• 한국생산제조학회지
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• 제25권6호
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• pp.434-439
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• 2016

Optical fiber splice closure serves to protect connection parts from external environment. Moreover, it functions as a connection, junction, and distribution in diverse surroundings such as aerial, underground, duct, and pole. In this research, first, the optical fiber splice closure, its configuration, and the design problem were briefly investigated. Second, the design and application for in-line cable closure were studied to satisfy its construction and technical features. The injection molding conditions and optimal design were conducted to save time and cost during the manufacturing process. Third, methods to minimize loss via of optical fiber cable while strongly fixing optical fiber cable with optical cable holder to prevent fracture were researched, and tests such as perfect air tightness and mechanical and environmental performance were conducted.

• Journal of Chest Surgery
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• 제22권5호
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• pp.760-765
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• 1989

Cardiac injury remains one of the most spectacular injuries which the present day cardiac surgeon is called upon to treat. Eight consecutive patients with penetrating or blunt injury to the heart underwent operation at the Department of Thoracic and Cardiovascular Surgery, Masan Koryo General Hospital from April 22 88 to April 6 89. l. Among the 8 cases of cardiac injured patients, 7 cases were penetrating injury [stab injury] and one case was blunt injury [traffic accident]. 2. The site of cardiac injury was LV mainly and the next RV, SVC-RA junction in order. 3. The all patients were admitted to our hospital via ER and most of cases, CVP was elevated above 15 cmH2O and 7 of 8 cases were shock state. 4. In 6 of 8 cases revealed cardiomegaly in simple chest X * ray. 5. 7 cases were operated through the median sternotomy, 1 case the right anterolateral thoracotomy. 6. Associated injuries in penetrating cardiac injury were hemothorax, pneumothorax, sternal fracture, lung laceration, LAD transaction in blunt injury, hemoperitoneum.

• 대한정형외과스포츠의학회지
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• 제5권2호
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• pp.155-160
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• 2006

목적: 경골과 골절과 동반된 외측 반월상 연골 손상에서 봉합술 및 부분 절제술 후 치료 결과를 분석 하고자 하였다. 대상 및 방법: 1953년 2월부터 2004년 8월까지 경골과 골절로 치료 한 23명, 24예의 외측 반월상 연골 파열을 대상으로 하였다. 파열의 형태는 반월상 연골-관절낭 경계부의 종 파열 (14예, 66.7%)이 가장 많았다. 모든 골절은 관절경과 영상 증폭기의 감시하에 정복을 하였으며 반월상 연골 종 파열은 관절경하 수직 봉합술을, 나머지는 부분 절제술로 치료 하였다. 임상적 결과를 Ikeuchi의 평가 기준에 따라 분류하고 수술 전과 후의 Lysholm 점수를 비교 하였다(paired t-test). 결과: Ikeuchi 평가 기준에 따른 결과는 봉합술을 시행한 14예중 우수 12예 (85.7%), 양호 12예 (7.1%), 보통1예 (7.1%)였으며, 부분 절제술을 시행한 6예 중 우수는 4예 (66.7%), 양호는 2예(33.3%)를 보였다. Lysholm 점수는 수술 전 평균 56.6점에서 수술 후 92.3점으로 증가 하였다(p<0.0001, paired t-test). 결론: 경골과 골절은 외측 반월상 연골의 봉합술이나 부분 제거술의 결과에 나쁜 영향을 끼치지 않는 것으로 사료된다.

• Journal of Korean Dental Science
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• 제4권1호
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• pp.1-5
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• 2011

Purpose: Exact knowledge of the location and dimension of the pulp chamber help to maintain the pulp healthy during operative procedure and also reduces the risk of perforation of pulp chamber during root canal treatment. This in-vivo study was carried out to measure critical morphology of pulp chamber of mandibular molar using intra-oral periapical radiograph. Materials and Methods: Mandibular molar teeth of 56 patients were evaluated. The mandibular molar teeth whose pulp chamber was not violated by caries, restoration, fracture crown and those having closed apex were included in the study. The intraoral periapical radiographs were taken with paralleling angle technique using radio-opaque grid with 1 mm space. This grid was placed directly on the film. Results: In 94% of the mandibular first molars specimens the pulp chamber ceiling was at the level of the cemento-enamel junction. The measurements showing the lowest percentage variance were buccal cusp to furcation (approximately 11%) and buccal cusp to pulp chamber ceiling (approximately 15%). The distance from the cusp tip to pulp chamber ceiling height was approximately 6.0 mm, the distance from the pulpal floor to the furcation was approximately 3.0 mm, and the average height of a pulp chamber was 1.5 to 2.0 mm. Conclusion: The exact knowledge of distances of pulp chamber from various anatomical landmarks helps in proper assessment of root canals and ultimately avoids the failure of root canal treatment.

