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β-Ga2O3 is a well-known semiconductor material for power devices and other applications. Recently, β-Ga2O3 has also been reported as a scintillator material with a light yield of approximately 8400 ph./MeV, scintillation decay time of

In this paper, feedback attitude control of an underactuated spacecraft with two single gimbal control moment gyros (SGCMGs) is considered. For a two-SGCMG system in an arbitrary configuration, a feedback control method based on a real-time optimization approach is proposed. Here, the gimbal angle trajectories as the solution to the minimum-time control are parameterized by the time polynomials, and their coefficients are modified at each sampling period. Numerical simulations are performed to demonstrate the validity of the proposed method as well as a certain robustness against unmodeled dynamics. Furthermore, the experimental verification is also conducted to demonstrate the actual effectiveness.

A male patient in his 70s visited our hospital with a complaint of tarry stool. A detailed examination revealed gastric cancer( pap, tub1, HER2[3+]), with multiple lungs and liver metastases. Chemotherapy with 4 courses of capecitabine, cisplatin, and trastuzumab(Tmab)and 4 courses of weekly paclitaxel(wPTX)plus 3w-Tmab were administered, and CR was achieved. Thereafter, Tmab was administered alone; however, local recurrence of the primary lesion was observed 24 months after diagnosis, and treatment with PTX and Tmab was resumed. After 68 months of diagnosis, the recurrent tumor increased in size. Therapy with nab-PTX plus ramucirumab was initiated, following which, the tumor growth was restricted. Eventually, the patient died of another disease after 6 years and 5 months of diagnosis. Chemotherapy for unresectable advanced/recurrent gastric cancer has a remarkable antitumor effect; however, a complete cure with chemotherapy alone is difficult. Therefore, a multimodal treatment, including chemotherapy, surgical treatment, and radiation therapy, is important.

In this paper, the attitude control of spacecraft using a pyramid-type variable-speed control moment gyro (VSCMG) system is considered. For successive attitude maneuvers, it is desirable that the wheel angular momentums are regulated to nominal values after an attitude maneuver. In addition, avoidance of reference aligned singularity (RAS) is also important. RAS is a singularity point where the singular direction of the constant-speed control moment gyro (CSCMG) system is aligned to a reference torque. Regarding the motivations, this paper proposes a steering law which achieves attitude control and regulates the wheel angular momentums while successfully avoiding RAS. Both numerical simulations and experimental verification are performed to demonstrate not only the validity of the proposed method, but also a certain robustness against unmodeled dynamics and the gravity torque.

Background The embryonic stem cell-specific transcription factor, ZFP57, has been shown to play an important role in tumor formation. In this study, we examined if ZFP57 is involved in colorectal cancer metastasis. Materials and methods First, we used colorectal cancer cell lines to perform in vivo metastatic experiments with nude mice. Next, we carried out immunohistochemical analysis of clinical specimens of colorectal cancers. Results In liver metastatic experiments using human colorectal cancer HT29 and HCT116 cells, liver polymetastases occurred at high frequency in ZFP57-overexpressing HT29 and HCT116 cells, whereas both control cells only resulted in oligometastases. Next, we analyzed ZFP57 expression using clinical specimens. Liver metastasis-positive cases were more frequently associated with ZFP57 overexpression than negative cases in primary lesions of colorectal cancer, and the overexpression was particularly remarkable in tumor invasive lesions. Furthermore, ZFP57 overexpression was significantly correlated not only with liver metastasis but also with lymph node metastasis. In addition, the expression level of ZFP57 was significantly correlated with that of the metastasis-related gene NANOG. We also found that ZFP57 overexpression reduced the progression-free survival rate of patients with colorectal cancer. Conclusions This study demonstrated that ZFP57 plays an important role in the hematogenous metastasis of colorectal cancer, suggesting that it could be used as a novel treatment target.

