• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.543-544
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• 2006

Pentacene thin film transistors fabricated without photolithographic patterning were fabricated on the plastic substrates. Both the organic/inorganic thin films and metallic electrode were patterned by shifting the position of the shadow mask which accompanies the substrate throughout the deposition process. By using an optically transparent zirconium oxide ($ZrO_2$) as a gate insulator and octadecyltrimethoxysilane (OTMS) as an organic molecule for self-assembled monolayer (SAM) to increase the adhesion between the plastic substrate and gate insulator and the mobility with surface treatment, high-performance transistor with field effect mobility $.66\;cm^2$/V s and $I_{on}/I_{off}$>$10^5$ was formed on the plastic substrate. This technique will be applicable to all structure deposited at low temperature and suitable for an easy process for flexible display.

• Journal of Welding and Joining
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• 제18권2호
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• pp.222-222
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• 2000

PBGA(Plastic Ball Grid Array) is composed of some materials such as PCB(Printed Circuit Board), epoxy molding compound, die attach and so on. Reliability of PBGA package is weak compared with plastic packages. The weak points of reliability are the lower resistance to popcorn cracking, which is induced by moisture absorption in PCB, and the pressure cooker test corrosion, which is the basic problem due to the material characteristics of PCB. Introducing the PCB baking and the plasma treatment cleared the popcorn cracking phenomenon. The PCB baking and plasma treatment reduced the epoxy void by eliminating the source of moisture vaporization during the epoxy curing and enhanced the adhesion between PCB and epoxy. Also, plasma treatment enhanced the wettability of epoxy on PCB. The problem of corrosion is cleared using multi-functional epoxy. This type of EMC(Epoxy Molding Compound) is recommended in package using PCB as a substrate. (Received November 19, 1999)

• Journal of Welding and Joining
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• 제18권2호
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• pp.95-99
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• 2000

PBGA(Plastic Ball Grid Array) is composed of some materials such as PCB(Printed Circuit Board), epoxy molding compound, die attach and so on. Reliability of PBGA package is weak compared with plastic packages. The weak points of reliability are the lower resistance to popcorn cracking, which is induced by moisture absorption in PCB, and the pressure cooker test corrosion, which is the basic problem due to the material characteristics of PCB. Introducing the PCB banking and the plasma treatment cleared the popcorn cracking phenomenon. The PCB banking and plasma treatment reduced the epoxy void by eliminating the source of moisture vaporization during the epoxy curing and enhanced the adhesion between PCB and epoxy. Also, plasma treatment enhanced the wettability of epoxy on PCB. The problem of corrosion is cleared using multi-functional epoxy. This type of EMC(Epoxy Molding Compound) is recommended in package using PCB as a substrate.

• Archives of Plastic Surgery
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• 제36권3호
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• pp.344-347
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• 2009

Purpose: Malignant soft tissue tumors, known as sarcomas, are well known to be locally aggressive, frequently metastatic, and highly recurrent. In other hands, intermediate soft tissue tumors often recur locally with adjacent tissue infiltration so the clinical management is difficult as sarcoma. In the present study, we evaluate the clinical course of the intermediate soft tissue tumors and consider the management plan for those. Methods: From March, 1998 to April 2008, total 3 patients of intermediate soft tissue tumors underwent operations. A patient with fibrohistiocytic neoplasm, a free flap reconstruction was performed, and he underwent several more operations because of recurrences. Other patients with desmoids - type fibromatosis showed local invasion and adhesion, and one of them underwent reoperation due to local recurrence. Results: 2 of 3 patients underwent recurrences of tumors and reoperations were performed. In another patient with no recurrence, follow-up period was just 5 months, so there may be recurrence of tumor in long term follow-up. Conclusion: The clinical course of intermediate soft tissue tumors shows high recurrence rate. So clinically, intermediate soft tissue tumors should be considered as sarcomas. The successful management requires wide resection, carefully planned reconstruction, and close follow up with radiologic evaluation.

