• Archives of Plastic Surgery
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• 제50권6호
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• pp.601-609
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• 2023

Background The anterolateral thigh (ALT) flap is a preferred option in the reconstruction of a wide variety of defects, enabling multiple tissue components and thicknesses. Methods This study was conducted to investigate the correlation of the thickness of the traditional subfascial ALT flap and superficial fat flap with age, gender, and body mass index (BMI). A total of 42 patients (28 males and 14 females) were included in the study. Results Mean age was 50.2 (range, 16-75) years and mean BMI was 24.68 ± 4.02 (range, 16.5-34.7) kg/m². The subfascial flap thickness was significantly thinner in male patients (16.07 ± 2.77 mm) than in female patients (24.07 ± 3.93 mm; p < 0.05), whereas no significant difference was found between male (4.28 ± 1.15 mm) and female patients (4.85 ± 1.09 mm) regarding superficial fat flap thickness (p = 0.13). The thickness of both flaps had a positive correlation with BMI, and the strongest correlation was found for subfascial ALT thickness in female patients (r = 0.81). Age had no effect on both flap thickness measurements. The anterior thigh is thicker in women than in men, although it varies according to BMI. This shows that flap elevation is important in the superthin plane, especially if a thin flap is desired in female patients in defect reconstruction with the ALT flap. Thus, a single-stage reconstruction is achieved without the need for a defatting procedure after subfascial dissection or a second defatting procedure 3 to 6 months later. Conclusion The appropriate ALT flap plane should be selected considering the gender and BMI of the patient.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권2호
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• pp.118-126
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• 2006

In oral and maxillofacial surgery, bone graft is very important procedure for functional and esthetic reconstruction. So, many researcher studied about bone graft material like autogenous bone, allograft bone and artificial bone materials. The purpose of this study is to evaluate the quantity of bone generation induced by $Grafton^{(R)}$ graft, human allogenic demineralized bone matrix. Total 24 sites of artificial bony defects prepared using trephin bur(diameter 8 mm) on parietal bone of six adult New Zealand White rabbits. Experimental group had six defect sites which grafted $Grafton^{(R)}$(0.1 cc). Active control group had nine defect sites, into which fresh autogenous bone harvested from own parietal bone was grafted and passive control group had nine defect sites without bone graft. After six weeks postoperatively, the rabbits were sacrificed. The defects and surrounding tissue were harvested and decalcified in 10% EDTA, 10% foamic-acid. Specimens were stained with H&E. New bone area percentage in whole defect area was measured by IMT(VT) image analysis program. Quantity of bone by $Grafton^{(R)}$ graft was smaller than that of autograft and larger than that of empty defects. In histologic view $Grafton^{(R)}$ graft site and autograft site showed similar healing progress but it was observed that newly formed bone in active control group was more mature. In empty defect, quantity and thickness of new bone formation was smaller than in $Grafton^{(R)}$-grafted defect. $Grafton^{(R)}$ is supposed to be a useful bone graft material instead of autogenous bone if proper maintenance for graft material stability and enough healing time were obtained.

• Journal of Periodontal and Implant Science
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• 제45권1호
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• pp.30-35
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• 2015

Purpose: Implant beds with an insufficient amount of cortical bone or a loss of cortical bone can result in the initial instability of a dental implant. Thus, the objective of this study was to evaluate the effect of bone cement grafting on implant initial stability in areas with insufficient cortical bone. Methods: Two different circumferential defect depths (2.5 mm and 5 mm) and a control (no defect) were prepared in six bovine rib bones. Fourteen implants of the same type and size ($4mm{\pm}10mm$) were placed in each group. The thickness of the cortical bone was measured for each defect. After the implant stability quotient (ISQ) values were measured three times in four different directions, bone cement was grafted to increase the primary stability of the otherwise unstable implant. After grafting, the ISQ values were measured again. Results: As defect depth increased, the ISQ value decreased. In the controls, the ISQ value was $85.45{\pm}3.36$ ($mean{\pm}standard$ deviation). In circumferential 2.5-mm and 5-mm defect groups, the ISQ values were $69.42{\pm}7.06$ and $57.43{\pm}6.87$, respectively, before grafting. These three values were significantly different (P<0.001). After grafting the bone cement, the ISQ values significantly increased to $73.72{\pm}8.00$ and $67.88{\pm}10.09$ in the 2.5-mm and 5.0-mm defect groups, respectively (P<0.05 and P<0.001). The ISQ value increased to more than double that before grafting in the circumferential 5-mm defect group. The ISQ values did not significantly differ when measured in any of the four directions. Conclusions: The use of bone cement remarkably increased the stability of the implant that otherwise had an insufficient level of stability at placement, which was caused by insufficient cortical bone volume.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1778-1782
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• 2007

Based on three-dimensional (3-D) FE limit analyses, this paper estimates effect of internal pressure on plastic limit loads for elbows with circumferential through-wall crack under in-plane bending incorporating large geometry change effects. Circumferential through-wall crack in extrados is considered. The FE limit analyses using the large geometry change option provide plastic collapse loads (using the twice-elastic-slope method). For the bending mode, closing bending is considered. Other relevant variables affecting plastic limit loads are systematically varied, related to pipe bend geometry (the mean radius, thickness and bend curvature) and defect geometry (the length of circumferential through-wall crack).

