Thermodynamic, Kinetic, and Equilibrium Parameters for the Removal of Lead and Cadmium from Aqueous Solutions with Calcium Alginate Beads

The sorption of cadmium (Cd) and lead (Pb) by calcium alginate beads (CAB) from aqueous solutions in batch systems was investigated. The kinetic and thermodynamic parameters, as well as the sorption capacities of CAB in each system at different temperatures, were evaluated. The rate of sorption for both metals was rapid in the first 10 minutes and reached a maximum in 50 minutes. Sorption kinetic data were fitted to Lagergren, pseudo-second-order and Elovich models and it was found that the second-order kinetic model describes these data for the two metals; comparing kinetic parameters for Cd and Pb sorption a higher kinetic rate (K2) for Pb was observed, indicating that the interaction between lead cations and alginate beads was faster than for cadmium. Similarly, isotherm data were fitted to different models reported in literature and it was found that the Langmuir-Freundlich (L-F) and Dubinin-Radushkevich (D-R) models describe the isotherms in all cases. CAB sorption capacity for cadmium was 27.4 mg/g and 150.4 mg/g for lead, at 25°C. Sorption capacities of Cd and Pb increase as temperature rises. According to the thermodynamic parameters, the cadmium and lead adsorption process was spontaneous and endothermic. It was also found that pH has an important effect on the adsorption of these metals by CAB, as more were removed at pH values between 6 and 7

Thermodynamic, Kinetic, and Equilibrium Parameters for the Removal of Lead and Cadmium from Aqueous Solutions with Calcium Alginate Beads

The sorption of cadmium (Cd) and lead (Pb) by calcium alginate beads (CAB) from aqueous solutions in batch systems was investigated. The kinetic and thermodynamic parameters, as well as the sorption capacities of CAB in each system at different temperatures, were evaluated. The rate of sorption for both metals was rapid in the first 10 minutes and reached a maximum in 50 minutes. Sorption kinetic data were fitted to Lagergren, pseudo-second-order and Elovich models and it was found that the second-order kinetic model describes these data for the two metals; comparing kinetic parameters for Cd and Pb sorption a higher kinetic rate ( 2 ) for Pb was observed, indicating that the interaction between lead cations and alginate beads was faster than for cadmium. Similarly, isotherm data were fitted to different models reported in literature and it was found that the LangmuirFreundlich (L-F) and Dubinin-Radushkevich (D-R) models describe the isotherms in all cases. CAB sorption capacity for cadmium was 27.4 mg/g and 150.4 mg/g for lead, at 25 ∘ C. Sorption capacities of Cd and Pb increase as temperature rises. According to the thermodynamic parameters, the cadmium and lead adsorption process was spontaneous and endothermic. It was also found that pH has an important effect on the adsorption of these metals by CAB, as more were removed at pH values between 6 and 7

Case Report: Prone Positioning and Nasal High Flow Oxygen Therapy - An Alternative Strategy to Invasive and Non-Invasive Ventilation in a Case of Severe Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is associated with high rates of mortality, which is directly attributed to the pulmonary inflammatory response then compromising gaseous exchange. This case study describes the successful management of a 63-year-old male with severe ARDS who received a strategy which involved the following interventions: Nasal High Flow Oxygen (NHFO) therapy, and prone positioning. It is thought that this strategy improved the lung volume at end expiration to an extent that the patient was able to avoid both noninvasive (NIV) and invasive mechanical ventilation (MV) (and their known associated risks). There is limited evidence describing the use of NHF therapy in patients with ARDS. The use of prone positioning has been demonstrated to significantly improve 28-day mortality in patients with severe ARDS with a PaO2/FiO2< 150 mmHg. The authors acknowledge that until such time that controlled clinical trials considering the efficacy of strategy are conducted it would be premature to recommend it forall suchcases. The prone position is a promising therapy for patients with spontaneous ventilation with high-flow oxygen therapy; controlled and randomized studies should be done to demonstrate its safety and efficacy

Efecto de una formulación de propóleo en los medios de cultivo para la micropropagación de la papa var Desirée

In the efforts to improve the quality of the plants in the in vitro culture, different alternatives have been tested and put into practice going from the increasing of the asepsis measures, chemical treatment of the plants donors, to the subculture of plants in cultures media with antimicrobial products of synthetic or natural origin. At the Institute of Plants Biotechnology, at the Central University of Las Villas, the influence of a formulation of propolis was evaluated on the growth and multiplication of in vitro plants of potato (Solanum tuberosum L.) from Desirée variety. The phytotoxic effect of this product in culture media was determined in the in vitro multiplication phase, and dilutions of the propolis were made to obtain concentrations from 1 to 200 ppm in ranges of 10 units. After the phytotoxic evaluation the adequate propolis working dose was applied during three subcultures in the in vitro multiplication phase in a comparative way with two treatments; culture medium elaborated with ebullition methods for five minutes. A subculture was also carried out in the in vitro rooting phase and the behavior of these plants in the acclimatization phase was evaluated. Alterations in levels superior to 80 ppm were observed in the morphologic variables evaluated. The treatment with the formulation of propoli presented significantly superior results than control.Key words: aclimatization, multiplication, rootingCon la intención de acelerar el crecimiento de las plantas en el cultivo in vitro, se han estudiado diferentes alternativas entre las que se encuentran el manejo de las condiciones de cultivo y la aplicación de sustancias estimuladoras del crecimiento a los medios de cultivo. El propóleo es un producto de origen natural, a partir de la miel de las abejas; que posee compuestos con una variada actividad biológica, pero aún no se conoce bien la influencia de su aplicación en el crecimiento y desarrollo de las plantas. El presente trabajo se realizó con el objetivo de evaluar el efecto de una formulación del propóleo en los medios de cultivo para la micropropagación de la papa (Solanum tuberosum L.) variedad Desirée. Se determinó el efecto fitotóxico de este producto en la fase de multiplicación in vitro y además, se evaluó su acción sobre las plantas in vitro en la fase enraizamiento y en la fase de aclimatización. Se observaron alteraciones en las variables evaluadas a las plantas in vitro en fase de multiplicación cuando se añadió al medio de cultivo el propóleo desde 80ppm hasta 200ppm lo que indicó fitotoxicidad de la formulación. Sin embargo, a la concentración de 70ppm las plantas in vitro alcanzaron resultados superiores al control en las variables evaluadas, durante todas las fases de la micropropagación.Palabras clave: aclimatización, enraizamiento, multiplicació

