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1.
  • Buchanan, E. M., et al. (author)
  • The Psychological Science Accelerator's COVID-19 rapid-response dataset
  • 2023
  • In: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 10:1
  • Journal article (peer-reviewed)abstract
    • In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data.
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  • Kowalik, I. A., et al. (author)
  • Element-specific characterization of heterogeneous magnetism in (Ga,Fe)N films
  • 2012
  • In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 85:18, s. 184411-
  • Journal article (peer-reviewed)abstract
    • We employ x-ray spectroscopy to characterize the distribution and magnetism of particular alloy constituents in (Ga,Fe)N films grown by metal organic vapor phase epitaxy. Furthermore, photoelectron microscopy gives direct evidence for the aggregation of Fe ions, leading to the formation of Fe-rich nanoregions adjacent to the samples surface. A sizable x-ray magnetic circular dichroism (XMCD) signal at the Fe L edges in remanence and at moderate magnetic fields at 300 K links the high-temperature ferromagnetism with the Fe(3d) states. A sizable value of the orbital moment measured in remanence points to a large magnetic anisotropy and to a correspondingly high blocking temperature, which can stabilize the ferromagnetic-like response of the Fe-rich nanocrystals at 300 K. The XMCD response at the N K edge highlights that the N(2p) states, due to exchange coupling to Fe ions, carry considerable spin polarization. These results, supported by ab initio studies of XMCD spectra for various FeN delta nanocrystals, demonstrate that nanocrystals with delta > 0.25 account for the ferromagnetic behavior of (Ga,Fe)N films.
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  • Sawicki, M., et al. (author)
  • Homogeneous and heterogeneous magnetism in (Zn,Co)O : From a random antiferromagnet to a dipolar superferromagnet by changing the growth temperature
  • 2013
  • In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 88:8
  • Journal article (peer-reviewed)abstract
    • A series of (Zn,Co)O layers with Co contents x up to 40% grown by atomic layer deposition have been investigated. All structures deposited at 160 degrees C show magnetic properties specific to II-VI dilute magnetic semiconductors with localized spins S = 3/2 coupled by strong but short-range antiferromagnetic interactions resulting in low-temperature spin-glass freezing for x = 0.16 and 0.4. At higher growth temperature (200 degrees C) metallic Co nanocrystals precipitate in two locations giving rise to two different magnetic responses: (i) a superparamagnetic contribution coming from volume disperse nanocrystals; (ii) a ferromagneticlike behavior brought about by nanocrystals residing at the (Zn,Co)O/substrate interface. It is shown that the dipolar coupling within the interfacial two-dimensional dense dispersion of nanocrystals is responsible for the ferromagneticlike behavior.
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  • Ethier, J-F., et al. (author)
  • Clinical Data Integration Model : Core Interoperability Ontology for Research Using Primary Care Data
  • 2015
  • In: Methods of Information in Medicine. - 0026-1270 .- 2511-705X. ; 54:1, s. 16-23
  • Journal article (peer-reviewed)abstract
    • Introduction: This article is part of the Focus Theme of Methods of Information in Medicine on "Managing Interoperability and Complexity in Health Systems". Background: Primary care data is the single richest source of routine health care data. However its use, both in research and clinical work, often requires data from multiple clinical sites, clinical trials databases and registries. Data integration and interoperability are therefore of utmost importance. Objectives: TRANSFoRm's general approach relies on a unified interoperability frame-work, described in a previous paper. We developed a core ontology for an interoperability framework based on data mediation. This article presents how such an ontology, the Clinical Data Integration Model (CDIM), can be designed to support, in conjunction with appropriate terminologies, biomedical data federation within TRANSFoRm, an EU FP7 project that aims to develop the digital infrastructure for a learning healthcare system in European Primary Care. Methods: TRANSFoRm utilizes a unified structural /terminological interoperability framework, based on the local-as-view mediation paradigm. Such an approach mandates the global information model to describe the domain of interest independently of the data sources to be explored. Following a requirement analysis process, no ontology focusing on primary care research was identified and, thus we designed a realist ontology based on Basic Formal Ontology to support our framework in collaboration with various terminologies used in primary care. Results: The resulting ontology has 549 classes and 82 object properties and is used to support data integration for TRANSFoRm's use cases. Concepts identified by researchers were successfully expressed in queries using CDIM and pertinent terminologies. As an example, we illustrate how, in TRANSFoRm, the Query Formulation Workbench can capture eligibility criteria in a computable representation, which is based on CDIM. Conclusion: A unified mediation approach to semantic interoperability provides a flexible and extensible framework for all types of interaction between health record systems and research systems. CDIM, as core ontology of such an approach, enables simplicity and consistency of design across the heterogeneous software landscape and can support the specific needs of EHR-driven phenotyping research using primary care data.
