304 research outputs found

    Estudio del régimen de humedad de tres tipos de turba en la etapa de propagación de la albahaca (ocimum basilicum l.)

    Get PDF
    Se estudió el comportamiento del régi­men de humedad de tres tipos de con características diferentes y su efecto en la propagación de la albaha­ca; los sustratos utilizados fueron: turba 100% rubia de origen alemán (tratamiento 1), turba en mezcla 60% rubia y 40% negra también de origen alemán (tratamiento 2) y turba 100% rubia de origen cana­diense que presentaba adición de perlita y vermiculi­ta (tratamiento 3). En el ensayo para cada uno de los sustratos se evaluó la evaporación en bandejas de pro­pagación sin plántulas, la transpiración en bandejas de propagación con plántulas y el sustrato cubierto, y la evapotranspiración en bandejas de propagación con plántulas. Estas bandejas constituyeron la unidad experimental. El diseño escogido fue completamen­te al azar con tres tratamientos y cinco repeticiones. Las variables establecidas para la evaluación fueron: 1) pérdida de agua, 2) porcentaje de germinación, 3) altura de planta, 4) número de hojas y 5) peso fresco. Los resultados de este estudio permitieron concluir que el sustrato que perdió menos agua fue la turba 100% rubia de origen canadiense; en cuanto a la ger­minación, el crecimiento y el desarrollo de plantas, con la turba en mezcla 60% rubia y 40% negra de origen alemán se obtuvo la mejor respuesta

    Evaluation of residue levels of imidacloprid and thiamethoxam after foliar application to the citrus varieties Lane Late, Valencia Late, Rohde Summer, and Nules

    Get PDF
    Neonicotinoids are used to protect citrus trees against pests. Dissipation and persistence of neonicotinoids in pollen and nectar of citrus trees after foliar applications and their potential exposure to pollinators have not been well characterized. Field studies were conducted using three orange and one mandarin varieties to compare the imidacloprid and thiamethoxam residue levels and their decline in pollen and nectar after treatments in pre-bloom close to flowering period and their persistence 1 yr after treatment. The possible risk to honeybees was assessed. In nectar, thiamethoxam and imidacloprid residues were between 61 and 99% lower than in pollen, depending on the citrus variety or/and the days after treatment when applied close to blooming. At the end of the flowering period, imidacloprid in pollen and nectar was not detected in the mandarin variety after treatment in pre-bloom, whereas for thiamethoxam, no residues were detected in nectar but 10 ng/g was detected in pollen. There were no quantifiable levels of residues for either neonicotinoids in pollen or nectar during the flowering period of the following year. Neonicotinoid residue levels and their decline in nectar and pollen in citrus depended on the timing of applications relative to flowering and on the citrus variety. The absence of neonicotinoid residues 1 yr out after foliar applications in all varieties assayed demonstrated that none of the neonicotinoids tested were persistent. The results could be different in other citrus varieties, and therefore, also the exposure assessment for managed pollinators.info:eu-repo/semantics/acceptedVersio

    Liquid systems Based on Tetra(n-butyl)phosphonium Acetate for the Non-dissolving Pretreatment of a Microcrystalline Cellulose (Avicel PH-101)

    Get PDF
    A non-dissolving pretreatment consisting in the direct contact of cellulose and the ionic liquid tetra(n-butyl)phosphonium acetate, or its fluid mixtures with other phosphonium ionic liquids or with molecular liquids such as ethanol or DMSO, causes a reduction in the crystallinity of the popular microcrystalline cellulose-type Avicel PH-101 under mild conditions. At the same time, the degree of polymerization and the thermal stability of the pretreated Avicel remain essentially unaltered with respect to the untreated Avicel. The diminution of the crystallinity has been related to the increase of the reactivity of the pretreated Avicel samples via analysis of the kinetics of their enzymatic hydrolysis. For selected samples, this improved reactivity has been confirmed through their effective carboxymethylation under a simplified and milder reaction procedureThis work was supported by Xunta de Galicia through project ED431B 2020/021, co-funded by the European Regional Development Fund. A.V.P. thanks the Spanish Ministry of Science and Innovation, the Spanish Research State Agency, and the European Social Fund for a “Ramón y Cajal” contract (RYC-2017-22849)S

    Improved concentration of citrus essential oil by solvent extraction with acetate ionic liquids

