67 research outputs found

    Durabilidad del hormigón. Influencia de la concentración de cloruros en el agua de amasado y en disolución

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    The most aggressive situation which is responsible for most of the cases of steel reinforcement corrosion in concrete, takes place when chlorides are present in the environment. These chlorides destroy the passivating film of steel and promote the denominated pitting corrosion. In order to study the demonstrated corrosive action of chloride ions on concrete structures, a number of experiments have been designed, to quantify the effect of different amounts of this ion in concrete. Several mixes have been prepared with portland cement type II-C-35 to which it has been added, as an additive in mixing water, NaCl in increasing concentrations. The samples obtained were submerged in different dissolutions of NaCl. From the results obtained it is clear that the chloride content in mixing water does not affect the flux of calcium ions; however, its influence on the flux of chloride ions is significant. Likewise, it is confirmed that the existence of chloride ions in dissolution influences the migration of calcium and chloride ions.La situación más agresiva, y la responsable del mayor número de casos de corrosión de armaduras en el hormigón, se da cuando en el ambiente hay presencia de cloruros, pues éstos destruyen de forma puntual la capa pasivante del acero, lo que provoca la denominada corrosión por picaduras. Con objeto de estudiar la demostrada acción perniciosa de los cloruros sobre las estructuras de hormigón, se ha diseñado un conjunto de ensayos con el fin de cuantificar el efecto de las distintas cantidades de este ion en la masa de hormigón. Se han realizado diversas amasadas con cemento tipo II-C-35 a las que se añadió, como aditivo en el agua de amasado, NaCl en concentraciones crecientes. Las probetas obtenidas se sumergieron en disoluciones de NaCl de distintas concentraciones. De los resultados obtenidos se deduce que la presencia de cloruros en el agua de amasado no afecta al flujo de iones cálcicos, mientras que si es significativa su influencia sobre el flujo de iones cloruros. Asimismo, se comprueba la influencia de la presencia de cloruros en disolución sobre la migración de iones cálcicos y cloruros

    Criterios de implementación ISO 14000:2015 Caso Estudio Sector de Producción y comercialización de pulpa de fruta

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    En el presente documento se realiza el estudio de caso de una empresa cuya actividad productiva está encaminada al procesamiento de frutas para generar pulpa de fruta y posteriormente ser empacada y distribuida con los clientes que tiene la compañía, tanto pequeños y grandes compradores, dentro de los objetivos principales está la oferta de productos de buena calidad para el consumo humano de alimentos procesados y con un buen precio. Cuenta con un talento humano calificado y con última tecnología en procesamiento de frutas, lo cual brinda rapidez en la producción y una alternativa para la preparación de jugos de una forma ágil y funcional en los hogares. La fábrica cuenta dentro de su proceso de producción con la recepción de fruta, la cual es adquirida a diferentes productores y distribuidores según requerimientos de la demanda, posteriormente pasa por un proceso de pesaje, lavado o desinfección, escaldado, pelado, despulpado, clasificación de desechos orgánicos, empacado y almacenamiento en cuartos de refrigeración, algunas actividades realizadas directamente por los operarios de área y otras de forma mecánica a través de máquinas con funciones específicas. Dentro de las problemáticas ambientales identificadas, están los residuos de origen orgánico tales como; semillas, cascara de fruta entre otros similares, que no cuentan con información clara y confiable en términos de disposición final u aprovechamiento. Así mismo está el consumo elevado de agua para las actividades de lavado y procesamiento de fruta.In this document, the case study of a company whose productive activity is aimed at processing fruit is carried out to generate fruit pulp and later be packed and distributed with the clients that the company has, both small and large buyers, within the The main objectives are to offer good quality products for human consumption of processed foods and at a good price. It has a qualified human talent and the latest technology in fruit processing, which provides speed in production and an alternative for the preparation of juices in an agile and functional way in homes. The factory counts within its production process with the reception of fruit, which is acquired from different producers and distributors according to demand requirements, later it goes through a process of weighing, washing or disinfection, blanching, peeling, pulping, classification of organic waste, packaging and storage in refrigeration rooms, some activities carried out directly by area operators and others mechanically through machines with specific functions. Among the environmental problems identified, are organic waste such as; seeds, fruit peel among others similar, that do not have clear and reliable information in terms of final disposal or use. Likewise, there is the high consumption of water for washing and fruit processing activities

    Effects of high-intensity interval versus continuous exercise training on post-exercise heart rate recovery in coronary heart-disease patients.

