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Search Results: 1 - 10 of 874299 matches for " A. M.;Peralta-Sánchez "
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Viabilidade do uso de argilas cauliníticas do Quadrilátero Ferrífero para a indústria ceramica
Peralta-Sánchez, M. G.;Morales-Carrera, A. M.;Varaj?o, A. F. D. C.;Ferreira, M. M.;
Ceramica , 2011, DOI: 10.1590/S0366-69132011000300002
Abstract: seven samples from three kaolin deposits of the quadrilátero ferrífero were characterized by physical, mineralogical and chemical analyses in order to determine their use in the ceramic industry. despite the predominant presence of kaolinite, the variations in the fe2o3 content from 2 to 44%, due to presence of goethite and hematite, resulted in different colors, namely: white (acm and db), yellow (r5), yellowed red (fs) and red (dv, r1 and am). specimens were burned at 900 and 1100 °c and they almost didn't change color. however, only specimens made with dv and r1 samples reached the technical specifications for the ceramic industry, without fractures and with values of compression strength of 96.2 and 64.2 mpa, respectively. the other samples were made by mixing phyllite in the proportions of 5, 10, 15, 20 and 25% and burned at 900 and 1100 °c. the bricks made with acm+15f, db+5f, r5+5f, fs+5f, am+5f and burned at 900 oc reached the technical specifications for ceramic industry, without fractures and with values of compression strength between 69.15 and 29.6 mpa.
Transforma??es mineralógicas e cristaloquímicas decorrentes dos ensaios termais em argilas cauliníticas ferruginosas
Ferreira, M. M.;Varaj?o, A. F. D. C.;Morales-Carrera, A. M.;Peralta-Sánchez, M. G.;Costa, G. M. da;
Ceramica , 2012, DOI: 10.1590/S0366-69132012000100017
Abstract: mineralogical and crystallochemical transformations of representative ferruginous kaolinitic clay samples were investigated in specimens burned at 800, 1000 and 1200 °c. x-ray diffraction and differential thermal and thermogravimetric analyses showed that kaolinite was the predominant mineral in the raw samples. the m?ssbauer spectroscopy results showed that the high iron content (22.5 wt.%), as determined by x-ray fluorescence, is related to the presence of goethite (18 wt.%) and hematite (16 wt.%). however, after fe was extracted using a dithionite-citrate system buffered with sodium bicarbonate, a residue of this element (fe3+ and fe2+) was found in the structure of the kaolinite. the sintering process showed the destruction of kaolinite, as well as the transformation of the goethite into hematite, the crystals growing as the temperature increases. the hematite crystal size at 1200 °c is five times larger than in the raw sample. the mullite formation at 1000 °c is comprised of a solid solution of fe2o3 and al2o3, which results in a resistant product with a higher thermal stability.
Antimicrobial Activity and Genetic Profile of Enteroccoci Isolated from Hoopoes Uropygial Gland
Magdalena Ruiz-Rodríguez, Eva Valdivia, Manuel Martín-Vivaldi, Antonio M. Martín-Platero, Manuel Martínez-Bueno, María Méndez, Juan M. Peralta-Sánchez, Juan J. Soler
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0041843
Abstract: Symbiotic microorganisms may be directly transferred from parents to offspring or acquired from a particular environment that animals may be able to select. If benefits for hosts vary among microbial strains, natural selection may favour hosts holding the most beneficial one. Enterococci symbionts living in the hoopoe (Upupa epops) uropygial gland are able to synthesise bacteriocins (antimicrobial peptides that inhibit the growth of competitor bacteria). We explored variability in genetic profile (through RAPD-PCR analyses) and antimicrobial properties (by performing antagonistic tests against ten bacterial indicator strains) of the different isolates obtained from the uropygial glands of hoopoe females and nestlings. We found that the genetic profile of bacterial isolates was related to antimicrobial activity, as well as to individual host identity and the nest from which samples were obtained. This association suggest that variation in the inhibitory capacity of Enterococci symbionts should be under selection.
