420 research outputs found
Phase Diagram of Pressure-Induced Superconductivity in EuFe2As2 Probed by High-Pressure Resistivity up to 3.2 GPa
We have constructed a pressuretemperature () phase diagram of
-induced superconductivity in EuFeAs single crystals, via
resistivity () measurements up to 3.2 GPa. As hydrostatic pressure is
applied, an antiferromagnetic (AF) transition attributed to the FeAs layers at
shifts to lower temperatures, and the corresponding resistive
anomaly becomes undetectable for 2.5 GPa. This suggests that the
critical pressure where becomes zero is about 2.5
GPa. We have found that the AF order of the Eu moments survives up to
3.2 GPa without significant changes in the AF ordering temperature
. The superconducting (SC) ground state with a sharp transition
to zero resistivity at 30 K, indicative of bulk
superconductivity, emerges in a pressure range from 2.5
GPa to 3.0 GPa. At pressures close to but outside the SC phase, the
curve shows a partial SC transition (i.e., zero resistivity is not
attained) followed by a reentrant-like hump at approximately
with decreasing temperature. When nonhydrostatic pressure with a uniaxial-like
strain component is applied using a solid pressure medium, the partial
superconductivity is continuously observed in a wide pressure range from 1.1
GPa to 3.2 GPa.Comment: 7 pages, 6 figures, accepted for publication in Physical Review B,
selected as "Editors' Suggestion
Evolutionarily Conserved Interaction between the Phosphoproteins and X Proteins of Bornaviruses from Different Vertebrate Species.
Bornavirus, a non-segmented, negative-strand RNA viruses, is currently classified into several genetically distinct genotypes, such as Borna disease virus (BDV) and avian bornaviruses (ABVs). Recent studies revealed that bornavirus genotypes show unique sequence variability in the putative 5' untranslated region (5' UTR) of X/P mRNA, a bicistronic mRNA for the X protein and phosphoprotein (P). In this study, to understand the evolutionary relationship among the bornavirus genotypes, we investigated the functional interaction between the X and P proteins of four bornavirus genotypes, BDV, ABV genotype 4 and 5 and reptile bornavirus (RBV), the putative 5' UTRs of which exhibit variation in the length. Immunofluorescence and immunoprecipitation analyses using mammalian and avian cell lines revealed that the X proteins of bornaviruses conserve the ability to facilitate the export of P from the nucleus to the cytoplasm via interaction with P. Furthermore, we showed that inter-genotypic interactions may occur between X and P among the genotypes, except for X of RBV. In addition, a BDV minireplicon assay demonstrated that the X and P proteins of ABVs, but not RBV, can affect the polymerase activity of BDV. This study demonstrates that bornaviruses may have conserved the fundamental function of a regulatory protein during their evolution, whereas RBV has evolved distinctly from the other bornavirus genotypes
Preliminary report on the Yamato-86032 lunar meteorite: I. Recovery, sample descriptions, mineralogy and petrography
A preliminary consortium examination of the largest lunar meteorite (Y-86032) recovered from the Yamato Mountains revealed that it is a feldspathic breccia, but rather resembles feldspathic fragmental breccias than regolith breccias. Y-86032 is a rugged grayish stone penetrated by numerous compact clast-laden impact melt glassy veins. Distributions of pyroxene and plagioclase chemical compositions are similar to those of Y-82192 and Y-82193,and clast-laden glassy veins and granulitic breccias are abundant. A large light clast in the first consortium sample is another feldspathic fragmental breccia similar to that found in Y-82192
A ring laser gyroscope without lock-in phenomenon
We theoretically and numerically study the effect of backscattering on
rotating ring lasers by employing the Maxwell-Bloch equations. We show that
frequency shifts due to the Sagnac effect incorporating the effect of
backscattering can be observed without lock-in phenomenon, if the strength of
backscattering originating in the bumps of the refractive index is larger than
a certain value. It is also shown that the experimental results corresponding
to the theoretical ones can actually be obtained by using a semiconductor
fiber-optic ring laser gyroscope.Comment: 9 pages, 6figure
Thermomechanical Characterization of Carbon Black Reinforced Rubbers During Rapid Adiabatic Straining
