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951.
Yongkang Yue Tingting Zhao Yuting Wang Kaiqing Ma Xingkang Wu Fangjun Huo Fangqin Cheng Caixia Yin 《Chemical science》2021,13(1):218
The specific combination of human serum albumin and fluorescent dye will endow superior performance to a coupled fluorescent platform for in vivo fluorescence labeling. In this study, we found that lysine-161 in human serum albumin is a covalent binding site and could spontaneously bind a ketone skeleton quinoxaline–coumarin fluorescent dye with a specific turn-on fluorescence signal for the first time. Supported by the abundant drug binding domains in human serum albumin, drugs such as ibuprofen, warfarin and clopidogrel could interact with the fluorescent dye labeled human serum albumin to feature a substantial enhancement in fluorescence intensity (6.6-fold for ibuprofen, 4.5-fold for warfarin and 5-fold for clopidogrel). The drug concentration dependent fluorescence intensity amplification realized real-time, in situ blood drug concentration monitoring in mice, utilizing ibuprofen as a model drug. The non-invasive method avoided continuous blood sample collection, which fundamentally causes suffering and consumption of experimental animals in the study of pharmacokinetics. At the same time, the coupled fluorescent probe can be efficiently enriched in tumors in mice which could map a tumor with a high-contrast red fluorescence signal and could hold great potential in clinical tumor marking and surgical resection.HSA lysine-161 covalent bound quinoxaline–coumarin based fluorescent dye realized in situ blood drug concentration monitoring and tumor visualization. 相似文献
952.
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954.
使用近红外光谱分析方法测量培养后的胚胎培养液,结合偏最小二乘判别分析对胚胎发育潜能进行评价,鉴别具有妊娠能力与不具妊娠能力的胚胎。为了提高模型的判别能力,消除无信息变量对模型稳定性影响,分别采用基于蒙特卡罗的无信息变量消除法(MC-UVE)、竞争性自适应加权抽样法(CARS)与基于变量稳定性的竞争性自适应加权抽样法(SCARS),对光谱进行波长选择。结果表明,与采用全谱74%的正判率相比较,采用这3种波长选择方法,模型独立检验集的正判率分别提高至74.24%,77.12%与80.10%,建模使用变量数降至50以内。比较发现,SCARS的模型优化能力和稳定性均好于MC-UVE和CARS方法。采用近红外光谱结合化学计量学方法预测胚胎的发育潜能是可行的。 相似文献
955.
The aim of the presented work is the comparison of aqueous and 1-octanol solubilities of different acyclovir derivatives and their hydroxypropyl-β-cyclodextrin inclusion complexes. The solubility measurements were carried out at different temperatures over the range 25–45 °C using water, 1-octanol, water saturated with 1-octanol, 1-octanol saturated with water, buffered aqueous solutions (pH = 5.5 and 7.0) and buffered aqueous solutions containing cyclodextrin as solvents. The aqueous solubilities of the compounds are very low but may be enhanced by complexation with hydroxypropyl-β-cyclodextrin, especially if the acyclovir derivatives have aromatic groups which may be included in the cyclodextrin cavity. The values of 1-octanol–water partition coefficients of acyclovir derivatives, obtained using extraction experiments, showed a similar sequence as the solubility results in 1-octanol. Additionally, some molecular mechanics and molecular dynamic calculations were performed to determine optimized structures of acyclovir derivative complexes with β-cyclodextrin treated as a model. 相似文献
956.
Two pseudohalide hydride carbonyl ruthenium(II) complexes with formulae: [RuH(N3)(CO)(PPh3)3] (1) and [RuH(NCO)(CO)(PPh3)3] (2) have been synthesized by the reactions of [RuHCl(CO)(PPh3)3] with sodium azide or sodium cyanate, respectively, and are compared with the previously described thiocyanate analog [RuH(NCS)(CO)(PPh3)3]. The molecular structures of the new compounds were determined by X-ray crystallography and their spectroscopic properties have been studied. Based on the crystal structures, computational investigations have been carried out in order to determine the electronic structures of the complexes. The electronic spectra were calculated with the use of time-dependent DFT methods, and the electronic spectra of the transitions were correlated with the molecular orbitals of the complexes. 相似文献
957.
