Rosmarinic acid recovery from Lamiaceae plants

Póster presentado en las I Jornadas Científicas CIAL Forum 2014, celebrado en Madrid el 5 de junio de 2014.El ácido Rosmarínico es un ácido fenólico conocido por sus múltiples propiedades biológicas, tales como antioxidante, antiinflamatoria, anticancerígena y antibacteriana. Se encuentra en diferentes especies de la familia Lamiaceae, en concentraciones desde 0.01 a 9.30 mg/g. En este estudio el ácido rosmarínico ha sido recuperado de diferentes plantas de la familia de las Lamiaceae (Rosmarinus officinalis, Salvia officinalis, Melissa officinalis, Origanum Majorana) utilizando extracción sólido-líquido asistida por ultrasonidos (UAE) y extracción con líquidos presurizados (PLE). Debido a la naturaleza polar de este ácido fenólico, diferentes disolventes polares fueron estudiados, incluyendo metanol, etanol, agua y mezclas de metanol-agua (1:1). Los ensayos UAE fueron llevados a cabo usando una sonda (Branson Digital Sonifier, Branson Ultrasonics, model 250; Danbury, USA) durante 15 minutos, con agitación, y manteniendo la temperatura en 45°C. La mezcla de metanol:agua fue la que presentó mayor capacidad para la extracción de ácido rosmarínico. Además, Romero y Salvia fueron las plantas de las cuales se obtuvo extractos con mayor concentración de dicho ácido (61.7 y 46.5 mg/g, respectivamente). Los experimentos PLE fueron realizados con Salvia, a tres temperaturas diferentes: 100, 150 and 200°C utilizando la mezcla metanol:agua. Los rendimientos fueron considerablemente mayores que los obtenidos por UAE (61% a 200°C). El aumento de temperatura produce un incremento en el rendimiento de extracción y una disminución en la concentración de ácido rosmarínico en los extractos. Así, la mayor concentración de ácido rosmarínico en los ensayos PLE se obtuvo a la menor temperatura (100°C) y fue similar al obtenido mediante UAE. Por otro lado, en los extractos PLE las recuperaciones fueron aproximadamente dos veces mayores que las obtenidas por UAE (12.34 mg/g vs. 6.61 mg/g).Este trabajo ha sido financiado por el proyecto ALIBIRD-S2009/AGR-1469, de la Comunidad Autónoma de Madrid.Peer reviewe

Low temperature superlattice in monoclinic PZT

TEM has shown that the strongly piezoelectric material Pb(Zr0.52Ti0.48)O3 separates into two phases at low temperatures. The majority phase is the monoclinic phase previously found by x-ray diffraction. The minority phase, with a nanoscale coherence length, is a slightly distorted variant of the first resulting from the anti-phase rotation of the oxygen octahedra about [111]. This work clears up a recent controversy about the origin of superlattice peaks in these materials, and supports recent theoretical results predicting the coexistence of ferroelectric and rotational instabilities.Comment: REVTeX4, 4 eps figures embedded. JPG version of figs. 2&4 is also include

Electronic Structure and Thermoelectric Prospects of Phosphide Skutterudites

The prospects for high thermoelectric performance in phosphide skutterudites are investigated based on first principles calculations. We find that stoichiometric CoP_3 differs from the corresponding arsenide and antimonide in that it is metallic. As such the band structure must be modified if high thermopowers are to be achieved. In analogy to the antimonides it is expected that this may be done by filling with La. Calculations for LaFe_4P_12 show that a gap can in fact be opened by La filling, but that the valence band is too light to yield reasonable p-type thermopowers at appropriate carrier densities; n-type La filled material may be more favorable.Comment: 3 pages, 3 figures, 1 tabl

Gender differences in the association between education and the incidence of cardiovascular events in Northern Italy.

