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81.
Dietary exposure to acrylamide in a group of Japanese adults based on 24-hour duplicate diet samples
Junko Kawahara Yazhi Zheng Miho Terui Akiko Shinohara Kaori Uyama Miyuki Yoneyama 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2019,36(1):15-25
Acrylamide is a probable human carcinogen and known human neurotoxin that can be generated in food through heating. Using a mathematical modelling approach, our previous study estimated long-term average dietary exposure to acrylamide in the Japanese people; however, the validity of these estimates remained unknown. Here, we aimed to obtain a more accurate estimate of acrylamide exposure that would reflect the usual practice of heat processing and consumption of foods in the population. We collected duplicate diet samples and dietary records during 24 h from a group of Japanese adults. A total of 110 duplicate diet samples were analysed for acrylamide by LC-MS/MS. Data from individual dietary records were used to examine the association between dietary acrylamide exposure and consumption of selected food groups (e.g., coffee, tea, confectioneries, and vegetables prepared at high temperature [deep-frying, stir-frying, sautéing, and baking]). Of the 110 homogenised diet samples, 108 contained detectable levels of acrylamide. Dietary exposure to acrylamide ranged from 8 to 1582 ng/kg body weight (bw)/day, with the mean value of 215 ng/kg-bw/day and median value of 143 ng/kg-bw/day. This mean value was higher than the value we previously estimated for Japanese adults using a mathematical approach. Multiple linear regression analysis showed log dietary acrylamide exposure was significantly associated with consumption of coffee and vegetables prepared at high temperature during 24-hr of sampling (adj. R2 = 0.250, p < 0.001). We revealed significant difference in dietary acrylamide exposure between participants who had coffee and vegetables prepared at high temperature (median, 169 ng/kg-bw/day; range, 35–1224 ng/kg-bw/day, n = 42) and those who had none of them (median, 75 ng/kg-bw/day; range, 8–311 ng/kg-bw/day, n = 15) (Steel-Dwass test, p < 0.05). 相似文献
82.
Kazuhiko Takeuchi Taka-aki Hanaoka Takehiko Matsuzaki Matti Reinikainen Yoshihiro Sugi 《Catalysis Letters》1991,8(2-4):253-261
Vapor phase hydroformylation of ethylene was studied with silica-supported metal catalysts. A cobalt metal catalyst derived from Co2(CO)8 gave propanal and its derivatives in as high selectivity of about 36% as Rh/SiO2 catalyst under the reaction conditions of 1.1 MPa of a gas-mixture of ArCOC2H4H2 = 1333 at 423–503 K. On the other hand, conventional cobalt catalysts derived from cobalt nitrate, chloride, or acetate, and other noble metal catalysts (Pd/SiO2 and Ir/SiO2) produced mainly ethane. 相似文献
83.
Feng Ren Shingo Ishida Nobuyuki Takeuchi 《Journal of the American Ceramic Society》1993,76(7):1825-1831
The distribution and chemical states of vanadium in V-doped ZrO2 were studied to clarify the origin of the color of vanadium-zirconium yellow pigment in comparison with vanadium-tin yellow pigment. ESCA data and measurements of lattice constants of V-doped ZrO2 revealed that vanadium was dissolved mainly as V4+ substituting for Zr in ZrO2 lattice, and its solubility limit was 0.5 wt% as V2 O5 . It was found that the yellow color of vanadium-zirconium yellow was produced predominantly by the dissolved vanadium and that the contribution of vanadium oxide on ZrO2 grains to the yellow color was about 1/30 of that of the dissolved vanadium when compared on the basis of equimolar quantity of vanadium. Most of the undissolved vanadium oxide was in an amorphous or a poorly crystallized state. 相似文献
84.
Soichiro Ogi Tomohiro Ikeda Masayuki Takeuchi 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(1):193-199
New rotary molecular machines (1 and 2) were synthetically constructed from two distinct porphyrin-based rotors, a cerium(IV) bis(porphyrinate)s double-decker (CeDD) and a porphyrinatorhodium(III)-based rotor. These rotors are adjacently mounted on rotational axes aligned to near vertical as resembling the bevel-gear-shaped structure. Structural study using NMR analysis reveals that these distinct rotors are connected through a coordination bond between rhodium(III) and a pyridyl group. At temperature from 193 to 393 K, each rotor represents rotational motion driven by heat fluctuation without decomposition into the corresponding precursors in dichloromethane-d 2 and tetrachloroethane-d 4. Importantly, the mechanical interaction between the teeth of these rotors is strongly dependent on the central metal atom in a DD rotor and the teeth structure in a porphyrinatorhodium(III)-based rotor. Understanding such relationship between the chemical structures and mechanical interaction is of importance for generating cooperative motion in the hybrid machinery system. 相似文献
85.
