28 research outputs found
Fate of spin polarization in a relativistic fluid: An entropy-current analysis
We derive relativistic hydrodynamic equations with a dynamical spin degree of
freedom on the basis of an entropy-current analysis. The first and second laws
of local thermodynamics constrain possible structures of the constitutive
relations including a spin current and the antisymmetric part of the
(canonical) energy-momentum tensor. Solving the obtained hydrodynamic equations
within the linear-mode analysis, we find spin-diffusion modes, indicating that
spin density is damped out after a characteristic time scale controlled by
transport coefficients introduced in the antisymmetric part of the
energy-momentum tensor in the entropy-current analysis. This is a consequence
of mutual convertibility between spin and orbital angular momentum.Comment: 7 page
Gyrohydrodynamics: Relativistic spinful fluid with strong vorticity
We develop a relativistic (quasi-)hydrodynamic framework, dubbed the
gyrohydrodynamics, to describe fluid dynamics of many-body systems with spin
under strong vorticity based on entropy-current analysis. This framework
generalizes the recently-developed spin hydrodynamics to the regime where the
spin density is at the leading order in derivatives but suppressed by another
small parameter, the Planck constant , due to its quantum nature. Our
analysis shows that the complete first-order constitutive relations of
gyrohydrodynamics involve seventeen transport coefficients and are highly
anisotropic
Fabrication of Ultrafine Carbon Fibers Possessing a Nanoporous Structure from Electrospun Polyvinyl Alcohol Fibers Containing Silica Nanoparticles
Ultrafine carbon fibers with a nanoporous structure were fabricated by the template method using silica nanoparticles (NPs) embedded in fibers of approximate diameter 500 nm, electrospun from an aqueous solution of polyvinyl alcohol, CoCl2, silica NPs, and N,N-dimethylformamide. Black, conductive fibers were obtained by heat treatment in air and a chemical vapor deposition reaction under methanol vapor for more than 5 h. Transmission electron microscopy (TEM) demonstrated that the fabricated fibers after silica removal had a porous structure originating from 15 nm diameter silica NPs. Energy dispersive X-ray analysis combined with TEM confirmed the removal of silica from the fibers by NaOH treatment at 80°C. Total surface area and total pore volume of the fibers after silica removal, determined by nitrogen adsorption measurement, were 318 m2/g and 1.67 cm3/g, respectively. The sheet resistivities of the fabricated fibers were 35.1–477 Ω/□, which were relatively high, compared with that reported for polyacrylonitrile-based fibers carbonized at 800°C. D and G bands detected in the Raman spectrum of the NaOH-treated fibers showed that the prepared carbon fibers were more crystalline than natural carbonaceous materials
Human Herpesvirus 6-Associated Hemophagocytic Syndrome in a Healthy Adult
Virus-associated hemophagocytic syndrome is a fulminant disorder associated with systemic viral infection and characterized pathologically by multiple-organ infiltration of hemophagocytic histiocytes into the lymphoreticular tissues. This is the first report of a previously healthy adult in whom Human herpesvirus 6 reactivation induced this syndrome with severe hemodynamic and respiratory distress
Fabrication of Ultrafine Carbon Fibers Possessing a Nanoporous Structure from Electrospun Polyvinyl Alcohol Fibers Containing Silica Nanoparticles
Ultrafine carbon fibers with a nanoporous structure were fabricated by the template method using silica nanoparticles (NPs) embedded in fibers of approximate diameter 500 nm, electrospun from an aqueous solution of polyvinyl alcohol, CoCl 2 , silica NPs, and N,N-dimethylformamide. Black, conductive fibers were obtained by heat treatment in air and a chemical vapor deposition reaction under methanol vapor for more than 5 h. Transmission electron microscopy (TEM) demonstrated that the fabricated fibers after silica removal had a porous structure originating from 15 nm diameter silica NPs. Energy dispersive X-ray analysis combined with TEM confirmed the removal of silica from the fibers by NaOH treatment at 80 ∘ C. Total surface area and total pore volume of the fibers after silica removal, determined by nitrogen adsorption measurement, were 318 m 2 /g and 1.67 cm 3 /g, respectively. The sheet resistivities of the fabricated fibers were 35.1-477 Ω/◻, which were relatively high, compared with that reported for polyacrylonitrilebased fibers carbonized at 800 ∘ C. D and G bands detected in the Raman spectrum of the NaOH-treated fibers showed that the prepared carbon fibers were more crystalline than natural carbonaceous materials
Identification of Human Herpesvirus 6 Latency-Associated Transcripts
Four kinds of latency-associated transcripts of human herpesvirus 6 were identified which were detected only in latently infected cells. Although they were oriented in the same direction as the immediate-early 1 and 2 (IE1/IE2) genes and shared their protein-coding region with IE1/IE2, their transcription start sites and exon(s) were latency associated