• Clinical and Experimental Pediatrics
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• 제51권3호
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• pp.323-328
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• 2008

목 적 : 천식은 하부기도의 만성 염증으로 정의될 수 있으며, 기관지과민성은 천식의 병태생리적인 특징이다. 하부기도를 직접적으로 평가할 수는 없지만 최대호기중간유량(forced expiratory flow between 25 and 75 percent, $FEF_{25-75}$)이 하부기도의 직경을 비교적 잘 반영하는 것으로 알려져 있다. 본 연구에서는 1초간호기량(forced expiratory volume in 1 second, $FEV_1$)과 $FEF_{25-75}$를 이용하여 얻어진 이들의 차이(difference between $FEV_1$ and $FEF_{25-75}$, DFF)와 비(ratio between $FEV_1$ and $FEF_{25-75}$, RFF)를 분석하여 기관지과민성과의 연관성을 알아보고자 하였다. 방 법 : 만 6세에서 15세 사이의 583명을 대상으로 하였다. 전체 대상자에서 폐기능 검사, 메타콜린 흡입 유발시험을 시행하였고, 혈액 내 호산구수, 혈청 총 IgE 농도, 혈청 ECP 농도를 측정하였다. 메타콜린 흡입 유발시험으로 얻어진 $PC_{20}$을 기준으로 기관지과민성 양성군($PC_{20}$>16 mg/mL)과 음성군($PC_{20}=16mg/mL$)을 정의하였으며, 그 중증도에 따라 4군으로(Group 1: <1 mg/mL; Group 2: 1-4 mg/mL; Group 3: 4-16 mg/mL; Group 4: >16 mg/mL, by American Thoracic Society, 1999) 분류하여 분석하였다. 결 과 : DFF는 기관지과민성 양성군에서 4.0 (-6.0-13.0), 음성군에서 -5 (-18.0-6.0)로 양성군에서 음성군에 비해 유의하게 높게 나타났다 (P<.001). RFF도 기관지과민성 양성군에서 1.07 (0.93-1.21), 음성군에서 0.95 (0.84-1.07)로 양성군에시 음성군과 비교하여 의미있게 높았다(P<.001). 또한 기관지과민성 중증도에 따라 나눈 4군 사이에서도 DFF (P<.001)와 RFF (P<.001) 모두 유의한 차이를 나타내었다. $PC_{20}$은 DFF ($\gamma$=0.337, P< .001) 및 RFF ($\gamma$=0.337, P<.001)와 의미있는 음의 상관 관계를 보였다. 결 론 : $FEF_{25-75}$를 이용하여 얻어진 DFF와 RFF는 기관지과민성과 밀접한 연관성을 보였고 이를 반영하는 지표가 될 수 있는 가능성을 보여주었다.

• 한국인터넷방송통신학회논문지
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• 제13권5호
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• pp.49-54
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• 2013

1.25Gbps PON(Passive Optical Network)용 버스트 모드 광 수신기를 설계하고 $0.8{\mu}m$ BiCMOS공정을 사용해 제작하였다. 지수함수 증폭기를 이용하여 AGC(Automatic Gain Control) 신호 생성 소요 시간을 단축시켜 버스트 앞부분의 데이터 손실을 최소화하였다. 측정결과 버스트 모드 광 수신기의 AGC 기능은 정상적으로 잘 동작하고 특성도 양호함을 확인하였다. 한편, 아이패턴의 아이는 열려있기는 하나 심한 파형 왜곡이 있고, 이로 인해 지터 특성 저하되고 있었다.

• 대한임상검사과학회지
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• 제55권4호
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• pp.291-297
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• 2023

위염과 위궤양은 위 점막에 염증이 생기고 상처가 생기는 것을 말한다. 과거 연구는 주로 환경적 요인이 위 질환의 주요 요인이라는 관점에서 이루어졌으나, 최근 유전자 연구의 발전으로 유전적 요인의 중요성이 강조되고 있다. SLC25A26은 활성산 소종의 축적과 관련이 있는 유전자이다. 산화 스트레스는 염증반응을 촉진하여 활성 산소를 증가시키고 세포 손상을 유발하기 때문에 이는 위 질환의 발생과 관련이 있을 것이라 추정된다. 본 연구에서는 SLC25A26과 위 질환과의 연관성을 분석하였다. 국내 위 질환 환자 1,369명과 건강한 대조군 7,471명을 대상으로 SLC25A26 내 다형성을 분석하였다. 그 결과 11개의 단일 염기 다형성(single nucleotide polymorphism, SNP) (genotype)과 13개의 SNP (imputation)가 통계적인 유의성(P<0.05)을 가지고 높은 위 질환과의 상대 위험도를 보였다. 그 중 SLC25A26의 rs13874가 위 질환과 높은 연관성을 보였다. 유전자형 기반 mRNA 발현 분석에 따르면 SLC25A26이 minor allele를 가지면 mRNA 발현이 증가하고 이는 산화 스트레스를 증가시킬 가능성이 있다. 결론적으로 SLC25A26 다형성은 위질환과 관련이 있어 우리나라 인구에서 위 질환 관리의 새로운 지침에 대한 근거를 제공할 수 있을 것이다.

