• The Korean Journal of Ecology
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• v.27 no.1
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• pp.27-33
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• 2004

Cryptomeria japonica plantation was monitored every year during 15 years from 1983 to 1997 for stem diameter and volume. The reciprocal equation, 1/Y = A + B/N, was applied to the relationship between cumulative volume Y and cumulative number N from the largest tree in the stand each year. The parameters A and B, which means respectively the reciprocal of an asymptotic value of total stand stem volume and the reciprocal of the maximum stem volume, are related by a power function. The power functional relationship between A and B derived a linear relationship of B-points ( $N_{B}$, $V_{B}$; $N_{B}$ = B/A, $Y_{B}$ = 1/2A) of each Y-N curve on log-log coordinates. The gradient of B-point line was so steep that the Y-N curve moved parallel upward year by year. The time trajectory of mean stem volume (W) and density ($\rho$) provided evidence in favor of the 3/2 power law of self-thinning, because the gradient of W - $\rho$ trajectory on log-log coordinates approximated to -3/2 at the final stage of stand development. On the basis of the results of Y-N curves and W - $\rho$ trajectory, the time trajectory of maximum stem volume $W_{max obs}$ and $\rho$ was derived theoretically. The gradient of $W_{max obs}$ - $\rho$ trajectory on log-log coordinates is calculated to be -0.6105 at the final stage. The gradient of $W_{max obs}$ - $\rho$ trajectory was steeper than that of W - $\rho$ trajectory at the early stage, while the former is gentler than the latter at the later stage.stage.e.age.e.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.4849-4852
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• 2015

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been investigated as an effective agent to treat various cancers. Cancer stem cells are resistant to TRAIL treatment, but the mechanism of TRAIL resistance remains unknown. In this study, brain cancer stem cells were isolated by CD133 magnetic sorting, and the number of CD133 positive cells detected by flow cytometry. The self-renewing capacity of brain cancer stem cells was examined by a neurosphere formation assay, and the percentage of cell death after TRAIL treatment was examined by an MTS assay. Expression of DR5, FADD, caspase 8 and BCL2 proteins was detected by western blot. The amount of CD133 positive cells was enriched to 71% after CD133 magnetic sorting. Brain cancer stem cell neurosphere formation was significantly increased after TRAIL treatment. TRAIL treatment also reduced the amount of viable cells and this decrease was inhibited by a caspase 8 inhibitor or by the pan-caspase inhibitor z-VAD (P<0.05). Brain cancer stem cells expressed lower levels caspase 8 protein and higher levels of BCL2 protein when compared with CD133 negative cells (P<0.05). Our data suggest that TRAIL resistance is related to overexpression of BCL2 and low expression of caspase 8 which limit activation of caspase 8 in brain cancer stem cells.

• Journal of Life Science
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• v.12 no.3
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• pp.294-305
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• 2002

This study was performed to evaluate regenerative effects of intrasplenic stem cell transplantation after partial hepatectomy. To evaluate the regenerative effects, Sprague Dawley rats were used. In vivo the embryonic stem cells of blastocysts were collected from superovulated rats on day 3.5 after the vaginal plug checked. The embryonic stem cells were cocultured with hepatocytes for 8 days, they were transplanted into the spleen. After the intrasplenic transplantation of cultured stem cells, they were initially distributed near the periarterial lymphatic sheath after transplantation in the hematoxylin-eosin staining. Their number were formely increased and their size enlarged at forming small lobules. The embryonic stem cells in the culture proliferated and initially proliferated around the periarterial lymphatic sheath and later they around the trabecula with blood vessels. After the transplantation of stem cells, their cell organelles were well developed rough endoplasmic reticulum at the 20th with prominent epidermal growth factor reaction, developed smooth endoplasmic reticulum at the 30th day, well differentiated bile canaliculi with increased transforming growth factor-$\beta$ and apoptosis reactions.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.269-275
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• 1999

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi, and seonmi, whose source and sink are different, were cultivated at different planting densities, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem and leaf and tuberous root weight by planting density and defoliation rate of sweet potato varieties was different. Stem and leaf weight per m$^2$ increased along with dense planting by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number per m$^2$ was the most at 75$\times$20cm planting density, showing seonmi the most number. The number of stem and leaf and tuberous root increased along with the lowered rate of defoliation. In case of 75$\times$10cm and 75$\times$20cm planting density, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem and leaf and tuberous root number was low as defoliation rate increases. The tuberous root and total dry weight matter was the most at 75$\times$20cm planting density. The increase and decrease of source synchronized with those of sink at 75$\times$10cm and 75$\times$20cm, however the relationship occurred less at 75$\times$30cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.420-428
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• 1988

Root is supposed to be important role in growth and yield formation of soybeans and also there is expected to exist varietal differences between soybean root morphology and system. 30 soybean varieties including 10 Korean recommended, 10 Introduced and 10 Korean native varieties were grown at field and pot under standard culture condition. Top and root characteristics were investigated at V4, R1 and R5 stage and T/R relations, correlations with yield were calculated. Top characteristics showed significant difference between 3 variety groups of Korean recommended, Introduced and Korean native variety. Stem length at R1 stage and stem length, stem diameter, number of nodes, number of branches, number of pods and grain yield at R5 stage were significantly different top characteristics. Root characteristics showed significant difference between 3 variety groups were number of thick primary root at V4 stage, primary root angle and root cutting strength at R1 stage, thick root diameter and root dry weight at R5 stage. The correlations between top and root characteristics and soybean yield was greatly different by soybean variety groups, and the top characteristics was more highly correlated then root characteristics. All the top and root characteristics of Korean recommended variety showed no correlations with yield. However, leaf area, stem length, top dry weight in Introduced variety and leaf area, top dry weight, number of nodes, number of thick primary root in Korean native variety were highly correlated with soybean yield.

