Ikastorratza. e-Revista de didáctica

Resumen y palabras clave en español y en inglésResumen basado en el de la publicaciónLa herramienta EduQuim ha sido estructurada en Moodle con la modalidad de B-learning a fin de realizar investigación en la enseñanza y el aprendizaje de la Química en el estudiantado de educación media. En esta herramienta se implementan las teorías del aprendizaje a través de lecciones animadas, minijuegos, ejercicios interactivos, evaluaciones formales, encuestas, chats y foros, lo que le da a la misma un carácter dinámico, participativo y comunicativo con el alumnado. Además, se realizó una evaluación de la actitud y la percepción del estudiantado y del profesorado frente a la lección animada, Materia, mediante encuestas y entrevistas. Los resultados mostraron opiniones muy favorables en lo referente a la claridad, comprensión y explicaciones, tanto del alumnado como del profesorado. El alumnado sugirió correcciones en el sonido y en los personajes.ES

Assessment in the competition between steric and electronic effects in the elimination kinetic of hydrogen in 1,4-cyclohexadienes in the gas phase. Quantum chemical theory calculations

<div><p>The mechanisms of gas-phase thermal decomposition of alkyl-substituted cyclohexadienes were studied by the means of quantum chemical calculations with theory levels Møller-Plesset pertubation theory (MP2) and density functional theory (DFT) (B3LYP, MPW1PW91, PBEPBE, ωB97XD, CAM-B3LYP, M06, and M062X) with 6-31G(d,p), 6-31++G(d,p) basis sets. The examination of the reaction pathways of each substrate demonstrated a molecular mechanism through six-membered cyclic boat-like transition state (TS) structure. An alkyl group substituent causes a detrimental effect on the reaction rate, compared to the parent compound 1,4-cyclohexadiene; however, the reaction was favoured in the case of 3,6-dimethyl substitution. The 3,6-dimethyl-1,4-cyclohexadiene compound has activation energy 11.2 kJ/mol lower than the reference compound, which overcomes the effect of the most negative entropy of activation in the series. The effects of alkyl substituents in these reactions suggest a complex combination of electronic and steric influence. These reactions are characterised as highly synchronous concerted, with small predominance of C–H bond breaking in the TS.</p></div

Magnesium salts in pregnancy

Background: Magnesium is one of the most abundant elements in the body. Although the total serum magnesium content does not represent more than 1% of total body magnesium, serum magnesium determinations have been routinely used in clinical practice to assess body magnesium status. Thus, serum magnesium concentration ranges from 1.8 to 2.2 mg.dl−1 (0.75–0.95 mmol.l − 1 or 1.5–1.9 mEq.l − 1). Consequently, when serum magnesium levels fall below the range considered normal, the patient is diagnosed with hypomagnesemia. This deficiency has been associated with low-grade systemic inflammation, increased levels of proinflammatory molecules, mitochondrial dysfunction, increased reactive oxygen species production, and hypertriglyceridemia leading to an increase in the number of easily oxidizable lipoproteins in the circulation. Results: Several magnesium salts have been used to treat hypomagnesemia during pregnancy, with magnesium sulfate (MgSO4) being the most commonly used magnesium salt in current obstetric practice. However, the exact mechanism of action of MgSO4 remains largely an enigma, and its parenteral use poses a significant toxicological risk at high doses. In this review, we summarize the use of magnesium salts during pregnancy not only from a clinical point of view but also, with the use of computational simulations, discuss advances in the understanding of the molecular mechanisms of action of magnesium salts, with emphasis on MgSO4. These molecular simulations are required to unveil the pharmacological action of the magnesium salts during pregnancy. Conclusions: MgSO4 plays a role as an antioxidant agent at the plasma membrane level which can explain the mechanism of action of this salt in current obstetric practice