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排序方式: 共有127条查询结果,搜索用时 15 毫秒
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Koji Kamagata Christina Andica Ayumi Kato Yuya Saito Wataru Uchida Taku Hatano Matthew Lukies Takashi Ogawa Haruka Takeshige-Amano Toshiaki Akashi Akifumi Hagiwara Shohei Fujita Shigeki Aoki 《International journal of molecular sciences》2021,22(10)
There has been an increasing prevalence of neurodegenerative diseases with the rapid increase in aging societies worldwide. Biomarkers that can be used to detect pathological changes before the development of severe neuronal loss and consequently facilitate early intervention with disease-modifying therapeutic modalities are therefore urgently needed. Diffusion magnetic resonance imaging (MRI) is a promising tool that can be used to infer microstructural characteristics of the brain, such as microstructural integrity and complexity, as well as axonal density, order, and myelination, through the utilization of water molecules that are diffused within the tissue, with displacement at the micron scale. Diffusion tensor imaging is the most commonly used diffusion MRI technique to assess the pathophysiology of neurodegenerative diseases. However, diffusion tensor imaging has several limitations, and new technologies, including neurite orientation dispersion and density imaging, diffusion kurtosis imaging, and free-water imaging, have been recently developed as approaches to overcome these constraints. This review provides an overview of these technologies and their potential as biomarkers for the early diagnosis and disease progression of major neurodegenerative diseases. 相似文献
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Kakui M. Kato T. Kashiwada T. Nakazato K. Fukuda C. Onishi M. Nishimura M. 《Electronics letters》1995,31(1):51-52
Based on system optimisation through theoretical model simulations, 2.4 Gbit/s repeaterless transmission over 306 km nondispersion-shifted fibre has been demonstrated with no power penalty, using a directly modulated DFB laser with a bulk active layer and dispersion-compensating fibres 相似文献
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Substances with estrogenic activity are found in effluents of municipal sewage plants and dairy farms. These effluents have the potential to induce feminization in male fish. In this study, cyclodextrin polymers (CDPs) that are insoluble in both polar and non-polar solvents were selected for the removal of dissolved estrogens in the effluent of a municipal sewage plant. The removal capacity of CDPs was high in the order of β-CDP ≥ γ-CDP ? α-CDP. The mechanism for adsorption of estrogens to β-CDP was not only due to a host-guest interaction as molecular recognition by β-cyclodextrin (β-CD), but also due to adsorption by the polymer matrix. β-CDP of 0.2% (w/v) removed 17β-estradiol (E2) of about 70% from 10−11 mol/L, and more than 90% from ≥ 10−10 mol/L. The removal ratios of E2 in the presence of cholesterols, which are contained at higher concentrations than estrogens in sewage effluents and are adsorptive competitor for β-CDP, were about 85% at a cholesterol/E2 molar ratio of 100 and > 90% at molar ratios of 0.1, 1, and 10. The effluent from a municipal sewage plant had estrogenic activity corresponding to 5.5 × 10−11 molE2/L by yeast two-hybrid assay. The estrogens in the effluent were also removed > 90% by the β-CDP treatment. Therefore, β-CDP is able to remove dissolved estrogens over a wide range of concentrations in the presence of various contaminants such as wastewaters. 相似文献
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M Beppu T Takahashi M Kashiwada S Masukawa K Kikugawa 《Canadian Metallurgical Quarterly》1994,312(1):189-197
Mouse erythrocytes oxidized with an iron catalyst ADP/Fe3+ chelate attached to the monolayers of mouse resident and thioglycollate-induced peritoneal macrophages in the absence of serum, indicating that the macrophages recognized the oxidized erythrocytes. The recognition was partially prevented when the oxidized cells were treated with dithiothreitol, suggesting that disulfide formation is involved, in part, in the generation of the membrane sites recognized by macrophages. Phosphatidylserine is unlikely to be the determinant on the oxidized cells because it was not detected on the outer surface of the oxidized cells. The recognition by resident macrophages was effectively inhibited by N-acetylneuramin lactose, N-acetylneuraminic acid, glycophorin A, and disialoganglioside GD1a, but poorly by lactose, asialoglycophorin A, and monosialoganglioside GM1. In addition, the recognition was partially inhibited by L-fucose and human lactoferrin. The recognition by thioglycollate-induced macrophages was not inhibited by glycophorin A but was partially inhibited by L-fucose, lactoferrin, and oligosaccharides from band 3 glycoprotein. Enzymatic cleavage of the poly-N-acetyllactosaminyl saccharide chains of band 3 and lactoferrin resulted in a loss of the inhibitory activity. These results suggest that sialosaccharide chains of ADP/Fe(3+)-oxidized erythrocytes, possibly those on glycophorin A, are mainly involved in the recognition by resident macrophages, and poly-N-acetyllactosaminyl saccharide chains, possibly those on band 3, are partly involved in the recognition both by resident and thioglycollate-induced macrophages. Oxidation of erythrocytes may induce change in these membrane glycoproteins, like aggregation, which renders their saccharide chains susceptible to the macrophage recognition. 相似文献
