• Journal of Trauma and Injury
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• v.29 no.1
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• pp.22-27
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• 2016

Purpose: The optimal method of fixation of symphysis pubis (SP) diastasis in pelvic ring injuries is still controversial. In this study, we investigated the radiological and the clinical results of a precontoured 4.5-mm symphysis pubis (SP) plate with tension band wiring (TBW) after an anterior pelvic injury in pelvic fractures. Methods: We treated 25 patients with traumatic SP diastasis by open reduction and internal fixation with plates and wires. We used a four-hole 4.5-mm precontoured SP plate with a tension band wiring. Results: Patients with a SP with TBW fixation achieved excellent or good results at final follow-up. Post-operative complications included two (8%) patients with metal work movement. The mean symphyseal width was smaller in 4.5 mm SP plate with TBW during 1-year follow up period. Conclusion: A precontoured symphysis pubis plate (4.5 mm) with figure-of-eight fashion tension band wiring shows favorable radiological results, excellent or good clinical outcome, and a lower complication (hardware failure and revision surgery).

• Transactions of Materials Processing
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• v.22 no.1
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• pp.17-22
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• 2013

Tube hydroforming is a technology that utilizes hydraulic pressure to form a tube into desired shapes inside die cavities. Due to its advantages, such as weight reduction, increased strength, improved quality, and reduced tooling cost, single-layered tube hydroforming is widely used in industry. However in some special applications, it is necessary to produce multi-layered tubular components which have corrosion resistance, thermal resistance, conductivity, and abrasion resistance. In this study, a hollow forming process to fabricate a part from multi-layered tubes for structural purposes is proposed. To accomplish a successful hydroforming process, an analytical model that predicts optimal load path for various parameters such as tube material properties, thickness of tubes, diameter of holes and the number of holes was developed. Tubular hydroforming experiments to fabricate a hollow part were performed and the optimal loading path developed by the analytical model was successfully verified. The results show that the proposed hydroforming process can effectively produce hollow parts with multi-layered tube without defects such as wrinkling or fracture.

• The Korean Journal of Pain
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• v.13 no.1
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• pp.126-129
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• 2000

Age-related osteoporotic compression fractures occur frequently in old aged group recently. Percutaneous vertebroplasty has recently been introduced as a therapeutic method for the treatment of pain associated with osteoporotic vertebral compression fracture. Percutaneous intravertebral injection of PMMA (polymethylmethacrylate) results in marked reduction in pain and morbidity. Among complications during vertebroplasty with PMMA, pulmonary embolism is repotred occasionally but the reports about hypotension are not common. This case is a report of a patient whom significant hypotension occured during percutaneous vertebroplasty.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.2
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• pp.174-181
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• 2007

Today, endoscopic procedures are common in diagnostic and other surgical procedures, with endoscopically enhanced and magnified images permitting surgical access through minimal incisions. This has expanded the treatment options for many difficult anatomic sites, and the endoscope facilitated safe anatomic reduction and fixation. The use of the endoscope may reduce the disadvantages of open fracture repair and should be considered for broad application in the treatment of displaced facial bone fractures. Optical endoscopic magnification minimizes the disadvantages associated with open surgical repair, including the risk of facial nerve injury and external facial scarring, and no postoperative complications have been attributable to the endoscopic approach. This technique was used in 14 patients treated at Ulsan University Hospital, Korea, from September 2004 to August 2006, including six mandibular subcondyle fractures, five blowout fractures and three zygomaticomaxillary complex (ZMC) fractures. Careful preoperative evaluation and proper surgical technique were essential to achieve optimal results in the selected patients.

• Journal of Korean Neurosurgical Society
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• v.29 no.2
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• pp.255-260
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• 2000

The authors report a posttraumatic syringomyelia in a 30-year-old man who has complained pain, weakness of upper arm and dissociation sensory loss since 2 months before. He was underwent by decompressive laminectomy from T12 to L1, reduction of encroached bony fragments, transpedicular screw fixation from T12 to L2 and posterolateral bony fusion due to burst fracture of L1 at other hospital 3 years ago. Preoperative spinal MRI was highly suggestive of wide-spread, multiseptated syringomyelia from C3 to thoracolumbar junction. We performed wide decompressive laminectomy from T10 to L2 and subarachnoid space reconstrucion composed of microdissection of meningeal fibrosis widely, iatrogenic meningocele formation with lefting the dura mater opened for treatment of spinal-spinal pressure dissociation. Clinical manifestations and radiological findings of the patient were improved after the operation. This technique was thought to be superior to shunting procedures in cases of wide-spread, multiseptated post-traumatic syringomyelia.

