Synthesis and Dual-Emission Feature of Salen-Al/Triarylborane Dyads.

Novel salen-Al/triarylborane dyad complexes were prepared and characterized with their corresponding mononuclear compounds. The UV-vis and photoluminescence experiments for dyads exhibited photoinduced energy transfer from borane to the salen-Al moiety in an intramolecular manner. Theoretical calculation and fluoride titration results further supported these intramolecular energy-transfer features.

Novel aluminum-BODIPY dyads: intriguing dual-emission via photoinduced energy transfer.

Three novel BODIPY-based heterodinuclear complexes, [salen(3,5-(t)Bu)2Al-(OC6H4-BODIPY)] (6), [salen(3,5-(t)Bu)2Al-(OC6F2H2-BODIPY)] (7), and [(mq)2Al-(OC6H4-BODIPY)] (8) (salen = N,N'-bis(salicylidene)ethylenediamine, BODIPY = 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene, and mq = methyl-8-quinolinolato) were prepared and characterized by multinuclear NMR spectroscopy. The specific structures of 6-8 were also determined by single crystal X-ray analysis. In particular, the salen-based heterodinuclear complexes 6 and 7 exhibited higher thermal stability (Td5 = 309 and 306 °C, respectively) than that of the closely related mononuclear aluminum or BODIPY compounds, except for 8. The UV/vis absorption and PL spectra for 6 and 7 indicated a significant photoinduced energy transfer from the aluminum-salen moiety to the BODIPY group in an intramolecular manner. Theoretical calculations revealed independent transition states of the aluminum-salen moiety or the BODIPY group in the Al(III)-BODIPY dyads, further supporting these experimental results.

REM sleep estimation only using respiratory dynamics.

Polysomnography (PSG) is currently considered the gold standard for assessing sleep quality. However, the numerous sensors that must be attached to the subject can disturb sleep and limit monitoring to within hospitals and sleep clinics. If data could be obtained without such constraints, sleep monitoring would be more convenient and could be extended to ordinary homes. During rapid-eye-movement (REM) sleep, respiration rate and variability are known to be greater than in other sleep stages. Hence, we calculated the average rate and variability of respiration in an epoch (30 s) by applying appropriate smoothing algorithms. Increased and irregular respiratory patterns during REM sleep were extracted using adaptive and linear thresholds. When both parameters simultaneously showed higher values than the thresholds, the epochs were assumed to belong to REM sleep. Thermocouples and piezoelectric-type belts were used to acquire respiratory signals. Thirteen healthy adults and nine obstructive sleep apnea (OSA) patients participated in this study. Kappa statistics showed a substantial agreement (kappa > 0.60) between the standard and respiration-based methods. One-way ANOVA analysis showed no significant difference between the techniques for total REM sleep. This approach can also be applied to the non-intrusive measurement of respiration signals, making it possible to automatically detect REM sleep without disturbing the subject.

Intercalation of bulky Delta,Delta- and Lambda,Lambda-bis-Ru(II) complex between DNA base pairs.

Interaction of Delta,Delta- and Lambda,Lambda-bis-Ru(II) complexes with native DNA was investigated by isotropic absorption and polarized spectroscopy including circular and linear dichroism (CD and LD). Despite the steric hindrance originating from its four bulky phenanthroline ligands at both ends of the molecule, this molecule rapidly intercalates between DNA base pairs. Intercalation was judged by large hypochromism and red shift in the UV-visible absorption spectra in the absorption region of the bridging moiety as well as in the metal-to-ligand-charge transfer absorption region. Further support for the intercalation is found in the fact that the magnitude of negative reduced LD signal in the absorption region of the bridging moiety was comparable to that of the DNA absorption region, indicating that the bridge connecting the two Ru(II) complexes is nearly parallel to the DNA base planes. No difference in the binding mode between the two enantiomers was observed. In the presence of either bis-Ru(II) complex, ethidium bromide, a classical intercalator, can intercalate into the empty sites but was not able to replace the Ru(II) complexes. Near the saturation, ground state interaction between ethidium and bis-Ru(II) complex was evident by LD.