• Journal of Korean Neurosurgical Society
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• 제38권1호
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• pp.71-73
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• 2005

A case of intramedullary spinal cord lipoma is presented. A one month-old male infant presented with irritability and weakness on his upper extremities. A magnetic resonance[MR] image of the cervical spine demonstrated a well defined, high signal intensity lesion on both T1 and T2-weighted MR images and suppression on the fat saturation sequence. The tumor mass extended from the foramen magnum to T2 vertebra level. Ventral displacement of the spinal cord with kinking of the cervico-medullary junction was evident on the T2-weighted sagittal image. Partial resection of the tumor mass through laminoplastic laminotomy from C1 to T2 resulted in improved motor weakness on his upper extremities.

• 한국임상수의학회지
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• 제29권5호
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• pp.368-371
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• 2012

본 연구는 개흉술을 실시한 11 마리 개에서 수술 후 흉강 내 음압 형성을 위한 흉강 튜브 삽입방법으로 넓은 등근 아래 흉강 튜브 삽입 방법의 효과를 평가하기 위해 실시 하였다. 흉강 튜브 삽입을 위해 수술 창 뒤쪽으로 다섯 번째 늑간 늑골 위 피부와 넓은 등근에 작은 절개창을 형성하였다. 지혈겸자를 장착한 흉강 튜브를 근육 아래 터널을 통과하여 흉강 내로 삽입하였으며 튜브 장착 후 절개창 주위에 매트리스 봉합법을 이용하여 봉합사를 설치하였다. 수술 후 흉강 내 음압을 형성한 다음 흉강 튜브를 제거하였다. 튜브 관련 부작용을 확인 하기 위해 튜브 삽입 시 튜브 꺽임 현상과 수술 후 신체 검사 및 방사선 검사를 통한 기흉, 피하 기종, 호흡곤란 여부를 확인 하였다. 튜브 삽입 시 튜브 꺽임 현상과 수술 후 기흉 및 호흡 곤란 증상이 11 마리 개 모두에서 확인 되지 않았다. 신체 검사에서 튜브 삽입 주위 피하 기종이 한 마리에서 관찰 되었으나 별다른 치료 없이 3일 후에 사라졌음을 확인 할 수 있었다. 음압 형성 후 평균 (${\pm}SD$) 추적 기간은 $19{\pm}10$ 개월 이었다. 결론적으로 넓은 등근 아래 흉강 튜브 삽입 방법은 튜브가 흉강 내 유지 될 때와 튜브 제거 후 남게 되는 터널을 통한 흉강 내 공기 유입 차단에 효과적이며 흉강 튜브 장착 시 우선적으로 고려 되야 할 방법으로 사료 된다.

• Advances in nano research
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• 제8권3호
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• pp.255-264
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• 2020

Buckling and post-buckling cases are often occurred in aorta artery because it affected by higher pressure. Also, its stability has a vital importance to humans and animals. The loss of stability in arteries may lead to arterial tortuosity and kinking. In this paper, post-buckling analysis of aorta artery is investigated under axial compression loads on the basis of Euler-Bernoulli beam theory by using finite element method. It is known that post-buckling problems are geometrically nonlinear problems. In the geometrically nonlinear model, the Von Karman nonlinear kinematic relationship is employed. Two types of support conditions for the aorta artery are considered. The considered non-linear problem is solved by using incremental displacement-based finite element method in conjunction with Newton-Raphson iteration method. The aorta artery is modeled as a cylindrical tube with different average diameters. In the numerical results, the effects of the geometry parameters of aorta artery on the post-buckling case are investigated in detail. Nonlinear deflections and critical buckling loads are obtained and discussed on the post-buckling case.

