Presence of 3d Quadrupole Moment in LaTiO3 Studied by 47,49Ti NMR

Ti NMR spectra of LaTiO3 are reexamined and the orbital state of this compound is discussed. The NMR spectra of LaTiO3 taken at 1.5 K under zero external field indicate a large nuclear quadrupole splitting. This splitting is ascribed to the presence of the rather large quadrupole moment of 3d electrons at Ti sites, suggesting that the orbital liquid model proposed for LaTiO3 is inappropriate. The NMR spectra are well explained by the orbital ordering model expressed approximately as $1/\sqrt{3}(d_{xy}+d_{yz}+d_{zx})$ originating from a crystal field effect. It is also shown that most of the orbital moment is quenched.Comment: 4 pages, 3 fugures; to appear in Phys. Rev. Let

Urethan(ethyl carbamate)as a multipotential carcinogen in Balb/C,Zb and Db female mice.

1. The objective of this investigation was to test the influence of mammary cancer tissue extract on the induction of various tumors by urethan. Three strains of female mice, Balb/c, Zb and Db, were used in this experiment. 2. It was found that urethan was a multipotential carcinogen in the induction of (a) lung tumor, ovarian hemorrhagic cyst, and hemorrhagic lesions in various tissue in Balb/c mice, (b) lung tumor, hepatoma, leukemia, mammary cancer, Harderian gland tumor and hemorrhagic lesions in various tissues such as spleen, mesenteric lymphnode, liver and ovary in Zb strain, and (c) lung tumor, mediastinal lymphoma, leukemia, hepatoma and hemorrhagic lesions in the liver and ovary in Db mice. 3. Mammary cancer tissue extract seemed to have a promotive effect on the generalization of the mediastinal lymphoma induced by urethan in Db female mice.</p

Synthesis and Luminescence Properties of Near-Infrared N-Heterocyclic Luciferin Analogues for In Vivo Optical Imaging

As a means of achieving highly sensitive bioluminescence imaging of deep tissues utilizing the firefly luciferin-luciferase (L-L) reaction, we previously reported a luciferin analogue, AkaLumine, which exhibits high cell-permeability and emits near-infrared (NIR) light with high tissue-penetration by the L-L reaction. However, while AkaLumine enables us to observe targets in deep tissues, its poor solubility in aqueous media limits its utility for in vivo imaging. Herein, to address this issue, we have synthesized three AkaLumine derivatives with N-heterocyclic aromatic rings as new red luciferin analogues that have substantially higher solubility than that of AkaLumine in phosphate buffered saline solution. One of the derivatives (herein termed seMpai) exhibits an emission maximum at 675 nm upon L-L reaction with Photinus pyralis luciferase and presents an activity in mouse-tissue imaging similar to that of AkaLumine. It is hoped that seMpai will extend the application of high-sensitivity NIR bioluminescence imaging in a wide range of biomedical research fields