Showing papers by "Tokyo University of Science published in 1994"
197 citations
TL;DR: Results indicate that H MG1 protein can enhance expression in cells in culture at the step of gene transcription and that the DNA binding domains comprising two-thirds of the HMG1 protein molecule are responsible for the inhibition property.
Abstract: Several in vitro studies have suggested that high mobility group (HMG) protein 1 has a role in gene regulation as a trans activator or quasi-transcription factor. However, data on the molecular functions of HMG1 protein in these reactions are contradictory or obscure. In order to assess whether HMG1 protein does, in fact, have transcriptional activation potential, two assay systems in cultured cells were employed. HMG1 protein introduced into COS-1 cells as a complex with a reporter plasmid carrying the lacZ gene enhanced the level of the gene expression. Cotransfection of an expression plasmid carrying HMG1 cDNA into the cells with the reporter plasmid enhanced the activity of beta-galactosidase 2-3-fold in comparison with that of the control effector plasmid. The enhancement was proved to be dependent not on the replication but on the transcription of the reporter plasmid. In the cotransfection experiments, an expression plasmid the HMG1 molecule lacking the acidic carboxyl terminus repressed the expression of the reporter gene. The binding of an HMG1 protein variant lacking the acidic carboxyl terminus to DNA gave an extremely large shift of gel retardation in comparison with the complete HMG1 molecule. Together, these results indicate that HMG1 protein can enhance expression in cells in culture at the step of gene transcription and that the DNA binding domains comprising two-thirds of the HMG1 protein molecule are responsible for the inhibition property. Also, the acidic terminus of the HMG1 molecule is essential for the enhancement of gene expression in addition to elimination of the repression caused by the DNA binding. (ABSTRACT TRUNCATED AT 250 WORDS)
58 citations
Abstract: The motion of a single bubble is simulated directly using the full conservation equations for mass, momentum and energy when the surrounding pressure increases stepwise. The numerical results for several cases reveal that considerable distributions of temperature and concentration of vapor are formed inside the bubble, and heat and mass transfer inside the bubble have a great influence on the bubble motion. Heat transfer on the bubble wall, which is mainly governed by the temperature gradient, causes the thermal damping of the bubble motion. This damping behavior is influenced by the initial bubble radius. Mass transfer on the bubble wall, which is influenced by diffusion phenomena between vapor and noncondensable gas, also greatly effects the bubble motion.
51 citations
50 citations
TL;DR: In this paper, a single-phase Bi4Ti3O12 thin film with c-axis orientation perpendicular to the substrate surface was fabricated on Pt plates and exhibited good ferroelectric properties: coercive field of 7.7 kV/cm and remanent polarization of 8.2 µ C/cm2.
Abstract: Fabrication of ferroelectric Bi4Ti3O12 thin films was carried out by dipping pyrolysis of metal naphthenates. Single-phase Bi4Ti3O12 thin films with c-axis orientation perpendicular to the substrate surface were fabricated on Pt plates. They exhibited good ferroelectric properties: coercive field of 7.7 kV/cm and remanent polarization of 8.2 µ C/cm2. For the films fabricated on Pt/Ti/ SiO2/Si substrates, however, the Bi2Ti2O7 phase mainly grew because of Ti diffusion into the bismuth titanate layer during the heat treatment. Fine micropatterns with linewidth of less than 1 µ m in precursors of Bi4Ti3O12 were formed by spin-coating, irradiation with an electron beam and development. They were crystallized into the Bi4Ti3O12 phase by successive pyrolysis and annealing. The reaction between the metal naphthenate films and energized electrons was studied by IR spectroscopic analysis.
49 citations
TL;DR: In this paper, LiDS and PVP were simultaneously adsorbed to polystyrene latex particles (PS) with diameter of 261 nm from PVP−LiDS and pvinylpyrrolidone (PVP)-LiFOS binary mixed aqueous solutions, and the thickness of PVP was determined by photon correlation spectroscopy (PCS) after pre-fractionation by sedimentation field-flow fractionation (sedFFF).
