• The Korean Journal of Pharmacology
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• v.30 no.2
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• pp.205-215
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• 1994

It is well known that chronic stimulation with CCK gives rise to growth of exocrine pancreas and to increased content of enzyme proteins in pancreas. However, littls Is known about changes of the secretory function of exocrine pancreas which has been chronically stimulated with CCK, especially about the responsiveness to secretagogues such as CCK, caerulein and carbachol. The present study was performed to investigate the effect of camostat on secretory profiles and the responsiveness to secretagogues of exocrine pancreas by observing in vitro amylase release stimulated by cholecystokinin-octapeptide(CCK-8) and carbachol in dispersed isolated pancreatic acini from camostat-treated rats for 4 or 10 days. The results summarized as follows : 1) The maximal effective concentration of CCK-8 in amylase release in the camostat treated group was greater than control group, but that of carbachol was not different between groups. 2) Analysis of the stimulated amylase release as the percentage of the maximal response revealed that camostat treatment caused right-shift of the dose-response curve of CCK-8. Camostat did not cause significant changes in the dose-response curve of carbachol. 3) There were considerable increases in the amylase release in the camostat-treated group, compared to the control when acini were stimulated with CCK-8 $10^{-9}\;M$ and carbaochol $10^{-6}\;M$, and higher concentrations. 4) There was a reverse correlation between the tissue content and the maximal release(percent of the total content) of amylase. These results suggest that chronic exposure of exocrine pancreas to increased endogenous CCK can enhance the responsiveness of exocrine enzyme secretion to secretagogues, especially at higher concentrations of CCK and carbachol.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.7 s.349
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• pp.1-6
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• 2006

We show for the first time the optical properties of the selectively oxidized vertical cavity laser (VCL) - depleted optical thyristor (DOT), which has not only a low threshold current, but also a high sensitivity to the optical input light. In order to analyze their switching characteristics, nonlinear s-shaped current-voltage characteristics are calculated and the reverse full-depletion voltages (Vneg's) are obtained as function of semiconductor parameters by using a finite difference method (FDM). The selectively oxidized PnpN VCL-DOT clearly shows the nonlinear s-shaped current-voltage and lasing characteristics. A switching voltage of 5.24 V, a holding voltage of 1.50 V, a spectral response at 854.5 nm, and a very low threshold current of 0.65 mA is measured, making these devices attractive for optical processing applications.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.72.2-73
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• 2003

We found a soybean (Glycine max) cultivar 561 that was strongly resistant to a virulent bacterial strain of a Pseudomonas spp. Further identification revealed that the Pseudomonas spp. was a strain of Pseudomonas aeruginosa. Furthermore we identified specific genes involved in the resistance of soybean 561 and analyzed the pattern of gene expression against the Pseudomonas infection using differential-display reverse transcription PCR (DDRT-PCR). More than 126 cDNA fragments representing mRNAs were induced within 48 hours of bacteria inoculation. Among them, 28 cDNA fragments were cloned and sequenced. Twelve differentially displayed clones with open reading frames had unknown functions. Sixteen selected cDNA clones were homologous to known genes in the other organisms. Some of the identified cDNAs were pathogenesis-related genes (PR genes) and PR-like genes. These cDNAs included a putative calmodulin-binding protein, an endo-1,3-1,4-b-D-glucanase, a b-1,3-endoglucanase, a b-1,3-exoglucanase, a phytochelatin synthetase-like gene, a thiol pretense, a cycloartenol synthase, and a putative receptor-like sorineithreonine protein kinase. Among them, we found that four genes were putative pathogenesis-related genes (PR) induced significantly by the p. aeruginosa infection. These included a calmodulin-binding protein gene, a b-1,3-endoglucanase gene, a receptor-like sorine/threonine protein kinase gene, and pS321 (unknown function). These results suggest that the differentially expressed genes may mediate the strong resistance of soybean 561 to Pseudomonas aeruoginosa.

