• 대한수의학회지
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• 제43권3호
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• pp.471-476
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• 2003

Malignant catarrhal fever (MCF) is a systemic disease of ruminants caused by ovine herpesvirus 2 (OvHV-2). OvHV-2 is a gamma herpesvirus, which induces frequent latent infection and often difficult to detect its antigens and even specific nucleic acids because of its low viral copies in the infected tissues. Histopathology, serology and polymerase chain reaction (PCR) were compared for the diagnosis of MCF using 10 bison infected with OvHV-2. Histopathological diagnosis was performed using the criteria which was based upon the pathognomic lesions. Serological diagnosis was conducted using its serum with competitive ELISA for the detection of antibodies of OvHV-2. Also, the nest PCR was performed with peripheral blood leukocytes for the detection of OvHV-2-specific DNAs. Primers 556 and 775 were used for the primary amplification, and primers 556 and 555 were used for the secondary amplification. As the results, positive cases were 6 by histopahology, 9 by serology and 10 by PCR. As comparing with other diagnostic methods, PCR was found to be more sensitive than histopathology and serology. The recent development of molecular diagnostic assays has provided powerful tools for investigating how viruses survive in nature. Development of PCR specific for viruses has dramatically improved the accuracy of diagnosis of viruses in clinically infected animals. Furthermore, amplification of viral genomic material by nest PCR represents the most sensitive method for the detection of viruses and might be detected successfully even though very low viral DNA copies. So, it could be used as the first choice for the detection of viral DNAs with low copies such as the status of latent infection. However, it has also some limitation of application like as false negative results by PCR inhibitors and false positive results by contamination. The results of this study suggest that the use of molecular biological methods like PCR may increase the accuracy for the diagnosis of infectious diseases. However, in diagnostic laboratory, it is recommended that PCR assay must be conducted with other diagnostic methods for more reliable diagnosis.

• International Journal of Vascular Biomedical Engineering
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• 제2권2호
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• pp.1-9
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• 2004

The history of studies in biology regarding reactive oxygen species (ROS) is approximately 40 years. During the initial 30 years, it appeared that these studies were mainly focused on the toxicity of ROS. However, recent studies have identified another action regarding oxidative signaling, other than toxicity of ROS. Basically, it is suggested that ROS are reactive, and degenerate to biomolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have shown that ROS act as oxidative signaling in cells, resulting in various gene expressions. Recently ROS emerged as critical signaling molecules in cardiovascular research. Several studies over the past decade have shown that physiological effects of vasoactive factors are mediated by these reactive species and, conversely, that altered redox mechanisms are implicated in the occurrence of metabolic and cardiovascular diseases ROS is a collective term often used by scientist to include not only the oxygen radicals($O2^{-{\cdot}},\;{^{\cdot}}OH$), but also some non-radical derivatives of oxygen. These include hydrogen peroxide, hypochlorous acid (HOCl) and ozone (O3). The superoxide anion ($O2^{-{\cdot}}$) is formed by the univalent reduction of triplet-state molecular oxygen ($^3O_2$). Superoxide dismutase (SOD)s convert superoxide enzymically into hydrogen peroxide. In biological tissues superoxide can also be converted nonenzymically into the nonradical species hydrogen peroxide and singlet oxygen ($^1O_2$). In the presence of reduced transition metals (e.g., ferrous or cuprous ions), hydrogen peroxide can be converted into the highly reactive hydroxyl radical (${^{\cdot}}OH$). Alternatively, hydrogen peroxide may be converted into water by the enzymes catalase or glutathione peroxidase. In the glutathione peroxidase reaction glutathione is oxidized to glutathione disulfide, which can be converted back to glutathione by glutathione reductase in an NADPH-consuming process.

• 전기학회논문지
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• 제67권7호
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• pp.946-953
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• 2018

Photo-plethysmography (PPG), which measures changes in the peripheral blood flow of a human body using difference in absorption rate of light, is a measurement method that is studied and used in clinical and various applications due to its simple circuit configuration and measurement convenience. Magneto-plethysmography (MPG), which is newly developed by our team, is a method of measuring changes in the conductivity of biological tissues by using a eddy current induced by a time-varying magnetic field, and is not subject to optical interference. In this study, we investigated the detection characteristics of MPG according to the change of the conductivity of the object and fluid to be measured by simultaneously measuring PPG and MPG. In order to control the speed of fluid known in advance, a blood flow simulator was implemented and used. The fluid used in the experiment was general mineral water and physiological saline (0.9% NaCl) solution. Experimental results show that the amplitude change of the measured PPG was 0.3% in normal water and saline solution, and that of MPG was 77.3%. Therefore, it is considered that the magneto-plethysmography (MPG) has a strong correlation with the conductivity of the fluid.

