9 research outputs found
Surface modes in plasmonic stubbed structures
International audienceWe present an analytical and numerical study about the existence of surface localized modes, known as Tamm states, in a one-dimensional (1D) comb-like plasmonic band gap structure. Surface plasmon polaritons (SPPs) waveguides with coupled resonators have been widely studied in recent years, because of their potential applications in highly integrated optical circuits. The system studied here is composed of an infinite 1D waveguide, along which stubs of length d1are grafted periodically with spacing period d2. The analytical study has been performed by means of the Green's function method which allows the calculation of the dispersion relations of the bulk, surface states of the plasmonic structure and the transmission coefficient. The band structure, as well as the transmission spectrum exhibit passbands separated by stopbands. The surface modes inside the gaps of the semi-infinite structure can be introduced by a defect at its surface. The analytical results are confirmed by numerical simulation using finite element method via Comsol Multiphysics software. These structures can be used to realize highly sensitive plasmonic sensors
Spin and Orbital Magnetisms of NiFe Compound: Density Functional Theory Study and Monte Carlo Simulation
Fast and Stable Computation of the Charlier Moments and Their Inverses Using Digital Filters and Image Block Representation
Investigation of Electronic and Magnetic Properties of Iron(II)-Bromide Compound by First Principle, Mean Field, Series Expansion Calculations and Monte Carlo Simulation
Interplay between the structure and properties of new metastable carbon phases obtained under high pressures from fullerite C60 and carbyne
Features of cryptococcosis among 652 HIV-seronegative individuals in France: a cross-sectional observational study (2005-2020)
International audienceObjectives: We aimed to describe features and outcomes of cryptococcosis among HIV-seronegative individuals in a large surveillance network for cryptococcosis in France.Methods: We included incident cases of cryptococcosis in HIV-seronegative individuals from 2005 to 2020. We compared patient characteristics, disease presentations, cryptococcal antigen (CrAg) results, and induction antifungal treatments according to underlying disease. We examined factors associated with 90-day mortality. Among patients with disseminated infections, we investigated whether receipt of flucytosine and polyene combination was associated with lower mortality.Results: Among 652 individuals, 209 (32.1%) had malignancy, 130 (19.9%) were solid-organ transplant (SOT) recipients, 204 (31.3%) had other immunocompromising conditions, and 109 (16.7%) had no reported underlying factor. The commonest presentations were disseminated infections (63.3%, 413/652) and isolated pulmonary infections (25.3%, 165/652). SOT patients were most likely to have disseminated infections and a positive serum CrAg result. Patients with malignancy were older and less likely to receive a flucytosine-containing regimen for disseminated infections than others (58.7%, 78/133 vs. 73.2%, 194/265, p=0.029). The crude 90-day case-fatality ratio was 27.2% (95%CI: 23.5%-31.1%). Age ≥60 years (aOR: 2.75 [1.78-4.26], p<0.001), meningitis/fungaemia (aOR: 4.79 [1.80-12.7], p=0.002), and malignancy (aOR: 2.4 [1.14-5.07], p=0.02) were associated with higher 90-day mortality. Receipt of flucytosine and polyene combination was associated with lower 90-day mortality (aOR: 0.40 [0.23-0.71], p=0.002) in multivariable analysis and inverse probability of treatment weighted analysis (aOR: 0.45 [0.25-0.80], p=0.006).Conclusions: HIV-seronegative individuals with cryptococcosis comprise a wide range of underlying conditions with different presentations and outcomes, requiring a tailored approach to diagnosis and management