61 research outputs found

    Tratamiento hidrolítico de Luffa Cylindrica (LC) para la obtención de azúcares reductores

    Get PDF
    In this study, reducing sugars production by LuffaCylindrica (LC) hydrolysis was evaluated. The celluloseand lignin content (82.54% and 9.73%) of rawmaterial, was determined and reduced in size by acutter mill to a size of 100 mesh. The maximumreducing sugar content obtained was 1.207 mg/mL, 1.493 mg/mL and 2.441 mg/mL for acid, basicand enzymatic hydrolysis respectively. The optimalconditions of pH, time and temperature foracid hydrolysis ( pH 4.0, 60 min, 150°C), alkalinehydrolysis (pH 10, 30 min, 112,5 °C) and enzymatichydrolysis to pH, amount of cellulose and temperature(pH 6.2, 2.39 mL, 42.4°C) were determinedby a design type Box-Behnken. Fermentation studieswere performed with immobilized SaccharomycesCerevisiae at different conditions in order to validatemodels obtained for each type of hydrolysisand achieved yields of 10% ethanol content fortreatments studied.En este trabajo se evaluó la producción de azúcaresreductores a partir de hidrólisis de Luffa Cylindrica(LC). Se determinó el contenido de celulosa(82,54%) y lignina (9,73%), de la materia prima y seredujo de tamaño, mediante un molino de cuchillashasta malla 100. El máximo contenido de azúcaresreductores obtenidos fue 1.207 mg/mL, 1.493 mg/mL y 2.441 mg/mL para las hidrólisis acida, básicay enzimática, respectivamente. Un diseño tipo Box-Behnken, permitió determinar las condiciones óptimasde pH, tiempo y temperatura para las hidrólisisácida (pH 4.0, 60 min, 150°C) y básica (pH 10.0, 30min, 112.5°C), así como pH, volumen de celulasa,y temperatura para la hidrólisis enzimática (pH 6.2,2.39 mL y 42.4°C). Se realizaron estudios fermentativoscon Saccharomyces Cerevisiae inmovilizada, a diferentescondiciones, con el fin de validar los modelosobtenidos en cada tipo de hidrólisis y se alcanzaronrendimientos del orden del 10% en contenido de alcohol,para los tratamientos estudiados

    Caracterización morfoagronómica de cacao criollo (Theobroma cacao L.) y su incidencia en la selección de germoplasma promisorio en áreas de presencia natural en El Salvador

    Get PDF
    En El Salvador el cultivo de cacao, se proyecta como un rubro nuevo de producción agrícola tanto en el ámbito nacional como internacional, constituyendo una oportunidad para el desarrollo económico de productores interesados en este cultivo; por tal motivo se realizó un proceso de prospección de esta especie entre el período de octubre 2013 a junio 2014, iniciando colectas de frutos y material vegetativo de cacao en áreas de presencia natural de la especie. El objetivo fue identificar in situ árboles de cacao para la caracterización morfoagronómica, utilizando descriptores adaptados al catálogo de cultivares de cacao del Perú, CATIE y FEDECACAO, se identificaron zonas donde había presencia de la especie, en los municipios de Caluco, en Sonsonate; el Salitre, Ciudad Delgado y Planes de Renderos, San Salvador; Tenancingo, Cuscatlán; San Pedro Nonualco y Santa María Ostuma, La Paz; Ciudad Victoria, Cabañas y Jucuapa, Usulután. Se caracterizaron 21 árboles; cada uno con sus respectivos atributos cualitativos y cuantitativos como: altura del árbol, forma y tamaño de hojas, frutos, semillas y flores. Cada árbol muestreado, fue georeferenciado, con el fin de ubicarlo y generar el mapa de distribución de los mismos a nivel nacional. Asimismo, en el laboratorio de Química Agrícola de la Facultad de Ciencias Agronómicas, se realizó análisis bromatológicos a muestras de frutos, determinando: grasa, proteína, ceniza, hierro, zinc, humedad total, humedad parcial y materia seca. Como resultados de esta investigación, se inició una colección de cacao con atributos sobresalientes, los mayores porcentajes de grasa lo obtuvieron los árboles codificados como: UES-PDP-19, con 56.4%; UES-SPN-7 con 50.67% y UES-SPN-8 con 50.29%; y los mayores porcentajes de proteína se identificaron para las accesiones, UES-SLT-16, con 27.38%; UES-TNG-18, con 23.36%; y UES-SAL-3 con 21.31%; parámetros que son importantes al momento de hacer programas de producción, mejoramiento genético y en la preservación de este germoplasma

    Occurrence and distribution of Bemisia tabaci and Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) on tomato crops in Panama

