120 results on '"Iwao Hashimoto"'
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2. Multifaceted Growth and Change through failure experience in adolescence: In terms with related factors
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Iwao Hashimoto
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Related factors ,Psychology ,Developmental psychology - Published
- 2015
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3. Synthesis of sapphire nanoparticles with graphite shells by hot-filament chemical vapor deposition
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Yoshikazu Homma, Hiroki Kato, Iwao Hashimoto, and Miki Ishii
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Materials science ,Chemical engineering ,Hybrid physical-chemical vapor deposition ,Inorganic chemistry ,Sapphire ,Nanoparticle ,General Materials Science ,Graphite ,Chemical vapor deposition ,Hot filament ,Combustion chemical vapor deposition - Published
- 2014
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4. Graphite-encapsulated alumina nanoparticles fabricated by hot-filament chemical vapor deposition
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Hiroki Kato, Iwao Hashimoto, Yoshikazu Homma, and Miki Ishii
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Materials science ,Chemical engineering ,Hybrid physical-chemical vapor deposition ,Plasma-enhanced chemical vapor deposition ,Chemical vapor infiltration ,Nanoparticle ,General Materials Science ,Graphite ,Chemical vapor deposition ,Combustion chemical vapor deposition ,Electron beam physical vapor deposition - Published
- 2013
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5. Rate control of cell sheet recovery by incorporating hydrophilic pattern in thermoresponsive cell culture dish
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Masatoshi Kuroda, Teruyuki Matsunaga, Teruo Okano, Megumi Muraoka, Nobuyuki Tanaka, Masayuki Yamato, Yumiko Tomiyama, Kazuyoshi Itoga, Jun Kobayashi, Tatsuya Shimizu, Iwao Hashimoto, Yoshikazu Kumashiro, and Kazuo Umemura
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Materials science ,biology ,Radical polymerization ,Metals and Alloys ,Biomedical Engineering ,Photoresist ,Biomaterials ,Cell culture ,Polymer chemistry ,Ceramics and Composites ,biology.protein ,Biophysics ,Irradiation ,Bovine serum albumin ,Cell adhesion ,Cell sheet ,Micropatterning - Abstract
Thready stripe-polyacrylamide (PAAm) pattern was fabricated on a thermoresponsive poly(N-isopropylacrylamide) (PIPAAm) surface, and their surface properties were characterized. A PIPAAm surface spin-coated with positive photoresist was irradiated through a 5 µm/5 µm or a 10 µm/10-µm black and white striped photomask, resulting in the radical polymerization of AAm on the photoirradiated area. After staining with Alexa488 bovine serum albumin, the stripe-patterned surface was clearly observed and the patterned surface was also observed by a phase contrast image of an atomic force microscope. NIH-3T3 (3T3) single cells were able to be cultured at 37°C on the patterned surfaces as well as on a PIPAAm surface without pattern, and the detachment of adhered cells was more rapidly from the patterned surface after reducing temperature. Furthermore, the rate of detachment of 3T3 confluent cell sheet on the patterned surface was accelerated, compared with on a conventional PIPAAm surface under the static condition. The rate control of cell sheet recovery should contribute the preservations of cell phenotype and biological functions of cell sheet for applying to clinical trials.
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- 2013
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6. Emotional weeping in adolescence: Weeping proneness and intrapersonal effects of weeping
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Tadayuki Sawada, Iwao Hashimoto, and Koichiro Matsuo
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Psychology ,Developmental psychology ,Intrapersonal communication - Published
- 2013
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7. Interleukin-1β induces tumor necrosis factor-α secretion from rat hepatocytes
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Tominori Kimura, Masaki Kaibori, Hiroyuki Inaba, Iwao Hashimoto, Takafumi Hara, Tadayoshi Okumura, Yoshito Tanaka, Mikio Nishizawa, Emi Yoshigai, and A-Hon Kwon
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Messenger RNA ,Hepatology ,Lipopolysaccharide ,medicine.medical_treatment ,Monocyte ,Biology ,Molecular biology ,chemistry.chemical_compound ,Infectious Diseases ,Cytokine ,medicine.anatomical_structure ,chemistry ,Sense (molecular biology) ,Gene expression ,medicine ,Tumor necrosis factor alpha ,Northern blot - Abstract
Aim Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine involved in various inflammatory diseases. The only production of TNF-α in the liver is thought to be from hepatic macrophages known as Kupffer cells, predominantly in response to bacterial lipopolysaccharide (LPS). Methods Primary cultured rat hepatocytes were used to analyze TNF-α expression in response to the pro-inflammatory cytokine, interleukin-1β (IL-1β). Livers of rats subjected to LPS-induced endotoxemia were analyzed. Results Immunocytochemistry and enzyme-linked immunosorbent assays demonstrated that IL-1β-treated rat hepatocytes secreted TNF-α, and RNA analyses indicated that TNF-α mRNA was induced specifically by IL-1β. Northern blot analysis showed that not only mRNA, but also a natural antisense transcript (asRNA), was transcribed from the rat Tnf gene in IL-1β-treated hepatocytes. TNF-α was detected in the hepatocytes of LPS-treated rats. Both TNF-α mRNA and asRNA were expressed in the hepatocytes of LPS-treated rats, human hepatocellular carcinoma and human monocyte/macrophage cells. To disrupt the interaction between TNF-α asRNA and TNF-α mRNA, sense oligonucleotides corresponding to TNF-α mRNA were introduced into rat hepatocytes resulting in significantly increased levels of TNF-α mRNA. One of these sense oligonucleotides increased a half-life of TNF-α mRNA, suggesting that the TNF-α asRNA may reduce the stability of TNF-α mRNA. Conclusion IL-1β-stimulated rat hepatocytes are a newly identified source of TNF-α in the liver. TNF-α mRNA and asRNA are expressed in rats and humans, and the TNF-α asRNA reduces the stability of the TNF-α mRNA. Hepatocytes and TNF-α asRNA may be therapeutic targets to regulate levels of TNF-α mRNA.
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- 2013
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8. Nonlocality in spherical-aberration-corrected HAADF STEM images
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Masaru Shimizu, Kazuto Watanabe, Koichiro Honda, Takashi Yamazaki, Yasutoshi Kotaka, Iwao Hashimoto, Hironori Fujisawa, and Masahiro Ohtsuka
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Quantum nonlocality ,Spherical aberration ,Optics ,Diffuse scattering ,Structural Biology ,business.industry ,Chemistry ,Thermal ,Scanning transmission electron microscopy ,Absorption potential ,business - Abstract
Nonlocality in spherical-aberration-corrected high-angle annular dark-field (HAADF) scanning transmission electron microscope (STEM) images is theoretically and experimentally examined using the absorption potential describing thermal diffuse scattering (TDS). A detailed comparison between the simulated and the experimentally obtained high-quality HAADF STEM images of an Si(110) bulk structure and a PbTiO3(100)/SrTiO3(100) interfacial structure unambiguously demonstrates the need to use a nonlocal TDS absorption potential. The nonlocality in the TDS absorption potential cannot be ignored in a detailed analysis of spherical-aberration-corrected HAADF STEM images of materials consisting of several heavy elements, although it can be completely disregarded for those consisting of only light elements.
