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International audience; La génération d’états de photon cohérents puissants dans le proche-IR et THz, présentant une structuration 3D spatio-temporelle, représente un défi physique et technologique. Elle est d’intérêt pour les applications : pinces optiques, capteurs, microscopie, LIDAR, télécoms, spectroscopie… Ces états originaux sont ici générés en exploitant les nanotechnologies à semi-conducteur III-V et les lasers à cavité externe verticale intégrant une métasurface : lumière VORTEX, bi-fréquences pour le THz, ou sans mode.

This article reports a novel 3-D imaging approach for remote, nondestructive material inspection at depth. The approach is based on a frequency-modulated continuous-wave (FMCW) radar system operating in the 75–110-GHz frequency band. Time-domain spectroscopy (TDS) measurements demonstrate that such a frequency band has manage-able attenuation levels in centimeter-long materials, thereby offering an advantageous resolution-versus-measurement-depth tradeoff compared with higher frequencies. The proposed setup includes a long delay on the reference signal in order to cancel redundant signals that would otherwise degrade the measurement. Furthermore, specific signal-processing techniques used to improve the performance of the system, which requires stringent component performances in terms of radio-frequency nonlinearity and return loss, are presented. Radio-frequency nonlinearity correction is based on a reference measurement, and the impact of deleterious reflections is reduced by averaging measurements conducted on a target at different longitudinal positions. As a result, an improvement of the signal-to-noise (S/N) ratio up to 20 dB is demonstrated. Tomography experiments were conducted on building materials showing 3-D imaging with theoretically limited longitudinal and transverse resolutions of 5 and 20 mm, respectively, thus opening the door to civil infrastructure monitoring applications.

In this work, we analyze the absorption spectra of silica fibers doped with erbium (Er) and usual codoping atoms such as aluminum (Al) and germanium (Ge). This study is performed in the 400 nm to 1000 nm wavelength range. We describe and identify relations between the optical fiber composition and the changes in their absorption spectra after two consecutive processes: a 300-Gy gamma irradiation and then after photobleaching obtained with a 980 nm laser light. Among the results we obtained, we want to emphasize that the creation of Al-related defects, known to be the main origin of radio-darkening in aluminosilicate fibers, depends also on the Al/Er ratio. We also identify a new Al originated trap, different from Al-OHC and not referenced in the existing scientific literature to our knowledge. Its contribution to the RIA seems to be really significant. Moreover, photobleaching appears to be a possible recovery mechanism as the Al-colored centers vanish under 980 nm laser light.

PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR FUNDAÇÃO DE APOIO À PESQUISA DO ESTADO DO RIO DE JANEIRO PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO BOLSA NOTA 10 A partir da análise do texto Apologia de Sócrates de Platão, pretendo sustentar, com o apoio de uma rede de comentadores, o emprego que o personagem Sócrates faz de estratégias clássicas da retórica forense. Contudo, para além de uma mera apropriação genérica de tal retórica, o presente trabalho busca corroborar a tese que afirma uma forte relação entre a retórica na Apologia de Sócrates e a retórica na Apologia de Palamedes, de Górgias. A partir de uma análise de ambos os textos e do estabelecimento de suas possíveis relações, correspondentes aos capítulos dois e três desta pesquisa, dedico o capítulo seguinte à compreensão do que seria o discurso retórico para ambos os autores. Por um lado, o diálogo Górgias, de Platão, é utilizado como fonte para o possível posicionamento do filósofo acerca da questão da arte retórica, associada no caso à retórica sofística. Por outro, o Elogio de Helena, de Górgias, é o registro do sofista sobre o poder e o uso da linguagem. Tais textos são incluídos na pesquisa com o objetivo de esclarecer o pensamento de filósofos e sofistas, representados nessa análise de caso por Platão e Górgias, acerca da função dos discursos. Por fim, através do estudo empregado nos capítulos anteriores, procuro evidenciar no quinto capítulo que a retórica de verdade de Sócrates só é possível devido a uma relação diferenciada que o filósofo possui com sua própria mortalidade. A partir disso, este estudo pretende defender que a relação do filósofo com a retórica é possível sem que a mesma seja uma contradição entre comportamentos e valores. Through the analysis of Socrates Apology from Plato, I intent to support, based on a group of scholars, the use that the Socrates character does of classic forensic rhetorical strategies. Although, beyond a mere appropriation of the rhetoric in question, the following dissertation aims to corroborate the thesis that sustains a strong relation between the rhetoric in Socrates Apology and the one in Palamedes Apology, from Gorgias. Through an analysis of both texts and establishing their relations, done in the chapters 2 and 3 of this research, I dedicate the following chapter to the understanding of what would be the rhetorical discourse for both authors. In one side, the dialog Gorgias, from Plato, is used as source for the author s position regarding the rhetorical art, associated in this case with the sophistic rhetoric. On the other side, the Encomium of Helen, from Gorgias, is his statement on the power and usage of language. Such works are included in this research with the object of illuminating the thought of philosophers and sophists, represented in this study by Plato and Gorgias, regarding the function of discourse. In the end, through the study in the previous chapters, I aim to show that the rhetoric of truth from Socrates is only possible due to a different relationship that the philosopher has with his own mortality. With this, this dissertation aims to defend that the philosopher s relation with rhetoric is possible without it being a contradiction between behaviors and values.

