Insights into the room temperature magnetism of ZnO/Co3O4 mixtures

The origin of room temperature (RT) ferromagneticlike behavior in ZnO-based diluted magnetic semiconductors is still an unclear topic. The present work concentrates on the appearance of RT magnetic moments in just mixed ZnO/Co3O4 mixtures without thermal treatment. In this study, it is shown that the magnetism seems to be related to surface reduction of the Co3O4 nanoparticles, in which, an antiferromagnetic Co3O4 nanoparticle (core) is surrounded by a CoO-like shell. This singular superficial magnetism has also been found in other mixtures with semiconductors such as TiO2 and insulators such as Al2O3

Immobilization of chromium complexes in zeolite Y obtained from biosorbents : synthesis, characterization and catalytic behaviour

The goal of this study is the preparation of new heterogeneous catalytic materials to be used in oxidation reactions under mild conditions through the valuation of heavy metals in wastewater. The samples used in the immobilization of chromium complexes were prepared from a dichromate solution of 100 mgCr L−1. The zeolite CrNaY was prepared from a robust biosorption system consisting of a bacterial biofilm, Arthrobacter viscosus, supported on zeolite NaY. The biofilm performs the reduction of Cr(VI) to Cr(III) and this cation is retained in the zeolite by ion exchange. The immobilization of chromium complexes with heterocyclic ligands in the supercages of Y zeolite was performed by the in situ synthesis with three different ligands, 3-methoxy-6-chloropyridazine (A), 3-piperidino-6-chloropyridazine (B) and 1-(2-pyridylazo)-2-naphthol (C). A sample loaded with Cr from a liquid solution with the same initial concentration was prepared as a reference through the traditional direct ion-exchange method and coordinated with ligand (A). The resulting catalysts were fully characterized by different techniques (FTIR, XRD, TGA, SEM, Raman, cyclic voltammetric studies and chemical analysis) and the results confirmed that the Cr complexes were immobilized in supercages of NaY. Catalytic studies were performed in liquid phase for the cyclohexene oxidation, at 40 °C, using tert-butyl hydroperoxide (TBHP) as the oxidizing agent. All the prepared catalysts exhibited catalytic activity for the oxidation reaction.União Europeia. Fundo Europeu de Desenvolvimento Regional (FEDER)Fundação para a Ciência e a Tecnologia (FCT) - ref. POCTI/44449/CTA/2002, POCTI-SFA-3-68

A High-level Ab Initio Study of the Destruction of Methanimine under UV Radiation

13 pags., 9 figs., 1 tab. -- Unified Astronomy Thesaurus concepts: Complex organic molecules (2256); Photodissociation reactions (2266)The photodecomposition of methanimine (CH$_2$NH) in the interstellar medium through several possible pathways is investigated by means of high-level multireference configuration interaction {\it ab initio} calculations. Among them are photodissociation pathways involving hydrogen-atom elimination from both the CH$_2$ and NH groups, and fragmentation into CH$_2$ and NH. Potential-energy curves for the ground and several excited electronic states, as well as nonadiabatic couplings between them, are calculated. Possible dissociation mechanisms are discussed for the different pathways. It is found that the minimum excitation energy required for methanimine dissociation is above $7$ eV. By using a two-dimensional representation of methanimine, the CH$_2$NH $\rightarrow$ CHNH$_2$ isomerization is explored as an additional methanimine decomposition pathway. Hydrogen-atom elimination from the CH$_2$ group is also investigated along the isomerization pathway. The results show that the isomerization proceeds by overcoming a transition state that in the first two excited states would require excitation energies similar to or somewhat lower than the typical minimum energies needed for breaking the molecule through the fragmentation pathwys. Therefore, CH$_2$NH $\rightarrow$ CHNH$_2$ isomerization can effectively contribute to methanimine decomposition, competing efficiently with the photodissociation pathways. The radiation content present in the interstellar medium makes possible the occurrence of all the pathways studied.This work was funded by the Ministerio de Ciencia e Innovación (MICINN, Spain), grant Nos. PGC2018-096444-BI00, PID2019-107115GB-C21, PID2021-122549NB-C21, PID2021-122796NB-I00, and PID2021-122839NB-I00. A.B. acknowledges funding from the I-COOP program from CSIC, grant No. COOPB20364, which made possible a research stay at Instituto de Física Fundamental, CSIC. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Marie SkłodowskaCurie Grant Agreement No. 872081. The authors acknowledge the National Plan for Science, Technology and Innovation (MAARIFAH), King Abdulaziz City for Science and Technology, Kingdom of Saudi Arabia, grant No. 2-17-01-001-0061. The Centro de Supercomputación de Galicia (CESGA, Spain) is acknowledged for allowing the use of its resources

