76 research outputs found

    O-Alkylation of Dihydroxo(tetraarylporphyrinato)phosphorus(V) and Antimony(V) Complexes with Alkyl Halides

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    The O-alkylation of dihydroxo(tetraarylporphyrinato)phosphorus(V) complexes with several kinds of alkyl bromide in MeCN in the presence of K2CO3 and 18-crown-6 ether produced dialkoxo(tetraarylporphyrinato)phosphorus(V) complexes in-moderate-good yields. Similar O-alkylation was applied to dihydroxo(tetraarylporphyrinato)antimony(V) complexes. The O-alkylation proceeded by the occurrence of an SN2 attack of the alkoxide anion of the complexes at the carbon substituted with halides

    Fluorescence Responses on Ion Recognition with 2-(4-Dialkylaminophenyl)ethoxyantimony(V) Tetraphenylporphyrin

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    The effects of metal ions on the fluorescence spectra of 2-phenylethoxyhydroxyantimony(V) tetraphenylporphyrin hexa-fluorophosphate (1a–c) involving azacrown ether on axial ligands were investigated. Trivalent metal ions such as Al 3+, In3+, Ga3+, and Lu3+ which undergo the complexation with the azacrown ether remarkably enhanced the fluorescence quantum yields

    Effects of an Axial Ligand on the Reduction Potential, Proton Dissociation, and Fluorescence Quantum Yield of Hydroxo(porphyrinato)antimony(V) Complexes

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    The substituent effects on the reduction potentials (E1/2red), the proton dissociation constants of a hydroxo ligand (Ka), and the fluorescence quantum yields (Φ) in aryloxo(hydroxo)tetraarylporphyrinatoantimony(V) complexes were investigated. The E1/2red and Ka values were affected by substituents in the axial aryloxo ligand but, little affected by substituents in the porphyrin ring. Since E1/2red of tetraarylporphyrinatoantimony(V) complexes were higher than those of other metal-porphyrin complexes, it was suggested that the metal orbital greatly contributed to the LUMO level of the complex which can be related to the E1/2red and Ka values. Therefore, the substituent effects of the axial aryloxo ligand on the E1/2red and Ka values were attributed to the electron density of the antimony ion, which affected the LUMO level of the complexes. Moreover, the Φ of the porphyrin moiety depended on both the oxidation potential of the axial aryloxo ligands and the polarity of the solvent used. The fluorescences of the porphyrin moiety were quenched by the axial aryloxo ligands at rate constants of 108 - 1011 s-1

    Severe Gastritis after Administration of Nivolumab and Ipilimumab

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    Immune checkpoint inhibitors such as ipilimumab, a cytotoxic T-lymphocyte-associated antigen-4 inhibitor, have been widely used for advanced malignancies. As these inhibitors improve antitumor immunity via T-cell modulation, immune-mediated adverse events associated with T-cell activation, such as colitis, might occur. Herein, we describe a 75-year-old Japanese woman with metastatic malignant melanoma who developed hemorrhagic gastritis after ipilimumab treatment. There was no macroscopic or clinical improvement of gastritis after proton pump inhibitor treatment. However, her condition improved after approximately 3 weeks of corticosteroid therapy and Helicobacter pylori eradication. This case suggests a potential association between severe gastritis and immune checkpoint inhibitor treatment. Although several reports have mentioned ipilimumab-associated colitis, gastritis is considered to be rare. In the present case, H. pylori-associated gastritis might have been exacerbated by the T-cell modulation effect of ipilimumab. To date, no report has clarified the mechanism by which ipilimumab modifies H. pylori infection. The present treatment course provides a helpful perspective for similar cases

    Successful scaling-up of self-sustained pyrolysis of oil palm biomass under pool-type reactor

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    An appropriate technology for waste utilisation, especially for a large amount of abundant pressed-shredded oil palm empty fruit bunch (OFEFB), is important for the oil palm industry. Self-sustained pyrolysis, whereby oil palm biomass was combusted by itself to provide the heat for pyrolysis without an electrical heater, is more preferable owing to its simplicity, ease of operation and low energy requirement. In this study, biochar production under self-sustained pyrolysis of oil palm biomass in the form of oil palm empty fruit bunch was tested in a 3-t large-scale pool-type reactor. During the pyrolysis process, the biomass was loaded layer by layer when the smoke appeared on the top, to minimise the entrance of oxygen. This method had significantly increased the yield of biochar. In our previous report, we have tested on a 30-kg pilot-scale capacity under self-sustained pyrolysis and found that the higher heating value (HHV) obtained was 22.6–24.7 MJ kg−1 with a 23.5%−25.0% yield. In this scaled-up study, a 3-t large-scale procedure produced HHV of 22.0–24.3 MJ kg−1 with a 30%−34% yield based on a wet-weight basis. The maximum self-sustained pyrolysis temperature for the large-scale procedure can reach between 600 °C and 700 °C. We concluded that large-scale biochar production under self-sustained pyrolysis was successfully conducted owing to the comparable biochar produced, compared with medium-scale and other studies with an electrical heating element, making it an appropriate technology for waste utilisation, particularly for the oil palm industry

    Clinical background factors as predictors of the efficacy of 5-aminosalicylic acid suppositories in patients with ulcerative colitis

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    Introduction: Although the efficacy of 5-aminosalicylic acid (ASA) suppositories for ulcerative colitis (UC) has been reported in many studies, many studies have also described poor adherence to 5-ASA suppository regimens. We aimed to identify the clinical background factors that influence adherence to 5-ASA suppositories to improve adherence and efficacy of the treatment. Methods: We conducted a retrospective cohort study of 61 patients with active UC who were using 5-ASA suppositories. All patients underwent endoscopy and rectal biopsy for histological diagnosis prior to 5-ASA suppository treatment. The efficacy of 5-ASA suppository treatment was compared in relation to clinical background factors (sex, age, disease duration, disease type, clinical activity, Ulceratve colitis Endoscopic Index of Severity, histological activity, serum C-reactive protein level, concomitant use of immunomodulators, history of steroid use, and dose of oral 5-ASA). Results: The efficacy of 5-ASA suppositories was significantly related to low Lichtiger Colitis Activity Index (LCAI) scores and proctitis type prior to its use. In terms of sex, females tended to show higher efficacy. Multivariate logistic regression analysis using these three factors showed high predictive value for the efficacy of 5-ASA suppositories (AUC, 0.788; sensitivity, 87.2%; and specificity, 63.7%). Discussion/Conclusion: This study is the first to extract clinical background factors for predicting the efficacy of 5-ASA suppositories. The use of 5-ASA suppositories in patients who are expected to show efficacy will be effective in improving patient co-operation

    A New Approach to Stokes Wave Theory

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    Stokes wave theories to third-order approximation have widely been employed to calculate wave properties for waves propagating over finite depths of water in most engineering applications. However, different and often inconsistent expressions of wave variables can be observed from the numerous theories available. Examinations of the usual Stokes wave theories are on the so-called Stokes definitions of wave celerity and Bernoulli constant, as well as on the physical explanations of some theoretical problems involved. A new Stokes wave theory to third order approximation is derived by applying only necessary conditions and assumptions, without using the definitions of wave celerity. The resulting mathematical formulations for some pertinent wave variables are presented. Comparison is made between the new third-order approximation and the usual ones derived from using the Stokes definitions of wave celerity, showing different expressions of wave celerity, horizontal water particle velocity, and mass transport velocities. It is found that the mass transport velocity exists in the Eulerian description as well as the usual Stokes drift in the Lagrangian description
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