• The KSFM Journal of Fluid Machinery
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• v.19 no.6
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• pp.50-54
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• 2016

The performance of a scroll expander is the most important factor for the efficiency of small scale Organic Rankine cycle waste heat power generation systems. In this research, a scroll compressor was purchased and operated in reverse to function as a scroll expander. With air as a working fluid, a series of performance test were conducted on this expander by varying the inlet and outlet pressure. Secondly, We have tested through 2000 to 3500 rpm rotational speed to find the maximum power and efficiency of the expander. And last, It was observed in the initial experiments that the design of the expander's orbiting scroll wrap partially blocked the fluid intake which may have caused unnecessary flow resistance. To verify this theory, a small part of the scroll wrap was removed and the performance test was redone. It was observed that the lower back pressure assure the higher efficiency and power of expander and the rotational speed that shows maximum adiabetic efficiency of scroll expander is 69% at 2500 rpm. And by modified wrap of the scroll, we could get volume flow rate for 13% to 19% and power for 5% to 18% increased. But the maximum efficiency of the modified scroll was decreased 8%.

• Preventive Nutrition and Food Science
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• v.8 no.3
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• pp.239-244
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• 2003

Recently, we reported (J Korean Soc Food Sci Nutr, 31(3): 516-520, 2002) that Semisulcospira libertina (Marsh Snail) pretreatment has a hepatoprotective effect on $CCl_4$-induced liver damage in rats. The purpose of this study was to investigate the possible mechanisms of hepatoprotection by S. libertina (SL) on liver injury induced by acetaminophen (AA). Male ICR mice were pretreated with dehydrated powder of SL once daily for three consecutive days, given a single toxic dose of AA (450 mg/kg) and liver function determined 24 h later. Liver damage was assessed by quantifying serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and sorbitol dehydrogenase (SDH) activities, and by measuring hepatic lipid peroxidation. To confirm possible mechanism(s), the content of hepatic glutathione (GSH) and gene expression of tumor necrosis factor a (TNF $\alpha$) mRNA by reverse transcription-polymerase chain reaction (RTPCR) were also measured. Pretreatment with SL dramatically lowered AA-elevated ALT, AST and SDH activities. SL pretreatment decreased AA-produced lipid peroxidation by 11% and restored the AA-depleted hepatic GSH by 27%. Furthermore, SL markedly suppressed the expression of TNF $\alpha$ mRNA induced by AA. Our findings revealed that the possible hepatoprotective mechanisms of SL could be attributed, at least in part, to the glutathione-mediated detoxification as well as the regulation of TNF $\alpha$ mRNA expression.

• BMB Reports
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• v.32 no.4
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• pp.363-369
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• 1999

The orf8(chlD) gene cloned from Streptomyces antibioticus T$\"{u}$99 was overexpressed using an E. coli system to confirm its biological function. Induction of the E. coli strain transformed with recombinant plasmid pRFJ 1031 containing orf8 resulted in the production of a 43,000 dalton protein. Glucose-1-phosphate thymidylyltransferase activity of the cell extract obtained from the transformed strain was 4-5 times higher than that of the control strain. The expressed protein was purified 18-fold from E. coli cell lysate using three chromatographic steps with a 17% overall recovery to near homogeneity. The N-terminal amino acid sequence of the purified protein agrees with the nucleotide sequence predicted from the orf8 gene. The SDS-PAGE estimated subunit mass of 43,000 dalton agrees well with that calculated from the amino acid composition deduced from the nucleotide sequence of the orf8 gene (43,000 Da). Also, the native enzyme has a monomeric structure with a molecular mass of 43,000 dalton. The purified protein showed glucose-1-phosphate thymidylyltransferase activity catalyzing a reversible bimolecular group transfer reaction, and was highly specific for dTTP and ${\alpha}$-D-glucose 1-phosphate as substrates in the forward reaction, and for dTDP-D-glucose and pyrophosphate in the reverse reaction.

• BMB Reports
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• v.51 no.9
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• pp.450-455
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• 2018

Tamoxifen (TAM) is commonly used to treat estrogen receptor (ER)-positive breast cancer. Despite the remarkable benefits, resistance to TAM presents a serious therapeutic challenge. Since several HOX transcription factors have been proposed as strong candidates in the development of resistance to TAM therapy in breast cancer, we generated an in vitro model of acquired TAM resistance using ER-positive MCF7 breast cancer cells (MCF7-TAMR), and analyzed the expression pattern and epigenetic states of HOX genes. HOXB cluster genes were uniquely up-regulated in MCF7-TAMR cells. Survival analysis of in slico data showed the correlation of high expression of HOXB genes with poor response to TAM in ER-positive breast cancer patients treated with TAM. Gain- and loss-of-function experiments showed that the overexpression of multi HOXB genes in MCF7 renders cancer cells more resistant to TAM, whereas the knockdown restores TAM sensitivity. Furthermore, activation of HOXB genes in MCF7-TAMR was associated with histone modifications, particularly the gain of H3K9ac. These findings imply that the activation of HOXB genes mediate the development of TAM resistance, and represent a target for development of new strategies to prevent or reverse TAM resistance.

