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GROWTH AND MORPHOLOGY OF POLYMER-ACTIN COMPLEXES

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Chinese Journal of Polymer Science 2007年第1期25卷 47-55页

作者： Hyuck Joon Kwon Kazuhiro Shikinaka Akira Kakugo hidemitsu furukawa Yoshihito Osada 龚剑萍 Graduate School of Science Hokkaido UniversitySapporo 060-0810Japan Graduate School of Science Hokkaido UniversitySapporo 060-0810Japan SORSTJSTSapporo 060-0810Japan

F-actins are semi-flexible polyelectrolytes and can be assembled into large polymer-actin complex with polymorphism through electrostatic interaction with polycations. This study investigates the structural phase behavior and the growth of polymer-actin complexes in terms of its longitudinal and lateral sizes. Our results show that formation of polymer-actin complexes is cooperative, and morphology and growth of polymer-actin complexes depend on polycation species and concentrations of polycation and salt in a constant actin concentration. We found that the longitudinal growth and lateral growth of polymer-actin complexes are dominated by different factors. This induces the structural polymorphism of polymer-actin complexes. Major factors to influence the polymorphism of polymer-actin complexes in polyelectrolytc system have been discussed. Our results indicate that the semi-flexible polyelectrolyte nature of F-actins is important for controlling the morphology and growth ofactin architectures in cell.

关键词： F-actin Polymer-actin complex Polycation concentration (Cp) KCl concentration (Cs) Fluorescence microscopy Transmission electron microscopy (TEM) Rod-like polyelectrolyte.

Dynamic properties of a flexible metal-organic framework exhibiting a unique"picture frame"-like crystal morphology

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Nano Research 2021年第2期14卷 432-437页

作者： Kenji Sumida Nao Horike Shuhei furukawa Institute for Integrated Cell-Material Sciences(WPI-iCeMS) Kyoto UniversityYoshidaSakyo-kuKyoto 606-8501Japan Centre for Advanced Nanomaterials School of Physical SciencesUniversity of AdelaideSA 5005Australia

The precise control of the crystal morphology of metal-organic frameworks(MOFs)enables optimization of its adsorptive properties,as well as enables better integration within functional ***,the influence of such modifications on the dynamic properties of flexible MOFs is poorly understood Here,we report the synthesis of a series of Cu_(2)(bdc)_(2)(bpy)(bdc^(2-)=1,4-benzenedicarboxylate;bpy=4,4,-bipyridine)crystals having an unusual picture frame-like morphology that results from a restriction in the quantity of bpy pillars added to the reaction mixture during the intercalation of the Cu_(2)(bdc)_(2)(MeOH)_(2)*** width of the frames is found to correlate with the quantity of bpy,and importantly,causes the dynamic properties of the resulting Cu_(2)(bdc)_(2)(bpy)material to vary between rigid,elastic,and shape memory *** all,the results demonstrate the potential for the properties of MOFs to be optimized via subtle manipulations in the crystal morphology rather than changes in the overall material composition.

关键词： metal-organic frameworks morphology control framework flexibility shape-memory effect gas sorption

CONTRIBUTION OF MACROSCOPIC DIMENSION EFFECT TO PIEZOELFCTRICITY IN POLYVINYLIDENE FLUORIDE

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Chinese Journal of Polymer Science 1987年第4期5卷 292-297页

作者：闻建勋,TAKEO furukawa Shanghai Institute of Organic Chemistry Academia Sinica Shanghai The Institute of Physical and Chemical Research Japan

In this paper, we have studied the piezoelectricity in the poled uniaxially drawn polyvinylidene fluoride. The piezoelectric constants d31, d32, d33αand Young's moduli 1/s11 and 1/s22have been determined as a function of the remanent polarization Pr. The piezoelectric constants of the samples show a strong in-plane anisotropy. Such an anisotropy is mostly attributable to different Poisson's ratio. It is found that the piezoelectric activity mainly arises from macroscopic dimensional change.

关键词： Piezoelectricity Pyroelectricity Polyvinylidene fluoride.

