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排序方式: 共有312条查询结果,搜索用时 15 毫秒
1.
S Noguchi M Sata H Suzuki K Ohba M Mizokami K Tanikawa 《Canadian Metallurgical Quarterly》1997,24(5):992-994
Chinese hamster lung fibroblast V79 cells have been widely used in studies of DNA damage and DNA repair. Since the p53 gene is involved in normal responses to DNA damage, we have analyzed the molecular genetics and functional status of p53 in V79 cells and primary Chinese hamster embryonic fibroblast (CHEF) cells. The coding product of the p53 gene in CHEF cells was 76 and 75% homologous to human and mouse p53 respectively, and was 95% homologous to the Syrian hamster cells. The V79 p53 sequence contained two point mutations located within a presumed DNA binding domain, as compared with the CHEF cells. Additional immunocytochemical and molecular studies confirmed that the p53 protein in V79 cells was mutated and nonfunctional. Our results indicate that caution should be used in interpreting studies of DNA damage, DNA repair and apoptosis in V79 cells. 相似文献
2.
To study bone loss relationships to aging and menopause, cross-sectional bone mass measurements by digital image processing (DIP method), and menopause information collected by questionnaire, were analyzed on 291 women who live in Tsukude village. The results are as follows. 1) The mean DIP values (sigma GS/D, MCI) by age-stratified groups decrease with age after menopause. The rate of bone loss in sigma GS/D is almost constant, but in MCI it increases with aging. 2) In 30-year old and 40-year old age groups, the frequency distribution of DIP values is symmetrical and bell-shaped. But after the fifties the distribution is asymmetrical, with the mode of distribution deviated toward low bone mass. The change of mode with aging is larger than that of mean. This fact suggests that change of mean bone mass substantially underestimates actual bone loss from aging. 3) The change of the mean DIP values stratified by years elapsed since menopause is not especially large at start of menopause but becomes almost constant after menopause. DIP values reflect the bone loss from the aging rather than from menopause, and are beneficial to the study of bone loss in elderly women. 相似文献
3.
An intelligent tutoring system called Circuit Exerciser is described. The system is designed to help university students learn more about electric circuits. It can formulate drill problems, solve them, and infer mistakes in a student's answer. It can also provide helpful comments to the students on how the mistake was made. The system shows the circuit of the presented problem on graphic displays and is student-friendly. The system architecture, pedagogical cycle, and execution of the system are presented 相似文献
4.
Ohba A. Ohbayashi S. Shiomi T. Takano S. Anami K. Honda H. Ishigaki Y. Hatanaka M. Nagao S. Kayano S. 《Solid-State Circuits, IEEE Journal of》1991,26(4):507-512
A 7-Mb BiCMOS ECL (emitter coupled logic) SRAM was fabricated in a 0.8 μm BiCMOS process. An improved buffer with a high-level output of nearly V CC is adopted to eliminate the DC current in the level converter circuit, and the PMOS transistor has a wide operating margin in the level converter. The configurable bit organization is realized by using a sense-amplifier switch circuit with no access degradation. A wired-OR demultiplexer for the ×1 output, having the same critical path as the ×4 output circuit, allows for the same access time between the two modes. The ×1 or ×4 mode is electrically selected by the external signal. A simplified programming redundancy technology, shift redundancy, is utilized. Address programming is performed by cutting only one fuse in the shift redundancy. The RAM operates at the ECL-10K level with an access time of 7 ns. and the power dissipation at 50 MHz is 600 mW for the × mode 相似文献
5.
S. Ohba N. Akahane T. Wakabayashi T. Nakahara T. Yokochi K. Yanagi N. Ohshima 《Lipids》1997,32(6):593-598
The dietary effect of 1,3-biseicosapentaenoyl-2-γ-linolenoyl glycerol (STG) on the fatty acid composition of guinea pigs was
examined and compared with that of an eicosapentaenoic acid ethyl ester (EPA-F) and of a soybean oil (SBO) diet. In terms
of content of plasma lipid, EPA-E had a greater hypolipidemic effect than STG. On the other hand, in terms of EPA incorporation,
contents of EPA in liver lipid were almost the same in the STG and EPA-E groups. Considering that the amount of EPA administered
in the EPA-E group was almost 1.5 times that of the STG group, FPA may be absorbed more effectively as the glycerol ester
than as the ethyl ester in guinea pigs. In all the tissue lipids, the STG group had a higher unsaturation index (UI) than
the EPA-E group even though there is a lower UI in the STG diet than the EPA-E diet. These results suggest that greater amounts
of desaturase products as a whole were synthesized in the STG group than in the other two groups. The dihomo-γ-linolenic acid/arachidonic
acid (DGLA/AA) ratio in plasma total lipids in the STG group was 3.5 times that of SBO group, and the DGLA/AA ratio in the
EPA-E group was half that of the SBO group. In liver lipid, the ratios of DGLA/AA and EPA/AA in the STG group were 0.687 and
0.488 (phosphatidylcholine fraction) and 0.237 and 0.752 (phosphatidylethanolamine fraction), respectively. The ratio of DGLA/AA
as well as the high EPA/AA ratio obtained in the present study with the STG diet may lead to physiological alterations, including
enhanced synthesis of 1-and 3-series eicosanoids. 相似文献
6.
