50 research outputs found

    Fe-Containing MOFs as Seeds for the Preparation of Highly Active Fe/Al-SBA-15 Catalysts in the N-Alkylation of Aniline

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    We have successfully incorporated iron species into mesoporous aluminosilicates (AlSBA15) using a simple mechanochemical milling method. The catalysts were characterized by nitrogen physisorption, inductively coupled plasma mass spectrometry (ICP-MS), pyridine (PY) and 2,6-dimethylpyridine (DMPY) pulse chromatography titration, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The catalysts were tested in the N-alkylation reaction of aniline with benzyl alcohol for imine production. According to the results, the iron sources, acidity of catalyst and reaction conditions were important factors influencing the reaction. The catalyst showed excellent catalytic performance, achieving 97% of aniline conversion and 96% of imine selectivity under optimized conditions

    A Methodology for Buildings Access to Solar Radiation in Sustainable Cities

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    The growing need to improve the environmental and energy sustainability of buildings involves the use of solar radiation incident on their surfaces. However, in cities, this task is complicated due to the constructive geometry that leads to shading between buildings. In this context, this work presents a study of solar access to the façades of buildings in cities. The methodology is based on the determination of the incident annual solar radiation in 121 significant points of each façade considering the twelve representative days of the year. To characterize the influence of the different city typologies on solar access, the urban solar coefficient is proposed. A study of two neighborhoods in Cordoba (Spain) with different urban settings have been analyzed. Specifically, two typologies of neighborhoods have been compared: one with “L-shaped” and “U-shaped blocks” and another with “Grouped blocks”. For both of them, the Urban Solar Coefficient has been calculated, obtaining a higher mean value for the neighborhood with “L-shaped” and “U-shaped blocks” (0.317) than for the one with “Grouped blocks” (0.260). Accordingly, the results show that urban morphology can influence the Urban Solar Coefficient and solar access. Finally, a regression model for each neighborhood has been obtained in order to determine the dependence of the Urban Solar Coefficient on neighborhood geometry factors

    Accuracy of the Resting Energy Expenditure Estimation Equations for Healthy Women

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    Background: There exist several prediction equations for the estimation of resting energy expenditure (REE). However, none of these equations have been validated in the Chilean female population yet. The aims of this study are (1) to determine the accuracy of existing equations for prediction of REE and (2) to develop new equations in a sample of healthy Chilean women. Methods: A cross-sectional descriptive study was carried out on 620 Chilean women. The sample showed an age range between 18 and 73 years, a body mass index average of 28.5 ± 5.2 kg/m2, and a prevalence of overweight and obesity of 41% and 33.2%, respectively. REE was measured by indirect calorimetry (REEIC), which was used as the gold standard to determine the accuracy of twelve available REE prediction equations and to calculate alternative formulas for estimation of REE. Paired t-tests and Bland–Altman plots were used to know the accuracy of the estimation equations with REEIC. At the same time, multiple linear regressions were performed to propose possible alternative equations. The analyses were carried out by age groups and according to nutritional status. Results: All the equations showed a tendency to overestimate REE, regardless of age or nutritional status. Overall, the Ireton-Jones equation achieved the highest mean percentage difference from REEIC at 67.1 ± 31%. The alternative new equations, containing variables of body composition, reached a higher percentage of classification within ± 10% of REEIC. Conclusions: The available equations do not adequately estimate REE in this sample of Chilean women. Although they must be validated, the new formulas proposed show better adaptation to this Chilean sample

    Efficacy of biosecurity measures in the control of microorganisms associated to endometritis in sows. Preliminary study

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    Biosecurity can be defined as all the applied measurements that take as a target to minimize the sanitary risks in a stock farm, and include measurements related to the facilities and the management. The efficacy of these measurements must be reflected in a decrease of the microorganism in different productive phases. A study was carried out to evaluate if the set of applied measurements influences the microbial uterine contamination after farrowing of healthy sows. Two swine farms were been completed about biosecurity measurements was completed and a microbiological study of uterine swabs of sows after the farrowing was carried out. A total of 60 animals were studied, and 27 (45%, 95% CI [33.3%, 56.7%]) resulted positive. Significant differences between production and selection and multiplication farms were detected (OR = 3.44, IC 95%, 1.135-11.047). The colonization frequency was 65% CI [51.3%, 78.6%] and 35% CI [21%, 49%] in production and selection farm, respectively (P = 0.02). A total of 66 isolates were obtained, represented mainly by Staphylococcus spp. (33.33%) and Aerococcus spp. (27.27%), although other species included in the genus Streptococcus (9.09%), Enterococcus (6.06%) and Pseudomonas (4.55%), as well as different fungi species were also isolated. The frequency of isolation of different microorganisms was similar in both farms, with the exception of the genus Enterococcus that was not isolated in the production farm (P = 0.01). The questionnaire showed some differences in biosecurity measures in the selection and multiplication farm when it is compared to the production farm, which together with the increased uterine microbial contamination observed in the latter leads us to propose a preliminary hypothesis about the possible risk factors associated with this process, highlighting the absence of measures to avoid the presence of vectors and the establishment of strict protocols for cleaning and disinfectio

    Mechanochemically Synthesized Supported Magnetic Fe-Nanoparticles as Catalysts for Efficient Vanillin Production

