Gluino-mediated electroweak penguin with flavor-violating trilinear couplings

In light of a discrepancy of the direct $CP$ violation in $K\to\pi\pi$ decays, $\varepsilon'/\varepsilon_K$, we investigate gluino contributions to the electroweak penguin, where flavor violations are induced by squark trilinear couplings. Top-Yukawa contributions to $\Delta S = 2$ observables are taken into account, and vacuum stability conditions are evaluated in detail. It is found that this scenario can explain the discrepancy of $\varepsilon'/\varepsilon_K$ for the squark mass smaller than 5.6 TeV. We also show that the gluino contributions can amplify $\mathcal{B}(K \to \pi \nu \overline{\nu})$, $\mathcal{B}(K_S \to \mu^+ \mu^-)_{\rm eff}$ and $\Delta A_{\rm CP}(b\to s\gamma)$. Such large effects could be measured in future experiments.Comment: 30 pages, 8 figures; references added, version published in JHE

Position-controlled trapping of nanoparticles and quantum dots on a fiber taper

We investigate numerically and experimentally the properties of a two color optical fiber taper trap, for which the evanescent field of the modes in the fiber taper give rise to a three-dimensional trapping potential. Experimentally, we use the technique to confine colloidal nanoparticles near the surface of an optical fiber taper, and show that the trapping position of the particles is adjustable by controlling the relative power of two modes in the fiber. We also demonstrate a proof of principle application by trapping quantum dots together with gold nanoparticles in a configuration where the trapping fields double as the excitation field for the quantum dots. This scheme will allow the positioning of quantum emitters in order to adjust coupling to resonators combined with the fiber taper.Comment: 13 pages, 9 figures. Comments welcom

H4K20 monomethylation inhibition causes loss of genomic integrity in mouse preimplantation embryos

Maintaining genomic integrity in mammalian early embryos, which are deficient in DNA damage repair, is critical for normal preimplantation and subsequent development. Abnormalities in DNA damage repair in preimplantation embryos can cause not only developmental arrest, but also diseases such as congenital disorders and cancers. Histone H4 lysine 20 monomethylation (H4K20me1) is involved in DNA damage repair and regulation of gene expression. However, little is known about the role of H4K20me1 during mouse preimplantation development. In this study, we revealed that H4K20me1 mediated by SETD8 is involved in maintaining genomic integrity. H4K20me1 was present throughout preimplantation development. In addition, reduction in the level of H4K20me1 by inhibition of SETD8 activity or a dominant-negative mutant of histone H4 resulted in developmental arrest at the S/G2 phase and excessive accumulation of DNA double-strand breaks. Together, our results suggest that H4K20me1, a type of epigenetic modification, is associated with the maintenance of genomic integrity and is essential for preimplantation development. A better understanding of the mechanisms involved in maintaining genome integrity during preimplantation development could contribute to advances in reproductive medicine and technology

Differentiated adipose-derived stem cells promote peripheral nerve regeneration

13301甲第5170号博士（医学）金沢大学博士論文要旨Abstract 以下に掲載：Muscle & Nerve 62(1) pp.119-127 2020. Wiley. 共著者：Daiki Yamamoto, Kaoru Tada, Seigo Suganuma, Katsuhiro Hayashi,Tadahiro Nakajima, Mika Nakada, Masashi Matsuta, Hiroyuki Tsuchiy

Synthesis of 8-deoxypumiliotoxin 193H and 9-deoxyhomopumiliotoxin 207O

The asymmetric synthesis of 8-deoxypumiliotoxin 193H and 9-deoxyhomopumiliotoxin 207O has been achieved, starting from both enantiomers of (+)- and (−)-10. Enantiomerically pure alcohols (+)- and (−)-10 were obtained by lipase-mediated kinetic resolution of racemic 10, which was prepared in 3 steps from new lactam-type building block (−)-8 in a highly stereoselective manner