• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.2027-2032
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• 2007

[ ${\alpha}$ ]-Synuclein is the major component of Lewy bodies and responsible for the amyloid deposits observed in Parkinson's disease. Ordered filamentous aggregate formation of the natively unfolded ${\alpha}$-synuclein was investigated in vitro with the periodic ultrasonication. The ultrasonication induced the fibrillation of ${\alpha}$-synuclein, as the random structure gradually converted into a ${\beta}$-sheet structure. The resulting fibrils obtained at the stationary phase appeared heterogeneous in their size distribution, with the average length and height of $0.28\;{\mu}m{\pm}0.21\;{\mu}m$ and $5.6\;nm{\pm}1.9\;nm$, respectively. After additional extensive ultrasonication in the absence of monomeric ${\alpha}$-synuclein, the equilibrium between the fibril formation and its breakdown shifted to the disintegration of the preexisting fibrils. The resulting fragments served as nucleation centers for the subsequent seed-dependent accelerated fibrillation under a quiescent incubation condition. This self-seeding amplification process depended on the seed formation and subsequent alterations in their properties by the ultrasonication to a state that accretes the monomeric soluble protein more effectively than their reassociation of the seeds back to the original fibrils. Since many neurodegenerative disorders have been considered to be propagated via the seed-dependent amyloidosis, this study would provide a novel aspect of the significance of the seed structure and its properties leading to the acce]erated amyloid formation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.6
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• pp.570-578
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• 2006

A severely atrophic maxilla may disturb the proper implant placement. The various bone graft techniques are required for simultaneous or delayed implantation in the cases of atrophic alveolar ridges. We present 11 consecutive patients treated with simultaneous implantation using the autogenous inlay and/or onlay bone grafts from iliac crest to the floor of the maxillary sinus and the alveolar crest. In the cases of atrophic maxilla, a total 69 implants were simultaneously placed with autogenous iliac bone graft. 40 fixtures were inserted in the sinus floor simultaneously with subantral block bone graft, the other 29 fixtures were placed in the anterior or premolar areas with block or particulate bone graft. The vertical alveolar bone height was measured with Dental CT at the preoperation and 6 months postoperation. Moreover, the implant stability quotients (ISQ) were measured by $Osstell^{TM}$ during second implant surgery at 6 months later of first implantation. All implants were obtained successful osseointegration with the grafted bone. The mean vertical increases were 3.9mm in the anterior ridges and 12.8mm in the posterior ridges. During the second implant surgery, mean ISQ were 62.95 in the anterior ridge and 61.32 in the posterior ridge. We concluded that the simultaneous implantation with autogenous iliac bone graft were stable and available methods for severely atrophic maxilla.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.1
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• pp.85-92
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• 2005

Reconstruction of defect in the anterior part of the maxilla to enable implant placement or prothesis is a complicated treatment due to the anatomical position and lack of soft tissues. Two cases are presented in which autogenous iliac PMCB(particulate marrow and cancellous bone) with titanium mesh were used for premaxilla reconstruction and alveolar bone repair of the anterior maxillas prior to denture and implants fixation respectively. Cancellous bone from the anterior iliac crest was compressed and placed against a titanium mesh fixed to the bone of palate in a patient with severe defect of the anterior maxilla. There were no problem in the healing, and the anterior maxillas of two patients had increased height and width during the initial healing and remodeling. The clinical reports describe the use of titanium mesh for reconstruction of premaxilla. Autogenous bone grafts were harvested from the iliac crest and were loaded on a titanium mesh that were left in the patient's maxilla for 6 months before they were removed respectively. The radiographic analysis demonstrated that a 10mm vertical ridge augmentation had been achieved. In guided bone regeneration, the quantity of bone regenerated under the barrier has been demonstrated to be directly related to the amount of the space under the membrane. This space can diminish as a result of membrane collapse. To avoid this problem which involved the use of a titanium mesh barrier to protect the regenerating tissues and to achieve a rigid fixation of the bone segments, were used in association with autologous bone in 2 cases. The aim of this study was to evaluate the capability of a configured titanium mesh to serve as a mechanical and biologic device for restoring a vertically defected premaxilla.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.211-219
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• 2017