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    Background: Heart rate recovery (HRR) has been considered a prognostic and mortality indicator in both healthy and coronary patients. Physical exercise prescription has shown improvements in VO2peak and HRR, but most of the studies have been carried out applying continuous training at a moderate intensity, being very limited the use of protocols of high intensity interval training in coronary patients. We aimed to compare the effects of a moderate continous training (MCT) versus a high intensity interval training (HIIT) programme on VO2 peak and HRR. Methods: Seventy three coronary patients were assigned to either HIIT or MCT groups for 8 weeks. Incremental exercise tests in a cycloergometer were performed to obtain VO2peak data and heart rate was monitored during and after the exercise test to obtain heart rate recovery data. Results: Both exercise programmes significantly increase VO2peak with a higher increase in the HIIT group (HIIT: 4.5± 4.46 ml/kg/min vs MCT: 2.46±3.57 ml/kg/min; P=0.039). High intensity interval training resulted in a significantly increase in HRR at the first and second minute of the recovery phase (15,44±7,04 vs 21,22 ±6,62, P <0,0001 and 23,73±9,64 vs 31,52±8,02, p <0,0001, respectively). Conclusions: The results of our research show that the application of HIIT to patients with chronic ischemic heart disease of low risk resulted in an improvement in VO2peak, and also improvements in post-exercise heart-rate recovery, compared with continuous training.pre-print792 K

    Mechanical efficiency of high versus moderate intensity aerobic exercise in coronary heart disease patients: A randomized clinical trial

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    Background: Mechanical efficiency (ME) refers to the ability of an individual to transfer energy consumed by external work. A decreased ME, could represent an increased energy cost during exercise and may, therefore, be limited in terms of physical activity. This study aimed to compare the influence of two different exercise protocols: moderate continuous training (MCT) versus high intensity interval training (HIIT), as part of a cardiac rehabilitation program on ME values among coronary patients.  Methods: One hundred and ten coronary patients were assigned to either HIIT or MCT groups for 8 weeks. Incremental exercise tests in a cycle ergometer were performed to obtain VO2peak. Net energy expenditure (EE) and ME were obtained at intensities corresponding to the first (VT1) and second (VT2) ventilatory thresholds, and at VO2peak. Results: Both exercise programs significantly increase VO2peak with a higher increase in the HIIT group (2.96 ± 2.33 mL/kg/min vs. 3.88 ± 2.40 mL/kg/min, for patients of the MCT and HIIT groups, respectively, p &lt; 0.001). The ME at VO2peak and VT2 only significantly increased in the HIIT group. At VT1, ME significantly increased in both groups, with a greater increase in the HIIT group (2.20 ± ± 6.25% vs. 5.52 ± 5.53%, for patients of the MCT and HIIT groups, respectively, p &lt; 0.001).  Conclusions: The application of HIIT to patients with chronic ischemic heart disease of low risk re- sulted in a greater improvement in VO2peak and in ME at VT1, than when MCT was applied. Moreover, only the application of HIIT brought about a significant increase in ME at VT2 and at VO2peak.

    Cerebral insulin bolus revokes the changes in hepatic lipid metabolism induced by chronic central leptin infusion

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    Central actions of leptin and insulin on hepatic lipid metabolism can be opposing and the mechanism underlying this phenomenon remains unclear. Both hormones can modulate the central somatostatinergic system that has an inhibitory effect on growth hormone (GH) expression, which plays an important role in hepatic metabolism. Using a model of chronic central leptin infusion, we evaluated whether an increase in central leptin bioavailability modifies the serum lipid pattern through changes in hepatic lipid metabolism in male rats in response to an increase in central insulin and the possible involvement of the GH axis in these effects. We found a rise in serum GH in leptin plus insulin-treated rats, due to an increase in pituitary GH mRNA levels associated with lower hypothalamic somatostatin and pituitary somatostatin receptor-2 mRNA levels. An augment in hepatic lipolysis and a reduction in serum levels of non-esterified fatty acids (NEFA) and triglycerides were found in leptin-treated rats. These rats experienced a rise in lipogenic-related factors and normalization of serum levels of NEFA and triglycerides after insulin treatment. These results suggest that an increase in insulin in leptin-treated rats can act on the hepatic lipid metabolism through activation of the GH axisThis research was funded by the Spanish Ministry of Science and Innovation with the help of European FEDER funding (FIS PI19/00166), Ministerio de Economía y Competitividad (BFU 2017-82565-C2-1-R) and the Network Center for Biomedical Research on Obesity and Nutrition (CIBEROBN) Instituto Carlos III. S.C. was supported by CIBEROB

