In contrast to natural atoms, the potential energies for superconducting flux qubit (SFQ) circuits can be artificially controlled. When the inversion symmetry of the potential energy is broken, we find that multi-photon processes can coexist in multi-level SFQ circuits. Moreover, there are not only transverse but also longitudinal couplings between the external magnetic fields and the SFQs when the inversion symmetry of potential energy is broken. Longitudinal coupling would induce some new phenomena in the SFQs. Here we will show how longitudinal coupling can result in the coexistence of multi-photon processes in a two-level system formed by an SFQ circuit. We also show that the SFQs can become transparent to the transverse coupling fields when the longitudinal coupling fields satisfy certain conditions. We further show that the quantum Zeno effect can also be induced by longitudinal coupling in the SFQs. Finally, we clarify why longitudinal coupling can induce the coexistence and disappearance of single-and two-photon processes for a driven SFQ, which is coupled to a single-mode quantized field.
1-Hydroxymethylpyrene (HMP), a primary benzylic alcohol, and 4H-cyclopenta[def]chrysen-4-ol (OH-CPC), a secondary benzylic alcohol, were investigated for mutagenicity in Salmonella typhimurium (reversion of the his- strain TA98) in the presence of various xenobiotic-metabolizing systems. In the direct test, HMP was inactive and OH-CPC was very weakly active. In the presence of NADPH-fortified postmitochondrial fraction from rat liver (S9/NADPH), no activation of OH-CPC was observed, whereas strong mutagenic effects were elicited by HMP. In the presence of cytosol and 3'-phosphoadenosine-5'-phosphosulfate (PAPS), both alcohols were activated to potent mutagens. For equal mutagenic effects, approximately 650-fold lower concentrations of HMP were required in the cytosol/PAPS-mediated assay than in the S9/NADPH-mediated assay. The cytosol/PAPS-mediated mutagenicity of both alcohols was 3- to 4-fold enhanced, when KCl (125 mM) was present during the exposure. The authentic chloromethylarenes, 1-chloromethylpyrene and 4-chloro-4H-cyclopenta[def]chrysene, showed very strong direct mutagenicity. These results, taken together with previous findings, indicate that both primary and secondary benzylic alcohols derived from polycyclic aromatic hydrocarbons may be activated by sulfotransferases to electrophilic sulfuric acid esters, and by subsequent substitution reaction to further active species such as benzylic chlorides.
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