29 research outputs found
Josephson junction in cobalt-doped BaFe2As2 epitaxial thin films on (La, Sr)(Al, Ta)O3 bicrystal substrates
Josephson junctions were fabricated in epitaxial films of cobalt-doped
BaFe2As2 on [001]-tilt (La,Sr)(Al,Ta)O3 bicrystal substrates. 10m-wide
microbridges spanning a 30-degrees-tilted bicrystal grain boundary (BGB bridge)
exhibited resistively-shunted-junction (RSJ)-like current-voltage
characteristics up to 17 K, and the critical current was suppressed remarkably
by a magnetic field. Microbridges without a BGB did not show the RSJ-like
behavior, and their critical current densities were 20 times larger than those
of BGB bridges, confirming BGB bridges display a Josephson effect originating
from weakly-linked BGB
Biaxially textured cobalt-doped BaFe2As2 films with high critical current density over 1 MA/cm2 on MgO-buffered metal-tape flexible substrates
High critical current densities (Jc) > 1 MA/cm2 were realized in cobalt-doped
BaFe2As2 (BaFe2As2:Co) films on flexible metal substrates with
biaxially-textured MgO base-layers fabricated by an ion-beam assisted
deposition technique. The BaFe2As2:Co films showed small in-plane crystalline
misorientations (delta fai BaFe2As2:Co) of ~3o regardless of doubly larger
misorientaions of the MgO base-layers (delta fai MgO = 7.3o), and exhibited
high self-field Jc up to 3.5 MA/cm2 at 2 K. These values are comparable to that
on MgO single crystals and the highest Jc among iron pnictide superconducting
tapes and wires ever reported. High in-field Jc suggests the existence of
c-axis correlated vortex pinning centers.Comment: Published in Appl. Phys. Let
Increased urine level of amino-terminal peptide derivatives of type III procollagen in patients with liver diseases.
The amino-terminal peptides of type III procollagen (PIIIP) in the urine of 40 patients with various liver diseases were determined with a commercial radioimmunoassay kit. The level of urinary PIIIP (uPIIIP) was correlated well with serum PIIIP (sPIIIP) in 9 patients, the coefficient of correlation being r = 0.836 (p less than 0.01) and the regression line being y = 1.42x + 24. Urinary PIIIP consisted of at least 4 different molecular species with molecular weights of 49 k, 18 k, 10 k and 4.6 k as estimated by column chromatography on Sephadex G-100. Furthermore. uPIIIP was found to be significantly elevated in acute hepatitis, chronic hepatitis, liver cirrhosis, hepatocellular carcinoma and other liver diseases, in which the elevation of sPIIIP has been reported by others. The mean values +/- standard deviations of uPIIIP were 44.0 +/- 32.0, 60.4 +/- 32.0, 62.0 +/- 46.5, 53.0 +/- 27.1 and 48.1 +/- 22.8 ng/ml for the respective liver diseases, and 13.2 +/- 4.5 for the non-hepatic disease group
DC superconducting quantum interference devices fabricated using bicrystal grain boundary junctions in Co-doped BaFe2As2 epitaxial films
DC superconducting quantum interference devices (dc-SQUIDs) were fabricated
in Co-doped BaFe2As2 epitaxial films on (La, Sr)(Al, Ta)O3 bicrystal substrates
with 30deg misorientation angles. The 18 x 8 micro-meter^2 SQUID loop with an
estimated inductance of 13 pH contained two 3 micro-meter wide grain boundary
junctions. The voltage-flux characteristics clearly exhibited periodic
modulations with deltaV = 1.4 micro-volt at 14 K, while the intrinsic flux
noise of dc-SQUIDs was 7.8 x 10^-5 fai0/Hz^1/2 above 20 Hz. The rather high
flux noise is mainly attributed to the small voltage modulation depth which
results from the superconductor-normal metal-superconductor junction nature of
the bicrystal grain boundary
Percutaneous Transluminal Angioscopy During Coronary Intervention
To investigate the feasibility of angioscopic-guided percutaneous
transluminal coronary angioplasty and to elucidate the mechanism
of efficacy of coronary stenting for acute myocardial infarction,
we performed coronary angioscopy in 102 patients with stable
angina or acute myocardial infarction. Thrombi and intimal flaps
were observed in most patients after coronary angioplasty. Large
