Thermal conductivity profile determination in proton-irradiated ZrC by Spatial and frequency scanning thermal wave methods

Using complementary thermal wave methods, the irradiation damaged region of zirconium carbide (ZrC) is characterized by quantifiably profiling the thermophysical property degradation. The ZrC sample was irradiated by a 2.6 MeV proton beam at 600 °C to a dose of 1.75 displacements per atom. Spatial scanning techniques including scanning thermal microscopy (SThM), lock-in infrared thermography (lock-in IRT), and photothermal radiometry (PTR) were used to directly map the in-depth profile of thermal conductivity on a cross section of the ZrC sample. The advantages and limitations of each system are discussed and compared, finding consistent results from all techniques. SThM provides the best resolution finding a very uniform thermal conductivity envelope in the damaged region measuring ∼52 ± 2 μm deep. Frequency-based scanning PTR provides quantification of the thermal parameters of the sample using the SThM measured profile to provide validation of a heating model. Measured irradiated and virgin thermal conductivities are found to be 11.9 ± 0.5 W m−1 K−1 and 26.7 ±1 W m−1 K−1, respectively. A thermal resistance evidenced in the frequency spectra of the PTR results was calculated to be (1.58 ± 0.1) × 10−6 m2 K W−1. The measured thermal conductivity values compare well with the thermal conductivity extracted from the SThM calibrated signal and the spatially scanned PTR. Combined spatial and frequency scanning techniques are shown to provide a valuable, complementary combination for thermal property characterization of proton-irradiated ZrC. Such methodology could be useful for other studies of ion-irradiated materials

Micro-structured string-reactor for autothermal production of hydrogen

Novel micro-structured string-reactor designed as catalytically active wires placed in parallel into a tube was developed. The small diam. of the channels (.apprx.100 mm) leads to a short radial diffusion time, a narrow residence time distribution, and a low pressure drop. This reactor was applied for the oxidative steam-reforming of methanol to produce hydrogen in autothermal mode for fuel cells. The heat generated during methanol oxidn. at the reactor entrance is axially transferred to the reactor zone of the endothermic steam-reforming. The brass metal wires (Cu/Zn = 4/1) were used as precursors for the prepn. of string-catalysts. The brass wires have high thermal cond. (120 W/(m K)) and the chem. compn. is similar to the active phase of the Cu/ZnO/Al2O3 traditional catalyst during the steam-reforming of methanol. Brass-based string catalysts are obtained by metal/aluminum alloy formation on the outer surface of wires followed by an acid treatment leaching out aluminum. This treatment leads to an increase of the sp. surface area due to the formation of porous outer layer on the wire surface. The porous outer layer has the morphol. of Raney metals. The catalysts were first tested for the steam-reforming of methanol and showed high activity together with selectivities close to 100% towards hydrogen and carbon dioxide. Then, the optimized catalyst was tested during the methanol partial oxidn. and during steam reforming. Oxygen was obsd. to be totally converted via total oxidn. and therefore, higher methanol conversion in steam reforming together with CO2 selectivity of 99% and H2 selectivity of 60% were obtained. [on SciFinder (R)

Compact string reactor for authotermal hydrogen production

This study addresses the development of a compact reactor for oxidative steam-reforming of methanol (OSRM) to produce hydrogen in autothermal mode for fuel cells. The string reactor uses catalytically active brass wires with a diameter of 500 mu m placed in parallel into a tube. The micro-channels in the reactor for gases are formed between the wires presenting hydrodynamics similar to the one in multi-channel micro-reactors. Due to the high thermal conductivity of brass, the heat generated during methanol oxidation at the reactor entrance is transferred to the zone of the endothermic steam-reforming. The catalysts are prepared by Al-alloy formation on the surface of the brass wires followed by the partial leaching of Al. The catalyst presents a porous layer with the morphology of Raney metals and the chemical composition consistent with the Cu/Zn/Al-mixed oxide. The catalyst surface was additionally modified by incorporating chromium leading to Cr/Cu-spinel. This decreases the degree of the reduction of copper oxide and sintering leading to a stable catalyst. The catalyst was tested in OSRM showing high activity and selectivity to carbon dioxide and hydrogen. The string reactor presents nearly isothermal profile since the temperatures gradient within the reactor length is about 3 K. Micro-structured string reactor presents a short start-up and a fast transient behavior showing a rapid temperature change when adjusting the oxygen amount introduced into the reactor. (c) 2006 Elsevier B.V. All rights reserved

Evaluation of Mast Cell Activation Syndromes: Impact of Pathology and Immunohistology