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M Sunaga M Yoshikawa M Ebara F Kondo M Kashiwada T Takemori H Saisho 《Canadian Metallurgical Quarterly》1998,13(9):878-884
OBJECTIVE: Studying gender differences in fat mass and distribution in a homogeneous group of children. DESIGN: Cross-sectional study. SUBJECTS: 610 children aged 5-7 y in Kiel, Germany. METHODS: Anthropometric measures, bioelectrical impedance analysis (BIA). RESULTS: Although boys had increased body weights (P<0.05), body mass indexes (BMI's) (P<0.001) and waist/hip ratios (WHRs) (P<0.001), the %fat mass as assessed by BIA (P<0.05) was increased in girls. Although the increased BMI in boys was independent of the percentile used, gender differences (that is, lower values for boys than for girls at the same age) in WHR, the sum of four skinfolds and %fat were seen up to the 90th percentile. By contrast, above the 90th percentile there were no differences in skinfold thickness and %fat between boys and girls. Studying 42 BMI-matched pairs (boys and girls) also showed that the %fat estimated by BIA (P<0.001) was increased in girls. Plotting the average of %fat as obtained from skinfold- and BAI-measurements against the difference between data obtained by the use of the two methods shows that BIA %fat overestimates skinfold %fat at low or normal percent fat mass (that is, up to 20%) in both genders. By contrast, at increased fat mass, BIA %fat seems to underestimate skinfold %fat in both genders. CONCLUSIONS: Gender differences in fat mass and fat distribution are obvious in children aged 5-7 y. These differences are independent of gender differences in body weight. However, the nutritional state has an influence and gender differences cannot be detected in overweight and obese children. Our data also suggest that a children-specific formula used to calculate %fat from skinfold measurements is inappropriate. 相似文献
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The immunotoxic effects of some anthropogenic pollutants on aquatic organisms are among the causes of concern over the presence of these pollutants in the marine environment. The immune system is part of an organism’s biological defense necessarily for homeostasis. Thus, the immunotoxicological impacts on aquatic organisms are important to understand the effects of pollutant chemicals in the aquatic ecosystem. When aquatic organisms are exposed to pollutant chemicals with immunotoxicity, it results in poor health. In addition, aquatic organisms are exposed to pathogenic bacteria, viruses, parasites, and fungi. Exposure to pollutant chemicals has reportedly caused aquatic organisms to show various immunotoxic symptoms such as histological changes of lymphoid tissue, changes of immune functionality and the distribution of immune cells, and changes in the resistance of organisms to infection by pathogens. Alterations of immune systems by contaminants can therefore lead to the deaths of individual organisms, increase the general risk of infections by pathogens, and probably decrease the populations of some species. This review introduced the immunotoxicological impact of pollutant chemicals in aquatic organisms, including invertebrates, fish, amphibians, and marine mammals; described typical biomarkers used in aquatic immunotoxicological studies; and then, discussed the current issues on ecological risk assessment and how to address ecological risk assessment through immunotoxicology. Moreover, the usefulness of the population growth rate to estimate the immunotoxicological impact of pollution chemicals was proposed. 相似文献
9.
Kei Asada Sadao Eguchi Ayumi Tsunekawa Masaki Tsuji Sunao Itahashi Hidetaka Katou 《Nutrient Cycling in Agroecosystems》2015,102(2):209-225
A variety of process-based models have been developed for predicting nitrogen (N) dynamics in agro-ecosystem; however, no reliable models have been validated for N leaching from soils receiving a long-term application of different types of animal manure composts. The Leaching Estimation and Chemistry Model (LEACHM) was recently modified by incorporating the basic structure of Rothamsted Carbon Model for extending its ability to describe soil organic matter decomposition and subsequent N leaching in soils rich in organic matter. We evaluate the applicability of the modified LEACHM in cropped Yellow soils receiving 10-year application of cattle or swine manure compost in addition to chemical fertilizers, where high-frequency field monitoring data of soil water contents, soil N contents and leachate N concentrations were available for the last 3 years. Particular attention was paid to determine all input parameters from independent measurements, parameterization from known soil properties or databases without optimisation to fit the measured field data. The model reasonably predicted temporal changes in the soil NH4-N and NO3-N contents, and inorganic N concentrations in the leachate as well as their differences due to different manure compost/chemical fertilizer applications. The simulations of leached N concentration yielded a Willmott index of agreement (IA) of 0.62–0.68, with those for soil moisture, soil nitrate content and crop N uptake all within an acceptable IA range. In view of the good performance without site-specific calibrations, the modified LEACHM appears to be a valuable tool for predicting N leaching from cropped soils receiving long-term manure compost applications. 相似文献
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