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Organic Solvent-Free and Simple Method for Determining Cyromazine and Its Metabolite, Melamine, in Cow’s Milk

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Journal of Analytical Sciences, Methods and Instrumentation 2012年第2期2卷 68-73页

作者： naoto Furusawa Graduate School of Human Life Science Osaka City University Osaka Japan

This paper described an organic solvent-free, rapid, simple, and space-saving method of sample preparation followed by HPLC coupled photo-diode array (PDA) detector for simultaneous quantification of cyromazine (CYR) and its decy-cropropylated metabolite, melamine (MEL), in milk. The HPLC-PDA was performed on an Inertsil? HILIC column with an isocratic aqueous mobile phase. Analytes were extracted from the sample using water, and purified by Mono-Spin?-C18, a centrifugal monolithic silica spin mini-columns, and quantified within 20 min. The method, performed under 100% aqueous conditions, obtained average recoveries for CYR and MEL in the range of 93.2% - 99.1% with relative standard deviations ≤ 2.8%. The quantitation limits were 8.5 ng/mL for CYR and 10 ng/mL for MEL, respectively. No organic solvents were used at any stage of the analysis.

关键词： Cyromazine Melamine HPLC-PDA Milk: Organic Solvent-free

Design of Self-Assembling Molecules and Boundary Value Problem for Flows on a Space of <i>n</i>-Simplices

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Applied Mathematics 2019年第11期10卷 907-946页

作者： naoto Morikawa Genocript Zama Japan

Self-assembling molecules are ubiquitous in nature, among which are proteins, nucleic acids (DNA and RNA), peptides and lipids. Recognizing the ability of biomolecules to self-assemble into various 3D shapes at the nanoscale, researchers are mimicking the self-assembly strategy for engineering of complex nanostructures. However, the general principles underlying the design of self-assembled molecules have not yet been identified. The question is “How to obtain a well-defined shape with desired properties by folding a chain of subunits (such as amino acids and nucleic acids)”, where properties are determined by the precise spatial arrangement of the subunits on the surface. In this paper, we consider the question from the viewpoint of the discrete differential geometry of n-simplices. Self-assembling molecules are then represented as a union of trajectories of 3-simplices (i.e., tetrahedrons), and the question is rephrased as a “boundary value problem” for flows on a space of tetrahedrons. Also considered is a characterization of two types of surface flows of n-simplices. It is a rough classification of surface flows, but may be essential in characterizing important properties of biomolecules such as allosteric regulation. The author believes this paper not only provides a new perspective for the engineering of self-assembling molecules, but also promotes further collaboration between mathematics and other disciplines in life science.

关键词： Differential Geometry Self-Assembling Molecule Discrete Mathematics Boundary Value Problem Flows of n-Simplices

Discrete Differential Geometry and the Structural Study of Protein Complexes

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Open Journal of Discrete Mathematics 2017年第3期7卷 148-164页

作者： naoto Morikawa Genocript Kanagawa Japan

This paper proposes a novel four-dimensional approach to the structural study of protein complexes. In the approach, the surface of a protein molecule is to be described using the intersection of a pair of four-dimensional triangular cones (with multiple top vertexes). As a mathematical toy model of protein complexes, we consider complexes of closed trajectories of n-simplices (n=2,3,4...), where the design problem of protein complexes corresponds to an extended version of the Hamiltonian cycle problem. The problem is to find “a set of” closed trajectories of n-simplices which fills the n-dimensional region defined by a given pair of n+1 -dimensional triangular cones. Here we give a solution to the extended Hamiltonian cycle problem in the case of n=2 using the discrete differential geometry of triangles (i.e., 2-simplices).

关键词： Discrete Differential Geometry n-Simplices Hamiltonian Cycle Problem Protein Complexes Vector Bundle

Discrete Differential Geometry of <i>n</i>-Simplices and Protein Structure Analysis

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Applied Mathematics 2014年第16期5卷 2458-2463页

作者： naoto Morikawa Genocript Zama Japan

This paper proposes a novel discrete differential geometry of n-simplices. It was originally developed for protein structure analysis. Unlike previous works, we consider connection between space-filling n-simplices. Using cones of an integer lattice, we introduce tangent bundle-like structure on a collection of n-simplices naturally. We have applied the mathematical framework to analysis of protein structures. In this paper, we propose a simple encoding method which translates the conformation of a protein backbone into a 16-valued sequence.

