41 research outputs found

    Effect of Oxide Composition of Spinel-type Copper Chromites on the Catalytic Activity for the Simultaneous Removal of NOx and Soot Particulate

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    The catalytic activity of Cu-Cr oxides for the simultaneous removal of NO_x and diesel soot particulate has been investigated with special attention being placed on effects of the composition of oxide catalysts. The temperature programmed reaction technique in which the mixture of a catalyst and soot was heated at a constant rate in an NO+O_2 gas stream was used to evaluate the catalytic performance. Spinel-type CuCr_2O_4 was superior to CuO, Cr_2O_3 and their mechanical mixture in terms of the selectivity to NO_x reduction. The catalytic performance of Cu-Cr oxides depended significantly but complicatedly on the Cr/Cu molar ratio as well as the partial substitution of transition metal and alkali metal cations. The effect of preparation method of CuCr_2O_4 was also studied. As compared with the conventional acetate process, the citric acid-aided process gave the monophasic CuCr_2O_4 spinel at lower temperatures, and the oxides prepared by the citric acid-aided process were more active than those prepared by the acetate process

    REDUCTION MECHANISM OF COPPER IONS EXCHANGED IN Y TYPE ZEOLITES

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    Two distinct Cu(II) to Cu(I) processes have been discernible in temperature programmed reduction with hydrogen. The reduction peak with a maximum around 573-593 K is proposed to correspond to the reduction of Cu2+-02--Cu2+ species locating in sodalite cages. Another peak around 473-513 K has been attributed to the reduction of unpaired Cu(II) ions

    Fibrocytes activate fibroblasts by PDGF.

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    Fibrocytes, which are bone marrow-derived collagen-producing cells, were reported to play a role in the pathogenesis of pulmonary fibrosis. However, their function in pulmonary fibrosis is unclear. We analyzed their function compared with that of monocytes and localization in fibrotic tissues in patients with idiopathic pulmonary fibrosis (IPF). We compared the gene expression profile of monocyte-derived fibrocytes with that of monocytes by microarray analysis. Proliferation and differentiation into myofibroblasts were examined by 3H-thymidine incorporation assay and Western blotting. We measured the level of growth factors in the culture supernatant of fibrocytes by ELISA. The localization of fibrocytes in lung tissues of patients with IPF was determined by immunofluorescence staining. Compared with monocytes, fibrocytes had higher expression of extracellular matrix- and growth factor-encoding genes, including PDGF-B, FGF-2 and VEGF-B. Although fibrocytes did not proliferate in response to PDGF, co-culture of fibrocytes stimulated the growth of lung fibroblasts through the production of PDGF-BB. In the lung of IPF patients, CD45+Collagen-I+FSP-1+ cells, which have a similar phenotype to fibrocytes, were detected and co-stained with anti-PDGF antibody. This study suggested that fibrocytes function in pulmonary fibrosis partly by producing PDGF in the lungs of IPF patients

    Extracellular vesicles shed from gastric cancer mediate protumor macrophage differentiation

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    Background Peritoneal dissemination often develops in gastric cancer. Tumor-associated macrophages (TAMs) are present in the peritoneal cavity of gastric cancer patients with peritoneal dissemination, facilitating tumor progression. However, the mechanism by which macrophages differentiate into tumor-associated macrophages in the peritoneal cavity is not well understood. In this study, the interplay between gastric cancer-derived extracellular vesicles (EVs) and macrophages was investigated. Methods The association between macrophages and EVs in peritoneal ascitic fluid of gastric cancer patients, or from gastric cancer cell lines was examined, and their roles in differentiation of macrophages and potentiation of the malignancy of gastric cancer were further explored. Results Immunofluorescent assays of the ascitic fluid showed that M2 macrophages were predominant along with the cancer cells in the peritoneal cavity. EVs purified from gastric cancer cells, as well as malignant ascitic fluid, differentiated peripheral blood mononuclear cell-derived macrophages into the M2-like phenotype, which was demonstrated by their morphology and expression of CD163/206. The macrophages differentiated by gastric cancer-derived EVs promoted the migration ability of gastric cancer cells, and the EVs carried STAT3 protein. Conclusion EVs derived from gastric cancer play a role by affecting macrophage phenotypes, suggesting that this may be a part of the underlying mechanism that forms the intraperitoneal cancer microenvironment

    Targeting neutrophil extracellular traps with thrombomodulin prevents pancreatic cancer metastasis

