• 제목/요약/키워드: CCl$_4$

검색결과 825건 처리시간 0.026초

고온 초전도체 $Hg_{1-x}\;Tl_{x}\;Ba_{2}(Ca_{0.86}\;Sr_{0.14})_{2}\;Cu_{3}\;O_{8+\delta}$의 고분해능 TEM에 의한 구조 관찰 (High Resolution TEM Observations in $Hg_{1-x}\;Tl_{x}\;Ba_{2}(Ca_{0.86}\;Sr_{0.14})_{2}\;Cu_{3}\;O_{8+\delta}$ Superconductors)

  • 이확주;류현;허남회;박용기
    • Applied Microscopy
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    • 제25권4호
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    • pp.124-131
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    • 1995
  • 이상과 같은 실험결과를 다음과 같은 요약할 수 있다. 1) $Hg_{1-x}\;Tl_{x}\;Ba_{2}(Ca_{0.86}\;Sr_{0.14})_{2}\;Cu_{3}\;O_{8+\delta}$의 구조는 Hg-1223과 같은 구조를 이루며 Hg 위치에 T1이 치환되어 있음을 알 수 있다. 2) 격자상수는 탈륨이 증가할수록 감소하는 경향을 나타냈으나 x=0.25 시료에서는 현저히 감소됨을 보였다. 3) x=0.25 시료에서는 적층 결함 1234구조가 1223구조와 intergrowth함을 보였고 불순물 상이 다소 나타났다. 4) 탈륨이 증가할 수록 보다 치밀하고 결함이 없는 안정된 조직을 보였다. 5) 모든 시료가 관찰 도중 전자빔에 대하여 손상되었으나 탈륨의 양이 증가할 수록 손상에 대한 저항이 커져 보다 안정된 상을 보였다.

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사용후핵연료중의 미량 요오드 정량을 위한 용해 및 분리 연구 (A Study on the Dissolution and Separation for the Quantitative Analysis of Iodide in Spent Nuclear Fuel)

  • 최계천;이창헌;송병철;박양순;지광용;김원호
    • 분석과학
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    • 제13권6호
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    • pp.751-758
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    • 2000
  • 사용후핵연료에 미량 함유되어 있는 요오드를 정량하기 위하여 분리 및 회수를 위한 최적조건을 실험하였다. 사용후핵연료의 용해를 위하여 모의 사용후핵연료를 이용하였으며 용해과정에서 요오드가 휘발되지 않는 혼합산(질산:염산)의 최적 혼합비는 80:20 mol%이었으며 비휘발성 요오드의 생성을 촉진시키기 위하여 오존을 사용하였을 때 요오드의 회수율이 6회 평균 측정값이 9.6% 증가를 나타내었다. 사염화탄소에 의한 요오드 추출과정에서 ${IO_3}^-$$I_2$으로 환원시키기 위하여 $NH_2OH{\cdot}HCl$을 사용하였으며 요오드 환원에 적합한 용해용액의 산도는 2.5 M 그리고 $NH_2OH{\cdot}HCl$의 양은 $1.5{\times}10^{-3}mole$ 이상이었다. 분리된 요오드는 이온 크로마토그래피로 정량하였으며 이때 회수율은 $82.8{\pm}4.1%$로서 $^{131}I$를 추적자로 사용하여 보정하였다.

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희토류 금속이온 (Ln(III))과 Acetamide 사이의 상호작용에 대한 연구 (Studies on the Coordination of Acetamide to Rare Earth Metal Ion (Ln(II))

