187 research outputs found

    Theoretical study of the local atomic and electronic structure of dimetacyano azobenzene molecules on Bi (111) substrate

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    The present work is devoted to the local atomic and electronic structure of dimetacyano (DMC) molecules deposited on a Bi (111) substrate before and after irradiation by X-rays and UV light using density functional theory (DFT) and a theoretical analysis of the X-ray absorption near edge tructure (XANES) spectroscopy. As a result of the calculations the low-energy structure for DMC zobenzene molecules on a Bi (111) substrate was obtained.1\. Auflag

    ArgO145, a Stx2a prophage of a bovine O145:H- STEC strain, is closely related to phages of virulent human strains

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    Shiga toxins (Stx) are the main virulence factor of a pathogroup of Escherichia coli strains that cause severe human diseases. These toxins are encoded in prophages (Stx prophages), and generally their expression depends on prophage induction. Several studies have reported high diversity among both Stx prophages and Stx. In particular, the toxin subtype Stx2a is associated with high virulence and HUS. Here, we report the genome of ArgO145, an inducible Stx2a prophage identified in a bovine O145:H‐ strain which produced high levels of Shiga toxin and Stx phage particles. The ArgO145 genome shared lambda phage organization, with recombination, regulation, replication, lysis, and head and tail structural gene regions, although some lambda genes encoding regulatory proteins could not be identified. Remarkably, some Stx2a phages of strains isolated from patients in other countries showed high similarity to ArgO145.Fil: Krüger, Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Burgán, Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Friedrich, Alex. University Medical Center Groningen; Países BajosFil: Rossen, Johannes Wilhelmus Augustinus. University Medical Center Groningen; Países BajosFil: Lucchesi, Paula Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentin

    Spin crossover in a vacuum-deposited submonolayer of a molecular iron(II) complex

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    Spin-state switching of transition-metal complexes (spin crossover) is sensitive to a variety of tiny perturbations. It is often found to be suppressed for molecules directly adsorbed on solid surfaces. We present X-ray absorption spectroscopy measurements of a submonolayer of [FeII(NCS)2L] (L: 1-{6-[1,1-di(pyridin-2-yl)ethyl]-pyridin-2-yl}-N,N-dimethylmethanamine) deposited on a highly oriented pyrolytic graphite substrate in ultrahigh vacuum. These molecules undergo a thermally induced, fully reversible, gradual spin crossover with a transition temperature of T1/2 = 235(6) K and a transition width of ΔT80 = 115(8) K. Our results show that by using a carbon- based substrate the pin-crossover behavior can be preserved even for molecules that are in direct contact with a solid surface

    Site-specific bonding of copper adatoms to pyridine end groups mediating the formation of two-dimensional coordination networks on metal surfaces

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    We study the formation of a coordination network consisting of the organic pyridine-based 2,4,6-tris(4-pyridine)-1,3,5-triazine (T4PT) species and Cu atoms on Cu(111) and Ag(111) metal surfaces. Using scanning tunneling microscopy, we find that the organic molecule T4PT forms stable two- dimensional porous networks on the surface of Cu(111) and, by codeposition of Cu atoms, also on the Ag(111) crystal, in which Cu atoms are twofold coordinated by T4PT molecules. X-ray absorption spectroscopy measurements of the metal-organic network Cu–T4PT on Ag(111) accompanied by density-functional theory calculations show that the nitrogen atoms of the pyridine end groups of the T4PT molecules are the active sites in coordinating the Cu adatoms. X-ray magnetic circular dichroism experiments reveal that the Cu atom in such a metal-organic motif is in a low-valent d10 state and has no magnetic moment

    The influence of air-sea fluxes on atmospheric aerosols during the summer monsoon over the tropical Indian Ocean

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    During the summer monsoon, the western tropical Indian Ocean is predicted to be a hot spot for dimethylsulfide emissions, the major marine sulfur source to the atmosphere, and an important aerosol precursor. Other aerosol relevant fluxes, such as isoprene and sea spray, should also be enhanced, due to the steady strong winds during the monsoon. Marine air masses dominate the area during the summer monsoon, excluding the influence of continentally derived pollutants. During the SO234-2/235 cruise in the western tropical Indian Ocean from July to August 2014, directly measured eddy covariance DMS fluxes confirm that the area is a large source of sulfur to the atmosphere (cruise average 9.1 μmol m−2 d−1). The directly measured fluxes, as well as computed isoprene and sea spray fluxes, were combined with FLEXPART backward and forward trajectories to track the emissions in space and time. The fluxes show a significant positive correlation with aerosol data from the Terra and Suomi-NPP satellites, indicating a local influence of marine emissions on atmospheric aerosol numbers

    Sentence processing in anterior superior temporal cortex shows a social-emotional bias

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    The anterior region of the left superior temporal gyrus/superior temporal sulcus (aSTG/STS) has been implicated in two very different cognitive functions: sentence processing and social-emotional processing. However, the vast majority of the sentence stimuli in previous reports have been of a social or social-emotional nature suggesting that sentence processing may be confounded with semantic content. To evaluate this possibility we had subjects read word lists that differed in phrase/constituent size (single words, 3-word phrases, 6-word sentences) and semantic content (social-emotional, social, and inanimate objects) while scanned in a 7T environment. This allowed us to investigate if the aSTG/STS responded to increasing constituent structure (with increased activity as a function of constituent size) with or without regard to a specific domain of concepts, i.e., social and/or social-emotional content. Activity in the left aSTG/STS was found to increase with constituent size. This region was also modulated by content, however, such that social-emotional concepts were preferred over social and object stimuli. Reading also induced content type effects in domain-specific semantic regions. Those preferring social-emotional content included aSTG/STS, inferior frontal gyrus, posterior STS, lateral fusiform, ventromedial prefrontal cortex, and amygdala, regions included in the "social brain", while those preferring object content included parahippocampal gyrus, retrosplenial cortex, and caudate, regions involved in object processing. These results suggest that semantic content affects higher-level linguistic processing and should be taken into account in future studies

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

    HLA in isolated REM sleep behavior disorder and Lewy body dementia

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    peer reviewedSynucleinopathies-related disorders such as Lewy body dementia (LBD) and isolated/idiopathic REM sleep behavior disorder (iRBD) have been associated with neuroinflammation. In this study, we examined whether the human leukocyte antigen (HLA) locus plays a role in iRBD and LBD. In iRBD, HLA-DRB1*11:01 was the only allele passing FDR correction (OR = 1.57, 95 CI = 1.27–1.93, p = 2.70e-05). We also discovered associations between iRBD and HLA-DRB1 70D (OR = 1.26, 95\%CI = 1.12–1.41, p = 8.76e-05), 70Q (OR = 0.81, 95\%CI = 0.72–0.91, p = 3.65e-04) and 71R (OR = 1.21, 95\%CI = 1.08–1.35, p = 1.35e-03). Position 71 (pomnibus = 0.00102) and 70 (pomnibus = 0.00125) were associated with iRBD. Our results suggest that the HLA locus may have different roles across synucleinopathies
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