• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.239-244
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• 1999

aluminum sulfate (alum) as a representative retention aid in papermaking processes was added to pulp suspensions, and the aluminum components adsorbed on the pulp were investigated quantitatively by two types of X-ray elementary analyses with regard to simultaneous changes of their surface charges. X-ray photoelectron spectroscopy (XPS) and X-ray fluorescence analysis (XFA) were applied to determine the aluminum components retained in pulp pads up to ca. 10 nm and 100${\mu}$m depth, respectively. In other words, XPS was utilized to analyze the outermost surface layers of the samples, and XFA was available for measurement of their extensive regions. A particle charge detector (PCD) was used to monitor streaming potentials at various pHs of the pulp mixtures under moderate sharing conditions. At pH 4.5 of pulp suspensions containing alum, surface charges of pulp fibers varied from negative to slight negative (approximately neutral) according to adsorption of aluminum components onto the pulp fibers. Subsequently, when a dilute NaOH solution in limited amounts was added to pulp mixtures, both streaming potentials and surface aluminum content of the pulp fibers increased distinctly although little total aluminum retention increased. Further addition of alkali solutions brought drastic decreases of the surface charges and surface aluminum content, while total aluminum content, on the contrary, increased gradually under neutral conditions. These results indicate that residual aluminum ions remained in pulp suspensions are predominantly adsorbed on surfaces of pulp fibers by adequate alkali additions and they must sufficiently cationize the fiber surfaces with increases of somewhat cationic aluminum complexes formed on the surfaces. On the other hand, aluminum components formed in higher pH ranges have nearly no contribution to improvement of charge properties of the pulp fiber surfaces, even though aluminum retention in pulp pads increases. XPS and XFA analyses combined with streaming potential measurement using a PCD suggest close relationships between aluminum content on the pulp fiber surfaces and their charge properties.

• Journal of the Korean Society of Tobacco Science
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• v.29 no.2
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• pp.110-117
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• 2007

In vitro toxicity tests such as cytotoxicity, mutagenicity and genotoxicity assay are useful for evaluating the relative toxicity of smoke or smoke condensates obtained from different cigarette configurations. A major disadvantage of these tests is relatively time-consuming, complicated and expensive. Recently, a cell-free glutathione consumption assay (GCA) as a rapid and simple screening method for the toxicity assessment of smoke has been reported by Cahours et al. (CORESTA, 2006). This study was carried out to assess the GCA application capable of predicting the toxicity of gas/vapor phase (GVP) of cigarette smoke and to identify individual compounds responsible for the glutathione (GSH) consumption in smoke. Each GVPs from 2R4F, standard cigarette, carbon filter cigarette (ExC) and new carbon filter cigarette (ExN), test cigarettes were collected by automatic smoking machine and evaluated the relative toxicity by GCA and neutral red uptake (NRU) assay. Toxic compounds existed in smoke were also chosen, relative toxicities of these compounds were screened by using two methods and compared individually. The overall order of toxicity by GCA was 2R4F > ExC > ExN, which was consistent with the result of Neutral Red Uptake assay. The levels of carbonyl compounds of ExN were lower than those of 2R4F and ExC, indicating that GSH consumption was associated with carbonyl compound yields. A major toxicant under current study is acrolein, which contributed to more than half of the GSH consumption. Collectively, the toxicity of GVP determined by GCA method may be mainly attributed to acrolein.

• Journal of the Korean Society for Heat Treatment
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• v.23 no.3
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• pp.150-155
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• 2010

Generally, plasma nitriding process has composed with a nitriding layer within glow discharge region occurred by energy exchange. The dissociations of nitrogen molecules are very difficult to make neutral atoms or ionic nitrogen species via glow discharge area. However, the captured electrons in which a double-folded screen with same potential cathode can stimulate and come out some single atoms or activated ionic species. It was showed an important thing that is called "hat is a dominant component in this nitriding process?" in plasma nitriding process and it can take an effective species for without compound layer. During a plasma nitriding process, it was able to estimate with analyzing and identification by optical emission spectroscopy (OES) study. And then we can make comparative studies on the nitrogen transfer with plasma nitriding and ATONA process using plasma diagnosis and metallurgical observation. From these observations, we can understand role of active species of nitrogen, like N, $N^+$, ${N_2}^+$, ${N_2}^*$ and $NH_x$-radical, in bulk plasma of each process. And the same time, during DC plasma nitriding and other processes, the species of FeN atom or any ionic nitride species were not detected by OES analyzing.

