• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.29.2-29.2
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• 2011

B-site substitution with isovalent and donor impurities was compared in terms of the piezoelectric properties of Bi-based ABO3 perovskite ceramics. X-ray diffraction study revealed that both impurities bring about degradation in their ferroelectric properties as well as piezoelectric characteristics. However, there existed a difference between the isovalent and heterovalent impurities that influence a phase transformation of ferroelectric anisotropic-to-electrostrictive pseudocubic symmetry. Based upon analyses including the crystal, microstructure, dielectric, ferroelectric properties, we believed that A-site vacancies in the ABO3 ceramic significantly contribute to a ferroelectric-nonpolar phase transition, which give rise to lead to a giant strains. The present paper will discuss the origin of giant strains in Bi-based perovskite ceramics.

• Journal of Plant Biology
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• 제31권3호
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• pp.217-226
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• 1988

Effects of simazine [2-chloro-4,6-bis(methylamino)-s-triazine] on the photochemical reactions of isolaed spinach chloroplasts and crude thylakoids of Anabaena inequalis UTEX B-381 were compared. Simazine inhibited photosynthetic O2 evolution and increased the chlorophyll fluorescence in whole cells of Anabaena. The electron transfer from diphenylcarbazide to 2,6-dichlorophenolindophenol was inhibited by simazine treatment in spinach chloroplasts, but not in crude thylakoids of Anabaena. In spinach chloroplasts, the chlorophyll fluorescence was increased by simazine treatment in the presence of diphenylcarbazide and ferricyanide, but not in the presence of diphenylcarbazide and silicomolybdate. In crude thylakoids of Anabaena, simazine treatment did not increase the chlorophyll fluorescence in the presence of either diphenylcarbazide and silicomolybdate, or diphenylcarbazide and ferricyanide. There results suggest that the inhibitory site of simazine on photosynthetic electron transport chain of anabaena is different from that of spinach chloroplasts. And there may be a possiblity that the inhibition site of simazine in Anabaena lies on the donor side of photosystem II, before the site of electron donation by diphenylcarbazide.

• Archives of Plastic Surgery
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• 제37권5호
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• pp.565-570
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• 2010

Purpose: Due to the closed and humid condition of the perineal area, wound problems occurring at this site are sometimes complicated, especially following postoperative radiation therapy. Moreover, the anal sphincter is a very important functional structure but reconstruction of the anal sphincter after severe trauma poses a challenging problem to plastic surgeons. In this article, we demonstrate the usefulness of the pedicled gracilis flap in the reconstruction of the perineal area. Methods: From September 2008 to November 2009, 6 patients, 4 males and 2 females, underwent surgery of the perineal area. The age of the patients ranged from 21 to 62 years (mean age was 48). The mean follow up period was 14 months. In 4 cases, the patient presented with wound problems after postoperative radiation therapy for anal cancer. In 2 cases, the patient presented with traumatic sphincter damage. Only the gracilis muscle was used in the 4 cases and a musculocutaneous flap was used in the 2 cases involving skin defects, respectively. Results: Among the 6 patients, 1 patient underwent hematoma evacuation of the donor site, and 1 patient presented with prolapse of the vaginal mucosa which recovered spontaneously. There were no report of other complications and there were no wound recurrences. Minimal incontinence was observed in all patients who underwent sphincter reconstruction, but all were satisfied with the overall results. Conclusion: The gracilis flap is useful in the reconstruction of the perineal area, such as in cases of radiotherapy induced wound problems and sphincter damage following severe trauma, due to its easy accessibility, rich vascularity, and minimal donor site morbidity.

• Archives of Plastic Surgery
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• 제42권1호
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• pp.40-45
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• 2015

Background The eyelid and canthal areas are common locations for cutaneous tumors. The medial canthus includes, among many other apparatuses, the canthal tendon and lacrimal canaliculi, and its characteristic thin and supple skin is hard to mimic and restore using tissue from other regions. Accordingly, reconstruction of the canthal area can prove challenging for surgeons. Although various methods, such as skin grafts and local flaps from adjacent regions, have been utilized for reconstructive purposes, they present known disadvantages. However, we were able to successfully reconstruct both lateral and medial canthal area defects by using orbicularis oculi myocutaneous island flaps. Methods Our study included seven patients who underwent medial or lateral canthal region reconstruction, using orbicularis oculi myocutaneous island flaps, between 2011 and 2014, following either cutaneous tumor excision or traumatic avulsion injury. Results Five patients had basal cell carcinoma, one had squamous cell carcinoma of the eyelid, and one had sustained a traumatic avulsion injury of the eyelid and canthal area. Entire flap loss was not observed in any patient, but one-a heavy smoker-showed partial flap loss, which healed with secondary intention and yielded acceptable results. Donor site morbidity was not observed, and all patients were satisfied with their surgical outcomes. Conclusions The canthal regions can be successfully reconstructed with orbicularis oculi myocutaneous island flaps. These flaps offer several key advantages, including similarity in texture, color, and thickness to the recipient site and a negligible incidence of donor site morbidity.