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- 2013
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9. Stabilization of human interferon-α1 mRNA by its antisense RNA
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Iwao Hashimoto, Tominori Kimura, Emi Yoshigai, Hisao Yamada, Mikio Nishizawa, Tadayoshi Okumura, Shiwen Jiang, and Masao Nishikawa
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Small interfering RNA ,Interferon-α1 mRNA ,miR-1270 ,RNA Stability ,Guinea Pigs ,Biology ,Respirovirus Infections ,Sendai virus ,Cell Line ,Cellular and Molecular Neuroscience ,RNA interference ,Sense (molecular biology) ,Animals ,Humans ,RNA, Antisense ,Gene Silencing ,RNA, Messenger ,Molecular Biology ,Pharmacology ,B-Lymphocytes ,Base Sequence ,microRNA ,Interferon-α1 antisense RNA ,Interferon-alpha ,RNA ,Cell Biology ,MRNA stabilization ,Fibroblasts ,Non-coding RNA ,Molecular biology ,Up-Regulation ,Antisense RNA ,MicroRNAs ,RNA silencing ,Regulatory RNA ,Molecular Medicine ,mRNA stabilization ,Research Article - Abstract
Antisense transcription is a widespread phenomenon in the mammalian genome and is believed to play a role in regulating gene expression. However, the exact functional significance of antisense transcription is largely unknown. Here, we show that natural antisense (AS) RNA is an important modulator of interferon-α1 (IFN-α1) mRNA levels. A ~4-kb, spliced IFN-α1 AS RNA targets a single-stranded region within a conserved secondary structure element of the IFN-α1 mRNA, an element which was previously reported to function as the nuclear export element. Following infection of human Namalwa lymphocytes with Sendai virus or infection of guinea pig 104C1 fetal fibroblasts with influenza virus A/PR/8/34, expression of IFN-α1 AS RNA becomes elevated. This elevated expression results in increased IFN-α1 mRNA stability because of the cytoplasmic (but not nuclear) interaction of the AS RNA with the mRNA at the single-stranded region. This results in increased IFN-α protein production. The silencing of IFN-α1 AS RNA by sense oligonucleotides or over-expression of antisense oligoribonucleotides, which were both designed from the target region, confirmed the critical role of the AS RNA in the post-transcriptional regulation of IFN-α1 mRNA levels. This AS RNA stabilization effect is caused by the prevention of the microRNA (miRNA)-induced destabilization of IFN-α1 mRNA due to masking of the miR-1270 binding site. This discovery not only reveals a regulatory pathway for controlling IFN-α1 gene expression during the host innate immune response against virus infection but also suggests a reason for the large number of overlapping complementary transcripts with previously unknown function. Electronic supplementary material The online version of this article (doi:10.1007/s00018-012-1216-x) contains supplementary material, which is available to authorized users.
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- 2012
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10. Psychological effects of emotional crying in adults: Events that elicit crying and social reactions to crying
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Tadayuki Sawada, Koichiro Matsuo, and Iwao Hashimoto
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Adult ,media_common.quotation_subject ,Empathy ,Crying ,Negative attitude ,Interpersonal communication ,Developmental psychology ,Social support ,Surveys and Questionnaires ,medicine ,Humans ,Interpersonal Relations ,General Psychology ,media_common ,Communication ,Social Support ,Middle Aged ,Catharsis ,Criticism ,Female ,medicine.symptom ,Psychology ,Social psychology ,Intrapersonal communication - Abstract
This research focused on both the psychological benefits and costs of crying. We investigated the relationships of intrapersonal and interpersonal consequences of crying. Female nurses (N = 300) were requested to describe one of the most impressive negative episodes where they had cried. Then, they were asked to complete a questionnaire including a scale of their psychological changes after the crying episode and the social reactions when they cried. Factor analysis revealed five components of the psychological changes scale. Solitary crying had greater effects for both psychological benefits and costs after crying than crying in front of others. Factor analysis revealed three components of the scale of social reactions. When they cried in front of others, "catharsis", "positive attitude", and "recognition of the relationship with others" after crying were associated with "empathy and social support" from others. The factors of "recognition of negative reality" and "negative attitude" were associated with "criticism and slander" from others. These results were discussed in terms of the communicative functions and the reflective functions of adult crying.
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- 2012
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11. O-Acylation of Substituted Phenols with Various Alkanoyl Chlorides Under Phase-Transfer Catalyst Conditions
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Naoyoshi Egashira, Iwao Hashimoto, Cristian Simion, Yoshiharu Mitoma, and Alina Simion
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Hindered phenol ,O acylation ,chemistry.chemical_compound ,Aqueous solution ,chemistry ,Organic Chemistry ,Organic chemistry ,Phenols ,Phase-transfer catalyst ,Catalysis ,Dichloromethane ,Tetrabutylammonium chloride - Abstract
Esterification of several types of mono- and disubstituted phenols with various mono- and dialkanoyl chlorides was performed in phase-transfer catalysis conditions, using tetrabutylammonium chloride in a mixture of aqueous NaOH and dichloromethane. The process is particularly efficient (almost quantitative yields) as well as rapid (only 5 min reaction time, at a temperature of 0 °C).
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- 2011
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12. Nuclear and cytoplasmic effects of human CRM1 on HIV-1 production in rat cells
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Hisatoshi Shida, Tominori Kimura, Yoshiyuki Hakata, Mika Nagai-Fukataki, Iwao Hashimoto, and Takashi Ohashi
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Regulation of gene expression ,Messenger RNA ,Viral replication ,Cell culture ,Cytoplasm ,viruses ,Genetics ,Cell Biology ,Transfection ,Biology ,Group-specific antigen ,Nuclear export signal ,Molecular biology - Abstract
The human immunodeficiency virus type 1 (HIV-1) regulatory protein, Rev, mediates the nuclear export of unspliced gag and singly spliced env mRNAs by bridging viral RNA and the export receptor, CRM1. Recently, rat CRM1 was found to be less efficient than human CRM1 in supporting Rev function in rats. In this study, to understand the role of CRM1 in HIV propagation, the mechanism underlying the function of human and rat CRM1 in HIV-1 replication was investigated in rat cells. The production of viral particles, represented by the p24 Gag protein, was greatly enhanced by hCRM1 expression in rat cells; however, this effect was not simply because of the enhanced export of gag mRNA. The translation initiation rate of gag mRNA was not increased, nor was the Gag protein stabilized in the presence of hCRM1. However, the processing of the p55 Gag precursor and the release of viral particles were facilitated. These results indicated that hCRM1 exports gag mRNA to the cytoplasm, not only more efficiently than rCRM1 but also correctly, leading to efficient processing of Gag proteins and particle formation.
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- 2011
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13. Rapid and Convenient Thioester Synthesis Under Phase-Transfer Catalysis Conditions
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Yoshiharu Mitoma, Alina Marieta Simion, Cristian Simion, Naoyoshi Egashira, and Iwao Hashimoto
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Aqueous solution ,Chemistry ,Organic Chemistry ,S-acylation ,Biochemistry ,Catalysis ,Inorganic Chemistry ,Thioester synthesis ,chemistry.chemical_compound ,Phase (matter) ,Organic chemistry ,lipids (amino acids, peptides, and proteins) ,Tetrabutylammonium chloride ,Dichloromethane - Abstract
Various thioesters were obtained through an efficient phase-transfer catalysis method, by treating several thiophenols with different acyl chlorides, in a biphasic system composed of 10% aqueous NaOH and dichloromethane in the presence of tetrabutylammonium chloride. The thiolation reaction was complete in only 5 minutes, at 0°C.
