142 research outputs found

    Magnetic ground state and magnon-phonon interaction in multiferroic h-YMnO3_3

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    Inelastic neutron scattering has been used to study the magneto-elastic excitations in the multiferroic manganite hexagonal YMnO3_3. An avoided crossing is found between magnon and phonon modes close to the Brillouin zone boundary in the (a,b)(a,b)-plane. Neutron polarization analysis reveals that this mode has mixed magnon-phonon character. An external magnetic field along the cc-axis is observed to cause a linear field-induced splitting of one of the spin wave branches. A theoretical description is performed, using a Heisenberg model of localized spins, acoustic phonon modes and a magneto-elastic coupling via the single-ion magnetostriction. The model quantitatively reproduces the dispersion and intensities of all modes in the full Brillouin zone, describes the observed magnon-phonon hybridized modes, and quantifies the magneto-elastic coupling. The combined information, including the field-induced magnon splitting, allows us to exclude several of the earlier proposed models and point to the correct magnetic ground state symmetry, and provides an effective dynamic model relevant for the multiferroic hexagonal manganites.Comment: 12 pages, 10 figure

    The Artificial Sweetener Splenda Promotes Gut Proteobacteria, Dysbiosis, and Myeloperoxidase Reactivity in Crohn’s Disease–Like Ileitis

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    We thank John D. Ward and Lindsey N. Kaydo for their technical support and Dr. Wei Xin for the histological scoring of ileitis severity. ARP is an Assistant Professor of Medicine at CWRU School of Medicine. Metagenomic sequencing was conducted in the laboratory of Dr. Skip Virgin at Washington University, School of Medicine, St. Louis, MO. Raw sequencing data files will be available upon request.Peer reviewedPostprin

    Efecto De La Humedad Relativa Y La Temperatura En La Aplicacion De Insecticidas Organofosforados Y Carbamatos E Impacto En La Colinesterasa De Agro Productores De Tomate (Solanum Lycopersicum L.) En La Localidad De “San Luis, Chimborazo, Ecuador

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    This research aimed to determine the effect of relative humidity and temperature in the application of organophosphorus and carbamate insecticides and impact on the colinesterasa of tomato agro producers (Solanum lycopersicum L.) in the location of" San Luis, Chimborazo, Ecuador.The technique used was spectrophotometry. The cholinesterase test was performed on the one hundred and seventy patients of the five communities exposed between one year and more than ten years, in the handling and application of organophosphorus and carbamate insecticides. The method used was kinetic-spectrophotometric (405 nm at 37 ° C). Through the Kruskal Wallis test and the regression and correlation analysis it was determined the significance and the level of correlation and determination between the variables under study and their effect on cholinesterase levels. Concluding that the applications of the organophosphorus and carbamate insecticides under greenhouse with low relative humidity and high temperature, accompanied by the lack of precautions in the management of the crop, contribute to the decrease of the cholinesterase level of the agro producers

    Prevalence of hospital PCR-confirmed COVID-19 cases in patients with chronic inflammatory and autoimmune rheumatic diseases

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    [Abstract] Background: The susceptibility of patients with rheumatic diseases and the risks or benefits of immunosuppressive therapies for COVID-19 are unknown. Methods: We performed a retrospective study with patients under follow-up in rheumatology departments from seven hospitals in Spain. We matched updated databases of rheumatology patients with severe acute respiratory syndrome coronavirus 2-positive PCR tests performed in the hospital to the same reference populations. Rates of PCR+ confirmed COVID-19 were compared among groups. Results: Patients with chronic inflammatory diseases had 1.32-fold higher prevalence of hospital PCR+ COVID-19 than the reference population (0.76% vs 0.58%). Patients with systemic autoimmune or immune-mediated disease (AI/IMID) showed a significant increase, whereas patients with inflammatory arthritis (IA) or systemic lupus erythematosus did not. COVID-19 cases in some but not all diagnostic groups had older ages than cases in the reference population. Patients with IA on targeted-synthetic or biological disease-modifying antirheumatic drugs (DMARDs), but not those on conventional-synthetic DMARDs, had a greater prevalence despite a similar age distribution. Conclusion: Patients with AI/IMID show a variable risk of hospital-diagnosed COVID-19. Interplay of ageing, therapies and disease-specific factors seem to contribute. These data provide a basis to improve preventive recommendations to rheumatic patients and to analyse the specific factors involved in COVID-19 susceptibility.Instituto de Salud Carlos III; RD16/0012 RETICS Progra

