• Archives of Plastic Surgery
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• 제34권2호
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• pp.197-202
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• 2007

Purpose: The gluteal artery perforator flaps earned its popularity in buttock reconstruction due to the lower morbidity of the donor site and the flexibility in the design. Speedy and safe reconstruction is important for the success of buttock reconstruction. If a proper design is selected, satisfactory results can be obtained with more simple method of surgery. Methods: Between April 2005 and April 2006, buttock reconstruction by using gluteal artery perforator flaps were performed on sacral sores(6 cases), ischial sores(2 cases) and malignant melanoma on buttock(1 case). Various designs depending on the location and the size of the defect was made. In those designs, perforator was used as an axis for the minimal dissection of the vessel. Donor site from which sufficient amount of soft tissue can be transferred was selected, and also not causing high tension against the recipient site during the donor site closure. In addition, postoperative aesthetics, and the possibility of another design of a second operation which can be necessary in the future, was considered. Results: Patient follow up was for a mean period of 10.8 months. All flaps survived except for one that had undergone partial necrosis. Wound dehiscence was observed in one patient treated by secondary closure. Most patients presented with cosmetically and functionally satisfying results Conclusion: By designing the flap using the perforator as an axis, depending on the defect size and degree, reconstruction can be performed with only a small tension to the donor and the recipient site. And the minimal perforator dissection allowed easier and faster reconstruction. Selection of a proper design is the key procedure which greatly affects operation time and result success.

• 한국가금학회지
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• 제42권3호
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• pp.239-245
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• 2015

Transgenic animals have been widely used for developmental biology studies, as disease models, and even in industry such as transgenic bioreactor animals. For transgenic birds, quail has the great advantages of small body size, short generation time, and frequent egg production. To date, retroviral or lentiviral transduction has been used to generate transgenic quail for various purposes. However, the efficiency of transgenic offspring production with these methods is relatively low and viral vector usage has safety issues. Unfortunately, non-viral transgenesis has not been established in quail due to a deficiency of stem cell and germ cell culture systems. In this study, we established a direct in ovo lipofection method that could be used to create transgenic quail without germline-competent cells or viruses. To optimize the injection stage during embryo development, the liposome complex (containing piggyBacCMV-GFP and transposase plasmids) was introduced into an embryonic blood vessel at 50 hr, 55 hr or 60 hr. GFP expression was detected in various tissues (heart, kidney, liver and stomach) on day 12 of incubation under a fluorescence microscope. Additionally, GFP-positive cells were detected in the recipient embryonic gonads. In conclusion, the direct in ovo lipofection method with the piggyBac transposon could be an efficient and useful tool for generating transgenic quail.

• Journal of Chest Surgery
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• 제47권3호
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• pp.220-224
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• 2014

Background: For the surgical management of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), there have been various techniques that reduce the tension and kinking of the coronary artery during reimplantation to the aorta. The aim of this study is to describe the results of our modified technique of coronary reimplantation for the treatment of ALCAPA. Methods: Between October 2003 and February 2011, seven patients underwent coronary reimplantation with the modified technique (tubing formation with the sinus wall of the pulmonary artery and trapdoor formation at the site of implantation in the aorta). The median follow-up duration was 52 months (range, 4 to 72 months). Clinical outcomes and serial echocardiographic data were reviewed. Results: There was no mortality. One patient had a small amount of cerebral hemorrhage postoperatively and improved without any sequelae. Another patient had left diaphragm palsy and underwent diaphragm plication. Follow-up echocardiogram showed that all patients had normal ventricular function without chamber enlargement. Conclusion: Our modified technique (tubing formation with the sinus wall of the pulmonary artery and trapdoor formation at the site of implantation in the aorta) demonstrated successful clinical outcomes. We conclude that this surgical technique can be a potential alternative for the treatment of ALCAPA.

• Childhood Kidney Diseases
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• 제10권1호
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• pp.40-44
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• 2006

[ $Henoch-Sch{\"{o}}nlein$ ] 자반증은 소혈관의 혈관염으로 오는 전신적 혈관 장애로 자반, 위장 증세, 관절 증세, 신 증세를 주 증세로 하는 질환이다. HSP의 흔한 피부증상은 주로 궁둥이와 하지의 자반 증상이며 성인에서는 출혈성 수포를 동반하는 경우가 흔하나 소아에서는 드문 것으로 알려져 있다. 저자들은 관절통과 복통을 호소하는 환아에서 출혈성 수포가 동반되어 있어 피부조직 검사를 하였고 진피의 leukocytoclastic vasculitis와 면역 형광법상 소혈관의 IgA와 fibrinogen의 침착을 관찰하였다. HSP로 진단하여 스테로이드 치료를 하였고 수일 내로 관절통과 복통이 호전되어 문헌고찰과 함께 보고하는 바이다.