  • 이상원;유정아;윤창주;전유혁;최영상
    • 대한화학회지
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    • 제36권2호
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    • pp.205-211
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    • 1992
  • 아세트아미드(AA)의 CO기와 희토류 금속이온(Ln(II))을 포함하는 몇 가지 lanthanide shift reagent(LSR) 사이의 상호작용을 이해하기 위하여 AA의 $2{\nu}_{C=0}$ + amide III 조합띠를 $15^{\circ}$ ${\sim} 45^{\circ}C$에서 조사하였다. 묽은 $CCl_4$ 용액속에서 하나의 AA가 사용된 LSR에 배위되어 1 : 1 AA-LSR 복합체를 이루며, Ln(Ⅲ)이온에 대한 AA의 배위 위치는 카르보닐의 산소임을 알았다. 온도 및 농도에 따른 이 조합띠의 변화로부터 Ln(III)${\cdot}$O=C 결합에 대한 여러가지 열역학적 함수들을 구했다. Eu$(dpm)_3$, Yb$(dpm)_3$ 및 Pr$(dpm)_3$에 대한 AA의 결합의 세기를 나타내는 ${\Delta}H^{\circ}$는 각각 -39.1, -28.4 및 -25.5kJ/mol이다. 이들 값을 비교해보면 AA 분자가 배위될 때 중심금속이온의 ionic potential 효과보다는 이미 배위되어 있는 커다란 dpm 분자에 의한 입체장애효과가 더 큼을 알 수 있다.

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개에서 미만성 간장병변의 정량적 진단을 위한 초음파 및 방사선학적 평가 (Ultrasonographic and radiographic evaluation for the quantitative diagnosis of diffuse hepatic disease in dogs)

  • 성재기;이희천;윤정희;이영원;안용주;최호정;최지혜
    • 대한수의학회지
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    • 제38권4호
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    • pp.918-928
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    • 1998
  • The present study was done with two aims. First, to evaluate the radiographic measurements of liver volumes in normal and hepatomegaly dogs induced by carbon tetrachloride. Second, to investigate quantitative tissue echo pattern by ultrasonography. Gray level histogram of the normal liver and the kidney were estimated with carbon tetra-chloride intoxication. In normal, r-square for liver volume to body weight was 0.93372, and this showed direct linear regression. Gray level histograms of the normal liver and the kidney were $19.150{\pm}2.490$(mean${\pm}$SD) and $13.175{\pm}2.686$(mean${\pm}$SD) respectively(p < 0.01). Liver parenchymal echogenicity was more hyperechogenic than kidney cortex echogenicity. Liver/Kidney ratio was $1.504{\pm}0.313$ and it can be used relative comparison of liver and kidney parenchymal echogenicity. In carbon-tetrachloride($CCl_4$) intoxication, changes of liver volume appeared to increase up to 24 hours after administration (p < 0.05), and decreased gradually to normal level after 2~5 days. Gray level histogram of liver parenchyma decreased up to 24hours (p < 0.01) after intoxication and then gradually increased to normal level. But that of kidney cortex had no significant change. Liver/Kidney ratio also decreased by 2 days(p < 0.01) and then gradually increased to normal level. On histopathologic features of hepatic tissues in carbon tetrachloride intoxication, both coagulative necrosis of hepatic cell and hemorrhage of centrilobular & midzonal area were identified. Conclusively, plain radiography is a useful diagnostic method for evaluating liver volume in mild hepatomegaly. Especially, it is considered that an adequate numerical processing of the liver length, depth and thoracic width and depth measurement would be helpful. Using gray level histogram, ultrasonographic evaluation was useful objective methods in early diagnosis of diffuse hepatic disease.

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녹양보탕의 항피로 및 항산화작용 (Anti-fatigue and Hepatoprotective Activities of Nokyangbotang)

