• Wind and Structures
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• v.34 no.4
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• pp.385-394
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• 2022

Global Warming has been driven majorly by the consumption of fossil fuels. Harnessing energy from wind is viable solution towards reducing carbon footprint created due to burning such fuels, However, wind turbines have their problems of flow separation and aerodynamic stall to tackle with. In an attempt to delay the stall angle and improve the aerodynamic characteristics of the NACA 0015 symmetrical aerofoil, lateral cylindrical ridges were attached to its suction surface, at chord positions ranging from 0.1c to 0.5c. The characteristics of the original and ridged aerofoils were obtained using simultaneous pressure readings taken in a wind tunnel, at a free stream Reynolds number of R_e = 2.81 × 10⁵ for a wide range of free stream angles of attack ranging from -45° to 45°. Depending on the ridge size, a delay in stall angle varying from 5° to 20° was achieved together with the maximum increase in lift in the post-stall phases. Additionally, efforts were made to identify the optimum position for each ridge.

• Journal of Surface Science and Engineering
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• v.34 no.5
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• pp.510-515
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• 2001

It was first time that low frequency R.F. derived plasma enhanced MOCVD with frimethylborate precursor was used to fabricate a new ternary compound $BO_{x}$ $N_{y}$ . The formation of BON molecule was resulted from nitrogen nitrifying B-O, and forming the angular molecule structure proved by XPS and FT-IR results. The relationship between hardness and film thickness was studied. An thickness-independent hardness was fond about 10 GPa. The empirical calculation of band-gap and UV test result showed that our deposited $BO_{x}$ $N_{y}$ thin film was semiconductor material with 3.4eV of wide band gap. The electrical conductivity, $4.8$\times$10^{-2}$ /($\Omega$.cm)$^{-1}$ also confirmed that $BO_{x}$ $N_{y}$ has a semiconductor property. The roughness detected from the as-grown films showed that there was no serious bombarding effect due to anion in the plasma occurring in the RF frequency derived plasma.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.285-292
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• 2013

This study was carried out to validate the safety of ametoctradin residues in agricultural commodities by developing an official analysis method. An analytical method was developed and validated using HPLC-PDA detectors. The samples were extracted with methanol, subsequently partitioned with dichloromethane and purified with florisil column chromatograph using acetone/hexane (30/70, v/v) as solvent. The method was validated by using grape, hulled rice, mandarin, and potato spiked with ametoctradin at 0.05 and 5.0 mg/kg, and pepper at 0.05 and 2.0 mg/kg. Average recoveries were 76-114.8% with relative standard deviation less than 10%, and the limit of detection and limit of quantification were 0.0125 and 0.05 mg/kg, respectively. The result of recoveries and overall coefficient of variation of the laboratory results from Gwangju regional Food and Drug Administration (FDA) and Daejeon regional FDA was accorded with Codex Alimentarius Commission Guideline (CAC/GL 40). Based on these results, this method was found to be appropriate for ametoctradin residue determination and can be used as the official method of analysis.

• Journal of Life Science
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• v.29 no.12
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• pp.1305-1313
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• 2019

Licochalcone (LC), isolated from the roots of Glycyrrhiza inflata has multiple pharmacological effects including anti-inflammatory and anti-tumor activities. To date, Licochalcone C (LCC) has induced apoptosis and inhibited cell proliferation in oral and bladder cancer cells, but lung cancer has not yet been studied. In addition, no study reported LCC-induced autophagy in cancer until now. The present study was designed to investigate the effect of LCC on gefitinib-sensitive and -resistant lung cancer cells and elucidate the mechanism of its action. The 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay data showed that LCC significantly inhibited cell viability in non-small cell lung cancer (NSCLC) HCC827 (gefitinib-sensitive) and HCC827GR (gefitinib-resistant) cell lines. Interestingly, Annexin V/7-aminoactinomycin D double staining and cell cycle analysis showed an apoptosis rate within about 20% at the highest concentration of LCC. LCC induced G2/M arrest by reducing the expression of the cell cycle G2/M related proteins cyclin B1 and cdc2 in NSCLC cell lines. Treatment of LCC also induced autophagy by increasing the expression of the autophagy marker protein microtubule-associated protein 1 light chain 3 (LC3) and the protein autophagy-related gene 5 involved in the autophagy process. In addition, LCC increased the production of reactive oxygen species (ROS), and the cell viability was partially restored by treatment with the ROS inhibitor N-acetyl-L-cysteine. In western blotting analysis, the expression of cdc2 was increased and LC3 was decreased by the simultaneous treatment of NAC and LCC. These results indicate that LCC may contribute to anti-tumor effects by inducing ROS-dependent G2/M arrest and autophagy in NSCLC. In conclusion, LCC treatment may be useful as a potential therapeutic agent against NSCLC.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.6
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• pp.419-425
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• 2010

