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101.
102.
本文研究了DCS——偶氮胂与稀土的显色反应,在测定水中稀土时,用PMBP萃淋树脂分离干扰元素。用计算机处理实验数据,相关系数r=0.9992,分析结果令人满意。 相似文献
103.
104.
Isolating Reactions at the Picoliter Scale: Parallel Control of Reaction Kinetics at the Liquid–Liquid Interface 下载免费PDF全文
Gia Chuong Phan‐Quang Hiang Kwee Lee Prof. Xing Yi Ling 《Angewandte Chemie (International ed. in English)》2016,55(29):8304-8308
Miniaturized liquid–liquid interfacial reactors offer enhanced surface area and rapid confinement of compounds of opposite solubility, yet they are unable to provide in situ reaction monitoring at a molecular level at the interface. A picoreactor operative at the liquid–liquid interface is described, comprising plasmonic colloidosomes containing Ag octahedra strategically assembled at the water‐in‐decane emulsion interface. The plasmonic colloidosomes isolate ultrasmall amounts of solutions (<200 pL), allowing parallel monitoring of multiple reactions simultaneously. Using the surface‐enhanced Raman spectroscopy (SERS) technique, in situ monitoring of the interfacial protonation of dimethyl yellow (p‐dimethylaminoazobenzene (DY)) is performed, revealing an apparent rate constant of 0.09 min?1 for the first‐order reaction. The presence of isomeric products with similar physical properties is resolved, which would otherwise be indiscernible by other analytical methods. 相似文献
105.
Chen J Jiang J Gao X Liu G Shen G Yu R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(27):8374-8382
The present study reports the proof of principle of a reagentless aptameric sensor based on surface-enhanced Raman scattering (SERS) spectroscopy with "signal-on" architecture using a model target of cocaine. This new aptameric sensor is based on the conformational change of the surface-tethered aptamer on a binding target that draws a certain Raman reporter in close proximity to the SERS substrate, thereby increasing the Raman scattering signal due to the local enhancement effect of SERS. To improve the response performance, the sensor is fabricated from a cocaine-templated mixed self-assembly of a 3'-terminal tetramethylrhodamine (TMR)-labeled DNA aptamer on a silver colloid film by means of an alkanethiol moiety at the 5' end. This immobilization strategy optimizes the orientation of the aptamer on the surface and facilitates the folding on the binding target. Under optimized assay conditions, one can determine cocaine at a concentration of 1 muM, which compares favorably with analogous aptameric sensors based on electrochemical and fluorescence techniques. The sensor can be readily regenerated by being washed with a buffer. These results suggest that the SERS-based transducer might create a new dimension for future development of aptameric sensors for sensitive determination in biochemical and biomedical studies. 相似文献
106.
3‐Alkyl‐2,5‐bis[p‐(hexa‐2,4‐dienoyloxy)phenyl]‐thiophene derivatives were synthesized by using Kumada coupling and Suzuki coupling reactions as key steps. The thermotropic liquid crystalline behavior of these compounds was investigated by optical polarized microscopy, monotropic nematic mesophases were observed in such compounds. 相似文献
107.
Zejing Xing Xiaodan Gou Prof. Dr. Li-Ping Jiang Prof. Dr. Jun-Jie Zhu Dr. Cheng Ma 《Angewandte Chemie (International ed. in English)》2023,62(39):e202308950
Protein coronas are present extensively at the bio-nano interface due to the natural adsorption of proteins onto nanomaterials in biological fluids. Aside from the robust property of nanoparticles, the dynamics of the protein corona shell largely define their chemical identity by altering interface properties. However, the soft coronas are normally complex and rapidly changing. To real-time monitor the entire formation, we report here a self-regulated electrochemiluminescence (ECL) microscopy based on the interaction of the Ru(bpy)33+ with the nanoparticle surface. Thus, the heterogeneity of the protein corona is in situ observed in single nanoparticle “cores” before and after loading drugs in nanomedicine carriers. The label-free, optical stable and dynamic ECL microscopy minimize misinterpretations caused by the variation of nanoparticle size and polydispersity. Accordingly, the synergetic actions of proteins and nanoparticles properties are uncovered by chemically engineered protein corona. After comparing the protein corona formation kinetics in different complex systems and different nanomedicine carriers, the universality and accuracy of this technique were well demonstrated via the protein corona formation kinetics curves regulated by competitive adsorption of Ru(bpy)33+ and multiple proteins on surface of various carriers. The work is of great significance for studying bio-nano interface in drug delivery and targeted cancer treatment. 相似文献
108.
In this study, Co MFA, Co MSIA and HQSAR techniques were used to study the important characteristic activities of thieno [2,3-d] pyrimidine derivatives for effective antitumor activity. The q~2 value of cross validation of CoMFA model was 0.621, and r~2 value of non-cross validation was 0.959. The best cross validation q~2 value of CoMSIA model was 0.522, while the r~2 value of non-cross validation was 0.961. The most effective HQSAR model was obtained by taking atoms and bonds as fragments: the q~2 value of cross validation is 0.535, the r~2 value of non-cross validation is 0.871, the standard error of prediction is 0.488, and the optimal hologram length is 199. The statistical parameters from the model show that the data fit well and have high prediction ability. In addition, molecular docking is used to study the binding requirements between ligands and receptor proteins, including several hydrogen bonds between thieno [2,3-d] pyrimidine and active site residues. The results obtained from these QSAR modeling studies can be used to design promising anticancer drugs. 相似文献
109.
离子选择电极—流动注射分析法动力学测定葡萄糖存在下的果糖 总被引:3,自引:0,他引:3
本文将离子电极与流动注射分析相结合,利用30℃下,在强碱性介质中,果糖和葡萄糖与2,4-二硝基酚钠反应速度明显差异,动力学测定了葡萄糖存在下果糖的含量。自制了2,4-二硝基酚电极作为动力学电位测定用的工作电极。本法测定果糖的范围为0.02~1.00mol/L,其RSD为4.0%~4.9%,RE为1.0~5.0%;当C葡/C果≤3倍时,葡萄糖的干扰不超过5%;本法也曾成功地用于果葡萄浆测定,其RSD 相似文献
110.
A new cytotoxic 2-(2-phenylethyl)chromone from Chinese eaglewood 总被引:5,自引:0,他引:5
A new compound 8-chloro-5,6,7-trihydroxy-2-(3-hydroxy-4-methoxyphenethyl)-5,6,7,8-tetralaydro-4H-chromen-4-one (1) was isolated from the Chinese eaglewood [Aquilaria sinensis (Lour.) Gilg]. Its structure was elucidated on the basis of spectral data. Compound I showed cytotoxicity against human gastric cancer cell line (SGC-7901) in vitro by MTT method with the IC50 value of 14.6 μg/mL. 相似文献