• Journal of Ginseng Research
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• v.41 no.3
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• pp.379-385
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• 2017

In this study, white ginseng was used as the raw material, which was fermented with Paecilomyces hepiali through solid culture medium, to produce ginsenosides with modified chemical composition. The characteristic chemical markers of the products thus produced were investigated using rapid resolution liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (RRLC-QTOF-MS). Chemical profiling data were obtained, which were then subjected to multivariate statistical analysis for the systematic comparison of active ingredients in white ginseng and fermented ginseng to understand the beneficial properties of ginsenoside metabolites. In addition, the effects of these components on biological activity were investigated to understand the improvements in the phagocytic function of macrophages in zebrafish. According to the established RRLC-QTOF-MS chemical profiling, the contents in ginsenosides of high molecular weight, especially malonylated protopanaxadiol ginsenosides, were slightly reduced due to the fermentation, which were hydrolyzed into rare and minor ginsenosides. Moreover, the facilitation of macrophage phagocytic function in zebrafish following treatment with different ginseng extracts confirmed that the fermented ginseng is superior to white ginseng. Our results prove that there is a profound change in chemical constituents of ginsenosides during the fermentation process, which has a significant effect on the biological activity of these compounds.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.1
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• pp.101-105
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• 2024

4H-SiC power metal-oxide-semiconductor field effect transistors (MOSFETs) have been developed to achieve lower specific-on-resistance (R_on,sp), and the gate oxides have been thermally grown. The poor channel mobility resulting from the high interface trap density (D_it) at the SiO₂/4H-SiC interface significantly affects the higher switching loss of the power device. Therefore, the development of novel fabrication processes to enhance the quality of the SiO₂/4H-SiC interface is required. In this paper, NO post-oxidation annealing (POA) by using the conditions of N₂ diluted NO at a high temperature (1,300℃) is proposed to reduce the high interface trap density resulting from thermal oxidation. The NO POA is carried out in various NO ambient (0, 10, 50, and 100% NO mixed with 100, 90, 50, and 0% of high purity N₂ gas to achieve the optimized condition while maintaining a high temperature (1,300℃). To confirm the optimized condition of the NO POA, measuring capacitance-voltage (C-V) and current-voltage (I-V), and time-of-flight secondary-ion mass spectrometry (ToF-SIMS) are employed. It is confirmed that the POA condition of 50% NO at 1,300℃ facilitates the equilibrium state of both the oxidation and nitridation at the SiO₂/4H-SiC interface, thereby reducing the D_it.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.7
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• pp.29-36
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• 2004

In this work, the effect of composite couplings on hub loads of a hingeless rotor in forward flight is investigated. The hingeless composite rotor blade is idealized as a laminated thin-walled box-beam. The nonclassical effects such as transverse shear, torsional warping are considered in the structural formulation. The nonlinear differential equations of motion are obtained by applying Hamilton's principle. The blade response and hub loads are calculated using a finite element formulation in space and time. The aerodynamic forces acting on the blade are calculated by quasi-steady strip theory. The theory includes the effects of reversed flow and compressibility. The magnitude of elastic couplings obtained by MSC/NASTRAN is compared with the classical pitch-flap $({\delta}3)$ or $pitch-lag({\alpha}1)$ coupling. It is found that the elastic couplings have a substantial effect on the behavior of $N_b/rev$ hub loads. Nearly 10 to 40% of hub loads is reduced by appropriately tailoring the fiber orientation angles in the laminae of the composite blade.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.5
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• pp.336-342
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• 2006

Uniaxial stress in ail axisymmetric body is the simplest example of ultrasonic stress measurement. However, the birefringence theory cannot be applied for axisymmetric solids because the axisymmetric stress field in the body does not make shy velocity difference in SH waves propagating in the axisymmetric direction. Conventional ultrasonic technique using the time-of-flight method also needs ultrasonic lengths of the unstressed and stressed body, which is very impractical. In this paper, the birefringence effect in axisymmetric solids under uniaxial stress is formulated to evaluate the axial stress inside the solid without measuring tile ultrasonic length. Theoretical derivation for the birefringence characteristics in the axisymmetric solids is made using the longitudinal and shear waves instead of two horizontally polarized shear waves. Tension test is conducted for carbon-steel specimen to measure the birefringence coefficient and investigate the validity of the theory. It is observed from experimental results that the velocity difference in two differently polarized acoustic waves is proportional to the uniaxial stress in the axisymmetric solid with a good agreement with the theoretical value.

