30 research outputs found
Rotation and electric-field responses and absolute enantioselection in chiral crystals
Microscopic origin of chirality and possible electric-field induced rotation
and rotation-field induced electric polarization are investigated. By building
up a realistic tight-binding model for elemental Te crystal in terms of
symmetry-adopted basis, we identify the microscopic origin of the chirality and
essential couplings among polar and axial vectors with the same time-reversal
properties. Based on this microscopic model, we elucidate quantitatively that
the inter-band process, driven by the nearest-neighbor spin-dependent imaginary
hopping, is the key factor in the electric-field induced rotation and its
inverse response. From the symmetry point of view, these couplings are
characteristic common to any chiral material, leading to a possible
experimental approach to achieve absolute enantioselection by simultaneously
applied electric and rotation fields, or magnetic field and electric current,
and so on, as a conjugate field of the chirality.Comment: 5figure
Planar Hall effect and magnetoresistance induced by ferroaxial ordering
Transport property under ferroaxial ordering in an external magnetic field is
theoretically investigated. After presenting the relation between the
magnetoconductivity tensor and ferroaxial moment from the symmetry viewpoint,
we analyze the behavior of the planar Hall effect and magnetoconductivity for a
general five -orbital tight-binding model under the point group , where the ferroaxial moment is activated. We show that the crystalline
electric field that arises from the symmetry reduction from to
is essential for the ferroaxial-related magnetotransport, while
the relativistic spin-orbit coupling is not required. We also compare the
planar Hall effect driven by the ferroaxial moment with the conventional Hall
effect, the latter of which does not require the ferroaxial moment. The present
results provide characteristic transport properties in the ferroaxial systems,
which can be observed in various candidate materials like CaIrO.Comment: 15 pages, 6 figures, 2 table
Highly Purified Inner-Arm Dynein E from Chlamydomonas Reinhardtii Studied with in vitro Motility Assay
Activin E Controls Energy Homeostasis in Both Brown and White Adipose Tissues as a Hepatokine
Brown adipocyte activation or beige adipocyte emergence in white adipose tissue (WAT) increases energy expenditure, leading to a reduction in body fat mass and improved glucose metabolism. We found that activin E functions as a hepatokine that enhances thermogenesis in response to cold exposure through beige adipocyte emergence in inguinal WAT (ingWAT). Hepatic activin E overexpression activated thermogenesis through Ucp1 upregulation in ingWAT and other adipose tissues including interscapular brown adipose tissue and mesenteric WAT. Hepatic activin E-transgenic mice exhibited improved insulin sensitivity. Inhibin βE gene silencing inhibited cold-induced Ucp1 induction in ingWAT. Furthermore, in vitro experiments suggested that activin E directly stimulated expression of Ucp1 and Fgf21, which was mediated by transforming growth factor-β or activin type I receptors. We uncovered a function of activin E to stimulate energy expenditure through brown and beige adipocyte activation, suggesting a possible preventive or therapeutic target for obesity