3,484 research outputs found

    Phase Modulated Thermal Conductance of Josephson Weak Links

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    We present a theory for quasiparticle heat transport through superconducting weak links. The thermal conductance depends on the phase difference (ϕ\phi) of the superconducting leads. Branch conversion processes, low-energy Andreev bound states near the contact and the suppression of the local density of states near the gap edge are related to phase-sensitive transport processes. Theoretical results for the influence of junction transparency, temperature and disorder, on the phase modulation of the conductance are reported. For high-transmission weak links, D1D\to 1, the formation of an Andreev bound state at ϵb=Δcos(ϕ/2)\epsilon_{\text{\tiny b}}=\Delta\cos(\phi/2) leads to suppression of the density of states for the continuum excitations that transport heat, and thus, to a reduction in the conductance for ϕπ\phi\simeq\pi. For low-transmission (D1D\ll 1) barriers resonant scattering at energies ϵ(1+D/2)Δ\epsilon\simeq(1+D/2)\Delta leads to an increase in the thermal conductance as TT drops below TcT_c (for phase differences near ϕ=π\phi=\pi).Comment: 4 pages, 3 figures Expanded discussion of boundary conditions for Ricatti amplitude

    Геомеханика разрушения и регламент тампонажного упрочнения пород вокруг наклонных стволов вязкопластическими растворами

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    Наведено підсумки шахтних досліджень руйнування порід навколо стволів вугільних шахт та обґрунтовано параметри їх зміцнення вязкопластичними розчинами.Research results are mine destruction of rocks around the shafts of coal mines and reasonable options to strengthen viscoplastic solutions

    Multi-omic prediction of incident type 2 diabetes.

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    AIMS/HYPOTHESIS: The identification of people who are at high risk of developing type 2 diabetes is a key part of population-level prevention strategies. Previous studies have evaluated the predictive utility of omics measurements, such as metabolites, proteins or polygenic scores, but have considered these separately. The improvement that combined omics biomarkers can provide over and above current clinical standard models is unclear. The aim of this study was to test the predictive performance of genome, proteome, metabolome and clinical biomarkers when added to established clinical prediction models for type 2 diabetes. METHODS: We developed sparse interpretable prediction models in a prospective, nested type 2 diabetes case-cohort study (N=1105, incident type 2 diabetes cases=375) with 10,792 person-years of follow-up, selecting from 5759 features across the genome, proteome, metabolome and clinical biomarkers using least absolute shrinkage and selection operator (LASSO) regression. We compared the predictive performance of omics-derived predictors with a clinical model including the variables from the Cambridge Diabetes Risk Score and HbA1c. RESULTS: Among single omics prediction models that did not include clinical risk factors, the top ten proteins alone achieved the highest performance (concordance index [C index]=0.82 [95% CI 0.75, 0.88]), suggesting the proteome as the most informative single omic layer in the absence of clinical information. However, the largest improvement in prediction of type 2 diabetes incidence over and above the clinical model was achieved by the top ten features across several omic layers (C index=0.87 [95% CI 0.82, 0.92], Δ C index=0.05, p=0.045). This improvement by the top ten omic features was also evident in individuals with HbA1c <42 mmol/mol (6.0%), the threshold for prediabetes (C index=0.84 [95% CI 0.77, 0.90], Δ C index=0.07, p=0.03), the group in whom prediction would be most useful since they are not targeted for preventative interventions by current clinical guidelines. In this subgroup, the type 2 diabetes polygenic risk score was the major contributor to the improvement in prediction, and achieved a comparable improvement in performance when added onto the clinical model alone (C index=0.83 [95% CI 0.75, 0.90], Δ C index=0.06, p=0.002). However, compared with those with prediabetes, individuals at high polygenic risk in this group had only around half the absolute risk for type 2 diabetes over a 20 year period. CONCLUSIONS/INTERPRETATION: Omic approaches provided marginal improvements in prediction of incident type 2 diabetes. However, while a polygenic risk score does improve prediction in people with an HbA1c in the normoglycaemic range, the group in whom prediction would be most useful, even individuals with a high polygenic burden in that subgroup had a low absolute type 2 diabetes risk. This suggests a limited feasibility of implementing targeted population-based genetic screening for preventative interventions

    Tuning coherent-phonon heat transport in LaCoO3/SrTiO3 superlattices

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    Accessing the regime of coherent phonon propagation in nanostructures opens enormous possibilities to control the thermal conductivity in energy harvesting devices, phononic circuits, etc. In this paper we show that coherent phonons contribute substantially to the thermal conductivity of LaCoO3/SrTiO3 oxide superlattices, up to room temperature. We show that their contribution can be tuned through small variations of the superlattice periodicity, without changing the total superlattice thickness. Using this strategy, we tuned the thermal conductivity by 20% at room temperature. We also discuss the role of interface mixing and epitaxial relaxation as an extrinsic, material dependent key parameter for understanding the thermal conductivity of oxide superlattices. © 2021 The Authors. Published by American Chemical Society

    Synergistic insights into human health from aptamer- and antibody-based proteomic profiling

