• Archives of Reconstructive Microsurgery
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• 제10권2호
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• pp.105-110
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• 2001

Breast reconstruction is an aesthetically critical procedure and should be peformed to match the opposite breast in shape, contour, and position. Many methods were introduced to reconstruct the breast with autogenous tissue. But, free tissue transfer for breast reconstruction has become common method. The transverse rectus abdominis myocutaneous flap technique has been a widely accepted method of breast reconstruction after mastectomy, since the first introduction of free abdominoplasty flap in 1979. In breast reconstruction with a free flap the selection of suitable recipient vessels remains one of the most critical decision for surgeon. The most common recipient site for free flap breast reconstruction is the axillar system. But, the use of the axillary system as a recipient site limits flap movement and flexibility in breast shaping. The use of internal mammary vessels as a recipient site be able to achieve ideal breast symmetry, but that technique require the rib resection. The selection of suitable recipient vessels is most important for successful free tissue transfer. We have performed breast reconstruction with TRAM flaps anastomozed to the internal mammary vessel perforator. We came to the conclusion that this vessel perforator is useful as a recipient site in cases of immediate breast reconstruction with free TRAM flap.

• Archives of Plastic Surgery
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• 제36권5호
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• pp.670-673
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• 2009

Purpose: Epidural abscesses and subdural empyemas after craniotomy are uncommon, potentially lethal, complications of neurosurgery. Patients with these complications may be difficult to manage and dural reconstruction in these patients are challenging. Methods: A 28 - year - old female patient showed recurrent intracranial infection after craniotomy for evacuation of a arachnoid cyst and subdural hematoma. Despite prolonged systemic antibiotic administration and a debridement of the subdural space, infection persisted, as evidenced by persistent fever, an elevated WBC count, CSF leakage, low CSF glucose level, and purulent wound discharge. The authors removed the previously applied lyophilized dura and transferred free omental flap to reconstruct the dura, obliterate the cyst and cover the cerebral hemisphere in the craniotomy defect. Microvascular anastomosis was between gastroepiploic and superficial temporal vessels. Results: The postoperative course was uneventful and flap survival was excellent. The infection - resistant omental tissue allowed sufficient blood circulation and dead space control. The patient was discharged 1 month after surgery and wound discharge or recurrence was absent during 13 months of follow up periods. Conclusion: The use of vascularized free omentum proved useful in cases of intractable cranial wound infection and cerebrospinal fluid leakages.

• 한국실내디자인학회논문집
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• 제41호
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• pp.80-87
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• 2003

This paper attempts to examine the historical changes, the characteristics and the role of free-standing wall from the viewpoint of architectural composition. After modern times the wall gets free of structure and the view of formative art changes, which become a basis of the conscious use of free-standing wall. It plays a role of getting territoriality and placeness, by defining the space at the external territory and it is used as apparatus which controls circulation and orientation externally At the same time it is used as an instrument to blur the border to make mutual intersection and plays a role of introducing and controling the environment. The free-standing wall controls the architectural form to emphasize plasticity and is used to define a geometrical frame and maintain the urban context. In view of the results so far achieved, the free-standing wall is used as general vocabulary of modulating the border of space and the architectural form since modern architecture.

• 마이크로전자및패키징학회지
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• 제14권2호
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• pp.23-33
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• 2007

RoHS, WEEE 등에서의 각종 환경문제에 대한 제약으로 Pb의 사용에 대한 규제가 점차 증가 하고 있다. 따라서 무연 솔더에 대한 관심이 증폭되고 있으며, 마이크로 전자공학 산업에서 무연 솔더를 사용하기 위해서는 여러 가지 새로운 신뢰성 평가기준을 요구한다. 예를 들어 높은 온도공정을 만족하는 패키지, 새로운 솔더가 야기하는 복잡한 기계적 고장, 그리고 제품 수명을 최대한 유지시켜 줄 수 있는 무연 솔더 소재의 선택을 포함한다. 본 연구에서는 국내산 솔더바 소재를 사용하여 접합부의 기계적 특성 및 젖음성, 퍼짐성 등의 품질평가 방법을 해외규격과 비교하여 시험하고 새로운 평가기준을 찾고자 하였다. 젖음성 및 퍼짐성 시험 결과 Sn-0.7Cu 무연 솔더 소재는 평가기준을 충분히 만족하였다. 또한 이 소재를 사용한 솔더 접합부의 전단시험 결과, 열충격 및 고온방치 시험 후에도 솔더링 상태의 초기강도와 비교하여 접합부의 전단강도가 크게 저하하지 않은 상태에서 기준치를 크게 상회하였다.

