• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.2
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• pp.10-14
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• 2013

Purpose: Due to developed simultaneous PET/MRI, it has become possible to obtain more anatomical image information better than conventional PET/CT. By the way, in the PET/CT, the linear absorption coefficient is measured by X-ray directly. However in case of PET/MRI, the value is not measured from MRI images directly, but is calculated by dividing as 4 segmentation ${\mu}-map$. Therefore, in this paper, we will evaluate the SUV's difference of attenuation correction PET images from PET/MRI and PET/CT. Materials and Methods: Biograph mCT40 (Siemens, Germany), Biograph mMR were used as a PET/CT, PET/MRI scanner. For a phantom study, we used a solid type $^{68}Ge$ source, and a liquid type $^{18}F$ uniformity phantom. By using VIBE-DIXON sequence of PET/MRI, human anatomical structure was divided into air-lung-fat-soft tissue for attenuation correction coefficient. In case of PET/CT, the hounsfield unit of CT was used. By setting the ROI at five places of each PET phantom images that is corrected attenuation, the maximum SUV was measured, evaluated %diff about PET/CT vs. PET/MRI. In clinical study, the 18 patients who underwent simultaneous PET/CT and PET/MRI was selected and set the ROI at background, lung, liver, brain, muscle, fat, bone from the each attenuation correction PET images, and then evaluated, compared by measuring the maximum SUV. Results: For solid $^{68}Ge$ source, SUV from PET/MRI is measured lower 88.55% compared to PET/CT. In case of liquid $^{18}F$ uniform phantom, SUV of PET/MRI as compared to PET/CT is measured low 70.17%. If the clinical study, the background SUV of PET/MRI is same with PET/CT's and the one of lung was higher 2.51%. However, it is measured lower about 32.50, 40.35, 23.92, 13.92, 5.00% at liver, brain, muscle, fat, femoral head. Conclusion: In the case of a CT image, because there is a linear relationship between 511 keV ${\gamma}-ray$ and linear absorption coefficient of X-ray, it is possible to correct directly the attenuation of 511 keV ${\gamma}-ray$ by creating a ${\mu}$map from the CT image. However, in the case of the MRI, because the MRI signal has no relationship at all with linear absorption coefficient of ${\gamma}-ray$, the anatomical structure of the human body is divided into four segmentations to correct the attenuation of ${\gamma}-rays$. Even a number of protons in a bone is too low to make MRI signal and to localize segmentation of ${\mu}-map$. Therefore, to develope a proper sequence for measuring more accurate attenuation coefficient is indeed necessary in the future PET/MRI.

• Korean Journal of Plant Resources
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• v.26 no.6
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• pp.663-672
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• 2013

To characterize the nutraceutical property of Italian millet (Setaria italica) and sorghum (Sorghum bicolor), ten Korean landraces of each crop were collected and their vitamin E (tocopherols and tocotrienols), squalene and phytosterols (campesterol, stigmasterol and ${\beta}$-sitosterol) contents as well as fatty acid composition in seeds were evaluated. Italian millet seeds exhibited 5 forms of vitamin E isomers: three (${\alpha}$-, ${\gamma}$- and ${\delta}$-) tocopherols and two (${\alpha}$- and ${\gamma}$-) tocotrienols, while sorghum seeds showed only three forms of vitamin E isomers: ${\alpha}$- and ${\gamma}$-tocopherol and ${\alpha}$-tocotrienol. In both crops, ${\gamma}$-tocopherol was the major constituent of vitamin E in terms of highest quantity. Total vitamin E content in Italian millet and sorghum landraces were 88.3 mg/kg and 44.3 mg/kg, respectively. Among three phytosterols (campesterol, stigmasterol and ${\beta}$-sitosterol) analyzed, ${\beta}$-sitosterol was the major form comprising about 85% and 65% in Italian millet and sorghum landraces, respectively. Total phytosterols content ranged from 443.0 to 568.5 mg/kg and 442.3 to 719.2 mg/kg in Italian millet and sorghum, respectively. Squalene, a precursor of phytosterols biosynthesis, ranged from 6.8 to 10.2 mg/kg in Italian millet and from 62.2 to 115.2 mg/kg in sorghum. Linoleic, oleic and palmitic acids were the major fatty acids in both of the crops and about 80% of the total fatty acids were unsaturated fatty acids. Among the tested landraces, M09 and S10 showed relatively higher proportion of phytonutrients, suggesting their potential as a gene source for further breeding program.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4601-4607
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• 2014

