• Title/Summary/Keyword: proton magnetic resonance spectroscopy

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Isolation and Identification of Low Molecular Phenolic Antioxidants from Ethylacetate Layer of Korean Black Raspberry (Rubus coreanus Miquel) Wine (복분자(Rubus coreanus Miquel) 와인의 에틸아세테이트층으로부터 저분자 페놀성 항산화 화합물의 단리·동정)

  • Kim, Seong-Ja;Lee, Hyoung-Jae;Park, Keun-Hyung;Rhee, Chong-Ouk;Lim, Ik-Jae;Chung, Hee-Jong;Moon, Jae-Hak
    • Korean Journal of Food Science and Technology
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    • v.40 no.2
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    • pp.129-134
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    • 2008
  • Five antioxidative active substances were isolated from the EtOAc layer (20 g/56.2 g) of Korean black raspberry (Rubus coreanus Miquel) wine (11 L, black raspberry 15.7 kg fresh wt. eq.) by various column chromatography and high performance liquid chromatography (HPLC). Proton nuclear magnetic resonance ($^1H$-NMR) spectroscopy and gas chromatography Electro Ionization-Mass Spectrometry (GC-EI-MS) identified these as 4-hydroxybenzoic acid (1, 0.1 mg), 3,4-dihydroxybenzoic acid (2, 0.3 mg), 4-(2-hydroxyethyl)-phenol (3, 0.6 mg; tyrosol), pyrocatechol (4, 0.3 mg), 3,4,5-trihydroxybenzoic acid ethyl ester (5, 0.6 mg; ethyl gallate). The presence of 1 and 2 in Korean black raspberry has previously been reported. However, the presence of 3-5 in Korean black raspberry, and the identification of 1-5 from the Korean black raspberry wine have never before been reported.

Signal to Noise Ratio of MR Spectrum by variation echo time : comparison of 1.5T and 3.0T (Echo time에 따른 MR spectrum의 SNR: 1.5T와 3.0T비교)

  • Kim, Sung-Gil;Lee, Kyu-Su;Rim, Che-Pyeong
    • Journal of the Korean Society of Radiology
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    • v.5 no.6
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    • pp.401-407
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    • 2011
  • The purpose of this study is to know the differences of MR spectra, obtained from normal volunteers by variable TE value, through the quantitative analysis of brain metabolites by peak integral and SNR between 1.5T and 3.0T, together with PRESS and STEAM pulse sequence. Single-voxel MR proton spectra of the human brain obtained from normal volunteers at both 3.0T MR system (Magnetom Trio, SIEMENS, Germany) and 1.5T MR system (Signa Twinspeed, GE, USA) using the STEAM and PRESS pulse sequence. 10 healthy volunteers (3.0T:3 males, 2 females; 1.5T : 3 males, 2 females) with the range from 22 to 30 years old (mean 26 years) participated in our study. They had no personal or familial history of neurological diseases and had a normal neurological examination. Data acquisition parameters were closely matched between the two field strengths. Spectra were recorded in the white matter of the occipital lobe. Spectra were compared in terms of resolution and signal-to-noise ratio(SNR), and echo time(TE) were estimated at both field strengths. Imaging parameters was used for acquisition of the proton spectrum were as follow : TR 2000msec, TE 30ms, 40ms, 50ms, 60ms, 90ms, 144ms, 288ms, NA=96, VOI=$20{\times}20{\times}20mm3$. As the echo times were increased, the spectra obtained from 3.0T and 1.5T show decreased peak integral and SNR at both pulse sequence. PRESS pulse sequence shows higher SNR and signal intensity than those of STEAM. Especially, Spectra in normal volunteers at 3.0T demonstrated significantly improved overall SNR and spectral resolution compared to 1.5T(Fig1). The spectra acquired at short echo time, 3T MR system shows a twice improvement in SNR compared to 1.5T MR system(Table. 1). But, there was no significant difference between 3.0Tand 1.5T at long TE It is concluded that PRESS and short TE is useful for quantification of the brain metabolites at 3.0T MRS, our standardized protocol for quantification of the brain metabolites at 3.0T MRS is useful to evaluate the brain diseases by monitoring the systematic changes of biochemical metabolites concentration in vivo.