Search Results - (Author, Cooperation:K. Tobita)

2018-10-03

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2018-10-03

Institute of Physics (IOP)

1757-8981

1757-899X

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

2015-03-26

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Cilia/genetics/*pathology/physiology/ultrasonography ; DNA Mutational Analysis ; Electrocardiography ; Exome/genetics ; Genes, Recessive ; Genetic Testing ; Heart Defects, Congenital/*genetics/*pathology/ultrasonography ; Humans ; Male ; Mice ; Mice, Inbred C57BL ; Mutation/genetics ; Signal Transduction

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

A charge-exchange neutral particle analyzer for the measurement of the MeV energy range ions produced by nuclear fusion or radio frequency heating has been developed and installed in JT-60U. Neutral particles entering the analyzer are ionized with a carbon foil of thickness 400 A(ring). The energy and mass of the stripped ions are resolved by magnetic and electrostatic fields (E(parallel)B type). The analyzer has eight CsI(Tl) scintillator detectors. The energy range is 0.5–4 MeV for 4He0, the dynamic range is 4.08 and the energy resolution is 6%–11%. The detection efficiency for 4He0 with energy above 1 MeV is 30%–40%. A pulse height analysis (PHA) with 16 channels was adopted to distinguish particle signals from noise arising from neutrons, γ rays and optical lights emitted by JT-60U plasmas. The validity of the PHA was confirmed in a calibration experiment using a neutron source and in a high power heating experiment in JT-60U. © 1995 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Toroidal field (TF) ripple transport, wave-particle interaction, and large magnetohydrodynamic modes can enhance fast ion losses and result in localized heat deposition on the first wall. Two-dimensional (2D) thermal measurement on the first wall provides useful information concerning these fast ion behaviors. In this article, we focus on the application of the 2D measurement with an infrared TV camera to TF ripple loss study. The content is (1) the 2D heat flux profile on the wall due to ripple loss, (2) the effects of the radial electric field, and (3) the ICRF effect on TF ripple loss. These experimental data demonstrate a great potential of infrared thermography in fast ion behavior study. © 1995 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

Fusion gamma rays were measured in D–3He experiments using negative ion-based neutral beam injection (N-NBI) in reverse shear plasmas of the JT-60 tokamak. 3He gas was puffed at plasma initiation and just before N-NB injection. The D–3He reaction produces 3.6 MeV alphas and 14.7 MeV protons, but there is also a small branch which provides 5Li and 16.7 MeV gamma rays. The total D–3He reaction rate can be evaluated from measurement of gamma rays of the 3He (d,γ) 5Li reactions using a 3 in. diam by 3 in. long Bi4Ge3O12 scintillator. The gamma-ray detector was located 17 m below the plasma center and measured the gamma-rays in a vertical line of sight. The detector was mounted inside a heavy collimator with polyethylene and lead shielding. The floor penetration, a 4×8 cm2 hole, was used as a precollimator. Energy calibration of the detector was done with photopeaks for neutron capture gamma rays from the structural materials in D–D discharges. The detection efficiency was calculated with Monte Carlo code MCNP-4B for 16.7 MeV gammas. The pulse height analysis of the gamma rays resulted in the D–3He fusion power of 110±30 kW in this experiment. © 2001 American Institute of Physics.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

In order to measure the ion temperature of the JT-60 tokamak, we have developed a Rutherford scattering system using a helium atom beam. A positive-ion beam generated by an ion source which has a capability of beam energy 200 keV and drain current 3.5 A is converted to a helium atom beam by collision with cold helium gas. The He atom beam, equivalent to 0.6 A, reaches the center of the vacuum chamber of the JT-60 tokamak. The scattering angle is 7.0°. Scattered helium atoms are analyzed by an E(parallel)B-type neutral particle energy analyzer with a gas stripping cell. This scattering system has been applied to investigate additionally heated plasmas by the method of neutral beam injection (NBI), ion cyclotron wave (ICRH), lower hybrid wave (LHRH), and combined heating of NBI+LHRH or ICRH in a parameter range of Bt=4.0 to 4.5 T, Ip=1.0 to 3.2 MA, and n¯e(approximately-less-than)1×1020 m−3. The ion temperatures obtained by the system are consistent with those measured by Doppler broadenings of Ti xxi and Ti xxii resonance lines. To investigate the influence of ion temperature and density profiles and the beam component of NBI heating on the determination of ion temperature, we have evaluated an energy spectrum of scattered atoms by using a simulation code. The result shows that in JT-60 plasmas the beam component hardly exerts an important influence on the determination of ion temperature by this diagnostic system.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

In reactor-grade tokamaks, it is important to investigate confinement properties of alpha particles. A double charge-exchange method using a high-energy probing beam is considered to be the most reliable one in diagnostic methods proposed for the measurement. In JT-60U, an alpha particle production experiment by D-3He ICRF heating will be performed to study the behavior of fusion product alphas. The alpha particle measurement is planned using a helium diagnostic beam (200 keV) and a mass-resolved neutral particle energy analyzer. The expected flux and spectral shape were evaluated by taking into account multistep ionization of helium beam atoms and neutralized alphas. The beam energy is lower than desirable for measuring fast confined alphas near the birth energy. However, by using the beam system, it has been found from the evaluation that we can investigate the confinement properties of fusion product alphas from the spectral shape. And also such a system using a present-day He beam is useful to diagnose behavior of confined alphas in reactor-grade tokamak such as ITER.

