The Sr-induced reconstructions on Si(100) at elevated temperature were studied using scanning tunneling microscopy and reflection high energy electron diffraction. With the Sr coverage increasing from 0 to 0.5 monolayer, the surface exhibits phase transitions from 2×1-Sr to 2×3-Sr and then to 1×2-Sr. The bias-dependent, high resolution STM images unambiguously support a dimer-vacancy structural model for the 2×3-Sr phase. Furthermore, the coverage-dependent evolution of the surface from 2×3-Sr to 1×2-Sr can also be nicely explained by extending the 2×3-Sr model to the 1×2-Sr.

The 5-hydroxytryptamine 2C receptor (5-HTR2C) is a class G protein-coupled receptor (GPCR) enriched in the hypothalamus and the brain stem, where it has been shown to regulate energy homeostasis, including feeding and glucose metabolism. Accordingly, 5-HTR2C has been the target of several anti-obesity drugs, though the associated side effects greatly curbed their clinical applications. Dissecting the specific neural circuits of 5-HTR2C-expressing neurons and the detailed molecular pathways of 5-HTR2C signaling in metabolic regulation will help to develop better therapeutic strategies towards metabolic disorders. In this review, we introduced the regulatory role of 5-HTR2C in feeding behavior and glucose metabolism, with particular focus on the molecular pathways, neural network, and its interaction with other metabolic hormones, such as leptin, ghrelin, insulin, and estrogens. Moreover, the latest progress in the clinical research on 5-HTR2C agonists was also discussed.

Extraordinary transmission of organic photoluminescence through an otherwise opaque metal layer via surface plasmon cross couplingThe surface plasmon dispersion of Ag(111) tuned by adsorption of F4-TCNQ molecules has been investigated using high resolution electron energy loss spectroscopy. For the pristine Ag(111) film, the surface plasmon energy shows a positive quadratic dispersion. After adsorption of F4-TCNQ, the plasmon energy of Ag decreases significantly and the dispersion switches sign at small q jj . The deviation systematically increases with the coverage of F4-TCNQ. These behaviors are explained by charge transfer between the Ag substrate and the molecular gas layer. V C 2012 American Institute of Physics. [http://dx.

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It is known that, when Ag is deposited on Si(111)-7×7 substrates in a conventional growth procedure at room temperature, no atomically flat Ag film could be obtained. We use scanning tunneling microscopy and low-energy electron diffraction to investigate the growth of ultra-thin Ag films on the Si(111) substrates at room temperature. Our study reveals that, upon introducing a Si(111)-√ 3× √ 3-Ga buffer layer, atomically flat Ag films can easily grow on Si(111) with a critical thickness of two monolayers. Moreover, Ag film growth follows a layer-by-layer mode with further deposition. This novel growth behavior of Ag can be explained in terms of a free electron model (i.e., particle in a box) and kinetic Monte Carlo simulations.