• 대한의용생체공학회:의공학회지
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• 제19권2호
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• pp.153-162
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• 1998

인공 심장의 연구에 있어서 혈류 역학 변수의 추정은 두말할 필요도 없이 매우 중요하다. 그러나 이 중요도에 견주어 볼지라도 실세계에 적용될 수 있는 연구 결과는 희박하다. 본 논문에서는 이동 작동기형 완전 인공 심장을 위한 혈류 역학 변수 추정 문제가 연구되었다. 추정 방법론으로서 다차원 선형 보간 기법을 이용하였다. 모의 순환 장치의 실험으로 제안된 방법을 검증하였으며 좋은 성능을 보였다.

• Journal of Plant Biotechnology
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• 제32권4호
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• pp.275-279
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• 2005

Brassica campestris var. narinosa는 새싹채소로 애용되는 식물로서 간단한 용기에서 손쉽게 재배할 수 있다. 본 연구에서는 vacuum-infiltration을 통한 Agrobacterium-mediated transformation에 의해서 B. campestris var. narinosa 싹에서의 GUS일시발현을 성공적으로 확인하였다. 발아전의 종자가 발아를 이미 시작한 종자보다 그 형질전환 효율이 높게 나타났다. 한편, hydrogen peroxide를 2일 생장시킨 싹에 처리한 후 형질전환 하였을 때 GUS발현이 증가되는 것을 관찰하였다. 간염항원유전자의 형질전환과 ELISA에 의한 항원단백질의 발현량 분석 시 hydrogen peroxide 처리 싹이 비처리 형질전환 싹에서 보다 2배 이상의 발현량이 측정되었다.

• 대한의용생체공학회:의공학회지
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• 제14권4호
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• pp.307-314
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• 1993

Plasma protein adsorption is the first event in the blood-material interaction and influenc- es subsequent platelet adhesion towards thlㅈombus formation. Thiㅈomboembolic events are strongly influenced by surface characteristics of materials and fluid dynamics inside the blood pump. In vitro flow visualizaion and an amimal experiment with the moving actuator type TAH were Performed in order to investigate fluid dynamic effects on the protein adsorption. The diffel'encl level, j of shear rate inside the ventricle Lvere determined by consid- ering the direction of the major opening of four healt valves in the implanted TAH and the visualized flow patterns as well. Each ventricle of the explanted TAH was sectionalized into 12 segments according to the shear rate level. The adsorbed protein on each segment was quantified using the ELISA method after soaking in 2% (wye)SDS/PBS for two days. Adsorbed protein layer thicknesses Itvere measured by the Immunogotd method under TEM. The SEM observation show that right ventricle (RV) , immobilized with albumin, displayed different degrees of platelet adhesion on each segment, whereas the left ventricle (LV), grafted by PEO-sulronate, indicated nearly , iame platelet adhesion behavior, regardless of shear rates. The surface concentrations of adsorbed proteins in the low shear rate region are hlghel'than those in the high region, which was confirmed statistically. A modified adsorption model of plasma protein onto polyurethane surface was suggested by considering the effect of the fluid dynamic characteristics.

• The Korean Journal of Pain
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• 제11권2호
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• pp.253-257
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• 1998

Background: The purpose of this study was to examine the extent and evaluation of pain after total abdominal hysterectomy (TAH) and to establish correlation between three types of pain; pain at rest, pain with movement and pain with coughing (maximum pain). Methods: The present study compared quality of pain during pain management in 48 patients undergoing TAH. Patients received i.v. meperidine as loading dose in the recovery room and PCA with nalbuphine 90 mg, ketorolac 180 mg, buprenorphine 0.9 mg, droperidol 5 mg, plasma solution A 28 ml for 3 days. The PCA device used was the Baxter infusor$^{(R)}$ (PCA module PC-19-55, 0.5 ml/hr basal rate, 15 minute lockout interval). Patients were then interviewed on Operative Day (OPD), Postoperative Day 1, 2, and 3 (POD 1, 2 and 3) to assess their pain on a visual analogue scale (VAS) of 0 (none) to 10 (worst imaginable). Results: The mean pain score at rest was 2.0 on OPD and decreased to 0.7 on POD 3. The mean pain score with movement was 3.2 on OPD and decreased to 1.6 on POD 3. The mean pain score with coughing was 4.2 on OPD and decreased to 2.2 on POD 3. Conclusions: Patients' experience of three types of postoperative pain emphasizes the need for more effective pain management.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.249-250
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• 1998

In this study, we modeled moving-actuator type Total Artificial Heart (TAH) with cardiovascular system as a form of electric circuit. The bronchial circulation, important for the imbalance between the left cardiac output and the right one, was considered and added to the model. In the model, the relations of hemodynamic variables, just as blood pressures, volumes, or flow rates of each part of body, can be expressed as simultaneous first order ordinary differential equations. To solve the equations by the numerical analysis, Runge-Kutta forth order approximation method was adopted. The simulation software (SimTAH), implemented in C++ as a window-based application program, was developed to display the hemodynamic variables and to receive control inputs from users. SimTAH was evaluated by comparison of the simulation results with the results of mock-circulation tests, in vitro.

