Defining refractory migraine: results of the RHSIS Survey of American Headache Society members.
Schulman, Elliott A; Peterlin, B Lee; Lake, Alvin E; Lipton, Richard B; Hanlon, Alexandra; Siegel, Sherry; Levin, Morris; Goadsby, Peter J; Markley, Herbert G
2009-04-01
To gauge consensus regarding a proposed definition for refractory migraine proposed by Refractory Headache Special Interest Section, and where its use would be most appropriate. Headache experts have long recognized that a subgroup of headache sufferers remains refractory to treatment. Although different groups have proposed criteria to define refractory migraine, the definition remains controversial. The Refractory Headache Special Interest Section of the American Headache Society developed a definition through a consensus process, assisted by a literature review and initial membership survey. A 12-item questionnaire was distributed at the American Headache Society meeting in 2007 during a platform session and at the Refractory Headache Special Interest Section symposium. The same questionnaire was subsequently sent to all American Headache Society members via e-mail. A total of 151 responses from AHS members form the basis of this report. The survey instrument was designed using Survey Monkey. Frequencies and percentages of the survey were used to describe survey responses. American Headache Society members agreed that a definition for refractory migraine is needed (91%) that it should be added to the International Classification of Headache Disorders-2 (86%), and that refractory forms of non-migraine headache disorders should be defined (87%). Responders believed a refractory migraine definition would be of greatest value in selecting patients for clinical drug trials. The current refractory migraine definition requires a diagnosis of migraine, interference with function or quality of life despite modification of lifestyle factors, and adequate trials of acute and preventive medicines with established efficacy. The proposed criteria for the refractory migraine definition require failing 2 preventive medications to meet the threshold for failure. Although 42% of respondents agreed with the working definition of refractory migraine, 43% favored increasing the number to 3 (50%) or 4 (26%) preventive treatment failures. When respondents were asked if they felt that the proposed definition was appropriate to select patients for invasive procedures (patent foramen ovale repair or stimulators) only 44% agreed. There is a consensus for a need for a definition for refractory migraine and that it should be added to the International Classification of Headache Disorder-2. There was also general agreement by the responders that refractory forms of non-migraine headache disorders should be defined.
Anderson, Iver E.; Lograsso, Barbara K.; Ellis, Timothy W.
1994-01-01
A metallic melt is atomized using a high pressure atomizing gas wherein the temperature of the melt and the composition of the atomizing gas are selected such that the gas and melt react in the atomization spray zone to form a refractory or intermetallic compound in the as-atomized powder particles. A metallic melt is also atomized using a high pressure atomizing gas mixture gas wherein the temperature of the melt and the ratio of a reactive gas to a carrier gas are selected to form powder particles comprising a supersaturated solid solution of the atomic species of the reactive gas in the particles. The powder particles are then heat treated to precipitate dispersoids in-situ therein to form a dispersion strengthened material.
Refractory lining system for high wear area of high temperature reaction vessel
Hubble, David H.; Ulrich, Klaus H.
1998-01-01
A refractory-lined high temperature reaction vessel comprises a refractory ring lining constructed of refractory brick, a cooler, and a heat transfer medium disposed between the refractory ring lining and the cooler. The refractory brick comprises magnesia (MgO) and graphite. The heat transfer medium contacts the refractory brick and a cooling surface of the cooler, and is composed of a material that accommodates relative movement between the refractory brick and the cooler. The brick is manufactured such that the graphite has an orientation providing a high thermal conductivity in the lengthwise direction through the brick that is higher than the thermal conductivity in directions perpendicular to the lengthwise direction. The graphite preferably is flake graphite, in the range of about 10 to 20 wt %, and has a size distribution selected to provide maximum brick density. The reaction vessel may be used for performing a reaction process including the steps of forming a layer of slag on a melt in the vessel, the slag having a softening point temperature range, and forming a protective frozen layer of slag on the interior-facing surface of the refractory lining in at least a portion of a zone where the surface contacts the layer of slag, the protective frozen layer being maintained at or about the softening point of the slag.
Electrochemical cell with powdered electrically insulative material as a separator
Mathers, James P.; Olszanski, Theodore W.; Boquist, Carl W.
1978-01-01
A secondary electrochemical cell includes electrodes separated by a layer of electrically insulative powder. The powder includes refractory materials selected from the oxides and nitrides of metals and metaloids. The powdered refractory material, blended with electrolyte particles, can be compacted in layers with electrode materials to form an integral electrode structure or separately assembled into the cell. The assembled cell is heated to operating temperature leaving porous layers of electrically insulative, refractory particles, containing molten electrolyte between the electrodes.
Method of preparing a powdered, electrically insulative separator for use in an electrochemical cell
Cooper, Tom O.; Miller, William E.
1978-01-01
A secondary electrochemical cell includes electrodes separated by a layer of electrically insulative powder. The powder includes refractory materials selected from the oxides and nitrides of metals and metaloids. The powdered refractory material, blended with electrolyte particles, is compacted as layers onto an electrode to form an integral electrode structure and assembled into the cell. The assembled cell is heated to its operating temperature leaving porous layers of electrically insulative, refractory particles, containing molten electrolyte between the electrodes.
Anderson, I.E.; Lograsso, B.K.; Ellis, T.W.
1994-11-29
A metallic melt is atomized using a high pressure atomizing gas wherein the temperature of the melt and the composition of the atomizing gas are selected such that the gas and melt react in the atomization spray zone to form a refractory or intermetallic compound in the as-atomized powder particles. A metallic melt is also atomized using a high pressure atomizing gas mixture gas wherein the temperature of the melt and the ratio of a reactive gas to a carrier gas are selected to form powder particles comprising a supersaturated solid solution of the atomic species of the reactive gas in the particles. The powder particles are then heat treated to precipitate dispersoids in-situ therein to form a dispersion strengthened material. 9 figures.
Refractory lining system for high wear area of high temperature reaction vessel
Hubble, D.H.; Ulrich, K.H.
1998-04-21
A refractory-lined high temperature reaction vessel comprises a refractory ring lining constructed of refractory brick, a cooler, and a heat transfer medium disposed between the refractory ring lining and the cooler. The refractory brick comprises magnesia (MgO) and graphite. The heat transfer medium contacts the refractory brick and a cooling surface of the cooler, and is composed of a material that accommodates relative movement between the refractory brick and the cooler. The brick is manufactured such that the graphite has an orientation providing a high thermal conductivity in the lengthwise direction through the brick that is higher than the thermal conductivity in directions perpendicular to the lengthwise direction. The graphite preferably is flake graphite, in the range of about 10 to 20 wt %, and has a size distribution selected to provide maximum brick density. The reaction vessel may be used for performing a reaction process including the steps of forming a layer of slag on a melt in the vessel, the slag having a softening point temperature range, and forming a protective frozen layer of slag on the interior-facing surface of the refractory lining in at least a portion of a zone where the surface contacts the layer of slag, the protective frozen layer being maintained at or about the softening point of the slag. 10 figs.
Refractory lining system for high wear area of high temperature reaction vessel
Hubble, D.H.; Ulrich, K.H.
1998-09-22
A refractory-lined high temperature reaction vessel comprises a refractory ring lining constructed of refractory brick, a cooler, and a heat transfer medium disposed between the refractory ring lining and the cooler. The refractory brick comprises magnesia (MgO) and graphite. The heat transfer medium contacts the refractory brick and a cooling surface of the cooler, and is composed of a material that accommodates relative movement between the refractory brick and the cooler. The brick is manufactured such that the graphite has an orientation providing a high thermal conductivity in the lengthwise direction through the brick that is higher than the thermal conductivity in directions perpendicular to the lengthwise direction. The graphite preferably is flake graphite, in the range of about 10 to 20 wt %, and has a size distribution selected to provide maximum brick density. The reaction vessel may be used for performing a reaction process including the steps of forming a layer of slag on a melt in the vessel, the slag having a softening point temperature range, and forming a protective frozen layer of slag on the interior-facing surface of the refractory lining in at least a portion of a zone where the surface contacts the layer of slag, the protective frozen layer being maintained at or about the softening point of the slag. 10 figs.
Metal alloy coatings and methods for applying
Merz, Martin D.; Knoll, Robert W.
1991-01-01
A method of coating a substrate comprises plasma spraying a prealloyed feed powder onto a substrate, where the prealloyed feed powder comprises a significant amount of an alloy of stainless steel and at least one refractory element selected from the group consisting of titanium, zirconium, hafnium, niobium, tantalum, molybdenum, and tungsten. The plasma spraying of such a feed powder is conducted in an oxygen containing atmosphere and forms an adherent, corrosion resistant, and substantially homogenous metallic refractory alloy coating on the substrate.
Vacuum Plasma Spray (VPS) Forming of Solar Thermal Propulsion Components Using Refractory Metals
NASA Technical Reports Server (NTRS)
Zimmerman, Frank; Gerish, Harold; Davis, William; Hissam, D. Andy
1998-01-01
The Thermal Spray Laboratory at NASA's Marshall Space Flight Center has developed and demonstrated a fabrication technique using Vacuum Plasma Spray (VPS) to form structural components from a tungsten/rhenium alloy. The components were assembled into an absorption cavity for a fully-functioning, ground test unit of a solar thermal propulsion engine. The VPS process deposits refractory metal onto a graphite mandrel of the desired shape. The mandrel acts as a male mold, forming the required contour and dimensions of the inside surface of the deposit. Tungsten and tungsten/25% rhenium were used in the development and production of several absorber cavity components. These materials were selected for their high temperature (less than 2500 C) strength. Each absorber cavity comprises 3 coaxial shells with two, double-helical flow passages through which the propellant gas flows. This paper describes the processing techniques, design considerations, and process development associated with forming these engine components.
40 CFR 471.50 - Applicability; description of the refractory metals forming subcategory.
Code of Federal Regulations, 2010 CFR
2010-07-01
... refractory metals forming subcategory. 471.50 Section 471.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS NONFERROUS METALS FORMING AND METAL POWDERS POINT SOURCE CATEGORY Refractory Metals Forming Subcategory § 471.50 Applicability; description of the...
Transient liquid phase ceramic bonding
Glaeser, Andreas M.
1994-01-01
Ceramics are joined to themselves or to metals using a transient liquid phase method employing three layers, one of which is a refractory metal, ceramic or alloy. The refractory layer is placed between two metal layers, each of which has a lower melting point than the refractory layer. The three layers are pressed between the two articles to be bonded to form an assembly. The assembly is heated to a bonding temperature at which the refractory layer remains solid, but the two metal layers melt to form a liquid. The refractory layer reacts with the surrounding liquid and a single solid bonding layer is eventually formed. The layers may be designed to react completely with each other and form refractory intermetallic bonding layers. Impurities incorporated into the refractory metal may react with the metal layers to form refractory compounds. Another method for joining ceramic articles employs a ceramic interlayer sandwiched between two metal layers. In alternative embodiments, the metal layers may include sublayers. A method is also provided for joining two ceramic articles using a single interlayer. An alternate bonding method provides a refractory-metal oxide interlayer placed adjacent to a strong oxide former. Aluminum or aluminum alloys are joined together using metal interlayers.
High-quantum efficiency, long-lived luminescing refractory oxides
Chen, Yok; Gonzalez, Roberto; Summers, Geoffrey P.
1984-01-01
A crystal having a high-quantum efficiency and a long period of luminescence is formed of an oxide selected from the group consisting of magnesium oxide and calcium oxide and possessing a concentration ratio of H.sup.- ions to F centers in the range of about 0.05 to about 10.
Vacuum Plasma Spray (VPS) Forming of Solar Thermal Propulsion Components Using Refractory Metals
NASA Technical Reports Server (NTRS)
Zimmerman, Frank R.; Hissam, David A.; Gerrish, Harold P.; Davis, William M.
1999-01-01
The Thermal Spray Laboratory at NASA's Marshall Space Flight Center has developed and demonstrated a fabrication technique using Vacuum Plasma Spray (VPS) to form structural components from a tungsten/rhenium alloy. The components were assembled into an absorber cavity for a fully-functioning, ground test unit of a solar then-nal propulsion engine. The VPS process deposits refractory metal onto a graphite mandrel of the desired shape. The mandrel acts as a male mold, forming the required contour and dimensions of the inside surface of the deposit. Tungsten and tungsten/25% rhenium were used in the development and production of several absorber cavity components. These materials were selected for their high temperature (greater than 25000 C [greater than 4530 F]) strength. Each absorber cavity comprises 3 coaxial shells with two, double-helical flow passages through which the propellant gas flows. This paper describes the processing techniques, design considerations, and process development associated with forming these engine components.
Forming Refractory Insulation On Copper Wire
NASA Technical Reports Server (NTRS)
Setlock, J.; Roberts, G.
1995-01-01
Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.
Method of making a composite refractory material
Morrow, Marvin S.; Holcombe, Cressie E.
1995-01-01
A composite refractory material is prepared by combining boron carbide with furan resin to form a mixture containing about 8 wt. % furan resin. The mixture is formed into a pellet which is placed into a grit pack comprising an oxide of an element such as yttrium to form a sinterable body. The sinterable body is sintered under vacuum with microwave energy at a temperature no greater than 2000.degree. C. to form a composite refractory material.
Method of making a composite refractory material
Morrow, M.S.; Holcombe, C.E.
1995-09-26
A composite refractory material is prepared by combining boron carbide with furan resin to form a mixture containing about 8 wt. % furan resin. The mixture is formed into a pellet which is placed into a grit pack comprising an oxide of an element such as yttrium to form a sinterable body. The sinterable body is sintered under vacuum with microwave energy at a temperature no greater than 2000 C to form a composite refractory material.
Unconventional treatments for chronic inflammatory demyelinating polyneuropathy.
Rajabally, Yusuf A
2017-10-01
This article focuses on the unconventional treatments used in chronic inflammatory demyelinating polyneuropathy (CIDP). First line, evidence-based treatments for CIDP include corticosteroids, immunoglobulins and plasma exchanges. Several unproven treatments are however given in treatment-refractory disease or to reduce requirements in validated therapies for reasons of side effects/practical delivery/cost. Despite methodological issues, IFN-α, azathioprine and methotrexate have not been shown to be useful in randomized controlled trials. Cyclophosphamide, rituximab and, as final resort in highly selected cases, hematopoietic stem cell transplant may be options considered in severely disabled refractory patients. Debatably, azathioprine, methotrexate, cyclosporine and mycophenolate mofetil are still occasionally used, among others, in milder disease. Physical therapy may be of benefit in CIDP but is not systematically considered as an integral part of management strategies. Current literature relating to unconventional therapies in CIDP is reviewed here and the possible avenues that require consideration in severe refractory disease and less disabling forms are discussed.
Cufí, Sílvia; Vazquez-Martin, Alejandro; Oliveras-Ferraros, Cristina; Corominas-Faja, Bruna; Cuyàs, Elisabet; López-Bonet, Eugeni; Martin-Castillo, Begoña; Joven, Jorge; Menendez, Javier A.
2013-01-01
Autophagy may control the de novo refractoriness of HER2 gene-amplified breast carcinomas to the monoclonal antibody trastuzumab (Herceptin). Tumor cells originally obtained from a patient who rapidly progressed on trastuzumab ab initio display increased cellular levels of the LC3-II protein—a finding that correlates with increased numbers of autophagosomes—and decreased levels of the autophagy receptor p62/SQSTM1, a protein selectively degraded by autophagy. Trastuzumab-refractory cells are in a state of “autophagy addiction” because genetic ablation of autophagy-specific genes (ATG8, ATG5, ATG12) notably reduces intrinsic refractoriness to trastuzumab. When the anti-malarial lysosomotropic drug chloroquine impedes autophagic resolution of the accumulation of autophagolysosomes formed in the presence of trastuzumab, cells commit to die by apoptosis. Accordingly, combination treatment with trastuzumab and chloroquine radically suppresses tumor growth by > 90% in a tumor xenograft completely refractory to trastuzumab. Adding chloroquine to trastuzumab-based regimens may therefore improve outcomes among women with autophagy-addicted HER2-positive breast cancer. PMID:23965851
Cufí, Sílvia; Vazquez-Martin, Alejandro; Oliveras-Ferraros, Cristina; Corominas-Faja, Bruna; Cuyàs, Elisabet; López-Bonet, Eugeni; Martin-Castillo, Begoña; Joven, Jorge; Menendez, Javier A
2013-01-01
Autophagy may control the de novo refractoriness of HER2 gene-amplified breast carcinomas to the monoclonal antibody trastuzumab (Herceptin). Tumor cells originally obtained from a patient who rapidly progressed on trastuzumab ab initio display increased cellular levels of the LC3-II protein--a finding that correlates with increased numbers of autophagosomes--and decreased levels of the autophagy receptor p62/SQSTM1, a protein selectively degraded by autophagy. Trastuzumab-refractory cells are in a state of "autophagy addiction" because genetic ablation of autophagy-specific genes (ATG8, ATG5, ATG12) notably reduces intrinsic refractoriness to trastuzumab. When the anti-malarial lysosomotropic drug chloroquine impedes autophagic resolution of the accumulation of autophagolysosomes formed in the presence of trastuzumab, cells commit to die by apoptosis. Accordingly, combination treatment with trastuzumab and chloroquine radically suppresses tumor growth by > 90% in a tumor xenograft completely refractory to trastuzumab. Adding chloroquine to trastuzumab-based regimens may therefore improve outcomes among women with autophagy-addicted HER2-positive breast cancer.
Cometary dust: the diversity of primitive refractory grains
Ishii, H. A.
2017-01-01
Comet dust is primitive and shows significant diversity. Our knowledge of the properties of primitive cometary particles has expanded significantly through microscale investigations of cosmic dust samples (anhydrous interplanetary dust particles (IDPs), chondritic porous (CP) IDPs and UltraCarbonaceous Antarctic micrometeorites, Stardust and Rosetta), as well as through remote sensing (Spitzer IR spectroscopy). Comet dust are aggregate particles of materials unequilibrated at submicrometre scales. We discuss the properties and processes experienced by primitive matter in comets. Primitive particles exhibit a diverse range of: structure and typology; distribution of constituents; concentration and form of carbonaceous and refractory organic matter; Mg- and Fe-contents of the silicate minerals; sulfides; existence/abundance of type II chondrule fragments; high-temperature calcium–aluminium inclusions and ameboid-olivine aggregates; and rarely occurring Mg-carbonates and magnetite, whose explanation requires aqueous alteration on parent bodies. The properties of refractory materials imply there were disc processes that resulted in different comets having particular selections of primitive materials. The diversity of primitive particles has implications for the diversity of materials in the protoplanetary disc present at the time and in the region where the comets formed. This article is part of the themed issue ‘Cometary science after Rosetta’. PMID:28554979
Coated graphite articles useful in metallurgical processes and method for making same
Holcombe, Cressie E.; Bird, Eugene L.
1995-01-01
Graphite articles including crucibles and molds used in metallurgical processes involving the melting and the handling of molten metals and alloys that are reactive with carbon when in a molten state and at process temperatures up to about 2000.degree. C. are provided with a multiple-layer coating for inhibiting carbon diffusion from the graphite into the molten metal or alloys. The coating is provided by a first coating increment of a carbide-forming metal on selected surfaces of the graphite, a second coating increment of a carbide forming metal and a refractory metal oxide, and a third coating increment of a refractory metal oxide. The second coating increment provides thermal shock absorbing characteristics to prevent delamination of the coating during temperature cycling. A wash coat of unstabilized zirconia or titanium nitride can be applied onto the third coating increment to facilitate release of melts from the coating.
High Temperature Oxidation-Resistant Thruster Research
1990-02-01
substrates: Refractory metals, ! Ceramics, Composites and I Carbon - carbon . Rhenium and hafnium carbide were selected based on their properties I and... carbon . Rhenium was selected as the primary refractory metal candidate because of its high melting point, no ductile-to- brittle transition in the...of rhenium (Re) with those of other refractory metals. Rhenium has the second highest melting point of the elements, 3013 C, second only to tungsten
2018-03-05
Relapsed Acute Lymphoblastic Leukemia (ALL); Refractory Acute Lymphoblastic Leukemia (ALL); Relapsed Acute Myelogenous Leukemia (AML); Refractory Acute Myelogenous Leukemia (AML); Relapsed Mixed Lineage Leukemia; Refractory Mixed Lineage Leukemia; Relapsed Biphenotypic Leukemia; Refractory Biphenotypic Leukemia; Chronic Myelogenous Leukemia (CML) in Blast Crisis
Corrosion assessment of refractory materials for high temperature waste vitrification
DOE Office of Scientific and Technical Information (OSTI.GOV)
Marra, J.C.; Congdon, J.W.; Kielpinski, A.L.
1995-11-01
A variety of vitrification technologies are being evaluated to immobilize radioactive and hazardous wastes following years of nuclear materials production throughout the Department of Energy (DOE) complex. The compositions and physical forms of these wastes are diverse ranging from inorganic sludges to organic liquids to heterogeneous debris. Melt and off-gas products can be very corrosive at the high temperatures required to melt many of these waste streams. Ensuring material durability is required to develop viable treatment processes. Corrosion testing of materials in some of the anticipated severe environments is an important aspect of the materials identification and selection process. Corrosionmore » coupon tests on typical materials used in Joule heated melters were completed using glass compositions with high salt contents. The presence of chloride in the melts caused the most severe attack. In the metal alloys, oxidation was the predominant corrosion mechanism, while in the tested refractory material enhanced dissolution of the refractory into the glass was observed. Corrosion testing of numerous different refractory materials was performed in a plasma vitrification system using a surrogate heterogeneous debris waste. Extensive corrosion was observed in all tested materials.« less
Determining Surgical Candidacy in Temporal Lobe Epilepsy
Mansouri, Alireza; Fallah, Aria; Valiante, Taufik A.
2012-01-01
Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy that is amenable to surgical treatment. In the carefully selected patient, excellent seizure outcome can be achieved with minimal or no side effects from surgery. This may result in improved psychosocial functioning, achieving higher education, and maintaining or gaining employment. The objective of this paper is to discuss the surgical selection process of a patient with TLE. We define what constitutes a patient that has medically refractory TLE, describe the typical history and physical examination, and distinguish between mesial TLE and neocortical TLE. We then review the role of routine (ambulatory/sleep-deprived electroencephalography (EEG), video EEG, magnetic resonance imaging (MRI), neuropsychological testing, and Wada testing) and ancillary preoperative testing (positron emission tomography, single-photon emission computed tomography (SPECT), subtraction ictal SPECT correlated to MRI (SISCOM), magnetoencephalography, magnetic resonance spectroscopy, and functional MRI) in selecting surgical candidates. We describe the surgical options for resective epilepsy surgery in TLE and its commonly associated risks while highlighting some of the controversies. Lastly, we present teaching cases to illustrate the presurgical workup of patients with medically refractory TLE. PMID:22957238
Emergency Surgery for Refractory Status Epilepticus.
Botre, Abhijeet; Udani, Vrajesh; Desai, Neelu; Jagadish, Spoorthy; Sankhe, Milind
2017-08-15
Management of refractory status epilepticus in children is extremely challenging. Two children with medically refractory status epilepticus, both of whom had lesional pathology on MRI and concordant data on EEG and PET scan. Emergency hemispherotomy performed in both patients. A complete, sustained seizure freedom obtained postoperatively. Emergency surgery is a treatment option in selected cases of drug refractory status epilepticus with lesional pathology and concordant data.
Modification of surface properties of copper-refractory metal alloys
Verhoeven, John D.; Gibson, Edwin D.
1993-10-12
The surface properties of copper-refractory metal (CU-RF) alloy bodies are modified by heat treatments which cause the refractory metal to form a coating on the exterior surfaces of the alloy body. The alloys have a copper matrix with particles or dendrites of the refractory metal dispersed therein, which may be niobium, vanadium, tantalum, chromium, molybdenum, or tungsten. The surface properties of the bodies are changed from those of copper to that of the refractory metal.
Damm, Robert; Seidensticker, Ricarda; Ulrich, Gerhard; Breier, Leonie; Steffen, Ingo G; Seidensticker, Max; Garlipp, Benjamin; Mohnike, Konrad; Pech, Maciej; Amthauer, Holger; Ricke, Jens
2016-07-20
In treatment-refractory liver dominant metastatic colorectal cancer, the role of liver directed therapies still is unclear. We sought to determine a prognostic score for Y90 radioembolization in these patients. We analyzed 106 patients with refractory liver dominant mCRC who had undergone a total of 178 Y90 radioembolizations with resin microspheres was collected. Potential factors influencing survival were analyzed using a Cox regression. The Log rank test served to establish prognostic factors and to form a clinical score for outcome prediction after Y90 radioembolization. Median survival of all patients was 6.7 months. Neither age nor prior surgical or systemic therapy nor metastatic spread had an effect on survival. In contrast, hepatic tumor load, Karnofsky index as well as CEA and CA19-9 serums level had a significant influence (p < 0.001, p = 0.037, p = 0.023 and p < 0.001, respectively). These three factors formed a score with 1 point each for tumor load >20 %, CEA >130 ng/ml or CA19-9 > 200U/ml and Karnofsky index <80 %. Patients with a score of 0 and 1 displayed a median OS of 10.4 months. Patients with a score of 2 and 3 demonstrated a median OS of 5.1 months only (p < 0.001). Overaggressive patient selection for Y90 radioembolization of liver dominant chemorefractory mCRC is of questionable benefit. A scoring system comprising hepatic tumor load, CEA and CA19-9 serum levels and Karnofsky index (TuCK-score) may support an improved patient selection. In our cohort of liver only versus liver dominant disease, extrahepatic lung or lymphatic metastases did not significantly alter the prognosis.
Narayan, Jagdish; Chen, Yok
1983-01-01
This invention is a new process for producing refractory crystalline oxides having improved or unusual properties. The process comprises the steps of forming a doped-metal crystal of the oxide; exposing the doped crystal in a bomb to a reducing atmosphere at superatmospheric pressure and a temperature effecting precipitation of the dopant metal in the crystal lattice of the oxide but insufficient to effect net diffusion of the metal out of the lattice; and then cooling the crystal. Preferably, the cooling step is effected by quenching. The process forms colloidal precipitates of the metal in the oxide lattice. The process may be used, for example, to produce thermally stable black MgO crystalline bodies containing magnetic colloidal precipitates consisting of about 99% Ni. The Ni-containing bodies are solar-selective absorbers, having a room-temperature absorptivity of about 0.96 over virtually all of the solar-energy spectrum and exhibiting an absorption edge in the region of 2 .mu.m. The process parameters can be varied to control the average size of the precipitates. The process can produce a black MgO crystalline body containing colloidal Ni precipitates, some of which have the face-centered-cubic structure and others of which have the body-centered cubic structure. The products of the process are metal-precipitate-containing refractory crystalline oxides which have improved or unique optical, mechanical, magnetic, and/or electronic properties.
NASA Technical Reports Server (NTRS)
Gordon, W. A.
1975-01-01
Matrix effects related to the chemical form of analyzed materials were studied. An arc in argon was used which was buffered with silver chloride. The effect of chemical form was minimal for a variety of metals, oxides, and carbides representing the most refractory compounds and thermally stable metal-containing molecules. Only four of the most refractory materials known showed significant emission depressions due to incomplete volatilization in the arc system. These results are discussed in terms of vapor pressures of the solid materials placed on the anodes and dissociation reactions of the molecules in the gaseous environment.
High density-high purity graphite prepared by hot isostatic pressing in refractory metal containers
Hoenig, Clarence L.
1994-01-01
Porous graphite in solid form is hot isostatically pressed in a refractory metal container to produce a solid graphite monolith with a bulk density greater than or equal to 2.10 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed, chemically vapor deposited, or coated by some other suitable means onto graphite. Hot isostatic pressing at 2200.degree. C. and 30 KSI (206.8 MPa) argon pressure for two hours produces a bulk density of 2.10 g/cc. Complex shapes can be made.
High density-high purity graphite prepared by hot isostatic pressing in refractory metal containers
Hoenig, C.L.
1994-08-09
Porous graphite in solid form is hot isostatically pressed in a refractory metal container to produce a solid graphite monolith with a bulk density greater than or equal to 2.10 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed, chemically vapor deposited, or coated by some other suitable means onto graphite. Hot isostatic pressing at 2,200 C and 30 KSI (206.8 MPa) argon pressure for two hours produces a bulk density of 2.10 g/cc. Complex shapes can be made. 1 fig.
NASA Astrophysics Data System (ADS)
Kaneko, Tetsuya Kenneth
The penetration rate of molten mineral contents (slag) from spent carbonaceous feedstock into porous ceramic-oxide refractory linings is a critical parameter in determining the lifecycle of integrated gasification combined cycle energy production plants. Refractory linings that withstand longer operation without interruption are desirable because they can mitigate consumable and maintenance costs. Although refractory degradation has been extensively studied for many other high-temperature industrial processes, this work focuses on the mechanisms that are unique to entrained-flow gasification systems. The use of unique feedstock mixtures, temperatures from 1450 °C to 1600 °C, and oxygen partial pressures from 10-7 atm to 10-9 atm pose engineering challenges in designing an optimal refractory material. Experimentation, characterization, and modeling show that gasifier slag infiltration into porous refractory is determined by interactions between the slag and the refractory that either form a physical barrier that impedes fluid flow or induce an increased fluid viscosity that decelerates the velocity of the fluid body. The viscosity of the slag is modified by the thermal profile of the refractory along the penetration direction as well as reactions between the slag and refractory that alter the chemistry, and thereby the thermo-physical properties of the fluid. Infiltration experiments reveal that the temperature gradient inherently present along the refractory lining limits penetration. A refractory in near-isothermal conditions demonstrates deeper slag penetration as compared to one that experiences a steeper thermal profile. The decrease in the local temperatures of the slag as it travels deeper into the refractory increases the viscosity of the fluid, which in turn slows the infiltration velocity of fluid body into the pores of the refractory microstructure. With feedstock mixtures that exhibit high iron-oxide concentrations, a transition-metal-oxide, the oxygen partial pressure of the operating atmosphere regulates the penetration of slag into refractory. The viscosity of the slag, which dictates its penetration rate, is influenced by the oxidation state of the Fe cation. Slag penetrations are shallower in oxidizing conditions than they are in reducing conditions because the iron-oxide from the slag solutions into the corundum-structured refractory and the slag is depleted of iron-oxide, increasing the viscosity of slags. Equally, the chemistries of both the refractory and slag materials dictate the course of penetration. Cr2O3-Al2O3 refractory limits mixed feedstock slag penetration through formation of a chromium spinel layer that functions as a physical obstacle against fluid flow. Al2O 3-SiO2 refractory limits eastern coal feedstock slag penetration as a result of refractory dissolution of SiO2, which increases the viscosity of slags. A physical model, which considers unidirectional fluid flow of slag through each pore of the porous microstructure of the refractory, sufficiently approximates the penetration depth of the slag into the refractory. Agreement between experiments and the physical model demonstrates that the slag is driven into the refractory by capillary pressure. Since the viscosity of the slag continuously changes as the slag travels through the inherent temperature gradient of the refractory lining, the model incorporates dynamic viscosities that are dependent on both temperature and composition to project depths that are unique to the experimental parameters. The significantly different length scales of the radial and penetration directions of the pores allows for the application of a lubrication approximation onto the momentum equation. This process produces an analytical solution that effectively envelopes the variable viscosity into a single term.
Stevens, Courtney; Paulsen, David; Yasen, Alia; Neville, Helen
2015-02-01
Previous neuroimaging studies indicate that lower socio-economic status (SES) is associated with reduced effects of selective attention on auditory processing. Here, we investigated whether lower SES is also associated with differences in a stimulus-driven aspect of auditory processing: the neural refractory period, or reduced amplitude response at faster rates of stimulus presentation. Thirty-two children aged 3 to 8 years participated, and were divided into two SES groups based on maternal education. Event-related brain potentials were recorded to probe stimuli presented at interstimulus intervals (ISIs) of 200, 500, or 1000 ms. These probes were superimposed on story narratives when attended and ignored, permitting a simultaneous experimental manipulation of selective attention. Results indicated that group differences in refractory periods differed as a function of attention condition. Children from higher SES backgrounds showed full neural recovery by 500 ms for attended stimuli, but required at least 1000 ms for unattended stimuli. In contrast, children from lower SES backgrounds showed similar refractory effects to attended and unattended stimuli, with full neural recovery by 500 ms. Thus, in higher SES children only, one functional consequence of selective attention is attenuation of the response to unattended stimuli, particularly at rapid ISIs, altering basic properties of the auditory refractory period. Together, these data indicate that differences in selective attention impact basic aspects of auditory processing in children from lower SES backgrounds. Copyright © 2013 Elsevier B.V. All rights reserved.
Holcombe, Jr., Cressie E.
1979-01-01
Novel concrete compositions comprise particles of aggregate material embedded in a cement matrix, said cement matrix produced by contacting an oxide selected from the group of Y.sub.2 O.sub.3, La.sub.2 O.sub.3, Nd.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Eu.sub.2 O.sub.3 and Gd.sub.2 O.sub.3 with an aqueous solution of a salt selected from the group of NH.sub.4 NO.sub.3, NH.sub.4 Cl, YCl.sub.3 and Mg(NO.sub.3).sub.2 to form a fluid mixture; and allowing the fluid mixture to harden.
Method of coating graphite tubes with refractory metal carbides
Wohlberg, C.
1973-12-11
A method of coating graphite tubes with a refractory metal carbide is described. An alkali halide is reacted with a metallic oxide, the metallic portion being selected from the IVth or Vth group of the Periodic Table, the resulting salt reacting in turn with the carbon to give the desired refractory metal carbide coating. (Official Gazette)
Backward Response-Level Crosstalk in the Psychological Refractory Period Paradigm
ERIC Educational Resources Information Center
Miller, Jeff; Alderton, Mark
2006-01-01
Bottleneck models of psychological refractory period (PRP) tasks suggest that a Task 1 response should be unaffected by the Task 2 response in the same trial, because selection of the former finishes before selection of the latter begins. Contrary to this conception, the authors found backward response-level crosstalk effects in which Task 2…
REFRACTORY COATING FOR GRAPHITE MOLDS
Stoddard, S.D.
1958-06-24
Refractory coating for graphite molds used in the casting of uranium is described. The coating is an alumino-silicate refractory composition which may be used as a mold surface in solid form or as a coating applied to the graphite mold. The composition consists of a mixture of ball clay, kaolin, alumina cement, alumina, water, sodium silicate, and sodium carbonate.
Mineral resource of the month: kyanite
Potter, Michael J.
2007-01-01
Kyanite and related minerals are used in making refractories, which are materials that can withstand high-temperature environments, generally in excess of 1,100 degrees Celsius. Refractories form an inner lining to furnaces, kilns and other containers with which molten metals and glass come into contact. Fifty to 70 percent of global refractory consumption is related to the steel industry.
Refractory metals for ARPS AMTEC cells
DOE Office of Scientific and Technical Information (OSTI.GOV)
Svedberg, R.C.; Sievers, R.C.
1998-07-01
Alkali Metal Thermal-to-Electric Converter (AMTEC) cells for the Advanced Radioisotope Power Systems (ARPS) program are being developed with refractory metals and alloys as the basic structural materials. AMTEC cell efficiency increases with cell operating temperature. For space applications, long term reliability and high efficiency are essential and refractory metals were selected because of their high temperature strength, low vapor pressure, and compatibility with sodium. However, refractory metals are sensitive to oxygen, nitrogen and hydrogen contamination and refractory metal cells cannot be processed in air. Because of this sensitivity, new manufacturing and processing techniques are being developed. In addition to structuralmore » elements, development of other refractory metal components for the AMTEC cells, such as the artery and evaporator wicks, pinchoff tubes and feedthroughs are required. Changes in cell fabrication techniques and processing procedures being implemented to manufacture refractory metal cells are discussed.« less
Danilov, N M; Matchin, Iu G; Chazova, I E
2012-01-01
Excessive activation of the sympathetic nervous system forms the basis of pathogenesis of essential arterial hypertension (AH). The present work was aimed at evaluating efficacy and safety of endovascular radiofrequency denervation of renal arteries in patients with AH refractory AH based on the initial first experience in with using this methodology in the Russian Federation. The interventions were carried out on December 14-15th, 2011 in the first five patients presenting with AH refractory to antihypertensive therapy consisting of three and more drugs in therapeutic doses, one of which was a diuretic. The selection criteria were systolic arterial pressure (SAP) ≥160 mm Hg or ≥150 mm Hg in the presence of type 2 diabetes mellitus. The obligatory conditions for selection were the preserved renal function [glomerular filtration rate (GFR) ≥45 ml/min] and the absence of the secondary form of AH. The procedure of denervation was performed in the conditions of roentgen-operating room using special Medtronic Ardian Simplicity Catheter System™. In all cases we managed to perform bilateral denervation of renal arteries with the radiofrequency effect in not less than 4 zones of each of vessels. Efficacy of each of the effect was registered with due regard for reaching certain temperature and values of impedance. The interventions were not accompanied by the development of any complications either in the area of manipulations or the site of puncture. Neither were there any complications from the side of the cardiovascular or excretory systems of the body. Diurnal monitoring of AP (DMAP) registered a significant decrease in SAP averagely from 174±12 to 145±10 mm Hg three days after the intervention. A persistent antihypertensive effect was confirmed by the DMAP findings one month after denervation - the SAP level averagely amounted to 131±6 mm Hg. Endovascular radiofrequency denervation of renal arteries is a safe and efficient method of treatment of AH resistant to multicomponent antihypertensive therapy.
Low TCR nanocomposite strain gages
NASA Technical Reports Server (NTRS)
Gregory, Otto J. (Inventor); Chen, Ximing (Inventor)
2012-01-01
A high temperature thin film strain gage sensor capable of functioning at temperatures above 1400.degree. C. The sensor contains a substrate, a nanocomposite film comprised of an indium tin oxide alloy, zinc oxide doped with alumina or other oxide semiconductor and a refractory metal selected from the group consisting of Pt, Pd, Rh, Ni, W, Ir, NiCrAlY and NiCoCrAlY deposited onto the substrate to form an active strain element. The strain element being responsive to an applied force.
Apparatus for making environmentally stable reactive alloy powders
Anderson, I.E.; Lograsso, B.K.; Terpstra, R.L.
1996-12-31
Apparatus and method are disclosed for making powder from a metallic melt by atomizing the melt to form droplets and reacting the droplets downstream of the atomizing location with a reactive gas. The droplets are reacted with the gas at a temperature where a solidified exterior surface is formed thereon and where a protective refractory barrier layer (reaction layer) is formed whose penetration into the droplets is limited by the presence of the solidified surface so as to avoid selective reduction of key reactive alloyants needed to achieve desired powder end use properties. The barrier layer protects the reactive powder particles from environmental constituents such as air and water in the liquid or vapor form during subsequent fabrication of the powder to end-use shapes and during use in the intended service environment. 7 figs.
Improved refractory performance through partnership
DOE Office of Scientific and Technical Information (OSTI.GOV)
Linck, F.E.; Peters, D.
1995-12-31
From the early designs and construction of Circulating Fluidized Bed (CFB) boilers, many improvements have been made based upon observations of performance. Included in these improvements have been the refractory linings. The early refractory linings were subjected to extreme fluctuations in temperatures as the units experienced up and down conditions. As the designs were improved refractory failures were mostly due to the operating conditions and other mechanical stresses rather than continual shutdowns and startups. More recent problems observed with refractory linings are localized areas of high erosion, corrosion and cracking which result in hot spots and eventual shutdowns for repair.more » Today the objective of refractory suppliers and installers is to strive towards planned shutdowns rather than emergency shutdowns. This can be accomplished through partnerships between operations, material suppliers and installers. In essence, the concept is a cooperative effort between these groups to solve the variety of refractory problems in order to achieve longer refractory lining performance and less chance for emergency shutdowns. The reliability of the refractory lining is dependent on the successful combination of the material selected, proper design and the installation of the refractory material. Where these three elements combine, the lining has the best chance of performing its intended purpose.« less
High density crystalline boron prepared by hot isostatic pressing in refractory metal containers
Hoenig, C.L.
1993-08-31
Boron powder is hot isostatically pressed in a refractory metal container to produce a solid boron monolith with a bulk density at least 2.22 g/cc and up to or greater than 2.34 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1,800 C and 30 PSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.34 g/cc. Complex shapes can be made.
High density crystalline boron prepared by hot isostatic pressing in refractory metal containers
Hoenig, Clarence L.
1993-01-01
Boron powder is hot isostatically pressed in a refractory metal container to produce a solid boron monolith with a bulk density at least 2.22 g/cc and up to or greater than 2.34 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1800.degree. C. and 30 KSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.34 g/cc. Complex shapes can be made.
Selective arterial embolization with gelatin particles for refractory knee hemarthrosis.
Yamagami, Takuji; Yoshimatsu, Rika; Miura, Hiroshi; Arai, Yuji; Terauchi, Ryu; Nakagawa, Shuji; Yamada, Kei
2013-01-01
We aimed to evaluate the feasibility and safety of selective arterial embolization for refractory knee hemarthrosis. Transcatheter arterial embolization for refractory knee hemarthrosis was performed on five female patients (median age, 77 years; range, 71-80 years) between May 2009 and September 2012. Selective arterial embolization of the feeding artery was performed using a 2.5 F microcatheter coaxially advanced from a 5 F catheter with its tip positioned in the superficial femoral artery. One- or two-millimeter gelatin particles were used as embolic agents. In all patients, transarterial embolization performed successfully after arteriography showed nontumorous staining around the knee joint. The feeding arteries were the lateral superior genicular artery in all five patients, the lateral inferior genicular artery in four patients, the medial superior genicular artery in one patient, the medial inferior genicular artery in one patient, the middle genicular artery in one patient, and the descending genicular artery in one patient. In all five patients, staining was remarkably diminished around the knee joint after the embolization procedure. No complication was observed. The hemarthrosis improved after the embolization, and the postoperative course has been uneventful with no recurrence in any patient. These results suggest that selective arterial embolization for refractory hemarthrosis of the knee is safe and useful.
Alkali metal-refractory metal biphase electrode for AMTEC
NASA Technical Reports Server (NTRS)
Williams, Roger M. (Inventor); Bankston, Clyde P. (Inventor); Cole, Terry (Inventor); Khanna, Satish K. (Inventor); Jeffries-Nakamura, Barbara (Inventor); Wheeler, Bob L. (Inventor)
1989-01-01
An electrode having increased output with slower degradation is formed of a film applied to a beta-alumina solid electrolyte (BASE). The film comprises a refractory first metal M.sup.1 such as a platinum group metal, suitably platinum or rhodium, capable of forming a liquid or a strong surface adsorption phase with sodium at the operating temperature of an alkali metal thermoelectric converter (AMTEC) and a second refractory metal insoluble in sodium or the NaM.sup.1 liquid phase such as a Group IVB, VB or VIB metal, suitably tungsten, molybdenum, tantalum or niobium. The liquid phase or surface film provides fast transport through the electrode while the insoluble refractory metal provides a structural matrix for the electrode during operation. A trilayer structure that is stable and not subject to deadhesion comprises a first, thin layer of tungsten, an intermediate co-deposited layer of tungsten-platinum and a thin surface layer of platinum.
Refractory lining for electrochemical cell
Blander, Milton; Cook, Glenn M.
1987-01-01
Apparatus for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contcat with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight oxygen and not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom.
High Temperature Stability of Dissimilar Metal Joints in Fission Surface Power Systems
NASA Technical Reports Server (NTRS)
Locci, Ivan E.; Nesbitt, James A.; Ritzert, Frank J.; Bowman, Cheryl L.
2007-01-01
Future generations of power systems for spacecraft and lunar surface systems will likely require a strong dependence on nuclear power. The design of a space nuclear power plant involves integrating together major subsystems with varying materia1 requirements. Refractory alloys are repeatedly considered for major structural components in space power reactor designs because refractory alloys retain their strength at higher temperatures than other classes of metals. The relatively higher mass and lower ductility of the refractory alloys make them less attractive for lower temperature subsystems in the power plant such as the power conversion system. The power conversion system would consist more likely of intermediate temperature Ni-based superalloys. One of many unanswered questions about the use of refractory alloys in a space power plant is how to transition from the use of the structural refractory alloy to more traditional structural alloys. Because deleterious phases can form when complex alloys are joined and operated at elevated temperatures, dissimilar material diffusion analyses of refractory alloys and superalloys are needed to inform designers about options of joint temperature and operational lifetime. Combinations of four superalloys and six refractory alloys were bonded and annealed at 1150 K and 1300 K to examine diffusional interactions in this study. Joints formed through hot pressing and hot isostatic pressing were compared. Results on newer alloys compared favorably to historical data. Diffusional stability is promising for some combinations of Mo-Re alloys and superalloys at 1150 K, but it appears that lower joint temperatures would be required for other refractory alloy couples.
Assessment and Management of Treatment-Refractory Obsessive-Compulsive Disorder in Children
Bloch, Michael H.; Storch, Eric A.
2015-01-01
OBJECTIVE To review the assessment and treatment of treatment-refractory pediatric obsessive-compulsive disorder (OCD). METHOD A PubMed search was conducted to identify controlled trials in pediatric OCD. Additionally, practice guidelines for the treatment of adults and children were further reviewed for references in treatment-refractory OCD across the lifespan. RESULTS Pharmacotherapy with selective serotonin reuptake inhibitors (SSRIs) and cognitive-behavioral therapy are effective treatments for pediatric OCD. Evidence suggests that CBT is additionally effective even in pediatric patients with refractory OCD symptoms. Antipsychotic augmentation, raising SSRI dosage, and several glutamate-modulating agents have some evidence of efficacy in adults with treatment-refractory OCD but have not been studied in pediatric populations. CONCLUSION Several pharmacological treatment options exist for children with refractory OCD symptoms. However, little evidence-based data exist to guide treatment for our most challenging pediatric OCD patients. Further research is needed to evaluate the efficacy/side-effect profile of commonly used interventions in treatment-refractory pediatric OCD. PMID:25791142
Androgen receptor signaling and mutations in prostate cancer
Koochekpour, Shahriar
2010-01-01
Normal and neoplastic growth of the prostate gland are dependent on androgen receptor (AR) expression and function. Androgenic activation of the AR, in association with its coregulatory factors, is the classical pathway that leads to transcriptional activity of AR target genes. Alternatively, cytoplasmic signaling crosstalk of AR by growth factors, neurotrophic peptides, cytokines or nonandrogenic hormones may have important roles in prostate carcinogenesis and in metastatic or androgen-independent (AI) progression of the disease. In addition, cross-modulation by various nuclear transcription factors acting through basal transcriptional machinery could positively or negatively affect the AR or AR target genes expression and activity. Androgen ablation leads to an initial favorable response in a significant number of patients; however, almost invariably patients relapse with an aggressive form of the disease known as castration-resistant or hormone-refractory prostate cancer (PCa). Understanding critical molecular events that lead PCa cells to resist androgen-deprivation therapy is essential in developing successful treatments for hormone-refractory disease. In a significant number of hormone-refractory patients, the AR is overexpressed, mutated or genomically amplified. These genetic alterations maintain an active presence for a highly sensitive AR, which is responsive to androgens, antiandrogens or nonandrogenic hormones and collectively confer a selective growth advantage to PCa cells. This review provides a brief synopsis of the AR structure, AR coregulators, posttranslational modifications of AR, duality of AR function in prostate epithelial and stromal cells, AR-dependent signaling, genetic changes in the form of somatic and germline mutations and their known functional significance in PCa cells and tissues. PMID:20711217
Catalytic, hollow, refractory spheres, conversions with them
NASA Technical Reports Server (NTRS)
Wang, Taylor G. (Inventor); Elleman, Daniel D. (Inventor); Lee, Mark C. (Inventor); Kendall, Jr., James M. (Inventor)
1989-01-01
Improved, heterogeneous, refractory catalysts are in the form of gas-impervious, hollow, thin-walled spheres (10) suitable formed of a shell (12) of refractory such as alumina having a cavity (14) containing a gas at a pressure greater than atmospheric pressure. The wall material may be itself catalytic or a catalytically active material coated onto the sphere as a layer (16), suitably platinum or iron, which may be further coated with a layer (18) of activator or promoter. The density of the spheres (30) can be uniformly controlled to a preselected value within .+-.10 percent of the density of the fluid reactant such that the spheres either remain suspended or slowly fall or rise through the liquid reactant.
Catalytic, hollow, refractory spheres
NASA Technical Reports Server (NTRS)
Wang, Taylor G. (Inventor); Elleman, Daniel D. (Inventor); Lee, Mark C. (Inventor); Kendall, Jr., James M. (Inventor)
1987-01-01
Improved, heterogeneous, refractory catalysts are in the form of gas-impervious, hollow, thin-walled spheres (10) suitable formed of a shell (12) of refractory such as alumina having a cavity (14) containing a gas at a pressure greater than atmospheric pressure. The wall material may be itself catalytic or a catalytically active material coated onto the sphere as a layer (16), suitably platinum or iron, which may be further coated with a layer (18) of activator or promoter. The density of the spheres (30) can be uniformly controlled to a preselected value within .+-.10 percent of the density of the fluid reactant such that the spheres either remain suspended or slowly fall or rise through the liquid reactant.
Hoenig, Clarence L.
1992-01-01
Boron nitride powder with less than or equal to the oxygen content of starting powder (down to 0.5% or less) is hot isostatically pressed in a refractory metal container to produce hexagonal boron nitride with a bulk density greater than 2.0 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1800.degree. C. and 30 KSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.21 g/cc. Complex shapes can be made.
Pak, Nick; Devcich, Daniel A; Johnson, Malcolm H; Merry, Alan F
2014-03-28
To compare psychological and pain-related characteristics of patients with chronic pain and patients with refractory angina pectoris who had been treated with spinal cord stimulation (SCS) therapy. Twenty-four patients receiving SCS therapy were interviewed. Four psychological variables were assessed using standardised questionnaires for pain catastrophising, health locus of control, anxiety sensitivity, and self-efficacy. Patients also completed the revised version of the Short-Form McGill Pain Questionnaire, the Short-Form Health Survey, and self-reported measures of global perceived effect, pain, functionality, and satisfaction with SCS therapy. Most patients reported improvements in pain, functionality, and improvement overall. Some health locus of control dimensions were significantly higher for the angina group than the chronic pain group, and chronic angina patients reported significantly lower levels of intermittent pain. Virtually all patients reported being satisfied with SCS therapy. Most self-rated psychological and pain-related characteristics were no different between the two groups, which gives some support to the view that refractory angina is a form of chronic pain. The results also add to evidence supporting the use of SCS therapy for refractory angina pectoris; however, differences observed on a few variables may indicate points of focus for the assessment and treatment of such patients.
Treatment of Refractory and Super-refractory Status Epilepticus.
Rai, Samhitha; Drislane, Frank W
2018-06-19
Refractory and super-refractory status epilepticus (SE) are serious illnesses with a high risk of morbidity and even fatality. In the setting of refractory generalized convulsive SE (GCSE), there is ample justification to use continuous infusions of highly sedating medications-usually midazolam, pentobarbital, or propofol. Each of these medications has advantages and disadvantages, and the particulars of their use remain controversial. Continuous EEG monitoring is crucial in guiding the management of these critically ill patients: in diagnosis, in detecting relapse, and in adjusting medications. Forms of SE other than GCSE (and its continuation in a "subtle" or nonconvulsive form) should usually be treated far less aggressively, often with nonsedating anti-seizure drugs (ASDs). Management of "non-classic" NCSE in ICUs is very complicated and controversial, and some cases may require aggressive treatment. One of the largest problems in refractory SE (RSE) treatment is withdrawing coma-inducing drugs, as the prolonged ICU courses they prompt often lead to additional complications. In drug withdrawal after control of convulsive SE, nonsedating ASDs can assist; medical management is crucial; and some brief seizures may have to be tolerated. For the most refractory of cases, immunotherapy, ketamine, ketogenic diet, and focal surgery are among several newer or less standard treatments that can be considered. The morbidity and mortality of RSE is substantial, but many patients survive and even return to normal function, so RSE should be treated promptly and as aggressively as the individual patient and type of SE indicate.
Environmentally stable reactive alloy powders and method of making same
Anderson, I.E.; Lograsso, B.K.; Terpstra, R.L.
1998-09-22
Apparatus and method are disclosed for making powder from a metallic melt by atomizing the melt to form droplets and reacting the droplets downstream of the atomizing location with a reactive gas. The droplets are reacted with the gas at a temperature where a solidified exterior surface is formed thereon and where a protective refractory barrier layer (reaction layer) is formed whose penetration into the droplets is limited by the presence of the solidified surface so as to avoid selective reduction of key reactive alloys needed to achieve desired powder end use properties. The barrier layer protects the reactive powder particles from environmental constituents such as air and water in the liquid or vapor form during subsequent fabrication of the powder to end-use shapes and during use in the intended service environment. 7 figs.
NASA Technical Reports Server (NTRS)
Brandenburf, G. P.; Hoffman, E. E.; Smith, J. P.
1974-01-01
The performance was determined of refractory metal alloys and uranium nitride fuel element specimens in flowing 1900F (1083C) lithium. The results demonstrate the suitability of the selected materials to perform satisfactorily from a chemical compatibility standpoint.
Bone, W.H.; Schmidt, W.W.
1958-11-01
A method is presented for forming refractory liners in cylindrical reaction vessels used for the reductlon of uranium tetrafluoride to metallic uranium. A preliminary form, having positioning lugs attached thereto, is inserted into the reaction vessel and the refractory powder, usually CaO, is put in the annular space between the form and the inner wall of the reaction vessel. A jolting table is used to compact this charge of liner material ln place, and after thls has been done, the preliminary form is removed and the flnal form or plug is lnserted without disturbing the partially completed lining. The remainder of the lining charge is then introduced and compacted by jolting, after which the form is removed.
Pharmacological considerations in the use of stiripentol for the treatment of epilepsy.
Verrotti, Alberto; Prezioso, Giovanni; Stagi, Stefano; Paolino, Maria Chiara; Parisi, Pasquale
2016-01-01
Despite the fact that more than 20 antiepileptic drugs (AEDs) are currently available, about one-third of patients still present drug resistance. Further efforts are required to develop novel and more efficacious therapeutic strategies, especially for refractory epileptic syndromes showing few and anecdotic therapeutic options. Stiripentol (STP) is a second generation AED that shows GABAergic activity, with immature brain selectivity, and an indirect metabolic action on co-administered AEDs. Two pivotal studies demonstrated STP efficacy in patients with Dravet syndrome with refractory partial seizures, and marketing authorization in Europe, Canada and Japan was granted thereafter. Post-marketing surveys reported a good efficacy and tolerability profile. In addition, interesting data is currently emerging regarding off-label experimentation of STP in other forms of epilepsy. STP is an important addition to the limited treatment options available for patients resistant to common AEDs. The possibility to inhibit seizures through the metabolic pathway of lactate dehydrogenase and the inhibitory effects on the entry of Na(+) and Ca(2+) are the most recent findings to emerge about STP and could be proof of its neuroprotective action. Moreover, its positive effects on cognitive function, its good safety and tolerability profile and the increasing data about STP efficacy on other refractory epileptic syndromes may prove to be fertile grounds for further investigation.
Integrated structure vacuum tube
NASA Technical Reports Server (NTRS)
Dimeff, J.; Kerwin, W. J. (Inventor)
1976-01-01
High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.
A refractory inclusion returned by Stardust from comet 81P/Wild 2
NASA Astrophysics Data System (ADS)
Simon, S. B.; Joswiak, D. J.; Ishii, H. A.; Bradley, J. P.; Chi, M.; Grossman, L.; AlÉOn, J.; Brownlee, D. E.; Fallon, S.; Hutcheon, I. D.; Matrajt, G.; McKeegan, K. D.
2008-11-01
Among the samples returned from comet 81P/Wild 2 by the Stardust spacecraft is a suite of particles from one impact track (Track 25) that are Ca-, Al-rich and FeO-free. We studied three particles from this track that range in size from 5.3 × 3.2 μ to 15 × 10 μ. Scanning and transmission electron microscopy show that they consist of very fine-grained (typically from ˜0.5 to ˜2 μ) Al-rich, Ti-bearing and Ti-free clinopyroxene, Mg-Al spinel and anorthite, with trace amounts of fine perovskite, FeNi metal and osbornite (TiN) grains. In addition to these phases, the terminal particle, named "Inti", also contains melilite. All of these phases, with the exception of osbornite, are common in refractory inclusions and are predicted to condense at high temperature from a gas of solar composition. Osbornite, though very rare, has also been found in meteoritic refractory inclusions, and could have formed in a region of the nebula where carbon became enriched relative to oxygen compared to solar composition. Compositions of Ti-pyroxene in Inti are similar, but not identical, to those of fassaite from Allende inclusions. Electron energy loss spectroscopy shows that Ti-rich pyroxene in Inti has Ti3+/Ti4+within the range of typical meteoritic fassaite, consistent with formation under reducing conditions comparable to those of a system of solar composition. Inti is 16O-rich, with δ18O?δ17O?-40%0, like unaltered phases in refractory inclusions and refractory IDPs. With grain sizes, mineralogy, mineral chemistry, and an oxygen isotopic composition like those of refractory inclusions, we conclude that Inti is a refractory inclusion that formed in the inner solar nebula. Identification of a particle that formed in the inner solar system among the comet samples demonstrates that there was transport of materials from the inner to the outer nebula, probably either in a bipolar outflow or by turbulence.
[Nursing management of a refractory cardiac death donor].
Kaufmann, Marion
2016-09-01
The nursing management of a refractory circulatory death donor is a new procedure which forms an integral part of patient care. It comprises technical and organisational aspects, and requires a conceptual, ethical and deontological effort. Copyright © 2016. Published by Elsevier Masson SAS.
System and process for aluminization of metal-containing substrates
Chou, Yeong-Shyung; Stevenson, Jeffry W.
2017-12-12
A system and method are detailed for aluminizing surfaces of metallic substrates, parts, and components with a protective alumina layer in-situ. Aluminum (Al) foil sandwiched between the metallic components and a refractory material when heated in an oxidizing gas under a compression load at a selected temperature forms the protective alumina coating on the surface of the metallic components. The alumina coating minimizes evaporation of volatile metals from the metallic substrates, parts, and components in assembled devices that can degrade performance during operation at high temperature.
System and process for aluminization of metal-containing substrates
Chou, Yeong-Shyung; Stevenson, Jeffry W
2015-11-03
A system and method are detailed for aluminizing surfaces of metallic substrates, parts, and components with a protective alumina layer in-situ. Aluminum (Al) foil sandwiched between the metallic components and a refractory material when heated in an oxidizing gas under a compression load at a selected temperature forms the protective alumina coating on the surface of the metallic components. The alumina coating minimizes evaporation of volatile metals from the metallic substrates, parts, and components in assembled devices during operation at high temperature that can degrade performance.
Lee, Joseph W Y
2004-12-01
Logorrhea, verbigeration and echolalia persisted unremittingly for 3 years, with occasional short periods of motoric excitement, in a patient with mild intellectual handicap suffering from chronic schizophrenia. The speech catatonic symptoms, previously refractory to various antipsychotics, responded promptly to lorazepam, a benzodiazepine with documented efficacy in the treatment of acute catatonia but not chronic catatonia. It is suggested that pathways in speech production were selectively involved in the genesis of the chronic speech catatonic syndrome, possibly a rare form of chronic catatonia not previously described.
Dissolution Behavior of Mg from Magnesia-Chromite Refractory into Al-killed Molten Steel
NASA Astrophysics Data System (ADS)
Liu, Chunyang; Yagi, Motoki; Gao, Xu; Kim, Sun-Joong; Huang, Fuxiang; Ueda, Shigeru; Kitamura, Shin-ya
2018-06-01
Magnesia-chromite refractory materials are widely employed in steel production, and are considered a potential MgO source for the generation of MgO·Al2O3 spinel inclusions in steel melts. In this study, a square magnesia-chromite refractory rod was immersed into molten steel of various compositions held in an Al2O3 crucibles. As the immersion time was extended, Mg and Cr gradually dissolved from the magnesia-chromite refractory, and the Mg and Cr contents of the steel melts increased. However, it was found that the inclusions in the steel melts remained as almost pure Al2O3 because the Mg content of the steel melts was low, approximately 1 ppm. On the surface of the magnesia-chromite refractory, an MgO·Al2O3 spinel layer with a variable composition was formed, and the thickness of the MgO·Al2O3 spinel layer increased with the immersion time and the Al content of the steel melts. At the rod interface, the formed layer consisted of MgO-saturated MgO·Al2O3 spinel. The MgO content decreased along the thickness direction of the layer, and at the steel melts interface, the formed layer consisted of Al2O3-saturated MgO·Al2O3 spinel. Therefore, the low content of Mg in steel melts and the unchanged inclusions were because of the equilibrium between Al2O3-saturated MgO·Al2O3 layer and Al2O3. In addition, the effects of the Al and Cr contents of the steel melts on the dissolution of Mg from the magnesia-chromite refractory are insignificant.
Park, Hyung-Jin; Kim, Ja-Won; Song, Kun-Ho; Seo, Kyoung-Won
2015-01-01
Three dogs presented with refractory immune-mediated thrombocytopenia (IMT). All patients failed to respond to prednisone, which is considered a mainstay of immunosuppressive therapy. Vincristine-loaded platelets (VLPs), which act selectively on mononuclear phagocytes,were introduced. After the VLPs were transfused, two dogs responded quickly with improved clinical signs while the third dog with recurrent IMT was euthanized due to its deteriorating condition. This case report describes the efficacy of VLP therapy in refractory IMT patients.
Park, Hyung-Jin; Kim, Ja-Won; Song, Kun-Ho
2015-01-01
Three dogs presented with refractory immune-mediated thrombocytopenia (IMT). All patients failed to respond to prednisone, which is considered a mainstay of immunosuppressive therapy. Vincristine-loaded platelets (VLPs), which act selectively on mononuclear phagocytes,were introduced. After the VLPs were transfused, two dogs responded quickly withimproved clinical signs while the third dogwith recurrent IMT was euthanized due to its deteriorating condition. This case report describesthe efficacy of VLP therapy in refractory IMT patients. PMID:25269722
NASA Technical Reports Server (NTRS)
Nuth, J. A.; Rietmeijer, F. J. M.; Hallenbeck, S. L.; Withey, P. A.
1999-01-01
Starting with cooling, refractory vapors diluted in significant quantities of H and He there are four processes that most natural systems will undergo: nucleation, growth, annealing, and coagulation. Nucleation is the processes by which the first stable refractory nuclei form in the vapor. These are the seeds onto which the remaining vapors will condense during the growth stage. Solids of any composition will try to arrange themselves into the least energetic configuration, provided that there is sufficient energy available to support such processes as diffusion and the breaking of chemical bonds. There is a significant activation energy associated with the annealing process in refractory solids due to the relatively high energy of the chemical bonds in solids. The grains formed in most cosmochemical systems are extremely small and often tightly coupled to the gas. Because of their small physical cross sections coagulation may be a very slow process unless there is another driving force involved in addition to normal Brownian motion. In what follows we will briefly cover each of these four stages for refractory oxide and metal grains, although in inverse order.
Management of refractory epilepsy.
Muñana, Karen R
2013-05-01
The term refractory epilepsy is utilized in veterinary medicine to describe a condition in which an animal with epilepsy fails to attain satisfactory seizure control or suffers intolerable side effects despite appropriate therapy with conventional antiepileptic drugs. Refractory epilepsy is an important problem in small animal practice as it occurs in approximately one-third of dogs with epilepsy. Consequently, there is much interest in identifying ways to more effectively treat this population of animals. More than a dozen new antiepileptic drugs have been approved for humans over the last 2 decades, and several of these drugs, including gabapentin, zonisamide, levetiracetam, and pregabalin, have been evaluated for the treatment of refractory seizures in veterinary patients. Nonmedical methods to treat poorly controlled epilepsy are also being explored. The 2 alternative forms of therapy that have shown the most promise in humans with epilepsy are electrical stimulation of the brain and dietary modification, both of which have also been evaluated in dogs. This overview summarizes the available data on pharmacologic as well as nonmedical treatment options for dogs and cats with refractory epilepsy. Although many forms of therapy are currently being utilized in clinical practice, our knowledge of the safety and efficacy of these treatments is limited. Additional randomized controlled trials are needed to better evaluate these novel therapies for refractory epilepsy in dogs and cats. © 2013 Elsevier Inc. All rights reserved.
Lin, Lung-Chang; Ouyang, Chen-Sen; Chiang, Ching-Tai; Yang, Rei-Cheng; Wu, Rong-Ching; Wu, Hui-Chuan
2014-11-01
Refractory epilepsy often has deleterious effects on an individual's health and quality of life. Early identification of patients whose seizures are refractory to antiepileptic drugs is important in considering the use of alternative treatments. Although idiopathic epilepsy is regarded as having a significantly lower risk factor of developing refractory epilepsy, still a subset of patients with idiopathic epilepsy might be refractory to medical treatment. In this study, we developed an effective method to predict the refractoriness of idiopathic epilepsy. Sixteen EEG segments from 12 well-controlled patients and 14 EEG segments from 11 refractory patients were analyzed at the time of first EEG recordings before antiepileptic drug treatment. Ten crucial EEG feature descriptors were selected for classification. Three of 10 were related to decorrelation time, and four of 10 were related to relative power of delta/gamma. There were significantly higher values in these seven feature descriptors in the well-controlled group as compared to the refractory group. On the contrary, the remaining three feature descriptors related to spectral edge frequency, kurtosis, and energy of wavelet coefficients demonstrated significantly lower values in the well-controlled group as compared to the refractory group. The analyses yielded a weighted precision rate of 94.2%, and a 93.3% recall rate. Therefore, the developed method is a useful tool in identifying the possibility of developing refractory epilepsy in patients with idiopathic epilepsy.
Nanostructured refractory thin films for solar applications
NASA Astrophysics Data System (ADS)
Ollier, E.; Dunoyer, N.; Dellea, O.; Szambolics, H.
2014-08-01
Selective solar absorbers are key elements of all solar thermal systems. Solar thermal panels and Concentrated Solar Power (CSP) systems aim respectively at producing heat and electricity. In both cases, a surface receives the solar radiation and is designed to have the highest optical absorption (lowest optical reflectivity) of the solar radiation in the visible wavelength range where the solar intensity is the highest. It also has a low emissivity in the infrared (IR) range in order to avoid radiative thermal losses. Current solutions in the state of the art usually consist in deposited interferential thin films or in cermets [1]. Structured surfaces have been proposed and have been simulated because they are supposed to be more efficient when the solar radiation is not normal to the receiving surface and because they could potentially be fabricated with refractory materials able to sustain high operating temperatures. This work presents a new method to fabricate micro/nanostructured surfaces on molybdenum (refractory metal with a melting temperature of 2623°C). This method now allows obtaining a refractory selective surface with an excellent optical selectivity and a very high absorption in the visible range. This high absorption performance was obtained by achieving a double structuration at micro and nano scales thanks to an innovative process flow.
