La Grande Muraglia è crollata

La Grande Muraglia \ue8 davvero crollata e l'avanzata del mercato cinese verso occidente richiede profonde analisi tra percezioni, strategie, reazioni nelle politiche interne ed internazionali degli Stati

Energy distributions at the high-spin ferric sites in myoglobin crystals.

The orientation and temperature dependence (4.2-2.5 K) of electron paramagnetic resonance (EPR) power saturation and spin-lattice relaxation rate, and the orientation dependence of signal linewidth, were measured in single crystals of the aquo complex of ferric sperm whale skeletal muscle myoglobin. The spin-packet linewidth was found to be temperature independent and to vary by a factor of seven within the heme plane. An analysis is presented which enables one to arrive at (a) hyperfine component line-widths and, from the in-plane angular variation of the latter, at (b) the widths of distributions in energy differences between low-lying electronic levels and (c) the angular spread in the in-plane principal g-directions. The values of the energy level distributions in crystals obtained from the measurements and analysis reported here are compared with those obtained by a different method for the same protein complex in frozen solution. The spread in the rhombic energy splitting is significantly greater in solution than in the crystal

Protection of radar systems against nearby or direct lightning strokes

The paper deals with the characteristics of a Lightning Protection System (LPS) for a fixed and a mobile RADARS. The LPS design includes external (LPE) and internal (LPI) system as well as protection measures against lightning electromagnetic pulse (LEMP) of internal electrical and electronic systems (i.e. air terminations, down conductors, earthing arrangement, internal equipotential bonding, cable routing and shielding and surge protection) according to the IEC 62305 standard series. By means of computer simulations the most critical parameters have been evaluated and the results have been taken into account both in the electrical design of the LPS and in the selection of some RADAR components. © 2008 IEEE

Incidental cystadenoma after laparoscopic treatment of hepatic cysts: which strategy?

Biliary cystadenoma is a very rare hepatic neoplasm, accounting for fewer than 5% of cystic neoplasms of the liver; regardless of the various diagnostic modalities, such a lesion may be difficult to distinguish preoperatively from a cystadenocarcinoma. Although a diagnosis of cystadenoma during open hepatic surgery demands a complete surgical resection, there are few reports describing the correct approach to such lesions after a laparoscopic approach. This article presents the first case series of incidental cystadenoma after laparoscopic surgery for hepatic cystic lesions. One patient with a polycystic liver disease treated with a laparoscopic enucleation of the larger cyst declined the reintervention after the diagnosis of cystadenoma; she had no recurrence at follow-up. One patient with a large simple hepatic cyst laparoscopically enucleated had no recurrence at the 18-month follow-up. In one patient, there was a high suspicion of recurrence of cystadenoma after the laparoscopic fenestration of a large cyst, but a histopathological specimen obtained after the open surgical resection could not confirm any signs of cystadenoma. The incidental finding of biliary cystadenoma after laparoscopic fenestration of a cystic hepatic lesion requires an open hepatic resection. When a complete laparoscopic enucleation of the cyst may be assured, a strict clinical, biochemical, and radiologic follow-up could be considered as the definitive treatment, demanding the surgical intervention only in case of recurrence or high suspicion for malignancy