Search Results - (Author, Cooperation:T. Takagi)

2018-05-15

The American Society for Microbiology (ASM)

0022-538X

1098-5514

Medicine

2018-05-18

American Physical Society (APS)

0031-9007

1079-7114

Physics

Condensed Matter: Structure, etc.

2011-04-09

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Apoptosis Regulatory Proteins/deficiency/genetics ; Cell Death ; Cell Differentiation ; DNA-Binding Proteins/deficiency/genetics/*metabolism ; Membrane Proteins/deficiency/genetics ; Mice ; Mice, Inbred BALB C ; Mitochondria/metabolism/pathology ; Proto-Oncogene Proteins/deficiency/genetics ; Receptors, Antigen, T-Cell/immunology/metabolism ; Signal Transduction ; T-Lymphocytes/*cytology/immunology/metabolism ; Thymus Gland/cytology/immunology

2018-07-24

Institute of Physics (IOP)

1755-1307

1755-1315

Geography

Geosciences

Physics

2018-05-18

Nature Publishing Group (NPG)

2045-2322

Natural Sciences in General

1089-7550

AIP Digital Archive

Physics

Although BaPb0.75Bi0.25O3 (BPB) has a comparatively large superconducting coherence length of ∼7 nm and no reported anisotropy in its superconducting parameters, polycrystalline BPB exhibits the same rapid decrease in transport critical current density (Jct) with low applied field (〈∼50 Oe) that is characteristic of grain boundary weak links in cuprate superconductors (e.g., La2−xSrxCuO4, YBa2Cu3O7−x ). We have studied the effects of processing thermal history on the formation and morphology of grain boundary phases, and on the composition of BPB boundaries with and without second phase, in order to understand the origin of these weak links. Scanning transmission electron microscopy and Auger electron spectroscopy results show the presence of a Pb-Bi-Ba-O phase that is wetting and liquid above ∼570 °C, but which retracts to three-grain junctions upon slow cooling or annealing at lower temperatures. However, weak-link behavior persists in materials with retracted secondary phase, as well as in hot isostatically pressed samples that never exceed the secondary phase melting temperature. It is found that the grain boundaries remain Bi- and Pb-rich even after the retraction of secondary phases; samples that never exceed the melting temperature of the secondary phase show absence of segregation at some but not all grain boundaries. The composition of the grain boundaries as well as Jct vs temperature measurements indicate that the boundaries act as SIS tunnel junctions.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Titanium oxides films of 150–400 nm thickness were deposited on glass and Si substrates by reactive ionized cluster beam deposition. Characteristics of films deposited at different deposition conditions of oxygen partial pressure, ionization current, and acceleration voltage have been examined. The films prepared at an oxygen pressure of 1–2×10−4 Torr showed stoichiometry of TiO2. The film is a mixture of anatase and rutile structures. By increasing the ionization current from 0 to 400 mA, the refractive index of the film could be increased from 2.0 to 2.6. By deposition at a high ionization current, the film showed rutile structure, whereas the anatase structure could be formed at a low ionization current. The optical absorption of the films is low when the films are deposited at a higher acceleration voltage.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Al2O3 films about 1000 A(ring) thick were deposited on polished Si(100) substrates by the reactive ionized cluster beam method. It was found that the index of refraction, the etch rate in HF, and the microstructure of the films could be controlled by varying substrate temperatures up to 600 °C and acceleration voltages between 0.25 and 3 kV.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

A zinc oxide (ZnO) whisker crystal has been examined as a probing tip for scanning tunneling microscopy (STM). Atomic resolution images of the surfaces of highly oriented pyrolytic graphite and Si(111)-7×7 structures are successfully observed by STM using a ZnO whisker tip, demonstrating that the ZnO whisker crystal is applicable to a STM tip.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

The structures of melt-spun, and subsequently annealed, Zr70Pd30 alloys, which form a nanosized icosahedral quasicrystalline phase during the primary crystallization of the amorphous phase, have been investigated by means of electron-diffraction pair-distribution-function (PDF) analysis. The PDF analysis for this alloy was performed by precise measurements of elastic halo-electron-diffraction intensities. Possible structure models for as-quenched and annealed amorphous structures were constructed with the help of reverse Monte Carlo simulations. In order to obtain the local atomic structures, the Voronoi-polyhedra analysis was performed. A considerable number of icosahedral clusters with Zr atoms in the center are present in the simulated structure of the as-quenched state, and the number of the clusters increases by annealing. © 2001 American Institute of Physics.

Electronic Resource

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

p59fyn, a member of the src-family protein tyrosine kinase, is expressed abundantly in thymus. We examined the possible involvement of p59fyn in thymic involution induced by a fasting stress in Fyn–/– mice. An acute 48 h fast resulted in severe atrophy of the thymus and a marked decrease of the total thymocyte number with depletion of the CD4+CD8+[double positive (DP)] population in Fyn+/+ (control) mice. A remarkable increase in terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling-positive signals was detected in the fasted group of control mice. However, these findings were not observed in Fyn–/– mice. Interestingly, MRL/MPJ-lpr/lpr, a Fas-deficient model animal, also showed no significant decrease of DP cell numbers in the fasted group. p59fyn is known to interact with Fas signalling, and these findings suggest that p59fyn is involved in fasting-induced thymic involution, raising the possibility that Fas/p59fyn-mediated signalling may, at least partially, be associated with the phenomenon.

