• Clinical and Experimental Pediatrics
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• v.48 no.10
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• pp.1126-1131
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• 2005

Purpose : Bronchial hyperresponsiveness(BHR) is considered a hallmark of asthma. Increased levels of eosinophil cationic protein(ECP) have been identified in serum of asthma patients. Several studies have examined the relationship between serum ECP and bronchial responsiveness, expressed as methacholine $PC_{20}$ in asthmatic patients, with conflicting results. The aims of this study were to examine the relationship between serum ECP and ${\Delta}FVC$, another index of bronchial responsiveness, which reflects increased maximal airway response. Methods : Six to 8-year-old children with asthma(n=109) underwent methacholine bronchoprovocation testing. The $PC_{20}$ dose of methacholine and ${\Delta}FVC$ were calculated for each individual from the methacholine dose response curves. Serum ECP levels and blood total eosinophil counts were also measured. Results : Serum ECP correlated with ${\Delta}FVC$(r=0.217, P=0.023), as well as $PC_{20}$(r=-0.208, P=0.030). However, blood eosinophil counts failed to show any correlations with ${\Delta}FVC$(r=0.085, P=0.378) or $PC_{20}$(r=-0.148, P=0.125). ${\Delta}FVC$ did not correlate with $PC_{20}$(r=-0.079, P=0.417). Conclusion : Blood eosinophil activation is associated with both components of BHR including increased sensitivity and increased maximal response in 6-8 year old children with asthma.

• Magazine of the Korea Concrete Institute
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• v.20 no.1
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• pp.34-40
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• 2008

• Clinical and Experimental Pediatrics
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• v.49 no.11
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• pp.1216-1222
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• 2006

Purpose : Though atopic and nonatopic asthma have different clinical manifestations, bronchial hyperresponsiveness (BHR) and airway inflammations are common characteristics of them. We investigated BHR to both methacholine and adenosine 5'-monophosphate (AMP), and their relationships with blood eosinophil markers in nonatopic asthma as well as atopic asthma. Methods : We studied 116 children (82 atopics; 34 nonatopics) with mild to moderate asthma. Methacholine and AMP challenge tests were performed and bronchial responsiveness was expressed as $PC_{20}$ (provocative concentration causing a 20 percent fall in $FEV_1$); blood eosinopil counts (ETCs) and serum eosinophil cationic protein (ECP) levels were gauged. Results : In atopics, 95.1 percent and 90.2 percent showed hyperreactivity to methacholine ($PC_{20}$<16 mg/mL) and AMP ($PC_{20}$<200 mg/mL), respectively. Meanwhile, in nonatopics, 94.1 percent and 52.9 percent displayed hyperreactivity to methacholine and AMP, respectively. The geometric mean of AMP $PC_{20}$ was lower in atopics (31.6 mg/mL) than in nonatopics (125.9 mg/mL); that of methacholine $PC_{20}$ was similar in the two groups. AMP $PC_{20}$ correlated with blood ETCs in both atopics(r=-0.30, P<0.01) and nonatopics (r=-0.57, P<0.01), and correlated with serum ECP levels (r=-0.23, P<0.01) in atopics, but not in nonatopics. Apart from AMP, methacholine $PC_{20}$ was not associated with blood eosinophil markers in either group. Conclusion : Atopics more frequently displayed BHR to AMP than nonatopics. Furthermore, BHR to AMP was associated with not only blood ETCs, but serum ECP levels in atopics but was correlated with only blood ETCs in nonatopics. Those results suggest that BHR to AMP reflects airway inflammation in asthma and is more related to atopy.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.79-83
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• 1999

The effects of coralyne, a protoberberine isoquinoline compound, on dopamine biosynthesis in PC12 cells were investigated. Coralyne decreased the dopamine content dose-dependently $(46.3%\;inhibition\;at\;20\;{\mu}M\;for\;24 hr).$ Dopamine content was lowered at 6 hr and reached minimal level at 24 hr after exposure to coralyne at $20\;{\mu}M.$ The decreased dopamine level was maintained up to 48 hr and recovered to the control level at about 72 hr. Tyrosine hydroxylase, the rate-limiting enzyme in the catecholamine biosynthesis, was also inhibited at $20\;{\mu}M\;of\;coralyne$ by 16.1% relative to control. These results suggest that the inhibition of tyrosine hydroxylase by coralyne with a single treatment might be partially contributed to the decrease in dopamine content in PC12 cells.

• 정보화사회
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• s.6
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• pp.20-25
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• 1988

정보통신은 PC통신에 의해 꽃피워질 것이다. 특히 퍼스컴이 일반 전화망에 접속될 경우 그 이용도는 전화만큼이나 높아질 것이며, 활용은 부가가치 서비스에 의해 고도화될 것이다. 현재 정보통신이 앞서가는 나라들은 PC통신을 어느 정도 궤도에 올려놓고 있다. 우리 나라에서도 한국전기공사가 전화망을 이용한 퍼스컴통신을 계획하고 있어 PC통신에 대한 기대가 고조되고 있다. 비약적 발전이 기대되는 Pc통신과 망구성과 망의 종류, 이를 통한 서비스 내용들을 알아본다.

