Three series of basic proteins and peptides were selected for use in studying the adsorption behavior of fused-silica capillary electrophoresis columns. A comparative study of untreated and treated fused-silica columns was done. The polymers used as coating materials ranged from very hydrophobic to very hydrophilic. The average efficiency of weakly hydrophilic Ucon-coated capillaries for basic proteins was over 1 million theoretical plates at a buffer pH of 4.8. For this coating, it was found that the maximum column efficiency was obtained at a film thickness of approximately 100 nm. It was easily seen that both ionic and hydrophobic interaction forces can play important roles in protein adsorption onto the capillary walls. Furthermore, strongly hydrophilic polymer coatings may possibly lead to hydrogen-bonding interactions, which decrease column efficiency. Studies have been conducted using two series of polypeptides with varying chain lengths. One series was used to study the effect of polypeptide chain length on retention behavior. Efficient separations of bioactive peptide drugs on Ucon-coated columns were achieved. The results indicate that high efficiency and resolution of basic peptides tested can be realized on columns modified with weakly hydrophilic polymers at a pH value of about 5.
Sentence classification is one of the foundational tasks in spoken language understanding (SLU) and natural language processing (NLP). In this paper we propose a novel convolutional neural network (CNN) with attention mechanism to improve the performance of sentence classification. In traditional C-NN, it is not easy to encode long term contextual information and correlation between non-consecutive words effectively. In contrast, our attention-based CNN is able to capture these kinds of information for each word without any external features. We conducted experiments on various public and inhouse datasets. The experimental results demonstrate that our proposed model significantly outperforms the traditional CNN model and achieves competitive performance with the ones that exploit rich syntactic features.
Abstract.A simple method for the preparation of polymer-coated fused silica capillary columns for electrophoresis is presented. It is shown that the static coating technique used in GC and SFC can be conveniently utilized for the preparation of highly efficient capillary electrophoresis columns. In this method, the coating solution contains appropriate proportions of three ingredients: a polymer, a surface derivatization reagent, and a crosslinking reagent dissolved in a suitable low-boiling solvent. After coating, the column is subjected to heat treatment to immobilize the polymer film. Simplicity, rapidity, high column efficiency, batch-to-batch and run-to-run reproducibility, and long column life-time are advantageous features of the new method. Column efficiencies of as high as 1.2 million theoretical plates were achieved for cytochrome c on a 96 cm long Ucon 75 H-90,000 coated column. Efficient electrophoretic separation of five cytochrome c proteins was achieved on a Superox 4 coated column. The possibility of CE separation of histones on the new columns was also explored.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.