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    Affinity-based proteomics has enabled scalable quantification of thousands of protein targets in blood enhancing biomarker discovery, understanding of disease mechanisms, and genetic evaluation of drug targets in humans through protein quantitative trait loci (pQTLs). Here, we integrate two partly complementary techniques-the aptamer-based SomaScan® v4 assay and the antibody-based Olink assays-to systematically assess phenotypic consequences of hundreds of pQTLs discovered for 871 protein targets across both platforms. We create a genetically anchored cross-platform proteome-phenome network comprising 547 protein-phenotype connections, 36.3% of which were only seen with one of the two platforms suggesting that both techniques capture distinct aspects of protein biology. We further highlight discordance of genetically predicted effect directions between assays, such as for PILRA and Alzheimer's disease. Our results showcase the synergistic nature of these technologies to better understand and identify disease mechanisms and provide a benchmark for future cross-platform discoveries

    Causal relevance of blood lipid fractions in the development of carotid atherosclerosis: Mendelian randomization analysis.

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    BACKGROUND: Carotid intima-media thickness (CIMT), a subclinical measure of atherosclerosis, is associated with risk of coronary heart disease events. Statins reduce progression of CIMT and coronary heart disease risk in proportion to the reduction in low-density lipoprotein cholesterol. However, interventions targeting triglycerides (TGs) or high-density lipoprotein cholesterol (HDL-C) have produced inconsistent effects on CIMT and coronary heart disease risk, making it uncertain whether such agents are ineffective for coronary heart disease prevention or whether CIMT is an inadequate marker of HDL-C or TG-mediated effects. We aimed to determine the causal association among the 3 major blood lipid fractions and common CIMT using mendelian randomization analysis. METHODS AND RESULTS: Genetic scores specific for low-density lipoprotein cholesterol, HDL-C, and TGs were derived based on single nucleotide polymorphisms from a gene-centric array in ≈5000 individuals (Cardiochip scores) and from a genome-wide association meta-analysis in >100 000 individuals (Global Lipids Genetic Consortium scores). These were used as instruments in a mendelian randomization analysis in 2 prospective cohort studies. A genetically predicted 1 mmol/L higher low-density lipoprotein cholesterol concentration was associated with a higher common CIMT by 0.03 mm (95% confidence interval, 0.01-0.04) and 0.04 mm (95% confidence interval, 0.02-0.06) based on the Cardiochip and Global Lipids Genetic Consortium scores, respectively. HDL-C and TGs were not causally associated with CIMT. CONCLUSIONS: Our findings confirm a causal relationship between low-density lipoprotein cholesterol and CIMT but not with HDL-C and TGs. At present, the suitability of CIMT as a surrogate marker in trials of cardiovascular therapies targeting HDL-C and TGs is questionable and requires further study

    Spin-phonon coupling in epitaxial Sr0.6Ba0.4MnO3 thin films

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    Spin-phonon coupling is investigated in epitaxially strained Sr1-xBaxMnO3 thin films with perovskite structure by means of microwave (MW) and infrared (IR) spectroscopy. In this work we focus on the Sr0.6Ba0.4MnO3 composition grown on (LaAlO3)0.3(Sr2AlTaO6)0.7 substrate. The MW complex electromagnetic response shows a decrease in the real part and a clear anomaly in the imaginary part around 150 K. Moreover, it coincides with a 17% hardening of the lowest-frequency polar phonon seen in IR reflectance spectra. In order to further elucidate this phenomenon, low-energy muon-spin spectroscopy was carried out, signaling the emergence of antiferromagnetic order with Néel temperature (TN) around 150 K. Thus, our results confirm that epitaxial Sr0.6Ba0.4MnO3 thin films display strong spin-phonon coupling below TN, which may stimulate further research on tuning the magnetoelectric coupling by controlling the epitaxial strain and chemical pressure in the Sr1-xBaxMnO3 system

    Epinephrine auto-injector prescriptions to food-allergic patients in primary care in The Netherlands

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    BACKGROUND: The knowledge of general practitioner(s) (GPs) regarding food allergy and anaphylaxis and practices in the prescription of epinephrine auto-injector(s) (EAIs) among GPs has previously only been studied using questionnaires and hypothetical cases. Therefore, there are currently no data as to whether or not GPs prescribe EAIs to high risk food-allergic patients presenting to primary care practices. The aim of this study was therefore to describe and evaluate practice in EAI prescription by GPs to food-allergic patients in The Netherlands. METHODS: Patients aged 12–23 years who consulted their GP for allergic symptoms were identified in a primary care database. Patients were classified as probably or unlikely to be food-allergic. A risk factor assessment was done to identify probably food-allergic patients at high risk for anaphylaxis to assess the need for an EAI. RESULTS: One hundred forty-eight out of 1015 patients consulted their GP for allergic symptoms due to food. Eighty patients were excluded from analysis because of incomplete records. Thirty-four patients were classified as probably food-allergic. Twenty-seven of them were considered high risk patients and candidates for an EAI. Importantly, only 10 of them had actually been prescribed an EAI by their GP. CONCLUSIONS: This study shows that high risk food-allergic patients that visit their GPs are often not prescribed an EAI. Thus, previously identified low rates of EAI ownership may be partly due to GPs not prescribing this medication to patients for whom it would be appropriate to do so. These data suggest that there is a need for improvement of the quality of care for high risk food-allergic patients in primary care
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