• Journal of the Korean Arthroscopy Society
• /
• v.16 no.1
• /
• pp.98-103
• /
• 2012

The repair technique of rotator cuff tear has been markedly developed in recent years. When the natural history of rotator cuff tear was followed, the size of rotator cuff tear increased with time. The fatty infiltration which would come at the later period of rotator cuff tear and the rotator cuff tear arthropathy which would be occurred after massive rotator cuff tear may be the important factors in predicting the prognosis of rotator cuff tear or determining the timing of surgery. Because moderate supraspinatus fatty infiltration appeared an average of 3 years after onset of symptoms, the repair of rotator cuff tear was recommended to be performed before that. And if there was massive rotator cuff tear with cuff tear arthropathy, it was recommended that the rotator cuff repair should be performed before the occurrence of the narrowing of acromiohumeral interval. The techniques of arthroscopic rotator cuff repair were mainly the single row repair and the double row repair. The former is good in view of time consuming and cost, but the latter is superior in view of biomechanics. To maintain the benefit in biomechanics of double row technique and reduce the time of surgery, the suture-bridge technique was invented and widely used recently. There are several modified techniques in arthroscopic suture-bridge technique according to the characteristics of rotator cuff tear.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.34 no.1
• /
• pp.156-161
• /
• 2007

Pediatric dentists are frequently encountered with fractured root fragments of primary teeth caused either by the traumatic injuries or by the accidental fractures during the procedure of tooth extractions. In these situations, we often hesitate which method to choose, extract or retain it. In general, it is recommended to retain apical fragments, as the attempts to extract the apical fragments might harm the developing permanent tooth germ. This study was designed to ensure the validity of intentional retention of the root fragments of primary teeth in the situations described above. 6 children with intentionally root fragments who experienced root fracture in primary anterior teeth were available Periodic radiographic assessment was performed at 3 months interval for $7{\sim}37$ months. The results of this study showed that apical fragments had been resorbed through physiologic process in 5 patients. Apical fragment had been gingival emergence along with the erupting permanent tooth in 1 patient. There were no evidence of interference with eruption of permanent successors. In summary we have been ensured the validity of intentionally retention of the root fragments of primary teeth. Children with being remained apical root fragment should be recalled regularly for assessment and parents should be thoroughly informed about the situation with special emphasis on the necessity of periodic check-up.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.1
• /
• pp.43-52
• /
• 2006

Topical fluoride application for children is a widely peformed procedure in the field of pediatric dentistry to prevent dental caries. However, it is recently recognized as having some unwanted effects on several esthetic restorative materials as it roughens the surface of the restorative materials. The aim of this study was to evaluate the surface changes in composite resins to topical fluoride. Composite resins(Z $250^{(R)}$, Ultraseal $XT^{(R)}$ Filtek $flow^{(R)}$ $Revolution^{(R)}$, $Denfil^{(R)}$) in topical fluoride agents were immersed and their surface roughness, weight loss and SEM were evaluated. The results were as follows : 1. The 4 minutes-immersion groups showed more roughened surface than 1 minute-immersion groups and the control groups showed the smoothest surface among all the materials, and there was statistically significant difference except the revolution between the groups. 2. There was no significant difference between the 1 minute-immersion groups and 4 minutes-immersion groups in weight loss. 3. The experimental group treated with topical fluoride gel showed the generally mere roughened surface than control group in the SEM findings.

• Applied Chemistry for Engineering
• /
• v.17 no.2
• /
• pp.150-157
• /
• 2006

The alternate plating method was suggested by a tin-cobalt alloy plating process which has excellent mechanical characteristics and also favorable to environment. Tin-cobalt alloy plating has many advantages such as nontoxicity, variable color-tone, and no post-treatment process. In this study, the plating conditions such as temperature, pH, current density, plating time, and amount of additive (glycine) were determined in the tin-cobalt alloy plating process through Hull-cell test and surface analysis. As the result of Hull-cell analysis, brightness became superior as the amount of glycine increased. It was found that the optimum alloy ratio was 0.03 M of $SnCl_{2}{\cdot}2H_{2}O$ and 0.05 M of $CoSO_{4}{\cdot}7H_{2}O$ at $50^{\circ}C$, pH 8.5, and $0.5A/dm^2$. The optimum amount of additive was 15 g/L of glycine and 0.1 g/L of organic acid. Then, the solution including glycine was recommended as an optimum plating solution for a chromium plating process.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.4
• /
• pp.260-267
• /
• 2013

BACKGROUND: In most studies, soil carbon sequestration has been evaluated simply with change of soil organic carbon content. So far, information regarding stability of soil organic carbon is limited. METHODS AND RESULTS: This study was conducted to determine changes in soil organic carbon (SOC) content and stability of carbon in response to compost application rates and plastic mulching treatment during the hot pepper growing season. Under the pot experiment condition, compost was mixed with an arable soil at rates corresponding to 0, 10, 20, and 40 Mg/ha. To determine effects of plastic mulching on soil carbon sequestration, plastic mulching and no mulching treatments were set up in soils amended with the application rate of 20 Mg/ha. The SOC content did not significantly increase with application of compost and plastic mulching at harvest time. No significant changes in bulk density with compost application and plastic mulching was found. These might result from short duration of experiment. While hot water extractable organic carbon content significantly decreased with compost application and plastic mulching, humic substances increased. Belowground biomass of hot pepper was biggest at the recommended application rate (20 Mg/ha) of compost. CONCLUSION: From the above results, continuous application of compost at the recommended application rate could improve increase in SOC content and stability of carbon in long term aspect.

