• 한국건설순환자원학회논문집
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• 제7권4호
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• pp.302-309
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• 2019

본 논문은 5℃의 해수 환경에 노출한 알칼리 활성 플라이애시-슬래그 시멘트의 기본 특성에 관한 실험적 연구이다. 플라이애시와 슬래그의 배합비는 6:4, 7:3 및 8:2의 세 가지로 하였으며, 활성화제(수산화나트륨 및 규산나트륨)는 결합재 중량의 5%로 하였다. 실험 결과는 플라이애시의 치환율이 증가할수록 압축강도와 밀도는 감소하는 것으로 나타났으며, 또한 흡수율은 증가하는 것으로 나타났다. 경화된 샘플의 열중량 및 X선 회절분석을 통해 샘플 내에 생성된 반응물의 종류에는 변화가 없었으나, 슬래그의 치환율이 높을수록 C-S-H gel의 생성은 증가한 것을 알 수 있었다. 본 연구에서는 5℃의 해수에 노출된 알칼리 활성 플라이애시-슬래그 시멘트에서 플라이애시 보다 오히려 슬래그의 치환율이 샘플의 역학적 특성에 영향을 미치는 것으로 나타났다.

• 한국수정란이식학회지
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• 제31권1호
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• pp.53-59
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• 2016

This study was to investigate effect of progesterone ($P_4$) on prostaglandin (PG) synthases and plasminogen activators (PAs) system in bovine endometrium during estrous cycle. Endometrium tissues were collected from bovine uterus on follicular and luteal phase and were incubated with culture medium containing 0 (Control), 0.2, 2, 20 and 200 ng/ml $P_4$ for 24 h. The $PGF_{2{\alpha}}$ synthase (PGFS), $PGE_2$ synthase (PGES), cyclooxygenase-2 (COX-2), urokinase PA (uPA), and PA inhibitors 1 (PAI-1) mRNA in bovine endometrium were analyzed using reverse transcription PCR and PA activity was measured using spectrophotometry. In results, COX-2 was higher at 2 ng/ml $P_4$ group than control group in luteal phase (p<0.05), but, it did not change in follicular phase. Contrastively, PGES was significantly increased in 2 ng/ml $P_4$ group compared to control group in follicular phase, but there were no significant differ among the treatments in luteal phase. uPA was no significant difference between $P_4$ treatment groups and control group in both of different phase. PAI-1 was decreased in 20 ng/ml $P_4$ group compared to control group in follicular phase (p<0.05). PA activity was decreased in 2 ng/ml $P_4$ group compared to other groups in follicular and luteal phase (p<0.05). In conclusion, we suggest that $P_4$ may influence to translation and post-translation process of PG production and PA activation in bovine endometrium.

• Journal of Microbiology and Biotechnology
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• 제25권8호
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• pp.1216-1226
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• 2015

GlxR is considered as a global transcriptional regulator controlling a large number of genes having broad physiological aspects in Corynebacterium glutamicum. However, the expression profile revealing the transcriptional control of glxR has not yet been studied in detail. DNA affinity chromatography experiments revealed the binding of transcriptional regulators SucR, RamB, GlxR, and a GntR-type protein (hereafter denoted as GntR3) to the upstream region of glxR. The binding of different regulators to the glxR promoter was confirmed by EMSA experiments. The expression of glxR was analyzed in detail under various carbon sources in the wild-type and different mutant strains. The sucR and gntR3 deletion mutants showed decreased glxR promoter activities, when compared with the wild type, irrespective of the carbon sources. The promoter activity of glxR was derepressed in the ramB deletion mutant under all the tested carbon sources. These results indicate that SucR and GntR3 are acting as activators of GlxR, while RamB plays a repressor. As expected, the expression of glxR in the cyaB and glxR deletion mutants was derepressed under different media conditions, indicating that GlxR is autoregulated.

• 한국표면공학회지
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• 제49권2호
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• pp.211-217
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• 2016

Boride coating applied on steam turbine parts of power plants has provided good particle erosion resistance under temperature of $550^{\circ}C$, but it isn't able to protect the parts effectively any more in ultra super critical (USC) steam turbine which is being operated up to temperature of $650^{\circ}C$. To ensure stable durability for USC steam turbine parts, an alternative coating replacing boride coating should be developed. In this study, multi-component boride coatings containing elements such as chromium (Cr) and vanadium (V) were formed on base metal (B50A365B) using thermochemical treatment method called by pack cementation. The thermochemical treatments involve consecutive diffusion of boron(B) and Cr or/and V using pack powders containing diffusion element sources, activators and diluents. The top layer of Cr-boride coating is primarily consisted of $Cr_2B_3$ and $Cr_5B_3$, while that of V-boride coating is mostly consisted of $VB_2$ and $V_2B_3$. The (Cr,V)-boride coating is consisted of $Cr_2B_3$, $Cr_5B_3$ and $V_2B_3$ mostly. The top surfaces of 3 multi-component boride coatings show hardness of $3200-3400H_v$, which is much higher than that of boride, about $1600-2000H_v$. In 5 wt.% NaCl solution immersion tests, the multi-component boride coatings show much better corrosion resistance than boride coating.