• Journal of Powder Materials
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• v.16 no.4
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• pp.280-284
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• 2009

The pressureless sintering behavior of $Al_2O_3$/Cu powder mixtures, prepared from $Al_2O_3$/CuO and $Al_2O_3$/Cu-nitrate, has been investigated. Microstructural observation revealed that $Al_2O_3$ powders with nano-sized Cu particles could be synthesized by hydrogen reduction method. The specimens, pressureless-sintered at $1400^{\circ}C$ for 4 min using infrared heating furnace with the heating rate of $200^{\circ}C$/min, showed the relative density of above 90%. Maximum hardness of 16.1 GPa was obtained in $Al_2O_3$/MgO/Cu nanocomposites. The nanocomposites exhibited the enhanced fracture toughness of 4.3-5.7 $MPa{\cdot}m^{1/2}$, compared with monolithic $Al_2O_3$. The mechanical properties were discussed in terms of microstructural characteristics.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.167-178
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• 2007

In general, it is known that the concrete ballast track is possible to reduce a cost of maintenance activities cause of maintenance free by restrictive maintenance in application of track ballast structures. However, if deteriorations and fracture mechanism of a material are considered, proper maintenance activities and repairing are continually required. For the problems, we evaluated an economical efficiency of the gravel ballast and the concrete ballast on a proper level of maintenance activities. As the method based on history path is difficult to obtain sufficient reliabilities cause of an absence of real data for maintenance activities, we chose the delphi survey method by professional group, and we obtained the appropriate index and profiles for maintenance activities. As a result, we founded that effects for cost reduction can be expected by preventive maintenance management, and we proposed economical restrictions and life cycle cost for track ballast structures in a life cycle.

• Transactions of Materials Processing
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• v.15 no.6 s.87
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• pp.421-427
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• 2006

Drawing process of Al-1%Si bonding wire considering fine Si particle is analyzed in this study using FE-simulation. Al-1%Si boding wire requires electric conductivity because Al-1%Si bonding wire is used for interconnection in semiconductor device. About 1% of Si is added to Al wire for dispersion-strengthening. Distribution and shape of fine Si particle have strongly influence on the wire drawing process. In this study, therefore, the finite-element model based on the observation of wire by continuous casting is used to analyze the effect of various parameters, such as the reduction in area, the semi-die angle, the aspect ratio, the inter-particle spacing and orientation angle of the fine Si particle on wire drawing processes. The effect of each parameter on the wire drawing process is investigated from the aspect of ductility and defects of wire. From the results of the analysis, it is possible to obtain the important basic data which can be guaranteed in the fracture prevention of Al-1 %Si wire.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.376-379
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• 2001

There are many causes of trismus. Aetiology can be roughly divided into muscle spasm, mechanical interference, extracapsular ankylosis, intracapsular ankylosis. Trismus caused by mechanical interference between postero-lateral wall of zygoma-maxillary complex and coronoid process following reduction of fractured facial bone is rare. Especially on maxillary bone fracture, when we faced the trismus following removal of intermaxillary fixation, we got used to solve that problem by physical exercise. We obtained good results by coronoidectomy on patients with limited mouth opening who were referred from department of plastic surgery, St. Marys' hospital, the Catholic university of Korea. We report our experience with literature review.

• Archives of Craniofacial Surgery
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• v.17 no.4
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• pp.202-205
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• 2016

Background: Packing after closed reduction of nasal fracture causes uncomfortable nasal obstruction in patients. We packed the superior meatus with synthetic polyurethane foam (SPF) to support the nasal bone, and packed the middle nasal meatus with a nasal airway splint (NAS) and SPF. The aim of this article is prospectively to compare the subjective patient discomfort of SPF (Nasopore Forte plus) packing alone and SPF with NAS. Methods: We compared the prospectively subjective patient discomfort of SPF packing alone (group A) and SPF with NAS (group B) via visual analog scale (VAS; 0, no symptom; 100, most severe symptom). Results: At first postoperative day group B showed significant lower scores in dry mouth, sleep disturbance, conversation difficulty. However at third postoperative day, VAS scores of each group had no statistically significant differences. Moreover at fifth postoperative day group A had statistically significant lower scores for nasal pain, dry mouth than the group B. Conclusion: Combination method of using NAS and SPF have some advantage on the patient comfort from first postoperative day to third postoperative day.