On solutions of the Fréchet functional equation

AbstractIn this paper we give a new proof of a classical result by Fréchet [M. Fréchet, Une définition fonctionnelle des polynomes, Nouv. Ann. 9 (4) (1909) 145–162]. Concretely, we prove that, if Δhk+1f=0 and f is continuous at some point or bounded at some nonempty open set, then f∈Pk. Moreover, as a consequence of the technique developed for our proof, it is possible to give a description of the closure of the graph for the solutions of the equation. Finally, we characterize some spaces of polynomials of several variables by the use of adequate generalizations of the forward differences operator Δhk+1

Gas phase selective hydrogenation of furfural to furfuryl alcohol and 2-methylfuran over Cu-CeO2 coprecipitated catalysts

Furfural is an important chemical derived from lignocellulosic biomass, in particular from C5 sugars like xylose, and it is considered as a platform molecule of great potential for the synthesis of a broad spectrum of chemicals. In this sense, furfuryl alcohol and 2-methylfuran are two important chemicals which can be produced through furfural hydrogenation, either in liquid or vapor phase, although the latter is preferred because it can be carried out at atmospheric pressure. Industrially, a copper chromite catalyst is used, although this catalyst can become very toxic due to the presence of chromium. Therefore, much attention is being paid to the development of chromium-free catalysts, more sustainable and environmentally friendly, as those based on Cu or Ni which are active and selective towards the formation of furfuryl alcohol and 2-methylfuran. Furfuryl alcohol is mainly used for the production of thermostatic resins, intermediate in the manufacture of lysine, vitamin C and dispersing agents. Meanwhile, 2-methyl furan is used in the synthesis of pesticides, or in the pharmaceutical and fragrance industries. The aim of this work is the synthesis of a series of copper based catalysts, which have been synthesized by coprecipitation of copper and cerium(IV) and subsequent thermal programmed reduction. This method allows increasing the dispersion of Cu particles, while the use of a support like CeO2 can modify the electronic density of the active phase, which can influence the catalytic activity and resistance to deactivation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Economy and Competitiveness Ministry (Project CTQ2012-38204-C03-02), Junta de Andalucía (Project: RNM-1565) and FEDER funds of the European Unio

Mesoporous niobium oxide for dehydration of D-xylose into furfural

Se ha demostrado que el óxido de niobio mesoporoso es un catalizador eficaz para la deshidratación de D-xilosa a furfural, alcanzando una conversión del 92% y un rendimiento de furfural 49,3% a 170º C y 90 minutos. La lixiviación de Nb, determinada por ICP-MS, era inferior al 0,5% en peso de la concentración de Nb inicial, confirmando de este modo la estabilidad del catalizador ácido sólido.El furfural posee un gran potencial como molécula plataforma de origen renovable para la síntesis de una alta variedad de compuestos químicos. Se obtiene mediante la deshidratación de pentosas, principalmente a partir de D-xilosa, proceso catalizado por ácidos minerales en fase homogénea. Por tanto, dentro de la química verde y la búsqueda de sostenibilidad de los procesos catalíticos, es necesaria su sustitución por catalizadores sólidos ácidos que sean tolerantes al agua, ya que es el disolvente más utilizado para esta reacción. El óxido de niobio posee propiedades ácidas y es insoluble en agua, pero su superficie específica es muy baja. Por lo tanto, resulta muy interesante la síntesis de un óxido de niobio mesoporoso para emplearlo como catalizador en esta reacción. En este trabajo, se ha sintetizado un Nb2O5 mesoporoso y se ha evaluado su comportamiento catalítico en la obtención de furfural a partir de D-xilosa.Spanish Ministry of Science and Innovation (ENE2009-12743-C04-03 project)Junta de Andalucía (P09-FQM-5070).Ministry of Science and Innovation for the financial support under the Program Ramón y Cajal (RYC-2008-03387)

NEU screen shows high accuracy in detecting cognitive impairment in older persons living with HIV