Mast cell activation syndromes (MCAS) are clinically defined disease states with a largely unknown morphological background. Since mastocytosis may be associated with MCAS, it is crucial in every patient to document or exclude mastocytosis by appropriate histological, molecular, and serological investigations of tissues/organs that are commonly involved in mastocytosis like skin, mucosa of the gastrointestinal tract and bone marrow. Accordingly, histopathological investigation including immunohistological stains is crucial to reach the final diagnosis in such patients and to classify MCAS into primary MCAS, which can present with or without evidence of overt mastocytosis, or secondary MCAS, where an underlying disease with or without tissue inflammation is detected. Cases without evidence of mastocytosis, monoclonal mast cells, or any underlying disease should be termed idiopathic MCAS. When the activating point mutant KIT D816V is detectable but criteria for diagnosis of mastocytosis are not completely met, a so-called (mono)clonal MCAS as a subvariant of primary MCAS should be diagnosed. Copyright (C) 2012 S. Karger AG, Base

Palladium supported on filamentous active carbon as effective catalyst for liquid-phase hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol

Structured palladium catalysts suitable for three-phase reactions have been developed based on woven fabrics of active carbon fibers (ACF) as the catalytic supports. The Pd/ACF were tested in liq.-phase hydrogenation of 2-butyne-1,4-diol showing a selectivity towards 2-butene-1,4-diol up to 97% at conversions up to 80%. Multiple reuse of the catalyst with stable activity/selectivity in a batch reactor was also demonstrated. The reaction kinetics was studied and the main kinetic parameters were obtained. Assuming a Langmuir-Hinshelwood kinetics and a weak hydrogen adsorption a suitable kinetic model was developed consistent with the exptl. data. [on SciFinder (R)

Photothermal infrared thermography applied to the identification of thin layer thermophysical properties

Abstract: The aim of the present work is the thermal non-destructive characterisation of layers at the surface of metals. The sample is sinusoidally heated by means of an argon ion laser and a focal plane array infrared camera (CEDIP IRC 320-4 LW) is used to measure the temperature variations at the surface of the layer. A numerical lock-in procedure allows the detection of very weak temperature variations at the surface of the sample, down to a few mK when working from the acquisition of hundreds of images, yielding amplitude and absolute phase maps for modulation frequencies ranging from 0.1 Hz to 1000 Hz. An inverse procedure uses the Gauss-Newton parameter estimation method, in order to identify the thermal conductivity and the optical absorption coefficient of the layer. Confidence intervals on the parameters can also be estimated by the inverse procedure. More particular attention is devoted to the study of the sensitivity coefficients, as functions of the frequency range and of the radial range along the profiles, in order to optimise the identification procedure

Definitions, Criteria and Global Classification of Mast Cell Disorders with Special Reference to Mast Cell Activation Syndromes: A Consensus Proposal

Activation of tissue mast cells (MCs) and their abnormal growth and accumulation in various organs are typically found in primary MC disorders also referred to as mastocytosis. However, increasing numbers of patients are now being informed that their clinical findings are due to MC activation (MCA) that is neither associated with mastocytosis nor with a defined allergic or inflammatory reaction. In other patients with MCA, MCs appear to be clonal cells, but criteria for diagnosing mastocytosis are not met. A working conference was organized in 2010 with the aim to define criteria for diagnosing MCA and related disorders, and to propose a global unifying classification of all MC disorders and pathologic MC reactions. This classification includes three types of `MCA syndromes' (MCASs), namely primary MCAS, secondary MCAS and idiopathic MCAS. MCA is now defined by robust and generally applicable criteria, including (1) typical clinical symptoms, (2) a substantial transient increase in serum total tryptase level or an increase in other MC-derived mediators, such as histamine or prostaglandin D 2, or their urinary metabolites, and (3) a response of clinical symptoms to agents that attenuate the production or activities of MC mediators. These criteria should assist in the identification and diagnosis of patients with MCAS, and in avoiding misdiagnoses or overinterpretation of clinical symptoms in daily practice. Moreover, the MCAS concept should stimulate research in order to identify and exploit new molecular mechanisms and therapeutic targets. Copyright (C) 2011 S. Karger AG, Base

Midostaurin improves quality of life and mediator-related symptoms in advanced systemic mastocytosis

