• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.177-185
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• 2014

Purpose: This study is designed to investigate the various impacts of different types of scaler tips such as cooper alloy base tip and the others on the surface roughness of teeth and implant by the method which is currently in clinical use. Materials and methods: Four different types of disc shaped porcelain, titanium, zirconia, and Type III gold alloy dental materials sized 15 mm diameter, 1.5 mm thickness were used for the experiment. Plastic hand curette (Group PS), cooper alloy new tip (Group IS), and stainless steel tip (Group SS) were used as testing appliances. A total of 64 specimens were used for this study; Four specimens for each material and appliance group. Surface roughness was formed with 15 degree angle in ultrasonic scaler tip and with 45 degree angle in hand curette of instrument tip and the specimen surface with 5 mm long, one horizontal-reciprocating motion per second for 30 seconds by 40 g force. To survey the surface roughness of each specimen, a field emission scanning electron microscope, an atomic force microscope, and a surface profiler were used. (Ra, ${\mu}m$). Results: According to SEM, most increased surface roughness was observed in SS group while IS groups had minimal roughness change. Measurement by atomic force microscope presented that the surface roughness of SS group was significantly greater than those of PS, IS and control groups in the type III gold alloy group (P<.05). IS group showed lesser surface roughness changes compared to SS group in porcelain and gold alloy group (P<.05). According to surface profiler, surface roughness of SS group showed greater than those of PS, IS and control groups and IS group showed lesser than those of SS group in all specimen groups. Type III gold alloy group had large changes on surface roughness than those of porcelain, titanium, zirconia (P<.05). Conclusion: The result of this study showed that newly developed copper alloy scaler tip can cause minimal roughness impacts on the surface of implant and dental materials; therefore this may be a useful alternative for prophylaxis of implant and restored teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.102-107
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• 2009

In clinical pediatric dentistry, we have many chances to encounter the white spot like incipient enamel lesions on the mesial surfaces of the 1st molars with direct vision, especially just after the 2nd primary molars were exfoliated. But it was thought highly desirable to assess if these lesions are properly and effectively managed yet. This study aims at surveying the prevalence of incipient lesions on the mesial surfaces of the 1st molars in children through direct observation and examining the suitability of adhesive sealing on them as a pilot trial in searching for their proper management. 1. Among the 124 mesial surfaces of the 1st molars examined, 34% were sound, 53% had incipient carious lesions and 13% had cavitated lesions. 2. In the sectional views of the specimens, 20% showed microleakage after thermo-cycling and it was thought not recommendable as a permanent method. Therefore in order to effectively fight against the incipient caries lesions in children‘s permanent teeth, it was thought proper not to rely on any one method, but to perform reinforcing oral hygiene and promotion of remineralization in combination with therapeutic sealing which is stronger in short-term sealing effect. Although therapeutic sealing has been considered as the core in minimally invasive concept to treat the white spot lesions, its long-term clinical trials have not been suggested. Continuous research is strongly required for making this approach to acquire permanent nature, especially in regards of proper pretreatment and high molecular materials deeply penetrable into enamel.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.75-80
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• 2005

Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.

• Journal of Life Science
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• v.32 no.1
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• pp.1-10
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• 2022

Natural products have gained increasing attention due to their advantage of long-term safety and low toxicity for a very long time. Torreya nucifera is widespread in southern Korea and Jeju Island and its seeds are commonly used as edible food. Oriental ingredients have often been reported for their insecticidal, antioxidant and antibacterial properties, but there have not yet been any studies on their antidiabetic effect. In this study, we investigated several biological activities of T. nucifera pericarp (TNP) and seeds (TNS) extracts and proceeded to characterize the antidiabetic compounds of TNS. The initial results suggested that TNS extract at 15 and 10 ㎍/ml concentration has inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, that is 14.5 and 4.35 times higher than TNP, respectively. Thus, the stronger antidiabetic TNS was selected for the subsequent experiments to characterize its active compounds. Ultrafiltration was used to determine the apparent molecular weight of the active compounds, showing 300 kDa or more. Finally the mixture was then partially purified using Diaion HP-20 column chromatography by eluting with 50~100% methanol. Therefore we concluded that the active compounds of TNS have potential as therapeutic agents in functional food or supplemental treatment to improve diabetic diseases.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.2
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• pp.176-184
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• 1997

