Production of the Blood Pressure Lowing Peptides from Brown Alga （ Undaria pinnatifida ）     

Sato Minoru Oba Takashi Hosokawa Takao Yamaguchi Toshiyasu Nakano Toshiki Saito Tadao Muramoto Koji Kahara T akashi Funayama Katsura Kobayashi Akio Nakano Takahisa 《中国海洋大学学报(英文版)》2005,4(3):209-213

Brown alga （ Undaria pinnatifida） was treated with alginate lyase and hydrolyzed using 17 kinds of proteases and the inhibitory activity of the hydrolysates for the angiotensin-I-converting enzyme （ACE） was measured. Four hydrolysates with potent ACE-inhibitory activity were administered singly and orally to spontaneously hypertensive rats （SHRs）. The systolic blood pressure of SHRs decreases significantly after single oral administration of the brown alga hydrolysates by pro- tease S ＇ Amano＇ （from Bacillus stearothermophilus） at the concentration of 10 （mg protein） （kg body weight）^ - 1. In the 17 weeks of feeding experiment, 7-week-old SHRs were fed standard diet supplemented with the brown alga hydrolysates for 10 weeks. In SHRs fed 1.0 and 0.1% brown alga hydrolysates, elevating of systolic bloodpressure was significantly suppressed for 7 weeks. To elucidate the active components, the brown alga hydrolysates were fractionated by 1-butanol extraction and HPLC on a reverse-phase column. Seven kinds of ACE-inhibitory peptides were isolated and identified by amino acid composition analysis, sequence analysis, and LC-MS with the results Val-Tyr, Ile-Tyr, Ala-Trp, Phe-Tyr, Val-Trp, Ile-Trp, and Leu-Trp. Each peptide was determined to have an antihypertensive effect after a single oral administration in SHRs. The brown alga hydrolysates were also confirmed to decrease the blood pressure in humans.  相似文献   

Phase boundary between ilmenite and perovskite structures in MnGeO3 determined by in situ X-ray diffraction measurements     

Daisuke Yamazaki  Eiji Ito  Yoshinori Tange  Takashi Yoshino  Shuangmeng Zhai  Hiroshi Fukui  Anton Shatskiy  Tomoo Katsura  Ken-ichi Funakoshi 《Physics and Chemistry of Minerals》2007,34(4):269-273

In situ X-ray observations of the phase transition from ilmenite to perovskite structure in MnGeO₃ were carried out in a Kawai-type high-pressure apparatus interfaced with synchrotron radiation. The phase boundary between the ilmenite and perovskite structures in the temperature range of 700–1,400°C was determined to be P (GPa) = 16.5(±0.6) − 0.0034(±0.0006)T (°C) based on Anderson’s gold pressure scale. The Clapeyron slope, dP/dT, determined in this study is consistent with that for the transition boundary between the ilmenite and the perovskite structure in MgSiO₃.  相似文献   

Marine reservoir correction for the Pacific coast of central Japan using C ages of marine mollusks uplifted during historical earthquakes     

Masanobu Shishikura  Tomoo Echigo  Heitaro Kaneda 《Quaternary Research》2007,67(2):286-291

In this study we utilize marine shell samples from two levels of historically uplifted sessile mollusk assemblages and raised wave-cut benches to evaluate the marine reservoir correction (ΔR) for the Pacific coast of central Japan. Elevation measurements of the uplifted marine shells indicate that the lower assemblage emerged during the 1923 Taisho Kanto earthquake (M7.9), whereas uplift of the upper assemblage is most likely but less confidently ascribed to the 1703 Genroku Kanto earthquake (M8.2). Radiocarbon dating of carefully selected samples from the upper and lower assemblages yielded very similar ΔR values of 82 ± 33 and 77 ± 32 yr, respectively. We regard the former ΔR value as a representative and more reliable value given the uncertainty in correlation of the upper assemblage with the 1703 earthquake. This result is consistent with previously reported ΔR values for the Pacific coast of south-central Japan and areas around the Sea of Japan that are influenced by warm ocean currents. Radiocarbon dating of coseismically uplifted shells can aid in estimating marine reservoir ages in the tectonically active Japan Islands.  相似文献   

