• KSBB Journal
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• v.18 no.4
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• pp.340-345
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• 2003

Feasibility of large-scale photobioreactors for biological CO$_2$ fixation was investigated using Chlorella sp. HA-1. Generally, as the volume of photobioreactor increased, the CO$_2$ fixation rate decreased because of a lower illumination efficiency in large-scale than in small-scale photobioreactors. Though controlling the arrangement and the number of light source, the maximum CO$_2$ fixation rates that could be achieved were 530 and 357 gCO$_2$/㎡day for 40 L and 188 L photobioreactor, respectively, which was higher than the CO$_2$ fixation rate of lab-scale photobioreactor.

• Journal of Energy Engineering
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• v.2 no.3
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• pp.300-307
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• 1993

To develop high performance nickel-iron secondary battery, the characteristics of charge-discharge reaction of iron electrode were examined by cyclic voltammetry technique, SEM and XRD analysis. The capacity of the test electrodes was determined by the constant current charge-discharge method. It was found that the temperature and concentration of electrolyte were the major determinant factors of electrode capacity, and especially the 1st discharge capacity was increased with the increase of temperature. The effect of fore forming agent on the electrode capacity was negligible. The electrode capacity was above 350 ㎃h/g(36% utility) at 0.25C discharge rate. The stability of electrode was very good, but the activation occurred slowly.

• Applied Chemistry for Engineering
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• v.22 no.6
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• pp.711-717
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• 2011

Two dimensional simulation results of a capacitively coupled oxygen plasma in a cylindrical reactor geometry are presented. Detailed electron impact reaction rates, which strongly depend on electron energy, are computed from collision cross sections of electrons with $O_2$ and O. Through the coupling of a three moment plasma model with a neutral chemistry/transport model are predicted spatiotemporal distributions of both charged species (electron, $O_2{^+}$, $O^+$, $O_2{^-}$, and $O^-$) and neutral species including ground states ($O_2$ and O) and metastables, known to play important roles in oxygen plasma, such as $O_2(a^1{\Delta}_g)$, $O_2(b^1{{\Sigma}_g}^+)$, $O(^1D)$, and $O(^1S)$. The simulation results clearly verify the existence of a double layer near sheath boundaries in the electronegative plasma.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.71-71
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• 2018

현재 상용화된 Graphite 음극활물질의 경우 낮은 부피당, 무게당 용량을 가지며 이는 다양한 분야에 활용하는데 제약이 있다. $SiO_2$는 Si에 비해서는 낮은 용량이지만 metal oxide 계열 중 가장 높은 이론용량을 가지고 있으며, 리튬 이온과 반응 시 큰 부피팽창을 하며, 절연체로 전기전도도가 낮아 리튬이 차전지의 음극재로 상용화가 어려운 단점이 있다. 본 연구에서는 TEOS를 이용하여 탄소와 $SiO_2$를 동시에 $TiO_2$ microcone 구조에 코팅하여 3가지 물질의 복합체를 형성하여 용량을 증대시키고 구조적 안전성을 향상시키는 방법을 소개 한다. 음극재의 특성은 고분해능 주사전자현미경 (HR-SEM), 고분해능 엑스선 회절분석기 (XRD), 를 통해 조사하였으며, 순환전류법 (CV), 충 방전 싸이클 분석을 통해 리튬이차전지의 작동원리와 보다 향상된 성능을 규명하였다.

• Journal of Life Science
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• v.25 no.8
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• pp.889-895
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• 2015

