• Journal of Ginseng Research
• /
• v.45 no.2
• /
• pp.264-272
• /
• 2021

Background: Gintonin is a ginseng-derived exogenous G-protein-coupled lysophosphatidic acid (LPA) receptor ligand, which exhibits in vitro and in vivo functions against Alzheimer disease (AD) through lysophosphatidic acid 1/3 receptors. A recent study demonstrated that systemic treatment with gintonin enhances paracellular permeability of the blood-brain barrier (BBB) through the LPA1/3 receptor. However, little is known about whether gintonin can enhance brain delivery of donepezil (DPZ) (Aricept), which is a representative cognition-improving drug used in AD clinics. In the present study, we examined whether systemic administration of gintonin can stimulate brain delivery of DPZ. Methods: We administered gintonin and DPZ alone or coadministered gintonin with DPZ intravenously or orally to rats. Then we collected the cerebral spinal fluid (CSF) and serum and determined the DPZ concentration through liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Results: Intravenous, but not oral, coadministration of gintonin with DPZ increased the CSF concentration of DPZ in a concentration- and time-dependent manner. Gintonin-mediated enhancement of brain delivery of DPZ was blocked by Ki16425, a LPA1/3 receptor antagonist. Coadministration of vascular endothelial growth factor (VEGF) + gintonin with DPZ similarly increased CSF DPZ concentration. However, gintonin-mediated enhancement of brain delivery of DPZ was blocked by axitinip, a VEGF receptor antagonist. Mannitol, a BBB disrupting agent that increases the BBB permeability, enhanced gintonin-mediated enhancement of brain delivery of DPZ. Conclusions: We found that intravenous, but not oral, coadministration of gintonin facilitates brain delivery of DPZ from plasma via LPA1/3 and VEGF receptors. Gintonin is a potential candidate as a ginseng-derived novel agent for the brain delivery of DPZ for treatment of patients with AD.

• Fire Science and Engineering
• /
• v.26 no.6
• /
• pp.72-77
• /
• 2012

When the concrete and steel combined composite beam is exposed to high temperature, concrete could delay temperature rising of steel by covering or increase heat capacity of structural member. For becoming of structural reinforcing by unification between materials, fire resistance rate of composite beam would be higher than simple steel beam. The temperature rising of exposed steel of composite beam is directly related with section shape and exposure length of steel. In this study, fire resistant tests were carried out for composite beams and steel beam with same thickness of spray-type fire resistant materials in standard fire, and after that, temperature histories were analysed and compared with shape factor. The correlation between steel temperature and shape factor was showed very high. This result suggests that if it can be predict the comparative advantage of member by factor which cause the performance enhancement, it could be conclude that an Standard Accreditation method can be adjust to members without indivisual certifiicate of accreditation.

• Food Science of Animal Resources
• /
• v.44 no.1
• /
• pp.204-215
• /
• 2024

This study was designed to examine the effect of Lactilactobacillus curvatus LB-P9 on hair regeneration. The treatment of LB-P9 conditioned medium increased the proliferation of both hair follicle dermal papilla cells and hair germinal matrix cells (hGMCs). Moreover, the expression levels of hair growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor 7 were significantly elevated in hGMCs co-cultured with LB-P9. After time-synchronized depilation, mice were orally administered with either 4×10⁷ colony forming unit (CFU) of LB-P9 (low dose) or 4×10⁸ CFU of LB-P9 (high dose), once daily for 4 weeks. Compared with the vehicle (phosphate-buffered saline)-administrated group, the LB-P9-treated groups exhibited accelerated hair regrowth rate and enhanced hair thickness in a dose-dependent manner. Supporting this observation, both hair follicle numbers and the dermal thickness in skin tissues of the LB-P9-treated groups were increased, compared to those of the vehicle-treated group. These results might be explained by the increased level of β-catenin and number of hair follicle stem cells (CD34⁺ CD49f⁺ cells) in the skin tissues of mice administered with LB-P9, compared to the vehicle-treated mice. Also, increased serum levels of hair growth factors such as VEGF and insulin-like growth factor-1, and superoxide dismutase were found in the LB-P9-treated groups, compared to those of the vehicle-treated group. Taken together, these results might demonstrate that the oral administration of LB-P9 promotes hair regeneration by the enhancement of dermal papilla proliferation through the stimulation of hair growth factor production.

