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71.
72.
三聚氰胺甲醛树脂的光学性质 总被引:1,自引:0,他引:1
现代信息技术的发展和要求,使得光信息传输、光电子、全光子器件成为信息技术研究领域的热点.而光学传输损耗低,非线性系数大和响应速度快的新型光学材料和器件是决定信息研究领域发展的关键 [1] .目前新型光学材料研究领域之一是聚合物材料在光学中的应用.因此,近年来人们对一些聚合物材料的光学性质进行了研究,例如聚甲基丙烯酸甲酯 (PMMA)、聚碳酸酯 (PC)、聚酰亚胺、环氧树脂等等[2,3].对于聚合物材料在光学方面应用的基本要求是具有良好的成膜性、光学损耗低、热稳定性好.本文所研究的三聚氰胺甲醛树脂(Mel… 相似文献
73.
Alcohol‐Mediated Resistance‐Switching Behavior in Metal–Organic Framework‐Based Electronic Devices
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Dr. Yaqing Liu Dr. Hong Wang Dr. Wenxiong Shi Dr. Weina Zhang Dr. Jiancan Yu Bevita K. Chandran Chenlong Cui Bowen Zhu Zhiyuan Liu Dr. Bin Li Cai Xu Zhiling Xu Prof. Shuzhou Li Prof. Wei Huang Prof. Fengwei Huo Prof. Xiaodong Chen 《Angewandte Chemie (International ed. in English)》2016,55(31):8884-8888
Metal‐organic frameworks (MOFs) have drawn increasing attentions as promising candidates for functional devices. Herein, we present MOF films in constructing memory devices with alcohol mediated resistance switching property, where the resistance state is controlled by applying alcohol vapors to achieve multilevel information storage. The ordered packing mode and the hydrogen bonding system of the guest molecules adsorbed in MOF crystals are shown to be the reason for the alcohol mediated electrical switching. This chemically mediated memory device can be a candidate in achieving environment‐responsive devices and exhibits potential applications in wearable information storage systems. 相似文献
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Yunyun Yang Chen Hongwei Ming Zhong Zhiling Ma Jiuwei Teng Dehai Mu 《Frontiers of Chemistry in China》2006,1(2):138-144
In this paper, high performance liquid chromatography (HPLC) along with mass spectrometry (MS) and HPLC along with a diode
array detector (DAD) was used to study the compound Ilex pubescens extract. Two ionization techniques: electro spray ionization (ESI) and atmospheric pressure chemical ionization (APCI) were
used in this work. The liquid chromatograms obtained by DAD, total ion chromatograms (TIC) from positive-and negative-ion
ESI-MS and the positive-and negative-ion APCI-MS were compared. The liquid chromatograms obtained by TIC from ESI-MS provided
more information on chromatographic peaks than those obtained by DAD or TIC from APCI-MS. It is suggested that the fingerprints
of the compound Ilex pubescens extract should be provided by the liquid chromatograms obtained by DAD together with TIC from the negative-ion ESI-MS. The
molecular weights of the nine main components in an HPLC-DAD chromatogram were determined by the corresponding positive-and
negative-ion ESI and the positive-and negative-ion APCI mass spectra information. In the liquid chromatogram obtained by TIC
from the negative-ion ESI-MS, the molecular weights of 23 main components were determined based on the corresponding positive-and
negative-ion ESI mass spectra information. 相似文献
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In vitro fertilization (IVF) increases the risk of tumorigenesis in offspring. The increased oxidative damage during IVF may be involved in tumor formation. However, the molecular mechanisms underlying this phenomenon remain largely unclear. Using a well-established model of oxidatively damaged IVF mouse embryos, we applied the iTRAQ method to identify proteins differentially expressed between control and oxidatively damaged zygotes and explored the possible tumorigenic mechanisms, especially with regard to the effects of oxidative damage on ribosome biogenesis closely related to tumorigenesis. The iTRAQ results revealed that ribosomal proteins were upregulated by oxidative stress through the Nucleolin/β-Catenin/n-Myc pathway, which stimulated ribosomes to synthesize an abundance of repair proteins to correct the damaged DNA/chromosomes in IVF-derived embryos. However, the increased percentages of γH2AX-positive cells and apoptotic cells in the blastocyst suggested that DNA repair was insufficient, resulting in aberrant ribosome biogenesis. Overexpression of ribosomal proteins, particularly Rpl15, which gradually increased from the 1-cell to 8-cell stages, indicated persistent hyperactivation of ribosome biogenesis, which promoted tumorigenesis in offspring derived from oxidatively damaged IVF embryos by selectively enhancing the translation of β-Catenin and TGF-β1. The antioxidant epigallocatechin-3-gallate (EGCG) was added to the in vitro culture medium to protect embryos from oxidative damage, and the expression of ribosome-/tumor-related proteins returned to normal after EGCG treatment. This study suggests that regulation of ribosome biogenesis by EGCG may be a means of preventing tumor formation in human IVF-derived offspring, providing a scientific basis for optimizing in vitro culture conditions and improving human-assisted reproductive technology.Subject terms: Embryology, Cancer 相似文献
79.
We designed a temperature-controllable droplet microreactor with more precisely temperature control and shorter synthesis time for water-soluble AgInS2 QDs synthesis. When reaction temperature increased from 30 ℃ to 70 ℃, QDs fluorescence peak constantly red-shifted from 590 nm to 720 nm along with enhanced fluorescence QY and intensity, we can get products with the maximum fluorescence intensity and the QY of 8.8% at 70 ℃. 相似文献
80.
Qiaoling Yang Hongjing Li Mingzhu Gui Zhiling Li Huajun Sun 《Biomedical chromatography : BMC》2020,34(3):e4780
Polyphyllin II, a major steroidal saponin isolated from Paris polyphylla, exhibits significant pharmacological activities. In this study, a rapid and sensitive liquid chromatography–tandem mass spectrometry method was established and validated for the determination of polyphyllin II in plasma. Polyphyllin II and polyphyllin VII (internal standard) were separated on a Waters Acquity™ HSS T3 column and the mass analysis was performed in a triple quadrupole mass spectrometer equipped with an electrospray ionization ion source. Results showed that the method was sensitive (lower limit of quantitation 0.5 ng/ml), precise (<15%) and linear in the range of 0.5–500 ng/ml (r > 0.99). Interestingly, the sensitivity in current study was ~10 times higher than that in the previous study. The results of the pharmacokinetic study of polyphyllin II in rats suggested that polyphyllin II was poorly absorbed into blood and reached its highest concentration at ~3.67–5.00 h with a slow elimination half-life of 8.34–13.37 h. The bioavailability was 6.1–8.2%. The results indicated that the absorption of polyphyllin II may primarily occur via passive diffusion in rats. This study provides valuable information that can be used as a reference for the pharmacokinetic investigation of other steroidal saponins. 相似文献