• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.635-640
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• 1996

A thermo-elastic system in the production machine has highly nonlinear dynamic characteristics. In general, the finite element method is utilized for accurate analysis. However, it requires large computing time. Thus, thermo-elastic systems are usuallymodeled as electric and fluid system using lumped para,eter. In this paper. we propose the bondgraph model and transient simulation methodology of thermo-elastic system in consideration of various boundary and joint contact conditions. Consequently, the proposed method ensures a possibility of its on-line compensation about undesirable phenomena by using real time estimate process and electronic cooling device for thermal appropriate behavior. Thermo-elastic model consisting of bush and shaft including contact condition is presented.

• 혜화의학회지
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• 제9권2호
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• pp.123-134
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• 2001

In order to investigate the effect of Mori Folium on immunologic control function, the various immune responses were studied. The results were obtained as follows : 1. The transformation of lymphocyte was increased significantly in all concentration of Mori Folium treated group as compared with negative and positive control. 2. In FACS analysis, the population of helper T cell and T cell were increased significantly in Mori Folium treated group as compared with control. 3. IL-12(p35) and INF-${\gamma}$ were upregulated in Mori Folium treated group 4. NO and carbon clearance were significantly increased in Mori Folium treated group as compared with control. 5. The hemagglutinin titer and hemolysin titer were increased but insignificantly in Mori Folium treated group as compared with control.

• The Korean Journal of Physiology
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• 제21권2호
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• pp.297-304
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• 1987

A study was carried out to find out the relationship between arginine vasopressin (AVP) release and plasma osmolality in 15 young men (age: 21.4 yr). After an overnight fasting, wale. (20 ml/kg) was imbibed, and venous blood and urine samples were collected every 30 min for 90 min. then 5% saline was infused (0.06 ml/min/kg) for 120 min. AVP was extracted on Sep-Pak column and measured by radioimmunoassay. Under basal condition, plasma osmolality (pOsm), AVP (pAVP) and aldosterone (pAldo) levels were 286.5 mOsm/kg, 1.1 pg/ml, and 140 pg/ml, respectively. pAVP became undetectable during maximum water diuresis, and increased in response to hypertonic saline infusion. pAVP level began to increase when pOsm was above 280 mOsm/kg. Changes in urinary AVP excretion (uAVP) was parallel to pAVP levels. The fall in pAVP was followed by a decrease in uAVP, uOsm and an increase in free water clearance, while the later rise in pAVP was followed by an increase in uAVP, uOsm and a decrease in free water clearance. When pooling all data together, relationships between pAVP and pOsm, and uAVP and uOsm were best expressed by an exponential relationship (r=0.78, 0.86, respectively). pAldo level decreased to 71 pg/ml after water ingestion, and decreased further to 30 pg/ml 2 hr after 5% saline infusion. Even at the same pNa, pAldo level during dehydration state was significantly higher than during hydration state. Negative exponential relation (r=-0.59) was observed between pAldo and pNa. Response to change in body fluid volume was greater in aldosterone than in AVP release.

• Journal of Pharmaceutical Investigation
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• 제25권3호spc1호
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• pp.7-20
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• 1995