  • 김창종;김현준;이윤혜;이연아;이정근;문성원;박진형;장용운;조중형
    • 약학회지
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    • 제44권3호
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    • pp.224-231
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    • 2000
  • $Nokyangbotang^{TM}$ (NYBT) is a kind of powerful food for health and have been drunk at a oral dose of 80 ml (99.5 mg) three times per day: It has not been well studied about the anti-fatigue and hepatoprotective activity. In this experiments, we evaluated pathophysiologically the effect of NYBT on swimming time in mouse and hepatoprotective activity in rats intoxicated with carbon-tetrachloride. NYBT was nontoxic in orally acute toxicity test ($LD_{50}$, 320 ml/60 kg): a nontoxic food in more four times of one-shoot dosage (80 ml) to human. Weight-loaded forced swimming test was carried out to measure the swimming time of mice with a 4% load of body weight in plastic cylinder (diameter $10{\;}cm{\;}{\times}{\;}height{\;}20{\;}cm$) on water bath at $25^{\circ}C$, and the anti-fatigue activity represented the ratio of swimming time of experimental group to that of control group. NYBT had dose-dependent anti-fatigue activity Mice administered NYBT at a dose of 320 ml/60 kg once daily for 5 days could swim about two times more than control. Hepatoprotective activities of NYBT were examined by the determination of malonedialdehyde (MDA) and pathological survey in liver and liver function test of rat intoxicated with $CCl_4$ at i.m. dose of 2 ml/kg once daily for 7days. NYBT decreased dose-dependently thiobarbituric acid reactive substance: Oral administration of NYBT at a dose of 20 ml/60 kg was $38.51{\;}{\pm}{\;}3.02$ nmol MDA/g of tissue, that of 80 ml/60 kg was $33.76{\;}{\pm}{\;} 1.84$ nmol MDA/g of tissue, and that of 320 ml/60 kg was $32.87{\;}{\pm}{\;}1.90$ nmol MDA/g of tissue as compared with control group ($43.61{\;}{\pm}{\;}2.85$ nmol MDA/g of tissue). All rats administered NYBT at a dose of 320 ml/60 kg were survival as compared with 40% survival of control animals, and GPT activity of rats administered NYBT at a dose of 80 ml/60 kg was decreased as compared with control. In histopathological survey, NYBT improved slightly the fatty changes of hepatocytes around centrilobular area. These results suggest that NYBT has anti-fatigue and hepatoprotective activity in rats and mice.

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목질진흙버섯 자실체와 배양 균사체 유래 ${\beta}-Glucan$성 다당류의 생리활성 (Biological Activities of Polysaccharide Extracted from the Fruit Body and Cultured Mycelia of Phellinus linteus IY001)

  • 이준우;백성진;방광웅;강신욱;강상모;김병용;하익수
    • 한국식품과학회지
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    • 제32권3호
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    • pp.726-735
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    • 2000
  • 목질진흙버섯 자실체와 배양 균사체의 열수추출 및 열수 추출물의 에탄올, UF처리 분획들에 대한 약리 효과를 조사하여 다음과 같은 결과를 얻었다. Sarcoma 180 암세포 증식 저지율은 자실체 열수 총 분획(Fr. I)보다 비교적 고분자인 다당류 분획(Fr. II, Fr. III, Fr. IV)에서 $80.4{\sim}85.9%$로 높게 나타났다. 면역계에 미치는 영향으로 보체계 활성화는 $10.1{\sim}13.6%$, 대식세포의 NO 생성능은 자실체 및 균사체 모든 분획에서 생성되었으며, $TNF-{\alpha}$생성능은 NO 생성능이 높았던 분획들에서 높은 생성능을 나타내었다. 효소적 및 비효소적 지질과산화 유발에 대한 영향은 목질진흙버섯 자실체와 배양 균사체의 모든 분획에서 지질 과산화 억제능을 나타내었고, 유리기 제거능에 있어서는 농도의존적으로 효과가 있는 것으로 나타났으며, DPPH에 대한 Fr. III의 $SC_{50}$$32.0\;{\mu}g/mL$로 조사되었다. 상기와 같은 결과들로부터 목질진흙버섯 자실체와 배양 균사체의 열수추출 및 열수 추출물의 에탄올, UF처리 분획들은 항암활성, 면역활성, 지질 과산화 억제효과 및 유리기 제거능이 있음을 확인할 수 있었다.

