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

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

Role of stem cell transplantation in treatment of primary cutaneous T-cell lymphoma

Background. Within the heterogeneous group of cutaneous T-cell lymphomas (CTCL) the therapeutic options for advanced and progressive forms are particularly limited. Objective. The therapeutic value of hematopoietic stem cell transplantation in CTCL was analyzed. Material and methods. A literature search using the keywords hematopoietic stem cell transplantation and cutaneous T-cell lymphoma was performed in PubMed. Studies between 1990 and 2017 were taken into account. The studies identified were analyzed for relevance and being up to date. Results. After reviewing the currently available literature no prospective randomized studies were found. Wu et al. showed a superiority of allogeneic transplantation in a comparison of autologous and allogeneic stem cell transplantation for cutaneous lymphoma. The graft-versus-lymphoma effect plays a significant role in a prolonged progression-free survival after allogeneic transplantation. By using a non-myeloablative conditioning regimen, stem cell transplantation can also be an option for elderly patients. The most extensive long-term data after allogeneic stem cell transplantation were reported by Duarte et al. in 2014. Conclusion. Autologous stem cell transplantation does not currently represent a therapeutic option, whereas allogeneic stem cell transplantation for advanced cutaneous T-cell lymphoma, using a non-myeloablative conditioning scheme, does represent a therapeutic option. However, there is no consensus on the appropriate patients and the right timing. Morbidity and mortality of complications should be taken into account. Thus, this procedure is currently subject to an individual case decision

Characterization of Porous ß-Alumina and Perovskite based Materials for their Selective Catalytic NOx-Reduction Activity at Temperatures up to 700°C

High temperature lean-burn combustion is one of the most effective approaches for the improvement of engine efficiency in both gas turbines and diesel engines. Stringent legislation to be released beyond 2008 concerning emissions for turbines and vehicles is already underway. NOx-emission reduction can be dealt effectively by catalytic combustion as it offers the potential of ultra-low NOx emissions (< 3 ppm), improved flame stability and fewer pulsations. Drawbacks are extremely high gas temperatures, restrictions in provided space in combustor and problems related to pre-mixture conditions. Exhaust gas after treatment is common application for fuel engines and can be adapted into the diesel engines and stationary gas turbines. Possible positions for a NOx-catalytic converter are hot-gas outlets behind the combustor and turbo-engines which require high-temperature stability of materials. ß-alumina and perovskite based ceramics doped with redox-active elements (Mn, Co) are good candidates for such applications through their high oxygen vacancies. Such ceramics can be produced as porous layers by chemical processing or electron-beam vapor deposition on porous-matrix fiber reinforced oxide composites. Sol-Gel-processed powders with surface areas from 9 to 13 m2/g are tested for their catalytic activity in a rig where a pre-heated carrier gas having 100-500 ppm NO and 4-8% O2 with a space velocity of 75 sccm/h.kg is sent over the catalytic material. Outlet gas is analyzed by means of a mass spectroscopy to determine the quantity and type of produced gas after conversion on the catalytic material. The properties of the 5 different catalytic materials are tested for direct NO-decomposition capacity and for selective catalytic reduction with addition of methane or propane. As the FT-IR analysis indicated, Mn-doped ß-alumina materials are restricted in terms of methane reduction since the adsorbed NO-species are non-reactive with methane. The experiments are conducted to overcome this behavior by using high chained hydrocarbons for reduction and/or by altering the composition with incorporation of Sr

Entwicklung von ß-Alumina basierten Materialien zur katalytischen Reduktion von NOx-Emission