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    Magnetically separable nanocatalysts were synthesized by incorporating iron nanoparticles on a mesoporous aluminosilicate (Al-SBA-15) through a mechanochemical grinding pathway in a single step. Noticeably, magnetic features were achieved by employing biomass waste as a carbon source, which additionally may confer high oxygen functionalities to the resulting material. The resulting catalysts were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, porosimetry, and magnetic susceptibility. The magnetic nanocatalysts were tested in the selective oxidative cleavage reaction of isoeugenol and vanillyl alcohol to vanillin. As a result, the magnetic nanocatalysts demonstrated high catalytic activity, chemical stability, and enormous separation/reusability qualities. The origin of catalytic properties and its relationship with the iron oxide precursor were analyzed in terms of the chemical, morphological, and structural properties of the samples. Such analysis allows, thus, to highlight the superficial concentration of the iron entities and the interaction with Al as key factors to obtain a good catalytic response

    Productive and sanitary characterization of suckling calves breeding in Córdoba and Santa Fé (Argentina)

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    A study has been made in 72 dairy farms in the Argentine provinces of Cordoba and Santa Fe between years 2000 and 2002. This article is mainly referring to the calves in suckling stage, before its transfer to the pasture. The objective was to make a valuation of the main charac-teristics of farms and the breeding system of dairy calves in the zone. A questionnaire was designed, structuring the questions in six different sections: questions of general type, workers, feeding, handling, other species and contagious, and biosecurity and health. Among the results, it emphasizes the big size of farms, the great diffusion of open systems and the little pursuit of biosecurity measures.Se ha realizado un estudio, entre los años 2000 y 2002, en 72 explotaciones bovinas de aptitud láctea situadas en las provincias argentinas de Córdoba y Santa Fé. El estudio se centró principalmente en las primeras fases de producción de terneros, previamente a su traslado a los pastos. El objetivo fue realizar una valoración de las principales características de las explotaciones y el sistema de cría de terneros en la zona. Para ello, se diseñó un cuestionario, estructu-rándose las preguntas en seis apartados: cuestiones de tipo general, personal, alimentación, prácticas de manejo, otras especies y contagio y, bioseguridad y sanidad. Entre los resultados, destaca el gran tamaño de las explotaciones, la amplia difusión de sistemas abiertos y el escaso seguimiento de medidas de bioseguridad

    Risk factors associated with the antimicrobial resistance of staphylococci in canine pyoderma

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    This study reports the susceptibility to antimicrobial agents of staphylococci 4 (n=105) isolated from dogs, and the factors associated with this resistance. The study 5 animals were 23 healthy dogs (group A), 24 with first-time pyoderma (group B), and 27 6 with recurrent pyoderma that had undergone long-term antibiotic treatment (group C). 7 Staphylococci were more commonly isolated from the pyoderma-affected than the 8 healthy dogs (p<0.0001). 9 10 Some 78% of the isolates were resistant to at least one antimicrobial agent. 11 Resistance to amoxicillin-clavulanate,cephalosporins (OR 4.29, 95% CI [1.15, 16.3] 12 respectively), enrofloxacin (OR 9.47, 95% CI [1.53, 58.5]) and ciprofloxacin (OR 79.7 13 95% CI [3.26, 1947.4]) was more common among group C isolates. Some 32% of all 14 the isolates were multiresistant (MR) and 10.4% were methicillin-resistant (MRS). The 15 probability of isolating MRS staphylococci in group C increased by a factor of four 16 (95% CI [1.18, 17.9]) compared to A plus B. Multi-resistant (MR) isolates were 17 obtained more commonly from urban than rural dogs (OR 3.79, 95% CI [1.09, 13.17]). 18 All the MRS staphylococci encountered were obtained from urban dogs and more 19 commonly from male dogs (p= 0.07). 20 21 This study shows that dogs bred in urban habitat, with a history of antibiotic 22 therapy in the past year represents significant risk of being carriers of isolates resistant 23 to methicillin (MRS) and other antimicrobials. These factors should be considered 24 before applying an antimicrobial treatment in veterinary clinics

    Clinical outcomes of an innovative cefazolin delivery program for MSSA infections in OPAT

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    Cefazolin is a recommended treatment for methicillin-susceptible Staphylococcus aureus (MSSA) infections that has been successfully used in outpatient parenteral antibiotic therapy (OPAT) programs. The aim of this study was to assess the clinical outcomes of cefazolin delivered each day (Group 24) vs. every two days (Group 48) for MSSA infections in OPAT programs. It was a prospective observational study with retrospective analysis of a cohort of MSSA infections attended in OPAT. The primary outcome was treatment success, defined as completing the antimicrobial regimen without death, treatment discontinuation, or readmission during treatment and follow-up. A univariate and multivariate logistic regression model was built. A two-sided p < 0.05 was considered statistically significant. Of the 149 MSSA infections treated with cefazolin 2 g/8 h in OPATs, 94 and 55 patients were included in the delivery Group 24 and Group 48, respectively. Treatment failure and unplanned readmission rates were similar in both groups (11.7% vs. 7.3% p = 0.752 and 8.5% vs. 5.5% p = 0.491). There was a significant increase in vascular access complications in Group 24 (33.0%) with respect to Group 48 (7.3%) (p < 0.001). Treating uncomplicated MSSA infection with cefazolin home-delivered every two days through an OPAT program is not associated with an increased risk of treatment failure and entails a significant reduction in resource consumption compared to daily delivery
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