关键词： Differential Geometry n-Simplex Discrete Mathematics Protein Structure Tetrahedron

Is a nasogastric tube necessary after transumbilical laparoscopic-assisted appendectomy in children with perforated appendicitis?

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World Journal of Pediatrics 2019年第6期15卷 615-619页

作者： Akinori Sekioka Koji Fukumoto Toshiaki Takahashi Hiromu Miyake Kengo Nakaya Akiyoshi Nomura Yutaka Yamada naoto Urushihara Department of Pediatric Surgery Shizuoka Children's Hospital860 UrushiyamaAoi-kuShizuoka 420-8660Japan

Background This study assessed the necessity of postoperative nasogastric tube(NGT)use in acute pediatric cases of per-forated *** All cases of acute pediatric perforated appendicitis managed with transumbilical laparoscopic-assisted appendec-tomy at our hospital from 2011 to 2017 were retrospectively ***-two cases were selected and divided into two groups based on NGT *** There were no significant differences between the two groups in most parameters of patient demographics,or surgi-cal ***,the mean time to first oral intake and to regular diet was significantly shorter in no-NGT group(1 day vs 3 days,P<0.0001;and 4 days vs 7 days,P=0.003,respectively).Postoperative length of stay was significantly shorter in no-NGT group(7 days vs 9 days,P<0.0001).Conclusion Considering the results of our analysis,we believe that routine NGT placement is not always necessary in these situations.

关键词： Children Perforated appendicitis Postoperative care

Mutations in carboxy-terminal part of E2 including PKR/eIF2αphosphorylation homology domain and interferon sensitivity determining region of nonstructural 5A of hepatitis C virus 1b:Their correlation with response to interferon monotherapy and viral load

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World Journal of Gastroenterology 2006年第23期12卷 3722-3728页

作者： Koji Ukai Masatoshi Ishigami Kentaro Yoshioka naoto Kawabe Yoshiaki Katano Kazuhiko Hayashi Takashi Honda Motoyoshi Yano Hidemi Goto Division of Gastroenterology Department of Internal MedicineNagoya University Graduate School of MedicineNagoyaJapan Division of Liver and Biliary Diseases Department of Internal MedicineFujita Health University School of MedicineAichiJapan

AIM: To study the amino acid substitutions in the carboxy (C)-terminal part of E2 protein and in the interferon (IFN) sensitivity determining region (ISDR) and their correlation with response to IFN and viral load in 85 hepatitis C virus (HCV)-lb-infected patients treated with IFN. METHODS: The C-terminal part of E2 (codons 617-711) including PKR/eIF2a phosphorylation homology domain (PePHD) and ISDR was sequenced in 85 HCV-1b-infected patients treated by IFN monotherapy. RESULTS: The amino acid substitutions in PePHD detected only in 4 of 85 patients were not correlated either with response to IFN or with viral load. The presence of substitutions in a N-terminal variable region (codons 617-641) in the C-terminal part of E2 was significantly correlated with both small viral load (33.9% vs 13.8%, P = 0.0394) and sustained response to IFN (25.0% vs 6.9 %, P = 0.0429). Four or more substitutions in ISDR were significantly correlated with both small viral load (78.6% vs 16.2%, P < 0.0001) and sustained response to IFN (85.7% vs 2.9%, P < 0.0001). In multivariate analysis, ISDR in nonstructural (NS) 5A (OR = 0.39, P < 0.0001) and N-terminal variable region (OR = 0.51, P = 0.039) was selected as the independent predictors for small viral load, and ISDR (OR = 39.0, P < 0.0001) was selected as the only independent predictor for sustained response. CONCLUSION: The N-terminal variable region in the C-terminal part of E2 correlates with both response to IFN monotherapy and viral load and is one of the factors independently associated with a small viral load.

关键词：基因突变羧基端子磷酸化作用干扰素丙型肝炎病毒

MUC5AC/β-catenin expression and KRAS gene alteration in laterally spreading colorectal tumors

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World Journal of Gastroenterology 2012年第39期18卷 5551-5559页

作者： Kosaburo Nakae Hiroyuki Mitomi Tsuyoshi Saito Michiko Takahashi Takashi Morimoto Yasuhiro Hidaka naoto Sakamoto Takashi Yao Sumio Watanabe Department of Gas-troenterology Juntendo University School of Medicine2-1-1 HongoBunkyo-kuTokyo 113-8421Japan Department of Human Pathology Juntendo University School of Medicine1-1-19 HongoBunkyo-kuTokyo 113-0033Japan

