• Molecules and Cells
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• v.41 no.3
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• pp.244-255
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• 2018

Low-grade pro-inflammatory state and leptin resistance are important underlying mechanisms that contribute to obesity-associated hypertension. We tested the hypothesis that Astragaloside IV (As IV), known to counteract obesity and hypertension, could prevent obesity-associated hypertension by inhibiting pro-inflammatory reaction and leptin resistance. High-fat diet (HFD) induced obese rats were randomly assigned to three groups: the HFD control group (HF con group), As IV group, and the As IV + ${\alpha}$-bungaratoxin (${\alpha}-BGT$) group (As IV+${\alpha}-BGT$ group). As IV ($20mg{\cdot}Kg^{-1}{\cdot}d^{-1}$) was administrated to rats for 6 weeks via daily oral gavage. Body weight and blood pressure were continuously measured, and NE levels in the plasma and renal cortex was evaluated to reflect the sympathetic activity. The expressions of leptin receptor (LepRb) mRNA, phosphorylated signal transducer and activator of transcription-3 (p-STAT3), phosphorylated phosphatidylinositol 3-kinase (p-PI3K), suppressor of cytokine signaling 3 (SOCS3) mRNA, and protein-tyrosine phosphatase 1B (PTP1B) mRNA, pro-opiomelanocortin (POMC) mRNA and neuropeptide Y (NPY) mRNA were measured by Western blot or qRT-PCR to evaluate the hypothalamic leptin sensitivity. Additionally, we measured the protein or mRNA levels of ${\alpha}7nAChR$, inhibitor of nuclear factor ${\kappa}B$ kinase subunit ${\beta}/nuclear$ factor ${\kappa}B$ ($IKK{\beta}/NF-KB$) and pro-inflammatory cytokines ($IL-1{\beta}$ and $TNF-{\alpha}$) in hypothalamus and adipose tissue to reflect the anti-inflammatory effects of As IV through upregulating expression of ${\alpha}7nAChR$. We found that As IV prevented body weight gain and adipose accumulation, and also improved metabolic disorders in HFD rats. Furthermore, As IV decreased BP and HR, as well as NE levels in blood and renal tissue. In the hypothalamus, As IV alleviated leptin resistance as evidenced by the increased p-STAT3, LepRb mRNA and POMC mRNA, and decreased p-PI3K, SOCS3 mRNA, and PTP1B mRNA. The effects of As IV on leptin sensitivity were related in part to the up-regulated ${\alpha}7nAchR$ and suppressed $IKK{\beta}/NF-KB$ signaling and pro-inflammatory cytokines in the hypothalamus and adipose tissue, since co-administration of ${\alpha}7nAChR$ selective antagonist ${\alpha}-BGT$ could weaken the improved effect of As IV on central leptin resistance. Our study suggested that As IV could efficiently prevent obesityassociated hypertension through inhibiting inflammatory reaction and improving leptin resistance; furthermore, these effects of As IV was partly related to the increased ${\alpha}7nAchR$ expression.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.358-365
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• 2006

To study simultaneous water and solute transport kinetics during soaking in concentrated solution, the influence of the concentration and molecular weight of the solute(polyethylene glycol(PEG) and NaCl) in the soaking solution and the temperature on the water loss and solute gain rates were observed by using a model vegetable tissue(potato). When potato slices$(4cm{\times}4cm{\times}0.1cm)$ soaked in 60% PEG solutions, the water loss rate of the early phase decreased with increasing of the molecular weight of PEG from 200 to 6,000, while the final water loss increased with increasing the molecular weight of PEG and it reached to 80%. The cell wall of potato tissue was permeable to NaCl and PEGs of which average molecular weight is smaller than 400 but it was not permeable to PEG 600 and larger molecules. PEG which has average molecular weight below 600 induced plasmolysis and those above 600 induced cytorrhysis. The water loss rate of potato sample soaked in smaller molecular weight PEG solution was faster than those soaked in higher molecular weight PEG solution before cytorrhysis happened. The water loss rate was reversed after cytorrhysis happened. The volume change of potato within the first 60 minutes was larger in low molecular PEG solution but the final ratio of decreasing volume was larger in high molecular PEG solutions. In PEG 200 solution, the potato tissue was slightly shrinked without shape change. However, in PEG 4,000 solution, volume of potato was reduced significantly and potato tissue was twisted.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1705-1710
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• 2003