• 한국동물위생학회지
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• 제27권4호
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• pp.355-369
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• 2004

The equine herpesvirus type 1 (EHV-1) immediate-early (IE) protein is a potent transactivator responsible for the activation of both early and late genes during the course of infection and is comprised of discrete functional domains that mediate its many functions. Interaction between trans activators such as the IE protein and various components of the RNA polymerase II transcription initiation machinery has been demonstrated to be critical for transactivation. In the present report, it is addressed the hypothesis that the IE protein interacts with various components of transcription machinery to mediate transactivation of target viral genes. In these studies, it is demonstrated that in vitro transcribed and translated IE protein interacts with TFIIB-agarose conjugate but not with TFIID-agarose conjugate. Additional immunoprecipitation studies using nuclear extracts derived from EHV-1 infected RK-13 cells confirmed that the IE protein interacts strongly with TFIIB, but fails to interact with TFIID. IR2, a truncated form of the IE protein lacking the potent transactivation domain and involved in the down-regulation of the IE gene, also interacted with TFIIB but not with TFIID. Studies were also performed to ascertain if particular TBP-associated factors (TAFs) could mediate IE or IR2 binding to TFIID. In vitro transcribed and translated TAF250 added to nuclear extracts generated from EHV-1 infected cells also failed to mediate an interaction between the IE protein or the IR2 protein and TFIID. This study demonstrated that the IE protein mediates transactivation of target viral genes by a mechanism that involves TFIIB. This is in contrast to mechanisms that have been proposed for both the herpes simplex virus ICP4 and VP16 protein which have been proposed to transactivate viral genes through interactions involving both TFIIB and TFIID. This study also intimates that IR2 mediate its repressive effects during the course of EHV-1 infection by a mechanism that involves sequestration of various transcription factors.

• Molecules and Cells
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• 제27권4호
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• pp.417-422
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• 2009

Lipoxygenase (LO) metabolites are generated in inflamed tissues. However, it is unclear whether the inhibition of the LO activity regulates the expression of c-Fos protein, a pain marker in the spinal cord. Here we used a carrageenan-induced inflammation model to examine the role of LO in the development of c-Fos expression. Intradermally injected carrageenan caused elevated number of cells exhibiting Fos-like immunoreactivity (Fos-LI) in the spinal dorsal horn, and decreased the thermal and mechanical threshold in Hargreaves and von Frey tests. Pretreatment with an inhibitor of phospholipase A2, that generates the LO substrate, prior to the carrageenan injection significantly reduced the number of Fos-(+) cells. A general LO inhibitor NDGA, a 5-LO inhibitor AA-861 and a 12-LO inhibitor baicalein also exhibited the similar effects. Moreover, the LO inhibitors suppressed carrageenan-induced thermal and mechanical hyperalgesic behaviors, which inidcates that the changes in Fos expression correlates with those in the nociceptive behaviors in the inflamed rats. LO products are endogenous TRPV1 activators and pretreatment with BCTC, a TRPV1 antagonist inhibited the thermal but not the mechanical hypersensitivity. Overall, our results from the Fos-LI and behavior tests suggest that LO products released from inflamed tissues contribute to nociception during carrageenan-induced inflammation, indicating that the LO pathway is a possible target for modulating inflammatory pain.

• 한국건설순환자원학회논문집
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• 제9권4호
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• pp.650-657
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• 2021

광물질 혼화재를 자극하는 알칼리 활성화제는 고가의 소재이지만, 고 알칼리 성분의 산업부산물 대체하기 위해서는 제품성과 경제성을 모두 만족하여야 한다. 본 연구에서는 50MPa 이상의 고강도 콘크리트에 GGBFS의 알칼리 활성 반응을 위한 목적으로 LCD 제조 공정에서 발생하는 알칼리 산업부산물(LW)을 사용하였다. LW을 혼입한 콘크리트는 작업성이 다소 저하되었으나, 압축강도가 증진되는 특징이 있었다. ACI 209.2R-08 압축강도 모델식을 이용하여 분석하여 LW 혼입에 따른 강도계수의 변화를 비교하였다. 콘크리트의 내구성능 시험에서도 염화물 침투 저항성 및 탄산화 저항성에서 우수한 성능을 나타내었다. 단열온도 상승시험 결과에서는 LW를 혼입하면 초기 수화열이 빨라지는 효과가 있으나, 최종 단열온도상승량은 LW의 혼입 유, 무에 큰 영향을 받지 않았다.

