10 research outputs found

    Maternal calcium supplementation during pregnancy and dental caries of children at 12 years of age: Follow-up of a randomized controlled trial

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    Objectives. To evaluate if calcium supplementation during pregnancy could have any influence on primary dentition measured as the reduction of dental caries of the child. Design. Individual randomized controlled trial. Setting. One hospital in Rosario, Argentina. Population. Random sample of 195 12-year-old children from a follow-up study of 614 women who were randomized during pregnancy to calcium supplementation or placebo. Methods. An independent researcher blinded to the group where the mothers were assigned performed a dental examination of the children. Main outcome measures. Proportion of children with at least one decayed, missing or filled teeth (DMFT/dmft) and mean number of decayed, missing or filled surfaces (DMFS/dmfs) per children. Results. Ninety-eight children were assessed in the calcium supplementation group and 97 in the placebo group. 63.3% of the children whose mother took calcium supplementation had at least one DMFT/dmft compared to 86.6% in the placebo group (<0.001). The children whose mother received the intervention had a 27% reduction in the risk of developing at least one DMFT/dmft (RR: 0.73, CI 95%: [0.62; 0.87]). Conclusions. This study shows a modeling effect of calcium intake during pregnancy on dental caries of the offspring. At around 12 years of age children whose mothers received calcium supplementation when pregnant showed a significant reduction in dental caries.Fil: Bergel, Eduardo. Organizacion Mundial de la Salud; ArgentinaFil: Gibbons, Luz. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Rasines, María G.. No especifíca;Fil: Luetich, Alejandra. No especifíca;Fil: Belizan, Jose. Instituto de Efectividad Clínica y Sanitaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    On the use of diatomite as antishrinkage additive in the preparation of monolithic carbon aerogels

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    We have synthesized flexible monolithic carbon aerogels by incorporating diatomite as antishrinkage agent during the sol-gel polycondensation of the precursors. The materials displayed elastic properties and preserved their pristine dimensions upon densification by carbonization even after etching of the diatomite, due to the open pore structure of the siliceous additive in the material’s matrix. The aerogels displayed a well-developed porous structure, confirming that the polymerization of the precursors is not impeded; the effect of the additive was independent of the formulation of the aerogels, as evidenced by the behavior of aerogels with varied composition (molar ratio, pH, N-doping).This work was partially funded by MINECO (grant CTM2014/56770-R, IPT-2011-1450-310000 ADECAR and Feder cofunding). The help of Mr. D.L. García in the preparation of the specimens is greatly appreciated.Peer reviewe

    Mesoporous carbon black-aerogel composites with optimized properties for the electro-assisted removal of sodium chloride from brackish water

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    A simple modification of the sol–gel polymerization of resorcinol–formaldehyde mixtures allowed the preparation route of homogeneously dispersed carbon black-activated carbon aerogel composites with high pore volumes and improved electrical conductivity. These materials showed good performance as electrodes for the electro-assisted removal of sodium chloride from saline water using high voltages. Besides the effect of the carbon black additive, we have investigated the influence of resorcinol–water ratio on the textural and electrochemical properties of the resulting materials. Data has shown a slight dependence on the structural order of the aerogels with the R/W ratio, regardless the incorporation of the conductive additive. The effect of the carbon black on the textural features was also negligible, due to the low amount incorporated. Nonetheless, the samples showed higher capacitance values for the removal of ions from solution, due to the enhanced conductivity provided by the carbon black, being the effect more evident for the materials prepared using a low R/W ratio.The authors are indebted to the MICINN (Contract IPT-2011-1450-310000 (ADECAR), and CTM2011/23378) for the financial support. We also thank the fruitful collaboration of Isolux Ingeniería, S.A., Fundación Imdea Energia and Proingesa. University of Córdoba thanks to SCAI and IUIQFN for technical support and Junta de Andalucía (FQM-288) for financial support.Peer reviewe

    Early-Career Coordinated Distributed Experiments: Empowerment Through Collaboration

