Complete genome structure of the unicellular cyanobacterium Synechocystis sp. PCC6803

Cyanobacteria are photoautotrophic organisms capable of oxygen-producing photosynthesis similar to that in eukaryotic algae and plants, and because of this, they have been used as model organisms for the study of the mechanism and regulation of oxygen-producing photosynthesis. To understand the entire genetic system in cyanobacteria, the nucleotide sequence of the entire genome of the unicellular cyanobacterium Synechocystis sp. PCC6803 has been determined. The total length of the circular genome is 3,573,470 bp, with a GC content of 47.7%. A total of 3,168 potential protein coding genes were assigned. Of these, 145 (4.6%) were identical to reported genes, and 1,259 (39.6%) and 342 (10.8%) showed similarity to reported and hypothetical genes, respectively. The remaining 1,422 (45.0%) showed no apparent similarity to any genes registered in the databases. Classification of the genes by their biological function and comparison of the gene complement with those of other organisms have revealed a variety of features of the genetic information characteristic of a photoautotrophic organism. The sequence data, as well as other information on the Synechocystis genome, is presented in CyanoBase on WWW [http:/(/)www.kazusa.or.jp/cyano/].     

The vapour pressures and heats of sublimation of model disperse dyes

The vapour pressures and heats of sublimation of 23 model disperse dyes have been measured by the vapour saturation method (modified transpiration method). The data obtained were in good agreement with those produced by the other investigators using the effusion method. The heats of sublimation are discussed in terms of molecular structure.     

Electrostatic properties of antistatic cloth woven partly withelectrically conductive fibers

An electrically conductive fiber and an antistatic cloth woven partly with electrically conductive fibers have a high electrostatic elimination effect in wet as well as dry atmospheres. The electrostatic elimination effect of the antistatic cloth does not decay with repeated washing. Antistatic cloth has been widely used in industry to prevent the electrostatic risk caused by electrification of fiberware. Charge densities and discharge characteristics of various antistatic cloths, controlled primarily by weaving electrically conductive fibers into the cloth, have been investigated experimentally. The electrostatic elimination effect of these is evaluated     

High-performance genetic analysis on microfabricated capillary array electrophoresis plastic chips fabricated by injection molding

We have developed a novel technique for mass production of microfabricated capillary array electrophoresis (mu-CAE) plastic chips for high-speed, high-throughput genetic analysis. The mu-CAE chips, containing 10 individual separation channels of 50-microm width, 50-microm depth, and a 100-microm lane-to-lane spacing at the detection region and a sacrificial channel network, were fabricated on a poly(methyl methacrylate) substrate by injection molding and then bonded manually using a pressure-sensitive sealing tape within several seconds at room temperature. The conditions for injection molding and bonding were carefully characterized to yield mu-CAE chips with well-defined channel and injection structures. A CCD camera equipped with an image intensifier was used to monitor simultaneously the separation in a 10-channel array with laser-induced fluorescence detection. High-performance electrophoretic separations of phiX174 HaeIII DNA restriction fragments and PCR products related to the human beta-globin gene and SP-B gene (the surfactant protein B) have been demonstrated on mu-CAE plastic chips using a methylcellulose sieving matrix in individual channels. The current work demonstrated greatly simplified the fabrication process as well as a detection scheme for mu-CAE chips and will bring the low-cost mass production and application of mu-CAE plastic chips for genetic analysis.     

Permeation, diffusion and dissolution of hydrogen isotopes, methane and inert gases through/in a tetrafluoroethylene film

Tetrafluoroethylene (TFE) is widely used for conventional tritium handling systems such as vacuum seals, tubing and so on. We measured the permeation of the three hydrogen isotopes, methane and the inert gases through a TFE film at room temperature by means of the time-lag method in order to establish the physicochemical properties which determine the solubility and diffusivity of those gases. It was found that the diffusion constant of the inert gases changed exponentially with the heat of vaporization and the solubility was an exponential function of the Lennard-Jones force constant of the gases. On the other hand, hydrogen isotopes and methane deviated from these relations. It is concluded that chemical interactions between the solute and the solvent play an important role for the dissolution and the diffusion of these gases in TFE.     

Secondary ion emission from beryllium surfaces by Ar and /or (Ar+D2) mixed ion bombardments

With respect to the impurity emission and erosion of a Be first wall, a secondary ion mass spectrometric investigation was carried out along with surface characterization with X-ray photoelectron spectroscopy. It was found that Be is emitted as distinct types of chemical forms from the surface owing to sputtering with Ar⁺ and an (Ar⁺+ D⁺₂) mixture: (i) Be and Be-cluster, (ii) oxide and hydroxide, and (iii) hydride and/or deuteride.