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미세먼지 유도 기도염증에 대한 배암차즈기 추출물의 호흡기 보호 효과 (Respiratory Protective Effect of Salvia plebeia R. Br. Extracts against Ambient Particulate Matter-induced Airway Inflammation)

  • 송형우;지건영;김복규;양원경;한창균;신한재;박양춘;황지숙;강형식;김승형
    • 한국약용작물학회지
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    • 제25권5호
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    • pp.269-281
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    • 2017
  • Background: Small particles increase airway inflammation upon reaching the alveoli. Here, we investigated the protective or therapeutic effects of Salvia plebeia R. Br. (SP_R) extracts on airway inflammation. Methods and Results: To investigate the anti-inflammatory activity of SP_R extracts, we measured their inhibitory effect on the production of reactive oxygen species (ROS) expression of inflammatory mediators, and immune cell infiltration in MH-S alveolar macrophage cells and in the ambient particulate matter (APM)-exposed airway inflammation mice model. The SP_R extracts inhibited the production of ROS and expression of IL-4, IL-10, IL-15, and IL-17A mRNA in APM-stimulated MH-S cells. Oral administration of SP_R extracts suppressed APM-induced inflammatory symptoms, such as high alveolar wall thickness, excess collagen fibers, decreased mRNA expression of chemokines (Ccr9, Ccl5, Ccr3), inflammatory cytokines (IL-15, TNF-${\alpha}$), and IL-4 Th2 cytokine in the lung. The SP_R extracts also inhibited ROS production, granulocyte ($CD11b^+Gr-1^+$) infiltration, IL-17A, TNF-${\alpha}$, macrophage inflammatory protein (Mip-2), and chemokine (C-X-C motif) ligand 1 (Cxcl-1) production in the airway. The specific compounds in the SR-R extracts that mediate the anti-inflammatory effects were identified. Conclusions: In this study, SP_R extracts effectively inhibited airway inflammatory responses, such as ROS production and granulocyte infiltration into the airway, by regulating the expression of chemokines and inflammatory cytokines.

20(S)- Protopanaxadiol suppresses hepatic stellate cell activation via WIF1 demethylation-mediated inactivation of the Wnt/β-catenin pathway

  • Chunxue Li ;Yating Zhan ;Rongrong Zhang;Qiqi Tao ;Zhichao Lang ;Jianjian Zheng
    • Journal of Ginseng Research
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    • 제47권4호
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    • pp.515-523
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    • 2023
  • Background: 20(S)-protopanaxadiol (PPD), one of the main components of ginseng, has anti-inflammatory, anti-estrogenic, and anti-tumor activities. It is known that activated hepatic stellate cells (HSCs) are the primary producers of extracellular matrix (ECM) in the liver, and the Wnt/β-catenin pathway participates in the activation of HSCs. We aimed to explore whether PPD inhibits liver fibrosis is associated with the Wnt/β-catenin pathway inactivation. Methods: The anti-fibrotic roles of PPD were examined both in vitro and in vivo. We also examined the levels of Wnt inhibitory factor 1 (WIF1), DNA methyltransferase 1 (DNMT1) and WIF1 methylation. Results: PPD obviously ameliorated liver fibrosis in carbon tetrachloride (CCl4)-treated mice and reduced collagen deposition. PPD also suppressed the activation and proliferation of primary HSCs. Notably, PPD inhibited the Wnt/β-catenin pathway, reduced TCF activity, and increased P-β-catenin and GSK-3β levels. Interestingly, WIF1 was found to mediate the inactivation of the Wnt/β-catenin pathway in PPD-treated HSCs. WIF1 silencing suppressed the inhibitory effects of PPD on HSC activation and also restored α-SMA and type I collagen levels. The downregulation of WIF1 expression was associated with the methylation of its promoter. PPD induced WIF1 demethylation and restored WIF1 expression. Further experiments confirmed that DNMT1 overexpression blocked the effects of PPD on WIF1 expression and demethylation and enhanced HSC activation. Conclusion: PPD up-regulates WIF1 levels and impairs Wnt/β-catenin pathway activation via the downregulation of DNMT1-mediated WIF1 methylation, leading to HSC inactivation. Therefore, PPD may be a promising therapeutic drug for patients with liver fibrosis.

