• The Korean Journal of Physiology and Pharmacology
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• v.24 no.4
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• pp.329-338
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• 2020

Rhinorrhea in allergic rhinitis (AR) is characterized by the secretion of electrolytes in the nasal discharge. The secretion of Cl^- and HCO₃^- is mainly regulated by cystic fibrosis transmembrane conductance regulator (CFTR) or via the calcium-activated Cl^- channel anoctamin-1 (ANO1) in nasal gland serous cells. Interleukin-4 (IL-4), which is crucial in the development of allergic inflammation, increases the expression and activity of ANO1 by stimulating histamine receptors. In this study, we investigated ANO1 as a potential therapeutic target for rhinorrhea in AR using an ANO1 inhibitor derived from a natural herb. Ethanolic extracts (30%) of Spirodela polyrhiza (SP_EtOH) and its five major flavonoids constituents were prepared. To elucidate whether the activity of human ANO1 (hANO1) was modulated by SP_EtOH and its chemical constituents, a patch clamp experiment was performed in hANO1-HEK293T cells. Luteolin, one of the major chemical constituents in SP_EtOH, significantly inhibited hANO1 activity in hANO1-HEK293T cells. Further, SP_EtOH and luteolin specifically inhibited the calcium-activated chloride current, but not CFTR current in human airway epithelial Calu-3 cells. Calu-3 cells were cultured to confluency on transwell inserts in the presence of IL-4 to measure the electrolyte transport by Ussing chamber. Luteolin also significantly inhibited the ATP-induced increase in electrolyte transport, which was increased in IL-4 sensitized Calu-3 cells. Our findings indicate that SP_EtOH and luteolin may be suitable candidates for the prevention and treatment of allergic rhinitis. SP_EtOH^- and luteolin-mediated ANO1 regulation provides a basis for the development of novel approaches for the treatment of allergic rhinitis-induced rhinorrhea.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.831-840
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• 2019

Flush Air Data Sensing system (FADS) estimates air data states using pressure data measured at the surface of flight vehicles. The FADS system does not require intrusive probes, so it is suitable for high performance aircrafts, stealth vehicles, and hypersonic flight vehicles. In this study, calibration procedures and solution algorithms of the FADS for a sphere-cone shape vehicle are presented for the prediction of air data from subsonic to supersonic flights. Five flush pressure ports are arranged on the surface of nose section in order to measure surface pressure data. The algorithm selects the concept of separation for the prediction of flow angles and the prediction of pressure related variables, and it uses the pressure model which combines the potential flow solution for a subsonic flow with the modified Newtonian flow theory for a hypersonic flow. The CFD code which solves Euler equations is developed and used for the construction of calibration pressure data in the Mach number range of 0.5~3.0. Tests are conducted with various flight conditions for flight Mach numbers in the range of 0.6~3.0 and flow angles in the range of -10°~+10°. Air data such as angle of attack, angle of sideslip, Mach number, and freestream static pressure are predicted and their accuracies are analyzed by comparing predicted data with reference data.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.8
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• pp.1292-1300
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• 2020

Objective: To explore feed resources capable of replacing regular poor-quality fodder, this study was conducted to evaluate the effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry leaves silage. Methods: The mulberry leaves were ensiled either untreated (control) or treated with 1×10⁶ cfu/g fresh matter Lactobacillus plantarum (L), 1% glucose (G), 3% molasses (M), a combination of 1% glucose and Lactobacillus plantarum (L+G), and a combination of 3% molasses and Lactobacillus plantarum (L+M). The fermentation quality and chemical composition were analyzed after 7, 14, 30, and 60 d, respectively. The 60-d silages were subjected to an aerobic stability test and fermented with buffered rumen fluid to measure the digestibility. Results: Inoculating lactic acid bacteria (LAB) resulted in more rapid increase in lactic acid concentrations and decline in pH of mulberry leaves silage as compared control. Higher acetic acid and lower ethanol and ammonia nitrogen concentrations (p<0.05) were observed in the LAB-inoculated silages as opposed to control during ensiling. The LAB-inoculated silages contained lower water-soluble carbohydrates compared with control during the first 14 d of ensiling, and lower neutral detergent fibre (p<0.05) concentrations as compared with non-LAB inoculated silages. Adding molasses alone increased (p<0.05) the digestibility of dry matter (DM). The aerobic stability of mulberry leaves silage was increased by LAB inoculation, whereas decreased by adding glucose or molasses. Conclusion: The LAB inoculation improved fermentation quality and aerobic stability of mulberry leaves silage, while adding glucose or molasses failed to affect the fermentation and impaired the aerobic stability. Inoculating LAB alone is recommended for mulberry leaves especially when ensiled at a relatively high DM.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.309-320
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• 1998

