• 대한기계학회논문집A
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• 제30권4호
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• pp.457-464
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• 2006

The anterior cruciate ligament (ACL) is liable to a major injury that often results in a functional impairment requiring surgical reconstruction. The success of reconstruction depends on such factors as attachment positions, initial tension of ligament and surgical methods of fixation. The purpose of this study is to find isometric positions of the substitute during flexion/extension. The distance between selected attachments on the femur and tibia was computed from a set of measurements using a 6 degree-of-freedom magnetic sensor system. A three-dimensional knee model was constructed from CT images and was used to simulate length change during knee flexion/extension. This model was scaled for each subject. Twenty seven points on the tibia model and forty two points on the femur model were selected to calculate length change. This study determined the maximum and minimum distances to the tibial attachment during flexion/extension. The results showed that minimum length changes were $1.9{\sim}5.8mm$ (average $3.6{\pm}1.4mm$). The most isometric region was both the posterosuperior and anterior-diagonal areas from the over-the-top. The proposed method can be utilized and applied to an optimal reconstruction of ACL deficient knees.

• Journal of Chest Surgery
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• 제15권2호
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• pp.188-193
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• 1982

Between 1967 and 1980, a total of 99 patients with a benign stricture of esophagus, resulting from a chemical burn, underwent a reconstructive procedure in which various segments of colon were used to bridge the gap between the cervical esophagus and the stomach. There were 42 males and 57 females and most were in their twenties and thirties. The most frequent site of the stricture was upper 1/3 of the thoracic esophagus [48.5%] and the next most common site was the low cervical esophagus [23.2%]. In 89 cases, the right colon with or without the terminal ileum was used as the conduit in an isoperistaltic manner and in 10, the left colon was used in an antiperistaltic position, because the right colon was not suitable as the conduit. There was a higher incidence of regurgitation [90% vs 0%], leakage at cervical anastomosis [80% vs 27%] and stenosis at anastomotic site [70% vs 15%] in an antiperistaltic left colon anastomosis, as compared to isoperistaltic right colon anastomosis. This was felt to be due to the orad peristaltic motion of the transplanted colon which acted as a functional obstruction distal to the esophagocolic suture line, resulting in breakdown of the anastomosis, leakage and eventual stenosis at the site of anastomosis. In conclusion, colon is useful and effective conduit as an esophageal substitute. Either the right or the left colon can be used for this purpose, provided that it is placed in an isoperistaltic position to minimize some of the complications listed above.

• Journal of Microbiology
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• 제40권4호
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• pp.319-326
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• 2002

Cellular DNA in prokaryotes is organized in nucleic acid-protein self-assemblies referred to as the nucleoid. The physical forces responsible for its stability inside the poor solvent properties of the cytoplasm and their functional implications are not understood. Studies on the organisation and functioning of the cytosol of cells largely rely on experimental protocols performed in highly dilute solutions using biochemically purified molecules, which is not a reliable substitute for the situation existing in vivo. Our current research interest is focused on the characterization of biological and physical forces determining the compaction and phase separation of DNA in Escherichia coli cytoplasm. We have emphasized the effect of excluded volume in solutions with high macromolecular concentrations (macromolecular crowding) upon self-association patterns of reactions. The prokaryotic cytosol was simulated by addition of inert polymer polyethylene glycol (PEG) (average molecular weight 20000), as an agent which afterwards facilitates the self-association of macromolecules. Fluorescence microscopy was used for direct visualization of nucleoids in intact cells, after staining with DAPI (4',6-diamidino-2-phenylindole dihydrochloride). Addition of the crowding agent PEG 20,000, in increasing concentrations generated progressively enhanced nucleoid compaction, the effect being stronger in the presence of 0.2 M NaCl and 5 mM MgCl$\_$2/. Under these conditions, the nucleoids were compacted to volumes of around 2 ㎛$\^$3/ or comparable sizes with that of living cells.

