363 research outputs found
Algorithm for deriving magnetic space-group information
A crystal symmetry search is crucial for computational crystallography and
materials science. Although algorithms and implementations for the crystal
symmetry search have been developed, their extension to magnetic space groups
(MSGs) remains limited. In this paper, algorithms for determining magnetic
symmetry operations of magnetic crystal structures, identifying magnetic
space-group types of given MSGs, and symmetrizing the magnetic crystal
structures using the MSGs are presented. The determination of magnetic symmetry
operations is numerically stable and is implemented with minimal modifications
from the existing crystal symmetry search. Magnetic space-group types are
identified by combining space-group type identification and the use of affine
normalizers. Point coordinates and magnetic moments of the magnetic crystal
structures are symmetrized by projection operators for the MSGs. An
implementation is distributed with a permissive free software license in spglib
v2.0.2: https://github.com/spglib/spglib
Zero Poynting vector Eā„H Beltrami field cylindrical cavity resonators
In this paper, we present novel cylindrical cavity resonators accommodating spatially and temporally zero Poynting vector Beltrami standing waves with the parallel electric and magnetic fields (Eā„H). We introduce the special boundary conditions, i.e., longitudinal electromagnetic conductor (LEMC) on which zero longitudinal electromagnetic components are enforced and circumferential electromagnetic conductor (CEMC) on which zero circumference electromagnetic components are enforced in an axisymmetric waveguide system, and show that the zero Poynting vector Eā„H Beltrami standing wave is generated as a superposition of dual degenerated axisymmetric TM and TE standing waves in a cylindrical resonator using the LEMC and CEMC boundary conditions. We present physical implementation methods of the LEMC and CEMC boundary conditions composed of the circumferentially arranged corrugations and the concentrically aligned cylindrical thin fins, respectively. In addition, we numerically demonstrate the Beltrami standing field generation and reveal its peculiar electromagnetic properties: the spatially and temporally Eā„H with zero Poynting vector distribution, identical electric and magnetic energy density distributions, and zero local reactive energy flow
Quarter-wavelength EāH Beltrami cavity resonators
In this paper, we present the design and implementation methods of quarter-wavelength resonators accommodating Beltrami standing waves with parallel electric and magnetic (EāH) fields. The resonator is bounded by the quarter-wavelength longitudinal electromagnetic conductor (LEMC), the circumferential electromagnetic conductor (CMEC), and the radial electromagnetic conductor (REMC). The LEMC, CEMC, and REMC boundaries are artificially implemented by the circumferentially aligned corrugation, concentrically aligned circular fins, and axisymmetrically aligned radial fins, respectively. The coupling control methods by introducing slots in the CEMC and REMC with the external TM01 and TE01 circular waveguides are presented. We design the quarter-wavelength resonators with the implemented LEMC, CEMC, and REMC boundaries with controlled external couplings and numerically demonstrate their EāH properties, which confirms the validity of the proposed design method
High expression of a novel carnitine palmitoyltransferase I like protein in rat brown adipose tissue and heart: isolation and characterization of its cDNA clone
AbstractTo characterize energy metabolism in rat brown adipose tissue (BAT), we carried out differential screening of a cDNA library of BAT with a cDNA probe of white adipose tissue (WAT) and isolated one cDNA clone. It contained a single open reading frame of 2,316 bases which encodes a protein of 88.2 kDa. The predicted amino acid sequence showed the highest homology (62.6%) with that of rat carnitine palmitoyltransferase I (CPTI). The transcript corresponding to this cDNA was found to be abundantly expressed in BAT and heart. Therefore, the isolated clone is concluded to encode a CPTI like protein expressed in BAT and heart
Symmetry Analysis with Spin Crystallographic Groups: Disentangling Spin-Orbit-Free Effects in Emergent Electromagnetism
Recent studies identified spin-order-driven phenomena such as spin-charge
interconversion without relying on the relativistic spin-orbit interaction.
Those physical properties can be prominent in systems containing light magnetic
atoms due to sizable exchange splitting and may pave the way for realizations
of giant responses correlated with the spin degree of freedom. In this paper,
we present a systematic symmetry analysis based on the spin crystallographic
groups and identify physical property of a vast number of magnetic materials up
to 1500 in total. Absence of spin-orbital entanglement leads to the spin
crystallographic symmetry having richer property compared to the well-known
magnetic space group symmetry. By decoupling the spin and orbital degrees of
freedom, our analysis enables us to take a closer look into the relation
between the dimensionality of spin structures and the resultant physical
properties and to identify the spin and orbital contributions separately. In
stark contrast to the established analysis with magnetic space groups, the spin
crystallographic group manifests richer symmetry including spin translation
symmetry and leads to nontrivial emergent responses. For representative
examples, we discuss geometrical nature of the anomalous Hall effect and
magnetoelectric effect, and classify the spin Hall effect arising from the
spontaneous spin-charge coupling. Using the power of computational analysis, we
apply our symmetry analysis to a wide range of magnets, encompassing complex
magnets such as those with noncoplanar spin structures as well as collinear and
coplanar magnets. We identify emergent multipoles relevant to physical
responses and argue that our method provides a systematic tool for exploring
sizable electromagnetic responses driven by spin ordering.Comment: 58 pages, 7 figures, 6 table
Interdisciplinary therapy for severe periodontitis with Angle Class II Division 1 malocclusion : A case report with 7-year follow-up
Background: Previous studies have suggested that occlusal discrepancy is a risk factor contributing to periodontal disease. 1-3 Occlusal discrepancy could increase the risk of infrabony defects. This is a case of a patient with severe periodontitis who exhibited many infrabony defects in the molar region due to malocclusion-induced trauma. Here, we report the 7-year prognosis of the patient after periodontal regenerative and comprehensive orthodontic therapies for functional recovery with implant prosthodontics.
