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A soot composed of radial single-walled carbon nanotubes (r-SWCNTs), in which 70 nm length nanotubes are grown radially around the core metal particles, and nanohorn-like carbons (NHCs) was used as reinforcement for a styrene–butadiene rubber (SBR). The fracture stress of r-SWCNT soot (38 phr)/SBR was 6.3 MPa at 60% strain. Furthermore, the hardness value of r-SWCNT soot (38 phr)/SBR was 94, which is 1.38 times larger, and larger than carbon black/SBR. Additionally, the resilience of r-SWCNT soot/SBR with 38 phr filler content was markedly lower than 20% in comparison with standard carbon black filler. These results indicate that r-SWCNT soot/SBR possesses excellent kinetic energy absorbing properties.

To study the cyclic deformation and tribological behavior of amorphous alloy films and blocks (powder compacts), two types of fatigue test (cyclic bending) apparatus, wear rate test apparatus and an apparatus for measuring static and kinetic friction coefficients were constructed. From the strain amplitude-lifetime curves obtained, it was found that the fatigue limit of the amorphous films is higher than that of ordinary metal films such as 304 stainless steel films and that the fatigue limit obtained by testing three types of amorphous films, i.e. iron-based, cobalt-based and nickel-based ones, in dry argon gas and in vacuum is even higher than that obtained by testing in air. The wear rate of amorphous iron-based alloy films is much less than that of crystalline specimens tested, and the wear volume tends to saturate above a certain sliding speed of the disc. As regards the static and kinetic friction coefficients of the amorphous specimens (μ s and μ k , respectively), both are lower than those of crystalline specimens, in particular, in the case of μ k for amorphous-amorphous contact ( μ k = 0.04).

We are very grateful to M. Souma for his technical assistance, and Ian G. Gleadall for comments on the manuscript. This work was partly supported by the Project Fund of Graduate School of Medicine, Kitasato University.

Molecular analysis of a metastatic lesion of an atypical carcinoid tumor of the lung obtained from a 77-year-old man at autopsy revealed a point mutation in the p53 gene and a deletion in the retinoblastoma (Rb) mRNA. This case suggests that both these antioncogenes may be involved in the progression of atypical carcinoid tumor.

A computerized close-up video/photoamplifier system was implemented for the study of circadian locomotor rhythm in a population of a ciliate protozoan, Paramecium. This fully microcomputerized system facilitated automatic long-term measurement of three parameters in parallel: (1) numbers of specimens per 10 min traversing beneath a fixed point in an experimental vessel, (2) times taken by specimens to traverse the point, and (3) interval times between subsequent specimens traversing the point. Stochastic analyses using these parameters can derive the circadian fluctuation of physiological variables, such as swimming speed and the frequency of avoiding reaction (abrupt change in swimming direction). The computerized system simultaneously accomplished the acquisition of these three sets of data, their transient storage, and their graphic display according to given format. The system software was constituted so that an experimenter with little computer knowledge, could easily operate the system by answering questions displayed on the computer monitor.