Biomedical subjects

Guangming Zhu

Publications and source records attributed to Guangming Zhu.

4 recordsLinked to original sources

PubMed2005

[Scanning electron microscopic observation of the fetal stria vascularis].

OBJECTIVE: To get full appreciation of the ultrastructural features in the stria vascularis of human fetal cochlea. METHOD: The Stria vascularis in human fetal cochlea were observed by scanning electron microscope. RESULT: The cells of the fetal stria vascularis present round. All cell surfaces are covered with a thick layer of microvilli. The transition zone is between the stria vascularis and the spiral prominence. The shape of cells gradually changes on the spiral prominence and becomes more irregular. Several cells have a structure of elongated hexagons. The structure of the intermediate cells, basal cells and capillary were also observed from the fractural surface in the stria vascularis. CONCLUSION: The surface structures of the whole stria vascularis were observed by scanning electron microscope, especially the surface appearance of the marginal cells. New information will be provided for understanding the structure and function in the stria vascularis.

Cochlea↗

PubMed2005

[Shape-memory polymers for biomedical engineering applications].

The latest progress in shape-memory polymer for biomedical engineering applications was summarized in this paper. The mechanism responsible for shape memory effect was analyzed in reference to the polymer structure. Also introduced and reviewed were the characteristics of some shape-memory polymers (polyurethane polycaprolactone and polylactide) and their applications in medical engineering.

Alloys↗

PubMed2002

Enantioselective addition of diethylzinc to aldehydes catalyzed by optically active C2-symmetrical bis-beta-amino alcohols.

The syntheses of new optically active C(2)-symmetrical bis-beta-amino alcohols 1-6 from (S)-2-(1-hydroxy-1,1-diphenylmethyl)-pyrrolidine are described. Especially attention is focused on bridges, which link the two beta-amino alcohol units. These new chiral ligands have been successfully applied in the catalytic enantioselective addition of diethylzinc to aldehydes to give sec-alcohols in good yields with up to 95% enantiomeric excess.

Journal Article↗

PubMed2002

Kinetic thermal response and damage in laser coagulation of tissue.

BACKGROUND AND OBJECTIVES: Laser induced interstitial coagulation has become a method of treating different types of tumors. Theoretical modeling and analysis may be used to better understand the complex process involved in the laser coagulation and optimized the dosimetry of laser thermotherapy. STUDY DESIGN/MATERIALS AND METHODS: A full dynamic theoretical model was developed to simulate the dynamic evolution of coagulation in tissue, which accounted for the dynamics of the temperature and damage dependence of optical properties, thermal properties, and blood-perfusion rate. The simulation of the temperature distribution, coagulation depth and its hysteresis during laser thermotherapy for full-dynamic model are compared with the calculations from other models. RESULTS: Increased scattering in the near surface of applicator prevents light penetration into deeper region. Moreover, rise in temperature increases both blood flow at the periphery of coagulation region and thermal properties, which reduces the damage depth and its hysteresis. It results in a considerable overestimation of the temperature distribution and damage depth ignoring the dynamic of optical properties. The coagulation would be limited in a smaller region and there is no hysteresis if blood perfusion is regarded as a constant. In contrast, the hysteresis is overestimated if blood perfusion is ignored. Ignoring the dynamics of thermal parameters, there is also overestimation of the rise in temperature and damage depth. CONCLUSIONS: Mathematical modeling techniques that simulate laser coagulation may not provide reliable information unless they take into account these dynamic parameters.

Animals↗