• Structural Engineering and Mechanics
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• 제3권6호
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• pp.583-592
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• 1995

The concept of "Saturation Impulse" for rigid, perfectly plastic structures with finite-deflections subjected to dynamic loading was put forward by Zhao, Yu and Fang (1994a). This paper extends the concept of Saturation Impulse to the analysis of structures such as simply supported circular plates, simply supported and fully clamped square plates, and cylindrical shells subjected to rectangular pressure pulses in the medium load range. Both upper and lower bounds of nondimensional saturation impulses are presented.

• Archives of Plastic Surgery
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• 제35권6호
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• pp.692-697
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• 2008

Purpose: Gluteal perforator flap has evolved to one of the standard tools for coverage of pressure sore. We used this flap to cover the defect adjacent to the buttock. Methods: From September 2004 to August 2006, gluteal perforator flaps were performed in 3 patients with sore and 9 patients with tumor. We made the rule for free style design of the flap. First, the defect should be covered fully regardless of the shape or area. Second, the location of perforators was decided to maximize flap mobility. Third, the donor-site should be closed directly. Results: Successful reconstruction was fulfilled. In 2 cases, initial flap congestion was observed but medical leech was applied and it was resolved. Partial flap loss occurred in one case. Infection was observed in one case. But there were no major complications. Conclusion: Gluteal perforator flap is very good option for the reconstruction of the defects adjacent to the buttock.

• Archives of Plastic Surgery
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• 제32권1호
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• pp.131-134
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• 2005

It is often difficult to identify and localize intraorbital foreign bodies despite of modern high-resolution imaging investigation. Especially, posteriorly located foreign bodies have increased risks of morbidity that surgical approach is often complicated. No matter how trivial it seems, retained foreign body, particularly organic in nature, may give rise to severe orbital and cerebral complications. High clinical suspicion, proper diagnostic studies, timely referral to a skilled orbital surgeon are mandatory. We report a case of intraorbital wooden foreign body that required two separate exploration for removal. Initial exploration failed to identify and locate the foreign body completely. After the operation, fistula formation and purulent discharge were developed and the imaging investigation results were equivocal, complicating the management. A second exploration yielded multiple intraorbital wooden foreign body in the apex of orbit. The patient fully recovered without complication. The evaluations and the details of management strategy are discussed.

• Journal of Mechanical Science and Technology
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• 제18권3호
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• pp.357-369
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• 2004

The purposes of the paper are to analyze the fracture phenomenon by delamination and cracking when the encapsulant of plastic IC package with polyimide coating shows viscoelastic behavior under hygrothermal loading in the IR soldering process and to suggest more reliable design conditions by the approaches of stress analysis and fracture mechanics. The model is the plastic SOJ package with the polyimide coating surrounding chip and dimpled diepad. On the package without cracks, the optimum position and thickness of polyimide coating to decrease the maximum differences of strains at the bonding surfaces of parts of the package are studied. For the model delaminated fully between the chip and the dimpled diepad, C(t)-integral values are calculated for the various design variables. Finally, the optimal values of design variables to depress the delamination and crack growth in the plastic IC package are obtained.

• Archives of Plastic Surgery
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• 제48권6호
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• pp.641-645
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• 2021

A 3,480 g male neonate showed tachypnea symptom with a serum ionized calcium level of 0.66 mmol/L by routine clinical analysis. He was injected calcium gluconate intravenously through femoral vein catheter to treat the hypocalcemia. On second day after the injection, he started to show erythema in the flank area. The lesion became firm and changed into whitish crust consist of small crystals. Abdominal X-ray and ultrasonography showed the accumulation of calcium deposit in the subcutaneous layer of the lesion. Surgical debridement was performed to remove the crust with calcium deposit and acellular fish skin graft rich in omega-3 (Kerecis) was applied to the defect site for secondary intention of the defect wound. After 2 months, the skin and soft tissue defect were fully covered with healthy normal skin without depression or contracture. This report is a first case of iatrogenic calcinosis cutis without extravasation symptom.

• Archives of Plastic Surgery
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• 제41권2호
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• pp.140-147
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• 2014

Background Epidermal cysts are commonly occurring masses usually less than 5 cm in diameter, but in predisposed patients, epidermal cysts can grow relatively large due to chronic infection. Methods From June 2002 to July 2010, 17 patients received 19 regional perforator-based island flaps to cover defects due to the excision of large epidermal cysts (diameter >5 cm) in the buttocks. Eight patients had diabetes, and seven had rheumatoid arthritis. The pedicles were not fully isolated to prevent spasms or twisting. Results All the flaps survived completely, except for one case with partial necrosis of the flap, which necessitated another perforator-based island flap for coverage. There were two cases of wound dehiscence, which were reclosed after meticulous debridement. There were no recurrences of the masses during follow-up periods of 8.1 months (range, 6-12 months). Conclusions In patients with large epidermal cysts and underlying medical disorders, regional perforator-based island flaps can be the solution to coverage of the defects after excision.

