1,175 research outputs found

    A library of ab initio Raman spectra for automated identification of 2D materials

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    Raman spectroscopy is frequently used to identify composition, structure and layer thickness of 2D materials. Here, we describe an efficient first-principles workflow for calculating resonant first-order Raman spectra of solids within third-order perturbation theory employing a localized atomic orbital basis set. The method is used to obtain the Raman spectra of 733 different monolayers selected from the computational 2D materials database (C2DB). We benchmark the computational scheme against available experimental data for 15 known monolayers. Furthermore, we propose an automatic procedure for identifying a material based on an input experimental Raman spectrum and illustrate it for the cases of MoS2_2 (H-phase) and WTe2_2 (T′^\prime-phase). The Raman spectra of all materials at different excitation frequencies and polarization configurations are freely available from the C2DB. Our comprehensive and easily accessible library of \textit{ab initio} Raman spectra should be valuable for both theoreticians and experimentalists in the field of 2D materialsComment: 17 pages, 7 figure

    Living with chronic obstructive pulmonary disease and being followed uip through telemedicine - a phenomenological approach

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    Chronic obstructive pulmonary disease (COPD) provides substantially reduced health related quality of life (HQoL). Telemonitoring on COPD patients appears to have a positive effect on improving HQoL. This study has a phenomenological approach, and ten informants, who were followed-up between 1 and 3 months in their own homes through telemonitoring of COPD symptoms, narrated their lived experiences of HQoL. The results show that the informants experienced safety and increased knowledge through the digital dialog (telemedicine) with expertise nurses, which indirectly improved their HQoL, and in term lead to increased mastery and control in managing their disease. Several studies show an increased HQoL, but the benefits are still limited and there is a need for further research

    Unlocking the limitations: living with chronic obstructive pulmonary disease and receiving care through telemedicine - a phenomenological study

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    Aims and objectives To describe the lived experiences of quality of life among a group of patients living with chronic obstructive pulmonary disease who were included in a telemedical intervention after hospitalisation for disease exacerbation. Background Patients with chronic obstructive pulmonary disease have high symptom burden, poor control of symptoms and a need for greater requirements in care. Telemedicine can provide benefits for patients with chronic obstructive pulmonary disease by improving self-management. Design Descriptive phenomenological approach. Methods Ten in-depth interviews were conducted with chronic obstructive pulmonary disease patients participating in a telemedical intervention. The collected data were analysed using a descriptive phenomenological research method. Results Living with chronic obstructive pulmonary disease was experienced as creating physical and mental limitations of the diseased body and an increasing identity as a patient, which led to impaired quality of life. Being included in the telemedicine intervention increased accessibility to healthcare services and support from telemedicine nurses. Self-measurement of health data increased participants’ clinical insight and created a mutual clinical language in dialogue with telemedicine nurses, which led to increased quality of life. However, receiving care through telemedicine was also experienced as a dual chore. Conclusions Telemedicine can reduce the perceived limitations imposed by chronic obstructive pulmonary disease through four key elements: (i) improving accessibility to healthcare services, (ii) increasing support from health professionals, (iii) strengthening clinical insight and (iv) developing a mutual clinical language, thus increasing quality of life. The transparency facilitated through telemedicine in this healthcare context encourages open decision-making, where the participants can increase their knowledge and improve acknowledgement of and collaboration with telemedicine nurses. Relevance to clinical practice Telemedicine can be beneficial when rethinking care for chronic obstructive pulmonary disease by providing knowledge on how living with chronic obstructive pulmonary disease can affect the experience of receiving care through telemedicine and further determine for whom telemedicine is useful.måsjekke

    Evaluation of shared genetic susceptibility loci between autoimmune diseases and schizophrenia based on genome-wide association studies.

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    BACKGROUND: Epidemiological studies have documented higher than expected comorbidity (or, in some cases, inverse comorbidity) between schizophrenia and several autoimmune disorders. It remains unknown whether this comorbidity reflects shared genetic susceptibility loci. AIMS: The present study aimed to investigate whether verified genome wide significant variants of autoimmune disorders confer risk of schizophrenia, which could suggest a common genetic basis. METHODS: Seven hundred and fourteen genome wide significant risk variants of 25 autoimmune disorders were extracted from the NHGRI GWAS catalogue and examined for association to schizophrenia in the Psychiatric Genomics Consortium schizophrenia GWAS samples (36,989 cases and 113,075 controls). RESULTS: Two independent loci at 4q24 and 6p21.32-33 originally identified from GWAS of autoimmune diseases were found genome wide associated with schizophrenia (1.7 × 10(-8 )≥( )p ≥ 4.0 × 10(-21)). While these observations confirm the existence of shared genetic susceptibility loci between schizophrenia and autoimmune diseases, the findings did not show a significant enrichment. CONCLUSION: The findings do not support a genetic overlap in common SNPs between autoimmune diseases and schizophrenia that in part could explain the observed comorbidity from epidemiological studies