NASA Astrophysics Data System (ADS)
Bazyleva, O. A.; Povarova, K. B.; Kazanskaya, N. K.; Drozdov, A. A.
2009-04-01
The possibility of increasing the life of heterophase cast light Ni3Al-based superalloys at temperatures higher than 0.8 T m of Ni3Al is studied when their directional structure is additionally stabilized by nanoprecipitates, which form upon additional alloying of these alloys by refractory and active metals, and using special methods for preparing and melting of an alloy charge. The effect of the method of introducing the main components and refractory reaction-active and surface-active alloying elements into Ni3Al-based cast superalloys, which are thermally stable natural composite materials of the eutectic type, on the structure-phase state and the life of these alloys is studied. When these alloys are melted, it is necessary to perform a set of measures to form particles of refractory oxide cores covered with the β-NiAl phase and, then, γ'prim-Ni3Al phase precipitates during solidification. The latter phase forms the outer shell of grain nuclei, which provides high thermal stability and hot strength of an intermetallic compound-based alloy. As a result, a modified structure that is stabilized by the nanoprecipitates of nickel and aluminum lanthanides and the nanoprecipitates of phases containing refractory metals is formed. This structure enhances the life of the alloy at 1000 °C by a factor of 1.8-2.5.
2018-04-30
Acute Myeloid Leukemia With t(9;11)(p22.3;q23.3); MLLT3-KMT2A; Fibroblast Growth Factor Basic Form Measurement; FLT3 Internal Tandem Duplication; Recurrent Adult Acute Myeloid Leukemia; Refractory Acute Myeloid Leukemia
Niobium-Matrix-Composite High-Temperature Turbine Blades
NASA Technical Reports Server (NTRS)
Kaplan, Richard B.; Tuffias, Robert H.; La Ferla, Raffaele; Heng, Sangvavann; Harding, John T.
1995-01-01
High-temperture composite-material turbine blades comprising mainly niobium matrices reinforced with refractory-material fibers being developed. Of refractory fibrous materials investigated, FP-AL(2)0(3), tungsten, and polymer-based SiC fibers most promising. Blade of this type hollow and formed in nearly net shape by wrapping mesh of reinforcing refractory fibers around molybdenum mandrel, then using thermal-gradient chemical-vapor infiltration (CVI) to fill interstices with niobium. CVI process controllable and repeatable, and kinetics of both deposition and infiltration well understood.
HIGH TEMPERATURE REFRACTORY COATING FOR GRAPHITE MOLDS
Stoddard, S.D.
1958-10-21
An improved foundry mold coating for use with graphite molds used in the casting of uranium is presented. The refractory mold coating serves to keep the molten uranium from contact with graphite of the mold and thus prevents carbon pickup by the molten metal. The refractory coating is made by dry mixing certain specific amounts of aluminum oxide, bentonite, Tennessee ball clay, and a soluble silicate salt. Water is then added to the mixture and the suspension thus formed is applied by spraying onto the mold.
Reaction Behaviors of Al-Killed Medium-Manganese Steel with Different Refractories
NASA Astrophysics Data System (ADS)
Kong, Lingzhong; Deng, Zhiyin; Zhu, Miaoyong
2018-03-01
In order to understand the reaction mechanism between medium-manganese steel and different refractories, some laboratory experiments were carried out at 1873 K (1600 °C). Three types of refractory plates (Al2O3, MgO, and MgO·Al2O3) were used. The results show that Mn in liquid medium-manganese steel does not react easily with the Al2O3 refractory, but can react with the MgO refractory to generate a (Mn, Mg)O layer at the boundary between the refractory plate and liquid steel. After the formation of (Mn, Mg)O, a layer of (Mn, Mg)O·Al2O3 spinel is also formed at the edge of the MgO refractory. Similar to the MgO refractory, the dissolved Mn can react with the MgO·Al2O3 refractory as well, and a layer of (Mn, Mg)O·Al2O3 was also detected after reaction. It was found that the formation of (Mn, Mg)O·Al2O3 at the edge of the refractory is a source of (Mn, Mg)O·Al2O3 inclusions in liquid steel. The flush-off of the (Mn, Mg)O·Al2O3 layer would result in the formation of (Mn, Mg)O·Al2O3 inclusions.
Characterization of refractory brick based on local raw material from Lampung Province - Indonesia
NASA Astrophysics Data System (ADS)
Amin, Muhammad; Suryana, Yayat I.; Isnugroho, Kusno; Aji, Bramantyo B.; Birawidha, David C.; Hendronursito, Yusup
2018-04-01
Refractories are non-metallic inorganic materials that are difficult to melt at high temperatures and used in high-temperature casting industries. Refractories are classified into their constituent mineral feed stocks, refractories having typical plot properties commonly called fire bricks. In the manufacture of refractory bricks that exist in the market during the use of mangrove materials derived from abroad that is from China. In this research the refractory brick materials used are quartz sand, feldspart, kaolin, bentonite, and ball clay. All materials come from local Lampung Province - Indonesia. The experiment, there are 7 kinds of experimental composition, made of plot shape with size 230 mm, 65 mm in thickness, 114 mm height mould using manual press machine with 10 tons power and burning at 1400°C for 5 hours. Refractory brick product is done by physical test in the form of porosity, specific gravity, compressive strength and XRF and SEM characteristics. The result of XRF characteristic of refractory brick composition of 1 to 5 compared to the refractory brick type SK 34 in the market and the result of composition 1 is a composition close to refractory brick composition type SK 34 namely SiO2 is 54.21 %, Al2O3 is 25.38 % and test Physical of Bulk density is 2.25 g/cm3, porosity is 18.98 % and compressive strength is 325 kg/cm2.
Reaction Behaviors of Al-Killed Medium-Manganese Steel with Different Refractories
NASA Astrophysics Data System (ADS)
Kong, Lingzhong; Deng, Zhiyin; Zhu, Miaoyong
2018-06-01
In order to understand the reaction mechanism between medium-manganese steel and different refractories, some laboratory experiments were carried out at 1873 K (1600 °C). Three types of refractory plates (Al2O3, MgO, and MgO·Al2O3) were used. The results show that Mn in liquid medium-manganese steel does not react easily with the Al2O3 refractory, but can react with the MgO refractory to generate a (Mn, Mg)O layer at the boundary between the refractory plate and liquid steel. After the formation of (Mn, Mg)O, a layer of (Mn, Mg)O·Al2O3 spinel is also formed at the edge of the MgO refractory. Similar to the MgO refractory, the dissolved Mn can react with the MgO·Al2O3 refractory as well, and a layer of (Mn, Mg)O·Al2O3 was also detected after reaction. It was found that the formation of (Mn, Mg)O·Al2O3 at the edge of the refractory is a source of (Mn, Mg)O·Al2O3 inclusions in liquid steel. The flush-off of the (Mn, Mg)O·Al2O3 layer would result in the formation of (Mn, Mg)O·Al2O3 inclusions.
Friedberg, Jonathan W; Mahadevan, Daruka; Cebula, Erin; Persky, Daniel; Lossos, Izidore; Agarwal, Amit B; Jung, Jungah; Burack, Richard; Zhou, Xiaofei; Leonard, E Jane; Fingert, Howard; Danaee, Hadi; Bernstein, Steven H
2014-01-01
Aurora A kinase (AAK) is overexpressed in aggressive lymphomas and can correlate with more histologically aggressive forms of disease. We therefore designed a phase II study of alisertib, a selective AAK inhibitor, in patients with relapsed and refractory aggressive non-Hodgkin lymphomas. Patients age ≥ 18 years were eligible if they had relapsed or refractory diffuse large B-cell lymphoma (DLBCL), mantle-cell lymphoma (MCL), transformed follicular lymphoma, Burkitt's lymphoma, or noncutaneous T-cell lymphoma. Alisertib was administered orally at 50 mg twice daily for 7 days in 21-day cycles. We enrolled 48 patients. Histologies included DLBCL (n = 21), MCL (n = 13), peripheral T-cell lymphoma (n = 8), transformed follicular lymphoma (n = 5), and Burkitt's (n = 1). Most common grade 3 to 4 adverse events were neutropenia (63%), leukopenia (54%), anemia (35%), thrombocytopenia (33%), stomatitis (15%), febrile neutropenia (13%), and fatigue (6%). Four deaths during the study were attributed to progressive non-Hodgkin lymphoma (n = 2), treatment-related sepsis (n = 1), and unknown cause (n = 1). The overall response rate was 27%, including responses in three of 21 patients with DLBCL, three of 13 with MCL, one of one with Burkitt's lymphoma, two of five with transformed follicular lymphoma, and four of eight with noncutaneous T-cell lymphoma. The alisertib steady-state trough concentration (n = 25) revealed the expected pharmacokinetic variability, with a trend for higher incidence of adverse event-related dose reductions at higher trough concentrations. Analysis for AAK gene amplification and total AAK protein revealed no differences between histologies or correlation with clinical response. The novel AAK inhibitor alisertib seems clinically active in both B- and T-cell aggressive lymphomas. On the basis of these results, confirmatory single-agent and combination studies have been initiated.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Matyas, Josef; Cooley, Scott K.; Sundaram, S. K.
Slags of low viscosity readily penetrate the refractory lining in slagging gasifiers, causing rapid and severe corrosion called spalling. In addition, a low-viscosity slag that flows down the gasifier wall forms a relatively thin layer of slag on the refractory surface, allowing the corrosive gases in the gasifier to participate in the chemical reactions between the refractory and the slag. In contrast, a slag viscosity of <25 Pa•s at 1400°C is necessary to minimize the possibility of plugging the slag tap. There is a need to predict and optimize slag viscosity so slagging gasifiers can operate continuously at temperatures rangingmore » from 1300 to 1650°C. The approach adopted in this work was to statistically design and prepare simulated slags, measure the viscosity as a function of temperature, and develop a model to predict slag viscosity based on slag composition and temperature. Statistical design software was used to select compositions from a candidate set of all possible vertices that will optimally represent the composition space for 10 main components. A total of 21 slag compositions were generated, including 5 actual coal slag compositions. The Arrhenius equation was applied to measured viscosity versus temperature data of tested slags, and the Arrhenius coefficients (A and B in ln(vis) = A + B/T) were expressed as linear functions of the slag composition. The viscosity model was validated using 1) data splitting approach, and 2) viscosity/temperature data of selected slag compositions from the literature that were formulated and melted at Pacific Northwest National Laboratory. The capability of the model to predict the viscosity of coal slags was compared with the model developed by Browning et al. because this model can predict the viscosity of slags from coal ash better than the most commonly used empirical models found in the literature.« less
40 CFR 63.9824 - What definitions apply to this subpart?
Code of Federal Regulations, 2010 CFR
2010-07-01
... means an add-on air pollution control device that is designed specifically to destroy organic compounds... U.S. Geologic Survey: ball clay, bentonite, common clay and shale, fire clay, fuller's earth, and.... Refractory shape means any refractory piece forming a stable mass with specific dimensions. Research and...
40 CFR 63.9824 - What definitions apply to this subpart?
Code of Federal Regulations, 2011 CFR
2011-07-01
... means an add-on air pollution control device that is designed specifically to destroy organic compounds... U.S. Geologic Survey: ball clay, bentonite, common clay and shale, fire clay, fuller's earth, and.... Refractory shape means any refractory piece forming a stable mass with specific dimensions. Research and...
40 CFR 63.9824 - What definitions apply to this subpart?
Code of Federal Regulations, 2012 CFR
2012-07-01
... means an add-on air pollution control device that is designed specifically to destroy organic compounds... U.S. Geologic Survey: ball clay, bentonite, common clay and shale, fire clay, fuller's earth, and.... Refractory shape means any refractory piece forming a stable mass with specific dimensions. Research and...
40 CFR 63.9824 - What definitions apply to this subpart?
Code of Federal Regulations, 2013 CFR
2013-07-01
... means an add-on air pollution control device that is designed specifically to destroy organic compounds... U.S. Geologic Survey: ball clay, bentonite, common clay and shale, fire clay, fuller's earth, and.... Refractory shape means any refractory piece forming a stable mass with specific dimensions. Research and...
40 CFR 63.9824 - What definitions apply to this subpart?
Code of Federal Regulations, 2014 CFR
2014-07-01
... means an add-on air pollution control device that is designed specifically to destroy organic compounds... U.S. Geologic Survey: ball clay, bentonite, common clay and shale, fire clay, fuller's earth, and.... Refractory shape means any refractory piece forming a stable mass with specific dimensions. Research and...
Method for producing UO$sub 2$ loaded refractory metals
Baker, R.D.; Hayter, S.W.; Lewis, H.D.
1973-12-11
A finely divided dispersion of UO/sub 2/ in tungsten or molybdenum is prepared by co-precipitating the metals from mixed aqueous solution with oxine. The co-precipitate thus formed is separated from the solution, dried, calcined, and finally reduced to UO/sub 2/ and refractory metal. (Official Gazette)
NASA Astrophysics Data System (ADS)
Skripnyak, Vladimir A.; Skripnyak, Evgeniya G.; Skripnyak, Vladimir V.; Vaganova, Irina K.
A model for predicting mechanical properties of ultra-high temperature ceramics and composites manufactured by selective laser sintering (SLS) and spark plasma sintering (SPS) under shock loading is presented. The model takes into account the porous structure, the specific volume and average sizes of phases, and the temperature of sintering. Residual stresses in ceramic composites reinforced with particles of refractory borides, carbides and nitrides after SLS or SPS were calculated. It is shown that the spall strength of diboride-zirconium matrix composites can be increased by the decreasing of porosity and the introduction of inclusions of specially selected refractory strengthening phases.
Peascoe-Meisner, Roberta A [Knoxville, TN; Keiser, James R [Oak Ridge, TN; Hemric, James G [Knoxville, TN; Hubbard, Camden R [Oak Ridge, TN; Gorog, J Peter [Kent, WA; Gupta, Amul [Jamestown, NY
2008-10-21
A method includes containing a high-temperature alkali salt containing environment using a refractory containment liner containing MgAl.sub.2O.sub.4 spinel. A method, includes forming a refractory brick containing MgAl.sub.2O.sub.4 spinel having an exterior chill zone defined by substantially columnar crystallization and an interior zone defined by substantially equiaxed crystallization; and removing at least a portion of the exterior chill zone from the refractory brick containing MgAl.sub.2O.sub.4 spinel by scalping the refractory brick containing MgAl.sub.2O.sub.4 spinel to define at least one outer surface having an area of substantially equiaxed crystallization. A product of manufacture includes a refractory brick containing MgAl.sub.2O.sub.4 spinel including an interior zone defined by substantially equiaxed crystallization; and at least one outer surface having an area of substantially equiaxed crystallization.
Barathi, B; Chandra, Prabha S
2013-01-01
Background: Patients with advanced cancer often suffer from multiple refractory symptoms in the terminal phase of their life. Palliative sedation is one of the few ways to relieve this refractory suffering. Objectives: This systematic review investigated the effect of palliative sedation on survival time in terminally ill cancer patients. Materials and Methods: Six electronic databases were searched for both prospective and retrospective studies which evaluated the effect of palliative sedation on survival time. Only those studies which had a comparison group that did not receive palliative sedation were selected for the review. Abstracts of all retrieved studies were screened to include the most relevant studies and only studies which met inclusion criteria were selected. References of all retrieved studies were also screened for relevant studies. Selected studies were assessed for quality and data extraction was done using the structured data extraction form. Results: Eleven studies including four prospective and seven retrospective studies were identified. Mean survival time (MST) was measured as the time from last admission until death. A careful analysis of the results of all the 11 studies indicated that MST of sedated and non-sedated group was not statistically different in any of the studies. Conclusion: This systematic review supports the fact that palliative sedation does not shorten survival in terminally ill cancer patients. However, this conclusion needs to be taken with consideration of the methodology, study design, and the population studied of the included studies in this review. PMID:23766594
Barathi, B; Chandra, Prabha S
2013-01-01
Patients with advanced cancer often suffer from multiple refractory symptoms in the terminal phase of their life. Palliative sedation is one of the few ways to relieve this refractory suffering. This systematic review investigated the effect of palliative sedation on survival time in terminally ill cancer patients. Six electronic databases were searched for both prospective and retrospective studies which evaluated the effect of palliative sedation on survival time. Only those studies which had a comparison group that did not receive palliative sedation were selected for the review. Abstracts of all retrieved studies were screened to include the most relevant studies and only studies which met inclusion criteria were selected. References of all retrieved studies were also screened for relevant studies. Selected studies were assessed for quality and data extraction was done using the structured data extraction form. Eleven studies including four prospective and seven retrospective studies were identified. Mean survival time (MST) was measured as the time from last admission until death. A careful analysis of the results of all the 11 studies indicated that MST of sedated and non-sedated group was not statistically different in any of the studies. This systematic review supports the fact that palliative sedation does not shorten survival in terminally ill cancer patients. However, this conclusion needs to be taken with consideration of the methodology, study design, and the population studied of the included studies in this review.
A Refractory Inclusion Returned by Stardust from Comet 81P/Wild 2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Simon, S B; Joswiak, D J; Ishii, H A
2008-05-20
Among the samples returned from comet 81P/Wild 2 by the Stardust spacecraft is a suite of particles from one impact track (Track 25) that are Ca-, Al-rich and FeO-free. We studied three particles from this track that range in size from 5.3 x 3.2 {micro}m to 15 x 10 {micro}m. Scanning and transmission electron microscopy show that they consist of very fine-grained (from {approx}0.5 to {approx}2 {micro}m) Al-rich, Ti-bearing and Ti-free clinopyroxene, Mg-Al spinel, anorthite, perovskite, and osbornite (TiN). In addition to these phases, the terminal particle, named 'Inti', also contains melilite. All of these phases, with the exception ofmore » osbornite, are common in refractory inclusions and are predicted to condense at high temperature from a gas of solar composition. Osbornite, though very rare, has also been found in meteoritic refractory inclusions, and could have formed in a region of the nebula where carbon became enriched relative to oxygen compared to solar composition. Compositions of Ti-pyroxene in Inti are similar, but not identical, to those of fassaite from Allende inclusions. Electron energy loss spectroscopy shows that Ti-rich pyroxene in Inti has Ti{sup 3+}/Ti{sup 4+} within the range of typical meteoritic fassaite, consistent with formation under reducing conditions comparable to those of a system of solar composition. Inti is {sup 16}O-rich, with {delta}{sup 18}O {approx} {delta}{sup 17}O {approx} 40{per_thousand}, like unaltered phases in refractory inclusions and refractory IDPs. With grain sizes, mineralogy, mineral chemistry, and an oxygen isotopic composition like those of refractory inclusions, we conclude that Inti is a refractory inclusion that formed in the inner solar nebula. Identification of a particle that formed in the inner Solar System among the comet samples demonstrates that there was transport of materials from the inner to the outer nebula, probably either in a bipolar outflow or by turbulence.« less
Steel refining with an electrochemical cell
Blander, M.; Cook, G.M.
1988-05-17
Apparatus is described for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contact with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight oxygen and not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom. 2 figs.
Steel refining with an electrochemical cell
Blander, M.; Cook, G.M.
1985-05-21
Disclosed is an apparatus for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contact with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom.
Steel refining with an electrochemical cell
Blander, Milton; Cook, Glenn M.
1988-01-01
Apparatus for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contact with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight oxygen and not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom.
Gong, Feilong; Li, Peng; Li, Bin; Zhang, Shizhen; Zhang, Xinjie; Yang, Sen; Liu, Hongbin; Wang, Wei
2018-02-01
OBJECTIVE Anterior capsulotomy (AC) is sometimes used as a last resort for treatment-refractory obsessive-compulsive disorder (OCD). Previous studies assessing neuropsychological outcomes in patients with OCD have identified several forms of cognitive dysfunction that are associated with the disease, but few have focused on changes in cognitive function in OCD patients who have undergone surgery. In the present study, the authors investigated the effects of AC on the cognitive function of patients with treatment-refractory OCD. METHODS The authors selected 14 patients with treatment-refractory OCD who had undergone bilateral AC between 2007 and 2013, 14 nonsurgically treated OCD patients, and 14 healthy control subjects for this study. The 3 groups were matched for sex, age, and education. Several neuropsychological tests, including Similarities and Block Design, which are subsets of the Wechsler Abbreviated Scale of Intelligence; Immediate and Delayed Logical Memory and Immediate and Delayed Visual Reproduction, which are subsets of the Wechsler Memory Scale-Revised; and Corrects, Categories, Perseverative Errors, Nonperseverative Errors, and Errors, subtests of the Wisconsin Card Sorting Test, were conducted in all 42 subjects at baseline and after AC, after nonsurgical treatment, or at 6-month intervals, as appropriate. The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was used to measure OCD symptoms in all 28 OCD patients. RESULTS The Y-BOCS scores decreased significantly in both OCD groups during the 12-month follow-up period. Surgical patients showed higher levels of improvement in verbal memory, visual memory, visuospatial skills, and executive function than the nonsurgically treated OCD patients. CONCLUSIONS The findings of this study suggest that AC not only reduces OCD symptoms but also attenuates moderate cognitive deficits.
Rapid Method for Sodium Hydroxide/Sodium Peroxide Fusion ...
Technical Fact Sheet Analysis Purpose: Qualitative analysis Technique: Alpha spectrometry Method Developed for: Plutonium-238 and plutonium-239 in water and air filters Method Selected for: SAM lists this method as a pre-treatment technique supporting analysis of refractory radioisotopic forms of plutonium in drinking water and air filters using the following qualitative techniques: • Rapid methods for acid or fusion digestion • Rapid Radiochemical Method for Plutonium-238 and Plutonium 239/240 in Building Materials for Environmental Remediation Following Radiological Incidents. Summary of subject analytical method which will be posted to the SAM website to allow access to the method.
van de Kamp, Cornelis; Gawthrop, Peter J.; Gollee, Henrik; Lakie, Martin; Loram, Ian D.
2013-01-01
Modular organization in control architecture may underlie the versatility of human motor control; but the nature of the interface relating sensory input through task-selection in the space of performance variables to control actions in the space of the elemental variables is currently unknown. Our central question is whether the control architecture converges to a serial process along a single channel? In discrete reaction time experiments, psychologists have firmly associated a serial single channel hypothesis with refractoriness and response selection [psychological refractory period (PRP)]. Recently, we developed a methodology and evidence identifying refractoriness in sustained control of an external single degree-of-freedom system. We hypothesize that multi-segmental whole-body control also shows refractoriness. Eight participants controlled their whole body to ensure a head marker tracked a target as fast and accurately as possible. Analysis showed enhanced delays in response to stimuli with close temporal proximity to the preceding stimulus. Consistent with our preceding work, this evidence is incompatible with control as a linear time invariant process. This evidence is consistent with a single-channel serial ballistic process within the intermittent control paradigm with an intermittent interval of around 0.5 s. A control architecture reproducing intentional human movement control must reproduce refractoriness. Intermittent control is designed to provide computational time for an online optimization process and is appropriate for flexible adaptive control. For human motor control we suggest that parallel sensory input converges to a serial, single channel process involving planning, selection, and temporal inhibition of alternative responses prior to low dimensional motor output. Such design could aid robots to reproduce the flexibility of human control. PMID:23675342
Martlé, Valentine; Van Ham, Luc; Raedt, Robrecht; Vonck, Kristl; Boon, Paul; Bhatti, Sofie
2014-03-01
Refractory epilepsy is a common disorder both in humans and dogs and treatment protocols are difficult to optimise. In humans, different non-pharmacological treatment modalities currently available include surgery, the ketogenic diet and neurostimulation. Surgery leads to freedom from seizures in 50-75% of patients, but requires strict patient selection. The ketogenic diet is indicated in severe childhood epilepsies, but efficacy is limited and long-term compliance can be problematic. In the past decade, various types of neurostimulation have emerged as promising treatment modalities for humans with refractory epilepsy. Currently, none of these treatment options are used in routine daily clinical practice to treat dogs with the condition. Since many dogs with poorly controlled seizures do not survive, the search for alternative treatment options for canine refractory epilepsy should be prioritised. This review provides an overview of non-pharmacological treatment options for human refractory epilepsy. The current knowledge and limitations of these treatments in canine refractory epilepsy is also discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Curran, Jerome P.; Kolody, Mark; Perusich, Stephen; Whitten, Mary C.; Trejo, David; Zidek, Jason; Sampson, Jeffrey W.;
2009-01-01
Ceramics can be defmed as a material consisting of hard brittle properties produced from inorganic and nonmetallic minerals made by firing at high temperatures. These materials are compounds between metallic and nonmetallic elements and are either totally ionic, or predominately ionic but having some covalent character. This definition allows for a large range of materials, not all applicable to refractory applications. As this report is focused on potential ceramic materials for high temperature, aggressive exposure applications, the ceramics reviewed as part of this report will focus on refractory ceramics specifically designed and used for these applications. Ceramic materials consist of a wide variety of products. Callister (2000) 1 characterized ceramic materials into six classifications: glasses, clay products, refractories, cements, abrasives, and advanced ceramics. Figure 1 shows this classification system. This review will focus mainly on refractory ceramics and cements as in general, the other classifications are neither applicable nor economical for use in large structures such as the flame trench. Although much work has been done in advanced ceramics over the past decade or so, these materials are likely cost prohibitive and would have to be fabricated off-site, transported to the NASA facilities, and installed, which make these even less feasible. Although the authors reviewed the literature on advanced ceramic refractories 2 center dot 3 center dot 4 center dot 5 center dot 6 center dot 7 center dot 8 center dot 9 center dot 10 center dot 11 center dot 12 after the review it was concluded that these materials should not be ' the focus of this report. A review is in progress on materials and systems for prefabricated refractory ceramic panels, but this review is focusing more on typical refractory materials for prefabricated systems, which could make the system more economically feasible. Refractory ceramics are used for a wide variety of applications. Figure 2 shows many ofthese applications, their life expectancy or requirement, and the exposure temperature for the refractory ceramic. Note that the exposure temperatures for refractory ceramics are very similar to the exposure conditions for specialty ceramics (rocket nozzles, space vehicle re-entry fields, etc.) and yet the life expectancy or requirement is relatively low. Currently NASA is repairing the refractory lining in the flame trench after every launch - although this is not a direct indication of low life expectancy, it does indicate that the current system may not be sufficiently durable to maximize economy. Better performing refractory ceramics are needed to improve the performance, economy, and safety during and after launches at the flame trenches at Kennedy Space Center (KSC). To achieve this goal a current study is underway to assess different refractory systems for possible use in the flame trenches at KSC. This report will target the potential applicability of refractory ceramics for use in the flame trenches. An overview of the different refractory ceramics will be provided (see Figure I). This will be followed with a brief description of the structure of refractory products, the properties and characteristics of different systems, the methodology for selecting refractories, and then a general design methodology. Based on these sections, future challenges and opportunities will be identified with the objective of improving the durability, performance, economy, and safety of the launch complex. Refractory ceramics are used for a wide variety of applications. Figure 2 shows many ofthese applications, their life expectancy or requirement, and the exposure temperature for the refractory ceramic. Note that the exposure temperatures for refractory ceramics are very similar to the exposure conditions for specialty ceramics (rocket nozzles, space vehicle re-entry fields, etc.) and yet the life expectancy or requirement is relatively low. Currently NASA is repairing the refractory lining in the flame trench after every launch - although this is not a direct indication of low life expectancy, it does indicate that the current system may not be sufficiently durable to maximize economy. Better performing refractory ceramics are needed to improve the performance, economy, and safety during and after launches at the flame trenches at Kennedy Space Center (KSC). To achieve this goal a current study is underway to assess different refractory systems for possible use in the flame trenches at KSC. This report will target the potential applicability of refractory ceramics for use in the flame trenches. An overview of the different refractory ceramics will be provided (see Figure I). This will be followed with a brief description of the structure of refractory products, the properties and characteristics of different systems, the methodology for selecting refractories, and then a general design methodology. Based on these sections, future challenges and opportunities will be identified with the objective of improving the durability, performance, economy, and safety of the launch complex.
Experimental Design for Evaluation of Co-extruded Refractory Metal/Nickel Base Superalloy Joints
DOE Office of Scientific and Technical Information (OSTI.GOV)
ME Petrichek
2005-12-16
Prior to the restructuring of the Prometheus Program, the NRPCT was tasked with delivering a nuclear space reactor. Potential NRPCT nuclear space reactor designs for the Prometheus Project required dissimilar materials to be in contact with each other while operating at extreme temperatures under irradiation. As a result of the high reactor core temperatures, refractory metals were the primary candidates for many of the reactor structural and cladding components. They included the tantalum-base alloys ASTAR-811C and Ta-10W, the niobium-base alloy FS-85, and the molybdenum base alloys Moly 41-47.5 Rhenium. The refractory metals were to be joined to candidate nickel basemore » alloys such as Haynes 230, Alloy 617, or Nimonic PE 16 either within the core if the nickel-base alloys were ultimately selected to form the outer core barrel, or at a location exterior to the core if the nickel-base alloys were limited to components exterior to the core. To support the need for dissimilar metal joints in the Prometheus Project, a co-extrusion experiment was proposed. There are several potential methods for the formation of dissimilar metal joints, including explosive bonding, friction stir welding, plasma spray, inertia welding, HIP, and co-extrusion. Most of these joining methods are not viable options because they result in the immediate formation of brittle intermetallics. Upon cooling, intermetallics form in the weld fusion zone between the joined metals. Because brittle intermetallics do not form during the initial bonding process associated with HIP, co-extrusion, and explosive bonding, these three joining procedures are preferred for forming dissimilar metal joints. In reference to a Westinghouse Astronuclear Laboratory report done under a NASA sponsored program, joints that were fabricated between similar materials via explosive bonding had strengths that were directly affected by the width of the diffusion barrier. It was determined that the diffusion zone should not exceed a critical thickness (0.0005 in.). A diffusion barrier that exceeded this thickness would likely fail. The joint fabrication method must therefore mechanically bond the two materials causing little or no interdiffusion upon formation. Co-extrusion fits this description since it forms a mechanical joint between two materials by using heat and pressure. The two materials to be extruded are first assembled and sealed within a co-extrusion billet which is subsequently heated and then extruded through a die. For a production application, once the joint is formed, it is dejacketed to remove the outer canister. The remaining piece consists of two materials bonded together with a thin diffusion barrier. Therefore, the long-term stability of the joint is determined primarily by the kinetics of interdiffusion reaction between the two materials. An experimental design for co-extrusion of refractory metals and nickel-based superalloys was developed to evaluate this joining process and determine the long-term stability of the joints.« less
Office Procedures in Refractory Chronic Rhinosinusitis.
Thamboo, Andrew; Patel, Zara M
2017-02-01
Office procedures in chronic rhinosinusitis (CRS) can be considered before and after medical management, as well as before and after surgical management. This article focuses specifically on refractory CRS, meaning those patients who have failed medical and surgical management already. The options available in the management of refractory CRS depend on the personnel, equipment, and instrumentation available in the office setting; surgeon experience; and patient suitability and tolerability. This article provides readers with possible procedural options that can be done in their clinics with indications, patient selection, potential complications, and postoperative considerations. Copyright © 2016 Elsevier Inc. All rights reserved.
Chen, Yok; Gonzalez, Roberto
1986-01-01
Refractory oxide crystals having high-quantum efficiency and high thermal stability for use as broadly tunable laser host materials. The crystals are formed by removing hydrogen from a single crystal of the oxide material to a level below about 10.sup.12 protons per cm.sup.3 and subsequently thermochemically reducing the oxygen content of the crystal to form sufficient oxygen anion vacancies so that short-lived F.sup.+ luminescence is produced when the crystal is optically excited.
Chen, Yok; Gonzalez, R.
1985-07-03
Refractory oxide crystals having high-quantum efficiency and high thermal stability for use as broadly tunable laser host materials. The crystals are formed by removing hydrogen from a single crystal of the oxide material to a level below about 10/sup 12/ protons per cm/sup 3/ and subsequently thermochemically reducing the oxygen content of the crystal to form sufficient oxygen anion vacancies so that short-lived F/sup +/ luminescence is produced when the crystal is optically excited.
Compatibility of refractory materials for nuclear reactor poison control systems
NASA Technical Reports Server (NTRS)
Sinclair, J. H.
1974-01-01
Metal-clad poison rods have been considered for the control system of an advanced space power reactor concept studied at the NASA Lewis Research Center. Such control rods may be required to operate at temperatures of about 140O C. Selected poison materials (including boron carbide and the diborides of zirconium, hafnium, and tantalum) were subjected to 1000-hour screening tests in contact with candidate refractory metal cladding materials (including tungsten and alloys of tantalum, niobium, and molybdenum) to assess the compatibility of these materials combinations at the temperatures of interest. Zirconium and hafnium diborides were compatible with refractory metals at 1400 C, but boron carbide and tantalum diboride reacted with the refractory metals at this temperature. Zirconium diboride also showed promise as a reaction barrier between boron carbide and tungsten.
Bender, Angela D; Filmer, Hannah L; Garner, K G; Naughtin, Claire K; Dux, Paul E
2016-11-01
The abilities to select appropriate responses and suppress unwanted actions are key executive functions that enable flexible and goal-directed behavior. However, to date it has been unclear whether these two cognitive operations tap a common action control resource or reflect two distinct processes. In the present study, we used an individual differences approach to examine the underlying relationships across seven paradigms that varied in their response selection and response inhibition requirements: stop-signal, go-no-go, Stroop, flanker, single-response selection, psychological refractory period, and attentional blink tasks. A confirmatory factor analysis suggested that response inhibition and response selection are separable, with stop-signal and go-no-go task performance being related to response inhibition, and performance in the psychological refractory period, Stroop, single-response selection, and attentional blink tasks being related to response selection. These findings provide evidence in support of the hypothesis that response selection and response inhibition reflect two distinct cognitive operations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dangi, Beni B.; Kim, Yong S.; Krasnokutski, Serge A.
2015-05-20
We report on laboratory simulation experiments mimicking the chemical processing of model atmospheres of exoplanets containing C3 and C4 hydrocarbons at moderate temperatures of 400 K upon interaction of catalytic surfaces of micrometeoroids. By utilizing an ultrasonic levitator device and heating singly levitated particles under simulated microgravity conditions, Raman spectroscopy is utilized as a non-invasive tool to probe on line and in situ the conversion of C3 and C4 hydrocarbons to refractory carbonaceous matter on the surfaces of levitated particles. Secondary Ion Mass Spectrometry and electron microscopic imaging were also conducted to gain further insight into the elementary composition andmore » structures of the refractories formed. Our results provide compelling evidence that in the presence of a catalytic surface, which can be supplied in the form of micrometeoroids and atmospheric dust particles, hydrocarbon gases present in the atmospheres of exoplanets can be converted to refractory, carbon-rich carbonaceous matter of mainly graphitic structure with a carbon content of at least 90% at elevated temperatures. This finding might explain the low methane to carbon monoxide (CH{sub 4}–CO) ratio in the hot Neptune GJ 436b, where the abundant methane photochemically converts to higher order hydrocarbons and ultimately to refractory graphite-like carbon in the presence of a silicon surface.« less
Andréll, Paulin; Schultz, Tomas; Mannerkorpi, Kaisa; Nordeman, Lena; Börjesson, Mats; Mannheimer, Clas
2014-04-01
To compare health-related quality of life in 2 different populations with chronic pain: patients with fibromyalgia and patients with refractory angina pectoris. Previous separate studies have indicated that these patient groups report different impacts of pain on health-related quality of life. The Short-Form 36 was used to assess health- related quality of life. In order to adjust for age and gender differences between the groups, both patient groups were compared with age- and gender-matched normative controls. The difference in health-related quality of life between the 2 patient groups was assessed by transforming the Short-Form 36 subscale scores to a z-score. The patients with fibromyalgia (n = 203) reported poorer health-related quality of life in all the subscale scores of Short-Form 36 (p < 0.05-0.0001) than the patients with refractory angina (n = 146) when both groups were compared with their corresponding normal population (z-score). Patients with fibromyalgia experience greater impairment in health-related quality of life compared with the normal population than do patients with refractory angina pectoris, despite the fact that the latter have a potentially life-threatening disease. The great impairment in health- related quality of life in patients with fibromyalgia should be taken into consideration when planning rehabilitation.
Gonsalves, Wilson I; Buadi, Francis K; Kumar, Shaji K
2018-02-01
Primary plasma cell leukemia (pPCL) is the most aggressive form of the plasma cell (PC) malignancy, multiple myeloma (MM). It has been commonly associated with the presence of a chromosome translocation involving the immunoglobulin heavy chain (IgH) locus on 14q32, that is t (11;14). Results from early phase clinical trials utilizing the selective Bcl-2 inhibitor, venetoclax, as a single agent in patients with relapsed MM have had remarkable efficacy among patients with t (11;14) abnormality. The present case demonstrates the ability of a combination regimen incorporating Bcl-2 inhibition with daratumumab, bortezomib, venetoclax, and dexamethasone to induce a rapid and very deep hematologic response in a pPCL patient with t (11;14), even in a setting of very refractory disease. This case highlights the need to further study Bcl-2 inhibition-based therapy as an option for therapy in patients with pPCL with t (11;14). © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Design of refractory high-entropy alloys
Gao, M. C.; Carney, C. S.; Dogan, O. N.; ...
2015-09-15
Here, this report presents a design methodology for refractory high-entropy alloys with a body-centered cubic (bcc) structure using select empirical parameters (i.e., enthalpy of mixing, atomic size difference, Ω-parameter, and electronegativity difference) and CALPHAD approach. Sixteen alloys in equimolar compositions ranging from quinary to ennead systems were designed with experimental verification studies performed on two alloys using x-ray diffraction, energy-dispersive spectroscopy, and scanning electron microscopy. Two bcc phases were identified in the as-cast HfMoNbTaTiVZr, whereas multiple phases formed in the as-cast HfMoNbTaTiVWZr. Observed elemental segregation in the alloys qualitatively agrees with CALPHAD prediction. Comparisons of the thermodynamic mixing properties formore » liquid and bcc phases using the Miedema model and CALPHAD are presented. This study demonstrates that CALPHAD is more effective in predicting HEA formation than empirical parameters, and new single bcc HEAs are suggested: HfMoNbTiZr, HfMoTaTiZr, NbTaTiVZr, HfMoNbTaTiZr, HfMoTaTiVZr, and MoNbTaTiVZr.« less
Management of refractory status epilepticus in adults
Rossetti, Andrea O.; Lowenstein, Daniel H.
2011-01-01
Summary Refractory status epilepticus (RSE) can be defined as status epilepticus that continues despite treatment with benzodiazepines and one antiepileptic drug. RSE should be treated promptly to prevent morbidity and mortality; however, scarce evidence is available to support the choice of specific treatments. Major independent outcome predictors are age (not modifiable) and etiology (that should be actively targeted). Recent recommendations for adults, relying upon limited evidence, suggest that RSE treatment aggressiveness should be tailored to the clinical situation: to minimize ICU-related complications, focal RSE without major consciousness impairment might initially be approached more conservatively; conversely, early induction of pharmacological coma is advisable in generalized-convulsive forms. At this stage, midazolam, propofol or barbiturates represent the most used alternatives. Several other treatments, such as additional anesthetics, other antiepileptic or immunomodulatory compounds, or non-pharmacological approaches (electroconvulsive treatment, hypothermia), have been used in protracted RSE. Treatment lasting weeks or months may sometimes result in a good outcome, as in selected cases after cerebral anoxia and encephalitis. Well-designed prospective studies of this condition are urgently needed. PMID:21939901
Ceramic fiber reinforced filter
Stinton, David P.; McLaughlin, Jerry C.; Lowden, Richard A.
1991-01-01
A filter for removing particulate matter from high temperature flowing fluids, and in particular gases, that is reinforced with ceramic fibers. The filter has a ceramic base fiber material in the form of a fabric, felt, paper of the like, with the refractory fibers thereof coated with a thin layer of a protective and bonding refractory applied by chemical vapor deposition techniques. This coating causes each fiber to be physically joined to adjoining fibers so as to prevent movement of the fibers during use and to increase the strength and toughness of the composite filter. Further, the coating can be selected to minimize any reactions between the constituents of the fluids and the fibers. A description is given of the formation of a composite filter using a felt preform of commercial silicon carbide fibers together with the coating of these fibers with pure silicon carbide. Filter efficiency approaching 100% has been demonstrated with these filters. The fiber base material is alternately made from aluminosilicate fibers, zirconia fibers and alumina fibers. Coating with Al.sub.2 O.sub.3 is also described. Advanced configurations for the composite filter are suggested.
Clinical Outcomes and Quality of Life Following Surgical Treatment for Refractory Epilepsy
Liu, Shi-Yong; Yang, Xiao-Lin; Chen, Bing; Hou, Zhi; An, Ning; Yang, Mei-Hua; Yang, Hui
2015-01-01
Abstract Surgery for refractory epilepsy is widely used but the efficacy of this treatment for providing a seizure-free outcome and better quality of life remains unclear. This study aimed to update current evidence and to evaluate the effects of surgery on quality of life in patients with refractory epilepsy. A systematic review and meta-analysis of the literature were conducted and selected studies included 2 groups of refractory epilepsy patients, surgical and nonsurgical. The studies were assessed using the Newcastle–Ottawa Scale. The primary outcome was the seizure-free rate. The secondary outcome was quality of life. Adverse events were also reviewed. After screening, a total of 20 studies were selected: 8 were interventional, including 2 randomized controlled trials, and 12 were observational. All of the studies comprised 1959 patients with refractory epilepsy. The seizure-free rates were significantly higher for patients who received surgery compared with the patients who did not; the combined odds ratio was 19.35 (95% CI = 12.10–30.95, P < 0.001). After adjusting for publication bias the combined odds ratio was 10.25 (95% CI = 5.84–18.00). In both the interventional and observational studies, patients treated surgically had a significantly better quality of life compared with the patients not treated surgically. Complications were listed in 3 studies and the rates were similar in surgical and nonsurgical patients. Our meta-analysis found that for patients with refractory epilepsy, surgical treatment appears to provide a much greater likelihood of seizure-free outcome than nonsurgical treatment, although there is a need for more studies, particularly randomized studies, to confirm this conclusion. Based on more limited data, surgical treatment also appeared to provide a better quality of life and did not seem to increase complications. PMID:25674741
2014-01-01
Background Refractory angina is a severe chronic disease, defined as angina which cannot be controlled by usual treatments for heart disease. This disease is frightening, debilitating, and difficult to manage. Many people suffering refractory have inadequate pain relief, continually revisit emergency departments for help, undergo repeated cardiac investigations, and struggle with obtaining appropriate care. There is no clear framework to help people understand the risks and benefits of available treatment options in Canada. Some treatments for refractory angina are invasive, while others are not covered by provincial health insurance plans. Effective care for refractory angina sufferers in Canada is critically underdeveloped; it is important that healthcare professionals and refractory angina sufferers alike understand the treatment options and their implications. This proposal builds on the recent Canadian practice guidelines for the management of refractory angina. We propose to develop a decision support tool in order to help people suffering from refractory angina make well-informed decisions about their healthcare and reduce their uncertainty about treatment options. Methods This project will be conducted in three phases: a) development of the support tool with input from clinical experts, the Canadian refractory angina guidelines, and people living with refractory angina, b) pilot testing of the usability of the tool, and c) formal preliminary evaluation of the effectiveness of the support tool to help people make informed decisions about treatment options. Discussion A decision support tool for refractory angina is needed and the available data suggest that by developing such a tool, we may be able to help refractory angina sufferers better understand their condition and the effectiveness of available treatment options (in their respective clinical settings) as well as their implications (e.g. risks vs. benefits). By virtue of this tool, we may also be able to facilitate identification and inclusion of patients’ values and preferences in the decision making process. This is particularly important as refractory angina is an intractable condition, necessitating that the selected course of treatment be lifelong. This study will yield a much needed patient decision aid for people living with refractory angina and pilot data to support a subsequent effectiveness study. PMID:24920518
Development Study of Cartridge/Crucible Tube Materials
NASA Technical Reports Server (NTRS)
McKechnie, Timothy N.; ODell, Scott J.
1998-01-01
The limitations of traditional alloys and the desire for improved performance for components is driving the increased utilization of refractory metals in tile space industry. From advanced propulsion systems to high temperature furnace components for microgravity processing, refractory metals are being used for their high melting temperatures and inherent chemical stability. Techniques have been developed to produce near net shape refractory metal components utilizing vacuum plasma spraying. Material utilization is very high, and laborious machining can be avoided. As-spray formed components have been tested and found to perform adequately. However, increased mechanical and thermal properties are needed. To improve these properties, post processing thermal treatments such as hydrogen sintering and vacuum annealing have been performed. Components formed from alloys of tungsten, rhenium, tantalum, niobium, and molybdenum are discussed and a metallurgical analyses detailing the results are presented. A qualitative comparison of mechanical properties is also included.
New techniques for fusion bonding and replication for large glass reflectors
NASA Technical Reports Server (NTRS)
Angel, J. R. P.
1983-01-01
Lightweight, space-deployable glass honeycomb telescope primary mirror structures are produced by a novel method which involves the heating to softening temperature of many borosilicate or silica glass tube sections that are packed to form a honeycomb matrix and filled with a high expansion coefficient refractory sand. The close packed tubes yield a hexagonal-cell honeycomb. Attention is given to the results of an experiment in which a highly refractory master was used to shape a honeycomb of less refractory glass, employing a 1-micron thick, vacuum-deposited gold coating as a parting layer between the two.
Method for ultra-fast boriding
Erdemir, Ali; Sista, Vivekanand; Kahvecioglu, Ozgenur; Eryilmaz, Osman Levent
2017-01-31
An article of manufacture and method of forming a borided material. An electrochemical cell is used to process a substrate to deposit a plurality of borided layers on the substrate. The plurality of layers are co-deposited such that a refractory metal boride layer is disposed on a substrate and a rare earth metal boride conforming layer is disposed on the refractory metal boride layer.
Wang, Junfeng; Zhang, Qi; Chen, Mindong; Collier, Sonya; Zhou, Shan; Ge, Xinlei; Xu, Jianzhong; Shi, Jinsen; Xie, Conghui; Hu, Jianlin; Ge, Shun; Sun, Yele; Coe, Hugh
2017-12-19
Refractory black carbon (rBC) aerosol is an important climate forcer, and its impacts are greatly influenced by the species associated with rBC cores. However, relevant knowledge is particularly lacking at the Tibetan Plateau (TP). Here we report, for the first time, highly time-resolved measurement results of rBC and its coating species in central TP (4730 m a.s.l), using an Aerodyne soot particle aerosol mass spectrometer (SP-AMS), which selectively measured rBC-containing particles. We found that the rBC was overall thickly coated with an average mass ratio of coating to rBC (R BC ) of ∼7.7, and the coating species were predominantly secondarily formed by photochemical reactions. Interestingly, the thickly coated rBC was less oxygenated than the thinly coated rBC, mainly due to influence of the transported biomass burning organic aerosol (BBOA). This BBOA was relatively fresh but formed very thick coating on rBC. We further estimated the "lensing effect" of coating semiquantitatively by comparing the measurement data from a multiangle absorption photometer and SP-AMS, and found it could lead to up to 40% light absorption enhancement at R BC > 10. Our findings highlight that BBOA can significantly affect the "lensing effect", in addition to its relatively well-known role as light-absorbing "brown carbon."
Melatonin and childhood refractory epilepsy--a pilot study.
Paprocka, Justyna; Dec, Renata; Jamroz, Ewa; Marszał, Elzbieta
2010-09-01
The aim of the study was to assess diurnal melatonin secretion in children with refractory epilepsy (N=74) as compared to children without epileptic seizures (N=37) and to compare melatonin secretion in children with focal and generalized refractory epilepsy. In the study group 4 subgroups were defined: children with focal symptomatic epilepsy, focal cryptogenic epilepsy, generalized symptomatic epilepsy, and generalized cryptogenic epilepsy. Melatonin level was measured every 3 hours using the RIA method. Analysis of diurnal melatonin secretion indicated a lower level of the hormone in patients with refractory epilepsy. The daily rhythm of melatonin secretion in the study group was maintained, with a peak shift of melatonin secretion especially visible in the subgroup with generalized symptomatic refractory epilepsy in the age group between 6 months and 3 years of age. The hypothesis may be formed that a lowered level of melatonin in the study group in relation to the comparison group is the consequence of the natural course of epilepsy or is influenced by antiepileptic drugs.
Refractory metal particles in refractory inclusions in the Allende meteorite
NASA Technical Reports Server (NTRS)
Fuchs, L. H.; Blander, M.
1980-01-01
SEM and X-ray analysis were used to study refractory metal particles in five calcium-aluminum-rich inclusions in the Allende meteorite, and a complex variety of compositions and large departures from equilibrium were found. It is suggested that these particles could have been primordial condensates which were isolated from the nebula and from each other at different times by cocondensing oxides. Selective diffusion and/or oxidation of the more oxidizable metals (Mo, W, Fe, and Ni), phase segregations into different alloy phases (fcc, bcc, hcp, and, possibly, ordered phases), and the formation of metastable condensates could have been involved in the genesis of these materials
Spontaneous growth of polarizing refractory metal ‘nano-fins’
NASA Astrophysics Data System (ADS)
Tai, M. C.; Gentle, A. R.; Arnold, M. D.; Cortie, M. B.
2018-03-01
Traditional polymer polarizers degrade in harsh environments and at high temperatures, reducing the polarization effect. In contrast, polarizers produced with refractory metals have vastly improved thermal stability and resistance to harsh environments but are expensive to fabricate. Here we demonstrate prototype refractory metal wire grid polarizers produced by co-sputtering molybdenum and aluminum under specific conditions. Removal of the aluminum through selective dissolution enables the nanostructure array to transmit light. The polarization spans 500-1100 nm and the extinction ratio significantly increases to >100. Possessing broadband polarization and sufficient extinction ratios, the new polarizing film has potential applications in coatings for sunglasses, windows, pyrometers, scientific instruments, and LCD panels.
Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor
NASA Technical Reports Server (NTRS)
Gorti, Sridhar; Holmes, Richard; O'Dell, John; McKechnie, Timothy; Shchetkovskiy, Anatoliy
2013-01-01
Rhenium, with its high melting temperature, excellent elevated temperature properties, and lack of a ductile-to-brittle transition temperature (DBTT), is ideally suited for the hot gas components of the ACM (Attitude Control Motor), and other high-temperature applications. However, the high cost of rhenium makes fabricating these components using conventional fabrication techniques prohibitive. Therefore, near-net-shape forming techniques were investigated for producing cost-effective rhenium and rhenium alloy components for the ACM and other propulsion applications. During this investigation, electrochemical forming (EL-Form ) techniques were evaluated for producing the hot gas components. The investigation focused on demonstrating that EL-Form processing techniques could be used to produce the ACM flow distributor. Once the EL-Form processing techniques were established, a representative rhenium flow distributor was fabricated, and samples were harvested for material properties testing at both room and elevated temperatures. As a lower cost and lighter weight alternative to an all-rhenium component, rhenium- coated graphite and carbon-carbon were also evaluated. The rhenium-coated components were thermal-cycle tested to verify that they could withstand the expected thermal loads during service. High-temperature electroforming is based on electrochemical deposition of compact layers of metals onto a mandrel of the desired shape. Mandrels used for electro-deposition of near-net shaped parts are generally fabricated from high-density graphite. The graphite mandrel is easily machined and does not react with the molten electrolyte. For near-net shape components, the inner surface of the electroformed part replicates the polished graphite mandrel. During processing, the mandrel itself becomes the cathode, and scrap or refined refractory metal is the anode. Refractory metal atoms from the anode material are ionized in the molten electrolytic solution, and are deposited onto the cathodic mandrel by electrochemical reduction. Rotation of the mandrel ensures uniform distribution of refractory material. The EL-Form process allows for manufacturing in an inert atmosphere with deposition rates from 0.0004 to 0.002 in./h (10.2 to 50.8 m/h). Thicknesses typically range from microns to greater than 0.5 in. (13 mm). The refractory component produced is fabricated, dependably, to within one micron of the desired tolerances with no shrinkage or distortion as in other refractory metal manufacture techniques. The electroforming process has been used to produce solid, nonporous deposits of rhenium, iridium, niobium, tungsten, and their alloys.
Brouk, Hacene; Bertrand, Gérald; Zitouni, Selma; Djenouni, Amel; Martageix, Corinne; Griffi, Fatiha; Kaplan, Cecile; Ouelaa, Hanifa
2015-06-01
Patients receiving cellular blood components may form HLA or HPA antibodies. The frequency and the specificity of HPA antibodies after a series of blood transfusions have never been reported in the Algerian population which is ethnically diverse and runs a higher risk of platelet alloimmunization due to high b allelic frequencies observed for the HPA systems. 117 polytransfused patients were included in this study; the detection of HPA antibodies was performed by the Monoclonal Antibody-specific Immobilization of Platelet Antigens method (MAIPA). Post-transfusion platelet effectiveness was evaluated by the calculation of corrected count increment (CCI). The antibodies against platelets were detected in 10.26% of the patients. In this study, the platelet systems concerned by the alloimmunizations were specifically HPA-1, -3 and -5 with particular predominance of HPA-1. Twenty two patients were refractory to platelet transfusion, as assessed by a CCI; in which 64% have factors associated with increased platelet consumption. Platelet Immunization was found in 14% of platelet refractoriness (PTR) cases. 03 Anti-platelet antibodies were directed against GPIb-IX (n = 1), anti-HPA-1b (n = 1) and anti HPA-5b (n = 1) associated with anti-HLA antibodies in two cases. HLA and HPA alloimmunization is common among chronically transfused patients. PTR detection, identification of the underlying causes, and selection of the appropriate product for transfusion are fundamental to reduce the risk of major bleedings. Copyright © 2014 Elsevier Ltd. All rights reserved.
Organic Rankine cycle receiver development
NASA Technical Reports Server (NTRS)
Haskins, H. J.
1981-01-01
The selected receiver concept is a direct-heated, once-through, monotube boiler operated at supercritical pressure. The cavity is formed by a cylindrical copper shell and backwall, with stainless steel tubing brazed to the outside surface. This core is surrounded by lightweight refractory insulation, load-bearing struts, and an outer case. The aperture plate is made of copper to provide long life by conduction and reradiation of heat away from the aperture lip. The receiver thermal efficiency is estimated to be 97 percent at rated conditions (energy transferred to toluene divided by energy incident on aperture opening). Development of the core manufacturing and corrosion protection methods is complete.
Getting the best outcomes from epilepsy surgery
Vakharia, Vejay N.; Witt, Juri‐Alexander; Elger, Christian E.; Staba, Richard; Engel, Jerome
2018-01-01
Neurosurgery is an underutilized treatment that can potentially cure drug‐refractory epilepsy. Careful, multidisciplinary presurgical evaluation is vital for selecting patients and to ensure optimal outcomes. Advances in neuroimaging have improved diagnosis and guided surgical intervention. Invasive electroencephalography allows the evaluation of complex patients who would otherwise not be candidates for neurosurgery. We review the current state of the assessment and selection of patients and consider established and novel surgical procedures and associated outcome data. We aim to dispel myths that may inhibit physicians from referring and patients from considering neurosurgical intervention for drug‐refractory focal epilepsies. Ann Neurol 2018;83:676–690 PMID:29534299
[Underlying Mechanisms and Management of Refractory Gastroesophageal Reflux Disease].
Lee, Kwang Jae
2015-08-01
The prevalence of gastroesophageal reflux disease (GERD) in South Korea has increased over the past 10 years. Patients with erosive reflux disease (ERD) shows better response to proton pump inhibitors (PPIs) than those with non-erosive reflux disease (NERD). NERD is a heterogeneous condition, showing pathological gastroesophageal reflux or esophageal hypersensitivity to reflux contents. NERD patients with pathological gastroesophageal reflux or hypersensitivity to acid may respond to PPIs. However, many patients with esophageal hypersensitivity to nonacid or functional heartburn do not respond to PPIs. Therefore, careful history and investigations are required when managing patients with refractory GERD who show poor response to conventional dose PPIs. Combined pH-impedance studies and a PPI diagnostic trial are recommended to reveal underlying mechanisms of refractory symptoms. For those with ongoing reflux-related symptoms, split dose administration, change to long-acting PPIs or PPIs less influenced by CYP2C19 genotypes, increasing dose of PPIs, and the addition of alginate preparations, prokinetics, selective serotonin reuptake inhibitors, or tricyclic antidepressants can be considered. Pain modulators, selective serotonin reuptake inhibitors, or tricyclic antidepressants are more likely to be effective for those with reflux-unrelated symptoms. Surgery or endoscopic per oral fundoplication may be effective in selected patients.
Reforming of fuel inside fuel cell generator
Grimble, Ralph E.
1988-01-01
Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream I and spent fuel stream II. Spent fuel stream I is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream I and exhaust stream II, and exhaust stream I is vented. Exhaust stream II is mixed with spent fuel stream II to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells.
Reforming of fuel inside fuel cell generator
Grimble, R.E.
1988-03-08
Disclosed is an improved method of reforming a gaseous reformable fuel within a solid oxide fuel cell generator, wherein the solid oxide fuel cell generator has a plurality of individual fuel cells in a refractory container, the fuel cells generating a partially spent fuel stream and a partially spent oxidant stream. The partially spent fuel stream is divided into two streams, spent fuel stream 1 and spent fuel stream 2. Spent fuel stream 1 is burned with the partially spent oxidant stream inside the refractory container to produce an exhaust stream. The exhaust stream is divided into two streams, exhaust stream 1 and exhaust stream 2, and exhaust stream 1 is vented. Exhaust stream 2 is mixed with spent fuel stream 2 to form a recycle stream. The recycle stream is mixed with the gaseous reformable fuel within the refractory container to form a fuel stream which is supplied to the fuel cells. Also disclosed is an improved apparatus which permits the reforming of a reformable gaseous fuel within such a solid oxide fuel cell generator. The apparatus comprises a mixing chamber within the refractory container, means for diverting a portion of the partially spent fuel stream to the mixing chamber, means for diverting a portion of exhaust gas to the mixing chamber where it is mixed with the portion of the partially spent fuel stream to form a recycle stream, means for injecting the reformable gaseous fuel into the recycle stream, and means for circulating the recycle stream back to the fuel cells. 1 fig.
Layer Structure of a Refractory Multilayer Ti/Al Composite After Pressure Diffusion Welding
NASA Astrophysics Data System (ADS)
Karpov, M. I.; Korzhov, V. P.; Zheltyakova, I. S.
2016-05-01
A composite refractory material with layer structure obtained by the method of pressure diffusion welding of multilayer Ti/Al packets composed of Ti- and Al-foils is studied. The welding temperature of the packets does not exceed 1200 - 1250°C. A layer structure forms in the process of interdiffusion of titanium and aluminum during welding of the packets.
Bergman, Werner
1986-01-01
An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.
Taghdiri, Mohammd-Mehdi; Amanati, Ali; Abdolkarimi, Babak
2011-01-01
Background Acute disseminated encephalomyelitis (ADEM) is a rare, monophasic, demyelinating disease of the CNS which sometimes could be refractory to traditional treatment. Case Presentation We present a case of fulminant ADEM which is treated with combination of corticosteroid, intravenous immunoglobulin and cyclosporine. Conclusion Immunosuppressive agents such as cyclosporine may be effective especially in fulminant form of the disease. PMID:23056845
Bergman, W.
1985-01-09
An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.
T-111 Rankine system corrosion test loop, volume 1
NASA Technical Reports Server (NTRS)
Harrison, R. W.; Hoffman, E. E.; Smith, J. P.
1975-01-01
Results are given of a program whose objective was to determine the performance of refractory metal alloys in a two loop Rankine test system. The test system consisted of a circulating lithium circuit heated to 1230 C maximum transferring heat to a boiling potassium circuit with a 1170 C superheated vapor temperature. The results demonstrate the suitability of the selected refractory alloys to perform from a chemical compatibility standpoint.
Carbide and carbonitride surface treatment method for refractory metals
Meyer, G.A.; Schildbach, M.A.
1996-12-03
A carbide and carbonitride surface treatment method for refractory metals is provided, in steps including, heating a part formed of boron, chromium, hafnium, molybdenum, niobium, tantalum, titanium, tungsten or zirconium, or alloys thereof, in an evacuated chamber and then introducing reaction gases including nitrogen and hydrogen, either in elemental or water vapor form, which react with a source of elemental carbon to form carbon-containing gaseous reactants which then react with the metal part to form the desired surface layer. Apparatus for practicing the method is also provided, in the form of a carbide and carbonitride surface treatment system including a reaction chamber, a source of elemental carbon, a heating subassembly and a source of reaction gases. Alternative methods of providing the elemental carbon and the reaction gases are provided, as well as methods of supporting the metal part, evacuating the chamber with a vacuum subassembly and heating all of the components to the desired temperature. 5 figs.
da Cunha, Leonardo Fernandes; Gonzaga, Carla Castiglia; Saab, Rafaella; Mushashe, Amanda Mahammad; Correr, Gisele Maria
2015-01-01
Central dominance is an important element of an esthetic smile. Color, form, and size have been suggested as tools for assessing the dominance of maxillary teeth. A spectrophotometer can be used to determine the value, hue, and chroma. Correct sizing of restorations according to the central incisor dominance principle improves not only esthetics but also aspects of occlusion, such as anterior guidance. Refractory porcelain systems can effectively restore the color, shape, emergence profile, and incisal translucency. This report illustrates the esthetic and occlusal rehabilitation of the dominance of maxillary central incisors using fabricated minimal thickness refractory porcelain veneers.
PROCESS OF PRODUCING REFRACTORY URANIUM OXIDE ARTICLES
Hamilton, N.E.
1957-12-01
A method is presented for fabricating uranium oxide into a shaped refractory article by introducing a uranium halide fluxing reagent into the uranium oxide, and then mixing and compressing the materials into a shaped composite mass. The shaped mass of uranium oxide and uranium halide is then fired at an elevated temperature so as to form a refractory sintered article. It was found in the present invention that the introduction of a uraninm halide fluxing agent afforded a fluxing action with the uranium oxide particles and that excellent cohesion between these oxide particles was obtained. Approximately 90% of uranium dioxide and 10% of uranium tetrafluoride represent a preferred composition.
Friedberg, Jonathan W.; Mahadevan, Daruka; Cebula, Erin; Persky, Daniel; Lossos, Izidore; Agarwal, Amit B.; Jung, JungAh; Burack, Richard; Zhou, Xiaofei; Leonard, E. Jane; Fingert, Howard; Danaee, Hadi; Bernstein, Steven H.
2014-01-01
Purpose Aurora A kinase (AAK) is overexpressed in aggressive lymphomas and can correlate with more histologically aggressive forms of disease. We therefore designed a phase II study of alisertib, a selective AAK inhibitor, in patients with relapsed and refractory aggressive non-Hodgkin lymphomas. Patients and Methods Patients age ≥ 18 years were eligible if they had relapsed or refractory diffuse large B-cell lymphoma (DLBCL), mantle-cell lymphoma (MCL), transformed follicular lymphoma, Burkitt's lymphoma, or noncutaneous T-cell lymphoma. Alisertib was administered orally at 50 mg twice daily for 7 days in 21-day cycles. Results We enrolled 48 patients. Histologies included DLBCL (n = 21), MCL (n = 13), peripheral T-cell lymphoma (n = 8), transformed follicular lymphoma (n = 5), and Burkitt's (n = 1). Most common grade 3 to 4 adverse events were neutropenia (63%), leukopenia (54%), anemia (35%), thrombocytopenia (33%), stomatitis (15%), febrile neutropenia (13%), and fatigue (6%). Four deaths during the study were attributed to progressive non-Hodgkin lymphoma (n = 2), treatment-related sepsis (n = 1), and unknown cause (n = 1). The overall response rate was 27%, including responses in three of 21 patients with DLBCL, three of 13 with MCL, one of one with Burkitt's lymphoma, two of five with transformed follicular lymphoma, and four of eight with noncutaneous T-cell lymphoma. The alisertib steady-state trough concentration (n = 25) revealed the expected pharmacokinetic variability, with a trend for higher incidence of adverse event–related dose reductions at higher trough concentrations. Analysis for AAK gene amplification and total AAK protein revealed no differences between histologies or correlation with clinical response. Conclusion The novel AAK inhibitor alisertib seems clinically active in both B- and T-cell aggressive lymphomas. On the basis of these results, confirmatory single-agent and combination studies have been initiated. PMID:24043741
Single isotope fractionation of (16)O(-) implications for early history of solar system
NASA Technical Reports Server (NTRS)
Arrhenius, G.
1980-01-01
Chemical fractionation processes are investigated with emphasis on selective single isotope fractionation in polyisotopic systems, particularly in oxygen. The related temperature parameters of meteoritic condensates and of their source medium are investigated by a thermometric method that is independent of assumptions regarding temperatures and pressures in the solar nebula. The crucial nonlinear chemical fractionation of O-16 was demonstrated experimentally. The effect was achieved in condensed CO2 formed from CO with C-12 O-16 selectively excited by H Ly alpha. The effect was verified by mass spectrometric measurements. The meteorite paleotemperature estimates were advanced from defining only thermal exposure to evaluating time and temperature independently. Grain temperatures at condensation of refractory inclusion materials are indicated to be less than 900 K in agreement with radiation temperature considerations and observations in circumstellar dust shells.
Doherty, Brian J.
1984-07-10
A burner system particularly useful for downhole deployment includes a tubular combustion chamber unit housed within a tubular coolant jacket assembly. The combustion chamber unit includes a monolithic tube of refractory material whose inner surface defines the combustion zone. A metal reinforcing sleeve surrounds and extends the length of the refractory tube. The inner surface of the coolant jacket assembly and outer surface of the combustion chamber unit are dimensioned so that those surfaces are close to one another in standby condition so that the combustion chamber unit has limited freedom to expand with that expansion being stabilized by the coolant jacket assembly so that compression forces in the refractory tube do not exceed about one-half the safe compressive stress of the material; and the materials of the combustion chamber unit are selected to establish thermal gradient parameters across the combustion chamber unit to maintain the refractory tube in compression during combustion system start up and cool down sequences.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Martin, P.C.; DePoorter, G.L.; Munoz, D.R.
