Open heart surgery in patients with chronic dialysis

From January, 1986 to May, 1995, twelve patients with dialysis (11 hemodialysis; HD, and one continuous ambulatory peritoneal dialysis; CAPD) received open heart surgery. They consist of 10 males and two females aged between 35 and 66 with a mean of 58.8. The duration of dialysis was 6.8 years in a mean (the shortest for 2 months and the longest for 16 years). They classified into an equal number of four in NYHA class II, III and IV. Two of them had isolated coronary artery bypass grafting, four had aortic valve replacement (AVR) and two had mitral valve replacement (MVR). Others were each one of AVR and MVR, AVR plus MVR with tricuspid annuloplasty (TAP), AVR plus TAP, and removal of left atrial myxoma. All patients except for one of CAPD were dialysed daily 2 or 3 days before operation. Three patients were managed postoperatively with HD, one with PD, six with continuous hemodiafiltration, and two with continuous hemofiltration. The operative mortality was 25% (3/12). The causes of death were left ventricular rupture, bronchospasm, and respiratory failure. All patients who died were in class in III and IV. For the improvement of the results we emphasize the necessity of early operation that should be scheduled in class II period.     

Vitellogenesis-related ovary cathepsin D from Xenopus laevis: purification and properties in comparison with liver cathepsin D

Cathepsin D was purified from ovaries of Xenopus laevis by both QAE-cellulose and pepstatin-Sepharose chromatography and then characterized and compared with Xenopus liver cathepsin D. Ovary cathepsin D appeared predominantly as a 43-kilodalton (kDa) molecular mass, as revealed by SDS-polyacrylamide gel electrophoresis, whereas the liver enzyme was obtained exclusively as a 36-kDa protein. The purified 43-kDa ovary enzyme cleaved vitellogenin limitedly to produce yolk proteins at pH 5.6. The specific activity of ovary cathepsin D was five to six times lower than that of the liver enzyme, as measured by hemoglobin-hydrolysis at pH 3, but the ovary enzyme was shown to be superior to the liver enzyme in terms of vitellogenin-cleaving activity, as examined at pH 5.6. Ovarian enzyme preparations contained variable amounts of 36-kDa species; this form was considered to be an autolytic product of the 43-kDa form arising during purification, because it was not detected in oocyte extracts but was generated by incubation of the purified 43-kDa enzyme alone in an acid solution. The conversion of the 43-kDa form by hepatic factors was accompanied by a marked increase in hemoglobin-hydrolytic activity.     

Application of positron annihilation line-shape analysis to fatigue damage for nuclear plant materials

Positron annihilation line-shape analysis is sufficiently sensitive to detect microstructural defects such as vacancies and dislocations. We are developing a portable positron annihilation system and applying this technique to fatigue damage in type 316 stainless steel and SA508 low alloy steel. The positron annihilation technique was found to be sensitive in the early fatigue life, i.e. up to 10% of the fatigue life, but showed little sensitivity in later stages of the fatigue life in type 316 stainless steel and SA508 low alloy steel. Type 316 stainless steel a higher positron annihilation sensitivity than that of SA508. It was considered that the amount of dislocation density change in the stainless steel was greater than that in the low alloy steel, because the initial microstructure contained a low dislocation density because of the solution heat treatment for the type 316 stainless steel.     

Fully Radiative Current Path Structure (FRACS) for sub-0.1 μmemitter transistor

A new structure is proposed for bipolar transistors - FRACS (Fully Radiative Current Path Structure). A FRACS transistor has a line emitter and a cylindrical base and collector or a point emitter and a spherical base and collector. Device parameters of the FRACS transistor is obtained by extending the conventional one-dimensional transistor model to a two- or three-dimensional model. In this structure, base transit time is reduced as the emitter size is reduced by radiative collector current flow. Using this model, a general bipolar transistor with a shallow link base is found to increase the cutoff frequency as the emitter size is reduced. The Kirk effect is suppressed in this structure because of the small collector current density at the collector-base junction. The effect was experimentally examined. A cylindrical base was fabricated by thermal diffusion of boron to achieve the FRACS transistor. Cutoff frequency was observed to increase as the emitter size was reduced. Maximum cut-off frequency of 64 GHz was achieved by this transistor with a 25-nm thick base formed by rapid vapor-phase diffusion     

Conducting Langmuir-Blodgett films as electrode materials

Photoelectric cells based on Langmuir-Blodgett (LB) films were fabricated using dye monolayers as photoconductors and N-docosylpyridinium-di(tetracyanoquinodimethane) (PT) monolayers as one of the electrode materials. It is found that PT films can be used as a wiring material instead of large work function metals such as silver or Ni-Cr. However, in comparison with the photoelectric cells using the conventional metals, a few different properties were observed for those wired with PT. These differences are assignable to the difference between the LB film-metal and the LB film-LB film contacts.     

