1,402 research outputs found

    Comparative analysis of the alkyl breakdown products from soil humic acids by thermal and wet chemical degradation methods

    Get PDF
    6 pages. Comunicación presentada al citado simposio, celebrado del 17-20 de septiembre, 2002, en Leoben (Austria).Total amounts and distribution patterns of alkyl degradation compounds were analyzed in soil humic acids isolated from a variety of continental Mediterranean ecosystems in Central Spain. Soil physical and chemical characteristics, humic acid composition and biomarker assemblages were studied in 16 representative, undisturbed or degraded forest ecosystems including broad-leaved autochthonous forests, bush formations, cultures, pastures and pine forests. The humic acid fraction of these soils was previously characterized by routine spectroscopic methods (UV-visible, FTIR, 13C and 15N CPMAS NMR). In the present study qualitative and quantitative features of the alkyl domain of humic acids are examined by comparing the structural information provided by independent destructive techniques, with special emphasis on the mild alkaline degradation (sodium perborate) and thermal degradation by Curie-point pyrolysis.Peer reviewe

    Presión venosa central, tiempo de recalentamiento y líquidos totales son factores postoperatorios de morbi-mortalidad en cirugía cardiaca

    Get PDF
    Producción CientíficaOBJETIVOS: Analizar la influencia de factores del postoperatorio inmediato (primer día), como posibles marcadores de la evolución postoperatoria en los enfermos operados de cirugía cardiaca. PACIENTES Y MÉTODOS: Se diseñó un estudio transversal en el que se incluyeron consecutivamente pacientes intervenidos de cirugía cardiaca. Se analizó el efecto de la presión venosa central, el tiempo de recalentamiento hasta alcanzar los 35,5ºC de temperatura central y los líquidos totales administrados en 24 horas, sobre la mortalidad y las complicaciones cardiacas, pulmonares y renales. RESULTADOS: Se incluyeron 236 pacientes. Se observó que la presión venosa central mayor de 18 mmHg, el tiempo de recalentamiento mayor de 6 horas y la administración de líquidos mayores a 5 litros durante las primeras 24 horas, se asoció a un incremento de la mortalidad y a la aparición de complicaciones cardiovasculares, pulmonares y renales. CONCLUSIONES: La presión venosa central, el tiempo de recalentamiento y los líquidos administrados durante el primer día son determinantes de la evolución postoperatoria

    Comparative study of single-dose and 24-hour multiple-dose antibiotic prophylaxis for cardiac surgery

    Get PDF
    Producción CientíficaUse of single-dose antibiotic prophylaxis is associated with reduced antibiotic resistance, lower costs, and fewer problems with drug toxicity and superinfections. We tested the hypothesis that single doses of cefazolin are as effective as a 24-hour regimen of cefazolin in preventing surgical site infections in adults undergoing cardiac procedures. This random, prospective, clinical study included 838 adult patients undergoing elective coronary artery bypass grafting, valve operations, or both. These patients were randomly given a single dose of cefazolin (2 g) or a 24-hour treatment (2-g initial dose, followed by 1 g every 8 hours). Investigators blinded to the drug regimen diagnosed wound infections according to Centers for Disease Control and Prevention criteria. Patient clinical and demographic characteristics were noted, with follow-up for 12 postoperative months. The primary objective was to compare the incidence of surgical infections between groups up to 12 months postoperatively. Results: A total of 419 patients received single-dose cefazolin, and another 419 received the 24-hour treatment. Surgical site infection occurred in 35 (8.3%) patients receiving single doses and 15 (3.6%) patients administered the 24-hour treatment (P ¼ .004). We identified no differences between groups for mortality or duration of hospitalization (preoperative hospitalization, intensive care unit stay, and hospitalization after surgical intervention). The microorganisms isolated showed a similar distribution in both groups. The germs isolated were gram-positive cocci in 86% of the surgical site infections. Single-dose cefazolin used as antibiotic prophylaxis in cardiac surgery is associated with a higher surgical site infection rate than the 24-hour, multiple-dose cefazolin regimen

    Self-reported drug allergies and the diagnostic work-up in the surgical population

    Get PDF
    Producción CientíficaObjective The diagnostic work-up of a drug hypersensitivity reaction is indeed difficult. In general, medical documentation of allergic reactions in medical reports is usually highly deficient or non-existent. The aim of this study was to analyse the prevalence of selfreported drug allergies in the surgical population as well as the criteria used in the diagnosis of drug hypersensitivity reactions. Methods A prospective study with the consecutive participation of 1439 patients, following surgical intervention, attended the Post-Operative Care Unit. Previously, as a routine process during the pre-anesthesia consultation, all patients were questioned about whether they had any drug allergies to report and diagnostic work-up. Results The prevalence of self-reported drug allergies was 8.3% (119/1439): 3.6% considered themselves allergic to b-lactams and 2.4% to non-steroidal anti-inflammatory drugs. Approximately one-third of the subjects (40 out of the 119) had not been subjected to any allergy diagnostic procedure and with 79 (66.4%), the only diagnostic test used by the Allergy Unit had been the skin prick-test. None of those participating in the study had tryptase, methylhistamine, specific IgE or intradermal tests carried out to characterize the diagnosis of the allergic reaction. Conclusions These results show that self-reported drug allergies are highly prevalent and as yet little explored. It is an important prevalence which should bring about modifications to the prescription of certain medicaments. The medical personnel must be made aware of the need to make an accurate diagnosis of allergies to medicaments

