Effect of moir\'e superlattice reconstruction in the electronic excitation spectrum of graphene-metal heterostructures

We have studied the electronic excitation spectrum in periodically rippled graphene on Ru(0001) and flat, commensurate graphene on Ni(111) by means of high-resolution electron energy loss spectroscopy and a combination of density functional theory and tight-binding approaches. We show that the periodic moir\'e superlattice originated by the lattice mismatch in graphene/Ru(0001) induces the emergence of an extra mode, which is not present in graphene/Ni(111). Contrary to the ordinary intra-band plasmon of doped graphene, the extra mode is robust in charge-neutral graphene/metal contacts, having its origin in electron-hole inter-band transitions between van Hove singularities that emerge in the reconstructed band structure, due to the moir\'e pattern superlattice.Comment: Supplemental materials available at http://www.theorphys.science.ru.nl/people/yuan

DESCRIZIONE DI UN CASO DI SEVERA INSULINO-RESISTENZA E LIPODISTROFIA PARZIALE, CAUSATO DA UNA MUTAZIONE A CARICO DEL PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPAR-GAMMA): CARATTERIZZAZIONE CLINICA E MOLECOLARE.

Mutations affecting ligand or DNA binding functions of PPAR\u3b3 are associated with lipodystrophic insulin resistance. In the present study, we describe a 31 yr old female, heterozygous for a novel, mutation of PPAR\u3b3. Clinical features included hirsutism, polycystic ovarian syndrome, dyslipidaemia and hypertension. Hyperinsulinaemia during an OGTT and HOMA-IR 11.1% confirmed severe insulin resistance. She had distal limb and gluteal lipodystrophy with reduced subcutaneous adipose tissue (SCAT) but preserved visceral adipose tissue (VAT), with SCAT/VAT ratio of 0.619 (NR 0.19\ub10.084) and hepatic steatosis on MRS (Intrahepatic lipid 26.8% NR<5). In functional studies, the mutant receptor was more transcriptionally impaired with lower-affinity ligand (PGJ2) than synthetic agonist (rosiglitazone). Electrophoretic mobility shift assays (EMSA) with hFABP4 PPARE showed absent DNA binding. Modelling based on the PPAR\u3b3\u2013RXR heterodimer structure, indicates that this mutation involve a conserved aminoacid, which forms part of the extended DNA binding domain in the hinge region of the receptor. This residue interacts with bases in the minor groove upstream of the PPARE, and this substitution is predicted to destabilize such contacts. This mutation represents a novel mechanism whereby loss of receptor interaction with DNA is associated with human metabolic disease

Developing the Technique of Measurements of Magnetic Field in the CMS Steel Yoke Elements With Flux-Loops and Hall Probes

Compact muon solenoid (CMS) is a general-purpose detector designed to run at the highest luminosity at the CERN large hadron collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6 m diameter by 12.5 m long free bore, enclosed inside a 10000-ton return yoke made of construction steel. Accurate characterization of the magnetic field everywhere in theCMSdetector, including the large ferromagnetic parts of the yoke, is required. To measure the field in and around ferromagnetic parts, a set of flux-loops and Hall probe sensors will be installed on several of the steel pieces. Fast discharges of the solenoid during system commissioning tests will be used to induce voltages in the flux-loops that can be integrated to measure the flux in the steel at full excitation of the solenoid. The Hall sensors will give supplementary information on the axial magnetic field and permit estimation of the remanent field in the steel after the fast discharge. An experimental R&D program has been undertaken, using a test flux-loop, two Hall sensors, and sample disks made from the same construction steel used for the CMS magnet yoke. A sample disc, assembled with the test flux-loop and the Hall sensors, was inserted between the pole tips of a dipole electromagnet equipped with a computer-controlled power supply to measure the excitation of the steel from full saturation to zero field. The results of the measurements are presented and discussed.Comment: 6 pages, 8 figures, 6 reference