Pressure Dependence of Fragile-to-Strong Transition and a Possible Second Critical Point in Supercooled Confined Water

By confining water in nano-pores of silica glass, we can bypass the crystallization and study the pressure effect on the dynamical behavior in deeply supercooled state using neutron scattering. We observe a clear evidence of a cusp-like fragile-to-strong (F-S) dynamic transition. Here we show that the transition temperature decreases steadily with an increasing pressure, until it intersects the homogenous nucleation temperature line of bulk water at a pressure of 1600 bar. Above this pressure, it is no longer possible to discern the characteristic feature of the F-S transition. Identification of this end point with the possible second critical point is discussed.Comment: 4 pages, 3 figure

Synthesis of fluorophore and quencher monomers for use in Scorpion primers and nucleic acid structural probes

We report the syntheses of monomers to incorporate fluorescein and methyl red within the sequence and at the termini of modified oligonucleotides. These monomers have been used in the solid-phase synthesis of fluorogenic oligonucleotides for genetic analysis and the study of multi-stranded nucleic acid structures