• 한국작물학회지
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• 제43권2호
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• pp.77-82
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• 1998

Aerenchyma development in rice (Oryza sativa L.) roots is quite important for adaptation to waterlogged or reduced soil conditions. Anatomical observations were carried out to clarify the development of schizogenous and lysigenous aerenchyma in elongating crown roots of rice. The crown roots of 3rd and 4th phytomer were taken from rice plants of the 8th leaf stage grown by hydroponic culture. The schizogenous intercellular spaces in the cortex of crown root tip were observed using a light microscope with semi ultra-thin sections and the lysigenous aerenchyma in mature tissue of crown root were observed using a cryo scanning electron microscope (cryo-SEM) with freezing fracture method. The schizogenous intercellular spaces in the root tip exist obviously in the middle portion of cortical cell layers close to the root-root cap junction, but not in root cap, stele and outer cell layers of cortex. The air spaces were formed at the junction of four neighbouring cells of inner cortex in the transverse sections, and between longitudinal cell layer connected along the root axis. Although many of those spaces were filled with liquid, some spaces seem to exist as air spaces. The lysigenous aerenchyma in the cortex, which hardly filled with liquid, emerged at 3-4 cm segment from the root tip and increased toward the basal region of root axis. The developing process of lysigenous aerenchyma was primarily separation of a radial row of cells caused by the shrinking and collapsing of cortical cells and then formation of septa along the radial cell rows by the fusion of cell wall with each other. These results suggest that the schizogenous and lysigenous aerenchyma playa role as a passage for the movement of oxygen into the root tip region where oxygen is required for respiration.

• Clinics in Shoulder and Elbow
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• 제18권2호
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• pp.61-67
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• 2015

Background: The purposes of the study were to examine rotator cuff tendon degeneration with respect to harvesting location, to determine a rationale for debridement of the torn end, and thus, to determine adequate debridement extent. Methods: Twenty-four patients with a full-thickness rotator cuff tear were included in the study. Tendon specimens were harvested during arthroscopic rotator cuff repair from three locations; from torn ends after minimal regularization of fraying (native end group, NE group), from torn ends after complete freshening of the frayed end (freshened end group, FE group), and from the macroscopically intact portion just distal to the musculotendinous junction (musculotendinous junction group, MTJ group). Control samples were harvested from patients admitted for surgery for proximal humerus fracture. Harvested samples were evaluated using a semi-quantitative grading scale. Results: Mean total degeneration scores in the NE group ($13.3{\pm}3.21$), the FE group ($12.5{\pm}2.30$), and in the MTJ group ($10.8{\pm}3.10$) were significantly higher than those in the normal control group ($5.0{\pm}2.87$; all p<0.001). Mean total degeneration score in the NE group was significantly higher than that in the MTJ group (p=0.012), but was not from that of the FE group. Mean total degeneration score in the FE group was not significantly different from that of the MTJ group. Conclusions: Tendon degeneration exists throughout the entire tendon to the macroscopically intact portion of full-thickness rotator cuff tear. Therefore, aggressive debridement to grossly normal appearing, bleeding tendon is unnecessary for enhancing healing after repair.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권5호
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• pp.292-296
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• 2022

Objectives: During Le Fort I osteotomy, the separation of the pterygomaxillary junction (PMJ) is a difficult procedure for most surgeons because it is invisible. In this process, damage to the posterior structures constituting the sinus or those adjacent to it, including the maxillary sinus posterior wall and pterygoid plate, may occur. We would like to investigate the effects of this on the inside of the maxillary sinus after surgery and whether there are complications. Materials and Methods: One-hundred patients who underwent Le Fort I osteotomy from 2013 to 2020 using cone-beam computed tomography images were classified into two groups (clean-cut type and fractured type) according to the PMJ cutting pattern. In addition, the mucosal thickness in the maxillary sinus was divided into preoperative, postoperative three months, one year, and the change over the course of surgery was evaluated retrospectively. Results: Of the total 100 cases, the clean-cut type numbered 28 cases and the fractured type totaled 72 cases. Among the fracture types, part of the sinus wall and the pterygoid plate were broken in 69 cases, and the maxillary sinus posterior wall was detached in three cases. There was no statistically significant difference in sinus mucosal thickening between the clean-cut type and fractured type of the PMJ, three months and one year after surgery between the two groups. However, there was a significant difference in sinus mucosal thickness at postoperative one year in the case where a partial detachment of the maxillary sinus posterior wall occurred compared to not. Conclusion: Even if there is some damage to the structures behind the PMJ, it may not be reasonable to spend some time on the PMJ separation process considering the overall postoperative complications, if there is no significant difference inside the sinus, or increased probability of postoperative complications.