• 한국자기공명학회논문지
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• 제18권1호
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• pp.30-35
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• 2014

The transcription factor CP2 regulates various biological systems at diverse tissues and cells. However, none of the four CP2 isoforms has been solved in structure yet. In particular, two different regions of the CP2b isoform have been characterized to interact with the PIAS1 in nucleus to regulate the ${\alpha}$-globin gene expression. Among them, in this study, the region encompassing residues 251-309 of CP2b was prepared as a recombinant protein and its solution structure was characterized by NMR spectroscopy. The results indicated that the CP2b(251-309) fold belongs to typical IDRs (intrinsically disordered regions), likely to facilitate promiscuous interactions with various target proteins. Unfortunately, however, its interaction with the N-terminal domain of PIAS1 (residues 1-70), which has been identified as one of the CP2b-binding sites, was not observed in the NMR-based titration experiments. Therefore, it could be postulated that the 251-309 region of CP2b would not contact with the PIAS1(1-70), but alternatively interact with another CP2b-binding region that encompasses residues 400-651 of PIAS1.

• 한국통신학회논문지
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• 제39A권12호
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• pp.764-770
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• 2014

불규칙 매체를 투과하는 광학적 이미징 시스템은 피부나 생물학적 조직등의 내부를 비침습적 이미징 기법을 사용해 관찰할 수 있게 해줄 것으로 큰 기대를 받고 있다. 불규칙 매체를 통한 이미징은 대개 불규칙 매체의 투과 특성을 전달 행렬로 모델링 및 측정하고, 측정된 전달 행렬을 사용하여 이미지를 복구하는 방식을 사용한다. 이러한 전달 행렬 기반의 이미징 방법은 많은 양의 데이터를 측정 하고 후 신호 처리를 해야 한다는 어려움을 가지고 있다. 최근에는, 이 데이터 획득 문제를 압축센싱이라는 방법을 사용해 해결할 수 있다는 결과들이 있었다. 압축센싱은 상대적으로 새로운 신호 획득 및 복구 체계로써 아주 적은 양의 신호 측정만으로도 신호를 정확하게 복구해 낼 수 있다. 본 논문에서는 불규칙 매체를 통과하는 이미징에서의 전달 행렬 기반의 이미지 복구 방법이 검토되며, 또한 압축센싱을 사용한 최신 연구 동향을 소개하고자 한다.

• 한국의학물리학회지:의학물리
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• 제11권1호
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• pp.85-90
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• 2000

방사선치료에서 치료의 효과는 총선량, 치료회수, 1회 조사선량 등에 의해서 결정된다. 선량강도조절법을 사용하여 방사선치료를 행할 때 치료회수나 1회 조사선량을 고려하여 총선량에 미치는 효과를 살펴보고자 한다. 방사선치료의 목적은 암조직에는 충분한 선량을 조사하면서 주위 정상 조직에는 최소한의 선량을 조사되게 하여 치료성적의 향상으로 암환자의 생존율과 삶의 질을 높이는데 목적이 있다. 이러한 문제를 해결하기 위하여 많은 연구자들이 여러 가지 방법으로 해결하고자 노력한 결과 CT의 영상을 치료계획에 이용할 수 있게 되어 three dimensional conformal radiation therapy(3DCRT)를 개발하였다. 선량강도조절법을 시행하여 총선량을 75, 80, 85, 90Gy를 조사할 때, 처음부터 선량강도조절법을 사용하여 치료하는 경우와 일차적으로 45Gy를 조사하고 boost를 조사할 때 나머지 선량을 선량강도조절 법으로 사용하는 것을 TDF 환산법을 사용하여 비교하였다. 처음부터 선량강도조절법으로 치료할 경우에는 총선량에서 약 12.5 - 15 Gy 정도 감해서 조사하여야 하는 것으로 나타났다.

