1,174 research outputs found

    Vanishing Fe 3d orbital moments in single-crystalline magnetite

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    We show detailed magnetic absorption spectroscopy results of an in situ cleaved high quality single crystal of magnetite. In addition the experimental setup was carefully optimized to reduce drift, self absorption, and offset phenomena as far as possible. In strong contradiction to recently published data, our observed orbital moments are nearly vanishing and the spin moments are quite close to the integer values proposed by theory. This very important issue supports the half metallic full spin polarized picture of magnetite.Comment: 7 pages, 4 figure

    Repeated Recovery of Staphylococcus saprophyticus From the Urogenital Tracts of Women: Persistence Vs. Recurrence

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    Objective: The purpose of this study was to determine whether colonization was persistent or recurrent in a small group of women who had repeated recovery of Staphylococcus saprophyticus from their urogenital tracts

    Implications for Training on Smartphone Medication Reminder App Use by Adults With Chronic Conditions: Pilot Study Applying the Technology Acceptance Model

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    Background: The majority of middle-aged to older patients with chronic conditions report forgetting to take medications as prescribed. The promotion of patients’ smartphone medication reminder app (SMRA) use shows promise as a feasible and cost-effective way to support their medication adherence. Providing training on SMRA use, guided by the technology acceptance model (TAM), could be a promising intervention to promote patients’ app use. Objective: The aim of this pilot study was to (1) assess the feasibility of an SMRA training session designed to increase patients’ intention to use the app through targeting perceived usefulness of app, perceived ease of app use, and positive subjective norm regarding app use and (2) understand the ways to improve the design and implementation of the training session in a hospital setting. Methods: A two-group design was employed. A total of 11 patients older than 40 years (median=58, SD=9.55) and taking 3 or more prescribed medications took part in the study on one of two different dates as participants in either the training group (n=5) or nontraining group (n=6). The training group received an approximately 2-hour intervention training session designed to target TAM variables regarding one popular SMRA, the Medisafe app. The nontraining group received an approximately 2-hour control training session where the participants individually explored Medisafe app features. Each training session was concluded with a one-time survey and a one-time focus group. Results: Mann-Whitney U tests revealed that the level of perceived ease of use (P=.13) and the level of intention to use an SMRA (P=.33) were higher in the training group (median=7.00, median=6.67, respectively) than in the nontraining group (median=6.25, median=5.83). However, the level of perceived usefulness (U=4.50, Z=−1.99, P=.05) and the level of positive subjective norm (P=.25) were lower in the training group (median=6.50, median=4.29) than in the nontraining group (median=6.92, median=4.50). Focus groups revealed the following participants’ perceptions of SMRA use in the real-world setting that the intervention training session would need to emphasize in targeting perceived usefulness and positive subjective norm: (1) the participants would find an SMRA to be useful if they thought the app could help address specific struggles in medication adherence in their lives and (2) the participants think that their family members (or health care providers) might view positively the participants’ SMRA use in primary care settings (or during routine medical checkups). Conclusions: Intervention training session, guided by TAM, appeared feasible in targeting patients’ perceived ease of use and, thereby, increasing intention to use an SMRA. Emphasizing the real-world utility of SMRA, the training session could better target patients’ perceived usefulness and positive subjective norm that are also important in increasing their intention to use the app. [JMIR Formativ Res 2017;1(1):e5

    Dual HLA B*42 and B*81-reactive T cell receptors recognize more diverse HIV-1 Gag escape variants

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    Closely related HLA alleles presenting similar HIV-1 epitopes can be associated with variable clinical outcome. Here the authors report their findings on CD8+ T cell responses to the HIV-1 Gag-p24 TL9 immunodominant epitope in the context of closely related protective and less protective HLA alleles, and their differential effect on viral contro

    Assembly induced delaminations in composite structures

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    Experimental and analytical studies of the development of delaminations around fastener holes in composite structures are presented. This type of delamination is known to occur in composite skins that are mechanically fastened to a poorly mating substructure. Results of an experimental study to determine the resistance of laminates to the initiation of assembly induced delaminations and the residual strength of assembly damaged coupons are presented for AS4/3501-6, IM7/8551-7A, and AS4/PEEK material systems. A survey of existing analytical models for predicting the residual strength and stability of delaminations is presented, and the development of a new model for predicting the initiation of delaminations around a fastener hole is outlined. The fastener hole damage initiation model utilizes a finite element based Fourier series solution, and is validated through comparisons of analytical and experimental results

    An Intercultural Study in Health Literacy and Adherence among Patients with Diabetes

