Previous Article Next Article Table of Contents Science, Vol.276, No.5320, 1773-1774, 1997 DOI10.1126/science.276.5320.1773 Export Citation Italian Basic and Applied-Research Calissano P, Clementi F, Meldolesi J, Montecucco C, Salvato B, Schiaffino S Please enable JavaScript to view the comments powered by Disqus.
