Diffractive shadowing of coherent polarization radiation

We report on the study of shadowing of electromagnetic fields radiated in the Terahertz (THz) region from two consecutive sources of coherent diffraction and transition radiation. In these conditions, the formation length is predicted to be $\leq$ 100 m, and shadowing effects should result in an almost complete suppression of radiated fields within distances of the order of tens of centimeters. We experimentally measured that shadowing effects disappear for distances significantly shorter than those predicted. We propose a new model that explains our experimental observations by taking into account 3D diffraction effects. These findings will have a positive impact on the beneficial use of consecutive radiators both for the generation of intense electromagnetic radiation and for beam diagnostics using coherent polarization radiation from ultra-relativistic charged particles

Impairment of aryl hydrocarbon receptor signalling promotes hepatic disorders in cancer cachexia

Abstract Background The aryl hydrocarbon receptor (AHR) is expressed in the intestine and liver, where it has pleiotropic functions and target genes. This study aims to explore the potential implication of AHR in cancer cachexia, an inflammatory and metabolic syndrome contributing to cancer death. Specifically, we tested the hypothesis that targeting AHR can alleviate cachectic features, particularly through the gut–liver axis. Methods AHR pathways were explored in multiple tissues from four experimental mouse models of cancer cachexia (C26, BaF3, MC38 and APCMin/+) and from non‐cachectic mice (sham‐injected mice and non‐cachexia‐inducing [NC26] tumour‐bearing mice), as well as in liver biopsies from cancer patients. Cachectic mice were treated with an AHR agonist (6‐formylindolo(3,2‐b)carbazole [FICZ]) or an antibody neutralizing interleukin‐6 (IL‐6). Key mechanisms were validated in vitro on HepG2 cells. Results AHR activation, reflected by the expression of Cyp1a1 and Cyp1a2, two major AHR target genes, was deeply reduced in all models (C26 and BaF3, P < 0.001; MC38 and APCMin/+, P < 0.05) independently of anorexia. This reduction occurred early in the liver (P < 0.001; before the onset of cachexia), compared to the ileum and skeletal muscle (P < 0.01; pre‐cachexia stage), and was intrinsically related to cachexia (C26 vs. NC26, P < 0.001). We demonstrate a differential modulation of AHR activation in the liver (through the IL‐6/hypoxia‐inducing factor 1α pathway) compared to the ileum (attributed to the decreased levels of indolic AHR ligands, P < 0.001), and the muscle. In cachectic mice, FICZ treatment reduced hepatic inflammation: expression of cytokines (Ccl2, P = 0.005; Cxcl2, P = 0.018; Il1b, P = 0.088) with similar trends at the protein levels, expression of genes involved in the acute‐phase response (Apcs, P = 0.040; Saa1, P = 0.002; Saa2, P = 0.039; Alb, P = 0.003), macrophage activation (Cd68, P = 0.038) and extracellular matrix remodelling (Fga, P = 0.008; Pcolce, P = 0.025; Timp1, P = 0.003). We observed a decrease in blood glucose in cachectic mice (P < 0.0001), which was also improved by FICZ treatment (P = 0.026) through hepatic transcriptional promotion of a key marker of gluconeogenesis, namely, G6pc (C26 vs. C26 + FICZ, P = 0.029). Strikingly, these benefits on glycaemic disorders occurred independently of an amelioration of the gut barrier dysfunction. In cancer patients, the hepatic expression of G6pc was correlated to Cyp1a1 (Spearman's ρ = 0.52, P = 0.089) and Cyp1a2 (Spearman's ρ = 0.67, P = 0.020). Conclusions With this set of studies, we demonstrate that impairment of AHR signalling contributes to hepatic inflammatory and metabolic disorders characterizing cancer cachexia, paving the way for innovative therapeutic strategies in this context

Development of the self-modulation instability of a relativistic proton bunch in plasma

Self-modulation is a beam–plasma instability that is useful to drive large-amplitude wakefields with bunches much longer than the plasma skin depth. We present experimental results showing that, when increasing the ratio between the initial transverse size of the bunch and the plasma skin depth, the instability occurs later along the bunch, or not at all, over a fixed plasma length because the amplitude of the initial wakefields decreases. We show cases for which self-modulation does not develop, and we introduce a simple model discussing the conditions for which it would not occur after any plasma length. Changing bunch size and plasma electron density also changes the growth rate of the instability. We discuss the impact of these results on the design of a particle accelerator based on the self-modulation instability seeded by a relativistic ionization front, such as the future upgrade of the Advanced WAKefield Experiment

Combined Bacterial Meningitis and Infective Endocarditis: When Should We Search for the Other When Either One is Diagnosed?

Auteurs groupes collaboratifs AEPEI study group & the COMBAT study groupInternational audienc

Successful Thrombectomy Improves Functional Outcome in Tandem Occlusions with a Large Ischemic Core

International audienceBackground: Emergent stenting in tandem occlusions and mechanical thrombectomy (MT) of acute ischemic stroke related to large vessel occlusion (LVO-AIS) with a large core are tested independently. We aim to assess the impact of reperfusion with MT in patients with LVO-AIS with a large core and a tandem occlusion and to compare the safety of reperfusion between large core with tandem and nontandem occlusions in current practice. Methods: We analyzed data of all consecutive patients included in the prospective Endovascular Treatment in Ischemic Stroke Registry in France between January 2015 and March 2023 who presented with a pretreatment ASPECTS (Alberta Stroke Program Early CT Score) of 0–5 and angiographically proven tandem occlusion. The primary end point was a favorable outcome defined by a modified Rankin Scale (mRS) score of 0–3 at 90 days. Results: Among 262 included patients with a tandem occlusion and ASPECTS 0–5, 203 patients (77.5%) had a successful reperfusion (modified Thrombolysis in Cerebral Infarction grade 2b-3). Reperfused patients had a favorable shift in the overall mRS score distribution (adjusted odds ratio [aOR], 1.57 [1.22–2.03]; P < 0.001), higher rates of mRS score 0–3 (aOR, 7.03 [2.60–19.01]; P < 0.001) and mRS score 0–2 at 90 days (aOR, 3.85 [1.39–10.68]; P = 0.009) compared with nonreperfused. There was a trend between the occurrence of successful reperfusion and a decreased rate of symptomatic intracranial hemorrhage (aOR, 0.5 [0.22–1.13]; P = 0.096). Similar safety outcomes were observed after large core reperfusion in tandem and nontandem occlusions. Conclusions: Successful reperfusion was associated with a higher rate of favorable outcome in large core LVO-AIS with a tandem occlusion, with a safety profile similar to nontandem occlusion