6 results on '"Keita Shimizu"'
Search Results
2. Concise Synthesis of Anserine: Efficient Solvent Tuning in Asymmetric Hydrogenation Reaction
- Author
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Toshiyuki Kan, Yasuaki Koizumi, Yoshitaka Hamashima, Megumi Yamashita, Toshiyuki Wakimoto, Tomohiro Asakawa, Keita Shimizu, and Makoto Inai
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010405 organic chemistry ,Chemistry ,Organic Chemistry ,Anserine ,Asymmetric hydrogenation ,Enantioselective synthesis ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Solvent ,chemistry.chemical_compound ,Yield (chemistry) ,Organic chemistry ,Selectivity ,DuPhos - Abstract
A concise synthesis of anserine and related compounds was accomplished by Et-DuPhos-Rh-catalyzed asymmetric hydrogenation of dehydrohistidine derivatives in 2,2,2-trifluoroethanol, which played a key role in improving the yield and selectivity.
- Published
- 2016
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3. Correlation between health-care costs and salivary tests
- Author
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Keita Shimizu, Erika Kakuta, Nobuhiro Hanada, Keizo Koresawa, Yoshiaki Nomura, and Yoshinobu Naono
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Adult ,Male ,medicine.medical_specialty ,Gross Domestic Product ,media_common.quotation_subject ,Social issues ,Gross domestic product ,Correlation ,Hemoglobins ,chemistry.chemical_compound ,Japan ,Environmental health ,Lactate dehydrogenase ,Health care ,Humans ,Medicine ,Saliva ,General Dentistry ,Periodontal Diseases ,media_common ,Variables ,L-Lactate Dehydrogenase ,business.industry ,Health Care Costs ,Middle Aged ,medicine.disease ,Surgery ,Models, Economic ,Health promotion ,chemistry ,Female ,Original Article ,Neural Networks, Computer ,Health Expenditures ,Metabolic syndrome ,business - Abstract
The burden of health-care costs relative to gross domestic product in Japan is increasing. A large percentage (7.6% in 2009) of the Japanese gross domestic product has been spent on health care, and this percentage has been increasing annually. Soaring health-care costs have been recognised as a serious social problem. In this study, we attempted to estimate the relationship between periodontal disease and health-care costs. Subjects consisted of teachers and staff members (35 men, 26 women; mean age, 45 ± 9 years) from two high schools. The salivary levels of lactate dehydrogenase and haemoglobin were adopted as biomarkers to assess periodontal disease. After salivary tests, data for the health-care costs over the subsequent 6 months were provided by the mutual association of the public schools on an individual basis. Curve-fit estimations were then performed where health-care costs were used as a dependent variable and age or salivary levels of haemoglobin or lactate dehydrogenase were used as independent variables. However, no good fitness was obtained. Subsequently, multilayer perceptron neural networks were applied. With the neural networks, good fitness was obtained by using lactate dehydrogenase as an independent variable. The results of this study show that oral health, particularly periodontal disease, is correlated with total health-care costs. The data presented in this study suggests that, from the perspective of both oral and systemic health, oral health can be a signpost in well-being and health promotion.
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- 2013
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4. High efficiency penetration of antibody-immobilized nanoneedle thorough plasma membrane for in situ detection of cytoskeletal proteins in living cells
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Masumi Iijima, Shun'ichi Kuroda, Ryuzo Kawamura, Kazuhiko Ishihara, Ayana Yamagishi, Yuta Matsumoto, Keita Shimizu, Yaron R. Silberberg, Kyoko Fukazawa, and Chikashi Nakamura
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0301 basic medicine ,lcsh:Medical technology ,lcsh:Biotechnology ,Biomedical Engineering ,Pharmaceutical Science ,Medicine (miscellaneous) ,Bioengineering ,02 engineering and technology ,Microscopy, Atomic Force ,Applied Microbiology and Biotechnology ,Mechanobiology ,Atomic force microscopy ,03 medical and health sciences ,Single-cell analysis ,lcsh:TP248.13-248.65 ,Membrane fluidity ,Humans ,Nanotechnology ,Lipid bilayer ,Cytoskeleton ,Nanoneedle ,Intermediate filament ,Single cell analysis ,Chemistry ,Methodology ,021001 nanoscience & nanotechnology ,Cell biology ,Cytoskeletal Proteins ,030104 developmental biology ,Membrane ,lcsh:R855-855.5 ,Microscopy, Fluorescence ,Needles ,MCF-7 Cells ,Biophysics ,Molecular Medicine ,Single-Cell Analysis ,0210 nano-technology ,Antibodies, Immobilized ,Intracellular ,HeLa Cells - Abstract