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  • Gridneva, Lidia, et al. (author)
  • Experimental investigation of the spin reorientation of Co/Au based magnetic nanodot arrays
  • 2008
  • In: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121 .- 1550-235X. ; 77:10
  • Journal article (peer-reviewed)abstract
    • (Co/Au) and (Au/ Co/ Au) nanomagnet arrays grown on nanostructured self-organized SiGe templates have been characterized by means of x-ray photoemission electron microscopy, x-ray magnetic circular dichroism, and by extended x-ray absorption spectroscopy using synchrotron radiation. In-plane magnetization is observed at room temperature for practically all Co thicknesses, a stable macroscopic perpendicular magnetic order only at low temperature. The spin reorientation transition in these dot arrays takes place for smaller Co thicknesses over a broader thickness range than in two-dimensional systems. This finding appears to be related with structural relaxation modifications, occurring within the local Co atom environment, which are not necessarily connected with the orbital moment variations. These variations appear in the form of a systematic increase, correlated with the existence of out-of-plane magnetization.
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  • Luque, Francisco J., et al. (author)
  • Enantiosensitive Bonding of Chiral Molecules on a Magnetic Substrate Investigated by Means of Electron Spectroscopies
  • 2018
  • In: CHIMIA. - : Swiss Chemical Society. - 0009-4293 .- 2673-2424. ; 72:6, s. 418-423
  • Journal article (peer-reviewed)abstract
    • The adsorption of purely organic chiral molecules on ferromagnetic Co thin films is studied under ultra high vacuum conditions by means of synchrotron radiation-based electron spectroscopies, namely X-ray absorption and ultraviolet photoemission. X-ray absorption reveals that enantiomers with opposite handedness (R,R) - and (S,S)- of two different molecules adsorb with different strength on the Co surfaces and their valence band photoemission spectra also display distinctive features. In view of the recent reports describing the chiral-induced spin selectivity (CISS) effect these results lead us to consider the possibility that some enantiosensitivity may appear when bonding chiral molecules to a substrate with an initial asymmetry in the population of the different spin orientations.
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17.
  • Mulders, A. M., et al. (author)
  • On The Interface Magnetism Of Thin Oxidized Co Films : Orbital And Spin Moments
  • 2009
  • In: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 21:12, s. 124211-
  • Journal article (peer-reviewed)abstract
    • An x-ray magnetic circular dichroism study of a polycrystalline Co/CoO   bilayer is presented. Using both the chemical specificity and surface   sensitivity in the core level techniques, we find that uncompensated   Co2+ spin moments participate in the remanent ferromagnetic response of   the bilayer that has oxygen nearest neighbors. These are likely located   at the Co/CoO interface. As intermixing of magnetic species is not   present in Co/CoO, it is concluded that the observed interface moments   are due to interface roughness. Given their direction, these moments   appear to not directly correlate to the exchange bias in these bilayers.
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  • Sridhar, Arun R., et al. (author)
  • Identifying Risk of Adverse Outcomes in COVID-19 Patients via Artificial Intelligence-Powered Analysis of 12-Lead Intake Electrocardiogram.
  • 2022
  • In: Cardiovascular digital health journal. - : Elsevier. - 2666-6936. ; 3:2, s. 62-74
  • Journal article (peer-reviewed)abstract
    • Background: Adverse events in COVID-19 are difficult to predict. Risk stratification is encumbered by the need to protect healthcare workers. We hypothesize that AI can help identify subtle signs of myocardial involvement in the 12-lead electrocardiogram (ECG), which could help predict complications.Objective: Use intake ECGs from COVID-19 patients to train AI models to predict risk of mortality or major adverse cardiovascular events (MACE).Methods: We studied intake ECGs from 1448 COVID-19 patients (60.5% male, 63.4±16.9 years). Records were labeled by mortality (death vs. discharge) or MACE (no events vs. arrhythmic, heart failure [HF], or thromboembolic [TE] events), then used to train AI models; these were compared to conventional regression models developed using demographic and comorbidity data.Results: 245 (17.7%) patients died (67.3% male, 74.5±14.4 years); 352 (24.4%) experienced at least one MACE (119 arrhythmic; 107 HF; 130 TE). AI models predicted mortality and MACE with area under the curve (AUC) values of 0.60±0.05 and 0.55±0.07, respectively; these were comparable to AUC values for conventional models (0.73±0.07 and 0.65±0.10). There were no prominent temporal trends in mortality rate or MACE incidence in our cohort; holdout testing with data from after a cutoff date (June 9, 2020) did not degrade model performance.Conclusion: Using intake ECGs alone, our AI models had limited ability to predict hospitalized COVID-19 patients' risk of mortality or MACE. Our models' accuracy was comparable to that of conventional models built using more in-depth information, but translation to clinical use would require higher sensitivity and positive predictive value. In the future, we hope that mixed-input AI models utilizing both ECG and clinical data may be developed to enhance predictive accuracy.
