(C) 2010 Wiley Periodicals, Inc. Appl Polym Sci 117: 3121-1127, 2010″
“Previous reports have shown that CO2 dissolved in xylem sap in tree stems can move upward in the transpiration stream. To determine the fate of this dissolved CO2, the internal transport of respired CO2 at high concentration from the bole of the tree was simulated by allowing detached young branches of sycamore (Platanus occidentalis L.) to transpire water enriched with a known quantity of (CO2)-C-13 in sunlight. Simultaneously, leaf net photosynthesis

and CO2 efflux from woody tissue were measured. Branch and leaf tissues were subsequently analysed for C-13 content to determine the quantity of transported (CO2)-C-13 label that was fixed. Treatment branches assimilated an average of 35% (SE=2.4) of the (CO2)-C-13 label taken up in the treatment water. The majority was fixed in the woody tissue of the branches, with smaller amounts fixed in the leaves selleckchem and petioles. Overall, the fixation of internally transported SN-38 inhibitor (CO2)-C-13 label by woody tissues averaged 6% of the assimilation of CO2 from the atmosphere by the leaves. Woody tissue assimilation rates calculated from measurements of C-13 differed from rates calculated from measurements of CO2 efflux in the lower branch but not in the upper branch. The results of this study showed unequivocally that CO2 transported in

xylem sap can be fixed in photosynthetic cells in the leaves and branches of sycamore trees and provided evidence that recycling of xylem-transported CO2 may be an important means by which trees reduce the carbon cost of respiration.”
“Large auxetic properties of iron-gallium GW4869 inhibitor and iron-aluminum alloys have been investigated with both theoretical and experimental approaches. Tensile tests of single-crystal iron-gallium alloys

with compositions of 12%-25% gallium were conducted to determine the composition dependent values of the Poisson’s ratio. Systematic density functional calculations revealed a simple correlation between the Poisson’s ratio and tetragonal shear modulus. We attribute the auxetic properties of these intermetallic alloys to the drastic reduction in C’ with the presence of metalloid atoms in the DO(3)-type structures. (C) 2010 American Institute of Physics. [doi:10.1063/1.3445269]“
“This study presents the synthesis of a cross-linkable dextran as starting material for the development of new hydrogels as drug delivery system in dental applications. 2-Hydroxyethyl methacrylate (HEMA) was coupled to dextran after activation with carbonyldiimidazole as monitored by FTIR and (1)H-NMR spectroscopy. The Dex-HEMA was crosslinked by visible light in the presence of camphorquinone (CQ) as photoinitiator and a coinitiator in a proper solvent. Aliphatic or aromatic amines were used as coinitiators and the content of the coinitiator was varied from 0.25 to 3.