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    Surgery is the only curative treatment option for pancreatic cancer, but patients often develop postoperative recurrence. Surgical invasiveness might be involved in the mechanism of recurrence. The associations among inflammation caused by surgery, neutrophils, and cancer metastasis were investigated. At first, neutrophil extracellular traps (NETs) were examined in clinical specimens, and NETs were observed around metastatic tumors. To explore how NETs were induced, neutrophils were cultured with pancreatic cancer or in cancer-conditioned medium. Neutrophils formed NETs when they were cultured with pancreatic cancer or even its conditioned medium. The effects of NETs on cancer cells were further investigated in vitro and in vivo. NETs induced the epithelial to mesenchymal transition in cancer cells and thereby promoted their migration and invasion. HMGB1 derived from NETs appeared to potentiate the malignancy of cancer cells. In a mouse model of liver metastasis with inflammation, NETs participated in the metastatic process by enhancing extravasation. Interestingly, thrombomodulin degraded HMGB1 and consequently inhibited the induction of NETs, thereby preventing pancreatic cancer metastasis to the liver. In conclusion, NETs interact reciprocally with pancreatic cancer cells, which play a pivotal role in inflammation-associated metastasis. Targeting NETs with thrombomodulin can be a novel strategy to improve the surgical outcome of pancreatic cancer patients

    Intraperitoneal cancer-immune microenvironment promotes peritoneal dissemination of gastric cancer

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    A solid tumor consists of cancer and stromal cells, which comprise the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are usually abundant in the TME, contributing to tumor progression. In cases of peritoneal dissemination of gastric cancer (GC), the contribution of intraperitoneal TAMs remains unclear. Macrophages from peritoneal washings of GC patients were analyzed, and the link between intraperitoneal TAMs and GC cells was investigated to clarify the interaction between them in peritoneal dissemination. Macrophages were predominant among leukocytes constituting the microenvironment of the peritoneal cavity. The proportion of CD163-positive TAMs was significantly higher in stage IV than in stage I GC. Co-culture with TAMs potentiated migration and invasion of GC. IL-6 was the most increased in the medium of in vitro co-culture of macrophages and GC, and IL-6 elevation was also observed in the peritoneal washes with peritoneal dissemination. An elevated concentration of intraperitoneal IL-6 was correlated with a poor prognosis in clinical cases. In conclusion, intraperitoneal TAMs are involved in promoting peritoneal dissemination of GC via secreted IL-6. TAM-derived IL-6 could be a potential therapeutic target for peritoneal dissemination of GC

    ブレオマイシン肺線維症マウスに対するWnt/βカテニン/CBPシグナル新規阻害薬PRI-724の抗線維化効果

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    Purpose/Aim of the Study: Wnt/β-catenin signaling was reported to be activated in pulmonary fibrosis, and was focused on as a target for antifibrotic therapy. However, the mechanism how the inhibition of Wnt/β-catenin signaling ameliorate pulmonary fibrosis has not been fully elucidated. The purpose of this study is to explore the target cells of Wnt/β-catenin inhibition in pulmonary fibrosis and to examine the antifibrotic effect of the novel inhibitor PRI-724 specifically disrupting the interaction of β-catenin and CBP. Materials and Methods: The effect of C-82, an active metabolite of PRI-724, on the expression of TGF-β1 and α-smooth muscle actin (SMA) was examined on fibroblasts and macrophages. We also examined the effects of PRI-724 in mouse model of bleomycin-induced pulmonary fibrosis. Results: The activation and increased accumulation of β-catenin in the canonical pathway were detected in lung fibroblasts as well as macrophages stimulated by Wnt3a using Western blotting. Treatment with C-82 reduced CBP protein and increased p300 protein binding to β-catenin in the nucleus of lung fibroblasts. In addition, C-82 inhibited the expression of SMA in lung fibroblasts treated with TGF-β, indicating the inhibition of myofibroblast differentiation. In the fibrotic lungs induced by bleomycin, β-catenin was stained strongly in macrophages, but the staining of β-catenin in alveolar epithelial cells and fibroblasts was weak. The administration of PRI-724 ameliorated pulmonary fibrosis induced by bleomycin in mice when administered with a late, but not an early, treatment schedule. Analysis of bronchoalveolar fluid (BALF) showed a decreased number of alveolar macrophages. In addition, the level of TGF-β1 in BALF was decreased in mice treated with PRI-724. C-82 also inhibited the production of TGF-β1 by alveolar macrophages. Conclusions: These results suggest that the β-catenin/CBP inhibitor PRI-724 is a potent antifibrotic agent that acts by modulating the activity of macrophages in the lungs

