• Nuclear Engineering and Technology
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• v.48 no.5
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• pp.1140-1153
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• 2016

Since the inception of nuclear power as a commercial energy source, safety has been recognized as a prime consideration in the design, construction, operation, maintenance, and decommissioning of nuclear power plants. The release of radioactivity to the environment requires the failure of multiple safety systems and the breach of three physical barriers: fuel cladding, the reactor cooling system, and containment. In this study, nuclear reactor containment pressurization has been modeled in a large break-loss of coolant accident (LB-LOCA) by programming single-cell and multicell models in MATLAB. First, containment has been considered as a control volume (single-cell model). In addition, spray operation has been added to this model. In the second step, the single-cell model has been developed into a multicell model to consider the effects of the nodalization and spatial location of cells in the containment pressurization in comparison with the single-cell model. In the third step, the accident has been simulated using the CONTAIN 2.0 code. Finally, Bushehr nuclear power plant (BNPP) containment has been considered as a case study. The results of BNPP containment pressurization due to LB-LOCA have been compared between models, final safety analysis report, and CONTAIN code's results.

• Molecules and Cells
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• v.42 no.8
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• pp.589-596
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• 2019

${\beta}Pix$ is a guanine nucleotide exchange factor for the Rho family small GTPases, Rac1 and Cdc42. It is known to regulate focal adhesion dynamics and cell migration. However, the in vivo role of ${\beta}Pix$ is currently not well understood. Here, we report the production and characterization of ${\beta}Pix$-KO mice. Loss of ${\beta}Pix$ results in embryonic lethality accompanied by abnormal developmental features, such as incomplete neural tube closure, impaired axial rotation, and failure of allantois-chorion fusion. We also generated ${\beta}Pix$-KO mouse embryonic fibroblasts (MEFs) to examine ${\beta}Pix$ function in mouse fibroblasts. ${\beta}Pix$-KO MEFs exhibit decreased Rac1 activity, and defects in cell spreading and platelet-derived growth factor (PDGF)-induced ruffle formation and chemotaxis. The average size of focal adhesions is increased in ${\beta}Pix$-KO MEFs. Interestingly, ${\beta}Pix$-KO MEFs showed increased motility in random migration and rapid wound healing with elevated levels of MLC2 phosphorylation. Taken together, our data demonstrate that ${\beta}Pix$ plays essential roles in early embryonic development, cell spreading, and cell migration in fibroblasts.

• Environmental Mutagens and Carcinogens
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• v.24 no.1
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• pp.1-9
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• 2004

Three D-type cyelins (D1, D2, and D3) are expressed in G1 phase of the cell cyele and have been implicated in cell transformation and neoplasia in human and mouse. Cyclin D1 overexpression or amplification was described in various human cancers. However, there is controversy about the role of cyclin D2 in cell cyele progression and human carcinogenesis. Specially, loss of cyelin D2 is involved in a vital tumor suppressor function in normal breast tissue, and that its loss may be related to tumorigenesis. The author examined to effect over-expression of cyclin D2 on the cell proliferation, apoptosis, and cell cycle using cyclin D2 transfected stable T47D breast cancer cells to investigate whether cyclinD2 functions as a positive regulator or negative regulator in cell proliferation. Overexpression of cyclin D2 led to the suppression of cell growth in cyclin D2 transfected T47D in both in its expression level and a time dependent manner with up to 50% reduction of cell growth at 72 hours. Therefore, the authors performed the cell cycle phase analysis using the flow cytometry to investigate the effect of cyclin D2 on the cell cycle phase in cyclin D2 transfected stable T47D cells. The flow cytometry analysis revealed increased sub G0 phase in cyclin D2 transfeted cells up to 23% at 72 hours. To confirm these results induced by overexpression of cyclinD2, the apoptotic bodies were counted in control and cyclin D2 transfected T47 cells. There are markedly increases of apoptotic bodies in cyclin D2-transfected cells up to 18%. These results suggested that Cyclin D2 suppresses the cell proliferation in breast cancers cells via the induction of apotosis.

• Journal of Applied Biological Chemistry
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• v.59 no.2
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• pp.137-143
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• 2016

Hair is a dermal adjunctive organ that protects the body from external physical and chemical stimuli; hair undergoes anagen, catagen, and telogen phases, with hair-loss occurring during the telogen phase. Alopecia is a condition wherein a person undergoes hair-loss far exceeding the normal amount, owing to diverse external factors. Wild beans are rich in isoflavone and amino acids known to prevent hair-loss; compared to cultivated beans, many wild bean species have higher protein content. This study aimed to develop a hair growth promoting solution, with superior hair growth promoting effects and fewer side effects, using naturally obtained Glycine soja Siebold et Zucc (GSSZ) extracts. Seven-week-old C57BL/6N male mice were classified into different experimental groups. Hair growth was observed in GSSZ-treated mice, and compared against that seen in 3 % minoxidil (MXD, positive control)-treated mice. Visual observations revealed a greater reduction in hair-loss in MXD and GSSZ application groups, compared to that in TXN group (hair loss induction using 1 % testosterone). Evaluation using an image analysis software revealed that compared to the positive control, TXN + GSSZ group showed the highest hair growth. TXN + MXD and control groups exhibited similar follicular cell growth, while the hair growth promotion patterns were similar in the negative control (normal), TXN + GSSZ, and TXN groups, as observed via histological analysis. GSSZ did not induce cytotoxicity (even at 2 mg/mL) in keratinocytes and dermal papilla cells; alternately, dermal papilla cell proliferation was activated in a (GSSZ) concentration-dependent manner. Therefore, the GSSZ extract promoted hair growth and increased hair growth-related cell activity, and could therefore be utilized in alopecia treatment.

