• Radiation Oncology Journal
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• 제17권1호
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• pp.43-51
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• 1999

목적 : 연부조직종양을 제거한 직후 조직내 방사선치료용 도관을 삽입하여 근접방사선치료를 시행했던 증례들을 토대로 고선량율 조직내 방사선치료의 시술방법, 치료시기, 선량, 및 부작용 등에 대해 논의 하고자 한다. 재료 및 방법 : 1995년 5월에서 1997년 12월까지 10명의 원발성 혹은 재발성의 연부조직종양 환자가 종양의 제한적 절제술 후에 조직내 방사선치료 및 외부방사선치료를 시행받았다. 종양을 제거한 직후 도관을 종양이 있었던 자리에 1~l.5cm 간격으로 삽입하였고 종양 가까이에 신경혈관속 혹은 뼈가 있었던 경우에는 젤폼, 근육, 혹은 tissue expander로 덮어 이들 중요 구조물들과 도관이 적어도 0.5cm 간격을 유지하도록 하였다. 조직내 방사선치료는 이리디움-192가 장착된 고선량율 근접방사선치료기를 사용하여 수술 후 6일째부터 시작하였고 동위원소의 중심축으로부터 1cm 거리에 총 12~15Gy(2~2.SGy/fraction)를 일일 2회씩 3일간 시행하였다. 수술 후 한 달 이내에 외부방사선치료를 시행하였으며 총 50~55Gy를 조사하였다. 결과 : 모든 환자가 감염이나 출혈과 같은 근접방사선치료와 직접 관련된 부작용 없이 계획되어진 조직내 방사선치료를 마쳤다. 중앙 추적관찰기간 25개월째(범위 12~41개월)까지 국소재발은 관찰되지 않았고 RTOG/EORTC 등급 3 혹은 4의 만성 부작용도 없었다. 결론 : 주위정상조직에 조사되는 방사선량을 최소화하면서 수술 후 단기간 내에 시행할 수 있는 고선량율 조직내 방사선치료는 연부조직종양의 제한적 수술 후의 치료방법으로써 안전하고 손쉽게 이용할 수 있으며 또한 치료효과 및 부작용 측면에서도 우수한 치료방법이다.

• Archives of Plastic Surgery
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• 제41권6호
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• pp.661-667
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• 2014

Background Tissue expansion is an effective and valuable technique for the reconstruction of large skin lesions and scars. This study aimed to evaluate the applicability and safety of a newly designed skin expanding bioreactor system for maximizing the graft area and minimizing the donor site area. Methods A computer-controlled biaxial skin bioreactor system was used to expand skin in two directions while the culture media was changed daily. The aim was to achieve an expansion speed that enabled the skin to reach twice its original area in two weeks or less. Skin expansion and subsequent grafting were performed for 10 patients, and each patient was followed for 6 months postoperatively for clinical evaluation. Scar evaluation was performed through visual assessment and by using photos. Results The average skin expansion rate was $10.54%{\pm}6.25%$; take rate, $88.89%{\pm}11.39%$; and contraction rate, $4.2%{\pm}2.28%$ after 6 months. Evaluation of the donor and recipient sites by medical specialists resulted in an average score of 3.5 (out of a potential maximum of 5) at 3 months, and 3.9 at 6 months. The average score for patient satisfaction of the donor site was 6.2 (out of a potential maximum of 10), and an average score of 5.2 was noted for the recipient site. Histological examination performed before and after the skin expansion revealed an increase in porosity of the dermal layer. Conclusions This study confirmed the safety and applicability of the in vitro skin bioreactor, and further studies are needed to develop methods for increasing the skin expansion rate.

• 대한기계학회논문집B
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• 제36권9호
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• pp.937-944
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• 2012

선박의 주 추진용 디젤엔진에서 배출되는 배기가스의 폐열을 회수하는 발전시스템에 대하여, 작동유체로서 물이 적용된 3 변 사이클에 대한 열역학적 특성을 이론적으로 조사하였다. 그 결과로, 하나의 열원이 주어지면, 에너지 및 엑서지 효율은 터빈입구에서 작동유체에 대한 압력 및 온도의 특정한 조건에 의하여 최대화될 수 있었다. 그러한 조건에 대하여 응축온도의 증가에 따라, 터빈의 체적 팽창비를 적절하게 감소시킬 수 있었는데, 열원의 엑서지 손실률 및 응축기에서 엑서지 파괴율이 크게 증가되었다. 따라서, 상부 사이클에서 버려지는 엑서지를 회수하기 위하여, 저온 열원에 적합한 유기랭킨사이클을 하부 사이클로 적용하는 복합 사이클이 유용할 수 있다.

