XANES and EXAFS study of the local order in nanocrystalline yttria-stabilized zirconia

The local order around Zr and Y atoms of nanocrystalline yttria-stabilized zirconia (YSZ) powders with different grain sizes has been investigated by x-ray absorption spectroscopies. The samples were prepared by means of mechanical alloying with or without subsequent sintering treatment and also by milling commercial YSZ. Our study is motivated by the interest in the electrical properties of grain boundaries and the controversy about the level of disorder in the intergrain regions in nanocrystalline YSZ. The x-ray absorption near edge structure (XANES) analysis indicates that the local order of all the sintered samples is independent of the grain size. This is confirmed by the analysis of the extended x-ray absorption fine structure, which points out also that, in contrast to that found in sintered samples, the local order around the cation in the samples milled without further sintering treatment extends only to the first coordination shell. Finally, the results of ab initio Zr K-edge XANES calculations lead us to conclude that the observed changes of the shape of the white line are not related to a phase transformation but reflects the short-range order present in the as-milled samples

Ionic conductivity of nanocrystalline yttria-stabilized zirconia: grain boundary and size effects

We report on the effect of grain size on the ionic conductivity of yttria-stabilized zirconia samples synthesized by ball milling. Complex impedance measurements, as a function of temperature and frequency are performed on 10 mol % yttria-stabilized zirconia nanocrystalline samples with grain sizes ranging from 900 to 17 nm. Bulk ionic conductivity decreases dramatically for grain sizes below 100 nm, although its activation energy is essentially independent of grain size. The results are interpreted in terms of a space-charge layer resulting from segregation of mobile oxygen vacancies to the grain-boundary core. The thickness of this space-charge layer formed at the grain boundaries is on the order of 1 nm for large micron-sized grains but extends up to 7 nm when decreasing the grain size down to 17 nm. This gives rise to oxygen vacancies depletion over a large volume fraction of the grain and consequently to a significant decrease in oxide-ion conductivity

Update of variants identified in the pancreatic β-cell K ATP channel genes KCNJ11 and ABCC8 in individuals with congenital hyperinsulinism and diabetes

The most common genetic cause of neonatal diabetes and hyperinsulinism is pathogenic variants in ABCC8 and KCNJ11. These genes encode the subunits of the β-cell ATP-sensitive potassium channel, a key component of the glucose-stimulated insulin secretion pathway. Mutations in the two genes cause dysregulated insulin secretion; inactivating mutations cause an oversecretion of insulin, leading to congenital hyperinsulinism, whereas activating mutations cause the opposing phenotype, diabetes. This review focuses on variants identified in ABCC8 and KCNJ11, the phenotypic spectrum and the treatment implications for individuals with pathogenic variants.This article is freely available via Open Access. Click on the publisher URL to access it via the publisher's site.P30 DK020595/NH/NIH HHS/United States K23 DK094866/NH/NIH HHS/United States R03 DK103096/NH/NIH HHS/United States 1-11-CT-41/American Diabetes Association/International R01 DK104942/DK/NIDDK NIH HHS/United States WT_/Wellcome Trust/United Kingdom WT098395/Z/12/Z/WT_/Wellcome Trust/United Kingdom UL1 TR000430/NH/NIH HHS/United States P30 DK020595/DK/NIDDK NIH HHS/United States UL1 TR000430/TR/NCATS NIH HHS/United States 1-17-JDF-008/American Diabetes Association/International 105636/Z/14/Z/WT_/Wellcome Trust/United Kingdom 110675/European Association for the Study of Diabetes-Novo Nordisk/International 16/0005407/DUK_/Diabetes UK/United Kingdom R01 DK104942/NH/NIH HHS/United States R03 DK103096/DK/NIDDK NIH HHS/United States K23 DK094866/DK/NIDDK NIH HHS/United Statespublished version, accepted version (12 month embargo), submitted versio

Physicochemical characteristics of citrus jelly with non cariogenic and functional sweeteners

