VNP20009 is a genetically modified strain of Salmonella typhimurium possessing an excellent safety profile, including genetically stable attenuated virulence (a deletion in the purI gene), reduction of septic shock potential (a deletion in the msbB gene), and antibiotic susceptibility. VNP20009 is genetically stable after multiple generations in vitro and in vivo. In mice, VNP20009 is rapidly cleared from the blood from a peak level of 1x104 cfu/mL to undetectable levels in 24 h. In tumor-bearing mice, VNP20009 accumulates preferentially in tumors over livers at a ratio of 1000&rcolon;1. In nonhuman primates, VNP20009 was also rapidly cleared from the blood, from a peak level of 1.0x106 cfu/mL to undetectable levels in 24 h. VNP20009 was detected in the liver, spleen, and bone marrow of monkeys; the amount decreased over time, and VNP20009 was cleared from all organs by day 41; no VNP20009 could be detected in the urine or feces of the monkeys. VNP20009 is genetically stable after many generations of growth (>140) both in vitro and in vivo.

Enhanced Raman scattering from cesium suboxides on silver particles and the structure of S1 photocathodes Appl. Phys. Lett. 45, 1058Lett. 45, (1984; 10.1063/1.95067The role of cesium suboxides in lowworkfunction surface layers studied by xray photoelectron spectroscopy: Ag OCs Appl. Phys. Lett. 36, 675 (1980); 10.1063/1.91620Hypothetical mechanism of operation of the AgOCs (S1) photocathode involving the peroxide Cs2O2Raman spectra from photomultipliers having Ag-O-Cs photocathodes (S-l) are found to correspond to the vibrational spectrum ofCs l1 0 3 . The wavelength dependence of the CS l1 0 3 Raman intensity is compared with the radiant sensitivity of the S-l photocathode, and the possible role of Ag islands in enhancing the Raman intensity and photocurrent is discussed. The composition near the edge of the Bi-Ag-O-Cs photocathode (S-10) was found to be CS!!03'