• 국제지역연구
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• 제21권1호
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• pp.39-72
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• 2017

이 연구의 목적은 원조 범람이 수원국의 정부지출에 미친 영향을 패널데이터를 이용해 실증 분석하고, 이를 통해 향후 공적개발원조 사업의 운영 방향에 대한 함의를 얻는 데 있다. 이 연구에서는 아프리카 사하라 사막 이남 지역 국가들의 보건 부문에 대한 원조범람지수를 산정하고, 원조범람이 보건 부문에 대한 정부지출에 어떤 영향을 미치는지를 실증분석하였다. 이 연구에서 수행한 실증분석 결과, 원조범람은 보건 부문에 대한 정부지출 수준을 유의미하게 감소시키는 효과를 발생시키는 것을 확인하였다. 그리고 이와 같은 현상이 발생한 것은 신규 사업을 추구하는 공적개발원조 사업의 특징(공여국의 니즈)과 가능하면 더 많은 공적개발원조 자금을 수혜하고자 하는 수원국 정부 간 상호 이익추구에 따른 것으로 추론된다. 분석결과를 토대로, 이 연구에서는 경쟁적이고 과도한 공적개발원조 사업지원이 수원국 정부의 예산운영 과정에 대한 왜곡을 유도해 결과적으로 공적개발원조 사업의 비효율을 초래하므로, 사업지원 과정에서 수원국의 정책 능력에 관한 종합적인 고려가 필요하며, 개발원조위원회(Development Assistance Committee)의 종합조정 기능의 강화가 필요함을 제안하였다.

• Composites Research
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• 제13권4호
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• pp.54-66
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• 2000

탄소섬유/에폭시 복합재료의 계면 및 미세파괴 물성을 인장 fragmentation과 압축 Broutman 두 시험법과 음향방출 시험을 이용하여 평가하였다. Maleic anhydride polymeric coupling agent와 amino-silane를 각각 전기증착법 및 dipping을 통하여 섬유표면에 적용하였다. 두 coupling agents를 사용한 섬유와 기지간의 계면전단강도는 인장 및 압축 두 시험에서 모두 미처리와 비교하여 큰 증가를 나타내었다. 인장시험 동안에, 원추모양의 섬유파단과 기지의 cracking 그리고 부분적인 interlayer failure로 이루어진 전형적인 미세파괴 형태가 발생하였다. 이에 비하여, 압축시험에서는 부러진 섬유의 끝에서 대각선 방향이 슬립거동이 관찰되었다. 주어진 두 힘의 하중상태에서 섬유의 파단은 항복점 전후 부근에서 일어났다. 음향방출분포는 인장에서 섬유표면 처리와 미처리의 두 조건에서 미세파괴 신호가 잘 분리되었으며, 한편, 압축에서는 signal이 다소 중복되어 나타났다. 이는 탄소섬유의 인장력/압축력 간의 파괴에너지 차이에 기인한다고 고려된다. 탄소와 basalt 섬유복합재료의 섬유파단 waveform의 최대 voltage는 압축보다 인장시험에서 상당히 크게 나타났으며, 이들은 음향방출시험으로 파괴에너지 차이를 명확히 비교 및 확인할 수 있었다.

• 분석과학
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• 제28권4호
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• pp.278-287
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• 2015

Phosphodiesterase type 5 inhibitors (PDE-5 inhibitors) are used in the treatment of erectile dysfunction. In recent years, a number of reports have been conducted on dietary supplements contaminated with PDE-5 analogues. In this study, 58 analogues of PDE-5 inhibitors were sorted into five groups: tadalafil, sildenafil, hongdenafil, vardenafil, and other analogues. These analogues were then evaluated using a liquid chromatography-quadrupole-time of flight mass spectrometry (LC-QTOF-MS) electrospray ionization mass method. Each compound has a unique fragmentation ion, which can be easily analyzed qualitatively. The fragmentation pathways of the analogues were elucidated based on the QTOF-MS and MS/MS data. Common ions were confirmed for each group by analyzing the structural characteristics and fragmentation pathways. Specifically, common ions were observed at m/z 169.08 and 135.04 (tadalafil analogues), m/z 311.15 and 283.12 (sildenafil analogues and hongdenafil analogues), and m/z 312.16 and 151.09 (vardenafil analogues). The advantage of this method is that the structure of unknown components can be determined by interpreting the product ions. Hence, the developed method can be used for the identification of unknown compounds. Fragmentation pathways may also aid in the detection and identification of PDE-5 inhibitor analogues.

• 분석과학
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• 제30권1호
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• pp.10-19
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• 2017

Anabolic steroids have similar structures to testosterone, both of which promote the growth of muscle mass and increase strength. However, the side effects of anabolic steroid use may lead to heart attacks or strokes. Additionally, the excessive use of steroids inhibits the production of the sex hormones in the body via a negative feedback loop, which results in testicular atrophy in males and amenorrhea in females. Currently, the method of choice used to test for the presence of anabolic steroids is GC-MS. However, GC-MS methods require chemical derivatization of the steroid sample to ensure compatibility with the analytical method; therefore, analysis of many different samples is difficult and time consuming. Unlike GC-MS, the liquid chromatography-quadrupole-time of flight mass spectrometry (LC-Q-TOF-MS) method is suitable for many samples. Twenty-two different anabolic steroids were analyzed by LC-Q-TOF-MS with various collision energies (CE). Accurate mass spectral data were obtained using a Q-TOF-MS equipped with an electro-spray ionization source and operated in the positive MS/MS mode for several classes of steroids that are often the targets of testing. Based on the collected data, fragmentation pathways were carefully elucidated. The high selectivity and sensitivity of the LC-Q-TOF-MS instrument combined with these fragmentation pathways offers a new approach for the rapid and accurate screening of anabolic steroids. The obtained data from the 22 different anabolic steroids will be shared with the scientific community in order to establish a library to aid in the screening of illegal anabolic steroids.

