• Journal of the Korean Society for Precision Engineering
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• v.27 no.2
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• pp.153-159
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• 2010

Recently, it has been reported that mechanical stimulation takes a role in improving cell growth. Also, became generally known that skeletal system as bone or cartilage tissues take influence of compression loading. In this study, we fabricated a custom-made bioreactor and analyzed that conditions of compressive loading would influence cell growth. To compare the effect of intermittent compressive loading on cell-encapsulated agarose scaffold, we cultured preosteoblast cell (MC3T3-E1 cells) statically and dynamically. And dynamic culture conditions were produced by changing parameters such as the iteration time and interval delay time. Also, cellencapsulated agarose scaffold were subjected to 10 % dynamic compressive strain at 1㎐ frequency for 7 days. After cell culture, cell proliferation was assessed with PI stain assay for fluorescence images and flow cytometry (FACS).

• Journal of mucopolysaccharidosis and rare diseases
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• v.3 no.2
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• pp.41-43
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• 2017

Prader-Willi syndrome (PWS) is a genetic disorder that is considered, especially on child, to cause poor feeding, hypotonia, failure to thrive, developmental delay and hypogonadism which is known to affect between 1 in 10,000 and 30,000 people. The children with PWS are viewed as affected by growth hormone (GH) insufficiency, although the exact mechanisms of GH deficiency are not fully understood. However, the benefits of GH treatment in children with PWS are well established. Myers, et al. (2006), Grugni, et al. (2016) indicated its positive effects on linear growth, body composition, motor function, respiratory function and psychomotor development. Despite of its effectiveness and advantages had been well known and proven in many other studies, there is only one recombinant GH product that is approved for PWS in Korea, $Genotropin^{(R)}$, till now. A phase III clinical study of GH treatment with $Eutropin^{TM}$, in 34 Korean PWS children is in progress, which is expected to have comparable effects and safety profile with the active control by assessing auxological changes such as height standard deviation score, body composition changes such as lean body mass and percent body fat, motor and cognitive development using Bayley scale, and safety profiles.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.41-44
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• 2000

Because of internet's growth, today's network has a serious bandwidth problem. WDM(Wavelength Division Multiplexing) is a solution of this problem. In the WDM networks, QoS(Quality of Service) is as important as bandwidth. And today's voice over IP technology makes a lot of delay-sensitive internet traffic. De]ay-sensitive internet traffic is growing up, so more QoS is needed. We proposed effective solution to assign QoS.

• Journal of Applied Biological Chemistry
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• v.43 no.4
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• pp.211-217
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• 2000

Oxidative stress is implicated in a number of diseases, in ageing of organisms, and in damage to plants that have been exposed to freezing and thawing or water stress. From the perspective of yeast as a model eukaryotic system, this article reviews the systems that are involved in the cellular responses to exposure to reactive oxygen species (ROS) generated during aerobic growth of the organism. The discussion includes the defense systems involved, the ability of cells to adapt to ROS treatment, cell-division cycle delay and the systems regulating gene expression that are activated by oxidative stress.

• Journal of Industrial Technology
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• v.26 no.A
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• pp.69-73
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• 2006

Mach peening treatment is one of the various kinds of techniques to improve the fatigue properties. The mach peening process gives high-level work hardening and compressive residual stress near the surface layer, improving the fatigue strength. In addition, this treatment reduces slip bands that initiate the fatigue cracks near the surface. During impingement, a plastic indentation surrounded by a plastic zone is formed. Mach peening treatment characteristic is less energy consumption and is an environmental friendly processing methods that is not accompanied by pollution. It is machining process that can prevent fatigue fracture beforehand in structure using already as well as process of production. The test results showed that fatigue crack propagation delay appeared by drilling type 43%, mach peening type 110%.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.1
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• pp.17-25
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• 1986

Discussions on this paper are related to the effects of organic materials to treeing phenomena of low density polyethylene. As additives, 11 kinds of organic compounds are selected by considering the respective features such as melting point, boiling point, electron affinity as well as molecular structure, and then the specimens of low density polyethylene are prepared by blending with 10wt% of the selected additives. For the comparison of effectiveness of treeing resistance and interpretation of the mechanism of compounds as treeing retardants, several investigations such as the tree acceleration test, the prestressed test and the measurement of internally occurred partial discharge are carried out. As the results, meta-Cresol is regard as the most effective retardant among those, and it is supposed that this aromatic compound to be comprised of radical having large electron affinity has strong capability to accept energetic electron to prevent or delay the growth of discharge streamer. Furthermore, by activating partial discharge at the wall of tree pit through the function of trapped electron at this material, the gas pressure in the pit is increased up to prevent the growth of streamer.