Objective : This study aimed to compare the clinical and radiologic outcomes of patients with subaxial cervical injury who underwent anterior cervical discectomy and fusion (ACDF) with autologous iliac bone graft or polyetheretherketone (PEEK) cages using demineralized bone matrix (DBM). Methods : From January 2005 to December 2010, 70 patients who underwent one-level ACDF with plate fixation for post-traumatic subaxial cervical spinal injury in a single institution were retrospectively investigated. Autologous iliac crest grafts were used in 33 patients (Group I), whereas 37 patients underwent ACDF using a PEEK cage filled with DBM (Group II). Plain radiographs were used to assess bone fusion, interbody height (IBH), segmental angle (SA), overall cervical sagittal alignment (CSA, C2-7 angle), and development of adjacent segmental degeneration (ASD). Clinical outcome was assessed using a visual analog scale (VAS) for pain and Frankel grade. Results : The mean follow-up duration for patients in Group I and Group II was 28.9 and 25.4 months, respectively. All patients from both groups achieved solid fusion during the follow-up period. The IBH and SA of the fused segment and CSA in Group II were better maintained during the follow-up period. Nine patients in Group I and two patients in Group II developed radiologic ASD. There were no statistically significant differences in the VAS score and Frankel grade between the groups. Conclusion : This study showed that PEEK cage filled with DBM, and plate fixation is at least as safe and effective as ACDF using autograft, with good maintenance of cervical alignment. With advantages such as no donor site morbidity and no graft-related complications, PEEK cage filled with DBM, and plate fixation provide a promising surgical option for treating traumatic subaxial cervical spine injuries.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4B
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• pp.353-360
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• 2011

The objectives of this study were to analyzes temporal variation of local scour depth in the downstream of weir with shapes. Prediction of maximum or equilibrium scour depth was the main focus of engineers and researchers in the downstream of weir. However, it is necessary to analyzes temporal variation of local scour depth in the downstream of weir to predict real time scour depth. Experiment were performed with various weir shapes like sharp crest and inclined stepped with time variation and non-dimensional scourhole shapes, scour depths were proposed. A formula for predicting scour depths with temporal variation for weir were proposed through non-linear regression analysis. Temporal variation of scour depths could be estimated with suggested formula and 4 input data (Equilibrium scour depth, weir height, overflow depths, and water depth downstream). Suggested formula could make it possible to design a apron and bed protection economically in the downstream of a weir by considering flood duration time.

• Imaging Science in Dentistry
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• v.51 no.2
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• pp.175-185
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• 2021

Purpose: The primary objective of this study was to analyze the thickness and height of alveolar bone around the maxillary and mandibular incisors. Additionally, this study aimed to compare bone parameters between Caucasian (CC) and African American (AA) female patients. Materials and Methods: In this retrospective pilot study, 50 female subjects(25 CC and 25 AA) were included. The inclusion criteria were AA or CC women between the ages of 18 and 50 with a normo-divergent facial pattern and Angle's class I, end-on class II, or mild class III malocclusion. The distance from the cementoenamel junction (CEJ) to the buccal and lingual alveolar crest; the alveolar ridge thickness at the mid-root and apex; and the buccal and lingual bone thickness at 3, 6, and 9mm from the CEJ were measured. Results: No significant difference was found (P>0.05) in the cortical bone thickness at 3mm, 6mm, or 9mm from the alveolar crest between CC and AA populations for most measurements. A significant difference in bone thickness was found (P<0.05) for the lingual surface of the central incisor, with maxillary bone thickness found to be higher than mandibular bone thickness. The measurements of lingual thickness were larger than those of buccal thickness for both races. Conclusion: There were no differences in maxillomandibular anterior alveolar bone measurements between normo-divergent adult AA and CC women, except for a few parameters at varying locations. However, future studies can be planned based the current pilot study data, which may provide valuable information.

• Journal of the Earthquake Engineering Society of Korea
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• v.27 no.3
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• pp.147-155
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• 2023

This study aims to present a method to evaluate the relative risk of failure due to liquefaction of domestic small to medium-sized earthfill dams with a height of less than 15 m, which has little information on geotechnical properties. Based on the results of previous researches, a series of methods and procedures for estimating the probability of dam failure due to liquefaction, which calculates the probability of liquefaction occurrence of the dam body, the amount of settlement at the dam crest according to the estimation of the residual strength of the dam after liquefaction, the overtopping depth determined from the amount of settlement at the dam crest, and the probability of failure of the dam due to overtopping was explicitly presented. To this end, representative properties essential for estimating the probability of failure due to the liquefaction of small to medium-sized earthfill dams were presented. Since it is almost impossible to directly determine these representative properties for each of the target dams because it is almost impossible to obtain geotechnical property information, they were estimated and determined from the results of field and laboratory tests conducted on existing small to medium-sized earthfill dams in previous researches. The method and procedure presented in this study were applied to 12 earthfill dams on a trial basis, and the liquefaction failure probability was calculated. The analysis of the calculation results confirmed that the representative properties were reasonable and that the overall evaluation procedure and method were effective.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.432-439
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• 2012

