“
“The effect of particle size on enzymatic hydrolysis of cellulose has been investigated. The average size of microcrystalline cotton cellulose has been reduced to submicron scale by using a media mill. The milled products were further subjected to hydrolysis using cellulase. High cellulose concentration (7%) appeared to retard the size reduction and

resulted in greater particles and smaller specific surface areas than those at low concentration (3%) with the same milling time. Initial rate method was employed to explore the rate of enzymatic hydrolysis of cellulose. The production rate of cellobiose was increased at least 5-folds due to the size reduction. The yield of glucose was also significantly increased depending upon the ratio of selleck screening library enzyme to substrate. A high glucose yield (60%) was obtained in 10-h hydrolysis when the average particle size was in submicron scale. (C) 2009 Elsevier Ltd. All rights reserved.”
“Recent advances in our understanding of the mechanisms for the biosynthesis of the complex iron-sulfur (Fe-S) selleckchem containing prosthetic groups associated with [FeFe]-hydrogenases and nitrogenases have revealed interesting parallels. The biosynthesis,of the H-cluster ([FeFe]-hydrogenase) and the FeMo-co (nitrogenase)

occurs through a coordinated process that involves the modification of Fe-S cluster precursors synthesized by the general host cell machinery (lsc/Suf). Key modifications to the Fe-S precursors are introduced by the activity of radical S-adenosylmethionine (SAM) enzymes on unique scaffold proteins. The transfer of the modified clusters to a cofactor-less structural apo-protein completes maturation. Together these features provide the basis for establishing unifying paradigms for complex Fe-S cluster biosynthesis for these enzymes.”
“Although an important index, the level of bone mineral density (BMD) does not completely describe fracture risk. Another bone structural parameter, the orientation of type I

collagen, is known to add to risk determination, independently of BMD, ex vivo. We investigated the Haversian system of transiliac crest biopsies from postmenopausal women before and after selleck treatment with parathyroid hormone (PTH). We used the birefringent signal of circularly polarized light and its underlying collagen arrangements by confocal and electron microscopy, in conjunction with the degree of calcification by high-resolution micro-X-ray. We found that PTH treatment increased the Haversian system area by 11.92?+/-?5.82 mm2 to 12.76?+/-?4.50 mm2 (p?=?0.04); decreased bright birefringence from 0.45?+/-?0.02 to 0.40?+/-?0.01 (scale zero to one, p?=?0.0005); increased the average percent area of osteons with alternating birefringence from 48.15%?+/-?10.27% to 66.33%?+/-?7.73% (p?=?0.