• 대한두개안면성형외과학회지
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• 제12권1호
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• pp.48-52
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• 2011

Purpose: Many advances have been made in lower eyelid reconstruction surgical procedures after tumor ablative therapy. These include skin grafts, local flaps, free flaps, and skin expansion. When a full-thickness defect of the lower eyelid is reconstructed with many free flaps, ectropion and deformity of the medial and lateral canthal areas are common late complications caused by gravitational descent. The radial forearm free flap is widely used because of its lack of bulk, ease of dissection, malleability, and hairlessness. This report introduces a novel method for preventing ectropion using a composite radial forearm free flap reconstruction and palmaris longus suspension technique. Methods: A 70-year-old man had a malignant melanoma on his left lower eyelid. The patient was referred to our department after a biopsy confirmed the initial diagnosis. A full-thickness wide resection with a 25 mm free margin was performed, and a $5{\times}8cm$ radial forearm flap was elevated with a vascularised palmaris longus tendon. The palmaris longus tendon was fixed to the medial and lateral orbital rim perisoteum and the deep temporal fascia. The buccal mucosa was grafted to reconstruct the inner conjunctival layer. The pedicle vessels were anastomosed to the left superficial temporal artery and vein. Results: The postoperative clinical course was uneventful. The flap showed good texture and color match. No ectropion was noted 14 months after surgery and the tumor did not recur. The patient was quite satisfied with the final outcomes. Conclusion: Use of a radial forearm free flap and the palmaris longus tendon is an effective method for a full-thickness lower eyelid reconstruction.

• Archives of Pharmacal Research
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• 제26권6호
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• pp.504-510
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• 2003

The aim of this study is to prepare biodegradable microspheres without the use of surfactants or emulsifiers for a novel sustained delivery carriers of protein drugs. A poly($\varepsilon$-caprolactone)/poly(ethylene glycol)/poly($\varepsilon$-caprolactone) (CEC) triblock copolymer was synthesized by the ring-opening of $\varepsilon$-caprolactone with dihydroxy poly (ethylene glycol) to prepare surfactant-free microspheres. When dichloromethane (DCM) or ethyl formate (EF) was used as a solvent, the formation of microspheres did not occur. Although the microspheres could be formed prior to lyophilization under certain conditions, the morphology of microspheres was not maintained during the filtration and lyophilization process. Surfactant-free microspheres were only formed when ethyl acetate (EA) was used as the organic solvent and showed good spherical micro-spheres although the surfaces appeared irregular. The content of the protein in the micro-sphere was lower than expected, probably because of the presence of water channels and pores. The protein release kinetics showed a burst release until 2 days and after that sustained release pattern was showed. Therefore, these observations indicated that the formation of microsphere without the use of surfactant is feasible, and, this the improved process, the protein is readily incorporated in the microsphere.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.71-72
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• 2022

In the case of free-form buildings, it is difficult to reuse the form for panel production because the shape and size of the interior and exterior panels of the building are different. In general, it is a free-form concrete panel (FCP) production technology using the existing plywood formwork, and the form is produced in a different shape each time and is discarded after only one use. The production of these disposable forms requires enormous resources, including materials, labor and time. Hence, it is necessary to develop innovative forms that can be reused for sustainable FCP construction. In this study, a technology has been developed that combines 3D Plastering Technique (3DPT) to produce FCP. By applying this technology to free-form building projects, the time and cost required for FCP production can be reduced. However, specific studies on the production process for this technology have not been done yet. Therefore, the objective of this study is a basic study of free-form concrete panel production process using 3D plastering technique.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.289-296
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• 2017

