• Journal of the Korean Chemical Society
• /
• v.67 no.2
• /
• pp.137-144
• /
• 2023

In this study were evaluated the whitening and anti-oxidative activities from the extracts of Sorbus alnifolia branches, and identified the chemical structures of the active ingredients. In the whitening tests using α-MSH stimulated B16F10 melanoma cells, the 70% ethanol extract and n-butanol (n-BuOH) fractions concentration-dependently inhibited cellular melanogenesis and intracellular tyrosinase activities without causing cell toxicity. The total polyphenol content of n-BuOH and ethyl acetate (EtOAc) fractions were measured to be respectively 241.1 ± 1.1 and 222.9 ± 2.4 (mg/g GAE), and the total flavonoid content of EtOAc fraction was 75.3 ± 2.0 (mg/g QE). Upon anti-oxidant studies with DPPH and ABTS⁺ radicals, potent radical scavenging activities were observed in the EtOAc and n-BuOH fractions. Moreover, in the study of cell protection efficacy using HaCaT keratinocytes damaged by H₂O₂, the EtOAc and n-BuOH fractions showed a very positive results on prevention of oxidative stress. Phytochemical studies for this extract resulted in the isolation of four compounds; 2-oxopomolic acid (1), euscaphic acid (2), epi-catechin (3), prunasin (4). These results suggested that the extract of S. alnifolia branches containing compounds 1-4 as natural ingredients could be used as whitening and anti-oxidant ingredients in cosmetic formulations.

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

• Journal of Life Science
• /
• v.9 no.5
• /
• pp.531-536
• /
• 1999

As an attempt to preserve resources in marine biological organisms, we first constructed a cDNA library from the red alga Porphyra yezoensis. The library construction method from P. yezoensis consists of three steps; those include protoplast presparation, RNA isolation, and phage library construction. Protoplast was prepared in order to remove much of the carbohydrate compounds which are characteristics of algal cell walls. Carbohydrate contamination in the purified RNA may inhibit further enzyme reactions, those carbohydrates should be removed. RNA samples prepared from protoplast still seemed to contain residual amount of carbohydrate because mRNA isolation with conventional method failed. We therefore developed a method with Poly ATtract mRNA isolation system. The constructed phage library was tested by analyzing cDNA insert in phage vector from randomly picked ten independent white plagues. All of the phages contained cDNA inserts with sizes ranging 0.5kb and 2.0kb.

• Korean Journal of Pharmacognosy
• /
• v.50 no.4
• /
• pp.245-252
• /
• 2019

This study was initially explored to procure biomaterials capable of inhibiting cancer cell growth from nine Persicaria species (Polygonaceae). The extract of P. nepalensis that was selected from the initial screenings was further fractionated to identify bioactive compounds. The ethyl acetate (EtOAc) fraction was shown to be the most active in the inhibition of cell growth against six cancer cell lines (IC₅₀ value of 3.77-12.87 ㎍/ml). Phytochemical study led to the isolation of two galactolipids of 1,2-di-O-linolenoyl-3-O-β-D-galactospyranosyl-sn-glycerol (1) and 1-O-linolenoyl-3-O-β-D-galactospyranosyl-sn-glycerol (2) from the hexane fraction and three phenylpropanoyl sucroses of lapathoside A (3), vanicoside B (4) and lapathoside C (5) from the EtOAc fraction. These isolated compounds have not been reported from this plant. Compounds 3 and 4 exhibited the effective growth inhibition against a panel of cancer cell lines (IC₅₀ value of 6.90-18.09 μM). In addition, the anti-inflammatory activity was evaluated to determine lipopolysaccharide (LPS)-induced nitric oxide (NO) formation in RAW264.7 mouse macrophage cells. The EtOAc fraction (IC₅₀; 34.14 ㎍/ml) and its constituents, 3 (8.55 μM) and 4 (7.83 μM) were shown to be effective in the inhibition of LPS-induced NO production. Therefore, compounds 3 and 4 were considered to be active constituents for anti-inflammatory and antitumor activity from P. nepalensis.

• Journal of Internet Computing and Services
• /
• v.18 no.4
• /
• pp.89-97
• /
• 2017

The purpose of the present study was to estimate the effect of adolescents' depression on cell phone dependency and to identify mediating effects of parenting style and peer isolation. The study used data from the $6^{th}$ waves of 2015 KCYPS(Korean Children and Youth Panel Survey). Structural Equation Model(SEM) was conducted to examine the mediating effects of parenting style and peer isolation. The results showed that adolescents' depression had positive effects on cell phone dependency. In addition, the relationship between adolescents' depression and cell phone dependency was partially mediated by parenting style, not mediated by peer relationships. Based on these findings, further suggestions are provided to reduce adolescents' cell phone dependency by decreasing parent's over-involvement and improve adolescents' self control opportunities.