著者人数: 36名, Accepted: 2018-09-14, 資料番号: SA1180348000

GdTaO4 and (Gd1-xTbx)TaO4 (x = 0, 0.001, 0.02, 0.04, 0.10, and 0.16) single crystals were grown by the micro-pulling down method. The crystallographic system of the grown crystals was identified to be monoclinic (I2/a), which is the stable low-temperature phase of GdTaO4. In the photoluminescence (PL) spectra, intense emission was observed at 549 nm (5D3→7F4 transition of Tb3+) for every Tb doped GdTaO4. In the excitation spectra for the 549 nm emission, several excitation paths to the Tb3+ were attributed: 4f-4f transitions of Gd3+, 4f8-4f75d transitions of Tb3+ and charge transfer of TaO43− group. Radiolumincece spectra under X-ray irradiation were taken, and the highest emission peak was observed at 544 nm, which was ascribed to the 5D4→7F5 transition of Tb3+. The Tb 2% doped GdTaO4 showed the highest emission intensity at the 544 nm, and as increasing dopant concentration, the intensity decreased due to the cross-relaxation of Tb3+.

Ce-doped LaBr3/AEBr2 (AE = Mg, Ca, Sr, Ba) eutectics were grown using the Bridgman&ndash, Stockbarger (BS) method in quartz ampoules. The eutectics (AE = Mg and Ca) showed optical transparency like optical fiber bundles. A grown Ce-doped LaBr3/MgBr2 eutectic shows a 355 nm emission ascribed to Ce3+ 4f-5d transition under X-ray excitation. The smaller the ionic size of AE, the higher the light yield of the sample was. The light yield of Ce:LaBr3/MgBr2 was 34,300 photon/MeV, which is higher than Ce:LYSO standard. Scintillation decay time under 662 keV gamma-ray excitation was 18.8 ns.

A novel single-crystal growth method was developed, using arc plasma and metal melt, for a quick survey of high melting point materials. Single crystals of Yb-doped Lu2O3, Lu0.388Hf0.612O1.806, and Lu0.18Hf0.82O1.91, with melting points of 2460, 2900, and 2840 &deg, C, respectively, were grown by an indirect heating method using arc plasma. We refer to this indirect heating growth method as the core heating (CH) method. The CH-grown Yb1%-doped Lu2O3 sample showed a full width at half maximum of 286 arcsec in the X-ray rocking curve. This value is better than the 393 arcsec obtained for the crystal grown by the micro-pulling-down (&mu, PD) method. The Yb charge transfer state (CTS) emission was observed at 350 nm in the Yb1%-doped Lu2O3 and Lu0.18Hf0.82O1.91. In the case of the &mu, PD method, using a rhenium (Re) crucible, absorption due to Re contamination and a resulting reduction in the Yb CTS emission were confirmed. However, contamination did not influence the properties observed in the crystals grown by the CH method.

Ce-doped (Gd, La)2Si2O7 (Ce:La-GPS) scintillator was found to have a good light output of around 40 000 photons/MeV, while some other parameters have not been determined so far. In order to clarify the cause for such a high light yield, some physical parameters have been estimated in this paper. The bandgap energy of Ce:La-GPS was evaluated to be over 7.13 ± 0.03 eV for (Gd0.75, La0.25)2Si2O7. Although Ce:La-GPS had wider bandgap compared with the other oxide scintillators, its light output was larger than values for some other scintillators. Since quantum yield of Ce:La-GPS was as high as around 0.8, the product of transfer efficiency and electron–hole pair generation efficiency was estimated to be around 0.9, which was higher than for the other scintillators. Thus, Ce:La-GPS was suggested to have high the product of transfer efficiency and/or electron–hole pair generation efficiency.

Submicrometer diameter phase-separated scintillator fibers (PSSFs) were reported and they possessed both the properties of an optical fiber and radiation-to-light conversion. The PSSFs were fabricated using a directionally solidified eutectic system. High-resolution X-ray imaging can be developed using the PSSFs. In this paper, Tb- and Eu-doped GdAlO3 (GAP)/ $\alpha $ -Al2O3 eutectic scintillator was grown by the micro pulling down method with various growth rates in order to achieve the high light output and the high light-guiding efficiency. Relationship between radioluminescence intensity and dopant concentration of Eu and Tb was investigated. At the optimized dopant concentration, relationship between growth rate, eutectic period structure, diameter of PSSFs, and contrast transfer function was investigated to achieve high-resolution X-ray imaging.

