365 research outputs found
Activity of materials microporous and mesoporous (M41S, SBA-15) in the Friedel-Crafts alkylation of toluene with benzyl choride
Friedel-Crafts alkylation of p- xylene on Zr-SBA-15 material S:conventionasl heating versus microwave irradiation
Fertilización nitrogenada en olivo cv. Empeltre. II.- composición polifenólica de hojas y frutos y calidad del aceite
4 Pags.- 1 Tabl.- 3 Figs.El establecimiento de posibles relaciones entre el estado nutricional del olivo, la composición
polifenólica de sus hojas y frutos y la calidad del aceite, sólo puede llevarse a cabo en experimentos de
fertilización controlados, donde se estudie el efecto de un sólo elemento nutriente, manteniendo constantes
todos los demás parámetros agronómicos. Este es el objetivo del presente trabajo.
Realizar un estudio de este tipo, es tarea compleja, interdisciplinar, y exige un largo periodo de
tiempo de observación y seguimiento. Nuestro equipo la ha abordado, aunque consciente de que no se
puede llegar en corto plazo a resultados concluyentes. La reconocida calidad de los aceites de Aragón
(GRACIA, 1991, 1996, 2001) y la peculiaridad de las principales variedades aquí implantadas, Empeltre y
Arbequina, han motivado la puesta en marcha de dos experimentos de fertilización con árboles jóvenes (uno
en cada variedad), que puedan contribuir a mejorar su conocimiento. En dos trabajos previos (MONGE et
al., 2002 a y b) se da cuenta de los datos relativos a cada uno de los experimentos, así como de los primeros
resultados del estudio de los suelos, del estado nutritivo de los árboles y del crecimiento de éstos. El
presente trabajo sintetiza los primeros datos obtenidos en el ensayo de fertilización nitrogenada con la
variedad Empeltre sobre el contenido de los polifenoles en hoja y fruto y sobre la calidad del aceite.Este trabajo ha sido subvencionado por el MAPA, Programa de Mejora de la Calidad de la
Producción de Aceite de Oliva, proyecto CAO99-020-C2.Peer reviewe
Microwave-assisted versatile hydrogenation of carbonyl compounds using supported metal nanoparticles
Impact of using an evidence-based clinical guideline for the management of primary vesicoureteral reflux in children
Objective: To analyze changes in the therapeutic approach at a tertiary care hospital following the implementation of a clinical guideline for the treatment of primary vesicoureteral reflux (VUR) in children. Population and methods: Retrospective study conducted in a cohort of patients with primary VUR (1989-2015) aged 0-15 years at a tertiary care hospital. The therapeutic approach before and after the development of the clinical guideline (2008) was compared. Results: A total of 297 patients (49.8% boys, 50.2% girls) were included; their mean age at the time of diagnosis was 21.71 months. VUR grading was: VUR I-III 45.1%, VUR IV-V 54, 9%; 124 were treated after the implementation of the clinical guideline (group 1), and 173, before (group 2). The mean follow-up period was 124.32 months. A conservative approach was the initial treatment in 70.3% of group 1 patients and 67.9% of group 2 patients. The number of surgeries remains constant (31.45% versus 31.79%), with an increase in the number of endoscopic surgeries (p< 0.005). The profile of patients has changed based on the application of the algorithm proposed by the guideline. Fewer surgeries were done in patients with VUR IV-V (82.32% versus 59.9%, p= 0.000) and there were fewer cases of kidney damage at diagnosis (49.4% versus 9.8%, p= 0.000). Conclusions: The implementation of the clinical guideline has favored an initially conservative approach in patients with severe grade VUR and nephropathy, for whom surgery was traditionally indicated initially. Using clinical guidelines favors a unanimous, evidence-based approach that reduces the performance of unnecessary invasive procedures
A novel and chemoselective process of N-alkylation of aromatic nitrogen compounds using quaternary ammonium salts as starting material
Artículo Internacional Open AccesThe process of N-alkylation of several pyrroles, indoles, and derivative heterocycles is herein described, using quaternary ammonium salts as the source of an alkylating agent. These reactions were carried out on several heterocyclic rings with triethylbenzylammonium chloride or tetradecyltrimethyl ammonium bromide and an NaOH solution at 50%, leading to a chemoselective N-alkylated product and an average yield of 73%. This is an alternative process to the traditional benzylation and methylation of N-heterocycles with direct handling of alkyl halides.CONACYT, Secretaría de Investigación y Estudios Avanzados de la UAE
Correlates of ideal cardiovascular health in European adolescents: The HELENA study
Background and aims: The ideal cardiovascular health (iCVH) construct consists of 4 health behaviors (smoking status, body mass index, physical activity and diet) and 3 health factors (total cholesterol, blood pressure and fasting glucose). A greater number of iCVH components in adolescence are related to better cardiovascular health, but little is known about the correlates of iCVH in adolescents. Thus, the aim of the study was to examine correlates of iCVH in European adolescents.
Methods and results: The study comprised 637 European adolescents with complete iCVH data. Participants were part of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study, a cross-sectional, multicenter study conducted in 9 different European countries. Correlates investigated were sex and age, family affluence scale, maternal education, geographic location, sleep time, television viewing, duration of pregnancy, birth weight and breastfeeding. Younger adolescents, those whose mothers had medium/high education or those whowatched television less than 2 h per day had a greater number of iCVH components compared to those who were older, had a mother with low education or watched television 2 h or more daily (P <= 0.01).
