• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1120-1126
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• 2007

This study was performed to screen probiotic bifidobacteria for their ability to bind and neutralize lipopolysaccharides (LPS) from Escherichia coli and to verify the relationship between LPS-binding ability, cell surface hydrophobicity (CSH), and inhibition of LPS-induced interleukin-8 (IL-8) secretion by HT-29 cells of the various bifidobacterial strains. Ninety bifidobacteria isolates from human feces were assessed for their ability to bind fluorescein isothiocyanate (FITC)-labeled LPS from E. coli. Isolates showing 30-60% binding were designated LPS-high binding (LPS-H) and those with less than 15% binding were designated LPS-low binding (LPS-L). The CSH, autoaggregation (AA), and inhibition of LPS-induced IL-8 release from HT-29 cells of the LPS-H and LPS-L groups were evaluated. Five bifidobacteria strains showed high levels of LPS binding, CSH, AA, and inhibition of IL-8 release. However, statistically significant correlations between LPS binding, CSH, AA, and reduction of IL-8 release were not found. Although we could isolate bifidobacteria with high LPS-binding ability, CSH, AA, and inhibition of IL-8 release, each characteristic should be considered as strain dependent. Bifidobacteria with high LPS binding and inhibition of IL-8 release may be good agents for preventing inflammation by neutralizing Gram-negative endotoxins and improving intestinal health.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.9
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• pp.96-103
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• 1994

The GaAs epilayer was grown at low temperature (LT. 250.deg. C) by molecular beam epitaxy. The properties of the LTT GaAs, before and after Rapid Thermal Annealing(RTA), were analyzed by Reflection of High Energy Electron Diffraction (RHEED), Double Crystal X-ray(DCX), Raman spectroscopy, PL and Photo-Induced Current Transient Spectroscopy (PICTS). The LT GaAs before RTA, was analyzed by RHEED and DCX, with a result of an improved surface morphology under a relatively As-rich(As/Ga ratio :28) condition, and of an increased lattics parameter of 1.1 1.7% in comparison with a GaAs substrate. However DCX and Raman spectroscopy revealed that the expanded lattics parameter and the crystallinity of LT GaAs could be recovered after RTA. On the other hand, PL spectra indicated that LT GaAs after RTA showed low optical sensitivity unlike High Temperature(HT) GaAs, and that its surface morphology and crystallinity were corresponded with those of HT GaAs. Finally PICTS spectra proved the fact that low sensitivity of LT GaAs was due to the deep level defects (Ec-0.85eV) which were strogly formed by raising RTA temperature to 750.deg. C.

• Herbal Formula Science
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• v.17 no.2
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• pp.143-150
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• 2009

The effects of aqueous extract of Schizandrae Fructus (AESC) on lead (Pb)-induced changes of monoamine neurotransmitters in the hippocampus (HIP) of adult rats were investigated. Male Sprague-Dawley rats were received intraperitoneal (i.p.) administration of Pb acetate (5 mg/kg/d) for 28 days and sacrificed 7 days after the last administration. Concentrations of norepinephrine (NE), dopamine (DA), serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) in HIP were measured by HPLC. There were significant decreases of NE, DA, 5-HT and 5-HIAA in Pb treated rats (P < 0.05), while pretreatment with AESC (100 mg/kg/d or 300 mg/kg/d, p.o., 2 h before Pb) greatly inhibited the decrease of monoamine transmitters, respectively (P < 0.05). Also, AESC (300 mg/kg/d) significantly increased the reduction of glutathione contents and superoxide dismutase activities in HIP induced by chronic Pb. These results suggest that AESC ameliorates Pb-induced depletion of monoamine neurotransmitters in HIP through its antioxidant activity.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.586-589
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• 2010