Performance Test and Flow Measurement of Contra-Rotating Axial Flow Pump

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Journal of Thermal Science 2007年第1期16卷 7-13页

作者： Akinori furukawa Toru Shigemitsu Satoshi Watanabe Division of Mechanical Engineering Science Kyushu University744 MotookaNishi-kuFukuoka 819-0395JAPAN

An application of contra-rotating rotors has been proposed against a demand for developing higher specific speed axial flow pump. In the present paper, the advantage and disadvantage of using contra-rotating rotors are described in comparison with conventional type of rotor-stator, based on theoretical and experimental investigations. The advantages are as follows：（1） The pump is inherently designed as smaller sized and at lower rotational speed. （2） A stable head-characteristic curve for flow rate with negative slope appears. （3） As the rear rotor rotational speed is varied as independent control of front rotor, the wider range of high performance operation is obtained by rear rotor speed control in addition to front rotor speed control. The disadvantages are as follows：（1） The structure of double shaft system becomes complex. （2） The pump performance is inferior at over flow rate as the rear rotor loading is weakened. （3） The blade rows interaction from rear rotor to front rotor more strongly appears. Then the rear rotor design is a key to achieve higher pump performance. Some methods to overcome these disadvantages will be discussed in more details toward wider usage of contra-rotating axial flow pump in various industrial fields.

关键词： axial flow pump contra-rotating rotors multiphase flow rotational speed control blade rows interaction

STUDIES ON THE CHAIN STRUCTURAL EFFECT OF PVDF AND VDF (52)/TrFE(48) COPOLYMER BY MEANS OF THE METHOD OF DIELECTRIC RELAXATION

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Chinese Journal of Polymer Science 1994年第1期12卷 12-21页

作者：张兴元 furukawa Takeo Department of Materials Science and Engineering University of Science and Technology of China Hefei 230026 Department of Chemistry Science University of Tokyo Japan

Through improvements on a fully commercial and automatic system measuring frequency andtemperature spectra of the complex elastic, dielectric, and piezoelectric constants of polymerfilms, the precision for measuring complex dielectric constants achieved 2‰ from original 1%.The complex dielectric constants of PVDF, VDF （95 ）/VF （5）, VDF （52）/TrFE （48） and VDF（47. 5）/TrFE（47. 5）/HeFP （5） over a range of-120-140℃, 10-2-10;Hz were measured bythe described system. The diminution of chain regularity due to 5mol% vinyl fluoride in the chainof PVDF led to disappearing of α-relaxation and increase in T;（3℃） of VDF （95）/VF （5）.Because of the spatial impediment of 5mol% HeFP in copolymer chain, the Curie point of VDF（52）/TrFE（48） decreased by 30℃ and T;by 3℃. The behavior of dielectric relaxation indicatedthat 5mol% vinyl fluoride and HeFP made the relaxation strength of noncrystalline regionreduced, the activation energy of local relaxation increased and the relaxation time prolonged respectively.

关键词： Polyvinylidene fluoride VDF(52)/TrFE(48) Chain structure effect Dielectric relaxation

Dielectric Relaxations in Ferroelectric Copolymer VDF(73)/TrFE(27)

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Journal of Materials Science & Technology 1995年第1期11卷 31-37页

作者： ZHANG, XY furukawa, TK SCI UNIV TOKYO DEPT CHEMTOKYO 162JAPAN

The characteristics of molecular motion of ferroelectric copolymer VDF(73)/TrFE(27) have been investigated by means of dielectric relaxation. With the rise in crystallinity, the Curie point decreases and the dielectric constant increases in the region of ferroelectric-to-paraelectric phase transition. The frequency spectra of the copolymer below room temperature consist of low-frequency component ascribed to the micro-Brownian motions of molecular segments in the noncrystalline regions and high-frequency component associated with the local motions of small-scale segments. By using the fitting results with one or two Cole-Cole functions, and calculating with WLF equation acid Arrhenius formula,the glass transition temperature and the activation energy of local relaxation are obtained. the distribution of relaxation time in the molten and ferroelectric phases is located at a Same line, acid complies with Arrhenius rule, which suggests that the elementary motions are of same type for molecular motions provided by the high-temperature process and the low-temperature local mode process.

关键词： Dielectric Relaxations in Ferroelectric Copolymer VDF Figure TrFE

Does wild-type Cu/Zn-superoxide dismutase have pathogenic roles in amyotrophic lateral sclerosis?

