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排序方式: 共有495条查询结果,搜索用时 15 毫秒
11.
Sae Saigo Tabito Kino Kotaro Uchida Takuya Sugawara Lin Chen Michiko Sugiyama Kengo Azushima Hiromichi Wakui Kouichi Tamura Tomoaki Ishigami 《International journal of molecular sciences》2022,23(1)
The prorenin/renin receptor ((P)RR) is a multifunctional protein that is widely distributed in various organs. Despite intensive research for more than 20 years, this receptor has not been fully characterized. In this study, we generated mice overexpressing the tubular epithelial (P)RR gene ((P)RR-TG mice) to test the previously reported functional role of (P)RR by Ramkumar et al. in 2015 using tubular specific (P)RR KO mice. (P)RR-TG mice were maintained and analyzed in individual metabolic cages and were administered angiotensin II blocker (ARB), direct renin inhibitor (DRI), and bafilomycin, that is, vacuolar ATPase (V-ATPase) antagonist. (P)RR-TG mice were hypertensive and had alkalized urine with lower osmolality and Na+ excretion. ARB and DRI, but not bafilomycin, concurrently decreased blood pressure. Bafilomycin acidized urine of (P)RR-TG mice, or equivalently this phenomenon restored the effect of overexpressed transgene, suggesting that (P)RR functioned as a V-ATPase in renal tubules. Afterall, (P)RR-TG mice were mated with alternative renin transgenic mice (ARen2-TG), which we identified as intracellular renin previously, to generate double transgenic mice (DT-TG). Lethal renal tubular damage was observed in DT-TG mice, suggesting that intracellular renin may be a ligand for (P)RR in tubules. In summary, (P)RR did not substantially affect the tissue renin-angiotensin system (RAS) in our model of tubular specific (P)RR gene over-expression, but alternative intracellular renin may be involved in (P)RR signaling in addition to conventional V-ATPase function. Further investigations are warranted. 相似文献
12.
In-situ observations on α/γ phase transformation were made to study the effects of grain boundary microstructures on the formation of a new phase and the migration of α/γ interphase boundary in an iron-4. 2%Cr alloy. It was found that triple junctions with more random boundaries could be the primary nucleation sites for a new phase, while triple junctions with low angle or low ∑ coincidence boundaries did not play any role as preferential sites. The migration of α/γ interphase boundary during heating over the transformation temperature range showed the two stage behaviour characterized by a stage with a migration velocity of 0. 33~0. 75 mm/s and secondly by a stage with 3. 7~7. 6 mm/s. It was also found that abnormal grain growth and a high density of ∑3 coincidence boundaries could occur in a phase with bcc structure after cycling of α/γ phase transformation. A new mechanism of nucleation and growth of a new phase in α/γ phase transformation is proposed on the basis of roles of plane-matching interphase boundaries, as previously discussed on the origin of anisotropy of grain growth due to the migration of {110} plane-matching boundaries in Fe-3%Si alloy. The most recent theoretical work on the distribution of plane-matching boundaries in solids with different crystal structures was found to be useful for the understanding of nucleation and growth during α/γ phase transformation. 相似文献
13.
14.
Masaaki Takehisa Sueo Machi Hiromasa Watanabe Takashi Ueno Seiichi Takahashi Ryoji Tsuchiya Kanji Otaguro Isao Motoda Yoshio Takasaka Kazukiyo Miyanaga Waichiro Kawakami Kouichi Yamaguchi Takanobu Sugo Hayato Nakajima Terutaka Watanabe Chuhei Hinachi 《应用聚合物科学杂志》1979,24(3):853-864
Radiation-induced bulk polymerization of ethylene was carried out with use of a pilot plant with a 10 liter reactor at pressures of 225–400 kg/cm2, temperatures of 30–95°C, ethylene feed rates of 5–28 kg/hr, and dose rate of 3.8 × 105 rad/hr. Characteristics of the process are mild polymerization conditions and capability of producing medium density polyethylene in powder form. The spacetime yield and molecular weight of polymer were in the range of 3.5 to 13.1 g/liter hr and 2.2 × 104 to 14 × 104, respectively. The space-time yield increased with mean residence time and 2.4 powders of pressure, and decreased with temperature. Molecular weight changed similarly with the reaction conditions. These results were consistent with those of the bench plant experiment and the scale effect was small. Polymer deposit to the reactor wall limited a period of continuous operation of the plant. The amount of deposited polymer was increased with the square of reaction time. The rate of polymer deposit was proportional to polymer concentration and to the cube of pressure. The polymer deposit cannot be solved in the bulk process. 相似文献
15.
Hajime Miyama Kouichi Tanaka Yoshio Nosaka Nobuyuki Fujii Hiroshi Tanzawa Shoji Nagaoka 《应用聚合物科学杂志》1988,36(4):925-933
Polyacrylonitrile-g-poly(N,N-dimethylaminoethyl methacrylate) was synthesized photochemically and quaternized. The positively charged membranes made from the quaternized graftcopolymer showed high ultrafiltration rate for water by adding poly(vinyl alcohol) to casting solution and washing it out after the casting. In buffered saline solution, the permeability of the membranes was very small at pH below isoelectric point of albumin but increased markedly at higher pH. On the other hand, the permeability for γ-globulin was very small and did not show any pH dependence. 相似文献
16.