• 반도체디스플레이기술학회지
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• 제18권1호
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• pp.21-24
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• 2019

In this paper, 5.8GHz 25W microwave wireless power transmission system was developed. The transmission system is composed of a signal generator, a 1W drive amplifier, a 25W power amplifier, and a circularly polarized transmission antenna. The receiving system was fabricated with an integrated receiver that combines a circularly polarized receiving antenna, a pass band filter, and an RF-DC converter. And a multi-integrated receiver had twelve parts, including an integrated receiver. Under the conditions, voltage and current were measured for the system at 5cm intervals from a minimum distance of 5cm to a maximum distance of 80cm. The power was calculated for the system. The results of the system are shown in tables and graphs. The power decreases with distance, but the power does not drop sharply due to a multi-integrated receiver.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2227-2230
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• 2015

Background: Prostate cancer (PCa) is one of the most commonly diagnosed neoplasms and the second leading cause of cancer death in men in the Western world. Vitamin D (1,25dihydroxy vitamin D) is linked to many biological processes that influence oncogenesis but data on relations between its genetic variants and cancer risk have been inconsistent. The aim of this study was to determine associations between a vitamin D genetic polymorphism and 25-hydroxyvitamin D [25(OH)D] levels and prostate cancer. Materials and Methods: Genomic DNA was extracted from 124 Jordanian prostate cancer patients and 100 healthy volunteers. Ethical approval was granted from the ethical committee at Hashemite University and written consent was given by all patients. PCR was used to amplify the vitamin D receptor Fok1 polymorphism fragment. 25(OH)D serum levels were measured by competitive immunoassay. Results: All genotypes were in Hardy-Weinberg equilibrium. Genotype frequency for Fok1 genotypes FF, Ff and ff was 30.7%, 61.3% and 8.06%, for prostate cancer patients, while frequencies for the control group was 28.0%, 66.0% and 6.0%, respectively, with no significant differences. Vitamin D serum level was significantly lower in prostate cancer patients (mean 7.7 ng/ml) compared to the control group (21.8 ng/ml). No significant association was noted between 25(OH)D and VDR Fok1 gene polymorphism among Jordanians overall, but significant associations were evident among prostate cancer patients (FF, Ff and ff : 25(OH)D levels of 6.2, 8.2 and 9.9) and controls (19.0, 22.5 and 26.3, respectively). An inverse association was noted between 25(OH)D serum level less than 10ng/ml and prostate cancer risk (OR 35.5 and 95% CI 14.3- 88.0). Conclusions: There is strong inverse association between 25(OH)D serum level less than 10ng/ml level and prostate cancer risk.

• Journal of Nutrition and Health
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• 제56권1호
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• pp.1-11
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• 2023

Purpose: Obesity is associated with alterations in vitamin D metabolism and elevation of parathyroid hormone (PTH). Increased PTH level in obesity is likely one of the factors contributing to the dysregulation of vitamin D metabolism. We investigated the effects of lowering the PTH level in high-fat diet-induced obese mice on vitamin D metabolism. Methods: Five-week-old male C57BL/6N mice were fed either with control (10% energy as fat) or high-fat (60% energy as fat) diets ad libitum for 12 weeks, and vehicle or cinacalcet HCl (30 ㎍/g body weight) was gavaged daily during the final week of the experiment. The following groups were studied: CON (control diet + vehicle), HFD (high-fat diet + vehicle), and HFD-CIN (high-fat diet + cinacalcet HCl). PTH, 1,25-dihydroxyvitamin D (1,25[OH]₂D), 25-hydroxyvitamin D (25[OH]D), calcium, and phosphate levels in circulation, and the expression of genes related to vitamin D metabolism in the liver and kidneys were determined. Results: Renal 1α-hydroxylase expression in the HFD group was higher than that in the CON group despite the lack of a difference in the PTH levels between the 2 groups. The plasma PTH level in the HFD-CIN group was 60% lower than that in the HFD group (p < 0.05). In parallel, the HFD-CIN group had lower adipose tissue amount (9% lower), renal 1α-hydroxylase expression (48% lower), and plasma 1,25(OH)₂D concentration (38% lower) than the HFD group. Conclusion: Lowering the PTH levels in high-fat diet-induced obese mice recovered the expression of renal 1α-hydroxylase and might be associated with lower amounts of white adipose tissue.

