https://www.selleckchem.com/products/paeoniflorin.html The dependence of stability on the sequence of a DNA hairpin has been investigated through atomistic simulations. For this, a sequence of 16 bases of a hairpin, which consists of a loop of four bases and a stem of six base pairs, has been considered. We have taken eight different sequences, where the first five base pairs were kept fixed in all sequences, whereas the loop sequence and the identity of the duplex base pair closing the loop have been varied. For these hairpin structures, force-induced melting (unzipping) studies were carried out to investigate the effect of the variables on the stability of hairpin. The temperature at which half of the base pairs are open is termed the melting temperature. We defined the unzipping force F_h (half of the base pairs are open) and showed that it may not provide the effect of closing the base pair or loop sequence on the stability of the DNA hairpin. In order to have a better understanding of the stability of a DNA hairpin, the closing base pair or hairpin loop must be open. This requires complete opening of the stem. We defined a force F_c at which all base pairs of the stem are open, and we showed that the F_c gives better understanding of DNA hairpin stability.Collisional excitation kinetics for atomic oxygen is studied behind reflected shock waves in 1%O_2/Ar mixtures over 10 000-11 000K using laser absorption spectroscopy of the O(3s^5S^o) to O(3p^5P_3) transition at 777 nm and the O(3p^5P_3) to O(3d ^5D_2,3,4^o) transitions at 926 nm. Four time histories are inferred simultaneously from the absorbance of the two transitions the population density of level 4 of atomic oxygen, i.e., the O(3s ^5S^o) state, n_4; the population density of level 6 of atomic oxygen, i.e., the O(3p^5P_3) state, n_6; the electron number density, n_e; and the heavy-particle translational temperature, T_tr. Atomic oxygen in the levels 4 and 6 are not in equilibrium with the ground-state ato