Mirror-Mark Tests Performed on Jackdaws Reveal Potential Methodological Problems in the Use of Stickers in Avian Mark-Test Studies
Manuel Soler, Tomás Pérez-Contreras, Juan Manuel Peralta-Sánchez
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0086193
Abstract: Some animals are capable of recognizing themselves in a mirror, which is considered to be demonstrated by passing the mark test. Mirror self-recognition capacity has been found in just a few mammals having very large brains and only in one bird, the magpie (Pica pica). The results obtained in magpies have enormous biological and cognitive implications because the fact that magpies were able to pass the mark test meant that this species is at the same cognitive level with great apes, that mirror self-recognition has evolved independently in the magpie and great apes (which diverged 300 million years ago), and that the neocortex (which is not present in the bird's brains) is not a prerequisite for mirror self-recognition as previously believed. Here, we have replicated the experimental design used on magpies to determine whether jackdaws (Corvus monedula) are also capable of mirror self-recognition by passing the mark test. We found that our nine jackdaws showed a very high interest towards the mirror and exhibited self-contingent behavior as soon as mirrors were introduced. However, jackdaws were not able to pass the mark test: both sticker-directed actions and sticker removal were performed with a similar frequency in both the cardboard (control) and the mirror conditions. We conclude that our jackdaws' behaviour raises non-trivial questions about the methodology used in the avian mark test. Our study suggests that the use of self-adhesive stickers on sensitive throat feathers may open the way to artefactual results because birds might perceive the stickers tactilely.
Diabetes does not affect outcome in patients with Enterobacteriaceae bacteremia
Galo Peralta, M Blanca Sánchez, Ma Roiz, J Carlos Garrido, Ramón Teira, Fátima Mateos
BMC Infectious Diseases , 2009, DOI: 10.1186/1471-2334-9-94
Abstract: We reviewed the medical charts of 1112 patients who were treated at a community teaching hospital for Enterobacteriaceae bacteremia from January 1997 through June 2007. Factors associated with in-hospital mortality were analyzed by logistic regression analysis.Among the 1112 patients with Enterobacteriaceae bacteremia, 181 (16.3%) were diabetic patients; 90 patients (8.1%) died while in the hospital. Compared to non-diabetic patients, diabetic patients were older (75.4 ± 11.9 years vs. 70 ± 16.6 years, p < 0.001) and had more comorbidities. However, mortality among diabetic and non-diabetic patients was not different [7.2% vs. 8.2%, RR 1.13; 95% CI (0.67–1.9); p = 0.39]. In a multivariate analysis, the variables associated with in-hospital mortality were age, the origin of the bacteremia, and the presence of immunosuppression. Diabetes was not associated with outcome.In this cohort of patients with Enterobacteriaceae bacteremia, diabetes was not associated with a poorer prognosis.Enterobacteriaceae are the dominant causal agents of Gram-negative bacteremia and are a major cause of morbidity and mortality [1]. The prevalence of diabetes is increasing worldwide [2]; considering the predisposition of diabetes patients to Enterobacteriaceae bacteremia [3], the number of patients with both diabetes and bacteremia caused by Enterobacteriaceae is likely to increase as well. However, information about the effect of diabetes on the prognosis of patients with infections in general, and with Enterobacteriaceae bacteremia in particular, is limited. In addition, some data are contradictory [3-6]. It is significant to determine whether diabetes has a negative impact on the prognosis of Enterobacteriaceae bacteremia so this would support the convenience of a more aggressive approach for these patients. We performed a retrospective cohort study to identify possible correlations between diabetes and prognosis in patients with Enterobacteriaceae bacteremia.The Sierrallana Hospital is
Altered blood glucose concentration is associated with risk of death among patients with community-acquired Gram-negative rod bacteremia
Galo Peralta, M Blanca Sánchez, J Carlos Garrido, Bego?a Ceballos, Fátima Mateos, Inés De Benito, Ma Roiz
BMC Infectious Diseases , 2010, DOI: 10.1186/1471-2334-10-181