• Nutrition Research and Practice
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• v.9 no.5
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• pp.459-465
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• 2015

BACKGROUND/OBJECFTIVES: The effect of St. John's Wort extract (SJW) on MG-63 cell proliferation and trabecular bone loss induced by ovariectomy was examined. MATERIALS/METHODS: Proliferation, expression of estrogen receptor (ER) ${\alpha}$ and ER ${\beta}$, and gene expressions of osteoprotegerin (OPG), osteocalcin (OC) and alkaline phosphatase (ALP) were examined in MG-63 cells treated with or without SJW. Ovariectomized rats were treated with SJW at the dose of 100 or 200 mg/kg/day, ${\beta}$-estradiol-3-benzoate (E2), or vehicle only (OVX-C), and sham operated rats were treated with vehicle only (Sham-C). Serum ALP and C-telopeptide (CTX), and femoral trabecular bone loss were examined. RESULTS: SJW increased MG-63 cell proliferation and expression of ER ${\alpha}$ and ER ${\beta}$, and positive effect was shown on gene expressions of ALP, OC and OPG. SJW also showed estrogen like effect on bone associated with slowing down in trabecular bone loss. Histopathology by H&E showed rats treated with SJW displayed denser structure in metaphyseal region of distal femur compared with rats in OVX-C. SJW was shown to reduce serum CTX in OVX rats. CONCLUSION: The present study provides new insight in preventing estrogen deficiency induced bone loss of SJW and possibility for its application in bone health supplement.

• Journal of Electrical Engineering and Technology
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• v.4 no.2
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• pp.201-210
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• 2009

A loss minimizing controller is developed for a fuel cell electric vehicle (FCEV) permanent magnet synchronous motor (PMSM). The PMSM losses are modeled by some experimental equations. Applying Lagrangian to the loss function, a necessary condition for the optimality appears to be a fourth order polynomial, and the loss minimizing solutions are obtained by a simple numerical approach. On the other hand, the loss minimizing solutions are found by scanning the motor loss in the entire operating region. The two results agree well. The loss minimizing current sets for given torque and speed are made into a table, which is utilized as a look-up in the current control loop.

• Anatomy and Cell Biology
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• v.56 no.3
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• pp.382-393
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• 2023

Cell clusters are a histological hallmark feature of intervertebral disc degeneration. Clusters arise from cell proliferation, are associated with replicative senescence, and remain metabolically, but their precise role in various stages of disc degeneration remain obscure. The aim of this study was therefore to investigate small, medium, and large size cell-clusters. For this purpose, human disc samples were collected from 55 subjects, aged 37-72 years, 21 patients had disc herniation, 10 had degenerated non-herniated discs, and 9 had degenerative scoliosis with spinal curvature <45°. 15 non-degenerated control discs were from cadavers. Clusters and matrix changes were investigated with histology, immunohistochemistry, and Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Data obtained were analyzed with spearman rank correlation and ANOVA. Results revealed, small and medium-sized clusters were positive for cell proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) in control and slightly degenerated human discs, while large cell clusters were typically more abundant in severely degenerated and herniated discs. Large clusters associated with matrix fissures, proteoglycan loss, matrix metalloproteinase-1 (MMP-1), and Caspase-3. Spatial association findings were reconfirmed with SDS-PAGE that showed presence to these target markers based on its molecular weight. Controls, slightly degenerated discs showed smaller clusters, less proteoglycan loss, MMP-1, and Caspase-3. In conclusion, cell clusters in the early stages of degeneration could be indicative of repair, however sustained loading increases large cell clusters especially around microscopic fissures that accelerates inflammatory catabolism and alters cellular metabolism, thus attempted repair process initiated by cell clusters fails and is aborted at least in part via apoptosis.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.5
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• pp.52-59
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• 1996

The boroadband ISDN will transprot the traffics for a wide range of applications with different quality-of-service (QOS) requirements and the priorit control mechanism is an effective method to support multiple classes of services. This paper proposes a new mechanism to satisfy simultaneously the different levels of cell loss performance for the two classes of heterogeneous nonreal-time ATM traffics as well as the delay and loss requirements of real-time traffics. Its performance is analyzed using the stochastic integral approach with the cell arrivals of input streams modeled as markov modulated poisson processes.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.435-444
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• 1995

We propose a new approach to the calculation of the exact cells loss probability in a shared buffer ATM multiplexer, which is loaded with homogeneous discrete-time ON-OFF sources. Renewal cycles are identified in regard to the state of input sources and the buffer state on each renewal circle is modelled as a K(shared buffer size)-state Markov chain. We also analyze the behavior of queue build-up at the shared buffer whose distribution together with the steady-state probabilities of the Markov chain leads to the exact cell loss probability. Our approach to obtaining the exact cell loss probability seems to be more efficient than most of other existing ones since our underlying Markov chain has less number of states.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.65-69
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• 2017

This paper presents a Technology-CAD (TCAD) simulation of the characteristics of crystalline Si pillar array solar cells. The junction depth and the surface concentration of the solar cells were optimized to obtain the targeted sheet resistance of the emitter region. The diffusion model was determined by calibrating the emitter doping profile of the microscale silicon pillars. The dimension parameters determining the pillar shape, such as width, height, and spacing were varied within a simulation window from ${\sim}2{\mu}m$ to $5{\mu}m$. The simulation showed that increasing pillar width (or diameter) and spacing resulted in the decrease of current density due to surface area loss, light trapping loss, and high reflectance. Although increasing pillar height might improve the chances of light trapping, the recombination loss due to the increase in the carrier's transfer length canceled out the positive effect to the photo-generation component of the current. The silicon pillars were experimentally formed by photoresist patterning and electroless etching. The laboratory results of a fabricated Si pillar solar cell showed the efficiency and the fill factor to be close to the simulation results.