Desarrollo de experimentos y aplicaciones de RMN dirigidas al estudio de metabolitos y sus interacciones supramoleculares

La espectroscopía de resonancia magnética nuclear (RMN) ha probado ser una de las herramientas más versátiles en química y bioquímica. Permite conocer estructura, dinámica e interacciones moleculares tanto de pequeñas moléculas de origen sintético o metabólico como de biomoléculas de gran tamaño. Los estudios de RMN pueden realizarse en disolución (RMN de líquidos) en estado sólido o semi-sólido, e incluso, aunque es mucho menos común, en sistemas gaseosos

Obtaining and Structural Characterization of M-type Hexaferrites Doped with Two Cations in the Fe3+ Sites

A study of the microstructural and structural properties of M-type barium hexaferrites (BaM) samples doped with two dopants in the Fe3+ sites: (Co3+, Al3+), (Co2+, Ti4+) and (Co2+, Sn4+) is reported. The samples were obtained using the conventional ceramic method. The structure was investigated by using of X-ray diffraction (XRD) to determine the dopant distribution in the Fe3+ sites

A Spitzer-IRS view of early-type galaxies with cuspy/core nuclei and fast/slow rotation

The recent literature suggests that an evolutionary dichotomy exists for early-type galaxies (Es and S0s, ETGs) whereby their central photometric structure (cuspy vs. core central luminosity profiles), and figure of rotation (fast vs. slow rotators), are determined by whether they were formed by "wet" or "dry" mergers. Aims. We consider whether the mid-infrared (MIR) properties of ETGs, with their sensitivity to accretion processes in particular in the last few Gyr (on average z 72 0.2), can put further constraints on this picture. Methods. We investigate a sample of 49 ETGs for which nuclear MIR properties and detailed photometrical and kinematical classifications are available from the recent literature. Results. In the stellar light cuspy/core ETGs show a dichotomy that is mainly driven by their luminosity. However, in the MIR, the brightest core ETGs show evidence that accretions have triggered both AGN and star formation activity in the recent past, challenging a dry merger scenario. In contrast, we do find in the Virgo and Fornax clusters that cuspy ETGs, fainter than MKs =-24, are predominantly passively evolving in the same epoch, while in low-density environments they tend to be more active. A significant and statistically similar fraction of both fast rotators (FRs) (38-11+18 %) and slow rotators (SRs) (50-21+34%) shows polycyclic aromatic hydrocarbon features in their MIR spectra. Ionized and molecular gas are also frequently detected. Recent star formation episodes are then a common phenomenon in both kinematical classes, even in those dominated by AGN activity, suggesting a similar evolutionary path in the last few Gyrs. Conclusions. MIR spectra suggest that the photometric segregation between cuspy and core nuclei and the dynamical segregation between FRs and SRs must have originated before z ~ 0.2. \ua9 2014 ESO

Isotopic labelling reveals the efficient adaptation of wheat root TCA cycle flux modes to match carbon demand under ammonium nutrition

Proper carbon (C) supply is essential for nitrogen (N) assimilation especially when plants are grown under ammonium (NH4+) nutrition. However, how C and N metabolic fluxes adapt to achieve so remains uncertain. In this work, roots of wheat (Triticum aestivum L.) plants grown under exclusive NH4+ or nitrate (NO3−) supply were incubated with isotope-labelled substrates (15NH4+, 15NO3−, or [13C]Pyruvate) to follow the incorporation of 15N or 13C into amino acids and organic acids. Roots of plants adapted to ammonium nutrition presented higher capacity to incorporate both 15NH4+ and 15NO3− into amino acids, thanks to the previous induction of the NH4+ assimilative machinery. The 15N label was firstly incorporated into [15N]Gln vía glutamine synthetase; ultimately leading to [15N]Asn accumulation as an optimal NH4+ storage. The provision of [13C]Pyruvate led to [13C]Citrate and [13C]Malate accumulation and to rapid [13C]2-OG consumption for amino acid synthesis and highlighted the importance of the anaplerotic routes associated to tricarboxylic acid (TCA) cycle. Taken together, our results indicate that root adaptation to ammonium nutrition allowed efficient assimilation of N thanks to the promotion of TCA cycle open flux modes in order to sustain C skeleton availability for effective NH4+ detoxification into amino acids

New insights on arabidopsis thaliana root adaption to ammonium nutrition by the use of a quantitative proteomic approach

Nitrogen is an essential element for plant nutrition. Nitrate and ammonium are the two major inorganic nitrogen forms available for plant growth. Plant preference for one or the other form depends on the interplay between plant genetic background and environmental variables. Ammonium-based fertilization has been shown less environmentally harmful compared to nitrate fertilization, because of reducing, among others, nitrate leaching and nitrous oxide emissions. However, ammonium nutrition may become a stressful situation for a wide range of plant species when the ion is present at high concentrations. Although studied for long time, there is still an important lack of knowledge to explain plant tolerance or sensitivity towards ammonium nutrition. In this context, we performed a comparative proteomic study in roots of Arabidopsis thaliana plants grown under exclusive ammonium or nitrate supply. We identified and quantified 68 proteins with differential abundance between both conditions. These proteins revealed new potential important players on root response to ammonium nutrition, such as H+ -consuming metabolic pathways to regulate pH homeostasis and specific secondary metabolic pathways like brassinosteroid and glucosinolate biosynthetic pathways

Evidences towards deciphering the mode of action of dimethylpyrazole-based nitrification inhibitors in soil and pure cultures of Nitrosomonas europaea