• Archives of Plastic Surgery
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• 제40권6호
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• pp.697-704
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• 2013

Background We conducted an experimental study to compare the effect of massage using topical agents (Kelo-cote or Contractubex) on scar formation by massaging the healed burn wound on the dorsal area of Sprague-Dawley (SD) rats. Methods Four areas of second degree contact burn were made on the dorsal area of each of 15 SD rats, using a soldering iron 15 mm in diameter. After gross epithelialization in the defect, 15 SD rats were randomly divided into four groups: the Kelo-cote group, Contractubex group, Vaseline group, and control group. Rats in three of the groups (all but the Control group) were massaged twice per day for 5 minutes each day, while those in the Control group were left unattended. For histologic analysis, we performed a biopsy and evaluated the thickness of scar tissue. Results In the Kelo-cote and Contractubex groups, scar tissue thicknesses showed a significant decrease, compared with the Vaseline and control groups. However, no significant differences were observed between the Kelo-cote and Contractubex groups. In the Vaseline group, scar tissue thicknesses showed a significant decrease, compared with the control groups. Conclusions The findings of this study suggest that massage using a topical agent is helpful in the prevention of scar formation and that massage only with lubricant (no use of a topical agent) also has a considerable effect, although not as much as the use of a topical agent. Thus, we recommend massage with a topical agent on the post-burn scar as an effective method for decreasing the scar thickness.

• 한국진공학회지
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• 제14권3호
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• pp.153-158
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• 2005

순간 증착법으로 제조한 n형 $Bi_2Te_{2.4}Se_{0.6}$ 박막에 대하여 유효 평균 자유 행로 모델을 적용하여 박막의 두께가 열전 특성에 영향을 미치지 않는 임계 두께를 구하였다. 또한 열처리 전후 전자 농도 및 이동도의 변화를 조사하여 열처리에 의한 열전 특성의 변화를 역구조 결함과 관련하여 설명하였다. Seebeck 계수와 전기 비저항 모두 두레의 역수와 직선적인 관계를 보였으며, 이로부터 구한 평균 자유 행로는 $5120\AA$이었다. 열처리에 의해 전자의 이동도가 증가하였지만, 역구조 결함의 감소로 인해 운반자의 전자 농도가 현저히 감소하여, 결국 전기전도도가 감소하고 Seebeck 계수가 증가하였다 473k에서 1시간 동안 열처리한 Seebeck 계수와 전기전도도는 각각 $-200\;\mu V/k$와 $510\omega^{-1}cm^{-1}$이었다 또한, 열처리에 의해 열전 성능 인자가 상당히 향상되어 $20\times10^{-4}\;W/(mK^2)$를 나타내었다.

• 한방안이비인후피부과학회지
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• 제31권1호
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• pp.22-31
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• 2018

Objectives : In this study, we investigated whether Astragali Radix Pharmacocupuncture (ARP) has an effective on the full thickness defect wound healing process of mouse. Methods : A total of 50 mice (ICR mouse, 7 week-old male) were divided into control group and ARP group. A single full thickness skin defect was made on the dorsal side of the each mouse using an 8mm diameter biopsy punch. Control group were treated with 0.2㎖ saline and ARP group were treat with 0.2ml ARP at 8 points around the wound every three days total 4 times during the experimental period. The change in wound size, contraction rate, healing rate, and epithelization rate was measured by digital images taken on days 3, 6, 9, and 13, and evaluated using a digital image analysis program. Tissues were collected for histological analysis, RT-PCR, and Western blot on days 3, 6, 9, and 15. Results : The results are as follows. ARP group accelerated the rate of wound contraction, wound healing and epithelization compared to the control group. ARP group showed the decrease of inflammatory cells in early inflammatory phase compared to the control group. ARP group upregulated PECAM-1 mRNA and protein expression compared to the control group. ARP group inhibited the scar width and area compared to the control group. Conclusions: ARP showed positive effects on wound healing through the inhibition of inflammatory reaction and increase of PECAM-1 expression related to the wound healing process.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권3호
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• pp.189-199
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• 2006

