• Title/Summary/Keyword: Activators

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The Influence of Al2O3 on the Properties of Alkali-Activated Slag Cement (알칼리 활성화 슬래그 시멘트의 특성에 미치는 Al2O3의 영향)

  • Kim, Tae-Wan;Kang, Choong-Hyun
    • Journal of the Korea Concrete Institute
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    • v.28 no.2
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    • pp.205-212
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    • 2016
  • This research investigates the influence of ground granulated blast furnace slag (GGBFS) composition on the alkali-activated slag cement (AASC). Aluminum oxide ($Al_2O_3$) was added to GGBFS binder between 2% and 16% by weight. The alkaline activators KOH (potassium hydroxide) was used and the water to binder ratio of 0.50. The strength development results indicate that increasing the amount of $Al_2O_3$ enhanced hydration. The 2M KOH + 16% $Al_2O_3$ and 4M KOH + 16% $Al_2O_3$ specimens had the highest strength, with an average of 30.8 MPa and 45.2 MPa, after curing for 28days. The strength at 28days of 2M KOH + 16% $Al_2O_3$ was 46% higher than that of 2M KOH (without $Al_2O_3$). Also, the strength at 28days of 4M KOH + 16% $Al_2O_3$ was 44% higher than that of 4M KOH (without $Al_2O_3$). Increase the $Al_2O_3$ contents of the binder results in the strength development at all curing ages. The incorporation of AASC tended to increases the ultrasonic pulse velocity (UPV) due to the similar effects of strength, but increasing the amount of $Al_2O_3$ adversely decreases the water absorption and porosity. Higher addition of $Al_2O_3$ in the specimens increases the Al/Ca and Al/Si in the hydrated products. SEM and EDX analyses show that the formation of much denser microstructures with $Al_2O_3$ addition.

Hydration and Insulation Characteristics of a Ground Granulated Blast Furnace Slag Based Non-Sintered Cement Using Circulating Fluidized Bed Combustion Ash as a Activator (순환유동층 애시를 자극제로 사용한 고로슬래그 미분말 기반 비소성 시멘트의 수화 및 단열 특성)

  • Lee, Seung-Heun;Lee, Gang-Hyuk;Yoo, Dong-Woo;Ha, Ju-Hyung;Cho, Yun-Gu
    • Journal of the Korea Concrete Institute
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    • v.27 no.3
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    • pp.245-252
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    • 2015
  • As people have more interest in environment-friendly structures recently, many researchers are actively researching non-sintered cement in Korea and other countries. Non-sintered cement shows various characteristics of its reaction products and hardeners, depending on the kind of alkali activators. Thus, this study manufactures ground granulated blast furnace slag based non-sintered cement binder by using circulating fluidized bed combustion ash, which is a kind of industrial byproduct, as a stimulant, and investigated its hardening characteristics and hydration, depending on the rate of circulating fluidized bed combustion ash. Besides, this study investigated its insulation property according to the weight lightening of non-sintered cement. As a result, ettringite and C-S-H were mainly formed in the hydration, and it was possible to manufacture a non-sintered cement hardener over 50 MPa. Lastly, it was possible to manufacture a non-sintered cement hardener in a thermal conductivity level of $0.127W/m{\cdot}K$ when the compressive strength was 10 MPa for weight lightening.

Flavonoid Luteolin Inhibits LPS-induced Type I Interferon in Primary Macrophages (플라보노이드 루테올린의 lippopolysacharide로 유도한 type 1 interferon 억제 효과)

  • Jung, Won-Seok;Bae, Gi-Sang;Cho, Chang-Re;Park, Kyoung-Chel;Koo, Bon-Soon;Kim, Min-Sun;Ham, Kyung-Wan;Jo, Beom-Yeon;Cho, Gil-Hwan;Seo, Sang-Wan;Lee, Si-Woo;Song, Ho-Joon;Park, Sung-Joo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.5
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    • pp.986-992
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    • 2009
  • Type I interferons (IFNs) are critical mediators of the innate immune system to defend viral infection. Interferon regulatory factor (IRF) and signal transducer and activator of transcription (STAT) play critical roles in type I IFN production in response to viral infection. Luteolin is natural polyphenolic compounds that have anti-inflammatory, cytoprotective and anti-carcinogenic effects. However, the mechanism of action and impact of luteolin on innate immunity is still unknown. In this study, we examined the effects of luteolin on the lipopolysacchride (LPS)-induced inflammatory responses. Luteolin inhibited Type I IFNs expression of mRNA and increased interleukin(IL)-10 expression of mRNA. Next, we examined the protective effects of IL-10 using IL-10 neutralizing antibody (IL-10NA). Blockade of IL-10 action didn't cause a significant reduction of Type I IFNs than LPS-induced luteolin pretreatment. Pretreatment of luteolin inhibited the level of IRF-1, and IRF-7 mRNA and the nuclear translocation of IRF-3. Also, luteolin reduced the activation of STAT - 1, 3. Theses results suggest that luteolin inhibits LPS-induced the production of Type I IFNS by both IRFs and STATs not IL-10 and may be a beneficial drug for the treatment of inflammatory disease.