Lysine decarboxylase (CadA) converts ${\small{L}}-lysine$ into cadaverine (1,5-pentanediamine), which is an important platform chemical with many industrial applications. Although there have been many efforts to produce cadaverine through the soluble CadA enzyme or Escherichia coli whole cells overexpressing the CadA enzyme, there have been few reports concerning the immobilization of the CadA enzyme. Here, we have prepared a cross-linked enzyme aggregate (CLEA) of E. coli CadA and performed bioconversion using $CadA^{CLEA}$. $CadA^{free}$ and $CadA^{CLEA}$ were characterized for their enzymatic properties. The optimum temperatures of $CadA^{free}$ and $CadA^{CLEA}$ were $60^{\circ}C$ and $55^{\circ}C$, respectively. The thermostability of $CadA^{CLEA}$ was significantly higher than that of $CadA^{free}$. The optimum pH of both enzymes was 6.0. $CadA^{free}$ could not be recovered after use, whereas $CadA^{CLEA}$ was rapidly recovered and the residual activity was 53% after the $10^{th}$ recycle. These results demonstrate that $CadA^{CLEA}$ can be used as a potential catalyst for efficient production of cadaverine.

• Bulletin of the Korean Chemical Society
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• 제28권1호
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• pp.95-98
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• 2007

Polyethylenimine (PEI) has been widely investigated for delivery of DNA into cells. It was previously reported that there were at least two types of cytotoxicity in PEI-mediated gene delivery, immediate and delayed toxicities. PEI-mediated gene delivery protocols use net cationic complexes with an excess of PEI to maintain equilibrium between the complexed and dissociated forms in solution. In this study, toxicity of free PEI or PEI/ DNA complex was investigated. Human embryonic kidney 293 cells were incubated with free PEI or PEI/DNA complex for 4 hrs. Then, the cells were analyzed at 6, 24, 48, and 96 hrs after the incubation. In MTT assay, the viability of the cells incubated with PEI/DNA complex was continuously decreased with time, while that of the cells incubated with free PEI was not. On the contrary, the expression level of the luciferase gene increased gradually along with time. Release of DNAs from the complexes for transcription produces free PEIs in the cells. This process may proceed slowly due to high charge density of PEI and may be related to delayed toxicity. In addition, apoptotic cells were observed only in the cells incubated with the PEI/DNA complex from 24 hrs after the incubation. The results suggest that PEI/DNA complex contributes to the delayed toxicity by inducing apoptosis and that the delayed toxicity may be related to decomplexation of the complexes in the cells.

• Archives of Plastic Surgery
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• 제49권6호
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• pp.745-749
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• 2022

Background Soft tissue defects of the multiple finger present challenges to reconstruction surgeons. Here, we introduce the use of a lateral arm free flap and syndactylization for the coverage of multiple finger soft tissue defects. Methods This retrospective study was conducted based on reviews of the medical records of 13 patients with multiple soft tissue defects of fingers (n = 33) that underwent temporary syndactylization with a microvascular lateral arm flap for temporary syndactylization from January 2010 to December 2020. Surgical and functional outcomes, times of flap division, complications, and demographic data were analyzed. Results Middle fingers were most frequently affected, followed by ring and index fingers. Mean patient age was 43.58 years. The 13 patients had suffered 10 traumas, 2 thermal burns, and 1 scar contracture. Release of temporary syndactyly was performed 3 to 9 weeks after syndactylization. All flaps survived, but partial necrosis occurred in one patient, who required a local transposition flap after syndactylization release. The mean follow-up was 15.8 months. Conclusion Coverage of multiple finger defects by temporary syndactylization using a free lateral arm flap with subsequent division offers an alternative treatment option.