Purpose of study: Partial thickness skin graft is the golden standard regimen for full-thickness skin defect caused by burn or trauma. However, in case of extensive burns of more than 50% of total body surface area, the donor site is not sufficient to cover all defects. As a second choice, allograft, xenograft and synthetic materials have been used to treat skin defect. Among them the amniotic membrane(AM) was used as a biological dressing for centuries because of its potential for wound healing. In this study, quantification of EGF in AM and effect of AM-collagen complex on full thickness skin defects was examined. Materials & Methods: The concentration of EGF in fresh, deep frozen and freeze-dried AM was evaluated by ELISA. EGF-R immunostaining was performed in freeze-dried AM. SD rats weighing 250${\sim}$300g was used for wound healing experiment. Three full thickness skin defects(28mm diameter) were made on dorsal surface of SD rat. The control group was covered by Vaselin gauze and AM-collagen complex and $Terudermis^{(R)}$. was grafted in two other defects. Healing area, Cinamon's score were evaluated before biopsy. Grafted sites were retrieved at 3 days, 1 week, 2 weeks and 4 weeks after operation. H & E and Factor VIII immunohistochemical stain was performed to evaluate the microscopic adhesion and structural integrity and microvessel formation. Results: 1. EGF concentration of fresh, deep frozen and freeze-dried AM showed similar level and EGF-R was stained in epithelial layer of freeze-dried AM. 2. At 4 weeks after grafting, the healing area of AM-collagen and Terudermis group was 99.29${\pm}$0.71% and 99.19${\pm}$0.77 of original size. However, that of control group was 24.88${\pm}$2.90. 3. The Cinamon's score of AM-Collagen and $Terudermis^{(R)}$. group at 4 weeks was 15.6${\pm}$1.26 and 14.6${\pm}$3.13 and that of control group was 3.7${\pm}$0.95. Significant difference was observed among control and experimental groups(p<0.05). 4. Histologic examination revealed that AM protected leukocyte infiltration and epithelial migration was nearly completed at 4 weeks. $Terudermis^{(R)}$. group showed mild neutrophil infiltration until 2 weeks and completion of epithelization at 4 weeks. Control group showed massive leukocyte infiltration until 4 weeks. 5. Microvessels were increased sharply at 1 week and control group at 1 and 4 week showed significant differences with $Terudermis^{(R)}$. group of same interval(p<0.05) but no differences were found with AM group(p<0.05). Conclusion: EGF and EGF-R were well preserved in freeze-dried AM. AM attached to collagen acted as excellent biologic dressing which had similar effect with $Terudermis^{(R)}$. AM showed anti-inflammatory action and healing was completed at 4 weeks after full-thickness skin defect.

• Structural Engineering and Mechanics
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• 제61권2호
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• pp.255-266
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• 2017

In this study, self-supporting roofing elements especially convenient for large-span structures such as stadium, airport terminal, mall, coliseum, etc. were examined with respect to critical buckling load. These elements were assumed as laminated composite plates and, variation of free-edge forms, cutout types and lamination configurations were used as design parameters. Based on the architectural feature and structural requirements, the effects of curvilinear free-edge form on critical buckling load were focused on in this research. Within this scope, 14 types of lamination configuration were specified according to various orientation angle, number and thickness of plies with a constant value of total plate thickness. Besides that, 6 different types of cutout and 3 different free-edge forms were determined. By combining all these parameters 294 different critical buckling load analyses were performed by using ANSYS Mechanical software based on finite element method. Effects of those parameters on critical buckling load were evaluated referring to the obtained results. According to the results presented here, it may be concluded that lamination conditions have more significant influence on the critical buckling load values than the other parameters. On the other hand, it is perceived that curvilinear free-edge forms explicitly undergo changings depending on lamination conditions. For future work, existence of delamination might be considered and progression of the defect could be investigated by using non-linear analysis.

• Journal of Welding and Joining
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• 제32권1호
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• pp.87-92
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• 2014

Recently, use of thick Al 5083 plate has increased in production of LNG storage tank. In general, multi-pass welding has been used to achieve sufficient penetration in thick plate welding. High current welding which enables high deposition and deep penetration is preferred in thick plate welding because the increase of number of pass increases manufacturing cost and formation of weld defect. In this study, welding characteristics according to various Ar/He shielding gas composition was investigated in high current MIG welding. The bead-on-plate welding and V groove welding were conducted on Al 5083 alloy with a thickness of .25 mm. The effect of shielding gas composition on bead shape was evaluated and proper shielding gas composition was proposed. Also arc stability was examined under selected shielding gas composition. One side-one pass welding experiments were conducted for V groove specimen with a thickness of 25 mm. Mechanical properties and hardness profiles were measured for the V groove specimens.