5 research outputs found
Increased Cysteine Availability is Essential for Cadmium Tolerance and Accumulation in Arabidopsis Thaliana
Employing genetic transformation using an Atcys-3A cDNA construct expressing the cytosolic O-acetylserine(thiol)lyase (OASTL), we obtained two Arabidopsis lines with different capabilities for supplying cysteine under metal stress conditions. Lines 1-2 and 10-10, grown under standard conditions, showed similar levels of cysteine and glutathione (GSH) to those of the wild-type. However, in the presence of cadmium, line 10-10 showed significantly higher levels. The increased thiol content allowed line 10-10 to survive under severe heavy metal stress conditions (up to 400M of cadmium in the growth medium), and resulted in an accumulation of cadmium in the leaves to a level similar to that of metal hyperaccumulator plants. Investigation of the epidermal leaf surface clearly showed that most of the cadmium had accumulated in the trichomes. Furthermore, line 10-10 was able to accumulate more cadmium in its trichomes than the wild-type, whereas line 1-2 showed a reduced capacity for cadmium accumulation. Our results suggest that an increased rate of cysteine biosynthesis is responsible for the enhanced cadmium tolerance and accumulation in trichome leaves. Thus, molecular engineering of the cysteine biosynthesis pathway, together with modification of the number of leaf trichomes, may have considerable potential in increasing heavy metal accumulation for phytoremediation purposes.Dirección General de InvestigaciónJunta de Andalucí
Boron-doped diamond by 9 MeV microbeam implantation: Damage and recovery
Diamond properties can be tuned by doping and ion-beam irradiation is one of the most powerful techniques to do it in a controlled way, but it also produces damage and other aftereffects. Of particular interest is boron doping which, in moderate concentrations, causes diamond to become a p-type semiconductor and, at higher boron concentrations, a superconductor. Nevertheless, the preparation of superconducting boron-doped diamond by ion implantation is hampered by amorphization and subsequent graphitization after annealing. The aim of this work was to explore the possibility of creating boron-doped diamond superconducting regions and to provide a new perspective on the damage induced in diamond by MeV ion irradiation. Thus, a comprehensive analysis of the damage and eventual recovery of diamond when irradiated with 9 MeV B ions with different fluences has been carried out, combining Raman, photoluminescence, electrical resistivity, X-ray diffraction and Rutherford Backscattering/Ion-channeling. It is found that, as the B fluence increases, carbon migrates to interstitial sites outside of the implantation path and an amorphous fraction increases within the path. For low fluences (∼1015 ions/cm2), annealing at 1000 °C is capable to fully recovering the diamond structure without graphitization. However, for higher fluences (≥5 × 1016 ions/cm2), those required for superconductivity, the recovery is important, but some disorder still remains. For high fluences, annealing at 1200 °C is detrimental for the diamond lattice and graphite traces appear. The incomplete healing of the diamond lattice and the interstitial location of B can explain that optimally doped samples do not exhibit superconductivityThis work has been partially supported by the Ministerio de Ciencia e
Innovacion ´ of Spain (Project grants PID2020-112770RB-C22/MCIN/
AEI/10.13039/501100011033, PID2021-127033OB-C21/MCIN/AEI/
10.13039/501100011033, and PID2021-127498NB-I00/AEI/FEDER/
10.13039/501100011033). We also acknowledge financial support
from MCIN/AEI/10.13039/501100011033, through the “María de
Maeztu” Programme for Units of Excellence in R&D (CEX2018-000805-
M), as well as from the Autonomous Community of Madrid through
program S2018/NMT-4321 (NANOMAGCOST-CM
Process design for the manufacturing of soft X-ray gratings in single-crystal diamond by high-energy heavy-ion irradiation
The dataset that supports the findings of this study are archived in the Universidad Autónoma de Madrid data repository e‐cienciaDatos in https://doi.org/10.21950/ARZSJ1This paper describes in detail a novel manufacturing process for optical gratings suitable for use in the UV and soft X-ray regimes in a single-crystal diamond substrate based on highly focused swift heavy-ion irradiation. This type of grating is extensively used in light source facilities such as synchrotrons or free electron lasers, with ever-increasing demands in terms of thermal loads, depending on beamline operational parameters and architecture. The process proposed in this paper may be a future alternative to current manufacturing techniques, providing the advantage of being applicable to single-crystal diamond substrates, with their unique properties in terms of heat conductivity and radiation hardness. The paper summarizes the physical principle used for the grating patterns produced by swift heavy-ion irradiation and provides full details for the manufacturing process for a specific grating configuration, inspired in one of the beamlines at the ALBA synchrotron light source, while stressing the most challenging points for a potential implementation. Preliminary proof-of-concept experimental results are presented, showing the practical implementation of the methodology proposed herei
Consequences of a fat diet in the distribution of minerals within pancreatic tissues of rats and rabbits
10.1017/S1431927612001547Microscopy and Microanalysis1851060-1066MIMI
Tools for investigating electronic excitation: experiment and multi-scale modelling
This book collects the lectures presented in the first COST TUMIEE Training School held in Greece in 2019, supplemented with specific applications that illustrate how the multi-scale approach is implemented in specific cases of interest. The book is intended both as a reference in the field and as a textbook for people becoming interested or entering the field. The first part focuses on experimental methods, the second on theoretical approaches, and the third on cases of interest