• Archives of Reconstructive Microsurgery
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• 제15권2호
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• pp.51-57
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• 2006

Free flap having been used for reconstruction of skin and soft tissue defect in various areas in a body is spreading up its application for not only functional reconstruction but also aesthetic reconstruction. Authors met with good results minimizing the demerits of anastomosis using suture through microvascular anastomotic device, hereupon, we intend to report this. We worked with 27 cases that used microvascular anastomotic device for venous anastomoses among patients who were processed free flap in our hospital. Age ranged from 12 to 63 (average 43.2), and there were 12 females and 15 males. As a result of a follow-up by 3 months - 5years (average 11.3 months), there was no particular complication in the anastomosed vein except 1 cases among 27 cases that sutured their veins through microvascular anastomotic device. Use of microvascular anastomotic device at free flap shortened the time required for vascular anastomoses to reduce ischemic time of tissue, and minimized the damage of intima during anastomoses and made easy anastomoses possible even in case the difference of diameters of blood vessels being sutured is wide. As well, even for survival rate of flap, satisfactory results were obtained compared with using suture. Consequently, it is concluded that use of microvascular anastomotic device in free flap is a useful way that can substitute existing anastomosis using suture.

• 한국식품영양학회지
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• 제27권4호
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• pp.588-595
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• 2014

Aloe is an attractive potential food source because it has functional uses. It has been widely used as a well-being food and drink. The antioxidant activity was estimated by measuring DPPH free radical scavenging activity. We investigated the quality characteristics of cookies prepared by adding various concentrations of aloe powder (0%, 1%, 3%, 5%, all w/w) as a substitute for flour. In this study, the DPPH free radical scavenging activity, moisture content, and hardness of cookies significantly increased with increasing aloe powder, while the pH, spread factor and L and b values slightly decreased. Sensory evaluation scores in terms of texture were shown to be very similar statistically, but color, flavor, taste, and overall acceptability scores were lower than the control. As a result of this study, the quality of cookies with the addition of 1% aloe powder were the most suitable in terms of taste, flavor, texture, and sensory properties.

• 한국식품조리과학회지
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• 제24권4호
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• pp.511-516
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• 2008

In this study, composite flour and dough were prepared with concentrated sweet pumpkin powder(CSPP) at varying concentrations of 3, 6, 9, 12, and 15%. The samples and a control were then compared with regards to quality characteristics, including moisture, protein, and ash contents, farinogram characteristics, amylogram characteristics, and falling number of flour and extensogram characteristics of dough, in an effort to determine the optimal ratio of CSPP in the formulation. As the CSPP content increased, the moisture and protein contents of the flour increased, whereas the ash contents decreased. With regard to the farinogram characteristics of flour, water absorption, development time, and stability decreased with increasing CSPP content, while weakness increased. The control group evidenced a significantly higher beginning temperature of gelatinization as compared to the CSPP samples. The temperature of maximum viscosity, maximum viscosity, and falling number of flour decreased with increasing CSPP content. With regard to the extensogram characteristics of dough, extensibility decreased with increasing testing time and CSPP content, whereas resistance, maximum resistance, and R/E ratio increased. In conclusion, these results show that $6{\sim}9%$ CSPP may prove very useful as a substitute for wheat flour in the production of hardroll bread, and may provide good nutritional and functional properties.

• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.521-527
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• 2014

This case series evaluated the clinical efficacy of autogenous tooth bone graft material (AutoBT) in alveolar ridge preservation of an extraction socket. Thirteen patients who received extraction socket graft using AutoBT followed by delayed implant placements from Nov. 2008 to Aug. 2010 were evaluated. A total of fifteen implants were placed. The primary and secondary stability of the placed implants were an average of 58 ISQ and 77.9 ISQ, respectively. The average amount of crestal bone loss around the implant was 0.05 mm during an average of 22.5 months (from 12 to 34 months) of functional loading. Newly formed tissues were evident from the 3-month specimen. Within the limitations of this case, autogenous tooth bone graft material can be a favorable bone substitute for extraction socket graft due to its good bone remodeling and osteoconductivity.