• The Journal of Korean Physical Therapy
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• v.20 no.1
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• pp.57-65
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• 2008

Purpose: Heat shock proteins (HSPs) are a group of proteins that are activated when cells are exposed to a variety of environmental stresses, such as infection, inflammation, exposure to toxins, starvation, hypoxia, brain injury, or water deprivation. The activation of HSPs by environmental stress plays a key role in signal transduction, including cytoprotection, molecular chaperone, anti-apoptotic effect, and anti-aging effects. However, the precise mechanism for the action of small HSPs, such as HSP27 and mitogen-activated protein kinases (MAPKs: extracellular-regulated protein kinase 1/2 (ERK1/2), p38MAPK, stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), is not completely understood, particularly in application of cell stimulators including platelet-derived growth factor (PDGF), angiotensin II (AngII), tumor necrosis factor $\alpha$ (TNF$\alpha$), and $H_2O_2$. This study examined the relationship between stimulators-induced enzymatic activity of HSP27 and MAPKs from rat smooth and skeletal muscles. Methods: 2-dimensional electrophoresis (2DE) and matrix assisted laser desorption ionizationtime-of-flight/time-of-flight (MALDI-TOF/TOF) analysis were used to identify HSP27 from the intact vascular smooth and skeletal muscles. Three isoforms of HSP27 were detected on silver-stained gels of the whole protein extracts from the rat aortic smooth and skeletal muscle strips. Results: The expression of PDGF, AngII, TNF$\alpha$, and $H_2O_2$-induced activation of HSP27, p38MAPK, ERK1/2, and SAPK/JNK was higher in the smooth muscle cells than the control. SB203580 (30${\mu}$M), a p38MAPK inhibitor, increased the level of HSP27 phosphorylation induced by stimulators in smooth muscle cells. Furthermore, the age-related and starvation-induced activation of HSP27 was higher in skeletal muscle cells (L6 myoblast cell lines) and muscle strips than the control. Conclusion: These results suggest, in part, that the activity of HSP27 and MAPKs affect stressors, such as PDGF, AngII, TNF$\alpha$, $H_2O_2$, and starvation in rat smooth and skeletal muscles. However, more systemic research will be needed into physical therapy, including thermotherapy, electrotherapy, radiotherapy and others.

• Journal of the Korean Society of Propulsion Engineers
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• v.3 no.4
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• pp.93-103
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• 1999

The steady-state performance analysis program for turboprop engine which was used for a small, middle industrial aircraft and a basic trainer aircraft was developed and linear Gas Path Analysis method was applied to Engine Health Monitoring for Turboprop engine. This program was compared with TURBOMARCH program which is well known with performance and power according to flight Mach No. at the standard atmospheric condition to prove a steady-state performance analysis program. From the result, inlet, exit temperature and pressure of each component had error within 3% and especially power according to flight Mach No. had error within 2.4% so that this program could be assured. To make sure if linear Gas Path Analysis is reasonable four cases were selected. The first is the case that fouling is occurred in compressor only. The second is the case that fouling is occurred in compressor and erosion is occurred in turbine. The third is the case that erosion is occurred in both compressor and turbine and power turbine at the same time. Finally, the case that fouling and erosion are occurred in compressor, compressor turbine and power turbine was selected. Different parameters were selected impartially among the independent parameters so that the effect of measurement parameter selection was observed. From the result, the more measurement parameters the smaller RMS error and even though the number of measurement parameters was the same, the RMS error was obtained differently according to which measurement parameters were selected. The case using eight instrument parameters of case IV-4 had small error comparably and was economic and it was important to select optimal number of measurement and optimal measurement parameters.