    Dispersive and Covalent Interactions Between Graphene and Metal Surfaces from the Random Phase Approximation

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    We calculate the potential energy surfaces for graphene adsorbed on Cu(111), Ni(111), and Co(0001) using density functional theory and the Random Phase Approximation (RPA). For these adsorption systems covalent and dispersive interactions are equally important and while commonly used approximations for exchange-correlation functionals give inadequate descriptions of either van der Waals or chemical bonds, RPA accounts accurately for both. It is found that the adsorption is a delicate competition between a weak chemisorption minimum close to the surface and a physisorption minimum further from the surface

    Sounding stellar cycles with Kepler - II. Ground-based observations

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    We have monitored 20 Sun-like stars in the Kepler field-of-view for excess flux with the FIES spectrograph on the Nordic Optical Telescope since the launch of Kepler spacecraft in 2009. These 20 stars were selected based on their asteroseismic properties to sample the parameter space (effective temperature, surface gravity, activity level etc.) around the Sun. Though the ultimate goal is to improve stellar dynamo models, we focus the present paper on the combination of space-based and ground-based observations can be used to test the age-rotation-activity relations. In this paper we describe the considerations behind the selection of these 20 Sun-like stars and present an initial asteroseismic analysis, which includes stellar age estimates. We also describe the observations from the Nordic Optical Telescope and present mean values of measured excess fluxes. These measurements are combined with estimates of the rotation periods obtained from a simple analysis of the modulation in photometric observations from Kepler caused by starspots, and asteroseismic determinations of stellar ages, to test relations between between age, rotation and activity.Comment: Accepted for publication in MNRA

    The predictive value of ICD-10 diagnostic coding used to assess Charlson comorbidity index conditions in the population-based Danish National Registry of Patients

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    <p>Abstract</p> <p>Background</p> <p>The Charlson comorbidity index is often used to control for confounding in research based on medical databases. There are few studies of the accuracy of the codes obtained from these databases.</p> <p>We examined the positive predictive value (PPV) of the ICD-10 diagnostic coding in the Danish National Registry of Patients (NRP) for the 19 Charlson conditions.</p> <p>Methods</p> <p>Among all hospitalizations in Northern Denmark between 1 January 1998 and 31 December 2007 with a first-listed diagnosis of a Charlson condition in the NRP, we selected 50 hospital contacts for each condition. We reviewed discharge summaries and medical records to verify the NRP diagnoses, and computed the PPV as the proportion of confirmed diagnoses.</p> <p>Results</p> <p>A total of 950 records were reviewed. The overall PPV for the 19 Charlson conditions was 98.0% (95% CI; 96.9, 98.8). The PPVs ranged from 82.0% (95% CI; 68.6%, 91.4%) for diabetes with diabetic complications to 100% (one-sided 97.5% CI; 92.9%, 100%) for congestive heart failure, peripheral vascular disease, chronic pulmonary disease, mild and severe liver disease, hemiplegia, renal disease, leukaemia, lymphoma, metastatic tumour, and AIDS.</p> <p>Conclusion</p> <p>The PPV of NRP coding of the Charlson conditions was consistently high.</p

    Electron transport across a quantum wire in the presence of electron leakage to a substrate

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    We investigate electron transport through a mono-atomic wire which is tunnel coupled to two electrodes and also to the underlying substrate. The setup is modeled by a tight-binding Hamiltonian and can be realized with a scanning tunnel microscope (STM). The transmission of the wire is obtained from the corresponding Green's function. If the wire is scanned by the contacting STM tip, the conductance as a function of the tip position exhibits oscillations which may change significantly upon increasing the number of wire atoms. Our numerical studies reveal that the conductance depends strongly on whether or not the substrate electrons are localized. As a further ubiquitous feature, we observe the formation of charge oscillations.Comment: 7 pages, 7 figure

    Self-Reported Long COVID in the General Population: Sociodemographic and Health Correlates in a Cross-National Sample.

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    We aimed to gain knowledge of possible sociodemographic predictors of long COVID and whether long COVID was associated with health outcomes almost two years after the pandemic outbreak. There were 1649 adults who participated in the study by completing a cross-sectional online survey disseminated openly in Norway, the UK, the USA, and Australia between November 2021 and January 2022. Participants were defined as having long COVID based on self-reports that they had been infected by COVID-19 and were experiencing long-lasting COVID symptoms. Logistic regression analyses were used to examine possible sociodemographic predictors, and multivariate analysis of variance was used to examine whether long COVID status was associated with health outcomes. None of the sociodemographic variables was significantly associated with reporting long COVID. Having long COVID was associated with higher levels of psychological distress, fatigue, and perceived stress. The effect of long COVID on health outcomes was greater among men than among women. In conclusion, long COVID appeared across sociodemographic groups. People with long COVID reported worsened health outcomes compared to those who had had COVID-19 but without long-term symptoms. Men experiencing long COVID appear to be particularly vulnerable to experiencing poorer health outcomes; health services may pay extra attention to potentially unnoticed needs for support among men experiencing long COVID
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