    Cultivar differences in flowering response of okra (Abelmoschus esculentus) in spring and autumn

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    オクラの10系統と5品種を供試して,春季と秋季において花成反応の品種間差異を調査した。系統HE006, HE022, HE045, HE047, HE047-1と\u27Benny\u27, \u27Better Five\u27, \u27Clemson Spineless\u27, \u27Emerald\u27, \u27Green Rocket\u27の花芽は春季では2~6の低節位に,秋季には8~11節の低節位に形成された。秋季に比べて春季で品種間に差はあるが,出雷は0~11日早くおこった。季節に関わらず, HE015, HE050, HE050-1の花芽は播種後18~21日と早く形成されたが, HE025, HE035では32日~48日と遅く形成された。すべての系統と品種について,開花と結実時期は季節によって変動した。春季と秋季の環境条件に対する花成反応から,敏感な品種とそうでない品種に分けられた。敏感な品種にはHE006, HE022, HE045, HE047, HE047-1, \u27Benny\u27, \u27Better Five\u27, \u27Clemson Spineless\u27, \u27Emerald\u27と\u27Green Rocket\u27があった。敏感でない品種は2群に分けられ,花芽分化の早いのはHE015, HE050, HE050-1であり,遅いのはHE025, HE035であった。Differences in flowering response of ten accessions and five cultivars were investigated in spring and autumn. Flower buds of HE 006, HE 022, HE 045, HE 047, HE 047-1, \u27Benny\u27, \u27Better Five\u27, \u27Clemson Spineless\u27, \u27Emerald\u27 and \u27Green Rocket\u27 were initiated at the lower node from 2 to 6 in spring and from 8 to 11 in autumn and they appeared 0 to 11 days earlier in spring than in autumn, depending on the cultivars. Flower bud initiation of HE 015, HE 050 and HE 050-1 was early in 18 to 21 days after sowing (DAS) but the initiation of HE 025 and HE 035 was late in 32 to 48 DAS whether in spring or in autumn. The occurrence of anthesis and fruiting in all accessions and cultivars fluctuated in the different seasons. Based on these results, two groups of flowering response to environmental conditions in spring and autumn were identified as sensitive and non-sensitive cultivars. Sensitive cultivars comprised of HE 006, HE 022, HE 045, HE 047, HE 047-1, \u27Benny\u27, \u27Better Five\u27, \u27Clemson Spineless\u27, \u27Emerald\u27 and \u27Green Rocket\u27. Non-sensitive cultivars were divided into two subgroups as early and late flowering. Early flowering composed of HE 015, HE 050 and HE 050-1 and late flowering consisted of HE 025 and HE 035. (Accepted September 9, 2003

    Interconversion of Power Functional Rate Equation and Fractional Rate Equation

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    The apparent reaction order αi of reactant i was pointed out to be described as αi = ∂lnR/∂lnpi , where R is the reaction rate, and pi the partial pressure of reactant i. By substituting a fractional rate equation into this equation, apparent reaction orders could be correlated with parameters in the fractional rate equation, and a method of interconverting two types of rate expressions were proposed. A few examples of applications were shown

    Sorption and Diffusion of Normal Hydrocarbons in Natural Rubber

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    Solubility and diffusion coefficients of normal C2-C6 hydrocarbons in unvulcanized natural rubber have been determined. Data on concentration dependence of the solubility constant could be correlated by S=S0 exp(αc) and the parameter α are related to the Flory-Huggins interaction parameter χ approximately by α=2χ+1. The concentration dependence of diffusion coefficient are fitted by the expression D=D0(1-αc) exp (βc) derived from a first-approximation free volume theory. The diffusion coefficient, D0 extrapolated to zero concentration and its activation energy decrease with increasing molecular size up to C3 and reach a constant value for C4 and higher hydrocarbons. The parameter β is almost constant for C4-C6 hydrocarbons. It is demonstrated that these hydrocarbons would move through polymeric media like a needle in concert with the thermal motion of polymer segments and only the free volumes larger than the effective cross-sectional diameter of the diffusant molecule is available for diffusion
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