• Clinical and Experimental Reproductive Medicine
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• 제31권1호
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• pp.19-27
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• 2004

Objective: This study was to examine the in vitro neural cell differentiation patterns of human embryonic stem (hES) cells following treatment of various neurotrophic factors [basic fibroblast growth factor (bFGF), retinoic acid (RA), brain derived neurotrophic factor (BDNF) and transforming growth factor (TGF)-$\alpha$], particulary in dopaminergic neuron formation. Methods: The hES cells were induced to differentiate by bFGF and RA. Group I) In bFGF induction method, embryoid bodies (EBs, for 4 days) derived from hES were plated onto gelatin dish, selected for 8 days in ITSFn medium and expanded at the presence of bFGF (10 ng/ml) for another 6 days followed by a final differentiation in N2 medium for 7, 14 and 21 days. Group II) For RA induction, EBs were exposed of RA ($10^{-6}M$) for 4 days and allowed to differentiate in N2 medium for 7, 14 and 21 days. Group III) To examine the effects of additional neurotrophic factors, bFGF or RA induced cells were exposed to either BDNF (10 ng/ml) or TGF-$\alpha$ (10 ng/ml) during the 21 days of final differentiation. Neuron differentiation and dopamine secretion were examined by indirect immunocytochemistry and HPLC, respectively. Results: The bFGF or RA treated hES cells were resulted in similar neural cell differentiation patterns at the terminal differentiation stage, specifically, 75% neurons and 11% glial cells. Additionally, treatment of hES cells with BDNF or TGF-$\alpha$ during the terminal differentiation stage led to significantly increased tyrosine hydroxylase (TH) expression of a dopaminergic neuron marker, compared to control (p<0.05). In contrast, no effect was observed on the rate of mature neuron (NF-200) or glutamic acid decarboxylase-positive neurons. Immunocytochemistry and HPLC analyses revealed the higher levels of TH expression (20.3%) and dopamine secretion (265.5 $\pm$ 62.8 pmol/mg) in bFGF and TGF-sequentially treated hES cells than those in $\alpha$ RA or BDNF treated hES cells. Conclusion: These results indicate that the generation of dopamine secretory neurons from in vitro differentiated hES cells can be improved by TGF-$\alpha$ addition in the bFGF induction protocol.

• 근관절건강학회지
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• 제5권2호
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• pp.155-173
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• 1998

The purpose of this study was to evaluate the effects of self-help programs which had been conducted at each health center of Seoul using the protocol developed by Korean Rheumatology Health Professionals Society(KRHPS). This program was developed to initially increase self-efficacy, and then to decrease the symptoms and finally to increase the functions of the patients. This study was designed as one group pretest-posttest design. Data were collected by self-administered questionnaires for 140 out of 303 program participants, and only 102 subjects were analyzed because of missing values. The subjects were composed of 25.5% of rheumatoid arthritis patients and 60.8% of degenerative arthritis patients. The results showed that arthritis self-help program was effective in increasing self-efficacy and then improving pain, fatigue, depression, and activities of daily living. But the number of pain sites was not decreased. This result explains that degenerative arthritis patients composed of more than half of the participants has less number of pain sites than rheumatoid arthritis, and their pain was not completely relieved. As a result, it was confirmed that arthritis patients' physical and psychological states can be improved by self-help program in the community. These findings emphasize the implication of this program for each institute to promote health of arthritis patients.

• Journal of Dental Anesthesia and Pain Medicine
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• 제19권6호
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• pp.353-360
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• 2019

Background: Controlled hypotension (CH) provides a better surgical environment and reduces operative time. However, there are some risks related to organ hypoperfusion. The EV1000/FloTrac system can provide continuous cardiac output monitoring without the insertion of pulmonary arterial catheter. The present study investigated the efficacy of this device in double jaw surgery under CH. Methods: We retrospectively reviewed the medical records of patients who underwent double jaw surgery between 2010 and 2015. Patients were administered conventional general anesthesia with desflurane; CH was performed with remifentanil infusion and monitored with an invasive radial arterial pressure monitor or the EV1000/FloTrac system. We allocated the patients into two groups, namely an A-line group and an EV1000 group, according to the monitoring methods used, and the study variables were compared. Results: Eighty-five patients were reviewed. The A-line group reported a higher number of failed CH (P = 0.005). A significant correlation was found between preoperative hemoglobin and intraoperative packed red blood cell transfusion (r = 0.525; P < 0.001). In the EV1000 group, the mean arterial pressure (MAP) was significantly lower 2 h after CH (P = 0.014), and the cardiac index significantly decreased 1 h after CH (P = 0.001) and 2 h after CH (P = 0.007). Moreover, venous oxygen saturation (ScVO₂) decreased significantly at both 1 h (P = 0.002) and 2 h after CH (P = 0.029); however, these values were within normal limits. Conclusion: The EV1000 group reported a lower failure rate of CH than the A-line group. However, EV1000/FloTrac monitoring did not present with any specific advantage over the conventional arterial line monitoring when CH was performed with the same protocol and same mean blood pressure. Preoperative anemia treatment will be helpful to decrease intraoperative transfusion. Furthermore, ScVO₂ monitoring did not present with sufficient benefits over the risk and cost.