Oxidation of cyclohexanol and cyclohexene with triazenido complexes of chromium immobilized in biosorption FAU supports

This work presents the recovery of biosorption supports as an alternative source of benign production of heterogeneous catalysts for oxidation reactions in mild conditions. Cr-containing FAU zeolite, in sodium form (NaY) and in proton form (HY), was recovered from biosorption studies and reused as support for the preparation of heterogeneous catalysts by the flexible ligand method, using 1,3-diphenyltriazene derivatives. Results showed that the ligand play an important role in the coordination of Cr inside the zeolite. The catalysts showed good activity for the oxidation of cyclohexanol, reaching a maximum of 63.5% conversion. Cr leaching was evaluated and it was found that the Cr-FAU supports lost some of the Cr into the reaction medium, whereas immobilization of Cr-complexes reduced the referred leaching. For the cyclohexene oxidation, a maximum 72.9% conversion was achieved with a HY zeolite-based catalyst.H. Figueiredo and B. Silva are thankful to the "FCT - Fundacao para a Ciencia e Tecnologia" for their respective research grants. IKB thanks FO' for the contract under the program Ciencia 2007. This work was partially funded by the Centre of Biological Engineering and the Centre of Chemistry (University of Minho, Portugal) through FCT strategic projects PEst-OE/EQB/LA0023/ 2013 and PEst-C/QUI/UI0686/2011 (nF-COMP-01-0124-FEDER022716), the Project "BioEnv - Biotechnology and Bioengineering for a sustainable world", REF. NORTE-07-0124-FEDER-000048, co-funded by the Programa Operacional Regional do Norte (ON.2 - 0 Novo Norte), QREN and FEDER, and by the Spanish Ministry of Science and Innovation (CTQ2008-04261/PPQ)

Evaluation of the efficacy of essential oils of Lavandula angustifolia and Eucalyptus globulus for the control of Varroa destructor in Apis mellifera: A randomised field study

Varroa destructor is the most harmful and widespread parasite that spreads disease in bees. Eucalyptus spp essential oils (EOs), has been shown to be effective against V. destructor. Additionally, Lavender spp EOs treatment, resulted in mite mortality rates of 95% to 97% of V. destructor. During the treatments, 20 mL of each oil or the placebo was distributed on two sheets of papier-mâché located on the frames of the brood chamber inside each hive. The miticidal effects of Lavandula angustifolia and Eucalyptus globulus EOs were analysed. Parasitic load and mite fall were evaluated under field conditions. The mean infestation rate obtained from each of three treatment groups at the beginning of the study was less than 3.6%. Then, the infestation rate increased gradually in each group until day 36. The infestation rates in the groups treated with L. angustifolia and E. globulus EOs were lower than those in the control by more than two percentage points and never exceeded 10%; the differences between the control group and the L. angustifolia group were statistically significant (p <0.05). Both EO treatments were applied in four doses, which produced a prolonged effect that lowered the rates of parasite birth and reinfestation. The L. angustifolia EO was effective; in that treatment, parasitic loads were maintained at levels lower than those in the control group starting at the second treatment dose due to the reproductive cycles of both species

Biorecovery of Cr(VI) from wastewater and its catalytic reutilization

The performance of two zeolites with different structures and acidity properties was evaluated on the biosorption of Cr(VI) and catalytic oxidation of ethyl acetate. The starting zeolites, HY and HZSM5, were modified by ion exchange treatments in order to obtain zeolites with different acidity and sodium content. Arthrobacter viscosus supported on the different zeolites was used for Cr(VI) recovery from solution. The best removal efficiencies and uptake of chromium were achieved for the Y zeolites due to their higher ion exchange capacity. The Y and ZSM5 zeolites were characterized by ICP-AES, SEM, NH3 chemisorption, XRD and N2 adsorption. Y and ZSM5 zeolites obtained after biosorption of chromium were successfully reused as catalysts in the oxidation of ethyl acetate. The chromium-loaded ZSM5 zeolites were considerably more active and selective towards CO2 than chromium-loaded Y zeolites, essentially due to its different framework structure, textural and acidity properties

Effect of aspirin on the diagnostic accuracy of the faecal immunochemical test for colorectal advanced neoplasia