• Archives of Reconstructive Microsurgery
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• 제25권2호
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• pp.72-74
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• 2016

The keystone flap is a fascia-based island flap with two conjoined V-Y flaps. Here, we report a case of successful treatment of a trochanter pressure sore patient with the traditional keystone flap. A 50-year-old male patient visited our department with a $3{\times}5cm$ pressure sore (grade III) to the left of the greater trochanter that was covered with eschar. Debridement was done and the defect size increased to $5{\times}8cm$ in an elliptical shape. Doppler ultrasound was then used to locate the inferior gluteal artery perforator near the wound. The keystone flap was designed to the medial side. The perforator based keystone island flap covered the defect without resistance. The site remained clean, and no dehiscence, infection, hematoma, or seroma developed. In general, greater trochanter pressure sores are covered with a perforator based propeller flap or fascia lata flap. However, these flaps have the risk of pedicle kinking and require a large operation site. For the first time, we successfully applied the keystone flap to treat a greater trochanter pressure sore patient. Our design was also favorable with the relaxation skin tension lines. We conclude that the keystone flap including a perforator is a reliable option to reconstruct trochanteric pressure sores.

• 한국표면공학회지
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• 제32권6호
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• pp.647-657
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• 1999

Due to the inherently poor adhesion strength of Cu-based leadframe/EMC (Epoxy Molding Compound) interface, popcorn cracking of thin plastic packages frequently occurs during the solder reflow process. In the present work, in order to enhance the adhesion strength of Cu-based leadframe/EMC interface, black-oxide layer was formed on the leadframe surface by chemical oxidation of leadframe, and then oxidized leadframe sheets were molded with EMC and machined to form SDCB (Sandwiched Double-Cantilever Beam) and SBN (Sandwiched Brazil-Nut) specimens. SDCB and SBN specimens were designed to measure the adhesion strength between leadframe and EMC in terms of critical energy-release rate under quasi-Mode I ($G_{IC}$ ) and mixed Mode loading ($G_{C}$ /) conditions, respectively. Results showed that black-oxide treatment of Cu-based leadframe initially introduced pebble-like X$C_2$O crystals with smooth facets on its surface, and after the full growth of $Cu_2$O layer, acicular CuO crystals were formed atop of the $Cu_2$O layer. According to the result of SDCB test, $Cu_2$O crystals on the leadframe surface did not increase ($G_{IC}$), however, acicular CuO crystals on the $Cu_2$O layer enhanced $G_{IC}$ considerably. The main reason for the adhesion improvement seems to be associated with the adhesion of CuO to EMC by mechanical interlocking mechanism. On the other hand, as the Mode II component increased, $G_{C}$ was increased, and when the phase angle was -34$^{\circ}$, crack Kinking into EMC was occured.d.

• 대한안전경영과학회지
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• 제23권4호
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• pp.61-66
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• 2021

In this study, according to the staking method of the fire hose in the indoor hydrant system, the number of kinks when the fire hose is deployed was measured and analyzed to examine how the staking method of the fire hose affects the kink when the hose is deployed. The fire hose staking method was classified into three types: donut-type, accordion-type, and hose hanger-type, and the walking speed and number of kinks were measured by repeating the experiment 5 times for male and female students. The results of the study are as follows. (1) Among the three types of fire hose staking methods, the donut-type staking method had an average of 92 times for male students and 86 times for female students on average. (2) The accordion-type and hose hanger-type staking methods showed similar results with an average of one or two kinks for both male and female students. (3) Regardless of the staking method, it was found that in general, male students with high walking speed had more kinking than female students with slow walking speed.

• 한국분말재료학회지
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• 제21권4호
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• pp.277-285
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• 2014

The effects of processing parameters on the flow behavior and microstructures were investigated in hot compression of powder metallurgy (P/M) Ti-6Al-4V alloy. The alloy was fabricated by a blended elemental (B/E) approach and it exhibited lamellar ${\alpha}+{\beta}$ microstructure. The hot compression tests were performed in the range of temperature $800-1000^{\circ}C$ with $50^{\circ}C$ intervals, strain rate $10^{-4}-10s^{-1}$, and strain up to 0.5. At $800-950^{\circ}C$, continuous flow softening after a peak stress was observed with strain rates lower than $0.1s^{-1}$. At strain rates higher than $1s^{-1}$, rapid drop in flow stress with strain hardening or broad oscillations was recorded. The processing map of P/M Ti-6Al-4V was designed based on the compression test and revealed the peak efficiency at $850^{\circ}C$ and $0.001s^{-1}$. As the processing temperature increased, the volume fraction of ${\beta}$ phase was increased. In addition, below $950^{\circ}C$, the globularization of phase at the slower strain rate and kinking microstructures were found. Based on these data, the preferred working condition of the alloy may be in the range of $850-950^{\circ}C$ and strain rate of $0.001-0.01s^{-1}$.

