• Environmental Engineering Research
• /
• 제22권3호
• /
• pp.281-287
• /
• 2017

The joint effect of different concentrations (0.05-0.375 mmol/L) of $Cd^{2+}$ and various concentrations (50-400 mg/L) of [$C_3mim$][OAc] on the growth and physiology of wheat seedlings were investigated. The toxicity of $Cd^{2+}$ could be significantly reduced by lower concentrations (50-200 mg/L) of [$C_3mim$][OAc]. With higher concentration (${\geq}300mg/L$) of [$C_3mim$][OAc], the reduction became less, and compared to $Cd^{2+}$ stress only, the toxicity of 400 mg/L [$C_3mim$][OAc] increased. As for different $Cd^{2+}$ concentrations, the optimal reduction depends on the balance between the exact concentration of $Cd^{2+}$ and [$C_3mim$][OAc]: With low $Cd^{2+}$ concentration (0.05-0.250 mmol/L) requiring 50 mg/L [$C_3mim$][OAc], it could reach a dynamic equilibrium, while high $Cd^{2+}$ concentration (0.375 mmol/L) requiring 100 mg/L [$C_3mim$][OAc]. The growth and physiological indexes of wheat seedlings show a decrease in toxicity compared to the Cd alone treatment, when the dynamic equilibrium is reached. The concentration of $Cd^{2+}$ in leaf tissues showed that low concentration (50-200 mg/L) of [$C_3mim$][OAc] can reduce the toxicity of $Cd^{2+}$ (0.05-0.375 mmol/L) by decreasing the level of $Cd^{2+}$ concentration in the tissues, whereas the higher concentration (${\geq}300mg/L$) of [$C_3mim$][OAc] can increase the concentration of $Cd^{2+}$.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제7권2호
• /
• pp.151-154
• /
• 2003

The effect of photoperiodic regimes on the oviposition and colony development of Bombus ignitus queens was examined with 0L, 8L, and 16L under $27^{\circ}C$ and 65% R. H. Among these photoperiod regimes, the oviposition rate at 8L and 16L was 80.2% and 83.1%, respectively, which was 12-15% higher than that at the dark condition (0L). Duration up to first oviposition at 8L and 16L was 17.5 days and 16.5 days, respectively, which was 2-3 days shorter than that at 0L. The colony foundation rate at 8L and 16L was 9.2% and 10.4%, respectively, which corresponded to 1.7-2.0-fold higher than the value at 0L. In addition, the rate of progeny-queen production at 8L and 16L was also two fold higher than that at 0L. Taken these together, the light conditions (8L and 16L) rather than dark condition (0L) were more suitable for oviposition and colony development for B. ignitus in the indoor rearing condition.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2016년도 춘계학술대회
• /
• pp.450-452
• /
• 2016

2차원 TCAD 시뮬레이션을 이용하여 L-shaped 터널링 전계효과 트랜지스터(Tunnel Field-Effect Transistor; TFET)의 도핑농도에 따른 효과를 조사했다. 소스 도핑이 $10^{20}cm^{-3}$ 이상에서 subthreshold swing (SS)이 가장 낮고, 드레인 도핑농도는 $10^{18}cm^{-3}$이하로 하는 것이 음전압에 생기는 누설전류를 막을 수 있다.

• 말소리와 음성과학
• /
• 제16권2호
• /
• pp.11-17
• /
• 2024

The goal of the current study is to investigate whether L2 learners' perceptual ability regarding epenthetic vowels is interconnected with other aspects of speech recognition, such as lexical stress, sentence focus, and vowel recognition. Twenty-five Korean L2 learners of English participated in perception experiments assessing vowel epenthesis oddity, lexical stress oddity, sentence focus oddity, and vowel identification. Results indicate that accuracy on the vowel epenthesis oddity test is influenced by both lexical stress and sentence focus, suggesting that perceptual ability regarding epenthetic vowels is influenced by the acquisition of L2 rhythmic structure at both word and sentence levels. Additionally, this study identifies a proficiency effect on vowel epenthesis recognition, implying that the influence of L1 phonotactics diminishes as L2 proficiency increases. Taken together, this study illustrates the interaction between perceptual abilities in vowel epenthesis and prosodic stress in the field of L2 speech perception.