Abstract: A retrospective cohort study design for analyzing patients with Gram negative rod bacteremia was employed, with the main outcome measure being in-hospital mortality. Patients were stratified in quintiles accordingly deviation of the blood glucose concentration from a central value with lowest mortality. Cox proportional-hazards regression model was used for determining the relationship of same day of bacteremia blood glucose and death.Of 869 patients identified 63 (7.4%) died. Same day of bacteremia blood glucose concentration had a U-shaped relationship with in-hospital mortality. The lowest mortality (2%) was detected in the range of blood glucose concentration from 150 to 160 mg/dL. Greater deviation of blood glucose concentration from the central value of this range (155 mg/dL, reference value) was directly associated with higher risk of death (p = 0.002, chi for trend). The low-risk group (quintile 1) had a mortality of 3.3%, intermediate-risk group (quintiles 2, 3 and 4) a mortality of 7.1%, and the high-risk group (quintile 5) a mortality of 12.05%. In a multivariable Cox regression model, the hazard ratio for death among patients in the intermediate-risk group as compared with that in the low risk group was 2.88 (95% confidence interval, 1.01 to 8.18; P = 0.048), and for the high risk group it was 4.26 (95% confidence interval, 1.41 to 12.94; P = 0.01).Same day of bacteremia blood glucose concentration is related with outcome of patients with Gram-negative rod bacteremia. Lowest mortality is detected in patients with blood glucose concentration in an interval of 150-160 mg/dL. Deviations from these values are associated with an increased risk of death.Community acquired Gram-negative bacillus bacteremia (GNB) is a leading cause of hospitalization, sepsis and mortality [1]. Altered blood glucose concentration is frequently detected in patients with sepsis and has been associated with adverse outcome [2-9]. Variable cut-off values of hospital admission blood g
Prevalence of diabetes in a cancer population in a Malaga hospital Prevalencia de diabetes en una población con cáncer de un hospital de Málaga
A. M.a Sánchez Peralta,M.a J. Oliveras-López,R. Pérez González,F. Martínez Martínez
Nutrición Hospitalaria , 2012,
Abstract: Background: There are multiple risk factors for cancer, including obesity, sedentary lifestyle, diabetes (DM). Hormon Insulin is a growth factor that promotes cellular differentiation. Aims: The aim of our study is to observe impaired glycaemia in cancer population compared with control. Methods: We studied the prevalence of diabetes (DM) and impaired fasting glycaemia (IFG) in 374 patients with different types of cancer before treatment, by medical records in a Malaga hospital (Spain). We compared the prevalence of basal hyperglycaemia in these patients with general population, within an age range and by gender. Results and discussion: The prevalence of diabetes was 32.35% in our cancer patients. The comparison depends of age range, and by gender prevalence was: 45-54 years, DM: 40.91% in men cases, versus (vs.) 14.5% in men control (p = 0.005). 55-64 years, IFG: 23.08% in women cases, vs. 5.9% in women control (p = 0.001). 65-74 years, DM: 47.13% in men cases, vs. 25.4% in men control (p = 0.000), and IFG: 23.81% in women cases, vs. 9.5% in women control (p = 0.019). We found a higher prevalence of diabetes in specific types of cancer such as prostate (p < 0.005). Moreover, men had a higher prevalence of diabetes or less diabetes control than women in our cancer sample. Conclusions: We recommend an OGTT (oral glucose tolerance test) for better diagnosis of possible DM in patients with cancer, and an appropriate treatment. It may be an independent risk factor for cancer to have decreased insulin activity, or DM. Introducción: Existen múltiples factores de riesgo para que una célula degenere en crecimiento indiferenciado o cáncer. Entre otros factores se ha observado que la obesidad, el sedentarismo y la diabetes aumentan este riesgo. La insulina es un factor de crecimiento que promueve la diferenciación celular. Objetivos: El objetivo de nuestro estudio es observar la glucemia basal en una población con cáncer y comparar con una población control. Métodos: Estudiamos la presencia de diabetes mellitus (DM) y de glucosa alterada en ayunas (GAA) en 374 pacientes de distintos tipos de cáncer mediante sus historiales observando la glucemia basal del ingreso antes de su tratamiento. Comparamos con la glucemia basal en población normal por rangos de edad y sexo. Resultados y discusión: La prevalencia de diabetes en los pacientes con cáncer fue de 32,35%. Comparación por sexo y rangos de edad: observamos que entre 45-54 a os, DM: 40,91% en hombres cancerosos versus (vs) 14.5% en hombres control (p = 0,005). Entre 55-64 a os, GAA: 23,08% en mujeres cancerosas v
A Brief Review on Environmental Application of Boron Doped Diamond Electrodes as a New Way for Electrochemical Incineration of Synthetic Dyes
J. M. Peralta-Hernández,M. Méndez-Tovar,R. Guerra-Sánchez,C. A. Martínez-Huitle,J. L. Nava
International Journal of Electrochemistry , 2012, DOI: 10.1155/2012/154316
