308 research outputs found
Ecological Aspects and Conservation of Wild Grapevine Populations in the S.W. of the Iberian Peninsula
Populations of wild grapevine, Vitis vinifera L. subsp. sylvestris (Gmelin)
Hegi, were discovered in S.W. of the Iberian Peninsula over the last years. Location,
ecological aspects, sanitary characteristics, including the ELISA test to detect
specific virus attack, are described. In vitro propagation and conservation are also
considered. The paper also contains a global description of female and male
individuals. This material could be used to start breeding programs of cultivated
varieties and also to restore riverbank forests, which constitute one of the worst
preserved ecosystems in the area
Novel insights into the impact of anticancer drugs on the performance and microbial communities of a continuous-flow aerobic granular sludge system
Anticancer drugs are frequently found in domestic wastewater, but knowledge of their impacts on wastewater treatment processes is limited. The effects of three levels of concentrations (low, medium, and high) of three anticancer drugs on physicochemical parameters and prokaryotic communities of a continuous-flow aerobic granular sludge (AGS) system were examined. Drugs at medium and high concentrations reduced the removal of total nitrogen and organic matter during the first 15 days of operation by approximately 15–20 % compared to a control, but these effects disappeared afterward. Removal efficiencies of drugs were in the range of 51.2–100 % depending on the concentration level. Drugs at medium and high concentrations reduced the abundance and diversity and altered the composition of prokaryotic communities. Specific taxa were linked to variations in performance parameters after the addition of the drugs. This study provides improved knowledge of the impacts of anticancer drugs in AGS systems operated in continuous-flow reactor
Anticancer drugs impact the performance and prokaryotic microbiome of an aerobic granular sludge system operated in a sequential batch reactor
Increased concerns exist about the presence of anticancer drugs in wastewater. However, knowledge of the impacts of anticancer drugs on the performance of the system and microbial communities during wastewater treatment processes is limited. We examined the effect of three anticancer drugs commonly detected in influents of wastewater treatment plants applied at three different concentration levels on the performance, efficiency of anticancer drug removal, and prokaryotic microbiome in an aerobic granular sludge system (AGS) operated in a sequential batch reactor (SBR). We showed that an AGS can efficiently remove anticancer drugs, with removal rates in the range of 53–100% depending on the type of drug and concentration level. Anticancer drugs significantly decreased the abundance of total bacterial and archaeal communities, an effect that was linked to reduced nitrogen removal efficiency. Anticancer drugs also reduced the diversity, altered the prokaryotic community composition, reduced network complexity, and induced a decrease of a wide range of predicted bacterial functions. Specific bacterial taxa responsive to the addition of anticancer drugs with known roles in nitrification and denitrification were identified. This study shows anticancer drugs should be monitored in the future as they can induce changes in the performance and microbiome of wastewater treatment technologies
Effectiveness of an O-Alkyl Hydroxamate in Dogs with Naturally Acquired Canine Leishmaniosis: An Exploratory Clinical Trial
Canine leishmaniosis is a challenge in veterinary medicine and no drug to date has achieved
parasite clearance in dogs. Histone deacetylase inhibitors are a drug class widely used in cancer
chemotherapy. We have successfully used O-alkyl hydroxamates (vorinostat derivatives) in the
treatment of a laboratory model of visceral leishmaniasis without showing toxicity. In order to
test the effectiveness of a particular compound, MTC-305, a parallel-group, randomized, singlecentre,
exploratory study was designed in naturally infected dogs. In this clinical trial, 18 dogs
were allocated into 3 groups and were treated with either meglumine antimoniate (104 mg SbV/kg),
MTC-305 (3.75 mg/kg) or a combination of both using a lower MTC-305 dose (1.5 mg/kg) through
a subcutaneous route for 2 treatment courses of 30 days, separated by a 30-day rest period. After
treatment, a follow-up time of 4 months was established. Parasite burden in bone marrow, lymph
node and peripheral blood were quantified through qPCR. Antibody titres were determined through
an immunofluorescence antibody test, and cytokine expression values were calculated through RTqPCR.