The periodontal health has been evaluated clinically by various epidemiological indices, and in researches by measurement of gingival crevicular fluid. Laser Doppler flowmetry is a reliable and objective method that allows immediate measurement of erythrocyte flux in approximately one cubic mm of the capillary bed without disturbing the tissues. The purpose of the present study was to determine whether human gingival blood flow was different according to measuring area, measuring time, and sex or not. Forty volunteers with good general and periodontal health, aged early twenties and unmarried, were selected. Laser Doppler flowmetry($floLAB^{(R)}$, Moor Instruments Ltd., England) was applied to measure the gingival blood flow of marginal gingiva, interdental papilla, attached gingiva and alveolar mucosa. The blood flow of interdental papilla was measured at 9-10 AM, 1-2 PM, and 5-6 PM. The difference of blood flow according to measuring area and measuring time was statistically analyzed by one way AOVA and Dunkan test, and the difference of blood flow between men and women was statistically analyzed by t-test. (1) Mean blood flow was significantly higher in alveolar mucosa than in the gingiva(p<0.05), and there was no significant difference in blood flow between marginal gingiva and interdental papilla(p>0.1). (2) Mean blood flow was significantly higher at 5-6 PM than at 9-10 AM and 1-2 PM(p<0.05). But there was no significant difference in gingival blood flow between 9-10 AM and 1-2 PM(p>0.1). (3) There was no significant difference in gingival blood flow between men and women(p>0.1). The above results suggest that the measurment of gingival blood flow using laser Doppler flowmetry may be clinically applicable to early determination of gingival inflammation and evaluation of healing status, but further studies are necessary to standardize and simplify the measuring procedure.

• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.39-48
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• 2014

Objective: This entire study has two parts. Study I aimed to develop a psychological assessment scale and the study II aimed to investigate the effects of LFN (low frequency noise) on the psychological responses in humans, using the scale developed in the study I. Background: LFN is known to have a negative impact on the functioning of humans. The negative impact of LFN can be categorized into two major areas of functioning of humans, physiological and psychological areas of functioning. The physiological impact can cause abnormalities in threshold, balancing and/or vestibular system, cardiovascular system and, hormone changes. Psychological functioning includes cognition, communication, mental health, and annoyance. Method: 182 college students participated in the study I in development of a psychological assessment scale and 42 paid volunteers participated in the study II to measure psychological responses. The LFN stimuli consisted of 12 different pure tones and 12 different 1 octave-band white noises and each stimulus had 4 different frequencies and 3 different sounds pressure levels. Results: We developed the psychological assessment scale consisting of 17 items with 3 dimensions of psychological responses (i.e., perceived physical, perceived physiological, and emotional responses). The main findings of LFN on the responses were as follows: 1. Perceived psychological responses showed a linear relation with SPL (sound pressure level), that is the higher the SPL is, the higher the negative psychological responses were. 2. Psychological responses showed quadric relations with SPL in general. 3. More negative responses at 31.5Hz LFN than those of 63 and 125Hz were reported, which is deemed to be caused by perceived vibration by 31.5Hz. 'Perceived vibration' at 31.5Hz than those of other frequencies of LFN is deemed to have amplified the negative psychological response. Consequently there found different effects of low frequency noise with different frequencies and intensity (SPL) on multiple psychological responses. Conclusion: Three dimensions of psychological responses drawn in regard to this study differed from others in the frequencies and SLP of LFN. Negative psychological responses are deemed to be differently affected by the frequency, SPL of the LFN and 'feel vibration' induced by the LFN. Application: The psychological scale from our study can be applied in quantitative psychological measurement of LFN at home or industrial environment. In addition, it can also help design systems to block LFN to provide optimal conditions if used the study outcome, .i.e., the relations between physical and psychological responses of LFN.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.5
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• pp.1032-1043
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• 1989

