2,665 research outputs found
A year (2014-2015) of plants in Proteomics journal. Progress in wet and dry methodologies, moving from protein catalogs, and the view of classic plant biochemists
No full textSanchez-Lucas, R., Mehta, A., Valledor, L., Cabello-Hurtado, F., Romero-Rodriguez, M.C., Simova-Stoilova, L., Demir, S., Rodriguez-de-Francisco, L.E., Maldonado-Alconada, A.M., Jorrin-Prieto, A.L., Jorrín-Novo, J.V
Evaluating the effects of azelaic acid in the metabolism of Arabidopsis thaliana seedlings through untargeted metabolomics and ionomics approaches
No full textThe present study demonstrates that low concentrations of azelaic acid (AZA) significantly impact the metabolism of Arabidopsis thaliana seedlings, leading to imbalances in numerous minerals and metabolites due to AZA-induced stress. Untargeted metabolomic analyses were conducted on untreated and AZA-treated seedlings at two time points: 7 and 14 days after treatment initiation. The results revealed a general accumulation of sugars (e.g., glucose, mannose, xylose), amino acids (e.g., lysine, GABA, threonine, glutamine), and organic acids (e.g., glutaric acid, shikimic acid, succinic acid) in AZA treated-seedlings, suggesting that AZA triggers stress responses in Arabidopsis. Ionomic analysis revealed that AZA induces phosphorus deficiency, which plants compensate by increasing malate content in the roots. Additionally, AZA treatment induced putrescine accumulation within the root, a metabolic biomarker of potassium deficiency and plant stress. The metabolomic profile showed elevated levels of different specialized metabolites, such as nitrogen- and sulphur-containing compounds, and altered levels of various phytohormones, including jasmonates and brassinosteroids, implicated in plant protection under biotic and/or abiotic stresses. These findings support the hypothesis that AZA's mode of action is associated with an auxin imbalance, suggesting its function as an auxinic herbicide. The observed increases in starch and jasmonates, coupled with the disruptions in potassium homeostasis, are linked to the previously reported alterations in the auxin transport, root architecture and gravitropic root response. Statistical analyses were applied, including Kruskal-Wallis tests for ionomic data, as well as multifactor analysis, Principal Component Analysis, Orthogonal Partial Least Squares-Discriminant Analysis, and enrichment pathway analysis for metabolomic data, ensuring the robustness and validity of these findings
Azelaic acid can efficiently compete for the auxin binding site TIR1, altering auxin polar transport, gravitropic response, and root growth and architecture in Arabidopsis thaliana roots
No full textThe present study investigates the phytotoxic potential of azelaic acid (AZA) on Arabidopsis thaliana roots. Effects on root morphology, anatomy, auxin content and transport, gravitropic response and molecular docking were analysed. AZA inhibited root growth, stimulated lateral and adventitious roots, and altered the root apical meristem by reducing meristem cell number, length and width. The treatment also slowed down the roots' gravitropic response, likely due to a reduction in statoliths, starch-rich organelles involved in gravity perception. In addition, auxin content, transport and distribution, together with PIN proteins' expression and localisation were altered after AZA treatment, inducing a reduction in auxin transport and its distribution into the meristematic zone. Computational simulations showed that AZA has a high affinity for the auxin receptor TIR1, competing with auxin for the binding site. The AZA binding with TIR1 could interfere with the normal functioning of the TIR1/AFB complex, disrupting the ubiquitin E3 ligase complex and leading to alterations in the response of the plant, which could perceive AZA as an exogenous auxin. Our results suggest that AZA mode of action could involve the modulation of auxin-related processes in Arabidopsis roots. Understanding such mechanisms could lead to find environmentally friendly alternatives to synthetic herbicides
Microencapsulation of sodium diclofenac in alginate/chitosan particulate systems
No full textThe use of biodegradable polymeric carriers for the drug delivery systems has gained a wide interest, mainly for their biocompatibility and, among the microparticulate systems, microspheres show a special importance for providing local as well as temporal controlled release of the drug. Different types of polymers are encountered in the literature used to this purpose. In the case of the release of diclofenac are available: poly-3-caprolactone, poly-/vinylalcohol, poly-lactide-co-glycolide. Also natural polymers found their application in this field: albumin, alginate, carboxymethyl-cellulose, chitosan. The preparation and characterization of the samples are quite similar in most cases.
The anti-inflammatory drug (as sodium salt) is dissolved in an aqueous solution containing the soluble polymer and, in the case of carboxylate-containing polymers (alginate, carboxymethyl cellulose), the formation of microspheres was obtained by the addition of Ca2+ or Al3+: the hydrophilic colloids interact with metal ions to form crosslinked insoluble complexes, that precipitate incorporating the drug.