Thermoelastic properties of the high-pressure phase of SnO2 determined by in situ X-ray observations up to 30 GPa and 1400 K     

S. Ono  E. Ito  T. Katsura  A. Yoneda  M. J. Walter  S. Urakawa  W. Utsumi  K. Funakoshi 《Physics and Chemistry of Minerals》2000,27(9):618-622

 In situ synchrotron X-ray experiments in the system SnO₂ were made at pressures of 4–29 GPa and temperatures of 300–1400 K using sintered diamond anvils in a 6–8 type high-pressure apparatus. Orthorhombic phase (α-PbO₂ structure) underwent a transition to a cubic phase (Pa3ˉ structure) at 18 GPa. This transition was observed at significantly lower pressures in DAC experiments. We obtained the isothermal bulk modulus of cubic phase K ₀= 252(28) GPa and its pressure derivative K ^′=3.5(2.2). The thermal expansion coefficient of cubic phase at 25 GPa up to 1300 K was determined from interpolation of the P-V-T data obtained, and is 1.7(±0.7) × 10⁻⁵ K⁻¹ at 25 GPa. Received: 7 December 1999 / Accepted: 27 April 2000  相似文献   

Relative contribution of feedback processes to Arctic amplification of temperature change in MIROC GCM     

Masakazu Yoshimori  Masahiro Watanabe  Ayako Abe-Ouchi  Hideo Shiogama  Tomoo Ogura 《Climate Dynamics》2014,42(5-6):1613-1630

The finding that surface warming over the Arctic exceeds that over the rest of the world under global warming is a robust feature among general circulation models (GCMs). While various mechanisms have been proposed, quantifying their relative contributions is an important task in order to understand model behavior. Here we apply a recently proposed feedback analysis technique to an atmosphere–ocean GCM under two and four times CO₂ concentrations which approximately lead to seasonally and annually sea ice-free climates. The contribution of feedbacks to Arctic temperature change is investigated. The surface warming in the Arctic is contributed by albedo, water vapour and large-scale condensation feedbacks and reduced by the evaporative cooling feedback. The surface warming contrast between the Arctic and the global averages (AA) is maintained by albedo and evaporative cooling feedbacks. The latter contributes to AA predominantly by cooling the low latitudes more than the Arctic. Latent heat transport into the Arctic increases and hence evaporative cooling plus large-scale condensation feedback contributes positively to AA. On the other hand, dry-static energy transport into the Arctic decreases and hence dynamical heating feedback contributes negatively to AA. An important contribution is thus made via changes in hydrological cycle and not via the ‘dry’ heat transport process. A larger response near the surface than aloft in the Arctic is maintained by the albedo, water vapour, and dynamical heating feedbacks, in which the albedo and water vapour feedbacks contribute through warming the surface more than aloft, and the dynamical heating feedback contributes by cooling aloft more than the surface. In our experiments, ocean and sea ice dynamics play a secondary role. It is shown that a different level of CO₂ increase introduces a latitudinal and seasonal difference into the feedbacks.  相似文献   

Ordering in double carbonates and implications for processes at subduction zones   总被引：2，自引：0，他引：2  

