• KSBB Journal
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• v.6 no.1
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• pp.27-33
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• 1991

Hairy root induced by A. rhizogenes from potato tuber (Solanm tuberosum L.) synthesized the agropine and mannopine which were demonstrated with paper electrophoresis. And the starch contents in hairy root were increased gradually following the developmental stage. But protein contents were decreased. The activity of ${\beta}-glucan$ synthetase II(GSII) which is related to the cell wall biosynthesis was stimulated in hairy root on the developmental stage. And chloropromazine did not influence the activity of GS II while verapamil inhibited about 60% of the activity GS II. Therefore, these results showed $Ca^{2+}$ to be effective factor in the cell wall formation. Isozyme pattern of peroxidase was investigated in the callus and hairy root induced from potato tuber.

• Natural Product Sciences
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• v.17 no.2
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• pp.123-129
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• 2011

A screening of Nepalese wild herbs for their antioxidant and antiobesity activity was carried out. The herbs including Allium hyposistum, Crateva unilocularis, Dryoathyrium boryanum and Cuscuta reflexa are widely used traditionally for various medicinal purposes in Nepal. The ethyl acetate fraction of D. boryanum showed polyphenol content of 266 ${\mu}g$GAE/mg with potent antioxidative activity assessed by DPPH free radical scavenging activity and hydrogen peroxide scavenging activity. The EtOAC fraction of D. boryanum also inhibited the lipid formation with 35% at 100${\mu}g/ml$ in 3T3-L1 cell model. Along with this, butanol fraction of C. reflexa also showed potent antioxidative activity and inhibition of 80% of lipid formation at the test concentration of 75 ${\mu}g/ml$ in 3T3-L1 cell line. This showed that these plant extracts have potential of antioxidant and antiobesity activity.

• Solar Energy
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• v.19 no.3
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• pp.125-131
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• 1999

This paper deals with a novel structure of poly-Si solar cell. A grain boundary(GB) of poly-Si acts as potential barrier and recombination center for photo-generated carriers. To reduce unwanted side effects at the GB of poly-Si, we employed physical GB removal of poly-Si using chemical solutions. Various chemical etchants such as Sirtl, Yang, Secco, and Schimmel were investigated for the preferential GB etching. Etch depth about 10 ${\mu}m$ was achieved by a Schimmel etchant. After a chemical etching of poly-Si, we used $POCl_3$ for emitter junction formation. This paper used an easy method of top electrode formation using a RF sputter grown ITO film. ITO films with thickness of 300 nm showed resistivity of $1.26{\times}10^{-4}{\Omega}-cm$ and overall transmittance above 80%. Using a preferential GB etching and ITO top electrode, we developed a new fabrication procedure of poly-Si solar cells. Employing optimized process conditions, we were able to achieve conversion efficiency as high as 16.6% at an input power of 20 $mW/cm^2$. This paper investigates the effects of process parameters: etching conditions, ITO deposition factors, and emitter doping densities in a poly-Si cell fabrication procedure.

• International Journal of Oral Biology
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• v.34 no.1
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• pp.15-20
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• 2009

In our present study, total methanol extracts prepared from B. platyphylla var. japonica showed a significant increase in cell proliferation upon the induction of oxidative stress by hydrogen peroxide or $\gamma$-ray irradiation. Total methanol extracts were fractionated into five separate preparations i.e. n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these, the ethylacetate and butanol fractions of B. platyphylla var. japonica showed the highest protective effects against oxidative stress induced by hydrogen peroxide. These fractions also showed strong protective effects against $\gamma$-ray irradiation. When we evaluated the cytotoxicity of these fractions, the butanol fraction showed no effects in a colony formation assay. In addition, the butanol fraction showed a cell proliferation activation effect evidenced by significant increase in the colony formation of $\gamma$-ray irradiated cells. Both a radical scavenging activity and clonogenic activity assay suggested that the mechanism behind this protective effect against reactive oxygen species may be due to the radical scavenging and cell proliferation activity of B. platyphylla var. japonica extracts.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.775-783
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• 2005

The ethanol extract of the peony root (Paeonia Lactiflora Pall, Paeoniaceae) as well as its major active components including gallic acid and methyl gallate were evaluated for their protective effects against free radical generation and lipid peroxidation. In addition, the protective effects against hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line were examined. The ethanol extracts of the peony root (PREs) and its active constituents, gallic acid and methyl gallate, exhibited a significant free radical scavenging effect against 1,1-diphenyl-2-picryl hydrazine (DPPH) radical generation and had an inhibitory effect on lipid peroxidation, as measured by the level of malondialdehyde (MDA) formation. The PREs did not have any pro-oxidant effect. They strongly inhibited the hydrogen peroxide-induced DNA damage from NIH/3T3 fibroblasts, as assessed by single cell gel electrophoresis. Furthermore, the oral administration of 50% PRE (50% ethanol extract of peony root), gallic acid and methyl gallate potently inhibited the formation of micronucleated reticulocytes (MNRET) in the mouse peripheral blood induced by a $KBrO_3$ treatment in vivo. Therefore, PREs containing gallic acid and methyl gallate may be a useful antigenotoxic antioxidant by scavenging free radicals, inhibiting lipid peroxidation and protecting against oxidative DNA damage without exhibiting any pro-oxidant effect.

