Contributions of the cell structure of wood to water sorption were examined using the chemical potential change induced by restrained swelling. Thermodynamic analysis revealed that this potential was proportional to the product of moisture content and the bulk modulus of the restraining region in the wood. The modulus of the restricting region, which was calculated from isotherm curves of wood powder and block samples by using the thermodynamically derived relationship, was near that obtained from the swelling strain and stress in the cross section for whole wood. These results demonstrated that S1 and S3 layers in the cell wall, where thin crystal threads called microfibrils are wound helically in the circumference, act to resist swelling so that the isotherm curve of the block sample was lower than that of wood powder.
The relationship between hygroscopicity and the microsurface of heated wood was examined using
the fractal surface dimensionality. The hygroscopicity of heated wood decreased with the increase
in heating temperature to 250°C, and then decreased again above 350°C after increasing up
to 350°C. This change corresponded to chemical changes in the wood, especially a reduction in hydroxyl
groups, up to 250°C, and to the temperature dependence of the fractal dimensionality calculated
from nitrogen gas adsorption above 250°C. The fractal dimensionality increased gradually
from 100 to 250°C, followed by a rapid increase above 250°C with a peak at 350°C, and leveled off
above 400°C. From the results, it is concluded that hygroscopicity of heated wood changes at
250°C and that it is dependent upon the chemical properties of wood below 250°C and upon the
surface complexity above 250°C.
Liquid-crystalline gels and elastomers were prepared by polymerization of mixtures containing azobenzene monomers and cross linkers with azobenzene moieties. Oriented liquid-crystalline gels and elastomer films were found to undergo anisotropic bending and unbending behavior only along the rubbing direction, when exposed to alternate irradiation of unpolarized UV and visible light. In the case of polydomain liquid-crystalline elastomer films, the bending and unbending were induced exactly along the polarization direction of incident linearly polarized light. By altering the polarization direction of light, a single film could be bent repeatedly and precisely along any chosen direction.
We examined the published data for the binding affinity of typical ligands to the α-subtype of the human estrogen receptor with use of an approximate molecular orbital method applicable to interacting molecular clusters. An ab initio procedure for "molecular fragments" proposed recently to deal with such macromolecules as proteins was applied to the molecular orbital calculations. The receptor protein was primarily modeled using 50 amino acid residues surrounding the ligand. For a few ligand-receptor complexes, the binding energy was also calculated with use of 241 amino acid residues contained in the entire binding domain. No significant difference was found in the calculated binding energy between the complex modeled with ligand-surrounding 50 amino acids and that with residues of the entire domain. The calculated binding energy was correlated very well with the published relative binding affinity for typical ligands.
We describe a case of cord blood harvest for autologous
transfusion in a neonate weighing 3,992 g with a giant
sacrococcygeal teratoma. The umbilical vein was pierced
with an 18-gauge needle, and placental blood was withdrawn
into two 50-ml syringes filled with 4 ml of citratephosphate-dextrose
solution. Resection of the
sacrococcygeal teratoma was performed on day one.
During the operation the infant lost 46 ml of whole blood,
more than 15% of the estimated total blood volume, and
thus underwent autologous transfusion with 27.8 ml of
packed red cells obtained from autologous cord blood.
Consequently, she could avoid homologous blood transfusion
during the hospital stay. This case highlights the
safety of this procedure, with no evidence of consumption
coagulopathy, hemolysis or bacterial infection.
This paper provides a list of the most important terms from all areas of polymer science including polymer chemistry, polymer physics, polymer technology and polymer properties. These have been assembled into a representative list of terms that serves as an IUPAC recommended list of keywords for polymer science.