ZHAO MengMeng LI WanFang MA Xin FAN WeiZheng TAO XiaoMing LI XiaoMing XIE XiaoMin ZHANG ZhaoGuo 《中国科学:化学(英文版)》2013,56(3):342-348
Asymmetric hydrogenation of α-keto Weinreb amides has been realized with [Ru((S)-Sunphos)(benzene)Cl]Cl as the catalyst and CeCl 3·7H2O as the additive.A series of enantiopure α-hydroxy Weinreb amides(up to 97% ee) have been obtained.Catalytic amount of CeCl3·7H2O is essential for the high reactivity and enantioselectivity and the ratio of CeCl3·7H2O to [Ru((S)-Sunphos)(benzene)Cl]Cl plays an important role in the hydrogenation reaction. 相似文献
958.
One new cadmium coordination polymer, [Cd(2,4-Dcp)2(4,4-Bipy)] n (I) (2,4-HDcp = 2,4-dichlorophenoxyacetic acid, 4,4′-Bipy = 4,4′-bipyridine) with 2D layer structure, has been prepared by the hydrothermal synthesis and characterized by elemental analysis, IR, TGA and single-crystal X-ray diffraction. Complex I crystallizes belong to monoclinic system and has C2/c space group. Each Cd2+ ion is six-coordinated and located at an octahedral geometry. The Cd2+ ions are linked by bidentate 2,4-Dcp groups into a linear chain in which the benzene rings of 2,4-Dcp ligands point alternately up and down. These chains are further connected into a sandwich-like layer though 4,4′-Bipy ligands. Furthermore, the photoluminescence and life-time of I in the solid state have been studied. 相似文献
959.
A new cyano-substituted diarylethene derivative (R-NH2) with reversible far-red mechanofluorochromic property was synthesized and confirmed by standard spectroscopic methods. To the best of our knowledge, the 684 nm red-shifted wavelength of the ground R-NH2 is the longest wavelength that has appeared in the literature. The mechanofluorochromic mechanism was investigated by small and wide-angle X-ray scattering and was ascribed to the destruction of crystalline structure. More in-depth study by infrared spectra and time-resolved emission-decay behaviors showed that the changes of C–H out-of-plane bending vibrations in aryl group of the compound and the obvious increase of fluorescence lifetime might be the fundamental reasons. The synthetic strategy reported here can be extended to prepare more and more long-wavelength emission mechanofluorochromic materials, which can broaden the scope of application of such materials and for thoroughly understanding the mechanofluorochromic mechanism. 相似文献
960.
Weifu Dong Piming Ma Shifeng Wang Mingqing Chen Xiaoxia Cai Yong Zhang 《Polymer Degradation and Stability》2013
Poly(β-hydroxybutyrate) (PHB) is a bio-based and biodegradable aliphatic polyester, however its application is limited by some disadvantages such as high price, brittleness, poor processability and low melt-strength due to serious thermal degradation. Partial crosslinking initiated by dicumyl peroxide (DCP) was applied in this work to improve the performance of poly(β-hydroxybutyrate)/poly(d,l-lactic acid) (PHB/PDLLA) blends. The partial crosslinking of the blends and its effect on the properties, morphology, rheology and thermal behavior of the blends were investigated. The tensile strength and impact toughness of the PHB were increased by incorporation of the PDLLA, which were improved further after the partial crosslinking because of an increased compatibility between the PHB and the PDLLA phases. The rheological study revealed that the storage modulus (G′) and complex viscosity (η*) of the blends were increased after addition of the DCP. On the other hand, the crystallization of PHB in the blends was restricted to a certain extent by the formation of partially crosslinked network while its crystal form was not modified. 相似文献