Abstract: Lithium dodecyl sulfate (LiDS)/lithium perfluorooctanesulfonate (LiFOS) and poly(vinylpyrrolidone) (PVP) were simultaneously adsorbed to polystyrene latex particles (PS) with diameter of 261 nm from PVP−LiDS and PVP−LiFOS binary mixed aqueous solutions. The conformation of PVP adsorbed on PS was estimated by using ESR. The thickness of the adsorbed layer was also determined by photon correlation spectroscopy (PCS) after pre-fractionation by sedimentation field-flow fractionation (sedFFF) which removed the aggregates and permitted an accurate PCS-based determination of the thickness of the coating layer. The adsorption of PVP was enhanced in the presence of LiDS at low LiDS concentrations owing to the formation of a surface complex of PVP and LiDS, followed by a decrease at high LiDS concentrations. A similar trend was observed in the PVP−LiFOS system. In both the PVP−LiDS and PVP−LiFOS systems, the conformation of PVP adsorbed was changed remarkably from loops and tails to trains with the surfactant conce...
41 citations
TL;DR: Results indicate that Rabphilin-3A binds to beta-adducin in the presence of Ca2+ and phosphatidylserine.
37 citations
TL;DR: In this paper, high-resolution photoemission spectra of NiS have been obtained, showing that NiS undergoes a non-metal-metal transition at the level of 1.5V, where the band edge is essentially a step function broadened by 15 meV.
Abstract: We have measured high-resolution photoemission spectra of NiS, which undergoes a nonmetal-metal transition at ${T}_{t}\ensuremath{\sim}260$ K. Below ${T}_{t}$, a small band gap opens; the band edge is essentially a step function broadened only by \ensuremath{\sim} 15 meV. This observation is difficult to reconcile with one-electron band theory, which predicts a much broader band edge, implying a dramatic influence of electron correlation on quasiparticle excitations and on the opening of a band gap in 3D antiferromagnetic insulators.
29 citations
16 citations
TL;DR: In this paper, the aqueous solution properties of homo-and heterotelechelic polysilamine oligomers with vinylsilyl andsec-amino groups end groups were investigated.
Abstract: The aqueous solution properties of homo- and heterotelechelic polysilamine oligomers [N(Et)CH 2 CH 2 N(Et)CH 2 CH 2 SiR 2 CH 2 CH 2 ] n with vinylsilyl andsec-amino groups end groups are investigated
15 citations
TL;DR: It is suggested that EDTA-iron complexes of different charges are generated, depending on the amount of EDTA in the enzymatic system and, consequently, there is a switch between prooxidant and inhibitory effect at some critical ratio of EdTA/iron.
TL;DR: In this article, a single phase of Bi4Ti3O12 with c-axis orientation was fabricated by spin-coating pyrolysis of Bi and Ti naphthenates and successive heat treatments in O2 gas.
Abstract: Fabrication of ferroelectric Bi4Ti3O12 thin films was carried out by spin-coating pyrolysis of Bi and Ti naphthenates and successive heat treatments in O2 gas. Heat treatments in O2 gas were effective for fabrication of ferroelectric Bi4Ti3O12 thin films with c-axis orientation. It was confirmed that the film surface morphology strongly depends on the O2 gas pressure. Smooth platelike grains of the size greater than 10×10 µm2 formed extensively in thin films upon heat treatment at the O2 gas pressure of 4.0×105 Pa. The film thickness was 500 nm. The thin film was a single phase of Bi4Ti3O12 completely oriented along the c-axis with good ferroelectric properties at room temperature: coercive field of 15 kV/cm, remanent polarization of 1.9 µC/cm2, dielectric constant of 43 and loss of 0.02.
TL;DR: In this article, a detailed study on the influence of reading light on the resolution and amplification factor of a spatial light modulator is presented, which is defined as the ratio of the reading light intensity to the maximum intensity of writing light.
