• Biomedical Science Letters
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• v.23 no.4
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• pp.411-415
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• 2017

To evaluate the protective effects of Plantago Major extract (PME) in stimulated BV-2 microglial cells and its anti-oxidant properties, cell viability assessment was performed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Lipopolysaccharide (LPS) was used to activate BV-2 microglia. Nitric oxide (NO) levels were measured using Griess assay. Tumor necrosis factor-alpha (TNF-${\alpha}$) production was evaluated by enzyme-linked immunosorbent assay (ELISA). Antioxidant properties were evaluated by 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay. LPS-activated excessive release of NO in BV-2 cells was significantly inhibited by PME (P < 0.001 at $100{\mu}g/mL$). PME also scavenged DPPH radicals in a dose-dependent manner (P < 0.05 at $10{\mu}g/mL$ and P < 0.001 at $20{\sim}200{\mu}g/mL$). These results indicate that PME attenuated neuroinflammatory responses in LPS-activated BV-2 microglia by inhibiting excessive production of pro-inflammatory mediators such as NO and TNF-${\alpha}$. The anti-neuroinflammatory potential of PME may be related to its strong antioxidant properties.

• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.19-23
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• 1994

The tetrazolium dye, 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), is reduced by live but not dead cell, and this reaction is used as the end point in a rapid drug screening assay. It can also be used for accurate determinations of drug sensitivity but only if a quantative relationship is established between cell number and MTT-formazan production. Several conditions were examined to devise an in vitro assay method in primary cultured hepatocytes, such as optimum wavelength, optimal MTT concentration, optimal incubation time, and cell density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.470-473
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• 2002

In order to get proper original suspension for the electrophoresis process of making YBaCuO films, YBaCuO superconductor powder was prepared with the Sol-gel method. The composition of the powder was analyzed by X-ray diffraction, which was identified as YBa$_2$Cu$_3$O$\sub$7-x/(Yl23) phase. The form of YBaCuO single particle was showed to be spherical by scanning electronic microscope and its size was among 0.2-1 $\mu\textrm{m}$. The critical transition temperature (T$\sub$c/) and the critical current density (J$\sub$c/) were measured with the four-probe, method. The T$\sub$c/ was about 91 K, and the J$\sub$c/ was 5-30 A/$\textrm{cm}^2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.499-502
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• 2002

We synthesized Y$\sub$1.8/Ba$\sub$2.4/Cu$\sub$3.4/O$\sub$x/(Y123+Y211+1wt% CeO$_2$) powders using Polymeric Complex method and used raw materials; Y$_2$O$_3$, BaCO$_3$, CuO and CeO$_2$. It was formed by calcination at 850 $^{\circ}C$ for 24h in air. In comparison of solid-state method, sol-gel method etc., synthesis temperature decreased up to 100$^{\circ}C$.

• Journal of Forest and Environmental Science
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• v.23 no.2
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• pp.87-91
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• 2007

The needles of L. kaempferi was extracted with 95% ethanol and successively partitioned with n-hexane, $CH_2Cl_2$ and EtOAc. Repeated column chromatography on the EtOAc and $H_2O$ soluble fractions gave three flavan-3-ols, one flavone glycoside, six flavonol glycosides and one lignan derivative. Their structures were elucidated on the basis of chemical and spectroscopic evidences. The antioxidant activities of the isolated compounds were evaluated by DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging method. Flavan compounds indicated good antioxidative potentials compared with BHT (butylated hydroxytoluene) and ${\alpha}$-tocopherol as controls. In the anti-inflammatory test on most of the isolated compounds, NO (nitric oxide) assay against the RAW 264.7 (Mouse Macrophage) showed similar inhibitory potentials to NO production of the control. The cytotoxicity was determined by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and most of the isolated compounds indicated no toxicity in various concentration.

• Bulletin of the Korean Chemical Society
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• v.25 no.5
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• pp.652-656
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• 2004

A new luminescent polymer, poly{1,4-phenylene-1,2-ethenediyl-2'-[2"-(4'"-octyloxyphenyl)-(5"-yl)-1",3",4"-oxadiazole]-1,4-phenylene-1,2-ethenediyl-2,5-bis-dodecyloxy-1,4-phenylene-1,2-ethenediyl} (Oxd-PPV), was synthesized by the Heck coupling reaction. Electron withdrawing pendant, conjugated 1,3,4-oxadiazole (Oxd), is on the vinylene unit. The band gap of the polymer figured out from the UV-visible spectrum was 2.23 eV and the polymer film shows bright yellow emission maximum at 552 nm. The electroluminescence (EL) maximum of double layer structured device (ITO/PEDOT:PSS/Oxd-PPV/Al) appeared at 553 nm. Relative PL quantum yield of Oxd-PPV film is 3.6 times higher than that of MEH-PPV film. The HOMO and LUMO energy levels of Oxd-PPV figured out from the cyclic voltammogram and the UV-visible spectrum are -5.32 and -3.09 eV, respectively, so that more balanced hole and electron injection efficiency can be expected compared to MEH-PPV. A double layer EL of Oxd-PPV has an maximum efficiency of 0.15 cd/A and maximum brightness of 464 cd/$m^2$.