• The Journal of the Korea Contents Association
• /
• v.12 no.6
• /
• pp.371-379
• /
• 2012

The purpose of this study is to develop basic data in improving quality of life along with the enhancement in oral health, by arranging a plan for being able to reduce dental fear given the dental treatment in the future by grasping the subjective oral health recognition & status, and the dental fear level of the dental treatment field targeting patients of visiting dental clinics in Busan and Gyeongnam area. In the whole items of DFS, a sense of fear was higher in women than men. A factor of avoiding dental treatment stood at 1.72 points in men and 2.10 points(p<0.001) in women. A factor of response to stimulation stood at 2.75 points in men and 3.20 points(p=0.001) in women. A fear level according to dental kind was high in a factor of avoiding implant treatment(p=0.015), a factor of avoiding orthodontic treatment(p=0.002), physiological reaction(p=0.009), a factor of avoiding prosthesis treatment(p=0.014), a factor of avoiding pulpectomy treatment(p=0.005), a factor of physiological reaction(p=0.017), a factor of avoiding periodontal therapy(p=0.013), a factor of physiological reaction(p=0.004), and a factor of avoiding treatment given not receiving regular checkup(p=0.027). In the above results, to reduce dental fear, there will be a need of developing diverse programs and oral health eduction for regular checkup and preventive treatment.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.4
• /
• pp.316-323
• /
• 2013

The use of artificial roughness in various forms of shapes and sizes is the most common and effective way to improve the performance of a flat-plate solar collector. In the present study, numerical analysis on heat transfer and pressure drop was performed in a rectangular channel with various rib arrays. The uniform heat flux is applied to the channel from the upper side. The forms of ribs considered in this study were rib $90^{\circ}$, groove $90^{\circ}$, groove $60^{\circ}$, baffle $90^{\circ}$, baffle $60^{\circ}$, wave $90^{\circ}$ and wave $60^{\circ}$. Air is the working fluid, and the Reynolds number ranges from 3200 to 17800. Nusselt number and friction factor were investigated to predict the performance of the system with various type of ribs. The average Nusselt number and pressure drop were increased with the increase of velocity in all types of ribs. The highest heat transfer and pressure drop occurred for the baffle $90^{\circ}$, but highest performance factor considering heat transfer and pressure drop together occurred for the groove $60^{\circ}$. Therefore, heat transfer and pressure drop should be considered together when a flat plate solar collector is designed.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.1
• /
• pp.78-90
• /
• 2017

This paper presents the design of closed loop controllers operating a single-phase AC-DC three-level converter for improving power quality at AC mains. Closed loop inhibits outer voltage controller and inner current controller. Simulations of three level converter with three different voltage and current controller combinations such as PI-Hysteresis, Fuzzy-Hysteresis and Fuzzy tuned PI-Hysteresis are carried out in MATLAB/Simulink. Performance parameters such as input power factor and source current total harmonic distortion (THD) are considered for comparison of the three controller combinations. The fuzzy-tuned PI voltage controller with hysteresis current controller combination provides a better result, with a source-current THD of 0.93% and unity power factor without any source side filter for the three level converter. For load variations of 25% to 100%, a THD of less than 5% is obtained with a maximum value of only 1.67%. Finally, the fuzzy-tuned PI voltage with hysteresis controller combination is implemented in a Xilinx Spartan-6 XC6SLX25 FPGA board for experimental validation of power quality enhancement. A prototype 100 W, 0-24-48 V as output converter is considered for the testing of controller performance. A source-current THD of 1.351% is obtained in the experimental study with a power factor near unity. For load variations of 25% to 100%, the THD is found to be less than 5%, with a maximum value of only 2.698% in the experimental setup which matches with the simulation results.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.1
• /
• pp.40-46
• /
• 2013

Turbulent flow and heat transfer in a channel with a detached rib array have been simulated. The computations are based on the finite volume method with the SIMPLE algorithm. The forms of ribs considered in this study were rib with rectangular cross section, rib with groove, broken rib, and V-shaped rib. The ribs were deployed transverse or aligned $60^{\circ}$ to the main direction of the flow. Local heat transfer coefficients were obtained at various Reynolds numbers within the turbulent flow regime. Area-averaged data were calculated in order to compare the overall performance of the tested ribbed surfaces and to evaluate the degree of heat transfer enhancement induced by the ribs with respect to the smooth channel. The highest heat transfer occurred for the rib with groove which was aligned $60^{\circ}$ to the main flow direction. Performance factor was decreased with the increase of velocity, and it was found that the best performance factor was obtained in the low velocity region.