The NEUrocognitive (NEU) Screen is a practical tool proposed to screen for HIV-associated cognitive impairment in the clinical setting. This is a pencil-and-paper method that can be applied rapidly (<=10 minutes for administration) and has no copyright limitations. In this study, we aimed at investigating its diagnostic accuracy in an older population of persons living with HIV (PLWH), with cutoffs set at 30, 40, 50, and 60 years. Data were collected from a sample of 368 PLWH who underwent a comprehensive neuropsychological tests battery (gold standard). Results of statistical tests showed that accuracy of the NEU Screen increased with age of the participants. The highest degree of precision, with a sensitivity of 91% and specificity of 92%, was obtained for people ages 60 years or older (correct classification: 91%). These optimal results point to the great potential of the NEU Screen as a tool for detecting cognitive disorders in older PLWH

Influence of synthesis conditions in the catalytic performance of Nb-P catalysts

Glycerol is a natural byproduct of the manufacture of soaps from the hydrolysis of animal fats and vegetable oils. Due to the incessant increment of the worldwide production of biodiesel, the production of glycerol, a by-product of the biodiesel industry, has notably increased causing as consequence a drop in its price. In this way, glycerol has been turned into an interesting starting raw material for others chemical products, where the double dehydration of glycerol to acrolein is one of proposed routes for glycerol valorisation. Because of the crude glycerine is found diluted in water, the catalysts must be active and resistance to the presence of water avoiding a separation step of the glycerine from the water and therefore reducing the price of production of acrolein. Various solid acid catalysts have been tested in the dehydration of glycerol, including nio-bium oxide [1-3], phosphoric acid [4, 5] and zirconium niobium mixed oxides [6]. These catalysts reach the full conversion of glycerol and acrolein selectivities as high as 75mol% [3]. However, the main drawback of these cata-lysts is the deactivation with time on stream due to mainly to adsorption of high boiling point compounds. The characteristic features of the catalysts affecting to the catalytic activity are related to the amount of acid centers and the type of acid sites. The catalytic activity is related to Nb – OH groups and polymeric structures exposing Nb=O species [3, 6]. The main goal of this work is to evaluated how the preparation of the catalysts affect to the catalytic activity of supported niobia-phosporous on a mesoporous silica SBA-15 doped with zirconium. Doping with zirconium improves the acidity of the support and the stability of the catalysts as it has been shown previously [7]. 2 Experimental For the synthesis of mesoporous silica SBA-15 doped with zirconium (Si/Zr molar ratio of 5), 8 g of EO20-PO70-EO20 (Pluronic 123 from Aldrich) polymer was dissolved in 288 mL of a 1.7 M HCl aqueous solution and stirred at 313 K for 1 day. Then, 14.6 mL of tetraethoxysilane and 5.8 mL of zirconium n-propoxide were added, under vigorous stirring. The resulting solution was aged at room temperature for 3 days. The final product was fil-tered, washed with water and dried at 333 K. The solid was calcined at 823 K for 6 h. The support was labelled as SiZr This solid was impregnated with niobium oxalate to achieve a 8wt% of Nb2O5 by using the incipient wetness impregnation. The catalyst was dried and calcined at 673 K during 4h (heating rate 2 K/min) and labelled SiZr_8Nb2O5. The niobium-phosphorous catalysts were prepared following to two different strategies. In the first one, the support was impregnated with a solution of niobium oxalate (8wt%Nb2O5) and then dried over night at 333 K. Following, the phosphorous was added by using H3PO4 (85wt%) wiith Nb/P molar ratio of 0.2. Finally, the catalyst was dried and calcined at different temperatures (523, 673 and 973 K) during 4 hours. The catalysts were labelled 0.2NbP-x where x is the temperature of calcination. In the second strategy, the support was impregnated with a solution containing niobium oxale and phosphoric acid with the Nb/P molar ratio of 0.2. This catalyst was calcined at 673 K for 4 hours and labelled 0.2NbP-400-I. The support and catalysts were characterized by means of nitrogen adsorption, elemental analysis, XDR, XPS, TPD-NH3 and adsorption of pyridine coupled to FTIR. The dehydration of glycerol was performed, at atmospheric pressure, in a fixed-bed continuous-flow stainless steel reactor (9.1mm in diameter, and 230mm in length), operated in the down-flow mode Catalysts were pre-treated in situ at atmospheric pressure under a nitrogen flow of 30 mLmin−1 at 598 K for 30 min. The glycerol solu-tion (10 wt.% in water) was supplied by means of HPLC pump at 0.05 mLmin−1 feed rate in a N2 flow (30mLmin−1). The evolution of catalytic tests was studied by collecting liquid samples after 2, 5 and 8 h in a vial cooled in an isopropanol–liquid N2 trap. These vials were sealed for posterior analysis by gas chromatography. The products measured were acrolein, acetaldehyde, hydroxyacetone and allyl alcohol. 3 Results and discussion The support and catalysts were studied by XRD to confirm the presence of the mesoporous structure which was mantained after the impregnation and calcination of the active phases. Moreove, it was not detected neither niobium phase nor phosphate phaser at higher 2.The SiZr catalyst show a high glycerol conversion even higher than the SiZr_8Nb2O5 within the 8 hours of time on stream (TOS) although the selectivity of the SiZr_8Nb2O5 to-wards acrolein is higher (Table 1). This issue is related to higher Brönsted acid sites present in the SiZr_8Nb2O5 since the SiZr support only shows Lewis acid sites. When phosphorus is added to the SiZr_8Nb2O5 catalyst (Table 1), the catalytic performance is improved both in terms of glycerol conversion and acrolein selectivity. It is observed an increase of Brönsted acid sites, probably the presence of P – OH speccies and a decrease of Lewis acid sites compared to the SiZr_8Nb2O5 catalyst. This improvement is only shows when the catalyst is calcined at 673 K (Figure 1) higher and lower calcination temperatures had not beneficial effect on the catalytic activity. It was also compared the catalytic activity when the impregnation with phosphorous and niobium was carried out in one step (Figure 2). In this case, the catalytic performance is drastically improved since the acrolein yield is increased in a 20mol%. This fact point out the presence of an active phase, no detected by XRD analysis, formed by interaction of niobium and phosphorous. 4 Conclusions The catalytic performance of a Nb-P catalyst supported on a mesoporous silica SBA-15 doped with zirconium is ameliorated when the impregnation of the two active phases is carried out in one step reaching an acrolein yield of 46mol% and a glycerol conversion of 85mol%Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Spanish Ministry of Economy and Competitiveness CTQ2012-38204-C03-02 project), Junta de Andalucía RNM-1565) and FEDER funds

