Mechanistic Studies of the Oxidation of Lignin and Cellulose Models

Oxygen delignification is an environmentally friendly pulp bleaching system. To develop a selective delignification process that results in high DP retention of carbohydrate with lignin being removed, obtaining better knowledge of reactions occurring during oxygen delignification is essential. In this work, mixtures of guaiacol (model lignin) and methyl-ß-D-glucoside (model cellulose) were reacted in a pressurized oxygen reaction system (pH 12,65 psi O2, and 95°C in a glass reaction vessel). In the results, methyl-ß-D-glucoside degraded only in the presence of lignin. This indicates that hydroxyl radicals, that subsequently react with methyl-ß-D-glucoside, are generated in the system. Unfortunately, we could not develop the degradation mechanisms of methyl-ß-Dglucoside in this study because the identification of products derived from methyl-ß-D-glucoside could not be accomplished. Therefore, we undertook an alternative study of the oxidation reactions of cellulose using a UV/H2O2 system, which is a hydroxyl radical generation system. For the UV/H2O2 system, the cellulose models used were methyl-ß-D-glucoside, methyl-ß-D-cellobioside, and cellulose fiber. The reactions using hydroxyl radical scavengers in the UV/H2O2 system strongly support the hydroxyl radical reactions proposed in our lab previously. The results, from the qualitative analysis of the organic acids produced during the reaction, suggest that hydroxyl radicals have an important role in the formation of aldonic acids from aldoses. In the reactions with methyl-ß-D-cellobioside, the reaction chemistry was the same as in the reactions with methyl-ß-D-glucoside. However, the reactivity of methyl-ß-D-cellobioside toward hydroxyl radicals is considered to be larger than that of methyl-ß-D-glucoside. The cellulose fiber (filter paper) was degraded in the W/H202 system. In the presence of hydroxyl radical scavengers, tert-BuOH and 2-propanol, the degradation was inhibited in all three cellulose models used in this study. This supports that cellulose can be protected from the degradation by the hydroxyl radical using scavengers, tert-BuOH and 2-propanol

Costs of infrastructure deficiencies in manufacturing in Indonesia, Nigeria, and Thailand

Using fresh results from a sample survey of manufacturing establishments in Indonesia and Thailand, the authors contrast and compare with data from an earlier study on Nigeria. They compare especially: the extent and incidence of public infrastructure deficiencies; the extent of manufacturers'private provision of infrastructure in response to such deficiencies; the capital shares of various private infrastructure investments, including electric power, water, telecommunications, transport, and waste disposal; and the firms'costs for producing their own electricity and water. The extent of public infrastructure deficiencies and private provision of infrastructure services varies across countries and by firm size. The total share of capital investment in private infrastructure was similar among Nigerian and Indonesian firms (14 - 16 percent) which is twice that in Thai firms. The private costs of infrastructure deficiencies are substantial and the burdens are much greater on small firms than on large firms.Public Sector Economics&Finance,Decentralization,Environmental Economics&Policies,Banks&Banking Reform,Water and Industry,Environmental Economics&Policies,Agricultural Research,Urban Services to the Poor,Public Sector Economics&Finance,Banks&Banking Reform

Modulation of Pathogen Recognition by Autophagy

Autophagy is an ancient biological process for maintaining cellular homeostasis by degradation of long-lived cytosolic proteins and organelles. Recent studies demonstrated that autophagy is availed by immune cells to regulate innate immunity. On the one hand, cells exert direct effector function by degrading intracellular pathogens; on the other hand, autophagy modulates pathogen recognition and downstream signaling for innate immune responses. Pathogen recognition via pattern recognition receptors induces autophagy. The function of phagocytic cells is enhanced by recruitment of autophagy-related proteins. Moreover, autophagy acts as a delivery system for viral replication complexes to migrate to the endosomal compartments where virus sensing occurs. In another case, key molecules of the autophagic pathway have been found to negatively regulate immune signaling, thus preventing aberrant activation of cytokine production and consequent immune responses. In this review, we focus on the recent advances in the role of autophagy in pathogen recognition and modulation of innate immune responses

Synergistic multi-doping effects on the Li7La3Zr2O12 solid electrolyte for fast lithium ion conduction.

Here, we investigate the doping effects on the lithium ion transport behavior in garnet Li7La3Zr2O12 (LLZO) from the combined experimental and theoretical approach. The concentration of Li ion vacancy generated by the inclusion of aliovalent dopants such as Al(3+) plays a key role in stabilizing the cubic LLZO. However, it is found that the site preference of Al in 24d position hinders the three dimensionally connected Li ion movement when heavily doped according to the structural refinement and the DFT calculations. In this report, we demonstrate that the multi-doping using additional Ta dopants into the Al-doped LLZO shifts the most energetically favorable sites of Al in the crystal structure from 24d to 96 h Li site, thereby providing more open space for Li ion transport. As a result of these synergistic effects, the multi-doped LLZO shows about three times higher ionic conductivity of 6.14 × 10(-4) S cm(-1) than that of the singly-doped LLZO with a much less efforts in stabilizing cubic phases in the synthetic condition

Application of Artificial Neural Network to Search for Gravitational-Wave Signals Associated with Short Gamma-Ray Bursts

We apply a machine learning algorithm, the artificial neural network, to the search for gravitational-wave signals associated with short gamma-ray bursts. The multi-dimensional samples consisting of data corresponding to the statistical and physical quantities from the coherent search pipeline are fed into the artificial neural network to distinguish simulated gravitational-wave signals from background noise artifacts. Our result shows that the data classification efficiency at a fixed false alarm probability is improved by the artificial neural network in comparison to the conventional detection statistic. Therefore, this algorithm increases the distance at which a gravitational-wave signal could be observed in coincidence with a gamma-ray burst. In order to demonstrate the performance, we also evaluate a few seconds of gravitational-wave data segment using the trained networks and obtain the false alarm probability. We suggest that the artificial neural network can be a complementary method to the conventional detection statistic for identifying gravitational-wave signals related to the short gamma-ray bursts.Comment: 30 pages, 10 figure