In this paper, we prepared microspheres of alginate containing sodium diclofenac and examined the different influence of Ca2+ or Al3+ ions on the microsphere morphology and the influence of different amounts of chitosan on the release of diclofenac. Among polyanionic polymers alginate has been widely studied and applied for its possibilità to modulate the release, according to the properties of its carboxyl groups as well as its biodegradability and absence of toxicity. Also chitosan finds wide applications in pharmaceutical technology as tablet disintegrant, for the production of controlled release solid dosage forms or for improvement of drug dissolution
Diclofenac is a suitable candidate for incorporation into microspheres to minimize its adverse effect after oral administration; in fact, alginate microspheres containing diclofenac start to release the drug after the pH of the environment increases above 7, by-passing the gastric environment and avoid direct contact between the drug and the gastric mucosa
Microencapsulation of sodium diclofenac in arginate/chitosan particulate systems
No full textThe use of biodegradable polymeric carriers for the drug delivery systems has gained a wide interest, mainly for their biocompatibility and, among the microparticulate systems, microspheres show a special importance for providing local as well as temporal controlled release of the drug. Different types of polymers are encountered in the literature used to this purpose. In the case of the release of diclofenac are available: poly-3-caprolactone, poly-/vinylalcohol, poly-lactide-co-glycolide. Also natural polymers found their application in this field: albumin, alginate, carboxymethyl-cellulose, chitosan. The preparation and characterization of the samples are quite similar in most cases.
The anti-inflammatory drug (as sodium salt) is dissolved in an aqueous solution containing the soluble polymer and, in the case of carboxylate-containing polymers (alginate, carboxymethyl cellulose), the formation of microspheres was obtained by the addition of Ca2+ or Al3+: the hydrophilic colloids interact with metal ions to form crosslinked insoluble complexes, that precipitate incorporating the drug.
In this paper, we prepared microspheres of alginate containing sodium diclofenac and examined the different influence of Ca2+ or Al3+ ions on the microsphere morphology and the influence of different amounts of chitosan on the release of diclofenac. Among polyanionic polymers alginate has been widely studied and applied for the possibility to modulate the release, according to the properties of its carboxyl groups as well as its biodegradability and absence of toxicity. Also chitosan finds wide applications in pharmaceutical technology as tablet disintegrant, for the production of controlled release solid dosage forms or for improvement of drug dissolution
Diclofenac is a suitable candidate for incorporation into microspheres to minimize its adverse effect after oral administration; in fact, alginate microspheres containing diclofenac start to release the drug after the pH of the environment increases above 7, by-passing the gastric environment and avoid direct contact between the drug and the gastric mucosa.
RESULTS AND DISCUSSION
Morphology - Figure 1 shows a microsphere prepared adding Ca2+, exhibiting acceptable sphericity and a notable surface porosity, with a shape factor greater than 0.80 in all the cases. This morphology was found independent of the starting composition, provided that Ca2+ ions were the gelifying agent (left). The aspect and morphology of the particulates prepared with Al3+ ions is different (right): no formulation enabled the formation of a spherical morphology; on the contrary, the particles are flattened, disk-shaped with a collapsed center. The surface appears smooth and little porous with a shape factor less than 0.80. The trivalent ions cause more points of aggregation between two contiguous alginate chains, binding them so strictly and quickly that, as a consequence, there is no time to get spherical forms, during their formation and the morphology of the particle recalls the feature of a drop touching a water surface.
For the preparation of chitosan treated alginate beads containing sodium diclofenac, we dissolved sodium diclofenac in the aqueous solution of sodium alginate. The addition of the divalent (or trivalent) ions produced a partial neutralization of carboxylate groups present on the alginate chain, forming an insoluble (but permeable) transitory thin gelatinous film: Ionic gelation is the result of the formation of an ‘egg box’ between facing units of two different chains and depends on the inorganic ion/alginate ratio..