1991-02-01
We have initiated a three phase investigation of the development of high performance refractory fibers with enhanced insulating properties and longer usable lifetimes. This report presents the results of the first phase of the study, performed from Aug. 1989 through Feb. 1991, which shows that significant energy saving are possible through the use of high temperature insulating fibers that better retain their efficient insulating properties during the service lifetime of the fibers. The remaining phases of this program include the pilot scale development and then full scale production feasibility development and evaluation of enhanced high temperature refractory insulting fibers. Thismore » first proof of principle phase of the program presents a summary of the current use patterns of refractory fibers, a laboratory evaluation of the high temperature performance characteristics of selected typical refractory fibers and an analysis of the potential energy savings through the use of enhanced refractory fibers. The current use patterns of refractory fibers span a wide range of industries and high temperature furnaces within those industries. The majority of high temperature fiber applications are in furnaces operating between 2000 and 26000{degrees}F. The fibers used in furnaces operating within this range provide attractive thermal resistance and low thermal storage at reasonable cost. A series of heat treatment studies performed for this phase of the program has shown that the refractory fibers, as initially manufactured, have attractive thermal conductivities for high temperature applications but the fibers go through rapid devitrification and subsequent crystal growth upon high temperature exposure. Development of improved fibers, maintaining the favorable characteristics of the existing as-manufactured fibers, could save between 1 and 4% of the energy consumed in high temperature furnaces using refractory fibers.« less
Interactions of Alumina-Based and Magnesia-Based Refractories with Iron Melts and Slags: A Review
NASA Astrophysics Data System (ADS)
Sarkar, R.; Sohn, H. Y.
2018-06-01
A novel flash ironmaking technology (FIT) based on the direct reduction of iron ore concentrate with a reductant gas (such as hydrogen, natural gas, coal gas, or a combination thereof) in a flash furnace is being developed at the University of Utah. This technology which is undergoing large-scale laboratory testing aims at overcoming the limitations of blast furnace ironmaking by bypassing the problematic pelletization/sintering and cokemaking steps.[
Refractory electrodes for joule heating and methods of using same
Lamar, David A.; Chapman, Chris C.; Elliott, Michael L.
1998-01-01
A certain group of electrically conductive refractory materials presently known for use in high temperature applications as throat constructions, melter sidewalls, forehearth, stacks, port sills, hot face lining for slagging coal gasifiers, slag runners, and linings for nuclear waste encapsulation furnaces may be used as electrodes permitting joule heating at temperatures in excess of 1200 C. in excess of about 4400 hours even in the presence of transition group element(s). More specifically, the invention is an electrode for melting earthen materials, wherein the electrode is made from an electrically conductive refractory material, specifically at least one metal oxide wherein the metal is selected from the group consisting of chrome, ruthenium, rhodium, tin and combinations thereof.
Parker, Matthew J; Guha, Neil; Stedman, Brian; Hacking, Nigel; Wright, Mark
2013-01-01
Objective To assess the benefit of trans-jugular intrahepatic porto-systemic shunt (TIPS) placement for refractory ascites. Design A retrospective observational study of all patients undergoing TIPS for refractory ascites in our hospital between 2003 and 2012. Setting Secondary care. Patients Cirrhotic patients with refractory ascites. Main outcome measures We examined direct real-world (National Health Service) health related costs in the year before and after the TIPS procedure took place. Data were collected relating to the need for reintervention and hepatic encephalopathy. Results Data were available for 24 patients who underwent TIPS for refractory ascites (86% of eligible patients). TIPS was technically successful in all cases. Mean number of bed days in the year prior to TIPS was 30.3 and 14.3 in the year following (p=0.005). No patient had ascites at the end of the year after the TIPS with less requirement for paracentesis over the course of the year (p<0.001). Mean reduction in cost was £2759 per patient. TIPS was especially cost-effective in patients requiring between 6 and 12 drains per year with a mean saving of £9204 per patient. Conclusions TIPS is both a clinically effective and economically advantageous therapeutic option for selected patients with refractory ascites. PMID:28839725
Parker, Matthew J; Guha, Neil; Stedman, Brian; Hacking, Nigel; Wright, Mark
2013-07-01
To assess the benefit of trans-jugular intrahepatic porto-systemic shunt (TIPS) placement for refractory ascites. A retrospective observational study of all patients undergoing TIPS for refractory ascites in our hospital between 2003 and 2012. Secondary care. Cirrhotic patients with refractory ascites. We examined direct real-world (National Health Service) health related costs in the year before and after the TIPS procedure took place. Data were collected relating to the need for reintervention and hepatic encephalopathy. Data were available for 24 patients who underwent TIPS for refractory ascites (86% of eligible patients). TIPS was technically successful in all cases. Mean number of bed days in the year prior to TIPS was 30.3 and 14.3 in the year following (p=0.005). No patient had ascites at the end of the year after the TIPS with less requirement for paracentesis over the course of the year (p<0.001). Mean reduction in cost was £2759 per patient. TIPS was especially cost-effective in patients requiring between 6 and 12 drains per year with a mean saving of £9204 per patient. TIPS is both a clinically effective and economically advantageous therapeutic option for selected patients with refractory ascites.
REFRACTORY DIE FOR EXTRUDING URANIUM
Creutz, E.C.
1959-08-11
A die is presented for the extrusion of metals, said die being formed of a refractory complex oxide having the composition M/sub n/O/sub m/R/sub x/O/sub y/ where M is magnesium, zinc, manganese, or iron, R is aluminum, chromic chromium, ferric iron, or manganic manganese, and m, n, x, and y are whole numbers. Specific examples are spinel, magnesium aluminate, magnetite, magnesioferrite, chromite, and franklinite.
NASA Technical Reports Server (NTRS)
Lowell, C. E.; Probst, H. B.
1974-01-01
Four cast nickel-base superalloys were oxidized at 1000 and 1100 C for times up to 100 hr in static air and a Mach 1 gas stream. The oxidation resistance was judged by weight change, metal thickness loss, depletion-zone formation, and oxide formation and morphology. The alloys which formed mostly nickel aluminate (NiAl2O4) and aluminum oxide (Al2O3) (B-1900, VIA, and to a lesser extent 713C) were more oxidation resistant. Poorer oxidation resistance was associated with the appearance of chromium sesquioxide (Cr2O3) and chromite spinel (738X). Refractory metal content had little effect on oxidation resistance. Refractory metals appeared in the scale as tapiolite (NiM2O6, where M represents the refractory metal). Thermal cycling in static air appeared to supply sufficient data for the evaluation of oxidation resistance, especially for alloys which form oxides of low volatility. For alloys of higher chromium levels with high propensities toward forming a chromium-bearing scale of higher volatility, testing under conditions of high gas velocity is necessary to assess fully the behavior of the alloy.
Voordouw, Maarten J; Koella, Jacob C; Hurd, Hilary
2008-01-01
Background In female mosquitoes that transmit malaria, the benefits of being refractory to the Plasmodium parasite are balanced by the immunity costs in the absence of infection. Male mosquitoes, however, gain no advantage from being refractory to blood-transmitted parasites, so that any costs associated with an enhanced immune system in the males limit the evolution of female refractoriness and has practical implications for the release of transgenic males. Methods Aspects of the male cost of carrying Plasmodium-refractory genes were estimated by comparing the males' immune response and reproductive success among strains of Anopheles gambiae that had been selected for refractoriness or extreme susceptibility to the rodent malaria parasite, Plasmodium yoelii nigeriensis. The refractory males had a stronger melanization response than males from the susceptible line. Four traits were used as correlates of a male's reproductive success: the proportion of females that were inseminated by a fixed number of males in a cage within a fixed time frame, the proportion of females with motile sperm in their spermathecae, the proportion of ovipositing females, and the mean number of eggs per batch. Results Although there were significant differences among groups of males in sperm motility and oviposition success, these differences in male reproductive success were not associated with the refractory or susceptible male genotypes. Contrary to expectation, females mated to early emerging refractory males laid significantly more eggs per batch than females mated to later emerging susceptible males. Sperm motility and oviposition success were strongly correlated suggesting that variation in sperm motility influences female oviposition and ultimately male reproductive success. Conclusion An increased melanization response in male A. gambiae does not diminish male reproductive success under the experimental protocol used in this study. That refractory males induced ovipositing females to lay more eggs than susceptible males is an interesting result for any strategy considering the release of transgenic males. That sperm motility influences female oviposition is also important for the release of transgenic males. PMID:18534029
Removable Mandrels For Vacuum-Plasma-Spray Forming
NASA Technical Reports Server (NTRS)
Krotz, Phillip D.; Davis, William M.; Power, Christopher A.; Woodford, William H.; Todd, Douglas M.; Liaw, Yoon K.; Holmes, Richard R.; Zimmerman, Frank R.; Mckechnie, Timothy N.
1995-01-01
Improved mandrels developed for use in vacuum-plasma-spray (VPS) forming of refractory metal and ceramic furnace cartridge tubes. Designed so after tubes formed on them by VPS, mandrels shrink away from tubes upon cooling back to room temperature and simply slip out of tube.
Gurnsey, Kate; Salisbury, Dean; Sweet, Robert A.
2016-01-01
Auditory refractoriness refers to the finding of smaller electroencephalographic (EEG) responses to tones preceded by shorter periods of silence. To date, its physiological mechanisms remain unclear, limiting the insights gained from findings of abnormal refractoriness in individuals with schizophrenia. To resolve this roadblock, we studied auditory refractoriness in the rhesus, one of the most important animal models of auditory function, using grids of up to 32 chronically implanted cranial EEG electrodes. Four macaques passively listened to sounds whose identity and timing was random, thus preventing animals from forming valid predictions about upcoming sounds. Stimulus onset asynchrony ranged between 0.2 and 12.8 s, thus encompassing the clinically relevant timescale of refractoriness. Our results show refractoriness in all 8 previously identified middle- and long-latency components that peaked between 14 and 170 ms after tone onset. Refractoriness may reflect the formation and gradual decay of a basic sensory memory trace that may be mirrored by the expenditure and gradual recovery of a limited physiological resource that determines generator excitability. For all 8 components, results were consistent with the assumption that processing of each tone expends ∼65% of the available resource. Differences between components are caused by how quickly the resource recovers. Recovery time constants of different components ranged between 0.5 and 2 s. This work provides a solid conceptual, methodological, and computational foundation to dissect the physiological mechanisms of auditory refractoriness in the rhesus. Such knowledge may, in turn, help develop novel pharmacological, mechanism-targeted interventions. PMID:27512021
Alexander, Thomas B; Lacayo, Norman J; Choi, John K; Ribeiro, Raul C; Pui, Ching-Hon; Rubnitz, Jeffrey E
2016-12-01
Purpose To characterize the toxicity, pharmacokinetics, and pharmacodynamics of selinexor, a selective inhibitor of nuclear export, when combined with fludarabine and cytarabine, in children with relapsed or refractory leukemia. Patients and Methods Eighteen patients with relapsed or refractory acute leukemia were enrolled in the SELHEM (Selinexor With Fludarabine and Cytarabine for Treatment of Refractory or Relapsed Leukemia or Myelodysplastic Syndrome) clinical trial (NCT02212561). Selinexor, initially at 30 mg/m 2 per dose, was given orally on days 1, 3, 8, 10, 22, and 24 and was escalated according to a rolling-six design. Fludarabine 30 mg/m 2 and cytarabine 2 g/m 2 were administered on days 15 to 19. Pharmacokinetic and pharmacodynamic studies were performed on days 1 and 22. Response evaluations were performed on day 15 and at the completion of course 1. Results Among the 17 patients who were evaluable for toxicity, three were treated at 30 mg/m 2 , three at 40 mg/m 2 , six at 55 mg/m 2 , and five at 70 mg/m 2 . The most common grade 3 nonhematologic toxicity was asymptomatic hyponatremia. Two patients who were treated at 70 mg/m 2 experienced reversible cerebellar toxicity, thereby defining the dose-limiting toxicity. Pharmacokinetic parameters demonstrated that plasma exposure was dose proportional. Fifteen of 16 patients demonstrated at least a twofold increase of XPO1 mRNA, indicating inhibition of the XPO1 protein. In this group of heavily pretreated, relapsed, and refractory patients, seven of 15 evaluable patients (47%) achieved complete response or complete response with incomplete count recovery. Conclusion Selinexor, in combination with fludarabine and cytarabine, is tolerable at doses up to 55 mg/m 2 in pediatric patients with relapsed or refractory leukemia. All patients who received selinexor at ≥ 40 mg/m 2 demonstrated XPO1 target inhibition. Response rates are promising and will be further explored in a phase II trial.
Laboratory Investigation of Mineralization of Refractory Nitrogen from Sewage Treatment Plants
NASA Astrophysics Data System (ADS)
Benoit, Gaboury; Wang, Peng
2017-12-01
Laboratory studies were conducted and modeled to evaluate whether refractory organic nitrogen in tertiary-treated wastewater effluent could become bioavailable by conversion to mineral forms. Multiday incubations of effluent collected from the Branford and New Haven, Connecticut, waste water treatment plants (WWTP) revealed low but steady conversion of organic nitrogen to nitrate (NO3 -). In Branford, the principal form of organic nitrogen was dissolved, and in New Haven it was particulate. Modeling suggested that in both the cases conversion to NO3 - from organic forms occurred at several per cent per day, and appeared to happen via the intermediary NH4 +. The results suggest that organic nitrogen may be an important source of bioavailable N, contributing to the problem of hypoxia in Long Island Sound and other estuaries.
Laboratory Investigation of Mineralization of Refractory Nitrogen from Sewage Treatment Plants.
Benoit, Gaboury; Wang, Peng
2017-12-01
Laboratory studies were conducted and modeled to evaluate whether refractory organic nitrogen in tertiary-treated wastewater effluent could become bioavailable by conversion to mineral forms. Multiday incubations of effluent collected from the Branford and New Haven, Connecticut, waste water treatment plants (WWTP) revealed low but steady conversion of organic nitrogen to nitrate (NO 3 - ). In Branford, the principal form of organic nitrogen was dissolved, and in New Haven it was particulate. Modeling suggested that in both the cases conversion to NO 3 - from organic forms occurred at several per cent per day, and appeared to happen via the intermediary NH 4 + . The results suggest that organic nitrogen may be an important source of bioavailable N, contributing to the problem of hypoxia in Long Island Sound and other estuaries.
Methodology for Life Testing of Refractory Metal/Sodium Heat Pipes
NASA Technical Reports Server (NTRS)
Martin, James J.; Reid, Robert S.
2006-01-01
The focus of this work was to establish an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. To accomplish this goal acceleration is required to compress 10 years of operational life into 3 years of laboratory testing through a combination of increased temperature and mass fluence. Specific test series have been identi3ed, based on American Society for Testing and Materials (ASTM) specifications, to investigate long term corrosion rates. The refractory metal selected for demonstration purposes is a Molybdenum-44.5%Rhenium alloy formed by powder metallurgy. The heat pipe makes use of an annular crescent wick design formed by hot isostatic pressing of Molybdenum-Rhenium wire mesh. The heat pipes are filled using vacuum distillation and purity sampling is considered. Testing of these units is round-the-clock with 6-month destructive and non-destructive inspection intervals to identify the onset and level of corrosion. Non-contact techniques are employed for providing power to the evaporator (radio frequency induction heating at I to 5 kW per unit) and calorimetry at the condenser (static gas gap coupled water cooled calorimeter). The planned operating temperature range would extend from 1123 to 1323 K. Accomplishments prior to project cancellation included successful demonstration of the heat pipe wick fabrication technique, establishment of all engineering designs, baselined operational test requirements and procurement/assembly of supporting test hardware systems.
Bechard, Jeff; Gibson, John Ken; Killingsworth, Cheryl R; Wheeler, Jeffery J; Schneidkraut, Marlowe J; Huang, Jian; Ideker, Raymond E; McAfee, Donald A
2011-03-01
Vernakalant is a novel antiarrhythmic agent that has demonstrated clinical efficacy for the treatment of atrial fibrillation. Vernakalant blocks, to various degrees, cardiac sodium and potassium channels with a pattern that suggests atrial selectivity. We hypothesized, therefore, that vernakalant would affect atrial more than ventricular effective refractory period (ERP) and have little or no effect on ventricular defibrillation threshold (DFT). Atrial and ventricular ERP and ventricular DFT were determined before and after treatment with vernakalant or vehicle in 23 anesthetized male mixed-breed pigs. Vernakalant was infused at a rate designed to achieve stable plasma levels similar to those in human clinical trials. Atrial and ventricular ERP were determined by endocardial extrastimuli delivered to the right atria or right ventricle. Defibrillation was achieved using external biphasic shocks delivered through adhesive defibrillation patches placed on the thorax after 10 seconds of electrically induced ventricular fibrillation. The DFT was estimated using the Dixon "up-and-down" method. Vernakalant significantly increased atrial ERP compared with vehicle controls (34 ± 8 versus 9 ± 7 msec, respectively) without significantly affecting ventricular ERP or DFT. This is consistent with atrial selective actions and supports the conclusion that vernakalant does not alter the efficacy of electrical defibrillation.
Majumder, Muntasir Mamun; Silvennoinen, Raija; Anttila, Pekka; Tamborero, David; Eldfors, Samuli; Yadav, Bhagwan; Karjalainen, Riikka; Kuusanmäki, Heikki; Lievonen, Juha; Parsons, Alun; Suvela, Minna; Jantunen, Esa; Porkka, Kimmo; Heckman, Caroline A
2017-08-22
Novel agents have increased survival of multiple myeloma (MM) patients, however high-risk and relapsed/refractory patients remain challenging to treat and their outcome is poor. To identify novel therapies and aid treatment selection for MM, we assessed the ex vivo sensitivity of 50 MM patient samples to 308 approved and investigational drugs. With the results we i) classified patients based on their ex vivo drug response profile; ii) identified and matched potential drug candidates to recurrent cytogenetic alterations; and iii) correlated ex vivo drug sensitivity to patient outcome. Based on their drug sensitivity profiles, MM patients were stratified into four distinct subgroups with varied survival outcomes. Patients with progressive disease and poor survival clustered in a drug response group exhibiting high sensitivity to signal transduction inhibitors. Del(17p) positive samples were resistant to most drugs tested with the exception of histone deacetylase and BCL2 inhibitors. Samples positive for t(4;14) were highly sensitive to immunomodulatory drugs, proteasome inhibitors and several targeted drugs. Three patients treated based on the ex vivo results showed good response to the selected treatments. Our results demonstrate that ex vivo drug testing may potentially be applied to optimize treatment selection and achieve therapeutic benefit for relapsed/refractory MM.
Refractory electrodes for joule heating and methods of using same
Lamar, D.A.; Chapman, C.C.; Elliott, M.L.
1998-05-12
A certain group of electrically conductive refractory materials presently known for use in high temperature applications as throat constructions, melter sidewalls, forehearth, stacks, port sills, hot face lining for slagging coal gasifiers, slag runners, and linings for nuclear waste encapsulation furnaces may be used as electrodes permitting joule heating at temperatures in excess of 1,200 C in excess of about 4400 hours even in the presence of transition group element(s). More specifically, the invention is an electrode for melting earthen materials, wherein the electrode is made from an electrically conductive refractory material, specifically at least one metal oxide wherein the metal is selected from the group consisting of chrome, ruthenium, rhodium, tin and combinations thereof. 2 figs.
Corrosion resistance of ceramic refractories to simulated waste glasses at high temperature
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xing, S.B.; Lin, Y.; Mohr, R.K.
1996-08-01
In many vitrification processes, refractory materials are used to contain the waste glass melt. The corrosive nature of the high-temperature melt consumes the waste feed materials but also limits refractory life. As vitrification is applied to more diverse waste streams, and particularly in higher-temperature applications, increasingly severe demands are placed on the refractory materials. A variety of potential refractory materials including Fused-cast AZS, Monofrax K3, Monofrax E, and the Corhart refractories ER1195, ER2161, C1215, C1215Z, Rechrome, and T1186, were subjected to corrosion testing at 1,450 C using the ASTM C-621 procedure. A series of simulated waste glasses was used whichmore » included F, Cl, S, Cu, Zn, Pb; these minor components were found to cause significant, and in some cases drastic, increases in corrosion rates. The corrosion tests were conducted over a range of time intervals extending to 144 hrs in order to investigate the kinetics of the corrosion processes. The change of the concentrations of constituents in the glass was monitored by compositional analysis of glass samples and correlated to the observed extent of corrosion; typically, components of the material under test increase with time while key minor components, such as Co and Pb, decrease. The rate of corrosion of high-zirconia refractories was slowed considerably by adding zirconia to the waste glass composition; this has the added benefit of improving the aqueous leach resistance of the waste form that is produced.« less
Tioguanine in the treatment of refractory coeliac disease--a single centre experience.
Tack, G J; van Asseldonk, D P; van Wanrooij, R L J; van Bodegraven, A A; Mulder, C J
2012-08-01
Refractory coeliac disease type I is a complicated form of coeliac disease characterised by primary or secondary resistance to a gluten-free diet with persisting or reoccurring intestinal villous atrophy and symptoms of malabsorption. Besides corticosteroids, azathioprine has been advocated for the treatment of refractory coeliac disease type I. However, tioguanine (TG) might be better tolerated and more efficacious owing to a simpler metabolism towards bioactivation. To evaluate tolerability and effectiveness of the nonconventional thiopurine derivative TG in refractory coeliac disease type I. Refractory coeliac disease type I patients treated with TG between June 2001 and November 2010 with a follow-up period of at least 1 year were included. Adverse events, laboratory values, 6-thioguanine nucleotide concentrations and rates of both clinical and histological response were evaluated at baseline and during follow-up. Twelve adult refractory coeliac disease type I patients were included. The median TG treatment duration was 14 months. Ten patients tolerated TG treatment on the long term, whereas two patients withdrew treatment due to adverse events. No nodular regenerative hyperplasia of the liver was observed. During follow-up clinical and histological response was observed in 83% and 78%, respectively. Corticosteroid dependency decreased by 50%. Tioguanine appears to be a convenient drug for the treatment of refractory coeliac disease type I based on higher histological and similar clinical response rates as compared with historical conventional therapies. © 2012 Blackwell Publishing Ltd.
McCarthy, Rosaleen A; Warrington, Elizabeth K
2016-10-01
We summarize the main findings and conclusions of Warrington's (1975) paper, The Selective Impairment of Semantic memory, a neuropsychological paper that described three cases with degenerative neurological conditions [Warrington, E. K. (1975). The selective impairment of semantic memory. The Quarterly Journal of Experimental Psychology, 27, 635-657]. We consider the developments that have followed from its publication and give a selective overview of the field in 2014. The initial impact of the paper was on neuropsychological investigations of semantic loss followed some 14 years later by the identification of Semantic Dementia (the condition shown by the original cases) as a distinctive form of degenerative disease with unique clinical and pathological characteristics. We discuss the distinction between disorders of semantic storage and refractory semantic access, the evidence for category- and modality-specific impairments of semantics, and the light that has been shed on the structure and organization of semantic memory. Finally we consider the relationship between semantic memory and the skills of reading and writing, phonological processing, and autobiographical memory.
Liu, Anthony P Y; Lee, Pamela P W; Kwok, Janette S Y; Leung, Rock Y Y; Chiang, Alan K S; Ha, Shau-Yin; Cheuk, Daniel K L; Chan, Godfrey C F
2018-06-19
Relapsed/refractory NB carries a bleak outcome, warranting novel treatment options. HaploHSCT induces a graft-versus-NB effect via natural killer cell alloreactivity. Review of patients with relapsed/refractory NB who underwent haploHSCT with ex vivo T-cell depletion in our unit from 2013 through 2018. Ten patients were identified (male=5; median age at haploHSCT=6.45 y, range: 3.49-11.02 y). Indications were relapsed in 7 and refractoriness in 3; disease status at haploHSCT was CR in 2, PR in 6, and PD in 2. All patients received peripheral blood stem cell grafts after ex vivo T-cell depletion (CD3/CD19-depletion=1; TCR-αβ/CD19-depletion=4; CD3/CD45RA-depletion=4; and TCR-αβ/CD45RA-depletion=1). Conditioning regimens were fludarabine-based. Neutrophils engrafted on median D + 10 (range: D + 9 to +13), and platelets engrafted (≥20 × 10 9 /L) on median D + 8 (range: D + 5 to D + 14). Early T- and NK-cell recovery were evident. Of the 10 patients, acute rejection developed in 1 (who died of PD despite rescue HSCT), and 1 died of sepsis before engraftment; 8 experienced full donor-chimerism post-HSCT. Among the 8, 6 experienced CR, 1 died of PD, and 1 died of pulmonary hypertensive crisis before evaluation. At publication, 4 were in remission (2.8, 7.4, 28.5, and 58.9 months). No significant GvHD occurred. HaploHSCT with selective ex vivo T-cell depletion may be a safe and useful salvage strategy for relapsed/refractory NB. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Basire, A; Picard, C
2014-11-01
Platelet refractoriness is a serious complication for patients receiving recurrent platelet transfusions, which can be explained by non-immune and immune causes. Human Leukocyte Antigens (HLA) allo-immunization, especially against HLA class I, is the major cause for immune platelet refractoriness. To a lesser extent, allo-antibodies against specific Human Platelet Antigen (HPA) are also involved. Pregnancy, transplantation and previous transfusions can lead to allo-immune reaction against platelet antigens. After transfusion, platelet count is decreased by accelerated platelet destruction related to antibodies fixation on incompatible platelet antigens. New laboratory tests for allo-antibodies identification were developed to improve sensibility and specificity, especially with the LUMINEX(®) technology. The good use and interpretation of these antibodies assays can improve strategies for platelet refractoriness prevention and management with a patient adapted response. Compatible platelets units can be selected according to their identity with recipient typing or immune compatibility regarding HLA or HPA antibodies or HLA epitope compatibility. Prospective studies are needed to further confirm the clinical benefit of new allo-antibodies identification methods and consensus strategies for immune platelet refractoriness management. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Carbide and carbonitride surface treatment method for refractory metals
Meyer, Glenn A.; Schildbach, Marcus A.
1996-01-01
A carbide and carbonitride surface treatment method for refractory metals is provided, in steps including, heating a part formed of boron, chromium, hafnium, molybdenum, niobium, tantalum, titanium, tungsten or zirconium, or alloys thereof, in an evacuated chamber and then introducing reaction gases including nitrogen and hydrogen, either in elemental or water vapor form, which react with a source of elemental carbon to form carbon-containing gaseous reactants which then react with the metal part to form the desired surface layer. Apparatus for practicing the method is also provided, in the form of a carbide and carbonitride surface treatment system (10) including a reaction chamber (14), a source of elemental carbon (17), a heating subassembly (20) and a source of reaction gases (23). Alternative methods of providing the elemental carbon (17) and the reaction gases (23) are provided, as well as methods of supporting the metal part (12), evacuating the chamber (14) with a vacuum subassembly (18) and heating all of the components to the desired temperature.
Refractory of Furnaces to Reduce Environmental Impact
NASA Astrophysics Data System (ADS)
Hanzawa, Shigeru
2011-10-01
The energy load of furnaces used in the manufacturing process of ceramics is quite large. Most of the environmental impact of ceramics manufacturing is due to the CO2 produced from this high energy load. To improve this situation, R&D has focused on furnace systems and techniques of control in order to reduce energy load. Since furnaces are comprised of refractory, consideration of their mechanical and thermal characteristics is important. Herein are described several refractory types which were chosen through comparison of the characteristics which contribute to heat capacity reduction, heat insulating reinforcement and high emissivity, thereby improving thermal radiation heat transfer efficiency to the ceramic articles. One selected refractory material which will reduce the environmental impact of a furnace, chosen considering low heat capacity and high emissivity characteristics, is SiC. In this study, thermal radiation heat transfer efficiency improvement and its effect on ceramic articles in the furnace and oxidation behaviour were investigated at 1700K. A high density SiC refractory, built into the furnace at construction, has relatively high oxidation durability and has the ability to reduce environmental impact-CO2 by 10 percent by decreasing the furnace's energy load. However, new oxidation prevention techniques for SiC will be necessary for long-term use in industrial furnaces, because passive to active oxidation transition behaviour of commercial SiC refractory is coming to close ideal.
NASA Technical Reports Server (NTRS)
Phillips, W. M. (Inventor)
1978-01-01
High temperature oxidation resistance, high hardness and high abrasion and wear resistance are properties of cermet compositions particularly to provide high temperature resistant refractory coatings on metal substrates, for use as electrical insulation seals for thermionic converters. The compositions comprise a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride are also described.
Experimental Investigations And Numerical Modelling of 210CR12 Steel in Semi-Solid State
NASA Astrophysics Data System (ADS)
Macioł, Piotr; Zalecki, Władysław; Kuziak, Roman; Jakubowicz, Aleksandra; Weglarczyk, Stanisław
2011-05-01
Experimental investigation, including hot compression and simple closed die filling was performed. Temperature range of tests was between 1225 °C and 1320 °C. Temperature selection was adequate with liquid fraction between 20 and 60%, which is typical for thixoforming processes. In the die filling test, steel dies with ceramic layer was used (highly refractory air-setting mortar JM 3300 manufactured by Thermal Ceramics). Experiments were carried out on the Gleeble 3800 physical simulator with MCU unit. In the paper, methodology of experimental investigation is described. Dependency of forming forces on temperature and forming velocities is analysed. Obtained results are discussed. The second part of the paper concerns numerical modelling of semi-solid forming. Numerical models for both sets of test were developed. Structural and Computational Fluid Dynamics models are compared. Initial works in microstructural modelling of 210CR12 steel behaviour are described. Lattice Boltzman Method model for thixotropic flows is introduced. Microscale and macroscale models were integrated into multiscale simulation of semi-solid forming. Some fundamental issues related to multiscale modelling of thixoforming are discussed.
Khawaja, Ayaz M; Vines, Brannon L; Miller, David W; Szaflarski, Jerzy P; Amara, Amy W
2016-03-01
Glutamic acid decarboxylase antibodies (GAD-Abs) have been implicated in refractory epilepsy. The association with refractory status epilepticus in adults has been rarely described. We discuss our experience in managing three adult patients who presented with refractory status epilepticus associated with GAD-Abs. Case series with retrospective chart and literature review. Three patients without pre-existing epilepsy who presented to our institution with generalized seizures between 2013 and 2014 were identified. Seizures proved refractory to first and second-line therapies and persisted beyond 24 hours. Patient 1 was a 22-year-old female who had elevated serum GAD-Ab titres at 0.49 mmol/l (normal: <0.02) and was treated with multiple immuno- and chemotherapies, with eventual partial seizure control. Patient 2 was a 61-year-old black female whose serum GAD-Ab titre was 0.08 mmol/l. EEG showed persistent generalized periodic discharges despite maximized therapy with anticonvulsants but no immunotherapy, resulting in withdrawal of care and discharge to nursing home. Patient 3 was a 50-year-old black female whose serum GAD-Ab titre was 0.08 mmol/l, and was discovered to have pulmonary sarcoidosis. Treatment with steroids and intravenous immunoglobulin resulted in seizure resolution. Due to the responsiveness to immunotherapy, there may be an association between GAD-Abs and refractory seizures, including refractory status epilepticus. Causation cannot be established since GAD-Abs may be elevated secondary to concurrent autoimmune diseases or formed de novo in response to GAD antigen exposure by neuronal injury. Based on this report and available literature, there may be a role for immuno- and chemotherapy in the management of refractory status epilepticus associated with GAD-Abs.
Kulboka, Arūnas; Veikutis, Vincentas; Pauza, Dainius Haroldas; Lekas, Raimundas
2003-01-01
The aims of present study were to verify the topography of the intracardiac nerve subplexuses (INS) by using electrophysiological methods, its relations with sinoatrial (SA) node function and to investigate possibility of selective surgical SA node denervation. Fifteen mongrel dogs of either sex weighing 8 to 15 kg were used for electrophysiological studies. Both cervical vagosympathetic trunks were isolated and crushed by tight ligatures. Nervus subplexuses destructions were performed by cryocoagulation in three zones located around the right superior vena cava: ventral, lateral and dorsal. The sinus rhythm, SA node function recovery time, AV node conductivity, AV node and atrial effective refractory period were measured. Five experiments in each of three zones were performed. Experimental data show that destruction of the epicardial nerves has different effect on electrophysiological parameters. After destruction of the anterior zone of the right atrium the sinus rhythm decreased on an average by 11.6%; SA node function recovery time prolonged by 7.2%; AV node conductivity decreased by 13.1%; AV node effective refractory period prolonged by 12.9% and atrial effective refractory period, by 10.9 %. Measurements of electrophysiological parameters after intravenous injection of atropine sulphate show that sinus rhythm decreased on an average by 23.4%; SA node function recovery time increased by 9.1%; the conductivity of AV node decreased by 10.2%; AV node effective refractory period prolonged by 15.4% and atrial effective refractory period, by 13.2%. After destruction of the intracardiac nerves of the lateral zone, the sinus rhythm decreased by 15.7%; SA node function recovery time increased by 16.3%; AV node conductivity decreased by 8.3%; AV node effective refractory period and atrial effective refractory period prolonged by 11.9% and 10.0%, respectively. After the atropine sulphate intravenous injection, the sinus rhythm decreased on an average by 7.1%, SA node function recovery time prolonged by 7.1%, AV conductivity decreased by 9.1%, AV node effective refractory period increased by 12.4%, and atrial effective refractory period prolonged by 12.5%. After destruction of the nerves in the dorsal zone the changes of electrophysiological parameters were opposite to those obtained after destruction of the nerve tracts in the anterior or lateral zones: the sinus rhythm increased on an average by 4.3%; SA node function recovery time shortened by 8.8%; AV conductivity increased by 9.7%; AV node and atrial effective refractory period decreased by 12.3% and 12.1%, respectively. After intravenous atropine sulphate infusion, sinus rhythm decreased on an average by 8.3%; SA node function recovery time prolonged by 9.6%; AV node conductivity decreased by 5%; AV node and atrial effective refractory period prolonged by 4.2% and 5.2%, respectively. The average changes of electrophysiological parameters before and after INS destruction shows that cryocoagulation of ventral and lateral zones eliminates the effects of sympathetic tone to SA and AV nodal activity. Cryocoagulation of dorsal zone eliminates the effects of nervus vagus to both nodal structures. These findings shows the possibility alter or correct SA node function by making selective surgical SA node denervation.
Hashmi, Mubashira; Saleem, Feroza; Mustafa, Muhammad Shahid; Sheerani, Mughis; Ehtesham, Zeeshan; Siddiqui, Khurram
2010-01-01
Lafora disease is one of the rare, most fatal progressive myoclonic epilepsies reported. We present a case of a teenager with intractable seizures and progressive mental decline, diagnosed as Lafora body disease on axillary skin biopsy. He was admitted with status epilepticus with refractory myoclonic and generalised tonic clonic seizures. Despite on maximum doses of multiple antiepileptic drugs and infusions of propofol and midazolam, his seizures were refractory to all forms of medical therapy tried. Levetiracetam (LEV), a pyrrolidine derivative, was introduced; he showed a prompt response and was weaned off successfully from infusions of anticonvulsants and mechanical ventilation within 48 h of introduction of LEV, followed by an almost seizure-free status. PMID:22791845
METHOD FOR COATING GRAPHITE WITH METALLIC CARBIDES
Steinberg, M.A.
1960-03-22
A method for producing refractory coatings of metallic carbides on graphite was developed. In particular, the graphite piece to be coated is immersed in a molten solution of 4 to 5% by weight of zirconium, titanium, or niobium dissolved in tin. The solution is heated in an argon atmosphere to above 1400 deg C, whereby the refractory metal reacts with the surface of the graphite to form a layer of metalic carbide. The molten solution is cooled to 300 to 400 deg C, and the graphite piece is removed. Excess tin is wiped from the graphite, which is then heated in vacuum to above 2300 deg C. The tin vaporizes from the graphite surface, leaving the surface coated with a tenacious layer of refractory metallic carbide.
Surgical Management of Pediatric Epilepsy: Decision-Making and Outcomes.
Kellermann, Tanja S; Wagner, Janelle L; Smith, Gigi; Karia, Samir; Eskandari, Ramin
2016-11-01
First-line treatment for epilepsy is antiepileptic drug and requires an interdisciplinary approach and enduring commitment and adherence from the patient and family for successful outcome. Despite adherence to antiepileptic drugs, refractory epilepsy occurs in approximately 30% of children with epilepsy, and surgical treatment is an important intervention to consider. Surgical management of pediatric epilepsy is highly effective in selected patients with refractory epilepsy; however, an evidence-based protocol, including best methods of presurgical imaging assessments, and neurodevelopmental and/or behavioral health assessments, is not currently available for clinicians. Surgical treatment of epilepsy can be critical to avoid negative outcomes in functional, cognitive, and behavioral health status. Furthermore, it is often the only method to achieve seizure freedom in refractory epilepsy. Although a large literature base can be found for adults with refractory epilepsy undergoing surgical treatment, less is known about how surgical management affects outcomes in children with epilepsy. The purpose of the review was fourfold: (1) to evaluate the available literature regarding presurgical assessment and postsurgical outcomes in children with medically refractory epilepsy, (2) to identify gaps in our knowledge of surgical treatment and its outcomes in children with epilepsy, (3) to pose questions for further research, and (4) to advocate for a more unified presurgical evaluation protocol including earlier referral for surgical candidacy of pediatric patients with refractory epilepsy. Despite its effectiveness, epilepsy surgery remains an underutilized but evidence-based approach that could lead to positive short- and long-term outcomes for children with refractory epilepsy. Copyright © 2016 Elsevier Inc. All rights reserved.
Seed germination and life history syndromes in the California chaparral
Keeley, J.E.
1991-01-01
Syndromes are life history responses that are correlated to environmental regimes and are shared by a group of species (Stebbins, 1974). In the California chaparral there are two syndromes contrasted by the timing of seedling recruitment relative to wildfires. One syndrome, here called the fire-recruiter or refractory seed syndrome, includes species (both resprouting and non-resprouting) which share the feature that the timing of seedling establishment is specialized to the first rainy season after fire. Included are woody, suffrutescent and annual life forms but no geophytes have this syndrome. These species are linked by the characteristic that their seeds have a dormancy which is readily broken by environmental stimuli such as intense heat shock or chemicals leached from charred wood. Such seeds are referred to as “refractory” and dormancy, in some cases, is due to seed coat impermeability (such seeds are commonly called hardseeded), but in other cases the mechanism is unknown. Seeds of some may require cold stratification and/or light in addition to fire related stimuli. In the absence of fire related cues, a portion or all of a species’ seed pool remains dormant. Most have locally dispersed seeds that persist in the soil seed bank until the site burns. Dispersal of propagules is largely during spring and summer which facilitates the avoidance of flowering and fruiting during the summer and fall drought. Within a life form (e.g., shrub, suffrutescent, etc.), the seeds of these species have less mass than those of species with non-refractory seeds and this possibly reflects the environmental favorableness of the postfire environment for seedling establishment. Regardless of when fire occurs, germination is normally delayed until late winter or early spring. In the absence of fire, or other disturbance, opportunities for population expansion are largely lacking for species with this syndrome. The other syndrome, here called the fire-resister or non-refractory seed syndrome, includes species that are resilient to frequent fires (mostly by vegetative resprouting), but require fire-free periods for recruiting new seedlings. Included are shrubs, subshrubs, suffrutescents, lianas, geophytes and annuals. All are linked by the characteristic that their seeds germinate in the absence of cues related to wildfires. In many cases no form of seed dormancy is present and the seeds germinate soon after dispersal; consequently these species do not accumulate a persistent seed bank. Germination and seedling establishment is independent of fire and thus opportunities for population expansion are also independent of fire. The demographic pattern of seedling recruitment varies with the life form. For shrubs, seedling recruitment may be restricted to sites free of fire for periods of a hundred years or more. Recruitment appears to require relatively mesic conditions and this may account for the patchy distribution of these species within the matrix of relatively arid sites. Finding such sites has selected for propagules specialized for wind or animal dispersal; the majority are bird dispersed. These shrub species all disperse fruits in fall and winter and this may have been selected to take advantage of migratory birds as well as to time dispersal to the winter rains typical of the mediterranean-climate. Germination typically occurs within several weeks of the first fall or winter rains. Maturation of flowers and fruits during the summer and fall drought may account for the distribution of these species on more mesic sites. Seed mass of these species is large and this may have been selected to provide an advantage to seedlings establishing under the canopy of this dense shrub community.
Mahato, Ram S; San Gabriel, Maria Chona P; Longshore, Carrol T; Schnur, David B
2016-01-01
Body dysmorphic disorder is a common, often disabling condition, and is frequently comorbid with major depressive disorder. Selective serotonin reuptake inhibitors constitute first line set of somatic interventions but the management of refractory patients remains challenging. Electroconvulsive therapy, an often highly beneficial treatment for medication resistant-depression, is not considered an effective therapeutic alternative for treatment refractory body dysmorphic disorder. Here we present a 50-year-old woman with body dysmorphic disorder and comorbid major depressive disorder who remained incapacitated and suicidal despite several trials with selective serotonin reuptake inhibitors and antipsychotic medication. Depressive and dysmorphic symptoms appeared to resolve with electroconvulsive therapy, and remission was sustained for two months. Electroconvulsive therapy has an important place in the management of treatment- resistant depression associated with body dysmorphic disorder, and, in select cases, may be effective for dysmorphic symptoms as well.
THERMAL DECOMPOSITION OF URANIUM COMPOUNDS
Magel, T.T.; Brewer, L.
1959-02-10
A method is presented of preparing uranium metal of high purity consisting contacting impure U metal with halogen vapor at between 450 and 550 C to form uranium halide vapor, contacting the uranium halide vapor in the presence of H/sub 2/ with a refractory surface at about 1400 C to thermally decompose the uranium halides and deposit molten U on the refractory surface and collecting the molten U dripping from the surface. The entire operation is carried on at a sub-atmospheric pressure of below 1 mm mercury.
NASA Technical Reports Server (NTRS)
Keller, L. P.; Snead, C.; Rahman, Z.; McKeegan, K. D.
2012-01-01
Hibonite-rich Ca- and Al-rich inclusions (CAIs) are among the earliest formed solids that condensed in the early nebula. We discovered an unusual refractory inclusion from the Allende CV3 chondrite (SHAL) containing an approx 500 micron long single crystal of hibonite and co-existing coarse-grained perovskite. The mineralogy and petrography of SHAL show strong similarities to some FUN inclusions, especially HAL. Here we report on the mineralogy, petrography, mineral chemistry and oxygen isotopic compositions in SHAL.
Trace Element Abundances in an Unusual Hibonite-Perovskite Refractory Inclusion from Allende
NASA Technical Reports Server (NTRS)
Mane, Prajkta; Wadhwa, M.; Keller, L. P.
2013-01-01
Calcium-aluminum-rich refractory inclusions (CAIs) are thought to be the first-formed solids in the Solar protoplanetary disk and can provide information about the earliest Solar System processes (e.g., [1]). A hibonite-perovskitebearing CAI from the Allende CV3 chondrite (SHAL, [2]) contains a single of 500 micrometers hibonite grain and coarse-grained perovskite. The mineralogy and oxygen isotopic composition of this CAI shows similarities with FUN inclusions, especially HAL [2]. Here we present trace element abundances in SHAL.
Oxygen sensitive, refractory oxide composition
Holcombe, Jr., Cressie E.; Smith, Douglas D.
1976-01-01
Oxide compositions containing niobium pentoxide and an oxide selected from the group consisting of hafnia, titania, and zirconia have electrical conductivity characteristics which vary greatly depending on the oxygen content.
Emerging therapeutic options in GERD.
Woodland, Philip; Amarasinghe, Gehanjali; Sifrim, Daniel
2013-06-01
Gastroesophageal reflux disease (GERD) is a prevalent problem resulting in a high level of healthcare consultation and expenditure in the Western World. Although standard medical therapy (in the form of proton pump inhibitor drugs) is effective in the majority of cases, there remains a significant proportion who are refractory to treatment. In addition, surgical therapy (in the form of laparoscopic fundoplication) is not always effective, and in some can be associated with significant side-effects, particularly gas-bloat, flatulence and dysphagia. As such there remains an unmet need in GERD to develop new therapies for refractory cases, and to develop alternatives to fundoplication with fewer side-effects. This article discusses the current state of pharmacological and non-pharmacological emerging therapies for GERD. Copyright © 2013 Elsevier Ltd. All rights reserved.
Golowin, Roman; Portnyagin, Maxim; Hoernle, Kaj; Hauff, Folkmar; Gurenko, Andrey; Garbe-Schönberg, Dieter; Werner, Reinhard; Turner, Simon
2017-01-01
The Ontong Java and Manihiki oceanic plateaus are believed to have formed through high-degree melting of a mantle plume head. Boninite-like, low-Ti basement rocks at Manihiki, however, imply a more complex magma genesis compared with Ontong Java basement lavas that can be generated by ∼30% melting of a primitive mantle source. Here we show that the trace element and isotope compositions of low-Ti Manihiki rocks can best be explained by re-melting of an ultra-depleted source (possibly a common mantle component in the Ontong Java and Manihiki plume sources) re-enriched by ≤1% of an ocean-island-basalt-like melt component. Unlike boninites formed via hydrous flux melting of refractory mantle at subduction zones, these boninite-like intraplate rocks formed through adiabatic decompression melting of refractory plume material that has been metasomatized by ocean-island-basalt-like melts. Our results suggest that caution is required before assuming all Archaean boninites were formed in association with subduction processes. PMID:28181497
Method of nitriding refractory metal articles
Tiegs, Terry N.; Holcombe, Cressie E.; Dykes, Norman L.; Omatete, Ogbemi O.; Young, Albert C.
1994-01-01
A method of nitriding a refractory-nitride forming metal or metalloid articles and composite articles. A consolidated metal or metalloid article or composite is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article or composite is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article or composite is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid or composite to an article or composite of refractory nitride. In addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.
Method of nitriding refractory metal articles
Tiegs, T.N.; Holcombe, C.E.; Dykes, N.L.; Omatete, O.O.; Young, A.C.
1994-03-15
A method of nitriding a refractory-nitride forming metal or metalloid articles and composite articles. A consolidated metal or metalloid article or composite is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article or composite is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article or composite is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid or composite to an article or composite of refractory nitride. In addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.
Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves
Holcombe, Cressie E.; Dykes, Norman L.; Tiegs, Terry N.
1992-01-01
A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.
Method of nitriding, carburizing, or oxidizing refractory metal articles using microwaves
Holcombe, C.E.; Dykes, N.L.; Tiegs, T.N.
1992-10-13
A method of nitriding an article of refractory-nitride-forming metal or metalloids. A consolidated metal or metalloid article is placed inside a microwave oven and nitrogen containing gas is introduced into the microwave oven. The metal or metalloid article is heated to a temperature sufficient to react the metal or metalloid with the nitrogen by applying a microwave energy within the microwave oven. The metal or metalloid article is maintained at that temperature for a period of time sufficient to convert the article of metal or metalloid to an article of refractory nitride. in addition, a method of applying a coating, such as a coating of an oxide, a carbide, or a carbo-nitride, to an article of metal or metalloid by microwave heating.
Non-CI refractory lithophile abundances in bulk planetary materials
NASA Astrophysics Data System (ADS)
Dauphas, N.
2015-12-01
Refractory inclusions in meteorites show evidence for fractionation of refractory lithophile elements relative to one another. For bulk planetary materials, it is most often assumed that refractory lithophile elements (e.g., Ca, Al, Ti, REEs) are in proportions similar to CI carbonaceous chondrites, which is taken to be a proxy for solar composition. A diagnostic feature of REE patterns in refractory inclusions in meteorites is the presence of thulium anomalies, arising from the fact that this heavy REE is more volatile than the highly refractory HREEs surrounding it (Tm/Tm* is defined relative to either Er-Yb or Er-Lu). Tm anomalies thus represent an excellent diagnostic tool to test the assumption that refractory lithophile elements have uniform relative abundances at a bulk planetary scale. Prior to this work, high precision Tm measurements were lacking because it is mono-isotopic and as such is not amenable to high-precision single spike measurements. We have developed a multi-collector REE abundance measurement technique to measure all REEs at high precision, including the mono-isotopic ones. This technique was used to revise the abundance of CI and PAAS REE abundances (Pourmand et al. 2012) and the CI composition agrees well with an independent study (Barrat et al. 2012). The same technique was applied to measure REE patterns in 41 chondrites as well as terrestrial rocks (Dauphas and Pourmand, 2015). Our results reveal the presence of Tm anomalies of about -4.5 % in terrestrial rocks, enstatite and ordinary chondrites, relative to carbonaceous chondrites including CIs. This demonstrates that the assumption that refractory lithophile elements are in constant proportions among planetary bodies is unwarranted. It also shows that carbonaceous chondrites cannot be a major constituent of the Earth. The presence of Tm anomalies in meteorites and terrestrial rocks suggests that either (i) the material in the inner part of the solar system was formed from a gas reservoir that had been depleted in refractory dust or (ii) CI are enriched in refractory dust and are not representative of solar composition for refractory elements. Barrat J.A. et al. (2012) GCA 83, 79-92. Dauphas N., Pourmand A. (2015) GCA 163, 234-261. Pourmand et al. (2012) Chem. Geol. 291, 38-54.
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
1981-11-01
In response to a 1980 Department of Energy solicitation, the General Refractories Company submitted a Proposal for a feasibility study of a low Btu gasification facility for its Florence, KY plant. The proposed facility would substitute low Btu gas from a fixed bed gasifier for natural gas now used in the manufacture of insulation board. The Proposal from General Refractories was prompted by a concern over the rising costs of natural gas, and the anticipation of a severe increase in fuel costs resulting from deregulation. The proposed feasibility study is defined. The intent is to provide General Refractories with themore » basis upon which to determine the feasibility of incorporating such a facility in Florence. To perform the work, a Grant for which was awarded by the DOE, General Refractories selected Dravo Engineers and Contractors based upon their qualifications in the field of coal conversion, and the fact that Dravo has acquired the rights to the Wellman-Galusha technology. The LBG prices for the five-gasifier case are encouraging. Given the various natural gas forecasts available, there seems to be a reasonable possibility that the five-gasifier LBG prices will break even with natural gas prices somewhere between 1984 and 1989. General Refractories recognizes that there are many uncertainties in developing these natural gas forecasts, and if the present natural gas decontrol plan is not fully implemented some financial risks occur in undertaking the proposed gasification facility. Because of this, General Refractories has decided to wait for more substantiating evidence that natural gas prices will rise as is now being predicted.« less
Agarwalla, Anant; Small, Aaron J; Mendelson, Aaron H; Scott, Frank I; Kochman, Michael L
2015-07-01
Radiation therapy for head, neck, and esophageal cancer can result in esophageal strictures that may be difficult to manage. Radiation-induced esophageal strictures often require repeat dilation to obtain relief of dysphagia. This study aimed to determine the long-term clinical success and rates of recurrent and refractory stenosis in patients with radiation-induced strictures undergoing dilation. Retrospective cohort study of patients with radiation-induced strictures who underwent endoscopic dilation by a single provider from October 2007-October 2012. Outcomes measured included long-term clinical efficacy, interval between sessions, number of dilations, and proportion of radiation strictures that were recurrent or refractory. Risk factors for refractory strictures were assessed. 63 patients underwent 303 dilations. All presented with a stricture >30 days after last radiation session. Clinical success to target diameter was achieved in 52 patients (83%). A mean of 3.3 (±2.6) dilations over a median period of 4 weeks was needed to achieve initial patency. Recurrence occurred in 17 (33%) at a median of 22 weeks. Twenty-seven strictures (43%) were refractory to dilation therapy. Fluoroscopy during dilation (OR 22.88; 95% CI 3.19-164.07), severe esophageal stenosis (lumen <9 mm) (OR 10.51; 95% CI 1.94-56.88), and proximal location with prior malignancy extrinsic to the lumen (OR 6.96; 95% CI 1.33-36.29) were independent predictors of refractory strictures in multivariate analysis. (1) Radiation-induced strictures have a delayed onset (>30 days) from time of radiation injury. (2) Endoscopic dilation can achieve medium-term luminal remediation but the strictures have a high long-term recurrence rate of up to 33%. (3) Remediation of radiation strictures following laryngectomy can be achieved but require frequent dilations. (4) Clinical and procedural predictors may identify patients at high risk of refractory strictures. (5) The optimal strategy in highly selected refractory patients is not clear.
Agarwalla, Anant; Small, Aaron J.; Mendelson, Aaron H.; Scott, Frank I.; Kochman, Michael L.
2014-01-01
Background Radiation therapy for head, neck, and esophageal cancer can result in esophageal strictures that may be difficult to manage. Radiation-induced esophageal strictures often require repeat dilation to obtain relief of dysphagia. This study aimed to determine the long-term clinical success and rates of recurrent and refractory stenosis in patients with radiation-induced strictures undergoing dilation. Methods Retrospective cohort study of patients with radiation-induced strictures who underwent endoscopic dilation by a single provider from October 2007– October 2012. Outcomes measured included long-term clinical efficacy, interval between sessions, number of dilations, and proportion of radiation strictures that were recurrent or refractory. Risk factors for refractory strictures were assessed. Results 63 patients underwent 303 dilations. All presented with a stricture > 30 days after last radiation session. Clinical success to target diameter was achieved in 52 patients (83%). A mean of 3.3 (+/− 2.6) dilations over a median period of 4 weeks was needed to achieve initial patency. Recurrence occurred in 17 (33%) at a median of 22 weeks. Twenty-seven strictures (43%) were refractory to dilation therapy. Fluoroscopy during dilation (OR, 22.88; 95% CI, 3.19 – 164.07), severe esophageal stenosis (lumen <9 mm) (OR, 10.51; 95% CI, 1.94 – 56.88), and proximal location with prior malignancy extrinsic to the lumen (OR, 6.96; 95% CI, 1.33 – 36.29) were independent predictors of refractory strictures in multivariate analysis. Conclusions 1. Radiation-induced strictures have a delayed onset (>30 days) from time of radiation injury. 2. Endoscopic dilation can achieve medium-term luminal remediation but the strictures have a high long-term recurrence rate of up to 33%. 3. Remediation of radiation strictures following laryngectomy can be achieved but require frequent dilations. 4. Clinical and procedural predictors may identify patients at high risk of refractory strictures. 5. The optimal strategy in highly selected refractory patients is not clear. PMID:25277484
Synthesis of refractory materials
Holt, Joseph B.
1984-01-01
Refractory metal nitrides are synthesized during a self-propagating combustion process utilizing a solid source of nitrogren. For this purpose, a metal azide is employed, preferably NaN.sub.3. The azide is combusted with Mg or Ca, and a metal oxide is selected from Groups III-A, IV-A, III-B, IV-B, or a rare earth metal oxide. The mixture of azide, Ca or Mg and metal oxide is heated to the mixture's ignition temperature. At that temperature the mixture is ignited and undergoes self-sustaining combustion until the starter materials are exhausted, producing the metal nitride.
Synthesis of refractory materials
Holt, J.B.
1983-08-16
Refractory metal nitrides are synthesized during a self-propagating combustion process utilizing a solid source of nitrogen. For this purpose, a metal azide is employed, preferably NaN/sub 3/. The azide is combusted with Mg or Ca, and a metal oxide is selected from Groups III-A, IV-A, III-B, IV-B, or a rare earth metal oxide. The mixture of azide, Ca or Mg and metal oxide is heated to the mixture's ignition temperature. At that temperature the mixture is ignited and undergoes self-sustaining combustion until the starter materials are exhausted, producing the metal nitride.
Gregg, I
1977-01-01
The most common reason why asthma presents difficulties in management is the failure to treat it with drugs which are appropriate and taken in adequate dosage. An understanding of the pathophysiology and aetiology of asthma is essential if full advantage is to be taken of the wide range of drugs now available for treating it. Airflow obstruction due to bronchial muscle constriction is usually readily reversible by bronchodilators, whereas that due to the inflammatory component of asthma is refractory to the latter and can only be reversed by steroids. Refractory airflow obstruction is liable to be confused with irreversible obstruction which occurs in those patients whose asthma is complicated by chronic obstructive bronchitis or other lung disease. The choice between symptomatic, preventive and suppressive forms of treatment should be made only after a careful assessment has been carried out with objective measurement of airflow obstruction. The Wright peak flow meter is unsurpassed for this purpose. By its means it should be possible to estimate how much of a patient's airflow obstruction is readily reversible, how much is refractory and how much is irreversible. In general, the aim of treatment is to relieve airflow obstruction rather than to counteract supposed aetiological factors. Both doctor and patient must understand the purpose, limitations and possible dangers of any drug which is prescribed. Steroids are the only form of treatment which is effective in persistent refractory asthma. Prejudice against steroids has resulted in many patients being deprived of their benefit, but this situation may change with the recent introduction of steroid aerosols.
IMPROVED CORROSION RESISTANCE OF ALUMINA REFRACTORIES
DOE Office of Scientific and Technical Information (OSTI.GOV)
John P. Hurley; Patty L. Kleven
2001-09-30
The initial objective of this project was to do a literature search to define the problems of refractory selection in the metals and glass industries. The problems fall into three categories: Economic--What do the major problems cost the industries financially? Operational--How do the major problems affect production efficiency and impact the environment? and Scientific--What are the chemical and physical mechanisms that cause the problems to occur? This report presents a summary of these problems. It was used to determine the areas in which the EERC can provide the most assistance through bench-scale and laboratory testing. The final objective of thismore » project was to design and build a bench-scale high-temperature controlled atmosphere dynamic corrosion application furnace (CADCAF). The furnace will be used to evaluate refractory test samples in the presence of flowing corrodents for extended periods, to temperatures of 1600 C under controlled atmospheres. Corrodents will include molten slag, steel, and glass. This test should prove useful for the glass and steel industries when faced with the decision of choosing the best refractory for flowing corrodent conditions.« less
Experimental ammonia-free phosphate-bonded investments using Mg(H2PO4)2.
Zhang, Z; Tamaki, Y; Miyazaki, T
2001-12-01
In previous study, we found that Mg(H2PO4)2 instead of NH4H2PO4 was available as a binder material for phosphate-bonded investments and possibly could be used to develop the phosphate-bonded investment without ammonia gas release. The purpose of the present study was to develop the experimental ammonia-free phosphate-bonded investments by investigating suitable refractories. Mg(H2PO4)2.nH2O and MgO were prepared as a binder. Cristobalite and quartz were selected as refractories. The power ratio of MgO/Mg(H2PO4)2.nH2O was set constant at 1.2 according to our previous findings. Fundamental properties of dental investment such as strength, manipulation and expansion were evaluated. Using cristobalite as the refractory material, further investigations were performed. The refractory/binder ratio was definitely effective. The increase of this ratio led to low mold strength and large mold expansion. The present findings suggested that C5 was desirable for dental investment.
Corrosion Studies in Support of Medium Power Lead Alloy Cooled Reactor
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eric Loewen; Ronald Ballinger; Jeongyoun Lim
2004-09-01
The performance of structural materials in lead or lead-bismuth eutectic (LBE) systems is evaluated. The materials evaluated included refractory metals (W, Mo, and Ta), several U.S. steels [austenitic steel (316L), carbon steels (F-22, Fe-Si), ferritic/martensitic steels (HT-9 and 410)], and several experimental Fe-Si-Cr alloys that were expected to demonstrate corrosion resistance. The materials were exposed in either an LBE rotating electrode or a dynamic corrosion cell for periods from 100 to 1000 h at temperatures of 400, 500, 600, and 700°C, depending on material and exposure location. Weight change and optical scanning electron microscopy or X-ray analysis of the specimenmore » were used to characterize oxide film thickness, corrosion depth, microstructure, and composition changes. The results of corrosion tests validate the excellent resistance of refractory metals (W, Ta, and Mo) to LBE corrosion. The tests conducted with stainless steels (410, 316L, and HT-9) produced mass transfer of elements (e.g., Ni and Cr) into the LBE, resulting in degradation of the material. With Fe-Si alloys a Si-rich layer (as SiO2) is formed on the surface during exposure to LBE from the selective dissolution of Fe.« less
Corrosion Studies in Support of Medium-Power Lead-Alloy-Cooled Reactor
DOE Office of Scientific and Technical Information (OSTI.GOV)
Loewen, Eric P.; Ballinger, Ronald G.; Lim, Jeongyoun
2004-09-15
The performance of structural materials in lead or lead-bismuth eutectic (LBE) systems is evaluated. The materials evaluated included refractory metals (W, Mo, and Ta), several U.S. steels [austenitic steel (316L), carbon steels (F-22, Fe-Si), ferritic/martensitic steels (HT-9 and 410)], and several experimental Fe-Si-Cr alloys that were expected to demonstrate corrosion resistance. The materials were exposed in either an LBE rotating electrode or a dynamic corrosion cell for periods from 100 to 1000 h at temperatures of 400, 500, 600, and 700 deg. C, depending on material and exposure location. Weight change and optical scanning electron microscopy or X-ray analysis ofmore » the specimen were used to characterize oxide film thickness, corrosion depth, microstructure, and composition changes. The results of corrosion tests validate the excellent resistance of refractory metals (W, Ta, and Mo) to LBE corrosion. The tests conducted with stainless steels (410, 316L, and HT-9) produced mass transfer of elements (e.g., Ni and Cr) into the LBE, resulting in degradation of the material. With Fe-Si alloys a Si-rich layer (as SiO{sub 2}) is formed on the surface during exposure to LBE from the selective dissolution of Fe.« less
Place, Andrew E; Goldsmith, Kelly; Bourquin, Jean-Pierre; Loh, Mignon L; Gore, Lia; Morgenstern, Daniel A; Sanzgiri, Yeshwant; Hoffman, David; Zhou, Ying; Ross, Jeremy A; Prine, Betty; Shebley, Mohamad; McNamee, Megan; Farazi, Thalia; Kim, Su Young; Verdugo, Maria; Lash-Fleming, Leanne; Zwaan, C Michel; Vormoor, Josef
2018-03-29
Venetoclax is a highly selective, potent BCL-2 inhibitor that is approved for some patients previously treated for chronic lymphocytic leukemia, and has shown promising activity in adult studies across several hematologic malignancies. Preclinical studies have demonstrated venetoclax activity in pediatric patient-derived xenograft models and cell lines; however, clinical studies in pediatric patients have yet to be conducted. The prognosis is poor for children with most relapsed/refractory malignancies, and limited treatment options result in unmet clinical need. Herein, we describe the rationale and design of the first study of venetoclax in pediatric patients with relapsed/refractory malignancies: a Phase I trial investigating the safety and pharmacokinetics of venetoclax monotherapy followed by the addition of chemotherapy (Trial registration: EudraCT 2017-000439-14; NCT03236857).
NASA Astrophysics Data System (ADS)
Adabifiroozjaei, Esmaeil; Koshy, Pramod; Rastkerdar, Ebad
2011-08-01
An experimental study was conducted to investigate the interfacial phenomena between an Al alloy and andalusite low-cement castables (LCCs) containing fixed contents of barium compounds (BaO, BaSO4, and BaCO3) at 1123 K and 1433 K (850 °C and 1160 °C) using the Alcoa cup test. Interfacial reaction products and phases formed during heat treatment of the refractory samples were characterized using scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS) and X-ray diffraction analysis (XRD). The addition of both BaO and BaSO4 led to a significant reduction of alloy penetration into the refractory. Hexa-celsian formation was observed in both these refractories, which drastically increased their corrosion resistance. Barite decomposition was observed at 1373 K (1100 °C) in the presence of alumina and silica, which was the precursor for hexa-celsian formation. Barium silicates were formed in all samples containing additives; however, this did not have any major influence on the corrosion resistance. Solidified eutectics of BaSi2 and α-BaAl2Si2 formed in all these samples, which acted as an interfacial barrier that prevented additional molten aluminum penetration; however, the positive effect of intermetallic formation was offset by glassy phase formation in samples containing BaCO3 as the additive.
Design and development of advanced castable refractory materials
NASA Astrophysics Data System (ADS)
Davis, Robert Bruce
New formulations of castable refractory composite materials were studied. This technology is used to produce low cost composite concrete structures designed for high temperature stability, superior wear resistance and improved strength. An in situ fired, castable cement installation is a heterogeneous structure divided into three zones according to the temperature history and microstructure. The properties of each zone depend on the predominant bonding mode between constituents. Each zone has a characteristic microstructure that influences the integrity of the monolith. The hot side may have a highly dense and developed network of ceramic bonds between constituent particles while the cold side may never reach temperatures sufficient to drive off free water. The thermal, structural and tribological properties depend on the microstructure and the type of bonding that holds the monolith together. The phase distributions are defined by sets of metastable phase conditions driven by the local hydrated chemistry, nearest neighbor oxide compounds, impurities and sintering temperature. Equilibrium phase diagrams were used to select optimum compositions based on higher melting point phases. The phase diagrams were also used to target high temperature phase fields that are stable over wide temperature and stoichiometric ranges. Materials selection of candidate hydraulic clinkers, high temperature oxides, and reinforcement phases were based on requirements for high temperature stability. The calcium aluminate (CaO-Al2O3) and calcium dialuminate (CaO-(Al2O3)2) are common refractory clinkers used in castable refractory cements. The thermodynamics and kinetics of cement hydrate formation are well studied and suited to become the building block of a design for a superior refractory castable cement. The inert oxides mixed with the calcium aluminate clinkers are magnesia (MgO), alumina (Al 2O3), spinel (MgAl2O4) and chromic (Cr2O3). The bulk of the experiments concentrated in the Al2O3--MgO--CaO ternary system. Materials selection criteria for reinforcement materials was based on improved high temperature stability, increased strength, reduced thermal expansion mismatch, low thermal conductivity and increasing wear resistance. The reinforcement phases selected for this investigation are zircon (ZrSiO4), zirconia (ZrO2), spinel (MgAl2O4) and dead burnt magnesia (MgO). Batches of the formulations were tested for thermal conductivity, wear resistance and mechanical strength. Relative rankings of the formulations against commercial products indicate improved or similar performance with increased maximum temperature limits and improved thermal insulating power. The new cement formulations proved to exhibit superior high temperature stability with an increasing volume fraction of high temperature oxides. The addition of reinforcement aggregates and powder sizing to offset the loss of strength. The room temperature compression strength and wear resistance of the optimized formulations exceeded the properties of conventional refractory, brick and castable cement tested concurrently.
Hanafy, Amr S; Hassaneen, Ahmad M
2016-12-01
The occurrence of refractory ascites in nearly 17% of patients with decompensated cirrhosis is an unresolved issue. Advanced liver disease, functional renal impairment, and vascular insensitivity to vasopressors are the main causes of its refractoriness. Therefore, the aim of this study was to evaluate the impact on diuresis, weight loss, and short-term survival if midodrine and rifaximin were added to the diuretic therapy (DT). The study evaluated the eligibility of 650 patients with cirrhosis and refractory ascites who were selected during the period from November 2011 to May 2015. A total of 50 patients were excluded and finally 600 were selected and divided into the following groups: patients exposed to DT (n=200) as a control group, or DT with midodrine and rifaximin group (n=400). Body weight, mean arterial pressure, and glomerular filtration rate were determined. Plasma renin and aldosterone were also determined. Follow-up was performed after 2, 6, and 12 weeks, and then every 2 months for 24 months. The mean arterial pressure was significantly higher in the midodrine and rifaximin group (P=0.000), and there was a highly significant weight loss after 12 weeks (12.5 kg) (P=0.000), a highly significant increase in serum sodium, urine output, and urinary sodium excretion (P=0.000), and creatinine clearance was more reduced in the control group. With rifaximin and midodrine, a complete response occurred in 310 (78%) patients, a partial response in 72 (18%), and no response in 18 (4%) versus 30 (15%), 110 (55%), and 60 (30%) in the control group, respectively (P=0.000). Midodrine and rifaximin significantly reduced paracentesis needs when compared with the controls (18 study patients vs. 75 DT-only patients, P=0.000). Adding rifaximin and midodrine to DT enhanced diuresis in refractory ascites with improved systemic, renal hemodynamics and short-term survival.
