• International Journal of Concrete Structures and Materials
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• v.18 no.1E
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• pp.17-22
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• 2006

Artificial cracks were made in the cover concrete of specimens embedding ten types of steel rebars of different Cr contents. The research aims for developing Cr-bearing steel rebars resistant to macrocell corrosion environments induced by cracking in cover concrete. The cracks were subjected to intensive penetration of carbon dioxide (carbonation specimens) to form macrocells. The carbonation specimens were then treated with accelerated corrosion curing, during which current macrocell corrosion density was measured. The corrosion area and loss from corrosion were also measured at the end of 105 cycles of this accelerated curing. The results of the study showed that Cr-bearing steel with Cr content of 5% or more suppressed corrosion in a macrocell corrosion environment induced by the differences in the pH values due to carbonation of cracked parts. Cr-bearing steels with Cr content of 7% or more are proven to possess excellent corrosion resistance.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.271-275
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• 2001

Phytoalexin scoparone (6,7-dimethoxycoumarin) was induced in flavedo tissue of lemon fruit inoculated with Penicillium digitatum during heat treatment for 3 days at $36^{\circ}$. The compound was also induced in the flavedo tissue after UV illuminatiion. Induction of scoparone was deteected in the flavedo tissue by histological analysis. This fluorescent scoparone accumulated only on the 4-5 layers of cells adjacent to the inoculation site. Preinoculation with P. digitatum and subsequent heat-treatment induced resistance in the lemon fruit tissues after challenge-inoculation at the site of the first infection. the data obtained in the study suggest that lemon fruit acquired resistance against P. digitatum parallel with the scoparone production at the infection site.

• Archives of Pharmacal Research
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• v.17 no.2
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• pp.93-99
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• 1994

Macrtophages play an important role in defense against virus infection by intrinsic resistance and by extrinsic resistance. Since interferon-induced enzymes which are 2'-5' oligoadenylate synthetase and p1/eIF-2 protein kinase have been shown to be involved in the inhibition of viral replication, I examined the mechanism by which poly I:C, an interferon inducer, exerts its antiviral effects in inflammatory macrophages infected with herpes simplex virus type 1 (HSV-1). The data presented here demonstrate that poly I:C-induced antiviral activity is partially due to the activation of 2'-5' pligoadenylate synthetase. The activation of 2'-5' oligoadenlate A synthetase by poly I:C is also at least mediated via the production of interferon-.betha.. Taken together, these data indicate that interferon-.betha. produced in response to poly I:C acts in an autocrine manner to activate the 2'-5' oligoadenylate synthetase and to induce resistance to HSV-1.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1308-1316
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• 2018

Accurate tuning of parameter is very important in vector-controlled induction motor. Among the parameters of induction motor, detuning of rotor resistance used in controller design deteriorates drive performance. This paper presents a novel rotor resistance estimation strategy using slip angular velocity in vector-controlled induction motor drives. The slip angular velocity can be calculated by two methods. Firstly, it can be induced from the rotor voltage equation. Secondly, it can be induced from the difference between synchronous angular velocity and rotor angular velocity. The first method includes the rotor resistance, while the second method dose not include this parameter. From this fact, the rotor resistance can be identified by comparing the slip angular velocities in the two methods. In the tuned states of the rotor resistance, performances of flux estimator and speed drive are discussed. The simulation and experimental results are given to verify the validity of the proposed method in various situations.

• Nutrition Research and Practice
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• v.16 no.1
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• pp.46-59
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• 2022

BACKGROUND/OBJECTIVES: Aster yomena (Kitam.) Honda (AY) has remarkable bioactivities, such as antioxidant, anti-inflammation, and anti-cancer activities. On the other hand, the effects of AY against obesity-induced insulin resistance have not been reported. Therefore, this study examined the potential of AY against obesity-associated insulin resistance in high-fat diet (HFD)-fed mice. MATERIALS/METHODS: An obesity model was established by feeding C57BL/6J mice a 60% HFD for 16 weeks. The C57BL6/When ethyl acetate fraction from AY (EFAY) at doses of 100 and 200 mg/kg/day was administered orally to mice fed a HFD for the last 4 weeks. Normal and control groups were administered water orally. The body weight and fasting blood glucose were measured every week. Dietary intake was measured every other day. After dissection, blood and tissues were collected from the mice. RESULTS: The administration of EFAY reduced body and organ weights significantly compared to HFD-fed control mice. The EFAY-administered groups also improved the serum lipid profile by decreasing the triglyceride, total cholesterol, and low-density lipoprotein compared to the control group. In addition, EFAY ameliorated the insulin resistance-related metabolic dysfunctions, including the fasting blood glucose and serum insulin level, compared to the HFD-fed control mice. The EFAY inhibited lipid synthesis and insulin resistance by down-regulation of hepatic fatty acid synthase and up-regulation of the AMP-activated protein kinase pathway. EFAY also reduced lipid peroxidation in the liver, indicating that EFAY protected hepatic injury induced by obesity. CONCLUSIONS: These results suggest that EFAY improved obesity-associated insulin resistance by regulating the lipid and glucose metabolism, suggesting that AY could be used as a functional food to prevent obesity and insulin resistance.

