12 results on '"Toshiki, Nakamura"'
Search Results
2. Evaluation of large deflection response of circular mesh tubes (2nd report: in case of considering the effect of tube ovalization across the cross-section)
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Toshiki NAKAMURA, Kuniharu USHIJIMA, and Keigo TOKUMARU
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mechanical properties ,structural analysis ,elastic analysis ,flattening ,pure bending ,fem ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
In this paper, the large deflection response of a circular mesh tube under pure bending was investigated by using FE analysis. In the previous study[Nakamura, T., Ushijima, K., Evaluation of large deflection response of circular mesh tubes, Transaction of the JSME (in Japanese), Vol. 88, No. 915 (2022)], the effect of the ovalization across the cross-section on the bending response was neglected, but in this study, the influence of cross-sectional flattening on the nonlinear bending moment versus curvature was taken into consideration. There are three reasons for arising the maximum bending moment, but in this paper, we mainly focused on the two mechanisms (the large flattening response in elastic deformation and the plastic yielding behaviour) to the maximum bending moment. Based on our FE analysis, we proposed theoretical equations for predicting the maximum bending moment as a function of tube geometries and material parameters such as Poisson’s ratio and the plastic yielding stress.
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- 2023
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3. Effects of wearing surgical masks on fraction of inspired oxygen in spontaneously breathing patients: improving safety for frontline healthcare professionals under pandemic situations
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Kazuhiro Minoguchi, Akira Isii, Toshiki Nakamura, Hitoshi Sato, Takeru Abe, Hiromasa Kawakami, Kyota Nakamura, and Takahisa Goto
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COVID-19 ,Fraction of inspired oxygen ,Oxygen mask ,Respiratory infections ,Surgical mask ,Preventing infection ,Anesthesiology ,RD78.3-87.3 - Abstract
Abstract Background During pandemic situations, many guidelines recommend that surgical masks be worn by both healthcare professionals and infected patients in healthcare settings. The purpose of this study was to clarify the levels and changes of oxygen concentration over time while oxygen was administered over a surgical mask. Methods Patients scheduled to undergo general anesthesia (n = 99) were enrolled in this study. First, patients were administered oxygen at 6 L/min via an oxygen mask over a surgical mask for 5 min. The patients removed the surgical mask and then took a 3-min break; thereafter, the same amount of oxygen was administered for another 5 min via the oxygen mask. We measured the fraction of inspired oxygen (FiO2), the end-tidal CO2 (EtCO2), and respiratory frequency every minute for 5 min, both while administering oxygen with and without a surgical mask. The FiO2 was measured at the beginning of inspiration and the EtCO2 was measured at the end of expiration. Results The FiO2 at 5 min was significantly lower when breathing with a surgical mask than that without it (mean difference: 0.08 [95% CI: 0.067–0.10]; p
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- 2022
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4. Evaluation of large deflection response of circular mesh tubes (1st report: without considering the effect of the ovalization)
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Toshiki NAKAMURA and Kuniharu USHIJIMA
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mesh structure ,mechanical properties ,structural analysis ,circular tube ,fem ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
In this paper, the large deflection of a circular mesh tube was investigated by using a finite element method. During this investigation, it is assumed that the tube is deformed elastically, and its structural nonlinearity due to large deflection was considered. In addition, a theoretical model of an arc-shaped beam is proposed in order to predict the equivalent stiffness. The equivalent stiffness can be used to estimate the nonlinear large deflection response of the tube. In particular, the effects of the number of spirals and the number of turns on the prediction accuracy was discussed.