Fabrication of lightweight geopolymer based on the IGCC slag (IGCC 용융 슬래그를 이용한 경량 지오폴리머 제조)

  • Park, Soo-bin;Kim, Kang-duk;Kang, Seung-gu
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.27 no.6
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    • pp.319-326
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    • 2017
  • In this study, a lightweight geopolymer was prepared using by slag discharged from IGCC (Integrated Gasification Combined Cycle) power plant and its physical properties, the density and compressive strength, were analyzed as a function of the concentration of alkali activators, W/S ratio and aging times. Also the possibility of applying it to lightweight materials by adding Si sludge as a foaming agent to the geopolymerg was investigated. In particular, a complex composition of alkali activator and a pre-curing process were applied to improve the strength properties of lightweight geopolymers. While the compressive strength of the lightweight geopolymer using a single activator was 9.5 MPa, the specimen made with a complex composition of alkali activator had compressive strength of 2~5 times higher. In addition, the lightweight geopolymer with pre-curing process showed a compressive strength value of 18~48 % higher than that of specimen made with no precuring process. In this study, by using a complex activator and a pre-curing process. the maximum compressive strength of lightweight geopolymer was obtained as 40 MPa (The specimen was aged for 3 days and had density of $1.83g/cm^3$), which is comparable to cement concrete. By analyzing the crystal phase and microstructure of geopolymers obtained in this study using by XRD and SEM, respectively, it was confirmed that the flower-bud-like zeolite crystal was homogeneously distributed on the surface of the C-S-H gel (sodium silicate hydrate gel) in the geopolymer.

Association Study of Single-Nucleotide Polymorphisms of STAT2/STAT3/IFN-γ Genes in Cervical Cancer in Southern Chinese Han Women

  • Yuan, Yuan;Fan, Jie-Lin;Yao, Fang-Ling;Wang, Kang-Tao;Yu, Ying;Carlson, Jennifer;Li, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3117-3120
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    • 2015
  • Objective: Interferon-${\gamma}$ (IFN-${\gamma}$) and signal transducers and activators of transcription (STATs) each play an important role in carcinogenesis associated with viral infection. Cervical cancer is almost invariably associated with infection by human papillomavirus (HPV), and previous studies suggested that dysregulation of the signal pathway involved in IFN-${\gamma}$ and STATs is associated. Our objective was to evaluate the association of SNPs in STAT2, STAT3, and IFN-${\gamma}$ with cervical cancer susceptibility in Chinese Han women in Hunan province. Materials and Methods: Genomic DNA was extracted from peripheral blood samples of 234 cervical cancer patients and 216 healthy female controls. STAT2 and STAT3 genotyping was performed using polymerase chain reaction-restriction enzyme (PCR-RE) analysis. IFN-${\gamma}$ genotyping was detected by PCR-amplification of specific allele (PASA). Results: For STAT2 rs2066807 polymorphisms, there was no significant difference of genotype distribution (P=0.827) and allele frequencies (P=0.830, OR=1.09, 95% CI: 0.51-2.31) between cases and controls. For STAT3 rs957970 polymorphisms, there was no significant difference of genotype distribution (P=0.455) and allele frequencies (P=0.560, OR=0.92, 95% CI: 0.71-1.20) between cases and controls. For IFN-${\gamma}$ +874A/T polymorphisms, there was no significant difference of genotype distribution (P=0.652) and allele frequencies (P=0.527, OR=1.12, 95% CI: 0.79-1.59) between cases and controls. Conclusion: These results suggest that polymorphisms in STAT2, STAT3 and IFN-${\gamma}$ genes are not likely to be strong predictors of cervical cancer in Han women in southern China.