• Journal of computational fluids engineering
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• v.21 no.2
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• pp.99-105
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• 2016

The present study has been carried out to analyze the flow characteristics with geometric shape and control conditions in subsea by-pass valve. The function of by-pass valve is to prevent reverse flow. In this study, the static analysis has been perform for analyzing fluid flow in open state. In order to consider the turbulent effect, the standard ${\kappa}-{\varepsilon}$ model was used. A variety of parametric studies, such as by-pass valve type or size, volume flow rate, leakage hole size, leakage hole position, block type, block shape, were performed. The pressure difference across the valve in the model broadened the flow channel cross-sectional area was greater than the base model for the same operating conditions. As the pipe diameter in the block decreases the pressure difference is greatly increased. The pressure difference according to block shape such as edge type and round was almost negligible. For the same Reynolds number the pressure difference was little changed according to the size of the valve.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.147-154
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• 2001

In Korea and Japan, dried oak mushrooms are classified into 12 to 16 different categories based on its external visual quality. And grading used to be done manually by the human expert and is limited to the randomly sampled oak mushrooms. Visual features of dried oak mushrooms dominate its quality and are distributed over both sides of the gill and the cap. The 2nd prototype computer vision based automatic grading and sorting system for dried oak mushrooms was developed based on the 1st prototype. Sorting function was improved and overall system for grading was simplified to one stage grading instead of two stage grading by inspecting both front and back sides of mushrooms. Neuro-net based side(gill or cap) recognition algorithm of the fed mushroom was adopted. Grading was performed with both images of gill and cap using neural network. A real time simultaneous discharge algorithm, which is good for objects randomly fed individually and for multi-objects located along a series of discharge buckets, was developed and implemented to the controller and the performance was verified. Two hundreds samples chosen from 10 samples per 20 grade categories were used to verify the performance of each unit such as feeding, reversing, grading, and discharging unites. Test results showed that success rates of one-line feeding, reversing, grading, and discharging functions were 93%, 95%, 94%, and 99% respectively. The developed prototype revealed successful performance such as the approximate sorting capability of 3,600 mushrooms/hr per each line i.e. average 1sec/mushroom. Considering processing time of approximate 0.2 sec for grading, it was desired to reduce time to reverse a mushroom to acquire the reversed surface image.

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.381-397
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• 2001

In the patients with hemiplegia caused by stroke and TBI. postural sway is increased and open displaced laterally over the non-affected leg, reflecting asymmetry in weight bearing on lower extremities during standing balance. Recovery of symmetric weight bearing and postural stability is an important aim in physical therapy. Plastic AFO has been used for hemiplegic patients in order to help their abnormal walking patterns. Past studies have mainly focused on the AFO influences on hemiplegic walking patterns without balance function approaches. The purpose of this study was to identify the immediate effects of plastic AFO and shoes on the static balance in hemiplegic patients. The scale for static balance were weight bearing on affected leg(%), sway area(mm2), sway path(mm), maximal sway velocity(mm/s), anteroposterior sway angle($^{\circ}$ ), and lateral angle($^{\circ}$ ). Seventeen hemiplegic patients participated in this study: 13 men and 4 women, with an average age of 50.18 years. Static balance was measured using BPM(balance performance monitor; dataprint software version 5.3) under four standing condition namely bare-foot standing. standing in shoes, standing with AFO, and standing in shoes with AFO. In order to assure the statistical significance of the results, an one-way ANOVA, the independent t-test. and a pearson's correlation were applied at the .05 level of significant. The results of this study were as follows: 1) There were statistically significant differences in weight bearing(%) on the static balance between affected leg and non-affected leg(p<.01). 2) There were statistically significant differences in sway reverse frequence(Hz) in standing with AFO between affected leg and non-affected leg(p<.05). 3) Sway area(mm2) on standing in shoes with AFO was lower than bare-foot standing(p<.05), Lateral sway angle($^{\circ}$ ) on standing in shoes with AFO was lower than bare-foot standing and standing in shoes(p<.05). 4) Weight bearing in affected leg was not significantly correlated with postural sway.