• The Journal of the Korean dental association
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• v.48 no.8
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• pp.615-620
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• 2010

Purpose: The short dental implant is considered as possible solution in the alveolar bone height deficient cases. The aim of this study was to evaluate clinical availability of short implants by measuring the marginal bone loss of short length implants and comparing with that of conventional length implants. Materials and Methods: The groups were composed of patients who had received at least one implant. The samples of this study were selected from patients who with functional loading after prosthetic treatment for 1 year follow up period. The implants with a length of 5.7 mm and 6mm were considered short. (Bicon Dental implants, USA). The experiment group was composed of $4.5{\times}6mm$, $5{\times}6mm$, $6{\times}5.7mm$ implants (total 18 implants were placed in 14 patients, 8 on maxilla, 10 on mandible). The control group was composed of $4.5{\times}8mm$, $5{\times}8mm$, $4.5{\times}11mm$, $5{\times}11mm$. All implants were selected only by implants placed on molar area. We evaluated marginal bone loss in radiographic images at baseline (implant loading) and 3, 6, 12 months after loading. Additionally, crown-to-implant ratio was evaluated, and marginal bone loss according to crown-to-implant ratio after functional loading was analyzed. Results: The short implant group had a mean marginal bone level of $-0.52{\pm}0.69mm$; the 8mm group, $-0.22{\pm}0.82mm$; and the II mm group, $-0.10{\pm}1.09mm$ after I year of functional loading. But significant differences were not detected between three groups at every follow-up period. Crown-to-implant ratio in short implant group was $1.55{\pm}0.23$; 8mm group was $1.15{\pm}0.18$; and 11mm group was $0.92{\pm}0.15$. Additionally, significant differences between three groups were founded. (P<.0001) The greatest marginal bone loss after 1 year follow-up was founded at crown-to-implant ratio 1~1.49 range in short implant. Conclusion: The marginal bone loss of short implants was comparable to that of long implants. So, the short implants can be a clinically acceptable option.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.1
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• pp.33-43
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• 2008

Purpose: To evaluate the clinical usability of reconstructive methods, and how to select flap after wide excision of malignant soft tissue tumor in ankle and foot. Materials and Methods: The 15 cases shown in the 14 patients (In case of a male patient, reconstruction was performed two times due to local recurrence.) with malignant soft tissue tumor in ankle and foot, who underwent reconstruction after wide excision from March 2000 until March 2007. Oncologic, surgical and functional results were evaluated. Results: The method of reconstruction used were anterolateral thigh perforator flap (5cases), Reversed superficial sural artery flap (4 cases), dorsalis pedis flap (3 cases), local flap (3cases). The defect, mean size was $5.5{\times}5.7\;cm$, was reconstructed with rotation flap or free flap, mean size was $5.9{\times}6.0\;cm$, skin graft for remnant. The mean operation time was 310 minutes (120~540 minutes); it took 256 minutes to reconstruct by rotation flap, and 420 minutes by free flap. As oncologic results, 7 patients were no evidence of disease, 6 patients were alive with disease and 1 patient was expired by pulmonary metastasis at the time of the last follow-up. 4 patients had local recurrence and 4 pateints had distant metastases. As functional results, 14 patients were evaluated with average score of 68.8% using the system of the Musculoskeletal Tumor Society. Conclusion: The dorsalis pedis and reverse superficial sural artery rotation flap which is easy procedure, has less complication and takes short operation time, can be primarily considered to reconstruct a small defect. And the anterolateral thigh perforator flap is suitable for coverage of a large defects after wide excision of malignant soft tissue tumor in ankle and foot.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.09a
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• pp.21-36
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• 2005

Although the main geology of Korea consists of granite and gneiss, it Is not uncommon to encounter anisotropy Phenomena in crosshole radar tomography even when the basement is crystalline rock. To solve the anisotropy Problem, we have developed and continuously upgraded an anisotropic inversion algorithm assuming a heterogeneous elliptic anisotropy to reconstruct three kinds of tomograms: tomograms of maximum and minimum velocities, and of the direction of the symmetry axis. In this paper, we discuss the developed algorithm and introduce some case histories on the application of anisotropic radar tomography in Korea. The first two case histories were conducted for the construction of infrastructure, and their main objective was to locate cavities in limestone. The last two were performed In a granite and gneiss area. The anisotropy in the granite area was caused by fine fissures aligned in the same direction, while that in the gneiss and limestone area by the alignment of the constituent minerals. Through these case histories we showed that the anisotropic characteristic itself gives us additional important information for understanding the internal status of basement rock. In particular, the anisotropy ratio defined by the normalized difference between maximum and minimum velocities as well as the direction of maximum velocity are helpful to interpret the borehole radar tomogram.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.2
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• pp.154-163
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• 1995