• Archives of Plastic Surgery
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• 제38권4호
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• pp.451-457
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• 2011

Purpose: As a central feature of the face, the nose has considerable significance in appearance and expression. Reconstruction of full thickness defects of the nasal ala has always been a challenge because of the 3-dimensional structure. For reconstruction of post burn defects of ala, skin graft, local or pedicled flap and composite graft are optionally available. We have reconstructed the ala defects using adiposocutaneous graft and observed the outcome. Methods: From March 2003 to December 2010, 19 cases in 11 patients with scar contracture and defect on ala portion were performed operation using adiposocutaneous graft. As a donor site, we used the inguinal crease and posterior auricular area and the donor site was primarily closed. We made incision through the superior rim of ala and released fully. A graft is applied to recipient site with larger size than recipient volume. Results: The mean age of the patient was 38.6 years (16~51), males are seven patients and females are four patients. The operation was performed bilaterally in 5 patients and unilaterally in 6 patients. Composite grafts were harvested from inguinal area in 13 cases and posterior auricular area in 6 cases. In one case, we did 4 times of operation to get enough volume. All the grafts were well taken. The mean size of the graft was 3.63 $cm^2$. Conclusion: For reconstruction of post burn defects of ala, it's not easy to use local flap or pedicled flap because of hardness and fibrosis of surrounding tissue. So, we choose adiposocutaneous graft for ala deformity reconstruction, got satisfactory outcome in color matching and texture.

• 대한화상학회지
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• 제23권1호
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• pp.20-24
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• 2020

Diabetic patients have an increased risk of burn injuries on foot. Because of their diabetic neuropathy, they could contact with hot water or warming device without being aware of it. Split-thickness skin graft (STSG) is successful in treatment of various wound types; however, donor site wounds are sometimes problematic, and complications such as pain and impaired healing often occur. Although, donor site wounds in healthy young individuals can rapidly heal without complications, the wound-healing capacity of elderly patients or those with a comorbidity has been reported to be low. The dermatome is the most commonly used tool because it can harvest a large skin graft in one attempt. However, it is difficult to harvest tissues if the area is not flat. Furthermore, because the harvested skin is usually rectangular, additional skin usually remains after skin grafting. Therefore, use of razor blade and fragmented STSG on a large defect area is advantageous for harvesting a graft with a desired size, shape, and thickness. From January 2018 to July 2018, fragmented STSG was used in 9 patients who suffered from burn induced open wound on foot with diabetic neuropathy. With this approach, healing process was relatively rapid. The mean age of patients was 70 (57~86 years) and all of 9 patients had diabetes mellitus type 2. In all patients, the skin graft on the defect site healed well and did not result in complications such as hematoma or seroma.

• Archives of Reconstructive Microsurgery
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• 제5권1호
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• pp.46-55
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• 1996

The purpose of this study is to investigate if there is a higher rate of free flap failure in cases of vein grafts compared to non-vein graft, and to analyze the clinical usefulness and necessity in elective free flap surgery. We have used 24 vein grafts in 208 free flaps from May, 1986 until August, 1995. Vein grafts were from 2cm to 50cm in length between the recipient and donor vessels. Reconstructed sites were 10 lower extremities, 8 head and neck, 4 hand, and 2 trunk. Vein grafts were used 14 for arterial, 6 venous, 4 in both arterial and venous anastomoses. We intentionally used long vein grafts longer than 5cm for improved blood flow in cases of peripheral vascular disease, radionecrotic wounds, lower leg trauma. Short vein grafts of about 3cm in length were used to overcome the shortage of vascular length in cases of unexpected vessel anomaly, short donor vessel, and difficult access to recipient vessels after radical neck dissection. All veins were carefully handled with ligation of very small branches and were transferred to the recipient site without irrigation. 8 flaps were failed out of a total of 208 free flaps, however there was no failure among the 24 cases that needed vein grafts between the donor and recipient vessels. Success rates between non-vein grafts free flaps and vein graft free flaps were 95.6%(8/184) and 100%(0/24). Even though the vein grafts increase the operation time and the number of anastomoses, they do not result in any increased failure rate of free flap surgery(4.4% versus 0%). In addition to the reducing tension between recipient and donor vessels, the surgeon can select better recipient vessels with excellent blood flow so that vein grfats in microsurgery can provide a high success rate of free flaps.