Ce0.5%: Ce:Gd3Ga3Al2O12(GGAG) single crystals co-doped with 500at.ppm Li+, Na+ and K+ were grown by using the micro-pulling down method. The smooth Ce4+ charge transfer absorption below 350 nm and decay time acceleration were observed in Li co-doped sample. Na+ and K+ co-doping did not show a large effect on the acceleration of decay time compared with Li co-doping. Ce0.5%:GGAG single crystals co-doped with 500 at.ppm Li+ were also grown by the Czochralski method. Optical, scintillation properties and timing performance were evaluated to investigate the effect of univalent alkali metal ions co-doping on Ce:GGAG scintillators. The scintillation decay curves were accelerated by Li co-doping: the decay time was significantly accelerated to 54.8 ns (47%) for the faster component and 158 ns (53%) for the slower component. The light output was 94% of the non co-doped Ce:GGAG standard. The coincidence time resolution was improved to 258 ps by Li co-doping.

Single crystals of (La0.25Gd0.75)2Si2O7 and (La0.235Ce0.015Gd0.75)2Si2O7 were grown by the Czochralski method. Structure analysis of the single crystals by X-ray diffraction (XRD) revealed that (La0.25Gd0.75)2Si2O7 and (La0.235Ce0.015Gd0.75)2Si2O7 crystalize in monoclinic cells (space group P21/c), a = 5.3905(8) A, b = 8.5605(11) A, c = 13.957(2) A, β = 112.223(6)o, and a = 5.3921(7) A, b = 8.5688(10) A, c = 13.9172(14) A, β = 111.980(5)o, respectively. One of the two different rare-earth sites is preferentially occupied by La and Gd atoms or by La, Ce and Gd atoms, and the other is occupied by Gd atoms only. Peaks attributed to the 4f-4f transitions (8S7/2–6G7/2 and 8S7/2–6Ix) of Gd3+ and 4f-5d transitions of Ce3+ were observed in the absorption spectra of (La0.25Gd0.75)2Si2O7 and (La0.235Ce0.015Gd0.75)2Si2O7 single crystals.

This paper addresses several aspects of the µ-PD growth technology as applied to submillimeter diameter sapphire tubes for UFD application. The μ-PD method has been successfully adapted for single crystal sapphire tube growth. A compound crucible made possible the growth of single crystal sapphire tube as small as around 0.70–0.72 mm in outer diameter and 0.28–0.29 in inner diameter over 160 mm in length at growth rate of 2–4 mm/min along 〈0 0 1〉 direction. An Ir crucible with a die composed of an equivalent hole and Ir wire was heated by RF coil in N2 atmosphere. The μ-PD method has been successfully adapted for single crystal sapphire tube growth. Grown crystal tube showed good XRC value of 30.2 arcsec.

The sealed vertical Bridgman (VB) method is the main technique used to grow SrI2(Eu) crystals because SrI2(Eu) is very hygroscopic. In this study, we grew SrI2(Eu) single crystals with two-inch diameters and four-inch lengths using the VB method equipped with a removable chamber. The SrI2(Eu) single crystals were produced by the Liquinert process, which requires careful consideration of the crucible material and growth atmosphere. After a review of available materials, carbon crucibles were selected due to their several advantages over traditional quartz ampules: (1) they are suitable for large size crystal growth due to which they do not require any process for sealing of quartz ampule before the growth; (2) ease in controlling the temperature gradient because carbon crucibles can be heated directly via a high frequency induction heating system; and (3) carbon crucibles can assist in removing oxygen and moisture from the melt. The starting material, seed, and hot zone were prepared inside the glovebox in...

The fabrication and thermal electromotive force characteristics of Ir/Ir-Rh thermocouples capable of repeated bending deformation are described. Ir and Ir-Rh wires with a diameter of 0.5 mm were fabricated using the alloy-micro-pulling-down method. Scanning electron microscopy and electron backscattering diffraction of the radial cross section of the grown wires were performed to investigate the microstructure and orientation of the crystal grains. At the start of growth, the microstructure was polycrystalline with diameters of several hundred micrometers, while at the 8-m growth point it was found to be monocrystalline. The observed single crystals of pure Ir and Ir-Rh alloy were oriented in the 〈1 1 3〉 and 〈1 1 2〉 directions, respectively, whereas the polycrystalline Ir-Rh samples showed preferential growth in the 〈1 0 0〉 direction. The thermal electromotive force of the fabricated Ir/Ir-Rh thermocouple was measured by the comparison technique and the fixed-point technique, and the thermoelectric power was estimated to be 5.9 μV/°C in the range from 600°C to 1100°C.