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Journal of Biophysical Chemistry 2016年第2期7卷 43-48页

作者： Yusuke Kobayashi Rina Hirai daiki ito Yasushi Yamamoto Keijiro Taga Zameer Shervani Department of Life Science and Material Engineering Nagoya Institute of Technology Nagoya Japan Department of Life Science and Material Engineering Nagoya Institute of Technology Nagoya Japan 2Tohoku Foods Corporation Limited Sendai Japan Tohoku Foods Corporation Limited Sendai Japan

We have investigated the morphology of novel 3, 4-bis-alkyloxycarbonyl-hexanedioic acid monolayer (alkyl chain number n = 12, 14, and 16) formed on the water surface by dropping method using Surface Tension measurement (STm) and Brewster Angle Microscopy (BAM). Surfactant of 3, 4-bis-alkyloxycarbonyl-hexanedioic acid has a gemini type structure. π-A isotherm curves (STm) of two gemini surfactants of n = 12 and 14 showed gradual increase in surface pressure, while that of n = 16 showed gradual increase, a stagnant range and finally steep increase. BAM observation showed each image corresponding to the result of STm measurement. From STm and BAM results of surfactants, it is found that surfactant of n = 12 and 14 form Liquid-Expand (LE) type monolayer, while that of n = 16 formed Liquid-Condensed (LC) type monolayer including LE-LC phase transition.

关键词： 3 4-Bis-Alkyloxycarbonyl-Hexanedioic Acid Gemini Surfactants Gemsurfs Monolayer Morphology

Partial Volume Effect on MR Elastography

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Open Journal of Medical Imaging 2017年第4期7卷 131-143页

作者： daiki ito Tomokazu Numano Kazuyuki Mizuhara Toshikatsu Washio Masaki Misawa Naotaka Nitta Department of Radiological Science Graduate School of Human Health Science Tokyo Metropolitan University Tokyo Japan Health Research Institute National Institute of Advanced Industrial Science and Technology Tsukuba Japan Office of Radiation Technology Keio University Hospital Tokyo Japan Department of Mechanical Engineering Tokyo Denki University Tokyo Japan

Magnetic resonance elastography (MRE) allows the quantitative assessment of the stiffness of tissues based on the tissue response to oscillatory shear stress. Shear wave displacements of the tissues are encoded as phase shifts and converted to stiffness (elastogram). Generally, a partial volume effect occurs when different materials are encompassed on the same voxel. In MRE, however, the partial volume effect occurs even if the voxel is filled with the same materials because wave displacements due to vibrations are spatially distributed. The purpose of this study was to investigate how the partial volume effect can affect the phase shift and the elastogram in MRE. We assumed that the partial volume effect appears only in the slice thickness direction and performed a simulation and MRE experiment with various slice thicknesses (1 - 19 mm), two types of imaging plane (coronal and axial) and two types of vibration frequency (100 and 200 Hz). The results of the simulation and the MRE experiment were similar, and indicated that the phase shift and the elastogram changed variously depending on the slice thickness, the wave pattern and the vibration frequency, even if the voxel was filled with the same material. To reduce the partial volume effect, it is necessary to perform the MRE under the following conditions: Use a wave pattern which barely causes this artefact, a smaller voxel size and a lower vibration frequency.

关键词： Magnetic Resonance Elastography Partial Volume Effect Artefact Elasticity Viscoelasticity

Structural Change in Dimyristoyl Phosphatidyl Choline (DMPC) Molecule Alkyl Chains on the Addition of Cholesterol to DMPC Monolayer: Specific Addition Effect of Cholesterol

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Journal of Biophysical Chemistry 2019年第2期10卷 15-29页

作者： daiki ito Takanari Ikeda Keijiro Taga Yasushi Yamamoto Zameer Shervani Masato Yamamoto Department of Life Science and Applied Chemistry Graduate School of Engineering Nagoya Institute of Technology Nagoya Aichi Japan Nanomaterials Production Division Food and Energy Security Research and Product Center Sendai Japan Department of Chemistry School of Arts and Sciences Showa University Kamiyoshida Fujiyoshida Yamanashi Japan

We have investigated the morphology of dimyristoyl phosphatidyl choline (DMPC)—cholesterol mixed monolayer formed on the water surface by dropping method using surface tension measurement (STm), Brewster angle microscopy (BAM), and infrared external reflection spectroscopy (IERS). STm results showed negative deviation of the limiting molecular area (A0) of cholesterol occurred when cholesterol was added to the DMPC monolayer. BAM images showed the expandable DMPC monolayer changed to the condensed rigid monolayer at more than cholesterol mole fraction (xChol) 0.4. IERS recordings showed that the addition of cholesterol at xChol = 0.4 occurred structural change from gauche- to trans- conformation of two DMPC molecule alkyl chains. From these results, it is found that cholesterol molecule has specific properties that cause structural transition of DMPC molecule alkyl chains.

