59 research outputs found
The importance of C-terminal residues of vertebrate and invertebrate tachykinins for their contractile activities in gut tissues
AbstractThe C-terminal residues of mammalian tachykinins and urechistachykinins (Uru-TKs), tachykinin-related peptides of echiuroid worm origin, were substituted for each other. Their contractile effects were assayed on the cockroach hindgut and the guinea pig ileum. [Met10] substitution of Uru-TKs caused a 1000 times lower activity on the hindgut, but a 1000 times higher activity on the ileum. In contrast, [Arg11]substance P (SP) was 100 times more and 400 times less potent than SP on the hindgut and ileum, respectively. A SP antagonist blocked these Uru-TK activities on the hindgut. These results demonstrated that the C-terminal Met-NH2 is necessary for ileum contraction and the Arg-NH2 is required for hindgut contraction, which was caused by binding to the cockroach’s neurokinin-like receptor
GRB 100418A: a Long GRB without a Bright Supernova in a High-Metallicity Host Galaxy
We present results of a search for a supernova (SN) component associated with
GRB 100418A at the redshift of 0.624. The field of GRB 100418A was observed
with FOCAS on Subaru 8.2m telescope under a photometric condition (seeing
0.3"-0.4") on 2010 May 14 (UT). The date corresponds to 25.6 days after the
burst trigger (15.8 days in the restframe). We did imaging observations in V,
Rc, and Ic bands, and two hours of spectrophotometric observations. We got the
resolved host galaxy image which elongated 1.6" (= 11 kpc) from north to south.
No point source was detected on the host galaxy. The time variation of Rc-band
magnitude shows that the afterglow of GRB 100418A has faded to Rc \sim > 24
without SN like rebrightening, when we compare our measurement to the reports
in GCN circulars. We could not identify any SN feature such as broad
emission-lines or bumps in our spectrum. Assuming the SN is fainter than the
3{\sigma} noise spectrum of our observation, we estimate the upper limit on the
SN absolute magnitude MIc,obs > -17.2 in observer frame Ic-band. This magnitude
is comparable to the faintest type Ic SNe. We also estimate host galaxy
properties from the spectrum. The host galaxy of GRB 100418A is relatively
massive (log M_{star}/M_{sun} = 9.54) compared to typical long GRB host
galaxies, and has 12+log(O/H) = 8.75.Comment: 8 pages, 8 figures, accepted for publication in PASJ, changed figure
8 and related tex
Correlation-driven organic 3D topological insulator with relativistic fermions
Exploring new topological phenomena and functionalities induced by strong
electron correlation has been a central issue in modern condensed-matter
physics. One example is a topological insulator (TI) state and its
functionality driven by the Coulomb repulsion rather than a spin-orbit
coupling. Here, we report a "correlation-driven" TI state realized in an
organic zero-gap system -(BETS)I. The surface metallic state
that emerges at low temperatures exhibits characteristic transport properties
of a gapless Dirac semimetal, evidencing the presence of a topological surface
state in this compound. Moreover, we observe a topological phase switching
between the TI state and non-equilibrium Dirac semimetal state by a dc current,
which is a unique functionality of a correlation-driven TI state. Our findings
demonstrate that correlation-driven TIs are promising candidates not only for
practical electronic devices but also as a field for discovering new
topological phenomena and phases.Comment: 36 pages including 10 figure
Direct measurement of magnetocaloric effect (MCE) in frustrated Gd-based molecular complexes
The version of record of this article, first published in Journal of Thermal Analysis and Calorimetry, is available online at Publisher’s website: https://doi.org/10.1007/s10973-024-13344-9.Generation of low temperatures below 1 K has been required for applications and fundamental research, given this, development of new materials utilized for demagnetization cooling has extensively been performed in recent years. Here, we studied two polynuclear Gd3+-based molecular compounds of Gd0.33[Gd4(OH)4(OAc)3][Rh4Zn4(L-cys)12]·32H2O (1Gd) and Gd0.33[Gd4(OH)4(OAc)3][Ir4Zn4(L-cys)12]·28H2O (2Gd) (L-cys = L-cysteinate) which show paramagnetic even at low temperatures due to their frustrated arrangement of Gd3+ ions. We discuss the magnitude of the magnetocaloric effect (MCE) in them inferred from the isothermal magnetic entropy change (ΔSM) from isothermal magnetization data. The − ΔSMmax of 1Gd and 2Gd are 15.15 J kg−1 K−1 and 17.49 J kg−1 K−1 occur at 2.0 K under an applied field from 0 to 7 T, respectively. We also discussed the results of heat capacity measurement under magnetic fields to confirm the validity of the entropy change for 1Gd. Furthermore, with an aim of detecting their MCE directly, we have developed a new non-magnetic and metal-free magnetocaloric measurement cell. The adiabatic temperature change (ΔTad) occurs in a small amount of sample on an order of 102-microgram with the application and removal of various magnitude magnetic fields starting from several initial temperatures were detected directly, to evaluate the potential of them to be a refrigerant for an adiabatic demagnetization refrigerator. The instrumental design for direct measurements of MCE is described along with the construction details