Taurine, a ${\beta}-amino$ acid, plays an important role as a neuromodulator and is necessary for the normal development of the brain. Since de novo synthesis of taurine in the brain is minimal and in vivo studies suggest that taurine dose not cross the blood-brain barrier, we examined whether the choroid plexus, the blood-cerebrospinal fluid (CSF) barrier, plays a role in taurine transport in the central nervous system. The uptake of $[^3H]-taurine$ into ATP depleted choroid plexus from rabbit was substantially greater in the presence of an inwardly directed $Na^+$ gradient taurine accumulation was negligible. A transient in side-negative potential gradient enhanced the $Na^+-driven$ uptake of taurine into the tissue slices, suggesting that the transport process is electrogenic, $Na^+-driven$ taurine uptake was saturable with an estimated $V_{max}$ of $111\;{\pm}\;20.2\;nmole/g/15\;min$ and a $K_M\;of\;99.8{\pm}29.9\;{\mu}M$. The estimated coupling ratio of $Na^+$ and taurine was $1.80\;{\pm}\;0.122.$ $Na^+-dependent$ taurine uptake was significantly inhibited by ${\beta}-amino$ acids, but not by ${\alpha}-amino$ acids, indicating that the transporter is selective for ${\beta}-amino$ acids. Since it is known that the physiological concentration of taurine in the CSF is lower than that in the plasma, the active transport system we characterized may face the brush border (i.e., CSF facing) side of the choroid plexus and actively transport taurine out of the CSF. Therefore, we examined in vivo elimination of taurine from the CSF in the rat to determine whether elimination kinetics of taurine from the CSF is consistent with the in vitro study. Using a stereotaxic device, cannulaes were placed into the lateral ventricle and the cisterna magna of the rat. Radio-labelled taurine and inulin (a marker of CSF flow) were injected into the lateral ventricle, and the concentrations of the labelled compounds in the CSF were monitored for upto 3 hrs in the cisterna magna. The apparent clearance of taurine from CSF was greater than the estimated CSF flow (p<0.005) indicating that there is a clearance process in addition to the CSF flow. Taurine distribution into the choroid plexus was at least 10 fold higher than that found in other brain areas (e. g., cerebellum, olfactory bulb and cortex). When unlabelled taurine was co-administered with radio-labelled taurine, the apparent clearance of taurine was reduced (p<0.0l), suggesting a saturable disposition of taurine from CSF. Distribution of taurine into the choroid plexus, cerebellum, olfactory bulb and cortex was similarly diminished, indicating that the saturable uptake of taurine into these tissues is responsible for the non-linear disposition. A pharmacokinetic model involving first order elimination and saturable distribution described these data adequately. The Michaelis-Menten rate constant estimated from in vivo elimination study is similar to that obtained in the in vitro uptake experiment. Collectively, our results demonstrate that taurine is transported in the choroid plexus via a $Na^+-dependent,saturable$ and apparently ${\beta}-amino$ acid selective mechanism. This process may be functionally relevant to taurine homeostasis in the brain.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제12권1호
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• pp.23-29
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• 2009

목 적: HBeAg 음성 만성 B형 간염 환자에서 라미부딘의 적절한 치료 기간에 대한 연구는 국내외에 보고된 바 없다. 저자 등은 라미부딘의 장기 치료 효과를 분석하여 HBeAg 음성 소아 만성 B형 간염의 적절한 치료 기간을 결정하는데 예비자료로 제공하고자 하였다. 방 법: 1999년 7월부터 2006년 8월까지 경북대학교병원 소아청소년과에 내원하여 만성 B형 간염으로 진단받은 83명 중 HBeAg 음성 만성 B형 간염으로 진단되어 라미부딘 치료를 시작하였던 환자 7명 중 2년 이상 경과한 6명을 대상으로 하였다. 대상 환자들은 모두 혈청 ALT치가 정상 상한치의 2배 이상으로 증가되어 있었다. 라미부딘을 3 mg/kg (최대 100 mg)으로 매일 1회, 최소 2년 이상 경구 투여하였다. HBV DNA의 소실과 혈청 ALT 수치의 정상화를 1차 목표로 하였고 라미부딘 종료 후 관해 유지를 최종 목표로 하였다. 라미부딘은 HBV DNA의 음전화 및 ALT치의 정상화 후 2년 이상 추가 투여하기로 하였다. 치료 시작 후 매 2~3 개월 마다 HBV DNA, 혈청 ALT, HBeAg과 anti-HBe 역가의 변화 추이를 조사하였다. 결 과: 라미부딘 치료 기간은 평균 32.3개월(26~40개월)이었고 평균 추적 관찰 기간은 59.5개월(26~110개월)이었다. 라미부딘 치료를 받은 모든 환자에서 3개월 이내에 HBV DNA가 0.5 pg/mL 미만으로 감소하였다. 2005년 이후에 치료를 시작한 환자는 3명이었는데 3명 모두에서 3~23개월에 0.007 pg/mL (=357 IU/mL) 미만으로 감소하였다. 혈청 ALT치 정상화에 걸린 기간은 6명의 환자에서 평균 3.5개월(2~7개월)이었다. 라미부딘으로 치료한 환자 중 5명은 HBV DNA PCR에서 357 IU/mL 미만으로 유지되고 있으나 한 명의 환자에서 18개월에 생화학적 돌파현상(breakthrough)이 관찰 되어 28개월째에 투여를 중단하였다. 라미부딘 치료가 종료된 4명에서 평균 23.8개월(4~75개월)동안 추적 관찰하였지만 재발의 소견은 보이지 않았다. 결 론: HBeAg 음성 만성 B형 간염 환자에서 라미부딘은 효과적으로 HBV 증식을 저지할 뿐 아니라 혈청 ALT치를 정상화시켰다. 치료 종료 후의 재발률을 낮추기 위해 HBeAg 음성 만성 B형 간염 환자에서 라미부딘의 적절 치료 기간은 HBV DNA 음전 및 혈청 ALT치 정상화 후 2년 추가가 필요할 것으로 추정할 수 있으나 더 많은 환자를 대상으로 한 연구가 필요하다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권8호
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• pp.1102-1110
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• 2016