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    Este artículo contiene 7 páginas, 1 tabla, 3 figuras.Coordinated distributed experiments (CDEs) enable the study of large-scale ecological patterns in geographically dispersed areas, while simultaneously providing broad academic and personal benefits for the participants. However, the effective involvement of early-career researchers (ECRs) presents major challenges. Here, we analyze the benefits and challenges of the first CDE exclusively led and conducted by ECRs (i.e. ECR-CDE), which sets a baseline for similar CDEs, and we provide recommendations for successful CDE execution. ECR-CDEs achieve most of the outcomes identified in conventional CDEs as well as extensive benefits for the young cohort of researchers, including: (i) receiving scientific credit, (ii) peer-training in new concepts and methods, (iii) developing leadership and communication skills, (iv) promoting a peer network among ECRs, and (v) building on individual engagement and independence. We also discuss the challenges of ECR-CDEs, which are mainly derived from the lack of independence and instability of the participants, and we suggest mechanisms to address them, such as resource re-allocation and communication strategies. We conclude that ECR-CDEs can be a relevant tool to empower ECRs across disciplines by fostering their training, networking and personal well-being.The authors were supported by the following founding: NC the support of the Beatriu de Pinós postdoctoral program of the Government of Catalonia’s Secretariat for Universities and Research of the Ministry of Economy and Knowledge (BP2016- 00215), EE by a predoctoral grant from the Basque Government (2014-2017), AB by a Generalitat de Catalunya—Beatriu de Pinós (BP-00385-2016), AMG-F by a predoctoral research grant (BES-2013-065770) from the Spanish Ministry of Economy and Competitiveness, MAr by a postdoctoral grant from the Basque Government, MIA by a Juan de la Cierva postdoctoral grant (FJCI-2015-26192), PR-L by a Margalida Comas postdoctoral contract (PD/031/2018) funded by the Government of the Balearic Islands and the European Social Fund, AP by a Ramón Areces Foundation Postdoctoral Scholarship, and AL by a Kempe Foundation stipend. DOMIPEX project was founded by the First Call of Collaborative Projects among Young Researchers of the Iberian Association of Limnology (AIL; 2013-2015).Peer reviewe

    A novel method for metal oxide deposition on carbon aerogels with potential application in capacitive deionization of saline water

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    Carbon aerogels doped with manganese or iron oxides were prepared by the resorcinol-formaldehyde method as potential electrodes for the capacitive deionization of sodium chloride from saline water. The solution containing the metal precursors was mixed with the hydrogel before the supercritical drying step ensuring a highly homogeneous dispersion of the nanometric metal oxides as determined by X-ray diffraction and electron microscopy. XPS spectra revealed the increased contribution of hydroxyl and carboxylic groups after the activation process. Also, an enhanced metal oxidation at the outer particle surface was observed. Nitrogen isotherms have revealed a decrease of the pore volume in doped samples ascribed to the partial blocking of the pore structure by the embedded nanometric metal oxide particles. Capacitance values as large as 99 F/g and 91 F/g were respectively recorded for CAGDFeAct and CAGDMnAct by cyclic voltammetry. The large capacitance detected for the iron containing activated aerogel was confirmed by deionization experiments. An electrosorption capacity of 0.133 mmol/g was recorded for CAGDFeAct in a 0.025 M NaCl solution when 1.5 V were applied during the charge period. The study of the kinetic response of the electrodes showed a poor behavior for CAGDMnAct and was correlated to the partial blocking of pore structure exerted by the embedded nanometric metal oxide particles.The authors are indebted to the MICINN (Contract IPT-2011-1450-310000 (ADECAR) and CTM2011-23378) and Junta de Andalucía (Research group FQM-288) for the financial support. We also thank the fruitful collaboration of Isolux Ingeniería, S.A., Fundación Imdea Energia and Proingesa.Peer reviewe

    On the use of carbon black loaded nitrogen-doped carbon aerogel for the electrosorption of sodium chloride from saline water

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    Highly micro-mesoporous carbon electrodes have been synthesized by the polycondensation of resorcinol-formaldehyde-melamine mixtures in the presence of a carbon conductive additive. The materials showed high surface functionalization (N- and O- groups) provided by the precursors. Despite the low amount used, the conductive additive had a marked effect on the porosity of the aerogels; for a given series, the carbon black loaded materials showed similar micropore volumes and a more developed mesoporosity than the pristine aerogels. Furthermore, the activation treatment under CO2 atmosphere led to an increase in the surface area along with a widening of the mesoporosity. The synthesized aerogels were explored as electrodes for the electro-assisted removal of sodium chloride from saline water. A desalting capacity of 7.3 mg/g was obtained for monolith electrodes of sample MRF-Act/CB, along with an excellent chemical stability upon charge and discharge at high polarization voltages. Such good electrochemical performance is due to the combination of an adequate pore network and surface functionalization with an enhanced electrical conductivity achieved upon the incorporation of the carbon black additive during the polycondensation of the aerogel precursors.The authors are indebted to the MICINN (Contract IPT-2011-1450-310000 (ADECAR), and CTM2011/23378) for the financial support. We also thank the fruitful collaboration of Isolux Ingeniería, S.A., Fundación Imdea Energia and Proingesa. University of Córdoba thanks to SCAI for technical and FEDER and Junta de Andalucía (FQM-288) for financial supports.Peer reviewe
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