Realization of four-level qudits using biphotons.

The novel experimental realization of four-level optical quantum systems (ququarts) is presented. We exploit the polarization properties of the frequency nondegenerate biphoton field to obtain such systems. A simple method that does not rely on am interferometer is used to generate and measure the sequence of states that can be used in quantum key distribution protocol.

Qutrit state engineering with biphotons.

The novel experimental realization of three-level optical quantum systems is presented. We use the polarization state of biphotons to generate a specific sequence of states that are used in the extended version of four-state QKD protocol quantum key distribution protocol. We experimentally verify the orthogonality of the basic states and demonstrate the ability to easily switch between them. The tomography procedure is employed to reconstruct the density matrices of generated states.

[Characteristics of immunomodulating effect of histamine in inbred strain mice]. / Osobennosti immunomoduliruiushchego deistviia gistamina u myshei inbrednykh linii.

The activity of 5'-nucleotidase of peritoneal exudate in subcutaneous injection of histamine in a dose of 1.0-100 microliters was studied in mice of different lines (CBA, C57, B1/6, Balb/c, NFS/n, NFR/n). There were interline differences in the influence of histamine on this metabolic index.

[Acute and latent influenzal infection in mice with altered endogenous serotonin metabolism]. / Ostraia i latentnaia grippoznaia infektsiia myshei pri izmenenii obmena éndogennogo serotonina.

A steady and long-term increase of the endogenous serotonine concentration in the lungs, spleen, and brain achieved by administration of nontoxic doses of indopan, an inhibitor of monoamineoxidase, caused a significant decrease of resistance of animals to influenza virus in acute infection. After natural route of inoculation with 20 LD50 of the allantoic influenza A3/WSN (HON1) virus strain in the animals treated with indopan the area of lung affection with specific influenza pneumonia increased, the virus concentration in the lungs and spleen rose sharply, the titre of IgM antibody in the blood decreased; the animal mortality in this group also increased. The level of serotonin in the blood and organs of latently infected animals became normal 6 weeks after virus inoculation. In some of these animals, however, indopan caused a greater increase of serotonin level in the lungs than in intact mice of the same weight and age. Without changing the amine levels in the spleen and the brain, indopan caused 4-16-fold increase in the titer of specific antihemagglutinins in the blood, mostly of IgM fraction, as compared with the controls. In latent influenza infection the balance of serotonin metabolism in the lungs in unstable.