242 research outputs found
Oxidative Stress Associated with Chilling Injury in Immature Fruit: Postharvest Technological and Biotechnological Solutions
Immature, vegetable-like fruits are produced by crops of great economic importance, including cucumbers, zucchini, eggplants and bell peppers, among others. Because of their high respiration rates, associated with high rates of dehydration and metabolism, and their susceptibility to chilling injury (CI), vegetable fruits are highly perishable commodities, requiring particular storage conditions to avoid postharvest losses. This review focuses on the oxidative stress that affects the postharvest quality of vegetable fruits under chilling storage. We define the physiological and biochemical factors that are associated with the oxidative stress and the development of CI symptoms in these commodities, and discuss the different physical, chemical and biotechnological approaches that have been proposed to reduce oxidative stress while enhancing the chilling tolerance of vegetable fruits
Divulgación nutricional. Resolviendo dudas mediante debates
Memoria ID-0036. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2015-2016
Diseño y aplicación de una rúbrica para evaluar debates sobre divulgación nutricional
Memoria ID-0080. Ayudas de la Universidad de Salamanca para la innovación docente, curso 2016-2017
Involvement of ethylene biosynthesis and signalling in fruit set and early fruit development in zucchini squash (Cucurbita pepo L.)
Background
We have identified a kind of parthenocarpy in zucchini squash which is associated with an incomplete andromonoecy, i.e. a partial conversion of female into bisexual flowers. Given that andromonoecy in this and other cucurbit species is caused by a reduction of ethylene production in the female flower, the associated parthenocarpic development of the fruit suggested the involvement of ethylene in fruit set and early fruit development.Results
We have compared the production of ethylene as well as the expression of 13 ethylene biosynthesis and signalling genes in pollinated and unpollinated ovaries/fruits of two cultivars, one of which is parthenocarpic (Cavili), while the other is non-parthenocarpic (Tosca). In the latter, unpollinated ovaries show an induction of ethylene biosynthesis and ethylene signal transduction pathway genes three days after anthesis, which is concomitant with the initiation of fruit abortion and senescence. Fruit set and early fruit development in pollinated flowers of both cultivars and unpollinated flowers of Cavili is coupled with low ethylene biosynthesis and signalling, which would also explain the partial andromonoecy in the parthenocarpic genotype. The reduction of ethylene production in the ovary cosegregates with parthenocarpy and partial andromonoecy in the selfing progeny of Cavili. Moreover, the induction of ethylene in anthesis (by ethephon treatments) reduced the percentage of bisexual parthenocarpic flowers in Cavili, while the inhibition of ethylene biosynthesis or response (by AVG and STS treatments) induces not only andromonoecy but also the parthenocarpic development of the fruit in both cultivars.Conclusions
Results demonstrate that a reduction of ethylene production or signalling in the zucchini flower is able to induce fruit set and early fruit development, and therefore that ethylene is actively involved in fruit set and early fruit development. Auxin and TIBA treatments, inducing fruit set and early fruit development in this species, also inhibit ethylene production and the expression of ethylene biosynthesis and response genes. A model is presented that discusses the crosstalk between ethylene and auxin in the control of fruit set and early fruit development in zucchini squash.This work was supported by grants AGL2008-05619-C02-02/ALI and AGL2011-30568-C02-02/ALI, partly funded by ERDF (European Regional Development Fund) and by the Spanish Ministry of Science and Innovation, and grant CVI-02617, funded by ERDF and by the Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía, Spain. C.M. and Z.M. acknowledge FPU program scholarships from MEC, Spain. S.M. is funded by grant PTA2011-479-I from the Spanish Ministry of Science and Innovation
Optical Coherence Tomography in Multiple Sclerosis and Neuromyelitis Optica: An Update
Optical coherence tomography (OCT) uses light interference patterns to produce a cross-sectional image of the retina. It is capable of measuring the unmyelinated axons of the retinal ganglionar cells as they converge on the optic disc. In a disease like multiple sclerosis (MS), in which axonal loss has been identified as an important cause of sustained disability, it may prove an invaluable tool. OCT has demonstrated that axonal loss occurs after each episode of optic neuritis and that the degree of axonal loss is correlated to visual outcomes. Furthermore, axonal loss occurs in MS even in the absence of inflammatory episodes, and the degree of this loss is correlated with the duration of the disease process, with more thinning as the disease advances and in progressive forms. Thus, OCT retinal nerve fiber layer measurements may represent an objective outcome measure with which to evaluate the effect of treatment
Elaboración de vídeos tutoriales con Kaltura e integración en Studium. Fomentando el aprendizaje autónomo en asignaturas de Nutrición
Memoria ID2022-231 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2022-2023
Influence of Different Phenolic Copigments on the Color of Malvidin 3-Glucoside
[EN]The effectiveness of seven phenolic compounds (catechin, epicatechin, procyanidin B2, caffeic acid,
p-coumaric acid, myricitrin, and quercitrin) as copigments of malvidin 3-glucoside, the major
anthocyanin in red wines from Vitis vinifera, using a copigment/pigment molar ratio of 1:1 was assayed
)
in model wine solutions under the same conditions (pH
3.6, 12% ethanol). The stability of the
copigment-
°
pigment complexes formed was studied during a storage period of 60 days at 25 °C.
