263 research outputs found

    Primary Exploration on the Development of Public Leisure Sport with Chinese Characteristics

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    The 21st century is an era featuring public leisure sport. With the continuous improvements of social living standards, leisure sport has gradually won the favor and attention of the public. Globally, due to the differences in thinking, value, manners, and customs, leisure sport in China and Western countries are quite different in terms of both form and content. While the flourish of leisure sport in China is an inexorable trend of social progress, it is also undeniable that currently the development of leisure sport in China is still facing difficulties and challenges. To achieve long-term development of leisure sport in China, it is necessary to analyze issues depending on specific situations, build a leisure sport-related theory system with Chinese characteristics in line with the national conditions, vigorously develop national and public sport events, and guide the public to do sports in a scientific and reasonable manner

    Dimensional Analysis Theory and Molecular Dynamics Simulation of Polypropylene Melt Flow during Injection Molding Process

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    Flow marks are common surface defects that occur in injection-molded products. Their formation may be related to the flow process of the melt in the mold. Through dimensional analysis, we have discovered that the geometric shape of the flow field is controlled by specific dimensionless quantities. These quantities can be summarized as follows: geometric dimensionless quantities related to the shape of the mold, material dimensionless quantities related to the melt and mold materials, and physical dimensionless quantities related to the flow. When the geometric shape of the mold changes proportionally, with the melt and mold material fixed, and the initial temperature of the melt and mold fixed, the geometric shape of the flow field will be solely controlled by the Weissenberg number Wi. If Wi is kept constant, changing the injection speed, changing the relaxation time of the polypropylene melt, or scaling the mold will result in similar geometric shapes of the flow field. If the size of the mold is not changed, the geometric shape of the flow field will be the same. Since the dimensionless equation represents a similar system of all sizes, we verified the above conclusion through molecular dynamics simulations at a smaller scale. After further improvement of the micro simulation system, there is a possibility of visualizing the formation process of flow marks. This would greatly aid in the advancement of theory and the elimination of flow marks in production and experiments. This work also illustrates that the methodology of dimensional analysis plus molecular dynamics simulation may be applied to a wider range of other systems, scaling down large systems and thus significantly reducing their computational effort

    Monitoring of the 2008 Chaitén Eruption Cloud Using MODIS Data and its Impacts

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    This chapter presents the monitoring of the 2008 Chaitén eruption cloud using Moderate Resolution Imaging Spectroradiometer (MODIS) data and its impacts. The 8-day MODIS data from 3 to 10 May 2008 were used to track the movement and dispersion of the eruption cloud of the Chaitén volcano in Chile following the eruption on 2 May 2008. For detecting volcanic particulates, the procedure is adopted based on the brightness temperature difference (BTD) algorithm, by which the thermal infrared channels were centered on 11–12 μm of multispectral satellite sensors. The BTD is generally negative for volcanic ash but positive for ice and water vapor. The eruption cloud was found to drift northeastward, eastward, and southeastward crossing the central and northern part of Argentina and over the Atlantic Ocean. The timing of heavy rainfall in South Africa during May–June, in central Australia during June 2008 and in Hong Kong during June (the wettest since record began in 1884), was considered to have been connected to the dispersion of the particulates from this Chaitén eruption to further impact downstream

    Preparation and Identification of α-Amylase Inhibitory Peptides from Mung Bean Protein

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    In this study, sequential hydrolysis with pepsin followed by trypsin was conducted on total protein and protein fractions from mung bean. The difference in α-amylase inhibitory activity among the resulting hydrolysates was compared and the underlying reason was analyzed in terms of degree of hydrolysis, amino acid composition and molecular mass. The results showed that the total protein hydrolysate had the highest α-amylase inhibitory activity (16.51%). Compared with its fractions, the total protein showed the highest content of hydrophobic amino acids (32.68%) and degree of hydrolysis (6.28%), and the molecular mass of its hydrolysate was the lowest (< 20 kDa). Therefore, the total protein was selected to prepare α-amylase inhibitory peptides. Finally, 17 peptides with potential α-amylase inhibitory activity were discovered by the isolation and identification of peptides from mung bean protein. This study suggests that mung bean protein is a better food source of α-amylase inhibitory peptides than its protein fractions, which can be used in blood glucose-lowering functional foods or drugs

    Bis{2,4-dibromo-6-[(2-phenyl­eth­yl)imino­meth­yl]phenolato-κ2 N,O}cobalt(II)

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    In the title complex, [Co(C15H12Br2NO)2], the CoII atom is four-coordinated by two N,O-bidentate chelate Schiff base ligands, displaying a flattened tetra­hedral coordination environment. The CoII atom occupies a special position on a twofold rotation axis. In the crystal, mol­ecules are linked via weak C—H⋯Br inter­actions

    miR-205-5p Mediated Downregulation of PTEN Contributes to Cisplatin Resistance in C13K Human Ovarian Cancer Cells

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    Cisplatin resistance is a major cause of treatment failure in advanced ovarian cancer. The limited evidence shows the paradoxical regulation of miR-205 on chemotherapy resistance in cancer. Herein, we found that miR-205-5p was enormously increased in cisplatin-resistant C13K ovarian cancer cells compared with its cisplatin-sensitive OV2008 parental cells using miRNA microarrays, which was further verified by quantitative PCR. Furthermore, we confirmed that inhibition of miR-205-5p upregulated PTEN and subsequently attenuated its downstream target p-AKT, which inversed C13K cells from cisplatin resistance to sensitivity. Our data suggest that miR-205-5p contributes to cisplatin resistance in C13K ovarian cancer cells may via targeting PTEN/AKT pathway
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