1,204 research outputs found
Integral equation method for the electromagnetic wave propagation in stratified anisotropic dielectric-magnetic materials
We investigate the propagation of electromagnetic waves in stratified
anisotropic dielectric-magnetic materials using the integral equation method
(IEM). Based on the superposition principle, we use Hertz vector formulations
of radiated fields to study the interaction of wave with matter. We derive in a
new way the dispersion relation, Snell's law and reflection/transmission
coefficients by self-consistent analyses. Moreover, we find two new forms of
the generalized extinction theorem. Applying the IEM, we investigate the wave
propagation through a slab and disclose the underlying physics which are
further verified by numerical simulations. The results lead to a unified
framework of the IEM for the propagation of wave incident either from a medium
or vacuum in stratified dielectric-magnetic materials.Comment: 14pages, 3figure
Routine care data and the benefits of GLP1 receptor agonists on slowing kidney function decline
Clinical epidemiolog
Suppression and enhancement of the critical current in multiterminal S/N/S mesoscopic structures
We analyse the measured critical current in a mesoscopic
4-terminal S/N/S structure. The current through the S/N interface is shown to
consist not only of the Josephson component but also a
phase-coherent part of the subgap current. The current
is determined by the both components and and depends
in a nonmonotonic way on the voltage between superconductors and normal
reservoirs reaching a maximum at . The obtained theoretical
resultas are in qualitative agreement with recent experimental data.Comment: 4 page, 3 figures. To be puplished in PRB Rapid co
Szeg\"o kernel asymptotics and Morse inequalities on CR manifolds
We consider an abstract compact orientable Cauchy-Riemann manifold endowed
with a Cauchy-Riemann complex line bundle. We assume that the manifold
satisfies condition Y(q) everywhere. In this paper we obtain a scaling
upper-bound for the Szeg\"o kernel on (0, q)-forms with values in the high
tensor powers of the line bundle. This gives after integration weak Morse
inequalities, analogues of the holomorphic Morse inequalities of Demailly. By a
refined spectral analysis we obtain also strong Morse inequalities which we
apply to the embedding of some convex-concave manifolds.Comment: 40 pages, the constants in Theorems 1.1-1.8 have been modified by a
multiplicative constant 1/2 ; v.2 is a final updat
Association between beta-blocker use and mortality/morbidity in patients with heart failure with reduced, midrange, and preserved ejection fraction and advanced chronic kidney disease
Background:It is unknown if beta-blockers reduce mortality/morbidity in patients with heart failure (HF) and advanced chronic kidney disease (CKD), a population underrepresented in HF trials.Methods:Observational cohort of HF patients with advanced CKD (estimated glomerular filtration rate <30 mL/min per 1.73 m(2)) from the Swedish Heart Failure Registry between 2001 and 2016. We first explored associations between beta-blocker use, 5-year death, and the composite of cardiovascular death/HF hospitalization among 3775 patients with HF with reduced ejection fraction (HFrEF) and advanced CKD. We compared observed hazards with those from a control cohort of 15 346 patients with HFrEF and moderate CKD (estimated glomerular filtration rate <60-30 mL/min per 1.73 m(2)), for whom beta-blocker trials demonstrate benefit. Second, we explored outcomes associated to beta-blocker among advanced CKD participants with preserved (HFpEF; N=2009) and midrange ejection fraction (HFmrEF; N=1514).Results:During a median follow-up of 1.3 years, 2012 patients had a subsequent HF hospitalization, and 2849 died in the HFrEF cohort, of which 2016 died due to cardiovascular causes. Among patients with HFrEF, beta-blocker use was associated with lower risk of death (adjusted hazard ratio 0.85 [95% CI, 0.75-0.96]) and cardiovascular mortality/HF hospitalization (0.87 [0.77-0.98]) compared with nonuse. The magnitude of the associations was similar to that observed for HFrEF patients with moderate CKD. Conversely, no significant association was observed for beta-blocker users in advanced CKD with HFpEF (death: 0.88 [0.77-1.02], cardiovascular mortality/HF hospitalization: 1.05 [0.90-1.23]) or HFmrEF (death: 0.95 [0.79-1.14], cardiovascular mortality/HF hospitalization: 1.09 [0.90-1.31]).Conclusions:In HFrEF patients with advanced CKD, the use of beta-blockers was associated with lower morbidity and mortality. Although inconclusive due to limited power, these benefits were not observed in similar patients with HFpEF or HFmrEF.Clinical epidemiolog