A small body size of Brown Tsaiya laying duck is desirable to reduce maintenance requirements, so the body weight at 40 weeks of age (BW40) has to be maintained at its current level. Egg weight has to be maintained at around 65 g to meet market requirements. Eggshell strength at 40 weeks of age (ES40) must to be increased in order to maintain a low incidence of broken eggs. Thus, number of eggs laid up to 52 weeks of age (EN52) has to be increased without negative correlated response on ES40. A new linear genetic selection index was used: $I_g=a_0{\times}GEW40\;(g)+a_1{\times}GBW40\;(g)+a_2{\times}GES40\;(kg/cm^2)+a_3{\times}GEN52\;(eggs)$ where GEW40, GBW40, GES40 and GEN52 were the multitrait best linear unbiased prediction (MT-BLUP) animal model predictors of the breeding values respectively of egg weight and body weight at 40 weeks of age (EW40, BW40), ES40 and EN52. The coefficients $a_0$, $a_1$, $a_2$ and $a_3$ were calculated with constraints of 0.0 g, 0.0 g and $0.013kg/cm^2$ for expected genetic gains in EW40, BW40 and ES40 respectively and maximum gain in EN52. Since 1997, the drakes and the ducks were selected according to their own indexes, with this new genetic selection index. From G0 to G4, the average per generation predicted genetic responses in female duck were +0.05 g for EW40, +0.92 g for BW40, $+0.035kg/cm^2$ for ES40 and +2.13 eggs for EN52. Which represented respectively 0.07%, 0.06%, 0.67% and 1.0% of the means of the EW40, BW40, ES40 and EN52. For ES40 and EN52, it represented also respectively 16.1% and 21.6% of the additive genetic standard deviation of these traits. Thevse results indicated that selection of laying Brown Tsaiya by a restricted genetic selection index and with MT-BLUP animal model could be an efficient tool for improving the efficiency of egg production, increasing egg shell strength and egg number while holding egg weight and body weight constants.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.25 no.1
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• pp.57-81
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• 1997

Numerical prediction of nocturnal thermal high in summer of the 1995 near Taegu city located in a basin has been carried out by a non-hydrostatic numerical model over complex terrain through one-way double nesting technique in the Z following coordinate system. Under the prevailing westerly winds, vertical turbulent fluxes of momentum and heat over mountains for daytime hours are quite strong with a large magnitude of more than $120W/\textrm{m}^2$, but a small one of $5W/\textrm{m}^2$ at the surface of the basin. Convective boundary layer (CBL) is developed with a thickness of about 600m over the ground in the lee side of Mt. Hyungje, and extends to the edge of inland at the interface of land sea in the east. Sensible heat flux near the surface of the top of the mountain is $50W/\textrm{m}^2$, but its flux in the basin is almost zero. Convergence of sensible heat flux occurs from the ground surface toward the atmosphere in the lower layer, causing the layer over the mountain to be warmed up, but no convergance of the flux over the basin results from the significant mixing of air within the CBL. As horizontal transport of sensible heat flux from the top of the mountain toward over the basin results in the continuous accumulation of heat with time, enhancing air temperature at the surface of the basin, especially Taegu city to be higher than $39.3^{\circ}C$. Since latent heat fluxes are $270W/\textrm{m}^2$ near the top of the mountain and $300W/\textrm{m}^2$ along the slope of the mountain and the basin, evaporation of water vapor from the surface of the basin is much higher than one from the mountain and then, horizontal transport of latent heat flux is from the basin toward the mountain, showing relative humidity of 65 to 75% over the mountain to be much greater than 50% to 55% in the basin. At night, sensible heat fluxes have negative values of $-120W/\textrm{m}^2$ along the slope near the top of the mountain and $-50W/\textrm{m}^2$ at the surface of the basin, which indicate gain of heat from the lower atmosphere. Nighttime radiative cooling produces a shallow nocturnal surface inversion layer with a thickness of about 100m, which is much lower than common surface inversion layer, and lifts extremely heated air masses for daytime hours, namely, a warm pool of $34^{\circ}C$ to be isolated over the ground surface in the basin. As heat transfer from the warm pool in the lower atmosphere toward the ground of the basin occurs, the air near the surface of the basin does not much cool down, resulting in the persistence of high temperature at night, called nocturnal thermal high or tropical night. High relative humidity of 75% is found at the surface of the basin under the moderate wind, while slightly low relative humidity of 60% is along the eastern slope of the high mountain, due to adiabatic heating by the srong downslope wind. Air temperature near the surface of the basin with high moisture in the evening does not get lower than that during the day and the high temperature produces nocturnal warming situation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.4 s.346
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• pp.8-15
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• 2006

