• Journal of Food Hygiene and Safety
• /
• v.24 no.3
• /
• pp.189-193
• /
• 2009

The purpose of this study was to investigate the antimicrobial activities of natural antimicrobials (10 formulas, $F1{\sim}F10$) against yeasts in functional beverages. The growth rates of yeasts were different with the ten different natural antimicrobial formulas tested. Yeasts grew for 14 days and the antimicrobial effect was observed between 14 and 18 days. Levels of S. cerevisiae, Z. bailii, and P. membranaefaciens were reduced to the limit of detection (ND) < 10 CFU/mL) after 28 days. Resistance against the antimicrobial effect was greatest for P. membranaefaciens, which grew to a level of $0.12{\sim}1.48\;\log_{10}\;CFU$/mL after 14 days and was reduced to a level of $1.61{\sim}3.55\;\log_{10}\;CFU$/mL after 28 days. The resistance of C. albicans was also high with a growth level of $0.13{\sim}1.28\;\log_{10}\;CFU$/mL after 14 days and reduction to $1.51{\sim}5.30\;\log_{10}\;CFU$/mL after 28 days. The antimicrobial effect of F10 was strongest for P. membranaefaciens. Every treatment reduced the microbial levels to $2.68{\sim}5.62\;\log_{10}\;CFU$/mL after 6 months. F2, F4, F5, F6, and F10 reduced the C. albicans level to ND after 28 days while F1, F3, F8, and F9 reduced yeasts to the ND level after 6 months. The antimicrobial activities observed here will be useful for development of natural antimicrobials.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.12
• /
• pp.1226-1231
• /
• 2008

A design of attitude controller for a tiltrotor is presented augmenting L1 adaptive control, neural networks, and feedback linearization. The neural networks compensate for the modeling error caused by the lack of knowledge of tiltrotor dynamics while the L1 adaptive control allows high adaptation gains in adaptation laws thereby, satisfying tracking performance requirement. The efficacy of this control methodology is illustrated in high-fidelity nonlinear simulation of a tiltrotor by flying the tiltrotor in different flight modes from where the L1 adaptive controller with neural networks is originally designed for.

• The Journal of the Korean Society for Microbiology
• /
• v.13 no.1
• /
• pp.75-79
• /
• 1978

There has been many investigations on phytoagglutinin and especially, Moon et al reported a number of research works on phytoagglutinins prepared from the Korean plants. The present report describes results of experiment on the biological effect of 14 Korean phytoagglutinins to microorganism for the first time. 1) Kaolin rubi and Ricinus communis L. among 14 different species of Korean phytoagglutinins had agglutinating activities to microoganisms. 2) Kaolin rubi agglutinated E. coli, Staph. aureus, Ps. aeruginosa, Prot. vulgaris, B. subtilis, Sal. typhi, Sh. dysenteriae, C. albicans and Sa. cerevisiae but Ricinus communis L. showed only agglutination of Sa. cerevisiae. 3) Agglutinating titers of Kaolin rubi to various microorganisms were 500-1,000 but titer of Ricinus communis L. was only 50. 4) Ricinus communis L. showed bactericidal action to Sa. cerevisiae but Kaolin rubi had no such effect.

• Biomolecules & Therapeutics
• /
• v.2 no.2
• /
• pp.131-135
• /
• 1994

The effect of ginsenoside (GS) from Panax ginseng on basal and nitro-L-arginine suppressed nitric oxide (NO) production was studied in rat kidney. NO production was determined by conversion to [$^{14C}$]=L-citrulline from [$^{14C}$]-L-arginine both in whole kidney and three renal segments; glomerulus, cortex excluding glomerulus (cortex-) and medulla. Nitro-L-arginine (total dose of 30 mg/kg/3 days, i.p.) significantly reduced NO production in whole kidney, which was prevented by GS pretreatment (30 mg/kg/3 days, i.p.). Relative high dose of GS (120 mg/kg/4 days, i.p..) selectively increased NO production in glomerulus and cortex-. Protein content, on wet weight basis, in cortex- and glomerular DNA content were significantly reduced by GS. Our results confirm the existence of constitutive nitric oxide synthase in kidney and it seems that target nephron segment for volume expansion due to GS'NO-mediated vasodilation and for NO production stimulated by GS is cortex including glomerulus.lus.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.6
• /
• pp.682-686
• /
• 1993