关键词： Dimyristoyl Phosphatidyl Choline (DMPC) Cholesterol Surface Tension Measurement (STm) Brewster Angle Microscopy (BAM) Infrared External Reflection Microscopy (IERS) Structural Transition

Phase Unwrapping in Magnetic Resonance Elastography

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Open Journal of Medical Imaging 2018年第4期8卷 111-125页

作者： Surendra Maharjan Tomokazu Numano Tetsushi Habe daiki ito Takamichi Ueki Keisuke Igarashi Toshiki Maeno Department of Radiological Sciences Graduate School of Human Health Sciences Tokyo Metropolitan University Tokyo Japan Health Research Institute National Institute of Advanced Industrial Science and Technology Tsukuba Japan Office of Radiation Technology Keio University Hospital Tokyo Japan

Phase Unwrapping (PU) is an ill-posed problem in Magnetic Resonance Elastography (MRE). The phase information is not usable until the phases are retrieved by using PU algorithms. In this present study, we attempt to determine the ideal PU method for MRE using both phantom and volunteer psoas major (PM) muscle images. All the MRE experiments were carried out in Philips MRI (Achieva 3.0 T, Best, The Netherlands). A multi-echo gradient-echo MRE pulse sequence was employed and the four PU methods were considered based on their easy user platform. They are namely, Minimum Discontinuity (MD), Laplacian-Based Estimate (LBE), Region Growing (RG) and Dilate-Erode (DE) Propagate. Phantom images were successfully unwrapped by all four methods, whereas MD and LBE could only unwrap PM muscle images properly. RG and DE failed to unwrap the PM muscle images.

关键词： Phase Unwrapping Magnetic Resonance Elastography Minimum Discontinuity Laplacian-Based Estimate Region Growing Dilate-Erode Propagate

Directional Filter, Local Frequency Estimate and Algebraic Inversion of Differential Equation of Psoas Major Magnetic Resonance Elastography

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Open Journal of Medical Imaging 2020年第1期10卷 1-16页

作者： Surendra Maharjan Tomokazu Numano Tetsushi Habe daiki ito Takamichi Ueki Keisuke Igarashi Toshiki Maeno Department of Radiological Science Graduate School of Human Health Science Tokyo Metropolitan University Higashiogu Arakawa-ku Tokyo Japan National Institute of Advanced Industrial Science and Technology (AIST) Tsukuba Japan Office of Radiation Technology Keio University Hospital Tokyo Japan

Magnetic resonance elastography (MRE) can visualize the shear wave propagation of in vivo tissues, which can be mapped into viscoelastic properties. No study has measured the biomechanical properties of the PM muscle in vivo using MRE. In this study, we evaluated stiffness values calculated by local frequency estimate (LFE) and algebraic inversion of differential equation (AIDE) in PM-MRE. The PM muscles of 17 healthy male volunteers were scanned in supine position by MRE. The Laplacian-based estimate (LBE) phase wrapped image data were filtered by gaussian-bandpass filter (GBF), and by both directional and GBF. LFE (MREWave) and AIDE wave inversion methods were used to calculate the respective elastograms. The wave interferences were removed by directional filtering, and smooth wave fields were obtained. The stiffness values calculated by LFE of non-DF images were 1.39 ± 0.25 kPa and 1.33 ± 0.22 kPa for right and left PM respectively, whereas for DF images, they were 1.26 ± 0.20 kPa for right PM and 1.18 ± 0.28 kPa for left PM. The stiffness values calculated by AIDE of non-DF images were 0.78 ± 0.10 kPa and 0.78 ± 0.13 kPa for right and left PM respectively, whereas for DF images, they were 0.73 ± 0.12 kPa for right PM and 0.74 ± 0.11 kPa for left PM. There was no statistically significant difference in mean values of stiffness with/without applying directional filter whereas there was a statistically significant difference in mean values of stiffness between LFE and AIDE. Both LFE and AIDE could be used for psoas major MR Elastography.

关键词： Magnetic Resonance Elastography MRE Psoas Major Muscle Local Frequency Estimate LFE Algebraic Inversion of Differential Equation AIDE

Design and Development of Oblique-Incident Interferometer for Form Measurement of Hand-Scraped Surfaces

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Nanomanufacturing and Metrology 2021年第2期4卷 69-76页

作者： So ito daiki Kameoka Kimihisa Matsumoto Kazuhide Kamiya Department of Intelligent Robotics Faculty of EngineeringToyama Prefectural University5180KurokawaImizuToyama939-0398Japan

