为解决移动机器人在非视距(non-line of sight,NLOS)环境下定位系统误差大和稳定性差的问题,提出一种抗NLOS误差的N-CTK(NLOS Chan-Taylor-Kalman)组合算法。首先在Chan-Taylor协同算法基础上,融入卡尔曼滤波算法,提出一种CTK组合定位算...为解决移动机器人在非视距(non-line of sight,NLOS)环境下定位系统误差大和稳定性差的问题,提出一种抗NLOS误差的N-CTK(NLOS Chan-Taylor-Kalman)组合算法。首先在Chan-Taylor协同算法基础上,融入卡尔曼滤波算法,提出一种CTK组合定位算法,然后基于TDOA(time difference of arrival)测量值构建NLOS误差模型,引入NLOS误差转化因子,融合扩展卡尔曼滤波算法,并结合所提CTK组合算法,最终获得标签的估计值。实验测试表明:视距(line of sight,LOS)环境下误差为6 cm时,N-CTK组合算法相比CTK组合算法的累积分布函数提高了13.5%,NLOS环境下误差为15 cm时,N-CTK组合算法相比CTK组合算法的累积分布函数提高了55%,定位精度明显提高。展开更多
Surface-enhanced Raman scattering（SERS） spectra of different silver nanoplate selt-assembled tllmS at different excitation wavelengths were fairly compared. Shape conversion from silver nanoprisms to nanodisks on sl...Surface-enhanced Raman scattering（SERS） spectra of different silver nanoplate selt-assembled tllmS at different excitation wavelengths were fairly compared. Shape conversion from silver nanoprisms to nanodisks on slides was in situ carried out. The SERS spectra of 4-mercaptopyridine（4-MPY） on these anisotropic silver nanopar- ticle self-assembled films present that strong enhancement appeared when the excitation line and the surface plasmon resonance（SPR） band of silver substrate overlapped. In this model, the influence of the crystal planes of silver na- noplates on SERS enhancement could be ignored because the basal planes were nearly unchanged in two kinds of silver nanoplate self-assembled films.展开更多
Background Lumiracoxib is a highly selective cyclooxygenase-2 （COX-2） inhibitor with antiinflammatory, analgesic and antipyretic activities comparable with class specific drugs, but with much improved gastrointestin...Background Lumiracoxib is a highly selective cyclooxygenase-2 （COX-2） inhibitor with antiinflammatory, analgesic and antipyretic activities comparable with class specific drugs, but with much improved gastrointestinal safety. No studies have examined lumiracoxib for antitumorigenic activity on human nonsmall cell lung cancer cell lines in vitro or its possible molecular mechanisms. Methods The antiproliferative effect of lumiracoxib alone or combined with docetaxol on A549 and NCI-H460 lines was assessed by 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay. Drug-drug interactions were analyzed using the coefficient of drug interaction （CDI） to characterize the interactions as synergism, additivity or antagonism. Morphological changes were observed by acridine orange fluorescent staining. Extent of apoptosis was determined by flow cytometry. Results Lumiracoxib （15-240 pmol/L） has an inhibitory effect on the proliferation of A549 and NCI-H460 cell lines in concentration- and time-dependent manners with the ICso values of 2597 pmol/L and 833 pmol/L, respectively. The synergistic effect was prominent when lumiracoxib （15-240 pmoVL） was combined with docetaxol （0.2-2 pmol/L） （CDI 〈1）. Fluorescent staining showed that lumiracoxib could induce apoptosis in A549 and NCI-H460 cells. Lumiracoxib treatment also caused an increase of the sub-G1 fraction in each cell line and resulted in an increase of G0/Gl-phase cells and a decrease of S-phase cells. Conclusions Lumiracoxib had antiproliferative effect on the human nonsmall cell lung cancer cell lines A549 and NCI-H460 and had a significant synergy with docetaxol, which may be related to apoptotic induction and cell cycle arrest.展开更多
文摘为解决移动机器人在非视距(non-line of sight,NLOS)环境下定位系统误差大和稳定性差的问题,提出一种抗NLOS误差的N-CTK(NLOS Chan-Taylor-Kalman)组合算法。首先在Chan-Taylor协同算法基础上,融入卡尔曼滤波算法,提出一种CTK组合定位算法,然后基于TDOA(time difference of arrival)测量值构建NLOS误差模型,引入NLOS误差转化因子,融合扩展卡尔曼滤波算法,并结合所提CTK组合算法,最终获得标签的估计值。实验测试表明:视距(line of sight,LOS)环境下误差为6 cm时,N-CTK组合算法相比CTK组合算法的累积分布函数提高了13.5%,NLOS环境下误差为15 cm时,N-CTK组合算法相比CTK组合算法的累积分布函数提高了55%,定位精度明显提高。
基金Supported by the National Natural Science Foundation of China(Nos.91027010,21073073,20903043,20973075,20773045)the Research Fund for the Doctoral Program of Higher Education of China(No.20090061120089)the Open Project of State Key Laboratory for Supramolecular Structure and Materials of China(No.201125)
文摘Surface-enhanced Raman scattering（SERS） spectra of different silver nanoplate selt-assembled tllmS at different excitation wavelengths were fairly compared. Shape conversion from silver nanoprisms to nanodisks on slides was in situ carried out. The SERS spectra of 4-mercaptopyridine（4-MPY） on these anisotropic silver nanopar- ticle self-assembled films present that strong enhancement appeared when the excitation line and the surface plasmon resonance（SPR） band of silver substrate overlapped. In this model, the influence of the crystal planes of silver na- noplates on SERS enhancement could be ignored because the basal planes were nearly unchanged in two kinds of silver nanoplate self-assembled films.
基金This work was supported by grants from the Natural Science Foundation of Anhui Province （No. 07021008） and the General Project of the Natural Science Foundation of the Department of Education, Anhui Province （No. KJ2007B142）.
文摘Background Lumiracoxib is a highly selective cyclooxygenase-2 （COX-2） inhibitor with antiinflammatory, analgesic and antipyretic activities comparable with class specific drugs, but with much improved gastrointestinal safety. No studies have examined lumiracoxib for antitumorigenic activity on human nonsmall cell lung cancer cell lines in vitro or its possible molecular mechanisms. Methods The antiproliferative effect of lumiracoxib alone or combined with docetaxol on A549 and NCI-H460 lines was assessed by 3-（4, 5-dimethylthiazol-2-yl）-2, 5-diphenyltetrazolium bromide （MTT） assay. Drug-drug interactions were analyzed using the coefficient of drug interaction （CDI） to characterize the interactions as synergism, additivity or antagonism. Morphological changes were observed by acridine orange fluorescent staining. Extent of apoptosis was determined by flow cytometry. Results Lumiracoxib （15-240 pmol/L） has an inhibitory effect on the proliferation of A549 and NCI-H460 cell lines in concentration- and time-dependent manners with the ICso values of 2597 pmol/L and 833 pmol/L, respectively. The synergistic effect was prominent when lumiracoxib （15-240 pmoVL） was combined with docetaxol （0.2-2 pmol/L） （CDI 〈1）. Fluorescent staining showed that lumiracoxib could induce apoptosis in A549 and NCI-H460 cells. Lumiracoxib treatment also caused an increase of the sub-G1 fraction in each cell line and resulted in an increase of G0/Gl-phase cells and a decrease of S-phase cells. Conclusions Lumiracoxib had antiproliferative effect on the human nonsmall cell lung cancer cell lines A549 and NCI-H460 and had a significant synergy with docetaxol, which may be related to apoptotic induction and cell cycle arrest.