• Journal of Ginseng Research
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• 제43권4호
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• pp.580-588
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• 2019

Background: Ginsenoside Rg1 has been shown to clear senescence-associated beta-galactosidase (SA-${\beta}$-gal) in cultured cells. It remains unknown whether Rg1 can influence SA-${\beta}$-gal in exercising human skeletal muscle. Methods: To examine SA-${\beta}$-gal change, 12 young men (age $21{\pm}0.2years$) were enrolled in a randomized double-blind placebo controlled crossover study, under two occasions: placebo (PLA) and Rg1 (5 mg) supplementations 1 h prior to a high-intensity cycling (70% $VO_{2max}$). Muscle samples were collected by multiple biopsies before and after cycling exercise (0 h and 3 h). To avoid potential effect of muscle biopsy on performance assessment, cycling time to exhaustion test (80% $VO_{2max}$) was conducted on another 12 participants (age $23{\pm}0.5years$) with the same experimental design. Results: No changes of SA-${\beta}$-gal were observed after cycling in the PLA trial. On the contrary, nine of the 12 participants showed complete elimination of SA-${\beta}$-gal in exercised muscle after cycling in the Rg1 trial (p < 0.05). Increases in apoptotic DNA fragmentation (PLA: +87% vs. Rg1: +133%, p < 0.05) and $CD68^+$ (PLA:+78% vs. Rg1:+121%, p = 0.17) occurred immediately after cycling in both trials. During the 3-h recovery, reverses in apoptotic nuclei content (PLA:+5% vs. Rg1 -32%, p < 0.01) and increases in inducible nitrate oxide synthase and interleukin 6 mRNA levels of exercised muscle were observed only in the Rg1 trial (p < 0.01). Conclusion: Rg1 supplementation effectively eliminates senescent cells in exercising human skeletal muscle and improves high-intensity endurance performance.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4517-4525
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• 2016

Background: Sperm DNA damage is underlying aetiology of poor implantation and pregnancy rates but also affects health of offspring and may also result in denovo mutations in germ line and post fertilization. This may result in complex diseases, polygenic disorders and childhood cancers. Childhood cancer like retinoblastoma (RB) is more prevalent in developing countries and the incidence of RB has increased more than three fold in India in the last decade. Recent studies have documented increased incidence of cancers in children born to fathers who consume alcohol in excess and tobacco or who were conceived by assisted conception. The aetiology of childhood cancer and increased disease burden in these children is lin ked to oxidative stress (OS) and oxidative DNA damage( ODD) in sperm of their fathers. Though several antioxidants are in use to combat oxidative stress, the effect of majority of these formulations on DNA is not known. Yoga and meditation cause significant decline in OS and ODD and aid in regulating OS levels such that reactive oxygen speues meditated signal transduction, gene expression and several other physiological functions are not disrupted. Thus, this study aimed to analyze sperm ODD as a possible etiological factor in childhood cancer and role of simple life style interventions like yoga and meditation in significantly decreasing seminal oxidative stress and oxidative DNA damage and thereby decreasing incidence of childhood cancers. Materials and Methods: A total of 131 fathers of children with RB (non-familial sporadic heritable) and 50 controls (fathers of healthy children) were recruited at a tertiary center in India. Sperm parameters as per WHO 2010 guidelines and reactive oxygen species (ROS), DNA fragmentation index (DFI), 8-hydroxy-2'-deoxy guanosine (8-OHdG) and telomere length were estimated at day 0, and after 3 and 6 months of intervention. We also examined the compliance with yoga and meditation practice and smoking status at each follow-up. Results: The seminal mean ROS levels (p<0.05), sperm DFI (p<0.001), 8-OHdG (p<0.01) levels were significantly higher in fathers of children with RB, as compared to controls and the relative mean telomere length in the sperm was shorter. Levels of ROS were significantly reduced in tobacco users (p<0.05) as well as in alcoholics (p<0.05) after intervention. DFI reduced significantly (p<0.05) after 6 months of yoga and meditation practice in all groups. The levels of oxidative DNA damage marker 8-OHdG were reduced significantly after 3 months (p<0.05) and 6 months (p<0.05) of practice. Conclusions: Our results suggest that OS and ODD DNA may contribute to the development of childhood cancer. This may be due to accumulation of oxidized mutagenic base 8OHdG, and elevated MDA levels which results in MDA dimers which are also mutagenic, aberrant methylation pattern, altered gene expression which affect cell proliferation and survival through activation of transcription factors. Increased mt DNA mutations and aberrant repair of mt and nuclear DNA due to highly truncatred DNA repair mechanisms all contribute to sperm genome hypermutability and persistant oxidative DNA damage. Oxidative stress is also associated with genome wide hypomethylation, telomere shortening and mitochondrial dysfunction leading to genome hypermutability and instability. To the best of our knowledge, this is the first study to report decline in OS and ODD and improvement in sperm DNA integrity following adoption of meditation and yoga based life style modification.This may reduce disease burden in next generation and reduce incidence of childhood cancers.