The mammalian target of rapamycin (mTOR) regulates cellular processes such as cell growth, metabolism, transcription, translation, and autophagy. Rapamycin is a selective inhibitor of mTOR, and induces autophagy in various systems. Autophagy contributes to clearance and recycling of macromolecules and organelles in response to stress. We previously reported that vitrified-warmed mouse oocytes show acute increases in autophagy during warming, and suggested that it is a natural response to cold stress. In this follow-up study, we examined whether the modulation of autophagy influences survival, fertilization, and developmental rates of vitrified-warmed mouse oocytes. We used rapamycin to enhance autophagy in metaphase II (MII) oocytes before and after vitrification. The oocytes were then subjected to in vitro fertilization (IVF). The fertilization and developmental rates of vitrified-warmed oocytes after rapamycin treatment were significantly lower than those for control groups. Modulation of autophagy with rapamycin treatment shows that rapamycin-induced autophagy exerts a negative influence on fertilization and development of vitrified-warmed oocytes.

• 대한기계학회논문집B
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• 제31권4호
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• pp.349-356
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• 2007

The present study investigated local heat/mass transfer characteristics on the tip of the rotating turbine blade with various incoming flow incidence angles. The experiments are conducted in a low speed annular cascade with a single stage turbine. The blade has a flat tip with a mean tip clearance of 2.5% of the blade chord. The incoming flow Reynolds number is $1.5{\times}10^5$ at design condition. To examine the effect of off-design condition, the experiments with various incidence angles ranging between $-15^{\circ}$ and $+7{\circ}$ were conducted. A naphthalene sublimation method is used to measure detailed mass transfer coefficient on the blade. The results indicated that the incidence angle strongly affects the behavior of tip leakage flow around the blade tip and consequently plays an important role in determining heat transfer characteristics on the tip. For negative incidence angles, the heat/mass transfer in the upstream region on the tip decreases by up to 20%. On the contrary, for positive incidence angles, much higher heat transfer coefficients are observed even with small increase of incidence angle.

• The Journal of Advanced Prosthodontics
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• 제16권4호
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• pp.221-230
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• 2024

PURPOSE. This in vitro study was conducted to investigate the accuracy of intraoral scanner (IOS) for recording maximal intercuspal position (MIP) and border positions of the mandible. MATERIALS AND METHODS. Maxillary and mandibular master casts were articulated in MIP, protrusive, and lateral interocclusal position sequentially on a semi-adjustable articulator. For each articulation relation, sites of occlusal contacts (SOCs) and sites of clearance (SCs) were identified on the master casts with articulating paper (reference sites). IOS was used to take full arch scans and nine virtual interocclusal records (VIRs) for virtual articulation of models. Virtual SOCs and SCs were detected with 3D processing software and compared to those identified with the articulating paper. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each articulation relation. RESULTS. For MIP, IOS showed adequate sensitivity and NPV of 100%, and specificity and a PPV of 99%. For protrusive position, the IOS showed a sensitivity and a NPV of 100%, a high PPV of 86%, and a specificity of 83%. For lateral positions, the specificity and the PPV were high (93% and 79%, respectively), but the sensitivity and the NPV were below the clinically acceptable limits (28% and 56%, respectively). CONCLUSION. IOS displayed clinically acceptable accuracy for recording MIP and protrusive border mandibular position. However, IOS had less accuracy for lateral border mandibular position.