With the development of anticancer chemotherapy and improved radiographic imaging studies, limb salvage operation became possible in the treatment of malignant and aggressive benign tumors. High grade sarcomas of the shoulder or the upper extremity can be surgically treated with a forequarter amputation, shoulder disarticulation or limb salvage surgery such as Tikhoff-Linberg procedure, segmental resection and replacement with endoprosthesis, segmental resection and replantation, or segmental resection and free vascularized bone graft. Among them the limb salvage surgery showed not only preservation of the remained upper extremity but also the excellent functional results. When comparing amputation and limb salvage operation while performing anticancer chemotherapy in both cases, 5 year survival rate, local recurrence, and distant metastasis did not show much difference. We studied 13 cases of limb salvage for the malignant and aggressive benign bone tumor of the upper extremity from March 1986 to December 1993 at Severance hospital. The summarized results were as follows. 1. There were 21 cases of malignant bone tumors and 5 cases of benign aggressive ones. 2. Of the 26 cases of malignant and benign aggressive bone tumors, limb salvage procedures such as Tikhoff-Linberg operation(8 cases), endoprosthetic replacement(2 cases), segmental resection and replantation(2 cases), and segmental resection and free vascularized fibular graft(l case) were done in 13 cases. 3. In 13 patient on whom the limb salvage procedure was performed, there were 3 osteosarcomas, 4 chondrosarcomas, 3 giant cell tumors, 1 Ewing's sarcoma, 1 leiomyosarcoma and 1 chondroblastoma. 4. In 13 patients, there was no local recurrence nor distant metastasis except one who had a segmental resection of the entire humerus part including glenoid and then postoperative anticancer chemotherapy for the treatment of the Ewing's sarcoma of the entire shaft of the humerus with pathological fracture. Local recurrence occurred 2 years and 6 months postoperatively in this Ewing's sarcoma patient, so forequarter amputation was performed and the irradiation and the anticancer chemontherapy were performed, but multiple bony metastasis developed and died of the disease 22 months after local recurrence. 5. The patients were followed-up for I year to 7 years and 5 months(average 4 years 5 months). 6. In 8 cases in which Tikhoff-Linberg procedure was performed, the function of the hand was almost normal. 7. Segmental resection and endoprosthetic replacement was performed in 2 cases, and the function of the remained upper extremity was good with no evidence of aseptic loosening or nerve palsy. 8. In 1 case of segmental resection and free vascularized fibular graft for the patient of the chon drosarcoma in the humerus, the function of the shoulder, elbow and hand was nearly normal. 9. In I case of leiomyosarcoma which involved both forearm muscles and bone near wrist joint, segmental resection and replantation was performed, and the patient has useful hand function.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.52-60
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• 2003

Purpose: To analyse their end results and also to differentiate the single or multiple giant cell tumor(GCT) of tendon sheath in hand. Materials & Methods: Total 21 cases with GCT of tendon sheath in hand were treated surgically and analyzed their end results with clinically, radiologically and pathologically to allowed for average 16 months after surgical excision. Results: The finger flexor tendons, especially on index and ring finger, involving distal interphalangeal joint and mid-phalanges in fourth decades (average age of 47 years old) were frequently involved, and the mass was not exceed than 2 cm in size, fixed on tendon sheath with rubbery hard tenderness but rare bony involvements except 4 cases of bony erosion and cortical perforation. The three cases with multiple GCT of hand was also combined with familial hypercholesterolemia, and are commonly involved the extensor tendons as well as achilles tendons bilaterally, treated with partial excision because of multiplicity. Average 16 months after surgical excision for single GCT cases was followed and showed the recurrence in 3 cases(3/18,16.7%), treated with wide excision. The single and multifocal GCT are similar in pathologic changes but different soft tissue tumors in their pathogenesis, treatment and prognosis. Conclusion: Incomplete excision of GCT of tendon sheath in hand are thought to be the cause of recurrence, especially in cases with incomplete lesional excision, in multilobular and bony involvement etc. So careful wide excision is necessary to prevent the recurrence.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.1
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• pp.84-92
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• 2003

Purpose: To report two cases of bone tumors other than osteoid osteoma in the proximal femur and treated with percutaneous high frequency radioablation method. Cases: We reviewed two cases with intracortical chondroma and enchondroma in the femoral head retrospectively. The patient with intracortical chondroma was a thirty one year old woman and had suffered right hip pain of 1 year duration. The lesion was located in the head of right femur and treated with CT guided percutaneous high frequency radioablation after needle biopsy under general anesthesia. The symptom was gone immediately after the procedure and was discharged postop. 1 day. 15 months has passed without symptom recurrence. Second case having enchondroma, was 56 year old woman complaining of gluteal area pain for 3 months. Radiologic evaluation showed osteolytic lesion with sclerotic rim on the inferior portion of the left femoral head. She received a same therapy with CT guided radiofrequency ablation following needle biopsy. She reported dramatic pain relief after the procedure and was discharged postop. 1 day. No symptom has occurred for 3 months until now. Conclusion: We present 2 cases of bone tumor occurred in the hip joint area other than osteoid osteoma which were treated with CT guided radiofrequency ablation.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.2
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• pp.45-55
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• 1990

