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Biomedical subjects

A Horiuchi

Publications and source records attributed to A Horiuchi.

At least 271 records · Page 15Linked to original sources
PubMed1979

[Aging effect on mechanical properties in fluid resin. (Part 1). Affection of residual monomer (author's transl)].

Aging effect on the mechanical properties in fluid resins was pointed out, but little was studied on this point. Relationship between amount of residual monomer in the samples prepared by fluid resin and the mechanical properties, brinell hardness, tensile strength, were studied. Test pieces just as polymerized in the size were used. Weights of specimens kept at three different circumstances, in the air at 20 degrees C, in a water bath at 37 degrees C and in a desiccator at 11 mmHg and 40 degrees C, was checked at the prescribed time to clarify the amount of residual monomer and the mechanical properties were measured at the same time. Amount of weight loss, due to evaporation of MMA, must improve the mechanical properties. The improvement by postpolymerization could be neglected. Rate of the weight loss suggests that residual monomer must mainly be at the surface. Molecular weight of PMMA, 86.4 X 10(4) did not have any effect on the mechanical properties and on the evaporation rate of monomers from polymerized specimens. To improve the mechanical properties of fluid resin must be to decrease residual monomer as much as possible in the fluid resin especially at the surface area.

Acrylic Resins↗
PubMed1979

[Aging effect on mechanical properties in fluid resin. (Part 2). Effect of a cross-linking agent, neopentylglycol dimethacrylate (author's transl)].

Brinell hardness and tensile strength were measured, weight decrease of specimens due to evaporation of residual monomer were also checked, and the relationship between amount of residual monomer and the mechanical properties were studied. The addition of neopentylglycol dimethacrylate (NPG) in MMA improved the mechanical properties nearly same as the heat processed resins and was effective to decrease residual monomers. Rate of polymerization must increase and the heat of polymerization raised the temperature of curing mass. Properties of the new NPG fluid resin must be improved by loss residual monomer and cross-linking structure.

Acrylates↗
PubMed1977

Studies on function of lymphocytes in NZB X NZW F 1 hybrid mice; autoantibody-producing cells and cytotoxicity of lymphocytes.

Several experiments were performed using B/W mice, experimental model of human systemic lupus crythematosus, with a view to explore the pathogenesis of autoimmune diseases. As a result of the Investigation by the immunocyte adherence method, autoantibody-producing cells were demonstrated at a ration of 1 to 4% in the spleen, thymus and lymph nodes of B/W mice, but nearly absent in the bone marrow. B/W mouse lymphocytes showed the cytotoxic activity to allgeneic target cells (L cells), but ANA positive sera from B/W mice also had a remarkable cytotoxic activity in the presence of the complement of a high concentration. It was also disclosed that there are Ig+ and theta-lymphocytes in the B/W mouse thymus at a nearly equal percentage, and the possible identity of the two was suggested.

Antibody-Producing Cells↗