• Journal of Korean Neurosurgical Society
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• 제29권1호
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• pp.58-65
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• 2000

Objective : Thoracolumbar junction is second most common level of injury next to cervical spine. The object of this study is to study the usefulness of surgical titanium mesh instead of bone graft, as well as to evaluate the correction of spinal deformity and safety of early ambulation in patients with injury at thoracolumbar junction. Patients and Methods : This review included 51 patients who were operated from July 1994 to December 1997. The injured spine is considered to be unstable, if it shows involvement of two or more columns, translatory displacement more than 3.5mm, decrease more than 35% in height of vertebral body and progression of malalignment in serial X-ray. The decision to operate was determined by (1) compression of spinal cord or cauda eguina, (2) unstable fracture, (3) malalignment and (4) fracture dislocation. The procedure consisted of anterior decompression through corpectomy and internal fixation with anterior instrument and surgical titanium mesh which was impacted with gathered bone chip from corpectomy. Results : Fifty-one patients were followed up for at least 12 months. The main causes of injury were fall and vehicle accident. The twelfth thoracic and the first and the second lumbar vertebrae were frequently involved. Complete neural decompression was possible under direct vision in all cases. Kyphotic angulation occurred in a patient. Radiologic evaluation showed correction of deformity and no distortion or loosening of surgical titanium mesh with satisfactory fixation postoperatively. Conclusions : We could obtain neurological improvement, relief of pain, immediate stabilization and early return to normal activities postoperatively. Based on these results, authors recommend anterior decompression and internal fixation with surgical titanium mesh in thoracolumbar unstable spine injuries.

• Journal of Korean Neurosurgical Society
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• 제48권2호
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• pp.129-133
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• 2010

Objective : The use of segmental instrumentation technique using pedicle screw has been increasingly popular in recent years owing to its biomechanical stability. Recently, intralaminar screws have been used as a potentially safer alternative to traditional fusion constructs involving fixation of C2 and the cervicothoracic junction including C7. However, to date, there have been few clinical series of C7 laminar screw fixation in the literature. Thus, the purpose of this study is to report our clinical experiences using C7 laminar screw and the early clinical outcome of this rather new fixation technique. Methods : Thirteen patients underwent C7 intralaminar fixation to treat lesions from trauma or degenerative disease. Seventeen intralaminar screws were placed at C7. The patients were assessed both clinically and radiographically with postoperative computed tomographic scans. Results : There was no violation of the screw into the spinal canal during the procedure and no neurological worsening or vascular injury from screw placement. The mean clinical and radiographic follow up was about 19 months, at which time there were no cases of screw pull-out, screw fracture or non-union. Complications included two cases of dorsal breech of intralaminar screw and one case of postoperative infection. Conclusion : Intralaminar screws can be potentially safe alternative technique for C7 fixation. Even though this technique cannot be used in the cases of C7 laminar fracture, large margin of safety and the ease of screw placement create a niche for this technique in the armamentarium of spine surgeons.

• Journal of Welding and Joining
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• 제34권5호
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• pp.70-76
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• 2016

In this study, Microstructure and tensile properties in arc brazed joints of 1000MPa grade DP steel using Cu-Si insert metal were investigated. The fusion zone was composed of Cu phase which solidified a little Fe and Si. The former phase formed due to dilute the edge of base material by arc, although Fe was not solid solution in Cu at the room temperature. Cu3Si particles formed by crystallization at $1100^{\circ}C$ during faster cooling. After the tensile shear test, there are no differences between the brazed joint efficiencies. The maximum joint efficient was about 37% compared to strength of base metal. It is better than that of arc brazed joint of DP steel using Cu-Sn filler metal. Fracture position of all brazing conditions was in the fusion zone. Crack initiation occurred at three junction point which was a stress singularity point of upper sheet, lower sheet and the fusion zone. And then crack propagated across the fusion zone. The reason why the fracture occurred at fusion zone was that the hardness of fusion zone was lower than that of base material and heat affected zone. The correlation among maximum load and hardness of fusion zone and EST at fractured position was $R^2=0.9338$. Therefore, this means that hardness and EST can have great impact on maximum load.