    Mechanical efficiency of high versus moderate intensity aerobic exercise in coronary heart disease patients: A randomized clinical trial.

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    Background: Mechanical efficiency (ME) refers to the ability of an individual to transfer energy consumed by external work. A decreased ME, could represent an increased energy cost during exercise and may, therefore, be limited in terms of physical activity. This study aimed to compare the influence of two different exercise protocols: moderate continuous training (MCT) versus high intensity interval training (HIIT), as part of a cardiac rehabilitation program on ME values among coronary patients. Methods: One hundred and ten coronary patients were assigned to either HIIT or MCT groups for 8 weeks. Incremental exercise tests in a cycle ergometer were performed to obtain VO2peak. Net energy expenditure (EE) and ME were obtained at intensities corresponding to the first (VT1) and second (VT2) ventilatory thresholds, and at VO2peak. Results: Both exercise programs significantly increase VO2peak with a higher increase in the HIIT group (2.96 ± 2.33 mL/kg/min vs. 3.88 ± 2.40 mL/kg/min, for patients of the MCT and HIIT groups, respectively, p < 0.001). The ME at VO2peak and VT2 only significantly increased in the HIIT group. At VT1, ME significantly increased in both groups, with a greater increase in the HIIT group (2.20 ± ± 6.25% vs. 5.52 ± 5.53%, for patients of the MCT and HIIT groups, respectively, p < 0.001). Conclusions: The application of HIIT to patients with chronic ischemic heart disease of low risk resulted in a greater improvement in VO2peak and in ME at VT1, than when MCT was applied. Moreover, only the application of HIIT brought about a significant increase in ME at VT2 and at VO2peak. (Cardiol J 2019; 26, 2: 130–137)post-print251 K

    Retinal Molecular Changes Are Associated with Neuroinflammation and Loss of RGCs in an Experimental Model of Glaucoma

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    Signaling mediated by cytokines and chemokines is involved in glaucoma-associated neuroinflammation and in the damage of retinal ganglion cells (RGCs). Using multiplexed immunoassay and immunohistochemical techniques in a glaucoma mouse model at different time points after ocular hypertension (OHT), we analyzed (i) the expression of pro-inflammatory cytokines, anti-inflammatory cytokines, BDNF, VEGF, and fractalkine; and (ii) the number of Brn3a+ RGCs. In OHT eyes, there was an upregulation of (i) IFN-γ at days 3, 5, and 15; (ii) IL-4 at days 1, 3, 5, and 7 and IL-10 at days 3 and 5 (coinciding with downregulation of IL1-β at days 1, 5, and 7); (iii) IL-6 at days 1, 3, and 5; (iv) fractalkine and VEGF at day 1; and (v) BDNF at days 1, 3, 7, and 15. In contralateral eyes, there were (i) an upregulation of IL-1β at days 1 and 3 and a downregulation at day 7, coinciding with the downregulation of IL4 at days 3 and 5 and the upregulation at day 7; (ii) an upregulation of IL-6 at days 1, 5, and 7 and a downregulation at 15 days; (iii) an upregulation of IL-10 at days 3 and 7; and (iv) an upregulation of IL-17 at day 15. In OHT eyes, there was a reduction in the Brn3a+ RGCs number at days 3, 5, 7, and 15. OHT changes cytokine levels in both OHT and contralateral eyes at different time points after OHT induction, confirming the immune system involvement in glaucomatous neurodegeneration

