4,758 research outputs found

    Zastosowanie programu gwarancji dla zdrowia jamy ustnej w opiece nad kobietą w ciÄ…ĆŒy w rodzinnym centrum zdrowia w ConcepciĂłn, Chile, w latach 2014–2015

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    IndexaciĂłn: Scopus.Background. Oral health plays a crucial role in general health, quality of life and well-being of pregnant women and their newborns. In Chile, pregnant women have dental care guaranteed by law. However, due to the lack of previous epidemiological studies on the benefits of this guarantee, it is necessary to describe this situation and evaluate the need to change the methods of providing dental services. Objectives. The objective of this study was to describe the pattern of providing dental benefits resulting from the Explicit Health Guarantee – Integral Oral Health in Pregnant Women (GES-SOIE) program to pregnant women attending the Juan Soto FernĂĄndez Family Health Center, ConcepciĂłn, Chile, in 2014–2015. Material and methods. A cross-sectional study of the electronic dental records of patients admitted to GES-SOIE was conducted. The variables studied were sociodemographic data, dental chair hours, non-attendance, treatment completion, and the type of referral to secondary healthcare (SHC). Results. Of 233 pregnant women, 65.2% were registered for non-attendance, 21.2% required referral to SHC and 76.4% completed their treatment. When performing logistic regression, it was found that for each non-attendance the chance of not completing the treatment increased 1.4 times. Conclusions. The level of non-attendance and opting out of the treatment in pregnant women is high, which hinders the proper functioning and effectiveness of GES-SOIE. © 2018 by Wroclaw Medical University and Polish Dental Society.http://www.dmp.umed.wroc.pl/en/article/2018/55/2/179

    Stellar and gaseous abundances in M82

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    The near infrared (IR) absorption spectra of starburst galaxies show several atomic and molecular lines from red supergiants which can be used to infer reliable stellar abundances. The metals locked in stars give a picture of the galaxy metallicity prior to the last burst of star formation. The enrichment of the new generation of stars born in the last burst can be traced by measuring the hot gas in the X-rays. For the first time detailed stellar abundances in the nuclear region of the starburst galaxy M82 have been obtained. They are compared with those of the hot gas as derived from an accurate re-analysis of the XMM and Chandra nuclear X-ray spectra. The cool stars and the hot gas suggest [Fe/H]=-0.35+/-0.2 dex, and an overall [Si,Mg/Fe] enhancement by 0.4 and 0.5 dex, respectively. This is consistent with a major chemical enrichment by SNe II explosions in recursive bursts on short timescales. Oxygen is more puzzling to interpret since it is enhanced by 0.3 dex in stars and depleted by 0.2 dex in the hot gas. None of the standard enrichment scenarios can fully explain such a behavior when compared with the other alpha-elements.Comment: APJ, in pres

    AGN Black Hole Masses and Bolometric Luminosities

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    Black hole mass, along with mass accretion rate, is a fundamental property of active galactic nuclei. Black hole mass sets an approximate upper limit to AGN energetics via the Eddington limit. We collect and compare all AGN black hole mass estimates from the literature; these 177 masses are mostly based on the virial assumption for the broad emission lines, with the broad-line region size determined from either reverberation mapping or optical luminosity. We introduce 200 additional black hole mass estimates based on properties of the host galaxy bulges, using either the observed stellar velocity dispersion or using the fundamental plane relation to infer σ\sigma; these methods assume that AGN hosts are normal galaxies. We compare 36 cases for which black hole mass has been generated by different methods and find, for individual objects, a scatter as high as a couple of orders of magnitude. The less direct the method, the larger the discrepancy with other estimates, probably due to the large scatter in the underlying correlations assumed. Using published fluxes, we calculate bolometric luminosities for 234 AGNs and investigate the relation between black hole mass and luminosity. In contrast to other studies, we find no significant correlation of black hole mass with luminosity, other than those induced by circular reasoning in the estimation of black hole mass. The Eddington limit defines an approximate upper envelope to the distribution of luminosities, but the lower envelope depends entirely on the sample of AGN included. For any given black hole mass, there is a range in Eddington ratio of up to three orders of magnitude.Comment: 43 pages with 10 figures. Accepted for publication in Ap

    The Nuclear Stellar Cluster in the Seyfert~1 Galaxy NGC 3227: High Angular Resolution NIR Imaging and Spectroscopy

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    NIR high angular resolution speckle imaging and imaging spectroscopy of the nuclear region (10'' ~ 840pc) of the Seyfert1 galaxy NGC3227 are presented. A nuclear stellar cluster is slightly resolved in the J and H band with increasing contribution to the NIR continuum from the K to the J band. The stellar absorption lines are extended compared to the neighboring continuum suggesting a cluster size of ~ 70pc FWHM. Analysis of those lines suggests that the stars are contributing about 65% (40%) of the total continuum emission in the H (K) band in a 3.6'' aperture. Population synthesis in conjunction with NIR spectral synthesis indicates an age of 25 to 50 Myr when red supergiants contribute most to the NIR light. This is supported by published optical data on the MgIb line and the CaII triplet. Although a higher age of ~ 0.5 Gyr where AGB stars dominate the NIR light can not be excluded, the observed parameters are at the limit of those expected for a cluster dominated by AGB stars. However, in either case the resolved stellar cluster contributes only about ~ 15 % of the total dynamical mass in the inner 300pc implying another much older stellar population. Pure constant star formation over the last 10 Gyr can be excluded. Therefore, at least two star formation/starburst events took place in the nucleus of NGC3227. Since such sequences in the nuclear star formation history are also observed in the nuclei of other galaxies a link between the activity of the star formation and the AGN itself seems likely.Comment: accepted for publication in the Astrophysical Journal, 46 pages, 15 figure