• Journal of Communications and Networks
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• v.8 no.3
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• pp.351-359
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• 2006

In this article, we present a new slow-start variant, which improves the throughput of transmission control protocol (TCP) Vegas. We call this new mechanism Gallop-Vegas because it quickly ramps up to the available bandwidth and reduces the burstiness during the slow-start phase. TCP is known to send bursts of packets during its slow-start phase due to the fast window increase and the ACK-clock based transmission. This phenomenon causes TCP Vegas to change from slow-start phase to congestion-avoidance phase too early in the large bandwidth-delay product (BDP) links. Therefore, in Gallop-Vegas, we increase the congestion window size with a rate between exponential growth and linear growth during slow-start phase. Our analysis, simulation results, and measurements on the Internet show that Gallop-Vegas significantly improves the performance of a connection, especially during the slow-start phase. Furthermore, it is implementation feasible because only sending part needs to be modified.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.290-296
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• 1987

Some streptomycin resistant strains of Rhizobium trifolii having nodulation ability were selected, and their nitrogenase activities, symbiotic effects on plant growth, and nodule electronmicroscope were compared with those of the wild type. After NTG treatment, as a mutagen, at the concentration exhibiting 99.7% lethal rate, 5 strains of streptomycin resistant mutant having nodulating ability were selected. Among these nodulating mutant strains, 3 strains produced more nodules and 2 strains showed less nodules than wild type. But their nitrogenase activities were decreased significantly, and nodule formation time was also delay compared with those of the wild type, and there was no remarkable difference in effects on plant growth. Microstructure of nodules by electronmicroscopy had mant distinctive differences between red clover nodules inoculated with wild type and mutants.

• The Journal of Pediatrics of Korean Medicine
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• v.23 no.3
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• pp.177-191
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• 2009

Objectives To evaluate the effect of InsamGobonHwan (IGH) on growth of rats. Methods We divided male Sprague-Dawley rats into 4 groups(IGHE1, IGHE2, IGHE3 and sham group). IGHE1, IGHE2, IGHE3 groups were administered with IGHE water extracts once a day at the dose of 1,000, 500 and 250mg/kg/$10m{ell}$ for 1 week, 2 weeks, and 3 weeks. Sham group was administered with normal saline with using the same method. We measured body weight, amount of body weight increasing, length of femur, serum Growth Hormone(GH), serum Insulin-like Growth Factor-I(IGF-I), serum Thyroid-stimulating Hormone(TSH) and serum testosterone at 1 week, 2 weeks, and 3 weeks of experiment. Results The body weight and the changes of body weight increased significantly in IGHE1 group compared to sham group after 2 and 3 weeks, and in IGHE2 group after 2 weeks. The lengths of the femur increased significantly in IGHE1 group as compared with sham group after 1, 2 and 3 weeks, and in IGHE3 group after 1 week. The level of IGF-I in the serum increased significantly in S1 group as compared tosham group after 1 and 3 weeks, and in IGHE13 group after 3 weeks. The level of TSH in the serum increased significantly in IGHE1group as compared to sham group after 2 and 3 weeks. The level of GH and testosterone in the serum does not change significantly. Conclusions SGT have an effect of promoting growth of rats and might be effect to treat various kinds of growth delay in children.

• Toxicological Research
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• v.29 no.4
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• pp.241-247
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• 2013

This study was carried out to examine the action mechanism of Chamaecyparis obtusa oil (CO) on hair growth in C57BL/6 mice. For alkaline phosphatase (ALP) and ${\gamma}$-glutamyl transpeptidase (${\gamma}$-GT) activities in the skin tissue, at week 4, the 3% minoxidil (MXD) and 3% CO treatment groups showed an ALP activity that was significantly higher by 85% (p < 0.001) and 48% (p < 0.05) and an ${\gamma}$-GT activity that was significantly higher by 294% (p < 0.01) and 254% (p < 0.05) respectively, as compared to the saline (SA) treatment group. For insulin-like growth factor-1 (IGF-1) mRNA expression in the skin tissue, at week 4, the MXD and CO groups showed a significantly higher expression by 204% (p < 0.05) and 426% (p < 0.01) respectively, as compared to the SA group. At week 4, vascular endothelial growth factor (VEGF) expression in the MXD and CO groups showed a significantly higher expression by 74% and 96% (p < 0.05) respectively, however, epidermal growth factor (EGF) expression in the MXD and CO groups showed a significantly lower expression by 66% and 61% (p < 0.05) respectively, as compared to the SA group. Stem cell factor (SCF) expression in the MXD and CO groups was observed by immunohis-tochemistry as significant in a part of the bulge around the hair follicle and in a part of the basal layer of the epidermis. Taking all the results together, on the basis of effects on ALP and ${\gamma}$-GT activity, and the expression of IGF-1, VEGF and SCF, which are related to the promotion of hair growth, it can be concluded that CO induced a proliferation and division of hair follicle cells and maintained the anagen phase. Because EGF expression was decreased significantly, CO could delay the transition to the catagen phase.