Brazing refractory metals used in high-temperature nuclear instrumentation

Energy Technology Data Exchange (ETDEWEB)

Palmer, A. J. [Idaho National Laboratory, MS 3840, P.O. Box 1625, Idaho Falls, ID 83415-3840 (United States); Woolstenhulme, C. J. [EG and G Services, Inc., (United States)

2009-07-01

As part of the U. S. Department of Energy (DOE)-sponsored Next Generation Nuclear Project (NGNP) currently ongoing at Idaho National Laboratory (INL), the irradiation performance of candidate high-temperature gas reactor fuels and materials is being evaluated at INL's Advanced Test Reactor (ATR). The design of the first Advanced Gas Reactor (AGR-1) TRISO fuel experiment, currently being irradiated in the ATR, required development of special techniques for brazing niobium and molybdenum. Brazing is one technique used to join refractory metals to each other and to stainless steel alloys. Although brazing processes are well established, it is difficult to braze niobium, molybdenum, and most other refractory metals because they quickly develop adherent oxides when exposed to room-temperature air. Specialized techniques and methods were developed by INL to overcome these obstacles. This paper describes the techniques developed for removing these oxides, as well as the ASME Section IX-qualified braze procedures that were developed as part of the AGR-1 project. All brazes were made using an induction coil with an inert or reducing atmosphere at low pressure. Other parameters, such as filler metals, fluxes used, and general setup procedures, are also discussed. (authors)

Brazing refractory metals used in high-temperature nuclear instrumentation

International Nuclear Information System (INIS)

Palmer, A. J.; Woolstenhulme, C. J.

2009-01-01

As part of the U. S. Department of Energy (DOE)-sponsored Next Generation Nuclear Project (NGNP) currently ongoing at Idaho National Laboratory (INL), the irradiation performance of candidate high-temperature gas reactor fuels and materials is being evaluated at INL's Advanced Test Reactor (ATR). The design of the first Advanced Gas Reactor (AGR-1) TRISO fuel experiment, currently being irradiated in the ATR, required development of special techniques for brazing niobium and molybdenum. Brazing is one technique used to join refractory metals to each other and to stainless steel alloys. Although brazing processes are well established, it is difficult to braze niobium, molybdenum, and most other refractory metals because they quickly develop adherent oxides when exposed to room-temperature air. Specialized techniques and methods were developed by INL to overcome these obstacles. This paper describes the techniques developed for removing these oxides, as well as the ASME Section IX-qualified braze procedures that were developed as part of the AGR-1 project. All brazes were made using an induction coil with an inert or reducing atmosphere at low pressure. Other parameters, such as filler metals, fluxes used, and general setup procedures, are also discussed. (authors)

Usefulness of high-dose intravenous human immunoglobulins treatment for refractory recurrent pericarditis.

Science.gov (United States)

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.

Refractories materials characterization for aluminum melting and holding furnaces: an alternative for a better performance

International Nuclear Information System (INIS)

Novo, M.M.M.; Pandolfelli, V.C.

2011-01-01

The industrial needs in reducing the energy consumption is part of a continuing search towards higher levels of sustainability and competitiveness. Considering these aspects, the aluminum industry seeks new alternatives for a better performance of aluminum melting and holding furnaces and this aim is directly dependent on the refractory materials ability to conserve heat and withstand the mechanical, chemical and thermal degradation processes. This paper presents the thermo-mechanical characterization of five aluminous dense commercial refractory (average density of 2.7 g / cm ³), used in such equipment. The results indicated that choosing the most suitable composition requires the evaluation of the microstructure aspects, such as porosity, permeability and pore size, and also the refractory's physical integrity, such as thermal shock resistance, abrasion resistance and high temperature modulus of rupture. The laboratory tests allowed the characterization of all the materials at the same conditions. Moreover, it was possible to optimize the selection of lining materials for melting and holding furnaces and to provide basis to a possible costs improvements synergy. (author)

Sorption techniques for production of high purity refractory metals

International Nuclear Information System (INIS)

Shatalov, V.V.; Peganov, V.A.; Logvinenko, I.A.; Molchanova, T.V.

2004-01-01

A consideration is given to potentialities of sorption processes tot provide a high quality of refractory metal and their alloys when using hydrometallurgical methods for raw material processing. The efficiency of application of ion exchange technology is shown for complex solutions reprocessing for various types of polymetallic raw materials, among them uranium ores, enriched concentrates of refractory metal ores, intermediate products, waste solutions. Based on investigation results on the behaviour of elements in process solutions and the mechanism of their sorption and elution, the process of pure chemical compounds production are developed which provide thereafter manufacturing compact metals. The flowsheets developed are mastered on a commercial scale [ru

Comparative evaluation of the locally manufactured low-alumina fireclay refractories

International Nuclear Information System (INIS)

Mohammad, D.; Ahmed, W.; Khan, M.I.

2007-01-01

Properties of domestically produced low-alumina refractories commonly known as medium duty fireclay refractories were studied and a comparative evaluation was performed. Refractory properties such as density, porosity, cold strength, reheat change and deformation at high-temperature were determined. Significant differences were discovered between these products sold as medium duty fireclay refractories. One brand marketed as medium duty refractory was found to be too inferior to be designated as medium duty firebrick. Absence of any standards and lack of awareness on the part of users of the various test methods appear to be the cause of this situation. (author)

Design of Refractory High-Entropy Alloys

Science.gov (United States)

Gao, M. C.; Carney, C. S.; Doğan, Ö. N.; Jablonksi, P. D.; Hawk, J. A.; Alman, D. E.

2015-11-01

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 for 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.

High-dose chemotherapy and auto-SCT for relapsed and refractory Hodgkin's lymphoma patients refractory to first-line salvage chemotherapy but responsive to second-line salvage chemotherapy.

Science.gov (United States)

Rauf, Muhammad Shahzad; Maghfoor, Irfan; Elhassan, Tusneem Ahmed M; Akhtar, Saad

2015-01-01

Relapsed or primary refractory Hodgkin's lymphoma (HL) patients refractory to first-line salvage chemotherapy (first salvage) and unable to undergo high-dose chemotherapy (HDC) and autologous stem cell transplant (auto-SCT) have very poor outcome. Some patients are offered second-line salvage chemotherapy (second salvage), if they are responsive and may receive HDC auto-SCT. We identified 31 patients (18 males, 13 females) from 1996-2012 who received second salvage prior to auto-SCT. Median age at auto-SCT is 22 years. Patients were grouped as (1) relapsed-refractory (Rel:Ref): patients with prior complete response (CR) and on relapse found refractory to first salvage and received second salvage and (2) refractory-refractory (Ref:Ref): patients refractory to both primary treatment and first salvage and received second salvage. Median follow-up is 63 months (18-170). Disease status after second salvage prior to HDC was CR 16 %, partial response (PR) 71 % and stable disease 13 %. After HDC auto-SCT, CR:PR: progressive disease was observed in 18 (58 %): four (12 %): nine (29 %) patients, respectively. Five-year overall survival (OS) for whole group is 57 % (Rel:Ref vs. Ref:Ref, 73 % vs. 48 %, p = 0.48). Progression-free survival (PFS) for whole group is 52 % (Rel:Ref vs. Ref:Ref, 73 % vs. 40 % respectively, p = 0.11). Second-line salvage is a valid approach with no long-term side effects for those HL patients who do not respond to first-line salvage chemotherapy and they can be candidate of HDC and stem cell transplant with a high ORR, the PFS and OS in relapse-refractory and refractory-refractory group of patients.

Autoradiographic study of corrosion of refractories

International Nuclear Information System (INIS)

Lisenenkova, S.B.; Kucheryavyi, M.N.; Bursteva, T.A.

1988-01-01

A comparative study was made of the character of the interaction between a container-glass melt consisting of sodium calcium silicate and refractories in various furnace sections using an autoradiographic method. Static tests were conducted on specimens of the following refractories: chrome-aluminum-zircon, Bakor 41, corundum, a high alumina refractory, and a refractory based on tin dioxide. The specimens were activated by calcium 45. Autoradiography and photomicrography indicated that an intrinsic feature of all refractories was that calcium from the melt penetrated the refractories along the weak link; for fused-cast refractories, the glass phase; and for sintered refractories, through the binder and cracks

Powder metallurgical high performance materials. Proceedings. Volume 3: general topics

International Nuclear Information System (INIS)

Kneringer, G.; Roedhammer, P.; Wildner, H.

2001-01-01

The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. The 15 th Plansee Seminar was convened under the general theme 'Powder Metallurgy High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (boteke)

Production of small diameter high-temperature-strength refractory metal wires

Science.gov (United States)

Petrasek, D. W.; Signorelli, R. A.; King, G. W.

1973-01-01

Special thermomechanical techniques (schedules) have been developed to produce small diameter wire from three refractory metal alloys: colombian base alloy, tantalum base alloy, and tungsten base alloy. High strengths of these wires indicate their potential for contributing increased strength to metallic composites.

Perspectives on environmental protection of refractory metals

International Nuclear Information System (INIS)

Perking, R.A.

1992-01-01

Alloys of refractory metals which combine high strength to weight ratios with useful low-temperature toughness and ductility have been designed to meet the requirements for the next generation of high-temperature aerospace structural materials with one exception: long term resistance to oxidation. It is considered unlikely that refractory metal alloys can be modified to possess useful resistance to oxidation as bulk materials or that coating can be designed to provide high reliability fail-safe protection for the structural alloys developed to date. Recent developments indicate that bulk alloys of W and Mo can be designed to possess short term resistance to oxidation, providing a base material which can be coated to extend useful life with fail-safe protection in the event of random coating failures. Current research on silicide coatings indicates that significant improvements in coating reliability and performance also are feasible. The technical basis for these conclusions is presented in this paper and the direction of future work that could lead to environmentally stable refractory metal alloy/coating systems is discussed

Preparation and characterization of clay bonded high strength silica refractory by utilizing agriculture waste

International Nuclear Information System (INIS)

Bhardwaj, A.; Hossain, S.K.S.; Majh, M.R.