Mast cells are activated by specific allergens and also by various nonspecific stimuli, which might induce physical urticaria. This study investigated the functional expression of temperature sensitive transient receptor potential vanilloid (TRPV) subfamily in the human mast cell line (HMC-1) using whole-cell patch clamp techniques. The temperature of perfusate was raised from room temperature (RT, $23{\sim}25^{\circ}C$) to a moderately high temperature (MHT, $37{\sim}39^{\circ}C$) to activate TRPV3/4, a high temperature (HT, $44{\sim}46^{\circ}C$) to activate TRPV1, or a very high temperature (VHT, $53{\sim}55^{\circ}C$) to activate TRPV2. The membrane conductance of HMC-1 was increased by MHT and HT in about 50% (21 of 40) of the tested cells, and the I/V curves showed weak outward rectification. VHT-induced current was 10-fold larger than those induced by MHT and HT. The application of the TRPV 4 activator $3{\alpha}$-phorbol 12,13-didecanoate ($4{\alpha}$ PDD, $1\;{\mu}M$) induced weakly outward rectifying currents similar to those induced by MHT. However, the TRPV3 agonist camphor or TRPV1 agonist capsaicin had no effect. RT-PCR analysis of HMC-1 demonstrated the expression of TRPV4 as well as potent expression of TRPV2. The $[Ca^{2+}]_c$ of HMC-1 cells was also increased by MHT or by $4{\alpha}$ PDD. In summary, our present study indicates that HMC-1 cells express $Ca^{2+}$-permeable TRPV4 channels in addition to the previously reported expression of TRPV2 with a higher threshold of activating temperature.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.2
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• pp.154-159
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• 1991

A field experiment was conducted to know the feasibility of direct-seeded rice. Dry seeds of a Japonica type rice variety, Donghaebyeo, was sown from May 10 to June 20 at the 10-day intervals. The number of days from seeding to emergence decreased as planting date delayed; 13, 12, 10, 9, and 7 days at May 10, May 20. May 30. and June 10 seedings, respectively. The number of maximum tillers per ㎡ was about 700-800 at all the seeding dates and effective tiller ratio ranged 40-45%. The number of days from seeding to heading decreased as seeding date delayed; from 97 days at May 10 planting to 71 days at June 20 planting. The cumulative effective temperature (mean air temperature-15$^{\circ}C$) from seeding to heading was fairly constant having 870$^{\circ}C$ with 2.3% C.V. The number of panicles per unit area at June 10 planting was higher than that of other planting dates. Panicle length and the number of spikelets per panicle tended to decrease as seeding date delayed. The number of spikelets per unit area, 1000-grain weight, and grain yield were similar among the seeding dates except June 20 seeding. At the June 20 seeding the number of spikelets and grain yield were much lower, but 1000-grain weight was higher compared with other seeding dates. Grain fertility and percent ripened grains was similar among all seeding dates.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.327-333
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• 2005