    Get PDF
    © 2014. This is the accepted manuscript of the following article: Lago, S., Rodríguez, H., Arce, A., & Soto, A. (2014). Improved concentration of citrus essential oil by solvent extraction with acetate ionic liquids. Fluid Phase Equilibria, 361, 37-44. doi: 10.1016/j.fluid.2013.10.036Citrus essential oils have numerous applications in multiple sectors, including food, drink and personal care industries. Although mainly constituted by terpenes, the appealing characteristics of citrus essential oils are due to oxyterpenes and other derived oxygenated compounds. In fact, the presence of terpenes in the essential oil may lead to instability or loss of quality. Therefore, concentration of the oil in its oxyterpene compounds by removal of terpenes is desirable. The techniques currently in use for deterpenation of essential oils present a series of issues. In the search for better deterpenation processes, here the use of ionic liquids as solvents in liquid-liquid extraction is explored. In particular, the ionic liquids 1-ethyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium acetate are investigated for their extraction of oxyterpene from a modelled citrus essential oil composed of limonene (terpene) and linalool (oxyterpene). The choice of the ionic liquids, in addition to other complementary characteristics, was based on a rationale of potential interactions that can be created preferentially with the linalool. The results show a great performance of these acetate-based ionic liquids, as compared to any other ionic or molecular solvent tested to date, for the concentration in oxyterpenes of the citrus essential oilThe authors acknowledge the Ministry of Economy and Competitiveness of Spain for financial support through project CQT2012-33359 (including European Regional Development Fund advanced funding), and through the Ramón y Cajal programme (H.R.)S

    Evaluation of Risk and Preventive Factors for Necrotizing Enterocolitis in Premature Newborns. A Systematic Review of the Literature.

    Get PDF
    Necrotizing enterocolitis (NEC) is a serious condition related to prematurity and the initiation of enteral feeding. In this article, we review the evidence published in recent years on necrotizing enterocolitis risk factors (prematurity, feeding with low-weight formula, existence of intestinal dysbiosis) and protective factors (human milk or donated milk supply, supplementation of human milk with oligosaccharides, probiotics administration, and the determination of disease predictive biomarkers). A systematic review was conducted of preventive, risk and predictive factors for necrotizing enterocolitis in neonates prior to 37 weeks’ gestational age, based on a literature search for clinical trials, meta-analyses, randomized controlled trials and systematic reviews published betweenJanuary2018andOctober2021.Forthispurpose,thePubMed,MEDLINE,and Cochrane Library databases were consulted. The literature search obtained 113 articles, of which 19 were selected for further analysis after applying the inclusion and exclusion criteria. The conclusions drawn from this analysis were that adequate knowledge of risk factors that can be prevented or modified (such as alteration of the intestinal microbiota, oxidative stress, metabolic dysfunction at birth, or alteration of the immunity modulation) can reduce the incidence of NEC in premature infants. These factors include the supplementation of enteral nutrition with human milk oligosaccharides (with prebiotic and immunomodulatory effects), the combined administration of probiotics (especially the Lactobacillus spp and Bifidobacterium spp combination, which inhibits bacterial adhesion effects, improves the intestinal mucosa barrier function, strengthens the innate and adaptive immune system and increases the secretion of bioactive metabolites), the supplementation of human milk with lactoferrin and the use of donated milk fortified in accordance with the characteristics of the premature newborn. The determination of factors that can predict the existence of NEC, such as fecal calprotectin, increased TLR4 activity, and IL6 receptor, can lead to an early diagnosis of NEC. Although further studies should be conducted to determine the values of predictive biomarkers of NEC, and/or the recommended doses and strains of probiotics, lactoferrin or oligosaccharides, the knowledge acquired in recent years is encouraging

    Sensitivity and Specificity of the Newborn Infant Parasympathetic Evaluation Index in Pain Assessment of Very Low Birth Weight Infants

    Get PDF
    Objective This article describes the results of a study investigating the sensitivity and specificity of the Newborn Infant Parasympathetic Evaluation (NIPE) index for detecting the physiological changes resulting from nociception in painful procedures in very low birth weight (VLBW) infants. Study Design A prospective observational study was carried on of 44 newborns at 23 to 32 weeks' gestational age. The sensitivity and specificity of the NIPE index are analyzed using a receiver operating characteristic curve. Most of the painful procedures performed were skin-lancing and venipunctures. Nonpainful procedures consist of no intervention, with an interval of at least 1 hour with painful procedures in each newborn. Results The accuracy of the NIPE index to diagnose mild nociceptive stimulation in VLBW newborns is 73.2%. Conclusion The NIPE index is a useful technique for assessing nociceptive stimulation in newborns, presenting less observer-dependent variability than other pain assessment scales

    Late Neonatal Sepsis in Very-low-birth-weight Premature Newborns Is Associated With Alterations in Neurodevelopment at Twenty-five Months of Age

