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21.
Chi Fang Ting Xiong Jie Hou Jing Wei Gu Mei Hu Sheng 《Journal of Dispersion Science and Technology》2013,34(4):604-610
Amidoxime (AO)/amine co-functionalized polypropylene fiber adsorbents were prepared. The all-polymeric structures were characterized by using Fourier transform infrared spectroscopy (FTIR), optical microscope, contact angle meter and electron spin resonance (ESR) analysis methods, confirming the grafting, modification, and amidoximation stages gravimetrically, spectroscopically, and visually. The properties for the removal of uranyl(VI) from aqueous solutions were investigated. For amidoxime (AO) fiber, high adsorption rate was observed within the first 30 minutes and the plateau value of 40.6% uranium loading (0.0812 mg/g) was reached at around 30 minutes. The adsorption equilibrium for AO/amine fiber was attained within 20 minutes, resulting in the adsorption of 92.6% uranium loading (0.185 mg/g). The percentage of adsorption increases with increasing pH value (2–6), reaches a maximum at pH 6.0 and then remains almost constant for AO/amine fiber, whereas reduces slightly for AO fiber. 相似文献
22.
Fangyuan Zheng Prof. Fang Zeng Changmin Yu Xianfeng Hou Prof. Shuizhu Wu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(3):936-942
Owing to the considerable significance of fluoride anions for health and environmental issues, it is of great importance to develop methods that can rapidly, sensitively and selectively detect the fluoride anion in aqueous media and biological samples. Herein, we demonstrate a robust fluorescent turn‐on sensor for detecting the fluoride ion in a totally aqueous solution. In this study, a biocompatible hydrophilic polymer poly(ethylene glycol) (PEG) is incorporated into the sensing system to ensure water solubility and to enhance biocompatibility. tert‐Butyldiphenylsilyl (TBDPS) groups were then covalently introduced onto the fluorescein moiety, which effectively quenched the fluorescence of the sensor. Upon addition of fluoride ion, the selective fluoride‐mediated cleavage of the Si? O bond leads to the recovery of the fluorescein moiety, resulting in a dramatic increase in fluorescence intensity under visible light excitation. The sensor is responsive and highly selective for the fluoride anion over other common anions; it also exhibits a very low detection limit of 19 ppb. In addition, this sensor is operative in some real samples such as running water, urine, and serum and can accurately detect fluoride ions in these samples. The cytotoxicity of the sensor was determined to be Grade I toxicity according to United States Pharmacopoeia and ISO 10993‐5, suggesting the very low cytotoxicity of the sensor. Moreover, it was found that the senor could be readily internalized by both HeLa and L929 cells and the sensor could be utilized to track fluoride level changes inside the cells. 相似文献
23.
Yi-Tzu Cho Min-Zong Huang Sih-You Wu Ming-Feng Hou Jianjun Li Jentaie Shiea 《Analytical and bioanalytical chemistry》2014,406(2):577-586
Electrospray laser desorption ionization mass spectrometry (ELDI/MS) allows the rapid desorption and ionization of proteins from solutions under ambient conditions. In this study, we have demonstrated the use of ELDI/MS to efficiently examine the integrity of the proteins stored in various solutions before they were further used for other biochemical tests. The protein standards were prepared in the solutions containing buffers, organic salts, inorganic salts, strong acid, strong base, and organic solvents, respectively, to simulate those collected from solvent extraction, filtration, dialysis, or chromatographic separation. Other than the deposit of a drop of the sample solution on the metallic sample plate in an ELDI source, no additional sample pretreatment is needed. The sample drop was then irradiated with a pulsed laser; this led to desorption of the analyte molecules, which subsequently entered the ESI plume to undergo post-ionization. Because adjustment of the composition of the sample solution is unnecessary, this technique appears to be useful for rapidly evaluating the integrity of proteins after storage or prior to further biochemical treatment. In addition, when using acid-free and low-organic-solvent ESI solutions for ELDI/MS analysis, the native conformations of the proteins in solution could be detected. Figure
? 相似文献
24.