The heat transfer characteristics of the drag reducing polymer solutions are investigated experimentally in the thermal entrance region of circular tube flows. Fluids used in experiments are the aqueous solutions of high molecular polymer, polyacrylamide Separan AP-273 and the range of polymer concentrations is from 20 to 1000 wppm. Two stainless steel tubes with inside diameter 8.5mm(L/D=712) and 10.3mm(L/D=1160) are used for the heat transfer flow loops. The flow loop is set up to measure friction factors and heat transfer coefficients of test sections in two different modes; the recirculating flow system and once-through flow system. The test tubes are heated directly by electricity to apply the constant heat flux boundary conditions to the wall. Three different types of adaptors are used to observe the effects of the upstream flow conditions of the heat transfer test sections. The viscosity and characteristic relaxation time of the test fluids circulating in the flow system are measured by the capillary tube viscometer and falling ball viscometer at regular time intervals. The installed adaptors exhibit slight effect on the entrance heat transfer of Newtonian fluid. However, no noticeable effects are observed for the entrance heat transfer of the drag reducing fluids. The order of magnitude of the thermal entrance lengths of the drag reducing fluids which follow the minimum friction asymptote is much longer than that of Newtonian fluids in turbulent flows. A new dimensionless parameter, the viscoelastic Graetz number, is defined and all the experimental data are recasted in terms of the viscoelastic Graetz number. The local Nusselt number of the viscoelastic fluids is represented as a function of flow behavior index n and the viscoelastic Graetz number. As degradation continues the viscosity and the characteristic relaxation time of the testing fluids decrease. Weissenberg number defined by the relaxation time and D/V appears to be a proper dimensionless parameter in describing degradation effects on heat transfer of the viscoelastic fluids.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.4
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• pp.278-285
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• 1991

The authors propose to use the slot system in order to improve of the efficiency for the cambered otter boards. The experiment is divided into 2 parts, one is the efficiency model test, and the other is the visualization model test. The hydrodynamic characteristics of the model otter boards were tested by efficiency model test to measure the shearing, drag force of the models and visualization test using hydrogen bubble method to observe the streak-line and time-line of flow around the models, and milk spout method to observe the separation zone in the wake behind the models. This study tested for 5 models such ad without slot, slot position 0.2C, 0.4C, 0.6C and 0.8C. The results obtained are as follows: \circled1 The maximum C sub(L) of model otter board with slot position 0.6C in attack angle 27$^{\circ}$ was the highest of all models, it's value was 1.59. \circled2 In general, the L/D ratio of the one slot otter boards were 16~28% higher than otter board without slot. \circled3 The slot position 0.6C was better than any other slot position, and it's conformed by visiualization. \circled4 As to the model otter board with slot position 0.6C, flow speed of the back side was faster 1.3 to 1.7 times than in the front side. \circled5 The size of the separated zone in case of the model otter board with 0.6C was smaller than that of any other models.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.4
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• pp.418-425
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• 1988