    Get PDF
    Aim: To evaluate the impact of late-onset sepsis (LOS) on the neurodevelopment of very-low–birth-weight (VLBW) premature infants. Methods: This is a retrospective cohort study of VLBW premature infants.The Mental Development Index (MDI) was determined for a population of 546 VLBW infants, at 14 and 25 months of age, and evaluated using the Bayley test. A history of meningitis or early neonatal sepsis was considered an exclusion criterion. The study parameters analyzed included perinatal variables, the development of neonatal comorbidities and a history of LOS. Multivariate linear regression and multinomial logistic regression analyses were performed. Results: LOS was observed in 115 newborns, among whom microbiological testing showed that 65.0% presented Gram-positive bacteria, with Staphylococcus epidermidis being responsible for 55.4%. There was a significant association between the 25-month MDI and a history of LOS. This represents a decrease of 7.9 points in the MDI evaluation of newborns with a history of LOS. The latter history is also associated with the following neurodevelopmental alternations: mild motor disorders [odds ratio (OR): 2.75; 95% confidence intervals (CI): 1.07–7.05], moderate cognitive delay (OR: 3.07; 95% CI: 1.17–8.00) and cerebral palsy (OR: 2.41; 95% CI: 1.09–5.35). Conclusions: In our study cohort, LOS was associated with alterations in neurodevelopment, including reduced MDI, together with motor and cognitive disorders and cerebral palsy. To improve neurodevelopmental outcomes in this group of newborns, neonatal intensive care unit personnel should focus attention on preventing hospital-acquired infections

    Breast-feeding as protective factor against bronchopulmonary dysplasia in preterm infants

    Get PDF
    Breast-feeding is associated with fewer comorbidities in very-low-birth-weight (VLBW) preterm infants. Bronchopulmonary dysplasia (BPD) of VLBW infants is a multifactorial pathology in which nutritional aspects may be of special importance. The aim of this study is to determine, in a cohort of VLBW infants, whether breast milk nutrition is associated with a reduced prevalence and severity of BPD. A retrospective study was conducted to record the intake of mother's own milk (MOM), pasteurised donor human milk or preterm formula milk in the first 2 weeks of postnatal life of 566 VLBW newborns at our hospital during the period January 2008-December 2021. After applying the relevant exclusion criteria, data for 489 VLBW infants were analysed; 195 developed some degree of BPD. Moderate or severe BPD is associated with less weight gain. Moreover, the preferential ingestion of breast milk in the first and second postnatal weeks had effects associated with lower OR for BPD, which were statistically demonstrable for mild (OR 0·16; 95 % CI 0·03, 0·71) and severe (OR 0·08; 95 % CI 0·009, 0·91) BPD. Breast-feeding during the first weeks of postnatal life is associated with a reduced prevalence of BPD, which is frequently associated with less weight gain as a result of greater respiratory effort with greater energy expenditure

    The Escalada Formation: Characterization of a potential chert supply source in the Cantabrian Mountains (NW Spain) during prehistory

    Get PDF
    [EN] A study of the chert nodules found in the Escalada Formation (Carboniferous, Ponga region, Cantabrian Zone) was carried out as a means to characterise a number of lithic raw materials found in several prehistoric sites of the Cantabrian Mountains (NW Spain). This study comprises fieldwork aimed at locating the outcrops and obtaining samples. Some selected samples from two localities were used for both petrological (macroscopic and microscopic analyses from thin sections) and geochemical (X-ray fluorescence and powder diffraction) analysis. The macroscopic study shows a rather homogeneus coloration and a conchoidal fracture although two extreme types of cherts with a variety of intermediate forms can be differentiated according to the matrix composition. The microscopic analysis shows a high heterogeneity in carbonate versus silica percentage and gentle differences in some other features such as type of silica, origin of carbonates, occurrence of organic matter and type of skeletal components. The results of several geochemical analysis suggest that there are not geochemical features neither in the major elements nor in the traces that allows us to clearly distinguish between the analysed samples. All these studies allow us to define the main features of these chert nodules and to establish several types and varieties among them. Those varieties with high percentage of silica and with a more homogeneous matrix are the most suitable samples for knapping. These results together with the study of the geological and geographical location of archaeological sites suggest that the nodules from the Escalada Formation likely were lithic material supply sources used in knapping activities When aiming to demonstrate the use of these materials at archaeological sites the sole macroscopic analysis of the pieces does not suffice; further analyses, such as those involving thin sections, are necessary. The absence of chert from Escalada Formation in some Mesolithic sites in the area was confirmed via these additional analyses.SIThis study was supported by funds from project AF-87 “Análisis de industrias líticas prehistóricas: materias primas y tecnología” of the Vicerrectorado de Investigación (Universidad de León, Spain)

    Spectral BRDF-based determination of proper measurement geometries to characterize color shift of special effect coatings

    Get PDF
    A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description of the spectral bidirectional reflectance distribution function (BRDF). The analysis of experimental spectral BRDF was carried out by means of principal component analysis. From this analysis, a set of nine measurement geometries was proposed to characterize special effect coatings. It was shown that, for two different special effect coatings, these geometries provide a good prediction of their complete color shift.The authors are grateful to “Plan Nacional de Física” for funding this work (FIS2010-19756-E), to CSIC’s JAE Program, and the “European Social Fund” for awarding us a research trainee. This study was also supported by the Spanish Ministry of Economy and Competitiveness under the grant DPI2011-30090-C02-02 and the European Union
    corecore