Room Temperature Coherent and Voltage Tunable Terahertz Emission from Nanometer-Sized Field Effect Transistors

We report on reflective electro-optic sampling measurements of TeraHertz emission from nanometer-gate-length InGaAs-based high electron mobility transistors. The room temperature coherent gate-voltage tunable emission is demonstrated. We establish that the physical mechanism of the coherent TeraHertz emission is related to the plasma waves driven by simultaneous current and optical excitation. A significant shift of the plasma frequency and the narrowing of the emission with increasing channel's current are observed and explained as due to the increase of the carriers density and drift velocity.Comment: 3 figure

The Comprehensive Roadmap Toward Malaria Elimination Using Graphene and its Promising 2D Analogs

Malaria is a major public health concern with over 200 million new cases annually, resulting in significant financial costs. Preventive measures and diagnostic remedies are crucial in saving lives from malaria, and especially in developing nations. 2D materials are, therefore, ideal for fighting such an epidemic. Graphene and its derivatives are extensively studied due to their exceptional properties in this case. The biomedical applications of graphene-based nanomaterials have gained significant interest in recent years due to their remarkable biocompatibility, solubility, and selectivity. Their unique physicochemical characteristics, like ample surface area, biofunctionality, high purity, solubility, substantial drug-loading capacity, and superior ability to penetrate cell membranes, make them up-and-coming candidates as biodelivery carriers. In this review, crucial graphene-based technologies to combat malaria are discussed. The advancements in preventing and diagnosing malaria and the biocompatibility of graphene-based nanomaterials are emphasized. The roadmap for using graphene-based technology toward achieving the WHO global malaria elimination by 2030 is presented and discussed in detail. Graphene oxide, the most critical biocompatible graphene derivative for health sensors, is also discussed. Additionally, 2D chalcogenides, specifically sulfide-based transition-metal dichalcogenides, are reviewed in detecting malaria during its early stages

In Situ SR-XPS Observation of Ni-Assisted Low-Temperature Formation of Epitaxial Graphene on 3C-SiC/Si

Low-temperature (~1073 K) formation of graphene was performed on Si substrates by using an ultrathin (2 nm) Ni layer deposited on a 3C-SiC thin film heteroepitaxially grown on a Si substrate. Angle-resolved, synchrotron-radiation X-ray photoemission spectroscopy (SR-XPS) results show that the stacking order is, from the surface to the bulk, Ni carbides(Ni(3)C/NiC(x))/graphene/Ni/Ni silicides (Ni(2)Si/NiSi)/3C-SiC/Si. In situ SR-XPS during the graphitization annealing clarified that graphene is formed during the cooling stage. We conclude that Ni silicide and Ni carbide formation play an essential role in the formation of graphene

Brazilian cave heritage under siege

info:eu-repo/semantics/publishe

Identification of the 33-kDa alkaline protease of Aspergillus fumigatus in vitro and in vivo

Aspergillus fumigatus produced a 33-kDa serine protease (ALP) in vitro and in vivo. In vitro, this alkaline protease was secreted when the fungus was cultivated in the absence of protein, if the pH of the medium remained close to neutrality. Western blotting and immunoelectronmicroscopy studies showed that ALP was localised in the wall of the fungus and was degraded after secretion in the culture medium under conditions of low pH. Although present in the lung during infection, ALP did not appear to be diagnostically useful and was different from the precipitating chymotrypsin antigen used in the diagnosis of aspergilloma

Acceptabilité du don de cornée : sondage auprès de la population de Marrakech

Le prélèvement de cornée au Maroc reste en deçà des besoins. Ceci est en partie dû à la pénurie du don et au refus des familles à ce que l’on prélève les organes de leurs proches en mort encéphalique. Nous avons réalisé une enquête sur un échantillon représentatif de la population de la ville de Marrakech (909000 habitants). Notre objectif est d’évaluer les connaissances et de décrire les attitudes de cette population quant au don de cornée pour pouvoir individualiser des pistes d’action. Ce sondage d’opinion a été effectué dans la ville de Marrakech entre le mois de mars 2012 et le mois de Mars 2013. 73,1 % des 1000 individus sondés étaient au courant de la possibilité de la greffe d’organes au Maroc. 72,1% de notre population étaient pour le don de cornée alors que seulement une personne sur deux acceptait de donner ses cornées après sa mort. Les principaux arguments avancés par le groupe d’enquêtés refusant le don de cornée étaient les croyances religieuses dans 38% la peur dans 17% et la crainte de défiguration dans 13,6%. Outre l’ignorance du sujet attestée par les données descriptives, deux idées originales ressortent de ces résultats de sondage d’opinion le premier concept est l’altruisme social éprouvé par la population de la ville de Marrakech, le second constat est le manque d’information vis-à-vis d’un sujet aussi important