Case Description: A 54-year-old female presented with the chief complaint of masticatory disturbance. In the molar region, significant tooth mobility, deep periodontal pockets, and infrabony defects were observed. She had excessive overjet, resulting in collapse of anterior guidance. Malocclusion was considered to be an exacerbating factor of the infrabony defects. After initial periodontal therapy, we performed periodontal regenerative therapy in the mandibular molar regions. We carefully placed implants in a position in the maxillary molar region that would ensure an appropriate anterior dental relationship after orthodontic treatment. Comprehensive orthodontic treatment was subsequently performed using implants as anchoring units. Then, definitive surgery was performed on the mandibular molars before placing the final prosthesis. A favorable periodontal condition and a stable occlusion have been maintained for the 7-year post-treatment period.
Practical Implications: Comprehensive and interdisciplinary treatment enables stable occlusion and establishment of periodontal tissue and peri-implant tissues with high cleansability, even in patients with severe periodontitis and malocclusion. In the present case, a favorable long-term treatment outcome can be expected
Algorithm for spin symmetry operation search
A spin space group provides a suitable way to fully exploit the symmetry of a
spin arrangement with a negligible spin-orbit coupling. There has been a
growing interest in applying spin symmetry analysis with the spin space group
in the field of magnetism. However, there is no established algorithm to search
for spin symmetry operations of the spin space group. This paper presents an
exhaustive algorithm for determining spin symmetry operations of commensurate
spin arrangements. The present algorithm searches for spin symmetry operations
from the symmetry operations of a corresponding nonmagnetic crystal structure
and determines their spin-rotation parts by solving a Procrustes problem. An
implementation is distributed under a permissive free software license in
spinspg v0.1.1: https://github.com/spglib/spinspg.Comment: The implementation will be released after publicatio
Comprehensive treatment for severe periodontitis with pathologic tooth migrationārelated bimaxillary protrusion : A case report with 3-year follow-up
Background: Patients with severe periodontitis often experience pathologic tooth migration (PTM), which impairs esthetics and leads to occlusal disharmony (e.g., premature contacts and/or traumatic occlusion) that can further exacerbate periodontitis. Here, we describe a patient who exhibited severe periodontitis with PTM-related bimaxillary protrusion. This report includes 3-year clinical outcomes following periodontal regenerative therapy, implant-anchored orthodontic therapy, and implant prosthodontics intended to achieve both functional and esthetic improvements.
Case Description: A 63-year-old woman presented with the chief complaint of upper anterior tooth mobility. Clinical examination revealed excessive tooth mobility, deep periodontal pockets, and infrabony defects in all teeth. All teeth exhibited PTM; the mandibular anterior teeth exhibited marked protrusion caused by the progression of periodontitis. After initial periodontal therapy, periodontal regenerative therapy was performed in all molar regions. At 9 and 6 months postoperatively, comprehensive orthodontic treatment was initiated for the mandible and maxilla, respectively, using orthodontic anchorage devices to achieve acceptable functional occlusion. After orthodontic treatment, staged guided bone regeneration was performed and dental implants were placed in the severely resorbed maxillary anterior ridge. This comprehensive treatment yielded favorable periodontal conditions, stable occlusion, and good esthetic outcomes.
Practical Implications: Favorable esthetics, stable occlusion, and highly cleansable periodontal tissues were achieved with well-planned interdisciplinary and comprehensive treatment, although the patient had severe periodontitis and PTM-related bimaxillary protrusion
FIGNL1 AAA+ ATPase remodels RAD51 and DMC1 filaments in pre-meiotic DNA replication and meiotic recombination
Ito M., Furukohri A., Matsuzaki K., et al. FIGNL1 AAA+ ATPase remodels RAD51 and DMC1 filaments in pre-meiotic DNA replication and meiotic recombination. Nature Communications 14, 6857 (2023); https://doi.org/10.1038/s41467-023-42576-w.The formation of RAD51/DMC1 filaments on single-stranded (ss)DNAs essential for homology search and strand exchange in DNA double-strand break (DSB) repair is tightly regulated. FIGNL1 AAA+++ ATPase controls RAD51-mediated recombination in human cells. However, its role in gametogenesis remains unsolved. Here, we characterized a germĀ line-specific conditional knockout (cKO) mouse of FIGNL1. Fignl1 cKO male mice showed defective chromosome synapsis and impaired meiotic DSB repair with the accumulation of RAD51/DMC1 on meiotic chromosomes, supporting a positive role of FIGNL1 in homologous recombination at a post-assembly stage of RAD51/DMC1 filaments. Fignl1 cKO spermatocytes also accumulate RAD51/DMC1 on chromosomes in pre-meiotic S-phase. These RAD51/DMC1 assemblies are independent of meiotic DSB formation. We also showed that purified FIGNL1 dismantles RAD51 filament on double-stranded (ds)DNA as well as ssDNA. These results suggest an additional role of FIGNL1 in limiting the non-productive assembly of RAD51/DMC1 on native dsDNAs during pre-meiotic S-phase and meiotic prophase I
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