• Journal of the Korean earth science society
• /
• v.34 no.1
• /
• pp.41-50
• /
• 2013

To analyze the distribution pattern of flood sediment deposits near the mouth of Chucheoncheon (river), side scan sonar images and seafloor sediment properties were investigated in the offshore area within about 50 m deep in water. Based on the analysis result of the sonar images, the seafloor of the study area is divided into three areas of basement, sandy-mud, and dispersed flood sediment. The colors of sonar images in each area are represented by dark black, light grey, and greyish black, respectively. The sediment composition in the grey black area shows 33.73% of gravel, 62.88% of sand, 3.37% of silt, and 0.02% of clay. On the other hand, the composition of the light grey area is 10.31% of sand, 56.42% of silt, and 33.27% of clay. Especially the sediment of the grey black area contains the considerable amount of burned plant fragments in black color, which could distinctly be differentiated from those in the offshore. The distribution pattern of the flood sediment deposits suggests that the land-originated detrital sediments seem to be transported from the Chucheon river into offshore along the shore rather than transversely. In conclusion, the longshore current of the study area is probably dominant to affect the spatial distribution of bottom features.

• Childhood Kidney Diseases
• /
• v.7 no.1
• /
• pp.60-66
• /
• 2003

Purpose : Neonatal hydronephrosis has been detected with increasing frequency with the widespread use of prenatal ultrasonography, but the consensus about its postnatal management has not yet been reached, especially about surgical intervention. We attempted to determine the guideline of follow-up study and surgical intervention of hydronephrosis by analyzing clinical outcomes of neonates with hydronephrosis. Materials and Methods : Between 1994 and 2000, 128 hydronephrotic kidneys were postnatally confirmed. Cases associated with other urologic anomalies were excluded and 90 unilateral hydronephrotic kidneys with a minimum follow-up of 12 months were enrolled in this study. We classified the patients into 6 groups according to the anterior posterior pelvic diameter(APPD) at initial ultrasonography(USG) within 1 month after birth. Renal USG and $Tc^{99m}-mercaptoacetyl$ triglycerine(MAG3) scan were done according to a set protocol, and pyeloplasty was performed when indicated according to our protocol. Results : Most cases whose APPD were below 10 mm improved or resolved. Only few cases with APPD above 20 mm showed spontaneous improvement and most(88%) had undergone operation. Those with initial APPD within 10-19 mm showed variable outcomes. When the risk factors for irreversible renal functional deterioration were analyzed, the age at pyeloplasty and pre-operative functional deficit were significant. Conclusion : We concluded that in infants with initial APPD below 10 mm, consideration of surgery is not needed, and in those with initial APPD above 20 mm, early operation is recommended. Our set protocol based on initial USG is useful, but the cut-off value of relative renal function(RRF) for operation might be increased to 40% to improve post operative RRF.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.35 no.3
• /
• pp.160-169
• /
• 2019

Purpose: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. Materials and Methods: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. Results: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. Conclusion: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.

• Journal of The Korean Association of Information Education
• /
• v.19 no.2
• /
• pp.175-186
• /
• 2015

In this study, we developed the PATROL teaching and learning model by using digital textbooks in Smart Classrooms to correct the disadvantages of Flipped Classrooms. PATROL is an acronym for Planning, Action, Tracking, Recommending, Ordering, and Leading. In the Planning phase, teachers should make a lesson plan. Next, students take Action by watching online contents and completing assignments in their digital textbook. After that, Tracking is needed to analyze the students' activities and the results. Then, Recommending is used to provide suggested instructional activities to teachers based on that analysis. Next, Ordering requires that students request new materials for class activities. Finally, Leading allows teachers to provide materials at the appropriate level to their students based on the students' learning activities. Applying the PATROL model at two elementary schools resulted in an increase in student-directed speech as well as an increase in the number of group and individual activities. Teachers also had more time to walk around the classroom.

• Journal of Chest Surgery
• /
• v.36 no.3
• /
• pp.202-205
• /
• 2003

Deep vein thrombosis (DVT) is a common disease. However, May-Thurner syndrome, which is the cause of DVT, is an uncommon processes in which there is an impaired venous return due to compression of the left iliac vein by the overlying right common artery. This condition results in a left iliofemoral deep thrombosis and severe leg edema. It is, therefore, called iliac compression syndrome. Catheter-directed thrombolytic therapy of acute extensive iliofemoral DVT and balloon angioplasty with venous stenting are recommended. Two cases with history of left leg swelling are diagnosed as May-Thurner syndrome, which was demonstrated by venography. We successfully treated the patients with thrombolysis, balloon angioplasty, and stent insertion at the site of common iliac vein compression. Therefore, we report the cases with overall review of the literature.