152 research outputs found
P3HT Nanofibrils Thin-Film Transistors by Adsorbing Deposition in Suspension
A novel film preparation method utilizing polymer suspension, entitled adsorbing deposition in suspensions (ADS), has been proposed. The poly(3-hexylthiophene) (P3HT) toluene solution forms P3HT nanofibrils dispersed suspension by aging. P3HT nanofibrils are highly crystallized with sharp vibronic absorption spectra. By the ADS method, only P3HT nanofibrils in suspension can be deposited on the substrate surface without any disordered fraction from the dissolved P3HT in suspension. Formed ADS film contains only the nanostructured conjugated polymer. Fabricated polymer thin-film transistor (TFT) utilizing ADS P3HT film shows good TFT performances with low off current, narrow subthreshold swing and large on/off current ratio
Structural insights into the differences among lactisole derivatives in inhibitory mechanisms against the human sweet taste receptor
Lactisole, an inhibitor of the human sweet taste receptor, has a 2-phenoxypropionic acid skeleton and has been shown to interact with the transmembrane domain of the T1R3 subunit (T1R3-TMD) of the receptor. Another inhibitor, 2,4-DP, which shares the same molecular skeleton as lactisole, was confirmed to be approximately 10-fold more potent in its inhibitory activity than lactisole; however the structural basis of their inhibitory mechanisms against the receptor remains to be elucidated. Crystal structures of the TMD of metabotropic glutamate receptors, which along with T1Rs are categorized as class C G-protein coupled receptors, have recently been reported and made it possible to create an accurate structural model for T1R3-TMD. In this study, the detailed structural mechanism underlying sweet taste inhibition was characterized by comparing the action of lactisole on T1R3-TMD with that of 2,4-DP. We first performed a series of experiments using cultured cells expressing the sweet taste receptor with mutations and examined the interactions with these inhibitors. Based on the results, we next performed docking simulations and then applied molecular dynamics-based energy minimization. Our analyses clearly revealed that the (S)-isomers of both lactisole and 2,4-DP, interacted with the same seven residues in T1R3-TMD and that the inhibitory potencies of those inhibitors were mainly due to stabilizing interactions mediated via their carboxyl groups in the vertical dimension of the ligand pocket of T1R3-TMD. In addition, 2,4-DP engaged in a hydrophobic interaction mediated by its o-Cl group, and this interaction may be chiefly responsible for the higher inhibitory potency of 2,4-DP
Properties of a novel hard-carbon optimized to large size Lion secondary battery studied by 7Li NMR
The state of lithium in a novel hard-carbon optimized to the anode of large size Li ion secondary battery, which has been recently commercialized, was investigated and compared with other existing hard-carbon samples by 7Li NMR method. The new carbon material showed a peak at 85 ppm with a shoulder signal at 7 ppm at room temperature in static NMR spectrum, and the former shifted to 210 ppm at 180 K. The latter at room temperature was attributed to Li doped in small particles contained in the sample. The new carbon sample showed weaker intensity of cluster-lithium signal than the other hard-carbon samples in NMR, which corresponded to a tendency of less "Constant Voltage" (CV) capacity in charge-discharge curves of electrochemical evaluation. Smaller CV capacity and initial irreversible capacity, which are the features of the novel hard-carbon, are considered to correspond to a blockade of the diffusion of Li into pore of carbon.</p
Analysis of bis(trifluoromethylsulfonyl)imide-doped paramagnetic graphite intercalation compound using F-19 very fast magic angle spinning nuclear magnetic resonance
F atoms bonding to paramagnetic/conductive graphene layers in accepter-type graphite intercalation compounds (GICs) are analyzed using very fast magic angle spinning nuclear magnetic resonance, which is applied for the first time on F-19 nuclei to investigate paramagnetic materials. In the bis(trifluoromethylsulfonyl)imide(TFSI)-doped GIC, C-F bonds between fluorine atoms and graphene layers conform to a weak bonding of F to the graphene sheets. TFSI anions intercalated in the GIC do not show overall molecular motion; even at room temperature only the CF3 groups rotate
Whistler Wave in a Magnetized Plasma
It is verified that the wave excited by a coaxialantenna propagates along the
magnetic field. Tbe dispersion relation determined by measuring the propagating
wave patterns is consistent with a theoretical prediction for the Whist1er
wave. The fact that the wave is right-bandedly polarized and can propagate
only within the resonance cone,confirms that the observed wave is the Whist1er
one. The spatial damping may be explained by the cyc1otron damping,since it
