81 research outputs found

    High Field Magnetooptics of Diluted Magnetic Semiconductors(Magnetooptics)

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    Absorption and luminescence spectra of Cd_Mn_xSe (x=0.10 and 0.38) and reflectance spectra of Cd_Co_xSe (x=0.012) were investigated in high magnetic fields up to 25 T by a hybrid magnet and a magnetospectrometer with an optical fiber system

    Photoinduced hydrogen release from hydrogen boride sheets

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    Hydrogen boride nanosheets (HB sheets) are facilely synthesized via ion-exchange treatment on magnesium diboride (MgB2) in an acetonitrile solution. Optical absorption and fluorescence spectra of HB sheets indicate that their bandgap energy is 2.8 eV. According to first-principles calculations, optical absorption seen at 2.8 eV is assigned to the electron transition between the sigma-bonding states of B and H orbitals. In addition, density functional theory (DFT) calculations suggest the other allowed transition from the s-bonding state of B and H orbitals to the antibonding state with the gap of 3.8 eV. Significant gaseous H-2 release is found to occur only under photoirradiation, which causes the electron transition from the s-bonding state to the antibonding state even under mild ambient conditions. The amount of H-2 released from the irradiated HB sheets is estimated to be 8 wt%, indicating that the sheets have a high H-2-storage capacity compared with previously reported metal H-2-storage materials

    Enzyme histochemical study on bone tumors.

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    A total of 19 cases with bone tumors, including six osteosarcomas. three giant cell tumors of bone, one malignant fibrous histiocytoma, four nonossifying fibromas, four chondromas and one chondrosarcoma, were examined as to enzyme histochemistry; the enzymes consisted of alkaline phosphatase (ALPase), acid phosphatase (ACPase), nonspecific esterase (NSE), adenosine triphosphatase (ATPase), 5'-nucleotidase (5'-Nucl) and beta-glucuronidase (beta-Gl). Osteosarcoma was strongly positive for ALPase followed by 5'-Nucl. Giant cell tumor, malignant fibrous histiocytoma and nonossifying fibroma showed enzyme histochemistry similar to each other: multinucleated giant cells and round cells in these tumors were strongly positive for ACPase, NSE, ATPase and 5'-Nucl simulating osteoclasts and histiocytes, whereas spindle cells were positive for ATPase and 5'-Nucl in their cytoplasm and weakly positive for ACPase. Chondroma and chondrosarcoma were focally positive for ACPase and NSE; the ACPase was sensitive to tartaric acid treatment. These observations showed that ALPase activity is very characteristic to osteosarcoma, and is useful for its diagnosis. From enzyme histochemistry, giant cell tumor, malignant fibrous histiocytoma and nonossifying fibroma can be regarded as a histiocyte-derived tumor of bone in contrast to osteosarcoma and cartilaginous tumors.</p

    Comparison of Targeted vs Random Biopsies for Surveillance of Ulcerative Colitis-Associated Colorectal Cancer

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    Background & AimsA random biopsy is recommended for surveillance of ulcerative colitis (UC)-associated colorectal cancer. However, a targeted biopsy might be more effective. We conducted a randomized controlled trial to compare rates of neoplasia detection by targeted vs random biopsies in patients with UC.MethodsWe performed a study of 246 patients with UC for 7 years or more, seen at 52 institutions in Japan from October 1, 2008 through December 31, 2010. Patients were randomly assigned to the random group (4 random biopsies collected every 10 cm in addition to targeted biopsies, n = 122) or the target group (biopsies collected from locations of suspected neoplasia, n = 124). The primary end point was the number of neoplastic lesions detected in a single surveillance colonoscopy. We estimated the ratio and difference in the mean number of neoplastic lesions between the groups. We also evaluated the non-inferiority between the groups as an exploratory study. A non-inferiority margin of 0.65 (0.13 of 0.20) was considered for the ratio of the mean number of neoplastic lesions between groups.ResultsThe mean number of biopsies found to contain neoplastic tissue per colonoscopy was 0.211 (24 of 114) in the target group and 0.168 (18 of 107) in the random group (ratio of 1.251; 95% confidence interval, 0.679–2.306). The lower limit was above the non-inferiority margin of 0.65. Neoplasias were detected in 11.4% of patients in the target group and 9.3% of patients in the random group (P = .617). Larger numbers of biopsy samples per colonoscopy were collected in the random group (34.8 vs 3.1 in the target group; P < .001), and the total examination time was longer (41.7 vs 26.6 minutes in the target group; P < .001). In the random group, all neoplastic tissues found in random biopsies were collected from areas of the mucosa with a history or presence of inflammation.ConclusionsIn a randomized controlled trial, we found that targeted and random biopsies detect similar proportions of neoplasias. However, a targeted biopsy appears to be a more cost-effective method. Random biopsies from areas without any signs of present or past inflammation were not found to contain neoplastic tissues. Clinical Trial Registry: UMIN000001608

    Seismic exploration at Fuji volcano with active sources : The outline of the experiment and the arrival time data

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    Fuji volcano (altitude 3,776m) is the largest basaltic stratovolcano in Japan. In late August and early September 2003, seismic exploration was conducted around Fuji volcano by the detonation of 500 kg charges of dynamite to investigate the seismic structure of that area. Seismographs with an eigenfrequency of 2 Hz were used for observation, positioned along a WSW-ENE line passing through the summit of the mountain. A total of 469 seismic stations were installed at intervals of 250-500 m. The data were stored in memory on-site using data loggers. The sampling interval was 4 ms. Charges were detonated at 5 points, one at each end of the observation line and 3 along its length. The first arrival times and the later-phase arrival times at each station for each detonation were recorded as data. P-wave velocities in the surface layer were estimated from the travel time curves near the explosion points, with results of 2.5 km/s obtained for the vicinity of Fuji volcano and 4.0 km5/s elsewhere

    Number of Pollen Grains in Rice Cultivars with Different Cool-Weather Resistance at the Young Microspore Stage

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    The difference in the number of pollen grains may be the primary factor determining the resistance to cool weather at the young microspore stage in rice (Oryza sativa L.) cultivars. To confirm this hypothesis, we compared the number of pollen grains among the cultivars or lines with various cool-weather resistance. The cultivars or lines used in the experiments were mainly released or grown in the Tohoku district (the northern part of the mainland of Japan). The number of pollen grains showed high correlation with the degree of cool-weather resistance, but considerably varied with the cultivar or line, even in the group having the same cool-weather resistance. Each group with different cool-weather resistance was divided into two subgroups, implying the existence of another genetic factor determining the resistance. The number of pollen grains in the plants cooled at the young microspore stage showed higher correlation with the degree of the cool-weather resistance than that in the control plants without exposure to low temperature. The correlation between the pollen number and spikelet sterility was also analyzed using the data of Satake and Shibata (1992, Jpn. J. Crop Sci. 61 :454–462), who primarily used the cultivars in Hokkaido (the northernmost island of Japan). The results were basically the same as those obtained in the present experiments. These results confirmed the hypothesis that the variation in the number of pollen grains is a primary factor of the resistance to cool weather at the booting stage in the cultivars in the northern part of Japan. The results also suggested the existence of another genetic factor determining the resistance
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