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Reported here is a precise electro-reduction strategy for radical defluorinative alkylation towards the synthesis of gem-difluoroalkenes from α-trifluoromethylstyrenes. According to the redox-potential difference of the radical precursors, direct or indirect electrolysis is respectively adopted to realize the precise reduction. An easy-to-handle, catalyst-and metal-free condition is developed for the reduction of alkyl radical precursors that are generally easier to be reduced than α-trifluorome...  相似文献   
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应用性能优良的2-乙基己基膦酸单2-乙基已基酯HEH(EHP)萃取剂,首次制备了一系列不同孔结构的萃淋树脂,针对难以分离的镧系元素中最难分离的镨、钕,研究了孔结构等与分离效能之关系,探寻出最适宜的孔结构。其比表面积S为 209 m2/g,平均孔径为 7.7nm,孔体积Vg 0.401mL/g;HEH(EHP)最适宜量为46.5%,从而达到最佳分离。  相似文献   
3.
Ionic liquid-β-cyclodextrin polymer (ILs-β-CDCP) was firstly synthesised and characterised with FTIR, 13C CP/MAS NMR, X-ray powder diffraction, TGA and scanning electron microscope. A novel method of solid phase extraction (SPE) coupled with Ultraviolet–vis spectrophotometry for separation/analysis of lornoxicam was established. ILs-β-CDCP showed a higher adsorption capacity towards lornoxicam than β-CDCP. Adsorption mechanism of ILs-β-CDCP was elucidated by adsorption thermodynamics model, adsorption kinetic model, inclusion constants and FTIR analysis. ILs-β-CDCP exhibited favourable adsorption performance towards lornoxicam from serum and tablet samples. The experimental results herein suggested that ILs-β-CDCP could be successfully applied in the field of pharmic content especially in the treatment of serum.  相似文献   
4.
Fe3O4@ionic liquids β-cyclodextrin polymer(Fe3O4@mono-6-deoxy-6-(1-ethyl-imidazolium)-β-cyclodextrin iodide polymer, Fe3O4@ILs-β-CDCP) was prepared. Magnetic solid phase extraction coupled with high-performance liquid chromatography for the separation/analysis of congo red (CR) in water and drysaltery was established. Fe3O4@ILs-β-CDCP showed a higher adsorption capacity toward CR. CR was adsorbed rapidly by Fe3O4@ILs-β-CDCP (adsorption efficiency: 95%) and eluted by ethanol (elution efficiency: 96%) at room temperature. Under the optimal conditions, preconcentration factor of the proposed method was 20-fold. The linear range, correlation coefficient (R 2), detection limit (DL) and relative standard deviation were found to be 0.005–100.00 µg mL?1, 0.9910, 1.8 g L?1 and 0.61% (n = 3, c = 5.00 µg mL?1), respectively. The adsorption mechanism of CR on Fe3O4@ILs-β-CDCP was studied through the FTIR analysis. The accuracy of the developed method was confirmed by spiking city water, lake water, pond water and drysaltery. Fe3O4@ILs-β-CDCP can be used repeatedly for 10 times. This proposed method had been successfully applied to the determination of CR in real samples.  相似文献   
5.
Band structures, density of states, dielectric and vibrational properties of XAs (X=Al, Ga and In) alloys with zinc-blende structure have been studied using the density functional theory (DFT). The calculated lattice constants, band gap, static dielectric constants and phonon frequencies are all in good agreement with the available experimental data and other theoretical results. The calculated results show that Born effective charges ZB increase with cation mass. A similar tendency has been observed for phonon frequencies ωTO and ωLO. Calculation results prove that static dielectric constants ε(0) increase with atomic weight, i.e. in the sequences AlAs–GaAs–InAs, and show an inverse sequence for band gap.  相似文献   
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Cell–cell interactions are critical for transmitting signals among cells and maintaining their normal functions from the single-cell level to tissues. In cancer studies, interactions between drug-resistant and drug-sensitive cells play an important role in the development of chemotherapy resistance of tumors. As metabolites directly reflect the cell status, metabolomics studies provide insight into cell–cell communication. Mass spectrometry (MS) is a powerful tool for metabolomics studies, and single cell MS (SCMS) analysis can provide unique information for understanding interactions among heterogeneous cells. In the current study, we utilized a direct co-culture system (with cell–cell contact) to study metabolomics of single cells affected by cell–cell interactions in their living status. A fluorescence microscope was utilized to distinguish these two types of cells for SCMS metabolomics studies using the Single-probe SCMS technique under ambient conditions. Our results show that through interactions with drug-resistant cells, drug-sensitive cancer cells acquired significantly increased drug resistance and exhibited drastically altered metabolites. Further investigation found that the increased drug resistance was associated with multiple metabolism regulations in drug-sensitive cells through co-culture such as the upregulation of sphingomyelins lipids and lactic acid and the downregulation of TCA cycle intermediates. The method allows for direct MS metabolomics studies of individual cells labeled with fluorescent proteins or dyes among heterogeneous populations.

We combined single cell mass spectrometry and fluorescence microscopy techniques to study metabolites affected by interactions between different types of cells under ambient conditions.  相似文献   
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