Biexciton in carbon nanotubes

National audienceThe questions of the existence and stability of multi-excitonic states, in which the one-dimensional character of carbon nanotubes implies strong Coulomb interactions, are currently the subject of intense debates. These states and their coupling with excitonic states play a fundamental role within the exploitation of excitonic properties. Recently, experimental studies reported the observation of the trion (exciton-carrier bound state). In order to study the biexciton, we have performed nonlinear spectral-hole burning experiments at a low temperature, bringing the first evidence for biexcitonic induced-absorption

Dual Invasive Infection with Phaeoacremonium parasiticum and Paraconiothyrium cyclothyrioides in a Renal Transplant Recipient: Case Report and Comprehensive Review of the Literature of Phaeoacremonium Phaeohyphomycosis

International audienceDespite increasing reports of human infection, data about the optimal care of Phaeoacremonium infections are missing. We report a case of an infection due to Phaeoacremonium parasiticum and Paraconiothyrium cyclothyrioides, initially localized to skin and soft tissue, in a kidney transplant patient. Despite surgical drainage and excision of the lesion and combination antifungal therapy with voriconazole and liposomal amphotericin B, a disseminated infection involving the lungs and brain developed and led to death. We performed a systematic literature review to assess the general features and outcome of human infections due to Phaeoacremonium species. Thirty-six articles were selected, and 42 patients, including ours, were reviewed. Thirty-one patients (74%) were immunocompromised because of organ or bone marrow transplantation (n = 17), diabetes or glucose intolerance (n = 10), rheumatoid arthritis or Still's disease (n = 4), chronic hematological diseases (n = 3), or chronic granulomatous disease (n = 3). Ten patients (24%) reported initial cutaneous trauma. Skin and soft tissue infections represented 57% of infections (n = 24), and disseminated infections, all occurring in immunocompromised patients, represented 14% of infections (n = 6). The main antifungal drugs used were azoles (n = 41) and amphotericin B (n = 16). Surgical excision or drainage was performed in 64% of cases (n = 27). The cure rate was 67% (n = 28). There were 10% cases of treatment failure or partial response (n = 4), 19% relapses (n = 8), and 7% losses to follow-up (n = 3). The death rate was 19% (n = 8). Management of Phaeoacremonium infections is complex because of slow laboratory identification and limited clinical data, and treatment relies on a combination of surgery and systemic antifungal therapy

L'énergie à découvert

L'énergie est devenue une question vitale pour les sociétés, le citoyen, l'humanité tout entière. Sujet scientifique, économique, politique et écologique majeur, elle suscite des débats, parfois violents, sur les choix à faire aujourd'hui et leurs conséquences pour l'avenir des hommes et de la planète. Mais, alors que se tient le grand débat national sur la transition énergétique, comment se forger une opinion objective sans connaître les données scientifiques les plus complètes sur les potentiels et les limites de chaque source d'énergie ? Ce livre les met enfin à la disposition du public. L'énergie, qu'est-ce que c'est ? Quelles sont les grandes lois physiques qui la gouvernent ? Comment la produire, la transporter, la stocker ? Le solaire, la biomasse, l'éolien, l'hydraulique sont-ils des solutions alternatives suffisantes ? Et quelle part leur réserver à l'avenir ? Les nombreux articles de ce livre (près de 130) proposent au citoyen des outils pour se faire une opinion face à ces questions. Physiciens, chimistes, biologistes, géophysiciens, environnementalistes, géographes, économistes, y précisent, chiffres et schémas à l'appui, la place respective des énergies fossiles, du nucléaire et des énergies renouvelables. Au-delà, ils expliquent quelles sont les perspectives offertes par la science sur le mix énergétique, le problème du stockage, l'amélioration de nos usages de l'énergie, ses impacts environnementaux et sanitaires