    Stationary motion of a self gravitating toroidal incompressible liquid layer

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    We consider an incompressible fluid contained in a toroidal stratum which is only subjected to Newtonian self-attraction. Under the assumption of infinitesimal tickness of the stratum we show the existence of stationary motions during which the stratum is approximatly a round torus (with radii r, R and R>>r) that rotates around its axis and at the same time rolls on itself. Therefore each particle of the stratum describes an helix-like trajectory around the circumference of radius R that connects the centers of the cross sections of the torus

    Cheese whey valorisation: Production of valuable gaseous and liquid chemicals from lactose by aqueous phase reforming

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    Cheese effluent management has become an important issue owing to its high biochemical oxygen demand and chemical oxygen demand values. Given this scenario, this work addresses the valorisation of lactose (the largest organic constituent of this waste) by aqueous phase reforming, analysing the influence of the most important operating variables (temperature, pressure, lactose concentration and mass of catalyst/lactose mass flow rate ratio) as well as optimising the process for the production of either gaseous or liquid value-added chemicals. The carbon converted into gas, liquid and solid products varied as follows: 5–41%, 33–97% and 0–59%, respectively. The gas phase was made up of a mixture of H2 (8–58 vol.%), CO2 (33–85 vol.%), CO (0–15 vol.%) and CH4 (0–14 vol.%). The liquid phase consisted of a mixture of aldehydes: 0–11%, carboxylic acids: 0–22%, monohydric alcohols: 0–23%, polyhydric-alcohols: 0–48%, C3-ketones: 4–100%, C4-ketones: 0–18%, cyclic-ketones: 0–15% and furans: 0–85%. H2 production is favoured at high pressure, elevated temperature, employing a high amount of catalyst and a concentrated lactose solution. Liquid production is preferential using diluted lactose solutions. At high pressure, the production of C3-ketones is preferential using a high temperature and a low amount of catalyst, while a medium temperature and a high amount of catalyst favours the production of furans. The production of alcohols is preferential using medium temperature and pressure and a low amount of catalyst

    Effect of biodiesel-derived impurities (acetic acid, methanol and potassium hydroxide) on the aqueous phase reforming of glycerol

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    This work analyses the influence of three biodiesel-derived impurities (CH3OH, CH3COOH and KOH) on the aqueous phase reforming of glycerol at 220 °C and 44 bar using a Ni-La/Al2O3 catalyst. The experiments were planed according to a factorial 2k design and analysed by means of an analysis of variance (ANOVA) test to identify the effect of each impurity and all possible binary and ternary combinations. The presence of CH3OH decreased the glycerol conversion, while CH3COOH and KOH decreased and increased the gas production, respectively. Catalyst deactivation took place under acidic conditions due to the loss of part of the active phase of the catalyst through leaching. The gas phase was made up of H2, CO2, CO and CH4. KOH exerted the greatest influence on the gas composition, increasing H2 production due to the greater gas production and the lower H2 consumption in the hydrogenation reactions. The liquid phase was made up of aldehydes, monohydric and polyhydric alcohols, C3 and C4 ketones and esters. CH3OH increased the proportion of monohydric alcohols, while CH3COOH promoted dehydration reactions, leading to an increase in the relative amount of C3-ketones

    An insight into the separation of 1, 2-propanediol, ethylene glycol, acetol and glycerol from an aqueous solution by adsorption on activated carbon

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    Glycerol conversion processes such as aqueous phase reforming and hydrogenolysis generate value-added compounds highly diluted in water. Because distillation is a high energy demand separation step, adsorption could be an attractive alternative to recover these chemicals. Adsorption isotherms of 1, 2-propanediol, acetol, ethylene glycol and glycerol onto activated carbon were determined by batch adsorption experiments. These isotherms were fitted slightly better to the Freundlich equation than to the Langmuir equation. Acetol is the compound with the highest adsorption at concentrations smaller than 1 M. Properties of the adsorbate such as the -OH group number, chain length, molecular size and dipole moment, besides characteristics of the adsorbent such as the surface area, oxygen and ash content, are considered to explain the observed results. Moreover, adsorption experiments were performed with mixtures of compounds and it was determined that the molar amount adsorbed is less than predicted from the adsorption isotherms of the individual compounds treated separately. In addition, the influence of the activated carbon thermal pretreatment temperature on the adsorption capacity has been studied, the optimum being 800¿C. An analysis of the influence of the activated carbon characteristics showed that the most important parameters are the total pore volume and the ash content. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

    Limits to Sympathetic Evaporative Cooling of a Two-Component Fermi Gas

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    We find a limit cycle in a quasi-equilibrium model of evaporative cooling of a two-component fermion gas. The existence of such a limit cycle represents an obstruction to reaching the quantum ground state evaporatively. We show that evaporatively the \beta\mu ~ 1. We speculate that one may be able to cool an atomic fermi gas further by photoassociating dimers near the bottom of the fermi sea.Comment: Submitted to Phys. Rev
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