Abnormal illness behavior in patients with somatoform disorders were known formed by their traditional disease concepts and somatization-prone socio-cultural factors. The authors evaluated the characteristics of abnormal illness behavior in patients with somatoform disorders(who had somatization) by using abnormal illness behavior questionnaire. Methods : 29 somatoform disorders(SD) and 57 disease controls were compared by clinical characteristics, severity of pain, state anxiety(by Spielberger's State & Trait Anxiety Inventory), depression(by Beck's Depression Inventory) and level of psychosocial stess(by DSM-III-R). The illness behavior was measured by illness Behavior Questionnaire(IBQ). Results SD group had longer period of somatic symptoms with less severity in pain. The degree of anxiety and depression were higher in SB compared with controls. However, the degree of psychosocial stress was almost same between both groups. In IBQ, SD showed higher scores in general hypochondriasis, disease conviction, and affective disturbance subscales compared to control group. Conclusion: High disease conviction and hypochondriacal nature revealed by IBQ seemed to be a role in making somatization by way of somatic focusing and hypervigilance. And those tended to lead patients visit hospital frequently and report various somatic complaints. Evaluating abnormal illness behavior in somatoform disorders would be not only helpful in understanding the natures of somatoform disorders but also useful differentiating SD with other psychiatric conditions.

• The korean journal of orthodontics
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• v.36 no.5
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• pp.339-348
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• 2006

Objective: With development of the skeletal anchorage system, orthodontic mini-implant (OMI) assisted on masse sliding retraction has become part of general orthodontic treatment. But compared to the emphasis on successful anchorage preparation, the control of anterior teeth axis has not been emphasized enough. Methods: A 3-D finite element Base model of maxillary dental arch and a Lingual tipping model with lingually inclined anterior teeth were constructed. To evaluate factors influencing the axis of anterior teeth when OMI was used as anchorage, models were simulated with 2 mm or 5 mm retraction hooks and/or by the addition of 4 mm of compensating curve (CC) on the main archwire. The stress distribution on the roots and a 25000 times enlarged axis graph were evaluated. Results: Intrusive component of retraction force directed postero-superiorly from the 2 mm height hook did not reduce the lingual tipping of anterior teeth. When hook height was increased to 5 mm, lateral incisor showed crown-labial and root-lingual torque and uncontrolled tipping of the canine was increased.4 mm of CC added to the main archwire also induced crown-labial and root-lingual torque of the lateral incisor but uncontrolled tipping of the canine was decreased. Lingual tipping model showed very similar results compared with the Base model. Conclusion: The results of this study showed that height of the hook and compensating curve on the main archwire can influence the axis of anterior teeth. These data can be used as guidelines for clinical application.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.467-473
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• 2004

Background: The sinus conversion rate after the maze procedure in chronic atrial fibrillation using radiofrequency energy is lower than with either conventional 'cut and saw' technique or cryothermia. The creation of incomplete transmural lesions due to poor tissue-catheter contact is thought to be the main cause. To address this problem, the current study was aimed to evaluate the effectiveness of a specially constructed compression device designed to enhance tissue catheter contact during unipolar radiofrequency catheter ablation. Material and Method: Circum-ferential right auricular epicardial lesions were created with a linear radiofrequency catheter in 10 anesthetized pigs. A device specially designed to increase contact by compression of the catheter to the atrial wall was used in 5 pigs (study group). This device was not used in the control group (5 pigs). Conduction block across the right auricular lesion was assessed by pacing, and the transmurality of the lesions were confirmed by microscopic examination. Result: Conduction block was observed in a total of 8 pigs; 5 in study group and 3 in control group. Transmural injury was confirmed microscopically by the accumulation of acute inflammatory cells and loss of elastic fibers in the endocardium. In two pigs with failed conduction block, microscopic examination of the endocardium appeared normal. Conclusion: Failed radiofrequency ablation is strongly related to non-transmural energy delivery. The specially constructed compression device in the current study was successful in creating firm tissue-catheter contact and thereby generating transmural lesions during unipolar radiofrequency ablation.

