Use of superheated liquids for the extraction of non-volatile compounds from wood: HPLC studies

A study of the extraction of oak wood compounds using superheated water-ethanol mixtures ranging from 10 to 60% ethanol is reported. Identification and characterization of the extracted compounds have been made by high performance liquid chromatography. The extraction has been performed using the static mode by single or repetitive cycles. The variables affecting the extraction process have been studied and their optimum values established (extraction time: 50 min; pressure: 40 atm; extraction temperature: 180º C). The study allows to compare the non-volatile polyphenol fractions obtained in this way with those present in commercial samples with fully agreement between them. In addition, the method allows manipulation of the extract composition by changing the working pressure, temperature and water-ethanol ratio

Exact-Diagonalization Studies of Inelastic Light Scattering in Self-Assembled Quantum Dots

We report exact diagonalization studies of inelastic light scattering in few-electron quantum dots under the strong confinement regime characteristic of self-assembled dots. We apply the orthodox (second-order) theory for scattering due to electronic excitations, leaving for the future the consideration of higher-order effects in the formalism (phonons, for example), which seem relevant in the theoretical description of available experiments. Our numerical results stress the dominance of monopole peaks in Raman spectra and the breakdown of selection rules in open-shell dots. The dependence of these spectra on the number of electrons in the dot and the incident photon energy is explicitly shown. Qualitative comparisons are made with recent experimental results.Comment: 11 pages, 11 figure

On the nature of the near-UV extended light in Seyfert galaxies

We study the nature of the extended near-UV emission in the inner kiloparsec of a sample of 15 Seyfert galaxies which have both near-UV (F330W) and narrow band [OIII] high resolution Hubble images. For the majority of the objects we find a very similar morphology in both bands. From the [OIII] images we construct synthetic images of the nebular continuum plus the emission line contribution expected through the F330W filter, which can be subtracted from the F330W images. We find that the emission of the ionised gas dominates the near-UV extended emission in half of the objects. A further broad band photometric study, in the bands F330W (U), F547M (V) and F160W (H), shows that the remaining emission is dominated by the underlying galactic bulge contribution. We also find a blue component whose nature is not clear in 4 out of 15 objects. This component may be attributed to scattered light from the AGN, to a young stellar population in unresolved star clusters, or to early-disrupted clusters. Star forming regions and/or bright off-nuclear star clusters are observed in 4/15 galaxies of the sample.Comment: 23 pages, 6 figures, 3 tables; accepted for publication in MNRA

Importancia de la estática del raquis lumbar y pelvis en la estenosis degenerativa del canal raquídeo lumbar

El objetivo de este trabajo es examinar algunos parámetros de la estática del caquis lumbosacro en 50 pacientes diagnosticados de estrechez degenerativa del caneal raquídeo lumbar (EDCL), y en un grupo control de 31 sujetos sin antecedentes de patología raquídea, y evaluar las diferencias entre ambos grupos. Los parámetros estudiados mediante radiología simple han sido: Altura discal, la lordosis lumbar, el ángulo lumbosacro de Ferguson, la pendiente sacra, el índice de Taillard, el ángulo discal L5-S1, el nivel de crestas iliacas, y el ángulo de Cauchoix. El ángulo de inclinación del platillo de S1 respecto de la horizontal fue significativamente mayor en el grupo de pacientes que en el de controles. La lordosis no varió significativamente entre ambos grupos. Pero si se observaron diferencias significativas en función del número de niveles estrechados. En el grupo de control, predominaron de forma significativas las disposiciones pélvicas estables, donde las crestas iliacas coinciden con la cuarta vértebra lumbar.The objective of this paper is to examine some parameters of the static of the lumbosacral spine in 50 patients with degenerative stenose of lumbar spine, and in a control groupe of 31 subjects without antecedents of spine pathology, and to evaluate the differences between both groups. We studied by means of simple radiology: the discal height, the lumbar lordosis, the index of Taillard, the discal angle L5-S1, the level of the iliacs crests, and the angle of Cauchoix. The angel of Ferguson was significantly smaller in the group of patients that in that of the controls. The lordosis didn't vary significantly between groups, but it was significantly different if it was observed in function of the number of narrowed levels. In the control group, the stable pelvic despositions (where the crests iliacas coincides with fourth lumbar vertebra) prevailed in a significant way

Kinematics of gas and stars in circumnuclear star-forming regions of early type spirals