The DREZotomy (Dorsal Root Entry Zone tomy) is an analgesic procedure. The analgesic effect is evaluated on 30 patients with chronic pain resulting from respectively: brachial plexus avulsion (66.6%), postherpetic pain (10%), hyperspastic states (6.6%), phantom pain (6.6%), the pain in the stump (6.6%), and spinal cord injuries (3.3%). Pain intensity was evaluated using a visual analogue scale (VAS). At last evaluation, between 12 and 60 months, after DREZotomy, 93% had a good or excellent global pain relief after surgery. According to the component types of pain, 9.6% of patients had good or excellent control of the paroxysmal pain, and 84% of the continuous pain. Kaplan–Meier prediction of lasting global pain control at 60 months of follow-up was calculated at 75.5%. Comparison of the 2 corresponding Kaplan–Meier curves at long term, namely, pain control in 82.8% for the paroxysmal component and in 51.7% for the continuous component, showed a statistically significant difference (P < 0.0001). Functional effects are improved by more than 70% according to patients.

Spatially Localized States are individually addressable structures that may appear in large aspect-ratio optical resonators. They can be used as bits of information for all-optical buffering. We design and operate a modeless laser cavity based on a 1/2 VCSEL coupled to a distant mirror in self-imaging condition. Our study indicates how a VeCSEL can be specially designed to provide a robust system potentially capable of emitting Spatially Localized States and paves the way towards the observation of three dimensional - in space and time - confined states, the so-called light bullets.

International audience

Pluripotent stem cells have been investigated as a renewable source of therapeutic hepatic cells, in order to overcome the lack of transplantable donor hepatocytes. Whereas different studies were able to correct hepatic defects in animal models, they focused on the most mature phenotype of hepatocyte-like cells (HLCs) derived from pluripotent stem cells and needed freshly prepared cells, which limits clinical applications of HLCs. Here, we report the production of hepatic stem cells (pHSCs) from human-induced pluripotent stem cells (hiPSCs) in xeno-free, feeder-free, and chemically defined conditions using as extracellular matrix a recombinant laminin instead of Matrigel, an undefined animal-derived matrix. Freshly prepared and frozen pHSCs were transplanted via splenic injection in Gunn rats, the animal model for Crigler-Najjar syndrome. Following cell transplantation and daily immunosuppression treatment, bilirubinemia was significantly decreased (around 30% decrease, P.05) and remained stable throughout the 6-month study. The transplanted pHSCs underwent maturation in vivo to restore the deficient metabolic hepatic function (bilirubin glucuronidation by UGT1A1). In conclusion, we demonstrate for the first time the differentiation of hiPSCs into pHSCs that (a) are produced using a differentiation protocol compatible with Good Manufacturing Practices, (b) can be frozen, and (c) are sufficient to demonstrate in vivo therapeutic efficacy to significantly lower hyperbilirubinemia in a model of inherited liver disease, despite their immature phenotype. Thus, our approach provides major advances toward future clinical applications and would facilitate cell therapy manufacturing from human pluripotent stem cells.

Background Oral cholic acid (CA) replacement has been shown to be an effective therapy in children with primary bile acid synthesis defects, which are rare and severe genetic liver diseases. To date there has been no report of the effects of this therapy in children reaching adulthood. The aim of the study was to evaluate the long-term effectiveness and safety of CA therapy. Methods Fifteen patients with either 3β-hydroxy-Δ5-C27-steroid oxidoreductase (3β-HSD) (n = 13) or Δ4–3-oxosteroid 5β-reductase (Δ4–3-oxo-R) (n = 2) deficiency confirmed by mass spectrometry and gene sequencing received oral CA and were followed prospectively. Results The median age at last follow-up and the median time of follow-up with treatment were 24.3 years (range: 15.3–37.2) and 21.4 years (range: 14.6–24.1), respectively. At last evaluation, physical examination findings and blood laboratory test results were normal in all patients. Liver sonograms were normal in most patients. Mean daily CA dose was 6.9 mg/kg of body weight. Mass spectrometry analysis of urine showed that excretion of the atypical metabolites remained low or traces in amount with CA therapy. Liver fibrosis scored in liver biopsies or assessed by elastography in 14 patients, after 10 to 24 years with CA therapy, showed a marked improvement with disappearance of cirrhosis (median score

The authors are investigating self-complementary adeno-associated virus (scAAV) as a vector for intra-articular gene-delivery of interleukin-1 receptor antagonist (IL-1Ra), and its therapeutic capacity in the treatment of osteoarthritis (OA). To model gene transfer on a scale proportional to the human knee, a frequent site of OA incidence, studies were focused on the joints of the equine forelimb. Using AAV2.5 capsid and equine IL-1Ra as a homologous transgene, a functional ceiling dose of ∼5 × 10(12) viral genomes was previously identified, which elevated the steady state levels of eqIL-1Ra in synovial fluids by >40-fold over endogenous production for at least 6 months. Here, using an osteochondral fragmentation model of early OA, the functional capacity of scAAV.IL-1Ra gene-delivery was examined in equine joints over a period of 12 weeks. In the disease model, transgenic eqIL-1Ra expression was several fold higher than seen previously in healthy joints, and correlated directly with the severity of joint pathology at the time of treatment. Despite wide variation in expression, the steady-state eqIL-1Ra in synovial fluids exceeded that of IL-1 by >400-fold in all animals, and a consistent treatment effect was observed. This included a 30–40% reduction in lameness and ∼25% improvement in total joint pathology by both magnetic resonance imaging and arthroscopic assessments, which included reduced joint effusion and synovitis, and improved repair of the osteochondral lesion. No vector-related increase in eqIL-1Ra levels in blood or urine was noted. Cumulatively, these studies in the equine model indicate scAAV.IL-1Ra administration is reasonably safe and capable of sustained therapeutic IL-1Ra production intra-articularly in joints of human scale. This profile supports consideration for human testing in OA.