• Imaging Science in Dentistry
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• 제50권3호
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• pp.217-226
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• 2020

Purpose: The purpose of this study was to analyze the quantity and quality of the mandibular anterior alveolar bone in terms of alveolar width, density, and total alveolar height (TAH) based on dental status, gender, and age. Additionally, this study aimed to quantitatively evaluate the available alveolar height for graft harvesting (AHGH) and examine its variability based on the aforementioned factors. Materials and Methods: This retrospective cone-beam computed tomographic study included a total of 100 subjects. On the basis of gender, dental status, and age, the scans were divided into 3 primary groups and 8 subgroups. The mandibular alveolar width and density were measured 5 mm mesial to the mental foramen bilaterally and at the midline. The TAH was measured at the midline, and the AHGH was measured as the midline distance between 5 mm apical to the root of the canines and 5 mm superior to the lower border. Results: The mandibular alveolar width was statistically similar between dentulous and edentulous patients (P>0.05). A significantly greater density was observed at the midline in edentulous patients (P<0.05). The TAH was significantly greater in edentulous male patients than in edentulous female patients (P<0.05). Dentulous and male patients had significantly greater AHGH than edentulous and female patients, respectively (P<0.05). Conclusion: Based on the data evaluated in this study, it can be concluded that the mandibular symphyseal area has adequate bone quality and quantity for bone graft harvesting for dental implant therapy.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.82-83
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• 1996

In this paper, we present a simplified model for complicance determination of the moving-actuator type totally implantable artificial heart (TAH). The modeling equations are derived from the mechanics and geometry of the TAH components. The interventricular pressure and volume are computed for determining the compliance of the interventricular space using this model. The model is capable of generating realistic hemodynamic variables such as the left atrial pressure and interventricular pressure and is proved to be acceptable. This model can be used as an initial step for analyzing characteristics of the moving-actuator type TAH.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.88-90
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• 1996

The right and left atrial pressures are important parameters in automatic control of a total artificial heart (TAH) within normal physiological ranges. Our TAH is composed of a moving actuator, right and left ventricles and the interventricular space enclosed by a semi-rigid housing. During operation of the TAH, the jnterventpicular space's volume is changed dynamically by the difference between the ejection volume of one ventricle and the inflow volume of the other. Therefore, the changes in pressure of the interventricular space is related to both atrial pressures. We measured the interventricular pressure (IVP) waveform using a pressure sensor and attempted to indirectly estimate the changes of atrial pressures. This method has an advantage that the sensor does not contact the blood directly. Furthermore, the IVP waveforms have its zero baseline in each pump cycle, thus the pressure measurements are free from the transducer drift problems by measuring the peak pressure from these baseline values. From the In vitro experiments, we found that the IVP waveform contained several useful parameters such as negative peak, dP/dT on the initial break, the area enclosed by the profile in each stroke, which are associated with atrial pressures and the filling conditions of the ventricles. The measured atrial pressures were linearly related to the negative peak of the interventricular pressure.

• 한국식품저장유통학회지
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• 제19권1호
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• pp.19-25
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• 2012

새싹이나 어린잎과 같이 싹을 길러 이용할 수 있는 채소에 대한 관심이 커지고 있으나, 조직이 연해 수확 후 급격히 품질이 저하되어, 품질을 유지할 수 있도록 수확 전 재배에서부터 개선방법을 강구하고자 하였다. 본 실험에서는 다채의 어린잎 채소를 재배 중에 brushing처리를 주어 생육 및 재배 후 포장하여, 중량감소, 선도와 SPAD 등의 수확 전 요인에 따른 수확 후 변화 요인을 조사하였다. 수확 시 다채의 생육은 무처리구에 비해 물리적 brushing처리구에서 초장이나 생체중은 적었으나, 조직이 치밀한 것으로 나타났다. 재배 중 brushing처리한 어린 다채 잎은 저장 중 생체중량 변화, $O_2$ 소모나 $CO_2$ 축적 정도, 색차 변화가 적은 경향을 보였다. 그러나 SPAD값이나 선도에서는 처리간의 큰 차이를 보이지 않았다. 어린 다채 잎은 재배 중 물리적 brushing처리로 식물 조직이 치밀해지고, 생육은 적어졌으나, 포장 후 저장 특성은 다소 차이가 있었으나, 선도에는 큰 차이를 보이지 않은 것으로 나타났다. 어린잎 채소 다채는 재배 중 brushing처리에 의한 물리적 처리가 수확 후 미치는 영향이 크지 않아, 다른 방법으로 품질을 개선할 수 있는 연구가 필요할 것으로 생각된다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1992년도 추계학술대회
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• pp.153-156
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• 1992