期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
High-precision measurement of low reflectivity specular object based on phase measuring deflectometry 被引量:1
1
作者 Yuxiang Wu huimin yue Yong Liu 《光电工程》 CAS CSCD 北大核心 2017年第8期772-780,共9页
Phase measuring deflectometry(PMD)is a robust,noncoherent technique for the characterization of specular surface.For measuring high specular reflectivity surface,PMD can deliver micron radian range local gradient.Howe... Phase measuring deflectometry(PMD)is a robust,noncoherent technique for the characterization of specular surface.For measuring high specular reflectivity surface,PMD can deliver micron radian range local gradient.However,when the measured surface has low specular reflectivity,the accuracy of the measured gradient is low since the captured fringe pattern shows low signal to noise ratio.The phase error characteristics in PMD system when testing low reflectivity surfaces are analyzed.The analysis illustrates that the random phase error increases rapidly while the nonlinear error drops slowly with the decreasing of the tested surface reflectivity.In order to attain high precision measurement of low reflectivity specular surface,a robust error reduction method based on wavelet de-noising is proposed to reduce the phase error.This error reduction method is compared with several other normally used methods in both simulation and experiment work.The method based on the wavelet de-noising shows better performance when measuring the low reflectivity specular surface. 展开更多
关键词 光电工程 电学技术 测试 调整
下载PDF
制备用于间充质干细胞成像的荧光成像/磁共振成像/正电子发射断层扫描三模态纳米探针
2
作者 徐洋洋 任荣 +8 位作者 岳惠敏 钟燕 王晓燕 和庆钢 谷岩 毛峥伟 孙继红 田梅 张宏 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2021年第6期154-165,共12页
为了在间充质干细胞移植的各个阶段更好地获取移植干细胞的命运信息,制备了一种能同时实现荧光成像(FI)、磁共振成像(MRI)和正电子发射断层扫描(PET)的影像探针。首先制备了一种新型两亲性嵌段共聚物,第1嵌段为叔丁氧羰基保护的2-((叔... 为了在间充质干细胞移植的各个阶段更好地获取移植干细胞的命运信息,制备了一种能同时实现荧光成像(FI)、磁共振成像(MRI)和正电子发射断层扫描(PET)的影像探针。首先制备了一种新型两亲性嵌段共聚物,第1嵌段为叔丁氧羰基保护的2-((叔丁氧羰基)氨基)丙烯酸乙酯的均聚物,第2嵌段为短链聚乙二醇丙烯酸酯和五氟苯酚丙烯酸酯的无规共聚物,再通过氨解和酰胺化反应为聚合物修饰上双功能螯合剂DOTA和近红外染料Cy5.5,通过核磁共振和凝胶渗透色谱对聚合物结构及相对分子质量进行了表征和分析。聚合物在水中自组装并螯合Gd^(3+)得到1 mg/mL的纳米探针Gd-DOTA-Cy5.5-NP,动态光散射和透射电镜观察到探针为平均粒径30 nm的球形颗粒,并用电感耦合等离子体光谱法测得Gd^(3+)浓度为0.084 mmol/L。将纳米探针与间充质干细胞共孵育,通过Cell Counting Kit-8试剂验证1 mg/mL以下的Gd-DOTA-Cy5.5-NP相对细胞毒性较低,同时激光共聚焦显微镜在675 nm激发波长下观测细胞出现红色荧光,利用3.0 T磁共振成像系统测得探针纵向弛豫率为46.969 mmol/(L·s)。最后Gd-DOTA-Cy5.5-NP螯合^(68)Ga^(3+),得到三模态纳米探针^(68)Ga/Gd-DOTA-Cy5.5-NP,伽马计数仪测得间充质干细胞对该探针的摄取在90 min达到饱和。 展开更多
关键词 两亲性嵌段共聚物 纳米探针 磁共振成像 荧光成像 正电子发射断层扫描成像 间充质干细胞
下载PDF
Ligation of CD180 inhibits IFN-α signaling in a Lyn-PI3K-BTK-dependent manner in B cells
3
作者 Ming You Guanjun Dong +7 位作者 Fanlin Li Feiya Ma Jing Ren Yujun Xu huimin yue Ruijing Tang Deshan Ren Yayi Hou 《Cellular & Molecular Immunology》 SCIE CAS CSCD 2017年第2期192-202,共11页
A hallmark of systemic lupus erythematosus (SLE) is the consistent production of various auto-antibodies by auto-reactive B cells. Interferon-α(IFN-α) signaling is highly activated in SLE B cells and plays a vit... A hallmark of systemic lupus erythematosus (SLE) is the consistent production of various auto-antibodies by auto-reactive B cells. Interferon-α(IFN-α) signaling is highly activated in SLE B cells and plays a vital role in the antibody response by B cells. Previous studies have shown that CD180-negative B cells, which are dramatically increased in SLE patients, are responsible for the production of auto-antibodies. However, the association between CD180 and IFN-αsignaling remains unknown. In the present study, we explored the effect of CD180 on regulating the activation of IFN-α signaling in B cells. We found that the number of CD180-negative B cells was increased in MRIJMp-Fas(Ipr/Ipr) lupus-prone mice compared with wild-type mice. Phenotypic analysis showed that CD180-negative B cells comprised CD138+ plasmablast/plasma cells and GL-7+ germinal center (GC) B cells. Notably, ligation of CD180 significantly inhibited the I FN-α-induced phosphorylation of signal transducer and activator of transcription 2 (STAT-2) and expression of IFN-stimulated genes (ISGs) in a Lyn-PI3K-BTK-dependent manner in vitro. Moreover, ligation of CD180 could also inhibit IFN-α-induced ISG expression in B cells in vivo. Furthermore, the Toll-like receptor 7 and Toll-like receptor 9 signaling pathways could significantly downregulate CD180 expression and modulate the inhibitory effect of CD180 signaling on the activation of I FN-a signaling. Collectively, our results highlight the close association between the increased proportion of CD180-negative B cells and the activation of IFN-α signaling in SLE. Our data provide molecular insight into the mechanism of IFN-α signaling activation in SLE B cells and a potential therapeutic approach for SLE treatment. 展开更多
关键词 B cells CD180 IFN-Α SLE
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部