排序方式: 共有47条查询结果,搜索用时 31 毫秒
11.
Mengkai Luo Dr. Xuping Li Longjiang Ding Dr. Gleb Baryshnikov Shen Shen Dr. Mingjie Zhu Dr. Lulu Zhou Dr. Man Zhang Prof. Dr. Jianjun Lu Prof. Dr. Hans Ågren Prof. Dr. Xu-dong Wang Prof. Dr. Liangliang Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17166-17173
The fact that the lifetime of photoluminescence is often difficult to access because of the weakness of the emission signals, seriously limits the possibility to gain local bioimaging information in time-resolved luminescence probing. We aim to provide a solution to this problem by creating a general photophysical strategy based on the use of molecular probes designed for single-luminophore dual thermally activated delayed fluorescence (TADF). The structural and conformational design makes the dual TADF strong in both diluted solution and in an aggregated state, thereby reducing sensitivity to oxygen quenching and enabling a unique dual-channel time-resolved imaging capability. As the two TADF signals show mutual complementarity during probing, a dual-channel means that lifetime mapping is established to reduce the time-resolved imaging distortion by 30–40 %. Consequently, the leading intracellular local imaging information is serialized and integrated, which allows comparison to any single time-resolved signal, and leads to a significant improvement of the probing capacity. 相似文献
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Lycoris species have been known since long ago as a multi-utility ethnomedicinal herbal in China. It has been reported to exhibit a number of properties such as anticancer, neuroprotective, and antibacterial activities. In the present study, the anticancer efficacy of dichloromethane extracts of Lycoris aurea (DELA), was evaluated both in vivo and in vitro using murine sarcoma 180 cells. To evaluate the effects of DELA on apoptotic cell death, flow cytometry and Western blotting were performed. DELA demonstrated promising inhibition effects on sarcoma 180 cells in vitro and a 53.49% inhibitory rate on cancer cells in vivo. DELA treatment increased thymus indices and spleen indices in vivo, indicating that it reduced tumours, but did not damage the main immune organs. The DELA-evoked increase in apoptotic cell death was accompanied by occurrence of cleaved caspase-3 and decreases in the ratio of Bcl-2/Bax. Further purification and LCMS analysis showed DELA contained homolycorine, 2α-hydroxyoduline, oduline, hippeastrine, 2α-hydroxy-6-O- methyloduline, and 2α-methoxy-6-O-methyloduline. These results indicate that DELA exerted its anticancer effects, at least in part, by inducing cancer cell apoptosis and thus can be considered as a potential candidate agent for treatment of cancer. 相似文献
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聚苯胺衍生物电致变色薄膜的制备与物性研究 总被引:1,自引:0,他引:1
采用循环伏安电化学沉积方式分别制备了聚邻甲氧基苯胺(1)和聚邻甲氧基苯胺/邻硝基苯胺(2)电致变色薄膜, 并通过UV-Vis、分光光度仪、场发射扫描电子显微镜(SEM)对其进行性能表征. 结果显示: 变色膜1在不同电压下能实现湖绿色(U=-0.5 V)和淡紫色(U=0.9 V)变化, 响应时间约15 s, 最大透光率变化(DTmax)约10% (500 nm)|变色膜2在不同电压下能实现橄榄绿色(U=-0.9 V)和深酞蓝色(U=1.4 V)变化, 响应时间约2 s, 最大透光率变化(DTmax)约为20% (497 nm)|SEM测试得到薄膜2的厚度约550 nm, 且不同颜色状态下其表面形貌及导电性能有较大的差别. 由以上结果可以看出: 电致变色薄膜2比1具有更快的响应速度和较好的颜色对比度, 因此薄膜2是更好的电致变色材料. 相似文献
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Polymeric Nanoparticles with a Glutathione‐Sensitive Heterodimeric Multifunctional Prodrug for In Vivo Drug Monitoring and Synergistic Cancer Therapy
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Dr. Fuwu Zhang Qianqian Ni Dr. Orit Jacobson Siyuan Cheng Arthur Liao Dr. Zhantong Wang Zhimei He Dr. Guocan Yu Dr. Jibin Song Dr. Ying Ma Dr. Gang Niu Dr. Longjiang Zhang Dr. Guizhi Zhu Dr. Xiaoyuan Chen 《Angewandte Chemie (International ed. in English)》2018,57(24):7066-7070