• Tuberculosis and Respiratory Diseases
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• 제77권3호
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• pp.136-140
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• 2014

Primary ciliary dyskinesia (PCD) is characterized by the congenital impairment of mucociliary clearance. When accompanied by situs inversus, chronic sinusitis and bronchiectasis, PCD is known as Kartagener syndrome. The main consequence of impaired ciliary function is a reduced mucus clearance from the lungs, and susceptibility to chronic respiratory infections due to opportunistic pathogens, including nontuberculous mycobacteria (NTM). There has been no report of NTM lung disease combined with Kartagener syndrome in Korea. Here, we report an adult patient with Kartagener syndrome complicated with Mycobacterium abscessus lung disease. A 37-year-old female presented to our hospital with chronic cough and sputum. She was ultimately diagnosed with M. abscessus lung disease and Kartagener syndrome. M. abscessus was repeatedly isolated from sputum specimens collected from the patient, despite prolonged antibiotic treatment. The patient's condition improved and negative sputum culture conversion was achieved after sequential bilateral pulmonary resection.

• 한국임상약학회지
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• 제23권4호
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• pp.307-315
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• 2013

Objective: Colistimethate was first became available in 1950s and used until the early 1980s to treat infections caused by gram-negative bacteria and was abandoned due to its nephrotoxicity and neurotoxicity. However, it was recently reintroduced into the clinical practices due to emergence of multidrug-resistance gram-negative bacteria, particularly Pseudomonas aeruginosa and Acinetobacter baumanii. Therefore, it is increasingly used in the intensive care unit settings as a salvage therapy. This study was designed to investigate the incidence rates and risk factors of acute kidney injury associated with colistimethate by using the standardized definition in critically ill patients. Methods: This study retrospectively reviewed the electronic medical records of 71 adult patients above 18 years old receiving intravenous colistimethate at least 48 hours at intensive care unit, university-affiliated hospital from Nov 2012 to Aug 2013 and excluded patients with end-stage renal disease (ESRD) and required renal replacement therapy before initiation of the colistimethate therapy. Acute kidney injury (AKI) was determined by using the standardized RIFLE criteria, classified with risk, injury, failure, loss and ESRD according to serum creatinine (Scr) levels. Results: Among the 71 patients included in the analysis, AKI developed in 40 patients (56.3%) and 6 patients (8.4%) had irreversible kidney injury. AKI occurred within 5 days in 20 patients (50.0%). Maximum Scr level showed a significant increase in the patients with AKI ($1.92{\pm}0.86mg/dL$ vs. $1.12{\pm}0.46mg/dL$ p=0.001), maximum BUN also increased ($64.2{\pm}28.7mg/dL$ vs. $48.4{\pm}24.9mg/dL$ p=0.017) and minimum creatinine clearance (CLcr) was significantly decreased in the patients with AKI than non-AKI ($34.5{\pm}18.6ml/min$ vs. $64.4{\pm}33.7ml/min$ p=0.185). The patients with AKI had significantly longer duration of colistimethate therapy ($21.1{\pm}17.0$ days vs. $13.0{\pm}11.5$ days, p=0.020) and larger cumulative doses of colistimethate ($6465.9{\pm}4717.0mg$ vs. $4438.1{\pm}3426.7mg$, p=0.040). Conclusion: The incidence and severity of AKI associated with colistimethate in critically ill patients was high and serious. Drug monitoring program should be performed to shorten duration of therapy and reduce cumulative dose from initiation of colistimethate therapy for minimizing AKI of colistimethate.