• The Korean Journal of Physiology and Pharmacology
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• 제6권4호
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• pp.173-181
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• 2002

The sinoatrial (SA) node is a complex and inhomogeneous tissue in terms of cell morphology and electrical activity. There are two models of the cellular organisation of the sinoatrial node: the gradient and mosaic models. According to the gradient model there is a gradual transition in morphology and electrical properties of SA node cells from the centre to the periphery of the SA node. In the mosaic model, there is a variable mix of atrial and sinoatrial node cells from the centre to the periphery. This review focuses on the cellular organisation of the rabbit sinoatrial node in terms of the expression of connexin (Cx40, Cx43 and Cx45), L-type $Ca^{2+}$ channel and $Na^+-Ca^{2+}$ exchanger proteins. These immunocytochemical data, together with morphological and electrophysiological data, obtained from the intact sinoatrial node and isolated sinoatrial node cells support the gradient model of the cellular organisation of the SA node. The complex organisation of the sinoatrial node is important for the normal functioning of the sinoatrial node: (i) it allows the sinoatrial node to drive the surrounding hyperpolarized atrial muscle without being suppressed by it; (ii) it helps the pacemaker activity of the sinoatrial node continue under a wide range of physiological and pathophysiological conditions; (iii) it helps protect the sinoatrial node from reentrant arrhythmias.

• ETRI Journal
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• 제30권1호
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• pp.13-20
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• 2008

We evaluate the sink capacity of wireless code division multiple access (CDMA) sensor networks with layered architecture. We introduce a model of interference at a sink considering two kinds of interference: multiple access interference (MAI) and node interference (NI). We also investigate the activity of sensor nodes around the sink in relation to gathering data under a layered architecture. Based on the interference model and the activity of sensor nodes around the sink, we derive the failure probability of the transmission from a source node located one hop away from the sink using Gaussian approximation. Under the requirement of 1% failure probability of transmission, we determine the sink capacity, which is defined as the maximum number of concurrent sensor nodes located one hop away from the sink. We demonstrate that as the node activity of the MAI decreases, the variation of the sink capacity due to the node activity of the NI becomes more significant. The analysis results are verified through computer simulations.

• 센서학회지
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• 제18권6호
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• pp.432-440
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• 2009

This paper presents an accelerometer based system for physical activity decision that are capable of recognizing three different types of physical activities, i.e., standing, walking and running, using by rough sets. To collect physical acceleration data, we developed the body sensor node which consists of two custom boards for physical activity monitoring applications, a wireless sensor node and an accelerometer sensor module. The physical activity decision is based on the acceleration data collected from body sensor node attached on the user's chest. We proposed a method to classify physical activities using rough sets which can be generated rules as attributes of the preprocessed data and by constructing a new decision table, rules reduction. Our experimental results have successfully validated that performance of the rule patterns after removing the redundant attribute values are better and exactly same compare with before.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권4호
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• pp.289-300
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• 2001

Telomerase is a ribonucleoprotein that synthesizes telomere repeats. It has been reported that activation of telomerase was associtated with immortalization, proliferative activity and carcinogenesis. Recently, telomerase activity has been extensively studied in many kinds of malignant tumors for clinical diagnostic and/or prognostic utilities. In neuroblastoma, breast carcinoma, gastric carcinoma, non-small cell lung carcinoma, close relationship has been reported between high telomerase activity and lymph node metastasis, tumor aggressiveness and poor prognosis. The purpose of this study is to investigate the clinical implication of telomerase activity assay as an adjunctive factor in decision-making on neck node management, speedy pre-operative judging on histologic malignancy grading. Thus we performed semi-quantitative assay of telomerase activity using Telomerase PCR ELISA $kit^{(R)}$(Boeringer Manheim, Germany) and evaluated correlation between telomerase activity and tumor size, neck node metastasis, Anneroth malignancy score and influence of pre-operative chemotherapy on its activity in 27 cases of oral squamous cell carcinomas and 18 cases of normal oral epithelium. Also, correlation between telomerase activities and PCNA indices was evaluated. The results were obtained as follows: 1. The telomerase activities were detected in 24 specimens out of 27 oral squamous cell carcinoma specimens (88.9%) and in 5 specimens out of 18 normal oral epithelium specimens (27.8%). The mean value of telomerase activities was $0.9793{\pm}0.3428$ in 24 oral squamous cell carcinoma specimens and $0.4855{\pm}0.1117$ in 5 normal oral epithelium specimens. The positivity rate and mean value of telomerase activities in oral squamous cell carcinoma specimens were significantly higher than those of normal oral epithelium specimens (p<0.05). 2. There was no significant correlation between total Anneroth malignancy score and telomerase activity (p>0.05), but points of mitosis index and depth of invasion were significantly correlated with telomerase activities (p<0.05). 3. The positive immunohistochemical staining for PCNA(proliferating cell nuclear antigen) was observed in 26 specimens out of 27 oral squamous cell carcinoma specimens and mean value of PCNA indices of 26 specimens was $53.67{\pm}26.46$. PCNA indices were significantly correlated with telomerase activities (p<0.05). 4. The mean value of telomerase activities was significantly higher in pathologic T3/T4 group than in T1/T2 group (p<0.01). There was no significant difference of mean value of telomerase activities between pathologic neck node positive group and negative group (p> 0.05). Pre-operative chemotherapy significantly lowered the telomerase activities (p<0.05). The above results suggested telomerase activity could be used as diagnostic marker and adjunctive parameter for judging on histologic malignancy in oral squamous cell carcinoma.