This study describes on the erosion control effects of the several grasses and its mixtures for the man-made slopes. The grasses used for this experiment include cool-season grasses such as Festuca rubra L. (Creeping redfescue), Poa pratensis L. (Kentucky bluegrass), Lolium perenne L. (Perenial ryegrass), Lolium multiflorum LAM. (Italian ryegrass), Festuca arundinacea Schrel. (Tall fescue), and warm-season grasses such as Eragrostis curvula Schrad. (Weeping lovegrass), Zoysia japonica Steud. (Zoysiass) and native plants (Artemisia princeps var. orientalis Hara, Lespedeza cuneata G. Don, Arundinella hirta var. ciliata K.) This study was conducted at Dan-kook University from April, 1988 to Octover, 1989. The results are summurized as follows; 1.Cool-season grasses covered the ground quickly in early stage, and weekened slowly during sumer season. Warm-season grasses and native-plants covered the ground slowly in early stage, but during summer season they grew vigorously, so outweighed cool season grasses. 2. The amount of aboveground growth of weeping locearass and underground growth of Artemisia prinoepts are quite differant from others. Since Arumdinella hirta has deep root system, it is thought to very useful protection of unstable for hrdro-seeding. Because cool-season grasses are useful for quick coverage, and native plants or warm-season grow well during summer season with the better compatability to weeds. 3.Mixture III(cool-season and warm-season grasses), mixtureIV(native spp. and Italian ruegrass), and mixtureV(native spp.) resulted in better control of erosion control on man-made slopes. Native spp. has equivallent capacity of erosion control compared to several foreign grasses.

• Journal of Korean Orthopaedic Sports Medicine
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• v.9 no.1
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• pp.48-57
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• 2010

Purpose: To compare the incidence and risk factors for osteoarthritis after anterior cruciate ligament (ACL) reconstruction between two groups using bone-patellar tendon-bone (BPTB) and hamstring tendon (HT) autograft. Materials and Methods: 53 cases of ACL reconstruction using patellar tendon and 40 cases using hamstring tendon were followed up at least 8 years. Radiographic evaluation was done according to the Kellgren and Lawrence's classification. Clinical functional testing (Lysholm Knee Scores, the Tegner activity scores) and laxity testing (Lachman, pivot shift tests), and the instrumented laxity testing with $Telos^{(R)}$ were all examined in relation to the development of osteoarthritis. Results: Radiographic osteoarthritic changes were detected in 24 patients (45.3%) in BPTB group and 14 patients (35.0%) in HT group. Accompanying meniscal injury (BPTB p<0.001; HT p=0.091), intervals from the injury to reconstruction of > 12 months (BPTB p=0.037; HT p=0.021), and patient's age at reconstruction of > 25 years (BPTB p=0.003; HT p=0.048) were found to be significant independent predictors of osteoarthritis. However, no statistically significant correlations were found between the development of osteoarthritis and the clinical outcome or the radiographic stability in both groups. Conclusion: Although ACL reconstruction using BPTB or HT autograft had good clinical results at an average follow-up of 10 years, considerable incidence of radiographic osteoarthritic changes were noted. Various factors such as accompanying meniscal injury, protracted time from injury to reconstruction, more than 25 years old at the time of reconstruction were related to radiographic osteoarthritic changes.

• Composites Research
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• v.12 no.4
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• pp.71-78
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• 1999

To determine the effect of chemical structure of linear amine curing agents on thermal and mechanical properties, standard epoxy resin DGEBA was cured with diaminodiphenyl methane (DDM), diaminodiphenyl sulphone (DDS) in a stoichiometrically equivalent ratio. From this work, the effect of aromatic amine curing agents. In contrast, the results show that the DGEBA/DDS cure system having the sulfone structure between the benzene rings had higher values in the conversion of epoxide, density, shrinkage (%), glass transition temperature, tensile modulus and strength, flexural modulus and strength than the DGEBA/DDM cure system having methylene structure between the benzene rings, whereas the DGEBA/DDM cure system presented higher values in the maximum exothermic temperature, thermal expansion coefficient, and thermal stability. These results are caused by the relative effects of sulfone group having strong electronegativity and methylene group having (+) repulsive property and stem from the effect of the conversion ratio of epoxide group. The result of fractography shows that the each grain size of the DDM/DGEBA system with feather-like structure is larger than that of the DDS/DGEBA system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.441-449
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• 1996

This study was conducted to find the changes of growth, seed yield and several characteristics of sesame by leaf spray of boron as a solution which is likely to be lack in the soil. It is carried out at low land developed 5 years ago. The amount of 200l /l0a boron as boric acid is sprayed in each treatment at the 11 node stage of sesame in main stem. The spraying concentrations of boric acid are 0.0, 0.2 and 0.4% in each treatment of the level low plot and the ridge height 15cm plot. The result shows that leaf area is increased in proportion to the concentration of boric acid in each treatment of the level low and the ridge height 15cm, and the degree of increase of each node order is remarkable in lower leaves and is more remarkable in the treatment of level low plot. The effects of leaf spray of boric acid are not only the increase of leaf area but also dry weight, no. of capsule per plant, 1,000 grains weight of capsule setting under middle position. As a result, the amount of seed is increased in 53% in the treatment of level low. The change of major characteristics according to leaf spray of boric acid is generally great in the treatment of level low. Especially the increase of leaf area in the part of upper leaves and low leaves is effective to improve other characteristics.