Cross-sectional study of height and weight in the population of Andalusia from age 3 to adulthood

<p>Abstract</p> <p>Background and objectives</p> <p>In Andalusia there were no studies including a representative sample of children and adolescent population assessing growth and weight increase. Our objectives were to develop reference standards for weight, height and BMI for the Andalusian pediatric population, from 3 to 18 years of age for both genders, and to identify the final adult height in Andalusia.</p> <p>Subjects and methods</p> <p>Two samples were collected. The first included individuals from 3 to 18 years of age (3592 girls and 3605 boys). They were stratified according type of study center, size of population of origin, age (32 categories of 0.5 years) and gender, using cluster sampling. Subjects from >18 to 23 years of age (947 women and 921 men) were sampled in 6 non-university educational centers and several university centers in Granada. Exclusion criteria included sons of non-Spanish mother or father, and individuals with chronic conditions and/or therapies affecting growth. Two trained fellows collected the data through February to December 2004, for the first sample, and through January to May 2005, for the second.</p> <p>Reference curves were adjusted using Cole's LMS method, and the quality of the adjustment was assessed using the tests proposed by Royston. In addition, a sensitivity analysis was applied to the final models obtained.</p> <p>Results</p> <p>Data for 9065 cases (4539 women and 4526 men) were obtained; 79.39% (n = 7197) in the up to 18 years of age group. In the first sampling only 0.07% (3 girls and 2 boys) refused to participate in the study. In addition, 327 students (4.5%) were absent when sampling was done. We present mean and standard deviation fort height, weight and BMI at 0.5 years intervals, from 3 to 23 years of age, for both genders. After adjustment with the different models, percentiles for height, weight (percentiles 3, 5, 10, 25, 50, 75, 90, 95, and 97) and BMI (percentiles 3, 5, 50, 85, 95, and 97) are presented for both genders.</p> <p>Conclusion</p> <p>This is the first study in Andalusia with a representative sample from the child-juvenile population to investigate weight, height and BMI in subjects from 3 to 23 years of age. The great variability observed in the values from sample of 18 to 23 years of age individuals, ensures the inclusion of extreme values, although random sampling was not used. There still is a lack of standard reference values for the Andalusian population younger done 3 years of age.</p