• Molecules and Cells
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• v.41 no.7
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• pp.639-645
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• 2018

Liver transplantation is recommended for patients with liver failure, but liver donors are limited. This necessitates the development of artificial livers, and hepatocytes are necessary to develop such artificial livers. Although induced hepatocyte-like cells are used in artificial livers, the characteristics of mouse induced hepatocyte-like cells (miHeps) reprogrammed with embryonic fibroblasts have not yet been clarified. Therefore, this study investigated the mechanisms underlying the survival, function, and death of miHeps. miHeps showed decreased cell viability, increased cytotoxicity, decreased hepatic function, and albumin and urea secretion at passage 14. Addition of necrostatin-1 (NEC-1) to miHeps inhibited necrosome formation and reactive oxygen species generation and increased cell survival. However, NEC-1 did not affect the hepatic function of miHeps. These results provide a basis for development of artificial livers using hepatocytes.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1325-1326
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• 2007

We have demonstrated new functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of silver via photo-induced diffusion in thin chalcogenide films is considered. The influence of silver on the properties of the newly formed materials is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Silver saturated is related to the composition of the hosting material. Silver saturated Ge-Ch glasses have been used in the formation of solid electrolyte which is the active medium in programmable metallization cell (PMC) devices. This paper concerns our more recent work on silver-doped germanium selenide electrolytes and describes the electrical characteristics of PMC devices made from these materials following annealing at $300^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1221-1229
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• 2019

Mycobacterium tuberculosis, a causative pathogen of tuberculosis (TB), still threatens human health worldwide. To find a novel drug to eradicate this pathogen, we tested taurine-5-bromosalicylaldehyde Schiff base (TBSSB) as an innovative anti-mycobacterial drug using Mycobacterium smegmatis as a surrogate model for M. tuberculosis. We investigated the antimicrobial activity of TBSSB against M. smegmatis by plotting growth curves, examined the effect of TBSSB on biofilm formation, observed morphological changes by scanning electron microscopy and transmission electron microscopy, and detected differentially expressed proteins using two-dimensional gel electrophoresis coupled with mass spectrometry. TBSSB inhibited mycobacterial growth and biofilm formation, altered cell ultrastructure and intracellular content, and inhibited cell division. Furthermore, M. smegmatis adapted itself to TBSSB inhibition by regulating the metabolic pathways and enzymatic activities of the identified proteins. NDMA-dependent methanol dehydrogenase, NAD(P)H nitroreductase, and amidohydrolase AmiB1 appear to be pivotal factors to regulate the M. smegmatis survival under TBSSB. Our dataset reinforced the idea that Schiff base-taurine compounds have the potential to be developed as novel anti-mycobacterial drugs.

• Mycobiology
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• v.51 no.3
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• pp.178-185
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• 2023

The cell wall integrity (CWI) signaling pathway plays important roles in the dissemination and infection of several plant pathogenic fungi. However, its roles in the pepper fruit anthracnose fungus Colletotrichum scovillei remain uninvestigated. In this study, the major components of the CWI signaling pathway-CsMCK1 (MAPKKK), CsMKK1 (MAPKK), and CsMPS1 (MAPK)-were functionally characterized in C. scovillei via homology-dependent gene replacement. The ΔCsmck1, DCsmkk1, and ΔCsmps1 mutants showed impairments in fungal growth, conidiation, and tolerance to CWI and salt stresses. Moreover, ΔCsmck1, ΔCsmkk1, and ΔCsmps1 failed to develop anthracnose disease on pepper fruits due to defects in appressorium formation and invasive hyphae growth. These results suggest that CsMCK1, CsMKK1, and CsMPS1 play important roles in mycelial growth, conidiation, appressorium formation, plant infection, and stress adaption of C. scovillei. These findings will contribute to a better understanding of the roles of the CWI signaling pathway in the development of pepper fruit anthracnose disease.

• Journal of Veterinary Clinics
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• v.40 no.5
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• pp.323-329
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• 2023

Peripheral blood-derived mesenchymal stem cells (PB-MSCs) have shown promise in cell-based therapy, as they can be harvested with ease through minimally invasive procedures. This study aimed to isolate PB-MSCs from foals and mares and to compare the proliferation and cellular characteristics of the PB-MSCs between the two groups. Six pairs of mares and their foals were used in this study. MSCs were isolated from PB by direct plating in a tissue culture medium, and cell proliferation (population doubling time [PDT], and colony-forming unit-fibroblast assay [CFU-F]), and characterization (morphology, plastic adhesiveness, colony formation, trilineage differentiation) were examined. There was no significant difference in the PB-MSC yield, CFU-F, and PDT between the mares and foals. PB-MSCs from both mares and foals showed typical MSC characteristics in terms of spindle-shaped morphology, plastic adhesive properties, formation of colonies, trilineage differentiation. These results suggest that PB-MSCs isolated from horses, both adult horses, and foals, can be used for equine cell-based therapy.