Matching emission centers of electrons and photons in current-carrying silver nanoparticle films.

Current flow through a nanoparticle film (two-dimensional ensemble of small tunnel-coupled metal particles on a dielectric substrate) is accompanied by electron and photon emission. It has a localized character (originates from emission centers). With an increase in applied voltage, the number of emission centers increases, and with further increase, some of them may burn out. In dark conditions, photon emission centers are visible with a bare eye. To visualize electron emission centers, emission electron microscopy is used. The conducted measurements allow comparison of the number and relative positions of electron and photon emission centers. It is shown that electrons and photons are emitted from the same centers.

Sub-poissonian loading of single atoms in a microscopic dipole trap.

The ability to manipulate individual atoms, ions or photons allows controlled engineering of the quantum state of small sets of trapped particles; this is necessary to encode and process information at the quantum level. Recent achievements in this direction have used either trapped ions or trapped photons in cavity quantum-electrodynamical systems. A third possibility that has been studied theoretically is to use trapped neutral atoms. Such schemes would benefit greatly from the ability to trap and address individual atoms with high spatial resolution. Here we demonstrate a method for loading and detecting individual atoms in an optical dipole trap of submicrometre size. Because of the extremely small trapping volume, only one atom can be loaded at a time, so that the statistics of the number of atoms in the trap, N, are strongly sub-poissonian (DeltaN2 approximately 0.5N). We present a simple model for describing the observed behaviour, and we discuss the possibilities for trapping and addressing several atoms in separate traps, for applications in quantum information processing.

[Emergency in children with implanted cerebrospinal fluid shunt]. / Neotlozhnoe sostoianie u detei s implantirovannoi likvoroshuntiruiushchei sistemoi.

In 455 pediatric patients with progressive hydrocephaly of non-tumour genesis, a valve liquoro-shunting system was implanted. At different periods after the operation (up to 5 years), 4.8% of the patients developed the purulent-infective complications, dysfunction of a system occurred--in 20.4%. The causes, clinical signs of the emergency state are analysed, the recommendations on carrying out the therapeutic measures are given.