Molecular biologic mechanism of obesity by GGEx18 (경신강지환(輕身降脂丸)18의 분자생물학적인 비만조절 기전에 관한 연구)

  • Lee, Hee-Young;Yoon, Ki-Hyeon;Seo, Bu-Il;Park, Gyu-Ryeol;Yoon, Mi-Chung;Shen, Zhi-Bin;Cui, Hong-Hua;Shin, Soon-Shik
    • The Korea Journal of Herbology
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    • v.26 no.1
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    • pp.65-74
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    • 2011
  • Objectives : This study was undertaken to verify the modulation mechanism of Gyeongshingangjeehwan18 (GGEx18) in ob/ob male mice. Methods : Eight-week old mice (wild-type C57BL/6J and ob/ob) were used for all experiments. Wild-type C57BL/6J mice were used as lean control and obese ob/ob mice were randomly divided into 5 groups : obese control, GGEx15 (Ephedra sinica Stapf + Rheum palmatum L.), GGEx16 (Ephedra sinica Stapf + Laminaria japonica Aresch), GGEx17 (Rheum palmatum L. + Laminaria japonica Aresch), and GGEx18 (Ephedra sinica Stapf + Laminaria japonica Aresch + Rheum palmatum L.). After mice were treated with several kinds of GGEx for 11 weeks, the mRNA expression of peroxisome proliferator-activated receptor (PPAR) target genes and uncoupling protein (UCP) were measured. In addition, $PPAR{\alpha}$ and $PPAR{\beta}$ transactivation was examined in NMu2Li hepatocytes, C2C12 myocytes, and 3T3-L1 preadipocytes using transient transfection assays. Results : 1. Hepatic $PPAR{\alpha}$ target genes, such as ACOX and VLCAD mRNA levels were significantly increased by GGEx18 compared with obese controls. In skeletal muscle, LCAD mRNA expression was stimulated by GGEx16, GGEx17, and GGEx18, whereas MCAD mRNA expression by GGEx17 and GGEx18. $PPAR{\beta}$ target LPL mRNA levels were also increased by GGEx16, GGEx17, and GGEx18 in skeletal muscle, but adipose LPL mRNA levels were decreased. In addition, GGEx18 upregulated UCP mRNA expression in skeletal muslce. 2. $PPAR{\alpha}$ reporter gene expression was increased by GGEx18 in NMu2Li cells compared with vehicle. $PPAR{\alpha}$ and $PPAR{\beta}$ reporter activities were also increased by all GGEx treatments in C2C12 and 3T3-L1 cells. Conclusions : These results suggest that GGEx can act as $PPAR{\alpha}$ and $PPAR{\beta}$ activators, and that GGEx may regulate obesity by stimulating $PPAR{\alpha}$, $PPAR{\beta}$, and UCP activity. Of the 4 compositions, GGEx18 seems to be most effective in improving obesity and lipid disorders.

Characteristics of the alkaline protease from the moderate halophile, Halomonas sp. ES 10 (Halomonas sp. ES 10이 생산하는 alkaline protease의 특성)

  • Kim, Chan-Jo;Oh, Man-Jin;Choi, Seong-Hyun
    • Applied Biological Chemistry
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    • v.35 no.4
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    • pp.237-241
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    • 1992
  • The protease from Halomonas sp. ES 10 was purified by methanol precipitation, gel filtration on Sephadex G-150 and G-200, and ion exchange chromatography on DEAE-Sephadex A-50. The purified enzyme was found to be homogeneous by polyacrylamide gel electrophoresis. The specific activity of purified enzyme was 1,014 units/mg protein, and the yield of the total activity from the culture filtrate was 7%. The optimal temperature and pH for the enzyme activity were $35^{\circ}C$, and pH 11.0, respectively. And the enzyme was stable in the range of $pH\;7.5{\sim}11.0$. The residual activity of the enzyme was 70%, when the enzyme was incubated at $50^{\circ}C$ for 40 min. The Km value of the enzyme was 7.4 mg/ml to milk casein. $Li^+$, $Ca^{2+}$, SDS and Tween 80 were appeared to activators, whereas $Hg^{2+}$ and EDTA to inhibitors. The addition of DFP and PMSF showed the relative enzyme activities of 63% and 107%, respectively, suggesting that the enzyme may not belong to serine type protease. When the alkaline protease was treated with 0.5 M and 1 M NaCl, the relative enzyme activities were 95% and 65%, respectively. This enzyme showed 20% and 15% higher enzyme activity than that of Aspergillus oryzae (Sigma Chemical Company product, P4755) in the presence of 0.5 M and 1 M NaCl.