Purpose: The aim of this study was to investigate the blood supply to the maxillary sinus in Koreans using computed tomography of the lateral wall of the sinus, and to analyze the data according to demographic data, and to compare our results with previously published research. Methods: One hundred and three patients (males 51, females 52) who visited the dental clinic were evaluated. We investigated the canals with cone-beam computed tomography, and measured the diameter and length from the bony notch of the vascular canal at the lateral wall of the sinus to each of the reference planes. Results: Most types of vascular canal were type I & II (total 72.2%) which were driving through inside the sinus wall. Type IV, V were frequently investigated in 1st premolar and 2nd molar. Mean height; from anterior nasal spine-posterior nasal spine plane to vascular canal was 5.56 mm in 1st premolar, 2.11 mm in 2nd premolar, 0.98 mm in 1st molar, 4.32 mm in 2nd molar; from the basal layer of the sinus was 4.93 mm in 1st premolar, 5.00 mm in 2nd premolar, 6.05 mm in 1st molar, 7.91 mm in 2nd molar; and from alveolar crest, 20.80 mm in 1st premolar, 16.57 mm in 2nd premolar, 14.01 mm in 1st molar, 16.17 mm in 2nd molar. The mean height of the vascular canal of each reference plane showed no significant difference between sex, site (left or right) and age. The mean diameters of the canals were 1.76 mm in male, and 1.50 mm in female. Diameter decreased with age, and tooth site (from 1st premolar to 2nd molar). Conclusion: These results show that the mean diameter of the vascular canal of the maxillary sinus varies according to age, sex, and tooth site, but that the mean height of canal had no significant difference based on these three factors.

• The Journal of Pediatrics of Korean Medicine
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• v.31 no.4
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• pp.31-38
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• 2017

Objectives The purpose of this study was to find out the clinically reliable relationships between the Risser sign and chronological age, bone age, menarche, and adult height prediction (AHP) and to evidence the reliability of the Risser sign. Methods This study had been carried out with 50 children who had their growth checked in an oriental medical hospital from January 2015 to February 2017. We investigated Risser sign in AP X-rays with iliac crest, bone age, AHP for all 50 children and the timing of menarche from the 22 girls in the study subjects. We also investigated a correlation between the Risser stage and the other indicators to analyze statistical data. Results The mean chronological ages of Risser 1, 2, 3 and 4 were 11.2, 12.6, 14.4, and 15.5 years respectively for the boys and 10.8, 12.2, 13.8 and 14.8 years respectively for the girls. The mean bone ages of Risser 1, 2, 3 and 4 were 12.3, 13.6, 15.7 and 16.5 years respectively for the boys and 11.7, 13.8, 14.3 and 14.9 years respectively for the girls. We analyzed 22 girls' Risser stages in accordance with the duration from menarche. The result showed that in the first six months after menarche, all girls were in Risser 1 and 2; in the next six months, the girls were in Risser 2 on average; in the next 12 months, all girls were in Risser 3 and 4; after more than two years from menarche, all girls were in Risser 4. The mean remaining growth height of Risser 1, 2, 3 and 4 were 27.8, 17.3, 4.4 and 1.0 cm respectively for the boys and 14.5, 5.1, 3.1 and 1.1 cm respectively for the girls. The Risser stage was correlated strongly with chronological age (Spearman's rho=0.707 (boy), 0.841 (girl)), bone age (Spearman's rho=0.869 (boy), 0.875 (girl)), duration from menarche (Spearman's rho=0.909) and remaining growth height (Spearman's rho=-0.784 (boy), -0.878 (girl)). Conclusions This study showed that the Risser sign can be useful in assessing skeletal maturity and predicting remaining growth height based on the Risser stage and the other growth indicators.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.209-217
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• 1999

This study was concerned with comparing the measured values of labial alveolar bone through the lateral cephalometric radiography and mandibular incisor cross-sectional tomogram between two groups, one group of mandibular prognathism patients who needed an orthognathic surgery as an experimental group and the other group who had normal molar relationships as a control group. The purpose of the study was to find out the predisposing factor of bone resorption and gingival recession before orthodontic treatment. The results were as follows: 1. The cross-sectional area of labial alveolar bony plate in mandibular prognathism was significantly smaller than that of control group. 2. In mandibular prognathism, the distance between cementoenamel junction and alveolar crest was significantly greater than control group. 3. There were negative correlations between area of labial alveolar bony plate and distance from cementoenamel junction to alveolar crest, and positive correlations between area of labial alveolar bony plate and distance from alveolar crest to root apex. 4. In mandibular prognathism, there were positive correlations between IMPA and thickness of symphysis, and negative correlations between IMPA and the alveolar bony height. The results of the present study suggest the mandibular prognathism patients are prone to the gingival recession due to the small amount of labial alveolar bone around lower incisors.