PubMed Health⌕ Search

Biomedical subjects

Y Kinouchi

Publications and source records attributed to Y Kinouchi.

82 records · Page 5Linked to original sources
PubMed1981

Pd-Co dental casting ferromagnetic alloys.

Three kinds of Pd-Co alloys have been newly developed. Their magnetic and physical properties and corrosion resistances have been examined. As a result, it was found that they are available as the dental casting ferromagnetic alloy which can be used in combination with Sm-Co magnets, overcoming such problems as non-castability and brittleness.

Chemical Phenomena↗
PubMed1979

Studies on the Sm-Co magnet as a dental material.

The Sm-Co magnet has superior and convenient magnetic properties as compared with conventional ones used hitherto in prosthesis, and even very small pieces can provide the force necessary in dentistry. Also, the magnet has high corrosion resistance and is innocuous to tissues. Therefore, it can be used as a dental material, overcoming the limitations in past applications.

Animals↗
PubMed1978

[Studies on dental casting ferromagnetic alloys (author's transl)].

We previously reported successful applications of rare earth-cobalt magnets to dental prostheses. In order to use magnets more effectively, ferromagnetic materials with a high magnetic permeability and a high saturation flux density should be used as prosthetic materials. This type of material will form a good magnetic path, and consequently tighten the magnetic attracting force by preventing the magnetic flux from leaking into the mouth tissue. A few alloys were newly prepared by using Pd, Co and Cr, the usual dental metals, and tested. It was found that: (1) These alloys have suitable magnetic properties. (2) The corrosion resistances of the Pd-Co and Pd-Co-Cr alloys are as good as those of dental casting Ag and Ni-Cr alloys, respectively. (3) The physical and mechanical constants of the alloys are similar to those of the usual dental casting alloys. (4) These alloys can be used as dental casting ferromagnetic alloys. (5) The Pd-Co alloy can also be used as a porcelain bonding alloy.

Cobalt↗
PubMedDate not supplied

A study of the electrical bio-impedance of tumors.

A new system of impedance measurement over a frequency range of 0 to 200 kHz was developed by a three-electrode method. In this study, the electrical impedances of various tumors were measured in vivo in 54 patients with breast disease (31 breast cancers, 13 fibroadenomas, and 10 fibrocystic diseases) and 57 patients with pulmonary disease (44 lung cancers, 5 metastatic pulmonary tumors, 4 pulmonary tuberculoses, and 4 organized pneumonias). On the basis of those impedance measurements and the equivalent circuits in vivo, we calculated the extracellular resistance (Re), intracellular fluid resistance (Ri), and cell membrane capacitance (Cm) in tissues, all of which were compared among the various diseases. It was found that Re and Ri were significantly higher in breast cancers than in benign tumors and normal breast tissues and that Cm was significantly lower in breast cancers than in other tissues. On the other hand, Re and Ri were significantly higher, and Cm was significantly lower, in normal lung tissues than in pulmonary masses. Re and Ri were significantly higher, and Cm was significantly lower, in malignant tumors than in organized pneumonias. The results showed that these parameters (Re, Ri, and Cm) exhibit significant differences among various tissues and tumors, suggesting possible applications in tumor diagnosis.

Breast Neoplasms↗
PubMedDate not supplied

Noninvasive measurement of the electrical bioimpedance of breast tumors.

The purpose of this study was to evaluate the possibility of differential diagnosis of tumors, such as breast cancer, by measuring the mammary electrical bioimpedance via the skin surface noninvasively and by examining the relationship between the tissue structure of the breast and electrical bioimpedance. The mammary electrical bioimpedance was measured in 24 patients with breast cancer. Taking into account the measurement results and the distribution of the mammary glands and fatty tissue, a breast model with tumors was proposed. Based on this model, the distributions of the electric potential and electric field in the tissue were theoretically analyzed by the three-dimensional finite element method. In clinical cases, the Re values of the diseased breast were significantly larger than those of the contralateral healthy breast. In theoretical analysis based on the breast model, the Re value of mammary electrical bioimpedance varied due to the structure of the breast, that is, the ratio of fatty tissue to mammary gland and the presence of mammary tumors. The results of the measurement agreed with the theoretical analyses. These results suggest that differential diagnosis of breast tumors is possible by measuring the mammary electrical bioimpedance using noninvasive electrodes on the skin.

Adipose Tissue↗