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- 2010
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14. Analysis of the nitrogen pollution load potential from farmland in the Tedori River Alluvial Fan Areas in Japan
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Kazuo Murashima, Toshisuke Maruyama, Keiu Kitada, Fumikazu Noto, and Iwao Hashimoto
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Pollution ,Hydrology ,Nitrogen balance ,Environmental Engineering ,media_common.quotation_subject ,engineering.material ,Agronomy ,Agricultural land ,Nutrient pollution ,engineering ,Environmental science ,Fertilizer ,Water quality ,Water pollution ,Eutrophication ,Agronomy and Crop Science ,Water Science and Technology ,media_common - Abstract
A nitrogen balance study was carried out by setting up a test paddy in order to estimate the nitrogen pollution load potential (NPLP) from farmland in the Tedori River Alluvial Fan Areas and the load from the entire area under consideration was estimated using the cropping record and fertilizer application rate (FAR). The total NPLP was estimated to be 261 tons/year and the load from the paddy 79 tons/year for 5,704 ha, which would translate to an intensity of 14 kg/ha, while the load from the vegetable field was estimated to be 118 tons/year for 215 ha, which would equate to an intensity of 549 kg/ha. The pollution loads for the vegetables were significantly greater than those for the rice. The load for the barley was 57 tons/year for 261 ha (216 kg/ha) and that for the orchards was 23 tons/year for 64 ha (359 kg/ha). The estimation of soybean load was a negative 15 tons/year for 717 ha (−21 kg/ha), which meant that the nitrogen in the yield was greater than the FAR. The results also confirmed the yield absorption ratio in relation to the FAR. The load from the paddy for the entire area was also estimated using the percolation rate and the water quality load underneath the farmland was estimated to be 89 tons/year.
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- 2010
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15. Irrigation practice and water usage characteristics in sand dune upland fields in the Hokuriku Region, with much rainfall in Japan: case studies on watermelon and Japanese radish
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Fumikazu Noto, Toshisuke Maruyama, Iwao Hashimoto, Masateru Senge, and Kengo Ito
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Crop ,Irrigation ,Environmental Engineering ,Agronomy ,Evapotranspiration ,Environmental science ,Sowing ,Growing season ,Transplanting ,Agronomy and Crop Science ,Water content ,Water use ,Water Science and Technology - Abstract
We investigated the use of irrigation water for a successive planting of watermelon followed by Japanese radish in a sand dune area in the Hokuriku Region. The main results were as follows: (1) Upland field tested in the study used a large volume of irrigation water in spite of its location in the Hokuriku Region where rainfall was plentiful. Notwithstanding this, frequent irrigation was considered necessary. (2) Watermelon was cultivated as a Spring–Summer crop with a mean cultivation period of 102 days, during which it was irrigated for 59 days at 1.7-day average intervals with an irrigation volume of 7.1 mm/watering and a total irrigation volume of 428 mm over its entire growing season. The amount of rainfall during the period was 604 mm during 42 days of rainfall. Soil moisture levels in the upland field were kept at relatively high values ranging between pF1.3 and pF1.5 at 15-cm depth with frequent irrigation during no-rainfall period. (3) Japanese radish was cultivated as a Summer–Autumn crop with a mean cultivation period of 71 days during which it was irrigated for 39 days at 1.9-day average intervals with an irrigation volume of 9.4 mm/watering and a total irrigation volume of 358 mm over its entire growing season. The amount of rainfall during the period was 376 mm during 29 days of rainfall. Frequent irrigations were used to maintain the soil moisture levels in the upland field within the range of pF1.4–pF1.6 at 15 cm depth. (4) During the irrigation period, the amount of water used for irrigation was 5.9 mm/day in watermelon and 6.1 mm/day in Japanese radish which are greater than evapotranspiration (ET). In addition, during pre-irrigation, the preparation of the seeding bed can be carried out at the right time which contributes to producing high-quality Japanese radish in adequate quantity. In addition, pre-irrigation for preparation of bed for watermelon transplanting is very important for better time management and high-quality production. For this purpose, the irrigation facilities need to be functioning very well.
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- 2010
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16. Effect of chromatic aberration on atomic-resolved spherical aberration corrected STEM images
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Kazuto Watanabe, Yasutoshi Kotaka, Koji Kuramochi, Takashi Yamazaki, Iwao Hashimoto, and Masahiro Ohtsuka
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Physics ,Contrast transfer function ,business.industry ,Dark field microscopy ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Lens (optics) ,Spherical aberration ,Optics ,law ,Chromatic aberration ,Scanning transmission electron microscopy ,business ,Instrumentation ,Noise (radio) - Abstract
The effect of the chromatic aberration (C(c)) coefficient in a spherical aberration (C(s))- corrected electromagnetic lens on high-resolution high-angle annular dark field (HAADF) scanning transmission electron microscope (STEM) images is explored in detail. A new method for precise determination of the C(c) coefficient is demonstrated, requiring measurement of an atomic-resolution one-frame through-focal HAADF STEM image. This method is robust with respect to instrumental drift, sample thickness, all lens parameters except C(c), and experimental noise. It is also demonstrated that semi-quantitative structural analysis on the nanometer scale can be achieved by comparing experimental C(s)- corrected HAADF STEM images with their corresponding simulated images when the effects of the C(c) coefficient and spatial incoherence are included.
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- 2009
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17. Nucleocytoplasmic transport of luciferase gene mRNA requires CRM1/Exportin1 and RanGTPase
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Tominori Kimura, Hisao Yamada, Masao Nishikawa, and Iwao Hashimoto
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viruses ,Active Transport, Cell Nucleus ,Receptors, Cytoplasmic and Nuclear ,Karyopherins ,Biology ,Transfection ,Pathology and Forensic Medicine ,Luciferases, Firefly ,Cell Line, Tumor ,Humans ,RNA, Messenger ,Nuclear export signal ,Molecular Biology ,Gene ,Cell Nucleus ,Nuclear Export Signals ,Messenger RNA ,RNA-Binding Proteins ,RNA ,General Medicine ,Molecular biology ,Genes, rev ,Nuclear Pore Complex Proteins ,ran GTP-Binding Protein ,Cell culture ,Nucleocytoplasmic Transport ,Ran ,Fatty Acids, Unsaturated ,HIV-1 ,HeLa Cells - Abstract
Human immunodeficiency virus type 1 Rev (regulator of the expression of the virion) protein was shown to reduce the expression level of the co-transfected luciferase reporter gene (luc+) introduced to monitor transfection efficiency. We studied the mechanism of the inhibitory Rev effect. The effect, caused by nuclear retention of luc+ mRNA, was reversed if rev had a point mutation that makes its nuclear export signal (NES) unable to associate with cellular transport factors. The Rev NES receptor CRM1 (chromosome region maintenance 1)-specific inhibitor, leptomycin B, blocked luc+ mRNA export. This finding was also supported by the overexpression of delta CAN, another specific CRM1 inhibitor that caused inhibition of luciferase gene expression. Experiments involving tsBN2 cells, which have a temperature-sensitive RCC1 (regulator of chromosome condensation 1) allele, demonstrated that luc+ expression required generation of the GTP-bound form of RanGTPase (RanGTP) by RCC1. The constitutive transport element (CTE)-mediated nuclear export of luc+ mRNA was found to also depend upon RanGTP. Nuclear export of luc+ mRNA is thus suggested to involve CRM1 and RanGTP, which Rev employs to transport viral mRNA. The Rev effect is therefore considered to involve competition between two molecules for common transport factors.
