Biomedical subjects

Young Ku

Publications and source records attributed to Young Ku.

22 records · Page 2Linked to original sources

PubMed2003

Enhanced bone augmentation by controlled release of recombinant human bone morphogenetic protein-2 from bioabsorbable membranes.

BACKGROUND: The present study was undertaken to determine the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded biodegradable membranes on bone augmentation in a rabbit calvarial model. METHODS: Five microg of rhBMP-2 was loaded into a stiff hemispherical dome membrane made of poly(L-lactide) and tricalcium phosphate (PLLA/TCP). The release kinetics of rhBMP-2 from the membrane were determined in vitro using a human BMP-2 immunoassay. Twelve rhBMP-2-loaded dome membranes (test group) and 12 control dome membranes (control group) were placed on the partial-thickness calvarial defects of 24 rabbits. The animals were sacrificed at 4 and 8 weeks, and undecalcified ground sections were prepared. Newly formed bone area and height were measured histomorphometrically and calculated by percentage ratio to the total submembranous space area and height below the dome. RESULTS: In vitro release results demonstrated that rhBMP-2 was released consistently over a 4-week period following a high initial burst release on the first day. At both 4 and 8 weeks, histomorphometric analysis revealed that the test group showed significantly higher newly formed bone heights and areas than the control group (P < 0.01). In the control group, new bone height was 36.3% of the dome height and the new bone area reached 8.2% of the submembranous space area at 8 weeks, while the test group reached 87.3% and 35.4%, respectively. CONCLUSION: These results suggest that the use of rhBMP-2-loaded PLLA/TCP membranes can result in additional bone augmentation, which is due to the osteoinductive properties of rhBMP-2 released from the membrane during healing.

Absorbable Implants↗

PubMed2002

Decomposition of phorate in aqueous solution by photolytic ozonation.

The degradation of phorate, a highly toxic organic phosphate pesticide, in aqueous solution by photolytic ozonation was studied under various experimental conditions. The rate constants of phorate decomposition and formation of various anions by photolytic ozonation were roughly independent of the solution's pH value. The initial step of the photolytic decomposition of phorate is considered to be the breakage and subsequent oxidation of the P=S double bond on the phorate molecule, followed by isomerization and consequent oxidation of various organic intermediates.

Hydrogen-Ion Concentration↗

PubMed2002

Mercury removal from aqueous solutions by zinc cementation.

The main purpose of this research is to study the addition effect of the surfactant and other operating factors on the treatment of wastewater containing mercury ions in aqueous solution by cementation with sacrificing metal, zinc. The removal of mercury ions from aqueous solutions by cementation of zinc powder was found to be a function of solution pH and temperature, amount of zinc, concentration of mercury ion, contact time and the addition of several organic surfactants. Cementation of mercury was shown to be a feasible process to achieve a very high degree of mercury removal over a broad operational range within a fairly reasonable contact time. The reaction rate is approximately first order with respect to the concentration of mercury ion in aqueous solution. Among the surfactants used in this study, only the presence of SDS, an anionic surfactant, slightly enhanced the cementation rate of mercury. The presence of CTAB and Triton-X100 retarded the cementation of mercury by zinc.

Hydrogen-Ion Concentration↗

PubMed2002

A 3-year longitudinal evaluation of subpedicle free connective tissue graft for gingival recession coverage.

BACKGROUND: The purpose of this study was to longitudinally evaluate, over a 3-year period, the reduction of gingival recession through use of a subepithelial free connective tissue graft placed under a coronally advanced partial-thickness pedicle flap. METHODS: Twenty-one buccal recession defects (mean 3.67 mm; range 3 to 4.5 mm; Miller Class I, II, and III) in 15 patients were treated using this technique. Amount of gingival recession (GR), clinical attachment loss (CAL), and width of keratinized gingiva (WKG) were followed for 3 years after surgery. The measurements were performed at presurgery, and 1, 3, 6, 12, 18, 24, and 36 months postsurgery. RESULTS: GR decreased from 3.67 +/- 0.58 mm at baseline to 0.33 +/- 0.43 mm at 36 months, representing a reduction of 3.33 mm, corresponding to 91.28% mean root coverage. CAL was significantly decreased at 36 months from 5.26 +/- 0.77 mm to 2.14 +/- 0.57 mm. At 36 months, 3.12 mm of attachment gain was obtained. WKG significantly increased after 36 months (1.95 mm). GR, CAL, and WKG had the most positive outcomes at 12 months and were maintained at stable levels throughout the 36-month observation period. CONCLUSIONS: These results indicate that the connective tissue graft with a partial thickness coronal advancement pedicle is a predictable method for root coverage and, provided that optimal maintenance care is provided, the clinical outcomes gained by this technique can be well maintained.

Adult↗