Ginsenoside Rg1 Epigenetically Modulates Smad7 Expression in Liver Fibrosis via MicroRNA-152

  • Rongrong Zhang ;Xinmiao Li ;Yuxiang Gao ;Qiqi Tao;Zhichao Lang;Yating Zhan;Chunxue Li;Jianjian Zheng
    • Journal of Ginseng Research
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    • 제47권4호
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    • pp.534-542
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    • 2023
  • Background: Ginsenoside Rg1, a bioactive component of Ginseng, has demonstrated anti-inflammatory, anti-cancer, and hepatoprotective effects. It is known that the epithelial-mesenchymal transition (EMT) plays a key role in the activation of hepatic stellate cells (HSCs). Recently, Rg1 has been shown to reverse liver fibrosis by suppressing EMT, although the mechanism of Rg1-mediated anti-fibrosis effects is still largely unclear. Interestingly, Smad7, a negative regulator of the transforming growth factor β (TGF-β) pathway, is often methylated during liver fibrosis. Whether Smad7 methylation plays a vital role in the effects of Rg1 on liver fibrosis remains unclear. Methods: Anti-fibrosis effects were examined after Rg1 processing in vivo and in vitro. Smad7 expression, Smad7 methylation, and microRNA-152 (miR-152) levels were also analyzed. Results: Rg1 significantly reduced the liver fibrosis caused by carbon tetrachloride, and reduced collagen deposition was also observed. Rg1 also contributed to the suppression of collagenation and HSC reproduction in vitro. Rg1 caused EMT inactivation, reducing Desmin and increasing E-cadherin levels. Notably, the effect of Rg1 on HSC activation was mediated by the TGF-β pathway. Rg1 induced Smad7 expression and demethylation. The over-expression of DNA methyltransferase 1 (DNMT1) blocked the Rg1-mediated inhibition of Smad7 methylation, and miR-152 targeted DNMT1. Further experiments suggested that Rg1 repressed Smad7 methylation via miR-152-mediated DNMT1 inhibition. MiR-152 inhibition reversed the Rg1-induced promotion of Smad7 expression and demethylation. In addition, miR-152 silencing led to the inhibition of the Rg1-induced EMT inactivation. Conclusion: Rg1 inhibits HSC activation by epigenetically modulating Smad7 expression and at least by partly inhibiting EMT.

Morin Hydrate Inhibits Influenza Virus entry into Host Cells and Has Anti-inflammatory Effect in Influenza-infected Mice

  • Eun-Hye Hong;Jae-Hyoung Song;Seong-Ryeol Kim;Jaewon Cho;Birang Jeong;Heejung Yang;Jae-Hyeon Jeong;Jae-Hee Ahn;Hyunjin Jeong;Seong-Eun Kim;Sun-Young Chang;Hyun-Jeong Ko
    • IMMUNE NETWORK
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    • 제20권4호
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    • pp.32.1-32.15
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    • 2020
  • Influenza virus is the major cause of seasonal and pandemic flu. Currently, oseltamivir, a potent and selective inhibitor of neuraminidase of influenza A and B viruses, is the drug of choice for treating patients with influenza virus infection. However, recent emergence of oseltamivir-resistant influenza viruses has limited its efficacy. Morin hydrate (3,5,7,2',4'-pentahydroxyflavone) is a flavonoid isolated from Morus alba L. It has antioxidant, anti-inflammatory, neuroprotective, and anticancer effects partly by the inhibition of the NF-κB signaling pathway. However, its effects on influenza virus have not been studied. We evaluated the antiviral activity of morin hydrate against influenza A/Puerto Rico/8/1934 (A/PR/8; H1N1) and oseltamivir-resistant A/PR/8 influenza viruses in vitro. To determine its mode of action, we carried out time course experiments, and time of addition, hemolysis inhibition, and hemagglutination assays. The effects of the co-administration of morin hydrate and oseltamivir were assessed using the murine model of A/PR/8 infection. We found that morin hydrate reduced hemagglutination by A/PR/8 in vitro. It alleviated the symptoms of A/PR/8-infection, and reduced the levels of pro-inflammatory cytokines and chemokines, such as TNF-α and CCL2, in infected mice. Co-administration of morin hydrate and oseltamivir phosphate reduced the virus titers and attenuated pulmonary inflammation. Our results suggest that morin hydrate exhibits antiviral activity by inhibiting the entry of the virus.