The new beamline ALOISA, now operational at the Elettra Synchrotron, is designed for surface studies by means of several experimental techniques: surface x-ray diffraction and reflectivity, photoemission spectroscopy, photoelectron diffraction, e Ϫ -Auger coincidence spectroscopy. A new monochromator has been specifically designed and realized for this multipurpose beamline: it makes use of a channel-cut Si crystal dispersive element for the 3-8 keV range and of a plane mirror-plane grating element for the 200-2000 eV range. Both dispersive elements share the same optical system. In the low energy range ͑200-900 eV͒ the spectral resolving power exceeds 5000 while maintaining a throughput higher than 10 10 photons/s/200 mA/0.02% BW. In the case of the N 2 1s →* and Ne 1s→3 p transitions, the extremely high signal-to-noise ratio of the absorption spectra allowed a very accurate determination of the corresponding natural linewidth (116Ϯ2 and 250 Ϯ10 eV, respectively͒. Moreover, the vibrational structure of the CO-oxygen 1s→* transition has been fully resolved. In the high energy range, the measured flux exceeds 10 10 photons/s/200 mA up to 6.5 keV with a resolving power of ϳ7500.

Nonthermal generation of coherent-acoustic phonons is observed in metallic nanoparticles of tin and gallium, which are solid and liquid, respectively, at room temperature, by applying femtosecond pump-and-probe spectroscopy. Oscillations in the photo-induced differential reflection are clearly detected in the picosecond time domain. The measured period increases approximately linearly with size over a wide range and extracted sound velocities are consistent with those of bulk. Transition to ballistic regime in carrier excitation is also discussed on the basis of the disappearance of oscillations for particle sizes below hot-carrier mean free paths.

No abstract

Until relatively recently, the role of adipose tissue in the development of obesity and its consequences was considered to be a passive one. Mounting evidence highlights the role of adipose tissue in the development of a systemic inflammatory state that contributes to obesity-associated vasculopathy and cardiovascular risk. It is now clear that, in addition to storing calories as triglycerides, adipocytes secrete a large variety of cytokines, chemokines and hormone-like factors, such as leptin, resistin, and acute-phase proteins. In addition, insulin resistance, both in nondiabetic and diabetic subjects, is frequently associated with obesity, particularly with an excess of intraabdominal fat. This production of pro-atherogenic substances is of particular interest since an increase in the plasma levels of these mediators may provide a novel mechanistic link between obesity and its vascular complications.