• 센서학회지
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• 제20권2호
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• pp.137-144
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• 2011

Wireless sensor network(WSN) has the potential to greatly effect many aspects of u-healthcare. By outfitting the potential with WSN, wearable sensor node can collects real-time data on physiological status and transmits through base station to server PC. However, there is a significant gap between WSN and healthcare. WSN has the limited resource about computing capability and data transmission according to bio-sensor sampling rates and channels to apply healthcare system. If a wearable node transmits ECG and accelerometer data of 4 channel sampled at 100 Hz, these data may occur high loss packets for transmitting human activity and ECG to server PC. Therefore current wearable sensor nodes have to solve above mentioned problems to be suited for u-healthcare system. Most WSN based activity and ECG monitoring system have been implemented some algorithms which are applied for signal vector magnitude(SVM) algorithm and ECG noise algorithm in server PC. In this paper, A wearable sensor node using integrated ECG and 3-axial accelerometer based on wireless sensor network is designed and developed. It can form multi-hop network with relay nodes to extend network range in WSN. Our wearable nodes can transmit 1-channel activity data processed activity classification data vector using SVM algorithm to 3-channel accelerometer data. ECG signals are contaminated with high frequency noise such as power line interference and muscle artifact. Our wearable sensor nodes can remove high frequency noise to clear original ECG signal for healthcare monitoring.

• 한국응용과학기술학회지
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• 제34권3호
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• pp.657-665
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• 2017

본 연구는 화장품 소재로서 연근과 우절의 가능성을 확인하기 위한 것이다. 이를 위해 우리는 연근과 우절 에탄올 추출물을 사용하여 항산화, 항염증 및 항주름에 대한 생물학적 활성 평가를 수행하였다. 연근과 우절을 95% 에탄올로 추출한 다음 항산화 평가를 위해 샘플을 농도 (100, 500, 1000) ${\mu}g/mL$에 따라 처리하여 1,1-diphenyl-2-picrylhydrazyl (DPPH) 라디칼 소거능과 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) 양이온 라디칼 소거능을 확인하였다. 또한 항주름 효과를 평가하기 위해 Elastase 저해 활성 평가를 수행 하였다. 항염증 효과를 평가하기 위해서 대식세포 (Raw 264.7 cells)를 이용해 MTT assay를 통한 샘플의 독성평가와 nitric oxide 생성 저해 활성을 평가하였다. 그 결과 연근과 우절의 $1000{\mu}g/mL$ 농도에서 DPPH 라디칼 소거능 활성이 각 66.7%, 99.5% 로 $ABTS^+$ 라디칼 소거능 활성은 동일농도에서 각 51.2%, 98.3%로 나타났다. elastase저해 활성 결과 우절이 연근에 비해 높은 항주름 효능을 나타내었다. 우절은 $1000{\mu}g/mL$ 농도에서 대조군 EGCG 보다 높은 활성을 나타내었다. Nitric oxide 저해 활성 결과에 따르면 연근은 55.8%의 효과를 나타내었고 우절은 66.6%의 효과를 각각 나타내어 우절 추출물이 연근보다 항염증 효과가 더 우수함을 나타내었다. 결과적으로 연근 및 우절 추출물은 안전한 항산화 항염증 및 항주름 천연화장품소재로 사용될 수 있음을 시사한다.