intimal splits were seen in one third of patients. Stents were
inserted in 10 patients who were revealed to have a large flap or
protruding split to the inner lumen. Thrombolytic agents were
administered in 2 patients with large thrombi. Additional
treatments were required in 32% of patients. No acute
myocardial infarction or unstable angina occurred in patients
during hospitalization. Thus, angioscopy of the coronary lumen
enables clinicians to determine the most appropriate and least
risky coronary intervention strategy. In patients with acute
myocardial infarction, angioscopy revealed occlusive or protruding
thrombi in 34 of 35 patients. The protruding thrombi disappeared
after stenting. The frequency of large intimal flaps increased
after predilatation with balloon, but these disappeared after
stenting. The present angioscopic study demonstrates that the
coronary stent compresses the occlusive or protruding thrombi and
covers the ruptured thrombogenic plaque Consequently,
smooth-surfaced and wide vessel lumen are obtained
Spectral evolution of GRB 060904A observed with Swift and Suzaku -- Possibility of Inefficient Electron Acceleration
We observed an X-ray afterglow of GRB 060904A with the Swift and Suzaku
satellites. We found rapid spectral softening during both the prompt tail phase
and the decline phase of an X-ray flare in the BAT and XRT data. The observed
spectra were fit by power-law photon indices which rapidly changed from to within a few hundred
seconds in the prompt tail. This is one of the steepest X-ray spectra ever
observed, making it quite difficult to explain by simple electron acceleration
and synchrotron radiation. Then, we applied an alternative spectral fitting
using a broken power-law with exponential cutoff (BPEC) model. It is valid to
consider the situation that the cutoff energy is equivalent to the synchrotron
frequency of the maximum energy electrons in their energy distribution. Since
the spectral cutoff appears in the soft X-ray band, we conclude the electron
acceleration has been inefficient in the internal shocks of GRB 060904A. These
cutoff spectra suddenly disappeared at the transition time from the prompt tail
phase to the shallow decay one. After that, typical afterglow spectra with the
photon indices of 2.0 are continuously and preciously monitored by both XRT and
Suzaku/XIS up to 1 day since the burst trigger time. We could successfully
trace the temporal history of two characteristic break energies (peak energy
and cutoff energy) and they show the time dependence of while the following afterglow spectra are quite stable. This fact
indicates that the emitting material of prompt tail is due to completely
different dynamics from the shallow decay component. Therefore we conclude the
emission sites of two distinct phenomena obviously differ from each other.Comment: 19 pages, 9 figures, accepted for publication in PASJ (Suzaku 2nd
Special Issue
The presence of vermipodia-like processes on the free surfaces of multicellular spheroids composed of adult rat hepatocytes in the primary culture
The presence and function of vermipodia-like processes of hepatocytes-multicellular spheroids formed in primary culture was described. Cine microscopy and scanning electron microscopy revealed that about 1-5% hepatocytes in single cell after culture initiation already posessed the processes. The processes disappeared when the hepatocytes attached and spread, and than appeared again on the surface of multicellular spheroides. The processes were moving by extending, shrinking and twisting, and sometimes extended 50 um. Five to ten percent of spheroids had 1-5 processes. Occasional collision of two spheroids resulted in the fusion of spheroids after their processes intertwined, attached to the partner spheroid and shrunk. Electron microscopy revealed that the processes were larger in size than the numerous microvilli co-present on the free surface of spheroids and their cytoplasm had scarece orgalella. The morphological characterisitcs of the processes most resembled those of vermipodia reported in histiocytic leukemia cells