Short-term microbial response after laboratory heating and ground mulching adition

Fire alters soil organic matter inducing quantitative and qualitative changes that presumably will affect post-fire soil microbial recolonisation. Several studies have evidenced marked soil organic carbon reduction after moderate and high intensity fire, which limit the total recovery of microbial biomass during years. In order to evaluate the role of soil organic matter alteration in short-term microbial colonization process, we perform a preliminary experiment where unaltered soil from Sierra Nevada Natural Park was heated at 300 ºC during 20 minutes in a muffle furnace (H300) to simulate a medium-high intensity fire. After heating, soil samples were inoculated with unaltered fresh soil, rewetted at 55-65% of water holding capacity and incubated during 3 weeks. At the same time, unheated soil samples were incubated under the same conditions as control (UH). In addition, trying to partially alleviate soil organic matter fire-induced alterations effects on microbial colonization, we include an organic amendment treatment (M+). So, part of heated and unheated samples were amended with a mix of ground alfalfa:straw (1:1) and soil microbial abundance and activity were monitored together with soil organic matter changes. Heating process reduces total organic carbon content. After one week of incubation carbon content in heated samples was lower than the control one, in both, amended and un-amended samples. Microbial biomass and respiration were negatively affected by heating. Ground mulching addition increase microbial biomass and respiration but was not enough to reach control values during the whole study. Nevertheless, viable and cultivable fungi and bacteria showed different pattern. After two weeks of incubation both, fungi and bacteria were higher in heated samples. Ground mulching addition appears to stimulate fungal response in both, heated and unheated samples. Preliminary results of this experiment evidence the transcendence of soil organic matter fire-induced changes on microbial colonization process and the importance to determine several microbial parameters to obtain a more faithful conclusion about microbial response. The organic amendment appears to alleviate partially heated-induced damage, highlighting the positive stimulation on fungal abundance in both, heated and unheated samples.Ministerio de Economía y Competitividad CGL2013-47862-C2-1- RMinisterio de Economía y Competitividad CGL2012-38655-C04-0

Infant Gut Microbiota Associated with Fine Motor Skills

BACKGROUND: During early life, dynamic gut colonization and brain development co-occur with potential cross-talk mechanisms affecting behaviour. METHODS: We used 16S rRNA gene sequencing to examine the associations between gut microbiota and neurodevelopmental outcomes assessed by the Bayley Scales of Infant Development III in 71 full-term healthy infants at 18 months of age. We hypothesized that children would differ in gut microbial diversity, enterotypes obtained by Dirichlet multinomial mixture analysis and specific taxa based on their behavioural characteristics. RESULTS: In children dichotomized by behavioural trait performance in above- and below-median groups, weighted Unifrac b-diversity exhibited significant differences in fine motor (FM) activity. Dirichlet multinomial mixture modelling identified two enterotypes strongly associated with FM outcomes. When controlling for maternal pre-gestational BMI and breastfeeding for up to 3 months, the examination of signature taxa in FM groups showed that Turicibacter and Parabacteroides were highly abundant in the below-median FM group, while Collinsella, Coprococcus, Enterococcus, Fusobacterium, Holdemanella, Propionibacterium, Roseburia, Veillonella, an unassigned genus within Veillonellaceae and, interestingly, probiotic Bifidobacterium and Lactobacillus were more abundant in the above-median FM group. CONCLUSIONS: Our results suggest an association between enterotypes and specific genera with FM activity and may represent an opportunity for probiotic interventions relevant to treatment for motor disorders.Spanish Ministry of Innovation and ScienceJunta de Andalucía: Excellence Projects (P06-CTS-02341)Spanish Ministry of Economy and Competitiveness (BFU2012-40254-C03-02) and partially funded by the European Commission MyNewGut FP7 EU Project (Grant agreement n◦ 613979)MyNewGut FP7 EU Project (Grant agreement n◦ 613979)DynaHEALTH EU Project HORIZON 2020 (Grant agreement n◦ : 633595-2)Marie Curie post-doctoral fellowship (FP7, no. 329812, NutriOmics)Spanish Ministry of Education, Culture and Sports (FPU16/04587