    Fuel poverty analysis in three spanish autonomous regions. Some retrofitting policy considerations

    Get PDF
    A person is to be regarded as living ‘in fuel poverty’ if he is a member of a household living on a lower income in a home which cannot be kept warm at a reasonable cost. This situation is mainly triggered by three factors: low household income, lack of energy efficiency and high energy invoices. Some European countries have already made some advantages towards officially defining fuel poverty in their countries. Nevertheless, in Spain only some research has been done and an official definition of the term is yet to come. This research explores the relation among households’ income, energy expenditure and housing stock in three autonomous regions in Spain in order to evaluate the housing stock of the fuel poor as well as to identify those households more in need. The results of the research allow establishing energy retrofitting priorities of existing housing stock as well as identifying current retrofitting policies limitations on order to tackle fuel poverty

    Crystallization and preliminary X-ray diffraction analysis of the N-terminal domain of Paenibacillus barcinonensis xylanase 10C containing the CBM22-1-CBM22-2 tandem

    Get PDF
    A construct containing the CBM22-1-CBM22-2 tandem forming the N-terminal domain of Paenibacillus barcinonensis xylanase 10C (Xyn10C) has been purified and crystallized. A xylan-binding function and an affinity for mixed [beta]-1,3/[beta]-1,4 glucans have previously been demonstrated for some members of the CBM22 family. The sequence of the tandem is homologous to the N-terminal domains found in several thermophilic enzymes. Crystals of this tandem were grown by the streak-seeding method after a long optimization strategy. The structure has been determined by molecular replacement to a resolution of 2.43 Å and refinement is under way. This study represents the first structure containing two contiguous CBM22 modules, which will contribute to a better understanding of the role that this multiplicity plays in fine-tuning substrate affinit

    R&D internationalization and the strategic relevance of the institutional framework in host locations

    Get PDF
    The configuration of host national systems of innovation and the technological international networks established by multinational enterprises (MNE) can become key aspects for the internationalisation decision that may also concern knowledge related activities such as R&D. Through the combination of a theoretical model and empirical analysis, this paper shows to what extent institutional quality becomes a determinant factor for the attraction of foreign R&D activities, these latter being conditioned by the technological and productive capabilities of local contexts and the competitive pressures MNE face in foreign countries. Our contribution is a step further in the explanatory framework of R&D internationalisation and also provides new insights about what are the key reinforcement mechanisms for the attraction of new knowledge intensive investments

    Basalt Fiber Composites with Reduced Thermal Expansion for Additive Manufacturing

    Get PDF
    Fused filament fabrication (FFF) is gaining attention as an efficient way to create parts and replacements on demand using thermoplastics. This technology requires the development of new materials with a reliable printability that satisfies the requirement of final parts. In this context, a series of composites based on acrylonitrile styrene acrylate (ASA) reinforced with basalt fiber (BF) are reported in this work. First, several surface modification treatments are applied onto the BF to increase their compatibility with the ASA matrix. Then, once the best treatment is identified, the mechanical properties, coefficient of thermal expansion (CTE) and warping distortion of the different specimens designed and prepared by FFF are studied. It was found that the silanized BF is appropriate for an adequate printing, obtaining composites with higher stiffness, tensile strength, low CTE and a significant reduction in part distortion. These composites are of potential interest in the design and manufacturing of final products by FFF, as they show much lower CTE values than pure ASA, which is essential to successfully fabricate large objects using this technique

    Cambios coroideos en pacientes glaucomatosos

    Get PDF
    El objetivo de este trabajo fue valorar el espesor coroideo en pacientes glaucomatosos en fases avanzadas de la enfermedad mediante Tomografía de Coherencia Óptica, así como su comparación con una base de sujetos sanos. Se estudiaron 19 pacientes, correspondiendo a un total de 34 ojos diagnosticados de glaucoma en fase avanzada. Las pruebas se realizaron mediante SD-OCT Spectralis OCT (Spectralis®; Heidelberg EngineeringGmbH, Heidelberg, Alemania) identificando la coroides mediante el software EDI. Se adquirieron imágenes tomográficas tanto de retina como de coroides mediante un mapa de rastreo de 25 cortes.El espesor coroideo fue significativamente mayor en el grupo control (302,27 ± 70,83 μm) que en el grupo patológico (235,30 ± 66,40 μm), aunque no pudimos justificar que esta diferencia se debiese al glaucoma debido a la diferencia de edad entre el grupo patológico y el grupo control. En conclusión, la Tomografía de Coherencia Óptica (OCT), mediante el protocolo EDI, es un proceso no invasivocon una excelente resolución para visualizar la capa vascular coroidea en el polo posterior y cuantificarla, tanto en espesores como en volúmenes por cuadrantes. El cuadrante que presenta menor espesor coroideo, tanto para pacientes glaucomatosos como para pacientes sanos, es el nasal. Por el contrario el de mayor espesor es el superior seguido del temporal y del inferior. No hemos podido confirmar que exista una relación directa entre el glaucoma y la disminución de espesor coroideo, al no ser comparables los grupos control y gluacomatoso estudiado
    corecore