In this study the effect of sweeteners with low glycemic index and non-cariogenic characteristics (isomaltulose, oligofructose and tagatose) in jelly prepared with citrus juice has been evaluated considering a citrus jelly formulated with sucrose as reference. The soluble solids, moisture content, pH, water activity, antioxidant capacity, optical and mechanical properties of jelly made using different sweeteners was determined during storage. Besides, mesophilic aerobics and moulds and yeasts was also counted to determine their stability over time. Sensory evaluation of the citrus jelly has also been done. The results showed the antioxidant activity decreased during storage in all formulations. Tagatose increased lightness whereas coordinates a*, b* and chrome of all the jellies prepared using new sweeteners were lower than jellies with sucrose. However, citrus jelly with only oligofructose or tagatose or with the mixture of isomaltulose and tagatose were most closely resembled to the control jelly with respect to mechanical properties. Jelly prepared with the combination of isomaltulose and tagatose in equal proportions obtained the best score in the sensorial analysis.The authors would like to thank the Serigo-Andres family for donating the raw materials, and also the GVA projects GV/2013/029, GV/2014/012 as well as the Universitat Politecnica de Valencia (Spain) for the financial support given to this research study (UPV PAID-06-12 SP20120889).Rubio-Arraez, S.; Capella Hernández, JV.; Castelló Gómez, ML.; Ortolá Ortolá, MD. (2016). Physicochemical characteristics of citrus jelly with non cariogenic and functional sweeteners. Journal of Food Science and Technology. 53(10):3642-3650. https://doi.org/10.1007/s13197-016-2319-4S364236505310Álvarez J, Pastoriza S, Alonso-Olalla R, Delgado-Andrade C, Rufián-Henares JA (2014) Nutritional and physicochemical characteristic of commercial Spanish citrus juices. Food Chem 164:396–405AOAC (2000) Official methods of analysis of AOAC international, 17th edn. Gaithersburg, MDCalzada-León R, Ruiz-Reyes ML, Altamirano-Bustamante N, Padrón-Martínez MM (2013) Features of the noncaloric sweeteners and their use in children. Acta Pediatr Méx 34(3):141–153Chacón-Villalobos A (2006) Current perspectives agribusiness oligofructosaccharides (FOS). Agron Mesoam 17(2):265–286De Oliva-Neto P, Menão PTP (2009) Isomaltulose production from sucrose by protaminobacter rubrum immobilized in calcium alginate. Bioresour Technol 100:252–4256de Queiroz Pane D, Dias CB, Meinhart AD, Ballus CA, Godoy HT (2015) Evaluation of the sweetener content in diet/light/zero foods and drinks by HPLC-DAD. J Food Sci Tech 52(11):6900–6913Edwards WP (2002) The science of goodies. Acribia S.A, SpainFood and Drug Administration (FDA) (2005) GRAS Notification Isomaltulose (PALATINOSE). http://www.fda.gov/ucm/groups/fdagov-public/@fdagovfoodsgen/documents/document/ucm268989.pdf . Accessed 12 July 2015Food and Drug Administration (FDA) (2010) GRAS Notification Tagatose. GRN No.352. http://www.fda.gov/ucm/groups/fdagov-public/@fdagov-foods-gen/documents/document/ucm269560.pdf . Accessed 12 July 2015Food and Drug Administration (FDA) (2011) GRAS Notification Oligofructose. GRN No.392. http://www.fda.gov/ucm/groups/fdagov-public/@fdagov-foodsgen/documents/document/ucm277112.pdf . Accessed 12 July 2015GME (2015) Gelatine manufactured Europe gelatine properties. http://www.gelatine.org/en/about-gelatine/properties.html . Accessed 12 July 2015ISO (2003) Sensory analysis. Guidelines for the use of quantitative response scales [ref. no.ISO 4121:2003]. International Organization for Standardization, GenevaISO (2008) Sensory analysis Vocabulary [ref. no.ISO 5492:2008]. International Organization for Standardization, GenevaLedur MJ, Tessaro I, Zapata CP (2013) Physicochemical characterization of Saccharides Powder obtained from Yacon Roots (Smallanthus sonchifolius) by membrane technology. Braz Arch Biol Technol 56(6):1024–1033Levin GV (2002) Tagatose, the new GRAS sweetener and health product. J Med Food 5(1):23–36Lina BAR, Jonker G, Kozianowski G (2002) Isomaltulose (Palatinose review of biological and toxicologycal studies). Food Chem Toxicol 40(10):1375–1381O’Donnell K, Kearsley M (2012) Sweeteners and sugar alternatives in food technology, 2nd edn. Wiley, ChichesterOh DK (2007) Tagatose: properties, applications, and biotechnological processes. Appl Microb Biotechnol 76(1):1–8Pacual MR, Calderón-Pascual V (2000) Food Microbiology. Analytical methodology for foods and drinks, 2nd edn. Diaz de Santos, MadridPeinado I, Rosa E, Heredia A, Andrés A (2012) Rheological characteristics of healthy sugar substituted spreadable strawberry product. J Food Eng 113(3):365–373Peinado I, Rosa E, Heredia A, Escriche I, Andrés A (2013) Optical, mechanical and sensorial properties of strawberry spreadable products formulated with isomaltulose. Food Bioprocess Tech 6(9):2353–2364Periche A, Heredia A, Escriche I, Andrés A, Castelló ML (2014) Optical, mechanical and sensory properties of based-isomaltulose gummy confections. Food Biosci 7:37–44Periche A, Heredia A, Escriche I, Andrés A, Castelló ML (2015a) Potential use of isomaltulose to produce healthier marshmallows. LWT-Food Sci Technol 62(1):605–612Periche Á, Castelló ML, Heredia A, Escriche I (2015b) Stevia rebaudiana, Oligofructose and isomaltulose as sugar replacers in Marshmallows: stability and antioxidant properties. J Food Process Preserv. doi: 10.1111/jfpp.12653Petersen-Skytte U (2006) Tagatose. In: Mitchell H (ed) Sweeteners and sugar alternatives in food technology. Blackwell Publishing, Oxford, pp 262–292Pimentel TC, Madrona GS, Prudencio SH (2015) Probiotic clarified apple juice with oligofructose or sucralose as sugar substitutes: sensory profile and acceptability. LWT–Food. Sci Technol 62(1):838–846Rababah TM, Al-Mahasneh MA, Kilani I, Yang W, Alhamad MN, Ereifeja E, Al-U’datta M (2011) Effect of jam processing and storage on total phenolics, antioxidant activity, and anthocyanins of different fruits. J Sci Food Agric 91:1096–1102Rubio-Arraez S, Sahuquillo S, Capella JV, Ortolá MD, Castelló ML (2015) Influence of healthy sweeteners (Tagatose and Oligofructose) on the physicochemical characteristics of orange marmalade. J Texture Stud 46(4):272–280Shahidi F, Liyana-Pathirana CM, Wall DS (2006) Antioxidant activity of white and black sesame seeds and their hull fractions. Food Chem 99(3):478–483Shukla V, Kandra P (2015) Development, physico-chemical and sensory evaluation of natural nutra candy. J Food Sci Tech Mys 52(11):7535–7539Taylor TP, Fasina O, Bell LN (2008) Physical properties and consumer liking of cookies prepared by replacing sucrose with tagatose. J Food Sci 73(3):145–151Van Den Heuvel EGHM, Muys T, Van Dokkum W, Schaafsma G (1999) Oligofructose stimulates calcium absorption in adolescents. Am J Clinic Nutr 69:544–548Vastenavond CM, Bertelsen H, Hansen SJ, Laursen RS, Saunders J, Eriknauer K (2012) Tagatose (D-tagatose). In: Nabors L (ed) Alternative sweeteners. Boca Ratón, Florida, USA, p 197–222Zeng Y, Zhang X, Guan Y, Sun Y (2012) Enzymatic hydrolysates from tuna backbone and the subsequent Maillard reaction with different ketohexoses. Int J Food Sci Technol 47:1293–130

