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排序方式: 共有338条查询结果,搜索用时 73 毫秒
101.
Yasuyuki Nagasawa Ryota Nomura Taro Misaki Seigo Ito Shuhei Naka Kaoruko Wato Mieko Okunaka Maiko Watabe Katsuya Fushimi Kenzo Tsuzuki Michiyo Matsumoto-Nakano Kazuhiko Nakano 《International journal of molecular sciences》2021,22(23)
IgA nephropathy (IgAN) has been considered to have a relationship with infection in the tonsil, because IgAN patients often manifest macro hematuria just after tonsillitis. In terms of oral-area infection, the red complex of periodontal bacteria (Porphyromonas gingivalis (P. gingivalis), Treponema denticol (T. denticola) and Tannerella forsythia (T. forsythia)) is important, but the relationship between these bacteria and IgAN remains unknown. In this study, the prevalence of the red complex of periodontal bacteria in tonsil was compared between IgAN and tonsillitis patients. The pathogenicity of IgAN induced by P. gingivalis was confirmed by the mice model treated with this bacterium. The prevalence of P. gingivalis and T. forsythia in IgAN patients was significantly higher than that in tonsillitis patients (p < 0.001 and p < 0.05, respectively). A total of 92% of tonsillitis patients were free from red complex bacteria, while only 48% of IgAN patients had any of these bacteria. Nasal administration of P. gingivalis in mice caused mesangial proliferation (p < 0.05 at days 28a nd 42; p < 0.01 at days 14 and 56) and IgA deposition (p < 0.001 at day 42 and 56 after administration). Scanning-electron-microscopic observation revealed that a high-density Electron-Dense Deposit was widely distributed in the mesangial region in the mice kidneys treated with P. gingivalis. These findings suggest that P. gingivalis is involved in the pathogenesis of IgAN. 相似文献
102.
Hideaki Itoh Toshiya Uemura Hirofumi Yamaguchi Shigeharu Naka 《Journal of Materials Science》1989,24(10):3549-3552
Epitaxial (Ni, Zn)Fe2O4 films were prepared on (100) MgO single crystal substrate by lowpressure chemical vapour deposition using a thermal decomposition
of acetylacetonatocomplexes, Ni(acac)2, Zn(acac)2 and Fe(acac)3. These complexes were evaporated at 157, 79 and 146° C, respectively, and transported with nitrogen carrier gas (flow rate
100 ml min−1) to the deposition furnace. Polycrystalline and epitaxial films were grown at 500 to 600 and 600 to 650° C, respectively,
under a pressure of 12 torr. The epitaxial film of Ni1−xZnxFe2O4 (x⋍0.4) treated at 600° C for 60 min, showed the saturation magnetization of 67 e.m.u. g−1 and the coercive force of 20 to 30 Oe. 相似文献
103.
Summary. Homogeneous polystyrene and silica gel polymer hybrids were prepared by in-situ radical polymerization method. Styrene monomer
was introduced into a sol-gel reaction mixture of tetramethoxysilane (TMOS) and the polymerization was initiated by Azobisisobutyronitrile
(AIBN), while sol-gel reaction of TMOS proceeded to form a silica gel. The homogeneity of the hybrids was found to be dependent
on the amount of the acid catalyst. The homogeneity was confirmed quantitatively by measuring porosity of charred hybrids
with nitrogen porosimetry method. It was found that polystyrene was dispersed at a nano-meter level in the silica gel matrix.
Received: 8 July 1997/Revised: 29 July 1997/Accepted: 1 August 1997 相似文献
104.