Treatment safety was evaluated through the assessment of haematological and biochemical
parameters in blood, weight, and gastrointestinal alterations. Assessment was carried out before,
between and after treatment series. Treatment with MTC-305 was effective at reducing parasite
burdens and improving the animals’ clinical picture. Dogs treated with this compound did not
present significant toxicity signs. These results were superior to those obtained using the reference
drug, meglumine antimoniate, in monotherapy. These results would support a broader clinical trial,
optimised dosage, and an expanded follow-up stage to confirm the efficacy of this drug.University of GranadaAndalusian GovernmentEuropean Commission B-CTS-270UGR18
P20_0013
Elasto-plastic hardening models adjustment to ferritic, austenitic and austenoferritic Rebar
The elastoplastic behaviour of steel used for structural member fabrication has received attention to facilitate a mechanical-resistant design. New Zealand and South African standards have adopted various theoreti-cal approaches to describe such behaviour in stainless steels. With respect to the building industry, describing the tensile behaviour of steel rebar used to produce reinforced concrete structures is of interest. Differences compared with the homogenous material described in the above mentioned standards and related literatures are discussed in this paper. Specifically, the presence of ribs and the TEMPCORE® technology used to produce carbon steel rebar may alter the elastoplastic model. Carbon steel rebar is shown to fit a Hollomon model giving hardening exponent values on the order of 0.17. Austenitic stainless steel rebar behaviour is better described using a modified Rasmussen model with a free fitted exponent of 6. Duplex stainless steel shows a poor fit to any previous model.Ajuste de los aceros corrugados ferríticos, austeníticos y austenoferríticos a los modelos de endureci-miento elastoplástico por deformación. Uno de los principales factores tenidos en cuenta en la fabricación de aceros estructurales es su comportamiento durante la fase elastoplástica o de endurecimiento por deformación. Normas neozelandesas y sudafricanas plantean diversas aproximaciones teóricas para describir dicho comportamiento en el caso de los aceros inoxidables. En el campo de la construcción resulta de interés la descripción del comporta-miento tenso-deformacional de los aceros corrugados utilizados en las estructuras de hormigón armado. En este artículo se discuten los modelos planteados en las normas citadas anteriormente así como los existentes en la litera-tura tanto para los aceros corrugados inoxidables como para los aceros al carbono fabricados mediante el proceso denominado TEMPCORE® Los aceros TEMPCORE® analizados arrojan un valor del exponente de endureci-miento por deformación según el modelo de Hollomon de 0.17. Los aceros inoxidables austeníticos se ajustan mejor al modelo de Rasmussen presentando un exponente de valor 6 realizando un ajuste libre de la función correspondiente. Para los aceros inoxidables Dúplex se obtienen muy bajos ajustes para los dos modelos citados
Microstructure and impedance spectroscopy of 3YTZP/SWNT ceramic nanocomposites
This work provides new insights on microstructure and electrical properties of 3 mol% Y2O3–ZrO2 (3YTZP) composites with 0.5, 1, and 1.5 vol% single walled carbon nanotubes (SWNTs). The composites were spark plasma sintered (SPS) in identical conditions at 1250 °C from powder prepared by two different processing routines, with the aim of optimizing the SWNTs dispersion throughout the ceramic matrix. High densification and submicrometric grain size were achieved in all the composites. Electrical properties of the composites were characterized in a wide temperature range, and modeling of the impedance properties was approached by means of an equivalent circuit that allows separation of the individual SWNT bundles contribution to resistance from the resistance due to junctions between bundles. Effects of the homogeneous distribution of SWNTs at the ceramic grain boundaries on the crystalline phases, percolation threshold, total conductivity and evolution of junctions׳ resistivity with temperature were analyzed and discussed.España Ministerio de Ciencia e Innovación MAT2012-34217Junta de Andalucia P12-FQM107
Magnetite Mineralization inside Cross-Linked Protein Crystals
Crystallization in confined spaces is a widespread process in nature that also has important implications for the
stability and durability of many man-made materials. It has been reported that confinement can alter essential crystallization events,
such as nucleation and growth and, thus, have an impact on crystal size, polymorphism, morphology, and stability. Therefore, the
study of nucleation in confined spaces can help us understand similar events that occur in nature, such as biomineralization, design
new methods to control crystallization, and expand our knowledge in the field of crystallography. Although the fundamental interest
is clear, basic models at the laboratory scale are scarce mainly due to the difficulty in obtaining well-defined confined spaces allowing