    Get PDF
    The main open-field and greenhouse producer regions of tomato in Panama (Los Santos, Herrera, Veraguas and Chiriquí provinces) were surveyed to determine the occurrence and distribution of Bemisia tabaci and Trialeurodes vaporariorum during the growing seasons of 2017 and 2018. Twenty-two plots were surveyed, and DNA extracts of 112 adult whiteflies were analyzed by multiplex PCR, using a set of specific primers of B. tabaci MEAM1, B. tabaci NW, and T. vaporariorum. DNA extracts corresponding to 57 individual whiteflies (50.9 %) rendered PCR products of expected size with B. tabaci-specific primers (37 belonged to B. tabaci MEAM1 and 20 to B. tabaci NW), whereas the remaining DNA extracts corresponding to 55 individual whiteflies (49.1 %) rendered the product of the expected size with T. vaporariorumspecific primers. The sequencing of those PCR products and BLAST analysis allowed for the identification of B. tabaci MEAM1, B. tabaci NW, and T. vaporariorum. Bemisia tabaci NW was detected in all four provinces, while B. tabaci MEAM1 was detected in the provinces of Los Santos, Herrera and Chiriquí, and T. vaporariorum was detected only in the province of Chiriquí. Bemisia tabaci MEAM1, B. tabaci NW and T. vaporariorum were detected in both production systems (open fields and greenhouse). Bemisia tabaci MEAM1 and B. tabaci NW were detected in the tropical rainforest (Af) and tropical savanna (Aw) climates, at an altitudinal range of 19–1543 meters above sea level (MASL), while Trialeurodes vaporariorum was found only in the Af climate, at an altitudinal range of 818–1661 MASL. To our knowledge, this is not only the first report of B. tabaci MEAM1 and B. tabaci NW at an altitude above 1000 MASL in Panama, but it is also the first report of T. vaporariorum at an altitude under 1000 MASL in this country. Information about the identification and geographic distribution of whiteflies in Panama will help to design effective strategies for pest management

    Healthcare providers' adherence to breast cancer guidelines in Europe : a systematic literature review

    Get PDF
    Clinical guidelines' (CGs) adherence supports high-quality care. However, healthcare providers do not always comply with CGs recommendations. This systematic literature review aims to assess the extent of healthcare providers' adherence to breast cancer CGs in Europe and to identify the factors that impact on healthcare providers' adherence. We searched for systematic reviews and quantitative or qualitative primary studies in MEDLINE and Embase up to May 2019. The eligibility assessment, data extraction, and risk of bias assessment were conducted by one author and cross-checked by a second author. We conducted a narrative synthesis attending to the modality of the healthcare process, methods to measure adherence, the scope of the CGs, and population characteristics. Out of 8137 references, we included 41 primary studies conducted in eight European countries. Most followed a retrospective cohort design (19/41; 46%) and were at low or moderate risk of bias. Adherence for overall breast cancer care process (from diagnosis to follow-up) ranged from 54 to 69%; for overall treatment process [including surgery, chemotherapy (CT), endocrine therapy (ET), and radiotherapy (RT)] the median adherence was 57.5% (interquartile range (IQR) 38.8-67.3%), while for systemic therapy (CT and ET) it was 76% (IQR 68-77%). The median adherence for the processes assessed individually was higher, ranging from 74% (IQR 10-80%), for the follow-up, to 90% (IQR 87-92.5%) for ET. Internal factors that potentially impact on healthcare providers' adherence were their perceptions, preferences, lack of knowledge, or intentional decisions. A substantial proportion of breast cancer patients are not receiving CGs-recommended care. Healthcare providers' adherence to breast cancer CGs in Europe has room for improvement in almost all care processes. CGs development and implementation processes should address the main factors that influence healthcare providers' adherence, especially patient-related ones. Registration:: PROSPERO (CRD42018092884)

    Concentration Endurance Test (d2): Normative data for Spanish-speaking pediatric population

    Get PDF
    OBJECTIVE: To generate normative data for the Concentration Endurance Test (d2) in Spanish-speaking pediatric populations. METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the d2 test as part of a larger neuropsychological battery. The Total number of items processed (TN), Total number of correct responses (CR), Total performance (TP), and Concentration performance (CP) scores were normed using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental education (MLPE) were included as predictors in the analyses. RESULTS: The final multiple linear regression models showed main effects for age on all scores, such that scores increased linearly as a function of age. TN scores were affected by age2 for Guatemala and Puerto Rico; CR scores were affected by age2 for Mexico; TP scores were affected by age2 for Chile, Mexico, Puerto Rico, and Spain; and CP scores for Mexico and Spain. Models indicated that children whose parents had a MLPE >12 years obtained higher scores compared to children whose parents had a MLPE≤12 years for Mexico and Spain in all scores, and Puerto Rico for TN, CR, and TP, and Guatemala and Paraguay for CP scores. Sex affect the scores for Ecuador and Honduras (CP scores). CONCLUSIONS: This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate approach to interpret the d2 test in pediatric populations

    A mistletoe tale: postglacial invasion of Psittacanthus schiedeanus (Loranthaceae) to Mesoamerican cloud forests revealed by molecular data and species distribution modeling

    Full text link

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

    Get PDF
    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
    corecore