• Tuberculosis and Respiratory Diseases
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• v.57 no.4
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• pp.311-319
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• 2004

Background : It has been well known that bronchiectasis (BE) is a predisposing condition for pulmonary NTM infection, whereas there are some suggestions that BE, especially nodular BE, may be a result of NTM pulmonary infection. This retrospective study was done to investigate the prevalence of NTM pulmonary infection in the patients with BE. Methods : Eight hundred sixty-six patients, who underwent chest CT and sputum AFB examination and had BE detected by chest CT at Asan Medical Center in 2002, were included in this study. They were divided into Group I (bilateral BE, especially in RML, lingular or both lower lobes; 134), Group II (BE accompanied with fibrocavitary lesions commonly found in tuberculosis, usually both upper lobes; 233) and Group III (except Group I, II; 499) according to the radiological findings. Group I was subdivided into Group I+ (62) or Group I- (72) according to the presence or absence of centrilobular nodules, respectively. The sputum AFB examination, clinical and radiological findings were analyzed and compared between groups. Results : The number of patients who had at least one positive NTM culture was significantly higher in Group I+ compared with others (p<0.05); 24.2% in Group I+, 6.9% in Group I-, 9.9% in Group II, 6.0% in Group III and 4.1% in control. The number of patients who had true NTM infection defined by ATS guideline was higher in Group I+ (5, 8.1%) compared with others (p<0.05). In all groups, M. avium-intracellulare comlex was the most common isolates. Conclusion : Even though true NTM pulmonary disease was more prevalent in the patients with nodular BE, especially located in RML, left linguar, or both lower lobes, only a small population of the patients with nodular BE met the ATS diagnostic criteria for NTM pulmonary disease. The other patients in nodular BE group may have subclinical stage of NTM infection or completely different diseases from NTM infection. Long-term clinical studies are needed to clarify this issue.

• Journal of Chest Surgery
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• v.36 no.4
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• pp.261-266
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• 2003

Background: Surgery of abdominal aortic aneurysm revealed high operative mortality. We reviewed our 11-years' experiences of abdominal aortic aneurysm operation and wish to obtain information on the treatment. Material and Method: From Jan. 1990 to Dec. 2000, 48 patients were operated due to abdominal aortic aneurysm in Yonsei Cardiovascular Center Mean age was $62.8{\pm}12.7$ and there were 40 males and 8 females. Among 48 patients, nine patients had ruptured abdominal aortic aneurysm, and mean aneurysm diameter of non-ruptured cases was $8.8{\pm}2.4$cm. Result: There were 6 early deaths, and early mortality was 12.5%. Among 9 patients of preoperative aneurysm rupture, three patients died (33.3%), and among 39 patients of non-ruptured cases, 3 patients died (7.7%). Among preoperative variables, age (p<0.05), preoperative BUN level (p<0.05), and DM (p<0.05) were risk factors of early mortality. Among discharged 42 patients, 40 patients were followed up (f/u rate=95.2%) and mean follow up was $3.6{\pm}0.2$ years. During follow up periods, five patients died (late mortality=11.9%), and Kaplan-Meier survival analysis revealed $81.7{\pm}7.6$% survival rate at five and ten year. Linealized incidence of graft related event was 3.53% per patient-year. Conclusion: Surgical mortality of ruptured abdominal aortic aneurysm was higher than non-ruptured cases; therefore, early resection of the aneurysm can decrease the surgical mortality.

• Journal of Life Science
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• v.26 no.1
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• pp.109-116
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• 2016

Ulmi cortex is the elm bark or root bark of Ulmus macrocarpa Hance and has been used as an ingredient of traditional medicine for anti-inflammatory, analgesic, anti-cancer and wound healing on both the East and the West. This study investigated whether the Ulmus macrocarpa Hance Water extract (UMWE) has the in vivo and in vitro immune activating effect. Animals were orally administrated for 14 days as follows: no treat group with distilled water, cyclophosphamide (CY) group with 120 mg/kg of CY, UMWE 100+CY group with 100 mg/kg of UMWE and 120 mg/kg of CY, UMWE 200+CY group with 200 mg/kg of UMWE and 120 mg/kg of CY, UMWE 100 group with 100 mg/kg of UMWE and UMWE 200 group with 200 mg/kg of UMWE. The immunosuppressive drug CY was intraperitoneally injected to induce immune suppression. Spleen indices showed small changes in CY injected groups but splenocyte indices showed greater decrease in the same groups. However, UMWE appeared to relieve CY’s immunosuppression. UMWE also delayed in vitro splenocyte death increasing its longevity. These data obtained by MTT assay and 7-amino-actinomycin D which stains preferentially dead than live cells. UMWE alone did not show cytotoxicity based on its apoptototic effect on splenocytes in vitro and in vivo. Splenic NK cell activity was maintained by UMWE under the presence of CY in vitro. The data indicated that UMWE protects splenocytes from the immunosuppressive drug CY under in vitro and in vivo conditions.