Solving Optimization Problems by the Public Goods Game
This document is the Accepted Manuscript version of the following article: Marco Alberto Javarone, ‘Solving optimization problems by the public goods game’, The European Physical Journal B, 90:17, September 2017. Under embargo. Embargo end date: 18 September 2018. The final, published version is available online at doi: https://doi.org/10.1140/epjb/e2017-80346-6. Published by Springer Berlin Heidelberg.We introduce a method based on the Public Goods Game for solving optimization tasks. In particular, we focus on the Traveling Salesman Problem, i.e. a NP-hard problem whose search space exponentially grows increasing the number of cities. The proposed method considers a population whose agents are provided with a random solution to the given problem. In doing so, agents interact by playing the Public Goods Game using the fitness of their solution as currency of the game. Notably, agents with better solutions provide higher contributions, while those with lower ones tend to imitate the solution of richer agents for increasing their fitness. Numerical simulations show that the proposed method allows to compute exact solutions, and suboptimal ones, in the considered search spaces. As result, beyond to propose a new heuristic for combinatorial optimization problems, our work aims to highlight the potentiality of evolutionary game theory beyond its current horizons.Peer reviewedFinal Accepted Versio
Long-term visit-to-visit variability in hemoglobin A1c and kidney-related outcomes in persons with diabetes
Rationale & Objective: To characterize associations between long-term visit-to-visit variability of hemoglobin A(1c) (HbA(1c)) and risk of adverse kidney outcomes in patients with diabetes.Study Design: Observational study.Setting & Participants: 93,598 adults with diabetes undergoing routine care in Stockholm, Sweden.Exposures and Predictors: Categories of baseline and time-varying HbA(1c) variability score (HVS, the percentage of total HbA(1c) measures that vary by >0.5% [5.5 mmol/mol] during a 3-year window): 0-20%, 21%-40%, 41%-60%, 61%-80%, and 81%-100%, with 0-20% as the reference group.Outcome: Chronic kidney disease (CKD) progression (composite of >50% estimated glomerular filtration rate [eGFR] decline and kidney failure), acute kidney disease (AKI by clinical diagnosis or transient creatinine elevations ac-cording to KDIGO criteria), and worsening of albuminuria.Analytical Approach: Multivariable Cox proportional hazards regression.Results: Compared with persons showing low HbA(1c) variability (HVS 0-20%), any increase in variability was associated with a higher risk of adverse kidney outcomes beyond mean HbA(1c). For example, for patients with a baseline HbA(1c) variability of 81%-100%, the adjusted HR was 1.6 (95% CI, 1.47-1.74) for CKD progression, 1.23 [1.16-1.3] for AKI, and 1.28 [1.21-1.3 6] for worsening of albuminuria. The results were consistent across subgroups (diabetes subtypes, baseline eGFR, or albuminuria categories), in time-varying analyses and in sensitivity analyses including time-weighted average HbA(1c) or alternative metrics of variability.Limitations: Observational study, limitations of claims data, lack of information on diet, body mass index, medication changes, and diabetes duration.Conclusions: Higher long-term visit-to-visit HbA1c variability is consistently associated with the risks of CKD progression, AKI, and worsening of albuminuria.Clinical epidemiolog
Mechanism for Selective Binding of Aromatic Compounds on Oxygen-Rich Graphene Nanosheets Based on Molecule Size/Polarity Matching
Selective binding of organic compounds is the cornerstone of many important industrial and pharmaceutical applications. Here, we achieved highly selective binding of aromatic compounds in aqueous solution and gas phase by oxygen-enriched graphene oxide (GO) nanosheets via a previously unknown mechanism based on size matching and polarity matching. Oxygen-containing functional groups (predominately epoxies and hydroxyls) on the nongraphitized aliphatic carbons of the basal plane of GO formed highly polar regions that encompass graphitic regions slightly larger than the benzene ring. This facilitated size match–based interactions between small apolar compounds and the isolated aromatic region of GO, resulting in high binding selectivity relative to larger apolar compounds. The interactions between the functional group(s) of polar aromatics and the epoxy/hydroxyl groups around the isolated aromatic region of GO enhanced binding selectivity relative to similar-sized apolar aromatics. These findings provide opportunities for precision separations and molecular recognition enabled by size/polarity match–based selectivity
- …