542 research outputs found
Editorial: Polyamines and longevity - role of polyamine in plant survival
Polyamines (PAs) are organic polycations involved in stress and developmental
processes in plants (Gentile et al., 2012; Gupta et al., 2013). PAs occur in cells and
tissues in free (non-conjugated) or conjugated forms by binding to various molecules,
including DNA and RNA, proteins, and membrane phospholipids, thus regulating various
molecular and cellular processes (Aloisi et al., 2017). In recent years, genetic and molecular
evidence points to PAs as essential metabolites required for tolerance to biotic and abiotic
stresses. As stress-protective compounds, PAs are involved in developmental processes
mediated by specific signaling pathways or in cross-regulation with other plant hormones
(Alcázar et al., 2010)
Plant Transglutaminases: New Insights in Biochemistry, Genetics, and Physiology
Transglutaminases (TGases) are calcium-dependent enzymes that catalyse an acyl-transfer reaction between primary amino groups and protein-bound Gln residues. They are widely distributed in nature, being found in vertebrates, invertebrates, microorganisms, and plants. TGases and their functionality have been less studied in plants than humans and animals. TGases are distributed in all plant organs, such as leaves, tubers, roots, flowers, buds, pollen, and various cell compartments, including chloroplasts, the cytoplasm, and the cell wall. Recent molecular, physiological, and biochemical evidence pointing to the role of TGases in plant biology and the mechanisms in which they are involved allows us to consider their role in processes such as photosynthesis, plant fertilisation, responses to biotic and abiotic stresses, and leaf senescence. In the present paper, an in-depth description of the biochemical characteristics and a bioinformatics comparison of plant TGases is provided. We also present the phylogenetic relationship, gene structure, and sequence alignment of TGase proteins in various plant species, not described elsewhere. Currently, our knowledge of these proteins in plants is still insufficient. Further research with the aim of identifying and describing the regulatory components of these enzymes and the processes regulated by them is needed
Dehydrative etherification reactions of glycerol with alcohols catalyzed by recyclable nanoporous aluminosilicates: telescoped routes to glyceryl ethers
Catalytic
strategies for the efficient transformation of abundant
sustainable bioderived molecules, such as glycerol, into higher value
more useful products is an important research goal. In this study,
we demonstrate that atom efficient dehydrative etherification reactions
of glycerol with activated alcohols are effectively catalyzed by nanoporous
aluminosilicate materials in dimethylcarbonate (DMC) to produce the
corresponding 1-substituted glyceryl ethers in high yield. By carrying
out the reaction in acetone, it is possible to capitalize on the ability
of these materials to catalyze the corresponding acetalization reaction,
allowing for the development of novel, telescoped acetalization-dehydrative
etherification reaction sequences to selectively produce protected
solketal derivatives. These materials also catalyze the telescoped
reaction of glycerol with <i>tert</i>-butanol (TBA) in acetone
to produce the corresponding solketal mono <i>tert</i>-butyl
ether product in high yield, providing a potential route to convert
glycerol directly into a useful and sustainable fuel additive
Exploring lipophilic antioxidants accumulation in field-grown low temperature-stressed Ephedra monosperma
The seasonal patterns of changes in the content of lipophilic antioxidants -carotene (-Car), zeaxanthin (Zx), -tocopherol (-Toc), plastoquinone (PQ)/plastoquinol () were studied in the assimilating shoots of evergreen shrub Ephedra monosperma J.G. Gmel ex C.A. Mey under natural conditions of Central Yakutia. The shortening of the photoperiod and the seasonal decrease in temperature induced a 1.4-fold increase in -Toc content. The fall in the average daily temperature from 0.1 to in October led to a decrease in the content of -Car as a result of the accumulation of rhodoxanthin (Rhd). In this period a sharp increase in the content of Zx retained overnight was also detected. In winter, elevated content of Zx and -Toc persisted. During September, the content of PQH2 increased by 2.5 times and PQ by 1.4 times (compared to July). The beginning of exposure to freezing average daily temperatures from -3 to led to the depletion of the total PQ pool by 18%. However, the content of in the winter months was 1.5 times higher than at the end of July. The results revealed different timing and temperature ranges of variation for individual antioxidants during the development of frost resistance in ephedra
Everyday cosmopolitanism in representations of Europe among young Romanians in Britain
The paper presents an analysis of everyday cosmopolitanism in constructions of Europe among young Romanian nationals living in Britain. Adopting a social representations approach, cosmopolitanism is understood as a cultural symbolic resource that is part of everyday knowledge. Through a discursively-oriented analysis of focus group data, we explore the ways in which notions of cosmopolitanism intersect with images of Europeanness in the accounts of participants. We show that, for our participants, representations of Europe are anchored in an Orientalist schema of West-vs.-East, whereby the West is seen as epitomising European values of modernity and progress, while the East is seen as backward and traditional. Our findings further show that representations of cosmopolitanism reinforce this East/West dichotomy, within a discourse of ‘Occidental cosmopolitanism’. The paper concludes with a critical discussion of the diverse and complex ideological foundations of these constructions of European cosmopolitanism and their implications
Obesogenic dietary intake in families with 1-year-old infants at high and low obesity risk based on parental weight status: baseline data from a longitudinal intervention (Early STOPP)
PURPOSE:
To compare dietary intake in 1-year-old infants and their parents between families with high and low obesity risk, and to explore associations between infant dietary intake and relative weight.