• 대한기계학회논문집
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• 제18권11호
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• pp.2860-2870
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• 1994

When crack are detected in aged turbine rotors of power plants, information on fracture resistance of the aged material at operating temperature is needed for determination of critical loading condition and residual life of the turbine. In this study, fracture toughness (J$_lc$) and tearing modulus(T$_mat$) of virgin and thermally degraded 1Cr-1Mo-0.25V steel, which is one of the most widely used rotor steels, were measured at 538.deg. C according to ASTM E813 and ASTM E1152, respectively. Five kinds of specimen with different degradation levels were prepared by isothermal aging heat treatment at $630^{\circ}C.$ It was observed that J$_lc$ and T$_mat$ value decreased as the degradation level increased. Analysis of microstructures using a scanning electron microscope showed that the decrement of J$_lc$ is related to segregation of impurities at grain boundaries. It was also verified that the DC electric potential drop method is accurate and reliable for crack length monitoring at elevated temperature.

• Journal of Ginseng Research
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• 제39권2호
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• pp.148-154
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• 2015

Background: Ginseng is known to have antiapoptotic, anti-inflammatory, and antioxidant effects. The present study investigated a possible role of Korean Red Ginseng (KRG) in suppressing dopaminergic neuronal cell death and the cleavage of p35 to p25 in the substantia nigra (SN) and striatum (ST) using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. Methods: Ten-week-old male C57BL/6 mice were injected intraperitoneally with 30 mg/kg of MPTP at 24-h intervals for 5 d, and then administered KRG (1 mg/kg, 10 mg/kg, or 100 mg/kg) once a day for 12 consecutive days from the first injection. Pole tests were performed to assess the motor function of the mice, dopaminergic neuronal survival in the SN and ST was evaluated using tyrosine hydroxylase-immunohistochemistry, and the expressions of cyclin-dependent kinase 5 (Cdk5), p35, and p25 in the SN and ST were measured using Western blotting. Results: MPTP administration caused behavioral impairment, dopaminergic neuronal death, increased Cdk5 and p25 expression, and decreased p35 expression in the nigrostriatal system of mice, whereas KRG dose-dependently alleviated these MPTP-induced changes. Conclusion: These results indicate that KRG can inhibit MPTP-induced dopaminergic neuronal death and suppress the cleavage of p35 to p25 in the SN and the ST, suggesting a possible role for KRG in the treatment of Parkinson's disease.

• 대한수학회논문집
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• 제25권1호
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• pp.19-25
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• 2010

$3{\times}3{\times}3$ is the meaningful smallest product of three chains of each size 2n+1 since $1{\times}1{\times}1$ is a 1-element poset. The linear discrepancy of the product of three chains $2n{\times}2n{\times}2n$ is found as $6n^3-2n^2-1$. But the case of the product of three chains $(2n + 1){\times}(2n + 1){\times}(2n + 1)$ is not known yet. In this paper, we determine ld$(3{\times}3{\times}3)$ as a case to determine the linear discrepancy of the product of three chains of each size 2n + 1.

• Asian Pacific Journal of Cancer Prevention
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• 제16권6호
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• pp.2507-2513
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• 2015

Background: Serum vitamin D status can affect the prognosis of breast cancer patients. Our aim was to determine the association between alterations in the 25-hydroxyvitamin D [25(OH)D] status during follow-up and the prognosis of breast cancer patients. Additionally, we evaluated the association between the 25(OH)D status at the time of diagnosis and the prognosis using a detailed age and stage categorization. Materials and Methods: Four hundred and sixty-nine Korean breast cancer patients were included. We collected patient clinicopathological data, including their serum 25(OH)D concentration at diagnosis and at the annual follow-up until 4 years after diagnosis. The patients were divided according to their 25(OH)D status at diagnosis into a deficient (<20 ng/ml) and a non-deficient (${\geq}20ng/ml$) group. At follow-up, patients were categorized into the four following groups according to 25(OH)D status alterations: persistently deficient, improved, deteriorated and persistently non-deficient. Results: At diagnosis, 118 patients were classified into the deficient group and 351 into the non-deficient group. After a median follow-up period of $85.8{\pm}31.0$ months, the patients with advanced-stage disease or an older age in the non-deficient group showed a significantly better survival compared with the deficient group. Furthermore, at the 1-year follow-up of 25(OH)D status, the persistently non-deficient group and the improved group had better survival compared with the other two groups. Conclusions: Our results suggest that maintaining an optimal 25(OH)D status at diagnosis and during the 1-year follow-up period is important for improving breast cancer patient survival.