• 제목/요약/키워드: ME

검색결과 6,192건 처리시간 0.034초

Photocatalytic Oxidation of 2-Mercaptoethanol to Disulfide using Sb(V)-, P(V)-, and Ge(IV)-porphyrin Complexes

  • Shiragami, Tsutomu;Onitsuka, Dai;Matsumoto, Jin;Yasuda, Masahide
    • Rapid Communication in Photoscience
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    • 제3권4호
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    • pp.70-72
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    • 2014
  • Visible-light irradiation of MeCN solution containing di(hydroxo)metallo(tetraphenyl)porphyrin complex $(tppM(OH)_2$: 1a; $M=Sb(V)^+Br^-$, 1b; $M=P(V)^+Cl^-$, 1c; M=Ge(IV)) and 2-mercaptoethanol (2-ME) as a substrate under aerated condition gave bis(2-hydroxyethyl)disulfide (2-HEDS) as an oxidative product of 2-ME. It is indicated that the oxidation of 2-ME should proceed with a photocatalytic process by 1, because the turn over number (TON) for the formation of 2-HEDS was over unit. The TON was determined to be 642 as a maximum value when 1a was used as a sensitizer. The formation of 2-HDES was extremely slow under argon atmosphere. The fluorescence of 1 was not quenched by 2-ME at all, and the free energy change (${\Delta}G$) with electron transfer (ET) from 2-ME to excited triplet state of $1(^31^*)$ was estimated as a negative value. The quenching rate constant ($k_r$) of $^31^*$ by 2-ME, obtained by the kinetics for the formation of 2-HEDS, strongly depends on ${\Delta}G$. These findings indicate that 1-sensitized oxidation was initiated by photoinduced ET from 2-ME to $^31^*$ to generate both radical cation of 2-ME ($2-ME^{+\bulle}$) and porphyrin radical anion ($1^{-\bulle}$), resulting that the formation of 2-HEDS can be proceeded by the dimerization of $2-ME^{+\bulle}$, and through a catalytic cycle due to returning to 1 by the ET from $1^{-\bulle}$ to molecular oxygen.

Relationship between 25-hydroxyvitamin D and metabolic syndrome among Jordanian adults

  • Khader, Yousef S.;Batieha, Anwar;Jaddou, Hashim;Batieha, Zahi;El-Khateeb, Mohammed;Ajlouni, Kamel
    • Nutrition Research and Practice
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    • 제5권2호
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    • pp.132-139
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    • 2011
  • Evidence of the association between 25-hydroxyvitamin D (25(OH)D) and metabolic syndrome (MeS) remains uncertain and incongruent. This study aimed to determine the association between 25(OH)D and MeS among Jordanian adults. A complex multistage sampling technique was used to select a national population-based household sample. The present report deals exclusively with adults aged > 18 years who had complete information on all components of MeS (n = 3,234). A structured questionnaire was used to collect all relevant information. Anthropometric, clinical, and laboratory measurements were obtained. MeS was defined according to the International Diabetes Federation (IDF) definition. Of the total, 42.0% had MeS and 31.7% had 25(OH)D < 30 ng/ml. In a stratified analysis, the prevalence of MeS did not differ significantly between subjects with low and normal 25(OH)D levels for men and women in all age groups. In the multivariate analysis, the odds of MeS were not significantly different between subjects with low and normal 25(OH)D levels (OR = 0.85, 95% CI: 0.70, 1.05, P-value = 0.133). The association between 25(OH)D and MeS remained non-significant when 25(OH)D was analyzed as a continuous variable (OR = 1.004, 95% CI; 1.000, 1.008, P = 0.057) and when analyzed based on quartiles. None of the individual components of MeS were significantly associated with 25(OH)D level. This study does not provide evidence to support the association between 25(OH)D level and MeS or its individual components. Prospective studies are necessary to better determine the roles of 25(OH)D levels in the etiology of MeS.