Toshiyuki Iguchi Sakae Takenaka Keizo Nakagawa Yoshiki Orita Hideki Matsune Masahiro Kishida 《Topics in Catalysis》2009,52(6-7):563-570
Formation of carbon nanofibers (CNFs) and carbon nanotubes (CNTs) through the decomposition of ethylene at 973 K was achieved using various metal catalysts covered with silica layers. CNFs of various diameters were formed by ethylene decomposition over a Co metal catalyst supported on the outer surface of the silica. In contrast, silica-coated Co catalysts formed CNTs with uniform diameters by ethylene decomposition. Silica-coated Ni/SiO2 and Pt/carbon black also formed CNTs with uniform diameters, while CNFs and CNTs with various diameters were formed over Ni/SiO2 and Pt/carbon black without a silica coating. These results indicate that silica layers that envelop metal particles prevent sintering of the metal particles during ethylene decomposition. This results in the preferential formation of CNTs with a uniform diameter. 相似文献
17.
Nakagawa K 《Lipids》2005,40(7):745-750
Small spin probes in the vesicle and aqueous phases of mixed membranes made from poly(oxyethylene) hydrogenated castor oil (HCO) and hexadecane were investigated by ESR (electron spin resonance) spectroscopy. Partitioning (partition coefficients), rotational correlation times, and activation energies of the spin probes in the vesicle phase were determined. The quantitative results obtained by an ESR simulation indicated that the spin probe DTBN (di-tert-butyl nitroxide), in the vesicle of the mixed membrane, was partitioned similar to that of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) at 50 degrees C, and the partitioning for both probes showed no abrupt change across the temperatures examined. The results differed considerably from conventional analyses of the high-field signal intensities. Activation energies obtained by the simulation for DTBN and TEMPO were 21 and 20 kJ/mol, respectively. In addition, the hyperfine values of 15.8 (DTBN) and 16.1 G (TEMPO) in the vesicle phase were consistent with the activation energies and supported the probe environments in the membrane. Thus, the present ESR results provided detailed information regarding the probe behavior in the membrane. 相似文献
18.
Takanori Kondo Chihiro Yasui Dr. Taisuke Banno Prof. Dr. Kouichi Asakura Dr. Tokuma Fukuoka Dr. Kazunori Ushimaru Dr. Maito Koga Dr. Hiroyuki Minamikawa Dr. Azusa Saika Dr. Tomotake Morita Prof. Dr. Daisuke Takahashi Prof. Dr. Kazunobu Toshima 《Chembiochem : a European journal of chemical biology》2022,23(2):e202100631
Mannosylerythritol lipids (MELs), which are one of the representative sugar-based biosurfactants (BSs) produced by microorganisms, have attracted much attention in various fields in the sustainable development goals (SDGs) era. However, they are inseparable mixtures with respect to the chain length of the fatty acids. In this study, self-assembling properties and structure-activity relationship (SAR) studies of recovery effects on damaged skin cells using chemically synthesized MELs were investigated. It was revealed, for the first time, that synthetic and homogeneous MELs exhibited significant self-assembling properties to form droplets or giant vesicles. In addition, a small difference in the length of the fatty acid chains of the MELs significantly affected their recovery effects on the damaged skin cells. MELs with medium or longer length alkyl chains exhibited much higher recovery effects than that of C18-ceramide NP. 相似文献
19.
Takakazu Yamamoto Kouichi ShiraishiMahmut Abla Isao YamaguchiL.“Bert” Groenendaal 《Polymer》2002,43(3):711-719
Neutral and non-doped poly(3,4-ethylenedioxythiophene), PEDOTh(Ni), and its hexyl derivative, PEDOTh-C6(Ni), have been prepared by organometallic dehalogenation polycondensation of 2,5-dichloro-3,4-ethylenedioxythiophene and its hexyl derivative with a zerovalent nickel complex. PEDOTh-C6(Ni) was soluble in organic solvents and 1H NMR data indicated that it had an Mn of 11,000. MALDI-TOF mass analysis of PEDOTh(Ni) gave Mn and Mw of about 1700 and 2400, respectively. PEDOTh-C6(Ni) showed a UV-Vis absorption peak at 546 nm in CHCl3. Electrochemical oxidation of PEDOTh-C6(Ni) started at about −0.40 V vs Ag+/Ag and gave a peak at 0.20 V vs Ag+/Ag. Chemical and electrochemical oxidation (or p-doping) of PEDOTh-C6(Ni), both in solutions and in a solid state, led to weakening of the original π-π∗ peaks and rise of new peak(s) in a region of 800-1500 nm. The p-doping of PEDOTh-C6(Ni) caused not only a decrease in the intensity of 1H NMR signals of the bridging ethylene hydrogens but also a decrease in that of the hexyl side chain, suggesting a strong interaction of the p-dopant with the side chain. NMR data of poly(3-methoxythiophene-2,5-diyl) also supported an assumption that p-doping brings about a severe change in electronic state of the substituent attached to the polythiophene main chain. PEDOTh(Ni) had a density of 1.71 g cm−3; the molecular packing mode of PEDOTh(Ni) is discussed based on the density of the polymer and its XRD data. 相似文献
20.
Kouichi Harada Senji Shimanuki Tsuyoshi Kobayashi Yohachi Yamashita Shiroh Saitoh 《Journal of the American Ceramic Society》2002,85(1):145-149
A high-quality single crystal of Pb((Zn1/3 Nb2/3 )0.91 Ti0.09 )O3 (PZNT 91/9), 40 mm in diameter and 20 mm in length, was successfully grown using the solution Bridgman method with a slight excess amount of ZnO. High-quality wafers were sliced from the light-brown single crystal. No PbO inclusions or opaque areas were observed in the transparent wafers. An array probe for echocardiography was constructed with the single-crystal wafer, and its superior performance was demonstrated. 相似文献