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  • Wolska, A., et al. (author)
  • Structural and magnetic properties of Mn(+) implanted silicon crystals studied using X-ray absorption spectroscopy techniques
  • 2011
  • In: Radiation Physics and Chemistry. - : Elsevier BV. - 0969-806X .- 1879-0895. ; 80:10, s. 1119-1124
  • Journal article (peer-reviewed)abstract
    • The implantation of Mn ions into two Si substrates with different doping (P or B), resistivity and oxygen content was performed at low and high substrate temperatures. Different post-implantation processing was carried out to study its influence on the structural and magnetic properties of these samples. The local order around the Mn atoms was characterized by X-ray absorption fine structure techniques and the magnetic properties of the Mn ionic cores were determined by means of X-ray magnetic circular dichroism measurements. The results are discussed in relation to the structural and macroscopic magnetic properties. It is shown that the amorphous matrix speeds up the formation of MnSi(x) inclusions. However, the existence of inclusions or the type of electrically active dopants is not directly related to the magnetic properties. Therefore, in the performed studies, the importance of structural defects on the magnetic properties was confirmed. A localized magnetic moment carried by the Mn ionic cores could not be detected by means of dichroic measurements.
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  • Wolska, A., et al. (author)
  • Study of the Local Environment of Mn Ions Implanted in GaSb
  • 2010
  • In: Acta Physica Polonica. A. - 0587-4246 .- 1898-794X. ; 117:2, s. 286-292
  • Journal article (peer-reviewed)abstract
    • The first attempts to establish an implantation process leading to formation of ferromagnetic inclusions inside the GaSb matrix are presented. Gallium antimonide containing ferromagnetic MnSb precipitations is considered as a promising material for novel spintronic applications. It is possible to obtain such inclusions during the molecular beam epitaxy (MBE) growth. However, for commercial application it would be also important to find an optimal way of producing this kind of inclusions by Mn ions implantation. In order to achieve this goal, several parameters of implantation and post annealing procedures were tested. The ion energy was kept at 10 keV or 150 keV and four different ion doses were applied, as well as various annealing conditions. The analysis of X-ray absorption spectra allowed to estimate the local atomic order around Mn atoms. Depending on the implantation energy and annealing processes, the manganese oxides or manganese atoms located in a heavily defected GaSb matrix were observed. The performed analysis helped in indicating the main obstacles in formation of MnSb inclusions inside the GaSb matrix by Mn ion implantation.
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  • Zetterberg, Henrik, 1973, et al. (author)
  • Increased frequency of combined methylenetetrahydrofolate reductase C677T and A1298C mutated alleles in spontaneously aborted embryos.
  • 2002
  • In: European journal of human genetics : EJHG. - : Springer Science and Business Media LLC. - 1018-4813 .- 1476-5438. ; 10:2, s. 113-8
  • Journal article (peer-reviewed)abstract
    • The pathogenesis of spontaneous abortion is complex, presumably involving the interaction of several genetic and environmental factors. The methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms are commonly associated with defects in folate dependent homocysteine metabolism and have been implicated as risk factors for recurrent embryo loss in early pregnancy. In the present study we have determined the prevalence of combined MTHFR C677T and A1298C polymorphisms in DNA samples from spontaneously aborted embryos (foetal death between sixth and twentieth week after conception) and adult controls using solid-phase minisequencing technique. There was a significant odds ratio of 14.2 (95% CI 1.78-113) in spontaneously aborted embryos comparing the prevalence of one or more 677T and 1298C alleles vs the wild type combined genotype (677CC/1298AA), indicating that the MTHFR polymorphisms may have a major impact on foetal survival. Combined 677CT/1298CC, 677TT/1298AC or 677TT/1298CC genotypes, which contain three or four mutant alleles, were not detected in any of the groups, suggesting complete linkage disequilibrium between the two polymorphisms. The present finding of high prevalence of mutated MTHFR genotypes in spontaneously aborted embryos emphasises the potential protective role of periconceptional folic acid supplementation.
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  • Zetterberg, Henrik, 1973, et al. (author)
  • Influence of the apolipoprotein E epsilon4 allele on human embryonic development.
  • 2002
  • In: Neuroscience letters. - 0304-3940. ; 324:3, s. 189-92
  • Journal article (peer-reviewed)abstract
    • Human apolipoprotein E (apoE) exists in three major isoforms encoded by distinct alleles (APOE epsilon2, epsilon3 and epsilon4) and has important functions in nerve development and repair. Inheritance of the 4 allele is a major risk factor for the development of Alzheimer's disease. To investigate the role of APOE polymorphisms in embryonic development, we analyzed the APOE genotypes of 81 spontaneously aborted embryos and 110 adult controls using a solid-phase minisequencing technique. The epsilon4 allele was significantly less frequent in the spontaneous abortion group than in the control group (P=0.009), while the frequency of epsilon3 was significantly increased (P=0.005), suggesting that epsilon4 may have protective effects during embryogenesis. These protective effects might counterbalance the deleterious age-related effects of the epsilon4 allele in natural selection.
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25.
  • Arvanitis, D, et al. (author)
  • Magnetic X-ray circular dichroism on in situ grown 3d magnetic thin films on surfaces
  • 2001
  • In: JOURNAL OF SYNCHROTRON RADIATION. - : MUNKSGAARD INT PUBL LTD. - 0909-0495. ; 8, s. 120-124
  • Journal article (peer-reviewed)abstract
    • Epitaxic thin and ultrathin films on surfaces allow crystallographic phases that do not occur naturally in the bulk to be stabilized. They also offer new possibilities for an improved understanding of soft X-ray photoabsorption in magnetic systems. Data c
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