GRADE: A software environment for machine translation

GRADE, a software environment for machine translation is described. It has been developed for the Mu machine translation project, which was supported by the Science & Technology Agency of the Japanese Government. GRADE consists of 3 components: (1) a grammar writing language based on flexible tree-to-tree transformation rules with a control mechanism and an interpreter; (2) software tools for constructing and maintaining grammar rules; and (3) software tools for developing dictionary databases which are based on the concept ofneutral dictionary. In this paper, these software packages are discussed from the viewpoint of the development of a large scale machine translation system.The authors thank their colleagues in the Mu project, who helped in the development of the system and already returned to their private companies to develop their own machine translation systems. We also wish to thank the researchers at the Japan Information Center of Science and Technology, and the Electrotechnical Laboratory of Kyoto University for their cooperation.     

Analysis of skew antenna around a square tower for UHF TVbroadcasting

The authors discuss the installation and characteristics of a UHF skew antenna mounted on a tower that already supports seven other VHF arrays used for TV broadcasting. The skew antenna consists of four antenna arrays arranged in a circle with a radius of about 3 m and radiating tangentially. The phase difference between the antenna arrays is 90°. The skew antenna system produces a good omnidirectional pattern, but when located on the tower the reflections from the flat face and the wedge diffractions modify the pattern. The calculation of the horizontal radiation pattern using the geometrical theory of diffraction is compared with the measured pattern. Both the UHF antenna's radiation pattern and its mutual interference are compared with the existing VHF antennas     

An experimental investigation of minimum fluidization velocity at elevated temperatures and pressures

Minimum fluidization data at elevated temperatures and pressures are relatively scarce in the literature. This study was undertaken to provide some new data under these conditions. Minimum fluidization velocities at temperatures up to 800°K and pressures up to 5 MPa were measured for uniformly-sized glass beads with diameters between 0.2 mm and 4 mm in beds ranging in diameter from 30 mm to 50 mm. The experimental results are compared with a number of empirical correlations from the literature to determine the validity of the correlations under these elevated temperature and pressure conditions.     

The extraction of iron(III) from aqueous acid solutions by di(2-ethylhexyl)phosphoric acid

The extraction of iron(III) from aqueous solutions containing sulphuric, hydrochloric and nitric acids by di(2-ethylhexyl)phosphoric acid (DEHPA) in kerosene has been investigated under different conditions. As a result, it is found that although extraction is dominated by an ion-exchange reaction, the rate of iron(III) extraction from sulphuric acid solutions to reach equilibrium is relatively slow in comparison with that from hydrochloric or nitric acid solutions. In the extraction from aqueous solutions containing hydrochloric or nitric acid, however, the DEHPA combines with iron(III) according to the solvating reaction at higher aqueous acidity. From studies on the rate of the extraction from sulphuric acid solutions, examined under non-equilibrium, it is confirmed that dependencies of extraction rate on hydrogen ion and DEHPA concentrations are in the first and inverse first orders, respectively. The hydrolyzed species is considered to interpret the extraction mechanism in this system.     

The SH2 domain of Shc suppresses EGF-induced mitogenesis in a dominant negative manner

Recently, we have shown that an EGF-R-mutant lacking the autophosphorylation sites phosphorylates Shc and retains mitogenic activity. In this report, we have shown that in these cells, in response to EGF, Ras is fully activated with formation of the tyrosine-phosphorylated Shc-Grb2-mSOS complex without the receptor. This pointed out the importance of Shc in EGF-induced Ras activation. To investigate the mechanism of tyrosine phosphorylation of Shc by EGF-R, we carried out in vitro kinase assays using immunoprecipitated EGF-R and bacterially-expressed Shc proteins as substrates. The EGF-R phosphorylated Shc, but not the Shc SH2 mutant, lacking binding ability for phosphotyrosine. This suggests that intact Shc SH2 is essential for the full-length Shc to become phosphorylated, probably by inducing a conformational change in Shc. Thus a Shc SH2 peptide may inhibit competitively Shc phosphorylation. We microinjected the Shc SH2 domain into NIH3T3 cells overexpressing the EGF-R. Microinjected Shc SH2 greatly suppressed EGF-induced DNA synthesis. But microinjection of neither the Shc SH2 mutant nor PLC-gamma 1 SH2 had any effect. This suppressing effect was rescued by comicroinjection of the full-length Shc, suggesting Shc SH2 specifically suppressed the Shc pathway. Thus we concluded Shc phosphorylation is crucial, whereas receptor autophosphorylation is dispensable, in EGF-induced mitogenesis.