Shinya Ohtsuka Shunji Nagara Masaki Koumura Yousuke Hashimoto Michiaki Nakamura Masayuki Hikita 《Electrical Engineering in Japan》2002,140(3):34-43
This paper describes partial discharge (PD) inception and breakdown voltage characteristics of a CO2/N2/SF6 gas mixture in a nonuniform field. These voltage characteristics were investigated with ac high voltage by changing the mixture rate of each gas of CO2, N2, and SF6 gas and the gas pressure from 0.1 MPa to 0.6 MPa. It was found that adding a small amount of CO2 gas into a N2/SF6 mixture causes a drastic increase in the breakdown voltage. For instance, when the mixture rate of SF6 in N2/SF6 gas mixture is 50%, with the addition of 1% CO2 the maximum breakdown voltage becomes 1.31 and 1.15 times higher than that of a 50% N2/50% SF6 gas mixture and pure SF6 gas, respectively. Moreover, those voltage characteristics of a CO2/N2/SF6 gas mixture were also investigated by changing the electric field utilization factor as well as by applying positive and negative standard lightning impulse voltages in order to discuss the corona stabilization effect, which seems to be one reason for the drastic increase in the breakdown voltage. These results and breakdown mechanism of the CO2/N2/SF6 gas mixture are discussed on the basis of the corona stabilization effect and the dissociation energies of the component gases by observing PD light images, PD light intensities through a blue and red filter, and PD current waveforms. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 140(3): 34–43, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10019 相似文献
105.
Tongxiang Fan Di Zhang Renjie Wu T. Shibayanagi M. Naka 《Journal of Materials Science》2002,37(24):5191-5196
In the present work, the polytypism of SiC and the interfacial structure between SiC and Al were investigated using X-ray diffraction (XRD) and high resolution transmission electron microscopy (HREM). It was approved that 15R could be juxtaposed with 6H stacking sequences in the same SiC reinforcement and a structural transformation zone was also observed. The Al4C3 compound can nucleate on SiC at the SiC/Al interface with the growth orientation parallel to the C axis of SiC. Mechanisms for the observed phenomena were also discussed in detail. 相似文献
106.
Cubic BN was synthesized under high temperature and pressure conditions from BN powder formed by reaction of triammoniadecaborane (TAD) with ammonia. The BN powder formed from TAD and ammonia had a low degree of ordering. The crystal lattice of the BN powder increased in regularity with increasing synthesis temperature and time for the reaction of TAD with ammonia. The conversion yield of cubic BN at 1300 °C and 6.5 GPa in the presence of AIN increased with decreasing of reaction temperature of TAD and ammonia from 1000–700 °C. Cubic BN decreased in yield with increasing reaction time of TAD and ammonia at 800 °C. BN powder pre-heat treated at 1550 °C had a crystallite size,L
c, of 22 nm, and was converted to cubic BN in a 43% yield at 1300 °C and 6.5 GPa for 10 min. The activation energy for cubic BN synthesis from BN powder-20 mol% AIN was 97 kJ mol–1, when the starting BN was synthesized at 800 °C. The conversion yield of cubic BN from the disordered BN-20 mol% AIN was 100% after heat treatment at 1300 °C and 6.5 GPa for 20 min. 相似文献
107.
The process of the formation of diamond from the glassy carbon with its characteristic bond nature was investigated in the diamond stable region at high pressures (up to 10 GPa) and temperatures (up to 3000° C), without any intentional addition of metals as solvent. The process of diamond formation was found to obey Ostwalds's step rule as follows: amorphous glassy carbon crystallized to form fully well-crystallized graphite prior to diamond formation and then the graphite crystals were converted to diamond by further heat treatment at pressures above 9 GPa. The many trigons formed are considered to be essentially a record of growth failure in the growth period. As a result of heat treatment for a longer time and/or at a higher temperature close to the diamond—graphite stability boundary, the diamond tended to grow with the (111)-face composed of the thin growth layers. 相似文献
108.
Identification of Multi-Input Biological Systems 总被引:1,自引:0,他引:1
The Wiener theory of nonlinear system identification is extended to multi-input-output systems and experimentally applied. The experimental applicability of the method is discussed with regard to biological systems. It is shown that the method is well suited for the treatment of the idiosyncratic features of such systems: nonlinearities, short lifetimes of experimental preparations, and high noise content. A preliminary analysis is outlined, taking into account the characteristics of the system under study, which results in the determination of the parameters of the identifying experiment. An error analysis is made which can be used to increase the accuracy of the derived model within certain constraints. Several examples are given of the experimental application of the method to certain neural networks in a vertebrate retina (the catfish, Ictalurus punctatus, retina was used for these experiments). In addition to functional identification through white-noise stimulation, these same retinal neurons are identified morphologically through intracellular dye injection. The performance of the derived functional models, as compared to the physical system, is evaluated through a variety of tests and it is found to be very satisfactory. 相似文献
109.
110.