Dihydroxy-acid dehydratase (DHAD, 2,3-dihydroxy-acid hydrolyase, EC 4.2.1.9) is one of the key enzymes involved in the biosynthetic pathway of the branched chain amino acid isoleucine and valine. Although the enzyme have been purified and characterized in various mesophiles including bacteria and eukarya, the biochemical properties of DHAD has bee not yet reported from hyperthermophilic archaea. In this study, we cloned, expressed, and purified a DHAD homologue from the thermoacidophilic archaeon Sulfolobus solfataricus P2, which grows optimally at $80\;^{\circ}C$ and pH 3, in E. coli. Characterization of the recombinant S. solfataricus DHAD (rSso_DHAD) revealed that it is the dimeric protein with a subunit molecular weight of 64,000 Da in native structure. rDHAD showed the highest activity toward 2,3-dihydroxyisovaleric acid among 17 aldonic acid substrates Interestingly, this enzyme also displayed 50 % activities toward some pentonic acids and hexonic acids when compared with the activity of this enzyme to the natural substrate. Moreover, rSso_DHAD indicated relatively higher activity toward D-gluconate than any other hexonic acids tested in substrates. $K_m$ and $V_{max}$ values of rSso_DHAD were calculated as $0.54\;{\pm}\;0.04\;mM$ toward 2,3dihydroxyisovalerate and $2.42\;{\pm}\;0.19\;mM$ toward D-gluconate, and as $21.6\;{\pm}\;0.4\;U/mg$ toward 2,3-dihydroxyisovalerate and $13.8\;{\pm}\;0.4\;U/mg$ toward D-gluconate, respectively. In the study for biochemical properties, the enzyme shows maximal activity between $70^{\circ}C$ and $80^{\circ}C$, and the pH range of pH 7.5 to 8.5. The half life time at $80^{\circ}C$ was 30 min. A divalent metal ion, $Mn^{2+}$, was only powerful activators, whereas other metal ions made the enzyme activity reduced. $Hg^{2+}$, organic mercury, and EDTA also strongly inhibited enzyme activities. Particularly, the rSso_DHAD activity was very stable under aerobic condition although the counterparts reported from mesophiles had been deactivated by oxygen.

• Kyungpook Mathematical Journal
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• v.54 no.1
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• pp.95-101
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• 2014

An n-tuple ($a_1,a_2,{\ldots},a_n$) is symmetric, if $a_k$ = $a_{n-k+1}$, $1{\leq}k{\leq}n$. Let $H_n$ = {$(a_1,a_2,{\ldots},a_n)$ ; $a_k$ ${\in}$ {+,-}, $a_k$ = $a_{n-k+1}$, $1{\leq}k{\leq}n$} be the set of all symmetric n-tuples. A symmetric n-sigraph (symmetric n-marked graph) is an ordered pair $S_n$ = (G,${\sigma}$) ($S_n$ = (G,${\mu}$)), where G = (V,E) is a graph called the underlying graph of $S_n$ and ${\sigma}$:E ${\rightarrow}H_n({\mu}:V{\rightarrow}H_n)$ is a function. The restricted super line graph of index r of a graph G, denoted by $\mathcal{R}\mathcal{L}_r$(G). The vertices of $\mathcal{R}\mathcal{L}_r$(G) are the r-subsets of E(G) and two vertices P = ${p_1,p_2,{\ldots},p_r}$ and Q = ${q_1,q_2,{\ldots},q_r}$ are adjacent if there exists exactly one pair of edges, say $p_i$ and $q_j$, where $1{\leq}i$, $j{\leq}r$, that are adjacent edges in G. Analogously, one can define the restricted super line symmetric n-sigraph of index r of a symmetric n-sigraph $S_n$ = (G,${\sigma}$) as a symmetric n-sigraph $\mathcal{R}\mathcal{L}_r$($S_n$) = ($\mathcal{R}\mathcal{L}_r(G)$, ${\sigma}$'), where $\mathcal{R}\mathcal{L}_r(G)$ is the underlying graph of $\mathcal{R}\mathcal{L}_r(S_n)$, where for any edge PQ in $\mathcal{R}\mathcal{L}_r(S_n)$, ${\sigma}^{\prime}(PQ)$=${\sigma}(P){\sigma}(Q)$. It is shown that for any symmetric n-sigraph $S_n$, its $\mathcal{R}\mathcal{L}_r(S_n)$ is i-balanced and we offer a structural characterization of super line symmetric n-sigraphs of index r. Further, we characterize symmetric n-sigraphs $S_n$ for which $\mathcal{R}\mathcal{L}_r(S_n)$~$\mathcal{L}_r(S_n)$ and $$\mathcal{R}\mathcal{L}_r(S_n){\sim_=}\mathcal{L}_r(S_n)$$, where ~ and $$\sim_=$$ denotes switching equivalence and isomorphism and $\mathcal{R}\mathcal{L}_r(S_n)$ and $\mathcal{L}_r(S_n)$ are denotes the restricted super line symmetric n-sigraph of index r and super line symmetric n-sigraph of index r of $S_n$ respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.3
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• pp.274-282
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• 1998