• Archives of Plastic Surgery
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• 제37권1호
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• pp.46-51
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• 2010

Purpose: The loss of web space is caused by congenital syndactyly or acquired burn injury, trauma or surgery. Numerous surgical procedures have been described for restoration of the web space. Local flaps are usually preferred because of the easiness to perform and tolerable postoperative outcome. Among the various local flaps, the authors introduce V-M plasty for correction of web space contracture and syndactyly. Method: From March 2007 to Jun 2008, 4 patients underwent V-M plasty for correction of web space contracture and syndactyly. V-M plasty consists of 3 distinct triangular flaps. One triangular flap is designed next to the web region on the dorsal site of the hand, whereas the remaining 2 triangular flaps are placed on the volar site. The dorsal triangular flap is then placed between the volar adjacent triangular flaps. At the end of the operation, the involved fingers or toes are positioned in abduction to avoid kinking of the triangular flaps. Result: All the patients gained web functions with good esthetic appearance without any recurrence or complications. Mean follow-up was 8 months. Conclusion: V-M plasty is a safe, easy and rapid procedure to design and apply by using local tissues without the needs for a skin graft or risk of linear scarring and recurrence. The authors advise this versatile technique both in primary and recurrent cases of web space contracture and syndactyly.

• Journal of Chest Surgery
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• 제40권3호
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• pp.225-227
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• 2007

대동맥 wrap-inclusion 술식은 고유의 Bentall 수술에서 수술 후 지나친 수술의 예방을 위해 자주 사용되었다. 비록 이 수술이 대동맥근질환이 있는 환자의 경과를 향상시켰다고는 하나 관상동맥 연결부위의 관상동맥 협착, 비틀림, 가성동맥류 형성 등의 조기 및 만기 합병증의 발생률이 높은 것으로 알려져 있다. Wrap-inclusion 술식을 이용한 복합이식 후 대동맥 주위 가성동맥류 형성은 비교적 드물지만 치명적인 합병증으로 본원에서는 45세의 여자 환자에서 inclusion technique으로 Bentall수술을 받은 후 10년만에 발생한 대동맥주위 가성동맥류를 Cabrol 방법을 이용하여 성공적으로 치료하였기에 보고하는 바이다.

• Journal of Chest Surgery
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• 제5권2호
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• pp.107-112
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• 1972

Recently we experienced a case of the portal hypertension, extrahepatlc origin in the National Medical Center, Seoul. The case was a male aged 19 who was undergone the elective splenorenal shunt with splenectomy 9 years ago and emergency ligation of the coronary vein because of recurred variceal rupture 6 years later and had recurring esophageal varices with bleeding this time.At the age of 10 he had been occasionally suffering from nasal bleeding and visited to our Pediatric department, when there was encountered for the first time the splenomegaly, esophageal varices in the lower third esophagus on the esophagogram, and stenosis and kinking of the portal vein with rich collateral circulation on the splenoportography without hepatic functional impairment.The elective splenorenal shunt with splenectomy was undergone under the diagnosis of portal hypertension due to congenital anomaly of the portal vein and postoperatlvely no troubles had been obtained until postoperative 1st attack of massive hematemesis due to esophagenl variceal rupture recurred about 6 years later which was confirmed by control esophagogram and it was resulted by stenosis of previous anastomotic site of the splenorenal shunt.Then emergency ligation of the coronary vein was only made for bleeding control and no episodes of hematemesis had been encountered thereafter until April 1972 about 3 years after the 2nd operation, when hematemesis recurred again. In this time, recurring esophageal varices were noted in the lower third esophagus on the control esophagogram and he was employed side to end mesocaval shunt as the final step of portal decompression,and following results were obtained. 1] No postoperatlve troubles as leg edema or pain: Postoperatively leg elevation and elastic bandage on the both legs were employed until discharge. 2] During operation the portal pressure was 300 mm $H_2O$ and immediately lowered to 170 mm $H_2O$ after shunt.