• Journal of Korean Medical Science
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• 제33권46호
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• pp.289.1-289.10
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• 2018

Background: Cerebral microbleeds (CMBs) are associated with cerebrovascular risk factors and cognitive dysfunction among patients with Parkinson's disease (PD). However, whether CMBs themselves are associated with PD is to be elucidated. Methods: We analyzed the presence of CMBs using 3-Tesla brain magnetic resonance imaging in non-demented patients with PD and in age-, sex-, and hypertension-matched control subjects. PD patients were classified according to their motor subtypes: tremor-dominant, intermediate, and postural instability-gait disturbance (PIGD). Other cerebrovascular risk factors and small vessel disease (SVD) burdens were also evaluated. Results: Two-hundred and five patients with PD and 205 control subjects were included. The prevalence of CMBs was higher in PD patients than in controls (16.1% vs. 8.8%; odds ratio [OR], 2.126; P = 0.019); CMBs in the lobar area showed a significant difference between PD patients and controls (11.7% vs. 5.9%; OR, 2.234; P = 0.032). According to the motor subtype, CMBs in those with PIGD type showed significant difference from controls with respect to the overall brain area (21.1% vs. 8.9%; OR, 2.759; P = 0.010) and lobar area (14.6% vs. 4.9%; OR, 3.336; P = 0.016). Among PD patients, those with CMBs had higher age and more evidence of SVDs than those without CMBs. Conclusion: We found that CMBs are more frequent in PD patients than in controls, especially in those with the PIGD subtype and CMBs on the lobar area. Further study investigating the pathogenetic significance of CMBs is required.

• Nuclear Engineering and Technology
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• 제52권5호
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• pp.937-946
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• 2020

The aim in the present work is to simulate accident scenarios of AP1000 during the small-break loss-of-coolant accident (SBLOCA) and investigate the performance and behavior of automatic depressurization system (ADS) during accidents by using MIDAC (The Module In-vessel Degradation severe accident Analysis Code). Four types of accidents with different hypothetical conditions were analyzed in this study. The impact on the thermal-hydraulic of the reactor coolant system (RCS), the passive core cooling system and core degradation was researched by comparing these types. The results show that the RCS depressurization becomes faster, the core makeup tanks (CMT) and accumulators (ACC) are activated earlier and the effect of gravity water injection is more obvious along with more ADS valves open. The open of the only ADS1-3 can't stop the core degradation on the basis of the first type of the accident. The open of ADS1-3 has a great impact on the injection time of ACC and CMT. The core can remain intact for a long time and the core degradation can be prevent by the open of ADS-4. The all results are significant and meaningful to understand the performance and behavior of the ADS during the typical SBLOCA.

• Journal of Korean Neurosurgical Society
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• 제62권5호
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• pp.526-535
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• 2019

Objective : While the risk of aneurysmal rebleeding induced by catheter cerebral angiography is a serious concern and can delay angiography for a few hours after a subarachnoid hemorrhage (SAH), current angiographic technology and techniques have been much improved. Therefore, this study investigated the risk of aneurysmal rebleeding when using a recent angiographic technique immediately after SAH. Methods : Patients with acute SAH underwent immediate catheter angiography on admission. A four-vessel examination was conducted using a biplane digital subtraction angiography (DSA) system that applied a low injection rate and small volume of a diluted contrast, along with appropriate control of hypertension. Intra-angiographic aneurysmal rebleeding was diagnosed in cases of extravasation of the contrast medium during angiography or increased intracranial bleeding evident in flat-panel detector computed tomography scans. Results : In-hospital recurrent hemorrhages before definitive treatment to obliterate the ruptured aneurysm occurred in 11 of 266 patients (4.1%). Following a univariate analysis, a multivariate analysis using a logistic regression analysis revealed that modified Fisher grade 4 was a statistically significant risk factor for an in-hospital recurrent hemorrhage (p=0.032). Cerebral angiography after SAH was performed on 88 patients ${\leq}3$ hours, 74 patients between 3-6 hours, and 104 patients >6 hours. None of the time intervals showed any cases of intra-angiographic rebleeding. Moreover, even though the DSA ${\leq}3$ hours group included more patients with a poor clinical grade and modified Fisher grade 4, no case of aneurysmal rebleeding occurred during erebral angiography. Conclusion : Despite the high risk of aneurysmal rebleeding within a few hours after SAH, emergency cerebral angiography after SAH can be acceptable without increasing the risk of intra-angiographic rebleeding when using current angiographic techniques and equipment.