Tristimulus colorimetry was applied for color characterization of the copigmentation process, and
HPLC-DAD-
MS was used to monitor changes in the composition of the samples. Copigmentation
has been found to occur in all cases despite the low copigment/pigment molar ratio used, although
the effect was different depending on the compound. Flavan-3-ols appeared as the less effective
copigments, procyanidin B2 being even worse than monomeric flavanols, whereas flavonols behaved
as the best ones. These latter copigments also induced the most statistically significant bathochromic
shift in ìmax.
In the colorimetric analysis, it was observed that the lightness L* of the copigmented
solutions increased with time, chroma C*ab decreased, and the hue hab increased. The copigments
*ab
ab
that produced a greater increase in the hue angle were the monomeric flavan-3-ols, which therefore
showed to be the least protective cofactors against browning of the anthocyanin solution during the
storage. With the time of storage, the formation of new pigments was observed in the solutions
containing flavanols (xanthylium structures) and hydroxycinnamic acids (pyranoanthocyanins), whic
MTA apical barrier: in vitro study of the use of ultrasonic vibration
Background: The apexification is the first alternative treatment on a permanent tooth when, after a tooth trauma
and in the presence of immature apex trauma, pulp necrosis occurs. Many studies have demonstrated the efficacy of
mineral trioxide aggregate (MTA) as apical sealing material of choice in these cases, but has a degree of filtration as
all other materials. The objective of this study was to analyze the seal ability of MTA on the duct walls in immature
teeth unirradicular apexes, using indirect vibration.
Material and Methods: The study was conducted on 45 teeth divided into 3 groups: Group A or control group in
which no vibration for placing the MTA was used, Group B and C or groups where indirect vibration analysis was
used. All samples were immersed in methylene blue to assess filtration. After performing longitudinal cuts millimetric
measuring were made of the degree of filtration, divided into 3 degrees (2mm each grade filtration).
Results: Results obtained confirm our hypothesis, obtaining lesser degree of filtration those groups in which indirect
vibration (Groups B and C) was performed. It was shown that the degree of filtration is closely linked to the
degree of adaptation.
Conclusions: MTA vibration offers better results in its adaptation to the canal walls, significantly reducing the
degree of filtration
Higher use of techniques studied and performance in melee combat produce a higher psychophysiological stress response
We aimed to analyse the effectiveness of an operative training in soldiers' psychophysiological and melee combat performance. Nineteen soldiers performed a 50-hr training for 10 weeks. After training, they were divided into two groups: higher performance group (HPG) and lower performance group (LPG), then they conducted a realistic melee simulation where psychophysiological response, task performance, and the utilization of techniques learned were measured. HPG presented a significantly (p < 0.05) higher heart rate, blood lactate, and jump height; a lower blood oxygen saturation, task performance mark, use of studied techniques than LPG after the simulation; and a higher low frequency/high frequency ratio of heart rate variability previous the simulation than LPG. Independent of performance and the use of studied techniques by the participants, the melee simulation produced an increase in fight or flight response, increasing rated of stress and perceived exertion, sympathetic modulation, and physiological response. A specific melee combat training program induced different modifications in psychophysiological and task performance depending on the level of studied technique used. HPG presented a significantly higher cardiovascular response than LPG and time perception, and memory presented no differences between groups; also HPG presented a significantly higher use of studied techniques
Studies on the copigmentation between anthocyanins and flavan-3-ols and their influence in the colour expression of red wine
[ES] With the aim of evaluating the importance of the copigmentation process between anthocyanins and
flavanols on the colour expression of red wine, assays were carried out in wine model systems with mixtures of compounds obtained from two Vitis vinifera grape varieties (Graciano and Tempranillo). Spectrophotometric and chromatic analyses were performed to evaluate the magnitude of the copigmentation and the modifications induced in the colour of the solutions. Measurement of the changes in the anthocyanin hydration constant (Kh) was also used to determine the strength of the copigmentation process.
All the flavanols assayed induced significant changes in the colour, perceptible to the human eye, of the wine-like anthocyanin solutions at concentrations similar to those that can exist in red wines. The percentage contribution of the copigmentation with flavanols to the colour of the anthocyanin solutions was found to range from 2% to 20%. The extent of this effect was related not only to the concentration of flavanols but also to the qualitative composition of the flavanol preparations, as influenced by the part of the grape (either skin or seed) and the variety considered. Divergences were found between the evaluation of the copigmentation based on chromatic parameters in the CIELAB colour space and that based on the measurement at visible kmax, as the latter does not consider the integral colour changes produced in the visible spectrum. The results obtained confirmed the importance of the qualitative phenolic composition, determined in the wine by the type of grape and winemaking practices, to the production of an effective copigmentation process
- …