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51.
Xiaoji Cao Jingfang Qiao Liping Wang Xuemin Ye Lebin Zheng Nan Jiang Weimin Mo 《Rapid communications in mass spectrometry : RCM》2012,26(7):740-748
A powerful ionic liquid‐based ultrasonic‐assisted extraction (ILUAE) method combined with ultra‐performance liquid chromatography coupled to electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (UPLC/ESI‐QTOFMSn) was employed in the rapid simultaneous screening of iridoid glycosides, phenylethanoid glycosides, and cucurbitacin glycosides from P. scrophulariiflora. The ILUAE procedure was optimized over several ultrasonic parameters, including the ultrasonic power, concentration of the ionic liquid, and solid–liquid ratio. A comparison with conventional heat‐reflux extraction and regular UAE demonstrated that the optimized approach yielded a high extraction efficiency (Picroside I, 2.84%; Picroside II, 3.57%; 6‐O‐E‐feruloyl catalpol, 2.20%) within a short extraction time of 30 min. Negative ion mode ESI‐QTOFMS2 analysis of the fragmentation reactions of the [M–H]– ions was conducted to characterize the diagnostic ions related to the glycosyl moieties, aglycone units, and the type and substituted position of the ester groups. Interestingly, the positional isomers of the iridoid glycosides could be easily discriminated based on the characteristic ions. A total of 15 glycosides, including three groups of iridoid glycoside isomers and two groups of phenylethanoid glycoside isomers, were conveniently identified within 13.5 min. Moreover, 6'‐O‐vanilloyl catalpol was identified in P. scrophulariiflora for the first time. The method developed here was further validated by measuring the recovery, correlation coefficient (R2), and reproducibility (RSD, n = 5) of three iridoid glycosides: 89.60%–109.02%, 0.9991–0.9998, and 0.93%–1.44%, respectively. This study demonstrated the capabilities of ILUAE combined with UPLC/ESI‐QTOFMSn for the rapid screening of glycosides in P. scrophulariiflora. This method offers an approach to similar studies on other natural plants. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
52.
The intent of this study is to examine nonequilibrium heat transfer in a copper-argon nanofluid by molecular dynamics simulation. Two different methods, the physical definition method and the curve fitting method, are introduced to calculate the coupling factor between nanoparticles and base fluid. The results show that the coupling factors obtained by these two methods are consistent. The coupling factor is proportional to the volume fraction of the nanoparticle and inversely proportional to nanoparticle diameter. In the temperature range of 90-200 K, the coupling factor is not affected by temperature. The nanoparticle aggregation results in a decrease of the coupling factor. 相似文献
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The development of organic light emitting diodes (OLEDs) based on fluorescent materials has made a great progress in improving light emitting efficiency and full range colors. But it still encounters the low singlet excitons generation ratio of 25% in device. As a solution to this problem, thermally activated delayed fluorescent (TADF) materials can convert the triplet excitons to the singlet ones, thus achieve theoretically 100% exciton utilization efficiency. Up to now, the small TADF molecules have achieved great breakthrough in realizing high external quantum efficiency and full color range including blue, green, and red. While the OLED devices based on macromolecules possess the inherent advantages of simplicity and lower cost in the rapid deposition of large areas at room temperature, especially on large flexible substrates, it is still relatively difficult to realize TADF effect in macromolecules, although several reports have partially confirmed them promising candidates for practical applications. This review summarizes the recent progress in the field of TADF polymers and their device performances in OLEDs, and also gives some outlooks for the further exploration in this field at the end of this paper. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 575–584 相似文献
55.
Qinghua Xie Xia Li Guanquan Wang Xuan Hou Yujun Wang Hongbo Yu Changfa Qu Shunzhong Luo Yali Cui Chuanqin Xia Ruibing Wang 《Journal of Radioanalytical and Nuclear Chemistry》2017,311(3):1697-1708
Here we reported the radiolabeling and evaluation of a novel 131I-radiolabeled quercetin for the treatment of dedifferentiated thyroid cancers. The human thyroid cancer cell lines (FTC-133, TT and DRO) experienced much higher uptake of 131I-quercetin as compared to the free 131I. And the proliferation inhibition rate of 131I-quercetin on in vitro DRO cell line was 86.87 ± 7.15%. Biodistribution and SPECT analysis demonstrated that the injected radioactivity mainly accumulated in tumors. The tumor volume in the treatment group was dramatically inhibited in comparison with the control group. 相似文献
56.
Peng Jia-yin Bai Ming-qiang Mo Zhi-wen 《International Journal of Theoretical Physics》2017,56(10):3348-3358
International Journal of Theoretical Physics - Multi-hop teleportation is of great significance due to long-distance delivery of quantum information and wireless quantum communication networks. In... 相似文献
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Solvent‐Controlled Bifurcated Cascade Process for the Selective Preparation of Dihydrocarbazoles or Dihydropyridoindoles 下载免费PDF全文
Dr. Dong‐Liang Mo Dr. Donald J. Wink Dr. Laura L. Anderson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(41):13217-13225
A solvent‐controlled cascade process has been identified for the dual purpose of the preparation of either dihydrocarbazoles or dihydropyridoindoles from identical N‐aryl‐α,β‐unsaturated nitrones and electron‐deficient allene starting materials. These reactions proceed smoothly under mild metal‐free conditions affording a range of two types of skeletally distinct indole‐based heterocycles in high yield and diastereoselectivity. These transformations demonstrate the use of a bifurcated cascade process that hinges on the ring‐opening event of a benzazepine intermediate for the synthesis of skeletally diverse heterocyclic products and rapid access to biologically‐significant, indole‐based structures. 相似文献
59.
The influence of the flashlamp pump current pulse shape on Er:YAG laser efficiency and laser rod thermal focusing was studied theoretically and experimentally. Two pulse shapes, PFN (Pulse Forming Network) and VSP (Variable Square Pulse), were considered. Theoretical modeling and experimental measurements show that the pump pulse shape itself does not have a significant influence on the Er:YAG laser efficiency or thermal focusing. Instead, the major parameter influencing Er:YAG laser efficiency and thermal focusing was found to be the overall pulse duration. For PFN pulses, rise and fall times directly define the overall pulse duration, and therefore do have influence on thermal focusing. By contrast, VSP pulse duration is defined by the externally controlled on-time of the switching transistor. For square shaped pulses, short rise and fall times do not have a direct beneficial influence on thermal lensing. 相似文献
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