Red rice contains pharmacological substances including phenolics, oryzanol, tocotrienol and tocopherol. Recently, red rice extract has been employed as a source of antioxidants for inhibition of tumor growth. This study was carried out to evaluate the anti-invasion effects of red rice extract fractions on cancer cells. It was found that at $100{\mu}g/ml$ of crude ethanolic extract (CEE), hexane fraction (Hex) and dichloromethane fraction (DCM) could reduce HT1080 and MDA-MB-231 cancer cell invasion. Hex and DCM revealed higher potency levels than CEE, whereas an ethyl acetate fraction (EtOAc) had no effect. Gelatin zymography revealed that Hex decreased the secretion and activity of matrix metalloproteinase-2 and -9 (MMP-2 and-9). In contrast, the DCM fraction exhibited slightly effect on MMPs secretion and had no effect on MMPs activity. Collagenase activity was significantly inhibited by the Hex and DCM fractions. High amounts of ${\gamma}$-oryzanol and ${\gamma}$-tocotrienol were found in the Hex and DCM fractions and demonstrated an anti-invasion property. On the other hand, proanthocyanidin was detected only in the CEE fraction and reduced MDA-MB-231 cells invasion property. These observations suggest that proanthocyanidin, ${\gamma}$-oryzanol and ${\gamma}$-tocotrienol in the red rice fractions might be responsible for the anti invasion activity. The red rice extract may have a potential to serve as a food-derived chemotherapeutic agent for cancer patients.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.529-536
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• 2016

In this paper we proposed an unsupervised algorithm to estimate the reverberation time (RT) directly from the reverberant speech signal. For estimation process we use maximum likelihood estimation (MLE) which is a very well-known and state of the art method for estimation in the field of signal processing. All existing RT estimation methods are based on the decay rate distribution. The decay rate can be obtained either from the energy envelop decay curve analysis of noise source when it is switch off or from decay curve of impulse response of an enclosure. The analysis of a pre-existing method of reverberation time estimation is the foundation of the proposed method. In one of the state of the art method, the reverberation decay is modeled as a Laplacian distribution. In this paper, the proposed method models the reverberation decay as a Gamma distribution along with the unification of an effective technique for spotting free decay in reverberant speech. Maximum likelihood estimation technique is then used to estimate the RT from the free decays. The method was motivated by our observation that the RT of a reverberant signal when falls in specific range, then the decay rate of the signal follows Gamma distribution. Experiments are carried out on different reverberant speech signal to measure the accuracy of the suggested method. The experimental results reveal that the proposed method performs better and the accuracy is high in comparison to the state of the art method.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.1
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• pp.67-74
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• 2004

A bacterium which grow on phenol as an only carbon and energy source was isolated from the sewage sludge at Nangi municipal wastewater treatment plant in Seoul. This bacterium was found to be a Gram negative rod with high motility, and well grew on 0.05%, 0.1%, and 0.15% of phenol. No matching strain was found from the result of the BBL test. Phylogenetic analysis of the strain by comparison of the 16s-rDNA has revealed that this bacterium has 99% of similarity with Stenotrophomonas maltophilia strain of Xanthomonas group, which belongs t the Gamma (${\gamma}$) subdivision of Proteobacteria. This strain has also shown 98% of similarity with nitrogen fixing bacterium MAGDE3 and Pseudomonas cissicola strain, and 97% of similarity with Stenotrophomonas sp. LMG198 and Xanthomonas cucurbitae.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.107-110
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• 1995