Endothelial dysfunction is an initial step in atherosclerosis. B vitamins (B6, B12, and folate) are important contributing factors to vascular homeostasis. Deficiencies in these B vitamins induce cardiovascular diseases by altering vascular homeostasis. Folate plays important roles in nitric oxide homeostasis in the endothelium. To determine the dose-dependent effect of dietary folate on atherosclerosis, we studied aortic relaxation and hepatic C-reactive protein (CRP) levels in C57BL/6 mice. In this study, a total of 54 male C57BL/6, 8-wk old mice were split into 2 dietary groups (control and Western style diet). Each diet group was divided into 3 subgroups according to dietary folate dosage (0.2, 2, and 8 mg/kg). After 18 months, the relaxation response seen in aortic rings from mice fed 0.2 or 2 mg folate/kg in both diet groups. However, the aortic relaxation response was not seen and no differences were observed in mice fed 8mg folate/kg in either diet group (p<0.05). Hepatic CRP levels at all folate dosages (0.2, 2, 8 mg folate/kg) were higher in the groups fed a Western style diet than in mice fed a control diet (p=0.035). CRP levels were lower in mice fed 0.2 mg folate/kg than in mice fed 2 or 8 mg folate/kg in both diet groups (p<0.05). These results indicate that in C57BL/6 mice 0.2 mg folate/kg may be enough to prevent atherosclerosis by inducing the relaxation responses of the aorta and by reducing levels of hepatic CRP, regardless of dietary style.

• The Korean Journal of Applied Statistics
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• v.22 no.5
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• pp.1033-1046
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• 2009

In new drug development studies or clinical trials, zero-dose control is needed in general to determine the lowest dose level for a new drug which can act with our bodies. When the lowest dose level compared with zero-dose control has significant difference in effect, it is referred as minimum effective dose(MED). We propose, in this paper, parametric sequential test using updated control to identify the minimum effective dose(MED) level. Monte Carlo Simulation is adapted to examine the power and experimental significance levels of the proposed method with other methods.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.113-119
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• 1999

Purpose : To evaluate possible acute toxicity and early response of concurrent radiation therapy and low dose daily cisplatin as a radiosensitizer in patients with locally advanced uterine cervical carcinomas. Materials and Method : From December 1996 to January 1999, 38 previously untreated Patients with locally advanced squamous cell carcinoma of the uterine cervix (from stage IIB to stage IIIB) were treated at Inha University Hospital. All patients underwent standard pretreatment staging Procedures after the initial evaluation by gynecologists and radiation oncologists. Sixteen Patients with huge cervical mass (>4 cm) were submitted to the group treated with concurrent radiation therapy and low dose daily cisplatin while the remainder was treated with radiation therapy alone. Radiation therapy consisted of 4500 cGy external beam irradiation to whole pelvis (midline block after 3000 cGy), 900$\~$1000 cGy boost to involved parametrium, and high dose-rate intracavitary brachytherapy (a total dose of 3000$\~$3500 cGy/500 cGy per fraction to point A, twice per week). In the group treated with low dose cisplatin concurrently, 10 mg of daily intravenous cisplatin was given from the 1st day of radiation therapy to the 20th day of radiation therapy. Acute toxicity was measured according to expanded common toxicity criteria of the NCI (C) Clinical Trials. Early response data were analyzed at minimum 4 weeks' follow-up after completion of the treatment protocol. Results: Hematolgic toxici쇼 was more prominent in patients treated with radiation therapy and cisplatin. Six of 16 patients (37.5$\~$) treated with radiation therapy and cisplatin and one of 22 patients (4.5$\~$) treated with radiation therapy alone experienced grade 3 leukopenia. In Fisher's exact test, there was statistically significant difference between two groups regarding leukopenia (P=0.030). There was no apparent difference in the frequency of gastrointestinal and genitourinary toxicity between two groups (P=0.066). Three of 16 patients (18.7$\~$) treated with radiation therapy and cisplatin and two of 22 patients (9.1$\~$) treated with radiation therapy alone experienced more than 5 kg weight loss during the treatment. There was no statistically significant difference on weight loss between two groups (P=0.63). Two patients on each group were not evaluable for the early response because of incomplete treatment. The complete response rate at four weeks' follow-up was 80$\~$(16/20) for the radiation therapy alone group and 78$\~$ (11/14) for the radiation therapy and cisplatin group. There was no statistically significant difference in early response between two treatment groups (P=0.126). Conclusion : This study led to the conclusion that the hematologic toxicity from the treatment with concurrent radiation therapy and low dose daily cisplatin seems to be more prominent than that from the treatment of radiation therapy alone. There was no grade 4 hematologic toxicity or mortality in both groups. The hematologic toxicity in both treatment groups seems to be well managable modically. Since the risk factors were not balanced between two treatment groups, the direct comparison of early response of both groups was not possible. However, preliminary results regarding early response for patients with bulky cervical tumor mass treated with radiation therapy and low dose daily cisplatin was encouraging. Longer follow-up is necessary to evaluate the survival data. A phase III study is needed to evaluate the efficacy of concurrent daily low dose cisplatin with radiation therapy in bulky cervical cancer.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.11a
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• pp.81-85
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• 1997