In present work, oxidative addition reaction of 1,3-cycleohexandion (1,3-CHD) with ethyl vinyl ether (EVE) was attempted utilizing $Ag_2CO_3$/celite (SC) reagent. In order to optimize reaction conditions, we surveyed several solvents for the production of dihydrofuran with the (SC) system. The yield of the acetonitrile (AN), dimethyl sulfoxide (DMSO), benzene (BZ), and heptane (HT) are given 78, 40, 15, and 10%, respectively. Therefore, we studied the solvent effects on yields by using PM3 and ZINDO/1 parameter of semi-empirical method of HyperChem7.0 molecular modeling program.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.1
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• pp.126-130
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• 2008

Water extract from Prunella vulgaris L. (PVW) was tested for colon cancer chemopreventive activity by measuring the activities of cytochrome P450 1A1, phase Ⅱ detoxification enzyme [quinone reductase (QR) and glutathione S-transferase (GST)] and ornithine decarboxylase (ODC) and glutathione (GSH) levels in cultured human colorectal adenocarcinoma HT-29 cells. PVW significantly inhibited 7,12-dimethylbenz[a]anthracene (DMBA)-induced cytochrome P450 1A1 activity at 10 and 50 ${\mu}g/ml$. PVW induced QR activity in a dose-dependent manner over a concentration range of $1{\sim}50\;{\mu}g/ml$. GST activity was also induced with the treatment of PVW in HT-29 cells. In addition GSH levels were increased with PVW. PVW inhibited ODC activity, a key enzyme of polyamine biosynthesis, which is enhanced in tumor promotion. These results suggest that Prunella vulgaris L. has colon cancer chemopreventive activity by inhibiting cytochrome P450 1A1 and ODC activities and by increasing phase Ⅱ enzyme activity and GSH levels.

• The Korean Journal of Community Living Science
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• v.16 no.2
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• pp.3-9
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• 2005

The study was carried out to evaluate the antimutagenic and anticancer effects of small water dropwort. The methanol extracts from small water dropwort significantly reduced the mutagenicity induced by aflatoxin $B_1\;(AFB_1)$ and N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) in Salmonella typhimutium TA 100. Also, the methanol extracts inhibited the growth of AZ-521 human gastric cancer cells and HT-29 colon cancer cells. The chloroform fraction from methanol extracts of small water dropwort inhibited $40\;to\;80\%$ of the mutagenicity by $AFB_1$ in Sal. typhimurium TA 100 by the addition of 2.5 to $10\%$. To separate active compounds, the chloroform fraction was subjected to column chromatography on a silica gel and separated into five fractions. Among the five fractions, fraction 4 showed the highest antimutagenic effect against $AFB_1$ and an anticancer effect in the HT-29 colon cancer cell. As the result of the analysis in GC-MS, 1-napthalene carbonitrile, 5,6,7,8-tetrahydrol and benzene, 1,1'-(1,4-pentadiene-1,5-diyl) bis-,(E,E) were identified potentially from fraction 4.

• Journal of Nutrition and Health
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• v.27 no.2
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• pp.153-161
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• 1994

We fed high trypotophan diet(3.5% tryptophan/diet(w/w) to mice for 7 days and treated then with 3 hour immobilization(IMMB) stress to investigate tryptophan metabolism and immunomodulation. The levels of serum tryptophan, brain tryptophan, serotonin(5HT) and 5-hydroxyindoleacetic acid(5HIAA) in the tryptophan diet fed animals were higher than those of the normal diet fed animals. Feeding tryptophan supplemented diet to stressed animal significantly decreased the levels of serum and brain tryptophan and 5HT levels. However, the amount of 5HIAA which is the metabolite of serotonin was increased in brain. Plasma corticosterone level was increased by the stress in both groups but the degree of this increase was smaller in high tryptophan fed animals. The relative numbers of CD8+ T cells, CD4+ T cells and B cells in spleen were decreased in high tryptophan diet fed and stressed animals compared to control diet fed and no stressed animals. CD8+ T cells decreased more than CD4+ T cells. The decrease of CD8+ T cells in high tryptophan fed and stressed animals was similar to that in high tryptophan fed animals or normal diet fed and stressed animals. Stress and tryptophan supplement acted synergistically to decrease the number of B cells. This study suggests that stress and tryptophan supplement could modify the number of lymphocyte cells, and indicates that the interaction of stress and tryptophan supplement on immune fuction depends on the types of immune cells.