Are some job demands positively related to job well-being? further evidence for the differentiation between job hindrances and job challenges/demands
No full textstatus: Publishe
Application of indole-alkaloid harmaline induces physical damage to photosystem II antenna complexes in adult plants of Arabidopsis thaliana (L.) Heynh
No full textFinding herbicides with new and multiple modes of action is a solution to stop the increase in resistant weed species. Harmaline, a natural alkaloid with proven phytotoxic potential, was tested on Arabidopsis adult plants by watering and spraying; watering resulted as the more effective treatment. Harmaline altered several photosynthetic parameters, reducing the efficiency of the light- (ΦII) and dark-adapted (Fv/Fm) PSII, suggesting physical damages in photosystem II, although dissipation of the energy in excess under the form of heat was not compromised as demonstrated by the significant increase in ΦNPQ. Metabolomic alterations, such as osmoprotectant accumulation and reduction in sugars’ content, also indicate a reduction of photosynthetic efficiency and suggest early senescence and water status alteration induced by harmaline. Data suggest that harmaline might be considered a new phytotoxic molecule interesting for further studies.Ministerio de Ciencia e Innovación | Ref. RTI2018-094716-B-100Universidade de Vigo/CISU
Pelargonic acid's interaction with the auxin transporter PIN1: A potential mechanism behind its phytotoxic effects on plant metabolism
No full textPelargonic acid (PA) is a saturated fatty acid commonly found in several organisms, that is known for its phytotoxic effect and its use as bioherbicide for sustainable weed management. Although PA is already commercialised as bioherbicide, its molecular targets and mode of action is unknown according to the Herbicide Resistance Action Committee. Therefore, the aim of this work was focusing on the way this natural active substance impacts the plant metabolism of the model species Arabidopsis thaliana. PA caused increase of secondary and adventitious roots, as well as torsion, loss of gravitropism and phytotoxic effects. Moreover, PA altered the cellular arrangement and the PIN proteins activity. Computational simulations revealed that the intermolecular interactions between PA and the polar auxin transporter protein PIN1 are very similar to those established between the natural auxin IAA and PIN1. However, under intracellular conditions, the PA-PIN1 binding is more energetically stable than the IAA-PIN1. These results suggest that PA could act as an auxin-mimics bioherbicide. The exogenous application of PA would be responsible for the alterations observed both at structural and ultrastructural levels, which would be caused by the alteration on the transport of auxins into the plant, inducing root inhibition and ultimately total stop of root growth
Small scale testing of crawler outlet diffusers for plume reduction of offshore mining
No full textOver recent years, there has been an increase in demands for rare and precious minerals worldwide. Mostly this is due to the rise of the world’s population and the drive towards a green energy transition and low carbon economy. Prices are rapidly increasing, and there is an identifiable risk of an increasing supply shortage of raw materials, including those identified as critical to Europe’s high technology sector. The development of surveying techniques and advances in new technologies in remotely operated vehicles (ROV) has allowed detecting that the most valuable and rare mineral resources are spread out in the sea-floor and international waters. Currently, the most significant setback towards exploitation licenses is not because of lack of technology but because of a lack of knowledge on deep-sea biodiversity and the impacts of mining on ecosystems. The ISA (International Seabed Authority) is responsible for the regulation, and the control of mineral-related activities in the international waters is currently working on drafting environmental regulations. This presents significant opportunities for research on the development of technologies that incurs in the least environmental impact possible. Currently, the main concerns are regarding the horizontal sediment-laden plume that is generated as a result of the mining process. Therefore, the industry is working towards the development of equipment that lessens the plumes spread. Work done in this research focuses on small scale sized laboratory experiments in which the sea-floor crawler’s outlet shape is varied, and its plume’s effects of the sediment waste and other effluents (SWOE) are measured. Besides gaining insight in the horizontal plume spreading under different conditions and geometries, the outcome of the research is to provide a set of measurement data that can be used for future numerical model validation towards determining an optimal outlet shape for the seabed crawler. For this purpose, a total of three diffusers were designed and tested based on a specific scaling factor and input parameters defined by IHC Mining. Experiments consisted of capturing visual imagery of the generated plume on both top and side views for further analysis and performing velocity and concentration profile measurements in different locations. The offset jet transition from jet to plume and the respective impingement point for all diffusers was compared. Velocity and concentration measurements were analyzed and compared to determine an ideal diffuser. Using diffusers reduces the plume’s initial momentum while maintaining the density differences and therefore reduces the transition from jet to plume, allowing for gentler deposition over the surface and resuspending less material. All experiments show similar behavior in which a free jet can be observed initially. Then, after substantial entrainment takes place, the jet impacts the bed due to the negative buoyancy. Once the discharge impinges the lower boundary, it forms a radially spreading layer along the boundary which transitions into a wall jet. Lowering the momentum of the jet by diffusing the outlet gave better results in terms of drawing the impingement point, and the deposition profiles nearer to the diffuser. Also, the measured velocity and concentration profiles considerably decreased, reducing the plumes spread.Mechanical Engineerin
Spain and the First World War : neutrality and crisis.
No full textPhDThe subject of this thesis is a study of Spain during
the First World War. The Spanish case is analyzed as the regional
version of the general crisis which engulfed the rest of Europe
during these years. This crisis was produced by the ideological
militancy and social struggle caused by four years of
devastating international conflict. It heralded the arrival of
mass politics which put an end to a previous era marked by
hierarchical and clientelist politics.
This thesis examines how the maintenance of strict
neutrality did not save the existing regime in Spain from the
impact of the conflict raging in Europe. Spain did not enter the
war but the war entered the country and, ironically, a conflict
in which Spain did not take part was to alter its contemporary
history.
The analysis explores the gradual disintegration of the
foundations of the ruling system, the Liberal Monarchy restored
in December 1874, during and as a consequence of the First World
War. Considerable attention is paid to the impact and importance
of the war in producing the decay of the Liberal Monarchy. This
process is examined at two levels: the political polarization and
subsequent division of the country which was provoked by the
debate about belligerence or neutrality, and the social and
economic transformations that Spain underwent as consequence a
of its privileged position as a supplier to both sides. The
result was galloping inflation, widespread social discontent and political turmoil. Under these pressures, the hegemonic system,
based on electoral falsification, widespread patronage and mass
apathy, collapsed and gave way to an inexorable process of
growing working class and right-wing militancy which led to the
military coup of 1923
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