Fatty acid composition analysis was carried out from 60 species of Korean native medicinal plant to screen ${\gamma}-linolenic$ acid(GLA) resources. Oenothera odorata, SymPhytum officinal, and Lithospermum erythrorhizon contained ${\gamma}-linolenic$ acid with 9.5%, 3.5%, 7.2% of total fatty acid content, respectively. The vegetative organs usually contained higher level of ${\alpha}-linolenic$ acid than seeds. Some plants were found to be excellent source of unsaturated fatty acid.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.6
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• pp.603-606
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• 2005

Ralstonia eutropha NCIMB 11599 and ATCC 17699 were grown, and their productions of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] compared. In flask cultures of R. eutropha NCIMB 11599, cell concentration, P(3HB-co-4HB) concentration and polymer content decreased considerably with increases in the ${\gamma}-butyrolactone$ concentration, and the 4HB fraction was also very low (maximum 1.74 mol%). In fed-batch cultures of R. eutropha NCIMB 11599, glucose and ${\gamma}-butyrolactone$ were fed as the carbon sources, under a phosphate limitation strategy. When glucose was fed as the sole carbon source, with its concentration controlled using an on-line glucose analyzer, 86% of the P(3HB) homopolymer was obtained from 201g/L of cells. In a two-stage fed-batch culture, where the cell concentration was increased to 104g/L, with glucose fed in the first step and constant feeding of ${\gamma}-butyrolactone$, at 6g/h, in the second, final cell concentration at 67h was 106g/L, with a polymer content of 82%, while the 4HB fraction was only 0.7mol%. When the same feeding strategy was applied to the fedbatch culture of R. eutropha ATCC 17699, where the cell concentration was increased to 42 g/L, by feeding fructose in the first step and ${\gamma}-butyrolactone$ (1.5g/h) in the second, the final cell concentration, polymer content and 4HB fraction at 74h were 51g/L, 35% and 32 mol%, respectively. In summary, R. eutropha ATCC 17699 was better than R. eutropha NCIMB 11599 in terms of P(3HB-co-4HB) production with various 4HB fractions.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.111-114
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• 1995

To produce ${\gamma}$-linolenic acid (GLA) by cell cultures of Lithospermum erythrorhizon, we optimized medium compositions including carbon sources, nitrogen sources and growth regulators. MS basal medium supplemented with 1.0 mg/L 2, 4-D was effective for callus induction from mesophyll tissue. Addition of sucrose at 88mM concentration induced active proliferation of suspension cells and increased GLA content. Increased supplement of potassium nitrate as nitrogen source resulted in proliferous cell growth and increased total fatty acid content Abscisic acid increased cell growth and fatty acid content in callus culture, whereas as it had an inhibitory effect in suspension cell culture.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.123-127
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• 1992

When MOS devices is exposed to radiation, radiation effects of P-type MOS capacitor can cause modulation and/or degradation in devices characteristics and its operating life. The oxide layer is grown in $O_2$+T.C.E. and its thickness ranges from 40 to 80 nm. Irradiations on MOS capacitor were performed by Cobalt-60 gamma ray source and total dose ranges from $10^4$ to $10^8$ rads. The radiation effect on electrical conduction characteristics(I-V) in MOS capacitor was measured as a function of gate oxide thickness and total dose. From the experimental result, I-V characteristics is found to be influenced strongly by total dose in irradiated p-type MOS capacitors. The ohmic current is dependant on of total dose in irradiated P-type MOS capacitors. This results are explained using surface states at interface radiation-induced traps.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.365-368
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• 1997

We are developing a small gamma camera or imaging malignant breast tumors. The small scintillation camera system consists of NaI(Tl) crystal ($60\;{\times}\;60\;{\times}\;6\;mm^3$) coupled to position sensitive photomultiplier tube (PSPMT), nuclear instrument module (NIM), analog to digital converter (ADC), and personal computer. High quality flood source image and hole mask image were obtained using the gamma camera developed in this study. Breast phantom containing $2{\sim}7\;mm$ diameter spheres was successfully imaged with parallel hole collimator. The obtained image displayed accurate activity distribution over the imaging field of view. Linearity and uniformity correction algorithms are being developed. It is believed that the developed small gamma camera could be useful or detection of malignant breast cancer.