• 한국영어학회지:영어학
• /
• 제1권1호
• /
• pp.187-209
• /
• 2001

This study attempts to supplement what is known about the influence of prior knowledge on second language listening comprehension. To do so, the study examines the effect of prior knowledge and language proficiency on the ability of L2 listeners to understand texts. The purpose of an experiment was to determine the effect of topic familiarity on the L2 listening comprehension ability of subjects who varied in L2 listening proficiency level. The subjects (N=117) were selected from a population of college students enrolled in the Departments of English and Business in Korea. English listening proficiency levels were designated on the basis of TOEFL listening scores. Subjects listened twice each to texts (more familiar and less familiar). After listening to each text, a ten-item objective test was administered to test the subjects' comprehension of the information presented in the text. Objective tests were analyzed. using repeated measures analysis. A post hoc test was conducted to identify the means that were significantly different. This study yielded the following results: (1) subjects with high prior knowledge comprehended texts significantly better than did subjects with low prior knowledge; (2) the level of L2 listening proficiency had a significant effect on the L2 listening comprehension of texts, but there was no interaction between prior knowledge and the level of L2 listening proficiency.

• 대한통합의학회지
• /
• 제11권2호
• /
• pp.149-157
• /
• 2023

Purpose : In this study, to prove the antibacterial effect of Disocorea batatas, which is widely used for food, and to confirm the growth inhibitory effect, the antibacterial activity against L. gasseri, S. mutans, and P. gingivalis was verified. Based on this, it is intended to verify the utility as a preventive and therapeutic composition for dental caries and periodontal disease. Methods : RAW 264.7 cells were used to verify the cell survival rate and NO (Nitric Oxide) inhibitory effect on Disocorea batatas ethanol extract (DBEE). In order to verify the antibacterial effect against L. gasseri, S. mutans, and P. gingivalis, concentrations of 125, 250, and 500 ㎎/㎖ of DBEE were used and measured by the disk diffusion method. In order to confirm the growth inhibitory effect, the absorbance was measured at 600 ㎚ at 3, 6, 12, 18, and 24 hours using the liquid medium dilution method, and the growth inhibitory effect was measured compared to the control group. Results : The cell viability for DBEE was 91 % at 50 ㎎/㎖, and there was no cytotoxicity. The NO production inhibitory effect was shown from 10 ㎍/ml, and the higher the concentration, the greater the inhibitory effect. As for the antimicrobial effect using the disk diffusion method, the higher the concentration, the higher the antibacterial effect. At 125 ㎎/㎖ and 250 ㎎/㎖, S. mutans and L. gasseri showed high antimicrobial activity, and at 500 ㎎/㎖, the antibacterial effect was higher in L. gasseri. The growth inhibitory effect in DBEE was concentration-dependent as the higher the concentration, the higher the growth inhibitory effect, and all of them began to show growth inhibitory effects from 6 hours. Conclusion : Considering that it is widely used as an edible and medicinal material, Disocorea batatas has shown the potential to be used as a substance to prevent and alleviate dental caries and periodontal diseases, and it is believed that further research can be applied to oral health care products.

• 대한한방내과학회지
• /
• 제27권2호
• /
• pp.429-443
• /
• 2006

Objectives : The Purpose of this study was to identify anti-tumor effects of Curcuma longa L. on some kinds of cancer cells through molecular biologic methods. Materials & Methods : We used 4 kinds of cancer cell lines such as glioma cells(A172), cervical cancer cells(HeLa), Prostate cancer cells(PC3), lung cancer cells(A549). We injected the boiled extract of Curcuma longa L. $5{\mu}g,\;10{\mu}g$ to culture media(ml) for 24 hours. We measured the cytotoxic effect on 4 kinds of cancer cells through trypan blue exclusion test and the suppressive effect on viability of 4 kinds of cancer cells via MTT assay. We measured the change of mitochondria membrane potential via flow cytometry. The quantitative RT-PCR was used to examine the effect on the revelation of Bcl-2 and Bax which genes are related to apoptosis. We examined the effect on the revelation of Bcl-2 protein and Bax protein by western blot analysis. Results: 1. Extract of Curcuma longa L. showed significant cytotoxic effect on A172, HeLa, PC3 compared to the control group with density dependent manner. 2. Extract of Curcuma longs L. showed significant suppressive effect on viability of A172, HeLa, PC3 compared to the control group with density dependent manner. 3. Curcuma longs L. induced apoptosis by decreasing the membrane potential of mitochondria in A172, HeLa, PC3. 4. In the test about the revelation of genes related to apoptosis, the revelation of Bcl-2 decreased and the revelation of Bax increased in A172. HeLa, PC3 treated with Curcuma longa L. with density dependent manner. 5. In the test about the revelation of protein related to apoptosis, the protein levels of Bcl-2 decreased and the protein levels of Bax increased in A172, HeLa, PC3 treated with Curcuma longa L. Conclusions: This experiment shewed that Curcuma longs L. has anti-tumor effect on glioma, cervical, Prostate cancer cells except on lung cancer. We hope that anti-tumor effects of Curcuma longa L. will be more Practically identified.