Background: Aspirin (ASA) is a drug that can cause gastrointestinal lesions and symptoms. Colorectal cancer (CRC) is the most prevalent type of cancer in Western countries. We assessed the effect of aspirin on the diagnostic accuracy of the faecal immunochemical test (FIT) for CRC and/or advanced neoplasia (AN) in patients undergoing colonoscopy for gastrointestinal symptoms. Methods: We conducted a prospective multicentre observational study of diagnostic tests that included patients with gastrointestinal symptoms undergoing colonoscopy between March 2012 and 2014 (the COLONPREDICT study). Symptoms were assessed and a FIT and blood tests assessing haemoglobin and carcinoembryonic antigen (CEA) levels were performed. Results: The study included 3052 patients: A total of 2567 did not take aspirin (non-user group) and 485 (16%) took aspirin (user group). Continuous treatment with ASA did not change the AUC (0.88, 0.82; p = 0.06), sensitivity (92%, 88%; p = 0.5) or specificity (71%, 67%; p = 0.2) of the FIT for CRC detection. Similarly, we found no differences in the AUC (0.81, 0.79; p = 0.6), sensitivity (74%, 75.5%; p = 0.3) or specificity (76%, 73.6%; p = 0.3) for AN detection. Patients with an aspirin use of = 300 mg/day had a lower prevalence of AN and the sensitivity, specificity and AUC for AN for these patients were 54%, 68% and 0.66, significantly lower than for the non-user group (p = 0.03). Conclusions: Aspirin does not modify the diagnostic accuracy of FIT for CRC and/or AN in patients with gastrointestinal symptoms. Aspirin use of = 300 mg/day decreases the accuracy of the test

Inter- and intra-island speciation and their morphological and ecological correlates in Aeonium (Crassulaceae), a species-rich Macaronesian radiation

Background and Aims The most species-rich and ecologically diverse plant radiation on the Canary Islands is the Aeonium alliance (Crassulaceae). In island radiations like this, speciation can take place either within islands or following dispersal between islands. Aiming at quantifying intra- and inter-island speciation events in the evolution of Aeonium, and exploring their consequences, we hypothesized that (1) intra-island diversification resulted in stronger ecological divergence of sister lineages, and that (2) taxa on islands with a longer history of habitation by Aeonium show stronger ecological differentiation and produce fewer natural hybrids. Methods We studied the biogeographical and ecological setting of diversification processes in Aeonium with a fully sampled and dated phylogeny inferred using a ddRADseq approach. Ancestral areas and biogeographical events were reconstructed in BioGeoBEARS. Eleven morphological characters and three habitat characteristics were taken into account to quantify the morphological and ecological divergence between sister lineages. A co-occurrence matrix of all Aeonium taxa is presented to assess the spatial separation of taxa on each island. Key Results We found intra- and inter-island diversification events in almost equal numbers. In lineages that diversified within single islands, morphological and ecological divergence was more pronounced than in lineages derived from inter-island diversification, but only the difference in morphological divergence was significant. Those islands with the longest history of habitation by Aeonium had the lowest percentages of co-occurring and hybridizing taxon pairs compared with islands where Aeonium arrived later. Conclusions Our findings illustrate the importance of both inter- and intra-island speciation, the latter of which is potentially sympatric speciation. Speciation on the same island entailed significantly higher levels of morphological divergence compared with inter-island speciation, but ecological divergence was not significantly different. Longer periods of shared island habitation resulted in the evolution of a higher degree of spatial separation and stronger reproductive barriers.info:eu-repo/semantics/publishedVersio

The TechnoFusion Consortium of Spanish institutions and facilities towards the development of fusion materials and related technologies in Europe

14 pags., 10 figs.With the objective of contributing to the European development of materials, technologies and facilities for the demonstration of the thermonuclear fusion, the construction of the unique TechnoFusión facility was planned in 2009. The TechnoFusión consortium, formed by selected Spanish research groups and laboratories located in Madrid, has jointly advanced in the search for solutions to the remaining technological issues of nuclear fusion by magnetic and inertial confinement. In addition, the foundation of the TechnoFusión partnership has been essential to create a network of collaborations, and also to expand and specialize human resources, by training scientists and technical staff in the use of high-tech tools. Supported by the TechnoFusión_Comunidad Madrid (III) regional programme, the consortium is focused on providing support for the construction of medium-­sized, relevant facilities in Madrid (Spain). Regarding magnetic and inertial fusion issues, the programme is structured in several key experiments and infrastructures, which combine the development of materials, of cutting-edge technologies and the construction of associated facilities, with the progress in simulation and application of computational neutronics:The authors acknowledge the funding by Community of Madrid, co-financed with Structural Funds (ERDF and ESF)), through the TechnoFusión (III)-CM (S2018/EMT-4437) programme. This work has also been carried out within the framework of the EUROfusion Consortium and has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement number 633053. The views and opinions expressed in this document do not necessarily reflect those of the European Commission. In particular, R. González-Arrabal acknowledges the Convenio Plurianual con la Universidad Politécnica de Madrid en la línea de actuación Programa de Excelencia para el Profesorado Universitario of the CAM (Comunidad Autónoma Madrid)