대한치과마취과학회지 게재 논문들의 핵심용어와 MeSH 용어의 일치도 (The Equality of Key Words of the Journal of Korean Dental Society of Anesthesiology with Medical Subject Headings (MeSH) (2001-2014))

  • 심연수;김아현;유용욱;김일호;류송이;이광석;정채율;김은희;맹선우;안소연
    • 대한치과마취과학회지
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    • 제14권3호
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    • pp.143-149
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    • 2014
  • Background: The purpose of this study was to analyze the equality between key words used in the Journal of Korean Dental Society of Anesthesiology and Medical Subject Headings (MeSH). Methods: A total of 666 English key words in 187 papers (average 3.5 words in a paper) from 2001 to 2014 were eligible for this study. We classified them according to matched, and non-matched terms. After descriptive analysis, we assayed patterns of errors in using MeSH, and reviewed frequently used non-MeSH terms. Results: Fifty nine point six percent (59.6%) of total key words were completely coincident with MeSH terms, 40.39% were not MeSH terms. Conclusions: The results show that the coincidence rate of key words with MeSH terms was at a moderate level. However, there is a need for us to understand MeSH more specifically and accurately. Use of proper key words aligned with the international standards such as MeSH is important to be properly cited. The authors should pay attention and be educated on correct use of MeSH as key words.

Polymeric Precursor법에 의한 LaMeO3 (Me = Cr, Co)의 제조 및 NOx 가스 검지 특성 (Fabrication and NOx Gas Sensing Properties of LaMeO3 (Me = Cr, Co) by Polymeric Precursor Method)

  • 이영성;;송정환
    • 한국재료학회지
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    • 제21권8호
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    • pp.468-475
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    • 2011
  • [ $LaMeO_3$ ](Me = Cr, Co) powders were prepared using the polymeric precursor method. The effects of the chelating agent and the polymeric additive on the synthesis of the $LaMeO_3$ perovskite were studied. The samples were synthesized using ethylene glycol (EG) as the solvent, acetyl acetone (AcAc) as the chelating agent, and polyvinylpyrrolidone (PVP) as the polymer additive. The thermal decomposition behavior of the precursor powder was characterized using a thermal analysis (TG-DTA). The crystallization and particle sizes of the $LaMeO_3$ powders were investigated via powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and particle size analyzer, respectively. The as-prepared precursor primarily has $LaMeO_3$ at the optimum condition, i.e. for a molar ratio of both metal-source (a : a) : EG (80a : 80a) : AcAc (8a) inclusive of 1 wt% PVP. When the as-prepared precursor was calcined at $700^{\circ}C$, only a single phase was observed to correspond with the orthorhombic structure of $LaCrO_3$ and the rhombohedral structure of $LaCoO_3$. A solid-electrolyte impedance-metric sensor device composed of $Li_{1.5}Al_{0.5}Ti_{1.5}(PO_4)_3$ as a transducer and $LaMeO_3$ as a receptor has been systematically investigated for the detection of NOx in the range of 20 to 250 ppm at $400^{\circ}C$. The sensor responses were able to divide the component between resistance and capacitance. The impedance-metric sensor for the NO showed higher sensitivity compared with $NO_2$. The responses of the impedance-metric sensor device showed dependence on each value of the NOx concentration.

Methyl Jasmonate 및 Salicylic Acid 처리에 의한 더덕(Codonopsis lanceolata) 부정근의 항산화 활성 증가 (Increasement of antioxidative activity in Codonopsis lanceolata adventitious root treated by Methyl jasmonate and salicylic acid)