Background: The educational differences in the incidence of major cardiovascular events are under-studied in Southern Europe and among women. Methods: The study sample includes n\u2009=\u20095084 participants to 4 population-based Northern Italian cohorts, aged 35-74 at baseline and with no previous cardiovascular events. The follow-up to ascertain the first onset of coronary heart disease (CHD) or ischaemic stroke ended in 2002. At baseline, major cardiovascular risk factors were investigated adopting the standardized MONICA procedures. Two educational classes were obtained from years of schooling. Age- and risk factors-adjusted hazard ratios of first CHD or ischaemic stroke were estimated through sex-specific separate Cox models (high education as reference). RESULTS: Median follow-up time was 12 years. Event rates were 6.38 (CHD) and 2.12 (ischaemic stroke) per 1000 person-years in men; and 1.59 and 0.94 in women. In men, low education was associated with higher mean Body Mass Index and prevalence of diabetes and cigarette smokers; but also with higher HDL cholesterol and a more favourable alcohol intake pattern. Less-educated women had higher mean systolic blood pressure, Body Mass Index and HDL cholesterol and were more likely to have diabetes. Men and women in the low educational class had a 2-fold increase in ischaemic stroke and CHD incidence, respectively, after controlling for major risk factors. Education was not associated with CHD incidence in men. Higher ischaemic stroke rates were observed among more educated women. Conclusion: In this northern Italian population, the association between education and cardiovascular risk seems to vary by gender

The contribution of major risk factors and job strain to occupational class differences in coronary heart disease incidence: the MONICA Brianza and PAMELA population-based cohorts

Objectives We investigated the contribution of major coronary heart disease (CHD) risk factors and job strain to occupational class differences in CHD incidence in a pooled-cohort prospective study in northern Italy. Methods 2964 men aged 25-74 from four northern Italian population-based cohorts were investigated at baseline and followed for first fatal or non-fatal CHD event (171 events). Standardised procedures were used for baseline risk factor measurements, follow-up and validation of CHD events. Four occupational classes were derived from the Erikson-Goldthorpe-Portocarero social class scheme: higher and lower professionals and administrators, non-manual workers, skilled and unskilled manual workers, and the self-employed. HRs were estimated with Cox models. Results Among CHD-free subjects, with non-manual workers as the reference group, age-adjusted excess risks were found for professionals and administrators (+84%, p=0.02), the self-employed (+72%, p=0.04) and manual workers (+63%, p=0.04). The relationship was consistent across different CHD diagnostic categories. Adjusting for major risk factors only slightly reduced the reported excess risks. In a sub-sample of currently employed subjects, adjusting for major risk factors, sport physical activity and job strain reduced the excess risk for manual workers (relative change = -71.4%) but did not substantially modify the excess risks of professionals and administrators and the self-employed. Conclusions In our study, we found higher CHD incidence rates for manual workers, professionals and administrators, and the self-employed, compared to non-manual workers. When the entire spectrum of job categories is considered, the job strain model helped explain the CHD excess risk for manual workers but not for other occupational classes

Electronic, vibrational and transport properties of pnictogen substituted ternary skutterudites

First principles calculations are used to investigate electronic band structure and vibrational spectra of pnictogen substituted ternary skutterudites. We compare the results with the prototypical binary composition CoSb$_3$ to identify the effects of substitutions on the Sb site, and evaluate the potential of ternary skutterudites for thermoelectric applications. Electronic transport coefficients are computed within the Boltzmann transport formalism assuming a constant relaxation time, using a new methodology based on maximally localized Wannier function interpolation. Our results point to a large sensitivity of the electronic transport coefficients to carrier concentration and to scattering mechanisms associated with the enhanced polarity. The ionic character of the bonds is used to explain the detrimental effect on the thermoelectric properties

Role of defects in the electronic properties of amorphous/crystalline Si interface

The mechanism determining the band alignment of the amorphous/crystalline Si heterostructures is addressed with direct atomistic simulations of the interface performed using a hierarchical combination of various computational schemes ranging from classical model-potential molecular dynamics to ab-initio methods. We found that in coordination defect-free samples the band alignment is almost vanishing and independent on interface details. In defect-rich samples, instead, the band alignment is sizeably different with respect to the defect-free case, but, remarkably, almost independent on the concentration of defects. We rationalize these findings within the theory of semiconductor interfaces.Comment: 4 pages in two-column format, 2 postscript figures include