SU-F-R-14: PET Based Radiomics to Predict Outcomes in Patients with Hodgkin Lymphoma
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lee, J; Aristophanous, M; Akhtari, M
Purpose: To identify PET-based radiomics features associated with high refractory/relapsed disease risk for Hodgkin lymphoma patients. Methods: A total of 251 Hodgkin lymphoma patients including 19 primary refractory and 9 relapsed patients were investigated. All patients underwent an initial pre-treatment diagnostic FDG PET/CT scan. All cancerous lymph node regions (ROIs) were delineated by an experienced physician based on thresholding each volume of disease in the anatomical regions to SUV>2.5. We extracted 122 image features and evaluated the effect of ROI selection (the largest ROI, the ROI with highest mean SUV, merged ROI, and a single anatomic region [e.g. mediastinum]) onmore » classification accuracy. Random forest was used as a classifier and ROC analysis was used to assess the relationship between selected features and patient’s outcome status. Results: Each patient had between 1 and 9 separate ROIs, with much intra-patient variability in PET features. The best model, which used features from a single anatomic region (the mediastinal ROI, only volumes>5cc: 169 patients with 12 primary refractory) had a classification accuracy of 80.5% for primary refractory disease. The top five features, based on Gini index, consist of shape features (max 3D-diameter and volume) and texture features (correlation and information measure of correlation1&2). In the ROC analysis, sensitivity and specificity of the best model were 0.92 and 0.80, respectively. The area under the ROC (AUC) and the accuracy were 0.86 and 0.86, respectively. The classification accuracy was less than 60% for other ROI models or when ROIs less than 5cc were included. Conclusion: This study showed that PET-based radiomics features from the mediastinal lymph region are associated with primary refractory disease and therefore may play an important role in predicting outcomes in Hodgkin lymphoma patients. These features could be additive beyond baseline tumor and clinical characteristics, and may warrant more aggressive treatment.« less
Protective sheath for a continuous measurement thermocouple
Phillippi, R.M.
1991-12-03
Disclosed is a protective thermocouple sheath of a magnesia graphite refractory material for use in continuous temperature measurements of molten metal in a metallurgical ladle and having a basic slag layer thereon. The sheath includes an elongated torpedo-shaped sheath body formed of a refractory composition and having an interior borehole extending axially therethrough and adapted to receive a thermocouple. The sheath body includes a lower end which is closed about the borehole and forms a narrow, tapered tip. The sheath body also includes a first body portion integral with the tapered tip and having a relatively constant cross section and providing a thin wall around the borehole. The sheath body also includes a second body portion having a relatively constant cross section larger than the cross section of the first body portion and providing a thicker wall around the borehole. The borehole terminates in an open end at the second body portion. The tapered tip is adapted to penetrate the slag layer and the thicker second body portion and its magnesia constituent material are adapted to withstand chemical attack thereon from the slag layer. The graphite constituent improves thermal conductivity of the refractory material and, thus, enhances the thermal responsiveness of the device. 4 figures.
Protective sheath for a continuous measurement thermocouple
Phillippi, R. Michael
1991-01-01
Disclosed is a protective thermocouple sheath of a magnesia graphite refractory material for use in continuous temperature measurements of molten metal in a metallurgical ladle and having a basic slag layer thereon. The sheath includes an elongated torpedo-shaped sheath body formed of a refractory composition and having an interior borehole extending axially therethrough and adapted to receive a thermocouple. The sheath body includes a lower end which is closed about the borehole and forms a narrow, tapered tip. The sheath body also includes a first body portion integral with the tapered tip and having a relatively constant cross section and providing a thin wall around the borehole. The sheath body also includes a second body portion having a relatively constant cross section larger than the cross section of the first body portion and providing a thicker wall around the borehole. The borehole terminates in an open end at the second body portion. The tapered tip is adapted to penetrate the slag layer and the thicker second body portion and its magnesia constituent material are adapted to withstand chemical attack thereon from the slag layer. The graphite constituent improves thermal conductivity of the refractory material and, thus, enhances the thermal responsiveness of the device.
DEEP DESULFURIZATION OF DIESEL FUELS BY A NOVEL INTEGRATED APPROACH
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xiaoliang Ma; Uday Turaga; Shingo Watanabe
2004-05-01
The overall objective of this project is to explore a new desulfurization system concept, which consists of efficient separation of the refractory sulfur compounds from diesel fuel by selective adsorption, and effective hydrodesulfurization of the concentrated fraction of the refractory sulfur compounds in diesel fuels. Our approaches focused on (1) selecting and developing new adsorbents for selective adsorption of sulfur or sulfur compounds in commercial diesel fuel; (2) conducting the adsorption desulfurization of model fuels and real diesel fuels by the selective-adsorption-for-removing-sulfur (PSUSARS) process over various developed adsorbents, and examining the adsorptive desulfurization performance of various adsorbents; (3) developing andmore » evaluating the regeneration methods for various spent adsorbent; (4) developing new catalysts for hydrodesulfurization of the refractory sulfur existing in the commercial diesel fuel; (5) on the basis of the fundamental understanding of the adsorptive performance and regeneration natures of the adsorbents, further confirming and improving the conceptual design of the novel PSU-SARS process for deep desulfurization of diesel fuel Three types of adsorbents, the metal-chloride-based adsorbents, the activated nickel-based adsorbents and the metal-sulfide-based adsorbents, have been developed for selective adsorption desulfurization of liquid hydrocarbons. All of three types of the adsorbents exhibit the significant selectivity for sulfur compounds, including alkyl dibenzothiophenes (DBTs), in diesel fuel. Adsorption desulfurization of real diesel fuels (regular diesel fuel (DF), S: 325 ppmw; low sulfur diesel fuel (LSD-I), S: 47 ppmw) over the nickel-based adsorbents (A-2 and A-5) has been conducted at different conditions by using a flowing system. The adsorption capacity of DF over A-2 corresponding to an outlet sulfur level of 30 ppmw is 2.8 mg-S/g-A. The adsorption capacity of LSD-I over A-5 corresponding to the break-through point at 5.0 ppmw sulfur level is 0.35 mg-S/g-A. The spent A-5 can be regenerated by using H2 gas at a flowing rate of 40-50 ml/min, 500 C, and ambient pressure. Adsorption desulfurization of model diesel fuels over metal-sulfide-based adsorbents (A-6-1 and A-6-2) has been conducted at different temperatures to examine the capacity and selectivity of the adsorbents. A regeneration method for the spent metal-sulfide-based adsorbents has been developed. The spent A-6-1 can be easily regenerated by washing the spent adsorbent with a polar solvent followed by heating the adsorbent bed to remove the remainder solvent. Almost all adsorption capacity of the fresh A-6-1 can be recovered after the regeneration. On the other hand, a MCM-41-supported HDS catalyst was developed for deep desulfurization of the refractory sulfur compounds. The results show that the developed MCM-41-supported catalyst demonstrates consistently higher activity for the HDS of the refractory dibenzothiophenic sulfur compounds than the commercial catalyst. On the basis of the fundamental understanding of the adsorptive performance and regeneration natures of the adsorbents, the conceptual design of the novel PSU-SARS process for deep desulfurization of diesel fuel is confirmed and improved further.« less
Solid oxide fuel cell matrix and modules
Riley, B.
1988-04-22
Porous refractory ceramic blocks arranged in an abutting, stacked configuration and forming a three dimensional array provide a support structure and coupling means for a plurality of solid oxide fuel cells (SOFCs). The stack of ceramic blocks is self-supporting, with a plurality of such stacked arrays forming a matrix enclosed in an insulating refractory brick structure having an outer steel layer. The necessary connections for air, fuel, burnt gas, and anode and cathode connections are provided through the brick and steel outer shell. The ceramic blocks are so designed with respect to the strings of modules that by simple and logical design the strings could be replaced by hot reloading if one should fail. The hot reloading concept has not been included in any previous designs. 11 figs.
Weihs, Timothy P.; Barbee, Jr., Troy W.
2002-01-01
Cubic or metastable cubic refractory metal carbides act as barrier layers to isolate, adhere, and passivate copper in semiconductor fabrication. One or more barrier layers of the metal carbide are deposited in conjunction with copper metallizations to form a multilayer characterized by a cubic crystal structure with a strong (100) texture. Suitable barrier layer materials include refractory transition metal carbides such as vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (Cr.sub.3 C.sub.2), tungsten carbide (WC), and molybdenum carbide (MoC).
May, I.; Rowe, J.J.
1965-01-01
A modified Morey bomb was designed which contains a removable nichromecased 3.5-ml platinium crucible. This bomb is particularly useful for decompositions of refractory samples for micro- and semimicro-analysis. Temperatures of 400-450?? and pressures estimated as great as 6000 p.s.i. were maintained in the bomb for periods as long as 24 h. Complete decompositions of rocks, garnet, beryl, chrysoberyl, phenacite, sapphirine, and kyanite were obtained with hydrofluoric acid or a mixture of hydrofluoric and sulfuric acids; the decomposition of chrome refractory was made with hydrochloric acid. Aluminum-rich samples formed difficultly soluble aluminum fluoride precipitates. Because no volatilization losses occur, silica can be determined on sample solutions by a molybdenum-blue procedure using aluminum(III) to complex interfering fluoride. ?? 1965.
Hamanaka, Shinsaku; Nakagawa, Tomoo; Hiwasa, Takaki; Ohta, Yuki; Kasamatsu, Shingo; Ishigami, Hideaki; Taida, Takashi; Okimoto, Kenichiro; Saito, Keiko; Maruoka, Daisuke; Matsumura, Tomoaki; Takizawa, Hirotaka; Kashiwado, Koichi; Kobayashi, Sohei; Matsushita, Kazuyuki; Matsubara, Hisahiro; Katsuno, Tatsuro; Arai, Makoto; Kato, Naoya
2018-06-05
The clinical course of ulcerative colitis (UC) is characterized by repeated episodes of relapse and remission. We hypothesized that biomarkers that help distinguish refractory UC patients who are in remission using strong anti-immunotherapy could contribute in preventing the overuse of corticosteroids for treatment. Here we clarified novel autoantibodies for UC patients in remission as clinical indicators to distinguish between refractory and non-refractory UC. Antigen proteins recognized by serum antibodies of patients with UC in remission were screened using the protein array method. To validate the results, AlphaLISA was used to analyze the serum antibody titers with candidate protein antigens. Serum samples from 101 healthy controls, 121 patients with UC, and 39 patients with Crohn's disease were analyzed. Of 66 candidate protein antigens screened by ProtoArray™, 6 were selected for this study. The serum titers of anti-poly ADP-ribose glycohydrolase (PARG), anti-transcription elongation factor A protein-like 1 (TCEAL1), and anti-proline-rich 13 (PRR13) antibodies were significantly higher in patients with UC than in healthy controls. Anti-PARG and anti-PRR13 antibody titers were significantly higher in patients with refractory UC than in patients with non-refractory UC. There were no significant differences in any antibody titer between the active and remission phases. The serum titers of anti-PARG, anti-TCEAL1, and anti-PRR13 antibodies were elevated in patients with UC. Anti-PARG and anti-PRR13 antibody titers may be novel clinical indicators for detecting refractory UC in patients in remission. This article is protected by copyright. All rights reserved.
High temperature barrier coatings for refractory metals
NASA Technical Reports Server (NTRS)
Malone, G. A.; Walech, T.
1995-01-01
Improvements in high temperature oxidation resistant metal coating technology will allow NASA and commercial entities to develop competitive civil space transport and communication systems. The success of investigations completed in this program will have a positive impact on broadening the technology base for high temperature materials. The work reported herein describes processes and procedures for successfully depositing coherent oxidation barrier coatings on refractory metals to prevent degradation under very severe operating environments. Application of the new technology developed is now being utilized in numerous Phase 3 applications through several prominent aerospace firms. Major achievements have included: (1) development of means to deposit thick platinum and rhodium coatings with lower stress and fewer microcracks than could be previously achieved; (2) development of processes to deposit thick adherent coatings of platinum group metals on refractory substrates that remain bonded through high temperature excursions and without need for intermediate coatings (bonding processes unique to specific refractory metals and alloys have been defined; (3) demonstration that useful alloys of refractory and platinum coatings can be made through thermal diffusion means; (4) demonstration that selected barrier coatings on refractory substrates can withstand severe oxidizing environments in the range of 1260 deg and 1760 deg C for long time periods essential to the life requirements of the hardware; and (5) successful application of the processes and procedures to prototype hardware. The results of these studies have been instrumental in improved thermal oxidation barrier coatings for the NASP propulsion system. Other Phase 3 applications currently being exploited include small uncooled thrusters for spacecraft and microsatellite maneuvering systems.
Male accessory gland proteins induce female monogamy in anopheline mosquitoes.
Shutt, B; Stables, L; Aboagye-Antwi, F; Moran, J; Tripet, F
2010-03-01
The role of male accessory gland (MAG) secretions in inducing refractoriness to further mating in mosquitoes (Diptera: Culicidae) was established in the late 1960s. In a set of simple experiments, MAG extract was injected intra-thoraxically into the hemocoel of virgin Aedes aegypti (L.), Culex pipiens pipiens (L.) and Anopheles quadrimaculatus Say females. This subsequently caused most females to remain unmated when exposed to males. For anophelines these findings were later challenged by a study involving intra-abdominal injections of MAG extracts into Anopheles gambiae Giles s.l. and Anopheles albimanus Wiedmann females, which failed to induce refractoriness to further mating. These findings led to controversy about the respective role of sperm and accessory gland peptides in inducing female monogamy in Anopheles and are at odds with our current understanding of the mating process in Drosophila spp. (Diptera: Drosophillidae) and other dipterans. Here we confirm the function of MAG secretions in anophelines experimentally by showing that intra-thoracic injections in Anopheles stephensi Liston and in the M and S molecular forms of An. gambiae s.s. result in the expected female monogamy. Cross-injections of MAG extracts between the M and S molecular forms of An. gambiae, two cryptic taxa within An. gambiae s.s. which are thought to be undergoing incipient speciation, also elicited effective refractoriness, suggesting that the two sub-taxa have not diverged with regard to sex peptides responsible for female monogamy. Importantly, this also suggests that the rare cases of re-mating following cross-mating observed in this species may not be a form of reproductive barrier between molecular forms.
Radiative engineering with refractory epsilon-near-zero metamaterials (Conference Presentation)
NASA Astrophysics Data System (ADS)
Dyachenko, Pavel N.; Molesky, Sean; Petrov, Alexander Y.; Störmer, Michael; Krekeler, Tobias; Lang, Slawa; Ritter, Martin; Jacob, Zubin; Eich, Manfred
2016-04-01
Improvement in high-temperature stable spectrally selective absorbers and emitters is integral for the further development of thermophotovoltaic (TPV), lighting and solar thermal applications. However, the high operational temperatures (T>1000oC) required for efficient energy conversion, along with application specific criteria such as the operational range of low bandgap semiconductors, greatly restrict what can be accomplished with natural materials. Motivated by this challenge, we demonstrate the first example of high temperature thermal radiation engineering with metamaterials. By employing the naturally selective thermal excitation of radiative modes that occurs near topological transitions, we show that thermally stable highly selective emissivity features are achieved for temperatures up to 1000°C with low angular dependence in a sub-micron thick refractory tungsten/hafnium dioxide epsilon-near-zero (ENZ) metamaterial. We also investigate the main mechanisms of thermal degradation of the fabricated refractory metamaterial both in terms of optical performance and structural stability using spectral analysis and energy-dispersive X-ray spectroscopy (EDS) techniques. Importantly, we observe chemical stability of the constituent materials for temperatures up to 1000°C and structural stability beyond 1100°C. The scalable fabrication, requiring magnetron sputtering, and thermally robust optical properties of this metamaterial approach are ideally suited to high temperature emitter applications such as lighting or TPV. Our findings provide a first concrete proof of radiative engineering with high temperature topological transition in ENZ metamaterials, and establish a clear path for implementation in TPV energy harvesting applications.
NASA Astrophysics Data System (ADS)
Croat, T. K.; Floss, C.; Haas, B. A.; Burchell, M. J.; Kearsley, A. T.
2015-08-01
We present results of FIB-TEM studies of 12 Stardust analog Al foil craters which were created by firing refractory Si and Ti carbide and nitride grains into Al foils at 6.05 km s-1 with a light-gas gun to simulate capture of cometary grains by the Stardust mission. These foils were prepared primarily to understand the low presolar grain abundances (both SiC and silicates) measured by SIMS in Stardust Al foil samples. Our results demonstrate the intact survival of submicron SiC, TiC, TiN, and less-refractory Si3N4 grains. In small (<2 μm) craters that are formed by single grain impacts, the entire impacting crystalline grain is often preserved intact with minimal modification. While they also survive in crystalline form, grains at the bottom of larger craters (>5 μm) are typically fragmented and are somewhat flattened in the direction of impact due to partial melting and/or plastic deformation. The low presolar grain abundance estimates derived from SIMS measurements of large craters (mostly >50 μm) likely result from greater modification of these impactors (i.e., melting and isotopic dilution), due to higher peak temperatures/pressures in these crater impacts. The better survivability of grains in smaller craters suggests that more accurate presolar grain estimates may be achievable through measurement of such craters. It also suggests small craters can provide a complementary method of study of the Wild 2 fine fraction, especially for refractory CAI-like minerals.
Imatinib: A Breakthrough of Targeted Therapy in Cancer
Iqbal, Naveed
2014-01-01
Deregulated protein tyrosine kinase activity is central to the pathogenesis of human cancers. Targeted therapy in the form of selective tyrosine kinase inhibitors (TKIs) has transformed the approach to management of various cancers and represents a therapeutic breakthrough. Imatinib was one of the first cancer therapies to show the potential for such targeted action. Imatinib, an oral targeted therapy, inhibits tyrosine kinases specifically BCR-ABL, c-KIT, and PDGFRA. Apart from its remarkable success in CML and GIST, Imatinib benefits various other tumors caused by Imatinib-specific abnormalities of PDGFR and c-KIT. Imatinib has also been proven to be effective in steroid-refractory chronic graft-versus-host disease because of its anti-PDGFR action. This paper is a comprehensive review of the role of Imatinib in oncology. PMID:24963404
Development of refractory armored silicon carbide by infrared transient liquid phase processing
NASA Astrophysics Data System (ADS)
Hinoki, Tatsuya; Snead, Lance L.; Blue, Craig A.
2005-12-01
Tungsten (W) and molybdenum (Mo) were coated on silicon carbide (SiC) for use as a refractory armor using a high power plasma arc lamp at powers up to 23.5 MW/m 2 in an argon flow environment. Both tungsten powder and molybdenum powder melted and formed coating layers on silicon carbide within a few seconds. The effect of substrate pre-treatment (vapor deposition of titanium (Ti) and tungsten, and annealing) and sample heating conditions on microstructure of the coating and coating/substrate interface were investigated. The microstructure was observed by scanning electron microscopy (SEM) and optical microscopy (OM). The mechanical properties of the coated materials were evaluated by four-point flexural tests. A strong tungsten coating was successfully applied to the silicon carbide substrate. Tungsten vapor deposition and pre-heating at 5.2 MW/m 2 made for a refractory layer containing no cracks propagating into the silicon carbide substrate. The tungsten coating was formed without the thick reaction layer. For this study, small tungsten carbide grains were observed adjacent to the interface in all conditions. In addition, relatively large, widely scattered tungsten carbide grains and a eutectic structure of tungsten and silicon were observed through the thickness in the coatings formed at lower powers and longer heating times. The strength of the silicon carbide substrate was somewhat decreased as a result of the processing. Vapor deposition of tungsten prior to powder coating helped prevent this degradation. In contrast, molybdenum coating was more challenging than tungsten coating due to the larger coefficient of thermal expansion (CTE) mismatch as compared to tungsten and silicon carbide. From this work it is concluded that refractory armoring of silicon carbide by Infrared Transient Liquid Phase Processing is possible. The tungsten armored silicon carbide samples proved uniform, strong, and capable of withstanding thermal fatigue testing.
NASA Astrophysics Data System (ADS)
Fruhstorfer, Jens; Dudczig, Steffen; Rudolph, Martin; Schmidt, Gert; Brachhold, Nora; Schöttler, Leandro; Rafaja, David; Aneziris, Christos G.
2018-06-01
Corrosion tests of carbon-free and carbon-containing refractories were performed. The carbon-free crucibles corroded, whereas the carbon-containing crucibles were negligibly attacked. On them, inclusions were attached. This study investigates melt oxygen contents, interface properties, and steel compositions with their non-metallic inclusions in order to explore the inclusion formation and deposition mechanisms. The carbon-free crucibles were based on alumina, mullite, and zirconia- and titania-doped alumina (AZT). The carbon-containing (-C) ones were alumina-C and AZT-C. Furthermore, nanoscaled carbon and alumina additives (-n) were applied in an AZT-C-n material. In the crucibles, the case-hardened steel 17CrNiMo7-6 was remelted at 1580 °C. It was observed that the melt and steel oxygen contents were higher for the tests in the carbon-free crucibles. Into these crucibles, the deoxidizing alloying elements Mn and Si diffused. Reducing contents of deoxidizing elements resulted in higher steel oxygen levels and less inclusions, mainly of the inclusion group SiO2-core-MnS-shell (2.5 to 8 μ m). These developed from smaller SiO2 nuclei. The inclusion amount in the steel was highest after remelting in AZT-C-n for 30 minutes but decreased strongly with increasing remelting time (60 minutes) due to inclusions' deposition on the refractory surface. The Ti from the AZT and the nanoadditives supported inclusion growth and deposition. Other inclusion groups were alumina and calcium aluminate inclusions. Their contents were high after remelting in carbon- or AZT-containing crucibles but generally decreased during remelting. On the AZT-C-n crucible, a dense layer formed from vitreous compositions including Al, Ca, Mg, Si, and Ti. To summarize, for reducing forming inclusion amounts, mullite is recommended as refractory material. For capturing formed inclusions, AZT-C-n showed a high potential.
Improvements in Ionized Cluster-Beam Deposition
NASA Technical Reports Server (NTRS)
Fitzgerald, D. J.; Compton, L. E.; Pawlik, E. V.
1986-01-01
Lower temperatures result in higher purity and fewer equipment problems. In cluster-beam deposition, clusters of atoms formed by adiabatic expansion nozzle and with proper nozzle design, expanding vapor cools sufficiently to become supersaturated and form clusters of material deposited. Clusters are ionized and accelerated in electric field and then impacted on substrate where films form. Improved cluster-beam technique useful for deposition of refractory metals.
Lisanework, Mulu
2003-01-01
The response to supratarsal injection of dexamethasone in severe refractory vernal keratoconjunctivitis was studied in 20 patients (14 males and 6 females) at the ophthalmology department of Menelik II Hospital, Addis Ababa in 1997. Majority of the patients were in the age range of 11-20 years with mean age of 14.6 years. Although all patients experienced relief of symptoms in the first 2 days of dexamethasone injection, symptoms recurred in the majority 16 (80%) of the patients. Cobble stone papillae and limbal signs disappeared in 2 (11%) and 5 (38%) of the patients respectively. Resolution of limbal form of the disease is more dramatic when compared to the palpebral form. This study showed that supratarsal injection of dexamethasone in severe vernal keratoconjunctivitis is effective in few, partially effective in some and ineffective in many of our patients. Further studies, particularly a randomized controlled trial is recommended prior to utilization of this new therapeutic modality as a standard form of treatment in Ethiopian patients.
Barrier Coatings for Refractory Metals and Superalloys
DOE Office of Scientific and Technical Information (OSTI.GOV)
SM Sabol; BT Randall; JD Edington
2006-02-23
In the closed working fluid loop of the proposed Prometheus space nuclear power plant (SNPP), there is the potential for reaction of core and plant structural materials with gas phase impurities and gas phase transport of interstitial elements between superalloy and refractory metal alloy components during service. Primary concerns are surface oxidation, interstitial embrittlement of refractory metals and decarburization of superalloys. In parallel with kinetic investigations, this letter evaluates the ability of potential coatings to prevent or impede communication between reactor and plant components. Key coating requirements are identified and current technology coating materials are reviewed relative to these requirements.more » Candidate coatings are identified for future evaluation based on current knowledge of design parameters and anticipated environment. Coatings were identified for superalloys and refractory metals to provide diffusion barriers to interstitial transport and act as reactive barriers to potential oxidation. Due to their high stability at low oxygen potential, alumina formers are most promising for oxidation protection given the anticipated coolant gas chemistry. A sublayer of iridium is recommended to provide inherent diffusion resistance to interstitials. Based on specific base metal selection, a thin film substrate--coating interdiffusion barrier layer may be necessary to meet mission life.« less
Methods and apparatus for reducing corrosion in refractory linings
Poeppel, Roger B.; Greenberg, Sherman; Diercks, Dwight R.
1987-01-01
Methods and apparatus are provided for reducing corrosion in a refractory lining of a liquid-containing vessel used in direct steelmaking processes. The vessel operates at between about 1600.degree. C. and about 1800.degree. C. and an oxygen partial pressure of about 10.sup.-12 atmospheres, creating slag which is rich in FeO. The refractory lining includes a significant level of chromium oxide (Cr.sub.2 O.sub.3), and has small interconnected pores which may be filled with a gas mixture having a higher total pressure and oxygen partial pressure than the total pressure and oxygen partial pressure associted with the liquid against the lining of the vessel. The gas mixture is forced through the pores of the lining so that the pores are continuously filled with the mixture. In this manner, the gas mixture creates a blanket which increases the oxygen partial pressure at the lining enough to maintain the chromium in the lining in a selected valence state in which the chromium has decreased solubility in the FeO slag, thereby reducing corrosion by the FeO and increasing the useful life of the refractory lining.
Refractory ceramic has wide usage, low fabrication cost
NASA Technical Reports Server (NTRS)
1964-01-01
Particulate, fused amorphous silica is formed into complex shapes by casting in plaster molds. High temperature firing is not required. This ceramic is resistant to thermal shock and exhibits good strength properties.
Vijay, Sonam; Rawat, Manmeet; Adak, Tridibes; Dixit, Rajnikant; Nanda, Nutan; Srivastava, Harish; Sharma, Joginder K; Prasad, Godavarthi B K S; Sharma, Arun
2011-04-04
Anopheles culicifacies, the main vector of human malaria in rural India, is a complex of five sibling species. Despite being phylogenetically related, a naturally selected subgroup species B of this sibling species complex is found to be a poor vector of malaria. We have attempted to understand the differences between vector and non-vector Anopheles culicifacies mosquitoes in terms of transcriptionally activated nitric oxide synthase (AcNOS) physiologies to elucidate the mechanism of refractoriness. Identification of the differences between genes and gene products that may impart refractory phenotype can facilitate development of novel malaria transmission blocking strategies. We conducted a study on phylogenetically related susceptible (species A) and refractory (species B) sibling species of An. culicifacies mosquitoes to characterize biochemical and molecular differences in AcNOS gene and gene elements and their ability to inhibit oocyst growth. We demonstrate that in species B, AcNOS specific activity and nitrite/nitrates in mid-guts and haemolymph were higher as compared to species A after invasion of the mid-gut by P. vivax at the beginning and during the course of blood feeding. Semiquantitative RT-PCR and real time PCR data of AcNOS concluded that this gene is more abundantly expressed in midgut of species B than in species A and is transcriptionally upregulated post blood meals. Dietary feeding of L-NAME along with blood meals significantly inhibited midgut AcNOS activity leading to an increase in oocyst production in An. culicifacies species B. We hypothesize that upregulation of mosquito innate cytotoxicity due to NOS in refractory strain to Plasmodium vivax infection may contribute to natural refractoriness in An. culicifacies mosquito population. This innate capacity of refractory mosquitoes could represent the ancestral function of the mosquito immune system against the parasite and could be utilized to understand the molecular basis of refractoriness in planning effective vector control strategies.
Vijay, Sonam; Rawat, Manmeet; Adak, Tridibes; Dixit, Rajnikant; Nanda, Nutan; Srivastava, Harish; Sharma, Joginder K.; Prasad, Godavarthi B. K. S.; Sharma, Arun
2011-01-01
Background Anopheles culicifacies, the main vector of human malaria in rural India, is a complex of five sibling species. Despite being phylogenetically related, a naturally selected subgroup species B of this sibling species complex is found to be a poor vector of malaria. We have attempted to understand the differences between vector and non-vector Anopheles culicifacies mosquitoes in terms of transcriptionally activated nitric oxide synthase (AcNOS) physiologies to elucidate the mechanism of refractoriness. Identification of the differences between genes and gene products that may impart refractory phenotype can facilitate development of novel malaria transmission blocking strategies. Methodology/Principal Findings We conducted a study on phylogenetically related susceptible (species A) and refractory (species B) sibling species of An. culicifacies mosquitoes to characterize biochemical and molecular differences in AcNOS gene and gene elements and their ability to inhibit oocyst growth. We demonstrate that in species B, AcNOS specific activity and nitrite/nitrates in mid-guts and haemolymph were higher as compared to species A after invasion of the mid-gut by P. vivax at the beginning and during the course of blood feeding. Semiquantitative RT-PCR and real time PCR data of AcNOS concluded that this gene is more abundantly expressed in midgut of species B than in species A and is transcriptionally upregulated post blood meals. Dietary feeding of L-NAME along with blood meals significantly inhibited midgut AcNOS activity leading to an increase in oocyst production in An. culicifacies species B. Conclusions/Significance We hypothesize that upregulation of mosquito innate cytotoxicity due to NOS in refractory strain to Plasmodium vivax infection may contribute to natural refractoriness in An. culicifacies mosquito population. This innate capacity of refractory mosquitoes could represent the ancestral function of the mosquito immune system against the parasite and could be utilized to understand the molecular basis of refractoriness in planning effective vector control strategies. PMID:21483693
Combustion synthesis method and products
Holt, J.B.; Kelly, M.
1993-03-30
Disclosed is a method of producing dense refractory products, comprising: (a) obtaining a quantity of exoergic material in powder form capable of sustaining a combustion synthesis reaction; (b) removing absorbed water vapor therefrom; (c) cold-pressing said material into a formed body; (d) plasma spraying said formed body with a molten exoergic material to form a coat thereon; and (e) igniting said exoergic coated formed body under an inert gas atmosphere and pressure to produce self-sustained combustion synthesis. Also disclosed are products produced by the method.
Combustion synthesis method and products
Holt, J. Birch; Kelly, Michael
1993-01-01
Disclosed is a method of producing dense refractory products, comprising: (a) obtaining a quantity of exoergic material in powder form capable of sustaining a combustion synthesis reaction; (b) removing absorbed water vapor therefrom; (c) cold-pressing said material into a formed body; (d) plasma spraying said formed body with a molten exoergic material to form a coat thereon; and (e) igniting said exoergic coated formed body under an inert gas atmosphere and pressure to produce self-sustained combustion synthesis. Also disclosed are products produced by the method.
Immunomodulatory therapy in refractory/recurrent ovarian cancer.
Chen, Chao-Yu; Lai, Chyong-Huey; Yang, Lan-Yan; Tang, Yun-Hsin; Chou, Hung-Hsueh; Chang, Chee-Jen; Lin, Cheng-Tao
2015-04-01
To investigate the efficacy and toxicity of immunomodulatory therapy (IMT) alone or as an add-on to palliative/salvage chemotherapy in patients with refractory/recurrent epithelial ovarian cancer (EOC). We retrospectively analyzed the efficacy and toxicity of IMT in 15 patients with refractory/recurrent EOC who had previously received multiple chemotherapy regimens. The median age of the patients was 56 years (range, 41-75 years). Three patients were platinum-sensitive, two were platinum-resistant, and the remaining 10 patients were refractory to platinum-based front-line chemotherapy. IMT consisted of picibanil (OK-432) on Day 1, interleukin-2 and/or interferon-α on Day 2 administered by subcutaneous injection (every week or 2-weekly). Five patients never received metronomic oral cyclophosphamide. After IMT, three patients achieved partial remission (PR, lasting for 11 months, ≥ 12 months, and 16 months), and six patients had stable disease (SD). The disease stabilizing rate (PR+SD) was 60% (3/3 in platinum-sensitive and 6/12 in platinum-resistant/refractory patients). The absolute lymphocyte count (ALC) at 1 month after IMT was significantly higher in the PR+SD group (median 1242.0/μL) than in the progression group (median 325.0/μL) (p = 0.012). No ≥ Grade 3 toxicities were observed. The median post-IMT survival time was 12 months (range, 2-39 months). IMT alone or add-on to palliative/salvage chemotherapy for refractory/recurrent EOC achieves a substantial disease stabilizing rate without severe toxicity, which might be a potential option in selected patients. The ALC 1 month after IMT could be an early indicator to disease stabilization. Copyright © 2015. Published by Elsevier B.V.
Mutalib, Mohamed; Borrelli, Osvaldo; Blackstock, Sarah; Kiparissi, Fevronia; Elawad, Mamoun; Shah, Neil; Lindley, Keith
2014-12-01
Management of refractory inflammatory bowel disease (IBD) in children is challenging and once response to conventional medical therapy deviates from the expected, options are often limited. Sirolimus is commonly used in post-transplantation management and is used sparsely as rescue therapy in refractory Crohn's disease. In the present study, we report the efficacy of sirolimus as an adjuvant immunosuppressive therapy in a retrospective case review of a selected group of IBD children who were refractory to the conventional treatments. Medical records of children with refractory IBD unresponsive to conventional therapy and started on sirolimus between 2006 and 2012 were retrospectively reviewed. Clinical response, through Pediatric Ulcerative Colitis Activity Index (PUCAI) and Pediatric Crohn's Disease Activity Index (PCDAI), as well as intestinal inflammation, through specific histological scores, was evaluated. The records of 14 patients were analyzed. Eleven of them had ulcerative colitis (UC) and 3 Crohn's disease (CD); mean age at diagnosis was 9.1 years (standard deviation 3.8). Of UC patients, 5 (45%) achieved clinical remission and 2 (18%) showed clinical response. All CD patients went into clinical remission. Mucosal healing was achieved by 5 children (45%) with UC and 2 (67%) with CD patients. One child with ulcerative colitis was weaned off adalimumab, while 2 children with CD were weaned off prednisolone and methotrexate successfully. Our data provide evidence that sirolimus seems to be effective as rescue therapy in a subgroup of children with severe IBD refractory to conventional therapies by inducing both clinical remission and mucosal healing. Copyright © 2014 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.
Laursen, S B; Leontiadis, G I; Stanley, A J; Hallas, J; Schaffalitzky de Muckadell, O B
2017-08-01
Observational studies have consistently shown an increased risk of upper gastrointestinal bleeding in users of selective serotonin receptor inhibitors (SSRIs), probably explained by their inhibition of platelet aggregation. Therefore, treatment with SSRIs is often temporarily withheld in patients with peptic ulcer bleeding. However, abrupt discontinuation of SSRIs is associated with development of withdrawal symptoms in one-third of patients. Further data are needed to clarify whether treatment with SSRIs is associated with poor outcomes, which would support temporary discontinuation of treatment. To identify if treatment with SSRIs is associated with increased risk of: (1) endoscopy-refractory bleeding, (2) rebleeding or (3) 30-day mortality due to peptic ulcer bleeding. A nationwide cohort study. Analyses were performed on prospectively collected data on consecutive patients admitted to hospital with peptic ulcer bleeding in Denmark in the period 2006-2014. Logistic regression analyses were used to investigate the association between treatment with SSRIs and outcome following adjustment for pre-defined confounders. Sensitivity and subgroup analyses were performed to evaluate the validity of the findings. A total of 14 343 patients were included. Following adjustment, treatment with SSRIs was not associated with increased risk of endoscopy-refractory bleeding (odds ratio [OR] [95% Confidence Interval (CI)]: 1.03 [0.79-1.33]), rebleeding (OR [95% CI]: 0.96 [0.83-1.11]) or 30-day mortality (OR [95% CI]: 1.01 [0.85-1.19]. These findings were supported by sensitivity and subgroup analyses. According to our data, treatment with SSRIs does not influence the risk of endoscopy-refractory bleeding, rebleeding or 30-day mortality in peptic ulcer bleeding. © 2017 John Wiley & Sons Ltd.
Kolodney, M.
1959-07-01
Methods are presented for the electro-deposition of plutonium from fused mixtures of plutonium halides and halides of the alkali metals and alkaline earth metals. Th salts, preferably chlorides and with the plutonium prefer ably in the trivalent state, are placed in a refractory crucible such as tantalum or molybdenam and heated in a non-oxidizing atmosphere to 600 to 850 deg C, the higher temperatatures being used to obtain massive plutonium and the lower for the powder form. Electrodes of graphite or non reactive refractory metals are used, the crucible serving the cathode in one apparatus described in the patent.
Crack-Free, Nondistorting Can For Hot Isostatic Pressing
NASA Technical Reports Server (NTRS)
Juhas, John J.
1991-01-01
New method of canning specimens made of composites of arc-sprayed and plasma-sprayed tape reduces outgassing and warping during hot isostatic pressing. Produces can having reliable, crack-free seal and thereby helps to ensure pressed product of high quality. Specimen placed in ring of refractory metal between two face sheets, also of refractory metal. Assembly placed in die in vacuum hot press, where simultaneously heated and pressed until plates become diffusion-welded to ring, forming sealed can around specimen. Specimen becomes partially densified, and fits snugly within can. Ready for further densification by hot isostatic pressing.
Extra-adrenal phaeochromocytoma—a case report of refractory hypertension
Singh, V.P.; Singh, Manjeet; Malhotra, Mridul; Kumar, Ashok; Agarwal, A.K.
2012-01-01
There are at least 5% of all hypertensive patients whose blood pressure (BP) remains elevated despite adequate treatment. In these cases, the clinician is forced to search for a secondary cause of the chronic BP elevation. Certain environmental factors are known to induce resistant-hypertension. Additionally, there may be pseudo-resistance occurring or the patient may be suffering from a secondary form of hypertension such as renovascular or endocrinological hypertension (phaeochromocytoma, Cushing's syndrome, etc.). We report a case of extra-adrenal phaeochromocytoma who was on adequate antihypertensive medications but remained refractory to treatment prior to the exact diagnosis. PMID:22572502
Improved high temperature refractory. [MgCr/sub 2/O/sub 4/ composite with ZrO/sub 2/
Singh, J.P.; James, J.; Picciolo, J.J.
1985-12-10
A high chromia refractory composite has been developed with improved thermal shock resistance and containing about 5 to 30 wt % of unstabilized ZrO/sub 2/ having a temperature-dependent phase change resulting in large expansion mismatch between the ZrO/sub 2/ and the chromia matrix which causes microcracks to form during cooling in the high chromia matrix. The particle size preferably is primarily between about 0.6 to 5 microns and particularly below about 3 microns with an average size in the order of 1.2 to 1.8 microns.
High temperature refractory of MgCr.sub.2 O.sub.4 matrix and unstabilized ZrO.sub.2 particles
Singh, Jitendra P.; James, Jawana J.; Picciolo, John J.
1987-01-01
A high chromia refractory composite has been developed with improved thermal shock resistance and containing about 5-30 wt. % of unstabilized ZrO.sub.2 having a temperature-dependent phase change resulting in large expansion mismatch between the ZrO.sub.2 and the chromia matrix which causes microcracks to form during cooling in the high chromia matrix. The particle size preferably is primarily between about 0.6-5 microns and particularly below about 3 microns with an average size in the order of 1.2-1.8 microns.
Video electroencephalogram telemetry in temporal lobe epilepsy
Mani, Jayanti
2014-01-01
Temporal lobe epilepsy (TLE) is the most commonly encountered medically refractory epilepsy. It is also the substrate of refractory epilepsy that gives the most gratifying results in any epilepsy surgery program, with a minimum use of resources. Correlation of clinical behavior and the ictal patterns during ictal behavior is mandatory for success at epilepsy surgery. Video electroencephalogram (EEG) telemetry achieves this goal and hence plays a pivotal role in pre-surgical assessment. The role of telemetry is continuously evolving with the advent of digital EEG technology, of high-resolution volumetric magnetic resonance imaging and other functional imaging techniques. Most of surgical selection in patients with TLE can be done with a scalp video EEG monitoring. However, the limitations of the scalp EEG technique demand invasive recordings in a selected group of TLE patients. This subset of the patients can be a challenge to the epileptologist. PMID:24791089
Refractory materials from lunar resources
NASA Technical Reports Server (NTRS)
Fabes, B. D.; Poisl, W. H.
1991-01-01
Refractories - materials which are able to withstand extremely high temperatures - are sure to be an important part of any processing facility or human outpost which is built on Mars. Containers for processing lunar oxygen will need high temperature components. Fabrication of structural material from lunar resources need both containment vessels to hold high temperature melts and molds in which to form the final shapes. Certainly, it would be desirable to fabricate such vessels and molds on the Moon, rather than carrying them up from the Earth. At first glance, this might appear to be a trivial task, since the Moon's surface consists of a variety of refractory compositions. To turn the regolith into a useful fire brick or mold, however, will require water or other binders and additives which are likely to be in extremely short supply on the Moon. The steps needed to make fire bricks and molds for lunar-derived structural materials are examined, pointing out the critical steps and resources which will be needed. While these processes and applications may seem somewhat mundane, it is emphasized that it is precisely these rudimentary processes which must be mastered before discussing making aerobrakes, and other fancier refractories from lunar resources.
Adalimumab for the treatment of refractory noninfectious paediatric uveitis.
Muñoz-Gallego, Alicia; Barral, Estefanía; Enríquez, Eugenia; Tejada, Pilar; Barceló, Ana; de Inocencio, Jaime
2017-06-01
To report the experience of our center with the use of adalimumab (ADA) for the treatment of severe refractory noninfectious paediatric uveitis. The study is a retrospective case series of all paediatric patients with refractory uveitis who were treated with ADA at the Paediatric Uveitis Unit of our center from 2008 to 2015. We present 12 patients (6 Juvenile idiopathic arthritis-associated uveitis, 4 idiopathic panuveitis, 1 early-onset sarcoidosis-associated panuveitis, and 1 intermediate uveitis), with uveitis in 19/24 eyes. Once ADA therapy was started, all the patients presented improved activity according to Standardization of Uveitis Nomenclature (SUN) criteria. Nine out of the 12 patients had structural damage before ADA could be started: cataract (n = 4), glaucoma (n = 2), cystic macular edema (n = 1), exudative retinal detachment (n = 1), and optic disk edema (n = 5). Visual acuity improved or maintained stable in 17/19 affected eyes, and only 2 eyes decreased its visual acuity because of structural damage, which was already present before ADA therapy. In our experience, ADA presents a good safety profile and is efficacious in the treatment of paediatric patients with different forms of refractory noninfectious uveitis.
ERIC Educational Resources Information Center
Levay, Alexander N.; Kagle, Arlene
1977-01-01
Psychopathology, in the form of a deficiency in ego functions of pleasure, intimacy, or cooperation, is usually associated with sexual dysfunctions that prove refractory to sex therapy techniques alone. Each deficiency forms a distinct clinical syndrome with specific treatment requirements, necessitating further diagnostic subcategorization of…
Improving neuromodulation technique for refractory voiding dysfunctions: two-stage implant.
Janknegt, R A; Weil, E H; Eerdmans, P H
1997-03-01
Neuromodulation is a new technique that uses electrical stimulation of the sacral nerves for patients with refractory urinary urge/frequency or urge-incontinence, and some forms of urinary retention. The limiting factor for receiving an implant is often a failure of the percutaneous nerve evaluation (PNE) test. Present publications mention only about a 50% success score for PNE of all patients, although the micturition diaries and urodynamic parameters are similar. We wanted to investigate whether PNE results improved by using a permanent electrode as a PNE test. This would show that improvement of the PNE technique is feasible. In 10 patients where the original PNE had failed to improve the micturition diary parameters more than 50%, a permanent electrode was implanted by operation. It was connected to an external stimulator. In those cases where the patients improved according to their micturition diary by more than 50% during a period of 4 days, the external stimulator was replaced by a permanent subcutaneous neurostimulator. Eight of the 10 patients had a good to very good result (60% to 90% improvement) during the testing period and received their implant 5 to 14 days after the first stage. The good results of the two-stage implant technique we used indicate that the development of better PNE electrodes may lead to an improvement of the testing technique and better selection between nonresponders and technical failures.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sabolsky, Edward M.; Bhattacharyya, Debangsu; Graham, David
The objective of the work was to develop refractory “smart bricks”, which would contain embedded temperature, strain/stress, and spallation sensors throughout the volume of high-chromia (-Cr2O3) refractory brick. The proposed work included work to interconnect the sensors to the reactor exterior, where the sensor signals may be processed by low-power electronics and transmitted wirelessly to a central processing hub. The data processing and wireless transmitter hardware was specifically designed to be isolated (with low power consumption) and to be adaptable to future implementation of energy-harvesting strategies for extended life. Finally, the collected data was incorporated into a model to estimatemore » refractory degradation, a technique that could help monitor the health of the refractory in real-time. The long-term goal of this program was to demonstrate high-temperature, wireless sensor arrays for in situ three-dimensional (3-D) refractory monitoring or mapping for slagging gasification systems. The research was in collaboration with HarbisonWalker International (HWI) Technology Center in West Mifflin, PA. HWI is a leading developer and manufacturer of ceramic refractory products for high-temperature applications. The work completed focused on the following areas: 1) Investigation of the chemical stability, microstructural evolution, grain growth kinetics, degree of homogeneity (quantitative image analysis), and electrical properties of refractory oxide-silicide composites at temperatures between 750-1450ºC; 2) Fabrication of silicide-alumina composite and oxide thermocouples and thermistor preforms and the development of techniques to embed them into high-chromia refractory bricks to form “smart bricks”; 3) Utilization of commercial off-the-shelf discrete components to prototype circuits for interfacing between smart brick sensors and the wireless sensor network. The prototypes were then used to design an integrated circuit for thermistor, thermocouple, and capacitive-based smart brick sensor interfacing; 4) Interfacing of the smart bricks with embedded sensors with wireless motes thus yielding a complete signal chain. This end-to-end data collection system was tested on a furnace heated to 1350 °C; 5) Development of a slag penetration model and a nonlinear unknown input filter for the data from the embedded sensors for estimating temperature and extent of slag penetration.« less
[Surgical management of refractory dysphagia and aspiration].
Wang, Jian; Li, Wuyi; Liu, Jianhan; Xu, Chunxiao; Yang, Dahai; Huo, Hong; Tian, Xu; Zhang, Zhuhua; Chen, Yu
2015-02-01
To explore the methods and results of surgical management for refractory dysphagia and aspiration. The clinical data of 24 refractory dysphagia and aspiration patients who accepted surgical management were retrospectively analysed. Twenty-four refractory dysphagia and aspiration patients accepted 26 operations between 2001 and 2014. Of the 26 operations, 17 were cricopharyngeal myectomy (CPM), 6 were scarectomy, 3 were laryngeal-tracheal separation. No severe complications occurred. Assessments of dysphagia were completed in 18 operations before and after operation. Aspiration scores of videofluoroscopic swallowing study (VFSS) were 4.50 [4.00;7.00] vs 2.00 [1.00; 3.25], P = 0.000; swallow dysfunction scroes of VFSS were 5.00 [4.00; 12.00] vs 1.00 [1.50; 10.00], P = 0.001; aspiration scores of fibroptic endoscopic evaluation of swallowing (FEES) were 4.00 [5.00; 7.00] vs 2.00 [1.75; 3.00], P = 0.000. But the surgical results for post radiotherapy dysphagia were not successful (n = 5): aspiration scores of VFSS were 7.00 [6.50; 8.00] vs 6.00 [2.00; 7.50], P = 0.109;swallow dysfunction scroes of VFSS were 12.00 [10.50; 12.00] vs 12.00 [7.50; 12.00], P = 0.180;aspiration scores of FEES were 7.00 [6.50; 8.00] vs 6.00 [2.00; 7.50], P = 0.109. Surgical management was effective for refractory dysphagia and aspiration, but the surgical indication selection should be strict.
Schoenberg, Mike R; Clifton, William E; Sever, Ryan W; Vale, Fernando L
2018-06-01
Surgery is indicated in cases of mesial temporal lobe epilepsy(MTLE) that are refractory to medical management. The inferior temporal gyrus (ITG) approach provides access to the mesial temporal lobe (MTL) structures with minimal tissue disruption. Reported neuropsychology outcomes following this approach are limited. To report neuropsychological outcomes using an ITG approach to amygdalohippocampectomy (AH) in patients with medically refractory MTLE based on a prospective design. Fifty-four participants had Engel class I/II outcome following resection of MTL using the ITG approach. All participants had localization-related epilepsy confirmed by long-term surface video-electroencephalography and completed pre/postsurgical evaluations that included magnetic resonance imaging (MRI), Wada test or functional MRI, and neuropsychology assessment. Clinical semiology/video-electroencephalography indicated that of the 54 patients, 28 (52%) had left MTLE and 26 (48%) had right MTLE. Dominant hemisphere resections were performed on 23 patients (43%), nondominant on 31(57%). Twenty-nine (29) had pathology-confirmed mesial temporal sclerosis (MTS). Group level analyses found declines in verbal memory for patients with language-dominant resections (P < .05). No significant decline in neuropsychological measures occurred for patients with MTS. Participants without MTS who underwent a language-dominant lobe resection exhibited a significant decline in verbal and visual memory (P < .05). Nondominant resection participants did not exhibit significant change in neuropsychology scores (P > .05). Neuropsychology outcomes of an ITG approach for selective mesial temporal resection are comparable to other selective AH techniques showing minimal adverse cognitive effects. These data lend support to the ITG approach for selective AH as an option for MTLE.
Stevens, Courtney; Paulsen, David; Yasen, Alia; Mitsunaga, Leila; Neville, Helen
2012-01-01
Previous research indicates that at least some children with specific language impairment (SLI) show a reduced neural response when non-linguistic tones were presented at rapid rates. However, this past research has examined older children, and it is unclear whether such deficits emerge earlier in development. It is also unclear whether atypical refractory effects differ for linguistic versus non-linguistic stimuli or can be explained by deficits in selective auditory attention reported among children with SLI. In the present study, auditory refractory periods were compared in a group of 24 young children with SLI (age 3–8 years) and 24 matched control children. Event-related brain potentials (ERPs) were recorded and compared to 100 ms linguistic and non-linguistic probe stimuli presented at inter-stimulus intervals (ISIs) of 200, 500, or 1000 ms. These probes were superimposed on story narratives when attended and ignored, permitting an experimental manipulation of selective attention within the same paradigm. Across participants, clear refractory effects were observed with this paradigm, evidenced as a reduced amplitude response from 100 to 200 ms at shorter ISIs. Children with SLI showed reduced amplitude ERPs relative to the typically-developing group at only the shortest, 200 ms, ISI and this difference was over the left-hemisphere for linguistic probes and over the right-hemisphere for non-linguistic probes. None of these effects was influenced by the direction of selective attention. Taken together, these findings suggest that deficits in the neural representation of rapidly presented auditory stimuli may be one risk factor for atypical language development. PMID:22265331
The susceptibility of Liberian Culex quinquefasciatus to Wuchereria bancrofti in Sri Lanka.
Jayasekera, N; Curtis, C F; Zielke, E; Kuhlow, F; Jansen, C G; Chelliah, R V
1980-12-01
Strains of Culex quinquefasciatus collected in Liberia showed low susceptibility to Wuchereria bancrofti from Liberian donors. However, when the same mosquito strains were fed on W. bancrofti donors from Sri Lanka they showed equally high susceptibility as Sri Lankan C. quinquefasciatus simultaneously fed on the same donors. A Liberian strain did not respond to selection for refractoriness. Thus the strains of W. bancrofti from Liberia and Sri Lanka differ in their ability to infect specific mosquito strains and it is concluded that Liberian C. quinquefasciatus could not provide genes for use in the construction of a refractory strain intended for the replacement of Sri Lankan vector populations.
The influence of high temperatures on selected properties of calcium aluminous composites
NASA Astrophysics Data System (ADS)
KoÅáková, Dana; KoÅ¥átková, Jaroslava; Čáchová, Monika; Vejmelková, Eva; Čechmánek, René; Reiterman, Pavel; Černý, Robert
2017-07-01
The article compares different types of aluminate cements with the reference Portland cement, used in refractory composites. The rate of influence of elevated temperatures (400 °C and 1000 °C) is studied. The investigated parameters are basic physical characteristics and mechanical properties. Results show the best behaviour of the mixture containing Portland cement for the reference state (in the means of all studied parameters); which however after exposition to 1000 °C has the worst performance. Both aluminate cements behave better after heating, which proves its suitability for refractory composites. It is concluded, that the mixture with Gorkal cement achieves the best results.
When Should We Give Up Filtration Surgery: Indications, Techniques and Results of Cyclodestruction.
Masis Solano, Marisse; Huang, Guofu; Lin, Shan C
2017-01-01
Cyclodestructive procedures are traditionally used in cases of glaucoma that are refractory to medical and surgical therapy. The goal of this chapter is to describe the indications, contraindications, techniques, and pitfalls of cyclodestructive procedures, including transscleral cyclophotocoagulation (TCP), micropulse TCP (MP-TCP), endoscopic cyclophotocoagulation (ECP), and ultrasound cilioplasty. A literature search for cyclodestructive techniques was performed, and relevant studies were included for evaluation and review. It is encouraging that TCP seems relatively efficacious even for patients who have been refractory to other treatments, depending on the energy setting, follow-up period, and definition of success. Repeated TCP is often required. TCP was more often used in eyes with limited visual potential caused by severe forms of glaucoma than in eyes with good visual potential. Serious complications were significant vision loss, inflammation, hypotony, and phthisis. ECP came later into clinical use for the treatment of refractory glaucoma. ECP is able to specifically target the ciliary epithelium under direct viewing as compared to TCP, which is an indirect cyclodestructive procedure. In the literature, it has been demonstrated that ECP has overall good success with relatively low complication rates when used for adult forms of glaucoma. A new technology using MP-TCP is a promising alternative to conventional cyclophotocoagulation. Early evidence shows that MP-TCP has clinical utility and a good safety profile. Ultrasound cilioplasty is a possible alternative to laser cyclodestruction that is already being commercialized and is currently under investigation. Both TCP and ECP are effective cyclodestructive procedures and alternatives for the treatment of glaucoma refractory to medical and surgical therapy, though potential for serious complications exists. TCP, ECP, and ultrasound cilioplasty are being used increasingly as the primary surgery for various kinds and stages of glaucoma. © 2017 S. Karger AG, Basel.
2018-06-13
Advanced Malignant Solid Neoplasm; RB1 Positive; Recurrent Childhood Ependymoma; Recurrent Ewing Sarcoma; Recurrent Glioma; Recurrent Hepatoblastoma; Recurrent Kidney Wilms Tumor; Recurrent Langerhans Cell Histiocytosis; Recurrent Malignant Germ Cell Tumor; Recurrent Malignant Glioma; Recurrent Medulloblastoma; Recurrent Neuroblastoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Osteosarcoma; Recurrent Peripheral Primitive Neuroectodermal Tumor; Recurrent Rhabdoid Tumor; Recurrent Rhabdomyosarcoma; Recurrent Soft Tissue Sarcoma; Refractory Ependymoma; Refractory Ewing Sarcoma; Refractory Glioma; Refractory Hepatoblastoma; Refractory Langerhans Cell Histiocytosis; Refractory Malignant Germ Cell Tumor; Refractory Malignant Glioma; Refractory Medulloblastoma; Refractory Neuroblastoma; Refractory Non-Hodgkin Lymphoma; Refractory Osteosarcoma; Refractory Peripheral Primitive Neuroectodermal Tumor; Refractory Rhabdoid Tumor; Refractory Rhabdomyosarcoma; Refractory Soft Tissue Sarcoma
Refractory materials in comet samples
NASA Astrophysics Data System (ADS)
Joswiak, D. J.; Brownlee, D. E.; Nguyen, A. N.; Messenger, S.
2017-08-01
Transmission electron microscope examination of more than 250 fragments, >1 μm from comet Wild 2 and a giant cluster interplanetary dust particle (GCP) of probable cometary origin has revealed four new calcium-aluminum-rich inclusions (CAIs), an amoeboid olivine aggregate (AOA), and an additional AOA or Al-rich chondrule (ARC) object. All of the CAIs have concentric mineral structures and are composed of spinel + anorthite cores surrounded by Al,Ti clinopyroxenes and are similar to two previous CAIs discovered in Wild 2. All of the cometary refractory objects are of moderate refractory character. The mineral assemblages, textures, and bulk compositions of the comet CAIs are similar to nodules in fine-grained, spinel-rich inclusions (FGIs) found in primitive chondrites and like the nodules may be nebular condensates that were altered via solid-gas reactions in the solar nebula. Oxygen isotopes collected on one Wild 2 CAI also match FGIs. The lack of the most refractory inclusions in the comet samples may reflect the higher abundances of small moderately refractory CAI nodules that were produced in the nebula and the small sample sizes collected. In the comet samples, approximately 2-3% of all fragments larger than 1 μm, by number, are CAIs and nearly 50% of all bulbous Stardust tracks contain at least one CAI. We estimate that 0.5 volume % of Wild 2 material and 1 volume % of GCP is in the form of CAIs. ARCs and AOAs account for <1% of the Wild 2 and GCP grains by number.
Condensation of refractory metals in asymptotic giant branch and other stellar environments
DOE Office of Scientific and Technical Information (OSTI.GOV)
Schwander, D.; Berg, T.; Schönhense, G.
2014-09-20
The condensation of material from a gas of solar composition has been extensively studied, but less so condensation in the environment of evolved stars, which has been mainly restricted to major compounds and some specific element groups such as the Rare Earth elements. Also of interest, however, are refractory metals like Mo, Ru, Os, W, Ir, and Pt, which may condense to form refractory metal nuggets (RMNs) like the ones that have been found in association with presolar graphite. We have performed calculations describing the condensation of these elements in the outflows of s-process enriched AGB stars as well asmore » from gas enriched in r-process products. While in carbon-rich environments (C > O), the formation of carbides is expected to consume W, Mo, and V (Lodders and Fegley), the condensation sequence for the other refractory metals under these conditions does not significantly differ from the case of a cooling gas of solar composition. The composition in detail, however, is significantly different due to the completely different source composition. Condensation from an r-process enriched source differs less from the solar case. Elemental abundance ratios of the refractory metals can serve as a guide for finding candidate presolar grains among the RMNs in primitive meteorites—most of which have a solar system origin—for confirmation by isotopic analysis. We apply our calculations to the case of the four RMNs found by Croat et al., which may very well be presolar.« less
NASA Astrophysics Data System (ADS)
Kim, Tae Sung; Chung, Yongsug; Holappa, Lauri; Park, Joo Hyun
2017-06-01
Rice husk ash (RHA) has been widely used as an insulation powder in steel casting tundish. Its effect on the reoxidation of molten steel in tundish as well as on the corrosion of magnesia refractory was investigated. The reoxidation of the steel, indicated by an oxygen pickup, was progressed by increasing the ratio of RHA to the sum of RHA and carryover ladle slag ( R ratio) greater than about 0.2. The increase of the silica activity in the slag layer promoted the self-dissociation of SiO2 from the slag layer into the molten steel, resulting in the silicon and oxygen pickup as the R ratio increased. The total number of reoxidation inclusions dramatically increased and the relative fraction of Al2O3-rich inclusions increased by increasing the R ratio. Hence, the reoxidation of molten steel in tundish might become more serious due to the formation of alumina-rich inclusions as the casting sequence increases. MgO in the refractory directly dissolved into the molten slag layer without forming any intermediate compound layer ( e.g., spinel), which is a completely different situation from the general slag-refractory interfacial reaction. A flow was possibly induced by the bursting of gas bubbles at the ash-slag (-refractory) interface, since the silica in the RHA powder continuously dissolved into the molten slag pool. Thus, the RHA insulation powder has a negative effect on the corrosion of MgO refractory.
NASA Technical Reports Server (NTRS)
Lien, Mei-Ching; Proctor, Robert W.
2002-01-01
The purpose of this paper was to provide insight into the nature of response selection by reviewing the literature on stimulus-response compatibility (SRC) effects and the psychological refractory period (PRP) effect individually and jointly. The empirical findings and theoretical explanations of SRC effects that have been studied within a single-task context suggest that there are two response-selection routes-automatic activation and intentional translation. In contrast, all major PRP models reviewed in this paper have treated response selection as a single processing stage. In particular, the response-selection bottleneck (RSB) model assumes that the processing of Task 1 and Task 2 comprises two separate streams and that the PRP effect is due to a bottleneck located at response selection. Yet, considerable evidence from studies of SRC in the PRP paradigm shows that the processing of the two tasks is more interactive than is suggested by the RSB model and by most other models of the PRP effect. The major implication drawn from the studies of SRC effects in the PRP context is that response activation is a distinct process from final response selection. Response activation is based on both long-term and short-term task-defined S-R associations and occurs automatically and in parallel for the two tasks. The final response selection is an intentional act required even for highly compatible and practiced tasks and is restricted to processing one task at a time. Investigations of SRC effects and response-selection variables in dual-task contexts should be conducted more systematically because they provide significant insight into the nature of response-selection mechanisms.
Topcuoglu, Nursen; Kulekci, Guven
2015-10-01
DNA microarray analysis is a computer based technology, that a reverse capture, which targets 10 periodontal bacteria (ParoCheck) is available for rapid semi-quantitative determination. The aim of this three-year retrospective study was to display the microarray analysis results for the subgingival biofilm samples taken from patient cases diagnosed with different forms of periodontitis. A total of 84 patients with generalized aggressive periodontitis (GAP,n:29), generalized chronic periodontitis (GCP, n:25), peri-implantitis (PI,n:14), localized aggressive periodontitis (LAP,n:8) and refractory chronic periodontitis (RP,n:8) were consecutively selected from the archives of the Oral Microbiological Diagnostic Laboratory. The subgingival biofilm samples were analyzed by the microarray-based identification of 10 selected species. All the tested species were detected in the samples. The red complex bacteria were the most prevalent with very high levels in all groups. Fusobacterium nucleatum was detected in all samples at high levels. The green and blue complex bacteria were less prevalent compared with red and orange complex, except Aggregatibacter actinomycetemcomitas was detected in all LAP group. Positive correlations were found within all the red complex bacteria and between red and orange complex bacteria especially in GCP and GAP groups. Parocheck enables to monitoring of periodontal pathogens in all forms of periodontal disease and can be alternative to other guiding and reliable microbiologic tests. Copyright © 2015 Elsevier Ltd. All rights reserved.
Method for producing refractory nitrides
Quinby, Thomas C.
1989-01-24
A process for making fine, uniform metal nitride powders that can be hot pressed or sintered. A metal salt is placed in a solvent with Melamine and warmed until a metal-Melamine compound forms. The solution is cooled and the metal-Melamine precipitate is calcined at a temperature below 700.degree. C. to form the metal nitrides and to avoid formation of the metal oxide.
Method of forming impermeable carbide coats on graphite
Wohlberg, C.
1973-12-11
A method of forming an impermeable refractory metal carbide coating on graphite is described in which a metal containing oxidant and a carbide former are applied to the surface of the graphite, heated to a temperature of between 1200 and 1500 deg C in an inert gas, under a vacuum and continuing to heat to about 2300 deg C. (Official Gazette)
Molybdenum disilicide alloy matrix composite
Petrovic, John J.; Honnell, Richard E.; Gibbs, W. Scott
1990-01-01
Compositions of matter consisting of matrix matrials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.
Molybdenum disilicide alloy matrix composite
Petrovic, John J.; Honnell, Richard E.; Gibbs, W. Scott
1991-01-01
Compositions of matter consisting of matrix materials having silicon carbide dispersed throughout them and methods of making the compositions. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms.
Adult extracorporeal life support: a failed or forgotten concept?
Colafranceschi, Alexandre Siciliano; Monteiro, Andrey José de Oliveira; Canale, Leonardo Secchin; Campos, Luiz Antonio de Almeida; Montera, Marcelo Westerlund; Silva, Paulo Roberto Dutra da; Fernandes, Marcelo Ramalho; Pinto, Alexandre de Araújo; Molas, Stelmar Moura; Mesquita, Evandro Tinoco
2008-07-01
The extracorporeal membrane oxygenation (ECMO) has been used in the neonatal and childhood periods with excellent results. The adult experience has been modest with inferior immediate results. The intermediate survival, however, has been promising. We have been using the extracorporeal membrane oxygenation for temporary mechanical circulatory support of adults that present with acute refractory cardiogenic shock in our institution. There is no other published experience of the use of this system in this scenario in Brazil. To describe our experience with the use of the extracorporeal membrane oxygenation for circulatory support in adults. Retrospective analysis of the medical files of patients submitted to the implant of extracorporeal membrane oxygenation system for circulatory assistance in acute and refractory cardiogenic shock. Eleven patients (63,5 yo; 45,5% male) were considered for analysis from 2005 to 2007. Median support time was 77 hours (10-240 h) and 5 patients have survived 30 days (45,5%). Two patients were subsequently submitted to prolonged paracorporeal circulatory assistance. Mortality on ECMO (6 patients) was due to multiple organ failure (66,6%) and refractory bleeding (33,4%). ECMO system is an option to be used in acute refractory cardiogenic shock as a bridge to recovery or selecting patients that might benefit from prolonged paracorporeal assist devices (bridge to bridge).
