15 research outputs found
Espectros y reaccionabilidad frente a iones inorgánicos de los compuestos 2-piridilaldehido-2-quinolhidrazona, 2-piridilaldehido-2-quinolilhidracida y 6-metil-2-piridilaldehido-2-quinolilhidracida
Se obtienen dos nuevos reactivos 2-piridilaldehido-2-quinolilhidracida y 6-metil-2-piridilaldehido-2-quinolilhidracida, de los que se determina su punto de fusión, espectro i. r. y u. v. Se estudia la reaccíonabilidad de ambos, así como con la del 2-piridilaldehido-2-quinolilhidrazona
Determinación espectrofotométrica de V(V) mediante 2-piraldilaldehido-2-quinolilhidrazona
El vanadio reacciona con 2-piridilaldehido-2-quinolilhidrazona (PAQH) en medio hidroalcohólico, entre valores de pH aparentes comprendidos entre 3 y 5 (pD = 6'3) formando un complejo cuya estequiometria, determinada por métodos espectrofotométricos, es de 2: 1 (reactivo: catión); el complejo, de color rojo, es estable por lo menos durante 2 horas, presentando máxima absorción a los valores de pH comprendidos entre 4 y 5'2. Se establece un nuevo método para la determinación espectrofotométrica de V(V), con menor error dentro del intervalo comprendido entre 2 y 5 ppm. El coeficiente de extinción molar es de (10'0 ± 0'3). 103 y la constante de inestabilidad es de pK = 8'00 ± 0'04.Vanadium (V) reacts with the 2-pyridinealdehyde-2-quinolylhydrazone
in hydroalcoholic mixtures at pH values between 3 and 5 (pD = 6'3),
glving a complex which stoichlometry from spectrophotometric data has
been establ1shed as 2: 1 (reag,ent: cation). This red coloured complex is
stable 2 hours at least and its maximal absorption is shown between the
pH values 4 and 5"2. The opti- caI den sities of the solutlons of that complex
obey the Lambert-Beer law in the range of concentrations between 0'5
and 6 ppm. of vanadium. The molar absoptivity coefficient is (10'0 ±
0'3) . 103 and the unstability 'constant pK = 8'00 ± 0'04
Grain quality as Influenced by the structural properties of weed communities in Mediterranean wheat crops
Weed community structure, including composition, taxonomic and functional diversity,
may explain variability in crop quality, adding to the variability accounted by management, climatic
and genetic factors. Focusing on Mediterranean rainfed wheat crops, we sampled weed communities
from 26 fields in Spain that were either organically or conventionally managed. Weed communities
were characterized by their abundance and taxonomic, compositional and trait-based measures.
Grain protein concentration and the glutenin to gliadin ratio were used as indicators of wheat grain
quality. Linear mixed effects models were used to analyze the relationship between crop quality
and weed community variables, while accounting for environmental factors. Nitrogen fertilization,
previous crop and precipitation explained a large portion of the variation in wheat grain protein
concentration (R2marginal = 0.39) and composition (R2marginal = 0.26). Weed community measures had
limited effects on grain quality (increasing R2marginal of models by 1% on average). The weed effects
were related to the composition and the functional structure of their communities, but not to their
abundance. Environmental conditions promoting higher protein concentration were also selecting for
weed species with competitive attributes, whereas the role of weed functional diversity depended on
the functional trait and on the resource limiting crop grain quality. Understanding the mechanisms of
weed effects on crop quality could aid on designing sustainable weed management practices.This research was supported by grants AGL2012-33736 and AGL2015-64130-R funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”. D.J.G. was partially supported by the United States National Science Foundation (DUE 1758497 and DUE 1949969)Postprint (published version
Self-reported DHA supplementation during pregnancy and its association with obesity or gestational diabetes in relation to DHA concentration in cord and maternal plasma: results from NELA, a prospective mother-offspring cohort.