    Metabolomics Reveals Differential Levels of Oral Metabolites in HIV-Infected Patients: Toward Novel Diagnostic Targets

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    The objective of the current study was to characterize the profile of oral metabolites in HIV-infected patients using metabolomics. Oral wash samples were collected from 12 HIV-infected and 12 healthy individuals (matched for age, sex, and ethnicity), processed, and analyzed by metabolomics. We detected 198 identifiable and 85 nonidentifiable metabolites; 27 identifiable metabolites were differentially present (12 increased, 15 decreased) in HIV-infected patients. Elevated metabolites included p-cresol sulfate, nucleotides (e.g., allantoin), and amino acids (e.g., phenylalanine, tryptophan), whereas decreased oral metabolites included fucose, fumarate, and N-acetylglucosamine. Pathway network analysis revealed the largest multinode network in healthy versus HIV-infected patients to involve carbohydrate biosynthesis and degradation. HIV-infected patients on antiretroviral therapy (ART) showed the largest number (12) of statistically significant metabolite correlation differences compared with healthy controls. Interestingly, the oral phenlyalanine:tyrosine ratio increased in ART-naive HIV-infected patients (mean ± SEM = 2.58 ± 0.87) compared with healthy individuals (1.33 ± 0.10, p = 0.062) or ART-experienced patients (1.78 ± 0.30, p = 0.441). This is the first study to reveal differential levels of oral metabolites in HIV-infected patients compared withj healthy volunteers, and that oral phenlyalanine:tyrosine ratio may be a useful marker for noninvasive monitoring of the immune status during HIV infection

    Insights into the High Activity of Ruthenium Phosphide for the Production of Hydrogen in Proton Exchange Membrane Water Electrolyzers

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    The demand of green hydrogen, that is, the hydrogen produced from water electrolysis, is expected to increase dramatically in the coming years. State-of-the-art proton exchange membrane water electrolysis (PEMWE) uses high loadings of platinum group metals, such as Pt in the electrode where hydrogen is produced. Alternative electrodes based on phosphides, sulfides, nitrides, and other low-cost alternatives are under investigation. Herein, a simple process for the preparation of RuP electrodes with high activity for the hydrogen evolution reaction (HER) in acidic electrolyte is described. A straightforward one-pot synthesis that yields RuP nanoparticles with fine-tuned composition and stoichiometry is presented, as determined by multiple characterization techniques, including lab- and synchrotron-based experiments and theoretical modeling. The RuP nanoparticles exhibit a high activity of 10 mA cm−2 at 36 mV overpotential and a Tafel slope of 30 mV dec−1, which is comparable to Pt/C. Moreover, a RuP catalyst-coated membrane (CCM) with a low Ru loading of 0.6 mgRu cm−2 is produced and tested in a PEMWE cell configuration, yielding 1.7 A cm−2 at 2 V. © 2023 The Authors. Advanced Energy and Sustainability Research published by Wiley-VCH GmbH.The authors acknowledge the PROMET-H2 project. This project received funding from the European Union Horizon 2020 research and innovation programme under grant agreement no. 862253. The Deputyship for Research & Innovation, Ministry of Education of Saudi Arabia, is acknowl edged for funding this research work through the project number 341. The authors also acknowledge financial support from grants TED2021- 131033B-I00, PID2020-116712RB-C21, and PID2019-103967RJ-I00 funded by MCIN/AEI/10.13039/501100011033. Computing resources for this work were provided by STFC scientific computing departments of the SCARF cluster. J.T. wishes to acknowledge the Deutsche Akademische Austausch Dienst (DAAD), scholarship code number 57540124. The authors acknowledge Diamond Light Source for time on the VerSoX B07-B beamline under the commissioning proposal cm-28150Peer reviewe