T. Hammouda  D. Andrault  K. Koga  T. Katsura  A. M. Martin

《Contributions to Mineralogy and Petrology》2011,161(3):439-450

We have studied cation ordering in dolomite in situ as a function of pressure, temperature, and experimental time using the multi-anvil apparatus and synchrotron radiation. Starting with ordered dolomite, we observe the onset of disordering taking place at 950°C, while complete disordering is achieved at 1,070 (±20)°C, for pressures ranging between 3.37 and 4.05 GPa. Pressure does not appear to have significant effect on the order/disorder transition over the investigated range. We find that dolomite can reach its equilibrium ordering state above 900°C within duration of laboratory experiment (few hours), both from disordered state and from ordered state. In addition, we have reversed the dolomite breakdown reaction [magnesite + aragonite = dolomite] between 4.5 and 5.5 GPa, by monitoring diffraction peak intensity. We also have determined that dolomite is stable up to 7.4 GPa at 1,100°C. We confirm some earlier studies where a change in slope (dP/dT) has been observed, but we find a non-zero slope in the low pressure range. Combining the values of entropy obtained from dolomite degree of ordering with enthalpy values deduced from our bracketing of [magnesite + aragonite = dolomite] equilibrium, we model the location of dolomite breakdown in the P–T space as a function of cation ordering. By comparing previous conflicting studies, we show that, although kinetics of order/disorder is fast, disequilibrium dolomite breakdown is possible. Our modeling shows that subducted disordered dolomite present in carbonated sediments could be decomposed to [magnesite + aragonite] at lower pressure (3.5 GPa) than usually considered (>5 GPa). This 2-GPa (60 km) difference is valid on a fast subduction path and is possible if disorder inherited from sedimentation is preserved. On a slow subduction path, however, dolomite breakdown is encountered at about 250 km depth, which is 100 km deeper than currently considered.  相似文献   

Application of a coil‐type TDR probe for measuring the volumetric water content in weathered granitic bedrock     

Shin'ya Katsura  Ken'ichirou Kosugi  Takahisa Mizuyama 《水文研究》2008,22(6):750-763

As a first step toward describing water flow processes in bedrock, a coil‐type time domain reflectometry (TDR) probe capable of measuring volumetric water content, θ, in weathered bedrock at three depths was prepared. Because the coil‐type TDR probe is large in diameter (19 mm), it can be installed even in highly weathered bedrock more easily and appropriately than conventional TDR probes that consists of two or three rods of small diameter (5‐8 mm). The probe calibrations suggest that the values measured by the probe are very sensitive to changes in θ. Using the calibrated probe together with commercially available profile soil moisture sensors, the θ profile was monitored for 1 year. Even rainfall events with relatively small cumulative rainfall of 15 mm increased the bedrock θ, and the increments were comparable to those in the soil. After the end of the rainfall events, the bedrock θ displayed a more rapid drop than the soil, and varied little during the period of no rainfall. The water storage showed similar tendencies. These observations suggest that the bedrock θ is controlled by clearly distinguishable macropores and micropores within the bedrock. It is concluded that the coil‐type TDR probe is very effective in determining θ in weathered bedrock, and that bedrock, conventionally defined by conducting cone penetration tests and treated as impermeable, does conduct and hold substantial amounts of water, and therefore contribute greatly to hydrological processes in headwater catchments. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

3-D Spatial Variation of b-Values of Magnitude-Frequency Distribution Beneath the Kanto District, Japan     

Yosihiko Ogata  Masajiro Imoto  Koichi Katsura 《Geophysical Journal International》1991,104(1):135-146

  相似文献   

Generation of Palaeocene Adakitic Andesites by Magma Mixing; Yanji Area, NE China   总被引：26，自引：0，他引：26  

Guo  Feng; Nakamuru  Eizo; Fan  Weiming; Kobayoshi  Katsura; Li  Chaowen 《Journal of Petrology》2007,48(4):661-692