Since conventional computer program is workable only with velocity boundary condition, in practical fluid passage such as clean room which usually have wide inlets and outlets, it is not easy to measure velocity itself because of its vector property. Furthermore a certain assumption of velocity at boundaries may lead to physically unreasonable results. From this motivation, we have developed a computer program to predict whole flow field imposed on pressure-based boundary condition which can be measured by relatively simple method. The only additional velocity boundary condition that should be imposed on to make the problem unique, are no slip condition at all walls and zero cross stream velocity at inlet. The result of present study was compared with that by Bernoulli equation being used practically. They were coincident well each other within 5%, therefore the validity of the present method is proved. In the present work, the flow field in a clean room subject to pressure-based boundary conditions at an inlet and two exits was predicted numerically. The pressure difference between the inlet and the left exit which keeps relatively low pressure among two exits is fixed as 150[Pa] and the pressure at the right exit is varied from zero to 150[Pa] by the increment of 25[Pa]. For each cases the flow characteristics in the clean room, the velocity profile at the inlet, and the flow rate through the two exits was predicted. The flow rate through the right exit imposed on relatively higher pressure than the left exit decreased linearly according to the increase of pressure of the right exit. When the pressure of the right exit is increased enough to cause back flow at the exit, the flow rate is rapidly decreased.

• Geophysics and Geophysical Exploration
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• v.22 no.1
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• pp.1-11
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• 2019

Well logging technologies are used to measure the physical properties of reservoirs through boreholes. These technologies have been utilized to understand reservoir characteristics, such as porosity, fluid saturation, etc., using equations based on rock physics models. The analysis of well logs is performed by selecting a reliable rock physics model adequate for reservoir conditions or characteristics, comparing the results using the Archie's equation or simandoux method, and determining the most feasible reservoir properties. In this study, we developed a joint inversion algorithm to estimate physical properties in shaly sandstone reservoirs based on the pre-existing algorithm for sandstone reservoirs. For this purpose, we proposed a rock physics model with respect to shale volume, constructed the Jacobian matrix, and performed the sensitivity analysis for understanding the relationship between well-logging data and rock properties. The joint inversion algorithm was implemented by adopting the least-squares method using probabilistic approach. The developed algorithm was applied to the well-logging data obtained from the Colony gas sandstone reservoir. The results were compared with the simandox method and the joint inversion algorithms of sand stone reservoirs.

• The Korea Journal of Herbology
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• v.28 no.2
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• pp.67-73
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• 2013

Objective : Lithospermum Erythrorhizon (LE) has been used as an anti-bacterial and anti-inflammatory agent. However, it is unclear that LE aqueous extract could show the anti-inflammatory effects in RAW 264.7cells. The purpose of this study was to investigate the anti-inflammatory effect of aqueous extract from LE on lipopolysaccharide (LPS) - induced inflammatory response. Methods : To measure out the cytotoxicity of LE, we performed the MTT assay. To evaluate the anti-inflammatory effects of LE, we examined the inflammatory mediators such as nitric oxide (NO), prostaglandin E2 ($PGE_2$) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-${\alpha}$, interleukin, (IL)-$1{\beta}$ and (IL)-6) on RAW 264.7 cells. We also examined molecular mechanisms such as mitogen-activated protein kinases (MAPKs) and nuclear factor-B (NF-${\kappa}B$) activation by western blot. Results : Aqueous Extract from LE itself did not have any cytotoxic effect in RAW 264.7 cells. Aqueous extract from LE inhibited LPS-induced productions of inflammatory mediators such as NO, $PGE_2$, and pro-inflammatory cytokines including TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 in RAW 264.7cells. In addition, LE inhibited the phosphorylation of p38 kinases (p38), c-Jun $NH_2$-terminal kinase (JNK), and NF-${\kappa}B$ activation in RAW 264.7 cells. Conclusion : LE down-regulated LPS-induced production of inflammatory mediators through the inhibition of p38, JNK and NF-${\kappa}B$ activation. Taken together, these results could provide the evidence for the anti-inflammatory effects of LE. Therefore, LE may be a novel target in the management of inflammation and help to support a potential strategy for prevention and therapy of inflammatory diseases.