• Structural Engineering and Mechanics
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• v.91 no.2
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• pp.177-195
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• 2024

This research plans to investigate the simultaneous impact of bamboo fibers (BF) and steel fibers (SF) on the mechanical and spalling characteristics of ultra-high-performance concrete (UHPC) exposed to high temperatures (HT). To this aim, 25 mixtures were made and assessed. BF was added at five contents of 0, 2.5, 5, 7.5 and 10 kg/m³. Additionally, SF was used at five weight contents: 0%, 1%, 2%, 3% and 4%. Specimens were exposed to temperatures ranging between 25℃ and 800℃. Thus, com-pressive, tensile, and flexural strengths, elastic moduli, mass loss, and permeability were measured. Experiments revealed that the simultaneous use of low BF and SF contents could totally prevent spalling of UHPC, but the use of either SF or BF alone could not prevent spalling at high levels of fibers. Besides, the synergetic positive impact of BF and SF on the spalling resistance of UHPC was by reason of the rise of BF' permeability and the bridging role of SF at HT. Moreover, it was concluded that the use of SF could moderate the adverse influence of BF on the compressive resistance of UHPC.

• Journal of Food Hygiene and Safety
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• v.38 no.6
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• pp.430-441
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• 2023

Velvet antler is widely used as a traditional medicine, and numerous studies have demonstrated its tremendous nutritional and medicinal values including immunity-enhancing effects. This study aimed to investigate different deer velvet extracts (Sample 1: raw extract, Sample 2: dried extract, and Sample 3: freeze-dried extract) for proximate composition, uronic acid, sulfated glycosaminoglycan, sialic acid, collagen levels, and chemical components using ultra-performance liquid chromatography-quadrupole-time-of-light mass spectrometry. In addition, we evaluated the cytotoxic effect of the deer velvet extracts on BV2 microglia, HT22 hippocampal cells, HaCaT keratinocytes, and RAW264.7 macrophages using the cell viability MTT assay. Furthermore, we evaluated acute toxicity of the deer velvet extracts at different doses (0, 500, 1000, and 2000 mg/kg) administered orally to both male and female ICR mice for 14 d (five mice per group). After treatment, we evaluated general toxicity, survival rate, body weight changes, mortality, clinical signs, and necropsy findings in the experimental mice based on OECD guidelines. The results suggested that in vitro treatment with the evaluated extracts had no cytotoxic effect in HaCaT keratinocytes cells, whereas Sample-2 had a cytotoxic effect at 500 and 1000 ㎍/mL on HT22 hippocampal cells and RAW264.7 macrophages. Sample 3 was also cytotoxic at concentrations of 500 and 1000 ㎍/mL to RAW264.7 and BV2 microglial cells. However, the mice treated in vivo with the velvet extracts at doses of 500-2000 mg/kg BW showed no clinical signs, mortality, or necropsy findings, indicating that the LD50 is higher than this dosage. These findings indicate that there were no toxicological abnormalities connected with the deer velvet extract treatment in mice. However, further human and animal studies are needed before sufficient safety information is available to justify its use in humans.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.27-27
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• 1996

SecA protein which has a pivotal role in the preprotein cranslocation across the inner membrane of Escherichia coli is a water-soluble protein with an unusual property of penetrating the membrane readily. An interesting and important question is what structural characteristics of SecA enables its ready penetration of lipid bilayer. The conformational properties of SecA in solution at 3$0^{\circ}C$, pH 7.5 were observed by hydrogen-tritium (HT) exchange, and denaturant-induced denaturation/renaturation and thermal unfolding. (omitted)