OPLS multivariate regression of FTIR-ATR spectra of acrylic paints for age estimation in contemporary artworks.

In recent years the interest and demand for artworks has been increasing as they are an interesting commercial investment due to their growing value in the market. This explains the increasing number of counterfeits dealing with artworks that has led to the development of new methodologies for their characterization. The material characterization of these types of works can provide relevant information for both authentication and conservation/restoration. Thus, in this study multivariate chemometric methods were applied to FTIR-ATR spectroscopic data for artwork dating purposes. To that end, ageing prediction models were developed for Liquitex® and Hyplar® brands. Paint samples containing the green synthetic organic pigment (PG7), were exposed to artificial ageing and analysed with FTIR-ATR and Py-GC/MS for characterization and monitorization of the main components (binding medium, pigment and additives). Although the OPLS ageing models were mainly characterized by the modifications suffered by both the binder and the surfactants, a universal model could not be developed due to differences in the modification trends of the different brands. The applicability of the OPLS modelling for artwork dating purposes was tested in artworks provided by internationally recognized contemporary Basque artists. For Liquitex® a significant correlation (p < 0.05) between natural and accelerated ageing could be established, in which approximately 50 h of accelerated ageing under the applied conditions were equivalent to one natural year. This correlation might have possible applications in the dating of artworks for up to at least 22 years. Thus, the study demonstrates that FTIR-ATR combined with chemometrics is a potential method for artwork dating and a valuable source of information about the chemical processes involved in paint ageing, which can be of great help in the conservation and restoration steps.

Investigating low-valent compositions in the Na3V2O2x(PO4)2F3-2x family: structural transitions and their consequences.

A member of the family of compounds with the formula Na3V2O2x(PO4)2F3-2x is synthesized by carbothermal reduction and 2 consecutive hydrothermal processes. The initial structural and spectroscopic characterization indicates that there are two phases in the as-synthesized material, a mixed valent phase with an intermediate V oxidation state adopting a P42/mnm space group at about 66%, and another phase with a V oxidation state close to V3+ adopting an Amam space group at about 33%. The role of each species in the electrode function is interrogated using in situ synchrotron X-ray diffraction and these data indicate that soon after charge begins, the Amam phase transforms into the P42/mnm phase. Further structural evolution of the material shows a prevailing two-phase reaction at lower potentials and a significant solid solution region during the high potential feature in the electrochemical curve with a final two-phase region at the end of charge. The conversion of the Amam component into P42/mnm showed no reversibility upon discharge. This phase-mixed electrode appears to illustrate that the mixed valent P42/mnm phase dominates electrochemical behavior during cycling and this may prove vital when preparing members in the sodium vanadium fluorophosphate family, especially if there is an energetically preferred phase for cycling.

Alteraciones electrocardiográficas tras un traumatismo torácico cerrado / Electrocardiographic abnormalities after blunt chest trauma

Las lesiones cardiacas resultantes de un traumatismo sobre el corazón representan una afectación no demasiado frecuente (del 10% al 16%, según las series), pero importante por la morbimortalidad que pueden ocasionar, ya que pueden afectar a la pared libre, al septo, a las válvulas, a las coronarias o al sistema específico de conducción miocárdica y pueden provocar una inestabilidad hemodinámica con compromiso vital para el paciente. En España, la causa más frecuente de traumatismo cardiaco es el secundario al traumatismo torácico sufrido tras un accidente de tráfico, bien por contusión directa en el tórax o por aceleración-deceleración con afectación cardiaca y ocasionalmente valvular. Se describe el caso de un paciente que tras sufrir un accidente de tráfico presentó de manera transitoria un bloqueo auriculoventricular tipo 2/1 junto a semiología característica de infarto inferior, que se resolvió espontáneamente (AU)

Damage to the heart as a result of blunt chest trauma is relatively infrequent, with an incidence of 10% to 16%depending on the series. Nevertheless, damage can cause significant life-threatening events if there is rupture of the cardiac free wall, septa, valves or coronary vessels, or interruption of myocardial circulation and hemodynamic instability. Cardiac contusion most often occurs as a result of blunt chest trauma in a traffic accident, caused by direct chest trauma or acceleration/deceleration forces that affect the heart or, occasionally, the valves. We report a case in which a mantaken to our emergency department after a traffic accident developed transient type 2:1 atrioventricular block along with signs of myocardial infarction. The events resolved spontaneously (AU)

¿Nos puede matar el verano? / Can summer kill us?

El golpe de calor es una emergencia médica y causa tratable de fracaso multiorgánico (FMO). Aparece cuando el organismo pierde el control de la temperatura corporal por fracaso del sistema termorregulador, lo que causa un ascenso de la temperatura central hasta 41°C o más. La falta de regulación calórica produce una alteración de la función celular con daño en los tejidos muscular, cerebral, vascular, hepático y renal, y puede producir complicaciones graves como rabdomiolisis. Es fundamental el diagnóstico precoz ya que, si no se toman las medidas iniciales oportunas, la tasa de mortalidad es muy alta. Hay dos formas habituales de presentación, una relacionada con el ejercicio en ambientes calurosos y otra forma clásica, durante intensas olas de calor. El tratamiento se basa en el enfriamiento inmediato junto con el soporte de órganos y sistemas

Heat stroke is a medical emergency and treatable cause of multiorgan failure (MOF). It appears when the body losses control of body temperature due to thermoregulatory system failure, which causes an increase in central temperature to 41° or more. Lack of calorie regulation produces an alteration of cell function with injury to muscular, cerebral, vascular, hepatic and renal tissues, and can cause serious complications such as rhabdomyolysis. Early diagnosis is fundamental. If the adequate initial steps are not taken, mortality rate is very high. There are two common presentation forms, one related with exercise in hot environments, and another classical ones, during intense heat waves. Treatment is based on immediate cooling together with organ and system support

Polymorphisms in the presenilin 1 and presenilin 2 genes and risk for sporadic Alzheimer's disease.

We examined the possible involvement of polymorphisms of the presenilin 1 (PS1) and presenilin 2 (PS2) genes in the risk for sporadic Alzheimer's disease (AD), either through an independent effect or through interaction with the existing apolipoprotein E (ApoE) risk, in 211 AD cases and 188 age-matched control subjects. No significant differences were obtained in any of the comparisons relating the effect of the PS1 and PS2 polymorphisms; thus, these polymorphisms do not appear to be sufficient risk factors by themselves for sporadic AD. Although the ApoE varepsilon4 genotype is the only definite predictor of risk, homozygosity for either the 1 allele of the PS1 or the C allele of the PS2 genes may increase the risk conferred by the presence of an ApoE epsilon4 allele. Additionally, combination of PS1/11 and PS2/CC genotypes might have a small synergistic effect on the risk for AD.