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- 2009
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18. Assessment for nitrogen pollution loads from farmland, Japan, by objective yield and standard fertilizer usage
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Iwao Hashimoto, Hiroshi Takimoto, Denichi Nakade, and Toshisuke Maruyama
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Pollution ,Environmental Engineering ,business.industry ,Crop yield ,media_common.quotation_subject ,Environmental pollution ,engineering.material ,Agronomy ,Agricultural land ,Agriculture ,Nutrient pollution ,engineering ,Environmental science ,Paddy field ,Fertilizer ,business ,Agronomy and Crop Science ,Water Science and Technology ,media_common - Abstract
This research proposes an assessment for nitrogen (N) pollution loads potential from farmland, based on comparison of N in objective crop yields with standard fertilizer usage. N in the objective yield was calculated using the “Standard Table of Food Composition in Japan”. Three findings were made by considering yields removed from farmland. First, paddy rice and beans have a low pollution potential, with rice paddies showing a negative pollution potential for N (around −14 kg/ha). Second, almost all vegetable and orchard crops tested had a high pollution potential for N, although this differed from crop to crop. Third, our outcomes align well with farmland pollution potential and non-absorbed nitrogen (NAN) as defined by Nishio, although the latter and indices rely on a laborious and complicated method. The correlation coefficients were 0.745 (R 2 = 0.555). These outcomes show the effectiveness of our proposed assessment for potential environmental pollution loads.
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- 2009
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19. Many-beam dynamical simulation for multilayer structures without a superlattice cell
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Iwao Hashimoto, Takashi Yamazaki, Masahiro Ohtsuka, and Kazuto Watanabe
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Materials science ,business.industry ,Superlattice ,Relative shift ,Epitaxy ,Molecular physics ,Condensed Matter::Materials Science ,Optics ,Structural Biology ,Transmission electron microscopy ,Dynamical simulation ,business ,High-resolution transmission electron microscopy ,Beam (structure) - Abstract
A many-beam dynamical theory for plan-view high-resolution transmission electron microscopy (HRTEM) images of multilayer systems without the limitation of a superlattice cell is proposed. The accuracy of our method is examined by comparing convergent-beam electron-diffraction calculations of Si(011) and HRTEM calculations of a system of epitaxial Al(100) on GaAs(100). Furthermore, this method is applied to CdSe clusters embedded in MgO, where it is revealed that the relative shift of their crystal-lattice planes produces moiré-like fringes.
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- 2009
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20. Direct Observation of an Ordered Phase in (11\bar20) Plane InGaN Alloy
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Tokuma Furuzuki, Kazuhiro Ohkawa, Iwao Hashimoto, Takashi Yamazaki, Shizutoshi Ando, Kazuhide Kusakabe, and Koji Kuramochi
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Materials science ,Physics and Astronomy (miscellaneous) ,Condensed matter physics ,Band gap ,Alloy ,General Engineering ,General Physics and Astronomy ,Cathodoluminescence ,engineering.material ,Epitaxy ,Crystallography ,Transmission electron microscopy ,Phase (matter) ,engineering ,Polar ,Metalorganic vapour phase epitaxy - Abstract
A polar-dependent phase with spontaneous atomic ordering is found in a nonpolar (1120) plane In0.08Ga0.92N film grown by metalorganic vapor-phase epitaxy. An atomic arrangement is a periodic sequence of group-III sublattices, such as In0.04Ga0.96N/In0.12Ga0.88N, that is only observed in a nitrogen polar region through systematic transmission electron microscopy investigation. Cathodoluminescence (CL) in the nitrogen polar region, i.e., spontaneously ordered atomic structure of InGaN, reveals anomalous emission behavior, specifically an S-shape-like (increase–decrease) temperature dependence of CL peak energy. It is suggested that the spontaneous ordered atomic structure of InGaN plays the role of a localized center owing to band gap shrinkage, which has been reported in other III–V alloy systems.
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- 2008
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21. Quantitative structural analysis of twin boundary in α-Zn7Sb2O12 using HAADF STEM method
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Kentaro Suzuki, Kazutaka Mitsuishi, Kazuo Furuya, Kazuto Watanabe, Koji Kuramochi, Iwao Hashimoto, and Takashi Yamazaki
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Octahedron ,Chemistry ,Plane (geometry) ,Scanning transmission electron microscopy ,Analytical chemistry ,Maximum entropy method ,Crystal twinning ,Instrumentation ,Dark field microscopy ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Abstract
The structure and composition of the 1/4{1 1 0} twin boundary in α - Zn 7 Sb 2 O 12 have been determined by using quantitative high-angle annular dark field scanning transmission electron microscopy (HAADF STEM) analysis. The noise in the experimental HAADF STEM images is reduced by using the maximum entropy method and average processing, and the parameters used in dynamical simulations are experimentally determined. From the analysis, it has been found that octahedral sites in the twin boundary slightly shift parallel to the [1 1 0] direction, and a reduction of the Sb concentration at the octahedral sites on the plane adjacent to the twin boundary was detected. The reduction was measured from three regions in the same twin boundary, and the Sb concentrations were 4 ± 3 , 8 ± 3 and 19 ± 2 at % from 33 at%.
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- 2008
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22. Quantitative and easy estimation of a crystal bending effect using low-order CBED patterns
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Iwao Hashimoto, Takashi Yamazaki, Kazuto Watanabe, Masahiro Ohtsuka, Koji Kuramochi, and Akihiro Kashiwagi
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Crystal ,Crystallography ,Materials science ,Electron diffraction ,Present method ,Ultimate tensile strength ,Relaxation (NMR) ,Physics::Accelerator Physics ,Bending ,Convergent beam ,Instrumentation ,Molecular physics - Abstract
The quantitative measurement of a crystal bending effect is performed using low-order zone-axis convergent beam electron diffraction (CBED) patterns. Although the accuracy of the present method is inferior to that of the method of using split higher order Laue zone lines, this method enables us to estimate the crystal bending effect at a region very close to the interface and to easily judge whether the crystal bending effect results in a tensile bend or a compressive bend. As an application of the present method, the crystal bending effect at a region close to the SiGe/Si interface was measured. It was found that the crystal bending effect is due to a thin-foil relaxation of almost 0.3 degrees at a region that is approximately 10 nm away from the interface.
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- 2008
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23. Highlymeso-Diastereoselective Pinacol Coupling of Aromatic Aldehydes Mediated by Al Powder/Copper Sulfate in Water
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Naoyoshi Egashira, Masashi Tashiro, Yoshiharu Mitoma, Iwao Hashimoto, and Cristian Simion
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chemistry.chemical_compound ,chemistry ,Aqueous medium ,Pinacol ,Organic Chemistry ,Polymer chemistry ,Coupling (piping) ,Organic chemistry ,Copper sulfate ,Aluminium powder ,Al powder ,Coupling reaction ,Catalysis - Abstract
Pinacol-type coupling reaction products presenting a high meso-diastereoselectivity (the ratio dl/meso was 4/96 up to 1/99) were obtained in fair to good yields (24–69%) using several aromatic aldehydes as starting materials and aluminium powder/copper sulfate as catalysts, in water, under reflux conditions.
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- 2008
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24. Evaluation of N and P mass balance in paddy rice culture along Kahokugata Lake, Japan, to assess potential lake pollution
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Iwao Hashimoto, Toshisuke Maruyama, Kazuo Murashima, and Hiroshi Takimoto
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Pollutant ,Pollution ,Environmental Engineering ,business.industry ,media_common.quotation_subject ,engineering.material ,Straw ,Crop ,Agronomy ,Agriculture ,engineering ,Environmental science ,Fertilizer ,business ,Surface runoff ,Eutrophication ,Agronomy and Crop Science ,Water Science and Technology ,media_common - Abstract
Kahokugata Lake, a closed lake, has been subject to eutrophication. This research was conducted to clarify the actual phenomena and evaluation of the discharges of N and P from paddy test fields in the lowlands into Kahokugata Lake. A comprehensive mass balance of N and P was obtained from 4 years of study. About N, the mean value of harvested unhulled rice (79.9 kg/ha) was greater than mean controlled release fertilizer inputs (56.7 kg/ha). Other inputs and outputs include N in atmospheric acid deposition (21.4 kg/ha) and N fixation–denitrification (9.2 kg/ha). The rice straw recycled after harvest was balanced by straw produced in the succeeding year. The runoff and percolation losses discharged into the lake was 11.3 kg/ha, (8.6% of total inputs). Since the rice harvested was consumed domestically, which taking out from the farmland and, therefore, nitrogen pollutant into the lake was becoming small, paddy rice at this site is considered an “anti-polluting, purifying or cleansing” crop. The P content in harvested rice (39.4 kg/ha) was balanced by fertilizer inputs (36.4 kg/ha). Previous studies examining inflow–outflow relationships without considering a comprehensive mass balance may lead to erroneous conclusions. Our findings indicate paddy rice in lowlands could be an environmentally friendly crop and can play an important role in reducing pollution of lakes, and therefore should be considered in land use planning.
