Superluminal Localized Solutions to the wave equation, in (vacuum or) dispersive media, for arbitrary frequencies and with adjustable bandwidth

In this paper we set forth new exact analytical Superluminal localized solutions to the wave equation for arbitrary frequencies and adjustable bandwidth. The formulation presented here is rather simple, and its results can be expressed in terms of the ordinary, so-called "X-shaped waves". Moeover, by the present formalism we obtain the first analytical localized Superluminal approximate solutions which represent beams propagating in dispersive media. Our solutions may find application in different fields, like optics, microwaves, radio waves, and so on. [PACS nos.: 03.50.De ; 41.20.Jb ; 83.50.Vr ; 62.30.+d ; 43.60.+d ; 91.30.Fn ; 04.30.Nk ; 42.25.Bs ; 46.40.Cd ; 52.35.Lv. Keywords: Wave equation; Wave propagation; Optics; Localized beams; Superluminal waves; Bessel beams; X-shaped waves; Acoustics; Mechanical waves; Dispersion compensation; Seismology; Geophysics; Gravitational Waves; Elementary particle physics].Comment: plain LaTeX file (16 pages), plus 9 figure

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Polarization-independent hollow nanocuboid metasurfaces with robust quasi-bound states in the continuum

All-dielectric metasurfaces supporting resonant quasi-bound states in the continuum (qBIC) offer an ideal platform for various applications relying on intense light-matter interaction in highly localized and enhanced fields. Here, we propose a dielectric metasurface composed of hollow GaP nanocuboid quadrumers periodically arranged on a silica substrate. The metasurface supports a qBIC resonant mode with an antiferroelectric field configuration, which is very robust to large perturbations of the cuboid structure thanks to its perpendicular electric dipole field profile. The perturbed quadrumer arrangement retains C 4v symmetry, thus allowing for polarization-independent optical response for normally incident planewaves. In addition, the resonant mode dispersion is investigated, revealing interesting features, such as low birefringence along the contour of the Brillouin zone and very low dispersion for the TM polarization along the direction. The metasurface is designed to resonate close to , which is highly relevant for Raman spectroscopy, leveraging the strong field enhancement at the interface with the overlayer material. Moreover, its performance as a bulk refractometric sensor is discussed. The proposed dielectric metasurface is promising for emerging photonic phenomena where strong light-matter interaction plays a key role.This work was supported by the CNR-FAPESP biennial (2022–2023) bilateral project StReAM “Strongly Resonant All-dielectric Metasurfaces based on quasi-dark and toroidal modes” and by the projects PID2019-107270RB-C21, PDC2021-121172-C21 and TED2021-1303 78B-C21 funded by MCIN/AEI/10.13039/501100011033, FEDER and EU NextGenerationEU. J.F.A. received funding from Ministerio de Ciencia, Innovación Universidades of Spain under Juan de la Cierva-Incorporación grant. V.D. thanks the Brazilian Agency National Council of Technological and Scientific Development (CNPq) for financial support. D.C.Z. and F.D’O. acknowledge the support of the project PRIN-2022 ALPHA “ALl-dielectric resonant metasurfaces enhancing PHoton emission phenomenA” (CUP:D53D23001060006) funded by the Italian Ministry of University and Research. H.E.H.F. acknowledges the financial support of the São Paulo Research Foundation (FAPESP), projects 2015/24517-8 (Thematic), 2021/11380-5 (CCD/CPTEn), and 2021/06506-0 (CNR Italy); and the Brazilian Council for Scientific and Technological Development (CNPq), projects 312714/2019-0 (HEHF) and 433175/2018-4 (Universal). F. D.’O acknowledges the support of the European Union under the Italian National Recovery and Resilience Plan (NRRP) of NextGenerationEU , partnership on “Telecommunications of the Future” (PE00000001 - program “RESTART”)

Advances in the development of simulation tools for integrated optics devices: FDTD, BPM, and mode solving techniques

In the present paper we review the state of the art of two complementary propagation techniques with applications integrated optics device modeling: the Finite-Difference Time- Domain and the Beam Propagation Method. In both cases we focus its on their main features such as the types of propagation schemes and the material effects that can be modeled.In addition, we also consider a 2D mode solver based on a complex root finding procedure - a representative rnode solving technique that is of significant interest for design and modeling of leaky mode based devices. Each of the methods is illustrated with appropriate simulation examples of devices and waveguide structures being of current research interest: photonic band gap structures, waveguide gratings, ARROW waveguides etc. The selected examples show the power of the methods as well as the consistency and the complementarity of their results when applied together

Advances in the development of simulation tools for integrated optics devices: FDTD, BPM and mode solving techniques

In the present paper we review the state of the art of two complementary propagation techniques with applications for integrated optics device modeling: The Finite-Difference Time-Domain and the Beam Propagation Method. In both cases we focus on their main features such as the types of propagation schemes and the material effects that can be modeled. In addition, we also consider a 2D mode solver based on a complex root finding procedure-a representative mode solving technique that is of significant interest for design and modeling of leaky mode based devices. Each of the methods is illustrated with appropriate simulation examples of devices and waveguide structures being of current research interest: photonic band gap structures, waveguide gratings, ARROW waveguides etc. The selected examples show the power of the methods as well as the consistency and the complementarity of their results when applied together

Safety of hospital discharge before return of bowel function after elective colorectal surgery

© 2020 BJS Society Ltd Published by John Wiley & Sons LtdBackground: Ileus is common after colorectal surgery and is associated with an increased risk of postoperative complications. Identifying features of normal bowel recovery and the appropriateness for hospital discharge is challenging. This study explored the safety of hospital discharge before the return of bowel function. Methods: A prospective, multicentre cohort study was undertaken across an international collaborative network. Adult patients undergoing elective colorectal resection between January and April 2018 were included. The main outcome of interest was readmission to hospital within 30 days of surgery. The impact of discharge timing according to the return of bowel function was explored using multivariable regression analysis. Other outcomes were postoperative complications within 30 days of surgery, measured using the Clavien–Dindo classification system. Results: A total of 3288 patients were included in the analysis, of whom 301 (9·2 per cent) were discharged before the return of bowel function. The median duration of hospital stay for patients discharged before and after return of bowel function was 5 (i.q.r. 4–7) and 7 (6–8) days respectively (P < 0·001). There were no significant differences in rates of readmission between these groups (6·6 versus 8·0 per cent; P = 0·499), and this remained the case after multivariable adjustment for baseline differences (odds ratio 0·90, 95 per cent c.i. 0·55 to 1·46; P = 0·659). Rates of postoperative complications were also similar in those discharged before versus after return of bowel function (minor: 34·7 versus 39·5 per cent; major 3·3 versus 3·4 per cent; P = 0·110). Conclusion: Discharge before return of bowel function after elective colorectal surgery appears to be safe in appropriately selected patients