The Telescope Array (TA) experiment is the largest detector to observe ultra-high-energy cosmic rays in the northern hemisphere. The fluorescence detectors at two stations of TA are newly constructed ...and have now completed seven years of steady operation. One advantage of monocular analysis of the fluorescence detectors is a lower energy threshold for cosmic rays than that of other techniques like stereoscopic observations or coincidences with the surface detector array, allowing the measurement of an energy spectrum covering three orders of magnitude in energy. Analyzing data collected during those seven years, we report the energy spectrum of cosmic rays covering a broad range of energies above 1017.2eV measured by the fluorescence detectors and a comparison with previously published results.
Telomerase, an enzyme related with cellular immortality, has been extensively studied in many kinds of malignant tumours for clinical diagnostic or prognostic utilities. Telomerase activity is mainly ...regulated by the expression of hTERT (human telomerase reverse transcriptase), which is a catalytic component of human telomerase. To evaluate whether the levels of hTERT mRNA provides a molecular marker of hepatoblastoma malignancy, we examined hTERT mRNA expression levels in the primary hepatoblastoma tissues by fluorescent RT-PCR using LightCycler technology and followed up the clinical outcomes in 63 patients listed in the Japanese Study Group of Pediatric Liver Tumor between 1991 and 2002. The hTERT mRNA expression was detected in 61 (96.8%) specimens and their expression levels ranged between 0.1/1000 and 745.1/1000 copies of PBGD gene that was used as an internal control. Among these cases, frozen 39 tumour samples and 14 adjacent noncancerous liver tissues were analysed for semiquantitative telomerase assay. In the 39 tumour samples, the levels of telomerase activity ranged between 0.11 and 2709 TPG and 12 (30.7%) had high telomerase activity (>100 TPG), whereas only nine of 14 noncancerous liver tissue samples showed telomerase activity which was less than 1.0 TPG. The levels of telomerase activity were significantly correlated with the levels of hTERT mRNA expression (P<0.001). The frequency of high hTERT mRNA expression and/or high telomerase activity did not significantly associate with the clinicopathological factors except for stage of disease. The prognosis of the patients with high hTERT mRNA expression was significantly worse than that of others (P<0.01), as was the patients with high telomerase activity (P<0.01). Multivariate analysis indicated that high levels of hTERT mRNA expression as well as telomerase activity are independent prognosis-predicting factors in patients with hepatoblastoma.
Hyperhoneycomb iridate β − Li 2 IrO 3 is a three-dimensional analog of two-dimensional honeycomb iridates, such as α − Li 2 IrO 3 , which recently appeared as another playground for the physics of ...Kitaev-type spin liquid. β − Li 2 IrO 3 shows a noncollinear spiral ordering of spin-orbital-entangled J eff = 1 / 2 moments at low temperatures below 38 K, which is known to be suppressed under a pressure of ∼ 2 GPa. In addition, a structural transition is observed at P S ∼ 4 GPa at room temperature. Using the neutron powder diffraction technique, the crystal structure in the high-pressure phase of β − Li 2 IrO 3 above P S was refined, which indicates the formation of Ir 2 dimers on the zigzag chains, with an Ir-Ir distance of ∼ 2.66 Å , even shorter than that of metallic Ir. We argue that the strong dimerization stabilizes the bonding molecular-orbital state comprising the two local d z x orbitals in the Ir- O 2 -Ir bond plane, which conflicts with the equal superposition of d x y , d y z , and d z x orbitals in the J eff = 1 / 2 wave function produced by strong spin-orbit coupling. The results of resonant inelastic x-ray scattering measurements and the electronic structure calculations are fully consistent with the collapse of the J eff = 1 / 2 state. The competition between the spin-orbital-entangled J eff = 1 / 2 state and molecular-orbital formation is most likely universal in honeycomb-based Kitaev materials.
The laser-induced plasma-assisted ablation (LIPAA) process developed by us, in which only a single conventional pulsed laser is used, makes it possible to perform high-quality and high-speed glass ...microfabrication. We developed the LIPAA system, which uses the second harmonic of a diode pumped Q-switched Nd:YAG laser, for practical use in industry. The system comprises two optical components, which are the objective lens for high-resolution microfabrication and the galvano mirror type scanner for high-speed patterning of complicated microstructures. In addition to surface microstructuring of the glass, selective metallization of the glass by the LIPAA process, followed by electroless Cu plating, is demonstrated .
A remote monitoring system was developed based on the software infrastructure of the Experimental Physics and Industrial Control System (EPICS) for the cryogenic system of superconducting magnets in ...the interaction region of the SuperKEKB accelerator. The SuperKEKB has been constructed to conduct high-energy physics experiments at KEK. These superconducting magnets consist of three apparatuses, the Belle II detector solenoid, and QCSL and QCSR accelerator magnets. They are each contained in three cryostats cooled by dedicated helium cryogenic systems. The monitoring system was developed to read data of the EX-8000, which is an integrated instrumentation system to control all cryogenic components. The monitoring system uses the I/O control tools of EPICS software for TCP/IP, archiving techniques using a relational database, and easy human-computer interface. Using this monitoring system, it is possible to remotely monitor all real-time data of the superconducting magnets and cryogenic systems. It is also convenient to share data among multiple groups.
A pair of permanent magnets has formed enough intensity to realize electron cyclotron resonance condition for a 14 GHz microwave in a 2 cm diameter 9 cm long alumina discharge chamber. A ...three-electrode extraction system assembled in a magnetic shielding has formed a stable beam of negative hydrogen ions (H(-)) in a direction perpendicular to the magnetic field. The measured H(-) current density was about 1 mA∕cm(2) with only 50 W of discharge power, but the beam intensity had shown saturation against further increase in microwave power. The beam current decreased monotonically against increasing pressure.
Observations of the long-lived emission-or 'afterglow'-of long-duration γ-ray bursts place them at cosmological distances, but the origin of these energetic explosions remains a mystery. Observations ...of optical emission contemporaneous with the burst of γ-rays should provide insight into the details of the explosion, as well as into the structure of the surrounding environment. One bright optical flash was detected during a burst, but other efforts have produced negative results. Here we report the discovery of the optical counterpart of GRB021004 only 193 seconds after the event. The initial decline is unexpectedly slow and requires varying energy content in the γ-ray burst blastwave over the course of the first hour. Further analysis of the X-ray and optical afterglow suggests additional energy variations over the first few days.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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