@article{wang_yokoyama_chang_matsumoto_2009, title={Dissolution of beech and spruce milled woods in LiCl/DMSO}, volume={57}, DOI={10.1021/jf900441q}, abstractNote={A novel solvent system, lithium chloride/dimethyl sulfoxide (LiCl/DMSO), was developed for dissolving milled wood. This system completely dissolved beech and spruce milled woods prepared from the Wiley woods (coarse wood meals prepared by a Wiley mill) by 2 h planetary ball-milling under the milling conditions employed. The dependence of the structural change of lignin on the degree of milling was examined to evaluate the correlation between the dissolution and lignin structure. The nitrobenzene oxidation analyses showed that the 2 h milling caused almost no structural change in the aromatic part of lignin in the milled woods. The ozonation analyses suggested that the decrease of the erythro ratio [erythro/(erythro + threo)] obtained from beta-O-4 structure in lignin is only 0.35% after the 2 h milling. Although the yield decrease of the ozonation products was 9.8% after the 2 h milling, this value was fairly smaller than that after a longer time milling. When it is taken into consideration that the other solvent systems for dissolution of wood meal, which are proposed by Lu and Ralph, require 5 h of milling under the same milling conditions to dissolve the milled woods, it is safely stated that the LiCl/DMSO solvent system completely dissolves milled wood, the lignin of which is structurally less altered and, thus, is expected to provide an improved method for structural analysis of the entire lignin fraction in wood cell wall.}, number={14}, journal={Journal of Agricultural and Food Chemistry}, author={Wang, Z. G. and Yokoyama, T. and Chang, H. M. and Matsumoto, Y.}, year={2009}, pages={6167–6170} }
 @article{yokoyama_chang_reiner_atalla_weinstock_kadla_2004, title={Polyoxometalate oxidation of nonphenolic lignin subunits in water: Effect of substrate structure on reaction kinetics}, volume={58}, ISSN={["1437-434X"]}, DOI={10.1515/HF.2004.016}, abstractNote={Summary}, number={2}, journal={HOLZFORSCHUNG}, author={Yokoyama, T and Chang, HM and Reiner, RS and Atalla, RH and Weinstock, IA and Kadla, JF}, year={2004}, pages={116–121} }
 @article{yokoyama_matsumoto_meshitsuka_2002, title={Enhancement of the reaction between pulp components and hydroxyl radical produced by the decomposition of hydrogen peroxide under alkaline conditions}, volume={48}, ISSN={["1435-0211"]}, DOI={10.1007/BF00771366}, abstractNote={Experiments on alkaline hydrogen peroxide treatments with stepwise addition and oxygen pressurization were performed to determine whether they enhance the reaction between pulp components and hydroxyl radicals produced by the decomposition of hydrogen peroxide. In this study the degradation of methylβ-dglucopyranoside (MGP), a model compound of pulp components, was an indicator of the progression of the reaction between pulp components and hydroxyl radicals. When comparing the degradation of MGP in the stepwise and one-time addition systems, MGP was degraded more in the stepwise addition system than in the one-time addition system when Fe3+ was added. This result indicates that the hydroxyl radical produced by the decomposition of hydrogen peroxide efficiently attacks MGP in the stepwise addition system. MGP was degraded to the same degree in the stepwise addition system as in the one-time addition system when Fe2+ or Mn2+ was added. Aggregation and precipitation of metal ions might affect their catalysis. Oxygen-pressurized hydrogen peroxide treatment caused almost no enhancement of the degradation of MGP compared to the treatment under atmospheric pressure. Instead, high stability of hydrogen peroxide was produced by oxygen-pressurized hydrogen peroxide treatment. Such high stability can result in frequent attacks of the hydroperoxide anion, the conjugate base of hydrogen peroxide, against some chromophores and quinones.}, number={3}, journal={JOURNAL OF WOOD SCIENCE}, author={Yokoyama, T and Matsumoto, Y and Meshitsuka, G}, year={2002}, pages={191–196} }
 @article{yokoyama_kadla_chang_2002, title={Microanalytical method for the characterization of fiber components and morphology of woody plants}, volume={50}, ISSN={["0021-8561"]}, DOI={10.1021/jf011173q}, abstractNote={Microanalytical techniques were developed which allow the rapid characterization of fiber components and morphology of loblolly pine in a large number of samples. These techniques consist of extractives removal, holocellulose preparation, alpha-cellulose and lignin content determination, and fiber length and coarseness analyses. Greater than 95% of the nonvolatile extractives from an increment core sample of loblolly pine was removed by four successive two-day acetone extractions. Fiber morphology and alpha-cellulose content was determined from holocellulose prepared from only 100 mg of wood. Similarly, a microanalytical acetyl bromide method was developed that enabled the accurate determination of lignin content from less than 50 mg of wood. Through the development of these microanlytical methods, it is possible to accurately and rapidly analyze fiber morphology and chemical components in a large number of increment core samples.}, number={5}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={Yokoyama, T and Kadla, JF and Chang, HM}, year={2002}, month={Feb}, pages={1040–1044} }