• Journal of Mushroom
• /
• v.22 no.3
• /
• pp.87-91
• /
• 2024

Recently, active research in Korea and worldwide has begun to focus on gene function and cultivar development using gene editing tools. This research, in addition to studies on edible mushroom, aims to enhance the physical and biochemical characteristics of mushrooms for applications in materials and substance production. For these studies, efficient isolation of protoplasts from the target mushroom is critical. However, several commercial cell wall-lysing enzyme cocktails, including Novozyme234, Glucanex, and Lysing enzymes, have recently been discontinued. In this study, we aimed to identify alternative enzyme systems to replace the discontinued cell wall-lysing enzymes for stable isolation of protoplasts from Ganoderma lucidum. To select an optimal osmotic buffer, enzyme function in 0.6 and 1.2 M Sorbitol, Sucrose, Mannitol, and KCl was assessed. The effect of reaction time was also evaluated. Protoplast isolation efficiency of each alternative enzyme was tested using lysing enzymes from Trichoderma harzianum, Chimax-N, and Yatalase, either individually or in combination. This matrix of studies identified enzymes and optimal conditions that could replace the discontinued lysing enzymes.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.26 no.6
• /
• pp.124-130
• /
• 1989

For the higher density DRAM'S, innovations in fabrication process and circuit design which have led to dramatic density improvement are discussed from the desinger's perspective. A new dynamic RAM cell called Trench Epitaxial Transistor Cell(TETC) using trench technics and SEG have been developed for use in future megabit DRAMS. Storge electrode with $n^+$-polysilicon and $n^+$-source electrode are self-contacted in TETC. With keeping the storage capacitance large enough to prevent soft errors, the cell size reduced to 30% compare with existing BSE cell by utilizing the vertical capacitor made along the isolation region.

• The Journal of the Korea Contents Association
• /
• v.5 no.6
• /
• pp.129-137
• /
• 2005

A performance analysis of LEO Satellite Communication Service is being made in a variety of ways. In this paper we examined the variation of interference caused by the distribution of terminals within a cell and the maximum number of users according to the average distance between terminals, which had not been considered in former researches. Also we examined the interference made by sopt beam isolation value of some antennas(tapered-apertured antenna, gaussian antenna) which are used on LEO Satellite Communication Service Assigning this interference to the bandwidth of channels in LEO Satellite Communication Service, and with principal parameters(bandwidth, number of carrier) we made a performance analysis. And comparing tapered-apertured antenna with gaussian antenna we will find out which one is more effective and more suitable for interference.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.13 no.4
• /
• pp.402-409
• /
• 2013

An innovative application of voltage-contrast (VC) inspection allowed inline detection of NMOS leakage in dense SRAM cells is presented. Cell sizes of SRAM are continual to do the shrinkage with bit density promotion as semiconductor technology advanced, but the resulting challenges include not only development of smaller-scale devices, but also intra-devices isolation. The NMOS leakage caused by the underneath n+/P-well shorted to the adjacent PMOS/N-well was inspected by the proposed electron-beam (e-beam) scan in which VC images were compared during the in-line process step of post contact tungsten (W) CMP (Chemical Mechanical Planarization) instead of end-of-line electrical test, which has a long response time. A series of experiments based on the mechanism for improving the intra-well isolation was performed and verified by the inline VC inspection. An optimal process-integration condition involved to the tradeoff between the implant dosage and photo CD was carried out.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.5
• /
• pp.890-894
• /
• 2001

The isolation of genomic DNA from mammalian cells is usually performed by cell lysis followed by protein digestion, extraction, and finally, ethanol precipitation of the chromosomal DNA. However, in the case of large sample numbers or when only small amounts of starting materials are available, such conventional methods are not efficient and are cumbersome to be applied. Some alternative methods have been described as well as having commercial DNA isolation kits to be available, nevertheless, there is room left for much improvement. In the present study, a novel method is introduced, where it simplifies conventional protocols by omitting some time-consuming steps such as protease incubation or DNA precipitation and its resuspension. Using paramagnetic silica resins, the genomic DNA was purified over a magnetic field, and the bound DNA was eluted with a low-salt buffer. The fidelity and effectiveness of this novel method was determined by using normal and apoptotic cells as a starting material and then compared to other protocols. The high speed and convenience along with its high efficiency in detecting apoptotic chromosomal DNA will prove this method to be an improved alternative in the isolation of genomic DNA from mammalian cells.