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.207-213
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• 2013

This study was performed to investigate the effect of peroxisome proliferators activated receptor-${\gamma}$ (PPAR-${\gamma}$) ligand, pioglitazone, on production of regulated upon activation normal T-cell expressed and secreted (RANTES) and in vitro fertilization (IVF) outcome in infertile patients with endometriosis. Sixty-four infertile patients with stage III or IV endometriosis undergoing IVF were randomly allocated to the study or the control group. The long protocol of GnRH agonist (GnRH-a) was used for controlled ovarian stimulation (COS) in all patients. Patients in the study group were treated with pioglitazone at a dose of 15 mg/day orally from the starting day of GnRH-a treatment to the day of hCG injection. Blood samples were drawn for serologic assay of RANTES on the first day of GnRH-a treatment and the day of hCG injection. There were no differences between the study and control groups in patient characteristics. There were also no differences between the two groups in COS duration, and the numbers of retrieved oocytes, fertilized oocytes and embryos transferred. The clinical pregnancy rate per cycle was higher in the study group, but this difference was not statistically significant. However, embryo implantation rate was significantly higher in the study group of 12.5% compared with 8.6% in the control group (P<0.05). The serum RANTES levels after pioglitazone treatment were significantly lower than those before pioglitazone treatmen in the study group (P<0.05). Our data suggest that pioglitazone treatment can suppress RANTES production and improve the embryo implantation rate in patients with endometriosis undergoing IVF.

• 한국대기환경학회지
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• 제26권5호
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• pp.490-498
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• 2010

HCFC-22 (chlorodifluoromethane, $CHClF_2$), one of the major components in various refrigeration, is emitted mostly from developing countries, as its consumption is not limited until 2013 by the Montreal Protocol. In addition, HFC-23 (trifluoromethane, $CHF_3$), a by-product in the manufacture of HCFC-22, is also a powerful greenhouse gas. Here, we discuss the regional emission characteristics of these compounds based on high-frequency in-situ measurements using the "Medusa" GC-MS system. HCFC-22 and HFC-23 baseline concentrations measured at Gosan (Jeju Island, Korea) from November 2007 to December 2008 increased by 1.8 ppt/yr and 0.6 ppt/yr, respectively. Pollution events of these compounds were observed, very frequently (e.g., ~2~3 times) at Gosan than baseline levels. All the measurement data were divided into four groups by simultaneously considering the ratio (HFC-23/HCFC-22) and concentration (HCFC-22) at Trinidad Head (TH, California, USA). The residence time of trajectories were then analyzed in each of the four groups. The results exhibited the existence of a strong correlation with air mass origin for each group: 1) Air masses originating from Siberia in the north and from the Pacific in the south had ratios of 0.08~0.12 and concentrations of 196.9~254.3 ppt which is highly comparable to background air at TH. 2) Air masses passing over the Southern China exhibited similar ratios but higher HCFC-22 concentrations. 3) Air masses passing over the Northern China had ratios of 0.12~0.21. 4) Air masses passing over Korea and/or Japan had ratios of 0.01~0.08. Our results suggest that the HFC-23/HCFC-22 ratio can be used as a good indicator for the assessment of the pollution with Chinese origin. We also confirmed differences in air masses traveling over Northern and Southern China, most likely due to differences in air mass travelling speed over these regions before arriving at Gosan. This signature may be treated as one of the critical components in identifying the emission sources from different parts of China.