The rainfall runoff (R-R) process was studied for two small sub-basins having different sizes in a mountainous catchment of
Tono area Japan. The runoff and other meterological data have been collected in this catchment for the last 14 years. The
major objective of this study was to construct numerical models for these sub-basins to predict runoff after 1/2 and 1 h.
The effects of season and the size of the catchment on R-R process were also investigated. The hydrogeological conditions
of the catchment were studied prior to the analyses. The data obtained for summer (rainy) and winter (dry) seasons were treated
separately in order to study the seasonal effects on the model development. The back propagation artificial neural network
technique (BPANN) and the multivariate autoregressive and moving average models (ARMA) were adopted for the analysis. It was
found that for very small catchments the seasonal effects are dominant and therefore separate models should be developed for
each season to obtain better forecasting estimates. It was also found that the predictions by BPANN models were better than
multivariate ARMA models for intense rains having complex R-R relationships in summer. On the other hand, both the modelling
techniques yielded almost similar results for smaller rains in winter. It was also found clearly that the accuracy of prediction
decreased with the increase of the time period for prediction. 相似文献
86.
87.
Ralph Skomski Priyanka Manchanda Ichiro Takeuchi Jun Cui 《JOM Journal of the Minerals, Metals and Materials Society》2014,66(7):1144-1150
The geometrical optimization of aligned hard-soft permanent-magnet nanocomposites is investigated by model calculations. Considered criteria are the shapes of the soft and c-axis-aligned hard phases, the packing fraction of the soft phase, and magnetostatic interactions. Taking into account that the energy product is enhanced via the volume fraction of the soft phase, subject to maintaining coercivity, we find that the best structures are soft-magnetic cubes as well as long rods with a square cross section. Comparing embedded soft cubes with embedded soft spheres of the same size, our nucleation-field analysis shows that the volume fraction of the soft phase is enhanced by 91%, with a coercivity reduction of only 25%. Magnetostatic interactions often but not always deteriorate the permanent-magnet performance, as exemplified by the example of MnBi:FeCo bilayers and multilayers. 相似文献
88.
Noboru Nishioka Miyuki Funakoshi Kohji Inamoto Masakuni Uno Akira Ueda 《应用聚合物科学杂志》2010,118(4):2482-2487
Homogeneous grafting of styrene onto cellulose was carried out in a dimethylacetamide/lithium chloride solvent system. The grafted products were added to cellulose/polystyrene (PS) blends as compatibilizers. The thermal decomposition behavior of the blends was investigated by thermogravimetry. The thermal stability of the blends decreased with an increase in grafted product content. The crystallinity of the blends decreased with grafted product content. The microphase‐separated structures of the blends became finer with grafted product content. The glass transition temperatures for cellulose and PS in the blends were lowered with grafted product content. Differences in thermal decomposition behavior of the blends were correlated with compatibility. Thermogravimetry was effective for compatibility estimation in cellulose/PS blends containing grafted products. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
89.
Young Jin KimAmy C. Marschilok Kenneth J. TakeuchiEsther S. Takeuchi 《Journal of power sources》2011,196(16):6781-6787
Recently, we have shown silver vanadium phosphorous oxide (Ag2VO2PO4, SVPO) to be a promising cathode material for lithium based batteries. Whereas the first reported preparation of SVPO employed an elevated pressure, hydrothermal approach, we report herein a novel ambient pressure synthesis method to prepare SVPO, where our chimie douce preparation is readily scalable and provides material with a smaller, more consistent particle size and higher surface area relative to SVPO prepared via the hydrothermal method. Lithium electrochemical cells utilizing SVPO cathodes made by our new process show improved power capability under constant current and pulse conditions over cells containing cathode from SVPO prepared via the hydrothermal method. 相似文献
90.
A. Takeuchi N. Chen T. Wada Y. Yokoyama H. Kato A. Inoue J.W. Yeh 《Intermetallics》2011,19(10):1546-1554
A Pd20Pt20Cu20Ni20P20 bulk metallic glass (BMG) with a high-entropy (HE) alloy composition and a maximum diameter of 10 mm was fabricated by fluxed water quenching. The system and composition of the Pd20Pt20Cu20Ni20P20 alloy were determined from a prototype ternary Pd40Ni40P20 BMG in accordance with two strategic alloy designs of (1) HE alloy defined by an equi-atomic alloy with five or more elements and (2) exchangeability of the constituent elements with a similar chemical nature in the periodic table. Pd20Pt20Cu20Ni20P20 HE-BMG had a supercooled liquid range of 65 K and a reduced glass transition temperature of 0.71. Successful formation of Pd20Pt20Cu20Ni20P20 HE-BMG is significant to develop new alloys for HE alloys and BMGs. 相似文献