Abstract: The present study was stimulated by an authoritative review on decontamination of wastewaters containing synthetic organic dyes by electrochemical methods published in Martínez-Huitle and Brillas (2009). As reviewed by the authors, there have been significant efforts on investigating the decontamination of wastewaters containing synthetic dyes by electrochemical methods, and currently, more studies are being published. A high number of electrodes have been tested in this method, including boron doped diamond (BDD) anodes. In this context, many papers have demonstrated that the use of a BDD thin film in electrochemical oxidation provides total mineralization with high current efficiency of different organics in real wastewaters. And this synthetic material deposited on several supports has been recently applied to dyestuff treatment. Although, in the last two years, more reports have been published treating electrochemically synthetic dyes wastewaters using BDD, there are few reports on the use of electrooxidation processes to degrade real textile effluents. The aim of this paper is to summarize and discuss the most important and recent results available in the literature about the application of BDD electrodes for removing azo dyes in synthetic and real wastewaters. 1. Introduction Azo dyes are used in a wide variety of industrial processes such as, food production, cosmetics, and pharmaceuticals manufacturing and paper printing. Therefore, these dyes are frequently found in industrial wastewater effluents and are a principal cause of pollution around the world [1]. The release of colored effluents into the environment is undesirable, not only for aesthetic reasons but also because many azo dyes and their degradation byproducts are toxic to aquatic life and mutagenic to humans [2]. The effluents from the textile industry are frequently characterized by high alkalinity, biological oxygen demand, chemical oxygen demand, and total dissolved solids in addition to high dye concentrations (>1000?ppm). The synthetic origin and complex aromatic structures of dyes make them stable and difficult to biodegrade. Dyes are classified as anionic (direct, acid, and reactive dyes), cationic (basic dyes), and nonionic (disperse dyes). The chromophores in ionic and nonionic dyes mostly consist of azo groups or anthraquinone types [3]. In this context, azo dye compounds constitute about one-half of the dyes that are used in the textile industry [4]. The chemical structure of this group of compounds is characterized by the presence of the azo group (?N=N?) chromophore,
Determination of the species generated in atmospheric-pressure laser-induced plasmas by mass spectrometry techniques
F. Valle,C. Salgado,J. I. Api?aniz,A. V. Carpentier,M. Sánchez Albaneda,L. Roso,C. Raposo,C. Padilla,A. Peralta Conde
Physics , 2015,
Abstract: We present temporal information obtained by mass spectrometry techniques about the evolution of plasmas generated by laser filamentation in air. The experimental setup used in this work allowed us to study not only the dynamics of the filament core but also of the energy reservoir that surrounds it. Furthermore, valuable insights about the chemistry of such systems like the photofragmentation and/or formation of molecules were obtained. The interpretation of the experimental results are supported by PIC (particle in cell) simulations.
Prevalence of diabetes in a cancer population in a Malaga hospital
Sánchez Peralta,A. M.a; Oliveras-López,M.a J.; Pérez González,R.; Martínez Martínez,F.; López-García de la Serrana,H.;
Nutrición Hospitalaria , 2012,
Abstract: background: there are multiple risk factors for cancer, including obesity, sedentary lifestyle, diabetes (dm). hormon insulin is a growth factor that promotes cellular differentiation. aims: the aim of our study is to observe impaired glycaemia in cancer population compared with control. methods: we studied the prevalence of diabetes (dm) and impaired fasting glycaemia (ifg) in 374 patients with different types of cancer before treatment, by medical records in a malaga hospital (spain). we compared the prevalence of basal hyperglycaemia in these patients with general population, within an age range and by gender. results and discussion: the prevalence of diabetes was 32.35% in our cancer patients. the comparison depends of age range, and by gender prevalence was: 45-54 years, dm: 40.91% in men cases, versus (vs.) 14.5% in men control (p = 0.005). 55-64 years, ifg: 23.08% in women cases, vs. 5.9% in women control (p = 0.001). 65-74 years, dm: 47.13% in men cases, vs. 25.4% in men control (p = 0.000), and ifg: 23.81% in women cases, vs. 9.5% in women control (p = 0.019). we found a higher prevalence of diabetes in specific types of cancer such as prostate (p < 0.005). moreover, men had a higher prevalence of diabetes or less diabetes control than women in our cancer sample. conclusions: we recommend an ogtt (oral glucose tolerance test) for better diagnosis of possible dm in patients with cancer, and an appropriate treatment. it may be an independent risk factor for cancer to have decreased insulin activity, or dm.
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