Transcriptome profiling of gene expression during immunisation trial against Fasciola hepatica : Identification of genes and pathways involved in conferring immunoprotection in a murine model

Background: Fasciolosis remains a significant food-borne trematode disease causing high morbidity around the world and affecting grazing animals and humans. A deeper understanding concerning the molecular mechanisms by which Fasciola hepatica infection occurs, as well as the molecular basis involved in acquiring protection is extremely important when designing and selecting new vaccine candidates. The present study provides a first report of microarray-based technology for describing changes in the splenic gene expression profile for mice immunised with a highly effective, protection-inducing, multi-epitope, subunit-based, chemically-synthesised vaccine candidate against F. hepatica. Methods: The mice were immunised with synthetic peptides containing B- and T-cell epitopes, which are derived from F. hepatica cathepsin B and amoebapore proteins, as novel vaccine candidates against F. hepatica formulated in an adjuvant adaptation vaccination system; they were experimentally challenged with F. hepatica metacercariae. Spleen RNA from mice immunised with the highest protection-inducing synthetic peptides was isolated, amplified and labelled using Affymetrix standardised protocols. Data was then background corrected, normalised and the expression signal was calculated. The Ingenuity Pathway Analysis tool was then used for analysing differentially expressed gene identifiers for annotating bio-functions and constructing and visualising molecular interaction networks. Results: Mice immunised with a combination of three peptides containing T-cell epitopes induced high protection against experimental challenge according to survival rates and hepatic damage scores. It also induced differential expression of 820 genes, 168 genes being up-regulated and 652 genes being down-regulated, p value &lt;0.05, fold change ranging from -2.944 to 7.632. A functional study of these genes revealed changes in the pathways related to nitric oxide and reactive oxygen species production, Interleukin-12 signalling and production in macrophages and Interleukin-8 signalling with up-regulation of S100 calcium-binding protein A8, Matrix metallopeptidase 9 and CXC chemokine receptor 2 genes. Conclusion: The data obtained in the present study provided us with a more comprehensive overview concerning the possible molecular pathways implied in inducing protection against F. hepatica in a murine model, which could be useful for evaluating future vaccine candidates. © 2017 The Author(s)

Oxidation of lignocellulosic platform molecules to value-added chemicals using heterogeneous catalytic technologies

Currently, much attention is being paid to the development of sustainable catalytic processes for the production of chemicals (biofuels, bioproducts, and so on) from lignocellulosic biomass. This minireview pursues to give an exhaustive overview about the heterogeneous catalytic technologies proposed for the oxidation of four key platform molecules (glucose, 5-hydroxymethylfurfural, furfural and levulinic acid) into important chemicals, such as gluconic acid and gluconates, glucaric and formic acids, 2-diformylfuran, 2,5-furandicarboxylic acid, maleic acid and anhydride, succinic acid, furanones, furoic acid, alkyl furoates, furan-2-acrolein, succinic acid, butanone and 3-hydroxypropanoic acid. The different mechanistic pathways will be highlighted, as well as the requirements in terms of catalytic sites and catalyst stability. The challenges and opportunities will be put forward for each type of oxidation process.Spanish Ministry of Science, Innovation and Universities (RTI2018-94918) and FEDER (European Union) funds. J. A. C. thanks University of Malaga for contracts of PhD incorporation