The syntheses and reactivities with olefins of $[Ru^{II}(L_3)(L_2)OH_2]^{2+}$ $[L_3$= 2,6-bis(N-pyrazolyl)pyridine(bpp), 2,6-bis(3,5-dimethyl-N-pyrazolyl)pyridine $(Me_4bpp);\;L_2$= 2,2'-bipyridine(bpy), 4,4'-dimethyl-2,2'-bipyridine $(Me_2bpy)$] are described. Their spectral and redox properties in aqueous solution were investigated. Evidence for each one electron redox process for the $Ru^{IV}-Ru^{III}$ and $Ru^{III}-Ru^{II}$ couples has been obtained. Oxidation of $[Ru^{II}(bpp)(bpy)OH_2]^{2+}$ with $Ce^{IV}$ gave $[Ru^{IV}(bpp)(bpy)O]^{2+}$. The $[Ru^{IV}$= 0 complex is paramagnetic $({\mu}_{eff}=2.82)$ and the complexes $[Ru(L_3)(L_2)OH_2]^{2+}$ are robust catalysts for the oxidation of styrene, cyclohexene, and cyclooctene with cooxidant such as NaOCl. Product distributions and selectivities are discussed by varying the number of the substituted-methyl group in the ring.

• Phonetics and Speech Sciences
• /
• v.14 no.1
• /
• pp.29-36
• /
• 2022

The English word-final /rl/ cluster poses a particular problem for Korean learners of English because it is the sequence of two sounds, /r/ and /l/, which are not contrastive in Korean. This study compared the similarity distances between English and Korean speakers' /rl/ productions using the dynamic time warping (DTW) algorithm. The words with /rl/ (pearl, world) and without /rl/ (bird, word) were recorded by four English speakers and four Korean speakers, and compared pairwise. The F2-F1 trajectories, the acoustic correlate of velarized /l/, and F3 trajectories, the acoustic correlate of /r/, were examined. Formant analysis showed that English speakers lowered F2-F1 values toward the end of a word, unlike Korean speakers, suggesting the absence of /l/ in Korean speakers. In contrast, there was no significant difference in F3 values. Mixed-effects regression analyses of the DTW distances revealed that Korean speakers produced /r/ similarly to English speakers but failed to produce the velarized /l/ in /rl/ clusters.

• Journal of Environmental Science International
• /
• v.21 no.1
• /
• pp.83-88
• /
• 2012

This study was divided to three experiments for evaluating the effects of pre- or post-load 1-MCP on quality of 'Fuji' apples exposed to ethylene. The first experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between the control and 1-MCP-treated fruits followed storage of 130, 150, and 170 days. 1-MCP-treated fruits maintained higher fruit titratable acidity and firmness than those of control fruits. The second experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between fruits applied with pre-loaded-1-MCP on ethylene treatments (10 ${\mu}L/L$, 20 ${\mu}L/L$, and 40 ${\mu}L/L$) and control fruits. 1-MCP-treated fruits were not affected by ethylene concentrations, and had higher fruit weight and firmness than those of control. The third experiment was compared for fruit quality at room temperature at 7, 14, 21, and 28 days between fruits applied with pre-loading with ethylene (10 ${\mu}L/L$) followed by ventilation (8 h, or 32 h, or 56 h) and 1.0 ${\mu}L/L$ 1-MCP treatment. As observed above experiments, 1-MCP-treated fruits had higher fruit weight and firmness than those of control fruits, regardless of the delayed applications of 1-MCP.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.04a
• /
• pp.79-79
• /
• 2019