• 펄프종이기술
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• 제39권4호
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• pp.68-75
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• 2007

In order to supplement insufficient nutrients of paper sludges, additional materials such as saw dust and rice husk were added during preparation of bed soils. Rice husk was more finely ground, compared to saw dust. The fine particles of the rice husk prevented their flow in a barrel of the expander. The mixed additives with paper sludges could be used to control the quantity of required nutrients for raising plants. That is, except for potassium and manganese, most of nutrients were decreased with adding the additives to paper sludge. The acidity of the paper sludges mixed with the saw dust or the rice husk was a little decreased with the increased amount of the additives. Differently from the bulk density of the paper sludges, the moisture content and the water absorption rate of the paper sludges were incremented with increasing the additives.

• Archives of Plastic Surgery
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• 제48권5호
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• pp.483-493
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• 2021

Background Direct-to-implant (DTI) breast reconstruction after nipple-sparing mastectomy (NSM) with the use of acellular dermal matrix (ADM) provides reliable outcomes; however, the use of ADM is associated with a higher risk of complications. We analyzed our experiences of post-NSM DTI without ADM and identified the predictive factors of adverse surgical outcomes. Methods Patients who underwent NSM and immediate DTI or two-stage tissue expander (TE) breast reconstruction from 2009 to 2020 were enrolled. Predictors of adverse endpoints were analyzed. Results There were 100 DTI and 29 TE reconstructions. The TE group had a higher rate of postmastectomy radiotherapy (31% vs. 11%; P=0.009), larger specimens (317.37±176.42 g vs. 272.08±126.33 g; P=0.047), larger implants (360.84±85.19 g vs. 298.83±81.13 g; P=0.004) and a higher implant/TE exposure ratio (10.3% vs. 1%; P=0.035). In DTI reconstruction, age over 50 years (odds ratio [OR], 5.43; 95% confidence interval [CI], 1.50-19.74; P=0.010) and a larger mastectomy weight (OR, 1.65; 95% CI, 1.08-2.51; P=0.021) were associated with a higher risk of acute complications. Intraoperative radiotherapy for the nipple-areolar complex increased the risk of acute complications (OR, 4.05; 95% CI, 1.07-15.27; P=0.039) and the likelihood of revision surgery (OR, 5.57; 95% CI, 1.25-24.93; P=0.025). Conclusions Immediate DTI breast reconstruction following NSM is feasible in Asian patients with smaller breasts.

• 한국항해항만학회지
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• 제44권4호
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• pp.283-290
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• 2020

액화 수소 운반선에서 증발가스의 발생은 불가피하며, 화물탱크 내부의 압력 문제를 피하기 위해 적절한 조치가 필요하다. 이 증발 가스는 선박의 추진연료로 사용 될 수 있으며, 추진에 사용되고 남은 나머지 부분은 재액화 또는 연소시키는 등 효과적으로 관리해야 한다. 본 연구에서는 수소 추진 시스템을 갖춘 160,000㎥ 액화 수소 운반선에 최적화된 증발 가스 재액화 시스템을 제안한다. 이 시스템은 수소 압축 및 헬륨 냉매 섹션으로 구성되고, 화물탱크로부터 배출되는 증발가스의 냉열을 효과적으로 활용하여 효율을 증가시켰다. 본 연구에서는 공급 온도 -220℃인 수소 증발가스가 재액화 시스템에 들어가는 상태에서 증발가스의 재액화 비율에 따른 엑서지 효율 및 에너지 소모율 (SEC, Specific Energy Consumption) 분석을 통해 시스템을 평가하였다. 그 결과 재액화 비율 20%에서 4.11kWh/kgLH₂의 SEC와 60.1%의 엑서지 효율을 보여 주었다. 아울러, 수소 압축압력, 수소 팽창기의 입구온도, 공급 증발가스 온도변화에 따른 영향을 확인하였다.

• Archives of Plastic Surgery
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• 제44권6호
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• pp.516-522
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• 2017

Background Implant-based breast reconstruction is being performed more frequently, and implants are associated with an increased risk of infection. We reviewed the clinical features of cases of implant infection and investigated the risk factors for breast device salvage failure. Methods We retrospectively analyzed 771 patients who underwent implant-based breast reconstruction between January 2010 and December 2016. Age, body mass index, chemotherapy history, radiation exposure, and smoking history were assessed as potential risk factors for postoperative infection. We also evaluated the presence and onset of infection symptoms, wound culture pathogens, and other complications, including seroma, hematoma, and mastectomy skin necrosis. Additionally, we examined the mastectomy type, the use of acellular dermal matrix, the presence of an underlying disease such as hypertension or diabetes, and axillary node dissection. Results The total infection rate was 4.99% (58 of 1,163 cases) and the total salvage rate was 58.6% (34 of 58). The postoperative duration to closed suction drain removal was significantly different between the cellulitis and implant removal groups. Staphylococcus aureus infection was most frequently found, with methicillin resistance in 37.5% of the cases of explantation. Explantation after infection was performed more often in patients who had undergone 2-stage expander/implant reconstruction than in those who had undergone direct-to-implant reconstruction. Conclusions Preventing infection is essential in implant-based breast reconstruction. The high salvage rate argues against early implant removal. However, when infection is due to methicillin-resistant S. aureus and the patient's clinical symptoms do not improve, surgeons should consider implant removal.