Prevalence of Systemic Lupus Erythematosus in Spain: Higher than Previously Reported in other Countries?

[Abstract] Objectives: Prevalence of SLE varies among studies, being influenced by study design, geographical area and ethnicity. Data about the prevalence of SLE in Spain are scarce. In the EPISER2016 study, promoted by the Spanish Society of Rheumatology, the prevalence estimate of SLE in the general adult population in Spain has been updated and its association with sociodemographic, anthropometric and lifestyle variables has been explored. Methods: Population-based multicentre cross-sectional study, with multistage stratified and cluster random sampling. Participants were contacted by telephone to carry out a questionnaire for the screening of SLE. Investigating rheumatologists evaluated positive results (review of medical records and/or telephone interview, with medical visit if needed) to confirm the diagnosis. To calculate the prevalence and its 95% CI, the sample design was taken into account and weighing was calculated considering age, sex and geographic origin. Multivariate logistic regression models were defined to analyse which sociodemographic, anthropometric and lifestyle variables included in the telephone questionnaire were associated with the presence of SLE. Results: 4916 subjects aged 20 years or over were included. 16.52% (812/4916) had a positive screening result for SLE. 12 cases of SLE were detected. The estimated prevalence was 0.21% (95% CI: 0.11, 0.40). SLE was more prevalent in the rural municipalities, with an odds ratio (OR) = 4.041 (95% CI: 1.216, 13.424). Conclusion: The estimated prevalence of SLE in Spain is higher than that described in most international epidemiological studies, but lower than that observed in ethnic minorities in the United States or the United Kingdom

Towards a life cycle sustainability assessment method for the quantification and reduction of impacts of buildings life cycle

The construction and building sectorsare one of the highestconsumersof resourcesand energy. Literature evidences the potentialities of the design phase towardsthe improvement of environmental, economic and social performance of buildings. Thus, the Life Cycle Sustainability Assessment (LCSA) approach is recognized as suitable method. It isbased on the “triple bottom line”principle, to calculate environmental, economic, social impacts produced by buildings during itslife cycle. The present paper aims to present a methodological framework based on anLCSA, used during design stages of buildings and integrated into a building’s design technology such as Building Information Modeling (BIM). A conceptual approach to conduct the data integration and a possible workflow to integrate the LCSA into BIMis proposed. The value of the present approach is the possibility to conductquantitative environmental, economic and social assessment of buildings to guide designers to measure and predict the building’s performanc

Faculty of Business Administration Volume 3. No.4

La sociedad se encuentra en proceso de reforma tecnológica, social, económica y política en la que solamente sobrevivirán las empresas más aptas, siendo esta una época propicia para el liderazgo y la innovación.Editorial. - 5 La relación entre la dirección de empresa y sus asesores. -6 La dinámica de grupos en la empresa. - 7 Sobre la desocupación y la desubicación profesional. - 8 Mas administracií humanísitca. - 10 Situación económica del país y la actividad edificadora. - 11 La oportunidad de la crisis alimentaria. - 12 La importancia de una mayor integración entre la universidad y la industria. - 14 El consumidor en el marketing y en la teoría económica. - 15 El administrador de empresas y su labor de optimización de rendimientos. - 18 Aplicaciones informáticas la sistematización de la administración de condominios. - 21Qué es la función de organización administrativa. - 24 Estrategia competitiva- un enfoque de certidumbre hacia el futuro. - 26 ¿Circulos de calidad?. - 30 Finanzas: administración de la liquidez. - 32 Reseña económica de Santander 1985. - 33 Produce la educacióna distancia verdadera comunicación. - 37 Investigaciones: análisis e implementación de paquetes de software en las áreas de software en las áreas de finanzas, producción y mercadeo. - 38Society is in the process of technological, social, economic and political reform in which only the most suitable companies will survive, this being a propitious time for leadership and innovation

Inter-acciones: apuestas regionales de la investigación en comunicación

Transformación social, desarrollo y gestión de la comunicación en investigación; Educación y comunicación en procesos de transformación cultural; y Medios, convergencia y cibercultura. Además, responde a la pregunta: ¿qué líneas aborda la investigación en Comunicación Social desde la modalidad virtual y a distancia de UNIMINUTO? Lo anterior, con el objetivo de acoplar la investigación básica y aplicada desde el nivel de pregrado, en atención a los retos que afronta la formación del nuevo comunicador social con respecto al componente de investigación e innovación desde los semilleros de investigación; además, en consideración a que los semilleros son un espacio institucional para el fomento de la cultura investigativa institucional y de programas, propiciar la interacción entre la comunidad académica con miras al fortalecimiento de la excelencia académica, el desarrollo social y el progreso científico de la comunidad, así como la generación de la capacidad de trabajo en grupo, la interdisciplinariedad y el establecimiento de redes de investigación