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- 2022
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5. Sudden onset of sleep caused by hypothalamic infarction: a case report
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Takeo Matsubara, Keisuke Suzuki, Akiko Kawasaki, Masayuki Miyamoto, Madoka Okamura, Takashi Kanbayashi, Hidehiro Takekawa, Toshiki Nakamura, Yuji Watanabe, Masanori Matsubara, and Koichi Hirata
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Hypothalamic infarction ,Sudden onset of sleep ,Hypersomnia ,Horner syndrome ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Abstract Background Hypothalamic lesions, such as tumors and demyelinating diseases, reportedly cause abnormal sleepiness. However, stroke involving the hypothalamus has rarely been described. Here, we report a patient with infarction restricted to the hypothalamus who presented with sudden onset of sleep. Case presentation A 42-year-old woman with a history of migraine without aura presented with irresistible sleepiness and developed several episodes of sudden onset of sleep. Neurological examinations were unremarkable except for partial left Horner syndrome. Brain magnetic resonance imaging (MRI) revealed a high-intensity lesion restricted to the left hypothalamus on diffusion-weighted and fluid-attenuated inversion recovery MRI images. Cerebrospinal fluid (CSF) orexin-A levels obtained on hospital day 3 after her sleepiness had resolved were normal (337 pg/mL; normal > 200 pg/mL). Serum anti-nuclear and anti-aquaporin 4 (AQP4) antibodies and CSF myelin basic protein and oligoclonal band were negative. A small hypothalamic infarction was suspected, and the patient was treated with intravenous edaravone and argatroban, as well as oral clopidogrel. Three months later, there had been no clinical relapse, and the hypothalamic lesion had almost disappeared on follow-up MRI. No new lesion suggestive of demyelinating disease or tumor was observed. Conclusion Hypothalamic stroke should be considered a cause of sudden onset of sleep.
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- 2019
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6. Perspectives on Low Temperature Tolerance and Vernalization Sensitivity in Barley: Prospects for Facultative Growth Habit
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María Muñoz-Amatriaín, Javier Hernandez, Dustin Herb, P. Stephen Baenziger, Anne Marie Bochard, Flavio Capettini, Ana Casas, Alfonso Cuesta-Marcos, Claus Einfeldt, Scott Fisk, Amelie Genty, Laura Helgerson, Markus Herz, Gongshe Hu, Ernesto Igartua, Ildiko Karsai, Toshiki Nakamura, Kazuhiro Sato, Kevin Smith, Eric Stockinger, William Thomas, and Patrick Hayes
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barley ,low temperature tolerance ,GWAS ,meta-analysis ,facultative ,multi-environments ,Plant culture ,SB1-1110 - Abstract
One option to achieving greater resiliency for barley production in the face of climate change is to explore the potential of winter and facultative growth habits: for both types, low temperature tolerance (LTT) and vernalization sensitivity are key traits. Sensitivity to short-day photoperiod is a desirable attribute for facultative types. In order to broaden our understanding of the genetics of these phenotypes, we mapped quantitative trait loci (QTLs) and identified candidate genes using a genome-wide association studies (GWAS) panel composed of 882 barley accessions that was genotyped with the Illumina 9K single-nucleotide polymorphism (SNP) chip. Fifteen loci including 5 known and 10 novel QTL/genes were identified for LTT—assessed as winter survival in 10 field tests and mapped using a GWAS meta-analysis. FR-H1, FR-H2, and FR-H3 were major drivers of LTT, and candidate genes were identified for FR-H3. The principal determinants of vernalization sensitivity were VRN-H1, VRN-H2, and PPD-H1. VRN-H2 deletions conferred insensitive or intermediate sensitivity to vernalization. A subset of accessions with maximum LTT were identified as a resource for allele mining and further characterization. Facultative types comprised a small portion of the GWAS panel but may be useful for developing germplasm with this growth habit.
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- 2020
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7. Formulation of tactile Gestalt to express variation in velvet hand illusion caused by out-of-phase cycles of two wires
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Hiraku KOMURA, Toshiki NAKAMURA, and Masahiro OHKA
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actuator system ,virtual reality ,velvet hand illusion ,tactile gestalt ,formulation ,Engineering machinery, tools, and implements ,TA213-215 ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
To develop a tactile display, we focused on the Velvet Hand Illusion (VHI), which is a tactile illusion phenomenon. The most important feature of VHI is that VHI is not generated in one wire but is generated in two or more wires. This means that we recognize the area surrounded by wires as a Gestalt and a smooth surface sensation is generated in the Gestalt. We assume that the VHI mechanism is related to the law of closure and the law of common fate in Gestalt theory. In this paper, we investigate the relationship between VHI and the law of closure by means of variation in a phase difference of two wires’ cyclic movement, and formulate VHI variation, taking into account the law of closure. We try to divide the law of closure into two factors: one of them is a factor of translation and the other is a factor of elasticity. We formulate the tactile Gestalt and verify the validity of this formulation by comparing the result of the psychophysical experiment to the estimation via the formulation. This work shows that the law of closure in the tactile Gestalt consists of the translation factor and the elasticity factor, and the VHI mechanism is described by the formulation of the tactile Gestalt.
