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991.
992.
In the presence of a water-soluble pillar[6]arene WP6 containing 12 imidazolium groups, silver nanoparticles were successfully prepared and investigated in detail by ultraviolet visible spectroscopy, X-ray diffraction, and transmission electron microscopy. Excitingly, these pillar[6]arene stabilized silver nanoparticles were demonstrated to function as a colorimetric sensor to selectively probe glutamic acid in water. 相似文献
993.
Jae Cheol Lee Yong Koo Kyoung In Yong Song Jae Woo Lee Young Sik Shin Jin Seok Kim Shin‐ichi Iida 《Surface and interface analysis : SIA》2014,46(7):429-432
We have developed a simple and powerful method, which is called ‘angled sample holder method’, to characterize a topographic structured sample such as microsized via hole of ball grid array using time‐of‐flight SIMS. The diameter of via holes was 100 µm and the depth was 70 µm. To remove the shaded area by incidence primary ion beam and to extract secondary ions from the bottom of a via hole, several types of angled sample holders with compensation steering plate were applied on the basis of simulation results using SIMION code. And the analyses using angled sample holder method enabled us to characterize the bottom and side wall of a via hole in clear. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
994.
A multiplex single nucleotide polymorphism genotyping method using ligase‐based mismatch discrimination and CE‐SSCP 下载免费PDF全文
Woong Choi Gi Won Shin Hee Sung Hwang Seung Pil Pack Gyu Yong Jung Gyoo Yeol Jung 《Electrophoresis》2014,35(8):1196-1203
Accuracy, simplicity, and cost‐effectiveness are the most important criteria for a genotyping method for SNPs compatible with clinical use. One method developed for SNP genotyping, ligase‐based discrimination, is considered the simplest for clinical diagnosis. However, multiplex assays using this method are limited by the detection method. Although CE has been introduced as an alternative to error prone microarray‐based detection, the design process and multiplex assay procedure are complicated because of the DNA size‐dependent separation principle. In this study, we developed a simple and accurate multiplex genotyping method using reaction condition‐optimized ligation and high‐resolution CE‐based SSCP. With this high‐resolution CE‐SSCP system, we are able to use similar‐sized probes, thereby eliminating the complex probe design step and simplifying the optimization process. We found that this method could accurately discriminate single‐base mismatches in SNPs of the tp53 gene, used as targets for multiplex detection. 相似文献
995.
A simple fabrication method for tapered capillary tip and its applications in high‐speed CE and ESI‐MS 下载免费PDF全文
Yong‐Qiang Cheng Yuan Su Xiao‐Xia Fang Jian‐Zhang Pan Qun Fang 《Electrophoresis》2014,35(10):1484-1488
Fabrication of capillaries with tapered tips is an important technique that is required in many analytical chemistry areas, such as ESI‐MS, CE, electrochemical analysis, and microinjection. This paper describes a simple and effective grinding‐based fabrication method for capillaries with tapered tips. A novel grinding mode utilizing the combination of rotation and precession of an elastic capillary was developed, which significantly improved the controllability to the grinding process as well as the capillary tip shape. The capillary was fabricated by fixing it in an electric drill installed perpendicularly, and grind the capillary tip rotated around its own axis as well as the drill axis on sandpapers. Compared with conventional fabrication techniques for capillary tips, the present method is easy to control the capillary tip shape in routine laboratories without the requirement of expensive equipments or poisonous reagent (e.g. hydrofluoric acid (HF) solution). Various capillaries with different tip diameters and tip taper angles could be fabricated using the present method with good controllability and reproducibility. These capillaries were applied in high‐speed CE and ESI‐MS analysis to demonstrate the feasibility and potential of this fabrication method. 相似文献
996.
Hucheng Zhu Lijun Huan Chunmei Chen Jing Yang Jiangbo He Yong Chen Guangmin Yao Zengwei Luo Yongbo Xue Yonghui Zhang 《Tetrahedron letters》2014
A pair of unprecedented enantiomers (1a/1b) of cyclohexylethanoid bearing an unusual trioxabicyclo[4.2.1]nonane ring, along with two known structurally related cyclohexylethanoids, (+)-rengyolone (2) and cleroindicin E (3), were isolated from the aerial parts of Clerodendrum bungei. The structures and absolute configurations of the enantiomers were determined by comprehensive spectroscopic analysis, single-crystal X-ray diffraction, and quantum mechanical calculation of the electronic circular dichroic (ECD) spectra. The postulated biogenetic pathway of 1a/1b was also discussed. 相似文献
997.