Ting Hou Xiuzhong Wang Tingting Lu Xiaojuan Liu Feng Li 《Analytical and bioanalytical chemistry》2014,406(12):2943-2948
As a prominent member of the 5′-kinase family, T4 polynucleotide kinase (PNK) plays an important role in gene function regulations, and the study of PNK activity and its potential inhibitors is significant for research related to the DNA phosphorylation process. Here, we proposed a novel strategy for the detection of PNK activity and its inhibition, which combines exonuclease enzyme reaction and nicking enzyme-assisted fluorescence signal amplification. Through recycling cleavage of DNA fluorescence probe for signal amplification, a highly sensitive PNK sensing platform is developed, and a very low detection limit of 0.05 mU/mL is achieved, which is better than or comparable to that of the previously reported PNK assays. The present approach adopts a simple separation-free procedure in which the enzyme assay is conducted in homogeneous solutions. Additionally, the inhibitory effects of several known kinase inhibitors on PNK have been successfully detected. Since the proposed assay exhibits the advantages of high sensitivity and simplicity, it holds great potential in providing a promising platform for convenient and highly sensitive detection of PNK activity and its inhibitors. Figure
Schematic illustration of the strategy for sensitive PNK activity detection based on coupled lambda exonuclease reaction and nicking enzyme-assisted fluorescence signal amplification 相似文献
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In this study,the poly(D-lactide)-block-poly(butylene succinate)-block-poly(D-lactide)(PDLA-b-PBS-b-PDLA)triblock copolymers with a fixed length of PBS and various lengths of PDLA are synthesized,and the crystallization behaviors of the PDLA and PBS blocks are investigated.Although both the crystallization behaviors of PBS and PDLA blocks depend on composition,they exhibit different variations.For the PDLA block,its crystallization behaviors are mainly influenced by temperature and block length.The crystallization signals of PDLA block appear in the B-D 2-2 specimen,and these signals get enhanced with PDLA block length.The crystallization rates tend to decrease with increasing PDLA block lendth during crystallizing at 90 and 100°C.Crystallizing at higher temperature,the crystallization rates increase at first and then decrease with block length.The crystallization rates decrease as elevating the crystallization temperature.The melting temperatures of PDLA blocks increase with block lengths and crystallization temperatures.For the PBS block,its crystallization behaviors are mainly controlled by the nucleation and confinement from PDLA block.The crystallization and melting enthalpies as well as the crystallization and melting temperatures of PBS block reduce as a longer PDLA block has been copolymerized,while the crystallization rates of the PBS block exhibit unique component dependence,and the highest rate is observed in the B-D 2-2 specimen.The Avrami exponent of PBS crystallites is reduced as a longer PDLA block is incorporated or the sample is crystallized at higher temperature.This investigation provides a convenient route to tune the crystallization behavior of PBS and PLA. 相似文献
28.
Huaran Zhang Xuewei Wu Jinxia Wang Miaomiao Wang Xiaoning Wang Tao Shen 《Natural product research》2020,34(9):1256-1263
AbstractPhytochemical studies on the leaves of Epimedium koreanum Nakai have resulted in the discovery of two new flavonol glycosides, koreanoside F (1) and koreanoside G (2), along with six known flavonoids. Their structures were elucidated on the basis of HRESIMS, UV, IR, 1?D NMR and 2?D NMR data. Absolute configurations of 1 and 2 was further determined by 13C-NMR spectra with gate decoupling (GD). All of the compounds were evaluated for cytotoxic activities by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazoliumbromide (MTT) assay. The results indicated that compounds 3, 5, 6, 7 and 8 inhibited the proliferation of A549 and NCI-292 cells with IC50 values of 5.7–23.5?μM. Real-time monitoring in three kinds of lung cancer cells and a kind of human bronchial epithelial cells treated with compound 6 was also assessed. 相似文献
29.
S. Zhang Z. Hou K. E. Gonsalves 《Journal of polymer science. Part A, Polymer chemistry》1996,34(13):2737-2742
Various amounts of hydroxy terminated PDMS were linked into PLLA chains via in-situ ring opening polymerization at a very low content of SnOt2. The 1H and FTIR spectra provided evidence for the incorporation of the PDMS in the PLLA chains. The molecular weights, Tg, Tm, crystallinity and the heats of fusion decreased as the feed mole ratio of PDMS/LLA in the block copolymer increased. The molecular weight distribution broadened as the content of the PDMS increased, due the occurrence of two initiation and propagation mechanisms. Linking PDMS into the PLLA chains improved its thermal stability. © 1996 John Wiley & Sons, Inc. 相似文献
30.
Yi Ding Yan Wu Ying Tian Yuzeng Xu Minna Hou Bo Zhou Jingshan Luo Guofu Hou Ying Zhao Xiaodan Zhang 《Journal of Energy Chemistry》2021,(7):48-54
Guanidinium (GA) cations are intentionally introduced in MAPbl3 perovskite by considering its potential capability of stabilizing the material through plenty of... 相似文献