increases resonant1y near the electron cyc1otron frequency
Complications of Evans' syndrome in an infant with hereditary spherocytosis: a case report
Hereditary spherocytosis (HS) is a genetic disorder of the red blood cell membrane clinically characterized by anemia, jaundice and splenomegaly. Evans' syndrome is a clinical syndrome characterized by autoimmune hemolytic anemia (AIHA) accompanied by immune thrombocytopenic purpura (ITP). It results from a malfunction of the immune system that produces multiple autoantibodies targeting at least red blood cells and platelets. HS and Evans' syndrome have different mechanisms of pathophysiology one another. We reported the quite rare case of an infant who had these diseases concurrently. Possible explanations of the unexpected complication are discussed
Single Event Tolerance of X-ray SOI Pixel Sensors
We evaluate the single event tolerance of the X-ray silicon-on-insulator
(SOI) pixel sensor named XRPIX, developed for the future X-ray astronomical
satellite FORCE. In this work, we measure the cross-section of single event
upset (SEU) of the shift register on XRPIX by irradiating heavy ion beams with
linear energy transfer (LET) ranging from 0.022 MeV/(mg/cm2) to 68
MeV/(mg/cm2). From the SEU cross-section curve, the saturation cross-section
and threshold LET are successfully obtained to be and ,
respectively. Using these values, the SEU rate in orbit is estimated to be
0.1 event/year primarily due to the secondary particles induced by
cosmic-ray protons. This SEU rate of the shift register on XRPIX is negligible
in the FORCE orbit.Comment: 9 pages, 5 figures, accepted for publication in JATI
X-ray Radiation Damage Effects on Double-SOI Pixel Detectors for the Future Astronomical Satellite "FORCE"
We have been developing the monolithic active pixel detector "XRPIX" onboard
the future X-ray astronomical satellite "FORCE". XRPIX is composed of CMOS
pixel circuits, SiO2 insulator, and Si sensor by utilizing the
silicon-on-insulator (SOI) technology. When the semiconductor detector is
operated in orbit, it suffers from radiation damage due to X-rays emitted from
the celestial objects as well as cosmic rays. From previous studies, positive
charges trapped in the SiO2 insulator are known to cause the degradation of the
detector performance. To improve the radiation hardness, we developed XRPIX
equipped with Double-SOI (D-SOI) structure, introducing an additional silicon
layer in the SiO2 insulator. This structure is aimed at compensating for the
effect of the trapped positive charges. Although the radiation hardness to
cosmic rays of the D-SOI detectors has been evaluated, the radiation effect due
to the X-ray irradiation has not been evaluated. Then, we conduct an X-ray
irradiation experiment using an X-ray generator with a total dose of 10 krad at
the SiO2 insulator, equivalent to 7 years in orbit. As a result of this
experiment, the energy resolution in full-width half maximum for the 5.9 keV
X-ray degrades by 17.8 2.8% and the dark current increases by 89
13%. We also investigate the physical mechanism of the increase in the dark
current due to X-ray irradiation using TCAD simulation. It is found that the
increase in the dark current can be explained by the increase in the interface
state density at the Si/SiO2 interface.Comment: 15 pages, 12 figures, accepted for publication in Journal of
Astronomical Telescopes, Instruments, and System
Physicochemical Properties of the Mammalian Molecular Chaperone HSP60
The E. coli GroEL/GroES chaperonin complex acts as a folding cage by producing a bullet-like asymmetric complex, and GroEL exists as double rings regardless of the presence of adenosine triphosphate (ATP). Its mammalian chaperonin homolog, heat shock protein, HSP60, and co-chaperonin, HSP10, play an essential role in protein folding by capturing unfolded proteins in the HSP60/HSP10 complex. However, the structural transition in ATPase-dependent reaction cycle has remained unclear. We found nucleotide-dependent association and dissociation of the HSP60/HSP10 complex using various analytical techniques under near physiological conditions. Our results showed that HSP60 exist as a significant number of double-ring complexes (football- and bullet-type complexes) and a small number of single-ring complexes in the presence of ATP and HSP10. HSP10 binds to HSP60 in the presence of ATP, which increased the HSP60 double-ring formation. After ATP is hydrolyzed to Adenosine diphosphate (ADP), HSP60 released the HSP10 and the dissociation of the double-ring to single-rings occurred. These results indicated that HSP60/HSP10 undergoes an ATP-dependent transition between the single- and double-rings in their system that is highly distinctive from the GroEL/GroES system particularly in the manner of complex formation and the roles of ATP binding and hydrolysis in the reaction cycle
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