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- 2020
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8. Multifamily QTL analysis and comprehensive design of genotypes for high-quality soft wheat.
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Goro Ishikawa, Takeshi Hayashi, Kazuhiro Nakamura, Tsuyoshi Tanaka, Fuminori Kobayashi, Mika Saito, Hiroyuki Ito, Sachiko Ikenaga, Yoshinori Taniguchi, and Toshiki Nakamura
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Medicine ,Science - Abstract
Milling properties and flour color are essential selection criteria in soft wheat breeding. However, high phenotypic screening costs restrict selection to relatively few breeding lines in late generations. To achieve marker-based selection of these traits in early generations, we performed genetic dissection of quality traits using three doubled haploid populations that shared the high-quality soft wheat variety Kitahonami as the paternal parent. An amplicon sequencing approach allowed effective construction of well-saturated linkage maps of the populations. Marker-based heritability estimates revealed that target quality traits had relatively high values, indicating the possibility of selection in early generations. Taking advantage of Chinese Spring reference sequences, joint linkage maps of the three populations were generated. Based on the maps, multifamily quantitative trait locus (QTL) analysis revealed a total of 86 QTLs for ten traits investigated. In terms of target quality traits, 12 QTLs were detected for flour yield, and 12 were detected for flour redness (a* value). Among these QTLs, six for flour yield and nine for flour a* were segregating in more than two populations. Some relationships among traits were explained by QTL collocations on chromosomes, especially group 7 chromosomes. Ten different ideotypes with various combinations of favorable alleles for the flour yield and flour a* QTLs were generated. Phenotypes of derivatives from these ideotypes were predicted to design ideal genotypes for high-quality wheat. Simulations revealed the possibility of breeding varieties with better quality than Kitahonami.
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- 2020
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9. Investigation of Tactile Illusion Based on Gestalt Theory
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Hiraku Komura, Toshiki Nakamura, and Masahiro Ohka
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tactileology ,tactile gestalt ,principle of prägnanz ,law of closure ,formulation ,psychophysics ,Logic ,BC1-199 ,Philosophy (General) ,B1-5802 - Abstract
Time-evolving tactile sensations are important in communication between animals as well as humans. In recent years, this research area has been defined as “tactileology,” and various studies have been conducted. This study utilized the tactile Gestalt theory to investigate these sensations. Since humans recognize shapes with their visual sense and melodies with their auditory sense based on the Prägnanz principle in the Gestalt theory, this study assumed that a time-evolving texture sensation is induced by a tactile Gestalt. Therefore, the operation of such a tactile Gestalt was investigated. Two psychophysical experiments were conducted to clarify the operation of a tactile Gestalt using a tactile illusion phenomenon called the velvet hand illusion (VHI). It was confirmed that the VHI is induced in a tactile Gestalt when the laws of closure and common fate are satisfied. Furthermore, it was clarified that the tactile Gestalt could be formulated using the proposed factors, which included the laws of elasticity and translation, and it had the same properties as a visual Gestalt. For example, the strongest Gestalt factor had the highest priority among multiple competing factors.
