In recent years, a higher level of medical technology has been required. One such technology is regenerative medicine. In regenerative medicine, much research has been done on stem cells. Likewise, much research has been done on scaffold fabrication techniques. Ink-jet techniques have attracted attention as a method of fabrication of a three-dimensional scaffold. However, scaffolds fabricated by ink-jet techniques require further research. In this study, we have fabricated a highly biocompatible scaffold utilizing an ink-jet technique. The fabrication utilized an electrostatic ink-jet technology called the PELID method. Micro-fiber scaffolds must be suitable for the growth of cells, and film thickness must also be able to be controlled by a few microns. The scaffolds that we have fabricated were designed to satisfy these two requirements, using collagen. We fabricated the scaffolds in spinning mode, which is one of the ink-jet modes. When an applied voltage was high, the diameter of fibers narrowed and film thickness became uniform. In addition, we layered a film of this collagen (scaffold) on MDCK cells, and the cells grew well. We demonstrated that it is possible to fabricate scaffolds with a high biocompatibility by using this method. In the future, we hope to fabricate simple layered body tissue by applying this method.
High temperature superconducting current leads have been prepared by the TFA-MOD processed YBCO tapes. The YBCO tape is 5 mm in width, 190 mm in length and about 130 µm in overall thickness. The YBCO superconducting layer with 1.5 µm in thickness is formed on oxide buffer layers on Hastelloy substrate tape. Transport current is supplied through Ag layer deposited on YBCO layers. A current lead unit is composed of twenty YBCO tapes soldered to Cu caps at both of ends and a GFRP board. The twenty tapes are arrayed in five rows of stacked four tapes in parallel. The transport current of ten current lead units ranges from 1.5 kA to 2.5 kA at 77 K. The heat leakage of the current lead unit with 150 mm in length between 77 K and 4.2 K is estimated to be 281 mW. Therefore, the heat load at 2 kA corresponds to 140 mW/kA, which is around one order of magnitude smaller than that of conventional current lead. The small heat leakage results from high current performance and low thermal conductivity in the present HTS current lead.
In this study, we present the experimental simulation of the deivertor target geometry via detached plasma formation of hydrogen plasma in a linear divertor plasma simulator TPD-SheetIV. Three types of target geometry (V-shaped, oblique, and vertical targets) have been investigated. The eletron temperature (Te) and density (ne) of the plasma are measured with Langmuir probe. It is also intended to show that the observed hydrogen Lyman spectra could be explained by recombination processes. The V-shaped target enhances the recycling and reduction in heat load.
As a basic experiment for the development of neuromotor prostheses (NMPs), movement related neural signals were measured using rats. The electrodes were surgically implanted in the motor cortex, spinal cord, sciatic, and femoral nerves. The measurements were carried out under two conditions, which were voluntary movement and involuntary motion evoked by startle auditory stimuli. Obtained signal waveforms under two separate conditions were compared and analyzed. In both conditions, a descending transmitting signal was observed. However, remarkable readiness activity of the motor cortex was not seen in both cases with a 5 times averaging. Using our experimental model, neurophysiological characteristics of motor generation were revealed. Based upon these findings, the possibility of new NMPs for the disabled was discussed.
The effects of electron beam (EB) irradiation of 0.22 MGy on the adhesive peeling load (Lp) of composites laminated with polypropylen (PP) and polydimethylsiloxane (PDMS) polymers films were investigated. EB irradiation enhanced the mean Lp from 7.0 mN for untreated composite to 23 mN for 0.22 MGy EB irradiated one without glue. Since EB irradiation generated dangling bonds with electrons in PP, they probably induced the polarization of terminated atoms of PDMS, as well as enhancement of effective interface area, and then atrracted for each polymer at the interface. Results indicated that EB irradiation at 0.22 MGy enhanced the Lp, therefore, it was concluded that EB irradiation was probably a useful tool for quick lamination of different polymers with sterilization.