Background: Advanced systemic mastocytosis (advSM) is characterized by presence of the KIT D816V mutation and pathologic accumulation of neoplastic mast cells (MCs) in various tissues, leading to severe symptoms and organ damage (eg, cytopenias, liver dysfunction, portal hypertension, malabsorption, and weight loss). Treatment with midostaurin, an orally active multikinase/KIT inhibitor now approved for advSM in the United States and the European Union, resulted in a high rate of response accompanied by reduced MC infiltration of the bone marrow and lowered serum tryptase level. Objective: We aimed to determine whether midostaurin improves health-related quality of life (QOL) and MC mediator related symptoms in patients with advSM. Methods: In 116 patients with systemic mastocytosis (89 patients with advSM fulfilling the strict inclusion criteria of the D2201 study [ClinicalTrials.gov identifier NCT00782067]), QOL and symptom burden were assessed during treatment with midostaurin by using the 12-Item Short-Form Health Survey (SF-12) and the Memorial Symptom Assessment Scale patient reported questionnaires, respectively. MC mediator related symptoms were evaluated by using a specific physician-reported questionnaire Results: Over the first 6 cycles of treatment with midostaurin (ie, 6 months), patients experienced significant improvements in total SF-12 and Memorial Symptom Assessment Scale scores, as well as in subscores of each instrument. These improvements were durable during 36 months of follow-up. Similarly, we found substantial improvements (67%-100%) in all MC mediator related symptoms. Conclusion: QOL and MC mediator related symptoms significantly improve with midostaurin treatment in patients with advSM (ClinicalTrials.gov identifier, NCT00782067)

Standards of genetic testing in the diagnosis and prognostication of systemic mastocytosis in 2022: Recommendations of the EU-US cooperative group

Mastocytosis comprises rare heterogeneous diseases characterized by an increased accumulation of abnormal mast cells in various organs/tissues. The pathogenesis of mastocytosis is strongly linked to the presence of KIT-activating mutations. In systemic mastocytosis (SM), the most frequent mutation encountered is KIT p.D816V, whose presence constitutes one of the minor diagnostic criteria. Different techniques are used to search and quantify the KIT p.D816V mutant; however, allele-specific quantitative PCR and droplet digital PCR are today the most sensitive. The analysis of the KIT p.D816V allele burden has undeniable interest for diagnostic, prognostic, and therapeutic monitoring. The analysis of non–mast cell hematological compartments in SM is similarly important because KIT p.D816V multilineage involvement is associated with a worse prognosis. In addition, in advanced forms of SM, mutations in genes other than KIT are frequently identified and affect negatively disease outcome and response to therapy. Thus, combined quantitative and sensitive analysis of KIT mutations and next-generation sequencing of other recurrently involved myeloid genes make it possible to better characterize the extent of the affected cellular compartments and additional molecular aberrations, providing a more detailed overview of the complex mutational landscape of SM, in relation with the clinical heterogeneity of the disease. In this article, we report the latest recommendations of the EU-US Cooperative Group presented in September 2020 in Vienna during an international working conference, on the techniques we consider standard to detect and quantify the KIT p.D816V mutant in SM and additional myeloid mutations found in SM subtypes.D.D.M., J.J.L., and M.C.C. were supported by the Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health. P.V. was supported by the Austrian Science Fund (FWF) (grant nos. F4704-B20 and P32470-B)

Standards of pathology in the diagnosis of systemic mastocytosis: recommendations of the EU-US cooperative group

Pathology plays a central role in the diagnosis of systemic mastocytosis (SM), its delineation from other neoplasms and reactive conditions, and in monitoring of SM under therapy. The morphologic hallmark of SM is the accumulation of spindle-shaped, hypogranulated mast cells (MCs) in bone marrow (BM) and other extracutaneous tissues. Four of the 5 World Health Organization–defined diagnostic criteria (ie, compact MC aggregates [=major criterion]; atypical MC morphology; activating KIT point mutations; aberrant expression of CD25 and/or CD2 and/or CD30 in MCs [=minor criteria]) can be addressed by the pathologist. The final classification of SM variants as either BM mastocytosis, indolent SM, smoldering SM, aggressive SM (ASM), SM with an associated hematologic neoplasm (SM-AHN), or MC leukemia (MCL) has important prognostic significance and requires the integration of certain morphological, clinical, radiological, and biochemical data, referred to as B- and C-findings. Substantial diagnostic challenges may be posed to the pathologist and clinician especially in the so-called advanced SM variants, that is, ASM, MCL, and SM-AHN. In this article, updated recommendations of the EU-US Cooperative Group regarding standards of pathology in the diagnosis of SM, presented during the year 2020 Working Conference held in September in Vienna, are reported.T. I. George was supported by the ARUP Institute for Clinical and Experimental Pathology. K. Hartmann was supported by the Swiss National Science Foundation, grant number 310030_207705. D. D. Metcalfe, J. J. Lyons, and M. Carter were supported by the Division of Intramural Research, National Institutes of Allergic and Infectious Diseases, National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not represent the official views of the NIH. P. Valent was supported by the Austrian Science Funds (FWF), projects F4701-B20 and F4704-B20