• The Journal of Korean Academy of Prosthodontics
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• v.45 no.4
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• pp.506-521
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• 2007

Statement of problem: The cumulative success rate of wide implant is still controversial. Some previous reports have shown high success rate, and some other reports shown high failure rate. Purpose: The aim of this study was to analyze, and compare the biomechanics in wide implant system embeded in different width of crestal bone under different occlusal forces by finite element approach. Material and methods: Three-dimensional finite element models were created based on tracing of CT image of second premolar section of mandible with one implant embedded. One standard model (6mm-crestal bone width, 4.0mm implant diameter central position) was created. Varied crestal dimension(4, 6, 8 mm), different diameter of implants(3.3, 4.0, 5.5, 6.0mm), and buccal position implant models were generated. A 100-N vertical(L1) and 30 degree oblique load from lingual(L2) and buccal(L3) direction were applied to the occlusal surface of the crown. The analysis was performed for each load by means of the ANSYS V.9.0 program. Conclusion: 1. In all cases, maximum equivalent stress that applied $30^{\circ}$ oblique load around the alveolar bone crest was larger than that of the vertical load. Especially the equivalent stress that loaded obliquely in buccal side was larger. 2. In study of implant fixture diameter, stress around alveolar bone was decreased with the increase of implant diameter. In the vertical load, as the diameter of implant increased the equivalent stress decreased, but equivalent stress increased in case of the wide implant that have a little cortical bone in the buccal side. In the lateral oblique loading condition, the diameter of implant increased the equivalent stress decreased, but in the buccal oblique load, there was not significant difference between the 5.5mm and 6.0mm as the wide diameter implant. 3. In study of alveolar bone width, equivalent stress was decreased with the increase of alveolar bone width. In the vertical and oblique loading condition, the width of alveolar bone increased 6.0mm the equivalent stress decreased. But in the oblique loading condition, there was not a difference equivalent stress at more than 6.0mm of alveolar bone width. 4. In study of insertion position of implant fixture, even though the insertion position of implant fixture move there was not a difference equivalent stress, but in the case of little cortical bone in the buccal side, value of the equivalent stress was most unfavorable. 5. In all cases, it showed high stress around the top of fixture that contact cortical bone, but there was not a portion on the bottom of fixture that concentrate highly stress and play the role of stress dispersion. These results demonstrated that obtaining the more contact from the bucco-lingual cortical bone by installing wide diameter implant plays an important role in biomechanics.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.174-179
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• 2008

Purpose : The purpose of this study was to investigate the clinical features of adolescent TB. Methods : We retrospectively reviewed the medical records of the adolescents aged 12 to 18 years and who are hospitalized with the diagnosis of TB at Dong Kang General Hospital between January 2003 and December 2007. Results : Of the 29 patients who were identified, 65.5% were male. The median age at diagnosis was 16.9 years (range: 12.1-18.9 years). A tuberculin skin test (TST) was performed for 6 patients (20.7%). Among them, 5 (5 of 8[62.5%]) in the 12-15 years age group (Group A) and 1 (1 of 21[4.8%]) in the 16-18 years of age group (Group B) were TST positive, which showed that the TST performing rate decreased with age (P<0.01). Twenty-five patients (86.2%) were detected by evaluating the clinical symptoms that suggested TB and 4 patients (13.8%) were detected by screening, but no cases were detected by contact tracing. Twenty patients (69.0%) had isolated pulmonary disease. Seven patients (24.1%) had pulmonary and extrapulmonary disease and 2 patients (6.9%) had exclusively extrapulmonary disease. Most patients presented with multiple symptoms, and the most common were cough (79.3%), fever (75.9%), sputum (65.8%) and chest pain (34.5%). M. tuberculosis was isolated from the sputum of 20 patients (69.0%). The culture-positive rate increased with age (range: 62.5% in Group A to 71.4% in Group B), but the difference between the groups was not significant. Cavitary lesions were found 13 patients (44.8%). The cavitary lesion rate increased with age (range: 25.0% in Group A to 52.4% in Group B), but the difference between the groups was not significant. Four patients (13.8%) were lost during follow-up. One patient (6.9%) relapsed. Conclusion : Clinicians need to be aware of the unique features of adolescent TB, and they also need awareness of the importance of TST and contact investigation for an adult suspected of having TB for making the diagnosis of TB.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.38-61
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• 2019

Up until the early twentieth century in Germany, there were two research trends: 1) emphasizing objectives and making detailed observations of archaeological artifacts and sites, 2) tracing the remains of specific nations or ethnic groups and defining their temporal-spatial boundaries by conducting research on material culture in terms of nationalism or ethnocentrism. After the Second World War ended and Germany was divided, West German archaeology focused on observations of artifacts and sites, cataloging them, and doing research on chronology and distribution following their own traditional methodologies. East German archaeology attempted to prove the developing process of history and its Marxist principles based upon material culture and to examine the historic value of inherent specific cultural heritage based on criteria regarding how it corresponded to socialism and contributed to the development of socialism. Nevertheless, East and West German archaeology shared traditional archaeological methods inherited from German archaeology since the nineteenth century, and contact between archaeologists in West and East Germany continued to a degree. Furthermore, East German archaeology produced significant archaeological achievements acknowledged by West German and European archaeologists. These facts provided the momentum to complete rapid incorporation of the archaeologies of West and East Germany in spite of a one-sided process imposed by West German archaeology. In the case of Korea, it seems necessary to make an effort to share common research history and traditions and to encourage mutual academic exchange (e.g. joint excavation and archaeological research). Furthermore, it is also imperative to have open-minded attitudes toward accepting substantial results and interpretations achieved by North Korean archaeologists under scrutiny when and where necessary, despite seeming to have been fossilized by Marxism and Juche ideology. Any efforts to narrow the gap in archaeological research and conservation of cultural heritage between the archaeologies of South and North Korea should be made immediately. The case of Germany demonstrates how such a project could proceed efficaciously.