Stroboscopic Time-of-Flight Neutron Diffraction in Long Pulsed Magnetic Fields
We present proof-of-principle experiments of stroboscopic time-of-flight
(TOF) neutron diffraction in long pulsed magnetic fields. By utilizing electric
double-layer capacitors, we developed a long pulsed magnet for neutron
diffraction measurements, which generates pulsed magnetic fields with the full
widths at the half maximum of more than ms. The field variation is slow
enough to be approximated as a steady field within the time scale of a
polychromatic neutron pulse passing through a sample placed in a distance of
the order of m from the neutron source. This enables us to efficiently
explore the reciprocal space using a wide range of neutron wavelength in high
magnetic fields. We applied this technique to investigate field-induced
magnetic phases in the triangular lattice antiferromagnets
CuFeGaO ().Comment: 9 pages, 7 figure
Influence of istradefylline on non-motor symptoms of Parkinson\u27s disease: A subanalysis of a 1-year observational study in Japan (J-FIRST)
IntroductionThe non-motor symptoms (NMSs) of Parkinson\u27s disease (PD) significantly impact the patient\u27s health-related quality of life. This subanalysis of the J-FIRST study evaluated the effect of istradefylline, a selective adenosine A2A receptor antagonist, on NMSs in istradefylline-naïve Japanese patients with PD.MethodsPatients with PD and ≥1 NMS and ‘wearing-off’ with their current antiparkinsonian treatment were observed for up to 52 weeks. The effect of istradefylline on NMSs was measured in terms of changes in the Movement Disorder Society Unified Parkinson\u27s Disease Rating Scale (MDS-UPDRS) Part 1 total, individual sub-items scores and the 8 item PD questionnaire (PDQ-8) estimated by the marginal structural model.ResultsOverall, 732 patients were istradefylline-naïve prior to the study, of whom 171 were treated with istradefylline for ≥8 weeks during the observation period (istradefylline-treated patients). At baseline, istradefylline-treated patients were more likely to have a dyskinesia (49.7% vs 40.8%) and received a significantly higher daily dose of levodopa (462.8 mg vs 413.0 mg) than those who did not receive istradefylline (n = 561). MDS-UPDRS Part 1 total score at the end of the 52-week observational period slightly increased in patients who received istradefylline and those who did not (0.49 ± 0.41 vs 0.07 ± 0.20; P = 0.36). There were no statistically significant differences between the two groups of patients in terms of changes in the MDS-UPDRS Part 1 total score or any sub-items, or in the PDQ-8 total score.ConclusionNMSs remained generally controlled in istradefylline-treated Japanese patients with PD who exhibited wearing-off with their current antiparkinsonian treatment. Istradefylline could be a feasible treatment option for patients with advanced PD, without worsening existing NMSs
Diversity of Shiga toxin transducing phages in Escherichia coli O145:H28 and the different Shiga toxin 2 production levels associated with short- or long-tailed phages
Shiga toxin (Stx)-producing Escherichia coli (STEC) causes serious gastrointestinal illness, including hemorrhagic colitis and hemolytic uremic syndrome. Two types of Stxs (Stx1 and Stx2) are known and both are encoded by bacteriophages (Stx phages), but the production of Stx2 is known to be a major risk factor for severe STEC infections. The production of Stx2, but not Stx1, is tightly coupled with the induction of Stx phages, and Stx2 production levels vary between STEC strains even within the same serotype. Here, we analyzed the genomic diversity of all Stx phages in 71 strains representing the entire O145:H28 lineage, one of the often highly pathogenic STECs, and the relationship between the variations in Stx phage genomes and the levels of Stx2 production by host strains. Our analysis reveals highly dynamic natures of Stx phages in O145:H28, including the independent acquisition of similar Stx phages by different sublineages, the recent transfer of Stx phage between different sublineages, and the frequent gain and loss of Stx phages in some sublineages. We also show the association of the Stx2 phage types with the Stx2 production levels of host strains: strains carrying short-tailed Stx2 phages exhibited significantly higher Stx2 production levels than those carrying long-tailed Stx2 phages. Detailed analyses of the Stx2 phage genomes revealed that both of short- and long-tailed phages exhibited sequence diversification and they were divided into two groups, respectively, based on the sequence similarity of the phage early region encoding genes responsible for phage induction, short-tailed phages contained early regions clearly different in genetic organization from those in long-tailed phages. Therefore, the variations in the early regions between short-and long-tailed Stx2 phages appeared to be linked to a striking difference in Stx2 production levels in their host strains. These results broaden our understanding of the diversification and dynamism of Stx phages in O145:H28 and the association of Stx2 phage types with the Stx2 production level in this STEC lineage
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