Background The field of structural dynamics of cytoskeletons in living cells is gathering wide interest, since better understanding of cytoskeleton intracellular organization will provide us with not only insights into basic cell biology but may also enable development of new strategies in regenerative medicine and cancer therapy, fields in which cytoskeleton-dependent dynamics play a pivotal role. The nanoneedle technology is a powerful tool allowing for intracellular investigations, as it can be directly inserted into live cells by penetrating through the plasma membrane causing minimal damage to cells, under the precise manipulation using atomic force microscope. Modifications of the nanoneedles using antibodies have allowed for accurate mechanical detection of various cytoskeletal components, including actin, microtubules and intermediate filaments. However, successful penetration of the nanoneedle through the plasma membrane has been shown to vary greatly between different cell types and conditions. In an effort to overcome this problem and improve the success rate of nanoneedle insertion into the live cells, we have focused here on the fluidity of the membrane lipid bilayer, which may hinder nanoneedle penetration into the cytosolic environment. Results We aimed to reduce apparent fluidity of the membrane by either increasing the approach velocity or reducing experimental temperatures. Although changes in approach velocity did not have much effect, lowering the temperature was found to greatly improve the detection of unbinding forces, suggesting that alteration in the plasma membrane fluidity led to increase in nanoneedle penetration. Conclusions Operation at a lower temperature of 4 °C greatly improved the success rate of nanoneedle insertion to live cells at an optimized approach velocity, while it did not affect the binding of antibodies immobilized on the nanoneedle to vimentins for mechanical detection. As these experimental parameters can be applied to various cell types, these results may improve the versatility of the nanoneedle technology to other cell lines and platforms. Electronic supplementary material The online version of this article (doi:10.1186/s12951-016-0226-5) contains supplementary material, which is available to authorized users.
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- 2016
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5. Screening for periodontal diseases using salivary lactate dehydrogenase, hemoglobin level, and statistical modeling
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Nobuhiro Hanada, Fumihiko Hino, Keizo Koresawa, Daisuke Ogino, Erika Kakuta, Naoki Takahashi, Keita Shimizu, Akiko Eto, Yuichi Nakamura, Yoh Tamaki, and Yoshiaki Nomura
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saliva ,medicine.medical_specialty ,Saliva ,Dentistry(all) ,Smoking habit ,business.industry ,periodontal pocket probing ,periodontal disease ,Dentistry ,lactate dehydrogenase ,lcsh:RK1-715 ,chemistry.chemical_compound ,chemistry ,Periodontal disease ,lcsh:Dentistry ,Lactate dehydrogenase ,Internal medicine ,CPI ,medicine ,Hemoglobin ,Lactate dehydrogenases ,business ,Salivary biomarkers ,General Dentistry - Abstract
Background/Purpose The intracellular enzymes present in the saliva have been studied as markers of periodontal disease. The aim of this study was to establish procedures for using salivary biomarkers as an alternative to the Community Periodontal Index (CPI) for community-based screening for periodontal disease. Materials and methods The study included 101 adults aged between 19 and 77 years who were undergoing treatment for periodontal disease. We applied analysis of covariance (ANCOVA) to analyze the relationship between Community Periodontal Index (CPI) and levels of salivary factors for the 101 volunteers. Results Demographic characteristics, including age, number of remaining teeth, and smoking habits, showed a significant correlation with CPI. An overall correlation was shown between CP and both salivary lactate dehydrogenases (LD) and hemoglobin (Hb) levels, when analyzed using continuous demographic variables as covariates. Conclusion Results indicated that screening with statistical modeling can be an effective tool for detecting periodontal disease.
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- 2012
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6. Low-Temperature Aging of Delta-Ferrite in 316L SS Welds; Changes in Mechanical Properties and Etching Properties
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Hiroshi Abe, Keita Shimizu, and Yutaka Watanabe
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Austenite ,Materials science ,Spinodal decomposition ,Hydrochloric acid ,engineering.material ,Microstructure ,Isothermal process ,chemistry.chemical_compound ,chemistry ,Ferrite (iron) ,engineering ,Austenitic stainless steel ,Composite material ,Embrittlement - Abstract
Thermal aging embrittlement of LWR components made of stainless cast (e.g. CF-8 and CF-8M) is a potential degradation issue, and careful attention has been paid on it. Although welds of austenitic stainless steels (SSs) have γ-δ duplex microstructure, which is similar to that of the stainless cast, examination on thermal aging characteristics of the SS welds is very limited. In order to evaluate thermal aging behavior of weld metal of austenitic stainless steel, the 316L SS weld metal has been prepared and changes in mechanical properties and in etching properties at isothermal aging at 335°C have been investigated. The hardness of the ferrite phase has increased with aging, while the hardness of austenite phase has stayed same. It has been suggested that spinodal decomposition has occurred in δ-ferrite by the 335°C aging. The etching rates of δ-ferrite at immersion test in 5wt% hydrochloric acid solution have been also investigated using an AFM technique. The etching rate of ferrite phase has decreased consistently with the increase in hardness of ferrite phase. It has been thought that this characteristic is also caused by spinodal decomposition of ferrite into chromium-rich (α') and iron-rich (α).
- Published
- 2008
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