• Journal of the Korean Magnetics Society
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• v.25 no.3
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• pp.83-86
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• 2015

Nowadays the weapon systems are employed air bursting munition (ABM) as smart programmable 40 mm shells which have been developed in order to hit the target with programmed munition that can be air burst after a set distance in the battlefield. In order to improve the accuracy of such a bursting time, by measuring the speed of the munition from the barrel, weapon systems calculate the exact time of flight to the target and then the time information must be inputted to the munition. In this study, we introduce a device capable of detecting a shot at K4 40 mm automatic grenade. The shot is composed of a rotating copper band to convert linear motion into rotary motion when it passes through the barrel, the steel section is exert the effect of fragment and aluminum section to give fuze information. The aluminum section was used to detect munition using eddy current method. To measure muzzle velocity by means of non-contact method, two eddy current probes separated 10 cm was employed. Time interval between two eddy current probe detection times was used as muzzle velocity. The eddy current probe was fabricated U-shape Mn-Zn ferrite core with enamelled copper wire, and 200 kHz alternating current was used to detect inductance change. Measured muzzle velocity using the developed sensor was compared to the Doppler radar system. The difference was smaller than 1%.

• Animal Bioscience
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• v.34 no.12
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• pp.2003-2011
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• 2021

Objective: The aim of this study was to evaluate the effect of marinating turkey meat with buttermilk and acid whey on the technological traits and microbiological quality of the product. Methods: Slices of turkey meat muscles were marinated for 12 hours in buttermilk (n = 30), acid whey (n = 30) and comparatively, in lemon juice (n = 30). The control group (n = 30) consisted of unmarinated slices of turkey breast muscles. Physical parameters (pH, water holding capacity, colour L^*a^*b^*, shear force, weight loss) were assessed and quantitative and qualitative microbiological evaluation of raw and roasted products was performed. The microbiological parameters were determined as the total viable counts of mesophilic aerobic bacteria, of the Enterobacteriaceae family, and Pseudomonas spp. Bacterial identification was performed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: Marinating turkey meat in buttermilk and whey compared to marinating in lemon juice and the control sample resulted in a higher (p<0.05) degree of yellow color saturation (b^*) and a reduction (p<0.05) in the number of mesophilic aerobic bacteria, Pseudomonas spp. and Enterobacteriaceae family as well as the number of identified mesophilic aerobic bacteria in both raw and roasted samples. The lowest (p<0.05) shear force values were found in products marinated in whey. Conclusion: The use of buttermilk and acid whey as a marinade for meat increases the microbiological safety of the product compared to marinating in lemon juice, while maintaining good technological features of the product.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.946-951
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• 2006

To study the effect of iron on Saccharomyces cerevisiae, whole-cell proteins of Saccharomyces cerevisiae were extracted and subjected to two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and differentially expressed proteins were identified. The proteins separated were further identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and were compared with a protein database. Of more than 300 spots separated by molecular weight and isoelectric points, 27 differentially expressed spots were identified. Ten proteins were found to be differentially expressed at high iron concentration. Triosephosphate isomerase (TPI), YDR533C hypothetical protein, superoxide dismutase (SOD), 60 kDa heat-shock protein (HSP60), pyruvate dehydrogenase beta subunit 1 (PDB1), and old yellow enzyme 2 (OYE2) were upregulated, whereas thiol-specific antioxidant (TSA), regulatory particle non-ATPase subunit 8 (RPN8), thiol-specific peroxiredoxin 1 (AHP1), and fructose-1, 6-bisphosphate adolase (FBA) were downregulated by iron. Based on the result, we propose that SOD upregulated by iron would protect the yeast from oxidative stress by iron, and that TSA downregulated by iron would render cells hypersensitive to oxidative stress.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.7
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• pp.922-926
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• 2005

The present study was aimed to investigate proteome affected by Panax ginseng extracts in chicken muscles. The whole muscle proteins from chicken fed boiled extracts of 0% (control), 1%, 3%, and 5% Panax ginseng in water were separated by two-dimensional electrophoresis (2-DE) gels using immobilized non-linear gradient (pH 3-10) strips. More than 300 protein spots were detected on silver staining gels. Among them, four protein spots were distinctively up-regulated by Panax ginseng treatments and further investigated by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The obtained MS data were searched against SwissProt database using the Mascot search engine. The up-regulated proteins were finally identified as $\alpha$-tropomyosin (2 spots), triosephosphate isomerase, and one unknown protein. Based on the known functions of the identified proteins, they are highly related to muscle development and enhanced immunity in chickens. These proteins can give valuable information of biochemical roles for Panax ginseng in chicken meats.