2017-01-01

Clay bonded silica refractory was prepared by utilizing agriculture waste called rice husk ash (RHA) and refractory grog. Various samples were prepared with different compositions based upon partial replacement of quartz by RHA. Rectangular samples were prepared by following semi dry process prior to pressing in a uniaxial hydraulic press and sintering at a temperature of 1200°C in air atmosphere. Various physical, mechanical and thermal characterizations were done like X-ray diffraction (XRD), scanning electron microscope (SEM), apparent porosity (AP), bulk density (BD), cold crushing strength (CCS), refractoriness and thermal conductivity measurement. The sample utilizing 30% of RHA was considered most optimum composition which produced cold crushing strength of 38MPa and thermal conductivity of 2.08W/mK at 800°C with a considerable good refractoriness. Enhancement in the mechanical as well as thermal properties may be considered as attributed to the amorphous silica which has reacted more easily and efficiently with other material surrounding giving rise to the densification and produced stable crystalline phase to the refractory material. These promising characteristics suggests that the RHA may lead to be used as a potential material for the preparation of clay bonded high strength silica refractories. [es

Emergency Surgery for Refractory Status Epilepticus.

Science.gov (United States)

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.

Refractory thermowell for continuous high temperature measurement of molten metal

International Nuclear Information System (INIS)

Thiesen, T.J.

1992-01-01

This patent describes a vessel for handling molten metal having an interior refractory lining, apparatus for continuous high temperature measurement of the molten metal. It comprises a thermowell; the thermowell containing a multiplicity of thermocouples; leads being coupled to a means for continuously indicating the temperature of the molten metal in the vessel

Bulk Vitrification Performance Enhancement: Refractory Lining Protection Against Molten Salt Penetration

Energy Technology Data Exchange (ETDEWEB)

Hrma, Pavel R.; Bagaasen, Larry M.; Schweiger, Michael J.; Evans, Michael B.; Smith, Benjamin T.; Arrigoni, Benjamin M.; Kim, Dong-Sang; Rodriguez, Carmen P.; Yokuda, Satoru T.; Matyas, Josef; Buchmiller, William C.; Gallegos, Autumn B.; Fluegel, Alexander

2007-08-06

Bulk vitrification (BV) is a process that heats a feed material that consists of glass-forming solids and dried low-activity waste (LAW) in a disposable refractory-lined metal box using electrical power supplied through carbon electrodes. The feed is heated to the point that the LAW decomposes and combines with the solids to generate a vitreous waste form. This study supports the BV design and operations by exploring various methods aimed at reducing the quantities of soluble Tc in the castable refractory block portion of the refractory lining, which limits the effectiveness of the final waste form.

High performance structural ceramics for nuclear industry

International Nuclear Information System (INIS)

Pujari, Vimal K.; Faker, Paul

2006-01-01

A family of Saint-Gobain structural ceramic materials and products produced by its High performance Refractory Division is described. Over the last fifty years or so, Saint-Gobain has been a leader in developing non oxide ceramic based novel materials, processes and products for application in Nuclear, Chemical, Automotive, Defense and Mining industries

Refractory Research Group - U.S. DOE, Albany Research Center [Institution Profile

Energy Technology Data Exchange (ETDEWEB)

Bennett, James P.

2004-09-01

The refractory research group at the Albany Research Center (ARC) has a long history of conducting materials research within the U.S. Bureau of Mines, and more recently, within the U.S. Dept. of Energy. When under the U.S. Bureau of Mines, research was driven by national needs to develop substitute materials and to conserve raw materials. This mission was accomplished by improving refractory material properties and/or by recycling refractories using critical and strategic materials. Currently, as a U.S. Dept of Energy Fossil Energy field site, research is driven primarily by the need to assist DOE in meeting its vision to develop economically and environmentally viable technologies for the production of electricity from fossil fuels. Research at ARC impacts this vision by: • Providing information on the performance characteristics of materials being specified for the current generation of power systems; • Developing cost-effective, high performance materials for inclusion in the next generation of fossil power systems; and • Solving environmental emission and waste problems related to fossil energy systems. A brief history of past refractory research within the U.S. Bureau of Mines, the current refractory research at ARC, and the equipment and capabilities used to conduct refractory research at ARC will be discussed.

Theoretical and practical aspects about corrosion of refractories used in steel metallurgy: part 3: characterization of commercial refractories

International Nuclear Information System (INIS)

Braganca, S.R.

2012-01-01

In this study, it was reviewed the main aspects found in the literature about refractories corrosion, evaluating the feasibility of certain tests and relating them with experimental results. The physical properties and microstructure of commercial refractories were analyzed, considering the differences between them and the quality implications and probable life of the refractory. Thus, it was studied the various types of refractories used as lining on steel ladle. Magnesia-carbon and doloma-carbon refractories were analyzed, highlighting the differences between them. The examined refractory showed characteristics favoring high resistance to corrosion process, presenting a series of properties to be selected in accordance with industry practice. (author)

MICROWAVE MEASUREMENT OF REFRACTORY MATERIALS AT HIGH-TEMPERATURE

International Nuclear Information System (INIS)

Kharkovsky, S.; Zoughi, R.; Smith, J.; Davis, B.; Limmer, R.

2009-01-01

Knowledge of the electrical behavior of refractory materials may enable the development and optimization of microwave nondestructive techniques to detect and evaluate changes in their physical properties while the materials are in service. This paper presents the results of a limited and preliminary investigation in which two refractory materials (dense chrome and dense zircon) were subjected to increasing temperature in a furnace and in which a frequency-modulated continuous-wave radar operating in the frequency range of 8-18 GHz radar was used to evaluate their attenuation properties.

Microwave Measurement of Refractory Materials at High-Temperature

Science.gov (United States)

Kharkovsky, S.; Zoughi, R.; Smith, J.; Davis, B.; Limmer, R.

2009-03-01

Knowledge of the electrical behavior of refractory materials may enable the development and optimization of microwave nondestructive techniques to detect and evaluate changes in their physical properties while the materials are in service. This paper presents the results of a limited and preliminary investigation in which two refractory materials (dense chrome and dense zircon) were subjected to increasing temperature in a furnace and in which a frequency-modulated continuous-wave radar operating in the frequency range of 8-18 GHz radar was used to evaluate their attenuation properties.

Development of alumino-silicate refractories in Ghana

International Nuclear Information System (INIS)

Kisiedu, A. K.; Tetteh, D.M.B.; Obiri, H. A.; Brenya, E. F.; Ayensu, A.

2008-01-01

Alumino-silicate (bauxite), andalusite, kaolin and clay were investigated for suitability in production of alumina, mullite and fireclay brick refractories. The raw materials were characterized by X-ray diffraction, differential thermal and silicate analyses. The x-ray diffraction analysis of alumina and mullite refractories fired at 1450 0 C, and fireclay bricks fired at 1350 0 C, indicated presence of corundum and alpha-alumina crystals. The values of thermal (fired) shrinkage, crushing, strength, porosity, water absorption and bulk density determined were 31.1%, 2.3 x 10 3 kg/m 3 , 4.86 x 10 6 N/m 2 and 13.2 % for mullite; 30.2%, 2.4 x 10 3 kg/m 3 , 3.20 x 10 6 N/m 2 and W = 12.8 % for alumina; and 25.2 %, 2.1 x 10 3 kg/m 3 , 2.61 x 10 6 N/m 2 and W = 11.8% for fireclay, respectively. Bauxite, andalusite and special kaolin were identified as potential raw materials for developing alumina and mullite refractories for construction of high temperature kilns and furnaces operating at 1350 0 C. The clay and kaolin minerals could be used to produce fireclay refractories for construction of incinerators operating at maximum temperatures of about 1000 0 C. The performance of the refractories was demonstrated by producing bricks to construct kilns and incinerators for the ceramic industry and hospitals. (au)

MgAl2O4 spinel refractory as containment liner for high-temperature alkali salt containing environments

Science.gov (United States)

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.

Nanostructured refractory thin films for solar applications

Science.gov (United States)

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.

Influence of phase transformations on the mechanical behaviour of refractory ceramics at high temperature;Effets des transformations de phase sur la tenue mecanique a haute temperature des ceramiques refractaires

Energy Technology Data Exchange (ETDEWEB)

Schmitt, N. [LMT-Cachan, ENS de Cachan, UMR 8535 CNRS, Universite Paris 6, 94 - Cachan (France); IUFM de Creteil, Universite Paris-Est Creteil, 93 - Saint-Denis (France); Poirier, J. [CNRS-CEMHTI, 45 - Orleans (France); Polytech, Universite d' Orleans, 45 - Orleans (France)

2009-07-01

Refractories used at high temperature are subjected to high chemical and mechanical stresses. The mastery of their microstructure as well as the phase changes occurring in service is essential to ensure resistance to wear and failure of refractory linings. Great progress has been made: combining efficient techniques for the investigation of the microstructure with powerful numerical tools (thermochemical and thermo-mechanical computations) provides information (e.g., degradation mechanisms) that cannot be obtained directly. Also multi-physical and multi-scale models developing materials with high-performance for higher temperature and with longer lifetime. In this paper, through several examples we show some interactions between the mechanical behavior and the microstructure transformations of refractory ceramics. The tools developed to characterize their microstructure change in situ (e.g., at high temperature) and to identify their kinetics are described. Some methodologies and tools developed in recent years, today, provide a better understanding of in-service behavior of refractories while identifying the critical material and process parameters likely to increase life-time. (authors)

Energy conservation in industrial furnaces with vertical radiation roofs of reinforced refractory concrete

Energy Technology Data Exchange (ETDEWEB)

Grafe, E

1981-01-01

The paper discusses static systems for furnaces of reinforced refractory concrete, the temperature field over the finned-plate cross section, the calculation of the reinforced refractory concrete, experimental application in a flat open-hearth pusher furnace, a pack heating furnace, and a sinker furnace. There are cantilever beam plates, frames, and drop ceiling elements particularly suited for efficient use of high-performance burners.

Directed light fabrication of refractory metals and alloys

International Nuclear Information System (INIS)

Fonseca, J.C.; Lewis, G.K.; Dickerson, P.G.; Nemec, R.B.

