The interaction of lipid peroxides with cellular proteins has been postulated to contribute to cellular aging. A potential
target for such effects is tubulin, the building block of microtubules. We examined the concentration-dependent effects of
phosphatidylcholine hydroperoxides on the ability of tubulin to polymerize into microtubules. The results demonstrated that
even very low concentrations of peroxides were sufficient to interfere with the tubulin and, therefore, the microtubule function.
Decreased tubulin activity (as measured by tubulin GTPase activity) showed correlation with the modification of methionine
and cysteine in tubulin and a change in the tubulin conformational state as indicated by fluorescence and ultraviolet spectroscopic
measurements. As no effect on electric conductivity was observed, indicating that modulation of ionic binding was not involved,
the interaction mechanism may be a hydrophobic one. 相似文献
In this paper, the authors propose a method that incorporates mechanisms for handling ambiguity in speech and the ability of humans to create associations, and for formulating conversations based on rule base knowledge and common knowledge. Go beyond the level that can be achieved, using only conventional natural language processing and vast repositories of sample patterns. In this paper, the authors propose a method for computer conversation sentences generated using newspaper headlines as an example of how the common knowledge and associative ability are applied. 相似文献
The cover image, by Yuko Shimamura et al, is based on the Research Article Inhibitory effects of Japanese horseradish (Wasabia japonica) on the formation and genotoxicity of a potent carcinogen, acrylamide, DOI: 10.1002/jsfa.8055 .
This paper discusses requirements to be satisfied by future manufacturing systems and proposes a new concept of modular manufacturing to integrate intelligent and complex machines. In large-scale systems such as manufacturing systems, modularization is indispensable for clarifying logical structure and assuring a high degree of ease of construction. The parts, products and manufacturing equipments as well as the design and operating activities themselves are all described in units called modules. A manufacturing system is constructed and operated by combining these in building-block style. The creation of this manufacturing system relies on construction and operating systems that enable design and simulation in the virtual world, and production and control in the real world, in a unified approach. Hardware modules and software modules are compiled flexibly and hierarchically to fulfil specified tasks. A system in which modular manufacturing as a concept of system integration is applied to manufacturing robots is called a modular robot system. The robots are embedded in manufacturing systems as the highest application of model-based robotics. 相似文献
In this paper, the pendulum method for measuring the bistatic radar cross section of a target is proposed, based on the principle of modulated-scattering technique. A modulated wave is formed by swinging the target like a pendulum. This method has the advantages that the measuring procedure is very simple, an absorber-coated room is not required, and the measured value is independent of background waves. Theoretical aspects of the principle are first described, including various kinds of conditions; then the measuring method is given with experimental results. 相似文献
A dynamically reducing retransmission control scheme is proposed for slow-frequency-hopped communication systems. In the proposed scheme a transmitter defers transmission of a new packet until all the other transmitters receive positive acknowledgments, so that the number of active transmitters are dynamically reduced. The performance of the proposed scheme is compared with the conventional scheme, in which a transmitter is permitted to transmit a new packet in any slot, in terms of the normalized throughput and the 98% packet transmission delay. The numerical results show that the proposed scheme outperforms the conventional scheme, although for some values of the number of transmitters the conventional scheme has higher normalized throughput 相似文献