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81.
Nobuko Ohmido Kiichi Fukui Toshiro Kinoshita 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2010,86(2):103-116
Fluorescence in situ hybridization (FISH) is an effective method for the physical mapping of genes and repetitive DNA sequences on chromosomes. Physical mapping of unique nucleotide sequences on specific rice chromosome regions was performed using a combination of chromosome identification and highly sensitive FISH. Increases in the detection sensitivity of smaller DNA sequences and improvements in spatial resolution have ushered in a new phase in FISH technology. Thus, it is now possible to perform in situ hybridization on somatic chromosomes, pachytene chromosomes, and even on extended DNA fibers (EDFs). Pachytene-FISH allows the integration of genetic linkage maps and quantitative chromosome maps. Visualization methods using FISH can reveal the spatial organization of the centromere, heterochromatin/euchromatin, and the terminal structures of rice chromosomes. Furthermore, EDF-FISH and the DNA combing technique can resolve a spatial distance of 1 kb between adjacent DNA sequences, and the detection of even a 300-bp target is now feasible. The copy numbers of various repetitive sequences and the sizes of various DNA molecules were quantitatively measured using the molecular combing technique. This review describes the significance of these advances in molecular cytology in rice and discusses future applications in plant studies using visualization techniques. 相似文献
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84.
Unlike other natural network systems, assortativity can be observed in most human social networks, although it has been reported that a social dilemma situation represented by the prisoner’s dilemma favors dissortativity to enhance cooperation. We established a new coevolutionary model for both agents’ strategy and network topology, where teaching and learning agents coexist. Remarkably, this model enables agents’ enhancing cooperation more than a learners-only model on a time-frozen scale-free network and produces an underlying assortative network with a fair degree of power-law distribution. The model may imply how and why assortative networks are adaptive in human society. 相似文献
85.
Tomohiro Sato Katsuyoshi Ito Tsutomu Tamada Akihiko Kanki Shigeru Watanabe Hirotake Nishimura Daigo Tanimoto Hiroki Higashi Akira Yamamoto 《Magnetic resonance imaging》2013,31(8):1412-1417
ObjectivesTo quantify tissue gadolinium (Gd) deposition in renally impaired rats exposed to Gd-EOB-DTPA and other Gd-based MRI contrast agents by means of inductively coupled plasma mass spectrometry (ICP-MS), and to compare the differences in distribution among major organs as possible triggers for nephrogenic systemic fibrosis (NSF).MethodsA total of 15 renally impaired rats were injected with Gd-EOB-DTPA, Gd-DTPA-BMA and Gd-HP-DO3A. Gd contents of skin, liver, kidney, lung, heart, spleen, diaphragm and femoral muscle were measured by inductively coupled plasma mass spectrometry (ICP-MS). Histological assessment was also conducted.ResultsTissue Gd deposition in all organs was significantly higher (P = 0.005 ~ 0.009) in the Gd-DTPA-BMA group than in the Gd-HP-DO3A and Gd-EOB-DTPA groups. In the Gd-DTPA-BMA group, Gd was predominantly deposited in kidney (1306 ± 605.7 μg/g), followed by skin, liver, lung, spleen, femoral muscle, diaphragm and heart. Comparing Gd-HP-DO3A and Gd-EOB-DTPA groups, Gd depositions in the kidney, liver and lung were significantly lower (P = 0.009 ~ 0.011) in the Gd-EOB-DTPA group than in the Gd-HP-DO3A group although no significant differences were seen for any other organs.ConclusionsGd-EOB-DTPA is a stable and safe Gd-based contrast agent (GBCA) showing lower Gd deposition in major organs in renally impaired rats, compared with other GBCAs. This fact suggests that the risk of NSF onset would be low in the use of Gd-EOB-DTPA. 相似文献
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Green JS Ovchinnikov VM Evans RG Akli KU Azechi H Beg FN Bellei C Freeman RR Habara H Heathcote R Key MH King JA Lancaster KL Lopes NC Ma T MacKinnon AJ Markey K McPhee A Najmudin Z Nilson P Onofrei R Stephens R Takeda K Tanaka KA Theobald W Tanimoto T Waugh J Van Woerkom L Woolsey NC Zepf M Davies JR Norreys PA 《Physical review letters》2008,100(1):015003
Metal foil targets were irradiated with 1 mum wavelength (lambda) laser pulses of 5 ps duration and focused intensities (I) of up to 4x10;{19} W cm;{-2}, giving values of both Ilambda;{2} and pulse duration comparable to those required for fast ignition inertial fusion. The divergence of the electrons accelerated into the target was determined from spatially resolved measurements of x-ray K_{alpha} emission and from transverse probing of the plasma formed on the back of the foils. Comparison of the divergence with other published data shows that it increases with Ilambda;{2} and is independent of pulse duration. Two-dimensional particle-in-cell simulations reproduce these results, indicating that it is a fundamental property of the laser-plasma interaction. 相似文献
88.
Koich Akiyama Nobuyuki Tomita Yoshinori Nomura Toshiro Isu Hajime Ishihara Kikuo Cho 《Physica E: Low-dimensional Systems and Nanostructures》2000,7(3-4)
We demonstrate a remarkable thickness dependence of nonlinear optical response of exciton–polaritons in GaAs thin films by degenerate four-wave mixing (DFWM) at low temperature (T=5 K). High-quality samples of layer thickness from 80 to 200 nm were grown by molecular beam epitaxy. Confined mode of the exciton–polariton dominantly contributed to the reflection spectra, which were examined by the calculation using a transfer matrix method. The DFWM intensity at exciton resonance was enhanced at a particular thickness (110 nm). This thickness dependence is in good agreement with the nonlocal theory, which shows a remarkable size dependence of the internal field relevant to the confined mode of the exciton–polaritons. 相似文献
89.
Masahiro Ueda Fumitaka Murase Fumio Takahashi Toshiro Matsumoto 《Optics and Lasers in Engineering》1999,31(6):921-501
An optical system for measuring the eccentricity of the glass wool pipe has been developed for an industrial use. The system consists of a contact sensor, a photo light sensor and a signal processing system with a logic circuit. The system is simple, fast and efficient for practical use; it allows implementation of on-line process monitoring and alarm warning signals for unacceptable pipe eccentricity during manufacturing. 相似文献
90.
Yuta Kitamura Noriyuki Miyazaki Toshiro Mabuchi Teruhiko Nawata 《Journal of Crystal Growth》2009,311(15):3954-3962
We developed a method for simulating birefringence of an annealed ingot of MgF2 single crystal for lithography optics. This method provides the optical path difference caused by crystal symmetry and residual stress existing in the crystal. The method consists of the heat conduction analysis, the residual stress analysis and the birefringence analysis. Because there exists no experimental data on the inelastic behavior of MgF2 single crystal, the residual stress was estimated with the elastic thermal stress analysis using the finite element method by assuming a stress-free temperature. In this analysis, the temperature dependence of material properties and crystal anisotropy were taken into account. In the birefringence analysis, the distributions of optical path difference were calculated by an approximate method using the result of the residual stress analysis. This approximate method uses the average stress along the wave normal and is equivalent to the exact method in case of low stress dealt with the present study. In this analysis, it is possible to consider both the intrinsic birefringence and the stress birefringence in any crystal orientation. The distribution of the optical path difference in the annealed ingot obtained from the present calculation agrees qualitatively with that of the experiment. Its calculated value also agrees reasonably well with that of the experiment, when a stress-free temperature is adequately selected. 相似文献