Background: Agriculture relies on the intensive use of synthetic nitrogen (N) fertilizers to maximize crop yields, which has led to the transformation of agricultural soils into high-nitrifying environments. Nevertheless, nitrification inhibitors (Nis) have been developed to suppress soil-nitrifier activity and decrease N losses. The Nis 3,4-dimethylpyrazole phosphate (DMPP) and 2-(3,4-dimethyl-1H-pyrazol-1-yl) succinic acid isomeric mixture (DMPSA) are able to reduce N2O emissions and maintain soil NH4+ for a longer time. Although both Nls have been proven to be effective to inhibit soil nitrification, their exact mode of action has not been confirmed. We aimed to provide novel insights to further understand the mode of action of DMP-based Nis. We evaluated the performance of DMPP and DMPSA in soil and pure cultures of nitrifying bacteria Nitrosomonas europaea. Results: DMPSA did not inhibit nitrification in pure cultures of N. europaea. In the soil, we evidenced that DMPSA needs to be broken into DMP to achieve the inhibition of nitrification, which is mediated by a soil biological process that remains to be identified. Moreover, both DMPP and DMPSA are thought to inhibit nitrification due to their ability to chelate the Cu2+ cations that the ammonia monooxygenase enzyme (AMO) needs to carry on the first step of NH4+ oxidation. However, the efficiency of DMPP was not altered regardless the Cu2+ concentration in the medium. In addition, we also showed that DMPP targets AMO but not hydroxylamine oxidoreductase enzyme (HAO). Conclusions: The inability of DMPSA to inhibit nitrification in pure cultures together with the high efficiency of DMPP to inhibit nitrification even in presence of toxic Cu2+ concentration in the medium, suggest that the mode of action of DMP-based Nis does not rely on their capacity as metal chelators.This project was funded by the Spanish Government (RTI2018-094623-B-C21 MCIU/AEI/FEDER, UE), by the Basque Government (IT-932-16), and by EuroChem Agro Iberia S.L.U. Dr. Adrian Bozal-Leorri held a grant from the Basque Government (PRE-2020-2-0142)

Wavefront sensing using a graphical user interface

We present an open wavefront sensor setup assisted with MATLAB programming to be used to teach the operating principle of Shack-Hartmann aberrometry. A new Graphical User Interface (GUI) has also been developed to determine the wavefront parameters from experimental measurements and the associated aberrations, which is a fundamental issue in Optical Engineering. From a didactical point of view, the proposed method allows students to interpret the results in a visual and heuristic way.Contract grant sponsor: Ministerio de Economia y Competividad; Contract grant number: FIS2011-23175; Contract grant sponsor: Generalitat Valenciana; Contract grant number: PROMETEOII/2014/072; Contract grant sponsor: Universitat de Valencia; Contract grant number: UV-SFPIE_DINV14-222801Ferrando Martín, V.; Remón Martín, L.; Pons Martí, A.; Furlan, WD.; Monsoriu Serra, JA. (2016). Wavefront sensing using a graphical user interface. Computer Applications in Engineering Education. 24(2):255-262. https://doi.org/10.1002/cae.21703S25526224

Characterization of leakage verification procedures in refrigeration circuits applied to maritime containers

The evolution of portable refrigeration units and the refrigerants used with them has facilitated enormous advances in autonomous refrigerated maritime shipping containers and temperature control. This has permitted the shipping of products with very strict temperature requirements. It is very important to have a correctly designed system in which the amount of fluid is calculated for a specific construction. A mass above design requirements increases the cost of the finished product. If the mass of refrigerant is below design requirements, more energy is required to maintain the target temperature and, therefore, maintenance costs increase. This paper describes a process to test for leaks in refrigeration equipment. This process can assure the tightness of refrigeration circuits against small leaks over their working lives

Nearby early-type galaxies with ionized gas VI. The Spitzer-IRS view

We present low resolution Spitzer-IRS spectra of 40 ETGs, selected from a sample of 65 ETGs showing emission lines in their optical spectra. We homogeneously extract the mid-infrared (MIR) spectra, and after the proper subtraction of a "passive" ETG template, we derive the intensity of the ionic and molecular lines and of the polycyclic aromatic hydrocarbon emission features. We use MIR diagnostic diagrams to investigate the powering mechanisms of the ionized gas. The mid-infrared spectra of early-type galaxies show a variety of spectral characteristics. We empirically sub-divide the sample into five classes of spectra with common characteristics. Class-0, accounting for 20% of the sample, are purely passive ETGs with neither emission lines nor PAH features. Class-1 show emission lines but no PAH features, and account for 17.5% of the sample. Class-2, in which 50% of the ETGs are found, as well as having emission lines, show PAH features with unusual ratios, e.g. 7.7 {\mu}m/11.3 {\mu}m \leq 2.3. Class-3 objects have emission lines and PAH features with ratios typical of star-forming galaxies. 7.5% of objects fall in this class, likely to be objects in a starburst/post-starburst regime. Class-4, containing only 5% of the ETGs, is dominated by a hot dust continuum. The diagnostic diagram [Ne III]15.55{\mu}m/[Ne II]12.8{\mu}m vs. [S III]33.48{\mu}m/[Si II]34.82{\mu}m, is used to investigate the different mechanisms ionizing the gas. If we exclude NGC 3258 where a starburst seems present, most of our ETGs contain gas ionized via either AGN-like or shock phenomena, or both. Most of the spectra in the present sample are classified as LINERs in the optical window. The proposed MIR spectral classes show unambiguously the manifold of the physical processes and ionization mechanisms, from star formation, low level AGN activity, to shocks, present in LINER nuclei.Comment: Accepted for publication in Astronomy and Astrophysic