(Abbr.) We present high resolution (R~20000) spectra in the blue and the far red of cicumnuclear star-forming regions (CNSFRs) in three early type spirals (NGC3351, NGC2903 and NGC3310) which have allowed the study of the kinematics of stars and ionized gas in these structures and, for the first time, the derivation of their dynamical masses for the first two. In some cases these regions, about 100 to 150 pc in size, are seen to be composed of several individual star clusters with sizes between 1.5 and 4.9 pc estimated from Hubble Space Telescope (HST) images. The stellar dispersions have been obtained from the Calcium triplet (CaT) lines at $\lambda\lambda$ 8494,8542,8662 \AA, while the gas velocity dispersions have been measured by Gaussian fits to the H$\beta$ and [OIII] $\lambda\lambda$ 5007 \AA lines on the high dispersion spectra. Values of the stellar velocity dispersions are between 30 and 68 km/s. We apply the virial theorem to estimate dynamical masses of the clusters, assuming that systems are gravitationally bounded and spherically symmetric, and using previously measured sizes. The measured values of the stellar velocity dispersions yield dynamical masses of the order of 10$^7$ to 10$^8$ solar masses for the whole CNSFRs. Stellar and gas velocity dispersions are found to differ by about 20 to 30 km/s with the H$\beta$ emission lines being narrower than both the stellar lines and the [OIII] $\lambda\lambda$ 5007 \AA lines. The twice ionized oxygen, on the other hand, shows velocity dispersions comparable to those shown by stars, in some cases, even larger. We have found indications of the presence of two different kinematical components in the ionized gas of the regions...Comment: 4 pages, proceeding of the meeting "Young massive star clusters - Initial conditions and environments", Granada, Spain, 200

The Starburst-AGN connection: The role of stellar clusters in AGNs

Nuclear stellar clusters are a common phenomenon in spirals and in starbursts galaxies, and they may be a natural consequence of the star formation processes in the central regions of galaxies. HST UV imaging of a few Seyfert 2 galaxies have resolved nuclear starbursts in Seyfert 2 revealing stellar clusters as the main building blocks of the extended emission. However, we do not know whether stellar clusters are always associated with all types of nuclear activity. We present NUV and optical images provided by HST to find out the role that stellar clusters play in different types of AGNs (Seyferts and LLAGNs). Also with these images, we study the circumnuclear dust morphology as a probe of the circumnuclear environment of AGNs. Here we present a summary of the the first results obtained for the sample of Seyferts and LLAGN galaxies.Comment: Contribution to the conference proceedings "Space Astronomy: The UV window to the Universe", El Escorial (Spain), May 28-June 1 2007, submitted to Ap&SS, invited ed. Gomes de Castro, A.I. Further explanations are in Mu\~noz Marin, et al (2007) and Gonzalez Delgado et al (2007); and the full collection of figures are at the ULR: http://www.iaa.es/~rosa/research/LLAGNs2007/LLAGNs-HSTIma1.html http://www.iaa.es/~manuel/publications/paper01.htm

The cosmic evolution of the spatially-resolved star formation rate and stellar mass of the CALIFA survey

We investigate the cosmic evolution of the absolute and specific star formation rate (SFR, sSFR) of galaxies as derived from a spatially-resolved study of the stellar populations in a set of 366 nearby galaxies from the CALIFA survey. The analysis combines GALEX and SDSS images with the 4000 break, H_beta, and [MgFe] indices measured from the datacubes, to constrain parametric models for the SFH, which are then used to study the cosmic evolution of the star formation rate density (SFRD), the sSFR, the main sequence of star formation (MSSF), and the stellar mass density (SMD). A delayed-tau model, provides the best results, in good agreement with those obtained from cosmological surveys. Our main results from this model are: a) The time since the onset of the star formation is larger in the inner regions than in the outer ones, while tau is similar or smaller in the inner than in the outer regions. b) The sSFR declines rapidly as the Universe evolves, and faster for early than for late type galaxies, and for the inner than for the outer regions of galaxies. c) SFRD and SMD agree well with results from cosmological surveys. At z< 0.5, most star formation takes place in the outer regions of late spiral galaxies, while at z>2 the inner regions of the progenitors of the current E and S0 are the major contributors to SFRD. d) The inner regions of galaxies are the major contributor to SMD at z> 0.5, growing their mass faster than the outer regions, with a lookback time at 50% SMD of 9 and 6 Gyr for the inner and outer regions. e) The MSSF follows a power-law at high redshift, with the slope evolving with time, but always being sub-linear. f) In agreement with galaxy surveys at different redshifts, the average SFH of CALIFA galaxies indicates that galaxies grow their mass mainly in a mode that is well represented by a delayed-tau model, with the peak at z~2 and an e-folding time of 3.9 Gyr.Comment: 23 pages, 16 figures, 6 tables, accepted for publication in Astronomy & Astrophysics. *Abridged abstract