In this paper, the 94 GHz, low conversion loss, and high isolation single balanced mixer is designed and fabricated using GaAs-based metamorphic high electron mobility transistors (MHEMTs) with 70 nm gate length and the hybrid ring coupler with the micromachined transmission lines, dielectric-supported air-gapped microstrip lines (DAMLs). The 70 nm MHEMT devices exhibit DC characteristics with a drain current density of 607 mA/mm an extrinsic transconductance of 1015 mS/mm. The current gain cutoff frequency ($f_T$) and maximum oscillation frequency ($f_{max}$) are 320 GHz and 430 GHz, respectively. The fabricated hybrid ring coupler shows wideband characteristics of the coupling loss of $3.57{\pm}0.22dB$ and the transmission loss of $3.80{\pm}0.08dB$ in the measured frequency range of 85 GHz to 105 GHz. This mixer shows that the conversion loss and isolation characteristics are $2.5dB{\sim}>2.8dB$ and under -30 dB, respectively, in the range of $93.65GHz{\sim}94.25GHz$. At the center frequency of 94 GHz, this mixer shows the minimum conversion loss of 2.5 dB at a LO power of 6 dBm To our knowledge, these results are the best performances demonstrated from 94 GHz single balanced mixer utilizing GaAs-based HEMTs in terms of conversion loss as well as isolation characteristics.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.458-467
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• 2019

The purpose of this study is the suggestion of optimized parameters in OI (Optimal Interpolation) by experimental study. The observation of applying optimal interpolation is ADCP (Acoustic Doppler Current Profiler) data at the southwestern sea of Korea. FVCOM (Finite Volume Coastal Ocean Model) is used for the barotropic model. OI is to the estimation of the gain matrix by a minimum value between the background error covariance and the observation error covariance using the least square method. The scaling factor and correlation radius are very important parameters for OI. It is used to calculate the weight between observation data and model data in the model domain. The optimized parameters from the experiments were found by the Taylor diagram. Constantly each observation point requires optimizing each parameter for the best assimilation. Also, a high accuracy of numerical model means background error covariance is low and then it can decrease all of the parameters in OI. In conclusion, it is expected to have prepared the foundation for research for the selection of ocean observation points and the construction of ocean prediction systems in the future.

• Korean Journal of Ecology and Environment
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• v.33 no.4 s.92
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• pp.319-327
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• 2000

The feeding behavior of 1-year-old silver carp, Hypophthalmichthys molitrix (Val.) on phytoplankton species in a shallow hypertrophic lake was studied from 22 May to 18 September, 1997. Over the experimental period, the filter-pore sizes of the fish, the total biomass of the phytoplankton and the water temperature in each enclosure changed little with time. The fish biomass in each enclosure increased with time, while their percentage of weight gain correlated negatively to the stocking density, due perhaps to competition for prey. An analysis of gut contents of silver carp showed a strong similarity between the algal communities in the foregut and the water, and was significant for the fish enclosure with a low density (p<0.05). The presence of silver carp rarely suppressed the abundance of phytoplankton such as Oscillatoria, Anabaena and Melosira even at high ingestion levels. There were weak relationships between the IU values of each phytoplankton and the selectivity of fish on them (r = 0.001, p>0.5). There was no doubt that the silver carp fed unselectively when cyanobacteria populations were high, even though the selectivity index for diatoms was slightly higher than those for cyanobacteria, green algae and cryptomonads. Improvements in methodologies are needed to clearly understand and generalize the feeding behavior of silver carp.