• Biomolecules & Therapeutics
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• 제23권6호
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• pp.539-548
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• 2015

Prostaglandin $E_2$ ($PGE_2$), a major product of cyclooxygenase, binds to four different prostaglandin $E_2$ receptors (EP1, EP2, EP3, and EP4) which are G-protein coupled transmembrane receptors (GPCRs). Although GPCRs including EP receptors have been shown to be associated with their specific G proteins, recent evidences suggest that GPCRs can regulate MAPK signaling via non-G protein coupled pathways including Src. EP2 is differentially expressed in various tissues and the expression of EP2 is induced by extracellular stimuli. We hypothesized that an increased level of EP2 expression may affect MAPK signaling. The overexpression of EP2 in HEK 293 cells resulted in significant increase in intracellular cAMP levels response to treatment with butaprost, a specific EP2 agonist, while overexpression of EP2 alone did not increase intracellular cAMP levels. However, EP2 overexpression in the absence of $PGE_2$ induced an increase in the level of p38 phosphorylation as well as the kinase activity of p38, suggesting that up-regulation of EP2 may promote p38 activation via non-G protein coupled pathway. Inhibition of Src completely blocked EP2-induced p38 phosphorylation and overexpression of Src increased the level of p38 phosphorylation, indicating that Src is upstream kinase for EP2-induced p38 phosphorylation. EP2 overexpression also increased the Src activity and EP2 protein was co-immunoprecipitated with Src. Furthermore, sequential co-immunoprecipitation studies showed that EP2, Src, and ${\beta}$-arrestin can form a complex. Our study found a novel pathway in which EP2 is associated with Src, regulating p38 pathway.

• 한국방사선학회논문지
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• 제2권2호
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• pp.23-30
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• 2008

방사광 X-선 현미경은 임상실험에 유용한 도구로 높은 배율과 고 해상도로 동물 장기조직 시료의 세부 구조를 관찰할 수 있다. X-선 영상은 위상 대조도 메커니즘으로 설명할 수 있다. 우리는 쥐의 꼬리, 신경 및 허파의 in-vivo 및 in-vitro위상 대조도 영상을 8 KeV mono 빔으로부터 10배 현미경대물렌즈와 CCD 카메라를 이용하여 얻었다. 기존의 흡수 X-선 영상 보다 SR 영상이 세밀한 구조의 높은 분해능 영상을 볼 수 있었다. SR 영상은 생물학, 재료 및 임상 연구에 무한한 가능성을 가지고 있다.

• Journal of Animal Science and Technology
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• 제54권6호
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• pp.383-394
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• 2012

Microarray analyses provide information that can be used to enhance the efficiency of livestock production. For example, microarray profiling can potentially identify the biological processes responsible for the phenotypic characteristics of porcine liver. We performed transcriptome profiling to identify differentially expressed genes (DEGs) in liver of pigs from two breeds, the Korean native pigs (KNP) and Yorkshire pigs. We correctly identified expected DEGs using factor analysis for robust microarray summarization (FARMS) and robust multi-array average (RMA) strategies. We identified 366 DEGs in liver (p<0.05, fold-change>2). We also performed functional analyses, including gene ontology and molecular network analyses. In addition, we identified the regulatory relationship between DEGs and their transcription factors using in silico and qRT-PCR analysis. Our findings suggest that DEGs and their transcription factors may have a potential role in adipogenesis and/or lipid deposition in liver tissues of two pig breeds.

• 대한의용생체공학회:의공학회지
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• 제28권1호
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• pp.153-161
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• 2007

Stroke is the second most significant disease leading to death in Korea. The conventional therapeutic approach is mainly based on physical training, however, it usually provides the limited degree of recovery of the normal brain function. The electric stimulation therapy is a novel and candidate approach with high potential for stroke recovery. The feasibility was validated by preliminary rat experiments in which the motor function was recovered up to 80% of the normal performance level. It is thought to improve the neural plasticity of the nerve tissues around the diseased area in the stroked brain. However, there are not so much research achievements in the electric stimulation for stroke recovery as for the Parkinson's disease or Epilepsy. This study aims at the developments of a wireless variable pulse generator using ZigBee communication for future implantation into human brain. ZigBee is widely used in wireless personal area network (WPAN) and home network applications due to its low power consumption and simplicity. The developed wireless pulse generator controlled by ZigBee can generate various electric stimulations without any distortion. The electric stimulation includes monophasic and biphasic pulse with the variation of shape parameters, which can affect the level of recovery. The developed system can be used for the telerehabilitation of stroke patient by remote control of brain stimulation via ZigBee and internet. Furthermore, the ZigBee connection used in this study provides the potential neural signal transmission method for the Brain-Machine Interface (BMI).