Electronic Resource

1089-7623

AIP Digital Archive

Physics

Electrical Engineering, Measurement and Control Technology

An E//B type neutral particle analyzer with an acceleration tube between a stripping cell and a deflection magnet has been developed to measure ion energy distributions in a wide energy range from thermal ions to fast ions up to several hundred kiloelectron volts simultaneously without making the analyzer size large. In the acceleration tube, ions are accelerated up to the detectable energy before coming into the deflection magnetic field. The acceleration method enables us to detect low-energy ions even for a strong deflection magnetic field to measure high-energy ions. Calibration experiments confirmed that ions were well accelerated according to expectation without degrading the abilities of the analyzer. The energy dynamic range Emax/Emin was improved up to 100 by the acceleration method. Using the analyzer, ion energy distributions have been measured in various heating experiments of JT-60.

Electronic Resource

0920-3796

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Energy, Environment Protection, Nuclear Power Engineering

Physics

Electronic Resource

1432-1971

Key words: Children — Doppler echocardiography — Flow convergence region — Mitral regurgitation — Proximal isovelocity surface area method

Springer Online Journal Archives 1860-2000

Medicine

Abstract. The proximal isovelocity surface area (PISA) method for calculating volume flow through the regurgitant orifice has attracted significant attention. A number of in vitro studies and clinical studies in adults suggest that the method is accurate. However, when applying the method to children it must be noted that the absolute regurgitation volume is small, and the range of body sizes is wide. This study investigated the accuracy of the PISA method for quantitative assessment of the severity of mitral regurgitation in children. Twenty children aged 7 months to 12 years (average 4.7 years) with mitral regurgitation but without interventricular shunt or aortic stenosis were selected for this study. Underlying cardiac diseases included atrioventricular septal defects in nine, isolated mitral regurgitation in five, and association with other heart defects in six. The PISA radius (r) and the duration of regurgitation (T) were measured on color M-mode recordings, with the M line passing through the center of the PISA. Assuming that the PISA is a hemisphere, maximal regurgitant flow rate (MFR: ml/s) was calculated as MFR = 2π×~ r 2×~ V (r= maximal radius, V= aliasing velocity), and regurgitant stroke volume (RSVpisa) as RSVpisa = 2π×~ MSR ×~ V×~ T (MSR = mean square of the PISA radius during regurgitation). As a validating standard, total stroke volume (TSV) using two-dimensional echocardiography determined by the area–length volumetry method and forward stroke volume (FSV) by the pulsed Doppler method were measured, and regurgitant stroke volume (RSVD: RSVD= TSV − FSV) and regurgitant fraction (RF: RF = RSVD/TSV) were calculated. A linear correlation was found between MFR, RSVpisa, and RSVD (X) (MFR = 4.2X + 54.0, r= 0.84. RSVpisa = 1.0X + 9.8, r= 0.90), and both RSVpisa and MFR divided by body surface area (BSA: m2) revealed a significant correlation with regurgitant fraction (X) by nonlinear regression analysis (RSVpisa/BSA = 26.2 ×~ X/(1 − X) + 16.8, r= 0.85. MFR/BSA = 121.8 ×~ X/(1 − X) + 92.2, r= 0.79). It is concluded that maximal regurgitant flow rate, regurgitant stroke volume, and regurgitant fraction can be accurately predicted in children using the PISA method by Doppler echocardiography.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary The NS 2 messenger RNA (mRNA) of several influenza A viruses was shown to be synthesized in primary transcription. Analysis of in vitro translation products of mRNAs from infected MDCK cells treated with cycloheximide indicated that the NS 2 mRNA in addition to the NS 1 mRNA was synthesized with PR/8, Udorn, and Aichi viruses. The findings indicated that the NS 1 mRNA of these viruses was able to be spliced into the NS 2 mRNA as a primary transcript without viral protein synthesis, although the extent of splicing varied among different virus strains.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary Fusion (fusion from within) of polarized MDCK monolayer cells grown on porous membranes was examined after infection with Sendai viruses. Wild-type virus, that buds at the apical membrane domain, did not induce cell fusion even when the F glycoprotein expressed at the apical domain was activated with trypsin. On the other hand, a protease activation mutant, F 1-R, with F protein in the activated form and that buds bipolarly at the apical and basolateral domains, caused syncytia formation in the absence of exogenous protease. Anti-Sendai virus antibodies added to the basolateral side, but not at the apical side, inhibited cell fusion induced by F 1-R. In addition, T-9, a mutant with bipolar budding phenotype of F 1-R but with an uncleavable F protein phenotype like wild-type virus, induced cell fusion exclusively when trypsin was added to the basolateral medium. By electron microscopy, cell-to-cell fusion was shown to occur at the lateral domain of the plasma membrane. These results indicate that in addition to proteolytic activation of the F protein, basolateral expression of Sendai virus envelope glycoproteins is required to induce cell fusion.