• Journal of Practical Agriculture & Fisheries Research
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• v.6 no.1
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• pp.41-49
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• 2004

This study was carried out to investigate the effects of temperature and photoperiod on the growth of Fagopyrum tataricum. It showed a tendency to promote the germination rate and plant height of tatary buckwheat under high temperature. Plant height and number of leaves were promoted in the order of 25>20>15>30℃ under the different temperature after 30 days of the planting. In the 10, 12, 14hr photoperiods at 20℃, plant height, number of leaves and dry weight were increased as much as photoperiod became long except by 16hr. Rutin contents was not regular both common and tatary buckwheat under the photoperiods. The rutin content in leaves was higher than stem. Compared to yield of tatary and common buckwheat, plant height, number of leaves, number of branch and stem diameter of tatary buckwheat increased more than common buckwheat. Especially, number of leaves was increased about 2.5 times more than common buckwheat. And there was a difference in about 2.1 times in grain weight and about 5.4 times in number of grains. Rutin content of plant parts was higher in the order of leaf>stem>grain in common buckwheat at the harvest. But it was higher with order of leaf>grain>stem in tatary buckwheat. Rutin content was 1469.8mg/100g in grain of tatary buckwheat. It was about 60 times higher than 22mg/100g in grain of common buckwheat.

• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.4
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• pp.199-202
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• 1991

The esterase isozyme of several legume plants were separated and visualized by horizontal starch gel electrophoresis using enzyme-specific staining. Extracts used were prepared from fully expanded young leaf and stem of six legume species which were red clover(Trifolium Pretense L.), ladino clover(Trifolium repense L.), wild white clover(Trifolium repense L.), alfalfa(Medicage sativa L.), mimosoides(Cassia mimosoides var nomame Makino), and amoena(Vicia amoena Fisch). The number of band, Phenotype and staining intensity of esterase isozyme in leaf and stem varies depending on the plant species. However, there are little difference between leaf and stem esterase isozyme in same species except alfalfa. And in the leaf and stem of mimosoides and amoena showed not any esterase(Fig. 2). Among the examined plants, the highest staining intensity and the rapidest migrating esterase isozyme was Est 1.

• Korean Journal of Clinical Laboratory Science
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• v.40 no.2
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• pp.106-112
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• 2008

Bone marrow derived mesenchymal stem cells (BMSCs) are largely studied for their potential clinical use. But it is hard to get enough number of those cells for clinical trials and give serious pain to the patients. Adipose tissue is derived from the embryonic mesenchyme and contains a stroma that is easily isolated with large amount. This cell population (adipose derived stem cells: ADSCs) can be isolated from human lipoaspirates and like MSCs, differentiate toward the osteogenic, adipogenic, myogenic and chondrogenic lineages. To confirm whether adipose tissue contains stem cells, the ADSCs extracted from omental or subcutaneous fat tissue were expanded during third to fifth passages. The phenotype of the ADSCs was identified by the conventional cell surface markers using flow cytometry: positive for CD29 and CD44, but negative for CD34, CD45, CD117 and HLA-DR that similar to those observed on BMSCs. The ADSCs were able to differentiate into the osteoblast or adipocytes with induction media. Finally, ADACs expressed multiple CD marker antigens similar to those observed on BMSCs and differentiated into osteoblast, adipocyte. With this, human adipotissue contains multipotent cells and may represent an alternative stem cell source to bone marrow-derived MSCs.

• Plant Resources
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• v.5 no.2
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• pp.165-168
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• 2002

This study was carried out obtain basic information for growth characteristics by different age of Dendropanax morbifera in chonnam, such as Yosu, Sunchon, Haenam, Gangjin, Wando. The pH of soil in cultivation area was 5.2 to 5.6 and organic matter was very high up to 10.6% . P205 content of soil in cultivation area was 35.3 to 42.1 mg/L, C.E.S was 13.9 to 14.4 me/100g, and moisture rate was 19.2 to 21.1 % . The flowering of Dendropanax morbifera began from 6~7 years old tree. The flowering date was at 10th of July at Wando. The growth characteristics of 12 years old tree was 929.5cm in stem height, 134.1mm in stem diameter, and 15 years old tree was 1,117.9cm in stem height, 160.8mm in stem diameter. The number of leaf was 13.9 at five years old tree, and the petioles length was 12.6 at five years old tree. Xylem sap can be had at more than 10 years old tree with good growth more than 10 em stem diameter.

• Development and Reproduction
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• v.21 no.1
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• pp.1-10
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• 2017

The use of human mesenchymal stem cells (hMSCs) in cell-based therapy has attracted extensive interest in the field of regenerative medicine, and it shows applications to numerous incurable diseases. hMSCs show several superior properties for therapeutic use compared to other types of stem cells. Different cell types are discussed in terms of their advantages and disadvantages, with focus on the characteristics of hMSCs. hMSCs can proliferate readily and produce differentiated cells that can substitute for the targeted affected tissue. To maximize the therapeutic effects of hMSCs, a substantial number of these cells are essential, requiring extensive ex vivo cell expansion. However, hMSCs have a limited lifespan in an in vitro culture condition. The senescence of hMSCs is a double-edged sword from the viewpoint of clinical applications. Although their limited cell proliferation potency protects them from malignant transformation after transplantation, senescence can alter various cell functions including proliferation, differentiation, and migration, that are essential for their therapeutic efficacy. Numerous trials to overcome the limited lifespan of mesenchymal stem cells are discussed.