• Archives of Pharmacal Research
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• v.23 no.2
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• pp.139-146
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• 2000

7- Bromomethylbenz[a]anthracene is a known mutagen and carcinogen. The two major DNA adducts produced by this carcinogen, i.e., $N^2$-(benz[a]anthracen-7-yl methyl)-2'-deoxyguanosine (2, b[a]$a^2$G) and $N^6$-(benz[a]anthracen-7-ylmethyl)-2'-deoxyadenosine (4, b[a]$a^6$/A), as wel 1 as the simpler benzylated analogs,$N^2$-benzyl-2'deoxyguanosine (1, $bn^2$G) and $N^6$-benzyl-2'-deoxyadenosine (3, $bn^6$/A), were prepared by direct aralkylation of 2'-deoxyguanosine and 2'-deoxyadenosine. To determine the site-specific mutagenicity of these bulky exocyclic amino-substituted adducts, the suitably protected nucleosides were incorporated into 16-base oligodeoxyribonucleotides in place of a normal guanine or adenine residues which respectively are part of the ATG initiation codon for the lac Z' \alpha-complementation gene by using an in situ activation approach and automated phosphite triester synthetic methods. The base composition and the incorporation of the bulky adducts into synthetic oligonucleotides were characterized after purification of the modified oligonucleotides by enzymatic digestion and HPLC analysis.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.74-74
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• 2019

The aim of the study was to determine the antioxidant activities of the plants with origin of the Far East. The Carlemannia tetragona Hook f., which is a species of plant in the family Carlemanniaceae and Celastrus virens which is a species of plant in the family Celastraceae were tested for antioxidant activities. Samples were prepared using 95% ethanol using DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical) assay for assessing the antioxidant activity. Ascorbic acid was used for positive control for DPPH assay. DPPH assay experiment showed that extracts of the Carlemannia tetragona Hook. f., and Celastrus virens might have anti-oxidant activity 54.5% and 258% higher, respectively, compared to control. To determine the cell toxicity of these plant extracts, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used. MTT assay experiment showed that Carlemannia tetragona Hook. f., and Celastrus virens might have less toxicity 23.3% and 27.5%, respectively, compared to control. Taken together, these experiments showed that Celastrus virens extracts might have much higher antioxidant activities than Carlemannia tetragona Hook. f., with relatively lower toxicity. This implies that this study might provide a basis to develop a new powerful antioxidant candidate for human diseases therapeutics.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.364-368
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• 2021

We developed a highly efficient organic photovoltaic (OPV) cell with a poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene-)-2-carboxylate-2-6-diyl)]:[6,6]-phenyl-C71-butyric acid methyl ester active layer for harvesting lower-intensity indoor light energy to power various self-powered sensor systems that require power in the microwatt range. In order to achieve higher power conversion efficiency (PCE), we first optimized the thickness of the active layer of the OPV cell through optical simulations. Next, we fabricated an OPV cell with optimized active layer thickness. The device exhibited a PCE of 12.23%, open circuit voltage of 0.66 V, short-circuit current density of 97.7 ㎂/cm², and fill factor of 60.53%. Furthermore, the device showed a maximum power density of 45 ㎼/cm², which is suitable for powering a low-power (microwatt range) sensor system.

• Herbal Formula Science
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• v.23 no.1
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• pp.101-110
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• 2015

Objectives : The purpose of this study was to investigate the anti-cancer effects of Oldenlandia diffusa extract on WiDr human colorectal adenocarcinoma cells. Methods : We examined cell death by (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) MTT assay and the caspase 3 and 9 activity assay with Oldenlandia diffusa extract. To examine the inhibitory effects of Oldenlandia diffusa extract, we performed a cell cycle (sub-G1) analysis and mitochondrial membrane potential for the WiDr cells after 24 hours with Oldenlandia diffusa extract. Results : 1. Oldenlandia diffusa extract induced cell death in WiDr cells. 2. The sub-G1 peak was increased by Oldenlandia diffusa extract in WiDr cells. 3. Oldenlandia diffusa extract leads to increase the mitochondrial membrane depolarization in WiDr cells. 4. Oldenlandia diffusa extract increases caspase 3 and 9 activities in WiDr cells. 5. Oldenlandia diffusa extract combined with several anti-cancer drugs (paclitaxel, 5-fluorouracil, cisplatin, ectoposide, doxorubicin and docetaxel) markedly inhibited the growth of WiDr cells compared to Oldenlandia diffusa extract and anti-cancer drugs alone. Conclusions : Oldenlandia diffusa extract has an apoptotic role in human colorectal cancer cells and a potential role in developing therapeutic agents against colorectal cancer.