• 한국자원식물학회지
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• 제10권4호
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• pp.411-417
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• 1997

더덕의 재배기술 개선을 목적으로 Uniconazol 및 Paclobutrazol을 더덕의 생장기별로 엽면산포(葉面散布)를 행했다. Uniconazol 및 Paclobutrazol 처리는 처리시기에 관계 없이 농도가 높을수록 초장은 억제되었으며 엽면적(葉面積)의 감소를 나타냈다. Uniconazol 처리에 의한 지하부의 형질은 3절(節) 분화시의 처리를 제외한 모든 처리구에서 대조구와의 유의차가 인정되지 않았다. 그러나12절 분화시의 10mg $liter^1$ 와 100mg $liter^1$ 농도처리에서는 대조구보다 생체중(生體重)이 각각 64%, 100%의 증가를 보였다. 세포독성(細胞毒性) Screening의 결과는 대조구 및 6절 분화시 10mg $liter^1$ 처리구에서만 활성을 나타했다. Paclobutrazol 처리에 의한 지하부의 생체중(生體重)은 3절(節) 분화시의 처리를 제외한 모든 처리구에서 대조구와의 유의차가 인정되지 않았다. 그러나 12절 분화시의 10mg $liter^1$ 농도처리에 의해 조금의 증가를 보였다. 세포독성(細胞毒性) Screening의 결과는 대조구 및 모든 처리구에서 약한 활성치를 나타냈다.

• Natural Product Sciences
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• 제7권4호
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• pp.107-109
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• 2001

To investigate anti-diabetic component from the node of lotus rhizome (Nelumbo nucifera; Nymphaeaceae), activity guided isolation was conducted. One amino acid was isolated from active fraction of the aqueous methanolic extract. The structure of this compound was identified as tryptophan (1) by the analysis of spectroscopic evidences and comparisons with the data of authentic samples. Tryptophan reduced the blood glucose level significantly in glucose-fed hyperglycemic mice compared with glucose-treated group and exhibited 44.3% of activity compared with tolbutamide,.

• 한국컴퓨터정보학회논문지
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• 제14권7호
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• pp.49-56
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• 2009

본 논문에서는 무선 센서 네트워크를 이용한 일상생활 모니터링 시스템을 제안한다. 시스템은 활동 모니터리을 위해 장갑 형태로 구성되며, RFID 리더기는 센서 네트워크 기반으로 데이터를 전송하며, RFID 태그는 13.56MHz에서 동작하고, 사각형의 작은 사이즈로 구성된다. 센서 노드는 기구나 약병, 주방용품 등의 다양한 일상생활 물체에 부착된 RFID 태그를 읽는다. 센서 노드는 무선 패킷을 싱크노드로 전송하고, 싱크노드는 수신된 패킷을 서버로 전달한다. RFID 시스템에서 전달된 데이터는 데이터베이스에 저장되고, 사용자의 일상생활 활동정보를 표시한다. 웹기반의 모니터링 시스템을 제공하고, RFID 태그의 회수를 하루단위로 막대 차트로 확인할 수 있다. 실험을 통해서 제안한 방식이 노약자의 행동이나 생활 습관 등을 감지하고 인식할 수 있음을 확인하였다.

• Food Science and Biotechnology
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• 제15권6호
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• pp.877-883
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• 2006

The immunostimulatory activities of Lactobacillus plantarum, the major microorganism in kimchi fermentations were investigated. Five strains of L. plantarum exhibited weak immunopotentiating activity, but L. plantarum PS-21 showed as strong a mitogenic activity as Bifidobacterium adolescentis M101-4, a known positive strain. It is of interest that, L. plantarum PS-21 stimulated proliferation of Peyer's patch cells, one of the most important tissues in the gut-associated lymphoreticular system. Cell' wall fractions from L. plantarum PS-21 also showed strong mitogenic activity compared with the soluble cytoplasmic fraction. A peptidoglycan fraction (PG) extracted from the cell wall of L. plantarum PS-21 was identified as an active mitogenic component when used in murine lymph node and spleen cell test systems. PG showed dose-dependent mitogenic activity and significantly enhanced antibody production in lymph node cells when studied in vitro. The lysosomal enzyme activity of murine peritoneal macrophages was increased when analyzed following injection of PG to the host animal. Furthermore, PG enhanced the production of cytokines such ($TNF-{\alpha}$ and IL-6) in the in vitro culture of RAW 264.7 macrophage cells.