78 research outputs found
Two-step forming for improvement of forming limit in rotary nosing with relieved die for fabrication of axisymmetric and eccentric nosed tubes
This paper presents application of two-step forming for improving the forming limit in rotary nosing with a relieved die. Nosing is one method which is used for reducing the diameter of a tube tip. âTwo-step nosingâ is composed of two stages and different dies are applied for the two stages. The die shapes are determined based on the occurrence tendency of defects in âone-step nosingâ, where only one die is used through the whole process. In this research, a series of experiments and numerical analyses of one-step nosing was carried out for investigating the mechanism of the occurrence of defects. As a result, it is revealed that the occurrence of defects was highly relevant with the contact area between the die and tube. Based on the result of one-step nosing, the optimum die shapes were determined for the two stages, and then âtwo-step nosingâ improved the forming limit 9% higher than one-step nosing under the optimum condition. Furthermore, âtwo-step nosingâ was experimentally applied for forming eccentric nosed tubes, and its superiority was verified
Dichotomy Between Orbital and Magnetic Nematic Instabilities in BaFe2S3
Nematic orders emerge nearly universally in iron-based superconductors, but
elucidating their origins is challenging because of intimate couplings between
orbital and magnetic fluctuations. The iron-based ladder material BaFe2S3,
which superconducts under pressure, exhibits antiferromagnetic order below TN ~
117K and a weak resistivity anomaly at T* ~ 180K, whose nature remains elusive.
Here we report angle-resolved magnetoresistance (MR) and elastoresistance (ER)
measurements in BaFe2S3, which reveal distinct changes at T*. We find that MR
anisotropy and ER nematic response are both suppressed near T*, implying that
an orbital order promoting isotropic electronic states is stabilized at T*.
Such an isotropic state below T* competes with the antiferromagnetic order,
which is evidenced by the nonmonotonic temperature dependence of nematic
fluctuations. In contrast to the cooperative nematic orders in spin and orbital
channels in iron pnictides, the present competing orders can provide a new
platform to identify the separate roles of orbital and magnetic fluctuations.Comment: 7 pages 5 figures, to be published in Phys. Rev. Re
A Novel Curcumin Formulation, ASD-Cur, Suppressed the Development of Systolic Dysfunction After Myocardial Infarction in Rats
Impact of Cerebral Microbleeds in Stroke Patients with Atrial Fibrillation
OBJECTIVES: Cerebral microbleeds are associated with the risks of ischemic stroke and intracranial hemorrhage, causing clinical dilemmas for antithrombotic treatment decisions. We aimed to evaluate the risks of intracranial hemorrhage and ischemic stroke associated with microbleeds in patients with atrial fibrillation treated with Vitamin K antagonists, direct oral anticoagulants, antiplatelets, and combination therapy (i.e. concurrent oral anticoagulant and antiplatelet) METHODS: We included patients with documented atrial fibrillation from the pooled individual patient data analysis by the Microbleeds International Collaborative Network. Risks of subsequent intracranial hemorrhage and ischemic stroke were compared between patients with and without microbleeds, stratified by antithrombotic use. RESULTS: A total of 7,839 patients were included. The presence of microbleeds was associated with an increased relative risk of intracranial hemorrhage (aHR 2.74, 95% confidence interval 1.76 - 4.26) and ischemic stroke (aHR 1.29, 95% confidence interval 1.04 - 1.59). For the entire cohort, the absolute incidence of ischemic stroke was higher than intracranial hemorrhage regardless of microbleeds burden. However, for the subgroup of patients taking combination of anticoagulant and antiplatelet therapy, the absolute risk of intracranial hemorrhage exceeded that of ischemic stroke in those with 2-4 microbleeds (25 vs 12 per 1,000 patient-years) and â„11 microbleeds (94 vs 48 per 1,000 patient-years). INTERPRETATION: Patients with atrial fibrillation and high burden of microbleeds receiving combination therapy have a tendency of higher rate of intracranial hemorrhage than ischemic stroke, with potential for net harm. Further studies are needed to help optimize stroke preventive strategies in this high-risk group. This article is protected by copyright. All rights reserved
Biosorption of Lanthanides from Aqueous Solutions Using Pretreated Buccinum tenuissimum Shell Biomass
Biosorption experiment from aqueous solutions containing known amount of rare earth elements (REEs) using pre-treated Buccinum tenuissimum shell was explored to evaluate the efficiency of shell biomass as sorbent for REEs. In this work, four kinds of sieved shell samples: (a) âGround original sampleâ, (b) âHeat-treatment (480âC, 6 hours) sampleâ, (c) âHeat-treatment (950âC, 6 hours) sampleâ and (d) âHeat-treatment (950âC, 6 hours) and water added sampleâ were used. Furthermore, to confirm the characteristics of the shell biomass, the crystal structure, the surface morphology, and the specific surface area of these shell samples were determined. Consequently, the following matters have been mainly clarified. (1) The crystal structure of the shell biomass was transformed from aragonite (CaCO3) into calcite (CaCO3) phase by heat-treatment (480âC, 6 hours); then mainly transformed into calcium oxide (CaO) by heat-treatment (950âC, 6 hours), and calcium hydroxide (Ca(OH)2) by heat-treatment (950âC, 6 hours) and adding water. (2) The shell biomass showed excellent sorption capacity for lanthanides. (3) Adsorption isotherms using the shell biomass can be described by Langmuir and Freundlich isotherms satisfactorily for lanthanides except âheat-treatment (950âC, 6 hours) sampleâ. (4) Shell biomass (usually treated as waste material) can be an efficient sorbent for lanthanides in future
Preventive effect of curcumin and its highly bioavailable preparation on hearing loss induced by single or repeated exposure to noise: AÂ comparative and mechanistic study
We sought to determine the preventive effects of curcumin and its highly bioavailable preparation on noise-induced hearing loss in a novel murine model of permanent hearing loss developed by repeated exposure to noise. Upon exposure to noise (8-kHz octave band noise, 90Â dB sound pressure level, 1Â h), hearing ability was impaired in a temporary and reversible manner. During repeated noise exposure (1-h exposure per day, 5 days), there was a progressive increase in the auditory threshold shift at 12 and 20Â kHz. The threshold shift persisted for at least 6 days after noise exposure. Oral administration of curcumin for 3 days before and each day during noise exposure significantly alleviated the hearing loss induced by repeated noise exposure. Curcumin abolished intranuclear translocation of nuclear factor-ÎșB-p65 and generation of 4-hydroxynonenal-adducted proteins found in the cochlea after noise exposure. TheracurminÂź, a highly absorbable and bioavailable preparation of curcumin, had strong preventive effects on hearing loss induced by repeated noise exposure. Together, these data suggest that curcumin exerts a preventive effect on noise-induced hearing loss and is therefore a good therapeutic candidate for preventing sensorineural hearing loss
Biosorption of lanthanides from Aqueous Solutions using Pretreated Buccinum tenuissimum Shell Biomass
Adverse reactions to mRNA coronavirus disease 2019 (COVID-19) vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 576 medical staff
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