• 대한의생명과학회지
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• 제10권3호
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• pp.299-303
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• 2004

The number of acute drug intoxication who visiting to emergency department which is located near urban and rural area concomitantly is inclined to increase slightly, The purpose of this study was the investigation of methods and strategies of management of acute drug intoxication in emergency department Clinical trials were done on 92 cases of acute drug intoxication visiting to Emergency Department of Chungnam National University Hospital during 4 months from April to July 2003. 1. The total number of acute drug intoxication during this period was 92 patients, which presented 0.95％ of all the emergency department visiting patients during the study. The intentional ingestions were observed in 84 cases (91.3％). 2. The maximal point of age distribution was 4th decade. The number of that was 21 cases (22.8％). 3. The number of patients who had ingested benzodiazepines and doxylamine succinates was 26 cases (28.2％), organophosphorus was 20 (21.7％), paraquat was 10 (10.8％), others were 36 (39.3％). 4. Five kinds of po1ydrug ingestion was observed in 3 cases, four kinds was observed in 3, three kinds was observed in 5 and co-ingestion of alcohol was observed in 28 cases (30.4％). 5. The mortality was occurred in 4 cases, 2 of them were caused by paraquat, 1 of them was caused by organophosphorus (OP), 1 of them was caused by acetic acid. 6. The gastric larvage as a mean of treatment modality was done in 57 cases (61.9％). The use of activated charcoal was done in 8 (8.69％). The maintenance of tracheal intubation was done in 6 (6.52％). 7. The mean observational period in emergency department was 8 hours 42 minutes in benzodiazepine and doxylamine succinate group, 21 hours 46 minutes in OP, 20 hours 39 minutes in other germicidal except OP, 23 hours 9 minutes in paraquat group. Without a drug information and intoxication center in Korea, We should minimize the exhaustion of medical resources by establishment of determinant criteria which can be seen in relatively less-complicated cases of acute drug intoxication. Thus, we should consider the introduction of simple toxicology treatment protocol and toxicologic observation unit in emergency department as possible means to reduce economical and social burdens.

• 한국방사선학회논문지
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• 제12권5호
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• pp.593-601
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• 2018

최근 핵의학에서 진단가치의 향상을 위해 PET-CT에서 이용하고 있는 반정량지표인 SUV를 SPECT-CT에 도입하여 적용하고 있다. 따라서 두 가지 스캐너의 $SUV_{max}$를 팬텀실험을 통해 상관관계를 분석하여 임상적용 가능성을 평가하였다. 부피가 다른 6개의 구로 제작된 팬텀에 방사성의약품 ($^{18}F$, $^{99m}Tc$)을 배후방사능을 고려하여 8:1과 4:1 비율로 주입하고, 임상 프로토콜을 기반으로 PET-CT와 SPECT-CT 스캐너로 양성상을 획득한 후 관심영역을 ROI와 VOI로 구분하여 $SUV_{max}$를 측정하여 분석하였다. 실험결과 두 가지 스캐너로 측정한 $SUV_{max}$는 통계적으로 유의한 차이가 없었다 (P>0.05). 따라서 PET-CT와 SPECT-CT의 $SUV_{max}$는 유의한 수준 내에서 일정한 상관관계를 가지며, 같이 평가되었다. 따라서 SPECT-CT를 이용한 $SUV_{max}$ 정량 분석은 본 연구를 통해 일반화하기에 제한적이지만 임상에 실험적 정보를 제공할 수 있으므로, 임상실험과 같은 관련 실험을 통한 추가 연구가 필요할 것으로 판단된다.

• Journal of Preventive Medicine and Public Health
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• 제31권3호
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• pp.361-371
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• 1998

Recent increases of asthma and allergies in childhood made the need for a standardized approach to international and regional comparisons of their prevalence and severity. To address these issues, 'International Study of Asthma and Allergies in Childhood (ISAAC)' is currently underway. In Korea, 'Nationwide Study of Asthma and Allergies in Korean Children' began in 1995 according to ISAAC protocol. ISAAC written and video questionnaires were used in this survey, but their reliability and validity were not evaluated properly yet. In this study, our aim was to evaluate the reliability and validity of two kinds of questionnaires and their usefulness in international and regional comparisons. The test and retest of two questionniares were completed by male(n=110) and female(n=111) middle school students with two and three weeks interval each. Kappa(or weighted kappa) were calculated from each questions and validity coefficients were estimated from those statistics. In Korean version of written questionnaire, the questions for allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and food allergy proved to have high kappa values (or weighted kappa values) and validity coefficients and they can be used in further studies without any correction. But some questions about asthma(especially nocturnal cough, wheezing in exercise, and severe asthma) and drug allergy need to be revised for better under-standing to study subjects. Video questionnaire has the same degree of reliability and validity when compared to written questionnaire and this is the unexpected result. Accordingly, it also need to be revised to overcome the racial and cultural differences of the study subjects. In conclusion, the Korean version of written and video questionnaires may be considered to be useful methods in international and regional comparisons of asthma and allergic diseases in childhood after correction of some questions.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2009년도 학술대회
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• pp.1038-1044
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• 2009