• 대한기계학회논문집A
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• 제30권5호
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• pp.533-542
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• 2006

In order to assess the integrity of pipes with local thinning area, the plastic strain as well as the elastic strain at the root of thinned region are required particularly when fluctuating load is applied to the pipe. For estimating elastic-plastic strain at local wall thinning area in a straight pipe under tensile load, an estimation model with idealized fully circumferential constant depth wall thinning area is proposed. Based on the compatibility and equilibrium equations a nonlinear estimation equation, from which local elastic-plastic strain can be determined as a function of pipe/defect geometry, material and the applied strain was derived. Estimation results are compared with those from detailed elastic-plastic finite element analysis, which shows good agreements. Noting that practical wall thinning in nuclear piping has not only a circular shape but also a finite circumferential length, the proposed solution for the ideal geometry is extended based on two-dimensional and three-dimensional numerical analysis of pipes with circular wall thinning.

• Archives of Plastic Surgery
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• 제49권3호
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• pp.448-452
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• 2022

Total reconstruction of the penis (TPR) represents a challenge for urologists and plastic surgeons, especially when urethral length is severely reduced. We here describe, for the first time in an oncologic scenario, a double flap phalloplasty using a pedicled anterolateral thigh (ALT) flap for penile reconstruction and a radial forearm free flap (RFFF) for complete neourethra and glans reconstruction following penile amputation. A 48-year-old patient came to our department following a total penectomy with inferior urethral derivation. The indication for a double flap phalloplasty was posed as only way to fully reconstruct the urethra on its length avoiding possible complications of single flap reconstruction using tube-into-tube technique. Both flaps healed uneventfully with no neourethral strictures or fistulas described. At 18 months follow-up, the patient was extremely satisfied with the aesthetic result and was able to void in standing position. We think that a double free tissue transfer for TPR should be considered, particularly when a urethral length > 14 cm needs to be reconstructed. While the pedicled ALT can be used to reconstruct a proper penile shaft with an easily concealed scar, the RFFF can provide adequate neourethra length with satisfactory sensory recovery at the neoglans.

• Archives of Plastic Surgery
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• 제51권1호
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• pp.20-26
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• 2024

The etiology and pathophysiology of delayed inflammatory reactions caused by hyaluronic acid fillers have not yet been elucidated. Previous studies have suggested that the etiology can be attributed to the hyaluronic acid filler itself, patient's immunological status, infection, and injection technique. Hyaluronic acid fillers are composed of high-molecular weight hyaluronic acids that are chemically cross-linked using substances such as 1,4-butanediol diglycidyl ether (BDDE). The mechanism by which BDDE cross-links the two hyaluronic acid disaccharides is still unclear and it may exist as a fully reacted cross-linker, pendant cross-linker, deactivated cross-linker, and residual cross-linker. The hyaluronic acid filler also contains impurities such as silicone oil and aluminum during the manufacturing process. Impurities can induce a foreign body reaction when the hyaluronic acid filler is injected into the body. Aseptic hyaluronic acid filler injections should be performed while considering the possibility of biofilm formation or delayed inflammatory reaction. Delayed inflammatory reactions tend to occur when patients experience flu-like illnesses; thus, the patient's immunological status plays an important role in delayed inflammatory reactions. Large-bolus hyaluronic acid filler injections can induce foreign body reactions and carry a relatively high risk of granuloma formation.

• Archives of Plastic Surgery
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• 제32권3호
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• pp.327-334
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• 2005

This study was designed to investigate the effect of the surgical delay in the prefabricated cutaneous flap. Abdominal skin flaps (n=40), $4.5{\times}6.0cm$ in size, were created by the subcutaneous implantation of a saphenous vascular tissue in the male Sprague-Dawley rats. In the groups 1 and 2, the pedicle was skeletonized. In the groups 3 and 4, perivascular muscle cuff or gracilis fascia was retained, respectively. Six weeks later, each flap was elevated as an island flap and reposed in place. All flaps of the group 2 had a 72-hours of delay period. Five days after the flap repositioning, estimation of flap viability, microangiographies, and histological evaluation of vessel development were performed. The groups 2 and 3 showed higher viability in flap survival. The dilated choke vessels and fully developed vascular network were observed in the flap of the group 2, but not typically seen in the other groups. New vessels around the implanted pedicle were more developed in the group 2. Amount of the vessels in the mid-portion of the flap was significantly increased in the groups 2 and 4. In conclusion, the delay procedure enhanced the viability, and its effect was dependent on the new vessel formation around the implanted pedicle.