First-Principles Study on Electron-Conduction Properties of C60_{60} Chains

The electron-conduction properties of fullerene chains are examined by first-principles calculations based on the density functional theory. The conductivity of the C$_{60}$ dimer is low owing to the constraint of the junction of the molecules on electron conduction, whereas the C$_{60}$ monomer exhibits a conductance of $\sim$ 1 G$_0$. One of the three degenerate $t_{u1}$ states of C$_{60}$ is relevant to conduction and the contributions of the others are small. In addition, we found a more interesting result that the conductance of the fullerene chain is drastically increased by encapsuling metal atoms into cages.Comment: 10pages and 5 figure

Tissue culture of human thyroid cancer

Human thyroid cancer cells in the pleural effusion were serially cultivated in vitro. Three kinds of cell lines were established from the same primary culture and were designated as PS, TS and TR lines, respectively. These three have been cultured for 574 days up to May 1, 1968. The cells of PS and TR lines were epithelial-like, whereas those of TS line revealed fibroblastic character. The chromosome numbers of PS and TR lines exhibited the modes near the hypertetraploid region, while TS line showed the mode of hypo-triploid number. Eosinophilic particles which were stained metachromatically by toluidine blue were present in the cytoplasm of these cells. The histochemical findings of the cells of each line were identical with those of thyroid cancer cells in vivo. The cells aggregated by the gyratory culture showed epithelial characters under microscopic observation of the sectioned specimens. The tumors produced in conditoned hamsters demonstrated undifferentiated cancer, which resembled the metastatic thyroid cancer of the patient. Neither collagen nor argentaffine fibers were detected with Van Gieson staining or silver impregenation.</p