Precision flat surfaces finished by hand-scraping are extensively used in the sliding parts of precision positioning systems or the surface plates of precision measuring *** hand-scraped surfaces are employed to improve the flatness of the machined surfaces and the motion accuracy of the *** numerous depressions of micrometer-scale depth on a scraped surface are thought to prevent wringing and improve the lubrication properties by forming oil *** measurement of the micrometer-scale features of a hand-scraped surface is one of the reasonable methods for investigating its effect on the motion accuracy of the positioning systems or the lubrication properties of the sliding *** a hand-scraped surface is a rough surface composed of micrometric complex features,it is difficult to conduct precision measurement of the three-dimensional surface form using conventional measurement instruments,such as vertical-incident interferometers or stylus-type *** this study,an oblique-incident interferometer based on Abramson interferometry is introduced to measure the form of a rough surface produced by *** this technique can detect high-intensity reflected light on a rough surface,it allows the measurement of the form of the hand-scraped surface in noncontact *** order to shorten the measurement time,the form calculation based on a five-step phase shifting method was introduced.

关键词： Oblique-incident interferometer Abramson interferometry Hand-scraped surface Rough surface Surface form measurement

Systemic gemcitabine combined with intra-arterial low-dose cisplatin and 5-fluorouracil for advanced hepatocellular carcinoma: Seven cases

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World Journal of Gastroenterology 2008年第16期14卷 2602-2608页

作者： Kiminori Uka Hiroshi Aikata Shintaro Takaki Tomokazu Kawaoka Hiromi Saneto daiki Miki Shoichi Takahashi Naoyuki Toyota Katsuhide ito Kazuaki Chayama Department of Medicine and Molecular Science Division of Frontier Medical Science Programs for Biomedical Research Graduate School of Biomedical Sciences Hiroshima University Department of Radiology Hiroshima University Hospital

The combination of intra-arterial low-dose cisplatin and 5-fluorouracil (5-FU) is effective against advanced hepatocellular carcinoma (HCC). Systemic gemcitabine chemotherapy seems effective in many cancers. We report the results of combination therapy with systemic gemcitabine, intra-arterial low-dose cisplatin and 5-FU (GEMFP). Seven patients with non-resectable advanced HCC were treated with GEMFP. One course of chemotherapy consisted of daily intra-arterial cisplatin (20 mg/body weight/hour on d 1, 10 mg/body weight per 0.5 h on d 2-5 and 8-12), followed by 5-FU (250 mg/body weight per 5 h on d 1-5 and 8-12) via an injection port. Gemcitabine at 1000 mg/m2 was administered intravenously at 0.5 h on d 1 and 8. The objective response was 57%. The response to GEMFP was as follows: complete response (no patients), partial response (four patients), stable disease (three patients), and progressive disease (no patients). The median survival period was 8 mo (range, 5-55). With regard to the National Cancer Institute Common Toxicity Criteria (NCI-CTC) grade 3 or 4 adverse reactions, seven (100%), seven, six (86%) and one (14%) patients developed leukopenia, neutropenia, thrombocytopenia and anemia, respectively. GEMFP may potentially be effective for non- resectable advanced HCC, but it has severe hematologic toxicity.

关键词： 5-fluorouracil Cisplatin Gemcitabine Hepatocellular carcinoma

Laparoscopic appendectomy for acute appendicitis: How to discourage surgeons using inadequate therapy

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World Journal of Gastroenterology 2017年第32期23卷 5849-5859页

作者： tomohide hori takafumi machimoto yoshio kadokawa toshiyuki hata tatsuo ito shigeru kato daiki yasukawa yuki aisu yusuke kimura maho sasaki yuichi takamatsu taku kitano shigeo hisamori tsunehiro yoshimura department of gastrointestinal surgery tenriyorodusoudanjyo hospital

Acute appendicitis(AA) develops in a progressive and irreversible manner, even if the clinical course of AA can be temporarily modified by intentional medications. Reliable and real-time diagnosis of AA can be made based on findings of the white blood cell count and enhanced computed tomography. Emergent laparoscopic appendectomy(LA) is considered as the first therapeutic choice for AA. Interval/delayed appendectomy at 6-12 wk after disease onset is considered as unsafe with a high recurrent rate during the waiting time. However, this technique may have some advantages for avoiding unnecessary extended resection in patients with an appendiceal mass. Nonoperative management of AA may be tolerated only in children. Postoperative complications increase according to the patient's factors, and temporal avoidance of emergent general anesthesia may be beneficial for high-risk patients. The surgeon's skill and cooperation of the hospital are important for successful LA. Delaying appendectomy for less than 24 h from diagnosis is safe. Additionally, a semi-elective manner(i.e., LA within 24 h after onset of symptoms) may be paradoxically acceptable, according to the factors of the patient, physician, and institution. Prompt LA is mandatory for AA. Fortunately, the Japanese government uses a universal health insurance system, which covers LA.

关键词： Laparoscopic appendectomy Acute appendicitis Interval appendectomy Surgery Delayed appendectomy