1999-01-01

This report covers work performed under Order No. FA0000020 AN Contract DE-AC12-76SN00052 for deposition of refractory pure metals and alloys using the Directed Light Fabrication (DLF) process and represents the progress in depositing these materials through September 1998. In extending the DLF process technology to refractory metals for producing fully dense, structurally sound deposits, several problems have become evident. 1. Control of porosity in DLF-deposited refractory metal is difficult because of gases, apparently present in commercially purchased refractory metal powder starting materials. 2. The radiant heat from the molten pool during deposition melts the DLF powder feed nozzle. 3. The high reflectivity of molten refractory metals, at the Nd-YAG laser wavelength (1.06microm), produces damaging back reflections to the optical train and fiber optic delivery system that can terminate DLF processing. 4. The current limits on the maximum available laser power to prevent back reflection damage limit the parameter range available for densification of refractory metals. The work to date concentrated on niobium, W-25Re, and spherodized tungsten. Niobium samples, made from hydride-dehydride powder, had minimal gas porosity and the deposition parameters were optimized; however, test plates were not made at this time. W-25Re samples, containing sodium and potassium from a precipitation process, were made and porosity was a problem for all samples although minimized with some process parameters. Deposits made from potassium reduced tungsten that was plasma spherodized were made with minimized porosity. Results of this work indicate that further gas analysis of starting powders and de-gassing of starting powders and/or gas removal during deposition of refractory metals is required

Analysis of renal impairment in MM-003, a phase III study of pomalidomide + low - dose dexamethasone versus high - dose dexamethasone in refractory or relapsed and refractory multiple myeloma

Science.gov (United States)

Weisel, Katja C.; Dimopoulos, Meletios A.; Moreau, Philippe; Lacy, Martha Q.; Song, Kevin W.; Delforge, Michel; Karlin, Lionel; Goldschmidt, Hartmut; Banos, Anne; Oriol, Albert; Alegre, Adrian; Chen, Christine; Cavo, Michele; Garderet, Laurent; Ivanova, Valentina; Martinez-Lopez, Joaquin; Knop, Stefan; Yu, Xin; Hong, Kevin; Sternas, Lars; Jacques, Christian; Zaki, Mohamed H.; Miguel, Jesus San

2016-01-01

Pomalidomide + low-dose dexamethasone is effective and well tolerated for refractory or relapsed and refractory multiple myeloma after bortezomib and lenalidomide failure. The phase III trial MM-003 compared pomalidomide + low-dose dexamethasone with high-dose dexamethasone. This subanalysis grouped patients by baseline creatinine clearance ≥ 30 − < 60 mL/min (n=93, pomalidomide + low-dose dexamethasone; n=56, high-dose dexamethasone) or ≥ 60 mL/min (n=205, pomalidomide + low-dose dexamethasone; n=93, high-dose dexamethasone). Median progression-free survival was similar for both subgroups and favored pomalidomide + low-dose dexamethasone versus high-dose dexamethasone: 4.0 versus 1.9 months in the group with baseline creatinine clearance ≥ 30 − < 60 mL/min (P<0.001) and 4.0 versus 2.0 months in the group with baseline creatinine clearance ≥ 60 mL/min (P<0.001). Median overall survival for pomalidomide + low-dose dexamethasone versus high-dose dexamethasone was 10.4 versus 4.9 months (P=0.030) and 15.5 versus 9.2 months (P=0.133), respectively. Improved renal function, defined as an increase in creatinine clearance from < 60 to ≥ 60 mL/min, was similar in pomalidomide + low-dose dexamethasone and high-dose dexamethasone patients (42% and 47%, respectively). Improvement in progression-free and overall survival in these patients was comparable with that in patients without renal impairment. There was no increase in discontinuations of therapy, dose modifications, and adverse events in patients with moderate renal impairment. Pomalidomide at a starting dose of 4 mg + low-dose dexamethasone is well tolerated in patients with refractory or relapsed and refractory multiple myeloma, and of comparable efficacy if moderate renal impairment is present. This trial was registered with clinicaltrials.gov identifier 01311687 and EudraCT identifier 2010-019820-30. PMID:27081177

Refractory metal component technology for in-core sensor design

International Nuclear Information System (INIS)

Cannon, C.P.

1986-02-01

Within recent years, an increasing concern over reactor safety has prompted tests that characterize reactor core environments during transient conditions. Such tests include the Loss-of-Fluid-Tests (Idaho National Engineering Lab (INEL)), Severe Fuel Damage Tests (INEL), Core Debris Rubble Tests (Sandia National Laboratories (SNL)), and similar tests performed by foreign nations. The in-core sensors for these tests require refractory metal components to be compatible with electrical insulator materials as well as materials comprising highly corrosive service mediums. This paper presents the refractory metal technology utilized to provide basic sensor designs in the above mentioned reactor tests

Solidification of refractory materials processed in the ultra high vacuum drop tube at the CEREM-Grenoble

International Nuclear Information System (INIS)

Vinet, B.; Cini, E.; Tournier, S.; Cortella, L.

1994-01-01

Undercooling experiments have been performed on refractory materials by processing in a high drop-tube. Emphasis is put on general aspects of surface and bulk microstructures of solidified droplets, including pure metals (W, Re, Ta, Mo, Nb, Ir, Zr) and alloys (W-Re, Mo-Re, Ta-Zr). It is shown that recrystallization often causes polycrystallinity. Moreover, the microstructure is closely related to undercooling amount prior solidification. The effect of secondary cooling on microstructure can also be studied by quenching the samples in solid tin at the end of free-fall. (authors). 20 refs., 11 figs

A Review on Recent Advances on Magnesia-Doloma Refractories by Nano-Technology.

Directory of Open Access Journals (Sweden)

Salman Ghasemi-Kahrizsangi

2017-07-01

Full Text Available Due to exhibiting an excellent chemical resistance against basic environments at high temperature, good thermal shock resistance, thermodynamic stability in the presence of carbon, and a suitable abrasion resistance, MgO-CaO refractories are widely used in argon-oxygen decarburization furnaces in the metallurgy industry and cement rotary kilns. Furthermore, MgO-CaO refractories are beneficial to removing inclusions from molten steels; thus, they have been considered to be one of the effective refractory types for processing clean steel products. Also, MgO-CaO materials have become one of the attractive steelmaking refractories because of their low cost and high ore reserves.  However, in spite of these primary advantages, the application of MgO-CaO refractories has not been popular due to its tendency to hydration when exposed to the atmosphere.  In world most of MgO-CaO bricks producers used of organic components such as tar, pitch, and peck for produce MgO-CaO refractories. But during the application of these bricks in steel and cement and industrials, they released CO and CO2 gases to air and pollute the atmosphere. For this reason, recently some researcher investigate the effect of additive nanoparticles on MgO-CaO refractories performance. They reported the used of Nano-additive have acceptable results and additive nanoparticles can replace by aforementioned environment contaminating organic compounds. In this study, we reviewed all effort that done for improving the hydration resistance of MgO-CaO refractories by application of Nano-additives with an emphasis on the beneficial the use of additives nanoparticle for reduction of environmental pollution by various industries which used of MgO-CaO refractory bricks.

Development of electro fused aggregates for use in refractories for the burning zone of cement kilns

International Nuclear Information System (INIS)

Ferreira, Luis Leonardo Horne Curimbaba

2006-01-01

Electro fused aggregates are largely used in refractory production due to the better performance reached when they are employed. In this work electro fused aggregates were designed for application in refractories for the burning zone of cement kilns. Initially reaction evaluation was conducted aiming the identification of the most prone refractory systems when single refractory phases react with Portland cement phases at high temperatures. In the next step, raw materials of the best refractory systems were electro fused to generate different aggregate compositions. The electro fused aggregates properties were evaluated and the classified ones were used to produce refractory bricks for the burning zone of cement kilns. General characteristics of these bricks were measured and compared with a standard magnesia-spinel refractory. Aggregates of the system Mg O - TiO 2 - Ca O, more specifically aggregates belonged to the compatibility triangle Mg O - Mg 2 TiO 4 - CaTiO 3 , showed suitable characteristics for development of refractories for the burning zone cement kilns. (author)

Refractory of Furnaces to Reduce Environmental Impact

International Nuclear Information System (INIS)

Hanzawa, Shigeru

2011-01-01

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 CO 2 produced from this high energy load. To improve this situation, R and 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-CO 2 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.

Refractory of Furnaces to Reduce Environmental Impact

Science.gov (United States)

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.

High-Temperature Monitoring of Refractory Wall Recession Using Frequency-Modulated Continuous-wave (FM-CW) Radar Techniques

International Nuclear Information System (INIS)

Varghese, B.; DeConick, C.; Cartee, G.; Zoughi, R.; Velez, M.; Moore, R.

2005-01-01

Furnaces are among the most crucial components in the glass and metallurgical industry. Nowadays, furnaces are being operated at higher temperatures and for longer periods of time thus increasing the rate of wear on the furnace refractory lining. Consequently, there is a great need for a nondestructive tool that can accurately measure refractory wall thickness at high temperatures. In this paper the utility of a frequency-modulated continuous-wave (FM-CW) radar is investigated for this purpose

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Jun Wei

2005-03-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Modern materials based on refractory compounds

International Nuclear Information System (INIS)

Kosolapova, T.Ya.

1979-01-01

Discussed are the existing methods for synthesizing powders of binary refractory compounds and high-productivity techniques which hold promise as regards the manufacture of highly disperse and pure powders. Plasmochemical synthesis is shown to be an effective method for obtaining practically all carbides, nitrides and borides. A description is given of three main methods for obtaining single crystals of refractory compounds (TiN, TiC, ZrC, ZrB 2 , NbC) fairly perfect in structure and composition. These processes include deposition from vapour-gas phase, melting in arc plasma and crystallization from solutions in metallic melts. The advantages have been shown of the self-propagating high-temperature synthesis of refractory compounds, ensuring the manufacture of products, close in composition to stoichiometric ones simultaneously with forming of items. Mechanical, thermal, abrasive, and resistive characteristics of the above materials are presented

Ultra light weight refractory material for high temperature applications

Energy Technology Data Exchange (ETDEWEB)

Finke, V.; Kern, H. [Rath GmbH, Meissen (Germany); Springer, M. [Aug. Rath jun. GmbH, Vienna (Austria)

2007-07-01

The requirements on companies running high temperature processes, i.e. at temperatures about 1000 C and above, have increased dramatically within the last few years. For technological, economical and ecological purposes each application has to be checked carefully. As well the political discussion regarding environmental pollution, greenhouse effect and emission trading and the guidelines for climate and environmental protection exert massive influence on thermal process technology and pose an appropriate challenge for the companies. Next to costs of labour and raw materials the costs for energy and environmental costs play a decisive role more and more. The pressure on the management thereby incurred may have a lasting effect on innovations regarding increase of energy efficiency, decrease of CO{sub 2}-emission and often on non negligible increase of productivity. Mainly against the background of the highly scheduled European aims for emission reduction and also in consideration of the still proceeding globalisation the usage of state-of-the-art refractory technics in thermal process technology is of particular importance for business success, for reducing of environmental impact and last but not least for conservation and safeguarding of jobs in Europe and Germany. The applications for products made from high-temperature insulation wool in high temperature applications have strongly increased during the last five years. Especially the production capacities of polycrystalline wool (aluminium oxide wool e.g. Altra B72) have been doubled within the last three years. Primarily ultra light weight products made from HTIW are used in industrial furnaces with application temperatures above 1000 C and / or with high thermo-mechanical (thermal shock) and chemical exposure. The outstanding and essential advantages of these materials are obviously: Ultra light weight material with high resilience and flexibility, Optimised energy consumption (energy saving up to 50% compared