홍띠(Imperata cylindrica 'Rubra') 식물자원의 기내대량증식과 재분화식물체의 순화체계를 구축하고자 기내 재분화에 적합한 식물재료부위, 생장조절물질을 조사하고, 재분화 유식물체로부터 적정 순화조건을 구명하였다. 기본배지로 MS (Murashige and Skoog, 1962) 배지를 사용하였고, 배양은 $26{\times}2^{\circ}C$, $25{\mu}mol/m^2/s$, 14h/10h (day/night) 광조건 하의 배양실에서 수행하였다. 캘러스 형성은 뿌리 끝, 줄기절편, 생장점 부위 중생장점 부위에서 가장 양호하였고, 이 생장점 조직에 0.1 mg/L의 2,4-D와 2 mg/L의 BA를 처리하였을 때 양호하였다. 캘러스 증식은 0.1 mg/L의 2,4-D와 0.05 mg/L의 BA 배지, 0.05 mg/L의 2,4-D와 0.5 mg/L의 BA를 첨가한 배지 중 0.1 mg/L의 2,4-D와 0.05 mg/L의 BA 배지에서 양호하였고, 이들 캘러스로부터 신초 재분화는 0.01 mg/L의 NAA와 2 mg/L의 BA 처리에서 양호하였다. 초기 치상으로부터 실제 경과시간은 캘러스 유도에 19주간(2018. 03. 18~07. 27), 캘러스 증식 9주간(2018. 07. 27~09. 28), 신초 유도 11주간(2018. 09.28~12. 14), 순화에 10주간(2018. 12. 14~2019. 02. 23)에 걸쳐 진행하였으나 확립된 배양계를 적용하면 캘러스 유도 4주, 캘러스 증식 3주, 신초유도 및 증식 ４주, 순화 ７주 정도가 소요될 것으로 계측되었다. 순화는 다경줄기 형성후 MS배지를 멸균한 상토(버미큘라이트) 또는 종이포트로 교체하여 재분화식물체를 배양병에서 7주간 배양하고, 7주후에 배양병 뚜껑을 1/10 정도 1차 개방하여 1주일 후 3/10 정도 개방하여 2주간 경과한 후 컵포트(직경 6 cm)에 이식하여 성공적으로 활착시켰다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.32 no.3
• /
• pp.200-208
• /
• 2006

Amino acids are required for protein synthesis and energy sources in all living cells. The amino acid transport system L is a major nutrient transport system that is responsible for $Na^+$-independent transport of neutral amino acids including several essential amino acids. In malignant tumors, the L-type amino acid transporter 1 (LAT1), the first isoform of system L, is highly expressed to support tumor cell growth. In the present study, the expression and functional characterization of amino acid transport system L were, therefore, investigated in Saos2 human osteogenic sarcoma cells. RT-PCR and western blot analyses have revealed that the Saos2 cells expressed the LAT1 and the L-type amino acid transporter 2 (LAT2), the second isoform of system L, together with their associating protein heavy chain of 4F2 antigen (4F2hc) in the plasma membrane, but the expression of LAT2 was very weak. The uptakes of [${14}^C$]L-leucine by Saos2 cells were $Na^+$-independent and were completely inhibited by the system L selective inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH). The affinity of [${14}^C$]L-leucine uptake and the inhibition profiles of [${14}^C$]L-leucine uptake by various amino acids in the Saos2 cells were comparable with those for the LAT1 expressed in Xenopus oocytes. The majority of [${14}^C$]L-leucine uptake is, therefore, mediated by LAT1 in the Saos2 cells. These results suggest that the transports of neutral amino acids including several essential amino acids into Saos2 human osteogenic sarcoma cells are for the most part mediated by LAT1. Therefore, the Saos2 human osteogenic sarcoma cells are excellent tools for examine the properties of LAT1. Moreover, the specific inhibition of LAT1 in tumor cells might be a new rationale for anti-tumor therapy.

• KSBB Journal
• /
• v.13 no.3
• /
• pp.231-237
• /
• 1998

An attenuated Japanese encephalitis virus (JEV) clone SA-14-14-2(Vero) was obtained through successive adaptation of a primary cell adapted strain, SA-14-14-2(PDK) to Vero cell, a continuous line of monkey kidney cells. The virus titer reached above the 107 plaque forming unit (pfu) per mL of culture supernatant with 3 passages in Vero cells and was maintained close to this level in the further passages. The optimum temperature for the virus growth was $35^{\circ}C$. Growth pattern of the virus indicated that optimum time for the virus harvest is 4 days post infection and the virus accomplished rapid initial propagation even in medium containing no serum supplement. The roller bottle (RB) system and the spinner flask (SF) system using micro-carrier (Cytodex-1) for the JEV cultivation were explored. When RB, SF, and T-flask culture system were compared, there was no significant difference in virus yield. Furthermore, the results indicated that virus could be harvested multiple times from 3 days to 9 days post infection; neither severe cytopathic effect (CPE) in the infected cells nor the decrease in the titer was observed on duration of 9 days.