©2021. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by /4.0/
This document is the Published, version of a Published Work that appeared in final form in Nutrients. To access the final edited and published work see https://doi.org/10.3390/nu13030843Maternal supplementation of docosahexaenoic acid (DHA) during pregnancy has been recommended due to its role in infant development, but its effect on materno-fetal DHA status is not well established. We evaluated the associations between DHA supplementation in pregnant women with obesity or gestational diabetes mellitus (GDM) and maternal and neonatal DHA status. Serum fatty acids (FA) were analyzed in 641 pregnant women (24 weeks of gestation) and in 345 venous and 166 arterial cord blood samples of participants of the NELA cohort. Obese women (n = 47) presented lower DHA in serum than those lean (n = 397) or overweight (n = 116) before pregnancy. Linoleic acid in arterial cord was elevated in obese women, which indicates lower fetal retention. Maternal DHA supplementation (200 mg/d) during pregnancy was associated with enhanced maternal and fetal DHA levels regardless of pre-pregnancy body mass index (BMI), although higher arterial DHA in overweight women indicated an attenuated response. Maternal DHA supplementation was not associated with cord venous DHA in neonates of mothers with GDM. The cord arteriovenous difference was similar for DHA between GDM and controls. In conclusion, maternal DHA supplementation during pregnancy enhanced fetal DHA status regardless of the pre-pregnancy BMI while GDM may reduce the effect of DHA supplementation in newborns
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El vanadio reacciona con 2-piridilaldehido-2-quinolilhidrazona (PAQH) en medio hidroalcohólico, entre valores de pH aparentes comprendidos entre 3 y 5 (pD = 6'3) formando un complejo cuya estequiometria, determinada por métodos espectrofotométricos, es de 2: 1 (reactivo: catión); el complejo, de color rojo, es estable por lo menos durante 2 horas, presentando máxima absorción a los valores de pH comprendidos entre 4 y 5'2. Se establece un nuevo método para la determinación espectrofotométrica de V(V), con menor error dentro del intervalo comprendido entre 2 y 5 ppm. El coeficiente de extinción molar es de (10'0 ± 0'3). 103 y la constante de inestabilidad es de pK = 8'00 ± 0'04.Vanadium (V) reacts with the 2-pyridinealdehyde-2-quinolylhydrazone in hydroalcoholic mixtures at pH values between 3 and 5 (pD = 6'3), glving a complex which stoichlometry from spectrophotometric data has been established as 2: 1 (reagent: cation). This red coloured complex is stable 2 hours at least and its maximal absorption is shown between the pH values 4 and 5"2. The opti- caI den sities of the solutlons of that complex obey the Lambert-Beer law in the range of concentrations between 0'5 and 6 ppm of vanadium. The molar absoptivity coefficient is (10'0 ± 0'3) . 103 and the unstability constant pK = 8'00 ± 0'04
Grain Quality as Influenced by the Structural Properties of Weed Communities in Mediterranean Wheat Crops
Weed community structure, including composition, taxonomic and functional diversity, may explain variability in crop quality, adding to the variability accounted by management, climatic and genetic factors. Focusing on Mediterranean rainfed wheat crops, we sampled weed communities from 26 fields in Spain that were either organically or conventionally managed. Weed communities were characterized by their abundance and taxonomic, compositional and trait-based measures. Grain protein concentration and the glutenin to gliadin ratio were used as indicators of wheat grain quality. Linear mixed effects models were used to analyze the relationship between crop quality and weed community variables, while accounting for environmental factors. Nitrogen fertilization, previous crop and precipitation explained a large portion of the variation in wheat grain protein concentration (R2marginal = 0.39) and composition (R2marginal = 0.26). Weed community measures had limited effects on grain quality (increasing R2marginal of models by 1% on average). The weed effects were related to the composition and the functional structure of their communities, but not to their abundance. Environmental conditions promoting higher protein concentration were also selecting for weed species with competitive attributes, whereas the role of weed functional diversity depended on the functional trait and on the resource limiting crop grain quality. Understanding the mechanisms of weed effects on crop quality could aid on designing sustainable weed management practices
Weed vegetation, crop yield and quality and management of 26 wheat fields of Mediterranenan Spain