• 식품과학과 산업
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• 제51권4호
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• pp.313-324
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• 2018

As excessive intake of salt is regarded as a reason for health problems, the tendency of people to attempt to reduce intake of salt in their everyday lives is on the rise. In Korea, where many people have a higher intake of salt compared to those in other countries, there have been diverse efforts to improve on this eating habit. Protein hydrolysates are chemically, physically hydrolyzed protein that have been widely utilized as a material for not only regular food but health functional food due to have diverse biological effects such as anti-oxidation, anti-inflammation, prevention of diabetes, and regulation of blood pressure. Various amino acids such as glutamic acid, arginine and arginine dipeptides, which exist in the components of protein hydrolysates, have also been recently recognized as being helpful in decreasing the use of salt in foods as they can greatly enhance salty taste when used concurrently with salt due to having both salty and palatable flavors. In the case of protein hydrolysates that decompose soy protein or fish protein such as anchovy, they could reduce consumption of salt by as much as 50% without affecting people's food preferences when applied to food as they boost salty taste by approximately 10% to 70%. Although there are only a few studies on protein hydrolysates as a salty taste enhancer or salt substitute, the results of several studies are indicative of the potential of protein hydrolysates as a salty taste enhancing ingredient.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2453-2466
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• 2022

Nuclear power plant operators in the main control room are exposed to stressful conditions in emergency situations as immediate and appropriate mitigations are required. While emergency operating procedures (EOPs) provide operators with the appropriate tasks and diagnostic guidelines, EOPs have static properties that make it difficult to reflect the dynamic changes of the plant. Due to this static nature, operator workloads increase because unrelated information must be screened out and numerous displays must be checked to obtain the plant status. Generally, excessive workloads should be reduced because they can lead to human errors that may adversely affect nuclear power plant safety. This paper presents a framework for an operator support system that can substitute the initial responses of the EOPs, or in other words the immediate actions and diagnostic procedures, in the early stages of an emergency. The system assists operators in emergency operations as follows: performing the monitoring tasks in parallel, identifying current risk and latent risk causality, diagnosing the accident, and displaying all information intuitively with a master logic diagram. The risk causalities are analyzed with a functional modeling methodology called multilevel flow modeling. This system is expected to reduce workloads and the time for performing initial emergency response procedures.

• 청정기술
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• 제27권2호
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• pp.124-131
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• 2021

국제정치와 세계경제의 이슈가 되고 있는 '탄소중립'에 대한 선언이 전 세계적으로 이어지면서, 석유 기반 고분자를 생분해가 가능한 천연고분자로의 대체 연구가 활발히 진행되고 있다. 본 연구에서는 천연고분자 중에서도 세계에서 가장 많은 양을 차지하고 있는 나노셀룰로오스를 대체재로 제안하였다. 실란커플링제인 Glycidoxypropyl Trimethoxysilane (GPTMS)를 이용한 결정형 나노셀룰로오스의 표면작용기개질반응으로 하이브리드 나노셀룰로오스(hybrid nanocellulose, HNC)를 제조하였고, 저밀도폴리에틸렌(low density polyethylene, LDPE)과 함께 필름을 형성하였다. 친수성인 결정형나노셀룰로오스의 표면작용기개질반응을 확인하기 위해 소수성으로 바뀌는 것을 푸리에 변환 적외선 분광분석(fourier transform infrared spectrophotometer, FT-IR)과 친수/친유화도를 측정하였으며, 하이브리드 나노셀룰로오스를 적용한 고분자 복합체의 물성 확인을 위해 친수/친유화도, 인장강도, 투명도를 확인하였다. 석유기반 고분자와의 상용성은 pH 14에서 반응한 HNC가 LDPE 대비 1 wt%일 때, 인장강도와 투명도가 가장 우수하며, 결과적으로 실란커플링제를 이용한 나노셀룰로오스의 표면작용기개질이 가능하고 석유 기반 고분자와의 높은 상용성으로 인해 탄소중립을 위한 화석연료의 사용량을 줄일 수 있을 것으로 기대된다.