Yagi, Minami; Tanaka, Atsushi; Namisaki, Tadashi; Takahashi, Atsushi; Abe, Masanori; Honda, Akira; Matsuzaki, Yasushi; Ohira, Hiromasa; Yoshiji, Hitoshi; Takikawa, Hajime
2018-04-16
Patients with primary biliary cholangitis (PBC) frequently suffer from pruritus, which can severely impair their health-related quality of life (HRQOL). Nalfurafine hydrochloride, a selective κ-opioid receptor agonist, was recently approved in Japan for refractory pruritus in patients with chronic liver diseases, but it still remains unclear whether this treatment improves the patient-reported outcome (PRO) in PBC patients with refractory pruritus. Herein, we conducted a multicenter, post-marketing, single-arm prospective study to investigate the efficacy of nalfurafine in terms of PRO, and the associations of the efficacy with any clinical characteristics. After screening for pruritus in 496 patients with PBC using PBC-40 and the visual analog scale (VAS), we identified 141 patients with moderate to severe pruritus; these were invited to participate in the study. The participants received 2.5 μg nalfurafine once daily for 12 weeks, and pruritus and HRQOL were assessed in week 12 of this treatment. Generic HRQOL, short form 36, blood chemistries, and serum autotaxin levels were also measured at baseline and at week 12. Forty-four patients participated in this study. The mean PBC-40 itch domain scores and VAS declined during the study period, from 8.56 to 7.63 (P = 0.041) and from 42.9 to 29.3 (P = 0.001) at baseline and at week 12, respectively, indicating a significant effect of nalfurafine. The other domains of PBC-40 and all domains of SF-36 were not significantly altered by this treatment. We failed to find any association between the change in VAS and PBC-40 itch scores and any clinical variable. Serum autotaxin levels were significantly increased during the study period. This study demonstrated that nalfurafine improved pruritus in patients with PBC, independent of their clinical characteristics, but had a limited effect on the PRO.
Little Chondrules and Giant Impacts
NASA Astrophysics Data System (ADS)
Taylor, G. J.
2005-10-01
Alexander (Sasha) Krot (University of Hawaii), Yuri Amelin (University of Toronto), Pat Cassen (SETI Institute), and Anders Meibom (Museum National d'Histoire Naturelle, Paris) studied and then extracted frozen droplets of molten silicate (chondrules) from unusual meteorites rich in metallic iron-nickel. Called CB (Bencubbin-like) chondrites, these rare but fascinating meteorites contain chondrules with different properties than those in other types of chondrites. Most notably, the chondrules contain very small concentrations of volatile elements and variable concentrations of refractory elements. (Volatile elements condense from a gas at a relatively low temperature, or are boiled out of solids or liquids at relatively low temperature. Refractory elements are the opposite.) Some of the metal grains in CB chondrites are chemically zoned, indicating that they formed by condensation in a vapor cloud. The most intriguing feature of chondrules in CB chondrites is their relatively young age. Lead-lead isotopic dating of chondrules separated from two CB chondrites show that they formed 5 million years after formation of the first solids in the solar system (calcium-aluminum-rich inclusions), which is about at least two million years after formation of other chondrules, and after energetic events in the solar nebula stopped. Krot and his colleagues suggest that the CB chondrules formed as the result of an impact between Moon- to Mars-sized protoplanets. Such impacts were so energetic that huge amounts of material were vaporized and then condensed as chondrules or chemically zoned metal grains. This event enriched refractory elements and depleted volatile elements. Such large impacts appear to play important roles in planet formation, including the formation of the Moon.
Soni, V; Senkov, O N; Gwalani, B; Miracle, D B; Banerjee, R
2018-06-11
Typically, refractory high-entropy alloys (RHEAs), comprising a two-phase ordered B2 + BCC microstructure, exhibit extraordinarily high yield strengths, but poor ductility at room temperature, limiting their engineering application. The poor ductility is attributed to the continuous matrix being the ordered B2 phase in these alloys. This paper presents a novel approach to microstructural engineering of RHEAs to form an "inverted" BCC + B2 microstructure with discrete B2 precipitates dispersed within a continuous BCC matrix, resulting in improved room temperature compressive ductility, while maintaining high yield strength at both room and elevated temperature.
Miniature modified Faraday cup for micro electron beams
Teruya, Alan T.; Elmer, John W.; Palmer, Todd A.; Walton, Chris C.
2008-05-27
A micro beam Faraday cup assembly includes a refractory metal layer with an odd number of thin, radially positioned traces in this refractory metal layer. Some of the radially positioned traces are located at the edge of the micro modified Faraday cup body and some of the radially positioned traces are located in the central portion of the micro modified Faraday cup body. Each set of traces is connected to a separate data acquisition channel to form multiple independent diagnostic networks. The data obtained from the two diagnostic networks are combined and inputted into a computed tomography algorithm to reconstruct the beam shape, size, and power density distribution.
Lu, Yan; Li, Gang; Liu, Wei; Yuan, Hongyan; Xiao, Dan
2018-08-15
It is known that most of the refractory ore are the basis of national economy and widely applied in various fields, however, the complexity of the chemical composition and the diversity of the crystallinity in the mineral phases make the sample pre-treatment of refractory ore still remains a challenge. In this work, the complete decomposition of the refractory ore sample can be achieved just by exposing the solid fusion agent and the refractory ore sample in the microwave irradiation environment for a few minutes, and induced by a drop of water. A digestion time of 15 min for 3.0 g solid fusion agent mixture of sodium peroxide/sodium carbonate (Na 2 O 2 /Na 2 CO 3 ) in a corundum crucible via microwave heating is sufficient to decompose 0.1 g refractory ore sample. An excellent microwave digestion solid agent should meet the following conditions, a good decomposition ability, an outstanding ability of absorbing microwave energy and converting it into heat quickly, a higher melting point than the decomposing temperature of the ore sample. In the research, the induction effect of water plays an important role for the microwave digestion. The energy which is released by the reaction of water and the solid fusion agent (Na 2 O 2 ) is the key to decompose refractory ore samples with solid fusion agent, which replenished the total energy required for the microwave digestion and made the microwave digestion completed successfully. This microwave digestion technique has good reproducibility and precision, RSD % for Mo, Fe, Ti, Cr and W in the refractory ore samples were all better than 6, except RSD % for Be of about 8 because of the influence of matrix-effect. Meanwhile, the analysis results of the elements in the refractory ore samples provided by the microwave digestion technique were all in good agreement with the analysis results provided by the traditional fusion method except for Cr in the mixture ore samples. In the study, the non-linear dependence of the electromagnetic and thermal properties of the solid fusion agent on temperature under microwave irradiation and the selective heating of microwave are fully applied in this simple microwave technique. Comparing to the traditional fusion decomposition method, this microwave digestion technique is a simple, economical, fast and energy-saving sample pre-treatment technique. Copyright © 2018 Elsevier B.V. All rights reserved.
Fixture for forming evaporative pattern (EPC) process patterns
Turner, Paul C.; Jordan, Ronald R.; Hansen, Jeffrey S.
1993-01-01
A method of casting metal using evaporative pattern casting process patterns in combination with a fixture for creating and maintaining a desired configuration in flexible patterns. A pattern is constructed and gently bent to the curvature of a suitable fixture. String or thin wire, which burns off during casting, is used to tie the pattern to the fixture. The fixture with pattern is dipped in a commercially available refractory wash to prevent metal adherence and sticking to the fixture. When the refractory wash is dry, the fixture and pattern are placed in a flask, and sand is added and compacted by vibration. The pattern remains in position, restrained by the fixture. Metal that is poured directly into the pattern replaces the pattern exactly but does not contact or weld to the fixture due to the protective refractory layer. When solid, the casting is easily separated from the fixture. The fixture can be cleaned for reuse in conventional casting cleaning equipment.
Management of refractory pityriasis rubra pilaris: challenges and solutions
Moretta, Gaia; De Luca, Erika V; Di Stefani, Alessandro
2017-01-01
Pityriasis rubra pilaris (PRP) is a rare chronic inflammatory papulosquamous skin disease. Its clinical presentation and evolution is very variable. The most frequent clinical features are follicular papules, progressing to yellow-orange erythroderma with round small areas of normal skin and the well-demarcated palmoplantar keratoderma. Actually, six different types of PRP have been described based on clinical characteristics, age of onset, and prognosis. The pathogenesis is still unknown, and treatment can be challenging. Available treatments are mainly based on case reports or case series of clinical experience because no controlled randomized trials have never been performed because of the rarity of the condition. Traditional systemic treatment consists in retinoids, which are actually considered as first-line therapy, but refractory cases that do not respond or relapse after drug interruption do exist. In recent years, numerous reports have demonstrated the efficacy of new agents such as biological drugs. This article is an overview on available therapeutic options, in particular for refractory forms of PRP. PMID:29184428
DOE Office of Scientific and Technical Information (OSTI.GOV)
McGowan, Kenneth A; Cullen, Robert M; Keiser, James R
A method for improving the insulating character/and or penetration resistance of a liner in contact with at least one of an alkali and/or alkaline environments is provided. The method comprises lining a surface that is subject to wear by an alkali environment and/or an alkaline environment with a refractory composition comprising a refractory aggregate consisting essentially of a calcium hexa aluminate clinker having the formula CA.sub.6, wherein C is equal to calcium oxide, wherein A is equal to aluminum oxide, and wherein the hexa aluminate clinker has from zero to less than about fifty weight percent C.sub.12A.sub.7, and wherein greatermore » than 98 weight percent of the calcium hexa aluminate clinker having a particle size ranging from -20 microns to +3 millimeters, for forming a liner of the surface. This method improves the insulating character/and or penetration resistance of the liner.« less
Basic refractory and slag management for petcoke carbon feedstock in gasifiers
Kwong, Kyei-Sing; Bennett, James P; Nakano, Jinichiro
2014-04-22
The disclosure provides methods of operating a slagging gasifier using a carbon feedstock having a relatively high V.sub.2O.sub.5 to SiO.sub.2 ratio, such as petcoke. The disclosure generates a combined chemical composition in the feed mixture having less than 25 wt. % SiO.sub.2, greater than 20 wt. % V.sub.2O.sub.5, and greater than 20 wt. % CaO. The method takes advantage of a novel recognition that increased levels of SiO.sub.2 tend to decrease dissolution of the V.sub.2O.sub.3 which forms under the reducing conditions of the gasifier, and utilizes the CaO additive to establish a chemical phase equilibria comprised of lower melting compounds. The method further provides for control based on the presence of Al.sub.2O.sub.3 and FeO, and provides for a total combined chemical composition of greater than about 5 wt. % MgO for use with refractory linings comprised of MgO based refractory brick.
Chen, Yamei; Liu, Delong
2014-01-01
As a result of the recent advances in molecular immunology, virology, genetics, and cell processing, chimeric antigen receptor (CAR)-directed cancer therapy has finally arrived for clinical application. CAR-directed adoptive immunotherapy represents a novel form of gene therapy, cellular therapy, and immunotherapy, a combination of three in one. Early phase clinical trial was reported in patients with refractory chronic lymphoid leukemia with 17p deletion. Accompanying the cytokine storm and tumor lysis syndrome was the shocking disappearance of the leukemia cells refractory to chemotherapy and monoclonal antibodies. CAR therapy was reproduced in both children and adults with refractory acute lymphoid leukemia. The CAR technology is being explored for solid tumor therapy, such as glioma. Close to 30 clinical trials are underway in the related fields (www.clinicaltrials.gov). Further improvement in gene targeting, cell expansion, delivery constructs (such as using Sleeping Beauty or Piggyback transposons) will undoubtedly enhance clinical utility. It is foreseeable that CAR-engineered T cell therapy will bring targeted cancer therapy into a new era.
Gagnon, Maude-Marie; Savard, Martin; Mourabit Amari, Karim
2016-04-01
Autoimmune encephalitis is an inflammatory disorder of the brain that may be associated with different neuronal antibodies. Recently, an increasing number of valuable autoantibodies have been identified, including GABAAR antibodies, which appear to be associated with a severe form of encephalitis with refractory status epilepticus. We report here on a patient with encephalitis associated with GAD65 and GABAAR antibodies, an entity that remains an understudied topic, with an unanticipated clinical presentation and we describe the longitudinal follow-up. We report a case of encephalitis associated with GAD65 and GABAAR antibodies; we describe clinical and paraclinical features and the longitudinal follow-up. Our case presented with dysgueusia, dysosmia and episodes of hyperventilation that evolved into a refractory status epilepticus. Multiple anticonvulsant drugs were required. An aggressive immunotherapy was associated with a relative favorable outcome, in regard of epilepsy and cognitive functions. However, a relapse occurred and a full recovery was not observed at the last follow-up visit. There was no correlation between GAD65 antibodies titers and disease activity. Autoimmune encephalitis associated with GABAAR and GAD65 antibodies might be a severe and refractory disease. The appropriate treatment is currently unknown for those patients. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.
Walter, Harriet S; Rule, Simon A; Dyer, Martin J S; Karlin, Lionel; Jones, Ceri; Cazin, Bruno; Quittet, Philippe; Shah, Nimish; Hutchinson, Claire V; Honda, Hideyuki; Duffy, Kevin; Birkett, Joseph; Jamieson, Virginia; Courtenay-Luck, Nigel; Yoshizawa, Toshio; Sharpe, John; Ohno, Tomoya; Abe, Shinichiro; Nishimura, Akihisa; Cartron, Guillaume; Morschhauser, Franck; Fegan, Christopher; Salles, Gilles
2016-01-28
We report the results of a multicenter phase 1 dose-escalation study of the selective Bruton tyrosine kinase (BTK) inhibitor ONO/GS-4059 in 90 patients with relapsed/refractory B-cell malignancies. There were 9 dose-escalation cohorts ranging from 20 mg to 600 mg once daily with twice-daily regimens of 240 mg and 300 mg. Twenty-four of 25 evaluable chronic lymphocytic leukemia (CLL) patients (96%) responded to ONO/GS-4059, with a median treatment duration of 80 weeks; 21 CLL patients remain on treatment. Lymph node responses were rapid and associated with a concurrent lymphocytosis. Eleven of 12 evaluable patients with mantle cell lymphoma (92%) responded (median treatment duration, 40 weeks). Eleven of 31 non-germinal center B-cell diffuse large B-cell lymphoma patients (35%) responded but median treatment duration was 12 weeks due to development of progressive disease. ONO/GS-4059 was very well tolerated with 75% of adverse events (AEs) being Common Toxicity Criteria for Adverse Events version 4.0 grade 1 or grade 2. Grade 3/4 AEs were mainly hematologic and recovered spontaneously during therapy. One CLL patient experienced a grade 3 treatment-related bleeding event (spontaneous muscle hematoma) but no clinically significant diarrhea, cardiac dysrhythmias, or arthralgia were observed. No maximal tolerated dose (MTD) was reached in the CLL cohort. In the non-Hodgkin lymphoma cohort, 4 patients developed a dose-limiting toxicity, yielding an MTD of 480 mg once daily. ONO/GS-4059 has significant activity in relapsed/refractory B-cell malignancies without major drug-related toxicity. The selectivity of ONO/GS-4059 should confer advantages in combination therapies. This trial was registered at www.clinicaltrials.gov as #NCT01659255. © 2016 by The American Society of Hematology.
Salbu, Brit; Lind, Ole Christian
2016-10-01
After severe nuclear events, a major fraction of refractory radionuclides such as U and Pu are released to the environment in the form of radioactive particles. After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, Pu isotope ratio signals different from that of global fallout have been reported, indicating that spent fuel particles have been released from the reactors or reactor vessels. Radioactive particles containing (37) Cs and other volatile radionuclides, as well as a series of stable refractory metals (Cs, Fe, Zn, U, etc.), have been identified by several authors claiming that these particles originated from the FDNPP fuel. If so, long-lived radioactive isotopes of the refractory metals should have been identified in these particles. It is therefore most probable that volatile radionuclides released as gases during the accidents have deposited on available surfaces such as fly ash, forming condensation particles during release or transport. If spent fuel particles have been deposited in the FDNPP surroundings, information on particle characteristics influencing ecosystem transport, uptake, and effects is essential for assessing environmental impact and risk. More emphasis should therefore be put on the identification of hot spots in the FDNPP environment followed by the characterization of radioactive particles using nanoanalytical-microanalytical techniques to support environmental monitoring, as recommended in the present study. Integr Environ Assess Manag 2016;12:687-689. © 2016 SETAC. © 2016 SETAC.
What we talk about when we talk about access deficits
Mirman, Daniel; Britt, Allison E.
2014-01-01
Semantic impairments have been divided into storage deficits, in which the semantic representations themselves are damaged, and access deficits, in which the representations are intact but access to them is impaired. The behavioural phenomena that have been associated with access deficits include sensitivity to cueing, sensitivity to presentation rate, performance inconsistency, negative serial position effects, sensitivity to number and strength of competitors, semantic blocking effects, disordered selection between strong and weak competitors, correlation between semantic deficits and executive function deficits and reduced word frequency effects. Four general accounts have been proposed for different subsets of these phenomena: abnormal refractoriness, too much activation, impaired competitive selection and deficits of semantic control. A combination of abnormal refractoriness and impaired competitive selection can account for most of the behavioural phenomena, but there remain several open questions. In particular, it remains unclear whether access deficits represent a single syndrome, a syndrome with multiple subtypes or a variable collection of phenomena, whether the underlying deficit is domain-general or domain-specific, whether it is owing to disorders of inhibition, activation or selection, and the nature of the connection (if any) between access phenomena in aphasia and in neurologically intact controls. Computational models offer a promising approach to answering these questions. PMID:24324232
2018-04-23
Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Acute Biphenotypic Leukemia; Acute Leukemia of Ambiguous Lineage; Acute Undifferentiated Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Myelodysplastic Syndrome With Excess Blasts-1; Myelodysplastic Syndrome With Excess Blasts-2; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; Refractory Childhood Acute Lymphoblastic Leukemia
Gordillo, Gayle M; Sen, Chandan K
2009-06-01
Topical oxygen therapy provides another tool in the armamentarium of clinicians treating refractory lower extremity wounds. Devices suitable for providing topical oxygen therapy in a clinical setting have recently become available. This article reviews the evidence to justify the use of this treatment modality, including in vitro, preclinical data, and clinical data. It also provides a protocol for how to administer topical oxygen therapy as well as guidance on patient selection and management to optimize outcomes. Randomized controlled trials are not yet reported and clearly necessary. The current body of evidence suggests that topical oxygen therapy may be considered as a second line of therapy for refractory wounds.
Molybdenum disilicide alloy matrix composite
Petrovic, J.J.; Honnell, R.E.; Gibbs, W.S.
1991-12-03
Compositions of matter consisting of matrix materials having silicon carbide dispersed throughout them and methods of making the compositions are disclosed. A matrix material is an alloy of an intermetallic compound, molybdenum disilicide, and at least one secondary component which is a refractory silicide. The silicon carbide dispersant may be in the form of VLS whiskers, VS whiskers, or submicron powder or a mixture of these forms. 3 figures.
Anthropometric Indices in Children With Refractory Epilepsy.
Aminzadeh, Vahid; Dalili, Setila; Ashoorian, Yalda; Kohmanaee, Shahin; Hassanzadeh Rad, Afagh
2016-01-01
We aimed to assess the effect of body mass index (BMI) on reducing the risk of refractory seizure due to lipoid tissue factors. This matched case-control study, consisted of cases (Patients with refractory epilepsy) and controls (Healthy children) referred to 17 Shahrivar Hospital, Guilan University of Medical Sciences, Guilan, Iran during 2013-2014. Data were gathered by a form including demographic characteristics, type of epilepsy, predominant time of epilepsy, therapeutic approach, frequency of epilepsy, time of disease onset and anthropometric indices. We measured anthropometric indices and transformed them into Z-scores. Data were reported by descriptive statistics (mean and standard deviation) and analyzed by Pearson correlation coefficient, paired t test and multinomial regression analysis test using SPSS 19. There was no significant difference between sex groups regarding anthropometric indices. Generalized and focal types of epilepsies were noted on 57.5% and 38.75% of patients, respectively. Daytime epilepsies happened in 46.25% of patients and 33.75% noted no predominant time for epilepsies. Clinicians indicated poly-therapy for the majority of patients (92.5%). The most common onset times for epilepsies were 36-72 months for 32.5% of patients. Lower onset time indicated lower frequency of refractory epilepsies. Although, there was significant difference between Zheight and predominant time of epilepsies but no significant relation was found between types of epilepsies and frequency of epilepsies with anthropometric indices. Using multivariate regression analysis by backward LR, Zweight and birth weight were noted as the predicting factors of refractory epilepsies. This effect may be because of leptin. Therefore, researchers recommend further investigations regarding this issue in children with epilepsy.
NASA Astrophysics Data System (ADS)
Dyachenko, P. N.; Molesky, S.; Petrov, A. Yu; Störmer, M.; Krekeler, T.; Lang, S.; Ritter, M.; Jacob, Z.; Eich, M.
2016-06-01
Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C.
Portal hypertension and gastrointestinal bleeding: Diagnosis, prevention and management
Biecker, Erwin
2013-01-01
Bleeding from esophageal varices is a life threatening complication of portal hypertension. Primary prevention of bleeding in patients at risk for a first bleeding episode is therefore a major goal. Medical prophylaxis consists of non-selective beta-blockers like propranolol or carvedilol. Variceal endoscopic band ligation is equally effective but procedure related morbidity is a drawback of the method. Therapy of acute bleeding is based on three strategies: vasopressor drugs like terlipressin, antibiotics and endoscopic therapy. In refractory bleeding, self-expandable stents offer an option for bridging to definite treatments like transjugular intrahepatic portosystemic shunt (TIPS). Treatment of bleeding from gastric varices depends on vasopressor drugs and on injection of varices with cyanoacrylate. Strategies for primary or secondary prevention are based on non-selective beta-blockers but data from large clinical trials is lacking. Therapy of refractory bleeding relies on shunt-procedures like TIPS. Bleeding from ectopic varices, portal hypertensive gastropathy and gastric antral vascular ectasia-syndrome is less common. Possible medical and endoscopic treatment options are discussed. PMID:23964137
Dyachenko, P. N.; Molesky, S.; Petrov, A. Yu; Störmer, M.; Krekeler, T.; Lang, S.; Ritter, M.; Jacob, Z.; Eich, M.
2016-01-01
Control of thermal radiation at high temperatures is vital for waste heat recovery and for high-efficiency thermophotovoltaic (TPV) conversion. Previously, structural resonances utilizing gratings, thin film resonances, metasurfaces and photonic crystals were used to spectrally control thermal emission, often requiring lithographic structuring of the surface and causing significant angle dependence. In contrast, here, we demonstrate a refractory W-HfO2 metamaterial, which controls thermal emission through an engineered dielectric response function. The epsilon-near-zero frequency of a metamaterial and the connected optical topological transition (OTT) are adjusted to selectively enhance and suppress the thermal emission in the near-infrared spectrum, crucial for improved TPV efficiency. The near-omnidirectional and spectrally selective emitter is obtained as the emission changes due to material properties and not due to resonances or interference effects, marking a paradigm shift in thermal engineering approaches. We experimentally demonstrate the OTT in a thermally stable metamaterial at high temperatures of 1,000 °C. PMID:27263653
BC measurement activities at the U.S. Environmental Protection Agency
Black carbon (BC)--sometimes referred to as soot, char, or elemental carbon (EC)--is a refractory form of light-absorbing carbon produced from incomplete combustion. Accurate measurement of BC in combustion source emissions is important for understanding anthropogenic climate for...
High-quantum efficiency, long-lived luminescing refractory oxides
Chen, Y.; Gonzalez, R.; Summers, G.P.
A crystal having a high-quantum efficiency and a long period of luminescence is formed of MgO or CaO and possessing a concentration ratio of H/sup -/ ions to F centers in the range of about 0.05 to about 10.
Cost Estimate for Molybdenum and Tantalum Refractory Metal Alloy Flow Circuit Concepts
NASA Technical Reports Server (NTRS)
Hickman, Robert R.; Martin, James J.; Schmidt, George R.; Godfroy, Thomas J.; Bryhan, A.J.
2010-01-01
The Early Flight Fission-Test Facilities (EFF-TF) team at NASA Marshall Space Flight Center (MSFC) has been tasked by the Naval Reactors Prime Contract Team (NRPCT) to provide a cost and delivery rough order of magnitude estimate for a refractory metal-based lithium (Li) flow circuit. The design is based on the stainless steel Li flow circuit that is currently being assembled for an NRPCT task underway at the EFF-TF. While geometrically the flow circuit is not representative of a final flight prototype, knowledge has been gained to quantify (time and cost) the materials, manufacturing, fabrication, assembly, and operations to produce a testable configuration. This Technical Memorandum (TM) also identifies the following key issues that need to be addressed by the fabrication process: Alloy selection and forming, cost and availability, welding, bending, machining, assembly, and instrumentation. Several candidate materials were identified by NRPCT including molybdenum (Mo) alloy (Mo-47.5 %Re), tantalum (Ta) alloys (T-111, ASTAR-811C), and niobium (Nb) alloy (Nb-1 %Zr). This TM is focused only on the Mo and Ta alloys, since they are of higher concern to the ongoing effort. The initial estimate to complete a Mo-47%Re system ready for testing is =$9,000k over a period of 30 mo. The initial estimate to complete a T-111 or ASTAR-811C system ready for testing is =$12,000k over a period of 36 mo.
Carotenoids are the likely precursor of a significant fraction of marine dissolved organic matter
Arakawa, Neal; Aluwihare, Lihini I.; Simpson, Andre J.; Soong, Ronald; Stephens, Brandon M.; Lane-Coplen, Daniel
2017-01-01
The ocean’s biota sequester atmospheric carbon dioxide (CO2) in part by producing dissolved organic matter (DOM) that persists in the ocean for millennia. This long-term accumulation of carbon may be facilitated by abiotic and biotic production of chemical structures that resist degradation, consequently contributing disproportionately to refractory DOM. Compounds that are selectively preserved in seawater were identified in solid-phase extracted DOM (PPL-DOM) using comprehensive gas chromatography (GC) coupled to mass spectrometry (MS). These molecules contained cyclic head groups that were linked to isoprenoid tails, and their overall structures closely resembled carotenoid degradation products (CDP). The origin of these compounds in PPL-DOM was further confirmed with an in vitro β-carotene photooxidation experiment that generated water-soluble CDP with similar structural characteristics. The molecular-level identification linked at least 10% of PPL-DOM carbon, and thus 4% of total DOM carbon, to CDP. Nuclear magnetic resonance spectra of experimental CDP and environmental PPL-DOM overlapped considerably, which indicated that even a greater proportion of PPL-DOM was likely composed of CDP. The CDP-rich DOM fraction was depleted in radiocarbon (14C age > 1500 years), a finding that supports the possible long-term accumulation of CDP in seawater. By linking a specific class of widespread biochemicals to refractory DOM, this work provides a foundation for future studies that aim to examine how persistent DOM forms in the ocean. PMID:28959723
Mun, Eluned; Umbarger, Lillian; Ceria-Ulep, Clementina; Nakatsuka, Craig
2018-01-01
Palliative Care Teams have been shown to be instrumental in the early identification of multiple aspects of advanced care planning. Despite an increased number of services to meet the rising consultation demand, it is conceivable that the numbers of palliative care consultations generated from an ICU alone could become overwhelming for an existing palliative care team. Improve end-of-life care in the ICU by incorporating basic palliative care processes into the daily routine ICU workflow, thereby reserving the palliative care team for refractory situations. A structured, palliative care, quality-improvement program was implemented and evaluated in the ICU at Kaiser Permanente Medical Center in Hawaii. This included selecting trigger criteria, a care model, forming guidelines, and developing evaluation criteria. These included the early identification of the multiple features of advanced care planning, numbers of proactive ICU and palliative care family meetings, and changes in code status and treatment upon completion of either meeting. Early identification of Goals-of-Care, advance directives, and code status by the ICU staff led to a proactive ICU family meeting with resultant increases in changes in code status and treatment. The numbers of palliative care consultations also rose, but not significantly. Palliative care processes could be incorporated into a daily ICU workflow allowing for integration of aspects of advanced care planning to be identified in a systematic and proactive manner. This reserved the palliative care team for situations when palliative care efforts performed by the ICU staff were ineffective.
2018-03-20
B-Cell Prolymphocytic Leukemia; Recurrent Chronic Lymphocytic Leukemia; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Lymphoplasmacytic Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Marginal Zone Lymphoma; Refractory Non-Hodgkin Lymphoma; Refractory Small Lymphocytic Lymphoma; Richter Syndrome
Duncan, David B.
1992-01-01
An improved wick for a metal vapor laser is made of a refractory metal cylinder, preferably molybdenum or tungsten for a copper laser, which provides the wicking surface. Alternately, the inside surface of the ceramic laser tube can be metalized to form the wicking surface. Capillary action is enhanced by using wire screen, porous foam metal, or grooved surfaces. Graphite or carbon, in the form of chunks, strips, fibers or particles, is placed on the inside surface of the wick to reduce water, reduce metal oxides and form metal carbides.
Deep brain stimulation and treatment-resistant obsessive-compulsive disorder: A systematic review.
Vázquez-Bourgon, Javier; Martino, Juan; Sierra Peña, María; Infante Ceberio, Jon; Martínez Martínez, M Ángeles; Ocón, Roberto; Menchón, José Manuel; Crespo Facorro, Benedicto; Vázquez-Barquero, Alfonso
2017-07-01
At least 10% of patients with Obsessive-compulsive Disorder (OCD) are refractory to psychopharmacological treatment. The emergence of new technologies for the modulation of altered neuronal activity in Neurosurgery, deep brain stimulation (DBS), has enabled its use in severe and refractory OCD cases. The objective of this article is to review the current scientific evidence on the effectiveness and applicability of this technique to refractory OCD. We systematically reviewed the literature to identify the main characteristics of deep brain stimulation, its use and applicability as treatment for obsessive-compulsive disorder. Therefore, we reviewed PubMed/Medline, Embase and PsycINFO databases, combining the key-words 'Deep brain stimulation', 'DBS' and 'Obsessive-compulsive disorder' 'OCS'. The articles were selected by two of the authors independently, based on the abstracts, and if they described any of the main characteristics of the therapy referring to OCD: applicability; mechanism of action; brain therapeutic targets; efficacy; side-effects; co-therapies. All the information was subsequently extracted and analysed. The critical analysis of the evidence shows that the use of DBS in treatment-resistant OCD is providing satisfactory results regarding efficacy, with assumable side-effects. However, there is insufficient evidence to support the use of any single brain target over another. Patient selection has to be done following analyses of risks/benefits, being advisable to individualize the decision of continuing with concomitant psychopharmacological and psychological treatments. The use of DBS is still considered to be in the field of research, although it is increasingly used in refractory-OCD, producing in the majority of studies significant improvements in symptomatology, and in functionality and quality of life. It is essential to implement random and controlled studies regarding its long-term efficacy, cost-risk analyses and cost/benefit. Copyright © 2017 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.
NASA Astrophysics Data System (ADS)
Chen, Y. W.; Li, Y. K.; Cheng, X. W.; Wu, C.; Cheng, B.
2018-05-01
Refractory high entropy alloys (RHEAs), with excellent properties at high temperature, have several applications. In this work, the ZrTiHfNbMox (x=0.5, 1.0, 1.5) alloys were prepared by arc melting. All these alloys form body centered cubic (BCC) structure without other intermediate phases. The Mo element contributes to the strength of alloys at high temperature, but too much of Mo decreases the plasticity severely and enhances the strength. The ZrTiHfNbMo alloy, whose compressive stress is 1099 MPa at 800° C, is a promising material for high-temperature applications.
Isotopic compositions of cometary matter returned by Stardust.
McKeegan, Kevin D; Aléon, Jerome; Bradley, John; Brownlee, Donald; Busemann, Henner; Butterworth, Anna; Chaussidon, Marc; Fallon, Stewart; Floss, Christine; Gilmour, Jamie; Gounelle, Matthieu; Graham, Giles; Guan, Yunbin; Heck, Philipp R; Hoppe, Peter; Hutcheon, Ian D; Huth, Joachim; Ishii, Hope; Ito, Motoo; Jacobsen, Stein B; Kearsley, Anton; Leshin, Laurie A; Liu, Ming-Chang; Lyon, Ian; Marhas, Kuljeet; Marty, Bernard; Matrajt, Graciela; Meibom, Anders; Messenger, Scott; Mostefaoui, Smail; Mukhopadhyay, Sujoy; Nakamura-Messenger, Keiko; Nittler, Larry; Palma, Russ; Pepin, Robert O; Papanastassiou, Dimitri A; Robert, François; Schlutter, Dennis; Snead, Christopher J; Stadermann, Frank J; Stroud, Rhonda; Tsou, Peter; Westphal, Andrew; Young, Edward D; Ziegler, Karen; Zimmermann, Laurent; Zinner, Ernst
2006-12-15
Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild 2 particle fragments; however, extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Nonterrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single (17)O-enriched circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is (16)O-enriched, like refractory inclusions in meteorites, suggesting that Wild 2 contains material formed at high temperature in the inner solar system and transported to the Kuiper belt before comet accretion.
Abemaciclib in Children With DIPG or Recurrent/Refractory Solid Tumors
2017-07-14
Diffuse Intrinsic Pontine Glioma; Brain Tumor, Recurrent; Solid Tumor, Recurrent; Neuroblastoma, Recurrent, Refractory; Ewing Sarcoma, Recurrent, Refractory; Rhabdomyosarcoma, Recurrent, Refractory; Osteosarcoma, Recurrent, Refractory; Rhabdoid Tumor, Recurrent, Refractory
Ntsambi-Eba, G; Beltchika Kalubye, A; Kalala Okito, J P
2017-11-01
Surgery is a treatment to consider in epilepsy when the condition is refractory or epileptic events are related to a clearly identified brain abnormality. The tropical climate of the DRC explains the high risk of epilepsy and the potentially large number of refractory cases. The number of patients with epilepsy in Kinshasa is estimated to be at least 120 000, and almost one third may be refractory. Hence, the need to integrate the use of surgery in the treatment of this disease. Most neurosurgical techniques used for treating epilepsy are practiced with a neurosurgical microscope and neuronavigation. In most developing countries, neither the material conditions for optimum realization of these surgical techniques nor the equipment for epilepsy investigation are close to fully available. Nonetheless, the selection of a large number of patients for surgery often does not require the use of all these explorations.The current availability in Kinshasa of the equipment for the basic investigation of epilepsy, such as EEG and MRI instruments, and the experience of the local neurological/neurosurgical team together make it possible to diagnose this pathology and treat it surgically when necessary. The creation of a multidisciplinary team for epilepsy will enable the selection of candidates who can most effectively benefit from surgical treatment. This surgery should focus initially on well circumscribed lesions that do not require sophisticated methods of investigation and can be removed relatively easily, with a high probability of seizure suppression.
Reoperation for refractory epilepsy in childhood: a second chance for selected patients.
Ramantani, Georgia; Strobl, Karl; Stathi, Angeliki; Brandt, Armin; Schubert-Bast, Susanne; Wiegand, Gert; Korinthenberg, Rudolf; Stephani, Ulrich; van Velthoven, Vera; Zentner, Josef; Schulze-Bonhage, Andreas; Bast, Thomas
2013-10-01
Reoperations account for >10% in pediatric epilepsy surgery cohorts, and they are especially relevant in young children with catastrophic epilepsy. To determine surgical outcomes and their predictive factors in reoperations for refractory epilepsy in childhood. We retrospectively analyzed presurgical findings, resections, and outcomes of 23 consecutive children who underwent reoperations from 2000 to 2011. Etiology included cortical dysplasia with/without glioneuronal tumor in 19 patients (83%), sole glioneuronal tumor in 2, and tuberous sclerosis and Rasmussen encephalitis in 1 each. The reasons for the failure of the initial surgery were functional considerations in 8 (35%), incorrect delineation of the epileptogenic zone in 8 (35%), and resection not performed as initially planned in 7 (30%) cases. Final procedures included 8 (35%) intralobar, 8 (35%) multilobar resections, and 7 (30%) hemispherotomies. Following reoperations, 14 (61%) patients were seizure free, 6 (26%) showed significant or worthwhile improvement, and 3 (13%) did not respond to surgery. Six of 8 patients who underwent the first resection before the age of 3 years, 6 of 8 whose first resection was limited by functional considerations, and all 7 with hemispherotomy as the final resection achieved seizure freedom after reoperation. Reoperation is particularly beneficial for selected children with refractory epilepsy associated with cortical dysplasia that did not respond to an initial limited and/or early resection but achieved seizure freedom after extensive procedures. When indicated, reoperation should be performed at the youngest possible age to profit from higher functional plasticity in compensating for neurological deficit.
Miwa, Yosuke; Ikeda, Takanori; Mera, Hisaaki; Miyakoshi, Mutsumi; Hoshida, Kyoko; Yanagisawa, Ryoji; Ishiguro, Haruhisa; Tsukada, Takehiro; Abe, Atsuko; Yusu, Satoru; Yoshino, Hideaki
2010-05-01
Occasionally it is difficult to inhibit electrical storm (ES) with standard pharmacological treatment. In the present study the effect of landiolol, an ultra-short-acting beta(1)-selective blocker, on ES refractory to class III antiarrhythmic drugs was evaluated. The study group comprised 42 consecutive patients who developed ES for which intravenous class III antiarrhythmic drugs, such as amiodarone and nifekalant, were ineffective. Landiolol was administered intravenously with an initial dose of 2.5 microg x kg(-1) x min(-1), which was doubled if it was ineffective, up to a maximum dose of 80 microg x kg(-1) x min(-1). Landiolol inhibited ES in 33 patients (79%) at a mean dose of 7.5+/-12.2 microg x kg(-1) x min(-1). All patients in whom landiolol was ineffective died of arrhythmia. Of the 33 patients in whom landiolol was effective, 25 survived and were discharged (60% of all patients). Landiolol significantly decreased heart rate (P<0.0001), but did not affect blood pressure. Landiolol was not discontinued for adverse effects in any of the responders. Age, APACHE II score, and pH of arterial blood gas differed significantly between the responders and nonresponders. Landiolol is useful as a life-saving drug for class III antiarrhythmic drug-resistant ES. The main mechanism of ES refractory to class III antiarrhythmic drugs could be abnormal automaticity but not reentry.
Thermophotovoltaic energy conversion using photonic bandgap selective emitters
Gee, James M.; Lin, Shawn-Yu; Fleming, James G.; Moreno, James B.
2003-06-24
A method for thermophotovoltaic generation of electricity comprises heating a metallic photonic crystal to provide selective emission of radiation that is matched to the peak spectral response of a photovoltaic cell that converts the radiation to electricity. The use of a refractory metal, such as tungsten, for the photonic crystal enables high temperature operation for high radiant flux and high dielectric contrast for a full 3D photonic bandgap, preferable for efficient thermophotovoltaic energy conversion.
Petrology and mineralogy of the Ningqiang carbonaceous chondrite
NASA Astrophysics Data System (ADS)
Wang, Y.; Hsu, W.
2009-07-01
We report detailed chemical, petrological, and mineralogical studies on the Ningqiang carbonaceous chondrite. Ningqiang is a unique ungrouped type 3 carbonaceous chondrite. Its bulk composition is similar to that of CV and CK chondrites, but refractory lithophile elements (1.01 × CI) are distinctly depleted relative to CV (1.29 × CI) and CK (1.20 × CI) chondrites. Ningqiang consists of 47.5 vol% chondrules, 2.0 vol% Ca,Al-rich inclusions (CAIs), 4.5 vol% amoeboid olivine aggregates (AOAs), and 46.0 vol% matrix. Most chondrules (95%) in Ningqiang are Mgrich. The abundances of Fe-rich and Al-rich chondrules are very low. Al-rich chondrules (ARCs) in Ningqiang are composed mainly of olivine, plagioclase, spinel, and pyroxenes. In ARCs, spinel and plagioclase are enriched in moderately volatile elements (Cr, Mn, and Na), and low-Ca pyroxenes are enriched in refractory elements (Al and Ti). The petrology and mineralogy of ARCs in Ningqiang indicate that they were formed from hybrid precursors of ferromagnesian chondrules mixed with refractory materials during chondrule formation processes. We found 294 CAIs (55.0% type A, 39.5% spinel-pyroxene-rich, 4.4% hibonite-rich, and several type C and anorthite-spinelrich inclusions) and 73 AOAs in 15 Ningqiang sections (equivalent to 20 cm2 surface area). This is the first report of hibonite-rich inclusions in Ningqiang. They are texturally similar to those in CM, CH, and CB chondrites, and exhibit three textural forms: aggregates of euhedral hibonite single crystals, fine-grained aggregates of subhedral hibonite with minor spinel, and hibonite ± Al,Ti-diopside ± spinel spherules. Evidence of secondary alteration is ubiquitous in Ningqiang. Opaque assemblages, formed by secondary alteration of pre-existing alloys on the parent body, are widespread in chondrules and matrix. On the other hand, nepheline and sodalite, existing in all chondritic components, formed by alkali-halogen metasomatism in the solar nebula.
Method for Forming Fiber Reinforced Composite Bodies with Graded Composition and Stress Zones
NASA Technical Reports Server (NTRS)
Singh, Mrityunjay (Inventor); Levine, Stanley R. (Inventor); Smialek, James A. (Inventor)
1999-01-01
A near-net, complex shaped ceramic fiber reinforced silicon carbide based composite bodies with graded compositions and stress zones is disclosed. To provide the composite a fiber preform is first fabricated and an interphase is applied by chemical vapor infiltration, sol-gel or polymer processes. This first body is further infiltrated with a polymer mixture containing carbon, and/or silicon carbide, and additional oxide, carbide, or nitride phases forming a second body. One side of the second body is spray coated or infiltrated with slurries containing high thermal expansion and oxidation resistant. crack sealant phases and the other side of this second body is coated with low expansion phase materials to form a third body. This third body consisting of porous carbonaceous matrix surrounding the previously applied interphase materials, is then infiltrated with molten silicon or molten silicon-refractory metal alloys to form a fourth body. The resulting fourth body comprises dense composites consisting of fibers with the desired interphase which are surrounded by silicon carbide and other second phases materials at the outer and inner surfaces comprising material of silicon, germanium, refractory metal suicides, borides, carbides, oxides, and combinations thereof The resulting composite fourth body has different compositional patterns from one side to the other.
Moreau, Philippe; Chanan-Khan, Asher; Roberts, Andrew W; Agarwal, Amit B; Facon, Thierry; Kumar, Shaji; Touzeau, Cyrille; Punnoose, Elizabeth A; Cordero, Jaclyn; Munasinghe, Wijith; Jia, Jia; Salem, Ahmed Hamed; Freise, Kevin J; Leverson, Joel D; Enschede, Sari Heitner; Ross, Jeremy A; Maciag, Paulo C; Verdugo, Maria; Harrison, Simon J
2017-11-30
The antiapoptotic proteins BCL-2 and myeloid cell leukemia sequence 1 (MCL-1) promote multiple myeloma (MM) cell survival. Venetoclax is a selective, orally bioavailable small-molecule BCL-2 inhibitor; bortezomib can indirectly inhibit MCL-1. In preclinical studies, venetoclax enhanced bortezomib activity, suggesting that cotargeting of BCL-2 and MCL-1 could be an effective treatment strategy in myeloma. This phase 1b trial studied patients with relapsed/refractory MM receiving daily venetoclax (50-1200 mg per designated dose cohort; 800 mg in safety expansion) in combination with bortezomib and dexamethasone. A total of 66 patients were enrolled (54 in the dose-escalation cohorts and 12 in the safety expansion). Patients had received a median of 3 prior therapies (range, 1-13); 26 (39%) were refractory to prior bortezomib and 35 (53%) to lenalidomide; 39 (59%) had prior stem cell transplant. The combination was generally well tolerated, and common adverse events included mild gastrointestinal toxicities (diarrhea [46%], constipation [41%], and nausea [38%]) and grade 3/4 cytopenias (thrombocytopenia [29%] and anemia [15%]). The overall response rate (ORR) was 67% (44/66); 42% achieved very good partial response or better (≥VGPR). Median time to progression and duration of response were 9.5 and 9.7 months, respectively. ORR of 97% and ≥VGPR 73% were seen in patients not refractory to bortezomib who had 1 to 3 prior therapies. Patients with high BCL2 expression had a higher ORR (94% [17/18]) than patients with low BCL2 expression (59% [16/27]). This novel combination of venetoclax with bortezomib and dexamethasone has an acceptable safety profile and promising efficacy in patients with relapsed/refractory MM. This trial was registered at www.clinicaltrials.gov as #NCT01794507. © 2017 by The American Society of Hematology.
Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Anbo; Yu, Zhihao
This report summarizes technical progress on the program “Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health,” funded by the National Energy Technology Laboratory of the U.S. Department of Energy, and performed by the Center for Photonics Technology of the Bradley Department of Electrical and Computer Engineering at Virginia Tech. The scope of work entails analyses of traveling grating generation technologies in an optical fiber, as well as the interrogation of the gratings to infer a distributed temperature along the fiber, for the purpose of developing a real-time refractory health condition monitoring technology for coal gasifiers. Duringmore » the project period, which is from 2011-2015, three different sensing principles were studied, including four-wave mixing (FWM), coherent optical time-domain reflectometer (C-OTDR) and Brillouin optical time-domain analysis (BOTDA). By comparing the three methods, the BOTDA was selected for further development into a complete bench-top sensing system for the proposed high-temperature sensing application. Based on the input from Eastman Chemical, the industrial collaborator on this project, a cylindrical furnace was designed and constructed to simulate typical gasifier refractory temperature conditions in the laboratory, and verify the sensor’s capability to fully monitor refractory conditions on the back-side at temperatures up to 1000°C. In the later stages of the project, the sensing system was tested in the simulated environment for its sensing performance and high-temperature survivability. Through theoretical analyses and experimental research on the different factors affecting the sensor performance, a sensor field deployment strategy was proposed for possible future sensor field implementations.« less
Value of 3.0 T MR imaging in refractory partial epilepsy and negative 1.5 T MRI.
Nguyen, Dang Khoa; Rochette, Emilie; Leroux, Jean-Maxime; Beaudoin, Gilles; Cossette, Patrick; Lassonde, Maryse; Guilbert, François
2010-10-01
High-field 3.0 T MR scanners provide an improved signal-to-noise ratio which can be translated in higher image resolution, possibly allowing critical detection of subtle epileptogenic lesions missed on standard-field 1.0-1.5 T MRIs. In this study, the authors explore the potential value of re-imaging at 3.0 T patients with refractory partial epilepsy and negative 1.5 T MRI. We retrospectively identified all patients with refractory partial epilepsy candidate for surgery who had undergone a 3.0 T MR study after a negative 1.5 T MR study. High-field 3.0 T MRIs were reviewed qualitatively by neuroradiologists experienced in interpreting epilepsy studies with access to clinical information. Relevance and impact on clinical management were assessed by an epileptologist. Between November 2006 and August 2009, 36 patients with refractory partial epilepsy candidate for surgery underwent 3.0 T MR study after a 1.5 T MR study failed to disclose a relevant epileptogenic lesion. A potential lesion was found only in two patients (5.6%, 95% CI: 1.5-18.1%). Both were found to have hippocampal atrophy congruent with other presurgical localization techniques which resulted in omission of an invasive EEG study and direct passage to surgery. The frequency of detection of a new lesion by re-imaging at 3.0 T patients with refractory partial epilepsy candidate for surgery was found to be low, but seems to offer the potential of a significant clinical impact for selected patients. This finding needs to be validated in a prospective controlled study. Copyright © 2010 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.
Shin, Samuel M; Silverman, Joshua S; Bowden, Greg; Mathieu, David; Yang, Huai-Che; Lee, Cheng-Chia; Tam, Moses; Szelemej, Paul; Kaufmann, Anthony M; Cohen-Inbar, Or; Sheehan, Jason; Niranjan, Ajay; Lunsford, L Dade; Kondziolka, Douglas
2017-01-01
Stereotactic radiosurgery (SRS) can be used as part of multimodality management for patients with primary central nervous system lymphoma (PCNSL). The objective of this study is to evaluate outcomes of SRS for this disease. The International Gamma Knife Research Foundation identified 23 PCNSL patients who underwent SRS for either relapsed (intracerebral in-field or out-of-field tumor recurrences) or refractory disease from 1995-2014. All 23 patients presented with RPA Class I or II PCNSL, and were initially treated with a median of 7 cycles of methotrexate-based chemotherapy regimens (range, 3-26 cycles). Ten received prior whole brain radiation (WBRT) to a median dose of 43 Gy (range, 24-55 Gy). Sixteen presented with relapsed PCNSL, and seven presented with refractory disease. Twenty-three received 26 procedures of SRS. The median tumor volume was 4 cm 3 (range, 0.1-26 cm 3 ), and the median margin dose was 15 Gy (range, 8-20 Gy). Median follow-up from SRS was 11 months (interquartile range, 5.7-33.2 months). Twenty presented with treatment response to twenty-three tumors (12 complete, 11 partial). Fourteen patients relapsed or were refractory to salvage SRS, and local control was 95%, 91%, and 75% at 3, 6, and 12 months post SRS. Intracranial (in-field and out-of-field) and distant (systemic) PFS was 86%, 81%, and 55% at 3, 6, and 12 months post SRS. Toxicity of SRS was low, with one developing an adverse radiation effect requiring no additional intervention. Although methotrexate-based chemotherapy regimens with or without WBRT is the first-line management option for PCNSL, SRS may be used as an alternative option in properly selected patients with smaller relapsed or refractory PCNSL tumors.
Balmelli, Catharina; Railic, Nikola; Siano, Marco; Feuerlein, Kristin; Cathomas, Richard; Cristina, Valerie; Güthner, Christiane; Zimmermann, Stefan; Weidner, Sabine; Pless, Miklos; Stenner, Frank; Rothschild, Sacha I
2018-01-01
Purpose: Differentiated thyroid cancer (DTC) accounts for approximately 95% of thyroid carcinomas. In the metastatic RAI-refractory disease, chemotherapy has very limited efficacy and is associated with substantial toxicity. With increasing knowledge of the molecular pathogenesis of DTC, novel targeted therapies have been developed. Lenvatinib is a tyrosine kinase inhibitor (TKI) with promising clinical activity based on the randomized phase III SELECT trial. In Switzerland, a Named Patient Program (NPP) was installed to bridge the time gap to Swissmedic approval. Here, we report the results from the Swiss Lenvatinib NPP including patients with metastatic RAI-refractory DTC. Methods: Main inclusion criteria for the Swiss NPP were RAI-refractory DTC, documented disease progression, Eastern Cooperative Oncology Group (ECOG) performance status 0-3. The number of previous therapies was not limited. The Swiss Lenvatinib NPP was initiated in June 2014 and was closed in October 2015 with the approval of the drug. Results: Between June 2014 and October 2015, 13 patients with a median age of 72 years have been enrolled. Most patients (69%) had at least one prior systemic therapy, mainly sorafenib. 31% of patients showed a PR and 31% SD. Median progression free survival was 7.2 months and the median overall survival was 22.7 months. Dose reduction due to adverse events was necessary in 7 patients (53%). At the time of analysis 6 patients (47%) were still on treatment with a median time on treatment of 9.98 months. Conclusions: Our results show that lenvatinib has reasonable clinical activity in unselected patients with RAI-refractory thyroid cancer with nearly two-third of patients showing clinical benefit. The toxicity profile of lenvatinib is manageable.
Balmelli, Catharina; Railic, Nikola; Siano, Marco; Feuerlein, Kristin; Cathomas, Richard; Cristina, Valerie; Güthner, Christiane; Zimmermann, Stefan; Weidner, Sabine; Pless, Miklos; Stenner, Frank; Rothschild, Sacha I.
2018-01-01
Purpose:Differentiated thyroid cancer (DTC) accounts for approximately 95% of thyroid carcinomas. In the metastatic RAI-refractory disease, chemotherapy has very limited efficacy and is associated with substantial toxicity. With increasing knowledge of the molecular pathogenesis of DTC, novel targeted therapies have been developed. Lenvatinib is a tyrosine kinase inhibitor (TKI) with promising clinical activity based on the randomized phase III SELECT trial. In Switzerland, a Named Patient Program (NPP) was installed to bridge the time gap to Swissmedic approval. Here, we report the results from the Swiss Lenvatinib NPP including patients with metastatic RAI-refractory DTC. Methods:Main inclusion criteria for the Swiss NPP were RAI-refractory DTC, documented disease progression, Eastern Cooperative Oncology Group (ECOG) performance status 0-3. The number of previous therapies was not limited. The Swiss Lenvatinib NPP was initiated in June 2014 and was closed in October 2015 with the approval of the drug. Results:Between June 2014 and October 2015, 13 patients with a median age of 72 years have been enrolled. Most patients (69%) had at least one prior systemic therapy, mainly sorafenib. 31% of patients showed a PR and 31% SD. Median progression free survival was 7.2 months and the median overall survival was 22.7 months. Dose reduction due to adverse events was necessary in 7 patients (53%). At the time of analysis 6 patients (47%) were still on treatment with a median time on treatment of 9.98 months. Conclusions:Our results show that lenvatinib has reasonable clinical activity in unselected patients with RAI-refractory thyroid cancer with nearly two-third of patients showing clinical benefit. The toxicity profile of lenvatinib is manageable. PMID:29344270
Effect of Continued Medical Therapy on Productivity Costs for Refractory Chronic Rhinosinusitis.
Rudmik, Luke; Soler, Zachary M; Smith, Timothy L; Mace, Jess C; Schlosser, Rodney J; DeConde, Adam S
2015-11-01
It is estimated that lost productivity related to chronic rhinosinusitis (CRS) costs society in excess of $13 billion per year in the United States. Given this tremendous cost to society, it is important to evaluate the effect of current interventions on improving this productivity loss. To define the change in productivity costs in patients with refractory CRS who select continued medical therapy. Observational cohort study. Thirty-eight patients with a guideline-based diagnosis of CRS whose initial appropriate medical therapy failed were enrolled from 4 tertiary-level rhinology clinics. The study was conducted from December 6, 2010, to April 23, 2013, and data analysis was performed from December 6, 2010, to June 1, 2015. Continued medical therapy for CRS. The human capital approach was applied to quantify productivity costs. Absenteeism, presenteeism, and lost leisure time were quantified to define annual lost productive time, which was measured at enrollment (baseline) and at a minimum of 6 months after treatment. Lost productive time was monetized using the annual daily wage rates obtained from the 2012 US National Census and the 2013 US Department of Labor statistics. Thirty-eight patients with refractory CRS who selected continued medical therapy had a mean (SD) baseline annual productivity cost of $3464 ($4900) per patient. After continued medical therapy for a mean of 12.8 (4.8) months, productivity costs were $2730 ($3720) (before vs after continued medical therapy productivity cost, P = .74). Mean annual absenteeism was reduced from 5 (12) days to 2 (8) days (P = .02). Mean annual presenteeism (17 [27] days reduced to 15 [23] days; P = .93) and mean annual household days lost (7 [7] days reduced to 6 [6] days; P = .51) were maintained at baseline levels. There were no significant differences in productivity outcomes based on endoscopy, the 22-item Sinonasal Outcome Test score, age, or polyp status (all P ≥ .11). Patients with refractory CRS often make treatment decisions based on the degree of quality-of-life and productivity impairment. Outcomes from this study suggest that productivity in patients with refractory CRS who have minor reductions in baseline productivity can remain stable with continued medical therapy. Physicians can use this information to inform appropriate patients with CRS of their expected outcomes from continued medical therapy.
A review of recombinant factor VII for refractory bleeding in nonhemophilic trauma patients.
Barletta, Jeffrey F; Ahrens, Christine L; Tyburski, James G; Wilson, Robert F
2005-03-01
Recombinant factor VII (rFVII) is an attractive agent to control refractory, coagulopathic bleeding in patients following major surgery. The purpose of this review is to evaluate the published experiences of rFVII in adult, nonhemophilic, surgical and trauma patients. A computerized literature search was conducted to identify articles pertaining to rFVII use for refractory bleeding in adult, nonhemophilic, surgical patients. The selected articles were reviewed and the applicable data was analyzed. A total of 117 patients were found in 8 case series and 24 case reports. Overall, rFVII was effective in restoring hemostasis in 99/117 (85%) patients with 76/99 (77%) surviving to hospital discharge. In trauma patients, hemostasis was achieved in 20/26 (77%) patients and 17/20 (85%) survived. There were 5 (4%) thromboembolic events observed in the 117 cases and much disparity was noted with the initial dose. Severe acidosis affected the activity of rFVII. Recombinant factor VII is an effective therapeutic agent for achieving hemostasis in nonhemophilic surgical patients. Published clinical experiences, however, are limited to small case series and case reports.
High temperature electronic gain device
McCormick, J. Byron; Depp, Steven W.; Hamilton, Douglas J.; Kerwin, William J.
1979-01-01
An integrated thermionic device suitable for use in high temperature, high radiation environments. Cathode and control electrodes are deposited on a first substrate facing an anode on a second substrate. The substrates are sealed to a refractory wall and evacuated to form an integrated triode vacuum tube.
Geochemistry and genesis of the angrites
NASA Technical Reports Server (NTRS)
Mittlefehldt, David W.; Lindstrom, Marilyn M.
1990-01-01
The major and trace elements were analyzed in samples of LEW86010, LEW87051, and Angra dos Reis angrites were analyzed using INAA and fused-bead EMP techniques. Results suggest that all three angrites originated on a volatile-depleted (Na-poor) but oxidized parent body or on several bodies. The combination of low Na and high FeO/MnO found in these samples suggests that the extreme Na depletion was caused by parent-body outgassing during differentiation, rather than by nebular processes. It was also found that the refractory-element abundances observed in LEW86010 and LEW87051 are related via olivine control; it is suggested that LEW86010 may be a residual melt from a LEW87051-like precursor or that LEW87051 formed from a LEW86010-like precursor via olivine accumulation. On the other hand, the Angra dos Reis displayed an unusual refractory element pattern suggesting that either the angrite parent body was heterogeneous or that Angra dos Reis was formed on a parent body different from that of the other two angrites.
2018-06-18
Refractory Diffuse Large B Cell Lymphoma; Refractory Primary Mediastinal B Cell Lymphoma; Refractory Transformed Follicular Lymphoma; Relapsed/Refractory Transplant Ineligible Diffuse Large B Cell Lymphoma; Relapsed/Refractory Transplant Ineligible Primary Mediastinal B Cell Lymphoma; Relapsed/Refractory Transplant Ineligible Transformed Follicular Lymphoma; Relapsed/Refractory Large B Cell Lymphoma Including DLBCL, PMBCL, TFL and HGBCL After Two Systemic Lines of Therapy" in Phase 2 Expanded Cohorts
NASA Astrophysics Data System (ADS)
Lee, Mun Hyung; Park, Joo Hyun
2018-06-01
The effect of nitrogen content on the formation of an equiaxed solidification structure of Fe-16Cr steel was investigated. Moreover, two different kinds of refractory materials, i.e., alumina and magnesia, were employed to control the type of oxide inclusion. The characteristics of TiN(-oxide) inclusions were quantitatively analyzed in both molten steel and solidified samples. When the melting was carried out in the alumina refractory, the grain size continuously decreased with increasing nitrogen content. However, a minimum grain size was observed at a specific nitrogen content (approx. 150 ppm) when the steel was melted in the magnesia refractory. Most of the single TiN particles had a cuboidal shape and fine irregularly shaped particles were located along the grain boundary due to the microsegregation of Ti at the grain boundary during solidification. The type of TiN-oxide hybrid inclusion was strongly affected by the refractory material where Al2O3-TiN and MgAl2O4-TiN hybrid-type inclusions were obtained in the alumina and magnesia refractory experiments, respectively. The formation of oxide inclusions was well predicted by thermochemical computations and it was commonly found that oxide particles were initially formed, followed by the nucleation and growth of TiN. When the nitrogen content increased, the number density of TiN linearly increased in the alumina refractory experiments. However, the number of TiN exhibits a maximum at about [N] = 150 ppm, at which a minimum grain size was obtained in the magnesia refractory experiments. Therefore, the larger the number density of TiN, the smaller the primary grain size after solidification. The number density of TiN in the steel melted in the magnesia refractory was greater than that in the steel melted in the alumina refractory at given Ti and N contents, which was due to the lower planar lattice disregistry of MgAl2O4-TiN interface rather than that of Al2O3-TiN interface. When Δ T TiN (= difference between the TiN precipitation temperature and the liquidus of the steel) was 20 K to 40 K, the number density of effective TiN was maximized and thus, the grain size was minimized after solidification. Finally, although most of the TiN particles were smaller than 1 μm in the molten steel samples irrespective of the nitrogen content, TiN particles larger than 10 μm were observed in the solidified samples when the nitrogen content was greater than 150 ppm. The growth of TiN particles during melting and solidification was well predicted by the combinatorial simulation of the `Ostwald ripening model' based on the Lifshitz-Slyozov-Wagner theory in conjunction with the `Diffusion controlled model' using Ohnaka's microsegregation equation.
NASA Astrophysics Data System (ADS)
Lee, Mun Hyung; Park, Joo Hyun
2018-03-01
The effect of nitrogen content on the formation of an equiaxed solidification structure of Fe-16Cr steel was investigated. Moreover, two different kinds of refractory materials, i.e., alumina and magnesia, were employed to control the type of oxide inclusion. The characteristics of TiN(-oxide) inclusions were quantitatively analyzed in both molten steel and solidified samples. When the melting was carried out in the alumina refractory, the grain size continuously decreased with increasing nitrogen content. However, a minimum grain size was observed at a specific nitrogen content (approx. 150 ppm) when the steel was melted in the magnesia refractory. Most of the single TiN particles had a cuboidal shape and fine irregularly shaped particles were located along the grain boundary due to the microsegregation of Ti at the grain boundary during solidification. The type of TiN-oxide hybrid inclusion was strongly affected by the refractory material where Al2O3-TiN and MgAl2O4-TiN hybrid-type inclusions were obtained in the alumina and magnesia refractory experiments, respectively. The formation of oxide inclusions was well predicted by thermochemical computations and it was commonly found that oxide particles were initially formed, followed by the nucleation and growth of TiN. When the nitrogen content increased, the number density of TiN linearly increased in the alumina refractory experiments. However, the number of TiN exhibits a maximum at about [N] = 150 ppm, at which a minimum grain size was obtained in the magnesia refractory experiments. Therefore, the larger the number density of TiN, the smaller the primary grain size after solidification. The number density of TiN in the steel melted in the magnesia refractory was greater than that in the steel melted in the alumina refractory at given Ti and N contents, which was due to the lower planar lattice disregistry of MgAl2O4-TiN interface rather than that of Al2O3-TiN interface. When ΔT TiN (= difference between the TiN precipitation temperature and the liquidus of the steel) was 20 K to 40 K, the number density of effective TiN was maximized and thus, the grain size was minimized after solidification. Finally, although most of the TiN particles were smaller than 1 μm in the molten steel samples irrespective of the nitrogen content, TiN particles larger than 10 μm were observed in the solidified samples when the nitrogen content was greater than 150 ppm. The growth of TiN particles during melting and solidification was well predicted by the combinatorial simulation of the `Ostwald ripening model' based on the Lifshitz-Slyozov-Wagner theory in conjunction with the `Diffusion controlled model' using Ohnaka's microsegregation equation.
Design of Refractory Linings for Balanced Energy Efficiency, Uptime, and Capacity in Lime Kilns
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gorog, John Peter; Hemrick, James Gordon; Walker, Harold
2014-01-01
The rotary kilns used by the pulp and paper industry to regenerate lime in the Kraft process are very energy intensive. Throughout the 90 s, in response to increasing fuel prices, the industry used back up insulation in conjunction with the high alumina brick used to line the burning zones of their kilns. While this improved energy efficiency, the practice of installing insulating brick behind the working lining increased the inner wall temperatures. In the worst case, due to the increased temperatures, rapid brick failures occurred causing unscheduled outages and expensive repairs. Despite these issues, for the most part, themore » industry continued to use insulating refractory linings in that the energy savings were large enough to offset any increase in the cost of maintaining the refractory lining. Due to the dramatic decline in the price of natural gas in some areas combined with mounting pressures to increasing production of existing assets, over the last decade, many mills are focusing more on increasing the uptime of their kilns as opposed to energy savings. To this end, a growing number of mills are using basic (magnesia based) brick instead of high alumina brick to line the burning zone of the kiln since the lime mud does not react with these bricks at the operating temperatures of the burning zone of the kiln. In the extreme case, a few mills have chosen to install basic brick in the front end of the kiln running a length equivalent to 10 diameters. While the use of basic brick can increase the uptime of the kiln and reduce the cost to maintain the refractory lining, it does dramatically increase the heat losses resulting from the increased operating temperatures of the shell. Also, over long periods of time operating at these high temperatures, damage can occur in the shell. There are tradeoffs between energy efficiency, capacity and uptime. When fuel prices are very high, it makes sense to insulate the lining. When fuel prices are lower, trading some thermal efficiency for increased uptime and capacity seems reasonable. This paper considers a number of refractory linings in an effort to develop optimized operating strategies that balance these factors. In addition to considering a range of refractory materials, the paper examines other factors such as the chain area, discharge dams and other operating variables that impact the service life of the refractory lining. The paper provides recommendations that will help mill personnel develop a strategy to select a refractory lining that is optimized for their specific situation.« less
Solid oxide fuel cell matrix and modules
Riley, Brian
1990-01-01
Porous refractory ceramic blocks arranged in an abutting, stacked configuration and forming a three dimensional array provide a support structure and coupling means for a plurality of solid oxide fuel cells (SOFCs). Each of the blocks includes a square center channel which forms a vertical shaft when the blocks are arranged in a stacked array. Positioned within the channel is a SOFC unit cell such that a plurality of such SOFC units disposed within a vertical shaft form a string of SOFC units coupled in series. A first pair of facing inner walls of each of the blocks each include an interconnecting channel hole cut horizontally and vertically into the block walls to form gas exit channels. A second pair of facing lateral walls of each block further include a pair of inner half circular grooves which form sleeves to accommodate anode fuel and cathode air tubes. The stack of ceramic blocks is self-supporting, with a plurality of such stacked arrays forming a matrix enclosed in an insulating refractory brick structure having an outer steel layer. The necessary connections for air, fuel, burnt gas, and anode and cathode connections are provided through the brick and steel outer shell. The ceramic blocks are so designed with respect to the strings of modules that by simple and logical design the strings could be replaced by hot reloading if one should fail. The hot reloading concept has not been included in any previous designs.
Isotopic Dichotomy among Meteorites and Its Bearing on the Protoplanetary Disk
NASA Astrophysics Data System (ADS)
Scott, Edward R. D.; Krot, Alexander N.; Sanders, Ian S.
