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排序方式: 共有683条查询结果,搜索用时 31 毫秒
101.
Itoh H Iwasaki M Nakajima Y Endo Y Hanaoka T Sasaki H Tanaka T Yang B Tsugane S 《The Science of the total environment》2008,402(2-3):171-175
Cadmium may act like an estrogen and be a potential risk factor for estrogen-related diseases such as breast cancer and endometriosis. Here, we tested the hypothesis that higher cadmium exposure is associated with endometriosis among infertile Japanese women in a hospital-based case-control study. We recruited consecutive female patients aged 20-45 years who had complained of infertility and presented to a university hospital in Tokyo. The subjects were interviewed and provided a urine sample prior to a laparoscopic diagnosis of endometriosis between January 2000 and December 2001. The severity of endometriosis was then dichotomized into controls (stage 0 and I) and cases (stage II-IV). We finally measured urinary total cadmium concentration in 54 cases and 74 controls as a biomarker of long-term cumulative exposure. Odds ratios were adjusted for average menstrual cycle length, body-mass index and smoking status using unconditional logistic regression. Results showed no association between endometriosis and urinary cadmium concentration. Medians (interquartile ranges) of urinary cadmium concentration in cases and controls were 0.53 (0.40-0.73) and 0.54 (0.34-0.76) microg/g creatinine, respectively (P for difference=0.88). Adjusted odds ratio (95% confidence interval) for the highest versus lowest tertile of urinary creatinine-adjusted cadmium concentration was 0.86 (0.30 to 2.49, P for trend=0.79). Our results do not support the hypothesis that higher urinary cadmium concentration is associated with the risk of endometriosis. 相似文献
102.
Nagasako-Akazome Y Kanda T Ohtake Y Shimasaki H Kobayashi T 《Journal of oleo science》2007,56(8):417-428
We performed a randomized double-blind, placebo-controlled study on moderately obese male and female subjects (71 subjects) with a body mass index ranging from 23 to 30 to evaluate the efficacy of 12-week intake of polyphenols extracted from apples and hop bract (600 mg/day). We confirmed that 12-week ingestion of polyphenol-containing capsules significantly decreased total cholesterol and LDL-cholesterol levels. The effects of the apple polyphenol-containing capsules were more marked than those of the hop bract polyphenol-containing capsules. The visceral fat area and the level of adiponectin in the group administered apple polyphenols improved in comparison with the control group. Blood and physical examinations revealed on clinical problems, and no adverse reactions were observed during the ingestion period. These results demonstrate that apple polyphenols regulate fat metabolism in healthy subjects with relatively high body mass index. 相似文献
103.
Uchino K Katsumata Y Takeda T Arai H Shiraki M Saito T 《Journal of Bioscience and Bioengineering》2007,104(3):224-226
An intracellular 3-hydroxybutyrate-oligomer hydrolase was purified from a poly(3-hydroxybutyrate)-degrading bacterium, Paucimonas lemoignei. It hydrolyzed the 3-hydroxybutyrate dimer with the highest specific activity of any of the enzymes reported so far. The gene was cloned and sequenced. The deduced amino acid sequence showed that the enzyme is a homolog of the PhaZc of Ralstonia eutropha H16. 相似文献
104.
The evaluation of antioxidant activity in vivo is difficult. In this study, the effects of dietary natural and synthetic antioxidants
on the lipid peroxidation in mice were assessed using a biomarker, total hydroxyoctadecadienoic acid (tHODE). Biological samples
such as plasma, erythrocytes, and tissues were first reduced and then saponified to convert various oxidation products of
linoleates to tHODE. Subsequently, the absolute concentration of tHODE and its stereoisomer ratio, [9- and 13-(Z,E)-HODE)/[9- and 13-(E,E)-HODE], which is a measure of the hydrogen donor capacity of antioxidants, were determined by gas chromatography–mass spectrometry
(GC–MS) analyses. These were then compared with total 8-iso-prostaglandin F2α (t8-iso-PGF2α) which was also assessed after reduction and saponification. Remarkable increases in tHODE and t8-iso-PGF2α levels were observed in the plasma, erythrocytes, liver, and brain of mice that were fed an α-tocopherol (αT)-stripped (E-free)
diet for 1 month when compared with those of mice that were fed a standard diet (αT = 0.002 wt%). When mice were fed for 1 month
on an E-free diet supplemented with a lipophilic antioxidant (0.04 wt%), namely, αT, α-tocotrienol (αT3), γ-tocopherol (γT),
or 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran (BO-653), a potent synthetic antioxidant, the increases of tHODE and t8-iso-PGF2α in the plasma, erythrocytes, liver, and brain were suppressed to the levels lower than those of mice fed a standard diet.
The (Z,E/E,E) HODE ratio was decreased in the plasma and erythrocytes of mice fed the E-free diet when compared with that in mice fed
the standard diet. This stereo-isomeric ratio was significantly recovered by the addition of αT and BO-653. These results
show that the tHODE level and the (Z,E/E,E) HODE ratio are useful biomarkers for the assessment of antioxidant capacity in vivo and that the antioxidant capacity decreased
in the order: BO-653 > αT3 ≧ αT, γT, as assessed by tHODE levels from blood, liver, and brain. 相似文献
105.
