The optical method of measurement of sizes and the refractive index of nanoparticles Ag@Fe3O4.

The spectrophotometric method and the electron microscope have been used to determine the distribution function of Ag@Fe3O4 nanoparticles by sizes and to measure their complex refractive index. These particles have been synthesized as acomponent of magnetically controlled drugs with antibacterial properties. The algorithm of processing the results of the experiment has been designed to measure the sizes of nanoparticles (1-100 nm).Key words: nanoparticle sizes measuring spectrum attenuation.

Mantoux testing of 7th graders in Tel Aviv, Israel.

As part of a countrywide program of tuberculin testing of 7th graders, 10,133 children were examined in the Tel Aviv area over the 3-year period, Septemer 1991-June 1994. Of these, 655 were from families recently arrived from the former Soviet Union (I), and 9478 from long-time resident families of Israel (L). Of the I group 537 had received BCG at least once (82.0%), of the L group 5306 (56.0%). In the nonvaccinated I group 33.9% had reactions of 10 mm or more (clinically significant) while the rate was 6.1% in the L group, a statistically highly significant difference. In the vaccinated I group the rate of clinically significant reactions was 49.3% as compared to 10.3% in the L group, also statistically a highly significant difference. In general, the clinically significant reactions were more commonly found in the I group as opposed to the L group. Both BCG vaccination and prior place of residence appear to be statistically significant independent variables. No cases of tuberculosis occurred among the entire population tested. These data provide a base for surveillance of tuberculosis risk in Tel Aviv specifically and Israel in general.