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Non-Adrenergic Non-Cholinergic Responses of Gu mea- Pig Tracheal Smooth Muscle (기니피그 기도 평활근의 비아드레날린성 비꼴린성 반응에 관한 연구)

  • Jo, Eun-Yong;Choe, Hyeong-Ho;Jeon, Je-Yeol
    • Journal of Chest Surgery
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    • v.29 no.5
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    • pp.487-494
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    • 1996
  • The neurogenic responses of tracheal smooth muscles to electrical field stimulation (EFS) is biphasic, consisting firstly of cholinergic contraction followed by a slow and sustained relaxation. It is well known that a sustained relaxation involves the inhibitory non-adrenergic non-cholinergic systems. This study was done to Investigate the relaxing agents and their action mechanisms by use of an organ bath with plati- ilum . The tracheal smooth muscle relaxation due to EFS was suppressed by L-NAME, the WO (Nitric Oxide) synthase inhibitor, and these effects were reversed by L-arginine, the precursor of NO. Also, L-WAME (HG-nitro-L-arginine methyl ester) increased the basal tension. Nitroprusside, the NO-donor, suppressed the tracheal basal tension greatly. Methylene blue, the inhibitor of guanylate cyclase, decreased EFS-induced relaxations and increa ed basal tension. Forskolin and isoprenaline, which are activators of adenylate cyclase, suppressed tracheal basal tension in the same way as nitroprusside. TEA (tetraethylammonium), the non-specific K'channel blocker, and apamin, the Ca"-activated K'channel blocker, increased tracheal basal tension and EFS-induced relaxations. Our results indicate that Pr3 Is released upon stimulation of the NANC (Won Adrenergic Won Cholinergic) nerves in guinea-pig tracheal smooth muscle and that the release of NO related with the K+ channel, as well as the release of other inhibitory agents< e. g.)VIP (Vasoactive Intestinal Polypeptide), PHI (Peptide Histidine Isoleusine) > mediated via CAMP (cyclic Adenosine Monophosphate) may be Involved In sustained relaxation.

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Properties of Non-Sintered Cement Pastes Immersed in Sea Waters at Different Temperatures for Binders Mixed with Different Ratios (침지된 해수 온도 및 결합재 혼합비에 따른 비소성 시멘트의 강도 특성)

  • Jun, Yubin;Kim, Tae-Wan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.5
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    • pp.75-84
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    • 2016
  • This paper presents an investigation of the mechanical properties on non-sintered cement pastes immersed in sea waters at three different temperatures. The non-sintered cement pastes were synthesized using blended binder(Class F fly ash; FA and ground granulated blast furnace slag; GGBFS) and alkali activator(sodium hydroxide and sodium silicate). Binders were prepared by mixing the FA and GGBFS in different blend weight ratios of 6:4, 7:3 and 8:2. The alkali activators were used 5wt% of blended binder, respectively. Calcium carbonate was used as an chemical additive. The compressive strength, bulk density and absorption of alkali-activated FA-GGBFS blends pastes were measured at 3 and 28 days after immersed in sea waters at three different temperatures($5^{\circ}C$, $15^{\circ}C$ and $25^{\circ}C$). The XRD and SEM tests of the pastes were conducted at 28 days. Water-soluble chloride(free chloride) and acid-soluble chloride(total chloride) contents in the pastes were also measured after 28 days immersion in sea water. The experimental results showed that increasing the content of FA in alkali-activated FA-GGBFS blends pastes immersed in sea water increases the absorption, water-soluble chloride content and acid-soluble chloride content, and reduces the compressive strength and bulk density. And it was found that there was a variation of strength change for the alkali-activated FA-GGBFS blends pastes immersed in sea waters at three different temperatures that depends on the blending ratio of FA and GGBFS.

Transcriptional Regulation of Genes by Enhancer RNAs (인핸서 RNA에 의한 유전자 전사 조절)

  • Kim, Yea Woon;Kim, AeRi
    • Journal of Life Science
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    • v.26 no.1
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    • pp.140-145
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    • 2016
  • Genes in multicellular organisms are transcribed in development, differentiation, or tissue-specific manners. The transcription of genes is activated by enhancers, which are transcription regulatory elements located at long distances from the genes. Recent studies have reported that noncoding RNAs are transcribed from active enhancers by RNA polymerase II (RNA Pol II); these are called enhancer RNAs (eRNAs). eRNAs are transcribed bi-directionally from the enhancer core, and are capped on the 5’ end but not spliced or polyadenylated on the 3’ end. The transcription of eRNAs requires the binding of transcription activators on the enhancer and associates positively with the transcription of the target gene. The transcriptional inhibition of eRNAs or the removal of eRNA transcripts results in the transcriptional repression of the coding gene. The transcriptional procedure of eRNAs causes enhancer- specific histone modifications, such as histone H3K4me1/2. eRNA transcripts directly interact with Mediator and Rad21, a cohesin subunit, generating a chromatin loop structure between the enhancer and the promoter of the target gene. The recruitment of RNA Pol II into the promoter and its elongation through the coding region are facilitated by eRNAs. Here, we will review the features of eRNAs, and discuss the mechanism of eRNA transcription and the roles of eRNAs in the transcriptional activation of target genes.