• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1316-1317
• /
• 2011

This paper presents analysis of temperature and light intensity characteristics of PV modules with solar cell type. Taking the effect of sunlight irradiance on the cell temperature, the first experiment takes ambient temperature as reference input and uses the solar insolation as a unique varying parameter. Then taking the effect of the cell temperature on sunlight irradiance, the second experiment takes 1000W/$m^2$ as reference input and uses the cell temperature as a unique varying parameter. As a result, varying sunlight irradiance, the Cell-Type with the smallest change in output is HIT and the Cell-Type with the biggest change in output is a-Si. Varying the cell temperature, the Cell-Type with the smallest change in output is a-Si and the Cell-Type with the biggest change in output is Single-Si. And considering both temperature and light intensity characteristics, the Cell-Type with the smallest change in output is HIT.

• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.4
• /
• pp.311-319
• /
• 2013

A clear understanding on cell voltage-reversal behavior due to local hydrogen starvation in a stack is of paramount importance to operate the fuel cell vehicle (FCV) stably since it affects significantly the cell performance and durability. In the present study, a novel experimental method to simulate the local cell voltage-reversal behavior caused by local hydrogen starvation, which typically occurs only one or several cells out of several hundred cells in a stack of FCV, has been proposed. Contrary to the conventional method of overall fuel starvation, the present method of local hydrogen starvation caused the local cell voltage-reversal behavior in a stack very well. Degradation of both membrane electrode assembly (i.e., pin-hole formation) and gas diffusion layer due to an excessive exothermic heat under voltage-reversal condition was also observed clearly.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.17 no.2
• /
• pp.296-305
• /
• 2011

Purpose: This study was done to develop an educational needs scale for cell phone use, to investigate the scope of cell phone use in children and their parents' perception, and to compare the educational needs for children and parents regarding children's cell phone use. Method: The participants were 152 children and 152 parents in two cities. Data were collected through self-report questionnaires, and analyzed using the SPSS program. Result: Ten items regarding the educational needs for cell phone use were selected for the final scale, and categorized into 2 factors (cell phone use and cell phone addiction). The scope of cell phone use in children is different from their parents' perception. The educational needs of parents were higher than those of children. Conclusion: The findings indicate that the scope of cell phone use and the educational needs of children were different from their parents' perception and needs. Further research would be required to identify the educational needs for children and parents regarding children's cell phone use and related factors. In addition, development and effects of the educational programs for cell phone use in children and parents will be required.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.401-402
• /
• 2015

In this paper a direct cell-to-cell charge balancing circuit which can transfer the charge from any cell to any cell in the battery string is introduced. In the proposed topology the energy in the high voltage cell is transferred to the low voltage cell through the simple operation of a dc-dc converter to get fast equalization. Furthermore, the charge equalization can be performed regardless of the battery module operation whether it is being charged, discharged or relaxed. The monitoring circuit composed of a DSP and a battery monitoring IC is designed to monitor the cell voltage and protect the battery. In order to demonstrate the advantages of the proposed topology, a prototype circuit was designed and applied to 12 Lithium-Ion battery module. It has been verified with the experiments that the charge equalization time of the proposed method was shortest compared with those of other methods.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.18 no.1
• /
• pp.169-180
• /
• 2005

Objective : Spatholobus Suberectus Dunn stems, Chinese vine plants, have been used for the relief of menstrual disorders and rheumatic arthralgia. In this study, we investigated the antitumor effect of Spatholobus Suberectus Dunn on cervical cancer in vitro. Methods : HeLA cervical cancer cell lines were used as targets. We examined the effect of water extract from Spatholobus Suberectus Dunn on cell proliferation, cell cycle regulation and cell cycle-regulating gene expression. Further, we investigated the apoptotic effects of Spatholobus Suberectus Dunn on cervical cancer cell lines. Results : Spatholobus Suberectus Dunn significantly inhibited the proliferation of cervical cancer cell lines in a dose-dependent and time dependent manner. Fluorescence activated cell sorter (FACS) analysis indicated that Spatholobus Suberectus Dunn induced G1 cell cycle arrest. Spatholobus Suberectus Dunn enhanced the expression of $p21^{waf1}$ and $p27^{kip1}$ with cell cycle arrest. Further, Spatholobus Suberectus Dunn stimulated apoptosis via caspase3 pathway. Conclusions : These findings suggest that Spatholobus Suberectus Dunn is a candidate agent for the treatment of cervical cancer. p21waf1 and $p21^{waf1}$ and $p27^{kip1}$ may play an important role in Spatholobus Suberectus Dunn-induced cell cycle arrest and cell growth inhibition.

• Journal of Plant Biotechnology
• /
• v.5 no.2
• /
• pp.131-135
• /
• 2003

Callus and cell suspension cultures of Eurycoma longifolia Jack were initiated from leaves of different trees. The leaf explant of tree Eu9 produced the most calli and also induced high cell biomass in the cell suspension culture. Optimum production of cell biomass could be initiated in proliferating culture medium with a pH of 5.75 prior to autoclaving. The effects of macronutrient inorganic salts of Murashige and Skoog (MS) liquid medium supplemented with X on production of cell biomass of Eurycoma longifolia were also investigated. The highest cell biomass was produced in MS medium containing macronutrients of $21\;mM\;NH_4NO_3,\;12.25\;mM\;KNO_3,\;3.00\;mM\;CaCl_2.2H_2O,\;0.575\;mM\;MgSO_4.7H_2O$, and $1.83\;mM\;KH_2PO_4$. A new medium labeled as TAM was formulated for the production of Eurycoma longifolia cell biomass in the cell suspension culture.

