• Biomolecules & Therapeutics
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• v.26 no.4
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• pp.380-388
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• 2018

Neural stem cells (NSCs) have the ability to self-renew and differentiate into multiple nervous system cell types. During embryonic development, the concentrations of soluble biological molecules have a critical role in controlling cell proliferation, migration, differentiation and apoptosis. In an effort to find optimal culture conditions for the generation of desired cell types in vitro, we used a microfluidic chip-generated growth factor gradient system. In the current study, NSCs in the microfluidic device remained healthy during the entire period of cell culture, and proliferated and differentiated in response to the concentration gradient of growth factors (epithermal growth factor and basic fibroblast growth factor). We also showed that overexpression of ASCL1 in NSCs increased neuronal differentiation depending on the concentration gradient of growth factors generated in the microfluidic gradient chip. The microfluidic system allowed us to study concentration-dependent effects of growth factors within a single device, while a traditional system requires multiple independent cultures using fixed growth factor concentrations. Our study suggests that the microfluidic gradient-generating chip is a powerful tool for determining the optimal culture conditions.

• World Technopolis Review
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• v.3 no.3
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• pp.153-164
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• 2014

It is recent that STEM (Science, Technology, Engineering and Mathematics) education emerged as a great concern of the U.S. policy makers in terms of securing national and regional competitiveness. However, few attempts to embrace STEM education as a source for sustainable regional growth have been made mainly due to methodological challenges. This paper investigates the role of STEM education in achieving sustainable economic growth. For the purpose of the paper, a U.S. federal workforce development program named Workforce Innovation in Regional Economic Development (WIRED) in Southeastern Virginia that was implemented between 2007 and 2010 is selected and evaluated qualitatively. By identifying three themes as a result of three-stage coding methods, the evaluation results call for particular attention of local policy makers and key stakeholders to STEM education as a source of sustainable long-term economic growth in regions.

• Journal of Ginseng Research
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• v.9 no.1
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• pp.42-53
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• 1985

This study was carried out to obtain the basic information about the large scale propagation of ginseng (Panax ginseng C.A. Meyer). Therefore, the stem cuttings of 1-year old ginseng, treated with various concentrations of plant growth regulators for 5 seconds (quick dipping) and 24 hours (prolonged soaking), were cultured. The root formation of stem cuttings was varied with the concentrations, kinds, and treatment methods of plant growth regulators. Besides normal-looking roots various malformed roots were observed. In the prolonged soaking method, the culture of stem cuttings, treated with 10 ppm of IBA or NAA, resulted in profuse root regeneration. And stem cuttings, in quick dipping method, treated with 2000 ppm of IBA or NAA resulted in more excellent root regeneration. In general, IBA was more vigorous for the root formation than NAA, The treatment with 50 ppm kinetin or 100 ppm BA brought good result for the retardation of senescence of stem cuttings and BA treatment was more effective than kinetin. As for the saponin content of roots derived from stem cutting culture, the roots, formed by non-treatment of growth regulators, were higher in saponin content than those formed by treatment of growth regulators.

• Journal of Environmental Science International
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• v.11 no.4
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• pp.319-325
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• 2002

This experiment was carried out to investigate the effects of heavy metals (copper, cadmium, lead and chrome) on the growth of plant and seed germination of Arabidopsis thaliana treated with various concentrations of heavy metals. Cadmium and chrome among the 4 heavy metals had no effect on the growth of stem even in the concentration fifty times higher than the official standard concentration of pollutant exhaust notified by the Ministry of Environment. The official standard concentration of cadmium, however, stimulated the growth of stem in general, increasing leaf size and surface area, although it had no effect on the length of stem. But the growth of stem was decreased about 18% in the official standard concentration of pollutant exhaust of lead and copper. There was no growth of root in the concentration of lead and copper ten times higher than the official standard concentration. Cadmium and chrome had no effect on the seed germination, but lead and copper decreased the rate of seed germination. Seeds were not germinated in the concentration of copper ten times higher than the official standard concentration and in the concentration of lead fifty times higher than the official standard concentration. From this research three peculiar results were obtained. Chrome in the soil did not have much effect on the plant growth and seed germination of Arabidopsis thaliana. Cadmium stimulated the stem growth in an optimum concentration. But lead and copper reduced the plant growth and seed germination even in a small concentration, especially copper had the worse effect.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.5
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• pp.488-498
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• 2015

Research on stem cells can be divided into three categories : pluripotent stem cell, adult stem cell, and induced pluripotent stem cell. Technology life cycle (TLC) on research stage is analyzed for the three stem cell categories based on diffusion model. Three diffusion models-logistic, Bass, and Bass model with integration constant (BMIC)-are applied to the number of articles related to each stem cell category in SCOPUS lists. Two different parameter estimation methods is used for each of logistic and Bass model. Results show that (1) the current year, 2015, lies in growth period at pluripotent stem cell and adult stem cell, and lies in growth period or maturity period at induced pluripotent stem cell. (2) Model fitness is the highest at BMIC model. (3) Imitation effect works best at the research area of induced pluripotent stem cell.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.4
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• pp.25-35
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• 2001