Corrosion behavior of Al-Fe-sputtering-coated steel, high chromium steels, refractory metals and ceramics in high temperature Pb-Bi

International Nuclear Information System (INIS)

Abu Khalid, Rivai; Minoru, Takahashi

2007-01-01

Corrosion tests of Al-Fe-coated steel, high chromium steels, refractory metals and ceramics were carried out in high temperature Pb-Bi at 700 C degrees. Oxygen concentrations in this experiment were 6.8*10 -7 wt.% for Al-Fe-coated steels and 5*10 -6 wt.% for high chromium steels, refractory metals and ceramics. All specimens were immersed in molten Pb-Bi in a corrosion test pot for 1.000 hours. Coating was done with using the unbalanced magnetron sputtering (UBMS) technique to protect the steel from corrosion. Sputtering targets were Al and SUS-304. Al-Fe alloy was coated on STBA26 samples. The Al-Fe alloy-coated layer could be a good protection layer on the surface of steel. The whole of the Al-Fe-coated layer still remained on the base surface of specimen. No penetration of Pb-Bi into this layer and the matrix of the specimen. For high chromium steels i.e. SUS430 and Recloy10, the oxide layer formed in the early time could not prevent the penetration of Pb-Bi into the base of the steels. Refractory metals of tungsten (W) and molybdenum (Mo) had high corrosion resistance with no penetration of Pb-Bi into their matrix. Penetration of Pb-Bi into the matrix of niobium (Nb) was observed. Ceramic materials were SiC and Ti 3 SiC 2 . The ceramic materials of SiC and Ti 3 SiC 2 had high corrosion resistance with no penetration of Pb-Bi into their matrix. (authors)

Neuroimaging in refractory epilepsy. Current practice and evolving trends

Energy Technology Data Exchange (ETDEWEB)

Ramli, N. [Department of Biomedical Imaging, University Malaya Research Imaging Centre (Malaysia); Rahmat, K., E-mail: katt_xr2000@yahoo.com [Department of Biomedical Imaging, University Malaya Research Imaging Centre (Malaysia); Lim, K.S.; Tan, C.T. [Neurology Unit, Department of Medicine, University Malaya, Kuala Lumpur (Malaysia)

2015-09-15

Highlights: • Neuroimaging is imperative in diagnostic work up and therapeutic assessment of refractory epilepsy. • Identification of epileptogenic zone on EEG, MRI and functional imaging improves the success of surgery. • High performance MRI greatly enhanced metabolic information and elucidate brain functions. • Optimisation of epilepsy protocols in structural and functional MRI are presented in this article. - Abstract: Identification of the epileptogenic zone is of paramount importance in refractory epilepsy as the success of surgical treatment depends on complete resection of the epileptogenic zone. Imaging plays an important role in the locating and defining anatomic epileptogenic abnormalities in patients with medically refractory epilepsy. The aim of this article is to present an overview of the current MRI sequences used in epilepsy imaging with special emphasis of lesion seen in our practices. Optimisation of epilepsy imaging protocols are addressed and current trends in functional MRI sequences including MR spectroscopy, diffusion tensor imaging and fusion MR with PET and SPECT are discussed.

Neuroimaging in refractory epilepsy. Current practice and evolving trends

International Nuclear Information System (INIS)

Ramli, N.; Rahmat, K.; Lim, K.S.; Tan, C.T.

2015-01-01

Highlights: • Neuroimaging is imperative in diagnostic work up and therapeutic assessment of refractory epilepsy. • Identification of epileptogenic zone on EEG, MRI and functional imaging improves the success of surgery. • High performance MRI greatly enhanced metabolic information and elucidate brain functions. • Optimisation of epilepsy protocols in structural and functional MRI are presented in this article. - Abstract: Identification of the epileptogenic zone is of paramount importance in refractory epilepsy as the success of surgical treatment depends on complete resection of the epileptogenic zone. Imaging plays an important role in the locating and defining anatomic epileptogenic abnormalities in patients with medically refractory epilepsy. The aim of this article is to present an overview of the current MRI sequences used in epilepsy imaging with special emphasis of lesion seen in our practices. Optimisation of epilepsy imaging protocols are addressed and current trends in functional MRI sequences including MR spectroscopy, diffusion tensor imaging and fusion MR with PET and SPECT are discussed

Limited efficacy of the ketogenic diet in the treatment of highly refractory epileptic spasms.

Science.gov (United States)

Hussain, Shaun A; Shin, Ji Hyun; Shih, Evan J; Murata, Kristina K; Sewak, Sarika; Kezele, Michele E; Sankar, Raman; Matsumoto, Joyce H

2016-02-01

Numerous studies have suggested that the ketogenic diet is effective in the treatment of epileptic spasms, even in refractory cases. However, there has been very limited demonstration of prompt and complete (video-EEG confirmed) response. We set out to describe our center's experience with the ketogenic diet in the treatment of children with highly refractory epileptic spasms, with rigorous seizure outcome assessment. Children treated with the ketogenic diet for epileptic spasms between April, 2010 and June, 2014 were retrospectively identified. Seizure burden was tabulated at baseline and after 1, 3, 6, and 12-months of ketogenic diet exposure. Adverse events were similarly ascertained. We identified a cohort of 22 consecutive patients who received ketogenic diet therapy, with median age of onset of epileptic spasms of 5.2 (IQR 2.0-9.0) months, with diet initiation beginning a median of 26.4 (12.5-38.7) months after onset, and following a median of 7 (IQR 5-7) treatment failures. Only 2 patients exhibited a complete response during ketogenic diet exposure, and response was more reasonably attributed to alternative therapies in both cases. A modest early reduction in seizure frequency was not sustained beyond 1 month of diet exposure. The diet was well tolerated, and continued in 6 patients with subjective and/or partial response. In contrast to prior studies reporting substantial efficacy of the ketogenic diet, our findings suggest limited efficacy, albeit in a highly refractory cohort. Prospective studies in both refractory and new-onset populations, with both video-EEG confirmation of response and rigorous cognitive outcome assessment, would be of great value to more clearly define the utility of the ketogenic diet in the treatment of epileptic spasms. Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Transformations in refractory compounds, caused by high pressures and temperatures

International Nuclear Information System (INIS)

Zajnulin, Yu.G.; Alyamovskij, S.I.; Shvejkin, G.P.

1979-01-01

Considered is the effect of high pressures and temperatures on structural features of refractory carbides, nitrides and monooxides of transition metals. The results are discussed on the basis of one component of the theory on daltonides and bertollides by N.S. Kurnakov - the theory of imaginary compounds, developed by G.B. Bokij. Several new ideas, resulting from this consideration, are formulated, It is shown that at high pressures and temperatures it is possible to obtain new electron modifications of compounds and to expand sufficiently the region of the existance of variable composition phases. The concept on imaginary compounds is shown to be true. A supposition is made on realization of numerous imaginary compounds at high pressures and temperatures. Other ways of production of imaginary compounds are recommended

Migration of TRU-containing slag into candidate refractories for waste management

International Nuclear Information System (INIS)

Seymour, W.C.

1978-11-01

Results of initial tests on transuranic migration into commercial refractories are reported. Five castable refractories and a plastic-bonded refractory were tested using the cup test method. Initial results indicate that castable materials will not survive conditions expected in the slagging pyrolysis unit; plastic refractories appear to have better performance. The major mechanism of migration into the tested refractories is pore penetration. Al 2 O 3 and Al 2 O 3 -Cr 2 O 3 phases appear resistant to chemical diffusion of transuranics. 2 figures, 16 tables

Powder metallurgical high performance materials. Proceedings. Volume 2: P/M hard materials

Energy Technology Data Exchange (ETDEWEB)

Kneringer, G; Roedhammer, P; Wildner, H [eds.

2001-07-01

The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. There the ingenuity and assiduous work of thousands of scientists and engineers striving for progress in the field of powder metallurgy is documented in more than 2000 contributions covering some 30000 pages. The 15{sup th} Plansee Seminar was convened under the general theme 'Powder Metallurgical High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (author)

Powder metallurgical high performance materials. Proceedings. Volume 2: P/M hard materials

International Nuclear Information System (INIS)

Kneringer, G.; Roedhammer, P.; Wildner, H.

2001-01-01

The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. There the ingenuity and assiduous work of thousands of scientists and engineers striving for progress in the field of powder metallurgy is documented in more than 2000 contributions covering some 30000 pages. The 15 th Plansee Seminar was convened under the general theme 'Powder Metallurgical High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (author)

Potential refractory alloy requirements for space nuclear power applications

International Nuclear Information System (INIS)

Cooper, R.H. Jr.

1984-01-01

In reviewing design requirements for refractory alloys for space nuclear applications, several key points are identified. First, the successful utilization of refractory alloys is considered an enabling requirement for the successful deployment of high efficiency, lightweight, and small space nuclear systems. Second, the recapture of refractory alloy nuclear technology developed in the 1960s and early 1970s appears to be a pacing activity in the successful utilization of refractory alloys. Third, the successful application of refractory alloys for space nuclear applications will present a significant challenge to both the materials and the systems design communities

Refractory castables Al2O3-MgO advanced boron-containing

International Nuclear Information System (INIS)

Morbioli, G.G.; Braulio, M.A.L.; Pandolfelli, V.C.

2011-01-01

Alumina-magnesia refractory castables present high corrosion resistance mainly due to the in situ spinel (MgAl 2 O 4 ) formation. For the steel industry, the earlier its generation the best would be the castable's working performance. Taking this aspect into account, alternatives to replace silica fume, which is the most traditional liquid former inducer in this system, were evaluated in this study, by adding boron-containing compounds. Faster spinel and calcium hexaaluminate (CA 6 ) formation was attained through a transient liquid, ensuring remarkable castable's creep resistance and hot modulus of rupture. In this context, a novel route to design in situ spinel forming castable is presented, with great potential to increase the performance of this class of refractory. (author)

Application of a high-temperature neutron diffraction apparatus to the study of refractory oxides

International Nuclear Information System (INIS)

Aldebert, P.; Badie, J.-M.; Buevoz, J.-L.; Roult, G.