• Biomedical Science Letters
• /
• v.11 no.4
• /
• pp.441-446
• /
• 2005

The molecular mechanism of ischemia/reperfusion injury remains unclear. Reactive oxygen species (ROS) are implicated in cell death caused by ischemia/reperfusion in vivo or hypoxia in vitro. Poly (ADP-ribose) polymerase (PARP) activation has been reported to be involved in hydrogen peroxide-induced cell death in renal epithelial cells. This study was therefore undertaken to evaluate the role of P ARP activation in chemical hypoxia in opossum kidney (OK) cells. Chemical hypoxia was induced by incubating cells with antimycin A, an inhibitor of mitochondrial electron transport. Exposure of OK cells to chemical hypoxia resulted in a time-dependent cell death. In OK cells subjected to chemical hypoxia, the generation of ROS was increased, and this increase was prevented by the $H_2O_2$ scavenger catalase. Chemical hypoxia increased P ARP activity and chemical hypoxia-induced cell death was prevented by the inhibitor of PARP activation 3-aminobenzamide. Catalase prevented OK cell death induced by chemical hypoxia. $H_2O_2$ caused PARP activation and $H_2O_2-induced$ cell death was prevented by 3-aminobenzamide. Taken together, these results indicate that chemical hypoxia-induced cell injury is mediated by PARP activation through H202 generation in renal epithelial cells.

• Molecules and Cells
• /
• v.40 no.2
• /
• pp.109-116
• /
• 2017

Soybean agglutinin (SBA) is an anti-nutritional factor of soybean, affecting cell proliferation and inducing cytotoxicity. Integrins are transmembrane receptors, mediating a variety of cell biological processes. This research aims to study the effects of SBA on cell proliferation and cell cycle progression of the intestinal epithelial cell line from piglets (IPEC-J2), to identify the integrin subunits especially expressed in IPEC-J2s, and to analyze the functions of these integrins on IPEC-J2 cell cycle progression and SBA-induced IPEC-J2 cell cycle alteration. The results showed that SBA lowered cell proliferation rate as the cell cycle progression from G0/G1 to S phase (P < 0.05) was inhibited. Moreover, SBA lowered mRNA expression of cell cycle-related gene CDK4, Cyclin E and Cyclin D1 (P < 0.05). We successfully identified integrins ${\alpha}2$, ${\alpha}3$, ${\alpha}6$, ${\beta}1$, and ${\beta}4$ in IPEC-J2s. These five subunits were crucial to maintain normal cell proliferation and cell cycle progression in IPEC-J2s. Restrain of either these five subunits by their inhibitors, lowered cell proliferation rate, and arrested the cells at G0/G1 phase of cell cycle (P < 0.05). Further analysis indicated that integrin ${\alpha}2$, ${\alpha}6$, and ${\beta}1$ were involved in the blocking of G0/G1 phase induced by SBA. In conclusion, these results suggested that SBA lowered the IPEC-J2 cell proliferation rate through the perturbation of cell cycle progression. Furthermore, integrins were important for IPEC-J2 cell cycle progression, and they were involved in the process of SBA-induced cell cycle progression alteration, which provide a basis for further revealing SBA anti-proliferation and anti-nutritional mechanism.

• The Journal of Korean Medicine
• /
• v.24 no.4
• /
• pp.127-135
• /
• 2003

Objectives : Intracerebral hemorrhage (ICH) is one of the most devastating types of stroke. The effect of acupuncture on the intrastriatal hemorrhage-induced neuronal cell death and cell proliferation in rats is examined. Methods : Cell death and cell proliferation in rats was investigated via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay and immunohistochemistry for caspase-3 and 5-bromo-2'-deoxyuridine (BrdU). Results : Results showed that apoptotic cell death in the striatum and cell proliferation in the hippocampal dentate gyrus significantly increased following intrastriatal hemorrhage in rats, and that acupunctural treatment at the Zusanli acupoint suppressed the hemorrhage-induced increase in apoptosis in the striatum and cell proliferation in the dentate gyrus. Conclusions : It is suggested that acupunctural treatment, especially at the Zusanli acupoint, may aid recovery following central nervous system sequelae following ICH.

• Journal of Periodontal and Implant Science
• /
• v.25 no.1
• /
• pp.133-145
• /
• 1995

The migration and proliferation of periodontal ligament cells are desired goal of periodontal regeneration therapy. PDGF and $TGF-{\beta}1$ are well known to regulate the cell activity of mesenchymal origin cell. The purpose of this study was to determine the effects of these growth factors on human gingival fibroblast and periodontal ligament cell actvity, and to identify the regulatory effect of $TGF-{\beta}1$ on the response to PDGF by MIT assay. Human gingival fibroblast and periodontal ligament cells were cultured from extracted teeth for non-periodontal reason. Cultured human gingival fibroblast and periodontal ligament cells in vitro were treated with polyperpetide growth factor PDGF and $TGF-{\beta}1$ in both a dose and time - dependent manner. Cell morphology were determined by inverted microscope and cell acitivity were determined by MIT assay. The result of this study demonstrated that PDGF and $TGF-{\beta}1$ were not changed the morphology of these cell compared with control group. PDGF or $TGF-{\beta}1$ increased cell activity of periodontal ligament cell in dose and time dependent manner but gingival fibroblast were decreased to the level of control group at third day. Additionally, incubation with $TGF-{\beta}1$ addition to PDGF resulted in a enhanced cell activity of PDGF. Therefore, cell acitivty of gingival fibroblast were not changed compared with control group. This stiudy demonstrates that PDGF and $TGF-{\beta}1$ are major mitogens for human periodontal ligament cell in vitro, and $TGF-{\beta}1$ is a regulator of cell activity to PDGF in human gingival fibroblast and periodontal ligament cell.