Nano-sized titanium oxide nanoparticles (TiO2 NPs) are widely used as a dye in food and cosmetics. TiO2 NPs are known to induce DNA damage when incorporated into cells. However, no bioassay is currently available to e...Nano-sized titanium oxide nanoparticles (TiO2 NPs) are widely used as a dye in food and cosmetics. TiO2 NPs are known to induce DNA damage when incorporated into cells. However, no bioassay is currently available to easily determine the cell incorporation of TiO2 NPs or related DNA damage, and to date, few studies have examined the different degrees of incorporation into cells according to the size of the TiO2 NPs particles and the presence or absence of cell specificity regarding DNA damage. This present study was therefore designed to examine COS7 cells that had incorporated TiO2 NPs using atmospheric scanning electron microscopy (ASEM). The results indicated that absorption of TiO2 NPs into cells and nuclear abnormalities had occurred. ASEM is a rapid and simple technique that enables the observation of samples immediately after fixation with glutaraldehyde and staining with phosphotungstic acid, and this method was suggested to be useful in screening for DNA damage.展开更多
In this paper, we propose an accelerated search-extension method （ASEM） based on the interpolated coefficient finite element method, the search-extension method （SEM） and the two-grid method to obtain the multiple...In this paper, we propose an accelerated search-extension method （ASEM） based on the interpolated coefficient finite element method, the search-extension method （SEM） and the two-grid method to obtain the multiple solutions for semilinear elliptic equations. This strategy is not only successfully implemented to obtain multiple solutions for a class of semilinear elliptic boundary value problems, but also reduces the expensive computation greatly. The numerical results in I-D and 2-D cases will show the efficiency of our approach.展开更多
核电站在启停堆过程中,需要将压力、温度控制在压力温度限值曲线(P—T曲线)所规定的范围内。在P—T曲线的制定过程中,涉及与温度相关的参数包括升降温速率、一回路流体温度和裂纹前缘温度。对比分析最新版ASME(American Society of Mech...核电站在启停堆过程中,需要将压力、温度控制在压力温度限值曲线(P—T曲线)所规定的范围内。在P—T曲线的制定过程中,涉及与温度相关的参数包括升降温速率、一回路流体温度和裂纹前缘温度。对比分析最新版ASME(American Society of Mechanical Engineers)规范和RCCM(Design and Construction Rules for Mechanical Components for PWRNuclear Islands)规范在P—T曲线计算方面的差异,基于2007版RCCM规范提出新的P—T曲线计算流程,通过数值算例分别研究温度相关参数对基于ASME规范和基于RCCM规范得到的P—T曲线的影响。数值分析显示温度相关参数的影响与所采用的标准、升降温工况等因素有关。研究结果可供P—T曲线工程计算参考,有助于核电站安全、可靠的使用反应堆压力容器。展开更多
文摘Nano-sized titanium oxide nanoparticles (TiO2 NPs) are widely used as a dye in food and cosmetics. TiO2 NPs are known to induce DNA damage when incorporated into cells. However, no bioassay is currently available to easily determine the cell incorporation of TiO2 NPs or related DNA damage, and to date, few studies have examined the different degrees of incorporation into cells according to the size of the TiO2 NPs particles and the presence or absence of cell specificity regarding DNA damage. This present study was therefore designed to examine COS7 cells that had incorporated TiO2 NPs using atmospheric scanning electron microscopy (ASEM). The results indicated that absorption of TiO2 NPs into cells and nuclear abnormalities had occurred. ASEM is a rapid and simple technique that enables the observation of samples immediately after fixation with glutaraldehyde and staining with phosphotungstic acid, and this method was suggested to be useful in screening for DNA damage.
基金supported by the National Natural Science Foundation of China (10571053, 10871066, 10811120282)Programme for New Century Excellent Talents in University(NCET-06-0712)
文摘In this paper, we propose an accelerated search-extension method （ASEM） based on the interpolated coefficient finite element method, the search-extension method （SEM） and the two-grid method to obtain the multiple solutions for semilinear elliptic equations. This strategy is not only successfully implemented to obtain multiple solutions for a class of semilinear elliptic boundary value problems, but also reduces the expensive computation greatly. The numerical results in I-D and 2-D cases will show the efficiency of our approach.
文摘核电站在启停堆过程中,需要将压力、温度控制在压力温度限值曲线(P—T曲线)所规定的范围内。在P—T曲线的制定过程中,涉及与温度相关的参数包括升降温速率、一回路流体温度和裂纹前缘温度。对比分析最新版ASME(American Society of Mechanical Engineers)规范和RCCM(Design and Construction Rules for Mechanical Components for PWRNuclear Islands)规范在P—T曲线计算方面的差异,基于2007版RCCM规范提出新的P—T曲线计算流程,通过数值算例分别研究温度相关参数对基于ASME规范和基于RCCM规范得到的P—T曲线的影响。数值分析显示温度相关参数的影响与所采用的标准、升降温工况等因素有关。研究结果可供P—T曲线工程计算参考,有助于核电站安全、可靠的使用反应堆压力容器。