• Science of Emotion and Sensibility
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• v.6 no.3
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• pp.13-20
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• 2003

In an experimental study, we assessed human sensibility in terms of psychophysiological response according to change of speeds (40, 70, 100km/h) in a driving simulator and application of motion fitters (washout filter, non-washout later) in a roller coaster simulator. For the driving and roller coaster simulators, a group of 12 healthy men in their twenties and a group of 8 healthy men in their twenties, respectively, participated. Participants each completed a simulator sickness questionnaire (SSQ), a subjective assessment of sensations of pleasantness, tension, and arousal, and perception of speed. Physiological signals were measured by 1/f fluctuation of EEG (electroencephalogram), ECG (electrocardiogram), and GSR (galvanic skin response). These were measured pre-to-post under the experimental conditions for each simulator. Subjective pleasantness, tension, arousal, and perception of speed and physiological responses indicating a feeling of pleasantness by 1/f fluctuation were higher for the roller coaster simulator than those measured for low speed driving in the driving simulator. The mean frequency of alpha band (8-l3㎐) in EEG increased with exposure to the driving simulator relative to that for the roller coaster simulator. Heart rate variability and GSR were significantly changed between pre- and post- under each condition in the driving and roller coaster simulators. The data suggest that subjective sensibility was elevated according to gain of speed and variety of simulator motion, and physiological responses were activated with increased speed.

• Toxicological Research
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• v.23 no.4
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• pp.353-362
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• 2007

Deoxynivalenol (DON) is a common food borne mycotoxin and occurs predominantly in grains such as wheat, barley, oats, etc. DON induces systemic health problems such as loss of appetite, emesis and diarrhea in both human and farm animals. Reliable diagnostic parameters for DON intoxication are needed to prevent deep health impact. In order to establish useful diagnostic parameters, we investigated clinical signs, hematological values, serum biochemical values, gross-, histo- and toxico-pathological findings in B6C3F1 male mice after oral administration of DON (0.83, 2.5 and 7.5 mg/kg) for 8 days. Body weight gain was significantly decreased at the highest dose of DON. Anorexia, ataxia, for crudness and lack of vigor were observed at the highest dose DON group. In hematological values, the numbers of WBC and platelets and hemoglobin content were reduced with decreased neutrophil and monocytes by 7.5 mg/kg DON. Prothrombin time (PT) and activated partial thromboplastin time (aPTT) were prolonged in a dose-dependent manner and the content of fibrinogen was elevated at high dose of DON. Of serum biochemical values, total protein, globulin, BUN, cholesterol and test-osterone were reduced but total bilirubin and albumin/globulin ratio increased. The enzyme activity of alkaline phosphatase was decreased while that of alanine aminotransferase was elevated. Relative organ weights of thymus, seminal vesicle/prostate and testes were dose-dependently reduced but those of liver and left adrenal gland increased with dose dependency. As for pathological findings, atrophy of thymus, seminal vesicle/prostate and testes and submucosal edema and ulceration in stomach and depletion of lymphocytes in thymus cortex were observed. In conclusion, these clinical, hematological, blood biochemical and patholgical parameters obtained in the present studies can be used for diagnosis of DON-mycotoxicosis, especially, low WBC, platelets, protein, BUN and testosterone and delayed prothrombin time can be available as for reliable diagnostic parameters.

• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.63-70
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• 2005

The purpose of this study was to investigate how to modify the physical properties of cellulose after thermal treatment. Cellulose was treated between $225^{\circ}C$ and $325^{\circ}C$ for 3 hrs under air flow, and then the thermally treated cellulose was measured to specific surface area, constitute elements, consumption ofacid and base, as well as the adsorption capacity of ethylamine vapor. The higher was the treating temperature from $225^{\circ}C$ to $325^{\circ}C$, the lower was the total yield of cellulose. Elemental analysis revealed that carbon content in thermally treated cellulose was gradually increased in proportion to temperature increment. The amount of acidic functional groups tended to increase up to $300^{\circ}C$, after then to be lowered slightly. In principle, no alkaline functional groups were found in thermally treated cellulose. In case of treatment with $325^{\circ}C$, only a few amount of alkaline functional groups were detectable. Specific surface area of thermally treated cellulose are determined to $1.9m^2/g$, which value can become higher when the treated temperature rises. The thermally treated cellulose at $275^{\circ}C$ shows the highest adsorption capacity of ethylamine at $40^{\circ}C$ for 4 hrs. Solubility of those two celluloses with WPG (Weight Percent Gain) value of 113% and 108%, respectively, was determined to almost 100%. X-ray diffractogram of thermally treated cellulose suggested that the crystalline structure of cellulose began to be destroyed at the temperature of $275^{\circ}C$. As a conclusion, changes of such a physical properties make it possible to weaken inter and/or intra hydrogen bond in crystal region of cellulose macromolecules. When thermally treated cellulose adsorbs ethylamine, it turns to be well soluble to water.