Palaeocene (c. 55–58 Ma) adakitic andesites from the Yanjiarea, NE China, are typically clinopyroxene-bearing sodic andesitescontaining 60· 9–62· 2% SiO₂ and 4·02–4· 36% MgO, with high Mg-number [100 Mg/(Mg+ Fe) atomic ratio] from 65· 5 to 70· 1. Whole-rockgeochemical features include high Cr (128–161 ppm) andNi (86–117 ppm) concentrations, extremely high Sr (2013–2282ppm), low Y (10–11 ppm) and heavy rare earth elements(HREE; e.g. Yb = 0· 79–1· 01 ppm), and mid-oceanridge basalt (MORB)-like Sr–Nd–Pb isotopic compositions[e.g. ⁸⁷Sr/ ⁸⁶Sr(i) = 0· 70298–0· 70316,_Nd(t) = +3· 8 to +6· 3 and ²⁰⁶Pb/ ²⁰⁴Pb = 17·98 – 18· 06], analogous to high-Mg adakites occurringin modern subduction zones. However, mineralogical evidencefrom clinopyroxene phenocrysts and microcrystalline plagioclaseclearly points to magma mixing during magma evolution. Iron-richclinopyroxene (augite) cores with low Sr, high Y and heavy REEcontents, slightly fractionated REE patterns and large negativeEu anomalies probably crystallized along with low-Ca plagioclasefrom a lower crustal felsic magma. In contrast, high Mg-numberclinopyroxene (diopside and endiopside) mantles and rims havehigher Sr and lower HREE and Y concentrations, highly fractionatedREE patterns (high La/Yb) and negligible Eu anomalies, similarto those found in adakites from subduction zones. The Yanjiadakitic andesites can be interpreted as a mixture between acrust-derived magma having low Mg-number and Sr, and high Yand HREE, and a mantle-derived high Mg-number adakite havinghigh Sr and low Y and HREE concentrations. During storage and/orascent, the mixed magma experienced further crustal contaminationto capture zircons, of a range of ages, from the wall rocks.The absence of coeval arc magmatism and an extensional tectonicregime in the Yanji area and surrounding regions suggest thatthese Palaeocene adakitic andesites were formed during post-subductionextension that followed the late Cretaceous Izanagi–Farallonridge subduction. Generation of these adakitic andesites doesnot require contemporaneous subduction of a young, hot oceanicridge or delamination of eclogitic lower crust as suggestedby previous models. KEY WORDS: magma mixing; adakitic andesites; Palaeocene; NE China  相似文献   

Ephemeral landform development following rapid coastal uplift in the southern orogen of Taiwan     

Slawomir Jack Giletycz  Andrew Tien-Shun Lin  Katsura Yamada  Liang-Chi Wang  Chih-Wei Chien  Jiann-Yuh Lou  Neng-Wei Huang  Che-Yung Ting  Kuo-Wei Shih 《地球表面变化过程与地形》2021,46(12):2379-2394

Newly emerged landscapes above sea level are characterized by rapidly evolving geomorphic systems where the initial fluvial pattern adapts to a former submarine topography. Such an early formed fluvial system establishes drainage basins and unstable landforms that characterize high topographic asymmetry which are prone to fast removal or reorganization. Transitional landscapes might form depositional systems as lakes or ponds that subsequently are incised, captured and incorporated into drainage basins. In this study we focus on the recently emerged Hengchun Peninsula to survey its paleoenvironment evolution. Three drillings performed in the Gangkou basin with fieldwork revealed several indicators that reconstructed stages of the landscape reorganization. The major finding shows an ephemeral large lake in the central part of the Hengchun Peninsula that was drained to the Pacific c. 6000 bp . The lake belonged to an ephemeral lakeland that was created after the emergence of the peninsula. Currently, several areas as relict landforms indicate this stage of topography evolution that through high rates of incision and subsequent captures, transforms into drainage basins. Furthermore, two drillings show brackish waters at the present estuary of the Gangkou basin. These two different paleoenvironments today build one system – Gangkou catchment. Long-term uplift rates show that a hanging wall of the Hengchun Fault plays a significant role in the creation of a lakeland by tilting the peninsula's surface. The tilt impacts on asymmetrical emergence of the peninsula and catchment development. Our study shows that a new geomorphic system might create depositional ephemeral landforms (lakes) that represent phases of early topography evolution after emergence above a sea level that are subjected to instantaneous rearrangement and evolves through large-scale phases before it reaches a topographic steady-state.  相似文献