  • 황현정;송관필;김미향;도선길;배기화
    • Journal of Plant Biotechnology
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    • 제40권3호
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    • pp.178-183
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    • 2013
  • 본 연구의 목적은 더덕부정근 배양에서 MeJA 및 SA의 처리가 페놀화합물, 플라보노이드의 생산에 미치는 영향과 이러한 이차대사산물의 증가에 따른 더덕배양근의 항산화활성의 효과를 조사하기 위해 수행되었다. 다양한 농도의 MeJA 및 SA를 더덕배양근에 처리한 결과, 20 uM MeJA에서 총페놀 화합물의 생산은 74.53 mg/g으로 무처리구보다 2배 높은 함량을 보였다. 하지만, MeJA 및 SA의 처리는 부정근의 생장을 감소시키는 것으로 나타났다. 총플라보노이드의 함량 역시 20 uM MeJA의 처리구에서 38.45 mg/g으로 가장 높은 함량을 보였다. 20 uM의 MeJA 처리에 의한 총페놀화합물과 총플라보노이드 함량의 증가는 결과적으로 더덕부정근의 항산화활성을 $IC_{50}$ 값 수준에서 MeJA 무처리구에 비해 2배, 3년생 재배더덕에 비해서는 11배 이상 증가시키는 것으로 나타났다.

애기땅빈대 추출물의 지방산 조성 및 인체 암세포 증식 억제 효과 (Fatty Acid Composition and Antiproliferative Activity of Extracts from Euphorbia Supina)

  • 최향미;임선영
    • 생명과학회지
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    • 제24권1호
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    • pp.74-80
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    • 2014
  • 본 연구에서는 다양한 약효가 있다고 알려진 애기땅빈대(Euphorbia supina)의 추출물 및 분획물의 지방산 조성을 분석하고 인체 암세포 증식 억제효과에 대하여 살펴보았다. A+M과 MeOH 추출물의 지방산 조성 패턴은 유사했고 A+M과 MeOH 추출물은 각각 53.4% 및 42.1%의 18:3n-3를 함유하였다. 분획물들 중 85% aq. MeOH는 가장 높은 함량의 18:3n-3를 나타내었다. 애기땅빈대에 의한 암세포 증식 억제효과는 MeOH 추출물과 비교했을 때 A+M 추출물에 의한 억제효과가 높았으며 AGS 인체 위암세포에 대한 억제효과가 높았다. 분획물들 중에서는 n-Hexane과 85% aq. MeOH 분획물들에 의한 증식 억제효과가 높았다. 따라서 애기땅빈대의 항암 활성 성분은 n-Hexane과 85% aq. MeOH 분획물들에 함유되어 있는 것으로 여겨지며 향후 정제하여 규명할 필요가 있다고 사료된다.

사상체질의학회지 게재논문의 영문 주제어와 MeSH 용어의 비교 분석 (Comparison of Keywords of the Journal of Sasang Constitutional Medicine with MeSH Terms)

  • 김윤영;박혜주;이시우;유종향
    • 사상체질의학회지
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    • 제25권1호
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    • pp.34-42
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    • 2013
  • Objectives The purpose of this study was analyzing the equality between the MeSH terms and the keyword used in the papers published in Journal of Sasang Constitutional Medicine and investigating how to use an appropriate MeSH terms as keyword in the papers. Methods A total of 704 keyword used in 177 papers published from 2009 to 2012 in Journal of Sasang Constitutional Medicine were analyzed to investigate the equality between the keyword and the MeSH terms. The collected data was analyzed using SPSS 17.0 software for frequency analysis. Results Among the 704 keyword, 107 keyword(15.2%) was perfectly matched with the MeSH terms. 64 keyword(9.1%) showed partial difference was with the MeSH terms, and 11 keyword(1.7%) showed partial difference was with the Entry terms. 127 keyword(18.0%) were included in the exception item due to the nature of journal, and 395 keyword(56.1%) were not perfectly matched with the MeSH terms. In the yearly analysis result, the number of papers that keyword and MeSH terms perfectly matched was not significant changed, however the number of papers that keyword and MeSH terms did not matched was continuously increased, which clearly indicate use of MeSH terms as the keyword of the papers published in the journal of Sasang constitution medicine is insufficient. Conclusions The papers published in journal of Sasang constitutional medicine need to be cited in various fields and the paper's finding need to affect in other studies for the development of Korean medicine and Sasang constitutional medicine. The use of proper keyword aligned with the international standards is necessary to accomplish the globalization of them.