• Journal of Microbiology and Biotechnology
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• v.22 no.5
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• pp.659-667
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• 2012

2,3-Butanediol (2,3-BDO) is an organic compound with a wide range of industrial applications. Although Escherichia coli is often used for the production of organic compounds, the wild-type E. coli does not contain two essential genes in the 2,3-BDO biosynthesis pathway, and cannot ferment 2,3-BDO. Therefore, a 2,3-BDO biosynthesis mutant strain of Escherichia coli was constructed and cultured. To determine the optimum culture factors for 2,3-BDO production, experiments were conducted under different culture environments ranging from strongly acidic to neutral pH. The extracellular metabolite profiles were obtained using high-performance liquid chromatography (HPLC), and the intracellular metabolite profiles were analyzed by ultra-performance liquid chromatography and quadruple time-of-flight mass spectrometry (UPLC/Q-TOF-MS). Metabolic flux analysis (MFA) was used to integrate these profiles. The metabolite profiles showed that 2,3-BDO production favors an acidic environment (pH 5), whereas cell mass favors a neutral environment. Furthermore, when the pH of the culture fell below 5, both the cell growth and 2,3-BDO production were inhibited.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.205-213
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• 2009

This study reports on the geometry optimizations and electronic structure calculations for methyl pyropheophorbide (MPPa), tropolonyl methyl pyropheophorbides (TMPPa, ITMPPa), and cationic tropolonyl methyl pyropheophorbides ($TMPPa^+{{\cdot}BF_4}^-,\;ITMPPa^+{{\cdot}BF_4}^-,\;TMPPa^+,\;and\;ITMPPa^+$) using Local Spin Density Approximation (LSDA/ 6-31G*) and the Restricted Hatree-Fock (RHF/6-31G*) level theory. From the calculated results, we found that substituted cationic tropolonyl groups have larger structural effects than those of substituted neutral tropolonyl groups. The order of structural change effects is $ITMPPa^+ > ITMPPa^+{{\cdot}BF_4}^-$ > ITMPPa, as a result of the isopropyl group. Because it is an electron-releasing group, the substituted isopropyl group electronic effect on a 3-position tropolone increases the Highest Occupied Molecular Orbital and Lowest Unoccupied Molecular Orbital (HOMO-LUMO) energy gap. It was constituted that the larger the cationic characters of these photosensitizers, the smaller the HOMOLUMO band gaps are. The orbital energies of the cationic systems and the ions are stronger than those of a neutral system because of a strong electrostatic interaction. However, this stabilization of orbital energies are counteracted by the distortion of chlorin macrocycle, which results in a large destabilization of chlorin-based compound HOMOs and smaller destabilization of LUMOs as shown in TMPPa (ITMPPa), $TMPPa^+{{\cdot}BF_4}^- (ITMPPa^+{{\cdot}BF_4}^-),\;and\;TMPPa^+\;(ITMPPa^+)$ of Figure 6 and Table 6-7. These results are in reasonable agreement with normal-coordinate structural decomposition (NSD) results. The HOMO-LUMO gap is an important factor to consider in the development of photodynamic therapy (PDT).

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.656-659
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• 2005

Hot water extracts of Angelica keiskei aerial parts were solvent-fractionated with ethyl acetate (EtOAc) and buffers (5% $NaHCO_3$, pH 8.0; 1.0 N HCl, pH 3.0) to obtain EtOAc-soluble acidic and neutral fractions. EtOAc-soluble neutral fraction was purified by Sephadex LH-20 column chromatography and reverse phase HPLC. Assay for purification of antioxidative compounds was performed by spraying DPPH solution on thin layer chromatography. Two isolated substances were identified as pseudoisopsoralen and 8-methoxypsoralen(xanthotoxin) by FAB-MS and NMR analyses.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.557-564
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• 2013

We isolated and identified antioxidants from acidic and neutral ethyl acetate fractions of the peel of pear (Pyrus pyrifolia N. cv. Chuhwangbae). We isolated 4 compounds from the methanol extract, by using 3 different types of column chromatography (Sephadex LH-20, silica gel, and octadecylsilane) and preparative HPLC. We identified the isolated compounds as (S)-(+)-2-cis-abscisic acid O-${\beta}$-D-glucopyranosyl ester (compound 1), 1-[4-O-${\beta}$-D-glucopyranosyl]phenyl ethanone (picroside, compound 2), ${\beta}$-sitosterol (compound 3), and ${\beta}$-sitosteryl 3-O-${\beta}$-D-glucopyranoside (compound 4) by nuclear magnetic resonance analysis. We are the first to report the identification of compounds 1, 2, and 4 from pear.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.148-148
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• 2003