Conclusion: Since in our study older adolescents had worse iCVH than younger adolescents, early promotion of cardiovascular health may be important. Future studies mayalso investigate the usefulness of limiting television viewing to promote iCVH. Finally, since adolescents of mothers with low education had poorer iCVH, it may be of special interest to tailor public health promotion to adolescents from families with low socioeconomic status
Evaluating maize genotype performance under low nitrogen conditions using RGB UAV phenotyping techniques
Maize is the most cultivated cereal in Africa in terms of land area and production, but low soil nitrogen availability often constrains yields. Developing new maize varieties with high and reliable yields using traditional crop breeding techniques in field conditions can be slow and costly. Remote sensing has become an important tool in the modernization of field-based high-throughput plant phenotyping (HTPP), providing faster gains towards the improvement of yield potential and adaptation to abiotic and biotic limiting conditions. We evaluated the performance of a set of remote sensing indices derived from red–green–blue (RGB) images along with field-based multispectral normalized difference vegetation index (NDVI) and leaf chlorophyll content (SPAD values) as phenotypic traits for assessing maize performance under managed low-nitrogen conditions. HTPP measurements were conducted from the ground and from an unmanned aerial vehicle (UAV). For the ground-level RGB indices, the strongest correlations to yield were observed with hue, greener green area (GGA), and a newly developed RGB HTPP index, NDLab (normalized difference Commission Internationale de I´Edairage (CIE)Lab index), while GGA and crop senescence index (CSI) correlated better with grain yield from the UAV. Regarding ground sensors, SPAD exhibited the closest correlation with grain yield, notably increasing in its correlation when measured in the vegetative stage. Additionally, we evaluated how different HTPP indices contributed to the explanation of yield in combination with agronomic data, such as anthesis silking interval (ASI), anthesis date (AD), and plant height (PH). Multivariate regression models, including RGB indices (R2 > 0.60), outperformed other models using only agronomic parameters or field sensors (R2 > 0.50), reinforcing RGB HTPP’s potential to improve yield assessments. Finally, we compared the low-N results to the same panel of 64 maize genotypes grown under optimal conditions, noting that only 11% of the total genotypes appeared in the highest yield producing quartile for both trials. Furthermore, we calculated the grain yield loss index (GYLI) for each genotype, which showed a large range of variability, suggesting that low-N performance is not necessarily exclusive of high productivity in optimal conditions.This research and APC was funded by Bill & Melinda Gates Foundation and USAID Stress Tolerant Maize for Africa program, grant number [OPP1134248], and the MAIZE CGIAR research program. The CGIAR Research Program MAIZE receives W1&W2 support from the Governments of Australia, Belgium, Canada, China, France, India, Japan, Korea, Mexico, Netherlands, New Zealand, Norway, Sweden, Switzerland, U.K., U.S., and the World Bank
Leaf versus whole-canopy remote sensing methodologies for crop monitoring under conservation agriculture: a case of study with maize in Zimbabwe
Enhancing nitrogen fertilization efficiency for improving yield is a major challenge for smallholder farming systems. Rapid and cost-effective methodologies with the capability to assess the effects of fertilization are required to facilitate smallholder farm management. This study compares maize leaf and canopy-based approaches for assessing N fertilization performance under different tillage, residue coverage and top-dressing conditions in Zimbabwe. Among the measurements made on individual leaves, chlorophyll readings were the best indicators for both N content in leaves (R < 0.700) and grain yield (GY) (R < 0.800). Canopy indices reported even higher correlation coefficients when assessing GY, especially those based on the measurements of the vegetation density as the green area indices (R < 0.850). Canopy measurements from both ground and aerial platforms performed very similar, but indices assessed from the UAV performed best in capturing the most relevant information from the whole plot and correlations with GY and leaf N content were slightly higher. Leaf-based measurements demonstrated utility in monitoring N leaf content, though canopy measurements outperformed the leaf readings in assessing GY parameters, while providing the additional value derived from the affordability and easiness of using a pheno-pole system or the high-throughput capacities of the UAVs
Oral vaccination with heat inactivated Mycobacterium bovis activates the complement system to protect against tuberculosis
Tuberculosis (TB) remains a pandemic affecting billions of people worldwide, thus stressing the need for new vaccines. Defining the correlates of vaccine protection is essential to achieve this goal. In this study, we used the wild boar model for mycobacterial infection and TB to characterize the protective mechanisms elicited by a new heat inactivated Mycobacterium bovis vaccine (IV). Oral vaccination with the IV resulted in significantly lower culture and lesion scores, particularly in the thorax, suggesting that the IV might provide a novel vaccine for TB control with special impact on the prevention of pulmonary disease, which is one of the limitations of current vaccines. Oral vaccination with the IV induced an adaptive antibody response and activation of the innate immune response including the complement component C3 and inflammasome. Mycobacterial DNA/RNA was not involved in inflammasome activation but increased C3 production by a still unknown mechanism. The results also suggested a protective mechanism mediated by the activation of IFN-γ producing CD8+ T cells by MHC I antigen presenting dendritic cells (DCs) in response to vaccination with the IV, without a clear role for Th1 CD4+ T cells. These results support a role for DCs in triggering the immune response to the IV through a mechanism similar to the phagocyte response to PAMPs with a central role for C3 in protection against mycobacterial infection. Higher C3 levels may allow increased opsonophagocytosis and effective bacterial clearance, while interfering with CR3-mediated opsonic and nonopsonic phagocytosis of mycobacteria, a process that could be enhanced by specific antibodies against mycobacterial proteins induced by vaccination with the IV. These results suggest that the IV acts through novel mechanisms to protect against TB in wild boar.This research was supported by Plan Nacional I+D+I AGL2011-30041 from Ministerio de Economía y Competitividad (MINECO), Spain and FEDER. This is also a contribution to EU FP7 grant WildTBvac and the EU FP7 ANTIGONE project number 278976. R.C. Galindo was funded by MEC, Spain. B. Beltrán-Beck was supported by MINECO grant BES-2009-017401.Peer Reviewe
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