1975-01-01

A furnace allowing studies of refractory materials by neutron diffraction in situ up to 2500 deg C is described. It is fitted on to a new type of time of flight spectrometer the pulsed source of which is given by a correlation chopper. The advantages of this technique in comparison with fixed-wavelength goniometers are developped. The examination at high temperature of several refractory oxides has been carried out with this experimental device. The thermal expansion curve of α alumina has been established with accuracy up to near the melting point. Several high temperature cristalline forms, X form La 2 O 3 , the tetragonal and cubic ZrO 2 , tetragonal HfO 2 , have been studied. Concerning the latter two, the case of their solid solutions 2MO 2 -M' 2 O 3 (with M=Hf or Zr and M'=La or Y) has also been considered, at room temperature only [fr

CAR-T cells and allogeneic hematopoietic stem cell transplantation for relapsed/refractory B-cell acute lymphoblastic leukemia.

Science.gov (United States)

Liu, Jun; Zhang, Xi; Zhong, Jiang F; Zhang, Cheng

2017-10-01

Relapsed/refractory acute lymphoblastic leukemia (ALL) has a low remission rate after chemotherapy, a high relapse rate and poor long-term survival even when allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed. Chimeric antigen receptors redirected T cells (CAR-T cells) can enhance disease remission with a favorable outcome for relapsed/refractory ALL, though some cases quickly relapsed after CAR-T cell treatment. Thus, treatment with CAR-T cells followed by allo-HSCT may be the best way to treat relapsed/refractory ALL. In this review, we first discuss the different types of CAR-T cells. We then discuss the treatment of relapsed/refractory ALL using only CAR-T cells. Finally, we discuss the use of CAR-T cells, followed by allo-HSCT, for the treatment of relapsed/refractory ALL.

Refractory vasculitis

NARCIS (Netherlands)

Rutgers, Bram; Kallenberg, Cees G. M.

Refractory vasculitis occurs in 4-5% of patients with anti-neutrophil cytoplasmic antibody associated vasculitis (AAV). Differences between therapies used for refractory disease are mostly reflected in the percentages of complete and partial remissions, but also in the number of serious side

Powder metallurgical high performance materials. Proceedings. Volume 4: late papers

Energy Technology Data Exchange (ETDEWEB)

Kneringer, G; Roedhammer, P; Wildner, H [eds.

2001-07-01

This is the fourth volume (late papers) of the 15th International Plansee seminar 2001 which general theme was 'Powder metallurgical high performance materials'. The seminar looked beyond the refractory metals and cemented carbides, which remain as its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. This volume 4 contains papers dealing with high performance P/M metals (ITER and fusion reactors, solid targets, materials microstructure, novel alloys, etc.), P/M hard materials ( production and characterization, tungsten carbides, titanium carbides, microstructural design, coatings composition and performance, etc.) and general topics. From 37 papers 24 correspond to INIS subject scope and they were indexed separately. (nevyjel)

Powder metallurgical high performance materials. Proceedings. Volume 4: late papers

International Nuclear Information System (INIS)

Kneringer, G.; Roedhammer, P.; Wildner, H.

2001-01-01

This is the fourth volume (late papers) of the 15th International Plansee seminar 2001 which general theme was 'Powder metallurgical high performance materials'. The seminar looked beyond the refractory metals and cemented carbides, which remain as its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. This volume 4 contains papers dealing with high performance P/M metals (ITER and fusion reactors, solid targets, materials microstructure, novel alloys, etc.), P/M hard materials ( production and characterization, tungsten carbides, titanium carbides, microstructural design, coatings composition and performance, etc.) and general topics. From 37 papers 24 correspond to INIS subject scope and they were indexed separately. (nevyjel)

Pharmacotherapy for Refractory and Super-Refractory Status Epilepticus in Adults.

Science.gov (United States)

Holtkamp, Martin

2018-03-01

Patients with prolonged seizures that do not respond to intravenous benzodiazepines and a second-line anticonvulsant suffer from refractory status epilepticus and those with seizures that do not respond to continuous intravenous anesthetic anticonvulsants suffer from super-refractory status epilepticus. Both conditions are associated with significant morbidity and mortality. A strict pharmacological treatment regimen is urgently required, but the level of evidence for the available drugs is very low. Refractory complex focal status epilepticus generally does not require anesthetics, but all intravenous non-anesthetizing anticonvulsants may be used. Most descriptive data are available for levetiracetam, phenytoin and valproate. Refractory generalized convulsive status epilepticus is a life-threatening emergency, and long-term clinical consequences are eminent. Administration of intravenous anesthetics is mandatory, and drugs acting at the inhibitory gamma-aminobutyric acid (GABA) A receptor such as midazolam, propofol and thiopental/pentobarbital are recommended without preference for one of those. One in five patients with anesthetic treatment does not respond and has super-refractory status epilepticus. With sustained seizure activity, excitatory N-methyl-d-aspartate (NMDA) receptors are increasingly expressed post-synaptically. Ketamine is an antagonist at this receptor and may prove efficient in some patients at later stages. Neurosteroids such as allopregnanolone increase sensitivity at GABA A receptors; a Phase 1/2 trial demonstrated safety and tolerability, but randomized controlled data failed to demonstrate efficacy. Adjunct ketogenic diet may contribute to termination of difficult-to-treat status epilepticus. Randomized controlled trials are needed to increase evidence for treatment of refractory and super-refractory status epilepticus, but there are multiple obstacles for realization. Hitherto, prospective multicenter registries for pharmacological

An investigation into mineral processing of north Semnan refractory earth

International Nuclear Information System (INIS)

Aslani, S.; Samin-Bani-Hashemi, H.R.; Taghi-Zadeh, O.

2002-01-01

This paper is dealing with refractory earth of North Semnan. Having an area of 2000 square kilometers, Semnan province is mainly formed by sedimentary rocks with a verity of refractory earth, red earth and kaolin containing heavy minerals. The refractory earth of this area contains a considerable rate of aluminum oxide in shape of dia spore minerals, behemoth and gybsite along with heavy minerals of iron and titanium. To improve the quality of refractory earth, in order to be used in related industries, these minerals have to be separated. To assess the quality of refractory earth of North Semnan as the raw materials of refractory industries, their genesis and mineralogy properties have been precisely studied. Based on the rate of aluminium oxide of the refractory earth of North Semnan mines, a suitable mineral deposit has been selected for more investigation. Using XRD and X RF methods along with electronic and photo microscopes, the refractory earth and heavy minerals of them have been assessed. The elementary laboratory experiments of fragmentation and magnetic separation have been performed. It has been proved that the iron minerals can be separated and, therefore, the quality of the refractory earth can be improved. The separation of titanium minerals has to be investigated with other methods

Engineering high power induction plasma unit at BARC for mass synthesis of refractory nano-ceramics

International Nuclear Information System (INIS)

Ghorui, S.; Sahasrabudhe, S.N.; Dhamale, G.; Das, A.K.

2013-01-01

Atmospheric pressure RF thermal plasma sources are gaining increasing importance for production of high purity novel nano-materials in different high-end technological applications. Inherent electrode-less features of the discharge together with the large volume and high energy density of the produced plasma ensures contamination free process environment and mass production ability. Reported herewith is the development of an indigenous induction plasma system for mass synthesis of nanopowders of refractory ceramic materials. The system has been tested for continuous synthesis of Al 2 O 3 nano-powder at a rate of more than 600 gm per hour and checked for its viability for bulk production of nano-particles of other refractory ceramics like Yttrium oxide and Neodymium Oxide. From collected evidences, the process of formation of the nano-particles is identified as the evaporation and subsequent homogeneous nucleation. Major features observed for alumina are complete conversion into highly spherical nano-sized particles, small particle sizes, very narrow size distribution, highly crystallite nature and mixed phases depending on the zone of collection. For alumina, the particles are found to exhibit a uni-modal distribution with peak near 15 nm

Development of AZS refractories for the glass industry

International Nuclear Information System (INIS)

Guzman, A.M.; Rodriguez, P.

2004-01-01

Refractory materials can support high temperatures, thermal strength and the contact with aggressive environments, for this reason they are widely used in the cement, glass and steel industry. Commercial AZS (alumina-zirconia-silica) refractories are a good alternative in refractory materials for the glass industry' because they can support the aggressive conditions during liquid processing of glass. However, another problem encountered in glass industry is contamination by refractory' material that fall into the molten glass, which can produce a series of defects in the final product. This research was conducted to develop new formulations of AZS refractories with different amounts of ZrO 2 with the purpose of improving the characteristics, properties and the work conditions in the glass melting furnaces and, at the same time, lower the costs this type of refractories. The results obtained indicate that the composition with low content of ZrO 2 can provide better properties than the commercial product, with some modifications in the particle size distribution. Copyright (2004) AD-TECH - International Foundation for the Advancement of Technology Ltd

Distributed Fiber Optic Sensor for On-Line Monitoring of Coal Gasifier Refractory Health

Energy Technology Data Exchange (ETDEWEB)

Wang, Anbo [Center for Photonics Technology, Blacksburgh, VA (United States); Yu, Zhihao [Center for Photonics Technology, Blacksburgh, VA (United States)

2015-11-30

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. During 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.

Influence of Annealing on Microstructure and Mechanical Properties of Refractory CoCrMoNbTi0.4 High-Entropy Alloy

Science.gov (United States)

Zhang, Mina; Zhou, Xianglin; Zhu, Wuzhi; Li, Jinghao

2018-04-01

A novel refractory CoCrMoNbTi0.4 high-entropy alloy (HEA) was prepared via vacuum arc melting. After annealing treatment at different temperatures, the microstructure evolution, phase stability, and mechanical properties of the alloy were investigated. The alloy was composed of two primary body-centered cubic structures (BCC1 and BCC2) and a small amount of (Co, Cr)2Nb-type Laves phase under different annealing conditions. The microhardness and compressive strength of the heat-treated alloy was significantly enhanced by the solid-solution strengthening of the BCC phase matrix and newborn Laves phase. Especially, the alloy annealed at 1473 K (1200 °C) achieved the maximum hardness and compressive strength values of 959 ± 2 HV0.5 and 1790 MPa, respectively, owing to the enhanced volume fraction of the dispersed Laves phase. In particular, the HEAs exhibited promising high-temperature mechanical performance, when heated to an elevated temperature of 1473 K (1200 °C), with a compressive fracture strength higher than 580 MPa without fracture at a strain of more than 20 pct. This study suggests that the present refractory HEAs have immense potential for engineering applications as a new class of high-temperature structural materials.