• YAKHAK HOEJI
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• v.47 no.4
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• pp.230-233
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• 2003

Previously, protoberberine alkaloids such as berberine and palmatine have been found to lower dopamine content in PC12 cells (Shin et at., 2000). In this study, the effects of berberine and palmatine on L-DOPA-induced increase in dopamine level and cytotoxicity in PC12 cells were investigated. Treatment of PC12 with L-DOPA at concentration ranges of 20∼50 $\mu$M increased dopamine content and the increase in dopamine levels by L-DOPA was inhibited by 10∼40 $\mu$M berberine and 10∼80 $\mu$M palmatine, which the concentration ranges did not show a cytotoxicity. However, berberine and palmatine at concentrations higher than 50 $\mu$M and 100 $\mu$M caused a cytotoxicity, respectively. In addition, berberine (10∼20 $\mu$M) and palmatine (10∼50 $\mu$M) at non-cytotoxic concentration ranges aggravated L-DOPA-induced cytotoxicity in PC12 cells (L-DOPA concentration ranges, 20∼50 $\mu$M). The L-DOPA-induced cytotoxicity was also significantly potentiated by berberine (50 $\mu$M) and palmatine (100 $\mu$M) with cytotoxic ranges. These data demonstrate that berberine and palmatine inhibit L-DOPA-induced increase in dopamine content and stimulate L-DOPA-induced neurotoxicity. Therefore, the possibility that the long-term L-DOPA treated patients with berberine and palmatine could be checked the adverse symptoms.

• Biomolecules & Therapeutics
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• v.16 no.2
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• pp.106-112
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• 2008

The effects of harman and norharman on dopamine content and L-DOPA-induced cytotoxicity were investigated in PC12 cells. Harman and norharman decreased the intracellular dopamine content for 24 h. The $IC_{50}$ values of harman and norharman were 20.4 ${\mu}M$ and 95.8 ${\mu}M$, respectively. Tyrosine hydroxylase (TH) activity and TH mRNA levels were also decreased by 20 ${\mu}M$ harman and 100 ${\mu}M$ norharman. Under the same conditions, the intracellular cyclic AMP levels were decreased by harman and norharman. In addition, harman and norharman at concentrations higher than 80 ${\mu}M$ and 150 ${\mu}M$ caused cytotoxicity at 24 h in PC12 cells. Non-cytotoxic ranges of 10-30 ${\mu}M$ harman and 50-150 ${\mu}M$ norharman inhibited L-DOPA (20-50 ${\mu}M$)-induced increases of dopamine content at 24 h. Harman at 20-150 ${\mu}M$ and norharman at 100-300 ${\mu}M$ also enhanced LDOPA (20-100 ${\mu}M$)-induced cytotoxicity at 24 h. These results suggest that harman and norharman decrease dopamine content by reducing TH activity and aggravate L-DOPA-induced cytotoxicity in PC12 cells.

• Composites Research
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• v.34 no.1
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• pp.1-7
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• 2021

Fiber-reinforced thermoplastic composites are applied to transport industries to lightweight of body, and applications will be expanded gradually. In this study, the impregnation and mechanical properties of continuous glass fiber (GF) reinforced polycarbonate (PC) composites were evaluated with different molecular weights of PC. The continuous GF reinforced PC composite were prepared by using GF fabric and PC film via continuous compression molding method. The melting flow index and tensile strength of PC matrix were evaluated with different molecular weights. Mechanical properties (tensile, flexural, and compressive) and pore rate of GF/PC composite were evaluated with different molecular weights of PC. The fracture behavior was analyzed to fracture surface of GF/PC composite using FE-SEM images. As these results, it was condition of representing the best mechanical property that the GF/PC composite was prepared by using PC of 20,000 g/mol as matrix.

• 전기의세계
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• v.46 no.7
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• pp.45-47
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• 1997

올해는 마이크로소프트사가 설립되고, 애플 컴퓨터사가 Apple II를 발표한지 20년째 되는 해이다. 컴퓨터 특히 퍼스널 컴퓨터인 PC의 발전사를 보면 정말 체감적으로 느낄 수 있을 정도의 빠른 변화를 보여왔다. 국내에서는 1981년에 삼보컴퓨터가 최초로 PC라는 것을 만들어 발표했다. SE8001이라는 이름으로 발표되었으며 애플 호환기종이면서 모니터로는 TV를 개조한 것을 사용하였다. 국내에서는 H/W인 PC를 생산한다는 것 자체가 우리의 실력으로는 어렵다라는 생각이 보편화되어 있을 때였기 때문에 그 효과는 상당했다고 알려지고 있다. 81년도는 세게적으로 역사적인 사건이 발생된 해이기도 하다. IBM이라는 대형 컴퓨터의 왕자가 PC 분야에 뛰어든 해이기도 하다. 즉 81년도에 IBM PC를 발표하였다. 국내에서는 83년도에 처음으로 IBM PC 호환 PC가 국내에서 생산되기 시작했다.

• Journal of Environmental Health Sciences
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• v.28 no.1
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• pp.11-20
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• 2002

Tobacco smoke was confirmed as a human carcinogen by many research results. Because many adolescents stay long time in the PC game room, they are exposed to much of tobacco smoke. To evaluate the effect of passive smoking in the PC game room, airborne nicotine concentrations in 2 PC game rooms in Sung-nam city and urinary cotinine concentrations were measured for 20 adolescents. And the subjects were interviewed for duration and time in PC game room and smoking pattern. Subjects are composed of each of 10 smokers(5 males and 5 females) and 10 nonsmokers(5 males and 5 females). They stayed for three hours in the PC game room without smoking. Concentrations of nicotine in smokers and nonsmokers were 129.72 $\mu$g/$^3$ and 99.99 $\mu$g/m$^3$, respectively. Urinary cotinine concentrations were increased as time goes on after exposure to nicotine and showed maximum value at 9.45 hours after nicotine exposure and were 32.21 and 110.66 $\mu$g/L for nonsmoker and smokers. The more using time and frequency in PC game room, the higher urinary cotinine maximum concentration and the longer using duration, also the more increase urinary cotinine concentration. Urinary cotinine has a tendency to increase by passive smoking. Therefore, it is recommended that the effective control for indoor air quality and extensive research be needed to reduce nicotine concentration by passive smoking in the PC game room.