Magnetic Properties of Mn3ZnN Anti-perovskite Nanoparticles: A Monte Carlo Simulations

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Bound states in the continuum and Fano resonances in photonic and plasmonic loop structures

International audienceThe design and study of structures exhibiting bound states in the continuum (BICs) are the object of continuous works in wave physics. These long-lived states which are localized in some parts of the system without interacting with the background have found several potential applications due to their high sensitivities to weak perturbations, in particular in filtering and sensing. In this paper, we present a theoretical demonstration of BICs in an asymmetric loop composed of two arms of lengths d1 and d2 with both an experimental validation in the radio-frequency (RF) domain using coaxial cables and a numerical validation in the infrared (IR) domain using plasmonic metal-insulator-metal nanometric waveguides. The analytical study is performed by means of the Green’s function method, whereas the numerical calculation is obtained using finite element method. The BICs correspond to localized resonances of infinite lifetime inside the loop, without any leakage into the surrounding waveguides. We demonstrate that the condition for the existence of the BICs is to make the lengths of the two arms (d1 and d2) commensurate with each other. At the corresponding frequencies, one of the two degenerate modes of the isolated loop (associated with the clockwise and anti-clockwise propagations) couples to the waveguides while the other remains unaffected. When the lengths are slightly shifted from the BICs, the latter transform to Fano resonances exhibiting dips in the transmission spectra and sharp peaks in the density of states (DOS). As an application of our design, we show the efficiency of the Fano resonances in designing an efficient gaz-sensor with a high sensitivity and factor of merit in the IR domain. In addition, we derive an exact formula about the proportionality between DOS and the derivative of the argument of the determinant of the scattering matrix (Friedel phase) for a lossless structure; then, we discuss the validity and deviation from this rule when the loss is increased

Cryptococcus neoformans Infections Differ Among Human Immunodeficiency Virus (HIV)–Seropositive and HIV-Seronegative Individuals: Results From a Nationwide Surveillance Program in France

International audienceAmong 1107 cryptococcosis cases from the French surveillance network (2005–2020), the proportion of HIV-seronegative individuals has recently surpassed that of HIV-seropositive individuals. We observed marked differences in patient characteristics, disease presentations, cryptococcal antigen results, infecting species, and mortality according to HIV serostatus

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