• Journal of Families and Better Life
• /
• v.34 no.5
• /
• pp.21-33
• /
• 2016

The purpose of this study is to explore the relative influence of psychological well-being and social support on the burnout of infant care teachers. Participants were 194 infant care teachers from 52 infant daycare centers in Gyeong-gi-do. Psychological burnout was assessed by the Maslach Burnout Inventory(Lee, 2011), psychological well-being was measured by the Psychological well-being scale(Cho & Cha, 2001) and social support was measured by the social support questionnaire(Bak, 1985). Date were analyzed using descriptive statistics and analysis, t-test, Pearson's correlation analysis, and multiple regression analysis. The major results of this study were as follows; First, there were differences in burnout in terms of marital status, work experiences, classroom operation type and income. Second, Infant care teachers' burnout was negatively correlated with psychological well-being and social support. Third, the most influential factor on infant care teachers' burnout was purpose in life, the second most influential factor was self-acceptance, the third most influential factor was emotional support, and the least influential factor was environmental mastery. Results of this study indicate that a psychological well-being enhancement program should be developed and emotional support from a social relationship network should be enhanced in order to prevent infant care teachers' burnout.

• Journal of Korean Neurosurgical Society
• /
• v.62 no.2
• /
• pp.153-165
• /
• 2019

Objective : Spinal cord injury (SCI) is a very serious health problem, usually caused by a trauma and accompanied by elevated levels of inflammation indicators. Stem cell-based therapy is promising some valuable strategies for its functional recovery. Nestin-positive progenitor and/or stem cells (SC) isolated from pancreatic islets (PI) show mesenchymal stem cell (MSC) characteristics. For this reason, we aimed to analyze the effects of rat pancreatic islet derived stem cell (rPI-SC) delivery on functional recovery, as well as the levels of inflammation factors following SCI. Methods : rPI-SCs were isolated, cultured and their MSC characteristics were determined through flow cytometry and immunofluorescence analysis. The experimental rat population was divided into three groups : 1) laminectomy & trauma, 2) laminectomy & trauma & phosphate-buffered saline (PBS), and 3) laminectomy+trauma+SCs. Green fluorescent protein (GFP) labelled rPI-SCs were transplanted into the injured rat spinal cord. Their motilities were evaluated with Basso, Beattie and Bresnahan (BBB) Score. After 4-weeks, spinal cord sections were analyzed for GFP labeled SCs and stained for vimentin, $S100{\beta}$, brain derived neurotrophic factor (BDNF), 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase), vascular endothelial growth factor (VEGF) and proinflammatory (interleukin [IL]-6, transforming growth factor $[TGF]-{\beta}$, macrophage inflammatory protein [MIP]-2, myeloperoxidase [MPO]) and anti-inflammatory (IL-1 receptor antagonis) factors. Results : rPI-SCs were revealed to display MSC characteristics and express neural and glial cell markers including BDNF, glial fibrillary acidic protein (GFAP), fibronectin, microtubule associated protein-2a,b (MAP2a,b), ${\beta}3$-tubulin and nestin as well as anti-inflammatory prostaglandin E2 receptor, EP3. The BBB scores showed significant motor recovery in group 3. GFP-labelled cells were localized on the injury site. In addition, decreased proinflammatory factor levels and increased intensity of anti-inflammatory factors were determined. Conclusion : Transplantation of PI-SCs might be an effective strategy to improve functional recovery following spinal cord trauma.

• Plant Journal
• /
• v.17 no.2
• /
• pp.48-53
• /
• 2021

In the case of a 900 MW combined cycle power plant, most of the load on the site is a rotating device and is operated at a low power factor, and the power factor decrease increases the reactive power, which causes the efficiency of the device to be consumed and unnecessary unnecessary power consumption. This study intends to present the results by installing and operating a reactive power compensation device that absorbs and removes reactive power, which is a solution to this problem, on a 6.9 kV on-board bus. As a result of application of this system, first, it was confirmed that the power factor of the rotating machine was improved to 0.22 and the load power in the house was reduced by 1.4%, and the thermal efficiency of the generator was increased by 0.1% and the power generation power by 810 kW. Next, it was confirmed that the cost of construction and operation can be reduced in the future due to economic feasibility, with a decrease of 200 million won/year in electricity loss compared to 1.5 billion won in investment, an increase of 1 billion won/year in sales, and a one-year capital recovery period.