Preparation of Ta Thin Films by RF Sputtering Method

Ta thin films are prepared by sputtering under various conditions. Ar gas pressure during sputtering is in the range of l×10⁻³～1×10⁻² torr. Either α―Ta(b. C. C.) similar tO a bulk or β―Ta (tetragonal) obtained only on a film is deposited. It appears that α―Ta is formed in a contaminative atomosPhere, while β―Ta is formed in a clean atomosphere. The α or β Ta phase Of the sputtered films is determined by X―ray diffraction pattern or by measuring the specific resistivity. The α―Ta films show the main peak of the (110) plane parallel to the glass substrate and the β―Ta films show the main peak of the(200) plane parallel to the glass substrate. The X―ray oscillation Photographs also show that both the α―Ta and the β―Ta have fibre structures. Specific resistivities of the α―Ta and the β―Ta are 50～100 μΩ―cm and 180 ～230 μΩ-cm, respectively

The Electrical Characteristics of Anodic Oxidized Ta₂O₅ Films

The dielectric constant, the dielectric　loss, the breakdown voltage and the current at high electric fields of Ta₂O₅ 1ayers have been measured using Ta-Ta₂O₅-Au devices with various thicknesses. The Ta₂O₅ layer is prepared by anodizing sputtered Ta films. The rate of anodic oxidation is about 16-18Å/V. The Ta-Ta₂O₅-Au devices with the Ta₂O₅ layers more than 1500Å thick are electrically stable and show the dielectric constants of 20-25, which are slightly smaIIer than those of bulk (25-27). The current at high electric fields depends strongly upon temperature and therefore is considered to be the Schottky current. The breakdown electric field is about 5x10⁶V/cm. A few of the Ta-Ta₂O₅-Au devices studied show the remarkable rectifying characteristics, which may be due to the n― i―p junction of the Ta₂O₅ 1ayer

Fabrication of Electroluminesecent Thin Films Doped with Rare-Earth Ions by Evaporation Method

The fabrication conditions of the electroluminescent ZnS:TbF₃, ZnS:ErF₃, and ZnS;NdF₃ thin films have been investigated. The effects of pre-heating upon the electroluminescent properties, and the relationship between crucible temperature and deposition rate, have been studied. The optimum fabrication conditions of the strong electroluminescent films have been found to be as fol1ows; crucible temperature for ZnS of 760～780℃, crucible temperature for rare-earth fluorides of 780～820℃, and the deposition rate of 300Å/min. These conditions were independent of the rare-earth ions doped. The EL emission spectra of the films have been related to known energy level schemes of doped rare-earth ions. The external power efficiency of 5×10⁶ have been obtained

LATS1/2 kinases trigger self-renewal of cancer stem cells in aggressive oral cancer

Cancer stem cells (CSCs), which play important roles in tumor initiation and progression, are resistant to many types of therapies. However, the regulatory mechanisms underlying CSC-specific properties, including self-renewal, are poorly understood. Here, we found that LATS1/2, the core Hippo pathway-kinases, were highly expressed in the oral squamous cell carcinoma line SAS, which exhibits high capacity of CSCs, and that depletion of these kinases prevented SAS cells from forming spheres under serum-free conditions. Detailed examination of the expression and activation of LATS kinases and related proteins over a time course of sphere formation revealed that LATS1/2 were more highly expressed and markedly activated before initiation of self-renewal. Moreover, TAZ, SNAIL, CHK1/2, and Aurora-A were expressed in hierarchical, oscillating patterns during sphere formation, suggesting that the process consists of four sequential steps. Our results indicate that LATS1/2 trigger self-renewal of CSCs by regulating the Hippo pathway, the EMT, and cell division

Design of Picosecond Modelocked Nd : YAG Laser

Infrared picosecond puIse trains(～7 ns pulse separation) have been obtained from a passive modelocked Nd : YAG laser, Modelocking is achieved by a saturable absorber dye(NDL l12)in 1,2-dichloroethane. The pulse duration is measured by TPF technique to be～30 ps. The efficiency with which energy is transfered from a lamp to the Nd : YAG rod is determined by the delay time of emission from a krypton flashlamp. By varying the impedance characteristics of the krypton flashlamp, the optimum delay time (～105 μs) is obtained. In order to generate the stable picosecond pulse ( ～3 percent fluctuation), the output voltage fluctuation of Power supply must be held within ～2 percent. The SHG (532 nm) and the THG (355 nm) of picosecond pulses from the Nd : YAG laser were also obtained by using KDP(KH₂ P0₄)crystals of Type I and Type II Phase-matching, respectively

Crystal Growth of Rare‐Earth Pentaphosphates

The crystal growth conditions and some opticaI properties for neodymium pentaPhosphate crystals (NdP₅O₁₄) have been studied. The size, shape and quality of crystals are much affected by crystal growth conditions. The optically high quality crystals are obtained from phosphoric acid solution of the weight concentration ratio of 40 : 1 of H₃PO₄ and Nd₂O₃ at the temperature of about 500℃ in saturated water-vapour pressure. The crystals obtained are 2～4 mm in size, and 0.4～l mm in thikness, and their shapes are hexagonal plates. The absorption coefficient is intensitive to crystal growth cnditions, being nearly 13.l cm⁻¹ at 514.5 nm　excitation of Ar laser. The emission peaks are 0.89 μm and l.05 μm with linewidth of adout 10 nm. The lifetime is slightly affected by crystal growth temperature. The lifetime measured are 120 μs and 100 μs respectively, for growth temperature of 550℃ and 500℃

A Study of Computer-Aided Electronic Circuit Design (Ⅰ) : Frequency Response of Amplifiers.

The computer-aided design of electronic circuits (CAD) was carried out with using a rather small type computer, TOSBAC-3400, TOPS-XI. An electronic circuit with three transistors could be analyzed in our calculation. Hybrid-pi transistor model seems an insufficient model for calculations of frequency-response. It will be useful to employ small type computer for tools in CAD

Late cornified envelope 1C (LCE1C), a transcriptional target of TAp63 phosphorylated at T46/T281, interacts with PRMT5

Abstract p63, a transcriptional factor that belongs to the p53 family, regulates epidermal differentiation, stemness, cell death, tumorigenesis, metastasis, and senescence. However, its molecular mechanism remains elusive. We report here that TAp63 phosphorylated at T46/T281 specifically upregulates the late cornified envelope 1C (LCE1C) gene that is essential at a relatively late stage of epithelial development. We identified these phosphorylation sites during a search for the targets of Cyclin G-associated kinase (GAK) in vitro. LCE1C was drastically upregulated by doxycycline-dependent expression of Myc-TAp63 wild-type protein. Luciferase reporter assays using the promoter region of the LCE1C gene confirmed that the phosphorylations of TAp63-T46/T281 contributed to full transcriptional activation of the LCE1C gene. LCE1C interacted with protein arginine methyltransferase 5 (PRMT5) and translocated it from the nucleus to the cytoplasm. Mass spectrometry and co-immunoprecipitation identified importin-α as one of the association partners of LCE1C. In summary, we propose that the GAK_TAp63-pT46/pT281_LCE1C axis plays an important role in preventing the nuclear function of PRMT5