This study aims to find out the growth characteristics of riparian plants on the artificial floating islands (AFI). Three types of experiments were performed. The vegetation growth were compared by the plant-supporting materials; natural cotton mat, coir mat on the AFI or in the water, and natural soil at the waterfront. Major findings are; 1. The survival rate of riparian plants was 100% on both coir-mat and cotton-matislands, which implies that we may substitute cheaper cotton for expensive coir-mat. 2. Both natural cotton mat and coir mat were good for the growth of plants. Especially, the natural cotton mat was good for Sparganium stoloniferum and Miscanthus sacchariflorus, and the coir mat was good for Typha latifolia. 3. The growth rate of stem and root showed difference between the stem-removed plants and stem-remaining plants. As a whole, the growth rate of stem-removed plants was bigger than the one of stem-remaining plants. 4. The growth rate of plants showed difference between those grown on the AFI and those grown in the water. The growth rate of plant on the AFI was bigger than the one in the water. 5. The growth rate of plants on the AFI was bigger than the one on the natural soil at the waterfront.

• Journal of the Korean Society of Industry Convergence
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• v.17 no.3
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• pp.178-183
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• 2014

The objective of this study is to find out the effect of yeast on hair loss treatment and the role of hair follicle stem cell activator, which is important in hair growth. The authors have recently produced a substance, which has no disgusting odor, does not precipitates and does not easily corrupt, to use instead of yeast acquired from raw rice wine(Makgeolli). The substance is named Yeast Constituent Extract(YCE). In this research, the Produced YCE was applied on the hair loss area of 10 Androgenic alopecia patients, twice every day for 6 months, in order to test the effect of hair loss treatment and the role of stem cell activator. As a result, all of the patients showed a significant growth of hair after 3 months of test, and showed much more growing, thickening and strengthening of hair after 6 months. As a result of measuring the number of hair strings in the same scalp region of the patients after 6 months, it is found that the density of hair has increased, indicating that the hair loss treatment was effective. Also the hair follicle stem cell was isolated from the patients and the contents of growth factors (IGF, VEGF, FGF, HGF) derived from hair follicle stem cell were measured with ELISA. As result, the amount is found to be about 10 times greater than before the test. The hair follicle stem cell contains many growth factors that affect growth of hair, so it takes a highly important role in hair loss treatment. The YCE that the authors have produced was found to be effective in increasing the contents of growth factors that are derived from hair follicle stem cell. Thus it can be inferred that the YCE plays a role as a stem cell activator that activates the hair follicle stem cells. In conclusion, the YCE is considered to be highly effective for hair loss treatment and to have a role as a stem cell activator.

• Journal of Korean Society of Forest Science
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• v.83 no.1
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• pp.63-74
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• 1994

One of the essential factors to estimate the stem and stand growth is to correctly portray a stem form (profile). It is also required to numerically approximate a stem form in order to dynamically grasp and represent a stand growth. A whole stem form seems to be a conical form but a stem outline at various positions tapers off differently. Accordingly it is difficult to model a whole stand form with single taper equation. A stem taper equation with different coefficients on each subinterval can be useful tools to accurately portray a stem form. This article presents the derivation method of individual stem taper curve using spline function. It is also in this paper aimed to study how a stand taper curve car, be derived from the population of single stem taper curve in a stand. These taper equations numerically formulated enable to dynamically represent and prognosticate the development process of a stand and prepare the foundation of variety on growth model study and rational forest planning model.

• Journal of Plant Biology
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• v.16 no.1_2
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• pp.12-16
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• 1973

The inhibitory effect of Inula sesquiterpene lactones on the growth of Phaseolus vulgaris was tested and the abnormality of the stem organization caused by the lactones was also examined. The longitudinal growth of the young stem and the expansion of the young leaf were stopped by the application of the lactones. However, this inhibitory effect was appeared and strictly restricted within the treated area. So the young shoot was observed for possible bending as a result of the unilateral application of the lactones. When the application of the lactones into the medium, the growth of the plant was entirely repressed. However, the growth of shoot and re-initiation of root were started after the plant was transfered to the lactone free medium. And partial reversal of inhibition of the stem growth was achieved by the additions of gibberelline and the lactones.

• Journal of Korean Society of Forest Science
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• v.2 no.1
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• pp.10-16
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• 1962

The following are what this auther concluded in his recent research of bamboo cultivation. 1. The bamboo logging should be prohibited during the months of July and August, for during that season the growth of the terrestrial stem is most vigorous and active. 2. The growth of terrestrial stem of the phyllotachys pubescens is not likely to be affected the soil texture on which it grows and it is sappling sprout out well enough in any kind of soil, but it was found out that it grows in the best condition on the sand-clay soil and in next best condition on the clay-soil. 3. The bamboo blossoming takes always most of the nutritions needed for the growth of the terrestrial stem and causes to decay 90 percent of the next year buds which await in the terrestrial stem to sprout as the sappling. The remaining 10 percent of the buds is to be the "re-incarnated bamboos" 4. The terrestrial thin roots of blossoming bamboo are negative in their growth, too weak in absorbing the nutrition. The above stated facts show, to be brief, that growth of bamboo depends largely upon that of the terrestrial stem.