Piyasena Hewawasam Yong TuThomas W. Hudyma Xiaofan ZhangRobert G. Gentles John F. KadowNicholas A. Meanwell 《Tetrahedron letters》2014
A convenient and practical synthesis of 6-carboalkoxy-13-cycloalkyl-5H-indolo[2,1-a][2]benzazepine-10-carboxylic acid derivatives (6) has been developed. The key step in the synthesis utilizes an intramolecular tandem reaction sequence of a Michael addition followed by a Horner–Wadsworth–Emmons (HWE) olefination reaction between hemi-aminal 11 and methyl 2-(dimethoxyphosphoryl)acrylate 12. The ring construction occurred efficiently and purification of the products 6 was straightforward. The C-10 methyl ester of 6a was hydrolyzed selectively to the carboxylic acid 13 while the olefin of 6d was converted to the cyclopropane 14 using trimethylsulfoxonium iodide in DMSO in the presence of NaH. 相似文献
998.
Adsorptive removal of La(III) from aqueous solutions with 8-hydroxyquinoline immobilized GMZ bentonite 总被引:1,自引:0,他引:1
Yonggui Chen Runqiu Huang Chunming Zhu Dongbei Wu Yanhong Sun Yong He Weimin Ye 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(1):665-674
Due to the low permeability, high swelling capacity and good retardation properties, bentonite has been considered as the main component of buffer/backfill material for high level radioactive wastes repository all over the world. The adsorptions of metal ion were widely investigated recently. In this presentation, we provide an easy-to-use method to immobilize 8-hydroxyquinoline onto the surface of bentonite for the use of adsorption studies of La(III) from the aqueous solution. The effects of various parameters such as contact time, pH of the solution, ionic strength and metal ion concentration on the adsorption were investigated by the batch experiments. The biggest adsorption capacity is 41.7 mg/g, higher than the value reported by our previous work which is performed by the raw bentonite. Langmuir isotherm fits the experimental data well and the adsorption follows pseudo-second-order kinetic model. In summary, 8-hydroxyquinoline immobilized GMZ bentonite is an effective adsorbent for the removal of La(III) from aqueous solutions. 相似文献
999.
通过异亮氨酸甲酯盐酸盐与4-硝基苯基异硫氰酸酯或4-氰基苯基异硫氰酸酯反应合成2-硫代海因探针1和2.在N,N-二甲基甲酰胺(DMF)中,用系列含阴离子的四正丁基铵盐来评价其阴离子识别能力.加入F-后,1和2的DMF溶液由无色立即变为黄色,而加入Cl-,4HSO-,Br-,3NO-和3 2CH CO-均不变,表明1和2对氟离子显示出良好的识别性能.核磁滴定氢谱揭示了F-与2-硫代海因的氢键作用引发了1和2的识别,结合常数显示1比2对F-更敏感.此外,1作为化学传感器还可以制成试纸检测F-. 相似文献
1000.
Jingxin Mo Paul K. Eggers Colin L. Raston Lee Yong Lim 《Analytical and bioanalytical chemistry》2014,406(11):2659-2667
Carboplatin and paclitaxel co-loaded nanovesicles (CPT-PTX-CLV), a novel intravenous formulation void of cremophor EL, may have significant advantages over conventional carboplatin and paclitaxel formulations with respect to tumor targeting, sustained drug release, reduced toxicity, and synergistic efficacy profiles. The aim of this study was to develop and validate a rapid, specific, sensitive, and reliable liquid chromatography–time of flight–mass spectrometry (LC/TOF MS)-based bioanalytical method for the simultaneous quantification of CPT and PTX in a fetal bovine serum (FBS) vehicle containing the dispersed nanovesicles. The analytes were extracted from FBS by simple protein precipitation, with subsequent separation of CPT and PTX on a Waters HPLC SunFire C18 column at a flow rate of 0.25 ml/min using gradient elution mode. The total analytical time was only 12 min. Detection and quantitation was performed by electrospray ionization (ESI) in the positive ionization mode with selective ion monitoring (SIM) at m/z 310.0152 for CPT and 876.3224 for PTX. The calibration curves were linear over the concentration range of 10–4,000 ng/ml for CPT and 5–2,000 ng/ml for PTX (r 2 ?>?0.99), with the respective lower limit of quantification (LLOQ) at 10 and 5 ng/ml. The intra- and inter-day precision and accuracy of analysis of the quality control samples at low, medium, and high concentration levels were ≤13.6 % relative standard deviation (RSD) and ≤14.6 % relative errors (RE). The rapid, sensitive, and reproducible LC/TOF MS method may be used to support preclinical and clinical pharmacological studies of the CPT-PTX-CLV administered by injection in animal and human cancer models. Figure
Typical SIM chromatograms for the LLOQ samples: carboplatin (upper) at m/z 310.0152 and paclitaxel (lower) at m/z 876.3224. 相似文献