Mager-vorvermischte Verbrennung ist eine attraktive Methode, um bei Gasturbinen, die Verbrennungseffizienz zu steigern. Allerdings können bei dieser Art der Verbrennung Probleme, beispielsweise Mager-Verlöschung, Flameninstabilität und Druck- Schwankungen auftreten, genauso wie die Entstehung von toxischen Gasen, eventuelle sauren Regen und den Treibhaus Effekt. Daher sind besonderst NOx-Emissionen bei Automobilen durch den Gesetzgeber streng geregelt und eine solche Regelung wird für Turbinen ab dem Jahre 2008 ebenfalls erwartet. Da bei herkömmlichen 3-Wege-Katalysatoren, die NOx-Reduktion unter stoichiometrischen Verbrennungsbedingungen läuft, besteht ein dringender Bedarf für die Entwicklung an neuen Materialien. Die katalytische Verbrennung stellt als primäres NOx-Verminderungssystem die beste Alternative dar, wobei sehr tiefe NOx-Emissionen (&lt;3 ppm) erreicht werden können, sowie ein verbesserte Verbrennungsstabilität und verminderte Druck-Schwankungen. Alternativ kann NOx auch durch die Verwendung von HC-SCR in Abgasnachbehandlungssysteme reduziert werden. Mit redox-aktiven Elementen dotierten ß-Alumina Keramiken besitzen durch ihre viele Zwischengitter Oxidationsplätze und Sauerstoff Fehlstellen eine gute katalytische Aktivität zur NOx Reduktion bei der katalytischen Verbrennung. Diese Materialien wurden zunächst über Sol-Gel-Verfahren synthetisiert und anschließend mittels EB-PVD als Schichten hergestellt und mit RFA, XRD und EDX-REM analysiert. Deren katalytischen Eigenschaften wurden in einem speziell konstruierten Messstand ermittelt, in dem eine bestimmte Menge NO, gemischt mit synthetischer Luft, erhitzt und mit einem Fluss von 1000 sccm/Min über die Katalysatormaterialien geleitet wurde. Das über den Katalysator reagierte Gas wurde analysiert, um Menge und Art der Umwandlung zu bestimmen. Die katalytische Aktivität zur selektiven Reduktion von NO wurde außerdem mittels FTIR ausgewertet. Die so erhaltenen Ergebnisse wurden mit denen aus dem Messstand verglichen, um das Prinzip der katalytischen Reduktion von NOx-Spezies festzustellen

Brentuximab vedotin in CD30(+) cutaneous lymphoma: How do we treat, how shall we treat? A review of the literature

Brentuximab vedotin is an antibody-drug conjugate that brings the antimicrotubule agent monomethyl auristatin E into CD30-expressing cells. Some prior studies demonstrated good efficacy in cutaneous lymphomas. The standard therapeutic scheme is 18 mg kg(-1) every 3 weeks. The background of this work is the fact that cutaneous lymphoma has a different pathophysiology and a dynamic other than systemic lymphomas. The objectives of this review were to get an overview of the currently used therapeutic regimen, and to check whether dose reduction or modified time intervals could be of benefit in a similar way with less toxicity. Therefore, we conducted a systematic review of the literature indexed in PubMed and the Cochrane Central Register of Controlled Trials up to April 2016. The procedure was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The review showed that the currently used therapeutic regimen is 18 mg kg(-1) every 3 weeks. No publications of dose-finding studies in CD30(+) cutaneous T-cell lymphoma (CTCL) were found. Two cases of patients, treated with a dose < 18 mg kg(-1), have been published. Brentuximab vedotin seems to be a powerful treatment option in refractory CD30(+) CTCL, and there is a trend that dose reductions, as well as prolonged treatment intervals, work without any loss of response and with fewer side-effects. What's already known about this topic? Brentuximab vedotin, a Food and Drug Administration-approved drug for the treatment of refractory Hodgkin lymphoma and refractory systemic anaplastic large-cell lymphoma, also shows a good efficacy in CD30(+) cutaneous T-cell lymphoma. The standard therapeutic scheme is 18 mg kg(-1) every 3 weeks. What does this study add? This review indicates that modified therapy protocols with lower doses or less frequent dosing schedules may be effective and reduce side-effects like peripheral neuropathy. Linked Comment: Scarisbrick. Br J Dermatol 2017; 177:1474-1475