2018-02-01
Whole rock Δ17O and nucleosynthetic isotopic variations for chromium, titanium, nickel, and molybdenum in meteorites define two isotopically distinct populations: carbonaceous chondrites (CCs) and some achondrites, pallasites, and irons in one and all other chondrites and differentiated meteorites in the other. Since differentiated bodies accreted 1–3 Myr before the chondrites, the isotopic dichotomy cannot be attributed to temporal variations in the disk. Instead, the two populations were most likely separated in space, plausibly by proto-Jupiter. Formation of CCs outside Jupiter could account for their characteristic chemical and isotopic composition. The abundance of refractory inclusions in CCs can be explained if they were ejected by disk winds from near the Sun to the disk periphery where they spiraled inward due to gas drag. Once proto-Jupiter reached 10–20 M ⊕, its external pressure bump could have prevented millimeter- and centimeter-sized particles from reaching the inner disk. This scenario would account for the enrichment in CCs of refractory inclusions, refractory elements, and water. Chondrules in CCs show wide ranges in Δ17O as they formed in the presence of abundant 16O-rich refractory grains and 16O-poor ice particles. Chondrules in other chondrites (ordinary, E, R, and K groups) show relatively uniform, near-zero Δ17O values as refractory inclusions and ice were much less abundant in the inner solar system. The two populations were plausibly mixed together by the Grand Tack when Jupiter and Saturn migrated inward emptying and then repopulating the asteroid belt with roughly equal masses of planetesimals from inside and outside Jupiter’s orbit (S- and C-type asteroids).
Wu, Eline; Mårtensson, Jan; Broström, Anders
2013-10-01
Refractory angina pectoris (AP) is a persistent, painful condition characterized by angina caused by coronary insufficiency in the presence of coronary artery disease. It has been emphasized that there are possible underlying neuropathophysiological mechanisms for refractory AP but chronic ischemia is still considered to be the main problem. These patients suffer from severe AP and cannot be controlled by a combination of pharmacological therapies, angioplasty or coronary bypass surgery. AP has a negative impact on quality of life and daily life. Enhanced external counterpulsation (EECP) is a therapeutic option for these patients. The aim of this study was to evaluate EECP after six months regarding physical capacity and health-related quality of life (HRQoL) in patients with refractory AP. This was a study with single case research experimental design involving 34 patients treated with EECP. Six minute walk test (6MWT), functional class with Canadian Cardiological Society (CCS) classification and self-reported HRQoL questionnaires as Short Form 36 (SF-36) were collected at baseline and after treatment. CCS class and SF-36 were repeated at six months follow-up. Patients enhanced walk distance on average by 29 m after EECP (p<0.01). CCS class also improved (p<0.001) and persisted at six months follow-up (p<0.001). HRQoL improved significantly and the effects were maintained at follow-up after the treatment. Patients with refractory AP receive beneficial effects from EECP both in physical capacity and HRQoL. As other treatment options for this patient group are scarce, EECP should be offered to improve physical health and HRQoL in these patients.
Moretti, Michele; Buiatti, Alessandra; Merlo, Marco; Massa, Laura; Fabris, Enrico; Pinamonti, Bruno; Sinagra, Gianfranco
2013-11-01
The management of refractory recurrent pericarditis is challenging. Previous clinical reports have noted a beneficial effect of high-dose intravenous human immunoglobulins (IvIgs) in isolated and systemic inflammatory disease-related forms. In this article, we analyzed retrospectively our clinical experience with IvIg therapy in a series of clinical cases of pericarditis refractory to conventional treatment. We retrospectively analyzed 9 patients (1994 to 2010) with refractory recurrent pericarditis, who received high-dose IvIg as a part of their medical treatment. Nonsteroidal anti-inflammatory drugs (NSAIDs), steroids, or colchicine treatment was not discontinued during IvIg treatment. No patients had a history of autoimmune or connective tissue diseases. During an average period of 11 months from the first recurrence, patients had experienced a mean of 5 relapses before the first IvIg treatment. In 4 cases, patients showed complete clinical remission with no further relapse after the first IvIg cycle. Two patients experienced a single minor relapse, responsive to short-term nonsteroidal anti-inflammatory drugs. In 2 patients, we performed a second cycle of IvIg after a recurrence of pericarditis, with subsequent complete remission. One patient did not respond to 3 cycles of IvIg and subsequently underwent pericardial window and long-term immunosuppressive treatment. No major adverse effect was observed in consequence of IvIg administration in all the cases. In conclusion, although IvIg mode of action is still poorly understood in this setting, this treatment can be considered as an option in patients with recurrent pericarditis refractory to conventional medical treatment and, in our small series, has proved to be effective in 8 of 9 cases. Copyright © 2013 Elsevier Inc. All rights reserved.
High temperature oxidation resistant cermet compositions
NASA Technical Reports Server (NTRS)
Phillips, W. M. (Inventor)
1976-01-01
Cermet compositions are designed to provide high temperature resistant refractory coatings on stainless steel or molybdenum substrates. A ceramic mixture of chromium oxide and aluminum oxide form a coating of chromium oxide as an oxidation barrier around the metal particles, to provide oxidation resistance for the metal particles.
Chemical fractionation in the solar nebula
NASA Technical Reports Server (NTRS)
Grossman, L.
1977-01-01
The sequence of condensation of minerals from a cooling gas of solar composition has been calculated from thermodynamic data over the pressure range 0.001-0.00001 atm, assuming that complete chemical equilibrium is maintained. The results suggest that the Ca-Al-rich inclusions Allende and other carbonaceous chondrites are aggregates of the highest temperature condensates. Complete condensation of these elements is followed, 100 deg later, by the onset of the crystallization of nickel-iron, forsterite and enstatite. Transport of Ca-Al-rich refractory condensates from one part of the nebula to another before the condensation of these lower-temperature phases may have been responsible for the refractory element fractionations between the different classes of chondrites and possibly for the inferred refractory element enrichment of the Moon. The temperature gap between the condensation temperatures of nickel-iron and forsterite increases with increasing total pressure. Because pressure and temperature probably increased with decreasing heliocentric distance in the solar nebula, Mercury may have accreted from a condensate assemblage having a higher metal/silicate ratio than Venus or Earth which may, in turn, have formed from less oxidized material than Mars.
NASA Astrophysics Data System (ADS)
Ionov, Dmitri A.; Chanefo, Ingrid; Bodinier, Jean-Louis
2005-10-01
Lherzolite-wehrlite (LW) series xenoliths from the quaternary Tok volcanic field in the southeastern Siberian craton are distinguished from the more common lherzolite-harzburgite (LH) series by (a) low Mg numbers (0.84-0.89) at high modal olivine (66-84%) and (b) widespread replacement of orthopyroxene (0-12%) and spinel by clinopyroxene (7-22%). The LW series peridotites are typically enriched in Ca, Fe, Mn and Ti, and depleted in Si, Ni and Cr relative to refractory LH series rocks (Mg number ≥0.89), which are metasomatised partial melting residues. Numerical modelling of Fe-Mg solid/liquid exchange during melt percolation demonstrates that LW series rocks can form by reaction of host refractory peridotites with evolved (Mg numbers 0.6-0.7), silica-undersaturated silicate melts at high melt/rock ratios, which replace orthopyroxene with clinopyroxene and decrease Mg numbers. This process is most likely related to underplating and fractionation of basaltic magma in the shallow mantle, which also produced olivine-clinopyroxene cumulates found among the Tok xenoliths.
Rare Earth Oxide Fluoride Nanoparticles And Hydrothermal Method For Forming Nanoparticles
Fulton, John L.; Hoffmann, Markus M.
2003-12-23
A hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.
Rare earth oxide fluoride nanoparticles and hydrothermal method for forming nanoparticles
Fulton, John L [Richland, WA; Hoffmann, Markus M [Richland, WA
2001-11-13
A hydrothermal method for forming nanoparticles of a rare earth element, oxygen and fluorine has been discovered. Nanoparticles comprising a rare earth element, oxygen and fluorine are also described. These nanoparticles can exhibit excellent refractory properties as well as remarkable stability in hydrothermal conditions. The nanoparticles can exhibit excellent properties for numerous applications including fiber reinforcement of ceramic composites, catalyst supports, and corrosion resistant coatings for high-temperature aqueous solutions.
Nivolumab in Treating Patients With Relapsed or Refractory Peripheral T-cell Lymphoma
2018-04-27
Blastic Plasmacytoid Dendritic Cell Neoplasm; Hepatosplenic T-Cell Lymphoma; HTLV-1 Infection; NK-Cell Lymphoma, Unclassifiable; Primary Systemic Anaplastic Large Cell Lymphoma, ALK-Negative; Recurrent Adult T-Cell Leukemia/Lymphoma; Recurrent Anaplastic Large Cell Lymphoma; Recurrent Angioimmunoblastic T-cell Lymphoma; Recurrent Enteropathy-Associated T-Cell Lymphoma; Recurrent Mycosis Fungoides; Refractory Adult T-Cell Leukemia/Lymphoma; Refractory Anaplastic Large Cell Lymphoma; Refractory Angioimmunoblastic T-cell Lymphoma; Refractory Enteropathy-Associated T-Cell Lymphoma; Refractory Mycosis Fungoides; Refractory Nasal Type Extranodal NK/T-Cell Lymphoma; Refractory Peripheral T-Cell Lymphoma, Not Otherwise Specified
2018-03-12
Previously Treated Myelodysplastic Syndrome; Recurrent Adult Acute Myeloid Leukemia; Recurrent Anaplastic Large Cell Lymphoma; Recurrent Angioimmunoblastic T-cell Lymphoma; Recurrent Cutaneous T-Cell Non-Hodgkin Lymphoma; Recurrent Mycosis Fungoides; Recurrent Plasma Cell Myeloma; Recurrent T-Cell Non-Hodgkin Lymphoma; Refractory Anaplastic Large Cell Lymphoma; Refractory Angioimmunoblastic T-cell Lymphoma; Refractory Cutaneous T-Cell Non-Hodgkin Lymphoma; Refractory Mycosis Fungoides; Refractory Peripheral T-Cell Lymphoma, Not Otherwise Specified; Refractory Plasma Cell Myeloma; Refractory T-Cell Non-Hodgkin Lymphoma
Alisertib and Romidepsin in Treating Patients With Relapsed or Refractory B-Cell or T-Cell Lymphomas
2018-05-02
High Grade B-Cell Lymphoma With MYC and BCL2 or BCL6 Rearrangements; MYC Positive; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Mature T- and NK-Cell Non-Hodgkin Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Hodgkin Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Mature T-Cell and NK-Cell Non-Hodgkin Lymphoma
NASA Technical Reports Server (NTRS)
Belleau, C.; Ehlers, W. L.; Hagen, F. A.
1978-01-01
The potential role of superalloys, refractory alloys, and ceramics in the hottest sections of engines operating with turbine inlet temperatures as high as 1370 C is examined. The convential superalloys, directionally solidified eutectics, oxide dispersion strenghened alloys, and tungsten fiber reinforced superalloys are reviewed and compared on the basis of maximum turbine blade temperature capability. Improved high temperature protective coatings and special fabrication techniques for these advanced alloys are discussed. Chromium, columbium, molybdenum, tantalum, and tungsten alloys are also reviewed. Molbdenum alloys are found to be the most suitable for mass produced turbine wheels. Various forms and fabrication processes for silicon nitride, silicon carbide, and SIALON's are investigated for use in highstress and medium stress high temperature environments.
NASA Technical Reports Server (NTRS)
Calle, Luz M.; Hintze, Paul E.; Parlier, Christopher R.; Sampson, Jeffrey W.; Coffman, Brekke E.; Coffman, Brekke E.; Curran, Jerome P.; Kolody, Mark R.; Whitten, Mary; Perisich, Steven;
2009-01-01
When space vehicles are launched, extreme heat, exhaust, and chemicals are produced and these form a very aggressive exposure environment at the launch complex. The facilities in the launch complex are exposed to this aggressive environment. The vehicle exhaust directly impacts the flame deflectors, making these systems very susceptible to high wear and potential failure. A project was formulated to develop or identify new materials or systems such that the wear and/or damage to the flame deflector system, as a result of the severe environmental exposure conditions during launches, can be mitigated. This report provides a survey of potential protective coatings for the refractory concrete lining on the steel base structure on the flame deflectors at Kennedy Space Center (KSC).
The Use of an Air-Natural Gas Flame in Atomic Absorption.
ERIC Educational Resources Information Center
Melucci, Robert C.
1983-01-01
Points out that excellent results are obtained using an air-natural gas flame in atomic absorption experiments rather than using an air-acetylene flame. Good results are obtained for alkali metals, copper, cadmium, and zinc but not for the alkaline earths since they form refractory oxides. (Author/JN)
Direct photodecomposition and photochemically-mediated bacterial degradation (via photochemical modification of otherwise refractory DOM into biologically labile forms) provide
important pathways for the loss of dissolved organic matter in coastal waters. Here we report
lab...
2017-10-24
CD19-Positive Neoplastic Cells Present; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Chronic Lymphocytic Leukemia; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Acute Lymphoblastic Leukemia; Refractory Chronic Lymphocytic Leukemia; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Non-Hodgkin Lymphoma; Refractory Small Lymphocytic Lymphoma
Zschäbitz, Stefanie; Lasitschka, Felix; Hadaschik, Boris; Hofheinz, Ralf-Dieter; Jentsch-Ullrich, Kathleen; Grüner, Marcus; Jäger, Dirk; Grüllich, Carsten
2017-05-01
Treatment options for patients with platinum refractory metastatic germ cell tumours (GCT) relapsing after high-dose chemotherapy and autologous stem cell transplantation are limited and survival is poor. Antibodies directed against programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1) are currently assessed within clinical trials. We present updated data on our experience with checkpoint inhibitors as a compassionate use off-label treatment attempt for highly-pretreated patients with GCT and provide an overview of the current literature on PD-L1 expression in this rare tumour entity. We analysed all patients with platinum refractory GCT treated with checkpoint inhibitors at our institutions between 2015 and 2017. Data were retrieved retrospectively from the patient charts. Seven patients were treated with nivolumab or pembrolizumab. Four patients received single-dose treatment and died shortly afterwards due to tumour progression; the remaining three patients received treatment for at least 6 months. No significant treatment toxicity was observed. Long-term tumour response was achieved in two of the three patients, both of them highly positive for PD-L1 staining. We consider checkpoint inhibition to be efficient in carefully selected patients with platinum refractory GCT. However, predictive markers associated with tumour response are not yet known and larger prospective clinical trials are warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.
Yalcin, Samet; Yalcin, Bulent; Gecim, Ethem I
2009-01-01
Management of patients with chronic constipation (CC), irresponsive to medical treatment, is very difficult. There are some surgical approaches reported for the treatment. In this study we aimed to assess the results of different surgical procedures in patients with severe CC who were refractory to intensive medical treatments. Fifteen patients with refractory chronic constipation underwent surgical management between 1998 and 2003 in Ankara University School of Medicine Department of General Surgery. Median age of the patients was 40 years (range, 24-77), female/male ratio was 11/4, median duration of symptoms was 13 years (range, 4-35 years) and median interval of two subsequent bowel movements was 15 (range, 5-30) days. Preoperative evaluation including barium enema, colonoscopy, colonic transit time, and cinedefecography and balloon expulsion test were done in all patients. Clinical analysis of constipation with these tests indicated a simple slow transit colon in three patients but more complicated variations of combined anatomical functional disorders in the rest of the cases. Surgical procedures consisted of total colectomy, Frykman-Goldberg procedure, Wells procedure and appendisostomy, laparoscopically in 8 of them. Deep vein thrombosis developed in the postoperative period after rectopexy and pelvic floor repair in one case. The median follow-up time was 5.5 years. Fourteen (93.3%) patients had an excellent bowel movement and were highly satisfied with the surgical management. Surgical interventions may be beneficial in selected patients with refractory chronic constipation (Tab. 2, Ref. 13). Full Text (Free, PDF) www.bmj.sk.
Management of Status Epilepticus in Children
Smith, Douglas M.; McGinnis, Emily L.; Walleigh, Diana J.; Abend, Nicholas S.
2016-01-01
Status epilepticus is a common pediatric neurological emergency. Management includes prompt administration of appropriately selected anti-seizure medications, identification and treatment of seizure precipitant(s), as well as identification and management of associated systemic complications. This review discusses the definitions, classification, epidemiology and management of status epilepticus and refractory status epilepticus in children. PMID:27089373
2018-01-03
Acute Lymphoblastic Leukemia (ALL); Acute Myeloid Leukemia (AML); Myeloid Sarcoma; Chronic Myeloid Leukemia (CML); Juvenile Myelomonocytic Leukemia (JMML); Myelodysplastic Syndrome (MDS); Non-Hodgkin Lymphoma (NHL)
High temperature solar selective coatings
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kennedy, Cheryl E
Improved solar collectors (40) comprising glass tubing (42) attached to bellows (44) by airtight seals (56) enclose solar absorber tubes (50) inside an annular evacuated space (54. The exterior surfaces of the solar absorber tubes (50) are coated with improved solar selective coatings {48} which provide higher absorbance, lower emittance and resistance to atmospheric oxidation at elevated temperatures. The coatings are multilayered structures comprising solar absorbent layers (26) applied to the meta surface of the absorber tubes (50), typically stainless steel, topped with antireflective Savers (28) comprising at least two layers 30, 32) of refractory metal or metalloid oxides (suchmore » as titania and silica) with substantially differing indices of refraction in adjacent layers. Optionally, at least one layer of a noble metal such as platinum can be included between some of the layers. The absorbent layers cars include cermet materials comprising particles of metal compounds is a matrix, which can contain oxides of refractory metals or metalloids such as silicon. Reflective layers within the coating layers can comprise refractory metal silicides and related compounds characterized by the formulas TiSi. Ti.sub.3SiC.sub.2, TiAlSi, TiAN and similar compounds for Zr and Hf. The titania can be characterized by the formulas TiO.sub.2, Ti.sub.3O.sub.5. TiOx or TiO.sub.xN.sub.1-x with x 0 to 1. The silica can be at least one of SiO.sub.2, SiO.sub.2x or SiO.sub.2xN.sub.1-x with x=0 to 1.« less
Production method for making rare earth compounds
McCallum, R.W.; Ellis, T.W.; Dennis, K.W.; Hofer, R.J.; Branagan, D.J.
1997-11-25
A method of making a rare earth compound, such as a earth-transition metal permanent magnet compound, without the need for producing rare earth metal as a process step, comprises carbothermically reacting a rare earth oxide to form a rare earth carbide and heating the rare earth carbide, a compound-forming reactant (e.g., a transition metal and optional boron), and a carbide-forming element (e.g., a refractory metal) that forms a carbide that is more thermodynamically favorable than the rare earth carbide whereby the rare earth compound (e.g., Nd{sub 2}Fe{sub 14}B or LaNi{sub 5}) and a carbide of the carbide-forming element are formed.
Production method for making rare earth compounds
McCallum, R. William; Ellis, Timothy W.; Dennis, Kevin W.; Hofer, Robert J.; Branagan, Daniel J.
1997-11-25
A method of making a rare earth compound, such as a earth-transition metal permanent magnet compound, without the need for producing rare earth metal as a process step, comprises carbothermically reacting a rare earth oxide to form a rare earth carbide and heating the rare earth carbide, a compound-forming reactant (e.g. a transition metal and optional boron), and a carbide-forming element (e.g. a refractory metal) that forms a carbide that is more thermodynamically favorable than the rare earth carbide whereby the rare earth compound (e.g. Nd.sub.2 Fe.sub.14 B or LaNi.sub.5) and a carbide of the carbide-forming element are formed.
Ranaldo, Nunzio; Losurdo, Giuseppe; Iannone, Andrea; Principi, Mariabeatrice; Barone, Michele; De Carne, Massimo; Ierardi, Enzo; Di Leo, Alfredo
2017-09-07
A relevant percentage of non-erosive reflux disease (NERD) is refractory to proton pump inhibitors (PPIs) treatment. Multichannel intraluminal impedance pH (MII-pH) monitoring should give useful pathophysiological information about refractoriness. Therefore, our aim was to assess whether this technique could be useful to guide a 'tailored' therapy in refractory NERD. We retrospectively recruited NERD patients undergoing MII-pH monitoring for unsuccessful treatment. All patients had undergone upper endoscopy, and those with erosive esophagitis were excluded. No patient received PPI during MII-pH monitoring. Subjects were subgrouped into three categories: acid reflux, non-acid reflux and functional heartburn. MII-pH-guided therapy was performed for 4 weeks as follows: patients with acid reflux received PPI at double dose, patients with non-acid reflux PPI at full dose plus alginate four times a day and patients with functional heartburn levosulpiride 75 mg per day. A visual analog scale (VAS) ranging from 0 to 100 mm was administered before and after such tailored therapy to evaluate overall symptoms. Responders were defined by VAS improvement of at least 40%. Sixty-nine patients with refractory NERD were selected (female-male ratio 43 : 26, mean age 47.6±15.2 years). Overall effectiveness of tailored therapy was 84% without statistical difference among subgroups (88.5% acid reflux, 92% non-acid reflux, 66.6% functional heartburn; P=0.06). Univariate analysis showed that therapy failure directly correlated with functional heartburn diagnosis (OR=4.60) and suggested a trend toward a negative correlation with smoking and a positive one with nausea. However, at multivariate analysis, these parameters were not significant. Functional heartburn experienced a lower median percent VAS reduction than acid reflux (52.5% versus 66.6%, P<0.01) even if equal to non-acid reflux (66.6%). In conclusion, a tailored approach to refractory NERD, guided by MII-pH monitoring, demonstrated to be effective and should be promising to cure symptom persistence after conventional therapy failure. Nevertheless, standardized guidelines are advisable.
Zhou, Kesong; Ma, Wenyou; Attard, Bonnie; Zhang, Panpan; Kuang, Tongchun
2018-01-01
Abstract Selective laser melting (SLM) additive manufacturing of pure tungsten encounters nearly all intractable difficulties of SLM metals fields due to its intrinsic properties. The key factors, including powder characteristics, layer thickness, and laser parameters of SLM high density tungsten are elucidated and discussed in detail. The main parameters were designed from theoretical calculations prior to the SLM process and experimentally optimized. Pure tungsten products with a density of 19.01 g/cm3 (98.50% theoretical density) were produced using SLM with the optimized processing parameters. A high density microstructure is formed without significant balling or macrocracks. The formation mechanisms for pores and the densification behaviors are systematically elucidated. Electron backscattered diffraction analysis confirms that the columnar grains stretch across several layers and parallel to the maximum temperature gradient, which can ensure good bonding between the layers. The mechanical properties of the SLM-produced tungsten are comparable to that produced by the conventional fabrication methods, with hardness values exceeding 460 HV0.05 and an ultimate compressive strength of about 1 GPa. This finding offers new potential applications of refractory metals in additive manufacturing. PMID:29707073
Tan, Chaolin; Zhou, Kesong; Ma, Wenyou; Attard, Bonnie; Zhang, Panpan; Kuang, Tongchun
2018-01-01
Selective laser melting (SLM) additive manufacturing of pure tungsten encounters nearly all intractable difficulties of SLM metals fields due to its intrinsic properties. The key factors, including powder characteristics, layer thickness, and laser parameters of SLM high density tungsten are elucidated and discussed in detail. The main parameters were designed from theoretical calculations prior to the SLM process and experimentally optimized. Pure tungsten products with a density of 19.01 g/cm 3 (98.50% theoretical density) were produced using SLM with the optimized processing parameters. A high density microstructure is formed without significant balling or macrocracks. The formation mechanisms for pores and the densification behaviors are systematically elucidated. Electron backscattered diffraction analysis confirms that the columnar grains stretch across several layers and parallel to the maximum temperature gradient, which can ensure good bonding between the layers. The mechanical properties of the SLM-produced tungsten are comparable to that produced by the conventional fabrication methods, with hardness values exceeding 460 HV 0.05 and an ultimate compressive strength of about 1 GPa. This finding offers new potential applications of refractory metals in additive manufacturing.
2018-06-20
Advanced Malignant Solid Neoplasm; Ann Arbor Stage III Childhood Hodgkin Lymphoma; Ann Arbor Stage III Childhood Non-Hodgkin Lymphoma; Ann Arbor Stage IV Childhood Hodgkin Lymphoma; Ann Arbor Stage IV Childhood Non-Hodgkin Lymphoma; Ewing Sarcoma/Peripheral Primitive Neuroectodermal Tumor; EZH2 Gain of Function; EZH2 Gene Mutation; Histiocytosis; Loss of BRG1 Protein Expression; Loss of INI 1 Protein Expression; Low Grade Glioma; Recurrent Childhood Central Nervous System Neoplasm; Recurrent Childhood Ependymoma; Recurrent Childhood Soft Tissue Sarcoma; Recurrent Ewing Sarcoma; Recurrent Glioma; Recurrent Hepatoblastoma; Recurrent Hodgkin Lymphoma; Recurrent Langerhans Cell Histiocytosis; Recurrent Malignant Germ Cell Tumor; Recurrent Malignant Glioma; Recurrent Malignant Solid Neoplasm; Recurrent Medulloblastoma; Recurrent Neuroblastoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Osteosarcoma; Recurrent Peripheral Primitive Neuroectodermal Tumor; Recurrent Rhabdoid Tumor; Recurrent Rhabdomyosarcoma; Recurrent Soft Tissue Sarcoma; Refractory Central Nervous System Neoplasm; Refractory Hodgkin Lymphoma; Refractory Langerhans Cell Histiocytosis; Refractory Malignant Germ Cell Tumor; Refractory Malignant Glioma; Refractory Medulloblastoma; Refractory Neuroblastoma; Refractory Non-Hodgkin Lymphoma; Refractory Osteosarcoma; Refractory Peripheral Primitive Neuroectodermal Tumor; Refractory Rhabdoid Tumor; Refractory Soft Tissue Sarcoma; Rhabdoid Tumor; SMARCA4 Gene Inactivation; SMARCB1 Gene Inactivation; Stage III Soft Tissue Sarcoma AJCC v7; Stage IV Soft Tissue Sarcoma AJCC v7; Wilms Tumor
Vormoor, B; Veal, G J; Griffin, M J; Boddy, A V; Irving, J; Minto, L; Case, M; Banerji, U; Swales, K E; Tall, J R; Moore, A S; Toguchi, M; Acton, G; Dyer, K; Schwab, C; Harrison, C J; Grainger, J D; Lancaster, D; Kearns, P; Hargrave, D; Vormoor, J
2017-06-01
Aurora kinases regulate mitosis and are commonly overexpressed in leukemia. This phase I/IIa study of AT9283, a multikinase inhibitor, was designed to identify maximal tolerated doses, safety, pharmacokinetics, and pharmacodynamic activity in children with relapsed/refractory acute leukemia. The trial suffered from poor recruitment and terminated early, therefore failing to identify its primary endpoints. AT9283 caused tolerable toxicity, but failed to show clinical responses. Future trials should be based on robust preclinical data that provide an indication of which patients may benefit from the experimental agent, and recruitment should be improved through international collaborations and early combination with established treatment strategies. © 2016 Wiley Periodicals, Inc.
Proton pump inhibitor-refractory gastroesophageal reflux disease: challenges and solutions
Mermelstein, Joseph; Chait Mermelstein, Alanna; Chait, Maxwell M
2018-01-01
A significant percentage of patients with gastroesophageal reflux disease (GERD) will not respond to proton pump inhibitor (PPI) therapy. The causes of PPI-refractory GERD are numerous and diverse, and include adherence, persistent acid, functional disorders, nonacid reflux, and PPI bioavailability. The evaluation should start with a symptom assessment and may progress to imaging, endoscopy, and monitoring of esophageal pH, impedance, and bilirubin. There are a variety of pharmacologic and procedural interventions that should be selected based on the underlying mechanism of PPI failure. Pharmacologic treatments can include antacids, prokinetics, alginates, bile acid binders, reflux inhibitors, and antidepressants. Procedural options include laparoscopic fundoplication and LINX as well as endoscopic procedures, such as transoral incisionless fundoplication and Stretta. Several alternative and complementary treatments of possible benefit also exist. PMID:29606884
2017-10-25
Accelerated Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Acute Biphenotypic Leukemia; Acute Leukemia of Ambiguous Lineage; Acute Undifferentiated Leukemia; Adult Acute Lymphoblastic Leukemia in Remission; Adult Acute Myeloid Leukemia in Remission; Blast Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Blastic Plasmacytoid Dendritic Cell Neoplasm; Childhood Acute Lymphoblastic Leukemia in Remission; Childhood Acute Myeloid Leukemia in Remission; Lymphoblastic Lymphoma; Myelodysplastic Syndrome With Excess Blasts; Myelodysplastic Syndrome With Excess Blasts-1; Myelodysplastic Syndrome With Excess Blasts-2; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Recurrent Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Acute Lymphoblastic Leukemia; Refractory Acute Myeloid Leukemia
Abe, Mariko; Pelus, Louis M.; Singh, Pratibha; Hirade, Tomohiro; Onishi, Chie; Purevsuren, Jamiyan; Taketani, Takeshi; Yamaguchi, Seiji; Fukuda, Seiji
2016-01-01
Internal tandem duplication (ITD) mutations in the Fms-related tyrosine kinase 3 (FLT3) gene (FLT3-ITD) are associated with poor prognosis in patients with acute myeloid leukemia (AML). Due to the development of drug resistance, few FLT3-ITD inhibitors are effective against FLT3-ITD+ AML. In this study, we show that FLT3-ITD activates a novel pathway involving p21Cdkn1a (p21) and pre-B cell leukemia transcription factor 1 (Pbx1) that attenuates FLT3-ITD cell proliferation and is involved in the development of drug resistance. FLT3-ITD up-regulated p21 expression in both mouse bone marrow c-kit+-Sca-1+-Lin- (KSL) cells and Ba/F3 cells. The loss of p21 expression enhanced growth factor-independent proliferation and sensitivity to cytarabine as a consequence of concomitantly enriching the S+G2/M phase population and significantly increasing the expression of Pbx1, but not Evi-1, in FLT3-ITD+ cells. This enhanced cell proliferation following the loss of p21 was partially abrogated when Pbx1 expression was silenced in FLT3-ITD+ primary bone marrow colony-forming cells and Ba/F3 cells. When FLT3-ITD was antagonized with AC220, a selective inhibitor of FLT3-ITD, p21 expression was decreased coincident with Pbx1 mRNA up-regulation and a rapid decline in the number of viable FLT3-ITD+ Ba/F3 cells; however, the cells eventually became refractory to AC220. Overexpressing p21 in FLT3-ITD+ Ba/F3 cells delayed the emergence of cells that were refractory to AC220, whereas p21 silencing accelerated their development. These data indicate that FLT3-ITD is capable of inhibiting FLT3-ITD+ cell proliferation through the p21/Pbx1 axis and that treatments that antagonize FLT3-ITD contribute to the subsequent development of cells that are refractory to a FLT3-ITD inhibitor by disrupting p21 expression. PMID:27387666
Ibrutinib in Treating Patients With Refractory or Relapsed Lymphoma After Donor Stem Cell Transplant
2017-10-03
Blastoid Variant Mantle Cell Lymphoma; Recurrent Chronic Lymphocytic Leukemia; Recurrent Follicular Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent Mantle Cell Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Follicular Lymphoma; Refractory Hodgkin Lymphoma; Refractory Mantle Cell Lymphoma
Development of refractories and related products for steel melting, finishing, and casting
NASA Astrophysics Data System (ADS)
Smirnov, A. N.
2013-06-01
The transformation of the consumption of refractories for the production, out-of-furnace treatment, and casting of steel is considered. The main trends in developing the refractory market are shown to be a significant decrease in the specific consumption of refractories per 1 t liquid steel and the predominant application of refractories based on magnesia raw materials and fused corundum for the working layers of melting units, ladles, and tundishes. The main trend in decreasing the specific costs of refractories is the development of refractories based on alternative sources of raw materials, which are cheaper and more available for refractory manufacturers.
2017-06-30
Recurrent Chronic Lymphocytic Leukemia; Recurrent Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Nodal Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Recurrent Splenic Marginal Zone Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Extranodal Marginal Zone Lymphoma of Mucosa-Associated Lymphoid Tissue; Refractory Follicular Lymphoma; Refractory Lymphoplasmacytic Lymphoma; Refractory Nodal Marginal Zone Lymphoma; Refractory Small Lymphocytic Lymphoma; Refractory Splenic Marginal Zone Lymphoma; Richter Syndrome; Waldenstrom Macroglobulinemia
NASA Astrophysics Data System (ADS)
Oh, Semyeong; Price-Whelan, Adrian M.; Brewer, John M.; Hogg, David W.; Spergel, David N.; Myles, Justin
2018-02-01
We report and discuss the discovery of a significant difference in the chemical abundances of a comoving pair of bright solar-type stars, HD 240430 and HD 240429. The two stars have an estimated 3D separation of ≈0.6 pc (≈0.01 pc projected) at a distance of r ≈ 100 pc with nearly identical 3D velocities, as inferred from Gaia TGAS parallaxes and proper motions, and high-precision radial velocity measurements. Stellar parameters determined from high-resolution spectra obtained with the High Resolution Echelle Spectrometer (HIRES) at the Keck Observatory indicate that the two stars are ∼4 Gyr old. The more metal-rich of the two, HD 240430, shows an enhancement of refractory ({T}C> 1200 K) elements by ≈0.2 dex and a marginal enhancement of (moderately) volatile elements ({T}C< 1200 K; {{C}}, {{N}}, {{O}}, {Na}, and {Mn}). This is the largest metallicity difference found in a wide binary pair to date. Additionally, HD 240430 shows an anomalously high surface lithium abundance (A({Li})=2.75), higher than its cooler companion by 0.5 dex. The proximity in phase-space and ages between the two stars suggests that they formed together with the same composition, which is at odds with the observed differences in metallicity and abundance patterns. We therefore suggest that the star HD 240430, “Kronos,” accreted 15 {M}\\oplus of rocky material after birth, selectively enhancing the refractory elements as well as lithium in its surface and convective envelope.
Possible impact-induced refractory-lithophile fractionations in EL chondrites
NASA Astrophysics Data System (ADS)
Rubin, Alan E.; Huber, Heinz; Wasson, John T.
2009-03-01
Literature data show that refractory-lithophile elements in most chondrite groups are unfractionated relative to CI chondrites; the principal exception is the EL-chondrite group whose observed falls (all of which are type 6) are depleted in Ca and light REE. In contrast, literature data and our new INAA data on EL3 PCA 91020, EL3 MAC 88136 and EL4 Grein 002 show that some replicates of these samples have nearly flat REE patterns (unlike those of EL6 chondrites); other replicates exhibit fractionated REE patterns similar to those of EL6 chondrites. Petrographic examination shows that many EL6 (and some EL3 and EL4) chondrites are impact-melt breccias or contain impact-melted portions. We suggest that the same impact processes that formed these breccias and produced melt are responsible for the observed bulk compositional fractionations in refractory-lithophile elements, i.e., EL6 chondrites were produced from initially unequilibrated EL3 material. When large amounts of impact heat were deposited, plagioclase and/or oldhamite (CaS) (the major REE carriers in enstatite chondrites) may have been melted and then transported appreciable (>10 cm) distances. EL6 chondrites represent the residuum that is depleted in REE (particularly in LREE) and Ca. Unlike the case for EL chondrites, our new INAA data on ALH 84170, EET 87746 and SAH 97096 (all EH3) show some scatter but are consistent with the EH group having uniform refractory-lithophile abundances.
NASA Astrophysics Data System (ADS)
Adabifiroozjaei, Esmaeil; Saidi, Ali; Monshi, Ahmad; Koshy, Pramod
2011-04-01
Andalusite containing low-cement castables (LCCs) have been used in aluminum casthouses for several decades. CaF2 is commonly added to the refractory to improve its corrosion resistance mainly because of its role in the formation of anorthite (CaAl2Si2O8); the latter has been reported to decrease the penetration of molten aluminum alloys into refractories. This article investigates the effect of the addition of different calcium containing compounds (CaO, CaCO3, CaSO4, CaF2, Clinker white cement, calcia feldspar, wollastonite, and Ca3(PO4)2) on reactions with the refractory constituents to form anorthite as well as the effect of the additives on both the subsequent physical properties and the corrosion resistance of andalusite LCC refractories. Corrosion tests using the Alcoa cup test at temperatures (1123 K [850 °C] for 150 hours and 1433 K [1160 °C] for 72 hours) were conducted to determine the extent of penetration, whereas immersion tests in boiling water were conducted to determine the extent of open porosity in the material. Scanning electron microscopy coupled with energy dispersive spectrometer, optical microscopy, and X-ray diffraction techniques were employed to characterize the phase formations in the materials after the tests. The study demonstrated that both calcia feldspar and clinker white cement had the potential to be used as new additives for decreasing the penetration of molten Al-alloy into the refractory materials. Anorthite formation (in the refractory matrix), along with the absence of glassy phases, were responsible for the improvement in the corrosion resistance of the castables containing calcia feldspar. However, in the sample containing cement, the presence of calcium silicate phases were observed to resist reactions with molten aluminum. The observed results were validated using thermodynamic calculations, which indicated that tricalcium silicates (3CaO.SiO2) and dicalcium silicate (2CaO.SiO2) phases were more resistant than wollastonite (CaSiO3) for applications involving contact with molten aluminum.
Petit-Pedrol, Mar; Armangue, Thaís; Peng, Xiaoyu; Bataller, Luis; Cellucci, Tania; Davis, Rebecca; McCracken, Lindsey; Martinez-Hernandez, Eugenia; Mason, Warren P; Kruer, Michael C; Ritacco, David G; Grisold, Wolfgang; Meaney, Brandon F; Alcalá, Carmen; Sillevis-Smitt, Peter; Titulaer, Maarten J; Balice-Gordon, Rita; Graus, Francesc; Dalmau, Josep
2014-03-01
Increasing evidence suggests that seizures and status epilepticus can be immune-mediated. We aimed to describe the clinical features of a new epileptic disorder, and to establish the target antigen and the effects of patients' antibodies on neuronal cultures. In this observational study, we selected serum and CSF samples for antigen characterisation from 140 patients with encephalitis, seizures or status epilepticus, and antibodies to unknown neuropil antigens. The samples were obtained from worldwide referrals of patients with disorders suspected to be autoimmune between April 28, 2006, and April 25, 2013. We used samples from 75 healthy individuals and 416 patients with a range of neurological diseases as controls. We assessed the samples using immunoprecipitation, mass spectrometry, cell-based assay, and analysis of antibody effects in cultured rat hippocampal neurons with confocal microscopy. Neuronal cell-membrane immunoprecipitation with serum of two index patients revealed GABAA receptor sequences. Cell-based assay with HEK293 expressing α1/β3 subunits of the GABAA receptor showed high titre serum antibodies (>1:160) and CSF antibodies in six patients. All six patients (age 3-63 years, median 22 years; five male patients) developed refractory status epilepticus or epilepsia partialis continua along with extensive cortical-subcortical MRI abnormalities; four patients needed pharmacologically induced coma. 12 of 416 control patients with other diseases, but none of the healthy controls, had low-titre GABAA receptor antibodies detectable in only serum samples, five of them also had GAD-65 antibodies. These 12 patients (age 2-74 years, median 26.5 years; seven male patients) developed a broader spectrum of symptoms probably indicative of coexisting autoimmune disorders: six had encephalitis with seizures (one with status epilepticus needing pharmacologically induced coma; one with epilepsia partialis continua), four had stiff-person syndrome (one with seizures and limbic involvement), and two had opsoclonus-myoclonus. Overall, 12 of 15 patients for whom treatment and outcome were assessable had full (three patients) or partial (nine patients) response to immunotherapy or symptomatic treatment, and three died. Patients' antibodies caused a selective reduction of GABAA receptor clusters at synapses, but not along dendrites, without altering NMDA receptors and gephyrin (a protein that anchors the GABAA receptor). High titres of serum and CSF GABAA receptor antibodies are associated with a severe form of encephalitis with seizures, refractory status epilepticus, or both. The antibodies cause a selective reduction of synaptic GABAA receptors. The disorder often occurs with GABAergic and other coexisting autoimmune disorders and is potentially treatable. The National Institutes of Health, the McKnight Neuroscience of Brain Disorders, the Fondo de Investigaciones Sanitarias, Fundació la Marató de TV3, the Netherlands Organisation for Scientific Research (Veni-incentive), the Dutch Epilepsy Foundation. Copyright © 2014 Elsevier Ltd. All rights reserved.
[National consensus on the ketogenic diet].
Armeno, Marisa; Caraballo, Roberto; Vaccarezza, María; Alberti, M Julia; Ríos, Viviana; Galicchio, Santiago; de Grandis, Elizabeth S; Mestre, Graciela; Escobal, Nidia; Matarrese, Pablo; Viollaz, Rocío; Agostinho, Ariela; Díez, Cecilia; Cresta, Araceli; Cabrera, Analía; Blanco, Virginia; Ferrero, Hilario; Gambarini, Victoria; Sosa, Patricia; Bouquet, Cecilia; Caramuta, Luciana; Guisande, Silvina; Gamboni, Beatriz; Hassan, Amal; Pesce, Laura; Argumedo, Laura; Dlugoszewski, Corina; DeMartini, Martha G; Panico, Luis
2014-09-01
Epilepsy is a chronic disease with onset in infancy affecting 0.5-1% of the population. One third of the patients is refractory to antiepileptic drugs and they pose a challenge for the health care team. The ketogenic diet is an effective, non-pharmacological, alternative treatment for the management of refractory epilepsy. There is a need to establish guidelines for the adequate and increased use of the ketogenic diet in Spanish-speaking countries. The National Committee on the Ketogenic Diet, consisting of paediatric neurologists, clinical nutritionists, and dietitians, of the Argentine Society of Child Neurology has developed this consensus statement to standardize the use of the ketogenic diet based on the literature and clinical experience. Patient selection, pre-treatment family counseling, drug interactions, micronutrient supplementation, adverse effects, and discontinuation of the diet are discussed. The ketogenic diet is an effective treatment for children with refractory epilepsy. Education and collaboration of the patient and their family is essential. The patient should be managed by an experienced multidisciplinary team using a protocol. The formation of a national multidisciplinary team and the publication of this document provide possibilities for new centers to integrate the ketogenic diet into their treatment options.
Little, Jessica A; Sen, Ethan S; Strike, Helen; Hinchcliffe, Annie; Guly, Catherine M; Lee, Richard W J; Dick, Andrew D; Ramanan, Athimalaipet V
2014-01-01
To assess the safety and efficacy of noncorticosteroid triple immunosuppressive therapy in the treatment of refractory chronic noninfectious childhood uveitis. Subjects were retrospectively selected from a database. Patients were included if they were diagnosed with chronic, noninfectious uveitis at 16 years of age or under and treated with triple immunosuppressive therapy for at least 6 months (following failure of a combination of 2 immunosuppressants). Patient demographics, diagnoses, duration of uveitis, drug dosages, active joint inflammation, and ophthalmologic data were recorded. Efficacy outcomes for triple therapy were recorded at 6 months. Thirteen patients with bilateral uveitis were included. Using Standardized Uveitis Nomenclature (SUN) criteria, at 6 months only 11 eyes (42%) had a 2-step improvement in anterior chamber cell inflammation (n = 26). In addition, 2 patients required additional oral corticosteroid treatment. There were 4 significant infectious adverse events during a total of 21.9 patient-years (PY) on triple therapy (0.18 events per PY). In this group of children with refractory uveitis, addition of a third immunosuppressive agent did not confer substantial benefit in redressing ocular inflammation and was associated with significant infections in a minority of patients.
2018-02-12
Prolymphocytic Leukemia; Recurrent Adult Hodgkin Lymphoma; Recurrent Childhood Hodgkin Lymphoma; Recurrent Childhood Non-Hodgkin Lymphoma; Recurrent Chronic Lymphocytic Leukemia; Recurrent Non-Hodgkin Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory Childhood Hodgkin Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Hodgkin Lymphoma; Refractory Non-Hodgkin Lymphoma; Refractory Small Lymphocytic Lymphoma; T-Cell Chronic Lymphocytic Leukemia; T-Cell Prolymphocytic Leukemia
2018-01-25
Grade 3a Follicular Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Waldenstrom Macroglobulinemia; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Lymphoplasmacytic Lymphoma; Refractory Mantle Cell Lymphoma
2018-03-02
Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Lymphoplasmacytic Lymphoma; Refractory Mantle Cell Lymphoma
2014-06-10
Childhood Myelodysplastic Syndromes; de Novo Myelodysplastic Syndromes; Previously Treated Myelodysplastic Syndromes; Refractory Anemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Ringed Sideroblasts; Refractory Cytopenia With Multilineage Dysplasia; Secondary Myelodysplastic Syndromes; Unspecified Childhood Solid Tumor, Protocol Specific
2018-04-11
CD20 Positive; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Chronic Lymphocytic Leukemia; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Lymphoplasmacytic Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Transformed Indolent Non-Hodgkin Lymphoma
Making Space Travel to Jupiter Possible
NASA Technical Reports Server (NTRS)
Barker, Samuel P.
2004-01-01
From man landing on the moon to a simple satellite being launched into orbit, many incredible space accomplishments have been witnessed by us all. However, what goes un-noticed to the common man is the extensive research and testing that lasts months, years, and even decades. Much of this required research just so happens to take place in the corridors of the Glen Research Center building number 49. In the Advanced Materials division of G.R.C., a number of researchers have the responsibility of discovering which metal, ceramic, or polymer is best for a specific application. Under the guidance of mentor extraordinaire Frank Ritzert, I am involved in many critical projects dealing with refractory metals, two of which I will mention in this report. The Jupiter Icy Moons Orbiter (JIMO) project actually was under full swing back in the 50's and early 60's. To enable the 14 year trek to the icy moons of Europa, Callisto, and Ganymede, nuclear propulsion methods were selected. Due to the extreme temperature of the reactor and the extended time period, a refractory metal would need to be implemented. After years of research and progress, the program was suddenly canceled. About a decade ago, the JIMO project was re-instated and now has a goal for departure around 2014. However, a few obstacles lie in our way concerning the use of refractory metals. In certain areas of the orbiter a joint is required between the refractories and other less dense metals. Two of these joints are with nickel based super alloys. Being an intern for Frank Ritzert, the refractory metals expert, I have the opportunity to develop the best method to braze refractory metals to Nickel 201. This involves the actual brazing, electron microscopy and reporting the results. My second project involves a certain part of the orbiter where Niobium 1Zirconium, a refractory metal, is joined with Hastelloy-X a Ni based metal. Small quantities of oxygen, helium and other impurities in the Ni alloy could diffuse into the Nb1Zr causing imbrittlement and possibly major failure. I will be testing the effects of Hast-X on Nb1Zr in a high temperature for 10, 50, 100, and 500 hours. After the samples are run through the heat treatment, strength and chemistry will be tested and reported. My appreciation for the research that goes behind every project has and will continue to grow. By digging through old documents written in the 50's and 60's, scouring through forgotten closets, and learning from those with experience in the refractory metals, I am bound to have an incredible learning experience here at NASA.
Method of making tantalum capacitors
McMillan, April D.; Clausing, Robert E.; Vierow, William F.
1998-01-01
A method for manufacturing tantalum capacitors includes preparing a tantalum compact by cold pressing tantalum powder, placing the compact, along with loose refractory metal powder, in a microwave-transparent casket to form an assembly, and heating the assembly for a time sufficient to effect at least partial sintering of the compact and the product made by the method.
NASA Astrophysics Data System (ADS)
Piani, L.; Tachibana, S.; Hama, T.; Tanaka, H.; Endo, Y.; Sugawara, I.; Dessimoulie, L.; Kimura, Y.; Miyake, A.; Matsuno, J.; Tsuchiyama, A.; Fujita, K.; Nakatsubo, S.; Fukushi, H.; Mori, S.; Chigai, T.; Yurimoto, H.; Kouchi, A.
2017-03-01
Refractory organic compounds formed in molecular clouds are among the building blocks of the solar system objects and could be the precursors of organic matter found in primitive meteorites and cometary materials. However, little is known about the evolutionary pathways of molecular cloud organics from dense molecular clouds to planetary systems. In this study, we focus on the evolution of the morphological and viscoelastic properties of molecular cloud refractory organic matter. We found that the organic residue, experimentally synthesized at ˜10 K from UV-irradiated H2O-CH3OH-NH3 ice, changed significantly in terms of its nanometer- to micrometer-scale morphology and viscoelastic properties after UV irradiation at room temperature. The dose of this irradiation was equivalent to that experienced after short residence in diffuse clouds (≤104 years) or irradiation in outer protoplanetary disks. The irradiated organic residues became highly porous and more rigid and formed amorphous nanospherules. These nanospherules are morphologically similar to organic nanoglobules observed in the least-altered chondrites, chondritic porous interplanetary dust particles, and cometary samples, suggesting that irradiation of refractory organics could be a possible formation pathway for such nanoglobules. The storage modulus (elasticity) of photo-irradiated organic residues is ˜100 MPa irrespective of vibrational frequency, a value that is lower than the storage moduli of minerals and ice. Dust grains coated with such irradiated organics would therefore stick together efficiently, but growth to larger grains might be suppressed due to an increase in aggregate brittleness caused by the strong connections between grains.
Destruction of Refractory Carbon in Protoplanetary Disks
DOE Office of Scientific and Technical Information (OSTI.GOV)
Anderson, Dana E.; Blake, Geoffrey A.; Bergin, Edwin A.
The Earth and other rocky bodies in the inner solar system contain significantly less carbon than the primordial materials that seeded their formation. These carbon-poor objects include the parent bodies of primitive meteorites, suggesting that at least one process responsible for solid-phase carbon depletion was active prior to the early stages of planet formation. Potential mechanisms include the erosion of carbonaceous materials by photons or atomic oxygen in the surface layers of the protoplanetary disk. Under photochemically generated favorable conditions, these reactions can deplete the near-surface abundance of carbon grains and polycyclic aromatic hydrocarbons by several orders of magnitude onmore » short timescales relative to the lifetime of the disk out to radii of ∼20–100+ au from the central star depending on the form of refractory carbon present. Due to the reliance of destruction mechanisms on a high influx of photons, the extent of refractory carbon depletion is quite sensitive to the disk’s internal radiation field. Dust transport within the disk is required to affect the composition of the midplane. In our current model of a passive, constant- α disk, where α = 0.01, carbon grains can be turbulently lofted into the destructive surface layers and depleted out to radii of ∼3–10 au for 0.1–1 μ m grains. Smaller grains can be cleared out of the planet-forming region completely. Destruction may be more effective in an actively accreting disk or when considering individual grain trajectories in non-idealized disks.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Piani, L.; Tachibana, S.; Endo, Y.
Refractory organic compounds formed in molecular clouds are among the building blocks of the solar system objects and could be the precursors of organic matter found in primitive meteorites and cometary materials. However, little is known about the evolutionary pathways of molecular cloud organics from dense molecular clouds to planetary systems. In this study, we focus on the evolution of the morphological and viscoelastic properties of molecular cloud refractory organic matter. We found that the organic residue, experimentally synthesized at ∼10 K from UV-irradiated H{sub 2}O-CH{sub 3}OH-NH{sub 3} ice, changed significantly in terms of its nanometer- to micrometer-scale morphology andmore » viscoelastic properties after UV irradiation at room temperature. The dose of this irradiation was equivalent to that experienced after short residence in diffuse clouds (≤10{sup 4} years) or irradiation in outer protoplanetary disks. The irradiated organic residues became highly porous and more rigid and formed amorphous nanospherules. These nanospherules are morphologically similar to organic nanoglobules observed in the least-altered chondrites, chondritic porous interplanetary dust particles, and cometary samples, suggesting that irradiation of refractory organics could be a possible formation pathway for such nanoglobules. The storage modulus (elasticity) of photo-irradiated organic residues is ∼100 MPa irrespective of vibrational frequency, a value that is lower than the storage moduli of minerals and ice. Dust grains coated with such irradiated organics would therefore stick together efficiently, but growth to larger grains might be suppressed due to an increase in aggregate brittleness caused by the strong connections between grains.« less
Sera from cancer patients contain two oscillating ECTO-NOX activities with different period lengths
NASA Technical Reports Server (NTRS)
Wang, Sui; Morre, Dorothy M.; Morre, D. James
2003-01-01
ECTO-NOX protein's are cell surface-associated and growth-related hydroquinone oxidases with both protein disulfide-thiol interchange activity and the capacity to oxidize NAD(P)H. The activities of these ECTO-NOX proteins are not steady state but fluctuate to create a repeating pattern of oscillations. Two forms of ECTO-NOX activities have been distinguished. The constitutive ECTO-NOX (CNOX), is hormone responsive and refractory to quinone-site inhibitors. A tumor-associated NOX (tNOX) is unregulated, refractory to hormones and growth factors and responds to quinone-site inhibitors. CNOX proteins are widely distributed and exhibit oscillations in enzymatic activity with a period length of 24 min. tNOX proteins are cancer specific and exhibit oscillations with a period length of about 22 min. Our findings now demonstrate the presence of the novel oscillating tNOX activity in sera of patients with cancer whereas the constitutive NOX of non-cancer cells is present in sera of both cancer patients and healthy volunteers. We conclude that ECTO-NOX proteins in sera exhibit oscillatory characteristics similar to those of ECTO-NOX forms of the cell surface.
Elliott, Cameron A; Broad, Andrew; Narvacan, Karl; Steve, Trevor A; Snyder, Thomas; Urlacher, Jordan; Wheatley, B Matt; Sinclair, D Barry
2018-06-22
OBJECTIVE The aim of this study was to investigate long-term seizure outcome, rate of reoperation, and postoperative neuropsychological performance following selective amygdalohippocampectomy (SelAH) or anterior temporal lobectomy (ATL) in pediatric patients with medically refractory temporal lobe epilepsy (TLE). METHODS The authors performed a retrospective review of cases of medically refractory pediatric TLE treated initially with either SelAH or ATL. Standardized pre- and postoperative evaluation included seizure charting, surface and long-term video-electroencephalography, 1.5-T MRI, and neuropsychological testing. RESULTS A total of 79 patients treated initially with SelAH (n = 18) or ATL (n = 61) were included in this study, with a mean follow-up of 5.3 ± 4 years (range 1-16 years). The patients' average age at initial surgery was 10.6 ± 5 years, with an average surgical delay of 5.7 ± 4 years between seizure onset and surgery. Seizure freedom (Engel I) following the initial operation was significantly more likely following ATL (47/61, 77%) than SelAH (8/18, 44%; p = 0.017, Fisher's exact test). There was no statistically significant difference in the proportion of patients with postoperative neuropsychological deficits following SelAH (8/18, 44%) or ATL (21/61, 34%). However, reoperation was significantly more likely following SelAH (8/18, 44%) than after ATL (7/61, 11%; p = 0.004) and was more likely to result in Engel I outcome for ATL after failed SelAH (7/8, 88%) than for posterior extension after failed ATL (1/7, 14%; p = 0.01). Reoperation was well tolerated without significant neuropsychological deterioration. Ultimately, including 15 reoperations, 58 of 79 (73%) patients were free from disabling seizures at the most recent follow-up. CONCLUSIONS SelAH among pediatric patients with medically refractory unilateral TLE yields significantly worse rates of seizure control compared with ATL. Reoperation is significantly more likely following SelAH, is not associated with incremental neuropsychological deterioration, and frequently results in freedom from disabling seizures. These results are significant in that they argue against using SelAH for pediatric TLE surgery.
Friction and wear of radiofrequency-sputtered borides, silicides, and carbides
NASA Technical Reports Server (NTRS)
Brainard, W. A.; Wheeler, D. R.
1978-01-01
The friction and wear properties of several refractory compound coatings were examined. These compounds were applied to 440 C bearing steel surfaces by radiofrequency (RF) sputtering. The refractory compounds were the titanium and molybdenum borides, the titanium and molybdenum silicides, and the titanium, molybdenum, and boron carbides. Friction testing was done with a pin-on-disk wear apparatus at loads from 0.1 to 5.0 newtons. Generally, the best wear properties were obtained when the coatings were bias sputtered onto 440 C disks that had been preoxidized. Adherence was improved because of the better bonding of the coatings to the iron oxide formed during preoxidation. As a class the carbides provided wear protection to the highest loads. Titanium boride coatings provided low friction and good wear properties to moderate loads.
NASA research on refractory compounds.
NASA Technical Reports Server (NTRS)
Gangler, J. J.
1971-01-01
The behavior and properties of the refractory carbides, nitrides, and borides are being investigated by NASA as part of its research aimed at developing superior heat resistant materials for aerospace applications. Studies of the zirconium-carbon-oxygen system show that zirconium oxycarbides of different compositions and lattice parameters can be formed between 1500 C and 1900 C and are stable below 1500 C. More applied studies show that hot working generally improves the microstructure and therefore the strength of TiC and NbC. Sintering studies on UN indicate that very high densities can be achieved. Hot pressing of cermets of HfN and HfC produces good mechanical properties for high temperature bearing applications. Attempts to improve the impact resistance of boride composites by the addition of a nickel or carbon yarn were not overly successful.
Origin of cometary and chondritic refractory organics: Ion irradiation experiments
NASA Astrophysics Data System (ADS)
Quirico, E.; Faure, M.; Faure, A.; Baklouti, D.; Boduch, P.; Rothard, H.; Ballanzat, E.; Dartois, E.; Brunetto, R.; Bonal, L.; Beck, P.; Schmitt, B.; Duprat, J.; Engrand, C.
2017-09-01
The formation process of Refractory Organic matter present in chondrites and Interplanetary Dust Particles (IDPs) of cometary and asteroidal origin is a debated issue. Earlier studies have advocated a formation step in a hot environment, however the potential role of ion irradiation has been so far poorly constrained. We present here experimental simulations that address this issue, comprising thermal degradation and ion irradiation experiments conducted at GANIL (Caen France) and CSNSM (Orsay France). We show that unlike thermal reactions, ion irradiation might lead to ROM-like material under very stringent conditions on both the nuclear dose and the nature of precursor. These very narrow conditions suggest that forming ROM without any action of thermal reactions is extremely difficult in astrophysical environments, either ISM or the proto-solar disk.
Axicabtagene Ciloleucel Expanded Access Study
2018-05-29
Relapsed/Refractory Diffuse Large B Cell Lymphoma; Relapsed/Refractory Primary Mediastinal B Cell Lymphoma; Relapsed/Refractory Transformed Follicular Lymphoma; Relapsed/Refractory High-Grade B-Cell Lymphoma
Lancet, Michael S.; Curran, George P.
1981-08-18
A synthetic CO.sub.2 acceptor consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca.sub.5 (SiO.sub.4).sub.2 CO.sub.3. A method for producing the synthetic CO.sub.2 acceptor is also disclosed.
Wright, Michael T; Parker, David R; Amrhein, Christopher
2003-10-15
Sequential extraction procedures (SEPs) have been widely used to characterize the mobility, bioavailibility, and potential toxicity of trace elements in soils and sediments. Although oft-criticized, these methods may perform best with redox-labile elements (As, Hg, Se) for which more discrete biogeochemical phases may arise from variations in oxidation number. We critically evaluated two published SEPs for Se for their specificity and precision by applying them to four discrete components in an inert silica matrix: soluble Se(VI) (selenate), Se(IV) (selenite) adsorbed onto goethite, elemental Se, and a metal selenide (FeSe; achavalite). These were extracted both individually and in a mixed model sediment. The more selective of the two procedures was modified to further improve its selectivity (SEP 2M). Both SEP 1 and SEP 2M quantitatively recovered soluble selenate but yielded incomplete recoveries of adsorbed selenite (64% and 81%, respectively). SEP 1 utilizes 0.1 M K2S2O8 to target "organically associated" Se, but this extractant also solubilized most of the elemental (64%) and iron selenide (91%) components of the model sediment. In SEP 2M, the Na2SO3 used in step III is effective in extracting elemental Se but also extracted 17% of the Se from the iron selenide, such that the elemental fraction would be overestimated should both forms coexist. Application of SEP 2M to eight wetland sediments further suggested that the Na2SO3 in step III extracts some organically associated Se, so a NaOH extraction was inserted beforehand to yield a further modification, SEP 2OH. Results using this five-step procedure suggested that the four-step SEP 2M could overestimate elemental Se by as much as 43% due to solubilization of organic Se. Although still imperfect in its selectivity, SEP 20H may be the most suitable procedure for routine, accurate fractionation of Se in soils and sediments. However, the strong oxidant (NaOCl) used in the final step cannot distinguish between refractory organic forms of Se and pyritic Se that might form under sulfur-reducing conditions.
The influence of training on the attentional blink and psychological refractory period.
Garner, K G; Tombu, M N; Dux, P E
2014-05-01
A growing body of research suggests that dual-task interference in sensory consolidation (e.g., the attentional blink, AB) and response selection (e.g., the psychological refractory period, PRP) stems from a common central bottleneck of information processing. With regard to response selection, it is well known that training reduces dual-task interference. We tested whether training that is known to be effective for response selection can also reduce dual-task interference in sensory consolidation. Over two experiments, performance on a PRP paradigm (Exp. 1) and on AB paradigms (differing in their stimuli and task demands, Exps. 1 and 2) was examined after participants had completed a relevant training regimen (T1 practice for both paradigms), an irrelevant training regimen (comparable sensorimotor training, not related to T1 for both tasks), a visual-search training regimen (Exp. 2 only), or after participants had been allocated to a no-training control group. Training that had shown to be effective for reducing dual-task interference in response selection was also found to be effective for reducing interference in sensory consolidation. In addition, we found some evidence that training benefits transferred to the sensory consolidation of untrained stimuli. Collectively, these findings show that training benefits can transfer across cognitive operations that draw on the central bottleneck in information processing. These findings have implications for theories of the AB and for the design of cognitive-training regimens that aim to produce transferable training benefits.
2018-03-28
Breast Adenocarcinoma; Recurrent Breast Carcinoma; Recurrent Hodgkin Lymphoma; Recurrent Mycosis Fungoides; Recurrent Non-Hodgkin Lymphoma; Recurrent Primary Cutaneous T-Cell Non-Hodgkin Lymphoma; Refractory Hodgkin Lymphoma; Refractory Mycosis Fungoides; Refractory Nodal Marginal Zone Lymphoma; Refractory Non-Hodgkin Lymphoma; Refractory Primary Cutaneous T-Cell Non-Hodgkin Lymphoma; Stage IV Breast Cancer AJCC v6 and v7
Agarwal, Mohan B; Bhurani, Dinesh; Shah, Chirag; Sood, Nitin; Singhal, Manish; Kamat, Anil; Chezhian, Subash; Mishra, Suryaprakash; Nagrale, Dinesh
2017-01-01
This named patient program evaluated the safety and efficacy of ibrutinib, a selective inhibitor of Bruton's tyrosine kinase in Indian patients with relapsed/refractory chronic lymphocytic leukemia (CLL, with/without chromosome 17 deletion [del17p]) and mantle cell lymphoma (MCL). The eight enrolled patients (relapsed/refractory CLL: n = 6 [4/6 patients with del17p] and relapsed/refractory MCL: n = 2) had median age of 55 years (range, 52-60) and had received a median of 3 (CLL patients) and 4 (MCL patients) prior therapies. Patients received once-daily dose of ibrutinib (420 mg: CLL, 560 mg: MCL). In CLL patients, the median time to response was 3 months (range, 0.5-7) and five of six patients had partial response (PR) whereas one achieved complete response (CR). Median time on treatment was 11.5 months (range, 8-14); five patients continued treatment and one was recommended stem cell transplantation (SCT). Of the two MCL patients, one achieved PR and one showed CR and advanced to SCT. In CLL patients, the median (range) hemoglobin level improved from 9.8 g/dL (7.2-11) at baseline to 12.0 g/dL (9.5-13.2) and median (range) platelet count improved from 150,000 cells/μL (21,000-195,000) at baseline to 190,350 cells/μL (130,000-394,000) at the time of analysis (July 2016). Most adverse events (AEs) reported were infections ( n = 2). No Grade 3-4 or serious AEs, dose reductions, or treatment discontinuation due to AEs were reported. In this first real-world experience in Indian patients, ibrutinib demonstrated therapeutic efficacy in relapsed/refractory CLL (with/without del17p) and MCL. Safety results were consistent with the current known profile of ibrutinib.
Liang, Jackson J; Betensky, Brian P; Muser, Daniele; Zado, Erica S; Anter, Elad; Desai, Nimesh D; Callans, David J; Deo, Rajat; Frankel, David S; Hutchinson, Mathew D; Lin, David; Riley, Michael P; Schaller, Robert D; Supple, Gregory E; Santangeli, Pasquale; Acker, Michael A; Bavaria, Joseph E; Szeto, Wilson Y; Vallabhajosyula, Prashanth; Marchlinski, Francis E; Dixit, Sanjay
2018-03-01
Limited data exist on the long-term outcome of patients (pts) with non-ischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) refractory to conventional therapies undergoing surgical ablation (SA). We aimed to investigate the long-term survival and VT recurrence in NICM pts with VT refractory to radiofrequency catheter ablation (RFCA) who underwent SA. Consecutive pts with NICM and VT refractory to RFCA who underwent SA were included. VT substrate was characterized in the electrophysiology lab and targeted by RFCA. During SA, previous RFCA lesions/scars were identified and targeted with cryoablation (CA; 3 min/lesion; target -150 °C). Follow-up comprised office visits, ICD interrogations and the social security death index. Twenty consecutive patients with NICM who underwent SA (age 53 ± 16 years, 18 males, LVEF 41 ± 20%; dilated CM = 9, arrhythmogenic right ventricular CM = 3, hypertrophic CM = 2, valvular CM = 4, and mixed CM = 2) were studied. Percutaneous mapping/ablation in the electrophysiology lab was performed in 18 and 2 pts had primary SA. During surgery, 4.9 ± 4.0 CA lesions/pt were delivered to the endocardium (2) and epicardium (11) or both (7). VT-free survival was 72.5% at 1 year and over 43 ± 31 months (mos) (range 1-83mos), there was only one arrhythmia-related death. There was a significant reduction in ICD shocks in the 3-mos preceding SA vs. the entire follow-up period (6.6 ± 4.9 vs. 2.3 ± 4.3 shocks/pt, P = 0.001). In select pts with NICM and VT refractory to RFCA, SA guided by pre-operative electrophysiological mapping and ablation may be a therapeutic option. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.
Review and update of the Hong Kong Epilepsy Guideline on status epilepticus.
Fung, E Lw; Fung, B Bh
2017-02-01
Convulsive status epilepticus is the most extreme form of seizure. It is a medical and neurological emergency that requires prompt and appropriate treatment. Treatment of convulsive status epilepticus is usually divided into stages/steps. The International League Against Epilepsy has released a new definition of status epilepticus that may help to unify the definition in future studies. Over the last few years new information has become available regarding its management. The Rapid Anticonvulsant Medication Prior to Arrival Trial demonstrated non-inferiority of intramuscular midazolam in early status epilepticus compared with intravenous lorazepam. Valproate and levetiracetam have also emerged as possible alternatives to phenytoin in established status epilepticus. The potential role of lacosamide in this stage of status epilepticus remains to be defined. The ongoing Established Status Epilepticus Treatment Trial may help to determine the most effective treatment for benzodiazepine-resistant status epilepticus. Management of refractory status epilepticus and super-refractory status epilepticus remains mostly non-evidence-based. Increasing recognition of a possible autoimmune aetiology has led to the use of immune-modulation in super-refractory status epilepticus. Ketamine is also increasingly used in this challenging condition. There are also reports of potential use of a ketogenic diet and magnesium.