• 생명과학회지
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• 제18권7호
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• pp.952-957
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• 2008

본 실험에서는 THP-1 세포의 PMA에 의하여 유도되는 초기 세포부착에 관한 메카니즘을 이해하기 위하여 다양한 요인(혈청, 신규 단백질의 합성, 세포 골격 저해제, 단백질 인신화 저해제)들의 효과를 조사하였다. 또한 본 실험에서는 이들 세포부착의 정도를 일반적으로 세포증식 분석에 사용되고 있는 SRB염색법을 도입하여 세포부착 분석에 간편한 방법의 조건을 확립하였다. PMA에 의한 초기 세포부착에는 배양액중의 혈청의 유무는 영향이 없었으나, 신규 단백질의 합성이 요구되는 것을 확인하였다. 또한 이들 초기 세포부착에 PMA처리에 의한 PKC의 활성화는 필수적이나, 그 하류 활성화 인자로 잘 알려진 MAP-kinase (erk1/2)의 인산화는 필요치 않음을 알 수 있었다. 흥미롭게도 액틴 중합 저해제인 cytochalasin D의 PMA와 공 처리는 오히려 세포부착을 PMA 단독 처리시 보다 증가시켰다. 또한 본 실험에서 사용된 SRB 염색법을 통한 세포부착 분석법은 최근 암 등 다양한 질환의 신약 표적 분자로 주목을 받고 있는 PKC 저해제의 초기 세포 기반 분석에 매우 유용하리라고 생각된다.

• Archives of Plastic Surgery
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• 제40권6호
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• pp.773-778
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• 2013

Background In the management of mallet deformities, oblique retinacular ligament (ORL) reconstruction provides a mechanism for automatic distal interphalangeal (DIP) joint extension upon active proximal interphalangeal joint extension. The two variants of ORL reconstruction utilize either the lateral band or a free tendon graft. This study aims to compare these two surgical techniques and to assess any differences in functional outcome. As a secondary measure, the Mitek bone anchor and pull-in suture methods are compared. Methods A single-institutional retrospective review of ORL reconstruction was performed. The standard patient demographics, injury mechanism, type of ORL reconstruction, and pre/postoperative degree of extension lag were collected for the 27 cases identified. The cases were divided into lateral band (group A, n=15) and free tendon graft groups (group B, n=12). Group B was subdivided into the pull-in suture technique (B-I) and the Mitek bone anchor method (B-II). Results Overall, ORL reconstructions had improved the mean DIP extension lag by $10^{\circ}$ (P=0.027). Neither the reconstructive technique choice nor bone fixation method identified any statistically meaningful difference in functional outcome (P=0.51 and P=0.83, respectively). Soft-tissue injury was associated with $30.8^{\circ}$ of improvement in the extension lag. The most common complications were tendon adhesion and rupture. Conclusions The choice of the ORL reconstructive technique or the bone anchor method did not influence the primary functional outcome of extension lag in this study. Both lateral band and free tendon graft ORL reconstructions are valid treatment methods in the management of chronic mallet deformity.

• Archives of Plastic Surgery
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• 제40권6호
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• pp.711-714
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• 2013

Background The most common cause of skin graft failure is the collection of blood or serous fluid underneath the graft. In our study, we describe the use of silicone tube for tie-over dressing to secure the skin graft margins with the aim of decreasing loss of the skin graft, particularly in grafting of deep wounds. Methods Between March 2008 and July 2011, we used this technique in 17 patients with skin defects with depths ranging from 3.5 to 8 mm (mean, 5.5 mm). First, the skin graft was sutured with 3/0 silk suture material from its corners. Then, a silicone round drain tube was sutured with 3/0 absorbable polyglactin 910 over the margins of the graft. Finally, long silk threads were tied over the bolus dressing, and the tie-over dressing was completed in the usual fashion. Results The mean follow-up was 7 months (range, 2-10 months) in the outpatient clinic. Graft loss on the graft margins due to hematoma or seroma was not developed. The results of adhesion between the graft and wound bed peripherally was excellent. Conclusions In our study, we suggest that use of a silicone tube for additional pressure on the edges of skin grafts in case of reconstruction of deep skin defects.