• 해양환경안전학회지
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• 제25권5호
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• pp.627-633
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• 2019

본 논문의 주 관심사항은 전산유체역학과 기존 모형시험 데이터를 활용하여 주어진 선박의 저항 및 추진성능을 추정하고 그 결과를 이용하여 에너지효율설계지표(Energy Efficiency Design Index, EEDI)를 평가하는 방법을 제시하는 것이다. 대상선박의 모형선 크기에서의 전 저항을 계산하기 위해 점성 유동 해석을 수행하였다. 유동계산은 STAR-CCM+를 사용하였으며 자유표면, 트림과 싱키지를 고려하였다. 점성 유동 해석 결과를 바탕으로 대상선박의 유효동력을 산정하였다. 준 추진효율 계수는 기 보유한 모형시험 데이터베이스를 이용한 추정식 및 유사선박의 시험자료를 활용하여 산정하였다. 최종적으로 EEDI 산정식에 대하여 유체동역학적 결과, 선박의 정보, 사용하는 연료에 대한 $CO_2$의 환산계수, 연료소모량 등을 바탕으로 일반화된 계산 프로그램을 작성하였다.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1738-1748
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• 2019

Previous research has shown that the inclined condition has an impact on the natural circulation (natural circulation) mode operation of Floating Nuclear Power Plant (FNPP) mounted on the movable marine platform. Due to its compact structure, small volume, strong maneuverability, the Integral Pressurized Water Reactor (IPWR) is adopted as marine reactor in general. The OTSGs of IPWR are symmetrically arranged in the annular region between the reactor vessel and core support barrel in this paper. Therefore, many parallel natural circulation loops are built between the core and the OTSGs primary side when the main pump is stopped. and the inclined condition would lead to discrepancies of the natural circulation drive head among the OTSGs in different locations. In addition, the flow rate and temperature nonuniform distribution of the core caused by inclined condition are coupled with the thermal hydraulics parameters maldistribution caused by OTSG group operating mode on low power operation. By means of the RELAP5 codes were modified by adding module calculating the effect of inclined, heaving and rolling condition, the simulation model of IPWR in inclined condition was built. Using the models developed, the influences on natural circulation operation by inclined angle and OTSG position, the transitions between forced circulation (forced circulation) and natural circulation and the effect on natural circulation operation by different OTSG grouping situations in inclined condition were analyzed. It was observed that a larger inclined angle results the temperature of the core outlet is too high and the OTSG superheat steam is insufficient in natural circulation mode operation. In general, the inclined angle is smaller unless the hull is destroyed seriously or the platform overturn in the ocean. In consequence, the results indicated that the IPWR in the movable marine platform in natural circulation mode operation is safety. Selecting an appropriate average temperature setting value or operating the uplifted OTSG group individually is able to reduce the influence on natural circulation flow of IPWR by inclined condition.

• 대한금속재료학회지
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• 제48권3호
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• pp.194-202
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• 2010

Application of a stronger and more durable material for reactor pressure vessels (RPVs) might be an effective way to insure the integrity and increase the efficiency of nuclear power plants. A series of research projects to apply the SA508 Gr.4 steel in ASME code to RPVs are in progress because of its excellent strength and durability compared to commercial RPV steel (SA508 Gr.3 steel). In this study, the microstructural characteristics and mechanical properties of SA508 Gr.3 Mn-Mo-Ni low alloy steel and SA508 Gr.4N Ni-Mo-Cr low alloy steel were investigated. The differences in the stable phases between these two low alloy steels were evaluated by means of a thermodynamic calculation using ThermoCalc. They were then compared to microstructural features and correlated with mechanical properties. Mn-Mo-Ni low alloy steel shows the upper bainite structure that has coarse cementite in the lath boundaries. However, Ni-Mo-Cr low alloy steel shows the mixture of lower bainite and tempered martensite structure that homogeneously precipitates the small carbides such as $M_{23}C_6$ and $M_7C_3$ due to an increase of hardenability and Cr addition. In the mechanical properties, Ni-Mo-Cr low alloy steel has higher strength and toughness than Mn-Mo-Ni low alloy steel. Ni and Cr additions increase the strength by solid solution hardening. In addition, microstructural changes from upper bainite to tempered martensite improve the strength of the low alloy steel by grain refining effect, and the changes in the precipitation behavior by Cr addition improve the ductile-brittle transition behavior along with a toughening effect of Ni addition.