REFRACTORY THROMBOCYTOPENIA AND NEUTROPENIA: A DIAGNOSTIC CHALLENGE

Directory of Open Access Journals (Sweden)

Emmanuel Gyan

2015-02-01

Full Text Available Background. The 2008 WHO classification identified refractory cytopenia with unilineage dysplasia (RCUD as a composite entity encompassing refractory anemia, refractory thrombocytopenia (RT, and refractory neutropenia (RN, characterized by 10% or more dysplastic cells in the bone marrow respective lineage. The diagnosis of RT and RN is complicated by several factors.  Diagnosing RT first requires exclusion of familial thrombocytopenia, chronic auto-immune thrombocytopenia, concomitant medications, viral infections, or hypersplenism. Diagnosis of RN should also be made after ruling out differential diagnoses such as ethnic or familial neutropenia, as well as acquired, drug-induced, infection-related or malignancy-related neutropenia. An accurate quantification of dysplasia should be performed in order to distinguish RT or RN from the provisional entity named idiopathic cytopenia of unknown significance (ICUS. Cytogenetic analysis, and possibly in the future somatic mutation analysis (of genes most frequently mutated in MDS, and flow cytometry analysis aberrant antigen expression on myeloid cells may help in this differential diagnosis. Importantly, we and others found that, while isolated neutropenia and thrombocytopenia are not rare in MDS, those patients can generally be classified (according to WHO 2008 classification as refractory cytopenia with multilineage dysplasia or refractory anemia with excess blasts, while RT and RN (according to WHO 2008 are quite rare.These results suggest in particular that identification of RT and RN as distinct entities could be reconsidered in future WHO classification updates.

Forming Refractory Insulation On Copper Wire

Science.gov (United States)

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.

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr.; Alireza Rezaie

2003-12-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Alireza Rezaie

2003-12-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LFHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Alireza Rezaie; Xiaoting Liang; Musa Karakus; Jun Wei

2005-12-01

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected or developed that reacted with the gasifier environment to form protective surfaces in

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-10-01

The University of Missouri-Rolla identified materials that permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project was to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study attempted to define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials were selected/developed that either react with the gasifier environment to form protective surfaces in

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick; Musa Karakus; Alireza Rezaie

2004-03-30

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-07-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Alireza Rezaie

2004-10-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-01-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang; Jun Wei

2005-04-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Liang

2005-07-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

REFRACTORY FOR BLACK LIQUOR GASIFIERS

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr.; Alireza Rezaie

2004-04-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the materials problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Metronomic chemotherapy – promising therapeutical approach for recurrent/ refractory high risk tumours in children

International Nuclear Information System (INIS)

Deak, L.; Feketeova, J.; Haluskova, V.; Sencakova, I.; Jenco, I.; Oravkinova, I.

2011-01-01

Despite a great progress in the treatment of pediatric malignancies, the outcome of children with high risk refractory or relapsed tumours, as are some types of brain tumours or metastatic sarcomas, remain poor. In contrast to dose – intensified chemotherapy, utilizing „maximal tolerated doses“ of chemotherapy, the metronomic chemotherapy (MC) is based on chronic administration of significantly lower doses of chemotherapy in an uninterrupted manner, for prolonged periods. Because of different mechanism of action against conventional chemotherapy and no cross- resistance, this treatment modality is effective also in refractory and recurrent tumours. The predominant mechanism of action of MC is antiangiogenic. In last decades several studies confirmed the efficacy and low toxicity of this new treatment modality. It can be delivered on outpatient basis and is well tolerated even in heavily pretreated patients. The authors present an overview of studies on MC in pediatric oncology and their own experience. (author)

High Throughput Drug Sensitivity Assay and Genomics- Guided Treatment of Patients With Relapsed or Refractory Acute Leukemia

Science.gov (United States)

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

Testing of the melter lid refractory for the West Valley Demonstration Project (WVDP)

International Nuclear Information System (INIS)

Gupta, A.; Jain, V.; Mahoney, J.L.; Holman, T.M.

1991-01-01

Monofrax H and Mulfrax 202 refractory were tested for potential application as the melter lid refractory for the WVDP. Resistance to spalling and corrosion by the slurry and offgas salts were primary criteria for selection. Test specimens were subjected to thermal cycling between 450 and 1,100C for five weeks. Visual examination indicated some corrosion but no spalling. SEM/EDS analysis was performed to determine the glass/refractory interface corrosion mechanism. The refractory selection basis will be discussed

Performance testing of refractory alloy-clad fuel elements for space reactors

International Nuclear Information System (INIS)

Dutt, D.S.; Cox, C.M.; Karnesky, R.A.; Millhollen, M.K.

1985-01-01

Two fast reactor irradiation tests, SP-1 and SP-2, provide a unique and self-consistent data set with which to evaluate the technical feasibility of potential fuel systems for the SP-100 space reactor. Fuel pins fabricated with leading cladding candidates (Nb-1Zr, PWC-11, and Mo-13Re) and fuel forms (UN and UO 2 ) are operated at temperatures typical of those expected in the SP-100 design. The first US fast reactor irradiated, refractory alloy clad fuel pins, from the SP-1 test, reached 1 at. % burnup in EBR-II in March 1985. At that time selected pins were discharged for interim examination. These examinations confirmed the excellent performance of the Nb-1Zr clad uranium oxide and uranium nitride fuel elements, which are the baseline fuel systems for two SP-100 reactor concepts

Vorinostat Combined with High-Dose Gemcitabine, Busulfan, and Melphalan with Autologous Stem Cell Transplantation in Patients with Refractory Lymphomas.

Science.gov (United States)

Nieto, Yago; Valdez, Benigno C; Thall, Peter F; Ahmed, Sairah; Jones, Roy B; Hosing, Chitra; Popat, Uday; Shpall, Elizabeth J; Qazilbash, Muzaffar; Gulbis, Alison; Anderlini, Paolo; Alousi, Amin; Shah, Nina; Bashir, Qaiser; Liu, Yan; Oki, Yasuhiro; Hagemeister, Frederick; Fanale, Michelle; Dabaja, Bouthaina; Pinnix, Chelsea; Champlin, Richard; Andersson, Borje S

2015-11-01

More active high-dose regimens are needed for refractory/poor-risk relapsed lymphomas. We previously developed a regimen of infusional gemcitabine/busulfan/melphalan, exploiting the synergistic interaction. Its encouraging activity in refractory lymphomas led us to further enhance its use as a platform for epigenetic modulation. We previously observed increased cytotoxicity in refractory lymphoma cell lines when the histone deacetylase inhibitor vorinostat was added to gemcitabine/busulfan/melphalan, which prompted us to clinically study this four-drug combination. Patients ages 12 to 65 with refractory diffuse large B cell lymphoma (DLCL), Hodgkin (HL), or T lymphoma were eligible. Vorinostat was given at 200 mg/day to 1000 mg/day (days -8 to -3). Gemcitabine was infused continuously at 10 mg/m(2)/minute over 4.5 hours (days -8 and -3). Busulfan dosing targeted 4000 μM-minute/day (days -8 to -5). Melphalan was infused at 60 mg/m(2)/day (days -3 and -2). Patients with CD20(+) tumors received rituximab (375 mg/m(2), days +1 and +8). We enrolled 78 patients: 52 DLCL, 20 HL, and 6 T lymphoma; median age 44 years (range, 15 to 65); median 3 prior chemotherapy lines (range, 2 to 7); and 48% of patients had positron emission tomography-positive tumors at high-dose chemotherapy (29% unresponsive). The vorinostat dose was safely escalated up to 1000 mg/day, with no treatment-related deaths. Toxicities included mucositis and dermatitis. Neutrophils and platelets engrafted promptly. At median follow-up of 25 (range, 16 to 41) months, event-free and overall survival were 61.5% and 73%, respectively (DLCL) and 45% and 80%, respectively (HL). In conclusion, vorinostat/gemcitabine/busulfan/melphalan is safe and highly active in refractory/poor-risk relapsed lymphomas, warranting further evaluation. This trial was registered at ClinicalTrials.gov (NCI-2011-02891). Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights

Split-Course, High-Dose Palliative Pelvic Radiotherapy for Locally Progressive Hormone-Refractory Prostate Cancer

Energy Technology Data Exchange (ETDEWEB)

Gogna, Nirdosh Kumar, E-mail: kumar_gogna@health.qld.gov.au [Radiation Oncology Services, Mater Centre, Brisbane, Queensland (Australia); Baxi, Siddhartha; Hickey, Brigid; Baumann, Kathryn [Radiation Oncology Services, Mater Centre, Brisbane, Queensland (Australia); Burmeister, Elizabeth [Princess Alexandra Hospital, Brisbane, Queensland (Australia); Holt, Tanya [Radiation Oncology Services, Mater Centre, Brisbane, Queensland (Australia)

2012-06-01

Purpose: Local progression, in patients with hormone-refractory prostate cancer, often causes significant morbidity. Pelvic radiotherapy (RT) provides effective palliation in this setting, with most published studies supporting the use of high-dose regimens. The aim of the present study was to examine the role of split-course hypofractionated RT used at our institution in treating this group of patients. Methods and Materials: A total of 34 men with locoregionally progressive hormone-refractory prostate cancer, treated with a split course of pelvic RT (45-60 Gy in 18-24 fractions) between 2000 and 2008 were analyzed. The primary endpoints were the response rate and actuarial locoregional progression-free survival. Secondary endpoints included overall survival, compliance, and acute and late toxicity. Results: The median age was 71 years (range, 53-88). Treatment resulted in an overall initial response rate of 91%, a median locoregional progression-free survival of 43 months, and median overall survival of 28 months. Compliance was excellent and no significant late toxicity was reported. Conclusions: The split course pelvic RT described has an acceptable toxicity profile, is effective, and compares well with other high-dose palliative regimens that have been previously reported.

