Origin of Second Harmonic Generation from individual Silicon Nanowires

We investigate Second Harmonic Generation from individual silicon nanowires and study the influence of resonant optical modes on the far-field nonlinear emission. We find that the polarization of the Second Harmonic has a size-dependent behavior and explain this phenomenon by a combination of different surface and bulk nonlinear susceptibility contributions. We show that the Second Harmonic Generation has an entirely different origin, depending on whether the incident illumination is polarized parallel or perpendicularly to the nanowire axis. The results open perspectives for further geometry-based studies on the origin of Second Harmonic Generation in nanostructures of high-index centrosymmetric semiconductors.Comment: 7 Pages, 4 Figures + 3 Pages, 6 Figures in Appendi

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Amaurosis after spine surgery: survey of the literature and discussion of one case

Postoperative vision loss (POVL) associated with spine surgery is a well known, albeit very rare complication. POVL incidence after spinal surgery ranges from 0.028 to 0.2%; however, due to the increase in number and duration of annual complex spinal operations, the incidence may increase. Origin and pathogenesis of POVL remain frequently unknown. A 73-year-old patient presented with lumbar disc herniation with associated neurological deficits after conservative pre-treatment at a peripheral hospital. Known comorbidities included arterial hypertension, moderate arterial sclerosis, diabetes mellitus type 2, mildly elevated blood lipids and treated prostate gland cancer. During lumbar spine surgery in modified prone position the patient presented with an acute episode of severe hypotension, which required treatment with catecholamines and Trendelenburg positioning. Three hours postoperatively, a visual loss in the right eye occurred, resulting in a complete amaurosis. Antihypertensive medication, arteriosclerosis and intraoperative hypotension are possible causes for the POVL. Intraoperative administration of catecholamines and Trendelenburg positioning for treatment of systemic hypotension might further compromise ocular perfusion. In patients with comorbidities compromising arterial blood pressure, blood circulation and microcirculation, POVL must be considered as a severe postoperative complication. It is recommended to inform patients about such complications and obtain preoperative informed consent regarding POVL. Any recent modification of antihypertensive medication must be reported and analysed for potential intraoperative hemodynamic consequences, prior to spine surgery in prone positio

Theory of molecular excitation and relaxation near a plasmonic device

International audienceThe new optical concepts currently developed in the research field of plasmonics can have significant practical applications for integrated optical device miniaturization as well as for molecular sensing applications. Particularly, these new devices can offer interesting opportunities for optical addressing of quantum systems. In this article, we develop a realistic model able to explore the various functionalities of a plasmon device connected to a single fluorescing molecule. We show that this theoretical method provides a useful framework to understand how quantum and plasmonic entities interact in a small area. Thus, the fluorescence signal evolution from excitation control to relaxation control depending on the incident light power is clearly observed

Prolonged Neuromuscular Blockade Following Succinylcholine Administration to a Patient with a Reduced Butyrylcholinesterase Activity

This case is about a 48-year-old woman known with a reduced butyrylcholinesterase activity, who developed prolonged neuromuscular blockade following the unintentional administration of succinylcholine. We took the opportunity to monitor the development of neuromuscular function during this period and blood samples were taken for molecular genetic analysis and for quantitative and qualitative analysis since not all causative mutations are functionally characterized. Reduced butyrylcholinesterase activity is discussed in many aspects. Clinical considerations are suggested concerning genetic counselling

Coupled experiment/simulation approach for the design of radiation-hardened rare-earth doped optical fibers and amplifiers

We developed an approach to design radiation-hardened rare earth -doped fibers and amplifiers. This methodology combines testing experiments on these devices with particle swarm optimization (PSO) calculations. The composition of Er/Yb-doped phosphosilicate fibers was improved by introducing Cerium inside their cores. Such composition strongly reduces the amplifier radiation sensitivity, limiting its degradation: we observed a gain decreasing from 19 dB to 18 dB after 50 krad whereas previous studies reported higher degradations up to 0°dB at such doses. PSO calculations, taking only into account the radiation effects on the absorption efficiency around the pump and emission wavelengths, correctly reproduce the general trends of experimental results. This calculation tool has been used to study the influence of the amplifier design on its radiation response. The fiber length used to ensure the optimal amplification before irradiation may be rather defined and adjusted to optimize the amplifier performance over the whole space mission profile rather than before integration in the harsh environments. Both forward and backward pumping schemes lead to the same kind of degradation with our active fibers. By using this promising coupled approach, radiation-hardened amplifiers nearly insensitive to radiations may be designed in the future

Efficacy and safety of nivolumab for patients with pre-treated type B3 thymoma and thymic carcinoma: results from the EORTC-ETOP NIVOTHYM phase II trial

Immunotherapy; Thymic carcinoma; ThymomaImmunoteràpia; Carcinoma tímic; TimomaInmunoterapia; Carcinoma tímico; TimomaBackground Thymic malignancies are rare intrathoracic tumors, which may be aggressive and difficult to treat. They represent a therapeutic challenge in the advanced/metastatic setting, with limited treatment options after the failure of first-line platinum-based chemotherapy. They are frequently associated with autoimmune disorders that also impact oncological management. Materials and methods NIVOTHYM is an international, multicenter, phase II, two-cohort, single-arm trial evaluating the activity and safety of nivolumab [240 mg intravenously (i.v.) q2 weeks] alone or with ipilimumab (1 mg /kg i.v. q6 weeks) in patients with advanced/relapsed type B3 thymoma or thymic carcinoma, after exposure to platinum-based chemotherapy. The primary endpoint is progression-free survival rate at 6 months (PFSR-6) based on RECIST 1.1 as per independent radiological review. Results From April 2018 to February 2020, 55 patients were enrolled in 15 centers from 5 countries. Ten patients (18%) had type B3 thymoma and 43 (78%) had thymic carcinoma. The majority were male (64%), and the median age was 58 years. Among the 49 eligible patients who started treatment, PFSR-6 by central review was 35% [95% confidence interval (CI) 22% to 50%]. The overall response rate and disease control rate were 12% (95% CI 5% to 25%) and 63% (95% CI 48% to 77%), respectively. Using the Kaplan–Meier method, median progression-free survival and overall survival by local assessment were 6.0 (95% CI 3.1-10.4) months and 21.3 (95% CI 11.6-not estimable) months, respectively. In the safety population of 54 patients, adverse events (AEs) of grade 1/2 were observed in 22 (41%) patients and grade 3/4 in 31 (57%) patients. Treatment-related AEs of grade 4 included one case of neutropenia, one case of immune-mediated transaminitis, and two cases of myocarditis. Conclusions Nivolumab monotherapy demonstrated an acceptable safety profile and objective activity, although it has been insufficient to meet its primary objective. The second cohort of NIVOTHYM is currently ongoing to assess the combination of nivolumab plus ipilimumab