The thermo-mechanical properties of carbon black reinforced natural and styrene butadiene rubbers are investigated under rapid adiabatic conditions. Eleven carbon black grades with varying surface area and structure properties at 40 parts per hundred (phr) loading are studied and the unreinforced equivalents are included for reference. The results show a strong correlation of the modulus, mechanical hysteresis, temperature rise and calculated crystallinity of the rubbers measured in tensile extension with strain amplification factors. This highlights the influence of matrix overstraining on microstructural deformations of the rubber upon extension. The strain amplification factors are calculated via the Guth-Gold equation directly from carbon black type and loading, allowing a correlation of the fundamental morphological properties of carbon black with thermal and mechanical properties of rubbers upon extension. Analysis of the thermal measurements of the rubber compounds upon extension and retraction and contrasting between crystallizing and non-crystallizing rubbers reveals that a substantial irreversible heat generation is present upon extension of the rubber compounds. These irreversible effects most likely originate from microstructural damage mechanisms which have been proposed to account for the Mullins Effect in particle reinforced rubbers
Infrastructure Upgrades and Foreclosure with Coexistence of Service-Based and Facility-Based Firms
An RNA-dependent RNA polymerase gene in bat genomes derived from an ancient negative-strand RNA virus
Endogenous bornavirus-like L (EBLL) elements are inheritable sequences derived from ancient bornavirus L genes that encode a viral RNA-dependent RNA polymerase (RdRp) in many eukaryotic genomes. Here, we demonstrate that bats of the genus Eptesicus have preserved for more than 11.8 million years an EBLL element named eEBLL-1, which has an intact open reading frame of 1,718 codons. The eEBLL-1 coding sequence revealed that functional motifs essential for mononegaviral RdRp activity are well conserved in the EBLL-1 genes. Genetic analyses showed that natural selection operated on eEBLL-1 during the evolution of Eptesicus. Notably, we detected efficient transcription of eEBLL-1 in tissues from Eptesicus bats. To the best of our knowledge, this study is the first report showing that the eukaryotic genome has gained a riboviral polymerase gene from an ancient virus that has the potential to encode a functional RdRp
Prevalence of Antimicrobial Resistance in Haemophilus influenzae and Streptococcus pneumoniae : Comparison of Clinical Isolates of Japan and The Philippines
For clinical isolates of Haemophilus influenzae and Streptococcus pneumoniae in Japan (356 and 179 strains, respectively) and in the Philippines (98 and 59 strains, respectively), minimum inhibitory concentrations (MICs) of ampicillin, cefazolin, cefotiam, ceftizoxim, ofloxacin, erythromycin, and minocycline were examined. The rates of β-lactamase producing H. influenzae were 17.7% (63/356) in Japan and 2.0% (2/98) in the Philippines, and all of these strains were ampicillin MICs 〓1.56 ugml^. In addition, 5 strains in Japan that lacked β-lactamase activity were also less susceptible to ampicillin. Among the antimicrobials tested, ceftizoxim was the most active against H. influenzae in both countries (MICs 〓0.2 ugml^). Five strains of S. pneumoniae in Japan were relatively resistant to ampicillin (MIC=0.1 ugml^), whereas there were no such strains among isolates in the Philippines. Forty strains (22.3%) and 108 strains (60.3%) among S. pneumoniae in Japan exhibited erythromycin MICs 〓0.2 ugml^ and minocycline MICs 〓1.56 ugml^, respectively. In contrast, all isolates in the Philippines were erythromycin MICs 〓0.05 ugml^ and minocycline MICs 〓0.39 ugml^. Present study indicates that H. influenzae and S. pneumoniae in the Philippines remained still susceptible to the antimicrobials tested except for 2 β-lactamase-positive, ampicillin-resistant H. influenzae, whereas ampicillin-resistant H. influenzae mediated by β-lactamase or non-β-lactamase mechanisms and ampicillin-, erythromycin- or minocycline-resistant S. pneumoniae were included among isolates in Japan
An extracellular serine protease produced by Vibrio vulnificus NCIMB 2137, a metalloprotease-gene negative strain isolated from a diseased eel
Vibrio vulnificus is a ubiquitous estuarine microorganism but causes fatal systemic infections in immunocompromised humans, cultured eels or shrimps. An extracellular metalloprotease VVP/VvpE has been reported to be a potential virulence factor of the bacterium; however, a few strains isolated from a diseased eel or shrimp were recently found to produce a serine protease termed VvsA, but not VVP/VvpE. In the present study, we found that these strains had lost the 80 kb genomic region including the gene encoding VVP/VvpE. We also purified VvsA from the culture supernatant through ammonium sulfate fractionation, gel filtration and ion-exchange column chromatography, and the enzyme was demonstrated to be a chymotrypsin-like protease, as well as those from some vibrios. The gene vvsA was shown to constitute an operon with a downstream gene vvsB, and several Vibrio species were found to have orthologues of vvsAB. These findings indicate that the genes vvp/vvpE and vvsAB might be mobile genetic elements
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