Polymeric micelle‐based drug delivery systems have dramatically improved the delivery of small molecular drugs, yet multiple challenges remain to be overcome. A polymeric nanomedicine has now been engineered that possesses an ultrahigh loading (59 %) of a glutathione (GSH)‐sensitive heterodimeric multifunctional prodrug (HDMP) to effectively co‐deliver two synergistic drugs to tumors. An HDMP comprising of chemotherapeutic camptothecin (CPT) and photosensitizer 2‐(1‐hexyloxyethyl)‐2‐devinyl pyropheophorbide‐α (HPPH) was conjugated via a GSH‐cleavable linkage. The intrinsic fluorogenicity and label‐free radio‐chelation (64Cu) of HPPH enabled direct drug monitoring by fluorescence imaging and positron emission tomography (PET). Through quantitative PET imaging, HDMP significantly improves drug delivery to tumors. The high synergistic therapeutic efficacy of HDMP‐loaded NPs highlights the rational design of HDMP, and presents exciting opportunities for polymer NP‐based drug delivery. 相似文献
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Na Liu Hongchen Guo Xiangsheng Wang Lixing Chen Longjiang Zoub 《Reaction Kinetics and Catalysis Letters》2005,87(1):77-83
Summary Treating titanium silicalite (TS-1) with ammonia solution under hydrothermal conditions proves to be an effective post-synthesis
modification method for improving TS-1 catalytic activity in propylene epoxidation. Characterizations indicate that the treated
TS-1 did not change TS-1 composition and generate more Ti (IV)-superoxide species (gz = 2.0265, gy = 2.0090, gx = 2.0022) when interacting with aqueous H2O2(30 wt.%) compared with the as-synthesized one.</o:p> 相似文献
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Glabridin, a polyphenolic isoflavan of Glycyrrhiza glabra, has shown a variety of pharmaceutical properties. We have previously studied the isolation of glabridin using macroporous resin and found that it is partially degraded, giving a dark color. To illustrate the degradation of glabridin, the present work studied the stability of glabridin under various conditions. Licorice extract containing about 20% glabridin, obtained from G. glabra by silica gel column chromatography, was used in the stability study. Seven different factors (temperature, illumination, humidity, pH, solvent, oxygen, and oxidant) were studied and content changes were determined through HPLC analysis. Except for oxygen, all the above factors had an effect on the stability of glabridin, with illumination being the main one. Moreover, the interactions between temperature and pH, temperature and humidity, and illumination and pH can promote the degradation of glabridin. In conclusion, we suggest that a dark, dry and airtight environment provides the optimized condition for the long-term storage of glabridin. 相似文献
17.
Yutian Wang Longjiang Zheng Peiguo Hou Chunhai Hu 《Optics and Lasers in Engineering》2005,43(10):1145-1150
In this paper an electro-optic current transformer (CT) is designed which is used for measuring the super-high-voltage station's line current. The measurement system utilizes a conventional CT as the sensing probe whose electronics is optically powered. The paper describes the principle of measurement system, including the system design, optically powered sensing probe, the data link measurement signal processing and results showing current measurement by means of CT. 相似文献
18.
Microwave absorption properties of double-layer absorbers made of NiCoZn ferrites and hollow glass microspheres electroless plated with FeCoNiB 总被引:1,自引:0,他引:1
Amorphous FeCoNiB coatings were deposited by an electroless plating technique on the hollow glass microspheres. NiCoZn spinel ferrites sintered show two dispersion peaks (1.81 and 6.98 GHz). By fitting its permeability dispersion spectra, the one at low frequency is believed to be due to the domain wall movement mechanism, the other one is due to the spin rotation mechanism. Used in a single-layer absorber structure, neither the hollow glass microspheres coated nor the NiCoZn could meet the demand of light weight. However, if a double-layer absorber structure is used, not only the total weight of an absorber is reduced, but also the microwave absorption performance is enhanced. 相似文献
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本文建立了惯性系统三轴综合测试台的结构分析模型,用有限元法对其进行了结构静动态特性计算。给出了外框架在实际载荷作用下的静动态特性和整机的动态特性,并在此基础上,对该三轴台外框架进行了静态变形的实际测量。实测表明,理论分析和实测结果相吻合。 相似文献