Spanish sporadic MM cases to date

Mediator-assisted water oxidation by the ruthenium “blue dimer” cis,cis-[(bpy)2(H2O)RuORu(OH2)(bpy)2]4+

Light-driven water oxidation occurs in oxygenic photosynthesis in photosystem II and provides redox equivalents directed to photosystem I, in which carbon dioxide is reduced. Water oxidation is also essential in artificial photosynthesis and solar fuel-forming reactions, such as water splitting into hydrogen and oxygen (2 H2O + 4 hν → O2 + 2 H2) or water reduction of CO2 to methanol (2 H2O + CO2 + 6 hν → CH3OH + 3/2 O2), or hydrocarbons, which could provide clean, renewable energy. The “blue ruthenium dimer,” cis,cis-[(bpy)2(H2O)RuIIIORuIII(OH2)(bpy)2]4+, was the first well characterized molecule to catalyze water oxidation. On the basis of recent insight into the mechanism, we have devised a strategy for enhancing catalytic rates by using kinetically facile electron-transfer mediators. Rate enhancements by factors of up to ≈30 have been obtained, and preliminary electrochemical experiments have demonstrated that mediator-assisted electrocatalytic water oxidation is also attainable