• 한국재료학회지
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• 제29권11호
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• pp.690-696
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• 2019

Geopolymer is an alumina silicate-based ceramic material that has good heat-resistance and fire-resistance; it can be cured at room temperature, and thus its manufacturing process is simple. Geopolymer can be used as a reinforcement or floor finish for high-speed curing applications. In this manuscript, we investigate a high-speed curing geopolymer achieved by adding calcium to augment the curing rate. Metakaolin is used as the main raw material, and aqueous solutions of KOH and $K_2SiO_3$ are used as the activators. As a result of optimizing the high bending strength as a target factor for geopolymers with $SiO_2/Al_2O_3$ ratio of 4.1 ~ 4.8, the optimum ranges of the active agent are found to be $0.1{\leq}K_2O/SiO_2{\leq}0.4$ and $10{\leq}H_2O/K_2O{\leq}32.5$, and the optimum range of the curing accelerator is found to be $$0.82{\leq_-}Ca(OH)_2/Al_2O_3{\leq_-}2.87$$. The maximum flexural strength is found to be 1.35 MPa at $Ca(OH)_2/Al_2O_3=2.82$, $K_2O/SiO_2=0.3$, and $H_2O/K_2O=11.3$. The physical and thermal properties are analyzed to validate the applicability of these materials as industrial insulating parts or repairing finishing materials in construction.

• Journal of Korean Neurosurgical Society
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• 제64권2호
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• pp.207-216
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• 2021

Objective : Rapid dissolution of blood clots reduces vasospasm and hydrocephalus after subarachnoid hemorrhage (SAH), and locally administered fibrinolytic drugs (LAFDs) could facilitate the dissolution. However, the efficacy of LAFDs remains controversial. The aim of this meta-analysis was to determine the efficacy of LAFDs for vasospasm and hydrocephalus and in clinical outcomes. Methods : From PubMed, EMBASE, and Cochrane database, data were extracted by two authors. Meta-analysis was performed using a random effect model. Inclusion criteria were patients who had LAFDs with urokinase-type or recombinant tissue-plasminogen activator after SAH in comparison with medically untreated patients with fibrinolytic drugs. We only included randomized controlled trials (RCTs) in this analysis. The outcomes of interest were vasospasm, hydrocephalus, mortality, and 90-day unfavorable functional outcome. Results : Data from eight RCTs with 550 patients were included. Pooled-analysis revealed that the LAFDs were significantly associated with lower rates of vasospasm (LAFDs group vs. control group, 26.5% vs. 39.2%; odds ratio [OR], 0.48; 95% confidence interval [CI], 0.32-0.73); hydrocephalus (LAFDs group vs. control group, 26.0% vs. 31.6%; OR, 0.54; 95% CI, 0.32-0.91); and mortality (LAFDs group vs. control group, 10.5% vs. 15.7%; OR, 0.58; 95% CI, 0.34-0.99). The proportion of 90-day unfavorable outcomes was lower in the LAFDs group (LAFDs group vs. control group, 32.7% vs. 43.5%; OR, 0.55; 95% CI, 0.37-0.80). Conclusion : This meta-analysis with eight RCTs indicated that LAFDs were significantly associated with lower rates of vasospasm and hydrocephalus after SAH. Thus, LAFDs could consequently reduce mortality and improve clinical outcome after SAH.

• Journal of Ginseng Research
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• 제45권2호
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• pp.354-360
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• 2021

Background: Protopanaxatriol (PPT) is a secondary intestinal metabolite of ginsenoside in ginseng. Although the effects of PPT have been reported in various diseases including cancer, diabetes and inflammatory diseases, the skin protective effects of PPT are poorly understood. Methods: HaCaT cells were treated with PPT in a dose-dependent manner. mRNA and protein levels which related to skin barrier and hydration were detected compared with retinol. Luciferase assay was performed to explore the relative signaling pathway. Western blot was conducted to confirm these pathways and excavated further signals. Results: PPT enhanced the expression of filaggrin (FLG), transglutaminase (TGM)-1, claudin, occludin and hyaluronic acid synthase (HAS) -1, -2 and -3. The mRNA expression levels of FLG, TGM-1, HAS-1 and HAS-2 were suppressed under NF-κB inhibition. PPT significantly augmented NF-κB-luc activity and upregulated Src/AKT/NF-κB signaling. In addition, PPT also increased phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK, JNK and p38 and upstream MAPK activators (MEK and MKK). Furthermore, transcriptional activity of AP-1 and CREB, which are downstream signaling targets of MAPK, was enhanced by PPT. Conclusion: PPT improves skin barrier function and hydration through Src/AKT/NF-κB and MAPK signaling. Therefore, PPT may be a valuable component for cosmetics or treating skin disorders.