Characterization of LaMnAl11O19 by FT-IR spectroscopy of adsorbed NO and NO/O-2

Cataloged from PDF version of article.The nature of the NOx species produced during the adsorption of NO at room temperature and during its coadsorption with oxygen on LaMnAl11O19 sample with magnetoplumbite structure obtained by a sol–gel process has been investigated by means of in situ FT-IR spectroscopy. The adsorption of NO leads to formation of anionic nitrosyls and/or cis-hyponitrite ions and reveals the presence of coordinatively unsaturated Mn3+ ions. Upon NO/O2 adsorption at room temperature various nitro–nitrato structures are observed. The nitro–nitrato species produced with the participation of electrophilic oxygen species decompose at 350 8C directly to N2 and O2. No NO decomposition is observed in absence of molecular oxygen. The adsorbed nitro–nitrato species are inert towards the interaction with methane and block the active sites (Mn3+ ions) for its oxidation. Noticeable oxidation of the methane on the NOx -precovered sample is observed at temperatures higher than 350 8C due to the liberation of the active sites as a result of decomposition of the surface nitro–nitrato species. Mechanism explaining the promoting effect of the molecular oxygen in the NO decomposition is proposed. (c)2005 Elsevier B.V. All rights reserved

Clinical Outcomes of Advanced-Stage Cutaneous Lymphoma under Low-Dose Gemcitabine Treatment: Real-Life Data from the German Cutaneous Lymphoma Network

Background: Gemcitabine is an effective single-agent chemotherapy used in advanced stages of cutaneous T-cell lymphoma (CTCL). However, gemcitabine used in the current standard regimen is frequently associated with adverse events (AE), such as an increased risk for myelosuppression and severe infections. Objectives: We investigated in this retrospective study the effect of low-dose gemcitabine in pretreated advanced-stage CTCL and in blastic plasmacytoid dendritic cell neoplasia (BPDCN) regarding overall response (OR), progression-free survival (PFS), and AE. Material and Methods: A retrospective, multicenter study was conducted on 64 CTCL and BPDCN patients treated with gemcitabine in average absolute dosage of 1,800 mg/m(2) per cycle, which is 50% lower compared to standard dosage of 3,600 mg/m(2) per cycle (1,200 mg/m² day 1, 8, 15). Evaluation of response to therapy and AE was done 4-6 weeks after the sixth cycle. Results: OR was 62% with 11% demonstrating a complete response. The median time of PFS was 12 months and median time to next treatment was 7 months. Only 3/63 patients showed serious side effects, e.g., port infection or acute renal failure. Almost 73% of the patients experienced minor to moderate side effects (CTCAE grade 0-2). Fatigue (27.2%), fever (22.7%), and mild blood count alteration (18.2%) were the most common AE. Conclusions: This retrospective analysis supports the use of low-dose gemcitabine therapy in CTCL, demonstrating with 62% OR and PFS of 12 months an almost identical response rate and survival as compared to the standard dose therapy reported in previous studies but with a significantly improved safety profile and tolerability

Global patterns of care in advanced stage mycosis fungoides/Sezary syndrome: a multicenter retrospective follow-up study from the Cutaneous Lymphoma International Consortium

ABSTRACT Background Advanced-stage mycosis fungoides (MF)/Sezary syndrome (SS) patients are weighted by an unfavorable prognosis and share an unmet clinical need of effective treatments. International guidelines are available detailing treatment options for the different stages but without recommending treatments in any particular order due to lack of comparative trials. The aims of this second CLIC study were to retrospectively analyze the pattern of care worldwide for advanced-stage MF/SS patients, the distribution of treatments according to geographical areas (USA versus non-USA), and whether the heterogeneity of approaches has potential impact on survival. Patients and methods This study included 853 patients from 21 specialist centers (14 European, 4 USA, 1 each Australian, Brazilian, and Japanese). Results Heterogeneity of treatment approaches was found, with up to 24 different modalities or combinations used as first-line and 36% of patients receiving four or more treatments. Stage IIB disease was most frequently treated by total-skin-electron-beam radiotherapy, bexarotene and gemcitabine; erythrodermic and SS patients by extracorporeal photochemotherapy, and stage IVA2 by polychemotherapy. Significant differences were found between USA and non-USA centers, with bexarotene, photopheresis and histone deacetylase inhibitors most frequently prescribed for first-line treatment in USA while phototherapy, interferon, chlorambucil and gemcitabine in non-USA centers. These differences did not significantly impact on survival. However, when considering death and therapy change as competing risk events and the impact of first treatment line on both events, both monochemotherapy (SHR = 2.07) and polychemotherapy (SHR = 1.69) showed elevated relative risks. Conclusion This large multicenter retrospective study shows that there exist a large treatment heterogeneity in advanced MF/SS and differences between USA and non-USA centers but these were not related to survival, while our data reveal that chemotherapy as first treatment is associated with a higher risk of death and/or change of therapy and thus other therapeutic options should be preferable as first treatment approach

Planar, impedance- metric NO_x sensor with spinel- type SE for high temperature applications

This study displays the results obtained with a planar, impedance- metric sensors having a NiCr2O4- SE and a special FSZ electrolyte. The sensing characteristics to NO and to O2/NO gas mixtures were analyzed at temperatures up to 700 °C. The cross-selectivity to other flue gases was tested. As a new capable type of sensing parameter the total impedance was applied

Schichtentwicklung für Hochtemperatur- NOx Gassensoren

Übersichtsvortrag zu den Aktivitäten des Instituts für Werkstoff-Forschung auf dem Gebiet der Hochtemperatur NOx Gasensorik

Characterization of MnO-doped lanthanum hexaluminate (LaMnAl11O19) in terms of selective catalytic reduction of NOx by addition of hydrocarbon reductant (HC-SCR)

Environmental pollution by vehicles, turbines and aircrafts has enormously increased in the last decade. New generation lean-burn combustion engines which are more effective and require less fuel consumption will raise the emission of nitrogen oxides (NOX) even more. Thus, especially in urban areas, more stringed environmental regulations are to release which can only be met by development of new catalytic materials and concepts. Rare earth oxide catalysts are reported to offer highly effective conversion of NOX by methane (CH4) in the terms of selective catalytic reduction (HC-SCR). Especially La2Oa is reported to have a high NO reduction by CH4 to N2, although its technical realization as catalyst material has not yet reported and can be challenging due to the hydroscopic property of La2O3. Complex oxide compounds containing La2Oa however can be suitable alternatives and promising candidates for technical application as catalysts. In this study, LaMnAlnOi9 is characterized in terms of HC-SCR with methane. Phase and morphological characterization of the powder synthesized by sol-gel route and coatings by electron-beam physical vapor deposition (EB-PVD) deposition was presented. LaMnAlnOi9 crystallizes to the magnetoplumbite phase at about 1000°C and is then thermally stabile up to 1400°C. FTIR spectra of pressed sol-gel powder showed that NO is adsorbed superficially and oxidized by the surface. The addition of oxygen led to changes of the spectrum in the nitritenitrate region and the formation of NO+ and N2O4 species. The EB-PVD coated LaMnAlnOi9 layer was catalytically characterized at 200°, 400° and 600 °C and showed catalytic activity towards NO depending on temperature