• Computers and Concrete
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• v.20 no.1
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• pp.77-84
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• 2017

Shirasu, a pyroclastic flow deposit, showed considerable performance as aluminosilicate source in geopolymer, based on past research. However, the polymerization reactivity was somewhat lower compared to the traditional fly ash based geopolymer even though the long-term strength was fairly good. The present study concentrates on the development of higher initial strength performance of Shirasu based geopolymer by utilizing ground granulated blast furnace slag as an admixture. Mortars with various mix proportions were adopted to study the effect of parametric changes on strength development along with the addition of slag in different percentages. A combination of sodium hydroxide and sodium silicate was used as alkaline activators considering parameters like molar ratios of alkali to geopolymer water and silica to alkali molar ratio. The mortars were cured at elevated temperatures under different curing conditions to analyze the effect on strength development. Compressive strength test, mercury intrusion porosimetry and X-ray powder diffraction were carried out to assess the strength performance and microstructure of slag-Shirasu based geopolymer. Based on the experimental study, it was observed that the initial and long-term strength development of Slag-Shirasu geopolymer were improved by the addition of slag.

• Microbiology and Biotechnology Letters
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• v.32 no.2
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• pp.190-194
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• 2004

The gene product of dctD (DctD) activates transcription from the dctA promoter regulatory region by the $\sigma^{54}$ -holoenzyme form ofRNA polymerase ($E\sigma^{54}$ ) in Rhizobium meliloti and R. leguminosarum. The Escherichia coli integration host factor (IHF) stimulated DctD-mediated activation from the dctA promoter regulatory region of R. leguminosarum but not R. meliloti. In the absence of UAS, IHF inhibited DctD-mediated activation from both of these promoter regulatory regions. IHF also inhibited activation from R. leguminosarum dctA by nitrogen regulatory protein C (NtrC), another activator of $E\sigma^{54}$ but not by one which lacks a specific binding site in this promoter regulatory region. IHF, however, stimulated NtrC-mediated activation from the R. meliloti dctA promoter. Upon removal of the UAS, IHF inhibited NtrC-mediated transcription activation from the R. meliloti dctA promoter regulatory region. These data suggest that IHF likely faciliates productive contacts between the activators NtrC or DctD and $E\sigma^{54}$ to stimulate activation from dctA promoter.

• Biomedical Science Letters
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• v.18 no.4
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• pp.438-444
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• 2012

N-acylethanolamines (NAEs) including endocannabinoids, anadamide, are long chain fatty acid ethanolamines and express ubiquitously in animal and plant tissues. NAEs have several pharmacological effects including anti-inflammatory, analgesic and anorexic effects. The levels of NAEs in tissues are strictly regulated by synthesizing and hydrolyzing enzymes because NAEs are not stored in the cell but rather made on demand. NAEs are hydrolyzed to free fatty acids and ethanolamines by fatty acid amide hydrolase and N-acylethanolamine-hydrolyzing acid amidase (NAAA). Here, we suggest the fluorescence-based assay system for NAAA. We developed N-(4-methy-2-oxo-2H-chromen-7-yl)palmitamide (PAAC) as a fluorogenic substrate for NAAA and we also generated NAAA stably expressing COSM6 cell line. When extracts of cells expressing NAAA were incubated with PAAC, NAAA specifically hydrolyzed PAAC to palmitic acids and fluorogenic dye, coumarin. Release of coumarin was monitored by using fluorometer. NAAA hydrolyzed PAAC with an apparent Km of $20.05{\mu}M$ and Vmax of 32.18 pmol/mg protein/min. This assay system can be used to develop inhibitors or activators of NAAA.

