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Zheng W.,Beijing Information Science and Technology University | Zhu L.,Beijing Information Science and Technology University | Zhu L.,Beijing Key Laboratory for Optoelectronics Measurement Technology | Zhu L.,Beijing Laboratory for Biomedical Detection Technology and Instrument | And 2 more authors.
Zhongguo Jiguang/Chinese Journal of Lasers | Year: 2016

The electrode pulsed arc discharge excitation experiments on fiber Bragg grating (FBG) inscribed by ultraviolet exposure are reported. The effect of discharging at different grating positions on the spectral characteristics of fiber grating is studied especially. Experimental results show that the reflectivity of fiber grating is decreased,the grating spectrum is broadened and shows a red shift during electrode discharge excitation. The spectral changes induced by discharge are reversible. The spectral characteristics of fiber grating are analyzed in a non-uniform temperature field formed by electrode discharge with the transfer matrix method, and the theoretical results are in good agreement with the experimental results. Specifically, when the electrode discharges in the center of fiber grating, the decline amplitude of grating reflectivity reaches to maximum and the optical reflection spectrum is 12 dB less than initial spectrum, which shows switching characteristic. © 2016, Chinese Lasers Press. All right reserved.

Guan W.,Capital Medical University | Gu W.,Capital Medical University | Ye L.,Capital Medical University | Guo C.,Capital Medical University | And 5 more authors.
International Journal of Nanomedicine | Year: 2014

A green, one-step microwave-assisted polyol synthesis was employed to prepare blue luminescent carbon nitride dots (CNDs) using folic acid molecules as both carbon and nitrogen sources. The as-prepared CNDs had an average size of around 4.51 nm and could be well dispersed in water. Under excitation at 360 nm, the CNDs exhibited a strong blue luminescence and the quantum yield was estimated to be 18.9%, which is greater than that of other reported CNDs. Moreover, the CNDs showed low cytotoxicity and could efficiently label C6 glioma cells, demonstrating their potential in cell imaging. © 2014 Guan et al.

Su S.,Capital Medical University | Wang Y.,Peking Union Medical College | Bai L.,Capital Medical University | Xia B.,Capital Medical University | And 7 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2015

Isobavachalcone (IBC) is a prenylated chalcone and belongs to the class of flavonoids, which is an active component isolated from Psoralea corylifolia L. IBC showed a range of significant pharmacological activities, including antibacterial, anticancer, anti-reverse transcriptase and antioxidant actions. In this research, the mass spectral fragmentation pattern of IBC was investigated to predict the in vivo metabolites, and five phase I metabolites and ten phase II metabolites of IBC in rat bile were elucidated and identified after oral administration using novel LC-ESI-MSn and LC-NMR method. The molecular structures of these metabolites were proposed on the basis of the characteristics of their precursor ions, product ions, MS/MS fragment behaviors and chromatographic retention time. The phase I metabolites were mainly biotransformed via the hydroxylation, reduction, cyclization and oxidative cleavage reactions. The phase II metabolites were mainly identified as the glucuronide conjugates and sulfated conjugates. All these findings were reported for the first time and would contribute to a further understanding of the in vivo intermediate processes and metabolic mechanism of isobavachalcone and its analogs. © 2014 Elsevier B.V.

Guo S.,Capital Medical University | Lu S.,Capital Medical University | Lu S.,China Rehabilitation Research Center | Xu P.,Capital Medical University | And 8 more authors.
Dalton Transactions | Year: 2016

Herein, we report a biomimetic method to synthesize needle-like calcium phosphate (CaP) with dimensions of ∼130 nm length and ∼30 nm width using carbon dots (CDs) and sodium carboxymethylcellulose as dual templates. In addition to acting as the template, the CDs enable the CaP/CDs hybrid composites to emit blue fluorescence under UV excitation. Moreover, the prepared CaP/CDs exhibited a negligible cytotoxicity towards HeLa cells. The potential of these CaP/CDs as a fluorescent probe for cell labeling was tested. In addition, it was demonstrated that the CaP/CDs were capable of selective detection of copper ions in drinking water. © 2016 The Royal Society of Chemistry.

Yao J.-F.,Capital Medical University | Zhou N.,Beijing Institute of Pharmacology and Toxicology | Bai L.,Capital Medical University | Bai L.,Beijing Laboratory for Biomedical Detection Technology and Instrument | And 5 more authors.
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2014

Long acting luteinizing hormone-releasing hormone (LHRH) antagonists designed to be protease-resistant were a series of novel decapeptides structurally similar to LHRH. In the present work, a high-throughput method based on a LC-MS/MS has been developed for the simultaneous determination of pharmacokinetics of five LHRH antagonists in rat via cassette dosing. The method was performed under selected reaction monitoring (SRM) in positive ion mode. The analytes were extracted from rat plasma by liquid-liquid extraction with acetonitrile. Chromatographic separation of the analytes was successfully achieved on a Hypersil Gold (100. mm. ×. 2.1. mm, 3. μm) using a mobile phase composed of acetonitrile-water (30:70) containing 0.05% (v/v) formic acid. The result showed good linearity and selectivity were obtained for all antagonists. The limits of quantification of the five LHRH antagonists were from 5 to 10. ng/mL. The average extract recoveries in the rat plasma were all over 72%. The intra-day and inter-day precisions (R.S.D. %) were all within 10% and the accuracy was ranged from 92.54 to 109.05%. This method has been successfully applied to the pharmacokinetic studies of the five LHRH antagonists. The results indicated that the plasma drug concentrations versus time curves after intravenous injection of five antagonists via cassette dosing were all fitted to a two-compartment model. The pharmacokinetic parameters of five LHRH antagonists suggested that LY616 could be the more stable candidate drugs and optimized as the candidate drug for further study. Our studies enabled high-throughput rapid screening for pharmacokinetic assessment of new peptide candidates, and provided abundant information on the metabolic properties of these LHRH antagonists. © 2014 Elsevier B.V.

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