Abstract: A spatial light modulator consisting of a polymer‐dispersed liquid crystal (PDLC) film, a dielectric mirror, and a Bi12SiO20 photoconductor is useful for projection‐type displays, optical image processing, and optical computing. However, a portion of the reading light scattered by the PDLC film passes through the dielectric mirror and illuminates the photoconductor, thus causing deterioration of display‐image quality. This article reports on the results of a detailed study on the influence of reading light on the resolution and amplification factor, which is the ratio of reading light intensity to the maximum intensity of writing light. Angular distributions of light scattered by a PDLC cell were measured and the results were used to calculate the intensity of scattered light absorbed by the photoconductor. We then analyzed the optical input/output characteristics of the spatial light modulator with regard to the optical feedback effect caused by the reading light in order to discover the parameter for ev...
Journal Article•
TL;DR: Bi 4 Ti 3 O 12 thin films were obtained by MOCVD method using triorthotolyl-bismuth, Bi(o-C 7 H 7 ) 3, and diisopropoxy-bis-(di-pivaloylmetanato)-titanium, as the metalorganic sources as mentioned in this paper.
Abstract: Bi 4 Ti 3 O 12 thin films were prepared by MOCVD method using triorthotolyl-bismuth, Bi(o-C 7 H 7 ) 3 , and diisopropoxy-bis-(di-pivaloylmetanato)-titanium, Ti(i-OC 3 H 7 ) 2 (DPM) 2 , as the metalorganic sources. Thin films obtained were characterized by XRD analysis and SEM observation. Bi 4 Ti 3 O 12 thin films with high c-axis orientation and most of single phase were deposited on Pt/Ti/SiO 2 /Si and Pt substrates above 500°C in air. Use of newly developed Bi(o-C 7 H 7 ) 3 and Ti(i-OC 3 H 7 ) 2 (DPM) 2 instead of normally used Bi(C 6 H 5 ) 3 and Ti(i-OC 3 H 7 ) 4 was advantageous in fabricating Bi 4 Ti 3 O 12 thin films with c-axis orientation at lower temperatures
TL;DR: From the study estimating the effect of neuraminidase treatment of lymphocytes on their retention to HA surfaces, sialic acid residues on the plasma membrane surface of lymphocyte are suggested as feasible anionic sites showing electrostatic interaction with polyamine grafts.
Abstract: Retention behavior of rat lymphocyte subpopulations (B- and T-cells) was investigated on poly(2-hydroxyethyl methacrylate)-graft-polyamine (HA) copolymers with various copolymer compositions. Separation mechanism of B- and T-cells was then evaluated by focusing on several parameters, such as pH, temperature, and ionic strength. The interaction of lymphocytes with HA surfaces was mainly through the electrostatic force from their retention profile at varying ionic strengths of the medium. Temperature also has a crucial effect on the response of lymphocytes toward pH-induced phase transition of polyamine grafts at the polymer interface with aqueous milieu. At 4 degrees C, both B- and T-cells showed minimal retention on HA surfaces at pH 8. At this pH, polyamine grafts existed in a compact conformation with a low degree of protonation. However, at pHs below 8, at which polyamine grafts existed in extended conformation, the resolution of B- and T-cells was achieved. In contrast, at 23 degrees C, the phase transition of polyamine grafts significantly influenced T-cell retention, resulting in a decrease in the retention of T-cells on HA with polyamine in a compact conformation. Consequently, preferential retention of B-cells was achieved under this condition. The polyamine content was found to be another important factor affecting the retention behavior of lymphocyte subpopulations. On HA copolymers with low polyamine content (HA7, HA10), conformational transition of polyamine grafts showed a significant influence for B-cell retention, although the influence decreased with increasing polyamine content. From the study estimating the effect of neuraminidase treatment of lymphocytes on their retention to HA surfaces, sialic acid residues on the plasma membrane surface of lymphocytes are suggested as feasible anionic sites showing electrostatic interaction with polyamine grafts.