AIM:To clarify differences in mucin phenotype, prolif-erative activity and oncogenetic alteration among subtypes of colorectal laterally spreading tumor (LST). METHODS:LSTs, defined as superficial elevated lesions greater than 10 mm in diameter with a low vertical axis, were macroscopically classified into two subtypes:(1) a granular type (Gr-LST) composed of superficially spreading aggregates of nodules forming a flat-based lesion with a granulonodular and uneven surface; and (2) a non-granular type (NGr-LST) with a flat smooth surface and an absence of granulonodular formation. A total of 69 LSTs, comprising 36 Gr-LSTs and 33 NGr-LSTs, were immunohistochemically stained with MUC2, MUC5AC,MUC6, CD10 (markers of gastrointestinal cell lineage), p53, β-catenin and Ki-67 antibodies, and examined for alteration in exon 1 of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and exon 15 of v-raf murine sarcoma viral oncogene homologue B1 (BRAF) by poly-merase chain reaction followed by direct sequencing. RESULTS:Histologically, 15 Gr-LST samples were adenomas with low-grade dysplasia (LGD), 12 were high-grade dysplasia (HGD) and 9 were adenocarcinomas invading the submucosa (INV), while 12 NGr-LSTs demonstrated LGD, 14 HGD and 7 INV. In the proximal colon, MUC5AC expression was significantly higher in the Gr-type than the NGr-type. MUC6 was expressed only in NGr-LST. MUC2 or CD10 did not differ. P53 expression demonstrated a significant stepwise increment in progression through LGD-HGD-INV with both types of LST. Nuclear β-catenin expression was significantly higher in the NGr-type. Ki-67 expression was signifi-cantly higher in the Gr-type in the lower one third zone of the tumor. In proximal, but not distal colon tumors, the incidence of KRAS provided mutation was signifi-cantly higher in the Gr-type harboring a specific mutational pattern (G12V). BRAF mutations (V600E) were detected only in two Gr-LSTs. CONCLUSION:The two subtypes of LST, especially in the pro

关键词：基因变异肠肿瘤细胞外信号调节激酶传播 RAS基因免疫组化染色聚合酶链反应 CD10

A 100% Water Mobile Phase HPLC-PDA Analysis of Meamine and Related Analogues

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American Journal of Analytical Chemistry 2012年第4期3卷 295-299页

作者： naoto Furusawa Graduate School of Human Life Science Osaka City University Osaka Japan

This paper describes a reserved-phase high performance liquid chromatographic method for detecting melamine (MEL) and related analogues, cyanuric acid (CYA), ammeline (AML), and ammelide (AMD), using a 100% water mobile phase. Chromatographic separation was performed an Inertsil? ODS-4 (250 × 4.6 mm, 5 μm) with a water mobile phase and a photodiode-array detector. The monitoring wavelength was adjusted to 210 nm which represents an average maximum for all the analytes. The total run time was < 8 min. The method shows high stability, significant linearity and satisfactory sensitivity. The detection limits were established in the range 23 - 46 ***–1. An inexpensive and harmless method for the simultaneous detection of MEL, CYA, AML, and AMD was developed and may be further applied to the quantification in foods.

关键词： Melamine Cyanuric acid Ammeline Ammelide High-Performance Liquid Chromatography 100% Water Mobile Phase

Novel Radio on Fiber Access Eliminating External Electric Power Supply at Base Station

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光学学报 2003年第S1期23卷 611-612页

作者： Tetsuya Miki Katsuyasu Kawano Nobuo Nakajima naoto Kishi Masaru Miyamoto Tetsu Aoki The University of Electro-Communications Tokyo JapanThe University of Electro-Communications Tokyo JapanThe University of Electro-Communications Tokyo JapanThe University of Electro-Communications Tokyo JapanIwatsu Co. LTD. Tokyo Japan 1-5-1 Chohugaoka Chohu-shi Tokyo 182-8585 JapanIwatsu Co. LTD. Tokyo Japan 1-5-1 Chohugaoka Chohu-shi Tokyo 182-8585 Japan

A novel Radio On Fiber(ROF) access is proposed and demonstrated which enables the pico-cell Base Station (BS) for high-speed wireless communications to eliminate external electric power supply facilities. We demonstrated 2.4-GHz band radio signal transmission through the BS without external electric power supply. The electrical power used for BS circuit is feeded by optical power over optical fiber from central station.

关键词： Radio be ROF BS LNA link Novel Radio on Fiber Access Eliminating External Electric Power Supply at Base Station EAM