• 한국가스학회지
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• 제19권3호
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• pp.9-17
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• 2015

한국에서 소비되는 대부분의 천연가스는 배관을 통한 수송을 위하여 높은 압력으로 압축되고, 수요처에 공급되기 전에 정압기지에서 다시 감압된다. 감압과정에서 간단하고 효율적인 설치를 위해 팽창밸브가 사용되었으나 팽창밸브에서는 압축을 통해 회수되는 에너지가 없다. 따라서 팽창밸브와 동일한 감압 기능을 수행하면서 압력에너지를 축일로 회수하여 전력을 생산할 수 있는 터보팽창기가 팽창밸브의 대안으로 제시되었다. 본 연구에서는 중압 정압기지에서 팽창밸브의 평균 입구, 출구 압력조건인 68.7 bar에서 23 bar로 감압될 때 입구의 온도, 유량조건에 따라서 생산 가능한 전력을 이론적으로 계산하였다. Peng-Robinson 상태방정식을 이용하여 천연가스를 순수한 메탄으로 고려한 경우와 소량의 질소와 탄화수소의 혼합물로 고려한 경우에 대한 열역학적 물성을 계산하였다. 2013년 공급량을 기준으로 터보팽창기 도입을 통해 회수 가능한 이론적인 최대 전력생산량은 순수한 메탄의 경우 1596 MW, 혼합물의 경우 1567 MW로 추산되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권12호
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• pp.1765-1772
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• 2002

Three experiments were conducted to determine the feed processing method best suited for early and conventionallyweaned pigs, and to investigate the effects of different extrusion temperatures on ileal digestibility of amino acids in diets containing different protein sources. In exp.1, a total of 108 pigs (Landrace${\times}$Yorkshire${\times}$Duroc; 24 d of age and 7.60 kg average body weight) were alloted on the basis of sex, weight and ancestry to three treatments in a randomized complete block design. Feed processing methods used were mash (M), simple pellet (SP), and expanded pellet (EP). In exp. 2, a total of 96 pigs (Landrace${\times}$Yorkshire${\times}$Duroc; 14 d of age) were allotted on the basis of sex, weight, and ancestry to three treatments in a randomized complete block design. Diets were mash (M), expanded pellet (EP), and expanded pellet crumble (EPC). In exp. 3, a study was designed to investigate the effect of different extrusion temperatures (100, 120, and $140^{\circ}C$) over the control (untreated) on the ileal digestibility of amino acids in diets containing protein sources such as spray-dried plasma protein (SDPP), whey protein concentrate (WPC), and fish meal (FM). Results in exp.1 showed that ADG, ADFI and the F/G ratio of pigs fed the SP diet were improved (p<0.05) compared with those fed the M or the EP diets, but the digestibility of nutrients was not different (p>0.05) among the treatments. In exp. 2, pigs fed expanded pellet treatments (EP or EPC) had a significantly improved (p<0.05) F/G ratio compared to the pigs fed the M diet which was primarily attributed to the significant reduction (p<0.05) in ADFI, but the overall growth rate of pigs fed expanded pellet diets was not improved. In exp. 3, there was a significant interaction effect (p<0.05) between the extrusion temperature and protein source on the ileal digestibility of amino acids. With an extrusion temperature of $100^{\circ}C$, the ileal digestibility of Lys, Val, Gly and Ser was significantly lower in the diet containing WPC compared to the diet containing SDPP. Increasing the temperature to $120^{\circ}C$ led to significant differences (p<0.05) in the digestibility of Thr and Tyr between diets containing WPC and SDPP. Regardless of extrusion temperatures, the weaned pigs' diet containing either SDPP or FM had significantly higher Lys, Phe, Thr, Val, and Gly digestibility relative to the WPC diet. Results of the present study suggest that simple pelleting of diets containing protein sources such as whey protein concentrate, spray-dried plasma protein and fish meal would be better than the extruded or expanded pellet diets. Extruder or expander processing of weaned pigs' feed could reduce palatability and ileal digestibility of several amino acids and therefore may be responsible for a negative growth response in weaned pigs.