• BMB Reports
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• v.46 no.12
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• pp.567-574
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• 2013

Liver plays a major role in maintaining glucose homeostasis in mammals. Under fasting conditions, hepatic glucose production is critical as a source of fuel to maintain the basic functions in other tissues, including skeletal muscle, red blood cells, and the brain. Fasting hormones glucagon and cortisol play major roles during the process, in part by activating the transcription of key enzyme genes in the gluconeogenesis such as phosphoenol pyruvate carboxykinase (PEPCK) and glucose 6 phosphatase catalytic subunit (G6Pase). Conversely, gluconeogenic transcription is repressed by pancreatic insulin under feeding conditions, which effectively inhibits transcriptional activator complexes by either promoting post-translational modifications or activating transcriptional inhibitors in the liver, resulting in the reduction of hepatic glucose output. The transcriptional regulatory machineries have been highlighted as targets for type 2 diabetes drugs to control glycemia, so understanding of the complex regulatory mechanisms for transcription circuits for hepatic gluconeogenesis is critical in the potential development of therapeutic tools for the treatment of this disease. In this review, the current understanding regarding the roles of two key transcriptional activators, CREB and FoxO1, in the regulation of hepatic gluconeogenic program is discussed.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.27-30
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• 2002

Ralstonia eutrupha JMP134 is a well-known soil bacterium which can metabolite diverse aromatic compounds and xenobiotics, such as phenol, 2,4-dichlorophenoxy acetic acid (2, 4-D), and trichloroethylene (TCE), etc. Phenol is degraded through chromosomally encoded phenol degradation pathway. Phenol is first metabolized into catechol by a multicomponent phenol hydroxylase, which is further metabolized to TCA cycle intermediates via a meta-cleavage pathway. The nucleotide sequences of the genes for the phenol hydroxylase have previously been determined, and found to composed of eight genes phlKLMNOPRX in an operon structure. The phlR, whose gene product is a NtrC-like transcriptional activator, was found to be located at the internal region of the structural genes, which is not the case in most bacteria where the regulatory genes lie near the structural genes. In addition to this regulatory gene, we found other regulatory genes, the phlA and phlR2, downstream of the phlX. These genes were found to be overlapped and hence likely to be co-transcribed. The protein similarity analysis has revealed that the PhlA belongs to the GntR family, which are known to be negative regulators, whereas the PhlR2 shares high homology with the NtrC-type family of transcriptional activators like the PhlR. Disruption of the phlA by insertional mutation has led to the constitutive expression of the activity of phenol hydroxylase in JMP134, indicating that PhlA is a negative regulator. Possible regulatory mechanisms of phenol metabolism in R. eutropha JMP134 has been discussed.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.766-770
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• 2013

Several upstream activators required for proper activation of brlA are involved in the development, vegetative growth, toxin production, and pathogenesis of Aspergillus fumigatus. In this study, we characterized the roles of two upstream developmental regulators, A. fumigatus flbB (AfuflbB) and flbE (AfuflbE), in toxin production and virulence. The deletion of AfuflbB and AfuflbE resulted in reduction of the expression of AfulaeA. Moreover, only about 8% to 10% of fumagillin was produced in the two mutants compared with that of wild type, and ${\Delta}AfuflbB$ strain produced 85% of gliotoxin compared with wild type, whereas none was produced by ${\Delta}AfuflbB$. Flow-cytometric analysis revealed decreased necrotic and apoptotic polymorphonuclear leukocytes cell death after exposure to supernatants from ${\Delta}AfuflbB$ and ${\Delta}AfuflbB$ strains compared with the wild type. These results indicate that FlbB and FlbE are necessary for the proper laeA expression, toxin production, and virulence of A. fumigatus.

• The Korean Journal of Pharmacology
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• v.5 no.2
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• pp.115-119
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• 1969