• 한국식품영양과학회지
• /
• 제28권1호
• /
• pp.191-198
• /
• 1999

Fifteen varieties of Oryza sativa mainly including those of Korean native rice were exactly cutted into three layers such as L1 layer(the outer part of 92% from rice center), L2 layer(the part of 81∼91% from the rice center) and L3 layer(the inner part of 80% from the rice center) We biologically evaluated the antioxidative effect on the every layer(L1, L2 and L3) of all the varieties, by observing malondialdehyde (MDA) produced by galactosamine in the mouse. L1 layer of some varieties showed significant antiox idative effect, while L2 and L3 layer didn't show the activity. It was also suggested that coloured rice(Suwon 425 and Sanggaehangbyeolna) showed stronger activity than other general rices, probably due to high contents of anthocyanins. Successively, we evaluated antihepatotoxic effect, based on the determination of serum ALT and AST activity. Some varieties of only L1 layer, except for L2 and L3 layer, significantly decreased the serum ALT and AST activity. This finding indicate that oral diet of some raw rice are able to protect hepatotoxicities. Among all the samples tested, L1 layer of Suwon 425 showed the strongest antihepatotoxic effect. From quantitative analysis on ferulic acid derivatives, it was found that the more it enters from the surface into the rice center, the more those secondary metabolites contents were highly reduced. These findings above suggested that Suwon 425 could be a promising candidate for the development of health rice food.

• 한국임상수의학회지
• /
• 제17권2호
• /
• pp.305-314
• /
• 2000

Recombinant inteileukin-2 (IL-2) is a potent inductive stimulus for nitric oxide synthesis (NO.) and has been demonstrated as an antineoplastic agent in mice and human. But it is not let clear whether NO. can contribute to IL-2-induced therapeutic responses. Therefore, the current experiment was undertaken to clarify the effect of IL-2 on antitumor response against subcutaneous Meth-A tumor in mice. At the beginning of each experiment, normal BALB/c mice were injected subcuta-neously with $5{\times}10^6 Meth-A$ tumor cells. Some mice were implanted with osmotic minipumps con- taining 225 $\mu$l of 3.38 M $N^{\gamma}$ -monomethyl-L-arginine (MLA. an NOS inhibitor). Beginning on day 7, experimental groups were treated with a f-day course of IL-2 (50,000 lU,75,000 nJ,100,0007, 50,000 IU+MLA, 75,000 IU+MLA, 100,000 IU+MLA intraperitoneal injection every 12 hours for 5 days). The result of this experiment revealed that Meth-A tumor grew progressively in control mice. Intraperitoneal IL-2 treatment decreased tumor growth and prolonged survival. compared with con-trol mice. But no significant differences among 50.000 lU.75.000 lU and 100,000 lU of 7-2 treat-ment were observed. MLA administration prevented partially the decrease tumor growth and prolong survival of IL-2 treated mice compared with mice receiving IL-2 alone.

• Biomolecules & Therapeutics
• /
• 제4권4호
• /
• pp.428-436
• /
• 1996

The protective effect of Carthamus tinctorius L. Semen on the carbon tetrachloride induced liver damaged rats were studied. First, methanol extract was prepared and the extract was fractionated with hexane, $CHCl_3$, BuOH and $H_2O$ respectively. Animals were divided into 6 groups and each group was treated with each fraction respectively. To investigate the hepato-protective effect of Carthamus tinctorius L. Semen AST, ALT, albumin, TP, cholesterol, TG, creatinine and total bilirubin values were measured in each treated group and compared with those of control group. GST activity was increased in BuOH group compared with the control group. In malondialdehyde levels, all fractions was decreased compared with the control group. In histopathologic examination, hexane and $H_2O$ fractions of Carthamus tinctorius L. Semen observed mild degree of ballooning degeneration. The results show the protective effect of Hexane,$CHCl_3$, BuOH and $H_2O$ fractions on hepatotoxicity of $CHl_4$ by decreasing ALT, AST, bilirubin, cholesterol, TG and BUN. It seems that the decrease of MDA are related to the recovery effect. The protective effects of Carthamus tinctorius L. Semen fractions in hepatotoxic pathogenesis by $CHl_4$ was suggested in blood chemistry analysis and histopathologic examination.