The fluorination effect: the importance of backbone planarity in achieving high performance ambipolar field effect transistors

We report here the synthesis and physico-chemical characterization of a series of donor–acceptor (D–A) copolymers consisting of 4,7-di(2-thienyl)-2,1,3-benzothiadiazole and isoindigo building blocks, which have been progressively fluorinated with the aim of enhancing intrachain interactions and thus increasing their electrical performances in organic field effect transistors (OFETs). The effect of the polymeric partially locked conformations, upon fluorination, on the material properties has been comprehensively analyzed by means of spectroscopic (UV-vis-NIR and Raman) and electrochemical techniques and density functional theory (DFT) calculations. Raman spectroscopy highlights that the impact of gradual fluorination on the molecular and electronic properties is highly dependent on the building blocks into which the fluorine atoms are introduced, being a much more efficient strategy to add them in the isoindigo unit. Electrical characterization of OFETs also shows that fluorination progressively increases the polymer coplanarity and electron affinity, varying the electrical performance from low hole dominated charge transport in the unfluorinated polymer to balanced ambipolar charge transport in the fluorinated ones. The best field-effect mobilities were recorded when fluorine atoms were added to the isoindigo unit, with values of 0.1 cm2 V−1 s−1 for both hole and electron transports.The work at the University of Málaga was supported by the MICINN (project PID2019-110305GB-I00) and by Junta de Andalucía (project P18-FR-4559). S. G.-V. thanks the MINECO for an FPU predoctoral fellowship (FPU17/04908). The authors would like to thank the computer resources, technical expertise and assistance provided by the SCBI (Supercomputing and Bioinformatics) centre of the University of Málaga. The Vibrational spectroscopy (EVI), XRD and AFM labs of the Research Central Services (SCAI) of the University of Málaga are also gratefully acknowledged. Al-Hashimi likes to acknowledge the financial support from the Qatar National Research Fund, Project Number NPRP12S-0304-190227. Notes and references // Funding for open access charge: Universidad de Málag

Vocación y profesionalismo: reflexiones de los estudiantes catalizadas por el cine de Spielberg

La profesión médica tiene un marcado sentido vocacional que está estrechamente vinculado a su dimensión ética; sin embargo, existen dudas sobre el papel que los estudios de grado están ejerciendo en su desarrollo. Con la finalidad de favorecer la reflexión al respecto, se celebró un seminario con estudiantes y profesores desarrollado en 3 fases: a) libre exposición de los alumnos sobre lo que consideraban que es la vocación médica; b) presentación por parte de los profesores del marco teórico de la educación médica, seguido del visionado de varias escenas de películas dirigidas por Steven Spielberg que facilitan la reflexión sobre el significado de los componentes éticos y humanos de la medicina, y c) discusión abierta entre alumnos y profesores. Se analizan las principales conclusiones: conviene crear espacios para la reflexión sobre la dimensión vocacional de la medicina a lo largo de los estudios del grado, lo cual, de algún modo, ya se debería considerar en los procedimientos de selección y acceso; en la tarea docente es fundamental el ejemplo de los formadores, así como una tutorización individualizada que «cuide» el desarrollo vocacional; es necesario promover una formación que vaya más allá de la adquisición de conocimientos y habilidades, prestando atención a la gestión de las emociones, el acompañamiento ante los problemas éticos y la educación de las actitudes; el contacto precoz con la actividad clínica, ya desde el comienzo de los estudios se valora como un factor decisivo para motivar a los alumnos ante la inmensa carga teórica que deben afrontar. The medical profession has a marked vocational sense that is closely linked to its ethical dimension. However, there are doubts about the role that undergraduate studies are playing in their development. In order to encourage reflection on this issue, a seminar was held with students and teachers, developed in 3 phases: a) free presentation by students about what they considered to be the medical vocation; b) presentation by professors of the theoretical framework of medical education, followed by the viewing of several scenes of films directed by Steven Spielberg that facilitate reflection on the meaning of the ethical and human components of medicine, and c) open discussion between students and teachers. The main conclusions were analysed: it is worth creating spaces for reflection on the vocational dimension of medicine throughout undergraduate studies. This, in some way, should already be considered in the selection and access procedures to medical school. In the teaching task it is essential that the lecturers are seen as role models, as well as providing individualised tutoring that includes vocational development. Thus, it is necessary to promote training that goes beyond the acquisition of knowledge and skills, paying attention to the management of emotions, the approach to the ethical problems, and the education of attitudes. Early contact with clinical activity, from the beginning of studies is considered a decisive factor to motivate students before the immense theoretical burden they have to face