인체에 투여된 약물의 반응은 개체간에 현저한 차이가 있으며 특히 환자에게 투여된 약물의 효과가 상이하게 나타남으로써 치료의 실패나 흑은 약물의 유해작용으로 나타나기도 한다. 이러한 개체 상호간의 약물반응의 차이는 환경적인 요소, 영양학적인 요소, 연령, 병용한 다른 약물 및 이미 앓고 있는 질병 등에 의해서도 영향을 받으나 특히 유전적으로 결정된 약물대사 능력의 차이에 의해서도 기인된다. 이러한 측면에서 약물 대사의 유전적인 다양성과 비정상적인 반응을 다루는 약물유전학의 중요성은 최근 두드러지게 대두되고 있다. 특히 유전적인 요인으로 개체간의 차이는 효소의 유전적인 결핍과 관련이 있으며 이 결핍은 생체이물질에 대한 반응의 다양성을 설명할 수 있는 약물대사 능력의 다형성에 기인한다. 또한 약물반응의 다양성은 인종간, 특히 동양인과 서양인에서의 약물반응에서도 차이가 있어 각 인종간의 약물반응의 차이에 대한 연구와 이의 원인규명에 대하여 많은 관심이 집중되고 있다. 이와 같은 견지에서 약물용량과 약물반응, 특히 약동학적 변화의 인종간의 차이와 각 개인의 차이 및 이의 원인에 대하여 살펴보고자 한다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.123-123
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• 1993

Acetylsalicylic acid (aspirin)와 인삼의 항산화 성분인 maltol의 축합반응으로 합성된 신물질 Aspalatene이 저용량: 장기 복용시 항산화활성과 더불어 지혈시간 연장효과가 탁월함을 보고 한 바 있다. Aspalatone은 aspirin과는 달리, 장기 복용시에도 위궤양 유발 작용이 거의 나타나지 않으므로 말초순환개선제로서의 개발이 기대된다. 본 연구에서는 Aspalatone의 항혈전작용을 in vivo, ex vivo 및 in vitro에서 연구하였다. Mouse thromboembolism test를 이용한 in vivo실험에서 Aspalatone은 aspirin과 유사하게 collagen에 의한 치사를 유의적으로 감소시켰으며 ADP에 의한 치사에는 영향을 미치지 않았다. 또한 10일간의 장기 투여 실험에서는 저용량에서 영향을 미치지 않았다. 또한 10일간의 장기 투여 실험에서는 저용량에서 항혈전 작용을 나타내며 투여 중단 4일 후에도 약효가 유지되는 것을 밝혔다. 이는 Aspalatone이 aspirin과 같이 cycloosygenase에 작용하여 항혈전 작용을 나타냄을 강력히 시사하고 있다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.190-190
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• 1994

아급성독성시험 : DA-125를 1.0, 0.2, 0.04 mg/kg/day의 용량으로 4주간 정맥내투여시 고용량군에서만 세포분화가 빠른 골수, 비장, 흉선 등의 장기에서 독성이 나타났으며 중간 및 저용량군에서는 독성변화가 나타나지 않았다. 2)항원성시험 : DA-125는 단독 또는 면역보조제(CFA)와의 혼합감작에 의하여 능동전신성 또는 수신피부 아나필라시스를 일으키지 않았으며 면역확산법에 의해서도 항체가 확인되지 않았다. 면역독성시험에서 DA-125는 흉선, 비장의 위축과 임파구중식억제를 나타냈으나 그 정도는 DXR보다 경미하였다. 3)혈완장해시험 : 0.4%의 DA-125 용액은 토끼의 이개정맥내 정맥주사 및 저류시에 혈전형성이나 염증반응 등의 혈관장해를 나타내지 않았으나, 0.2%의 DXR용액은 약한 염증반응을 보였다.