[Method] The study was carried out in 2013–2014 across 26 wheat fields (Triticum aestivum L. and Triticum turgidum subsp. durum Desf.) under a Mediterranean climate in Spain. Fields were either organically or conventionally managed and were located in cereal areas in four Spanish regions: Andalusia (15 fields), Madrid (3 fields), Castilla-La Mancha (4 fields) and Catalonia (4 fields). In each field, ten (1 m × 1 m) plots were established during crop tillering and maintained until harvest. Weeds were sampled at the end of the crop vegetative period (April with dates slightly varying depending on field location). In each plot we recorded the weed species present, and we visually assessed the cover (in cm2) of each weed species and the crop. We also measured plant height (cm). Immediately before crop harvest, we sampled the plots again to obtain crop yield. In each plot we counted the number of wheat stems with ears and cut 30 of them. We determined the dry weight (after 48 h at 65 °C) of the 30 stems, threshed the ears and weighed the grain for each sample. In doing this we obtained an average value for the grain weight of an ear. We calculated crop grain weight in each plot multiplying mean grain weight of each sample by the total number of fertile stems in the plot. In each plot, we obtained two measures of grain quality: the percentage of total dry protein content determined using the Kjeldahl standard method at the Laboratorio Agroalimentario de Córdoba (Córdoba, Spain) and the glutenin to gliadin ratio. The amount of glutenin and gliadin in each plot, was obtained from 100 mg of wheat flour. First, we ground the wheat grains of each sample using a ball mill to obtain flour of a 100 µm particle size. The extraction of gliadin and glutenin proteins was done using a modified classical Osborne procedure based on protein solubility. The method is described in detail in Wieser et al. (1998) and Pistón et al. (2011). Gliadin protein was extracted stepwise three times, samples were centrifuged, and the
supernatans were collected and pooled. The insoluble material from the previous step was used to obtain the glutenin fraction in a similar manner. Then, each of the extracts were filtered and they were applied to a 300SB-C8 reverse phase analytical column using a 1200 Series Quaternary LC System liquid chromatograph (Agilent Technologies) with a DAD UV-V detector. Absorbance was monitored with the DAD UV-V module at 210 nm. The amounts of both fractions were determined using bovine serum albumin as protein standard. Both fractions were expressed as μg/mg flour. The glutenin to gliadin ratio was calculated by dividing the amount of glutenins by gliadin content.
For each field we also recorded the crop species and the variety, and collected data on management practices: sowing date (month), fertilization rate (kg N/ha), preceding crop (legume, fallow, sunflower or cereal; categories depending on the nutrient demand of the crop), type of tillage and herbicides used. We also obtained data on the average monthly temperature (ºC) and total precipitation (mm) during crop growth season from the nearest meteorological stations.
[Methods for processing the data] Different plant community diversity indices were computed from data. Statistical analyses were performed to understand the relationship between crop quality and weeed community diversity as explained in: Paper accepted for publication.Grants AGL2012-33736 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”.Peer reviewe
Self-Reported DHA Supplementation during Pregnancy and Its Association with Obesity or Gestational Diabetes in Relation to DHA Concentration in Cord and Maternal Plasma: Results from NELA, a Prospective Mother-Offspring Cohort
Maternal supplementation of docosahexaenoic acid (DHA) during pregnancy has been recommended due to its role in infant development, but its effect on materno-fetal DHA status is not well established. We evaluated the associations between DHA supplementation in pregnant women with obesity or gestational diabetes mellitus (GDM) and maternal and neonatal DHA status. Serum fatty acids (FA) were analyzed in 641 pregnant women (24 weeks of gestation) and in 345 venous and 166 arterial cord blood samples of participants of the NELA cohort. Obese women (n = 47) presented lower DHA in serum than those lean (n = 397) or overweight (n = 116) before pregnancy. Linoleic acid in arterial cord was elevated in obese women, which indicates lower fetal retention. Maternal DHA supplementation (200 mg/d) during pregnancy was associated with enhanced maternal and fetal DHA levels regardless of pre-pregnancy body mass index (BMI), although higher arterial DHA in overweight women indicated an attenuated response. Maternal DHA supplementation was not associated with cord venous DHA in neonates of mothers with GDM. The cord arteriovenous difference was similar for DHA between GDM and controls. In conclusion, maternal DHA supplementation during pregnancy enhanced fetal DHA status regardless of the pre-pregnancy BMI while GDM may reduce the effect of DHA supplementation in newborns