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- 2008
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25. Shape effect of microtwins on high-resolution transmission electron microscope images
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Kazuto Watanabe, N. Nakanishi, T Yamazaki, Iwao Hashimoto, and K. Kuramochi
- Subjects
Silicon ,Chemistry ,business.industry ,High resolution ,chemistry.chemical_element ,Surfaces and Interfaces ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Optics ,Transmission electron microscopy ,Materials Chemistry ,Electrical and Electronic Engineering ,High-resolution transmission electron microscopy ,business - Abstract
The shape effect of microtwins on high-resolution transmission electron microscopy (HRTEM) images is demonstrated with the help of a detailed comparison between experimental HRTEM images of recrystallized silicon (including many microtwins) and corresponding dynamical simulations. The analysis points to an important fact: The shape effect of microtwins leads to artificial contrasts. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
- Published
- 2008
- Full Text
- View/download PDF
26. Developing the Creative Knowledge Capacity of Citizens Participating in Urban Environmental Planning
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Kozo Kurata, Toshihiro Hirosaki, Daigo Yoshida, Iwao Hashimoto, and Yoshinobu Kumata
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business.industry ,Environmental resource management ,General Social Sciences ,business ,Environmental planning ,General Environmental Science - Published
- 2007
- Full Text
- View/download PDF
27. Extended dynamical HAADF STEM image simulation using the Bloch-wave method
- Author
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Kazuto Watanabe, Iwao Hashimoto, Takashi Yamazaki, and Koji Kuramochi
- Subjects
Chemistry ,business.industry ,chemistry.chemical_element ,Germanium ,Ferroelectricity ,Crystal ,Optics ,Structural Biology ,Scanning transmission electron microscopy ,Atomic number ,Diamond cubic ,business ,Perovskite (structure) ,Bloch wave - Abstract
An extended method is proposed for the precise simulation of high-angle annular dark-field (HAADF) scanning transmission electron-microscope (STEM) images for materials containing elements with large atomic numbers and for thick specimens. The approach combines a previously reported method utilizing two kinds of optical potential [Watanabe, Yamazaki, HashimotoShiojiri (2001). Phys. Rev. B, 64, 115432] with a representation of a crystal sliced into multiple layers. The validity of the method is demonstrated by simulated images for elements with the diamond structure (Si, Ge and alpha-Sn) and for the perovskite BaTiO3.
- Published
- 2006
- Full Text
- View/download PDF
28. Local structural characterization of epitaxial a ‐plane InGaN/GaN thin films by transmission electron microscopy
- Author
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N. Nakanishi, Kazuhiro Ohkawa, Kazuhide Kusakabe, Iwao Hashimoto, and Takashi Yamazaki
- Subjects
Materials science ,business.industry ,Transmission electron microscopy ,Lattice (order) ,Optoelectronics ,Thin film ,Selected area diffraction ,Condensed Matter Physics ,Epitaxy ,business - Abstract
Structural analysis of the submicron area of an InGaN thin film was conducted using transmission electron microscopy. By obtaining the selected area diffraction patterns of c -plane InGaN/GaN and a -plane InGaN/GaN films, the local lattice parameters were measured. Coherent growths were checked at the respective samples for different growth orientations, and the In concentration of the InGaN layer was also measured. Furthermore, there is a slight tilt in the growth direction between the GaN and InGaN layers in the a -plane InGaN/GaN film. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
- Published
- 2006
- Full Text
- View/download PDF
29. In concentration and tilt of the a-plane InGaN/GaN film by TEM analysis
- Author
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Kazuhiro Ohkawa, Iwao Hashimoto, Takashi Yamazaki, Kazuhide Kusakabe, and N. Nakanishi
- Subjects
Materials science ,business.industry ,Plane (geometry) ,Condensed Matter Physics ,Epitaxy ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Materials Science ,symbols.namesake ,Optics ,Tilt (optics) ,Fourier transform ,Electron diffraction ,Transmission electron microscopy ,symbols ,Optoelectronics ,Electrical and Electronic Engineering ,business ,High-resolution transmission electron microscopy ,Spectroscopy - Abstract
A systematic structural analysis of a-plane InGaN/GaN was performed using electron diffraction, high-resolution transmission electron microscopy (HRTEM), and energy-dispersive X-ray spectroscopy. From the results of local structural analysis using Fourier diffractograms of HRTEM images, it was found that a-plane InGaN/GaN exhibits coherent epitaxial growth and a slight tilt of the growth direction between the GaN and InGaN layers. Furthermore, the In concentration and tilt angle increase simultaneously with increasing distance from the InGaN/GaN interface.
- Published
- 2006
- Full Text
- View/download PDF
30. Nanoparticles in interlayers of Bi2O3-doped ZnO ceramics
- Author
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Iwao Hashimoto, Takashi Yamazaki, H. Yamada, Kazutaka Mitsuishi, K. Watanabe, Kazuo Furuya, and Yumio Toda
- Subjects
Materials science ,Doping ,Nanoparticle ,Mineralogy ,Surfaces and Interfaces ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Chemical engineering ,Electron diffraction ,Transmission electron microscopy ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Ceramic ,Crystal twinning ,Spectroscopy ,Wurtzite crystal structure - Abstract
Nanoparticles found in interlayers between the grains of Bi2O3-doped ZnO were analyzed using electron diffraction, high-resolution transmission electron microscopy and energy-dispersive X-ray spectroscopy. Both ZnO multiple twinned particles (MTPs) and single nanoparticles of less than 5 nm in diameter were found in the Bi-poor interlayers. The MTPs with the wurtzite structure give rise to no defects or structural changes in the present size because the angular misgap of five-fold symmetry is very small. Furthermore, β-Bi2O3 nanoparticles reaching a few tens of nanometers in diameter were formed in the Bi-rich interlayers.
- Published
- 2005
- Full Text
- View/download PDF
31. Symmetries in BF and HAADF STEM image calculations
- Author
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Y. Kikuchi, Iwao Hashimoto, Takashi Yamazaki, K. Watanabe, and E. Asano
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Microscopy, Electron, Scanning Transmission ,Physics ,Surface (mathematics) ,business.industry ,Block matrix ,Models, Theoretical ,Atomic and Molecular Physics, and Optics ,Symmetry (physics) ,Electronic, Optical and Magnetic Materials ,Brillouin zone ,Crystal ,Imaging, Three-Dimensional ,Optics ,Scanning transmission electron microscopy ,business ,Translational symmetry ,Instrumentation ,Algorithms ,Bloch wave - Abstract
Reductions in bright-field (BF) scanning transmission electron microscopy (STEM) and high-angle annular dark-field (HAADF) STEM image calculations with the aid of Bloch wave symmetry are discussed under assumptions that an absorption potential is written by a local potential and a zero-order Laue zone lies parallel to the crystal surface. Translational symmetry allows us to take only partial incident beams in the first Brillouin zone instead of enormous number of partial incident beams in a large convergent disk. Two dimensional point group confines partial incident beams to an irreducible area in addition to factoring a dispersion matrix into noninteracting submatrices on a high symmetry line using the projection operator. The drastic reductions in computing time and memory enable us to readily calculate various BF STEM and HAADF STEM images. The validity and accuracy are demonstrated in comparisons with high resolution experimental BF STEM and HAADF STEM images.