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Translational Neurodegeneration 2020年第3期9卷 421-436页

作者： Yoshiaki furukawa Eichi Tokuda Department of Chemistry Laboratory for Mechanistic Chemistry of BiomoleculesKeio University3-14-1 HiyoshiKohokuYokohamaKanagawa 223-8522Japan Present address:Laboratory of Clinical Medicine School of PharmacyNihon University7-7-1 NarashinodaiFunabashiChiba 274-8555Japan

Amyotrophic lateral sclerosis(ALS)is characterized by adult-onset progressive degeneration of upper and lower motor *** numbers of genes are found to be associated with ALS;among those,the first identified gene,SOD1 coding a Cu/Zn-superoxide dismutase protein(SOD1),has been regarded as the gold standard in the research on a pathomechanism of *** accumulation of misfolded SOD1 in affected spinal motor neurons has been established as a pathological hallmark of ALS caused by mutations in SOD1(SOD1-ALS).Nonetheless,the involvement of wild-type SOD1 remains quite controversial in the pathology of ALS with no SOD1 mutations(non-SOD1 ALS),which occupies more than 90%of total ALS *** vitro studies have revealed post-translationally controlled misfolding and aggregation of wild-type as well as of mutant SOD1 proteins;therefore,SOD1 proteins could be a therapeutic target not only in SOD1-ALS but also in more prevailing cases,non-SOD1 *** order to search for evidence on misfolding and aggregation of wild-type SOD1 in vivo,we reviewed pathological studies using mouse models and patients and then summarized arguments for and against possible involvement of wild-type SOD1 in non-SOD1 ALS as well as in SOD1-ALS.

关键词： Amyotrophic lateral sclerosis Cu/Zn-superoxide dismutase Protein misfolding

Characteristics of glucose change in diabetes mellitus generalized through continuous wavelet transform processing:A preliminary study

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World Journal of Diabetes 2023年第10期14卷 1562-1572页

作者： Yoichi Nakamura Shinya furukawa Cardiovascular Medicine&Diabetology Specified Clinic of Soyokaze CardioVascular Medicine and Diabetes CareMatsuyama 790-0026EhimeJapan Health Services Center Ehime UniversityMatsuyama 790-8577EhimeJapan

BACKGROUND The continuous glucose monitoring(CGM)system has become a popular evaluation tool for glucose fluctuation,providing a detailed description of glucose change *** hypothesized that glucose fluctuations may contain specific information on differences in glucose change between type 1 diabetes mellitus(T1DM)and type 2 diabetes mellitus(T2DM),despite similarities in change patterns,because of different *** Fourier transform,continuous wavelet transform(CWT)is able to simultaneously analyze the time and frequency domains of oscillating *** To investigate whether CWT can detect glucose fluctuations in *** The 60-d and 296-d glucose fluctuation data of patients with T1DM(n=5)and T2DM(n=25)were evaluated *** data obtained every 15 min for 356 d were *** were assessed by CWT with Morlet form(n=7)as the mother *** methodology was employed to search for limited frequency glucose fluctuation in the daily glucose *** frequency and enclosed area(0.02625 scalogram value)of 18 emerged signals were *** specificity for T1DM was evaluated through multiple regression analysis using items that demonstrated significant differences between them as explanatory *** The high frequency at midnight(median:75 Hz,cycle time:19 min)and middle frequency at noon(median:45.5 Hz,cycle time:32 min)were higher in T1DM vs T2DM(median:73 and 44 Hz;P=0.006 and 0.005,respectively).The area of the>100 Hz zone at midnight to forenoon was more frequent and larger in T1DM vs *** a day,the lower frequency zone(15-35 Hz)was more frequent and the area was larger in T2DM than in *** threedimensional scatter diagrams,which consist of the time of day,frequency,and area of each signal after CWT,revealed that high frequency signals belonging to T1DM at midnight had a loose distribution of wave cycles that were 17-24 *** analysis revealed that the high frequency signal at midnight could c

关键词： Continuous glucose monitoring Pathophysiology Fourier,Pseudo-frequency Contour map Scalogram matrix

Intra-gastric triacetin alters upper gastrointestinal motility in conscious dogs

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World Journal of Gastroenterology 2014年第4期20卷 1054-1060页

作者： Kazumasa Oosaka Masaaki Tokuda Naohiro furukawa Research and Development Department Fushimi Pharmaceutical Co. Ltd. Department of Cell Physiology Faculty of Medicine Kagawa University Department of Clinical Nutrition Faculty of Health Science and Technology Kawasaki University of Medical Welfare

AIM: To examine the effect of intra-gastric triacetin on both upper gastrointestinal motility and proximal gastric tone in conscious dogs.

关键词： Gastrointestinal motility Barostat Proximal gastric relaxation Short-chain triglycerides