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排序方式: 共有243条查询结果,搜索用时 15 毫秒
191.
Hua Liu Hongna Shang Huan Yang Wenjie Liu Daisuke Tsugama Ken-Ichi Nonomura Aimin Zhou Wenwu Wu Tetsuo Takano Shenkui Liu 《International journal of molecular sciences》2022,23(4)
The development of floral organs is coordinated by an elaborate network of homeotic genes, and gibberellin (GA) signaling is involved in floral organ development; however, the underlying molecular mechanisms remain elusive. In the present study, we found that MOS4-ASSOCIATED COMPLEX 5A (MAC5A), which is a protein containing an RNA-binding motif, was involved in the development of sepals, petals, and stamens; either the loss or gain of MAC5A function resulted in stamen malformation and a reduced seed set. The exogenous application of GA considerably exacerbated the defects in mac5a null mutants, including fewer stamens and male sterility. MAC5A was predominantly expressed in pollen grains and stamens, and overexpression of MAC5A affected the expression of homeotic genes such as APETALA1 (AP1), AP2, and AGAMOUS (AG). MAC5A may interact with RABBIT EARS (RBE), a repressor of AG expression in Arabidopsis flowers. The petal defect in rbe null mutants was at least partly rescued in mac5a rbe double mutants. These findings suggest that MAC5A is a novel factor that is required for the normal development of stamens and depends on the GA signaling pathway. 相似文献
192.
Mitsutaka Hino Tetsuya Nagasaka Akitoshi Katsumata Ken-Ichi Higuchi Kazuyoshi Yamaguchi Norimitsu Kon-No 《Metallurgical and Materials Transactions B》1999,30(4):671-683
The alumina content in the iron ore imported to Japan is increasing year by year, and some problems in blast furnace operation,
due to the use of the high-alumina-containing sinter, have already been reported. In order to clarify the mechanism of the
harmful effect of alumina on the blast furnace operation, the behavior of the primary melt, which is formed in the sinter
at the cohesive zone of the blast furnace, has been simulated by dripping slag through an iron or oxide funnel. The effects
of basicity, Al2O3, and Fe
t
O contents in the five slag systems on the dripping temperature and weight of slag remaining on the funnel have been discussed.
It was found that the eutectic melt formed in the sinter would play an important role in the dripping behavior of the slag
in the blast furnace through the fine poreosity of the reduced iron and ore particles. Al2O3 increased the weight of the slag remaining on the funnel, and its effect became very significant in the acidic and low-Fe
t
O-containing slag. It was estimated that the increase of the weight of the slag remaining on the funnel by Al2O3 in the ore could result in a harmful effect on the permeability resistance and an indirect reduction rate of the sinter in
the blast furnace. 相似文献
193.
Velocities of single particles (magnetic tracer particles) were measured in the draft tube region and annular region of a draft-tube bubble columns by use of the magnet-detector coil technique. The relative particle to liquid velocity was also obtained. The observed distribution of particle velocity was broader than that of liquid velocity. The relative particle to liquid velocity depended significantly on superficial gas velocity. Those for the draft tube region had minimums with increasing gas velocity, while those for the annular region decreased monotonously. The effective drag coefficients for the particles were correlated with particle Reynolds number and gas holdup. 相似文献
194.
Ono K Kamihira M Kuga Y Matsumoto H Hotta A Itoh T Nishijima K Nakamura N Matsuda H Iijima S 《Journal of Bioscience and Bioengineering》2003,95(3):231-238
We constructed a replication-defective retroviral vector plasmid for the expression of a single-chain antibody fragment (scFv), derived from a chicken anti-human prion protein monoclonal antibody, fused with the Fc region of human IgG1. CHO-K1 and NS-1 cells were transformed with the viral vector pseudotyped with vesicular stomatitis virus G protein (VSV-G), and scFv-Fc producer clones were established. Among the established clones, CHO-2A9 cells produced a large amount of the product with an antibody-like dimerized structure in serum-free culture that facilitated the purification of scFv-Fc. The scFv-Fc specifically recognized the epitope sequence of prion protein in solid-phase enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. The injection test into quails revealed that the scFv became more stable in vivo by fusion with the Fc region. The scFv-Fc will be a useful tool for the detection of mammalian prion proteins. 相似文献
195.
Aso Y Nagao J Koga H Okuda K Kanemasa Y Sashihara T Nakayama J Sonomoto K 《Journal of Bioscience and Bioengineering》2004,98(6):429-436
Nukacin ISK-1 is a lantibiotic produced by Staphylococcus warneri ISK-1. The gene cluster of nukacin ISK-1 consists of at least nukAMTFEG, ORF1 and ORF7. In this study, we demonstrated the heterologous production of nukacin ISK-1 in Lactococcus lactis by the artificial polycistronic expression of nukAMTFEG-ORF7 under the control of the nisin-controlled expression (NICE) system. Consequently, the recombinant L. lactis showed antimicrobial activity. Mass analysis clarified the presence of nukacin ISK-1 produced in the culture supernatant. These results suggested that the recombinant L. lactis produced nukacin ISK-1 heterologously. Inactivation of nukA, -M or -T resulted in the complete loss of the nukacin ISK-1 production phenotype. This finding suggested that nukAMT are indispensably associated with the biosynthesis of nukacin ISK-1. To our knowledge, this is the first report of the heterologous production of lantibiotic using the NICE system. 相似文献
196.