Preparation and characterization of clay bonded high strength silica refractory by utilizing agriculture waste

Directory of Open Access Journals (Sweden)

Aman Bhardwaj

2017-11-01

Full Text Available Clay bonded silica refractory was prepared by utilizing agriculture waste called rice husk ash (RHA and refractory grog. Various samples were prepared with different compositions based upon partial replacement of quartz by RHA. Rectangular samples were prepared by following semi dry process prior to pressing in a uniaxial hydraulic press and sintering at a temperature of 1200 °C in air atmosphere. Various physical, mechanical and thermal characterizations were done like X-ray diffraction (XRD, scanning electron microscope (SEM, apparent porosity (AP, bulk density (BD, cold crushing strength (CCS, refractoriness and thermal conductivity measurement. The sample utilizing 30% of RHA was considered most optimum composition which produced cold crushing strength of 38 MPa and thermal conductivity of 2.08 W/m K at 800 °C with a considerable good refractoriness. Enhancement in the mechanical as well as thermal properties may be considered as attributed to the amorphous silica which has reacted more easily and efficiently with other material surrounding giving rise to the densification and produced stable crystalline phase to the refractory material. These promising characteristics suggests that the RHA may lead to be used as a potential material for the preparation of clay bonded high strength silica refractories. Resumen: Se preparó sílice refractaria unida a arcilla con residuos agrícolas conocidos como ceniza de cascarilla de arroz (rice husk ash [RHA] y grog refractario. Se prepararon varias muestras con diferentes composiciones basadas en la sustitución parcial de cuarzo por RHA. Las muestras rectangulares se prepararon siguiendo un proceso semiseco antes de prensarlas en una prensa hidráulica uniaxial y sinterizarlas a una temperatura de 1.200 °C en atmósfera de aire. Se realizaron diversas caracterizaciones físicas, mecánicas y térmicas, como la difracción de rayos X, el microscopio electrónico de barrido, la porosidad

High temperature resistant cermet and ceramic compositions. [for thermal resistant insulators and refractory coatings

Science.gov (United States)

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.

Development of a Refractory High Entropy Superalloy (Postprint)

Science.gov (United States)

2016-03-17

hardened with HfC precipitates [2], Co-Re- or Co-Al-W-based alloys [3] or two-phase ( FCC + L12) refractory superalloys based on platinum group metals...Ni-based superalloys consisting of cuboids with the ordered L12 structure embedded in an FCC solid-solution matrix. Based on this microstructural...and 5). A comparison of the average atomic radii with the measured lattice parameters allows us to conclude that the disordered BCC phase forming

Refractoriness in human atria

DEFF Research Database (Denmark)

Skibsbye, Lasse; Jespersen, Thomas; Christ, Torsten

2016-01-01

BACKGROUND: Refractoriness of cardiac cells limits maximum frequency of electrical activity and protects the heart from tonic contractions. Short refractory periods support major arrhythmogenic substrates and augmentation of refractoriness is therefore seen as a main mechanism of antiarrhythmic...... drugs. Cardiomyocyte excitability depends on availability of sodium channels, which involves both time- and voltage-dependent recovery from inactivation. This study therefore aims to characterise how sodium channel inactivation affects refractoriness in human atria. METHODS AND RESULTS: Steady......-state activation and inactivation parameters of sodium channels measured in vitro in isolated human atrial cardiomyocytes were used to parameterise a mathematical human atrial cell model. Action potential data were acquired from human atrial trabeculae of patients in either sinus rhythm or chronic atrial...

Production of lightweight refractory material by hydrothermal process

International Nuclear Information System (INIS)

Sulejmani, Ramiz B.

2002-01-01

Many different processes of production of lightweight refractories are well known over the World. Traditional production of lightweight refractories is by addition of combustibles or by a special frothing process. This work is concerned with hydrothermal of lightweight refractories from rice husk ash. The rice husk ash, used in present investigations were from Kocani region, R. Macedonia. The chemical analysis of the rice husk ash shows that it contains 91,8 - 93,7% SiO 2 and some alkaline and alkaline earth oxides. Microscopic and X - ray diffraction examinations of the rice husk ash have shown that it is composed of cristobalite, tridimite and amorphous silica. The composition of the mixture for lightweight refractory brick production is 93,4% rice husk ash and 6,6% Ca(OH) 2 . The mixtures were well mixed, moistened and pressed at 5 - 10 MPa. The hydrothermal reactions between calcium hydroxide and rice husk ash over the temperature range 80 - 160 o C were investigated. The period of autoclave treatment was from 2 to 72 h. After the hydrothermal treatment of the samples, the mineralogical composition, bulk density, density, cold crushing strength, porosity, refractoriness and thermal expansion were examined. Analysing the properties of the obtained samples it can be concluded that from rice husk ash and calcium hydroxide under hydrothermal condition it is possible to obtain lightweight acid refractory material with high quality.(Author)

Directed light fabrication of refractory metals and alloys

International Nuclear Information System (INIS)

Fonseca, J.C.; Lewis, G.K.; Dickerson, P.G.; Nemec, R.B.

1999-01-01

This report covers deposition of refractory pure metals and alloys using the Directed Light Fabrication (DLF) process and represents progress in depositing these materials through September 1998. In extending the DLF process technology to refractory metals for producing fully dense, structurally sound deposits, several problems have become evident. (1) Control of porosity in DLF-deposited refractory metal is difficult because of gases, apparently present in commercially purchased refractory metal powder starting materials. (2) The radiant heat from the molten pool during deposition melts the DLF powder feed nozzle. (3) The high reflectivity of molten refractory metals, at the Nd-YAG laser wavelength (1.06microm), produces damaging back reflections to the optical train and fiber optic delivery system that can terminate DLF processing. (4) The current limits on the maximum available laser power to prevent back reflection damage limit the parameter range available for densification of refractory metals. The work to date concentrated on niobium, W-25Re, and spherodized tungsten. Niobium samples, made from hydride-dehydride powder, had minimal gas porosity and the deposition parameters were optimized; however, test plates were not made at this time. W-25Re samples, containing sodium and potassium from a precipitation process, were made and porosity was a problem for all samples although minimized with some process parameters. Deposits made from potassium reduced tungsten that was plasma spherodized were made with minimized porosity. Results of this work indicate that further gas analysis of starting powders and de-gassing of starting powders and/or gas removal during deposition of refractory metals is required

Chemical analysis of refractories by plasma spectrometry

International Nuclear Information System (INIS)

Coutinho, C.A.

1990-01-01

X-ray spectrometry has been, since the last two or three decades, the traditional procedure for the chemical analysis of refractories, due to its high degree of accuracy and speed to produce analytical results. An interesting alternative to X-ray fluorescence is provided by the Inductively Coupled Plasma Spectrometry technique, for those laboratories where wet chemistry facilities are already available or process control is not required at high speed, or investiment costs have to be low. This paper presents results obtained by plasma spectroscopy for the analysis of silico - aluminous refractories, showing calibration curves, precion and detection limits. Considerations and comparisons with X-ray fluorescence are also made. (author) [pt

Beta-blockers in cirrhosis and refractory ascites

DEFF Research Database (Denmark)

Kimer, Nina; Feineis, Martin; Møller, Søren

2015-01-01

OBJECTIVE: It is currently discussed if beta-blockers exert harmful effects and increase mortality in patients with cirrhosis and refractory ascites. In this study, we provide an overview of the available literature in this field in combination with a retrospective analysis of 61 patients...... trials (9 trials on propranolol, 1 case-control study and 4 retrospective analyses) were identified. One trial suggested an increased mortality in patients treated with beta-blockers and refractory ascites. The results of the remaining trials were inconclusive. No increase in mortality among beta-blocker......-treated patients was found in the present retrospective analysis. CONCLUSIONS: Treatment with beta-blockers may increase mortality in patients with cirrhosis and refractory ascites. However, the current evidence is sparse and high-quality studies are warranted to clarify the matter....

Characterization of refractory brick based on local raw material from Lampung Province - Indonesia

Science.gov (United States)

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.

A one-year prospective study of refractory status epilepticus in Modena, Italy.

Science.gov (United States)

Giovannini, Giada; Monti, Giulia; Polisi, Michela M; Mirandola, Laura; Marudi, Andrea; Pinelli, Giovanni; Valzania, Franco; Girardis, Massimo; Nichelli, Paolo F; Meletti, Stefano

2015-08-01

Refractory status epilepticus (RSE) is a particular critical condition characterized by seizures that continue despite the use of first- and second-line therapies and by high mortality. To date, only one prospective study investigated clinical features and prognostic factors in RSE. In this study, we performed a one-year prospective survey to identify clinical features, outcomes, and variables associated with the development of RSE in the adolescent and adult population of Modena, northern Italy. We observed 83 episodes of SE in 83 patients. In 31% of the cases, third-line therapy (anesthetic drug) was needed. Among this group, 14% resolved and were classified as RSE, while, in 17%, seizures recurred at withdrawal of anesthetics and were classified as super-RSE. The development of RSE/super-RSE was associated with a stuporous/comatose state at presentation and with the absence of a previous history of epilepsy. Refractory status epilepticus/super-refractory status epilepticus showed a worse outcome compared with responsive SE: 54% versus 21% for 30-day mortality; 19% versus 56% for a return to baseline condition. This prospective study confirms stupor/coma at onset as a relevant clinical factor associated with SE refractoriness. We observed a rate of RSE comparable with previous reports, with high mortality and morbidity. Mortality in the observed RSE was higher than in previous studies; this result is probably related to the low rate of a previous epilepsy history in our population that reflects a high incidence of acute symptomatic etiologies, especially the inclusion of patients with postanoxic SE who have a bad prognosis per se. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015 Elsevier Inc. All rights reserved.

Plasma spraying of refractory metals and refractory hard materials. State of the art

International Nuclear Information System (INIS)

Eschnauer, H.; Lugscheider, E.; Jaeger, D.

1989-01-01

Suitable spraying processes for manufacturing refractory metals, refractory hard materials as well as spray materials with refractory components are the VPS- and IPS-spraying techniques. The advantages of these special spraying process variations are described. The reactive spraying materials are systematically organized. The characteristical properties used in purpose of improving the substrate surfaces are explained. Finally some examples of the latest results of research concerning plasma spraying of reactive materials are shown. 16 refs., 10 figs. (Author)

Refractory for Black Liquor Gasifiers

Energy Technology Data Exchange (ETDEWEB)

William L. Headrick Jr; Musa Karakus; Xiaoting Laing

2005-10-01

The University of Missouri-Rolla will identify materials that will permit the safe, reliable and economical operation of combined cycle gasifiers by the pulp and paper industry. The primary emphasis of this project will be to resolve the material problems encountered during the operation of low-pressure high-temperature (LPHT) and low-pressure low-temperature (LPLT) gasifiers while simultaneously understanding the materials barriers to the successful demonstration of high-pressure high-temperature (HPHT) black liquor gasifiers. This study will define the chemical, thermal and physical conditions in current and proposed gasifier designs and then modify existing materials and develop new materials to successfully meet the formidable material challenges. Resolving the material challenges of black liquor gasification combined cycle technology will provide energy, environmental, and economic benefits that include higher thermal efficiencies, up to three times greater electrical output per unit of fuel, and lower emissions. In the near term, adoption of this technology will allow the pulp and paper industry greater capital effectiveness and flexibility, as gasifiers are added to increase mill capacity. In the long term, combined-cycle gasification will lessen the industry's environmental impact while increasing its potential for energy production, allowing the production of all the mill's heat and power needs along with surplus electricity being returned to the grid. An added benefit will be the potential elimination of the possibility of smelt-water explosions, which constitute an important safety concern wherever conventional Tomlinson recovery boilers are operated. Developing cost-effective materials with improved performance in gasifier environments may be the best answer to the material challenges presented by black liquor gasification. Refractory materials may be selected/developed that either react with the gasifier environment to form protective

Development of various welding techniques for refractory and reactive metals and alloys

International Nuclear Information System (INIS)

Tonpe, Sunil; Saibaba, N.