Electronic Resource

0167-4781

(Tetrahymena pyriformis) ; (Tetrahymena thermophila) ; Amino acid sequencing ; Calmodulin ; cDNA cloning

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

0167-4781

(N. diversicolor) ; Amino acid sequence ; Exonintron boundary ; Hemoglobin ; Linker chain L2 ; cDNA

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

0003-2697

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Neutrophils activation and tumour necrosis factor-α (TNF-α) induction play a critical role in aspirin-induced gastric mucosal injury. Peroxisome proliferator-activated receptor-γ (PPAR-γ), a member of the nuclear hormone receptor superfamily, has recently been implicated as a regulator of inflammatory responses. The aim of the present study was to determine whether pioglitazone, a specific PPAR-γ ligand, can ameliorate aspirin-induced gastric mucosal injury in rats, and whether the agent can inhibit the increase in neutrophil accumulation associated with TNF-α expression.〈section xml:id="abs1-2"〉〈title type="main"〉Methods:Aspirin-induced injury was produced by the intragastric administration of aspirin (200 mg/kg) and HCl (0.15 N, 8.0 mL/kg). Pioglitazone was given to the rats by gastric intubation 1 h before the aspirin administration. Thiobarbituric acid-reactive substances and tissue-associated myeloperoxidase activity were measured in gastric mucosa as indices of lipid peroxidation and neutrophil infiltration. The gastric concentration of TNF-α and the expression of TNF-α mRNA was determined by ELISA and reverse transcriptase-polymerase chain reaction.〈section xml:id="abs1-3"〉〈title type="main"〉Results:The intragastric administration of acidified aspirin induced hyperemia and haemorrhagic erosions in rat stomachs. The increase in the total gastric erosive area after aspirin administration was significantly inhibited by treatment with pioglitazone in a dose-dependent manner. The increases in thiobarbituric acid-reactive substances and myeloperoxidase activity after aspirin administration were both significantly inhibited by pre-treatment with pioglitazone (10 mg/kg). The gastric content of TNF-α increased and the expression of TNF-α mRNA was up-regulated after aspirin treatment. However, the peak TNF-α mRNA expression 1 h after aspirin administration was inhibited by pioglitazone.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusion:Based on these data, the beneficial effects of pioglitazone on aspirin-induced gastric mucosal injury may be attributed to its anti-inflammatory properties.

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Tumour necrosis factor (TNF-α) is a candidate factor for involvement in inflammation-mediated gastric mucosal injury. However, the effect of this cytokine on gastric epithelial cells has been poorly investigated. In the present study, we examined whether gastric epithelial cells are resistant to TNF- α-induced apoptosis, and whether this resistance is related to ubiquitin-proteasome-associated nuclear factor-κB (NF-κB) activation.〈section xml:id="abs1-2"〉〈title type="main"〉Methods:The rat gastric mucosal cell line RGM-1 was grown in DMEM/F12 medium supplemented with 10% FCS. Confluent monolayers of cells were pretreated or not for 60 min with PSI, a peptide aldehyde known to specifically inhibit the chymotrypsin-like activity of 26S proteasome. Cells were subsequently stimulated with recombinant rat TNF-α and their viability was determined by WST-1 assay. Apoptosis was confirmed by fluorescence microscopy after staining with Hoechst 33342 and propidium iodide, and DNA fragmentation was determined by flow cytometry using an APO-BRDU kit. IκB-α and the p65 binding subunit of NF-κB were detected by Western blots.〈section xml:id="abs1-3"〉〈title type="main"〉Results:Twenty-four-hour incubation with TNF-α alone or PSI alone did not affect the cell viability of RGM-1 cells. Pretreatment with PSI significantly enhanced the level of apoptosis induced by TNF-α. In RGM-1 cells treated with TNF-α, cytoplasmic IκB-α decreased and p65 in nuclear extracts increased markedly 30 min after cytokine stimulation. Pretreatment with PSI at 12.5 μmol/L blocked these TNF-α-induced changes.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusion:PSI enhances TNF-α-induced apoptosis through inhibition of NF-κB activation in RGM-1 cells.

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Heme oxygenase (HO) is the rate-limiting enzyme in the catabolism of heme, followed by production of biliverdin, free iron and carbon monoxide (CO). Three mammalian HO isozymes have been identified, one of which, HO-1, is a stress-responsive protein induced by various oxidative agents. HO-2 and HO-3 genes are constitutively expressed. Recent studies demonstrate that the expression of HO-1 in response to different inflammatory mediators may contribute to the resolution of inflammation and have protective effects in several organs against oxidative injury. Although the mechanism underlying the anti-inflammatory actions of HO-1 remains poorly defined, both CO and biliverdin/bilirubin have been implicated in this response. In the intestinal tract, HO-1 is shown to be transcriptionally induced in response to oxidative stress, preconditioning and acute inflammation. Recent studies suggest that the induction of HO-1 expression plays a critical protective role in intestinal damage models induced by trinitrobenzene sulphonic acid or dextran sulphate sodium, indicating that activation of HO-1 may act as an endogenous defensive mechanism to reduce inflammation and tissue injury in the intestinal tract. These in vitro and in vivo data suggest that HO-1 may be a novel therapeutic target in patients with inflammatory bowel disease.

Electronic Resource

0005-2736

(Canine kidney) ; ATPase, Na^+/K^+- ; Dissociation-association equilibrium ; Laser light scattering ; Quaternary structure

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0005-2736

ATPase, Na^+ /K^+- ; Association-dissociation ; Membrane protein ; Molecular weight ; Oligomeric structure ; Phospholipid

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource