Mechanically-Induced Transport Switching Effect in Graphene-based Nanojunctions

We report a theoretical study suggesting a novel type of electronic switching effect, driven by the geometrical reconstruction of nanoscale graphene-based junctions. We considered junction struc- tures which have alternative metastable configurations transformed by rotations of local carbon dimers. The use of external mechanical strain allows a control of the energy barrier heights of the potential profiles and also changes the reaction character from endothermic to exothermic or vice-versa. The reshaping of the atomic details of the junction encode binary electronic ON or OFF states, with ON/OFF transmission ratio that can reach up to 10^4-10^5. Our results suggest the possibility to design modern logical switching devices or mechanophore sensors, monitored by mechanical strain and structural rearrangements.Comment: 10 pages, 4 figure

Treatment of keloids using 5‐fluorouracil in combination with crystalline triamcinolone acetonide suspension: evaluating therapeutic effects by using non‐invasive objective measures

Background Intralesional 5‐fluorouracil (5‐FU) in combination with triamcinolone acetonide (TAC) has been recommended as a promising alternative for keloids not responding to silicone‐based products, cryotherapy or intralesional corticosteroids alone. Although numerous studies support the efficacy of this regime, there is a lack of objective data. Objectives In this study, we evaluate the therapeutic effect of four courses of intralesional 5‐FU in combination with TAC (3 : 1) utilizing 3D analysis (PRIMOS®pico), ultrasound and scar scales such as the Patient and Observer Scar Assessment Scales (POSAS) and the Dermatology Life Quality Index (DLQI). Methods Twenty‐five patients with keloids were treated using 5‐FU and TAC every 4 weeks. Objective assessments were performed and the scar scales administered at baseline, as well as during consecutive visits at 1‐ and 12‐month follow‐up (FU). Routine laboratory tests were performed at baseline and at 1‐month FU. Results 3D PRIMOS and ultrasound measurements revealed highly significant and stable reductions in height (baseline mean score: 4.0 ± 1.7 mm, 1‐month FU mean score: 1.5 ± 0.8 mm, 12‐month FU mean score: 1.8 ± 0.9 mm, P = <0.0001), volume (baseline mean score: 1,105 ± 911.5 mm3, 1‐month FU mean score: 416.1 ± 218.1 mm3, 12‐month FU mean sore: 431.2 ± 253.6 mm3, P = <0.0001, respectively) and penetration depth of keloids (relative reduction between baseline and 12‐month FU of 74.4%, P = <0.0001). The POSAS and DLQI scales confirmed significant objective and subjective improvements in scar appearance in all categories. The life quality associated with keloid appearance improved from a ‘moderate effect’ to a ‘small effect’ throughout the course of the study. Conclusions Results of this study confirm the efficacy and safety of the combination of 5‐FU and TAC in keloids. Treatments were well tolerated and demonstrated stable results at 12‐month FU

Modeling graphene-based nanoelectromechanical devices

We report on a theoretical study of charge transport properties of graphene nanoribbons under external mechanical stress. The influence of mechanical forces on the ribbon conductance is shown to be strongly dependent on the ribbon edge symmetry, i.e., zigzag versus armchair. In contrast to zigzag-edge nanoribbons which remain robust against high strain deformations, a stretching-induced metal-semiconductor transition is obtained for armchair-edge configurations. Our results point out that armchair edge ribbons are consequently much better suited for electromechanical applications.Fil: Poetschke, M.. Technische Universität Dresden; AlemaniaFil: Rocha, C. G.. Technische Universität Dresden; AlemaniaFil: Foa Torres, Luis Eduardo Francisco. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; ArgentinaFil: Roche, Serge. Technische Universität Dresden; Alemania. Universite Grenoble Alpes. Institut Nanosciences et Cryogenie - Commissariat a L´Energie Atomique et Aux Energies Alternatives. Institut Nanosciences et Cryogenie; Francia. Centro de Investigación en Nanociencia y Nanotecnología (CIN2); EspañaFil: Cuniberti, G.. Technische Universität Dresden; Alemani

Socio-economic status is inversely related to bed net use in Gabon

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