Scarponi, Letizia; Mozzanica, Francesco; De Cristofaro, Valeria; Ginocchio, Daniela; Pizzorni, Nicole; Bottero, Alessandro; Schindler, Antonio
2015-01-01
The aim of this study was to evaluate the role of neuromuscular electrical stimulation (NMES) in tube-fed patients with severe and chronic dysphagia refractory to traditional swallowing therapy (TT). A total of 11 consecutive dysphagic patients with tube-dependent nutrition and who had not responded to 6 months of TT were enrolled. Each patient received NMES for 30 min and TT for 30 min, twice a day, 5 days per week for 4 weeks. In order to evaluate the swallowing impairment, each patient underwent a fiberoptic endoscopic examination of swallowing immediately before the beginning of the treatment, after 2 weeks and after 4 weeks. All enrolled patients managed to complete the swallowing treatment protocol for at least 2 weeks. After the 4-week treatment, 6 of 11 enrolled patients passed to a total oral diet with single or multiple consistencies despite specific food limitations or special preparation or compensation. Five patients, all affected by the most severe form of dysphagia, maintained tube-dependent nutrition. NMES as adjunctive treatment to TT may offer a new possibility for the management of tube-fed patients who are refractory to TT. © 2016 S. Karger AG, Basel.
Development program to produce mullite fiber insulation
NASA Technical Reports Server (NTRS)
Long, W. G.
1975-01-01
Processing methods were utilized to form a mullite fiber-Kaowool felt. The formation of a blended felt using the Rotoformer wet-laying method was successful. Felt products were evaluated for tensile strength, thermal stability, thermal conductivity and structural integrity at 1259 C and 1371 C. Textile processing methods failed in an attempt to form a yarn from staple and multifilament mullite fiber due to fiber damage through mechanical handling. The refractoriness of pure Kaowool ceramic fiber is improved with additions of 30% or greater mullite fiber.
Proliferative verrucous leukoplakia: an aggressive form of oral leukoplakia.
Shopper, Thomas P; Brannon, Robert B; Stalker, William H
2004-01-01
Proliferative verrucous leukoplakia (PVL) is an aggressive form of oral leukoplakia that is persistent, often multifocal, and refractory to treatment with a high risk of recurrence and malignant transformation. This article describes the clinical aspects and histologic features of a case that demonstrated the typical behavior pattern in a long-standing, persistent lesion of PVL of the mandibular gingiva and that ultimately developed into squamous cell carcinoma. Prognosis is poor for this seemingly harmless-appearing white lesion of the oral mucosa.
Dense protective coatings, methods for their preparation and coated articles
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tulyani, Sonia; Bhatia, Tania; Smeggil, John G.
A method for depositing a protective coating on a complex shaped substrate includes the steps of: (1) dipping a complex shaped substrate into a slurry to form a base coat thereon, the slurry comprising an aqueous solution, at least one refractory metal oxide, and at least one transient fluid additive present in an amount of about 0.1 percent to 10 percent by weight of the slurry; (2) curing the dipped substrate; (3) dipping the substrate into a precursor solution to form a top barrier coat thereon; and (4) heat treating the dipped, cured substrate to form a protective coating.
NASA Astrophysics Data System (ADS)
Turnewitsch, Robert; Domeyer, Bettina; Graf, Gerhard
2007-05-01
In most natural sedimentary systems labile and refractory organic material (OM) occur concomitantly. Little, however, is known on how different kinds of OM interact and how such interactions affect early diagenesis in sediments. In a simple sediment experiment, we investigated how interactions of OM substrates of different degradability affect benthic nitrogen (N) dynamics. Temporal evolution of a set of selected biogeochemical parameters was monitored in sandy sediment over 116 days in three experimental set-ups spiked with labile OM (tissue of Mytilus edulis), refractory OM (mostly aged Zostera marina and macroalgae), and a 1:1 mixture of labile and refractory OM. The initial amounts of particulate organic carbon (POC) were identical in the three set-ups. To check for non-linear interactions between labile and refractory OM, the evolution of the mixture system was compared with the evolution of the simple sum of the labile and refractory systems, divided by two. The sum system is the experimental control where labile and refractory OM are virtually combined but not allowed to interact. During the first 30 days there was evidence for net dissolved-inorganic-nitrogen (DIN) production followed by net DIN consumption. (Here 'DIN' is the sum of ammonium, nitrite and nitrate.) After ˜ 30 days a quasi steady state was reached. Non-linear interactions between the two types of OM were reflected by three main differences between the early-diagenetic evolutions of nitrogen dynamics of the mixture and sum (control) systems: (1) In the mixture system the phases of net DIN production and consumption commenced more rapidly and were more intense. (2) The mixture system was shifted towards a more oxidised state of DIN products [as indicated by increased (nitrite + nitrate)/(ammonium) ratios]. (3) There was some evidence that more OM, POC and particulate nitrogen were preserved in the mixture system. That is, in the mixture system more particulate OM was preserved while a higher proportion of the decomposed particulate N was converted into inorganic N. It can be concluded that during the first days and weeks of early diagenesis the magnitude and composition of the flux of decompositional dissolved N-compounds from sediments into the overlying water was influenced by non-linear interactions of OM substrates of different degradability. Given these experimental results it is likely that the relative spatial distributions of OM of differing degradability in sediments control the magnitude and composition of the return flux of dissolved N-bearing compounds from sediments into the overlying water column.
The Use Of Phosphates To Reduce Slag Penetration In Cr203-Based Refractories
Kwong, Kyei-Sing; Dogan, Cynthia P.; Bennett, James P.; Chinn, Richard E.; Petty, Arthur V.
2004-11-09
A high-chromium refractory material that provides improved resistance to coal slag penetration is presented. The refractory mixture comprises a blend of chromium oxide, aluminum oxide and phosphates. The refractory mixture may be blended with an aggregate and cured. In addition a phosphorous oxide may be blended with chromium oxide and aluminum oxide and additionally an aggregate. The refractory mixture reduces the rate of coal slag penetration into the surface of the cured refractory.
NASA Technical Reports Server (NTRS)
Barrett, Charles A.
1987-01-01
Cobalt levels were systematically varied in the Ni-base turbine alloys U-700 (cast), U-700m (PM/HIP), Waspaloy, Mar-M-247, In-738, Nimonic-115, U-720, and SX-R-150. the cobalt levels ranged from 0 wt pct to the nominal commercial content in each alloy. the alloys were tested in cyclic oxidation in static air at 1000, 1100 and 1150 C for 500, 200, and 100 hr, respectively. An oxidation attack parameter, Ka, derived from the specific weight change versus time data was used to evaluate the oxidation behavior of the alloys along with X-ray diffraction analysis of the surface oxides. The alloys tend to form either Cr2O3/chromite spinel or Al2O3/aluminate spinel depending on the Cr/Al ratio in the alloys. Alloys with a ratio of 3.5 or higher tend to favor the Cr oxides while those under 3.0 form mostly Al oxides. In general the Al2O3/aluminate spinel forming alloys have the better oxidation resistance. Increased cobalt content lowers the scaling resistance of the higher Cr allys while a 5.0 wt pct Co content is optimum for the Al controlling alloys. The refractory metals, particularly Ta, appear beneficial to both types of oxides, perhaps due to the formation of the omnipresent trirutile Ni(Ta, Cb, Mo, W)2O6. Both scales break down as increasing amounts of NiO are formed.
2018-06-28
Constitutional Mismatch Repair Deficiency Syndrome; Lynch Syndrome; Malignant Glioma; Progressive Ependymoma; Progressive Medulloblastoma; Recurrent Brain Neoplasm; Recurrent Childhood Ependymoma; Recurrent Diffuse Intrinsic Pontine Glioma; Recurrent Medulloblastoma; Refractory Brain Neoplasm; Refractory Diffuse Intrinsic Pontine Glioma; Refractory Ependymoma; Refractory Medulloblastoma
Asadi-Pooya, Ali A; Rakei, Seyed M; Kamgarpour, Ahmad; Taghipour, Mousa; Ashjazadeh, Nahid; Razmkon, Ali; Zare, Zahra; Bagheri, Mohammad H
2017-06-01
Epilepsy surgery has been proved to be feasible and cost-effective in developing countries. In the current paper, we discussed the outcome of patients with mesial temporal lobe epilepsy (MTLE) and medically-refractory seizures who had surgery at our center in Shiraz, Iran. Patients aged 18 years and older with refractory MTLE and mesial temporal sclerosis operated at Namazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran from May 2009 through December 2011 were enrolled. Presurgical evaluation included clinical history, neurological examination, 2-hour video-EEG recording, and 1.5-T MRI. All patients were submitted to standard temporal lobectomy at the side determined by MRI and video-EEG. Twenty-two patients (12 women and 10 men) underwent surgery between May 2009 and December 2011. All patients were followed postoperatively for at least 12 months (mean=24.8±7.7 months; minimum=12 months; maximum=36 months). At the last follow-up visit, 18 patients (81.8%) had a good outcome (15 patients [68.2%] had Engel class 1 and three others had Engel class 2). The total cost of presurgical evaluation and epilepsy surgery at our center was less than $500. Resources are limited for the vast majority of medically-refractory patients with epilepsy who live in the developing countries. However, it is feasible to select good surgical candidates for anterior temporal lobectomy relying on the clinical history and examination, MRI and interictal EEG. Broader application of epilepsy surgery should be encouraged in countries with limited financial resources.
Yang, Yangfan; Zhong, Jing; Dun, Zhongjun; Liu, Xiao-an; Yu, Minbin
2015-01-01
Abstract Refractory glaucoma refers to uncontrolled intraocular pressure (IOP) despite anti-glaucoma medication and surgical treatment, which remains a challenge to be treated. The objective of this study is to evaluate and statistically compare the clinical efficacy between endoscopic cyclophotocoagulation (ECP) and alternative surgical techniques in the treatment of refractory glaucoma in this article, as a meta-analysis. Data sources are China Biomedical Database (Sinomed, online version), China National Knowledge Infrastructure (CNKI), Cqvip, Wanfang database, and PubMed. The randomized controlled trial (RCT) and case–control study literatures evaluating the clinical efficacy between ECP and other surgical techniques were searched electronically from public databases. The methodology quality of the retrieved articles was evaluated according to the RCT or case–control study criteria. The success rate of treatment, intraocular pressure (IOP) and visual acuity were statistically compared. RevMan 5.3 software was used for the meta-analysis. In total, 6 relevant control studies were selected in this study with a total sampling of 429 cases (429 eyes), including 204 eyes in the ECP group and 225 in the non-ECP group. Meta-analysis demonstrated that the clinical efficacy did not significantly differ between 2 groups (P > 0.05). Postoperative IOP was dramatically reduced in both groups. However, it was difficult to evaluate the combined influence of ECP and non-ECP therapies upon IOP reduction. In conclusion, ECP and non-ECP treatment yielded almost equivalent clinical efficacy in treating refractory glaucoma. The IOP-lowering degree, safety, and incidence of complications remain to be further elucidated by RCTs with a larger sample size. PMID:26426659
NASA Astrophysics Data System (ADS)
Beaupre, S. R.; Kieber, D. J.; Keene, W. C.; Long, M. S.; Frossard, A. A.; Kinsey, J. D.; Duplessis, P.; Chang, R.; Maben, J. R.; Lu, X.; Zhu, Y.; Bisgrove, J.
2017-12-01
Nearly all organic carbon in seawater is dissolved (DOC), with more than 95% considered refractory based on modeled average lifetimes ( 16,000 years) and characteristically old bulk radiocarbon (14C) ages (4000 - 6000 years) that exceed the timescales of overturning circulation. Although this refractory dissolved organic carbon (RDOC) is present throughout the oceans as a major reservoir of the global carbon cycle, its sources and sinks are poorly constrained. Recently, RDOC was proposed to be removed from the oceans through adsorption onto the surfaces of rising bubble plumes produced by breaking waves, ejection into the atmosphere via bubble bursting as a component of primary marine aerosol (PMA), and subsequent oxidation in the atmosphere. To test this mechanism, we used natural abundance 14C (5730 ± 40 yr half-life) to trace the fraction of RDOC in PMA produced in a high capacity generator at two biologically-productive and two oligotrophic hydrographic stations in the Northwest Atlantic Ocean during a research cruise aboard the R/V Endeavor (Sep - Oct 2016). The 14C signatures of PMA separately generated day and night from near-surface (5 m) and deep (2500 m) seawater were compared with corresponding 14C signatures in seawater of near-surface dissolved inorganic carbon (DIC, a proxy for recently produced organic matter), bulk deep DOC (a proxy for RDOC), and near-surface bulk DOC. Results constrain the selectivity of PMA formation from RDOC in natural mixtures of recently produced and refractory DOC. The implications of these results for PMA formation and RDOC biogeochemistry will be discussed.
Tappeiner, Christoph; Mesquida, Marina; Adán, Alfredo; Anton, Jordi; Ramanan, Athimalaipet V; Carreno, Ester; Mackensen, Friederike; Kotaniemi, Kaisu; de Boer, Joke H; Bou, Rosa; de Vicuña, Carmen García; Heiligenhaus, Arnd
2016-12-01
To report on experience using the anti-interleukin 6 receptor antibody tocilizumab (TCZ) to treat severe and therapy-refractory uveitis associated with juvenile idiopathic arthritis (JIA). Retrospective data were gathered from patients with JIA receiving TCZ treatment for uveitis. JIA and related uveitis data (disease onset, activity, structural complications, and topical and systemic antiinflammatory treatment) were evaluated at the start of TCZ (baseline) and every 3 months during TCZ therapy. A total of 17 patients (14 women) with active uveitis were included (mean age 15.3 ± 6.9 yrs, mean followup time 8.5 mos). In all patients, uveitis had been refractory to previous topical and systemic corticosteroids, methotrexate (MTX), and other synthetic and biological disease-modifying antirheumatic drugs, including ≥ 1 tumor necrosis factor-α (TNF-α) inhibitor. Uveitis inactivity was achieved in 10 patients after a mean of 5.7 months of TCZ treatment (in 3 of them, it recurred during followup) and persisted in the remaining 7 patients. By using TCZ, systemic corticosteroids or immunosuppressives could be spared in 7 patients. Macular edema was present in 5 patients at baseline and improved in all of them under TCZ treatment. Arthritis was active in 11 patients at the initial and in 6 at the final followup visit. TCZ appears to represent a therapeutic option for severe JIA-associated uveitis that has been refractory to MTX and TNF-α inhibitors in selected patients. The present data indicate that inflammatory macular edema responds well to TCZ in patients with JIA-associated uveitis.
Dofetilide promotes repolarization abnormalities in perfused Guinea-pig heart.
Osadchii, Oleg E
2012-12-01
Dofetilide is class III antiarrhythmic agent which prolongs cardiac action potential duration because of selective inhibition of I (Kr), the rapid component of the delayed rectifier K(+) current. Although clinical studies reported on proarrhythmic risk associated with dofetilide treatment, the contributing electrophysiological mechanisms remain poorly understood. This study was designed to determine if dofetilide-induced proarrhythmia may be attributed to abnormalities in ventricular repolarization and refractoriness. The monophasic action potential duration and effective refractory periods (ERP) were assessed at distinct epicardial and endocardial sites along with volume-conducted ECG recordings in isolated, perfused guinea-pig heart preparations. Dofetilide was found to produce the reverse rate-dependent prolongation of ventricular repolarization, increased the steepness of action potential duration rate adaptation, and amplified transepicardial variability in electrical restitution kinetics. Dofetilide also prolonged the T peak-to-end interval on ECG, and elicited a greater prolongation of endocardial than epicardial ERP, thereby increasing transmural dispersion of refractoriness. At epicardium, dofetilide prolonged action potential duration to a greater extent than ERP, thus extending the critical interval for ventricular re-excitation. This change was associated with triangulation of epicardial action potential because of greater dofetilide-induced prolonging effect at 90 % than 30 % repolarization. Premature ectopic beats and spontaneous short-lasting episodes of monomorphic ventricular tachycardia were observed in 44 % of dofetilide-treated heart preparations. Proarrhythmic potential of dofetilide in guinea-pig heart is attributed to steepened electrical restitution, increased transepicardial variability in electrical restitution kinetics, amplified transmural dispersion of refractoriness, increased critical interval for ventricular re-excitation, and triangulation of epicardial action potential.
Phosphates in some Missouri refractory clays
Halley, Robert B.; Foord, Eugene E.; Keller, David J.; Keller, Walter D.
1997-01-01
This paper describes in detail phosphate minerals occurring in refractory clays of Missouri and their effect on the refractory degree of the clays. The minerals identified include carbonate-fluorapatite (francolite), crandallite, goyazite, wavellite, variscite and strengite. It is emphasized that these phosphates occur only in local isolated concentrations, and not generally in Missouri refractory clays.The Missouri fireclay region comprises 2 districts, northern and southern, separated by the Missouri River. In this region, clay constitutes a major part of the Lower Pennsylvanian Cheltenham Formation. The original Cheltenham mud was an argillic residue derived from leaching and dissolution of pre-Pennsylvanian carbonates. The mud accumulated on a karstic erosion surface truncating the pre-Cheltenham rocks. Fireclays of the northern district consist mainly of poorly ordered kaolinite, with variable but minor amounts of illite, chlorite and fine-grained detrital quartz. Clays of the southern district were subjected to extreme leaching that produced well-ordered kaolinite flint clays. Local desilication formed pockets of diaspore, or more commonly, kaolinite, with oolite-like nubs or burls of diaspore (“burley”" clay).The phosphate-bearing materials have been studied by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectral analysis (SEM-EDS) and chemical analysis. Calcian goyazite was identified in a sample of diaspore, and francolite in a sample of flint clay. A veinlet of wavellite occurs in flint clay at one locality, and a veinlet of variscite-strengite at another locality.The Missouri flint-clay-hosted francolite could not have formed in the same manner as marine francolite. The evidence suggests that the Cheltenham francolite precipitated from ion complexes in pore water, nearly simultaneously with crystallization of kaolinite flint clay from an alumina-silica gel. Calcian goyazite is an early diagenetic addition to its diaspore host. The wavellite and variscite-strengite veinlets are secondary, precipitated from ion complexes in ground water percolating along cracks in the flint clay. The flint clay host of the variscite-strengite veinlet contains strontian crandallite. All of the phosphates contain significant amounts of strontium. The source of P, Ca and Sr was the marine carbonates. Dissolution of these carbonates produced the argillic residue that became the primordial Cheltenham paludal mud, which ultimately altered to fireclay.Preliminary firing tests show that the presence of phosphates lowers fusion temperature. However, it is not clear whether poor refractoriness is due to the presence of phosphates, per se, or to Ca, Sr and other alkaline elements present in the phosphates.
Donor Umbilical Cord Blood Transplant in Treating Patients With Hematologic Cancer
2018-01-17
Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Aggressive Non-Hodgkin Lymphoma; Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Chronic Phase Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Indolent Non-Hodgkin Lymphoma; Lymphoma; Mixed Phenotype Acute Leukemia; Myelodysplastic Syndrome; Myeloproliferative Neoplasm; Recurrent Chronic Lymphocytic Leukemia; Recurrent Follicular Lymphoma; Recurrent Lymphoplasmacytic Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Plasma Cell Myeloma; Recurrent Small Lymphocytic Lymphoma; Recurrent T-Cell Non-Hodgkin Lymphoma; Refractory Chronic Lymphocytic Leukemia; Refractory Chronic Myelogenous Leukemia, BCR-ABL1 Positive; Refractory Follicular Lymphoma; Refractory Hodgkin Lymphoma; Refractory Lymphoplasmacytic Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Small Lymphocytic Lymphoma; T-Cell Non-Hodgkin Lymphoma
Differentiation Therapy With Decitabine in Treating Patients With Myelodysplastic Syndrome
2013-02-25
Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndromes; Myelodysplastic Syndromes; Refractory Anemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Ringed Sideroblasts; Refractory Cytopenia With Multilineage Dysplasia; Thrombocytopenia
Matsumoto, Hiroaki; Hanayama, Hiroaki; Okada, Takashi; Sakurai, Yasuo; Minami, Hiroaki; Masuda, Atsushi; Tominaga, Shogo; Miyaji, Katsuya; Yamaura, Ikuya; Yoshida, Yasuhisa; Yoshida, Kozo
2017-11-01
Chronic subdural hematoma (CSDH) is sometimes refractory, and this is troublesome for neurosurgeons. Although many studies have reported risk factors or treatments in efforts to prevent recurrence, those have focused on single recurrence, and few cumulative data are available to analyze refractory CSDH. We defined refractory CSDH as ≥2 recurrences, then analyzed and compared clinical factors between patients with single recurrence and those with refractory CSDH in a cohort study, to clarify whether patients with refractory CSDH experience different or more risk factors than patients with single recurrence, and whether burr-hole irrigation with closed-system drainage reduces refractory CSDH. Seventy-five patients had at least 1 recurrence, with single recurrence in 62 patients and ≥2 recurrences in 13 patients. In comparing clinical characteristics, patients with refractory CSDH were significantly younger (P = 0.04) and showed shorter interval to first recurrence (P < 0.001). Organized CSDH was also significantly associated with refractory CSDH (P = 0.02). Multivariate logistic regression analysis identified first recurrence interval <1 month (odds ratio, 6.66, P < 0.001) and age <71 years (odds ratio, 4.16, P < 0.001) as independent risk factors for refractory CSDH. On the other hand, burr-hole irrigation with closed-system drainage did not reduce refractory CSDH. When patients with risk factors for refractory CSDH experience recurrence, alternative surgical procedures may be considered as the second surgery, because burr-hole irrigation with closed-system drainage did not reduce refractory CSDH in our study. Copyright © 2017 Elsevier Inc. All rights reserved.
Kinoshita, Yoshikazu; Hongo, Michio; Kusano, Motoyasu; Furuhata, Yoshinori; Miyagishi, Hideaki; Ikeuchi, Satoshi
2017-01-01
Objective To investigate the effect of twice-daily rabeprazole doses on health-related quality of life in refractory patients. Methods and Patients Reflux esophagitis patients with an insufficient response to once-daily proton pump inhibitor therapy (Los Angeles Classification grade A-D) received rabeprazole 10 mg or 20 mg twice daily for 8 weeks. The health-related quality of life (SF-8™) and symptoms, using the Frequency Scale for the Symptoms of Gastroesophageal reflux disease, were evaluated before treatment and at weeks 4 and 8. Endoscopy was performed at baseline and at weeks 8 and 32 where possible. The rabeprazole dose was determined by the attending physician. Results There were 1,796 patients analyzed for the efficacy of the twice-daily treatment. Of these cases, 1,462 were treated with rabeprazole 10 mg twice daily, and 334 were treated with rabeprazole 20 mg twice daily. The factors that affected the selection of the twice-daily rabeprazole dose by physicians were evaluated, and as expected, “endoscopic findings when treatment was started” had a strong effect on the selection of the rabeprazole dose. With both regimens, health-related quality of life and subjective symptoms were significantly improved at weeks 4 and 8 compared to baseline (p<0.001). The recurrence rate of erosive esophagitis at week 32 was 9.7% in rabeprazole twice daily-treated patients and 28.4% in proton pump inhibitor (PPI) once daily-treated patients. Both regimens were well tolerated. Conclusion Twice-daily treatment with rabeprazole improved the subjective symptoms and health-related quality of life in patients with refractory reflux esophagitis more effectively than the standard once-daily dose. PMID:28502925
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gray, M. H.; Tirawat, R.; Kessinger, K. A.
The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from themore » receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (η sel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies η sel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.« less
Gray, M. H.; Tirawat, R.; Kessinger, K. A.; ...
2015-05-01
The roadmap to next-generation concentrating solar power plants anticipates a progression to central towers with operating temperatures in excess of 650°C. These higher temperatures are required to drive higher power-cycle efficiencies, resulting in lower cost energy. However, these conditions also place a greater burden on the materials making up the receiver. Any novel absorber material developed for next-generation receivers must be stable in air, cost effective, and survive thousands of heating and cooling cycles. The collection efficiency of a power tower plant can be increased if the energy absorbed by the receiver is maximized while the heat loss from themore » receiver to the environment is minimized. Thermal radiation losses can be significant (>7% annual energy loss) with receivers at temperatures above 650°C. We present progress toward highly efficient and durable solar selective absorbers (SSAs) intended for operating temperatures from 650°C to 1000°C. Selective efficiency (η sel) is defined as the energy retained by the absorber, accounting for both absorptance and emittance, relative to the energy incident on the surface. The low emittance layers of multilayer SSAs are binary compounds of refractory metals whose material properties indicate that coatings formed of these materials should be oxidation resistant in air to 800-1200°C. On this basis, we initially developed a solar selective coating for parabolic troughs. This development has been successfully extended to meet the absorptance and emittance objectives for the more demanding, high temperature regime. We show advancement in coating materials, processing and designs resulting in the initial attainment of target efficiencies η sel > 0.91 for proposed tower conditions. Additionally, spectral measurements show that these coatings continue to perform at targeted levels after cycling to temperatures of 1000°C in environments of nitrogen and forming gas.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bennett, J.P.; Kwong, K.S.; Clark, J.A.
1996-12-31
The Albany Research Center is conducting work on spent refractory recycling/alternate use, including a review of refractory usage and current recycling/disposal practices. Research has focused on the hazardous nature of some spent refractory materials, with emphasis on lead pickup. Information on the issues associated with the reuse of spent refractories will be presented, including those associated with hazardous materials.
Daniels, F.
1959-10-27
A reactor in which at least a portion of the moderator is in the form of movable refractory balls is described. In addition to their moderating capacity, these balls may serve as carriers for fissionable material or fertile material, or may serve in a coolant capacity to remove heat from the reactor. A pneumatic system is used to circulate the balls through the reactor.
Hariharan, Uma
Dexmedetomidine is a highly selective α-2 agonist which has recently revolutionized our anesthesia and intensive care practice. An obstetric patient presented for emergency cesarean delivery under general anesthesia, with pre-eclampsia and postpartum hemorrhage. In carefully selected cases with refractory hypertension and postpartum hemorrhage, dexmedetomidine can be used for improving overall patient outcome. It was beneficial in controlling both the blood pressure and uterine bleeding during cesarean section in our patient. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.
Current Topics in Deep Brain Stimulation for Parkinson Disease
UMEMURA, Atsushi; OYAMA, Genko; SHIMO, Yasushi; NAKAJIMA, Madoka; NAKAJIMA, Asuka; JO, Takayuki; SEKIMOTO, Satoko; ITO, Masanobu; MITSUHASHI, Takumi; HATTORI, Nobutaka; ARAI, Hajime
2016-01-01
There is a long history of surgical treatment for Parkinson disease (PD). After pioneering trials and errors, the current primary surgical treatment for PD is deep brain stimulation (DBS). DBS is a promising treatment option for patients with medically refractory PD. However, there are still many problems and controversies associated with DBS. In this review, we discuss current issues in DBS for PD, including patient selection, clinical outcomes, complications, target selection, long-term outcomes, management of axial symptoms, timing of surgery, surgical procedures, cost-effectiveness, and new technology. PMID:27349658
Surgical Management of Colonic Inertia
McCoy, Jacob A.; Beck, David E.
2012-01-01
For the select small number of constipated patients that cannot be managed medically, surgical options should be considered. Increases in our knowledge of colorectal physiology and experience have fostered improvements in patient evaluation and surgical management. Currently, patients with refractory colonic inertia are offered total abdominal colectomy and ileorectal anastomosis, often with laparoscopic techniques. With proper patient selection, the results have been excellent for resolving the frequency and quality of bowel movements. However, symptoms such as bloating and abdominal pain, which may be related to irritable bowel syndrome rather than the colonic inertia, may persist. PMID:23449085
Morphologies, Processing and Properties of Ceramic Foams and Their Potential as TPS Materials
NASA Technical Reports Server (NTRS)
Stackpoole, Mairead; Simoes, Conan R.; Johnson, Sylvia M.
2002-01-01
The current research is focused on processing ceramic foams with compositions that have potential as a thermal protection material. The use of pre-ceramic polymers with the addition of sacrificial blowing agents or sacrificial fillers offers a viable approach to form either open or closed cell insulation. Our work demonstrates that this is a feasible method to form refractory ceramic foams at relatively low processing temperatures. It is possible to foam complex shapes then pyrolize the system to form a ceramic while retaining the shape of the unfired foam. Initial work focused on identifying suitable pre-ceramic polymers with desired properties such as ceramic yield and chemical make up of the pyrolysis product after firing. We focused on making foams in the Si system (Sic, Si02, Si-0-C), which is in use in current acreage TPS systems. Ceramic foams with different architectures were formed from the pyrolysis of pre-ceramic polymers at 1200 C in different atmospheres. In some systems a sacrificial polyurethane was used as the blowing agent. We have also processed foams using sacrificial fillers to introduce controlled cell sizes. Each sacrificial filler or blowing agent leads to a unique morphology. The effect of different fillers on foam morphologies and the characterization of these foams in terms of mechanical and thermal properties are presented. We have conducted preliminary arc jet testing on selected foams with the materials being exposed to typical re-entry conditions for acreage TPS and these results will be discussed. Foams processed using these approaches have bulk densities ranging from 0.15 to 0.9 g/cm3 and cell sizes ranging from 5 to 500 pm. Compression strengths ranged from 2 to 7 MPa for these systems. Finally, preliminary oxidation studies have been conducted on selected systems and will be discussed.
Chemical evidence for differentiation, evaporation and recondensation from silicate clasts in Gujba
NASA Astrophysics Data System (ADS)
Oulton, Jonathan; Humayun, Munir; Fedkin, Alexei; Grossman, Lawrence
2016-03-01
The silicate and metal clasts in CB chondrites have been inferred to form as condensates from an impact-generated vapor plume between a metal-rich body and a silicate body. A detailed study of the condensation of impact-generated vapor plumes showed that the range of CB silicate clast compositions could not be successfully explained without invoking a chemically differentiated target. Here, we report the most comprehensive elemental study yet performed on CB silicates with 32 silicate clasts from nine slices of Gujba analyzed by laser ablation inductively coupled plasma mass spectrometry for 53 elements. Like in other studies of CBs, the silicate clasts are either barred olivine (BO) or cryptocrystalline (CC) in texture. In major elements, the Gujba silicate clasts ranged from chondritic to refractory enriched. Refractory element abundances ranged from 2 to 10 × CI, with notable anomalies in Ba, Ce, Eu, and U abundances. The two most refractory-enriched BO clasts exhibited negative Ce anomalies and were depleted in U relative to Th, characteristic of volatilization residues, while other BO clasts and the CC clasts exhibited positive Ce anomalies with excess U (1-3 × CI), and Ba (1-6 × CI) anomalies indicating re-condensation of ultra-refractory element depleted vapor. The Rare Earth Elements (REE) also exhibit light REE (LREE) enrichment or depletion in several clasts with a range of (La/Sm)CI of 0.9-1.8. This variation in the LREE is essentially impossible to accomplish by processes involving vapor-liquid or vapor-solid exchange of REE, and appears to have been inherited from a differentiated target. The most distinctive evidence for inherited chemical differentiation is observed in highly refractory element (Sc, Zr, Nb, Hf, Ta, Th) systematics. The Gujba clasts exhibit fractionations in Nb/Ta that correlate positively with Zr/Hf and span the range known from lunar and Martian basalts, and exceed the range in Zr/Hf variation known from eucrites. Variations of highly incompatible refractory elements (e.g., Th) against less incompatible elements (e.g., Zr, Sr, Sc) are not chondritic, but exhibit distinctly higher Th abundances requiring a differentiated crust to be admixed with depleted mantle in ratios that are biased to higher crust/mantle ratios than in a chondritic body. The possibility that these variations are due to admixture of refractory inclusion-debris into normal chondritic matter is raised but cannot be definitively tested because existing ;bulk; analyses of CAIs carry artifacts of unrepresentative sampling. The inferences drawn from the compositions of Gujba silicate clasts, here, complement what has been inferred from the compositions of metallic clasts, but provide surprisingly detailed insight into the structure of the target. Evidence that metal and silicate in CB chondrites both formed from impact-generated vapor plumes, taken together with recent work on metallic nodules in E chondrites, and on ordinary chondrites, indicates that chondrule formation occurs by this mechanism quite widely. However, the nature of the impact on the CB body is quite different than the popular conceptions of impact of partially or wholly molten chondritic bodies and the younger (5 Ma) age of CB chondrules is consistent with origin in a disk with more evolved targets and impactors gravitationally perturbed by nascent planets.
2018-05-10
Acute Myeloid Leukemia; Acute Myeloid Leukemia in Remission; Aplastic Anemia; Chronic Myelomonocytic Leukemia; Hodgkin Lymphoma; Indolent Non-Hodgkin Lymphoma; Malignant Neoplasm; Myelodysplastic Syndrome; Myeloproliferative Neoplasm; Plasma Cell Myeloma; Refractory Anemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Ring Sideroblasts; Refractory Cytopenia With Multilineage Dysplasia; Refractory Cytopenia With Multilineage Dysplasia and Ring Sideroblasts
Response Activation in Overlapping Tasks and the Response-Selection Bottleneck
ERIC Educational Resources Information Center
Schubert, Torsten; Fischer, Rico; Stelzel, Christine
2008-01-01
The authors investigated the impact of response activation on dual-task performance by presenting a subliminal prime before the stimulus in Task 2 (S2) of a psychological refractory period (PRP) task. Congruence between prime and S2 modulated the reaction times in Task 2 at short stimulus onset asynchrony despite a PRP effect. This Task 2…
A Study of CDX-1127 (Varlilumab) in Patients With Select Solid Tumor Types or Hematologic Cancers
2018-01-29
CD27 Expressing B-cell Malignancies for Example Hodgkin's Lymphoma; Chronic Lymphocytic Leukemia; Mantle Cell Lymphoma; Marginal Zone B Cell Lymphoma); Any T-cell Malignancy; Solid Tumors (Metastatic Melanoma, Renal (Clear) Cell Carcinoma; Hormone-refractory Prostate Adenocarcinoma, Ovarian Cancer; Colorectal Adenocarcinoma, Non-small Cell Lung Cancer); Burkett's Lymphoma; Primary Lymphoma of the Central Nervous System
A Slag Management Toolset for Determining Optimal Coal Gasification Temperatures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kwong, Kyei-Sing; Bennett, James P.
Abstract Gasifier operation is an intricate process because of the complex relationship between slag chemistry and temperature, limitations of feedstock materials, and operational preference. High gasification temperatures increase refractory degradation, while low gasification temperatures can lead to slag buildup on the gasifier sidewall or exit, either of which are problematic during operation. Maximizing refractory service life and gasifier performance require finding an optimized operating temperature range which is a function of the coal slag chemistry and viscosity. Gasifier operators typically use a slag’s viscosity-temperature relationship and/or ash-fusion fluid temperature to determine the gasification temperature range. NETL has built a slagmore » management toolset to determine the optimal temperature range for gasification of a carbon feedstock. This toolset is based on a viscosity database containing experimental data, and a number of models used to predict slag viscosity as a function of composition and temperature. Gasifier users typically have no scientific basis for selecting an operational temperature range for gasification, instead using experience to select operational conditions. The use of the toolset presented in this paper provides a basis for estimating or modifying carbon feedstock slags generated from ash impurities in carbon feedstock.« less
Use of acalabrutinib in patients with mantle cell lymphoma.
Awan, Farrukh T; Jurczak, Wojciech
2018-06-01
Acalabrutinib, a selective Bruton tyrosine kinase (BTK) inhibitor, was granted accelerated approval by the FDA on 31 October 2017 for the treatment of patients with mantle cell lymphoma (MCL) who have received at least one prior therapy. Areas covered: This narrative review provides an overview of acalabrutinib, its use in clinical practice and potential future developments. Expert commentary: BTK inhibitors have demonstrated efficacy in patients with relapsed or refractory MCL. To prepare patients for therapy, all preexisting infections should be diagnosed and treated, and infection prophylaxis undertaken. Serious adverse reactions are rare with acalabrutinib; however, patients should be made aware of common adverse events such as headaches, which usually resolve within one month without medical treatment. Interaction with other drugs appears to be less of an issue with acalabrutinib than with ibrutinib; however, patients receiving acalabrutinib therapy must be advised not to take any additional medications without first consulting with their treating physician. A key unmet medical need is treatment options for patients in whom BTK inhibitors are discontinued, because of either intolerance or refractory disease. Patients not tolerating ibrutinib could be switched to acalabrutinib, which has improved selectivity and increased tolerability. First-line treatment with acalabrutinib is being investigated.
A Slag Management Toolset for Determining Optimal Coal Gasification Temperatures
Kwong, Kyei-Sing; Bennett, James P.
2016-11-25
Abstract Gasifier operation is an intricate process because of the complex relationship between slag chemistry and temperature, limitations of feedstock materials, and operational preference. High gasification temperatures increase refractory degradation, while low gasification temperatures can lead to slag buildup on the gasifier sidewall or exit, either of which are problematic during operation. Maximizing refractory service life and gasifier performance require finding an optimized operating temperature range which is a function of the coal slag chemistry and viscosity. Gasifier operators typically use a slag’s viscosity-temperature relationship and/or ash-fusion fluid temperature to determine the gasification temperature range. NETL has built a slagmore » management toolset to determine the optimal temperature range for gasification of a carbon feedstock. This toolset is based on a viscosity database containing experimental data, and a number of models used to predict slag viscosity as a function of composition and temperature. Gasifier users typically have no scientific basis for selecting an operational temperature range for gasification, instead using experience to select operational conditions. The use of the toolset presented in this paper provides a basis for estimating or modifying carbon feedstock slags generated from ash impurities in carbon feedstock.« less
Current gamma knife treatment for ophthalmic branch of primary trigeminal neuralgia
Shan, Guo-Yong; Liang, Hao-Fang; Zhang, Jian-Hua
2011-01-01
AIM To probe into problems existing in gamma knife treatment of ophthalmic branch of primary trigeminal neuralgia (TN), and propose a safe and effective solution to the problem. METHODS Through sorting the literature reporting gamma knife treatment of refractory TN in recent years, this article analyzed the advantages and problems of gamma knife treatment of primary TN, and proposed reasonable assessment for existing problems and the possible solution. RESULTS Gamma knife treatment of TN has drawn increasing attention of clinicians due to its unique non-invasion, safety and effectiveness, but there are three related issues to be considered. The first one is the uncertainty of the optimal dose (70-90GY); the second one is the difference in radiotherapy target selection (using a single isocenter or two isocenters); and the third one is the big difference of recurrent pains (specific treatment methods need to be summarized and improved). CONCLUSION For patients with refractory TN, gamma knife treatment can be selected when the medical treatment fails or drug side effects emerge. The analysis of a large number of TN patients receiving gamma knife treatment has shown that this is a safe and effective treatment method. PMID:22553625
Convoluted nozzle design for the RL10 derivative 2B engine
NASA Technical Reports Server (NTRS)
1985-01-01
The convoluted nozzle is a conventional refractory metal nozzle extension that is formed with a portion of the nozzle convoluted to show the extendible nozzle within the length of the rocket engine. The convoluted nozzle (CN) was deployed by a system of four gas driven actuators. For spacecraft applications the optimum CN may be self-deployed by internal pressure retained, during deployment, by a jettisonable exit closure. The convoluted nozzle is included in a study of extendible nozzles for the RL10 Engine Derivative 2B for use in an early orbit transfer vehicle (OTV). Four extendible nozzle configurations for the RL10-2B engine were evaluated. Three configurations of the two position nozzle were studied including a hydrogen dump cooled metal nozzle and radiation cooled nozzles of refractory metal and carbon/carbon composite construction respectively.
Adherence of sputtered titanium carbides
NASA Technical Reports Server (NTRS)
Brainard, W. A.; Wheeler, D. R.
1979-01-01
The study searches for interface treatment that would increase the adhesion of TiC coating to nickel- and titanium-base alloys. Rene 41 (19 wt percent Cr, 11 wt percent Mo, 3 wt percent Ti, balance Ni) and Ti-6Al-4V (6 wt percent Al, 4 wt percent V, balance Ti) are considered. Adhesion of the coatings is evaluated in pin-and disk friction tests. The coatings and interface regions are examined by X-ray photoelectron spectroscopy. Results suggest that sputtered refractory compound coatings adhere best when a mixed compound of coating and substrate metals is formed in the interfacial region. The most effective type of refractory compound interface appears to depend on both substrate and coating material. A combination of metallic interlayer deposition and mixed compound interface formation may be more effective for some substrate coating combinations than either alone.
NASA research on refractory compounds.
NASA Technical Reports Server (NTRS)
Gangler, J. J.
1971-01-01
The behavior and properties of the refractory carbides, nitrides, and borides are being investigated by NASA as part of its research aimed at developing superior heat resistant materials for aerospace applications. Fundamental studies on the electronic and defect structures of the carbides indicate that there is promise for improving the strength and ductility of these materials. Studies of the zirconium-carbon-oxygen system show that zirconium oxycarbides of different compositions and lattice parameters can be formed between 1500 and 1900 C and are stable below 1500 C. More applied studies show that hot working generally improves the microstructure and therefore the strength of TiC and NbC. Sintering studies on UN indicate that very high densities can be achieved. Hot pressing of cermets of HfN and HfC produces good mechanical properties for high temperature bearing applications.
System and method for producing metallic iron
Englund, David J.; Schlichting, Mark; Meehan, John; Crouch, Jeremiah; Wilson, Logan
2014-07-29
A method of production of metallic iron nodules comprises assembling a hearth furnace having a moveable hearth comprising refractory material and having a conversion zone and a fusion zone, providing a hearth material layer comprising carbonaceous material on the refractory material, providing a layer of reducible material comprising and iron bearing material arranged in discrete portions over at least a portion of the hearth material layer, delivering oxygen gas into the hearth furnace to a ratio of at least 0.8:1 ponds of oxygen to pounds of iron in the reducible material to heat the conversion zone to a temperature sufficient to at least partially reduce the reducible material and to heat the fusion zone to a temperature sufficient to at least partially reduce the reducible material, and heating the reducible material to form one or more metallic iron nodules and slag.
Atomization from a tantalum surface in graphite furnace atomic absorption spectrometry
NASA Astrophysics Data System (ADS)
Gregoire, D. C.; Chakrabarti, C. L.
The mechanism of atom formation of U, V, Mo, Ni, Mn, Cu and Mg atomized from pyrolytic graphite and tantalum metal surfaces has been studied. The mechanism of atom formation for U from a graphite tube atomizer is reported for the first time. The peak absorbance for U and Cu is increased by factors of 59.7 and 2.0, respectively, whereas that of V, Mo and Ni is reduced by several orders of magnitude when they are atomized from a tantalum metal surface. The peak absorbance of Mn and Mg is not appreciably affected by the material of the atomization surface. Interaction of Mn and Mg with the graphite surface and formation of their refractory carbides was found to be negligible. Uranium forms a refractory carbide when heated from a graphite surface.
Chromia refractory brick with carbon treatment
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bennett, James P.; Kwong, Kyei-Sing
The disclosure provides a refractory brick system comprising a chromia refractory brick for operation in the slagging environment of an air-cooled gasifier. The chromia refractory brick comprises a ceramically-bonded porous chromia refractory having a porosity greater than 9% and having carbon deposits residing within the pores. The brick may be further comprised of Al.sub.2O.sub.3. The air-cooled gasifier generates a liquefied slag in contact with the refractory brick and generally operates at temperatures between 1250.degree. C. and 1575.degree. C. and pressures between 300 psi to 1000 psi, with oxygen partial pressures generally between 10.sup.-4 and 10.sup.-10 atm. The refractory brick performsmore » without substantial chromium carbide or chromium metal formation in the low oxygen partial pressure environment. The inclusion of carbon without chromium carbide formation provides for significant mitigation of slag penetration and significantly reduced refractory wear.« less
Reactive sintering of ceramic lithium ion electrolyte membranes
Badding, Michael Edward; Dutta, Indrajit; Iyer, Sriram Rangarajan; Kent, Brian Alan; Lonnroth, Nadja Teresia
2017-06-06
Disclosed herein are methods for making a solid lithium ion electrolyte membrane, the methods comprising combining a first reactant chosen from amorphous, glassy, or low melting temperature solid reactants with a second reactant chosen from refractory oxides to form a mixture; heating the mixture to a first temperature to form a homogenized composite, wherein the first temperature is between a glass transition temperature of the first reactant and a crystallization onset temperature of the mixture; milling the homogenized composite to form homogenized particles; casting the homogenized particles to form a green body; and sintering the green body at a second temperature to form a solid membrane. Solid lithium ion electrolyte membranes manufactured according to these methods are also disclosed herein.
2018-06-25
Adenoid Cystic Carcinoma; Adnexal Carcinoma; Apocrine Carcinoma; Eccrine Porocarcinoma; Extraocular Cutaneous Sebaceous Carcinoma; Hidradenocarcinoma; Keratoacanthoma; Malignant Sweat Gland Neoplasm; Merkel Cell Carcinoma; Microcystic Adnexal Carcinoma; NK-Cell Lymphoma, Unclassifiable; Non-Melanomatous Lesion; Paget Disease; Papillary Adenocarcinoma; Primary Cutaneous Mucinous Carcinoma; Refractory Anaplastic Large Cell Lymphoma; Refractory Mature T-Cell and NK-Cell Non-Hodgkin Lymphoma; Refractory Mycosis Fungoides; Refractory Primary Cutaneous T-Cell Non-Hodgkin Lymphoma; Refractory T-Cell Non-Hodgkin Lymphoma; Sezary Syndrome; Signet Ring Cell Carcinoma; Skin Basal Cell Carcinoma; Skin Basosquamous Cell Carcinoma; Skin Squamous Cell Carcinoma; Spiradenocarcinoma; Squamous Cell Carcinoma of Unknown Primary Origin; Stage III Skin Cancer; Stage IV Skin Cancer; Sweat Gland Carcinoma; Trichilemmocarcinoma; Vulvar Squamous Cell Carcinoma
Campbell, H E; Tait, S; Buxton, M J; Sharples, L D; Caine, N; Schofield, P M; Wallwork, J
2001-08-01
Transmyocardial laser revascularization (TMLR) is used to treat patients with refractory angina considered unsuitable for conventional forms of revascularization. Using patient specific data from a single centre UK randomised-controlled trial, we aimed to determine whether, from a UK National Health Service (NHS) perspective, TMLR plus standard medical management is cost-effective when compared with standard medical management alone. One hundred and eighty-eight patients assessed as having refractory angina, and not suitable for conventional forms of revascularization were randomized to receive TMLR and medical management (94) or medical management alone (94). Costs to the UK NHS of TMLR (where appropriate), and all secondary sector health care contacts and cardiac-related medication in the 12 months following randomization, were collected. Patient utility as measured using the EuroQol EQ-5D questionnaire was combined with 12-month survival data to generate quality adjusted life years (QALYs). The mean cost per patient over the year from hospitalization for TMLR was 11,470 pounds sterling and for medical management alone was 2586 pounds sterling, giving a cost difference of 8901 pounds sterling (95% confidence interval (CI) 7502 pounds sterling--10,008 pounds sterling: P < 0.0001). The mean QALY difference, in favour of TMLR was 0.039 (95% CI -0.033 to 0.113: P = 0.268). This gives an incremental cost per QALY of over 228,000 pounds sterling. Analysis of stochastic uncertainty and of sensitivity to gross changes in key parameters consistently produces very high costs per QALY. The policy implications are clear: for such patients TMLR is an inefficient use of UK health service resources. This conclusion would not be changed by considerable improvements in effectiveness or reductions in cost.
Neuroimaging evaluation in refractory epilepsy
Granados, Ana M; Orejuela, Juan F
2015-01-01
Purpose To describe the application of neuroimaging analysis, compared to neuropsychological tests and video-electroencephalogram, for the evaluation of refractory epilepsy in a reference centre in Cali, Colombia. Methods Between March 2013 and November 2014, 29 patients, 19 men and 10 women, aged 9–65 years and with refractory epilepsy, were assessed by structural and functional magnetic resonance imaging while performing tasks related to language, verbal and non-verbal memory. Also, volumetric evaluation was performed. A 1.5 Tesla magnetic resonance imaging scanner was used in all cases. Results Neuroimaging evaluation identified 13 patients with mesial temporal sclerosis. The remaining patients were classified as: 10 patients with neoplastic masses, two patients with cortical atrophy, two patients with scarring lesions and two patients with non-structural aetiology. Among patients with mesial temporal sclerosis, comparison between techniques for lateralising the epileptogenic foci was made; the κ index between functional magnetic resonance imaging and hippocampi volumetry was κ = 1.00, agreement between neuroimaging and video-electroencephalogram was good (κ = 0.78) and comparison with a neuropsychological test was mild (κ = 0.24). Conclusions Neuroimaging studies allow the assessment of functional and structural damage related to epileptogenic lesions and foci, and are helpful to select surgical treatment, conduct intraoperative neuronavigation techniques, predict surgical deficits and evaluate patient recovery. PMID:26427897
NASA Technical Reports Server (NTRS)
Yacobucci, H. G.; Waldron, W. D.; Walowit, J. A.
1973-01-01
The design of bearings for the control system of a fast reactor concept is presented. The bearings are required to operate at temperatures up to 2200 F in one of two fluids, lithium or argon. Basic bearing types are the same regardless of the fluid. Crowned cylindrical journals were selected for radially loaded bearings and modified spherical bearings were selected for bearings under combined thrust and radial loads. Graphite and aluminum oxide are the materials selected for the argon atmosphere bearings while cermet compositions (carbides or nitrides bonded with refractory metals) were selected for the lithium lubricated bearings. Mounting of components is by shrink fit or by axial clamping utilizing differential thermal expansion.
NASA Technical Reports Server (NTRS)
Soltysik, B.; Pawelek, A.; Witkowska, E.
1983-01-01
Phosphate binders, particularly acidic phosphates of Al and Cr, are used for binding Al silicate refractories used for lining of burners, SiC refractories, and refractory mortars. The binders have apparent d. 2.13-2.18 g/cu cm, porosity 21.4-23.8%, compressive strength 223 71 kg/ sq cm, total shrinkage 0.2-0.8%, and refractoriness 1240 deg.
Refractory inclusions in the Ornans C30 chondrite
NASA Technical Reports Server (NTRS)
Davis, A. M.
1985-01-01
Several types of metedorites contain unusual objects 10 micrometers to 2 centimeters across that are enriched in refractory elements such as calcium, aluminum and titanium. These objects, commonly known as refractory inclusions, are most abundant in the meteorites known as carbonaceous chondrites. The refractory inclusions that have been found in the Ornans metedorite, a member of a little-studied group of carbonaceous chondrites are described. Some refractory inclusions in Ornans resemble those found in other meteorites, while others are unlike any seen before. The unusual inclusions in Ornans contain minerals with extraordinary enrichments in highly refractory elements.
A RELICT Spinel Grain in an Allende Ferromagnesian Chondrule
NASA Astrophysics Data System (ADS)
Misawa, K.; Fujita, T.; Kitamura, M.; Nakamura, N.; Yurimoto, H.
1993-07-01
It is suggested that one of the refractory lithophile precursors in CV-CO chondrules was a hightemperature condensate from the nebular gas and was related to Ca,Al-rich inclusions (CAIs) [1-3]. However, little is known about refractory siderophile precursors in chondrules [4]. Allende barred olivine chondrule R-11 consists mainly of olivine (Fa(sub)7- 18), pyroxene (En(sub)93Fs(sub)1Wo(sub)6, En(sub)66Fs(sub)1Wo(sub)33), plagioclase (An(sub)80), Fe-poor spinel, and alkali-rich glass. The CI- chondrite normalized REE pattern of the chondrule, excluding a spinel grain, are fractionated, HREEdepleted (4.6-7.8 x CI) with a large positive Yb anomaly. The REE abundances are hump-shaped functions of elemental volatility, moderately refractory REE-enriched, suggesting that the refractory lithophile precursor component of R-11 could be a condensate from the nebular gas and related to Group 11 CAIs [1,2]. An interior portion of spinel is almost Fe-free, but in an outer zone (2040 micrometers in width) FeO contents increase rapidly. TiO(sub)2, Cr(sub)2O(sub)3, and V(sub)2O(sub)3 contents in core spinel are less than 0.5%, which is different from the V-rich nature of spinel in fluffy Type A CAIs [5]. The Fe-Mg zoning of spinel may have been generated by diffusional emplacement of Mg and Fe during chondrule-forming events. The spinel contains silicate inclusions and tiny metallic grains. The largest silicate inclusion is composed of Al,Ti-rich pyroxene and Ak 40 melilite. One of the submicrometersized grains was analyzed by SEM-EDS and found to be composed of refractory Pt-group metals with minor amounts of Fe and Ni. This is the first occurrence of refractory Pt-group metal nuggets in a ferromagnesian chondrule from the Allende meteorite. Tungsten, Os, Ir, Mo, and Ru are enriched 2-6 x 10^5 relative to CIs, and abundances of Pt and Rh decrease 2-10 x 10^4 with increasing volatility. In addition, abundances of Fe and Ni in the nugget are equal to or less than that CI chondrites. A depletion of Mo relative to other refractory metals may have resulted from high- temperature oxidation [6]. Chondrule R-11 exhibits both similarities (spinel and plagioclase chemistry; Group II REE pattern) and differences (fassaite chemistry; existence of refractory Pt-group metal nuggets and melilite) with respect to POIs [3] carrying isotopically fractionated Mg. Refractory Pt-group metal nuggets in CAIs are considered to have been produced during high-temperature events (at least 1300 degrees C) before total condensation of Fe in the early solar nebula [8-10]. In analogy with the formation history with CAIs, we suggest that one of the refractory siderophile precursor components of Allende chondrules is a high-temperature condensate from the nebular gas and is associated with refractory oxide and silicates. References: [1] Misawa K. and Nakamura N. (1988) GCA, 52, 1669. [2] Misawa K. and Nakamura N. (1988) Nature, 334, 47. [3] Sheng Y. J. et al. (1991) GCA, 55, 581. [4] Grossman J. N. et al. (1988) In Meteorites and the Early Solar System (J. F. Kerridge and M. S. Matthews, eds.), 619, Univ. of Arizona. [5] MacPherson G. J. and Grossman L. (1984) GCA, 48, 29. [6] Fegley B. Jr. and Palme H. (1985) EPSL, 72, 311. [7] Wark D. A. and Lovering J. F. (1976) LS VII, 912. [8] Palme H. and Wlotzka F. (1976) EPSL, 33, 45. [9] El Goresy A. et al. (1978) Proc. LPSC 9th, 1279. [10] Blander M. and Fuchs L. H. (1980) Proc. LPSC 11th, 929.
CAR T-cell immunotherapy: The path from the by-road to the freeway?
Whilding, Lynsey M; Maher, John
2015-12-01
Chimeric antigen receptors are genetically encoded artificial fusion molecules that can re-program the specificity of peripheral blood polyclonal T-cells against a selected cell surface target. Unparallelled clinical efficacy has recently been demonstrated using this approach to treat patients with refractory B-cell malignancy. However, the approach is technically challenging and can elicit severe toxicity in patients. Moreover, solid tumours have largely proven refractory to this approach. In this review, we describe the important structural features of CARs and how this may influence function. Emerging clinical experience is summarized in both solid tumours and haematological malignancies. Finally, we consider the particular challenges imposed by solid tumours to the successful development of CAR T-cell immunotherapy, together with a number of innovative strategies that have been developed in an effort to reverse the balance in favour of therapeutic benefit. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.
Effect of Different Structural Materials on Neutronic Performance of a Hybrid Reactor
NASA Astrophysics Data System (ADS)
Übeyli, Mustafa; Tel, Eyyüp
2003-06-01
Selection of structural material for a fusion-fission (hybrid) reactor is very important by taking into account of neutronic performance of the blanket. Refractory metals and alloys have much higher operating temperatures and neutron wall load (NWL) capabilities than low activation materials (ferritic/martensitic steels, vanadium alloys and SiC/SiC composites) and austenitic stainless steels. In this study, effect of primary candidate refractory alloys, namely, W-5Re, T111, TZM and Nb-1Zr on neutronic performance of the hybrid reactor was investigated. Neutron transport calculations were conducted with the help of SCALE 4.3 System by solving the Boltzmann transport equation with code XSDRNPM. Among the investigated structural materials, tantalum had the worst performance due to the fact that it has higher neutron absorption cross section than others. And W-5Re and TZM having similar results showed the best performance.
Shin, Yun Kyoung; Cho, Yang Seok; Lien, Mei-Ching; Proctor, Robert W
2007-09-01
It has been argued that the psychological refractory period (PRP) effect is eliminated with two ideomotor compatible tasks when instructions stress fast and simultaneous responding. Three experiments were conducted to test this hypothesis. In all experiments, Task 1 required spatially compatible manual responses (left or right) to the direction of an arrow, and Task 2 required saying the name of the auditory letter A or B. In Experiments 1 and 3, the manual responses were keypresses made with the left and right hands, whereas in Experiment 2 they were left-right toggle-switch movements made with the dominant hand. Instructions that stressed response speed reduced reaction time and increased error rate compared to standard instructions to respond fast and accurately, but did not eliminate the PRP effect on Task 2 reaction time. These results imply that, even when response speed is emphasized, ideomotor compatible tasks do not bypass response selection.
Stabilized Alumina/Ethanol Colloidal Dispersion for Seeding High Temperature Air Flows
NASA Technical Reports Server (NTRS)
Wernet, Judith H.; Wernet, Mark P.
1994-01-01
Seeding air flows with particles to enable measurements of gas velocities via laser anemometry and/or particle image velocimetry techniques can be quite exasperating. The seeding requirements are compounded when high temperature environments are encountered and special care must be used in selecting a refractory seed material. The pH stabilization techniques commonly employed in ceramic processing are used to obtain stable dispersions for generating aerosols of refractory seed material. By adding submicron alumina particles to a preadjusted pH solution of ethanol, a stable dispersion is obtained which when atomized produces a high quality aerosol. Commercial grade alumina powder is used with a moderate size distribution. The technique is not limited to alumina/ethanol and is also demonstrated with an alumina/H2O system. Other ceramic powders in various polar solvents could also be used once the point of zero charge (pH(sub pzc)) of the powder in the solvent has been determined.
Treatment-refractory anxiety; definition, risk factors, and treatment challenges
Roy-Byrne, Peter
2015-01-01
A sizable proportion of psychiatric patients will seek clinical evaluation and treatment for anxiety symptoms reportedly refractory to treatment. This apparent lack of response is either due to “pseudo-resistance” (a failure to have received and adhered to a recognized and effective treatment or treatments for their condition) or to true “treatment resistance.” Pseudo-resistance can be due to clinician errors in selecting and delivering an appropriate treatment effectively, or to patient nonadherence to a course of treatment. True treatment resistance can be due to unrecognized exogenous anxiogenic factors (eg, caffeine overuse, sleep deprivation, use of alcohol or marijuana) or an incorrect diagnosis (eg, atypical bipolar illness, occult substance abuse, attention deficit-hyperactivity disorder). Once the above factors are eliminated, treatment should focus on combining effective medications and cognitive behavioral therapy, combining several medications (augmentation), or employing novel medications or psychotherapies not typically indicated as first-line evidence-based anxiety treatments. PMID:26246793
Treatment-refractory anxiety; definition, risk factors, and treatment challenges.
Roy-Byrne, Peter
2015-06-01
A sizable proportion of psychiatric patients will seek clinical evaluation and treatment for anxiety symptoms reportedly refractory to treatment. This apparent lack of response is either due to "pseudo-resistance" (a failure to have received and adhered to a recognized and effective treatment or treatments for their condition) or to true "treatment resistance." Pseudo-resistance can be due to clinician errors in selecting and delivering an appropriate treatment effectively, or to patient nonadherence to a course of treatment. True treatment resistance can be due to unrecognized exogenous anxiogenic factors (eg, caffeine overuse, sleep deprivation, use of alcohol or marijuana) or an incorrect diagnosis (eg, atypical bipolar illness, occult substance abuse, attention deficit-hyperactivity disorder). Once the above factors are eliminated, treatment should focus on combining effective medications and cognitive behavioral therapy, combining several medications (augmentation), or employing novel medications or psychotherapies not typically indicated as first-line evidence-based anxiety treatments.
Recent progress in ankylosing spondylitis treatment.
Toussirot, Eric; Wendling, Daniel
2003-01-01
Ankylosing spondylitis (AS) is a systemic inflammatory rheumatic disease responsible for back pain, stiffness and loss of functional capacity. The therapeutic management of AS includes regular physical exercise together with the use of NSAIDs. Second-line treatments, such as sulfasalazine, are required in cases of NSAID-refractory AS. Some patients have severe and inadequately controlled disease, explaining the need for the development of new treatments. This therapeutic development in AS involves the assessment of new NSAIDs, namely COX2 selective agents and new second-line treatments, such as methotrexate (MTX), pamidronate and anti-TNFalpha agents. Controlled studies are lacking for MTX. Pamidronate showed to be effective in NSAID refractory AS patients in open and controlled trials. Anti-TNFalpha agents (infliximab and etanercept) gave promising results with dramatic improvement of AS symptoms in open and preliminary controlled trials, but further studies are required to evaluate the real long-term effects and tolerability of these drugs.
On the origin of the moon, with emphasis on bulk composition
NASA Technical Reports Server (NTRS)
Kaula, W. M.
1977-01-01
A new analysis of altimetric, gravimetric, and seismological results, together with petrological and thermal history constraints, obtains an estimated Al2O3 content of 5.0%, 2.1 times chondritic. Hence the moon definitely has a refractory lithophile excess as well as an iron deficiency. In addition, the lunar surface is characterized by refractory siderophile depletions. The combination of these properties appears to require a previous stage of differentiation in a planetary body or bodies. Siderophile and chalcolphile depletions and dispersions in eucrites suggest that these bodies are not necessarily large. Possible mechanisms of lunar formation include impacting of a very large body into the earth; tidal disruption of sizeable differentiated planetesimals by the earth; and selective capture of differentiated planetesimal material by small moonlets. Each mechanism has its difficulties; the major unknown affecting all of them is the size distribution of planetesimals.
Electromagnetic valve for controlling the flow of molten, magnetic material
Richter, T.
1998-06-16
An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.
Electromagnetic valve for controlling the flow of molten, magnetic material
Richter, Tomas
1998-01-01
An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell.
van de Kamp, Cornelis; Gawthrop, Peter J.; Gollee, Henrik; Loram, Ian D.
2013-01-01
Researchers have previously adopted the double stimulus paradigm to study refractoriness in human neuromotor control. Currently, refractoriness, such as the Psychological Refractory Period (PRP) has only been quantified in discrete movement conditions. Whether refractoriness and the associated serial ballistic hypothesis generalises to sustained control tasks has remained open for more than sixty years. Recently, a method of analysis has been presented that quantifies refractoriness in sustained control tasks and discriminates intermittent (serial ballistic) from continuous control. Following our recent demonstration that continuous control of an unstable second order system (i.e. balancing a ‘virtual’ inverted pendulum through a joystick interface) is unnecessary, we ask whether refractoriness of substantial duration (∼200 ms) is evident in sustained visual-manual control of external systems. We ask whether the refractory duration (i) is physiologically intrinsic, (ii) depends upon system properties like the order (0, 1st, and 2nd) or stability, (iii) depends upon target jump direction (reversal, same direction). Thirteen participants used discrete movements (zero order system) as well as more sustained control activity (1st and 2nd order systems) to track unpredictable step-sequence targets. Results show a substantial refractory duration that depends upon system order (250, 350 and 550 ms for 0, 1st and 2nd order respectively, n = 13, p<0.05), but not stability. In sustained control refractoriness was only found when the target reverses direction. In the presence of time varying actuators, systems and constraints, we propose that central refractoriness is an appropriate control mechanism for accommodating online optimization delays within the neural circuitry including the more variable processing times of higher order (complex) input-output relations. PMID:23300430
2018-03-28
Atypical Chronic Myeloid Leukemia, BCR-ABL1 Negative; Chronic Myelomonocytic Leukemia; de Novo Myelodysplastic Syndrome; Essential Thrombocythemia; Myeloproliferative Neoplasm; Paroxysmal Nocturnal Hemoglobinuria; Polycythemia Vera; Polycythemia Vera, Post-Polycythemic Myelofibrosis Phase; Primary Myelofibrosis; Refractory Anemia; Refractory Anemia With Excess Blasts; Refractory Anemia With Ring Sideroblasts; Refractory Cytopenia With Multilineage Dysplasia; Refractory Cytopenia With Multilineage Dysplasia and Ring Sideroblasts
2018-04-23
Grade 3a Follicular Lymphoma; Grade 3b Follicular Lymphoma; Recurrent Classical Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Follicular Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory Classical Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma
CVD method of forming self-lubricating composites
Besmann, T.M.; Blau, P.J.; Lee, W.Y.; Bae, Y.W.
1998-12-01
An article having a multiphase composite lubricant coating of a hard refractory matrix phase of titanium nitride dispersed with particles of a solid lubricating phase of molybdenum disulfide is prepared by heating the article to temperatures between 350 and 850 C in a reaction vessel at a reduced pressure and passing a gaseous mixture of Ti((CH{sub 3}){sub 2}N){sub 4}, MoF{sub 6}, H{sub 2}S and NH{sub 3} over the heated article forming a multiphase composite lubricant coating on the article. 1 fig.
CVD method of forming self-lubricating composites
Besmann, Theodore M.; Blau, Peter J.; Lee, Woo Y.; Bae, Yong W.
1998-01-01
An article having a multiphase composite lubricant coating of a hard refractory matrix phase of titanium nitride dispersed with particles of a solid lubricating phase of molybdenum disulfide is prepared by heating the article to temperatures between 350.degree. and 850.degree. C. in a reaction vessel at a reduced pressure and passing a gaseous mixture of Ti((CH.sub.3).sub.2 N).sub.4, MoF.sub.6, H.sub.2 S and NH.sub.3 over the heated article forming a multiphase composite lubricant coating on the article.
Pyrolysis Products Of Dimethyldichlorosilane
NASA Technical Reports Server (NTRS)
Cagliostro, D. E.; Riccitiello, S. R.; Carswell, M. G.
1990-01-01
Report describes experimental study of chemical reactions and chemical products of chemical-vapor deposition of silicon carbide from dimethyldichlorosilane. Topic important because it relates to current interest in lightweight refractory materials for use in advanced aircraft and spacecraft. Analyses showed that at temperature of 700 to 1,100 degrees C and contact time of about 1 minute, SiC forms by two chemical-reaction paths.
