492 research outputs found
Dynamic recrystallization model during hot working by coupling phase-field method and finite element method
Multiscale model for hot–working, which can investigate the macroscopic mechanical behavior based on the microstructure evolution, has been developed by coupling the finite element (FE) method and phase–field (PF) method. Here, the microstructure evolutions in dynamic recrystallization are simulated by the multi–phase–field-dynamic recrystallization (MPF–DRX) model. The microscopic simulations are performed in every element used in the finite element simulations to calculate the macroscopic mechanical behaviors
Correction: A gold isocyanide complex with a pendant carboxy group: orthogonal molecular arrangements and hypsochromically shifted luminescent mechanochromism
Correction for 'A gold isocyanide complex with a pendant carboxy group: orthogonal molecular arrangements and hypsochromically shifted luminescent mechanochromism' by Tomohiro Seki et al., Chem. Commun., 2018, 54, 11136–11139
Primary arm array during directional solidification of a single-crystal binary alloy: Large-scale phase-field study
AbstractPrimary arm arrays formed during the directional solidification of a single-crystal binary alloy were investigated by performing large-scale phase-field simulations using the GPU supercomputer TSUBAME2.5 at Tokyo Institute of Technology. The primary arm array and spacing were investigated by Voronoi decomposition and Delaunay triangulation, respectively. It was concluded that a hexagonal array was dominant for both the dendrite and cell structures and that penta–hepta defects, which are typical defects in hexagonal patterns, were formed. The primary arms continuously moved such that the number of hexagons increased, and the distribution of primary arm spacing became uniform over time even after the number of primary arms was constant. The order of array was highest in the growth condition of the dendrite close to the cell-to-dendrite transition region. In addition, we proposed a realistic and accurate evaluation method of primary arm array by removing small sides from the Voronoi polygons
Long-term Observation of Osteomalacia Caused by Adefovir-Induced Fanconi’s Syndrome
A 64-year-old man suffering polyarthralgia and bone pain was referred to our hospital. Renal dysfunction,
hypophosphatemia and increased levels of bone alkaline phosphatase were found. The patientʼs serum creatinine level had gradually increased after the initiation of adefovir dipivoxil administration for hepatitis B. In agreement with multifocal uptakes of bone scintigraphy, iliac bone biopsy revealed an abnormal increase in osteoid tissues. Reducing the dose of adefovir and initiating the administration of eldecalcitol were effective for reducing proteinuria and glucosuria, and for ameliorating bone pain with an increase in serum phosphate level. This case first showed a clinical course of hypophosphatemic osteomalacia caused by secondary Fanconiʼs syndrome for 8 years after adefovir administration. Early diagnosis is important for the reversibility of bone damage and for a better renal prognosis
Synthesis and Evaluation of 1,3a,6a-triazapentalene (TAP)-bonded system
A method of synthesizing a directly connected 1,3a,6a-triazapentalene (TAP) ring system as a linearly bonded aromatic system with a planar form was established. Various TAP-dimers and a 2-alkyl-TAP-trimer were synthesized and their fluorescence properties were evaluated. Although the direct connection of the TAP ring with other TAP rings did not affect the fluorescence properties in diluted solvent, TAP-dimers showed unique fluorescence properties derived from the aggregation state under highly concentrated conditions. In particular, TAP-dimer 5f showed aggregation-induced emission in highly concentrated solution, and 5b showed typical mechanochromic fluorescence in the solid state despite their compact molecular size
Relationship between strain rate concentration factor and stress concentration factor
In this study, the strain rate concentration is considered for high speed tensile test, which is now being recognized as a standard testing method. To evaluate the impact strength of engineering materials under high impact speed, Izod and Charpy tests are unsuitable since they cannot control the impact speeds and therefore do not coincide with the real failure of real products. For smooth specimens, the strain rate can be determined from the tensile speed u/t and specimen length l as ̇smooth =u/tl. For notched specimens, however, the strain rate at the notch root enotch should be analyzed accurately. In this study, therefore, the strain rate concentration factor defined as Kte=enotch/esmooth is studied with varying the notch geometry and specimen length. It is found that the strain concentration factor Kte can be estimated from stress concentration factor Kt
An isomorphous replacement method for efficient de novo phasing for serial femtosecond crystallography.
SACLAのX線自由電子レーザーを用いた新規タンパク質立体構造決定に世界で初めて成功. 京都大学プレスリリース. 2015-09-14.Serial femtosecond crystallography (SFX) with X-ray free electron lasers (XFELs) holds great potential for structure determination of challenging proteins that are not amenable to producing large well diffracting crystals. Efficient de novo phasing methods are highly demanding and as such most SFX structures have been determined by molecular replacement methods. Here we employed single isomorphous replacement with anomalous scattering (SIRAS) for phasing and demonstrate successful application to SFX de novo phasing. Only about 20,000 patterns in total were needed for SIRAS phasing while single wavelength anomalous dispersion (SAD) phasing was unsuccessful with more than 80,000 patterns of derivative crystals. We employed high energy X-rays from SACLA (12.6 keV) to take advantage of the large anomalous enhancement near the LIII absorption edge of Hg, which is one of the most widely used heavy atoms for phasing in conventional protein crystallography. Hard XFEL is of benefit for de novo phasing in the use of routinely used heavy atoms and high resolution data collection
Gain-of-function IKBKB mutation causes human combined immune deficiency
Genetic mutations account for many devastating early onset immune deficiencies. In contrast, less severe and later onset immune diseases, including in patients with no prior family history, remain poorly understood. Whole exome sequencing in two cohorts of such patients identified a novel heterozygous de novo IKBKB missense mutation (c.607G>A) in two separate kindreds in whom probands presented with immune dysregulation, combined T and B cell deficiency, inflammation, and epithelial defects. IKBKB encodes IKK2, which activates NF-κB signaling. IKK2V203I results in enhanced NF-κB signaling, as well as T and B cell functional defects. IKK2V203 is a highly conserved residue, and to prove causation, we generated an accurate mouse model by introducing the precise orthologous codon change in Ikbkb using CRISPR/Cas9. Mice and humans carrying this missense mutation exhibit remarkably similar cellular and biochemical phenotypes. Accurate mouse models engineered by CRISPR/Cas9 can help characterize novel syndromes arising from de novo germline mutations and yield insight into pathogenesis
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