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary To clarify the function of the NS gene of a highly cytolytic mutant of influenza virus B/Yamagata/1/73 which expresses an NS1 protein with a long carboxyl terminal deletion (clone 201), we prepared a single gene reassortant (201 L-77) and a control reassortant (YL-20) in which all the genes were of wild type influenza virus B/Lee/40 origin except NS gene which was derived from either clone 201 or wild type B/Yamagata. Comparative studies have revealed that 201 L-77 destructed infected cells more severely and much earlier after infection than did YL-20, although both produced comparable amount of infectious virus. The highly cytolytic reassortant 201 L-77 produced a small plaque, while the weakly cytolytic reassortant YL-20 produced a large plaque in MDCK cells. There was little difference between the two reassortants in the time course and the amount of synthesis of viral proteins within the infected cells. However, the mode of synthesis of viral RNA (vRNA) by 201 L-77 was greatly altered compared with YL-20.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary The protective effects of the passive administration of convalescent serum from mice infected with Sendai virus were evaluated in mice challenged intranasally with wild-type and a pantropic variant (F1-R) of Sendai virus. Adoptive transfer of the serum efficiently prevented F1-R from infecting the systemic organs, but it failed to protect the mice from infections of the respiratory tracts by either virus. Virus replication in nasal turbinates was not diminished while infection in the lung was suppressed sufficiently for the infected mice to survive the infection. These findings suggest that serum antibody is less effective for the protection against viral infections on the surface of the respiratory tract, but it is effective for inhibition of spread of the virus into the systemic organs.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary The MDBK-R cell line is a variant of the MDBK cell line, which was derived by three consecutive high multiplicity superinfections of MDBK cells with AWBY-140 virus, a mutant of influenza virus A/WSN (H 1N 1). MDBK-R cells are permissive for productive replication of AWBY-140, but resist lysis by the virus and grew normally without producing infectious virus after replication of the mutant occurred there. By polymerase chain reaction (PCR), we demonstrated nucleotide sequences specific to all the 8 genes of AWBY-140 in MDBK-R cells which had been infected with the mutant at a high multiplicity and subsequently received 25 passages. This suggests that the genes of influenza virus mutant persisted in the dividing host cells for a long time after productive infection, when none of the cells was producing virus. We were also able to amplify the M gene related sequence of the mutant from both poly(A)+ and poly(A)− fractions of the RNA extracted from the cells at 27th passage level by PCR, which suggests that the persisting genes were replicated and transcribed, but we failed to demonstrate any viral protein in the cells by Western blotting.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary Translation of poliovirus RNA is initiated by entry of ribosomes into the nucleotide sequence (internal ribosomal entry site; IRES) within the 5′-untranslated region (5′-UTR). Efficiency of this translation initiation in rabbit reticulocyte lysates (RRL) was very low and was greatly enhanced by addition of the ribosomal salt-wash fraction (RSW) prepared from HeLa cells. This stimulating activity in the RSW was partially purified by gel-filtration column chromatography and its molecular weight was estimated to be higher than 240 000. Several proteins that bind specifically to the poliovirus IRES were detected in the active fraction. Among those, a 57 kDa protein, recognized by antibodies against polypyrimidide tract-binding protein (PTB), was found. In addition, La protein (52 kDa) which is a human antigen recognized by antibodies from patients with autoimmune disorders was also detected. Further purification on a hydroxylapatite column resulted in considerable loss of the stimulatory activity, accompanied by a reduction of the apparent molecular weight of active component(s). These results suggest that fully active HeLa cell stimulatory factors for the translation initiation on poliovirus RNA function in RRL as a large complex consisted of several components including PTB and La protein.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary By serial subculture of MDCK cells which survived high multiplicity infections with AWBY-140, a weakly cytolytic mutant of influenza virus A/WSN (H1N1), we established a variant cell line (MDCK-L cells) that was uniquely resistant to infection with influenza A and B viruses, yielding 3 to 4 orders lower amount of progeny virus compared with MDCK cells. Competitive polymerase chain reaction revealed that the amount of primary transcript produced in MDCK-L cells infected with 10 PFU/cell of influenza virus A/Aichi was suppressed to 1/100 of that in MDCK cells similarly infected, although the amount of virus adsorbed to MDCK-L cells was 1/4 of MDCK cells. Even when MDCLK-L cells were infected with 40 PFU/cell of Aichi to overcome the lower amount of internalized virus in those cells, the results were the same. The synthesis of v-, c- and mRNAs, as well as proteins of infected A/Aichi was below detectable level in MDCK-L cells, in contrast with MDCK cells, where they were clearly demonstrable by ribonuclease protection assay or polyacrylamide gel electrophoresis.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary Growth of influenza B viruses is restricted at high temperatures. Within B/Yamagata-infected MDCK cells, the synthesis of the M protein was selectively inhibited at 39° C, accompanied by a reduced production of virus particles.

Electronic Resource