METHODS:
Baseline analyses of 1-year-old infants (n = 193) and their parents participating in a longitudinal obesity intervention (Early STOPP) were carried out. Dietary intake and diet quality indicators were compared between high- and low-risk families, where obesity risk was based on parental weight status. The odds for high diet quality in relation to parental diet quality were determined. Associations between measured infant relative weight and dietary intake were examined adjusting for obesity risk, socio-demographics, and infant feeding.
RESULTS:
Infant dietary intake did not differ between high- and low-risk families. The parents in high-risk families consumed soft drinks, French fries, and low-fat spread more frequently, and fish and fruits less frequently (p < 0.05) compared to parents in low-risk families. Paternal intake of vegetables and fish increased the odds for children being consumers of vegetables (OR 1.7; 95 % CI 1.0-2.9) and fish, respectively (OR 2.5; 95 % CI 1.4-4.4). Infant relative weight was weakly associated with a high intake of milk cereal drink (r = 0.15; p < 0.05), but not with any other aspect of dietary intake, obesity risk, or early feeding patterns.
CONCLUSIONS:
At the age of one, dietary intake in infants is not associated with family obesity risk, nor with parental obesogenic food intake. Milk cereal drink consumption but no other infant dietary marker reflects relative weight at this young age.published_or_final_versio
Міжнародна наукова конференція "Архівознавство як наука"
Проаналізовано внесок істориків і архівістів України в розвиток архівної науки. Вказуються основні розділи архівознавства як науки, що вимагають подальших досліджень.Проанализирован вклад историков и архивистов Украины в развитие архивной науки. Указываются основные разделы архивоведения как науки, которые требуют дальнейших исследований.A contribution of Ukrainian historians and archivists to the archival science development is covered. The basic sections of the archival science which need the further study are indicated
Using real particulate matter to evaluate combustion catalysts for direct regeneration of diesel soot filters
The particulate produced by internal combustion engines has a complex composition that includes a large proportion of porous soot within which condensed and adsorbed organic molecules are trapped. However, many studies of the catalytic combustion of particulate are based on the assumption that commercially produced carbon can be used as a reliable mimic of engine soot. Here we show that soot removed from a diesel particulate filter is rich in the polyaromatic molecules that are the precursors of the solid particulate. Through a combination of solvent extraction and evolved gas analysis, we have been able to track the release and transformation of these molecules in the absence and presence of combustion catalysts. Our results reveal that, although the rate of combustion of the elemental carbon in diesel soot is higher than that of graphite, deep oxidation of the polyaromatic molecules is a more demanding reaction. An active and stable Ag–K catalyst lowers the combustion temperature for elemental carbon by >200 °C, but has little effect on the condensed polyaromatic molecules. The addition of a secondary catalyst component, with aromatic-oxidation functionality is required to target these molecules. Although the combined catalyst would not enable a completely passive regeneration system for diesel passenger cars, it would improve the efficiency of existing active systems by reducing the amount of fuel-injection required for trap regeneration
Vacuum annealing phenomena in ultrathin TiDy/Pd bi-layer films evaporated on Si(100) as studied by TEM and XPS
Using a combination of TEM and XPS, we made an analysis of the complex high-temperature annealing effect on ultrathin titanium deuteride (TiDy) films evaporated on a Si(100) substrate and covered by an ultrathin palladium layer. Both the preparation and annealing of the TiDy/Pd bi-layer films were performed in situ under UHV conditions. It was found that the surface and bulk morphology of the bi-layer film as well as that of the Si substrate material undergo a microstructural and chemical conversion after annealing and annealing-induced deuterium evolution from the TiDy phase. Energy-filtered TEM (EFTEM) mapping of cross-section images and argon ion sputter depth profiling XPS analysis revealed both a broad intermixing between the Ti and Pd layers and an extensive inter-diffusion of Si from the substrate into the film bulk area. Segregation of Ti at the Pd top layer surface was found to occur by means of angle-resolved XPS (ARXPS) and the EFTEM analyses. Selected area diffraction (SAD) and XPS provided evidence for the formation of a new PdTi2 bimetallic phase within the top region of the annealed film. Moreover, these techniques allowed to detect the initial stages of TiSi phase formation within the film–substrate interlayer
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