TL;DR: The efficiency of this direct T cell stimulation with the ganglioside-containing liposome was closely related to the efficiency of the tumor growth suppression reported previously by ourselves.
TL;DR: H(ω)の理論式を蛍光寿命を一義的に決定することができる.
Abstract: 高速フーリエ変換を用いた演算により,エタノール溶媒中におけるアントラセンの蛍光放射の伝達関数H(ω)について検討した.H(ω)の理論式を蛍光放射モデルに基づいて導き,実験的に求めたH(ω)からの蛍光寿命の決定法及び検量線の作成法を提案した.この方法はH(ω)をボード線図又は複素平面上に描くもので,蛍光寿命を一義的に決定することができる.本法により,アントラセンの蛍光寿命として4.8±0.2nsを得た.更に検量線の傾きの値からアントラセンの蛍光量子収率を計算した結果,0.28の値を得た.これらの値は,従来の方法で得られた蛍光寿命及び文献値と良い一致を示した.
TL;DR: The results indicate that the in vitro fertilized eggs cryopreserved by ultrarapid freezing, can be, easily and conveniently, used for generation of transgenic mice.
Abstract: In vitro fertilized mouse eggs (C57BL/6N), followed by ultrarapid freezing were used for production of transgenic mice by microinjection of the chicken beta-actin promoter-driven the firefly luciferase cDNA (beta act-Luc). Following micromanipulation, the survival rates of the cryopreserved eggs and of the fresh in vitro fertilized eggs (control) were 70.8% (131/185) and 71.9% (159/221), respectively. After transferring them into oviducts of psudopregnant recipients on Day 1, 13.6% (17/125) of the cryopreserved eggs developed to live offspring and 14.1% (21/149) of fresh eggs did so. It was confirmed by Southern blotting analysis that each two transgenic mice were produced from the cryopreserved eggs (12%, 2/17) and the fresh eggs (10%, 2/21). All of transgenic mice produced from both eggs showed the expression of the luciferase gene. These results indicate that the in vitro fertilized eggs cryopreserved by ultrarapid freezing, can be, easily and conveniently, used for generation of transgenic mice.
TL;DR: In this paper, the first in situ electrical conductivity measurement of monolayers on water during compression on a Langmuir-Blodgett trough is reported for bis(ethylenedioxy)tetrathiafulvalene and 2-decyl-7,7, 8,8,8-tetracyanoquinodimethane systems.
Abstract: The first in situ electrical conductivity measurement of monolayers on water during compression on a Langmuir–Blodgett trough are reported for bis(ethylenedioxy)tetrathiafulvalene and 2-decyl-7,7,8,8-tetracyanoquinodimethane systems, the conductivity of the monolayers being ca. 0.6 S cm–1.
Journal Article•
Journal Article•
TL;DR: The BSA (BSA) and VN (VN) are committed to promoting sustainable development in the region through education, research and innovation.
Abstract: 側鎖 にジアミンの繰返 し構造 を有するポリア ミングラフト共重合体表面 上で血管内皮細胞を 培養 した結果、コポリマー中のアミノ基量の増加に従い、内皮細胞の接着、伸展、増殖が促 進 されることが明かとな った。 また、血清タンパ ク質の影響 を評価する ため、牛胎児血清 (FCS)あ る い はア ル ブ ミン(BSA)を コポ リマ ー表 面 に 吸 着 させ た表 面 上で内 皮細胞 の接 着、 伸展を評価した結果、FCS吸 着層上ではアミノ基量の増加に従い接着、伸 展が促進されたが、 BSA吸 着層上では阻害された。これにより血清タンパク質、特に細胞接着性タンパク質が関与 していると考 え、このコポリマー表面 に吸着 した血清 タンパク質のう ちフ ィブロネクチン (FN)、 ビトロネクチン(VN)の 定量を酵素免疫測定法 により行った。その結果アミノ基の 増加に従いFN、VNの 吸着量も増加 し、アミノ基含有表面がFN、VNの 吸着量の促進 を通じて 細胞増殖能を向上させていることが示唆 された。
01 Jan 1994
Proceedings Article•
01 Dec 1994TL;DR: In this paper, an access timing controlled direct detection optical code division multiple access (ATC-CDMA) system with PPM signaling was proposed to improve the performance of the direct-detection optical CDMA systems without narrowing the chip width.