Yoshikazu Kitajyo Yoko Sakai Hirofumi Tani Atsushi Narumi Noriaki Kaneko Toyoji Kakuchi 《Polymer》2007,48(5):1237-1244
The synthesis of a novel unimolecular reverse micelle, the hyperbranched d-glucan carbamate (3), was accomplished through the carbamation reaction of the hyperbranched d-glucan (1) with the N-carbonyl l-leucine ethyl ester (2) in pyridine at 100 °C. Polymer 3 was soluble in a large variety of organic solvents, such as methanol, acetone, chloroform, and ethyl acetate, and insoluble in water, which remarkably differed from the solubility of 1. The degree of carbamate substitution (DS) for 3 was controlled by the feed rate of 2, and the DS values were in the range of 46.0-93.7%. Polymer 3 possessed the encapsulation ability for water-soluble molecules, such as rose bengal, thymol blue, and alizarin yellow in chloroform, and the encapsulation ability depended on the hydrophilicity of 3 and the molecular size of the dye. The rose bengal (RB) encapsulated polymer (RB/3) showed a slow release from the RB/3 system into water at neutral pH, while the release rate was significantly accelerated by the hydrolysis of the hydrophobic polymer shell under basic conditions. 相似文献
106.
Takashi Kosaka Nobuyuki Matsui Yo‐Ichi Taniguchi Hideo Do‐meki 《Electrical Engineering in Japan》2000,130(1):118-128
Although the reluctance motors are attractive from the standpoints of simple construction and drive electronics, the relatively high torque ripple and acoustic noise are major drawbacks. These drawbacks limit motor applications. In this paper, the torque ripple suppression of the reluctance motor under the sinusoidal current drive is examined. The analysis shows that the torque ripple is caused by the spatial harmonics of inductance. One approach is based on the compensation current generated with the spatial harmonics of inductance. Another is based on the modification of rotor tooth configuration to eliminate the spatial harmonics. According to the proposed strategies, torque ripple suppression characteristics can be evaluated at the design stage of the motor. Both approaches have been verified by experiments. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 118–128, 2000 相似文献
107.
Colby C. Swan Iku Kosaka 《International journal for numerical methods in engineering》1997,40(16):3033-3057
The desired results of variable topology material layout computations are stable and discrete material distributions that optimize the performance of structural systems. To achieve such material layout designs a continuous topology design framework based on hybrid combinations of classical Reuss (compliant) and Voigt (stiff) mixing rules is investigated. To avoid checkerboarding instabilities, the continuous topology optimization formulation is coupled with a novel spatial filtering procedure. The issue of obtaining globally optimal discrete layout designs with the proposed formulation is investigated using a continuation method which gradually transitions from the stiff Voigt formulation to the compliant Reuss formulation. The very good performance of the proposed methods is demonstrated on four structural topology design optimization problems from the literature. © 1997 John Wiley & sons, Ltd. 相似文献
108.
109.
Yoko Ito Nicolas Esnay Louise Fougre Matthieu Pierre Platre Fabrice Cordelires Yvon Jaillais Yohann Boutt 《International journal of molecular sciences》2021,22(16)
A main characteristic of sphingolipids is the presence of a very long chain fatty acid (VLCFA) whose function in cellular processes is not yet fully understood. VLCFAs of sphingolipids are involved in the intracellular traffic to the vacuole and the maturation of early endosomes into late endosomes is one of the major pathways for vacuolar traffic. Additionally, the anionic phospholipid phosphatidylinositol-3-phosphate (PtdIns (3)P or PI3P) is involved in protein sorting and recruitment of small GTPase effectors at late endosomes/multivesicular bodies (MVBs) during vacuolar trafficking. In contrast to animal cells, PI3P mainly localizes to late endosomes in plant cells and to a minor extent to a discrete sub-domain of the plant’s early endosome (EE)/trans-Golgi network (TGN) where the endosomal maturation occurs. However, the mechanisms that control the relative levels of PI3P between TGN and MVBs are unknown. Using metazachlor, an inhibitor of VLCFA synthesis, we found that VLCFAs are involved in the TGN/MVB distribution of PI3P. This effect is independent from either synthesis of PI3P by PI3-kinase or degradation of PI(3,5)P2 into PI3P by the SUPPRESSOR OF ACTIN1 (SAC1) phosphatase. Using high-resolution live cell imaging microscopy, we detected transient associations between TGNs and MVBs but VLCFAs are not involved in those interactions. Nonetheless, our results suggest that PI3P might be transferable from TGN to MVBs and that VLCFAs act in this process. 相似文献
110.
Glass TR Ohmura N Morita K Sasaki K Saiki H Takagi Y Kataoka C Ando A 《Analytical chemistry》2006,78(20):7240-7247
Immunoassays for detection of a class of closely related antigens, e.g., PCBs, have often been too specific (responding strongly to some members of the class and missing others) and no general method for adjusting the response has been described. In this paper, the difference in the response of a model immunoassay to different Kanechlors (Japanese commercial mixtures of PCBs, analogous to Aroclors in the United States) is reduced from 20- or 50-fold (depending on which antibody is used) to 3-fold when the antibodies are mixed at the proper ratio. A mathematical model based on competitive binding of two antibodies for up to four antigens has been developed and used to describe the assay performance and to predict optimum mix ratios for the antibodies used. The model (based on separate measurement of each antibody's effective Kd for each Kanechlor) provides an excellent fit to the measured mixed antibody assay response. The model is also successful in identifying cases where mixing monoclonal antibodies will not improve the response. It is thought the method described will have applicability in a variety of cases where the analytical goal is semiquantitative screening based on the total quantity of an unknown mixture of related compounds. 相似文献