Yasuhide Shinohara Tadashi Dohi Shunji Osaki 《Computers & Industrial Engineering》1997,33(3-4):813-816
In a software product management, it is an important problem to determine the optimal release timing which minimizes the total expected cost incurred in both testing and operation phases. In this paper, we compare the performance between two kinds of software release methods, which are referred to as the T-policy and the N-policy. Based on the existing software reliability growth models, we formulate the expected cost functions and derive analytically the optimal policies under these control methods. Also, we derive a criterion for which control methods should be adopted. Finally, in numerical examples, we calculate the optimal release policies for several cost parameters. 相似文献
7.
Shaoying Liu Offutt A.J. Ho-Stuart C. Sun Y. Ohba M. 《IEEE transactions on pattern analysis and machine intelligence》1998,24(1):24-45
Formal methods have yet to achieve wide industrial acceptance for several reasons. They are not well integrated into established industrial software processes, their application requires significant abstraction and mathematical skills, and existing tools do not satisfactorily support the entire formal software development process. We have proposed a language called SOFL (Structured-Object-based-formal Language) and a SOFL methodology for system development that attempts to address these problems using an integration of formal methods, structured methods and object oriented methodology. Construction of a system uses structured methods in requirements analysis and specifications, and an object based methodology during design and implementation stages, with formal methods applied throughout the development in a manner that best suits their capabilities. The paper describes the SOFL methodology, which introduces some substantial changes from current formal methods practice. A comprehensive, practical case study of an actual industrial Residential Suites Management System illustrates how SOFL is used 相似文献
8.
Tomah Sogabe Akio Ogura Mitsuyoshi Ohba Yoshitaka Okada 《Progress in Photovoltaics: Research and Applications》2015,23(1):37-48
Spectral response of multi‐junction solar cell is complicated because of the interplay between external measurement conditions such as bias light intensity, monochromatic light intensity, bias voltage, and intrinsic electrical properties of series interconnected subcells. In this paper, we report an experimental study on the bias voltage‐dependent spectral response (SR) for multi‐junction solar cell. A self‐consistent iteration loop was developed from a nonlinear least square Powell hybrid algorithm that was used for curve fitting the experimental SR versus bias voltage data of each subcell. We demonstrated for the first time that this approach enabled us to derive the electrical parameters such as dark saturation currents (J0), shunt resistance (Rsh), series resistance (Rs), and spectra response (Jphoto) for each subcell of a Ga0.99In0.01As/Ge dual junction solar cell with stable convergence. The accuracies of the fitting results were confirmed by the agreement between the J–V curves calculated on the basis of these parameters and the experimental J–V curve of multi‐junction solar cell measured under AM1.5 and 1 sun condition. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
9.
Yasuhide Shindo Tomo Takeda Fumio Narita Nozomi Saito Shinya Watanabe Kazuaki Sanada 《Composites Science and Technology》2009,69(11-12):1904-1911
The purpose of this research is to characterize the cryogenic delamination growth behavior in woven glass fiber reinforced polymer (GFRP) composite laminates subjected to Mode II fatigue loading. Mode II fatigue delamination tests were performed at room temperature, liquid nitrogen temperature (77 K) and liquid helium temperature (4 K) using the four-point bend end-notched flexure (4ENF) test method, and the delamination growth rate data for the woven GFRP laminates were obtained. The energy release rate range was determined by the finite element method. Microscopic examinations of the specimen sections and fracture surfaces were also carried out. The present results are discussed to obtain an understanding of the fatigue delamination growth mechanisms in the woven GFRP laminates under Mode II loading at cryogenic temperatures. 相似文献
10.
The effects of an arbitrary small inclination between two cross gratings on the moiré fringes in Talbot interferometry are discussed when the frequencies of the grating differ in two perpendicular directions. We show that the small angles, alpha and beta, by which the beam-splitter cross grating is rotated around the two axes parallel to the two perpendicular line directions of the cross grating, have a greater influence on the moiré fringes with cross gratings than that with one-dimensional gratings. A simple and practical detection method for the angles between the two unparallel grating planes in Talbot interferometry is also proposed. The theoretical analyses are proved by experimental results. 相似文献