• The Journal of the Korean bone and joint tumor society
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• v.5 no.1
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• pp.9-16
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• 1999

A new method of limb sparing by resection, extracorporeal irradiation and reimplantation has several theoretical advantages. This method preserves the mobility of a joint and avoids the problem of loosening or breakage of tumor prosthesis. This study involved using extracorporeal irradiated autogenous joint transplantation for reconstruction after en bloc resection, and observed the periods of functional union and histological changes in irradiated tissue of the knee joint. This study also aimed to clarify whether the degeneration of articular cartilage is induced in rabbits by a single 50Gy dose of irradiation at the knee joint. Twenty New Zealand rabbits about three kilograms were randomized into two groups of 10 rabbits each. In group 1, as control, we resected the knee joint followed by reimplantation without irradiation. Group 2 received extracorporeal irradiation on the resected knee joint followed by reimplantation. Following are the results of these observations. The osteotomy site showed external callus formation in the roentgenographic finding eight weeks after reimplantation. There was marked degenerative changes in the collagen fiber of the irradiated anterior cruciate ligament and meniscus during the fourth week, but new blood-vessel formation was observed in the vicinity. There was degenerative changes in the collagen fiber of articular cartilage treated extracorporeal irradiation at four and eight weeks in the scanning electron micrographic findings. These findings was in contrast to those of subchondral bone which showed decreased cellularity and empty lacuna at four and eight weeks. Autoradiography demonstrated active [$^3H$]uridine incorporation by irradiated chondrocyte at eight weeks after reimplantation. These results indicate that when destruction of the articular cartilage and soft tissue of the knee joint is not severe, extracorporeal irradiation and reimplantation can be used with several advantage in maintaining movement of the joint while avoiding problems of tumor prosthesis and rejection, and therefore extracorporeal irradiated autogenous joint transplantation can be used as a limb-sparing procedure for temporary biological spacer in the childhood bone tumor around the knee.

• Journal of Adhesion and Interface
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• v.20 no.1
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• pp.1-8
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• 2019

Fabrication of monolayer is important method for enhancing physical and chemical characteristics such as light shielding and antireflection while maintaining thin film properties. In previous studies, monolayers were fabricated by various methods on small substrates, but processes were complicated and difficult to form monolayers with large area. We used rod coating equipment with a small amount of coating liquid to form a HCP (hexagonal closed packing) coating of PMMA beads on PET(poly(ethylene terephthalate)) substrate with $20cm{\times}20cm$ size. We observed that changes in morphologies of monolayers by using the solvents with different boiling points and vapor pressures, by adapting surfactants on particles and by applying plasma treatment on substrates. The coverage was increased by 20% by optimizing the coating conditions including meniscus of beads, control of the attraction - repulsion forces and surface energy. This result can potentially be applied to optical films and sensors because it is possible to make a uniform and large-scale monolayer in a simple and rapid manner when it is compared to the methods in previous studies.

• Journal of the Korean Arthroscopy Society
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• v.12 no.3
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• pp.191-197
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• 2008

Purpose: To evaluate the postoperative magnetic resonance image (MRI) findings of anterior cruciate ligament (ACL) reconstructed with a tension load technique using auto-Achilles tendon, and to compare the results with knees with a native ACL. Materials and Methods: We evaluated 21 postoperative MRI scan of 21 patients (group A) who had undergone ACL reconstruction between January 1995 and November 1996. The control group (group B) consisted of 50 patients whose meniscus tear had been operated by arthroscopy and whose ACL was intact. We measured the orientation of the graft in the sagittal and coronal planes and compared it with that of the native ACL. Results: The mean sagittal angle of the ACL angle in group A ($55.7{\pm}5.6^{\circ}$, range $47.2{\sim}68.8^{\circ}$) was statistically lesser than group B ($58.7{\pm}3.8^{\circ}$, range $50.4{\sim}67.5^{\circ}$) (p=0.036). But there was no statistically significant difference between the two groups with regard to the mean ACL-Blumensaat line angle (group A: $8.1^{\circ}{\pm}4.9^{\circ}$, range $1.7^{\circ}{\sim}22.0^{\circ}$, group B: $8.6^{\circ}{\pm}3.6^{\circ}$, range $2.6^{\circ}-18.1^{\circ}$) and the mean coronal angle of the ACL (group A: $64.9^{\circ}{\pm}9.1^{\circ}$, range $46.9^{\circ}{\sim}76.4^{\circ}$, group B: $65.9^{\circ}{\pm}4.4^{\circ}$, range $57.7^{\circ}{\sim}75.2^{\circ}$)(p=0.88, p= 0.62). In the sagittal plane, the mean center of tibial insertion of the ACL graft in group A ($31.9{\pm}7.1%$, range 22.4-47.9%) was positioned more anteriorly than group B ($37.0{\pm}4.9%$, range $18.5{\sim}44.7%$)(p=0.005). But in the coronal plane, there was no statistically significant difference between the two groups(group A: $46.3{\pm}2.8%$, range $42.1{\sim}52.5%$, group B: $45.7{\pm}2.8%$, range $41.0{\sim}49.1%$)(p=0.392). Conclusion: We performed an ACL reconstruction with the tension load technique using auto-Achilles tendon and we found that the graft orientation in MRI was as good as that of the native ACL.