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- 2021
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10. Ischemic Stroke as the Initial Manifestation of Neurosyphilis in a Young Adult Patient Positive for Human Immunodeficiency Virus
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Ayaka Numao, Keisuke Suzuki, Hidehiro Takekawa, Toshiki Nakamura, Hisatake Iwanami, Naoki Izawa, Akio Iwasaki, Hiroaki Fujita, Yuji Watanabe, and Koichi Hirata
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Neurosyphilis, human immunodeficiency virus, young adult, initial symptom ,Medicine - Abstract
A 31-year-old man with pontine infarction was referred to our hospital for further evaluation and treatment. At admission, his neurological examination was unremarkable. No lymphadenopathy or skin lesions were found. The Treponema pallidum haemagglutination test, rapid plasma regain test and fluorescent treponemal antibody absorption test of immunoglobulin G were positive in both serum and cerebrospinal fluid (CSF). CSF analysis showed lymphocytic pleocytosis. The patient had male-to-male sexual contact and was found to be HIV positive. Physicians should be aware that acute ischaemic stroke may be the first manifestation of neurosyphilis in a young adult, especially with HIV infection.
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- 2014
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11. Association mapping and validation of QTLs for flour yield in the soft winter wheat variety Kitahonami.
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Goro Ishikawa, Kazuhiro Nakamura, Hiroyuki Ito, Mika Saito, Mikako Sato, Hironobu Jinno, Yasuhiro Yoshimura, Tsutomu Nishimura, Hidekazu Maejima, Yasushi Uehara, Fuminori Kobayashi, and Toshiki Nakamura
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Medicine ,Science - Abstract
The winter wheat variety Kitahonami shows a superior flour yield in comparison to other Japanese soft wheat varieties. To map the quantitative trait loci (QTL) associated with this trait, association mapping was performed using a panel of lines from Kitahonami's pedigree, along with leading Japanese varieties and advanced breeding lines. Using a mixed linear model corrected for kernel types and familial relatedness, 62 marker-trait associations for flour yield were identified and classified into 21 QTLs. In eighteen of these, Kitahonami alleles showed positive effects. Pedigree analysis demonstrated that a continuous pyramiding of QTLs had occurred throughout the breeding history of Kitahonami. Linkage analyses using three sets of doubled haploid populations from crosses in which Kitahonami was used as a parent were performed, leading to the validation of five of the eight QTLs tested. Among these, QTLs on chromosomes 3B and 7A showed highly significant and consistent effects across the three populations. This study shows that pedigree-based association mapping using breeding materials can be a useful method for QTL identification at the early stages of breeding programs.
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- 2014
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12. Plasticizers May Activate Human Hepatic Peroxisome Proliferator-Activated Receptor α Less Than That of a Mouse but May Activate Constitutive Androstane Receptor in Liver
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Yuki Ito, Toshiki Nakamura, Yukie Yanagiba, Doni Hikmat Ramdhan, Nozomi Yamagishi, Hisao Naito, Michihiro Kamijima, Frank J. Gonzalez, and Tamie Nakajima
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Biology (General) ,QH301-705.5 - Abstract
Dibutylphthalate (DBP), di(2-ethylhexyl)phthalate (DEHP), and di(2-ethylhexyl)adipate (DEHA) are used as plasticizers. Their metabolites activate peroxisome proliferator-activated receptor (PPAR) α, which may be related to their toxicities. However, species differences in the receptor functions between rodents and human make it difficult to precisely extrapolate their toxicity from animal studies to human. In this paper, we compared the species differences in the activation of mouse and human hepatic PPARα by these plasticizers using wild-type (mPPARα) and humanized PPARα (hPPARα) mice. At 12 weeks old, each genotyped male mouse was classified into three groups, and fed daily for 2 weeks per os with corn oil (vehicle control), 2.5 or 5.0 mmol/kg DBP (696, 1392 mg/kg), DEHP (977, 1953 mg/kg), and DEHA (926, 1853 mg/kg), respectively. Generally, hepatic PPARα of mPPARα mice was more strongly activated than that of hPPARα mice when several target genes involving β-oxidation of fatty acids were evaluated. Interestingly, all plasticizers also activated hepatic constitutive androstane receptor (CAR) more in hPPARα mice than in mPPARα mice. Taken together, these plasticizers activated mouse and human hepatic PPARα as well as CAR. The activation of PPARα was stronger in mPPARα mice than in hPPARα mice, while the opposite was true of CAR.
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- 2012
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