- Published
- 2004
- Full Text
- View/download PDF
32. Effect of incident probe on HAADF STEM images
- Author
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Makoto Shiojiri, Iwao Hashimoto, N. Nakanishi, Takashi Yamazaki, Kenji Watanabe, and Masahiro Kawasaki
- Subjects
Physics ,Contrast transfer function ,business.industry ,Resolution (electron density) ,Condensed Matter Physics ,Dark field microscopy ,Electronic, Optical and Magnetic Materials ,law.invention ,Lens (optics) ,symbols.namesake ,Spherical aberration ,Optics ,Fourier transform ,law ,Scanning transmission electron microscopy ,symbols ,business ,Bloch wave - Abstract
Atomic-resolution incoherent high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) images of [011]-oriented Si have been recorded using different incident beam probes, and analysed by means of dynamical image calculation based on the Bloch wave description. It is shown how atomic-resolution images are influenced by the semiangle of the probe and the spherical aberration and defocus of the probe-forming lens. The resolution of an incoherent HAADF STEM image can be simply perceived by the contrast transfer function of incoherent imaging which is the Fourier transform of the incident probe intensity.
- Published
- 2003
- Full Text
- View/download PDF
33. Effect of small crystal tilt on atomic-resolution high-angle annular dark field STEM imaging
- Author
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Makoto Shiojiri, Kazuto Watanabe, Iwao Hashimoto, Takashi Yamazaki, and M Kawasaki
- Subjects
business.industry ,Chemistry ,Zone axis ,Dark field microscopy ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Crystal ,Lens (optics) ,Tilt (optics) ,Optics ,Electron diffraction ,law ,Scanning transmission electron microscopy ,business ,Instrumentation ,Beam (structure) - Abstract
Using a slightly tilted convergent electron beam, high-angle annular dark field scanning transmission electron microscopy observations have been performed of a [0 11]-oriented Si crystal. A small tilt of the crystal zone axis with respect to the coma-axis of the probe-forming lens causes a difference in intensity between bright spots of a Si dumbbell. The semiangle of the beam probe and the tilting angle with respect to the specimen hormal were determined by means of convergent beam micro-diffraction. The simulation using these parameters accounts for the image contrasts satisfactorily.
- Published
- 2002
- Full Text
- View/download PDF
34. [Untitled]
- Author
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Iwao Hashimoto and Wakana Kimura
- Published
- 2017
- Full Text
- View/download PDF
35. [Untitled]
- Author
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Iwao Hashimoto and Maki Takaoka
- Published
- 2017
- Full Text
- View/download PDF
36. Artificial bright spots in atomic-resolution high-angle annular dark field STEM images
- Author
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Kazuto Watanabe, Masahiro Kawasaki, Makoto Shiojiri, Iwao Hashimoto, and Takashi Yamazaki
- Subjects
Condensed Matter::Quantum Gases ,Physics ,Spots ,business.industry ,General Medicine ,Electron ,Dark field microscopy ,Optics ,Atomic resolution ,Thermal ,Scanning transmission electron microscopy ,High angle ,Physics::Atomic Physics ,business ,Instrumentation ,Astrophysics::Galaxy Astrophysics ,Bloch wave - Abstract
Artificial bright spots, which appear in some atomic resolution high-angle annular dark field scanning transmission electron microscope (HAADF STEM) images, have been accounted for by simulations based on Bloch wave description. This is illustrated with Si and SrTiO 3 images. The simulation reveals that bright spots on no-atomic columns in [011]-orientated Si images are produced by thermal diffuse scattering from Si atoms on their surrounding atomic columns, which are under the subsidiary peaks in the incident convergent electron probe. Similarly, bright spots on oxygen columns in [001]-orientated SrTiO 3 images are ascribed to Sr and Ti atoms in their surrounding atomic columns rather than O atoms in the O columns. The probe function, therefore, provides a simple explanation for the appearance of these artificial spots.
- Published
- 2001
- Full Text
- View/download PDF
37. Rev-dependent association of the intron-containing HIV-1gagmRNA with the nuclear actin bundles and the inhibition of its nucleocytoplasmic transport by latrunculin-B
- Author
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Jun-ichi Fujisawa, Akitsugu Yamamoto, Iwao Hashimoto, Masao Nishikawa, and Tominori Kimura
- Subjects
Messenger RNA ,biology ,viruses ,Intron ,Cell Biology ,Molecular biology ,Cytoplasm ,Nucleocytoplasmic Transport ,Gene expression ,Genetics ,biology.protein ,Nuclear export signal ,Glyceraldehyde 3-phosphate dehydrogenase ,Actin - Abstract
Background A hallmark of HIV-1 gene expression is that unspliced genomic RNA, which also acts as mRNA for the expression of Gag/Pol, is exported to the cytoplasm. Rev directs this transport through the nuclear export signal (NES). Results Fluorescence in situ hybridization and immunocytochemistry demonstrated that gag mRNA, Rev, and its NES receptor, CRM1, and RanGTPase formed nuclear tracks which were congruent with underlying β-actin bundles. Actin bundle formation was confirmed electron-microscopically. These bundles were observed upon Rev-containing gag RNP formation. The loss of bundles was associated with the nuclear retention of gag mRNA. Reverse transcription-polymerase chain reaction analysis of both cytoplasmic and nuclear gag mRNAs demonstrated that disruption of nuclear actin filament formation by latrunculin-B (LAT-B), an F-actin depolymerizing compound, resulted in the dose-dependent inhibition of gag mRNA export. The differential subtyping of the mRNA-positive cells confirmed morphologically the effect of LAT-B treatment. The export inhibition was specific to gag mRNA and export of fully spliced HIV-1 tat/rev mRNAs as well as cellular GAPDH mRNA was not affected by the compound. Conclusions Nuclear β-actin bundles are suggested to be functionally involved in the Rev-dependent nucleocytoplasmic transport of intron-containing HIV-1 gag mRNA.
- Published
- 2000
- Full Text
- View/download PDF
38. Structure and Formation of the Floor of the Pulp Chamber in Human Multirooted Teeth, with Special Reference to a Ground Section of Mandibular First Molar with Fluorescent Tetracycline Labelling Lines
- Author
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Iwao Hashimoto, Haruto Kodera, and Kouji Inoue
- Subjects
Materials science ,Tetracycline ,business.industry ,Section (archaeology) ,Labelling ,medicine ,Dentistry ,business ,General Dentistry ,Mandibular first molar ,Fluorescence ,medicine.drug - Published
- 2000
- Full Text
- View/download PDF
39. Distortion Measurement of Multi-Finger Transistor Using Split Higher-Order Laue Zone Lines Analysis
- Author
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Kenji Kojima, Shiro Takeno, Iwao Hashimoto, Takashi Yamazaki, Koji Kuramochi, and Fumihiko Uesugi
- Subjects
Physics ,Physics and Astronomy (miscellaneous) ,business.industry ,Transistor ,General Engineering ,General Physics and Astronomy ,Order (ring theory) ,Convergent beam ,Deformation (meteorology) ,Sample (graphics) ,law.invention ,Optics ,Electron diffraction ,law ,Distortion ,Line (geometry) ,business - Abstract
A distortion measurement in a region close to the interface between different materials in LSI is performed using a convergent beam electron diffraction (CBED) pattern. Split higher-order Laue zone (HOLZ) lines emerge in the CBED pattern so that a stressing region is observed close to the interface. The calculation method of the split HOLZ lines based on kinematical approximation with the sample's deformation model well reflects the experimental results. As a result of split HOLZ line analysis using the present method, it is found that there is distortion depending on the external form of a multi-finger transistor.