a simultaneous study of the mineralization process outside and inside the cavities. Herein, we have studied magnetite precipitation in
the channels of cross-linked protein crystals (CLPCs) with different channel pore sizes, as a model of crystallization in confined
spaces. Our results show that nucleation of an Fe-rich phase occurs inside the protein channels in all cases, but, by a combination of
chemical and physical effects, the channel diameter of CLPCs exerted a precise control on the size and stability of those Fe-rich
nanoparticles. The small diameters of protein channels restrain the growth of metastable intermediates to around 2 nm and stabilize
them over time. At larger pore diameters, recrystallization of the Fe-rich precursors into more stable phases was observed. This study
highlights the impact that crystallization in confined spaces can have on the physicochemical properties of the resulting crystals and
shows that CLPCs can be interesting substrates to study this process.Ministry of Science and Innovation, Spain (MICINN) PID2020-116261GB-I00
PID2020-118498GB-I00
PDC2021-121135.100FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain) A-FQM-340-UGR20
UCE-PP2016-0
Feasibility Study of a Proton Irradiation Facility for Radiobiological Measurements at an 18 MeV Cyclotron
A feasibility study of an experimental setup for the irradiation of biological samples at the cyclotron facility installed at the National Centre of Accelerators (Seville, Spain) is presented. This cyclotron, which counts on an external beam line for interdisciplinary research purposes, produces an 18 MeV proton beam, which is suitable for the irradiation of mono-layer cultures for the measurement of proton cell damages and Relative Biological Effectiveness (RBE) at energies below the beam nominal value. Measurements of this kind are of interest for proton therapy, since the variation of proton RBE at the distal edge of the Bragg curve may have implications in clinical proton therapy treatments. In the following, the characteristics of the beam line and the solutions implemented for the irradiation of biological samples are described. When dealing with the irradiation of cell cultures, low beam intensities and broad homogeneous irradiation fields are required, in order to assure that all the cells receive the same dose with a suitable dose rate. At the cyclotron, these constraints have been achieved by completely defocusing the beam, intercepting the beam path with tungsten scattering foils and varying the exit-window-to-sample distance. The properties of the proton beam thus obtained have been analysed and compared with Monte Carlo simulations. The results of this comparison, as well as the experimental measurement of the lateral dose profiles expected at the position of samples are presented. Meaningful dose rates of about 2–3 Gy/min have been obtained. Homogeneous lateral dose profiles, with maximum deviations of 5%, have been measured at a distance of approximately 50 cm in air from the exit window, placing a tungsten scattering foil of 200 μm in the beam path
Evidence of nanograin cluster coalescence in spark plasma sintered α-Al2O3
The aim of this study is to elucidate the coarsening kinetics involved during densification of fine-grained pure α-alumina by spark plasma sintering. Low temperature and short dwell time sintering conditions were used to preserve the nanocrystalline structure of the starting commercial powder (about 50 nm). Notwithstanding the above, submicron grain coarsened microstructures have been developed. The microstructure evolution of alumina under different sintering conditions points to a nanograin rotation densification mechanism as being responsible for the fast grain growth observed.Ministerio de Ciencia e Innovación MAT2009-1107
The role of carbon nanotubes on the stability of tetragonal zirconia polycrystals
The effect of single walled carbon nanotubes (SWNT) at zirconia grain boundaries on the stability of a tetragonal
zirconia polycrystalline matrix has been explored in as–sintered composites and after low–temperature hydrothermal degradation (LTD) experiments. For this purpose, highly–dense 3 mol% Y2O3–doped tetragonal zirconia
polycrystalline (3YTZP) ceramics and SWNT/3YTZP composites were prepared by spark plasma sintering (SPS).
Quantitative X–ray diffraction analysis and microstructural observations point out that an increasing amount of
well–dispersed SWNT bundles surrounding zirconia grains decreases the metastable tetragonal phase retention
in the ceramic matrix after sintering. In contrast, the tetragonal ceramic grains in composites with SWNTs are
less sensitive to the presence of water, i.e. to undergo a martensitic transformation under LTD conditions, than
monolithic 3YTZP ceramics. The SWNT incorporation diminishes micro–cracking due to tetragonal to monoclinic ZrO2 phase transformation in the composites.Ministerio de Economía y Competitividad de España y Fondos Europeos FEDER - MAT2015–67889–PJunta de Andalucía - P12–FQM–107
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