• Archives of Plastic Surgery
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• 제39권4호
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• pp.397-403
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• 2012

Background Nonabsorbable sutures are favorable for repairing flexor tendons. However, absorbable sutures have performed favorably in an animal model. Methods Two-strand sutures using the interlocking modified Kessler method with polydioxanone absorbable sutures 4-0 were used to repair completely ruptured flexor tendons in 55 fingers from 41 consecutive patients. The medical records of average 42 follow up weeks were analyzed retrospectively. The data analyzed using the chi-squared test, and Fisher's exact test was used for postoperative complications. The results were compared with those of other studies. Results Among the index, middle, ring, and little fingers were injured in 9, 17, 16, and 13 fingers, respectively. The injury levels varied from zone 1 to 5. Of the 55 digits in our study, there were 26 (47%) isolated flexor digitorum profundus (FDP) injuries and 29 (53%) combined FDP and with flexor digitorum superficialis injuries. Pulley repair was also conducted. Concomitant injuries of blood vessels and nerves were found in 17 patients (23 fingers); nerve injuries occurred in 5 patients (10 fingers). Two patients had ruptures (3.6%), and one patient had two adhesions (3.6%). Using the original Strickland criteria, all the patients were assessed to be excellent or good. Also, fibrosis and long-term foreign body tissue reactions such as stitch granuloma were less likely occurred in our study. Compared to the Cullen's report that used nonabsorbable sutures, there was no significant difference in the rupture or adhesion rates. Conclusions Therefore, this study suggests that appropriate absorbable core sutures can be used safely for flexor tendon repairs.

• Archives of Plastic Surgery
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• 제38권5호
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• pp.687-690
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• 2011

Purpose: Pemphigus vulgaris, a rare autoimmune blistering disease of the skin and mucous membranes remains a challenging disease to treat. Management is focused on immunotherapy against autoimmune antibodies that target keratinocyte cell adhesion molecules, and antibiotics preventing secondary infections. There is no established dressing protocol and skin is usually manipulated the least amount possible in order to minimize irritation. The authors suggest that early initiation of aggressive bathing and debridement of skin lesions, with nutritional support, is essential in accelerating resolution. Methods: A 40 year-old male previously diagnosed with pemphigus vulgaris was admitted due to exacerbation of mucocutaneous lesions involving the epidermis and mucosa of the whole body. Steroids, immunosuppressants, intravenous immunoglobulin and antibiotics were administrated, but infection and de-epithelialization progressed, while his general condition deteriorated with a weight loss of over 20 kilograms. The plastic surgery department intervened with daily bathing, debridement of unhealthy debris and non-traumatizing coverage of growing epithelium. Total parenteral nutrition and mobilization with rehabilitation therapy was initiated as early as possible. Results: After bathing, healthy epithelium gradually covered the patient's entire body, while his general condition improved with a corresponding weight gain of 14 kgs. Conclusion: Treatment of pemphigus vulgaris focuses on immunotherapy and infection control. However, an equal amount of attention should be laid on early intervention with daily dressings including bathing and irrigation, nutritional support, and exercise as this accelerates resolution of existing infections, promotes healthy epithelialization and leads to faster recovery.

• 한국군사과학기술학회지
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• 제11권2호
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• pp.109-115
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• 2008

A Plastic Bonded Explosive(PBX) is mainly composed of nitramine explosive and polymer binder. The great number of serious applications of PBX requires the good adhesion between nitramine crystals and binder, which depends on the surface characteristics of a filler and binder. In the pursuit of the better design to achieve the enhanced adhesion, profound knowledge of the surface and interfacial characteristics of explosive and binder should be exploited. In this study, the influences of physicochemical properties between RDX and binders such as interfacial tension($\gamma_{SL}$), latent heat($Q_m$), and density($\rho$) on impact sensitivity of PBX were investigated. As experimental results, the major contribution factor to impact sensitivity of PBX was the interfacial tension, compare with other surface properties. The correlation coefficient of $H_{50}$ versus $\gamma_{SL}$ is 0.9932 when a polynomial regression method was used.