    Consensus document for ultrasound training in the specialty of Nephrology

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    Grupo de Trabajo en Nefrología Diagnóstica e Intervencionista (GNDI) de la Sociedad Española de Nefrología (SEN).[ES] La ecografía es una herramienta esencial en el manejo del paciente nefrológico que permite el diagnóstico, el seguimiento y la realización de intervencionismo sobre el riñón. La utilidad de los ultrasonidos en Nefrología no se circunscribe exclusivamente al estudio ecográfico del riñón. Mediante ecografía el nefrólogo puede, además, optimizar el manejo de la fístula arteriovenosa para hemodiálisis, medir el riesgo cardiovascular (grosor íntima-media), implantar catéteres centrales para hemodiálisis ecoguiados y ayudar en la colocación de los peritoneales, así como calcular la volemia del paciente mediante ecografía cardiaca básica, ecografía de la vena cava inferior y pulmonar. Desde el Grupo de Trabajo en Nefrología Diagnóstica e Intervencionista (GNDI) de la Sociedad Española de Nefrología (SEN) hemos elaborado este documento de consenso en el que se resumen las principales aplicaciones de la ecografía en Nefrología, incluyendo los requisitos técnicos básicos necesarios, el marco normativo y el nivel de capacitación de los nefrólogos en esta materia. El objetivo de este trabajo es promover la inclusión de la ecografía, tanto diagnóstica como intervencionista, en la práctica clínica habitual del nefrólogo y en la cartera de servicios de Nefrología con la finalidad de ofrecer un manejo diligente, eficiente e integral al paciente nefrológico.[EN] Ultrasound is an essential tool in the management of the nephrological patient allowing the diagnosis, monitoring and performance of kidney intervention. However, the usefulness of ultrasound in the hands of the nephrologist is not limited exclusively to the ultrasound study of the kidney. By ultrasound, the nephrologist can also optimize the management of arteriovenous fistula for hemodialysis, measure cardiovascular risk (mean intimate thickness), implant central catheters for ultrasound-guided HD, as well as the patient's volemia using basic cardiac ultrasound, ultrasound of the cava inferior vein and lungs. From the Working Group on Interventional Nephrology (GNDI) of the Spanish Society of Nephrology (SEN) we have prepared this consensus document that summarizes the main applications of ultrasound to Nephrology, including the necessary basic technical requirements, the framework normative and the level of training of nephrologists in this area. The objective of this work is to promote the inclusion of ultrasound, both diagnostic and interventional, in the usual clinical practice of the nephrologist and in the Nephrology Services portfolio with the final objective of offering diligent, efficient and comprehensive management to the nephrological patient

    Diet quality index as a predictor of treatment efficacy in overweight and obese adolescents: The EVASYON study

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    Background & aim: A diet quality index (DQI) is a tool that provides an overall score of an individual''s dietary intake when assessing compliance with food-based dietary guidelines. A number of DQIs have emerged, albeit their associations with health-related outcomes are debated. The aim of the present study was to assess whether adherence to dietary intervention, and the overall quality of the diet, can predict body composition changes. Methods: To this purpose, overweight/obese adolescents (n = 117, aged: 13–16 years; 51 males, 66 females) were recruited into a multi-component (diet, physical activity and psychological support) family-based group treatment programme. We measured the adolescents’ compliance and body composition at baseline and after 2 months (intensive phase) and 13 months (extensive phase) of follow-up. Also, at baseline, after 6 months, and at the end of follow-up we calculated the DQI. Results: Global compliance with the dietary intervention was 37.4% during the intensive phase, and 14.3% during the extensive phase. Physical activity compliance was 94.1% at 2-months and 34.7% at 13months and psychological support compliance were growing over the intervention period (10.3% intensive phase and 45.3% during extensive phase). Adolescents complying with the meal frequency criteria at the end of the extensive phase had greater reductions in FMI z-scores than those did not complying (Cohen''s d = 0.53). A statistically significant association was observed with the diet quality index. DQI-A variation explained 98.1% of BMI z-score changes and 95.1% of FMI changes. Conclusions: We conclude that assessment of changes in diet quality could be a useful tool in predicting body composition changes in obese adolescents involved in a diet and physical activity intervention programme backed-up by psychological and family support
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