한국 의학학술논문의 저자선정 주제어와 MeSH 용어의 비교 분석 연구 (A Comparison Study of Subject Words of Korean Medical Papers: Author Keywords vs MeSH Terms Assigned by MEDLINE)

  • 이춘실;문혜원
    • 한국정보관리학회:학술대회논문집
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    • 한국정보관리학회 2000년도 제7회 학술대회 논문집
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    • pp.67-70
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    • 2000
  • 본 연구에서는 국내 의학학술논문의 저자가 선정한 주제용어(저자용어)와 MEDLINE 레코드의 MeSH 용어를 비교하여 국내 의학 학술논문 저자들이 얼마나 정확히 MeSH 용어를 사용하는지 일치도를 측정하였고, 사용방법상 어떠한 특징을 보이는지, 일치하지 않는 이유가 무엇인지 분석하였다. 1989년부터 1998년까지 Korean Journal of Parasitology에 발표된 415편의 논문에 사용된 1,826개의 저자용어 가운데 MEDLINE 레코드의 MeSH 용어와 일치한다고 볼 수 있는 용어는 35.5% (649개)로 한 논문에 평균 1.6개의 용어가 일치하였다. 이 가운데 완전히 일치하는 용어는 10.1%밖에 되지 않았다. 이와 같이 국내 의학학술논문 저자들은 MeSH 용어를 정확히 사용하기 위해 필수적인 체크태그 (Check tag), 계층구조 (Tree Structure), 부표목 사용 등 MeSH 용어 사용방법에 대한 지식이 부족한 것으로 나타났다.

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자기-전기(ME) 복합체를 활용한 초미세 자기장 감지 기술 (Sensing of ultra-low magnetic field by magnetoelectric (ME) composites)

  • 황건태;송현석;장종문;류정호;윤운하
    • 세라미스트
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    • 제23권1호
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    • pp.38-53
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    • 2020
  • Magnetoelectric (ME) composites composed of magnetostrictive and piezoelectric materials derive interfacial coupling of magnetoelectric conversion between magnetic and electric properties, thus enabling to detect ultra-low magnetic field. To improve the performance of ME composite sensors, various research teams have explored adopting highly efficient magnetostrictive and piezoelectric phases, tailoring of device geometry/structure, and developing signal process technique. As a result, latest ME composites have achieved not only outstanding ME conversion coefficient but also sensing of ultra-low magnetic field below 1pT. This article reviews the recent research trend of ME composites for sensing of ultra-low magnetic field.

Effects of Meretrix Extracts on the Collagenase Activity and Procollagen Synthesis in HS68 Human Fibroblasts and Tyrosinase Activity

  • Leem, Kang-Hyun
    • 동의생리병리학회지
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    • 제25권3호
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    • pp.528-532
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    • 2011
  • This study was designed to investigate the collagen metabolism and tyrosinase activity of Meretrix extracts (ME). The effect of ME on type I procollagen production and collagenase activity in human normal fibroblasts HS68 after UVB (312 nm) irradiation was measured by ELISA method. The tyrosinase activity after treatment of ME was measured as well. Type I procollagen production was recovered by ME in UVB damaged HS68 cells. The increased collagenase activity after UVB damage was significantly recovered by ME. The tyrosinase activity and L-DOPA oxidation were significantly reduced as well. However, the effects on tyrosinase activity and L-DOPA oxidation were not powerful enough to be used as whitening agents. ME showed the anti-wrinkle effects and some whitening effects in vitro. These results suggest that ME may be a useful drug as an anti-wrinkle treatments.