인터랙티브 TV 시장이 활성화됨에 따라 DCATV와 IPTV의 경쟁이 본격화되면서 사용성에 직접적인 영향을 주는 인터페이스에 대한 관심도 증대되고 있는 실정이다. 본 연구는 인터랙티브 TV의 서비스 및 인터페이스에 대한 사용자의 멘탈모델을 이해하는 것을 목적으로 진행하였다. 연구 방법은 다음과 같다. 첫째, 문헌 조사를 통해 인터랙티브 TV의 2가지 유형인 DCATV와 IPTV의 기술적 차이점과 서비스 동향을 파악하였다. 둘째, 헬로우TV, C&M, 브로드앤TV, 메가TV, 마이 엘지TV 등 인터랙티브 TV의 사례들을 비교,분석하였다. 셋째, 헬로우TV를 중심으로 사용성평가를 실시하고 그 결과를 종합.분석하였다. 이를 통해 본 연구에서는 DCATV와 IPTV의 서비스 및 인터페이스에 대한 사용자 멘탈모델이 다르다는 것을 파악할 수 있었다. 특히 실시간으로 방송되는 '케이블TV채널'과 요청에 따라 다운로드되는 'VOD'라는 두가지 서비스는 인터랙션 방식과 제공 단위에 있어서 상이하며, 따라서 개념적 혼란을 야기할 수 있다. IPTV와 달리 두가지 서비스를 함께 제공하는 DCATV에서는 대부분의 사용자들은 2가지의 멘탈모델을 병립시키지 못하고 인지적 혼란을 느끼고 있음을 알 수 있었다. 이러한 발견점은 차후 인터랙티브 TV의 인터페이스 개발시 컨셉 개발을 위한 기초 자료로 이용될 수 있을 것으로 사료된다.

• 정보처리학회논문지C
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• 제12C권5호
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• pp.623-632
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• 2005

애드혹 네트워크는 기존의 유무선 네트워크의 고정된 기반시설(infrastructure) 없이 이동 호스트들만으로 구성된 무선 환경의 네트워크이다. 애드혹 네트워크의 기본 특성, 즉, 링크의 불안정성, 각 노드의 물리적 보호의 한계, 노드간 연결의 산재성, 토폴로지의 동적인 변화 뿐 아니라 악의적인 노드의 활동으로 인해 라우팅 보안에 대한 위험성은 매우 높다 따라서 본 논문에서는 애드혹 네트워크에서 경로 탐색이나 설정 과정중 악의적인 노드가 라우팅 메시지를 변조, 위조하거나 다른 노드를 가장하여 잘못된 라우팅 정보를 네트워크에 주입시키는 공격을 방지하기 위하여 일방향 해쉬 함수를 기초로 한 one-time 전자 서명을 이용한 라우팅 보안 메커니즘을 제안한다. 제안하는 메커니즘에서 노드들은 라우팅 메시지를 서명하기 위하여 공개키 요소의 첫 세트를 반복적으로 해쉬 함수에 적용함으로써 해쉬 체인을 생성하고, 생성된 해쉬 체인으로부터 공개키 요소들을 여러 세트 유도하여 해쉬 테이블을 생성한다. 해쉬 테이블 생성 후, 노드들은 자신의 공개키 요소를 다른 노드들에게 공표하고 라우팅 메시지를 전송할 경우 one-time 전자 서명을 포함한다. 이러한 one-time 전자 서명은 라우팅 메시지를 인증하고 메시지에 무결성을 제공한다. 제안하는 라우팅 보안 메커니즘은 이동성이 높은 네트워크 환경에서는 보안을 고려하지 않은 라우팅 메커니즘에 비해 라우팅 오버헤드가 좀더 높아지지만, 경로를 탐색하고 설정하는 과정에서 악의적인 노드의 공격에 대하여 훨씬 높은 안전성을 제공함을 시뮬레이션을 통해서 확인할 수 있다.