Taniguchi M Kato K Shimauchi A Xu P Fujita K Tanaka T Tarui Y Hirasawa E 《Journal of Bioscience and Bioengineering》2005,99(2):130-135
Cross-linked poly-gamma-glutamic acid (C-L gamma-PGA) was prepared with gamma-PGA irradiated with gamma-ray at various kGy values. The physicochemical properties including viscosity and water absorption capacity were compared between C-L gamma-PGA and several typical flocculating agents. The viscosity of C-L gamma-PGA increased with the dose of gamma-irradiation, although the water absorption capacity of C-L gamma-PGA did not, which showed a maximum of 1005.6 ml/g at 20 kGy. Flocculating activity against kaolin suspension was not observed for any of the test compounds when used singly. However, the activity of C-L gamma-PGA markedly increased following the addition of polyaluminum chloride. The activity increased with temperature up to 80 degrees C and remained at 80 degrees C of heat pretreatment for 1 h, but did not at more than 50 degrees C of heat pretreatment for 24 h. The activity was also observed within a pH range of 4.5-10.0. Both the water absorption capacity and flocculating activity of C-L gamma-PGA decreased in parallel with increasing NaCl concentration, suggesting that the flocculating activity of C-L gamma-PGA was associated with its water absorption capacity, rather than viscosity. An investigation of the effects of various cations on the flocculating activity of C-L gamma-PGA showed that only trivalent cations had a synergistic effect. The mechanism of C-L gamma-PGA flocculating activity is discussed based on the results of preliminary experiments. 相似文献
197.
Toshiyuki Shimizu Akinobu Nagara Atsushi Kaji Shinya Higashiura Masakatsu Ohguchi 《应用聚合物科学杂志》2000,78(2):392-402
Structural study of two grafted polyesters, which were different in mechanical properties, was investigated by DMA, TEM, and high‐resolution solid‐state 13C‐NMR. Using DMA and TEM, a separated phase larger than 100 nm was not found in the grafted polyesters. The main chain and the side chain seemed miscible. Analysis of T1ρHs and their distributions made the difference of microstructure in the grafted polyesters clear. P(EA‐AA)‐grafted polyester, which was very brittle, had a separated phase in the grafted polyester. The separated phase was estimated to be at a size of about 3 nm. On the other hand, P(St‐DEF‐MAnh)‐grafted polyester, which was very ductile, had a homogeneous microstructure. The difference in the microstructures of the grafted polyesters seemed to effect the mechanical properties of the grafted polyesters. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 392–402, 2000 相似文献
198.
A method is developed for the measurement of the spatio-temporal receptive field (STRF) of neurons in the retina. The test input is an unsteady visual pattern randomly modulated in both space and time, and the output is the stochastic time course of the intracellular response. The STRF is expressed in terms of the spatio-temporal Wiener kernels calculated through a special cross-correlation algorithm between the response and the stimulus-related information. The method is an extension of existing white-noise identification techniques to include the spatial domain. Consideration is given to the practical implementation of the required stimulus pattern, and has led to several alternative approaches. 相似文献
199.
Ken-Ichi Sato Satoru Okamoto Atushi Watanabe 《International Journal of Communication Systems》1995,8(6):377-389
This paper explores the technologies that will enable a further leap forward in transport network evolution. First, requirements of the future transport network are elucidated. Existing network cost is evaluated and the viable means to reduce transport network cost are identified. It is demonstrated that optical path technologies such as WP (wavelength path) and VWP (virtual wavelength path) will play a key role in this. They enhance not only transmission capacity but also cross-connect node throughput cost-effectively by capitalizing on the wavelength routeing scheme. Optical path realization technologies focusing on optical path cross-connect systems are examined. Requirements for the optical path cross-connect system are then elucidated, and a new cross-connect system architecture is evaluated. The architecture exploits PLC (planar lightwave circuit) and other commercially available technologies suitable for large-scale production. The evaluations include cross-connect node upgradability, modular growth capability, total node cost, optical loss and switching power consumption. It is proved that the architecture has significant advantages over existing switch architectures. The optical path technologies provided in this paper will pave the way for a new transport network paradigm, a ubiquitous, bandwidth-abundant and affordable broadband ISDN. 相似文献
200.
This paper presents a novel approach for system identification of continuous-time stochastic state space models from random input-output continuous data. The approach is based on the introduction of random distribution theory in describing (higher) time derivatives of stochastic processes, and the input-output algebraic relationship is derived which is treated in the time-domain. The efficacy of the approach is examined by comparing with other approaches employing the filters. 相似文献