    Impact of the AHI1 Gene on the Vulnerability to Schizophrenia: A Case-Control Association Study

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    BackgroundThe Abelson helper integration-1 (AHI1) gene is required for both cerebellar and cortical development in humans. While the accelerated evolution of AHI1 in the human lineage indicates a role in cognitive (dys)function, a linkage scan in large pedigrees identified AHI1 as a positional candidate for schizophrenia. To further investigate the contribution of AHI1 to the susceptibility of schizophrenia, we evaluated the effect of AHI1 variation on the vulnerability to psychosis in two samples from Spain and Germany.Methodology/Principal Findings29 single-nucleotide polymorphisms (SNPs) located in a genomic region including the AHI1 gene were genotyped in two samples from Spain (280 patients with psychotic disorders; 348 controls) and Germany (247 patients with schizophrenic disorders; 360 controls). Allelic, genotypic and haplotype frequencies were compared between cases and controls in both samples separately, as well as in the combined sample. The effect of genotype on several psychopathological measures (BPRS, KGV, PANSS) assessed in a Spanish subsample was also evaluated. We found several significant associations in the Spanish sample. Particularly, rs7750586 and rs911507, both located upstream of the AHI1 coding region, were found to be associated with schizophrenia in the analysis of genotypic (p = 0.0033, and 0.031, respectively) and allelic frequencies (p = 0.001 in both cases). Moreover, several other risk and protective haplotypes were detected (0.006<p<0.036). Joint analysis also supported the association of rs7750586 and rs911507 with the risk for schizophrenia. The analysis of clinical measures also revealed an effect on symptom severity (minimum P value = 0.0037).Conclusions/SignificanceOur data support, in agreement with previous reports, an effect of AHI1 variation on the susceptibility to schizophrenia in central and southern European populations

    Active and durable R2MnRuO7 pyrochlores with low Ru content for acidic oxygen evolution

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    The production of green hydrogen in water electrolyzers is limited by the oxygen evolution reaction (OER). State-of-the-art electrocatalysts are based on Ir. Ru electrocatalysts are a suitable alternative provided their performance is improved. Here we show that low-Ru-content pyrochlores (R2MnRuO7, R = Y, Tb and Dy) display high activity and durability for the OER in acidic media. Y2MnRuO7 is the most stable catalyst, displaying 1.5 V at 10 mA cm−2 for 40 h, or 5000 cycles up to 1.7 V. Computational and experimental results show that the high performance is owed to Ru sites embedded in RuMnOx surface layers. A water electrolyser with Y2MnRuO7 (with only 0.2 mgRu cm−2) reaches 1 A cm−2 at 1.75 V, remaining stable at 200 mA cm−2 for more than 24 h. These results encourage further investigation on Ru catalysts in which a partial replacement of Ru by inexpensive cations can enhance the OER performance. © 2023, The Author(s).We acknowledge the funding granted to the PROMET-H2 project by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 862253. The Deputyship for Research & Innovation, Ministry of Education of Saudi Arabia is acknowledged for funding this research work through project number 341. Financial support from grants PID2019−103967RJ-I00, PID2020-116712RB-C21, and PID2021-122477OB-I00 funded by MCIN/AEI/10.13039/501100011033 is acknowledged. The authors acknowledge Diamond Light Source for time on Beamline B18 and ALBA synchrotron for beamtime at MSPD line. The authors wish to acknowledge the Deutsche Akademische Austausch Dienst (DAAD), Scholarship code number 57540124. F.C.V. and M.J.K. acknowledge that the grants RTI2018-095460-B-I00, RYC-2015-18996, and MDM-2017-0767 were funded by MCIN/AEI/ 10.13039/501100011033 and by the European Union. The use of supercomputing facilities at SURFsara was sponsored by NWO Physical Sciences, with financial support from NWO.Supplementary information The online version contains supplementary material available at https://doi.org/10.1038/s41467-023-37665-9.Peer reviewe
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