Ahmadiani, Saeed; Nikfar, Shekoufeh; Karimi, Somayeh; Jamshidi, Ahmad Reza; Akbari-Sari, Ali; Kebriaeezadeh, Abbas
2016-09-01
The aim of this study was to evaluate the effectiveness and cost-effectiveness of using rituximab as first line for patients with refractory rheumatoid arthritis in comparison with continuing conventional DMARDs, from a perspective of health service governors. A systematic review was implemented through searching PubMed, Scopus and Cochrane Library. Quality assessment was performed by Jadad scale. After meta-analysis of ACR index results, QALY gain was calculated through mapping ACR index to HAQ and utility index. To measure the direct and indirect medical costs, a set of interviews with patients were applied. Thirty-two patients were selected from three referral rheumatology clinics in Tehran with definite diagnosis of refractory rheumatoid arthritis in the year before and treatment regimen of either rituximab or DMARDs within last year. Incremental cost-effectiveness ratio was calculated for base case and scenario of generic rituximab. Threefold of GDP per capita was considered as threshold of cost-effectiveness. Four studies were eligible to be considered in this systematic review. Total risk differences of 0.3 for achieving ACR20 criteria, 0.21 for ACR50 and 0.1 for ACR70 were calculated. Also mean of total medical costs of patients for 24 weeks were $3985 in rituximab group and $932 for DMARDs group. Thus, the incremental cost per QALY ratio will be $45,900-$70,223 in base case and $32,386-$49,550 for generic scenario. Rituximab for treatment of patients with refractory rheumatoid arthritis is not considered as cost-effective in Iran in none of the scenarios.
An, Jing; Li, Yingnan; Middleton, Richard S.
2018-02-20
China is the largest producer of magnesia refractory materials and products in the world, resulting in significant energy consumption and carbon emissions. This paper analyzes measures to reduce both the energy consumption and carbon emissions in the production phase and use phase, providing a theoretical basis for a sustainable magnesia refractory industry. Results show that the total carbon emissions of carbon-containing magnesia bricks produced with fused magnesia are much higher than those of other products, and the total carbon emissions of both general magnesia brick and magnesia-carbon spray are lower than those of other products. Carbon emissions of magnesia productsmore » are mainly concentrated in the production process of magnesia. Manufacturers should select materials with lower environmental impacts and emphasize saving energy and reducing carbon emissions in the magnesia production process. Through scenario analysis we found that CO 2 capture is an effective measure to reduce carbon emissions compared with just improving energy consumption. However, a robust CO 2 market does not currently exist. Policy makers should plan on integrating CO 2 capture in the magnesia industry into a regional CO 2 capture and storage development planning in the long term. In particular, magnesia production is concentrated in a single geographical area which would and thus could take advantage of significant scale effects. Finally, in the use phase, extending the service lifetime reduces carbon emissions over the product lifetime, thus users should attempt to extend the service lifetime of a furnace as a whole. However, results show that it is not advisable to add a large number of repair refractories to extend the lifetime of existing furnaces.« less
Uber, Walter E; Toole, John M; Stroud, Martha R; Haney, Jason S; Lazarchick, John; Crawford, Fred A; Ikonomidis, John S
2011-06-01
Refractory bleeding after complex cardiovascular surgery often leads to increased length of stay, cost, morbidity, and mortality. Recombinant activated factor VII administered in the intensive care unit can reduce bleeding, transfusion, and surgical re-exploration. We retrospectively compared factor VII administration in the intensive care unit with reoperation for refractory bleeding after complex cardiovascular surgery. From 1501 patients who underwent cardiovascular procedures between December 2003 and September 2007, 415 high-risk patients were identified. From this cohort, 24 patients were divided into 2 groups based on whether they either received factor VII in the intensive care unit (n = 12) or underwent reoperation (n = 12) for refractory bleeding. Preoperative and postoperative data were collected to compare efficacy, safety, and economic outcomes. In-hospital survival for both groups was 100%. Factor VII was comparable with reoperation in achieving hemostasis, with both groups demonstrating decreases in chest tube output and need for blood products. Freedom from reoperation was achieved in 75% of patients receiving factor VII, whereas reoperation was effective in achieving hemostasis alone in 83.3% of patients. Prothrombin time, international normalized ratio, and median operating room time were significantly less (P < .05) in patients who received factor VII. Both groups had no statistically significant differences in other efficacy, safety, or economic outcomes. Factor VII administration in the intensive care unit appears comparable with reoperation for refractory bleeding after complex cardiovascular surgical procedures and might represent an alternative to reoperation in selected patients. Future prospective, randomized controlled trials might further define its role. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
An, Jing; Li, Yingnan; Middleton, Richard S.
China is the largest producer of magnesia refractory materials and products in the world, resulting in significant energy consumption and carbon emissions. This paper analyzes measures to reduce both the energy consumption and carbon emissions in the production phase and use phase, providing a theoretical basis for a sustainable magnesia refractory industry. Results show that the total carbon emissions of carbon-containing magnesia bricks produced with fused magnesia are much higher than those of other products, and the total carbon emissions of both general magnesia brick and magnesia-carbon spray are lower than those of other products. Carbon emissions of magnesia productsmore » are mainly concentrated in the production process of magnesia. Manufacturers should select materials with lower environmental impacts and emphasize saving energy and reducing carbon emissions in the magnesia production process. Through scenario analysis we found that CO 2 capture is an effective measure to reduce carbon emissions compared with just improving energy consumption. However, a robust CO 2 market does not currently exist. Policy makers should plan on integrating CO 2 capture in the magnesia industry into a regional CO 2 capture and storage development planning in the long term. In particular, magnesia production is concentrated in a single geographical area which would and thus could take advantage of significant scale effects. Finally, in the use phase, extending the service lifetime reduces carbon emissions over the product lifetime, thus users should attempt to extend the service lifetime of a furnace as a whole. However, results show that it is not advisable to add a large number of repair refractories to extend the lifetime of existing furnaces.« less
Younes, Anas; Gopal, Ajay K.; Smith, Scott E.; Ansell, Stephen M.; Rosenblatt, Joseph D.; Savage, Kerry J.; Ramchandren, Radhakrishnan; Bartlett, Nancy L.; Cheson, Bruce D.; de Vos, Sven; Forero-Torres, Andres; Moskowitz, Craig H.; Connors, Joseph M.; Engert, Andreas; Larsen, Emily K.; Kennedy, Dana A.; Sievers, Eric L.; Chen, Robert
2012-01-01
Purpose Brentuximab vedotin is an antibody-drug conjugate (ADC) that selectively delivers monomethyl auristatin E, an antimicrotubule agent, into CD30-expressing cells. In phase I studies, brentuximab vedotin demonstrated significant activity with a favorable safety profile in patients with relapsed or refractory CD30-positive lymphomas. Patients and Methods In this multinational, open-label, phase II study, the efficacy and safety of brentuximab vedotin were evaluated in patients with relapsed or refractory Hodgkin's lymphoma (HL) after autologous stem-cell transplantation (auto-SCT). Patients had histologically documented CD30-positive HL by central pathology review. A total of 102 patients were treated with brentuximab vedotin 1.8 mg/kg by intravenous infusion every 3 weeks. In the absence of disease progression or prohibitive toxicity, patients received a maximum of 16 cycles. The primary end point was the overall objective response rate (ORR) determined by an independent radiology review facility. Results The ORR was 75% with complete remission (CR) in 34% of patients. The median progression-free survival time for all patients was 5.6 months, and the median duration of response for those in CR was 20.5 months. After a median observation time of more than 1.5 years, 31 patients were alive and free of documented progressive disease. The most common treatment-related adverse events were peripheral sensory neuropathy, nausea, fatigue, neutropenia, and diarrhea. Conclusion The ADC brentuximab vedotin was associated with manageable toxicity and induced objective responses in 75% of patients with relapsed or refractory HL after auto-SCT. Durable CRs approaching 2 years were observed, supporting study in earlier lines of therapy. PMID:22454421
El Bary, Naser Abd; Hashem, Tarek; Metwally, Hasan; Ghany, Ashraf Abd; El Mageed, Hager Abd
2010-01-01
Relapsed, histologically aggressive non-Hodgkin lymphoma (NHL) has a poor prognosis; relapsed patients who do not respond to second line therapy or are unfit for BMT have a worse prognosis. Angiogenesis is increased in aggressive NHL and could be targeted by selective cyclooxygenase-2 inhibition and metronomic chemotherapy. We assessed the toxicity of metronomic chemotherapy and the response and progression-free survival in patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). We prospectively studied 41 patients with a diagnosis of relapsed and/or refractory DLBCL who may have received any number of preceding therapies (as long as one included an anthracycline) and were not candidates for bone marrow transplantation. They received oral cyclophosphamide (50 mg every day), oral methotrexate (2.5 mg 4 times/week) and high-dose oral celecoxib (400 mg twice daily) until there was disease progression or unacceptable toxicity. All 41 patients (median age, 56 years) were evaluable for toxicity and response, with a median follow up of 9.1 months (range, 4-35 months). At relapse, 51.2% had a high international prognostic index. The treatment protocol was well tolerated with no major toxicities. The most common toxicities were fatigue (61%), nausea (22%), neutropenia (19.5%), and anemia (22%). In 31.7% there was a partial response and 48.8% had stable disease. Progression-free survival was 12 months. The median response duration was 10 months. We conclude that metronomic chemotherapy can be used for patients with relapsed and or refractory DLBCL with reasonable outcome and acceptable toxicity. Standard approaches such as hematopoietic stem cell transplantation and chemo-immunotherapy combinations should be explored prior to a decision on metronomic chemotherapy.
Short-Term Effects of Pulsed Radiofrequency on Chronic Refractory Cervical Radicular Pain
Choi, Gyu-Sik; Cho, Yun-Woo; Lee, Dong-Kyu
2011-01-01
Objective To evaluate the short-term effectiveness of pulsed radiofrequency on the dorsal root ganglion (DRG) in patients with chronic refractory cervical radicular pain. Method Fifteen patients (13 males, 2 females; mean age, 55.9 years) with chronic radicular pain due to cervical disc herniation or foraminal stenosis refractory to active rehabilitative management, including transforaminal cervical epidural steroid injection and exercise, were selected. All patients received pulsed radiofrequency on the symptomatic cervical dorsal root ganglion and were carefully evaluated for neurologic deficits and side effects. The clinical outcomes were measured using a visual analogue scale (VAS) and a neck disability index (NDI) before treatment, one and three months after treatment. Successful pain relief was defined as a 50% or greater reduction in the VAS score as compared with the pre-treatment score. After three months, we categorized the patients' satisfaction. Results The average VAS for radicular pain was reduced significantly from 5.3 at pretreatment to 2.5 at 3 months post-treatment (p<0.05). Eleven of 15 patients (77.3%) after cervical pulsed RF stimulation reported pain relief of 50% or more at the 3 month follow-up. The average NDI was significantly reduced from 44.0% at pretreatment to 35.8% 3 months post-treatment (p<0.05). At 3 months post-treatment, eleven of fifteen patients (73.3%) were satisfied with their status. No adverse effects were observed. Conclusion The results demonstrate that the application of pulsed radiofrequency on DRG might be an effective short-term intervention for chronic refractory cervical radicular pain. Further studies, including a randomized controlled trial with long-term follow-up, are now needed. PMID:22506211
Dexmedetomidine for Refractory Adrenergic Crisis in Familial Dysautonomia
Dillon, Ryan C.; Palma, Jose-Alberto; Spalink, Christy L.; Altshuler, Diana; Norcliffe-Kaufmann, Lucy; Fridman, David; Papadopoulos, John; Kaufmann, Horacio
2016-01-01
Objective Adrenergic crises are a cardinal feature of familial dysautonomia (FD). Traditionally, adrenergic crisis have been treated with the sympatholytic agent clonidine or with benzodiazepines, which can cause excessive sedation and respiratory depression. Dexmedetomidine is an α2A-adrenergic agonist with greater selectivity and shorter half-life than clonidine. We aimed to evaluate the preliminary effectiveness and safety of intravenous dexmedetomidine in the treatment of refractory adrenergic crisis in patients with FD. Methods Retrospective chart review of patients with genetically confirmed FD who received intravenous dexmedetomidine for refractory adrenergic crises. The primary outcome was preliminary effectiveness of dexmedetomidine defined as change in blood pressure (BP) and heart rate (HR) 1-hour after the initiation of dexmedetomidine. Secondary outcomes included incidence of adverse events related to dexmedetomidine, hospital and intensive care unit (ICU) length of stay, and hemodynamic parameters 12-hours after dexmedetomidine cessation. Results Nine patients over 14 admissions were included in the final analysis. At 1-hour after the initiation of dexmedetomidine, systolic BP decreased from 160±7 to 122±7 mmHg (p=0.0005), diastolic BP decreased from 103±6 to 65±8 (p=0.0003), and HR decreased from 112±4 to 100±5 bpm (p=0.0047). The median total adverse events during dexmedetomidine infusion was 1 per admission. Median hospital length of stay was 9 days (IQR, 3 – 11 days) and median ICU length of stay was 7 days (IQR, 3 – 11 days). Conclusions Intravenous dexmedetomidine is safe in patients with FD and appears to be effective to treat refractory adrenergic crisis. Dexmedetomidine may be considered in FD patients who do not respond to conventional clonidine and benzodiazepine pharmacotherapy. PMID:27752785
Epperla, Narendranath; Hamadani, Mehdi; Cashen, Amanda F; Ahn, Kwang W; Oak, Eunhye; Kanate, Abraham S; Calzada, Oscar; Cohen, Jonathon B; Farmer, Luke; Ghosh, Nilanjan; Tallarico, Michael; Nabhan, Chadi; Costa, Luciano J; Kenkre, Vaishalee P; Hari, Parameswaran N; Fenske, Timothy S
2017-12-01
Ibrutinib has demonstrated significant activity in relapsed/refractory mantle cell lymphoma (MCL) in clinical trials. However, the impact of hematopoietic cell transplantation on the outcomes of ibrutinib and the predictive factors for ibrutinib response has not been well studied. Hence, we conducted a multicenter retrospective study of MCL patients who received ibrutinib to (1) determine the overall response rate (ORR), duration of response (DOR), progression-free survival (PFS), and overall survival (OS) of ibrutinib in routine clinical practice, (2) examine characteristics predictive of response to ibrutinib therapy, and (3) describe the outcomes of patients failing ibrutinib. Ninety-seven patients met the eligibility criteria. Overall response rate and median DOR to ibrutinib were 65% and 17 months, respectively. Only lack of primary refractory disease was predictive of ibrutinib response on multivariate analysis. Twenty-nine patients received postibrutinib therapies, with an ORR of 48% and a median DOR of 3 months. The median OS and PFS for the entire group (n = 97) was 22 and 15 months, respectively. On multivariate analysis, ibrutinib response, low MCL international prognostic index, and absence of primary refractory disease were predictors of better PFS, while ibrutinib response and Eastern Cooperative Oncology Group performance status ≤1 were predictors of better OS. The median OS postibrutinib failure was 2.5 months. Our results confirm the high ORR and DOR of ibrutinib in MCL and that prior hematopoietic cell transplantation does not negatively influence ibrutinib outcomes. Survival following ibrutinib failure is poor with no specific subsequent therapy showing superior activity in this setting. As a result, for select (transplant eligible) patients, allogeneic transplant should be strongly considered soon after ibrutinib response is documented to provide durable responses. Copyright © 2017 John Wiley & Sons, Ltd.
Targeted neural network interventions for auditory hallucinations: Can TMS inform DBS?
Taylor, Joseph J; Krystal, John H; D'Souza, Deepak C; Gerrard, Jason Lee; Corlett, Philip R
2018-05-01
The debilitating and refractory nature of auditory hallucinations (AH) in schizophrenia and other psychiatric disorders has stimulated investigations into neuromodulatory interventions that target the aberrant neural networks associated with them. Internal or invasive forms of brain stimulation such as deep brain stimulation (DBS) are currently being explored for treatment-refractory schizophrenia. The process of developing and implementing DBS is limited by symptom clustering within psychiatric constructs as well as a scarcity of causal tools with which to predict response, refine targeting or guide clinical decisions. Transcranial magnetic stimulation (TMS), an external or non-invasive form of brain stimulation, has shown some promise as a therapeutic intervention for AH but remains relatively underutilized as an investigational probe of clinically relevant neural networks. In this editorial, we propose that TMS has the potential to inform DBS by adding individualized causal evidence to an evaluation processes otherwise devoid of it in patients. Although there are significant limitations and safety concerns regarding DBS, the combination of TMS with computational modeling of neuroimaging and neurophysiological data could provide critical insights into more robust and adaptable network modulation. Copyright © 2017 Elsevier B.V. All rights reserved.
Blinatumomab: Enlisting serial killer T cells in the war against hematologic malignanciess
Rogala, Britny; Freyer, Craig W.; Ontiveros, Evelena P.; Griffiths, Elizabeth A.; Wang, Eunice S.; Wetzler, Meir
2016-01-01
Introduction The approval of blinatumomab signals the long awaited arrival of immunotherapy for acute lymphoblastic leukemia (ALL). Previous options for relapsed or refractory disease were restricted to combination cytotoxic chemotherapy with limited efficacy and significant toxicity. Through an innovative mechanism of action, blinatumomab stimulates a polyclonal antitumor T cell response, yielding unprecedented single agent efficacy in the relapsed/refractory setting. Success comes at the cost of immunological toxicities rarely encountered with previous therapies and challenging administration logistics requiring clinical expertise. Areas covered All published clinical and preclinical studies using blinatumomab were reviewed in addition to all registered ongoing clinical trials and data published in abstract form. The search was limited to the English language. The pharmacology, clinical efficacy, toxicity profile, and logistical considerations for drug administration are discussed. Expert Opinion Blinatumomab is an exciting addition to the treatment armamentarium for relapsed/refractory ALL, yet several questions remain regarding optimal implementation into the current treatment paradigm. A unique toxicity profile should be weighed against promising benefits in a poor prognosis population. Other emerging therapies, such as chimeric antigen receptor-modified T cells and inotuzumab ozogamicin, with different side effect profiles and administration schedules, may prove to be more beneficial for specific patient populations. PMID:25985814
Kissova, Miroslava; Maga, Giovanni; Crespan, Emmanuele
2016-10-01
The tyrosine kinase Kit, a receptor for Stem Cell Factor, is involved, among others, in processes associated to cell survival, proliferation and migration. Upon physiological conditions, the activity of Kit is tightly regulated. However, primary mutations that lead to its constitutive activation are the causal oncogenic driver of gastrointestinal stromal tumours (GISTs). GISTs are known to be refractory to conventional therapies but the introduction of Imatinib, a selective inhibitor of tyrosine kinases Abl and Kit, significantly ameliorated the treatment options of GISTs patients. However, the acquisition of secondary mutations renders Kit resistant towards all available drugs. Mutation involving gatekeeper residues (such as V654a and T670I) influence both the structure and the catalytic activity of the enzyme. Therefore, detailed knowledge of the enzymatic properties of the mutant forms, in comparison with the wild type enzyme, is an important pre-requisite for the rational development of specific inhibitors. In this paper we report a thorough kinetic analysis of the reaction catalyzed by the Kit kinase and its gatekeeper mutated form T670I. Our results revealed the different mechanisms of action of these two enzymes and may open a new avenue for the future design of specific Kit inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.
Lenalidomide and Blinatumomab in Treating Patients With Relapsed Non-Hodgkin Lymphoma
2018-06-11
CD19 Positive; Mediastinal Lymphoma; Recurrent B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classic Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Non-Hodgkin Lymphoma; Recurrent Small Lymphocytic Lymphoma; Refractory B-Cell Lymphoma, Unclassifiable, With Features Intermediate Between Diffuse Large B-Cell Lymphoma and Classic Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Follicular Lymphoma; Refractory Mantle Cell Lymphoma; Refractory Small Lymphocytic Lymphoma
Evaluation of Alternative Refractory Materials for the Main Flame Deflectors at KSC Launch Complexes
NASA Technical Reports Server (NTRS)
Calle, Luz Marina; Trejo, David; Rutkowsky, Justin
2006-01-01
The deterioration of the refractory materials used to protect the KSC launch complex steel base structures from the high temperatures during launches results in frequent and costly repairs and safety hazards. KSC-SPEC-P-0012, Specification for Refractory Concrete, is ineffective in qualifying refractory materials. This study of the specification and of alternative refractory materials recommends a complete revision of the specification and further investigation of materials that were found to withstand the environment of the Solid Rocket Booster main flame deflector better than the refractory materials in current use in terms of compressive strength, tensile strength, modulus of rupture, shrinkage, and abrasion.
Rodgers, Billy R.; Edwards, Michael S.
1977-01-01
Solids such as char, ash, and refractory organic compounds are removed from coal-derived liquids from coal liquefaction processes by the pressure precoat filtration method using particles of 85-350 mesh material selected from the group of bituminous coal, anthracite coal, lignite, and devolatilized coals as precoat materials and as body feed to the unfiltered coal-derived liquid.
Refractory ceramic compositions and method for preparing same
Holcombe, Jr., Cressie E.; Morrow, Margaret K.
1976-07-13
This invention relates to ceramic compositions of tungsten and tantalum oxides including 0 to 33 1/3 mole percent of a metal oxide such as hafnia. These ceramics are characterized by melting points greater than about 1400.degree.C and selectively controlled coefficients of thermal expansion of essentially zero to a negative value in the temperature range of 20.degree. to 1000.degree.C.
Field Emission Cold Cathode Devices Based on Eutectic Systems
1981-07-01
8217RADC-TR-811-170 ’,Final Technical Report July 1981 FIELD EMISSION COLD CATHODE DEVICES BASED ON EUTECTIC SYSTEMS Fulmer Research Institute Ltd...and identify by block numrber) Field Emission Eutectic Systems Cold Cathode Rod Eutectics Electron Emitter Array Directionally Solidified Eutectics...Identify by block number) A survey has been made of the performance as field emission cold cathodes of selected refractory materials fabricated as
High temperature composites. Status and future directions
NASA Technical Reports Server (NTRS)
Signorelli, R. A.
1982-01-01
A summary of research investigations of manufacturing methods, fabrication methods, and testing of high temperature composites for use in gas turbine engines is presented. Ceramic/ceramic, ceramic/metal, and metal/metal composites are considered. Directional solidification of superalloys and eutectic alloys, fiber reinforced metal and ceramic composites, ceramic fibers and whiskers, refractory coatings, metal fiber/metal composites, matrix metal selection, and the preparation of test specimens are discussed.
Understanding refractory failures
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bases, G.J.
2006-01-15
Compared to most pieces of a power plant, refractory costs very little to install. Yet, if improperly manufactured, specified, stored, mixed installed, cured, or dried, refractory may cause problems that can significantly decrease a plant's operating efficiency and flexibility. Like Rodney Dangerfield, refractory design and installation deserve more respect. 4 photos.
2018-05-22
Lymphocyte-Rich Classical Hodgkin Lymphoma; Recurrent Lymphocyte-Depleted Classical Hodgkin Lymphoma; Recurrent Mixed Cellularity Classical Hodgkin Lymphoma; Recurrent Nodular Sclerosis Classical Hodgkin Lymphoma; Refractory Lymphocyte-Depleted Classical Hodgkin Lymphoma; Refractory Mixed Cellularity Classical Hodgkin Lymphoma; Refractory Nodular Sclerosis Classical Hodgkin Lymphoma
2017-11-15
Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent T-Cell Non-Hodgkin Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Hodgkin Lymphoma; Refractory T-Cell Non-Hodgkin Lymphoma
Refractory Wear Mechanisms in the Nonferrous Metal Industry: Testing and Modeling Results
NASA Astrophysics Data System (ADS)
Gregurek, D.; Ressler, A.; Reiter, V.; Franzkowiak, A.; Spanring, A.; Prietl, T.
2013-11-01
Nonferrous pyrometallurgical processes today operate at a high intensity requiring the best standards for the furnace refractory systems. From one plant to another, there is a range of process conditions such as temperature, slag chemistry, and feed types, and each of these parameters can influence refractory life. It is generally understood that process changes at plants can impact refractory life. The ability to test and understand refractory responses to a wide range of furnace operating conditions is therefore important. The RHI Technology Centre in Leoben, Austria is well equipped with laboratory and pilot plant facilities to evaluate refractory suitability over the range of conditions encountered in modern nonferrous pyrometallurgical systems. This article describes refractory testing at the RHI Technology Centre of the impact of two metallurgical slags on a number of different RHI test bricks. The slags were a fayalite slag and a calcium ferrite slag supplied by two smelter plants. High-temperature corrosion tests were carried out in a 250-mm-diameter induction furnace and a 165-mm-diameter short rotary kiln; each unit was lined with a number of refractory bricks and tested against attack by the particular slag. After testing, the refractory bricks were subjected to several laboratory tests to determine the extent of corrosion. Optimal refractory choices for the customers' plants were developed based on the test results.
2018-05-23
ALK Positive; BCL6 Positive; Recurrent Anaplastic Large Cell Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mantle Cell Lymphoma; Refractory Anaplastic Large Cell Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mantle Cell Lymphoma
2018-02-28
Acute Leukemia of Ambiguous Lineage; Recurrent Adult Acute Lymphoblastic Leukemia; Recurrent Adult Acute Myeloid Leukemia; Recurrent Childhood Acute Lymphoblastic Leukemia; Recurrent Childhood Acute Myeloid Leukemia; Refractory Acute Myeloid Leukemia; Refractory Adult Acute Lymphoblastic Leukemia; Refractory Childhood Acute Lymphoblastic Leukemia
2018-05-22
Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Hodgkin Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent T-Cell Non-Hodgkin Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Hodgkin Lymphoma; Refractory Mantle Cell Lymphoma; Refractory T-Cell Non-Hodgkin Lymphoma
2017-12-04
Post-Transplant Lymphoproliferative Disorder; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Burkitt Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Burkitt Lymphoma; Refractory Diffuse Large B-Cell Lymphoma
Diagnostic yield of capsule endoscopy in refractory celiac disease.
Barret, Maximilien; Malamut, Georgia; Rahmi, Gabriel; Samaha, Elia; Edery, Joël; Verkarre, Virginie; Macintyre, Elizabeth; Lenain, Emilie; Chatellier, Gilles; Cerf-Bensussan, Nadine; Cellier, Christophe
2012-10-01
Capsule endoscopy (CE) allows for the assessment of the small bowel in numerous intestinal diseases, including celiac disease (CD). The main advantage of CE is the complete visualization of the intestinal mucosal surface. The objective of this study was to investigate whether CE can predict the severity of CD and detect complications. We retrospectively studied the medical files of 9 patients with symptomatic CD, 11 patients with refractory celiac disease type I (RCDI) and 18 patients with refractory celiac disease type II (RCDII), and 45 patients without CD who were investigated both CE and upper endoscopy or enteroscopy. The type of CD was diagnosed on the basis of a centralized histological review, flow cytometry analysis of intraepithelial lymphocytes, and the analysis of T-cell receptor rearrangement by multiplex polymerase chain reaction. A total of 47 CEs (10, 11, and 26 CEs in the symptomatic CD, RCDI, and RCDII groups, respectively) from the 38 celiac patients and 47 CEs from the 45 nonceliac patients were retrospectively reviewed. Villous atrophy, numerous, or distally located ulcers were more frequent in celiac patients than in controls. Among celiac patients, CE was of acceptable quality in 96% of cases and was complete in 62% of cases. The concordance of CE with histology for villous atrophy was better than that of optic endoscopy (κ coefficient =0.45 vs. 0.24, P<0.001). Extensive mucosal damage on CE was associated with low serum albumin (P=0.003) and the RCDII form (P=0.02). Three cases of overt lymphoma were detected by CE during the follow-up. CE findings have a satisfactory concordance with histology and nutritional status in patients with symptomatic or refractory CD. Moreover, CE may predict the type of RCD and allows for the early detection of overt lymphoma.
Zhang, Ming; Wang, Zhou; Li, Penghui; Zhang, Hua; Xie, Li
2017-07-01
An important portion of organic matter and colorants still remain in the biologically treated distillery wastewater, leaving the dark brown and odorous downstream with the heavy loading of chemical oxygen demand and the potential of forming disinfection byproducts. However, those bio-recalcitrant colorants have not been clearly recognized. The current study investigated the features of the bio-refractory organic matter and colorants in a typical distillery effluent, cassava distillery wastewater; special attention was paid to their change and behaviors in the coagulation treatment following the bio-processes. The wastewater analyses denoted that the fraction of high molecular weight (1-50 kDa and >50 kDa) became predominant after the anaerobic-aerobic processes. Importantly, the lignin breakdown products, melanoidins and lignin phenols were confirmed to be the leading colored components, according to the parallel factor analysis of fluorescence excitation-emission matrixes results. Compared with lignin phenols, the former two types of colorants exhibited stronger bio-refractory activity and resulted in smaller color reduction after the aerobic treatment. Neither advanced oxidation nor adsorption could perform efficiently as post-treatment for decolorization in this study. Nevertheless, high removal of color and dissolved organic matter (∼94.0% and ∼78.3%, respectively) could be achieved by the FeCl 3 -involved coagulation under the optimal conditions. The ferric coagulant was found to preferably interact with the aromatic compounds (such as lignin derivatives) and melanoidins via either surface complexation or electric charge neutralization, or both. The findings presented herein might provide an insight into the evaluation of bio-refractory organic colorants and the Fe(III)-involved decolorization mechanisms of ethanol production wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.
Landry, Zachary; Swan, Brandon K; Herndl, Gerhard J; Stepanauskas, Ramunas; Giovannoni, Stephen J
2017-04-18
Deep-ocean regions beyond the reach of sunlight contain an estimated 615 Pg of dissolved organic matter (DOM), much of which persists for thousands of years. It is thought that bacteria oxidize DOM until it is too dilute or refractory to support microbial activity. We analyzed five single-amplified genomes (SAGs) from the abundant SAR202 clade of dark-ocean bacterioplankton and found they encode multiple families of paralogous enzymes involved in carbon catabolism, including several families of oxidative enzymes that we hypothesize participate in the degradation of cyclic alkanes. The five partial genomes encoded 152 flavin mononucleotide/F420-dependent monooxygenases (FMNOs), many of which are predicted to be type II Baeyer-Villiger monooxygenases (BVMOs) that catalyze oxygen insertion into semilabile alicyclic alkanes. The large number of oxidative enzymes, as well as other families of enzymes that appear to play complementary roles in catabolic pathways, suggests that SAR202 might catalyze final steps in the biological oxidation of relatively recalcitrant organic compounds to refractory compounds that persist. IMPORTANCE Carbon in the ocean is massively sequestered in a complex mixture of biologically refractory molecules that accumulate as the chemical end member of biological oxidation and diagenetic change. However, few details are known about the biochemical machinery of carbon sequestration in the deep ocean. Reconstruction of the metabolism of a deep-ocean microbial clade, SAR202, led to postulation of new biochemical pathways that may be the penultimate stages of DOM oxidation to refractory forms that persist. These pathways are tied to a proliferation of oxidative enzymes. This research illuminates dark-ocean biochemistry that is broadly consequential for reconstructing the global carbon cycle. Copyright © 2017 Landry et al.
Mody, Rajen; Zhao, Lili; Yanik, Gregory Anthony; Opipari, Valerie
2017-11-01
Prognosis for relapsed/refractory high-risk neuroblastoma (HR-NBL) remains poor. Bortezomib, a proteasome inhibitor, has shown preclinical activity against NBL as a single agent and in combination with cytotoxic chemotherapy including irinotecan. Eighteen HR-NBL patients with primary refractory (n = 8) or relapsed (n = 10) disease were enrolled in a Phase I study using modified Time To Event Continual Reassessment Method. Bortezomib (1.2 mg/m 2 /day) was administered on days 1, 4, 8, and 11 intravenously (IV) and irinotecan was given IV on days 1-5 (35, 40, or 45 mg/m 2 /day, on dose levels [DL] 1-3, respectively). The maximum tolerated dose (MTD), dose-limiting toxicity (DLT), and response rate were examined. Eighteen NBL patients were evaluable for toxicity; 17 were evaluable for response assessment. A total of 142 courses were delivered (mean 8.2, median 2, range 1-48), with two patients receiving more than 40 courses of therapy. Two DLTs were reported, including a grade 4 thrombocytopenia (DL2) and a grade 3 irritability (DL3). MTD was estimated as DL3. Two of 17 (12%) evaluable patients showed objective responses (ORs) lasting more than 40 courses, including 1 partial remission and 1 complete remission. Four patients (23%) had prolonged stable disease (SD) lasting six or more courses, with a total of 35% study patients demonstrating clinical benefit in the form of prolonged OR or SD. The combination of bortezomib and irinotecan was well tolerated by patients with relapsed/refractory NBL with favorable toxicity profile. It also showed modest but promising clinical activity and merits further testing in Phase II studies. © 2017 Wiley Periodicals, Inc.
Plasma-Sprayed Refractory Oxide Coatings on Silicon-Base Ceramics
NASA Technical Reports Server (NTRS)
Tewari, Surendra
1997-01-01
Silicon-base ceramics are promising candidate materials for high temperature structural applications such as heat exchangers, gas turbines and advanced internal combustion engines. Composites based on these materials are leading candidates for combustor materials for HSCT gas turbine engines. These materials possess a combination of excellent physical and mechanical properties at high temperatures, for example, high strength, high toughness, high thermal shock resistance, high thermal conductivity, light weight and excellent oxidation resistance. However, environmental durability can be significantly reduced in certain conditions such as when molten salts, H2 or water vapor are present. The oxidation resistance of silicon-base materials is provided by SiO2 protective layer. Molten salt reacts with SiO2 and forms a mixture of SiO2 and liquid silicate at temperatures above 800C. Oxygen diffuses more easily through the chemically altered layer, resulting in a catastrophic degradation of the substrate. SiC and Si3N4 are not stable in pure H2 and decompose to silicon and gaseous species such as CH4, SiH, SiH4, N2, and NH3. Water vapor is known to slightly increase the oxidation rate of SiC and Si3N4. Refractory oxides such as alumina, yttria-stabilized zirconia, yttria and mullite (3Al2O3.2SiO2) possess excellent environmental durability in harsh conditions mentioned above. Therefore, refractory oxide coatings on silicon-base ceramics can substantially improve the environmental durability of these materials by acting as a chemical reaction barrier. These oxide coatings can also serve as a thermal barrier. The purpose of this research program has been to develop refractory oxide chemical/thermal barrier coatings on silicon-base ceramics to provide extended temperature range and lifetime to these materials in harsh environments.
Refractory thermowell for continuous high temperature measurement of molten metal
Thiesen, Todd J.
1992-01-01
An apparatus for the continuous high temperature measurement of materials in vessels lined with rammed or cast refractory materials. A refractory housing member is integral with the refractory lining of the vessel and contains a plurality of high temperature sensing means, such as thermocouples. A face of the housing is flush with the refractory lining and contacts the high temperature material contained in the vessel. Continuous temperature measurement is achieved by a means which is coupled to the thermocouples for indicating the temperature.
Task switching and response correspondence in the psychological refractory period paradigm
NASA Technical Reports Server (NTRS)
Lien, Mei-Ching; Schweickert, Richard; Proctor, Robert W.
2003-01-01
Three experiments examined the effects of task switching and response correspondence in a psychological refractory period paradigm. A letter task (vowel-consonant) and a digit task (odd-even) were combined to form 4 possible dual-task pairs in each trial: letter-letter, letter-digit, digit-digit, and digit-letter. Foreknowledge of task transition (repeat or switch) and task identity (letter or digit) was varied across experiments: no foreknowledge in Experiment 1, partial foreknowledge (task transition only) in Experiment 2, and full foreknowledge in Experiment 3. For all experiments, the switch cost for Task 2 was additive with stimulus onset asynchrony, and the response-correspondence effect for Task 2 was numerically smaller in the switch condition than in the repeat condition. These outcomes suggest that reconfiguration for Task 2 takes place after the central processing of Task 1 and that the crosstalk correspondence effect is due to response activation by way of stimulus-response associations.
Gao, Yan; Sun, Dezhi; Dang, Yan; Lei, Yuqing; Ji, Jiayang; Lv, Tingwei; Bian, Rui; Xiao, Zhihui; Yan, Liangming; Holmes, Dawn E
2017-05-01
Methanogenic treatment of municipal solid waste (MSW) incineration leachate can be hindered by high concentrations of refractory organic matter and humification of compounds in the leachate. In an attempt to overcome some of these impediments, microbial electrolysis cells (MECs) were incorporated into anaerobic digesters (ADMECs). COD removal efficiencies and methane production were 8.7% and 44.3% higher in ADMECs than in controls, and ADMEC reactors recovered more readily from souring caused by high organic loading rates. The degradation rate of large macromolecules was substantially higher (96% vs 81%) in ADMEC than control effluent, suggesting that MECs stimulated degradation of refractory organic matter and reduced humification. Exoelectrogenic bacteria and microorganisms known to form syntrophic partnerships were enriched in ADMECs. These results show that ADMECs were more effective at treatment of MSW incineration leachate, and should be taken into consideration when designing future treatment facilities. Copyright © 2017 Elsevier Ltd. All rights reserved.
Thyroid Functions and Bipolar Affective Disorder
Chakrabarti, Subho
2011-01-01
Accumulating evidence suggests that hypothalamo-pituitary-thyroid (HPT) axis dysfunction is relevant to the pathophysiology and clinical course of bipolar affective disorder. Hypothyroidism, either overt or more commonly subclinical, appears to the commonest abnormality found in bipolar disorder. The prevalence of thyroid dysfunction is also likely to be greater among patients with rapid cycling and other refractory forms of the disorder. Lithium-treatment has potent antithyroid effects and can induce hypothyroidism or exacerbate a preexisting hypothyroid state. Even minor perturbations of the HPT axis may affect the outcome of bipolar disorder, necessitating careful monitoring of thyroid functions of patients on treatment. Supplementation with high dose thyroxine can be considered in some patients with treatment-refractory bipolar disorder. Neurotransmitter, neuroimaging, and genetic studies have begun to provide clues, which could lead to an improved understanding of the thyroid-bipolar disorder connection, and more optimal ways of managing this potentially disabling condition. PMID:21808723
Liimatainen, Suvi; Peltola, Jukka; Hietaharju, Aki; Sabater, Lidia; Lang, Bethan
2014-03-01
Over the last few years autoantibodies against neuronal proteins have been identified in several forms of autoimmune encephalitis and epilepsy. NMDA receptor (NMDAR) and voltage gated potassium channel (VGKC) complex antibodies are mainly associated with limbic encephalitis (LE) whereas glutamic acid decarboxylase antibodies (GADA) and anticardiolipin (ACL) antibodies are more commonly detected in patients with chronic epilepsy. Clinical features vary between these antibodies suggesting the specificity of different neuronal antibodies in seizures. Serum samples of 14 GADA positive and 24 ACL positive patients with refractory epilepsy were analyzed for the presence of VGKC or NMDAR antibodies. No positive VGKC or NMDAR antibodies were found in these patients. The results confirm the different significance of these neuronal antibodies in seizure disorders. Different autoantibodies have different significance in seizures and probably have different pathophysiological mechanisms of actions. Copyright © 2014 Elsevier B.V. All rights reserved.
The effect of sintering time on recycled magnesia brick from kiln of the cement plant
NASA Astrophysics Data System (ADS)
Aji, B. B.; Rosalina, D.; Azhar; Amin, M.
2018-01-01
This research aim was to investigate the effect of sintering time on reuse waste of magnesia brick from the rotary kiln of the cement plant. Reuse of the magnesia brick was carried out by mixed the kaolin as the binder. Spent refractory was used as aggregate with the composition of 85% spent refractory and 15% kaolin clay, respectively. The reuse brick then was molded with the size of 5x5x5 cm using hydraulic press under a load of 10 tons in order to forms green body. Green body then dried and sintered at 1200 °C with time variation of 2 hours, 4 hours, 6 hours, 8 hours and 10 hours, respectively. Thus, for comparison reuse brick was tested to its apparent porosity, the bulk density, and Cold Crushing Strength (CCS). The effect of kaolin addition as binder was also discussed.
Presence, segregation and reactivity of H, C and N dissolved in some refractory oxides
NASA Technical Reports Server (NTRS)
Freund, F.
1986-01-01
The sources of impurities, particularly carbon, in high melting oxides and silicates are discussed, along with detection and quantification methods. The impurities are important for their effects on bulk material properties through the media of, e.g., surface or grain boundary characteristics. The impurities are usually encountered by the contact of the oxide (refractory) material with volatiles such as H2O and CO2, which become incorporated in the material and form anion complexes with oxygen acting as a covalent bonded ligand. The specific processes undergone by MgO in assimilating C impurities are delineated, using data obtained with X-ray photoelectron spectroscopy, Auger electron spectroscopy, secondary ion mass spectrometry and nuclear reaction profiling. Finally, maintenance of a supersaturated solid solution with C impurities by space charge control is described as a means of offset impurity effects.
Microstructure and Properties of Zircon-Added Carbon Refractories for Blast Furnace
NASA Astrophysics Data System (ADS)
Zhu, Tianbin; Li, Yawei; Sang, Shaobai; Chen, Xilai; Zhao, Lei; Li, Yuanbing; Li, Shujing
2012-11-01
Microstructure and properties of zircon-added carbon refractory specimens for blast furnace (BF) were investigated with the aid of X-ray diffraction (XRD), a scanning electron microscope (SEM), energy-dispersive X-ray, mercury porosimetry, and a laser thermal conductivity (TC) meter. Additives could influence the matrix structures and improve the properties of specimens. With the increase of zircon powder content, the amount of SiC whiskers formed increased and their aspect ratio became larger, and the SiC whiskers tended to be distributed homogeneously. Zircon powder additions decreased the mean pore diameter and increased <1- μm pore volume by filling in pores via SiC, improved the TC and the cold crushing strength (CCS) due to the in-situ formation of the more well-developed SiC whiskers with high TC, and significantly reduced the molten iron attack to carbon specimens.
Uranium carbide fission target R&D for RIA - an update
NASA Astrophysics Data System (ADS)
Greene, J. P.; Levand, A.; Nolen, J.; Burtseva, T.
2004-12-01
For the Rare Isotope Accelerator (RIA) facility, ISOL targets employing refractory compounds of uranium are being developed to produce radioactive ions for post-acceleration. The availability of refractory uranium compounds in forms that have good thermal conductivity, relatively high density, and adequate release properties for short-lived isotopes remains an important issue. Investigations using commercially obtained uranium carbide material and prepared into targets involving various binder materials have been carried out at ANL. Thin sample pellets have been produced for measurements of thermal conductivity using a new method based on electron bombardment with the thermal radiation observed using a two-color optical pyrometer and performed on samples as a function of grain size, pressing pressure and sintering temperature. Manufacture of uranium carbide powder has now been achieved at ANL. Simulations have been carried out on the thermal behavior of the secondary target assembly incorporating various heat shield configurations.
NASA Astrophysics Data System (ADS)
Antonov, Stoichko; Sun, Eugene; Tin, Sammy
2018-06-01
Detailed ex-situ electron microscopy and atom probe tomography (APT) were combined with in-situ synchrotron diffraction to systematically quantify the chemical, morphological, and lattice instabilities that occur during aging of a polycrystalline high-refractory content Ni-base superalloy. The morphological changes and splitting phenomenon associated with the secondary γ' precipitates were related to a combination of discrete chemical composition variations at the secondary γ'/γ interfaces and additional chemical energy arising from γ precipitates that form within the secondary γ' particles. The compositional phase inhomogeneities led to the precipitation of finely dispersed tertiary γ' particles within the γ matrix and secondary γ particles within the secondary γ' precipitates, which, along with surface grooving of the secondary γ' particles, likely due to a spike in the lattice misfit at the particle interfaces, contributed to the splitting of the precipitates during aging.
Zeolite-based SCR catalysts and their use in diesel engine emission treatment
Narula, Chaitanya K.; Yang, Xiaofan
2016-08-02
A catalyst comprising a zeolite loaded with copper ions and at least one trivalent metal ion other than Al.sup.+3, wherein the catalyst decreases NO.sub.x emissions in diesel exhaust. The trivalent metal ions are selected from, for example, trivalent transition metal ions, trivalent main group metal ions, and/or trivalent lanthanide metal ions. In particular embodiments, the catalysts are selected from Cu--Fe-ZSM5, Cu--La-ZSM-5, Fe--Cu--La-ZSM5, Cu--Sc-ZSM-5, and Cu--In-ZSM5. The catalysts are placed on refractory support materials and incorporated into catalytic converters.
Zeolite-based SCR catalysts and their use in diesel engine emission treatment
Narula, Chaitanya K; Yang, Xiaofan
2015-03-24
A catalyst comprising a zeolite loaded with copper ions and at least one trivalent metal ion other than Al.sup.+3, wherein the catalyst decreases NO.sub.x emissions in diesel exhaust. The trivalent metal ions are selected from, for example, trivalent transition metal ions, trivalent main group metal ions, and/or trivalent lanthanide metal ions. In particular embodiments, the catalysts are selected from Cu--Fe-ZSM5, Cu--La-ZSM-5, Fe--Cu--La-ZSM5, Cu--Sc-ZSM-5, and Cu--In-ZSM5. The catalysts are placed on refractory support materials and incorporated into catalytic converters.
Initial clinical experience of tube-shunt surgery in Ethiopian patients with refractory glaucoma.
T/Giorgis, Abeba
2012-04-01
In Ethiopia, it is not uncommon to encounter refractory glaucoma cases that could be managed with tube-shunt surgery. Tube-shunt implant surgery has been a standard procedure option and widely used for various forms of refractory glaucoma. To described the initial experience and outcome of Ahmed Tube shunt implant for refractory adult Ethiopian glaucoma cases. Retrospective review of consecutive adult patients with refractory glaucoma who underwent Ahmed glaucoma valve implant at the Department of ophthalmology, Menelik II Hospital, Addis Ababa between April 2009 and December 2010. intraocular pressure (IOP), visual acuity, use of supplemental medical therapy and surgical complications. Success was defined as IOP greater than 5 and less than 22 mmHg with at least 30% reduction in IOP from preoperative levels with and without supplemental glaucoma medications, no additional surgeries to lower the IOP and without visual loss of light perception from devastating postoperative complications. Thirteen eyes of 12 patients (10 men, 2 women; mean age 52.4 +/- 15. 7) who underwent glaucoma tube-shunt drainage surgery with Ahmed-tube valve were included in this analysis. The mean preoperative IOP was 31.38 +/- 8.67 mmHg with 2.23 +/- 0.44 antiglaucoma medications. Postoperatively, the mean IOP reduced to 15.52 +/- 8.80 mmHg at 1 week, 14.77 +/- 6.39 mmHg at 1 month, 16.62 +/- 4.48 mmHg at 3 months, and 17.15 +/- 3.87 mmHg at 6 months. The reduction from the preoperative mean IOP at last follow up was 45.3% with 1.08 +/- 0.44 supplemental glaucoma medications. The success rate of IOP controlling according to the definition was 76.9%. The pressure remained below 18 mmHg with and without medication in 9/13 (69.2%) eyes, while three eyes required no medication at all till the last follow-up with sustained IOP < 15 mmHg. At the last follow-up the visual acuity reduced by > or = 2 lines in two eyes while one patient's vision worsened from counting finger of one meter to hand movement. Visual improvement of one and two lines documented in two eyes. Hypotony, Tube-corneal touch, acceleration of cataract, choroidal effusion, flat anterior chamber, visual reduction and tube exposure were the types of complications encountered in 6 eyes, while 3 eyes had more than one complication. The study has shown that tube-shunt implant to be effective in lowering intraocular pressure in refractory glaucoma cases. The few cases reported are indicators of the importance of the procedure in salvaging vision of patients with refractory glaucoma and the need of large scale prospective study in the country.
Refractory overactive bladder: Beyond oral anticholinergic therapy
Glinski, Ronald W.; Siegel, Steven
2007-01-01
Objectives: In this review, we discuss the treatment of refractory overactive bladder (OAB) that has not adequately responded to medication therapy and we propose an appropriate care pathway to the treatment of OAB. We also attempt to address the cost of OAB treatments. Materials and Methods: A selective expert review of the current literature on the subject of refractory OAB using MEDLINE was performed and the data is summarized. We also review our experience in treating refractory OAB. The role and outcomes of various treatment options for refractory OAB are discussed and combined therapy with oral anticholinergics is explored. Emerging remedies including intravesical botulinum toxin injection and pudendal neuromodulation are also reviewed, along with conventional surgical options. Results: In general behavioral therapy, pelvic floor electrical stimulation, magnetic therapy and posterior tibial nerve stimulation (PTNS), have shown symptom decreases in 50-80% of patients with OAB. Depending on the study, combination therapy with oral anticholinergics seems to improve efficacy of behavioral therapy and PTNS in approximately 10-30%. In multicenter, long-term randomized controlled trials, sacral neuromodulation has been shown to improve symptoms of OAB and OAB incontinence in up to 80% of the patients treated. Studies involving emerging therapies such as pudendal serve stimulation suggest that there may be a 15-20% increase in efficacy over sacral neuromodulation, but long-term studies are not yet available. Another emerging therapy, botulinum toxin, is also showing similar success in reducing OAB symptoms in 80-90% of patients. Surgical approaches, such as bladder augmentation, are a last resort in the treatment of OAB and are rarely used at this point unless upper tract damage is a concern and all other treatment options have been exhausted. Conclusion: The vast majority of OAB patients can be managed successfully by behavioral options with or without anticholinergic medications. When those fail, neuromodulation or intravesical botulinum toxin therapies are successful alternatives for most of the remaining group. We encourage practitioners responsible for the care of OAB patients to gain experience with these options. More research is needed to assess the cost-effectiveness of various OAB treatments PMID:19675795
Zhou, Naibao; Fu, Zhijian; Li, Hao; Wang, Kaiguo
2017-04-01
Ketamine has been used as an analgesic adjuvant with morphine in the treatment of refractory cancer pain recently. But both morphine and ketamine have been reported to produce a number of immunomodulatory effects. The current study was performed to assess whether the concentration of ketamine, as adjuvant analgesics for patient with refractory cancer pain, was related to its effect on T cells interleukin-2 (IL-2)/interferon-γ (IFN-γ) expression in vitro. Peripheral blood mononuclear cells (PBMCs) were isolated from venous blood of patients with refractory cancer pain over a Ficoll-Hypaque density gradient. T cells were isolated from by positive selection using anti-CD3 beads. T cells were then treated with vehicle (C group), morphine (200 ng/mL, M group), morphine (200 ng/mL), and different dose of ketamine (100, 200, 1000 ng/mL; MK1, MK5, MK10 group) for 24 hours before stimulation with anti-CD3 and anti-CD28. Then supernatant IL-2 and IFN-γ protein analysis, quantitative reverse transcription polymerase chain reaction (RT-PCR) for IL-2 and IFN-γ were done. There were no significant difference of supernatant IL-2 and IFN-γ among C group, M group, and MK1 group, but the mRNA of M group and MK1 group were decreased compared with C group (P < .05). Compared with C group, both of the supernatant protein and the mRNA of MK5 group and MK10 group were all significantly decreased (P < .01). Compared with M group, both of the supernatant protein and the mRNA of MK5 group and MK10 group were all decreased (P < .05), while supernatant IL-2 and the mRNA of MK10 group were significantly decreased (P < .01). In conclusion, we confirmed that just as morphine, ketamine dose-dependently suppressed IL-2 and IFN-γ of activated T lymphocyte of patients with refractory cancer pain in vitro, but the inhibitory action of low dose ketamine could be neglected.
Zhou, Naibao; Fu, Zhijian; Li, Hao; Wang, Kaiguo
2017-01-01
Abstract Background: Ketamine has been used as an analgesic adjuvant with morphine in the treatment of refractory cancer pain recently. But both morphine and ketamine have been reported to produce a number of immunomodulatory effects. The current study was performed to assess whether the concentration of ketamine, as adjuvant analgesics for patient with refractory cancer pain, was related to its effect on T cells interleukin-2 (IL-2)/interferon-γ (IFN-γ) expression in vitro. Methods: Peripheral blood mononuclear cells (PBMCs) were isolated from venous blood of patients with refractory cancer pain over a Ficoll-Hypaque density gradient. T cells were isolated from by positive selection using anti-CD3 beads. T cells were then treated with vehicle (C group), morphine (200 ng/mL, M group), morphine (200 ng/mL), and different dose of ketamine (100, 200, 1000 ng/mL; MK1, MK5, MK10 group) for 24 hours before stimulation with anti-CD3 and anti-CD28. Then supernatant IL-2 and IFN-γ protein analysis, quantitative reverse transcription polymerase chain reaction (RT-PCR) for IL-2 and IFN-γ were done. Results: There were no significant difference of supernatant IL-2 and IFN-γ among C group, M group, and MK1 group, but the mRNA of M group and MK1 group were decreased compared with C group (P < .05). Compared with C group, both of the supernatant protein and the mRNA of MK5 group and MK10 group were all significantly decreased (P < .01). Compared with M group, both of the supernatant protein and the mRNA of MK5 group and MK10 group were all decreased (P < .05), while supernatant IL-2 and the mRNA of MK10 group were significantly decreased (P < .01). Conclusion: In conclusion, we confirmed that just as morphine, ketamine dose-dependently suppressed IL-2 and IFN-γ of activated T lymphocyte of patients with refractory cancer pain in vitro, but the inhibitory action of low dose ketamine could be neglected. PMID:28422864
Diagnosis and management of refractory celiac disease: a systematic review.
Labidi, Asma; Serghini, Meriem; Karoui, Sami; Boubaker, Jalel; Filali, Azza
2013-01-01
Refractory celiac disease is defined by persisting malabsorptive symptoms in spite of a strict gluten free diet for at least 6 to 12 months. Alternatives to gluten free diet seem to be still controversial. To describe the clinical and epidemiologic aspects of refractory celiac disease, and to identify therapeutic options in this condition. Systematic review and critical analysis of observational studies, clinical trials and case reports that focused on diagnosis and management of refractory celiac disease. Refractory celiac disease can be classified as type 1 or type 2 according to the phenotype of intraepithelial lymphocytes. Great complications such as enteropathy-associated T-cell lymphoma may occur in a subgroup of these patients mainly in refractory celiac disease type 2. Curative therapies are still lacking. Refractory celiac disease remains a diagnosis of exclusion. Its prognosis remains still dismal by the absence yet of curative therapies. However, some new treatments seem to hold promise during few cohort-studies.
2018-04-06
Folliculotropic Mycosis Fungoides; Recurrent Cutaneous T-Cell Non-Hodgkin Lymphoma; Recurrent Mycosis Fungoides; Refractory Cutaneous T-Cell Non-Hodgkin Lymphoma; Refractory Mycosis Fungoides; Refractory Peripheral T-Cell Lymphoma, Not Otherwise Specified; Sezary Syndrome; Recurrent Mature T- and NK-Cell Non-Hodgkin Lymphoma
von Tresckow, Bastian; Engert, Andreas
2013-09-01
Despite the advances in the treatment of Hodgkin Lymphoma, patients with refractory disease still have a poor prognosis. Hodgkin Lymphoma can be refractory at first diagnosis or might become refractory later in the course of treatment. Both situations represent a therapeutic challenge. Intensified chemotherapy with BEACOPP escalated has been evaluated in early unfavourable and advanced Hodgkin Lymphoma and led to an improved tumour control and reduced rates of refractory disease. Furthermore, there is growing evidence for the role of tandem autologous transplant in breaking refractory disease. For patients relapsing after autologous transplant, more recent analyses have reported outcome and defined risk factors. The antibody drug conjugate brentuximab vedotin is a new, highly effective therapeutic option for these patients. Dose-reduced allogeneic transplant is a therapeutic alternative for patients relapsing after autologous transplant, but induction of a remission is the prerequisite for a successful allogeneic transplant. Brentuximab vedotin has been evaluated as a bridge to allogeneic transplant for patients refractory to conventional treatment. Recent therapeutic advances have improved the prognosis of Hodgkin Lymphoma by prevention or successful treatment of refractory disease. The use of new drugs such as brentuximab vedotin will hopefully further increase the cure rates.
Donnelly, R.G.; Gilliland, R.G.; Slaughter, G.M.
1962-02-20
A brazing alloy is described which, in the molten state, is characterized by excellent wettability and flowability and is capable of forming a corrosion-resistant brazed joint. At least one component of said joint is graphite and the other component is a corrosion-resistant refractory metal. The brazing alloy consists essentially of 40 to 90 wt % of gold, 5 to 35 wt% of nickel, and 1 to 45 wt% of tantalum. (AEC)
2018-06-25
CD20 Positive; Recurrent B-Cell Non-Hodgkin Lymphoma; Recurrent Diffuse Large B-Cell Lymphoma; Recurrent Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Refractory B-Cell Non-Hodgkin Lymphoma; Refractory Diffuse Large B-Cell Lymphoma; Refractory Mediastinal (Thymic) Large B-Cell Cell Lymphoma; Transformed Recurrent Non-Hodgkin Lymphoma
Spent refractory reuse as a slag conditioning additive in the EAF
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bennett, James P.; Kwong, Kyei-Sing; Krabbe, Rick
2000-01-01
Refractories removed from service in EAF applications are typically landfilled. A joint USDOE and Steel Manufacturers Association program involving industrial cooperators is evaluating spent refractory recycling/reuse. A review of current recycling practices and a review of progress towards controlling EAF slag chemistry and properties with the additions of basic spent refractories will be discussed.
2018-06-25
Advanced Malignant Solid Neoplasm; Ann Arbor Stage III Childhood Non-Hodgkin Lymphoma; Ann Arbor Stage IV Childhood Non-Hodgkin Lymphoma; BRAF Gene Mutation; GNA11 Gene Mutation; GNAQ Gene Mutation; Histiocytosis; HRAS Gene Mutation; KRAS Gene Mutation; NF1 Gene Mutation; NRAS Gene Mutation; Recurrent Childhood Central Nervous System Neoplasm; Recurrent Childhood Non-Hodgkin Lymphoma; Recurrent Malignant Solid Neoplasm; Recurrent Neuroblastoma; Refractory Central Nervous System Neoplasm; Refractory Malignant Solid Neoplasm; Refractory Neuroblastoma; Refractory Non-Hodgkin Lymphoma
Forced guidance and distribution of practice in sequential information processing.
NASA Technical Reports Server (NTRS)
Decker, L. R.; Rogers, C. A., Jr.
1973-01-01
Distribution of practice and forced guidance were used in a sequential information-processing task in an attempt to increase the capacity of human information-processing mechanisms. A reaction time index of the psychological refractory period was used as the response measure. Massing of practice lengthened response times while forced guidance shortened them. Interpretation was in terms of load reduction upon the response-selection stage of the information-processing system.-
2018-05-18
Malignant Rhabdoid Tumors (MRT); Rhabdoid Tumors of the Kidney (RTK); Atypical Teratoid Rhabdoid Tumors (ATRT); Selected Tumors With Rhabdoid Features; Synovial Sarcoma; INI1-negative Tumors; Malignant Rhabdoid Tumor of Ovary; Renal Medullary Carcinoma; Epithelioid Sarcoma; Poorly Differentiated Chordoma (or Other Chordoma With Sponsor Approval); Any Solid Tumor With an EZH2 GOF Mutation
Lithography-free large-area metamaterials for stable thermophotovoltaic energy conversion
Coppens, Zachary J.; Kravchenko, Ivan I.; Valentine, Jason G.
2016-02-08
A large-area metamaterial thermal emitter is fabricated using facile, lithography-free techniques. The device is composed of conductive oxides, refractory ceramics, and noble metals and shows stable, selective emission after exposure to 1173 K for 22 h in oxidizing and inert atmospheres. Lastly, the results indicate that the metamaterial can be used to achieve high-performance thermophotovoltaic devices for applications such as portable power generation.
1994-07-01
psychological refractory period 15. Two-flash threshold 16. Critical flicker fusion (CFF) 17. Steady state visually evoked response 18. Auditory brain stem...States of awareness I: Subliminal erceoption relationships to situational awareness (AL-TR-1992-0085). Brooks Air Force BaSe, TX: Armstrong...the signals required different inputs (e.g., visual versus auditory ) (Colley & Beech, 1989). Despite support of this theory from such experiments
Process for gasification using a synthetic CO.sub.2 acceptor
Lancet, Michael S.; Curran, George P.
1980-01-01
A gasification process is disclosed using a synthetic CO.sub.2 acceptor consisting essentially of at least one compound selected from the group consisting of calcium oxide and calcium carbonate supported in a refractory carrier matrix, the carrier having the general formula Ca.sub.5 (SiO.sub.4).sub.2 CO.sub.3. A method for producing the synthetic CO.sub.2 acceptor is also disclosed.
Gene Expression Analysis Of Circulating Hormone Refractory Prostate Cancer Micrometastases
2011-02-01
of prostate cancer. We hypothesized that the copy number changes could be prognostic and aid in future chemotherapy regimen selection. After...Task 1 will be analyzed over the next year to elicit statistically meaningful prognostic DNA based biomarkers. Two of the patients (#8 and #13) had...HRPC), and to determine whether CECs can be used to predict survival in these patients. PATIENTS AND METHODS Several prognostic models that
NASA Technical Reports Server (NTRS)
Morton, Thomas L.; Ferguson, Dale C.
1997-01-01
In order to test their reactivity with Atomic Oxygen, twenty five materials were flown on the EOIM-3 (Evaluation of Oxygen Interactions with Materials) portion of the STS-46 Mission. These materials include refractory metals, candidate insulation materials, candidate radiator coatings, and a selection of miscellaneous materials. This report documents the results of the pre- and post-flight analysis of these materials.
Survey of selective solar absorbers and their limitations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mattox, D.M.; Sowell, R.R.
1980-01-01
A number of selective absorber coating systems with high solar absorptance exist which may be used in the mid-temperature range. Some of the systems are more chemically and thermally stable than others. Unfortunately, there are large gaps in the stability data for a large number of the systems. In an inert environment, the principle degradation mechanisms are interdiffusion between the layers or phases and changes in surface morphology. These degradation mechanisms would be minimized by using refractory metals and compounds for the absorbing layer and using refractory materials or diffusion barriers for the underlayer. For use in a reactive environment,more » the choice of materials is much more restrictive since internal chemical reactions can change phase compositions and interfacial reactions can lead to loss of adhesion. For a coating process to be useful, it is necessary to determine what parameters influence the performance of the coating and the limits to these parameters. This process sensitivity has a direct influence on the production process controls necessary to produce a good product. Experience with electroplated black chrome has been rather disappointing. Electroplating should be a low cost deposition process but the extensive bath analysis and optical monitoring necessary to produce a thermally stable produce for use to 320/sup 0/C has increased cost signficantly. 49 references.« less
Molecular Analyzer for Complex Refractory Organic-Rich Surfaces (MACROS)
NASA Technical Reports Server (NTRS)
Getty, Stephanie A.; Cook, Jamie E.; Balvin, Manuel; Brinckerhoff, William B.; Li, Xiang; Grubisic, Andrej; Cornish, Timothy; Ferrance, Jerome; Southard, Adrian
2017-01-01
The Molecular Analyzer for Complex Refractory Organic-rich Surfaces, MACROS, is a novel instrument package being developed at NASA Goddard Space Flight Center. MACROS enables the in situ characterization of a sample's composition by coupling two powerful techniques into one compact instrument package: (1) laser desorption/ionization time-of-flight mass spectrometry (LDMS) for broad detection of inorganic mineral composition and non-volatile organics, and (2) liquid-phase extraction methods to gently isolate the soluble organic and inorganic fraction of a planetary powder for enrichment and detailed analysis by liquid chromatographic separation coupled to LDMS. The LDMS is capable of positive and negative ion detection, precision mass selection, and fragment analysis. Two modes are included for LDMS: single laser LDMS as the broad survey mode and two step laser mass spectrometry (L2MS). The liquid-phase extraction will be done in a newly designed extraction module (EM) prototype, providing selectivity in the analysis of a complex sample. For the sample collection, a diamond drill front end will be used to collect rock/icy powder. With all these components and capabilities together, MACROS offers a versatile analytical instrument for a mission targeting an icy moon, carbonaceous asteroid, or comet, to fully characterize the surface composition and advance our understanding of the chemical inventory present on that body.
Church, Joseph T; Simha, Sidd; Wild, Laurie C; Teitelbaum, Daniel H; Ehrlich, Peter F
2017-05-01
Fecal incontinence is a socially debilitating problem for many children. We hypothesized that in selected patients with medically-refractory encopresis, placement of an appendicostomy or cecostomy tube for administration of antegrade continence enemas (ACE) would improve quality of life (QOL). We reviewed all patients with encopresis who underwent appendicostomy or cecostomy placement from 2003 to 2014 at our institution. We contacted subjects' parents by phone and administered 3 surveys: a survey reflecting current stooling habits, a disease-specific QOL survey, and the PedsQL™ QOL survey. QOL surveys were completed twice by parents, once reflecting pre-operative QOL, then again reflecting current QOL. Pre-procedure and post-procedure scores were compared by paired t-test. Ten patients underwent appendicostomy/cecostomy for encopresis. Eight completed phone surveys. All procedures were performed laparoscopically. All patients experienced fecal soiling pre-operatively, whereas 5/8 surveyed patients (63%) noted complete resolution of soiling post-procedure (p<0.01). General and disease-specific QOL improved from pre-procedure to post-procedure in the following domains: social habits, physical activity, ability to spend the night elsewhere, feeling, and overall QOL (p<0.05). PedsQL™ scores improved significantly in physical functioning, social functioning, and overall functioning (p<0.05). Antegrade continence enemas significantly improve quality of life in patients with medically-refractory encopresis, likely related to resolution of soiling. 4. Copyright © 2017. Published by Elsevier Inc.
Huang, Jia; Luo, Qingquan; Shentu, Yang; Zhao, Xiaojing
2010-10-01
The aim of this study is to analyze the impact on the cough after radical systematic mediastinal lymphadenectomy and prevention of refractory cough with mediastinal fat to fill the residual cavity after radical systematic mediastinal lymphadenectomy. Sixty patients clinically diagnosed of lung cancer were selected according to the adopt standardization, from January 2008 to December 2008. All of the patients were divided into two groups randomly: the filling-fat group and the non-filling-fat group. The surgical information such as operation duration time bleeding volume during operation, post-operation bleeding volume were recorded. After one month, FACT-L and LCQ were completed. There are no remarkably differences between the operation duration time, bleeding volume in operation and 1st postoperation day's drainage volume of the two groups. There's significant difference in the scores of cough at night after taking off the chest tube, as well as in the scores of LCQ after one month and in the scores of last items of FACT-L. Filling the fat of the mediastinal to cover the residual cavity left by completely systematic mediastinal lymphadenectomy can reduce the refractory cough after surgery, and can also improve the quality of the life. It has no effect on the the operation duration time, bleeding volume in operation and 1st post-operation day's drainage volume of the patients.