Latin American Consensus: Children Born Small for Gestational Age

72-87Cuatrimestra

International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

Transport, electronic, and structural properties of nanocrystalline CuAlO_(2) delafossites

This work reports on the effect of grain size on the electrical, thermal, and structural properties of CuAlO_(2) samples obtained by solid-state reaction combined with ball milling. Electrical characterization made in microcrystalline and nanocrystalline samples shows that the electrical conductivity decreases several orders of magnitude for the nanocrystalline samples, and, in addition, there is a large discrepancy between the activation energies associated to thermoelectric power ES . The study of the Cu K-edge x-ray absorption spectra of the CuAlO_(2) samples shows that the local structure around Cu is preserved after the sintering process, indicating that the observed behavior of the electrical conductivity is of intrinsic origin. Complex conductivity measurements as a function of frequency allow us to discard grain-boundaries effects on the electrical transport. Thus, the changes in σ(T ) and S(T ) are interpreted in terms of charge localization in the framework of small polarons. This is in agreement with the analysis of the near-edge region of the absorption spectra, which indicates that sintering favors the Cu-O hybridization. As a consequence, oxygen atoms progressively lose their capability of trapping holes, and the electrical conductivity is also enhanced

Paving the way to nanoionics: atomic origin of barriers for ionic transport through interfaces

The blocking of ion transport at interfaces strongly limits the performance of electrochemical nanodevices for energy applications. The barrier is believed to arise from space-charge regions generated by mobile ions by analogy to semiconductor junctions. Here we show that something different is at play by studying ion transport in a bicrystal of yttria (9% mol) stabilized zirconia (YSZ), an emblematic oxide ion conductor. Aberration-corrected scanning transmission electron microscopy (STEM) provides structure and composition at atomic resolution, with the sensitivity to directly reveal the oxygen ion profile. We find that Y segregates to the grain boundary at Zr sites, together with a depletion of oxygen that is confined to a small length scale of around 0.5nm. Contrary to the main thesis of the space-charge model, there exists no evidence of a long-range O vacancy depletion layer. Combining ion transport measurements across a single grain boundary by nanoscale electrochemical strain microscopy (ESM), broadband dielectric spectroscopy measurements, and density functional calculations, we show that grain-boundary-induced electronic states act as acceptors, resulting in a negatively charged core. Besides the possible effect of the modified chemical bonding, this negative charge gives rise to an additional barrier for ion transport at the grain boundary