최근 홍국색소는 천연계착색료로서 뿐만 아니라 발효식품, 발효조미료등에도 이용되어 기호에 맞는 새로운 홍국 개발도 적극적으로 진행되고 있어 인지도가 높아지고 있다. 혈청콜레스테롤저하작용, 혈압강하작용, 혈당강하작용, 항산화작용등 여러가지 약리효능을 지닌 홍국균을 이용해 재래적 방법에 근거하여 홍국주를 제조하여 그 제조공정을 확립하고 품질특성을 확인하였다. Monascus purpureus를 액체배양법에 의해서 홍국코지를 제조하고 코지의 역가는 $\alpha$-amylase와 $\beta$-amylase 활성은 400unit와 4.44unit를 나타났으며, acid protease 활성은 80unit, neutral protease 활성은 91.4unit로 나타났다. 홍국코지에 증자된 쌀과 물을 혼합하여 발효경과를 측정하고, 발효가 끝난 홍국주의 DPPH법에 의한 전자공여능, 아질산염 소거능, Total phenolic compound함량, ACE저해작용등을 측정하였다. 홍국주의 발효경과 분석은 알콜도수는 2차 담금 후 2일째-13.2도, 4일-13.5, 6일째-13.5, 8일째-13.5, 10일째-13.4로 나타났다. 환원당은 2일째-23.26, 4일-20.68, 6일째-21.74, 8일째-19.93, 10일째-14.23 $^{\circ}$Brix로 점점 감소한다는 것을 볼 수 있으며, 색도에서 적색을 나타태는 Hunter value a값은 2일째 -14.72, 4일-14.97, 6일째-15.70, 8일째-16.43, 10일째-17.29로 시간이 지날수록 붉은 색소가 증가한다는 것을 알 수 있었다. pH는 2일째-4.52, 4일-4.02, 6일째-4.11, 8일째-13.11, 10일째-13.18로 pH가 약간 낮아진 것을 볼 수 있다. 산가는 2일째-8.4, 4일-6.7, 6일째-7.0, 8일째-7.5, 10일째-11.5로 pH가 산성화 될 수록 산가는 증가하는 것을 볼 수 있다. 홍국주의 전자 공여능에 의한 항산화력은 25.6%, 아질산염 소거능은 27.6%, Total phenolic compound 함량은 12.34mg%, ACE저해작용은 38%의 항산화력을 나타냈다.

• Journal of Forest and Environmental Science
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• v.22 no.1
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• pp.83-100
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• 2006

Antibiotics which produced by mushrooms discovered for last 40 years were described. Any antibiotic has not been used as infectious disease remudy but will be used as physiological active substance in near future. The antibiotic of mushrooms have not been published much in papers and do not have various finds of structures, compared to those of Streptomyces. Triple bond having compounds, terpenoid compounds aromatic compounds and some other compound have been known. These compounds are not dissolved well in water and mainly fat-soluble, except for cordycepin. Also, they are generally neutral, and some of them are acidic and almost none of them are basic compounds. However, acetylene and terpenoid compounds are the characteristic compounds of mushroom, and are not found in other microorganisms and plants. Especially, there are various terpenoid compounds in mushrooms. These metabolites of mushrooms were not used as antibiotic, but are interested as physiological active substance, such as enzyme inhibitor and immunomodulator. To promote studying on the antibiotics of mushroom, new screening methods must be developed, because strain belonged to the different genus produces different antibiotics, even though mushrooms belonged to the same genus and species. It is also known that mushrooms collected in different areas produce different antibiotics. Now, it is difficult to separate each pure compound from mushroom. It is important to find mushrooms which is impossible to cultivate artificially, or grow in the back land where is difficult to collect. Thousands of mushrooms grow on earth now, so that which species will be screened if not known. The biochemical and mycological study for usability of the metabolites of mushrooms is thought, as one of the important research areas, must be performed.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.939-943
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• 1995

This study was carried out to investigate neutral volatile compounds and sensory quality of yogurt during the storage of 15 days at $10^{\circ}C$. The yogurt was manufactured with mixed culture containing Lactobacillus acidophilus, Bifidobacterium bifidum and Streptococcus salvarius subsp. thermophilus. Among the volatile compounds, acetaldehyde, acetone and ethanol increased significantly, and 2-butanone and 2-heptanone increased slightly but diacetyl did not increase during the storage periods. In sensory test, the flavor scores of yogurt were not different during the period, but those of off-flavor were significantly different (p<0.05). In correlation between the volatile compounds and sensory test, there was negative correlation between acetone and yogurt flavor, but positive correlations between ethanol and off-flavor (p<0.05). The results suggested that the volatile flavor compound may not affect the quality of yogurt during 15d storage period at $10^{\circ}C$.