- Published
- 2008
- Full Text
- View/download PDF
40. Organic reaction in water. Part 1. A convenient method for reduction of imines using zinc powder
- Author
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Masashi Tashiro, Yoshiharu Mitoma, Iwao Hashimoto, Satoko Nagashima, Takehito Tsukinoki, and Takatoshi Kawaji
- Subjects
Reduction (complexity) ,Chemistry ,Organic Chemistry ,Drug Discovery ,Inorganic chemistry ,chemistry.chemical_element ,Zinc ,Biochemistry - Abstract
Reduction of imines was performed with zinc powder in 5% aq NaOH solution without any organic solvents under mild conditions, and the corresponding amines were obtained in good yields.
- Published
- 1998
- Full Text
- View/download PDF
41. Rev Protein of Human Immunodeficiency Virus Type 1 Facilitates Translation of rev-dependent Viral Messenger RNAs
- Author
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Jun-ichi Fujisawa, Tominori Kimura, Iwao Hashimoto, and Masao Nishikawa
- Subjects
Messenger RNA ,Histology ,Expression vector ,Physiology ,viruses ,Structural gene ,Translation (biology) ,Cell Biology ,Transfection ,In situ hybridization ,Biology ,Biochemistry ,Molecular biology ,Pathology and Forensic Medicine ,Gene expression ,Translational regulation - Abstract
Human immunodeficiency virus type 1 (HIV1) Rev has been reported to act by inducing the nucleocytoplasmic transport of unspliced and singly spliced RNAs that encode viral structural proteins. However, our initial experiments indicated the cytoplasmic expression of intron-containing mRNAs in Rev-cells [12]. To determine whether or not the post-transcriptional induction of gene expression by Rev extends to the level of increasing the efficiency of translation, Rev+ and Rev-cells were morphologically examined by means of in situ hybridization and immunofluorescence assays. Hybridization to an intron-specific probe revealed that the transfection of HeLa cells with a rev-defective HIV-1 expression plasmid caused the export of overexpressed, unspliced gag mRNAs, possibly through a default process of nuclear retention. However, subsequent immunofluorescence assaying demonstrated that mRNA exported by Rev, but not mRNA directed through the default process, was translated into the corresponding protein. The findings were extended to a group of singly spliced viral mRNAs that produce Env in the following biochemical analyses. These findings suggest that Rev is directly or indirectly involved in the translational regulation of HIV-1 structural gene mRNAs. We discuss the possibility that Rev could cause the intron-containing transcripts to follow the appropriate pathway to reach the translational machinery.
- Published
- 1997
- Full Text
- View/download PDF
42. Synthesis of 1,2,9,10-tetrakis(N-phenylamino)[2.2]metacyclophane by SmI2-mediated reductive coupling of diimine
- Author
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Taisuke Matsumoto, Kikue Hayashi, Shuntaro Mataka, Iwao Hashimoto, Takatoshi Kawaji, and Thies Thiemann
- Subjects
Coupling (electronics) ,Chemistry ,Yield (chemistry) ,Organic Chemistry ,Drug Discovery ,Photochemistry ,Biochemistry ,Medicinal chemistry ,Diimine - Abstract
SmI 2 /HMPA-mediated double reductive coupling of N , N ′-( m -xylylidene)dianiline affords 1,2,9,10-tetrakis( N -phenylamino)[2.2]metacyclophane in good yield.
- Published
- 2005
- Full Text
- View/download PDF
43. Rate control of cell sheet recovery by incorporating hydrophilic pattern in thermoresponsive cell culture dish
- Author
-
Yoshikazu, Kumashiro, Teruyuki, Matsunaga, Megumi, Muraoka, Nobuyuki, Tanaka, Kazuyoshi, Itoga, Jun, Kobayashi, Yumiko, Tomiyama, Masatoshi, Kuroda, Tatsuya, Shimizu, Iwao, Hashimoto, Kazuo, Umemura, Masayuki, Yamato, and Teruo, Okano
- Subjects
Mice ,Time Factors ,Surface Properties ,Acrylic Resins ,Cell Adhesion ,Cell Culture Techniques ,NIH 3T3 Cells ,Temperature ,Animals ,Cell Count ,Hydrophobic and Hydrophilic Interactions - Abstract
Thready stripe-polyacrylamide (PAAm) pattern was fabricated on a thermoresponsive poly(N-isopropylacrylamide) (PIPAAm) surface, and their surface properties were characterized. A PIPAAm surface spin-coated with positive photoresist was irradiated through a 5 µm/5 µm or a 10 µm/10-µm black and white striped photomask, resulting in the radical polymerization of AAm on the photoirradiated area. After staining with Alexa488 bovine serum albumin, the stripe-patterned surface was clearly observed and the patterned surface was also observed by a phase contrast image of an atomic force microscope. NIH-3T3 (3T3) single cells were able to be cultured at 37°C on the patterned surfaces as well as on a PIPAAm surface without pattern, and the detachment of adhered cells was more rapidly from the patterned surface after reducing temperature. Furthermore, the rate of detachment of 3T3 confluent cell sheet on the patterned surface was accelerated, compared with on a conventional PIPAAm surface under the static condition. The rate control of cell sheet recovery should contribute the preservations of cell phenotype and biological functions of cell sheet for applying to clinical trials.
- Published
- 2013
44. Regioselectivity of Friedel-Crafts acylation of aromatic compounds with several cyclic anhydrides
- Author
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Masashi Tashiro, Shuntaro Mataka, Gouki Fukata, Tsuyoshi Sawada, Iwao Hashimoto, Takatoshi Kawaji, and Florin D. Badea
- Subjects
chemistry.chemical_compound ,chemistry ,Organic chemistry ,Regioselectivity ,Alkylbenzenes ,General Chemistry ,Ring (chemistry) ,Anisole ,Friedel–Crafts reaction ,Catalysis - Abstract
The Friedel-Crafts acylations of various aromatic compounds with cyclic anhydrides such as 2-(p-substituted phenyl)butanedioic, 3-phenylpentanedioic and homophathlic anhydrides were carried out under various conditions in order to obtain informations about the regioselectivity of the ring opening of the cyclic anhydrides and about the possible reaction pathways in the acylations.
- Published
- 1996
- Full Text
- View/download PDF
45. A Relativisticn-Beam Dynamical Theory for Fast Electron Diffraction
- Author
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S. Hara, Iwao Hashimoto, and Kazuto Watanabe
- Subjects
Diffraction ,Physics ,Physics::Optics ,Scalar potential ,Dynamical theory of diffraction ,Schrödinger equation ,Crystal ,symbols.namesake ,Electron diffraction ,Structural Biology ,Dirac equation ,Quantum mechanics ,symbols ,Physics::Accelerator Physics ,Beam (structure) - Abstract
From the Dirac equation with a periodic scalar potential, an n-beam dynamical formula for the matrix representation of high-energy electron diffraction by a crystal is developed. By combining this with the layer-doubling method, the diffraction from an assembly of crystal slabs having different structures and thicknesses can be evaluated. Dynamical calculations of aluminium, copper and gold at several accelerating voltages have been carried out in a completely parallel manner by the present method and the Bethe method derived from the relativistic Schrodinger equation by replacing corrected mass and wavelength. The relativistic Schrodinger equation is found to be applicable for n-beam dynamical calculations for the Laue case.