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    poster abstractHealth Literacy is believed to play an essential role in the ability of individuals to effectively manage their own health care. A report by the Institute of Medicine acknowledges that 90 million Americans with low literacy probably also have low health literacy, and that even individuals with adequate health literacy face challenges in the complex demands of health care contexts. This poster presents results of a 3-year study of an interdisciplinary project on health literacy and adherence at the Indiana Center for Intercultural Communication (ICIC) funded by the Eli Lilly & Co. Foundation. The purpose was to examine multiple dimensions of health literacy, based on patients’ perspectives (van Dulmen et al., 2008), with the goal of creating a new conceptualization and way of assessing health literacy in its broader sense that includes processing and acting on information in order to integrate those findings into interventions to improve health regimen adherence. Taking critical studies into account, we developed a model to identify the most important variables of adherence (Nutbeam, D., 2000; Levin-Zamir, D. and Peterburg, Y., 2001; Von Wagner, C., Steptoe, A., Wolf, M., and Wardle, J., 2008). The data consisted of video-taped interviews with 43 English-speakers and 21 Spanish-speakers, all of whom have diabetes. The interviews involved open-ended questions that elicited information about living with diabetes as well as questions on health beliefs, medication adherence, information sources and uses, literacy level and basic demographic information. These narratives were analyzed using grounded theory methodology of the patients’ own words. The quantitative data were analyzed using a multivariate analysis as well as an ordered probit analysis (Connor, U., et al., 2008, 2009, 2010; Lauten, K., et al., 2009, 2010; Lopez-Yunez, A., et al., 2009; Matthias, M.S. & Goering, E., 2008; Rozycki, W. & Connor, U., 2008; Wolf, M.S., et al, 2007). The model that ICIC has built provides practical interventions for patient-centered care. This poster presents examples of linguistic cues and phrases from the interviews, the results of the intercultural comparisons between which information sources were used in the English-speaking and Spanish-speaking subgroups, and the resultant model. Implications are discussed in terms of enhancing the patient-centered tailoring of health information and communication.

    Element-Specific Depth Profile of Magnetism and Stoichiometry at the La0.67Sr0.33MnO3/BiFeO3 Interface

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    Depth-sensitive magnetic, structural and chemical characterization is important in the understanding and optimization of novel physical phenomena emerging at interfaces of transition metal oxide heterostructures. In a simultaneous approach we have used polarized neutron and resonant X-ray reflectometry to determine the magnetic profile across atomically sharp interfaces of ferromagnetic La0.67Sr0.33MnO3 / multiferroic BiFeO3 bi-layers with sub-nanometer resolution. In particular, the X-ray resonant magnetic reflectivity measurements at the Fe and Mn resonance edges allowed us to determine the element specific depth profile of the ferromagnetic moments in both the La0.67Sr0.33MnO3 and BiFeO3 layers. Our measurements indicate a magnetically diluted interface layer within the La0.67Sr0.33MnO3 layer, in contrast to previous observations on inversely deposited layers. Additional resonant X-ray reflection measurements indicate a region of an altered Mn- and O-content at the interface, with a thickness matching that of the magnetic diluted layer, as origin of the reduction of the magnetic moment.Comment: 13 pages, 4 figures, supplemental material include

    Complex-Orbital Order in Fe_3O_4 and Mechanism of the Verwey Transition

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    Electronic state and the Verwey transition in magnetite (Fe_3O_4) are studied using a spinless three-band Hubbard model for 3d electrons on the B sites with the Hartree-Fock approximation and the exact diagonalisation method. Complex-orbital, e.g., 1/sqrt(2)[|zx> + i |yz>], ordered (COO) states having noncollinear orbital moments ~ 0.4 mu_B on the B sites are obtained with the cubic lattice structure of the high-temperature phase. The COO state is a novel form of magnetic ordering within the orbital degree of freedom. It arises from the formation of Hund's second rule states of spinless pseudo-d molecular orbitals in the Fe_4 tetrahedral units of the B sites and ferromagnetic alignment of their fictitious orbital moments. A COO state with longer periodicity is obtained with pseudo-orthorhombic Pmca and Pmc2_1 structures for the low-temperature phase. The state spontaneously lowers the crystal symmetry to the monoclinic and explains experimentally observed rhombohedral cell deformation and Jahn-Teller like distortion. From these findings, we consider that at the Verwey transition temperature, the COO state remaining to be short-range order impeded by dynamical lattice distortion in high temperature is developed into that with long-range order coupled with the monoclinic lattice distortion.Comment: 16 pages, 13 figures, 6 tables, accepted for publication in J. Phys. Soc. Jp

    Valence band excitations in V_2O_5

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    We present a joint theoretical and experimental investigation of the electronic and optical properties of vanadium pentoxide. Electron energy-loss spectroscopy in transmission was employed to measure the momentum-dependent loss function. This in turn was used to derive the optical conductivity, which is compared to the results of band structure calculations. A good qualitative and quantitative agreement between the theoretical and the experimental optical conductivity was observed. The experimentally observed anisotropy of the optical properties of V_2O_5 could be understood in the light of an analysis of the theoretical data involving the decomposition of the calculated optical conductivity into contributions from transitions into selected energy regions of the conduction band. In addition, based upon a tight binding fit to the band structure, values are given for the effective V3d_xy-O2p hopping terms and are compared to the corresponding values for alpha'-NaV_2O_5.Comment: 6 pages (revtex),6 figures (jpg
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