• Archives of Plastic Surgery
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• 제36권5호
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• pp.674-677
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• 2009

Purpose: Typical cross finger flap is still a good method for reconstruction of fingertip injuries. However, it is necessarily followed by great loss and aesthetically unpreferable result of donor finger. Hereby, we introduce a modification of cross finger flap with reduction pulp plasty and full thickness skin graft, with which we could reduce the defect size of injured fingertip and donor site morbidity at the same time, without any need for harvesting additional skin from other part of hand. Method: This method was performed in the patients with fingertip injuries of complete amputation or in case of loss of fingertip due to necrosis after replantation. Firstly, reduction pulp plasty was performed on the injured finger to reduce the size of defect of fingertip. Additional skin flap was obtained from the pulp plasty. Secondly, cross finger flap was elevated from the adjacent finger to cover the defect on the injured finger. At the same time, defect on the donor finger produced by the flap elevation was covered by full thickness skin graft with the skin obtained from the pulp plasty of injured finger. Results: Flap and graft survived without any necrosis after surgical delay and flap detachment. All of them were healed well and did not present any severe adversary symptoms. Conclusion: Cross finger flap with reduction pulp plasty and full thickness skin graft is an effective method that we can easily apply in reconstruction of fingertip injury. We think that it is more helpful than the usual manner, especially in cases of children with less soft tissue on their fingers for preservation and reduction of the morbidity of donor finger.

• 분석과학
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• 제7권2호
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• pp.225-232
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• 1994

$Pb^{2+}$에 대해 $Ag^+$의 높은 추출 선택성이 기대되는 비고리 폴리에테르인 포단드 I-VII을 설계하여 높은 수율로 합성하였다. 포단드 I-VII을 추출제로 이용하여 물/클로로포름계에서 $Ag^+$ 및 $Pb^{2+}$의 피크린산염에 대한 %추출률(%Ex)을 구하였다. 또한 $Ag^+$과 포단드 I-VII과의 착물 형성에 대한 안전도상수(log K)를 전위차 적정에 의해 구하였다. %Ex($Ag^+$)는 치환된 황주개원자 수에 비례하였으나, 황 주개원자가 3개 치환된 포단드 VI(log K:7.65)와 4개 치환된 포단드 VII(log K:9.15)은 모두 100%에 가까운 추출률을 나타내었다. %Ex($Ag^+/Pb^{2+}$)에 있어서는 산소-황 혼합주개 포단드(IV-VII)가 더 큰 값을 나타내었다. 한편, %Ex($Ag^+$) 및 log K의 크기는 황주개자리의 변화에 크게 의존하였는데, 이는 NMR 실험결과 방향족 말단기 사이의 ${\pi}-{\pi}$ 스텍킹 상호작용에 기인한 것으로 생각된다.

• Archives of Plastic Surgery
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• 제38권1호
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• pp.27-34
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• 2011

Purpose: Anterolateral thigh (ALT) perforator free flap is commonly used because of its various benefits. The author reports important factors of preoperative and perioperative ALT perforator free flap and causes of failure. Methods: 84 patients who were treated with ALT perforator free flap from December 2004 to 2008, and February 2010 to April 2010 were studied. 61 patients were male and 23 were female. The mean age of patients was 51.1. The main cause was neoplasm and the main reconstructive areas were head and neck area. The size of flap was various from $3{\times}4$ to $12{\times}18$ cm. 6 patients received split thickness skin graft at donor site. Preoperative angiography was checked to all patients. Results: Among the 84 patients, partial necrosis of flaps occurred in 4 patients because of atherosclerosis, varicose vein, or inattention of patient, etc. And total flap necrosis in 5 patients because of abnormal vessels of recipient area or delay of operation, etc. One case of serous cyst was found as the complication of donor area. Two cases of skin graft on donor site were done because of suspected muscle compartment syndrome, 4 cases of that because of large flap. Septocutaneous perforators were found in 7 cases. The author couldn't find reliable perforator in 3 cases, ipsilateral anteromedial thigh perforator and contralateral ALT perforator and latissimus dorsi musculocutaneous free flap were done instead of ALT. There was no case which needed reoperation because of the impairment of blood supply, and 3 cases were revised by leech because of the burn injury by a lamp or venous congestion. Conclusion: Although ALT perforator free flap is widely used with its various merits, many factors such as preoperative condition of donor or recipient area, morphology of defect and operating time need to consider to prevent flap necrosis. And operators should need careful technique because septocutaneous perforator is uncommon, and musculocutaneous perforator is common but difficult to dissect.