- Published
- 1996
- Full Text
- View/download PDF
46. A role for Rev in the association of HIV-1 gag mRNA with cytoskeletal β-actin and viral protein expression
- Author
-
M. Nishikawa, Tominori Kimura, Iwao Hashimoto, and J.I. Fujisawa
- Subjects
Viral protein ,RNA Splicing ,viruses ,Gene Products, gag ,Biology ,medicine.disease_cause ,Biochemistry ,medicine ,Animals ,Humans ,RNA, Messenger ,Cytoskeleton ,Viral Structural Proteins ,Messenger RNA ,Nucleoplasm ,RNA ,rev Gene Products, Human Immunodeficiency Virus ,General Medicine ,Transfection ,Group-specific antigen ,Genes, gag ,Molecular biology ,Actins ,Gene Products, rev ,Cytoplasm ,HIV-1 ,RNA, Viral - Abstract
Human immunodeficiency virus type-1 (HIV-1) Rev acts by inducing the specific nucleocytoplasmic transport of a class of incompletely spliced RNAs that encodes the viral structural proteins. The transfection of HeLA cells with a rev -defective HIV-1 expression plasmid, however, resulted in the export of overexpressed, intron-containing species of viral RNAs, possibly through a default process of nuclear retention. Thus, this system enabled us to directly compare Rev + and Rev − cells as to the usage of RRE-containing mRNAs by the cellular translational machinery. Biochemical examination of the transfected cells revealed that although significant levels of gag and env mRNAs were detected in both the presence and absence of Rev, efficient production of viral proteins was strictly dependent on the presence of Rev. A fluoroscence in situ hybridisation assay confirmed these findings and provided further evidence that even in the presence of Rev, not all of the viral mRNA was equally translated. At the early phase of RNA export in Rev + cells, gag mRNA was observed throughout both the cytoplasm and nucleoplasm as uniform fine stippling. In addition, the mRNA formed clusters mainly in the perinuclear region, which were not observed in Rev − cells. In the presence of Rev, expression of the gag protein was limited to these perinuclear sites where the mRNA accumulated. Subsequent staining of the cytoskeletal proteins demonstrated that in Rev + cells gag mRNA is colocalized with β-actin in the sites where the RNA formed clusters. In the absence of Rev, in contrast, the gag mRNA failed to associate with the cytoskeletal proteins. These results suggest that in addition to promoting the emergence of intron-containing RNA from the nucleus, Rev plays an important role in the compartmentation of translation by directing RRE-containing mRNAs to the β-actin to form the perinuclear clusters at which the synthesis of viral structural proteins begins.
- Published
- 1996
- Full Text
- View/download PDF
47. Precipitates in Antimony Implanted Silicon
- Author
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Yoshio Kikuchi, K. Watanabe, F. Uesugi, Iwao Hashimoto, Masataka Kase, Masamichi Yoshida, and S. Kaszczyszyn
- Subjects
Materials science ,Antimony ,chemistry ,Silicon ,Mechanics of Materials ,Precipitation (chemistry) ,Mechanical Engineering ,Metallurgy ,chemistry.chemical_element ,General Materials Science ,Condensed Matter Physics - Published
- 1995
- Full Text
- View/download PDF
48. Interleukin-1β induces tumor necrosis factor-α secretion from rat hepatocytes
- Author
-
Emi, Yoshigai, Takafumi, Hara, Hiroyuki, Inaba, Iwao, Hashimoto, Yoshito, Tanaka, Masaki, Kaibori, Tominori, Kimura, Tadayoshi, Okumura, A-Hon, Kwon, and Mikio, Nishizawa
- Abstract
Tumor necrosis factor-α (TNF-α) is a pleiotropic cytokine involved in various inflammatory diseases. The only production of TNF-α in the liver is thought to be from hepatic macrophages known as Kupffer cells, predominantly in response to bacterial lipopolysaccharide (LPS).Primary cultured rat hepatocytes were used to analyze TNF-α expression in response to the pro-inflammatory cytokine, interleukin-1β (IL-1β). Livers of rats subjected to LPS-induced endotoxemia were analyzed.Immunocytochemistry and enzyme-linked immunosorbent assays demonstrated that IL-1β-treated rat hepatocytes secreted TNF-α, and RNA analyses indicated that TNF-α mRNA was induced specifically by IL-1β. Northern blot analysis showed that not only mRNA, but also a natural antisense transcript (asRNA), was transcribed from the rat Tnf gene in IL-1β-treated hepatocytes. TNF-α was detected in the hepatocytes of LPS-treated rats. Both TNF-α mRNA and asRNA were expressed in the hepatocytes of LPS-treated rats, human hepatocellular carcinoma and human monocyte/macrophage cells. To disrupt the interaction between TNF-α asRNA and TNF-α mRNA, sense oligonucleotides corresponding to TNF-α mRNA were introduced into rat hepatocytes resulting in significantly increased levels of TNF-α mRNA. One of these sense oligonucleotides increased a half-life of TNF-α mRNA, suggesting that the TNF-α asRNA may reduce the stability of TNF-α mRNA.IL-1β-stimulated rat hepatocytes are a newly identified source of TNF-α in the liver. TNF-α mRNA and asRNA are expressed in rats and humans, and the TNF-α asRNA reduces the stability of the TNF-α mRNA. Hepatocytes and TNF-α asRNA may be therapeutic targets to regulate levels of TNF-α mRNA.
- Published
- 2012
49. ChemInform Abstract: O-Acylation of Substituted Phenols with Various Alkanoyl Chlorides under Phase-Transfer Catalyst Conditions
- Author
-
Naoyoshi Egashira, Cristian Simion, Iwao Hashimoto, Alina Simion, and Yoshiharu Mitoma
- Subjects
O acylation ,chemistry.chemical_compound ,Chemistry ,Organic chemistry ,General Medicine ,Phenols ,Phase-transfer catalyst - Abstract
The title method is rapid, extremely effective and superior to previously described procedures.
- Published
- 2012
- Full Text
- View/download PDF
50. Imaging of light and heavy atomic columns by spherical aberration corrected middle-angle bright-field STEM
- Author
-
Kazuto Watanabe, Iwao Hashimoto, Yasutoshi Kotaka, Masahiro Ohtsuka, and Takashi Yamazaki
- Subjects
Physics ,business.industry ,Electron ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,Crystal ,Lens (optics) ,Reciprocal lattice ,Spherical aberration ,Optics ,law ,Scanning transmission electron microscopy ,Absorption (electromagnetic radiation) ,business ,Instrumentation ,Astrophysics::Galaxy Astrophysics ,Bloch wave - Abstract
Simultaneous detection of both light and heavy atomic columns is theoretically and experimentally explored with spherical aberration (Cs)-corrected middle-angle bright-field (MABF) scanning transmission electron microscopy (STEM). Optimized MABF STEM visualizes both light O atomic columns and heavy Sr and Ti–O atomic columns for SrTiO3(001) as distinct bright spots and dark spots with characteristic bright rings, respectively, over practical ranges of the probe-forming lens defocus and sample thickness, although medium-heavy Ti–O atomic columns appear as blurred dark spots. The difference in contrast between heavy and light atomic columns is greater than that of annular BF STEM images. The formation of distinctive bright and dark spots is interpreted simply as the difference in the degrees of localization and inelastic absorption of channeling electrons in individual atomic columns by analyses of convergent wave fields inside the crystal in both real and reciprocal space. In addition, Bloch wave expansion of MABF STEM images suggests that bright rings are formed mainly by 2p-like convergent Bloch wave fields localized on heavy atomic columns.
- Published
- 2012
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