Abstract: We propose an access timing controlled direct detection optical code division multiple-access (ATC-CDMA) system with pulse position modulation (PPM) signaling to improve the performance of the direct-detection optical CDMA systems with PPM signaling without narrowing the chip width. In ATC-CDMA system, an access timing of each user to the network is controlled and the effect of channel crosstalk is reduced. We analyze the performance of the proposed system under the assumption of Poisson shot noise model for the receiver photodetector. We compare the performance of ATC-CDMA system using PPM signaling with that of conventional CDMA system using PPM signaling at the fixed bit rate and chip width. It is shown that ATC-CDMA system has better performance than conventional CDMA system. Moreover, it is shown that ATC-CDMA system with smaller M and lower access timing probability to the network has better performance at the fixed bit rate and chip width.
07 Aug 1994
TL;DR: In this paper, fine micropatterns with linewidth of 0.35 /spl mu/m were fabricated by irradiation with an electron beam of metal naphthenate films, being precursors of ferroelectric oxides, and development with a solvent.
Abstract: Fine micropatterns with linewidth of 0.35 /spl mu/m were fabricated by irradiation with an electron beam of metal naphthenate films, being precursors of ferroelectric oxides, and development with a solvent. Relatively large patterns were crystallized into the single phase Bi/sub 4/Ti/sub 3/O/sub 12/ with c-axis orientation by successive heat-treatment at 800/spl deg/C. Micropatterns with linewidth of 1 /spl mu/m were crystallized into single crystals and their volume was reduced to 15% by the heat-treatment of PZT and Bi/sub 4/Ti/sub 3/O/sub 12/ thin films formed by the dipping pyrolysis method, which is the base of this patterning process. Good ferroelectric properties were exhibited; the remanent polarization P/sub r/ and the coercive field E/sub c/ were 24 /spl mu/C/cm/sup 2/ and 39 kV/cm for PZT, and 1.6 /spl mu/C/cm/sup 2/ and 24 kV/cm for Bi/sub 4/Ti/sub 3/O/sub 12/, respectively.
TL;DR: In this article, the machining characteristics of diamond chips with electron beam assisted etching (EBAE) have been investigated, and very small holes with a diameter of about 05 ∼ 2 μm, and a depth of about 001 ∼ 07 μm were obtained Line and rectagular patterns with several μm and sub-μm depths were also fabricated.
Abstract: In order to fabricate ultra-precision diamond tools and delineate ultra-fine patterns into diamond chips without adding radiation damage, machining characteristics of diamond chips with electron beam assisted etching (EBAE) has been investigated This processing mechanism is considered as follows: Oxygen atoms or molecules activated by electron beam bombardment on or near the chip surface react with carbon atoms of the diamond surface, resulting in formation of volatile products such as CO or CO2 An EBAE system composed of a scanning electron microscope (SEM) which has an oxygen introduction system was used to etch synthetic single crystal diamond chips When a diamond chip was etched at an applied voltage of 10 kV and an irradiation beam current of 17nA, the depth of the holes increased with an increase of machining time and the diameter of the holes also increased with an increase of machining time When a diamond chip was etched at an applied voltage of 10 kV and an irradiation beam current of 13nA, the depth and diameter of the etched holes merely increased with an increase of flow rate of oxygen gas ranging from 5 cc/min to 30 cc/min, then the depth decreased rapidly with an increase of oxygen gas With this processing method, very small holes with a diameter of about 05 ∼ 2 μm, and a depth of about 001 ∼ 07 μm were obtained Line and rectagular patterns with several μm and sub-μm depths were also fabricated