Shear-induced phase separation in "nonentangled" oligomer mixture

Shear-induced phase separation was found in "nonentangled" oligomer mixture. The sheared mixture in one phase becomes turbid and its scattering pattern exhibits so-called "butterfly pattern" which is commonly observed in shear-induced phase separation of semidilute polymer solutions. The origin of the shear-induced phase separation is found to be dynamical asymmetry due to the difference in the glass transition temperature.     

Electrochemical Detection of Duplex DNA Using Intercalation‐Triggered Decomplexation of Ferrocene with β‐Cyclodextrin

The redox peak of ferrocenylnaphthalene diimide used as a threading intercalator shifted positively due to the formation of its complex with β‐cyclodextrin. This complex collapsed upon the addition of double‐stranded DNA, and its redox potential shifted negatively. This behavior was applied for the homogenous detection of a polymerase chain reaction (PCR) product from Porphyromonas gingivalis, which is important for the diagnosis of periodontal disease, and its quantitative detection was achieved with a detection limit of 2.7 nM.     

Screening for Oral Cancer Using Electrochemical Telomerase Assay

Electrochemical telomerase assay (ECTA) developed by our group was evaluated in an oral cancer screening using exfoliated oral cells and tissues obtained from patients of oral cancer, mucosa associated disease, or healthy volunteers. Telomerase activity from ECTA is correlated with hTERT mRNA expression level using a real‐time PCR and was increasing in the following order: healthy volunteer group<mucosa associated disease group<oral cancer group. Sensitivity and specificity of ECTA were 88 % and 72 %, respectively when used 17 % of the threshold value based on the receiver operating characteristic curve in ECTA data.     

Theoretical study on energy transfer from the excited C<Subscript>60</Subscript> to molecular oxygen

Singlet oxygen is used as an important oxidizer for various organic reactions, on the other hand, it has toxicity for the human body, since it destroys biological molecules such as DNA. Fullerene C₆₀ is known to act as a photosensitizer of singlet oxygen molecule, and it has been understood that energy transfer from the excited triplet C₆₀ to the ground triplet O₂ forming the singlet O₂ is a biologically important reaction. In the present study, we have analyzed these reaction pathways by means of the DFT (density functional theory) calculation.     

Proton NMR relaxation and molecular motion of long-chain cyclic paraffins in the solid state

Temperature-dependent measurements have been made on the proton NMR relaxations and proton linewidths of the cyclic paraffins (c-C₂₄H₄₈, c-C₂₈H₅₆, and c-C₁₂₈H₂₅₆) in the solid state. It is found that in c-C₂₄H₄₈ and c-C₁₂₈H₂₅₆ there exist two transitions, one due to the melting process and the other due to a rapid transition between trans and gauche conformers in a compact structure that consists of two parallel trans zigzag straight chains bridged at both ends in the crystalline state. In c-C₂₈H₅₆ there exists only the transition due to melting. Proton NMR relaxations have also been measured for c-C₄₀H₈₀ and c-C₁₆₀H₃₂₀ at room temperature, in addition to those for c-C₂₄H₄₈, c-C₂₈H₅₆, and c-C₁₂₈H₂₅₆. It is found that the extent of molecular motion decreases as the chain length increases.