• The Journal of Internal Korean Medicine
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• v.35 no.2
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• pp.195-207
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• 2014

Objectives : The purpose of this study was to investigate how Rhei Radix et Rhizoma affects on insulin resistance and adipose tissue inflammatory response in high fat diet induced obese C57BL/6 mice. Methods : Obesity was induced in C57BL/6 mice by high fat diet for 12 weeks. Models were divided into 3 groups (n=6) of normal diet, high fat diet (HFD), and high fat diet with Rhei Radix et Rhizoma and investigated for 12 weeks. We measured body weight, FBS and oral glucose tolerance test (OGTT), serum insulin, homeostatic model assessment-insulin resistance (HOMA-IR), weight of liver and epididymal fat pad. Inflammatory markers such as adipose tissue macrophage (ATM), tumor necrosis factor-${\alpha}$ and interlukin-10 and CD68 of epididymal adipocyte were determined to evaluate the effect of Rhei Radix et Rhizoma on adipose tissue inflammation. Results : Compared with the HFD group, we observed loss of body weight and epididymal fat pad weight, improvement of glucose level and HOMA-IR, reduction of ATM and gene expression of TNF-${\alpha}$, CD68 in the high fat diet with Rhei Radix et Rhizoma group. Conclusions : This study suggests that Rhei Radix et Rhizoma has effects on insulin resistance and adipose tissue inflammatory response in high fat diet induced obese mice.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.99-103
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• 2016

In perennial ginseng plantations, the effective control of various diseases is one of the most critical factors for increasing yields. Enhancing the resistance to disease through induced systemic resistance (ISR) and anti-microbial activity of beneficial soil bacteria, is currently considered to be a potential promising approach to integrate pathogen management for sustainable agriculture. However, the effective in vitro culture systems for testing ISR in ginseng plants have been rarely reported. In this study, I have successfully developed an in vitro germ-free culture system of Panax ginseng seedling for diverse purposes. With this useful system, we also tested BTH-induced priming effects against Botrytis cinerea and Colletotrichum panacicola. Compared to the drain method for enhancing ISR effects to ginseng seedlings, the direct method of spraying leaves somewhat increased the defense activity to these major fungal pathogens. Consistently, the expression of pathogen related PgPR10 and PgCAT were greatly and rapidly enhanced in the BTH-treated ginseng seedlings by treatment with C. panacicola. Our results revealed that the in vitro culture system can be used for developing eco-friendly and versatile bio-control agents for harmful diseases in ginseng cultivation.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.305-316
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• 2013

Non-protein amino acid, ${\beta}$-amino-n-butyric acid (BABA), has been involved in diverse physiological processes including seedling growth, stress tolerance and disease resistance of many plant species. In the current study, treatment of kimchi cabbage seedlings with BABA significantly reduced primary root elongation and cotyledon development in a dose-dependent manner, which adverse effects were similar to the plant response to exogenous abscisic acid (ABA) application. BABA was synergistically contributing ABA-induced growth arrest during the early seedling development. Kimchi cabbage leaves were highly damaged and seedling growth was delayed by foliar spraying with high concentrations of BABA (10 to 20 mM). BABA played roles differentially in in vitro fungal conidial germination, mycelial growth and conidation of necrotroph Alternaria brassicicola causing black spot disease and hemibiotroph Colletotrichum higginsianum causing anthracnose. Pretreatment with BABA conferred induced resistance of the kimchi cabbage against challenges by the two different classes of fungal pathogens in a dose-dependent manner. These results suggest that BABA is involved in plant development, fungal development as well as induced fungal disease resistance of kimchi cabbage plant.

• The Plant Pathology Journal
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• v.36 no.2
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• pp.121-132
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• 2020

β-Aminobutyric acid (BABA) has consistently been reported to enhance plant immunity. However, the specific mechanisms and downstream components that mediate this resistance are not yet agreed upon. Nitric oxide (NO) is an important signal molecule involved in a diverse range of physiological processes, and whether NO is involved in BABA-induced resistance is interesting. In this study, treatment with BABA significantly increased NO accumulation and reduced the sensitivity to Botrytis cinerea in tomato plants. BABA treatment reduced physical signs of infection and increased both the transcription of key defense marker genes and the activity of defensive enzymes. Interestingly, compared to treatment with BABA alone, treatment with BABA plus cPTIO (NO specific scavenger) not only significantly reduced NO accumulation, but also increased disease incidence and lesion area. These results suggest that NO accumulation plays an important role in BABA-induced resistance against B. cinerea in tomato plants.

• Korean Journal of Biological Psychiatry
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• v.19 no.4
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• pp.187-192
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• 2012

Objectives Although antipsychotic drug clozapine has superior efficacy, this is hampered by metabolic side effects such as weight gain and diabetes. Recent studies demonstrate that clozapine induces insulin resistance. However, the identity and location of insulin resistance induced by clozapine has not been clarified. In this study, the effect of clozapine on central insulin response was investigated in rats. Methods Male Sprague-Dawley rats received intraperitoneal injection of clozapine or vehicle, which was followed by intracerebroventricular injection of insulin or its vehicle. The effects of clozapine on insulin-induced changes in blood glucose level and Akt phosphorylation in hypothalamus were investigated. Results Intraperitoneal injection of clozapine (20 mg/kg) increased blood glucose in rats. Intracerebroventricular injection of insulin reduced blood glucose in rats, which was blunted by pretreatment of clozapine. Accompanied with the antagonistic effect of clozapine to central insulin action in terms of blood glucose, clozapine inhibited the insulin-induced phosphorylation of Akt at Ser473 in rat hypothalamus. Conclusion Administration of clozapine inhibited the central insulin-induced changes in blood glucose and Akt phosphorylation in rat hypothalamus. These findings suggest that hypothalamus could be the site of action for the clozapine-induced insulin resistance.