The authors studied the adrenotropic receptors of isolated urinary bladder from Sebastes inermis, using adrenergic activators such as epinephrine, nor-epinephrine, isoproterenol and phenylephrine and adrenergic blocking agents such as phenoxybenzamine, pronethalol and propranolol. The studies have revealed the following results. 1) The spontaneous motility of isolated bladder from Sebastes inermis was inhibited by epinephrine nor-epinephrine, isoproterenol and phenylephrine. 2) The inhibitory effect of phenylephrine on the Sebastes inermis bladder was blocked by phenoxybensamine. 3) The inhibitory effect of isoproterenol was blocked by pronethalol and propranolol. 4) The effect of epinephrine and nor-epinephrine on the Sebastes inermis bladder was usually not blocked by either kind of blocking agent alone, but was blocked by a combination of ${\alpha}\;and\;{\beta}$ blockades. 5) It is, therefore, concluded that the Sebastes inermis bladder has alpha and that both receptors, and that both receptors subserve retaxation or inhibition.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.88-89
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• 2000

The properties for self-frequency doubling (SFD) is unique phenomena for a small number of special single crystals. It is known that there are serious limitations to vary the concentration of active ions, for example high doping of active ions from 1 to 50 atomic %, in nonlinear materials. Until now, the Nd:YAl$_3$(BO$_3$)$_4$ (YAB) and Nd:(Ce,Gd)Sc$_3$(BO$_3$)$_4$ (CSB) crystals with high doping rates are well studied for the application of SFD purpose. They have much useful SFD properties, but also have big problems in crystal growth. In case of YAB crystal, it can be grown by solution melt method with very low growth rates and easy occurrence of inclusions. In case of CSB crystal, it has optically heterogeneity problems because of disarrangement of ions in huntite structure [1]. These problems make above crystals not so attractive for optical applications. Some popular nonlinear materials, such as LiNbO$_3$(LN), KTiOPO$_4$(KTP), LiB$_3$O$_{5}$ (LBO) crystals, are impossible to substitute by Rare Earth activators because of their crystallo-chemical problems of structure. When we dope active ions with the requisite concentrations for laser generation, it results in decreasing of optical quality of crystals or destroying of acentrosymmetric structure. (omitted)d)

• Natural Product Sciences
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• v.23 no.1
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• pp.1-4
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• 2017

Sinensetin, a pentamethoxyflavone, is known to exert various pharmacological activities including anti-angiogenesis, anti-diabetic and anti-inflammatory activities. However, its effects on the human mast cell - 1 (HMC-1) mediated inflammatory mechanism remain unknown. To explore the mediator and cellular inflammatory response of sinensetin, we examined its influence on phorbol 12-myristate 13-acetate (PMA) plus A23187 induced inflammatory mediator production in a human mast cell line. In this study, interleukin (IL)-6 production was measured using the enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction. Sinensetin inhibited PMA plus A23187 induced IL-6 production in a dose-dependent manner as well as IL-4, IL-5 and IL-8 mRNA expression. Furthermore, sinensetin inhibited signal transducer and activator of transcription 3 (STAT3) phosphorylation, suggesting that sinensetin inhibits the production of inflammatory mediators by blocking STAT3 phosphorylation. Moreover, sinensetin was found to inhibit nuclear factor kappa B activation. These findings suggest that sinensetin may be involved in the regulation of mast cell-mediated inflammatory responses.

• Natural Product Sciences
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• v.23 no.1
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• pp.21-28
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• 2017

In our program to search for new AMP-activated protein kinase (AMPK) activators from plants that exert potential anticancer property, we found that an EtOAc extract of Myristica fragrans (nutmeg) activated AMPK enzyme in human breast cancer MCF-7 cells. Two major diarylbutane-type lignans, macelignan and meso-dihydroguaiaretic acid (MDGA), were isolated as active principles from this extract. Treatment of breast cancer cells with two compounds induced cellular apoptosis, evidenced by cleavage of poly-(ADP-ribose) polymerase (PARP) and Ser 15 phosphorylation of p53. Moreover, macelignan and MDGA significantly inhibited the colony formation of MCF-7 breast cancer cells on soft agar. Intraperitoneal injection of macelignan and MDGA (20 mg/kg) suppressed the tumor growth of 4T1 mammary cancer cells. These results indicate that the chemopreventive effects of two major diarylbutane-type lignans from Myristica fragrans (nutmeg) may be associated with induction of apoptosis presumably through AMPK activation.