This study deals with sinking resistance for purse seine, in the case of different d/l, ratio of twine diameter and leg length. Experiments carried out on the six types simplified reduced model seines which were made of knotless netting. The nettings were woven in different leg length 4.3, 5.0, 5.5, 6.0, 6.6 and 7.7mm of polyester 28 tex two threads two -ply twine, and each of the seines were named I, II, III, IV, V and Ⅵ seine. Dimension of seine models were 450cm for corkline and 85cm for seine depth, each seines rigged up 160g of float for a floatline and 50g (underwater weight) of lead for a leadline. Experiments were measured in the observation channel of a flume tank at the static conditions Sinking motion was recorded by the two sets TV-camera for VTR which were placed in top and side of the model seine, and reading coordinate carried out by the video digitization system. An analysis were calculated out by simultaneous differential equations for numerical method by Runge - Kutta - Gill sub - routine. The results obtained were as follows: 1. Average sinking speed of seine of seine margin was fastest for Ⅵ seine followed by V, IV, III, II and I seines. 2. The coefficient of resistance for a seine wall was depended upon the ratio of d/l : KD =0.081 (d/l )-0.5 3. The coefficient of resistance for netting bundle was not depended upon the ratio of d/l :CR = 0.91 (), d : Twine diameter, l : Leg length, : Density of netting materals, $\omega$ : Density of water

• Journal of Pharmaceutical Investigation
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• v.31 no.4
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• pp.265-271
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• 2001

In order to elucidate the influence of intestinal and hepatic first-pass effect on the pharmacokinetics of triflusal, the biotransformation of triflusal in the gastrointestinal tract and liver was designed. Moreover, we tried to establish an HPLC method applicable for bioassay and available to pharmacokinetics, not only with the simultaneous determination of triflusal and its active metabolite, 2-hydroxy-4-trifluoromethyl benzoic acid (HTB), but also with improving sensitivity. After the administration of triflusal (10 mg/kg) and HTB (10 mg/kg) into femoral vein, portal vein (only triflusal) and oral route (only triflusal), pharmacokinetic parameters were investigated from the plasma concentration-time profiles of triflusal and HTB in rats. An HPLC method was developed for the simultaneous determination of triflusal and HTB in rat plasma, urine and bile. The HPLC analysis was carried out using a C18 column and acetonitrile-methanol-water (25:10:65, v/v/v) as the mobile phase and UV detection at 234 nm. Furosemide was used as the internal standard. The calibration curves were linear over the concentration range $0.05-5.0\;{\mu}g/ml$ for triflusal and $0.2-200.0\;{\mu}g/ml$ for HTB with correlation coefficients greater than 0.999 and with intra-day or inter-day coefficients of variation not exceeding 10.0%. This assay procedure was applied to the study of metabolite pharmacokinetics of triflusal and HTB in rats. It was supposed that triflusal was almost metabolized in vivo because urinary and biliary excreted amounts of triflusal could be ignored as it was lower than 1.2% of the administered dose. According to the gastrointestinal and hepatic biotransformation pathways of triflusal, it was found that triflusal was hydrolyzed by about 5% in intestine and metabolized by about 53% in liver, and that the bioavailability of triflusal after oral administration of triflusal was 0.44, and also that the fraction of total elimination rate of triflusal which formed HTB in liver $(F_{mi},\;%)$ was about 98%. These results showed that triflusal was almost metabolized in liver, and the total elimination of triflusal in the body was dependent to the formation rate of HTB from triflusal in liver.