2016-01-01

Nuclear Fuel Complex (NFC), Hyderabad, India with its excellent manufacturing facilities, produces nuclear fuel and structural components for nuclear reactors. NFC has taken up the challenging job of production of various critical components made out of refractory and reactive metals and alloys for nuclear and aerospace applications as an indigenization import substitute program. Refractory metals are prime candidates for many high temperature aerospace components because of refractory metal's high melting points and inherent creep resistance. The use of refractory metals is often limited because of their poor room temperature properties, inadequate oxidation resistance at elevated temperatures, difficulties associated with joining or welding etc. These advanced materials demand stringent requirement with respect to chemistry, dimensional tolerances, mechanical and metallurgical properties. This paper discusses in detail various welding techniques adopted in NFC for refractory and reactive metals and alloys such as Nb, Zr, Ti, Ta, Zircaloy, Titanium-half alloy etc. to manufacture various components and assemblies required for nuclear and aerospace applications

High dose phenobarbitone coma in pediatric refractory status epilepticus; a retrospective case record analysis, a proposed protocol and review of literature.

Science.gov (United States)

Gulati, Sheffali; Sondhi, Vishal; Chakrabarty, Biswaroop; Jauhari, Prashant; Lodha, Rakesh; Sankar, Jhuma

2018-04-01

Ongoing refractory status epilepticus is associated with significant morbidity and mortality. Therapeutic coma induction with midazolam, thiopentone, phenobarbitone or propofol is indicated when conventional antiepileptics fail to abort seizure. Of these, the most extensively studied is midazolam. Amongst the remaining three, phenobarbitone has the most favourable pharmacological profile, but has not been studied adequately, more so in the pediatric age group. The current retrospective case records analysis is an attempt to describe use of phenobarbitone coma in pediatric refractory status epilepticus. Case records of patients, admitted with status epilepticus to the pediatric inpatient services of a tertiary care teaching hospital of North India between January 2014 and December 2016 were reviewed. Those with refractory status epilepticus who failed to respond to midaolam infusion and phenobarbitone coma was used were included for analysis. Overall, 108 children presented in status, of which 34 developed refractory status epilepticus. Of these 34, 21 responded to midazolam infusion and in 13 high dose phenobarbitone coma following a standardised protocol was used. Amongst these 13 (8 males and 5 females, median age 6 years, IQR: 2.5-9.5), 12 responded and 1 succumbed. The median time to clinical seizure resolution and desired electroencephalographic changes post phenobarbitone initiation were 16 (IQR: 12-25) and 72 h (IQR: 48-120) respectively. High dose phenobarbitone appears to be an effective therapeutic modality in pediatric refractory status epilepticus. The current study provides a protocol for its use which can be validated in future studies with larger sample size. Copyright © 2018 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Clinical Features of Refractory Ascites in Outpatients

Directory of Open Access Journals (Sweden)

Wanda Regina Caly

Full Text Available OBJECTIVES: To present the clinical features and outcomes of outpatients who suffer from refractory ascites. METHODS: This prospective observational study consecutively enrolled patients with cirrhotic ascites who submitted to a clinical evaluation, a sodium restriction diet, biochemical blood tests, 24 hour urine tests and an ascitic fluid analysis. All patients received a multidisciplinary evaluation and diuretic treatment. Patients who did not respond to the diuretic treatment were controlled by therapeutic serial paracentesis, and a transjugular intrahepatic portosystemic shunt was indicated for patients who required therapeutic serial paracentesis up to twice a month. RESULTS: The most common etiology of cirrhosis in both groups was alcoholism [49 refractory (R and 11 non-refractory ascites (NR]. The majority of patients in the refractory group had Child-Pugh class B cirrhosis (p=0.034. The nutritional assessment showed protein-energy malnutrition in 81.6% of the patients in the R group and 35.5% of the patients in the NR group, while hepatic encephalopathy, hernia, spontaneous bacterial peritonitis, upper digestive hemorrhage and type 2 hepatorenal syndrome were present in 51%, 44.9%, 38.8%, 38.8% and 26.5% of the patients in the R group and 9.1%, 18.2%, 0%, 0% and 0% of the patients in the NR group, respectively (p=0.016, p=0.173, p=0.012, p=0.012, and p=0.100, respectively. Mortality occurred in 28.6% of the patients in the R group and in 9.1% of the patients in the NR group (p=0.262. CONCLUSION: Patients with refractory ascites were malnourished, suffered from hernias, had a high prevalence of complications and had a high postoperative death frequency, which was mostly due to infectious processes.

High-dose phenobarbital with intermittent short-acting barbiturates for acute encephalitis with refractory, repetitive partial seizures.

Science.gov (United States)

Uchida, Takashi; Takayanagi, Masaru; Kitamura, Taro; Nishio, Toshiyuki; Numata, Yurika; Endo, Wakaba; Haginoya, Kazuhiro; Ohura, Toshihiro

2016-08-01

Acute encephalitis with refractory, repetitive partial seizures (AERRPS) is characterized by repetitive seizures during the acute and chronic phases and has a poor neurological outcome. Burst-suppression coma via continuous i.v. infusion of a short-acting barbiturate is used to terminate refractory seizures, but the severe side-effects of short-acting barbiturates are problematic. We report on a 9-year-old boy with AERRPS who was effectively treated with very-high-dose phenobarbital (VHDPB) combined with intermittent short-acting barbiturates. VHDPB side-effects were mild, especially compared with those associated with continuous i.v. infusion of short-acting barbiturates (dosage, 40-75 mg/kg/day; maximum blood level, 290 μg/mL). Using VHDPB as the main treatment, short-acting barbiturates were used intermittently and in small amounts. This is the first report to show that VHDPB, combined with intermittent short-acting barbiturates, can effectively treat AERRPS. After treatment, convulsions were suppressed and daily life continued, but intellectual impairment and high-level dysfunction remained. © 2016 Japan Pediatric Society.

Evaluation of olivine refractories for TES

Science.gov (United States)

Gay, B. M.; Cochrane, R. L.; Palmour, H., III; Paisley, M. J.

1982-02-01

The principal objectives of this program are to (1) experimentally determine the degree of improvement in thermal and mechanical performance that can be obtained with an olivine thermal storage brick made of domestic materials using advanced processing techniques compared with state-of-the-art as represented by commercial European bricks, (2) conduct an assessment of existing German ceramic process technology and determine its adaptability to domestic raw materials and manufacturing practices, and (3) investigate, on a limited basis, method for further improvement of domestic-olivine brick. To date, accomplishments include (1) installation of improved, computer-based instrumentation, (2) the use of this system to determine performance characteristics of a set of heat storage refractories under cyclic use conditions, (3) acquisition of the services of a knowledgeable European consultant, (4) continued lab-scale process/property optimization studies, and (5) comparative testing of olivine-based and magnesite-based heat storage refractories in the calorimetric test facility at Purdue University.

Surgical disconnection of patent paraumbilical vein in refractory hepatic encephalopathy.

Science.gov (United States)

Ishikawa, Yoshinori; Yoshida, Hiroshi; Mamada, Yasuhiro; Taniai, Nobuhiko; Bando, Koichi; Mizuguchi, Yoshiaki; Kakinuma, Daisuke; Kanda, Tomohiro; Akimaru, Koho; Tajiri, Takashi

2008-06-01

Refractory hepatic encephalopathy (HE) frequently develops in patients with cirrhosis and portal-systemic shunt. Recently, patients with refractory HE associated with portal-systemic shunt have been treated with interventional radiology. We describe a promising new treatment for portal-systemic shunt, ligation of the patent paraumbilical vein (PUV) after partial splenic embolization, in patients with refractory HE. Four patients with cirrhosis (3 women and 1 man; mean age, 56 years) and refractory HE due to a patent PUV were studied. Patency of the PUV had recurred in 1 patient after primary occlusion by interventional radiological procedures. The Child-Pugh class was B in 2 patients and C in 2. Before the present treatment, all patients had been hospitalized at least 3 times because of recurrent HE. Partial splenic embolization was performed in all patients to decrease portal venous pressure before surgery. Surgical ligation of the patent PUV was performed under epidural anesthesia. The patent PUV was carefully skeletonized and doubly ligated. Esophageal varices were evaluated with upper gastrointestinal endoscopy before and after surgery. The mean follow-up duration was 15.8 months. After ligation, there were no clinically significant complications. Esophageal varices were unchanged. The serum ammonia level was higher before surgery (162.3 +/- 56.4 mug/dL, mean +/- SD) than after surgery (41.8 +/- 20.2 mug/dL; p=0.0299). No patient had symptoms of HE. Ligation of the patent PUV is an effective treatment for patients with refractory HE.

Interventional embolization for refractory hyperthyroidism

International Nuclear Information System (INIS)

Jiang Guomin; Zhang Yunping; Chen Yaxian; Zhao Jinwei; Yang Weihuai; Chen Jinluo

2001-01-01

Objective: To evaluate the clinical effects of the thyroid artery embolization for refractory hyperthyroidism. Methods: Super selective catheterization and interventional embolization of thyroid superior and inferior arteries were performed with PVA microspheres and Gelfoam particles. Changes of function and size of thyroid were investigated after embolization. Results: The procedures were succeeded in all 21 patients. Followed up by 3-12 months, serum level of thyroid hormones dropped significantly (median FT 3 from 17.1 pmol/L to 7.44 pmol/L, median FT 4 from 51.1 pmol/L to 23.3 pmol/L, P< 0.01). The size of thyroid glands decreased remarkably. Symptoms of hyperthyroidism were controlled in 4 patients and were effectively controlled through low dose antithyroid medication in 17 patients. No serious complications occurred. Conclusions: Thyroid artery embolization is a new safe and effective method for refractory hyperthyroidism

RESULTS OF OUTPATIENT PROGRAM ON EFFECTIVE THERAPY OF REFRACTORY ARTERIAL HYPERTENSION

Directory of Open Access Journals (Sweden)

M. M. Batyushin

2015-12-01

Full Text Available Aim. To increase in efficacy of antihypertensive therapy in patients with refractory arterial hypertension (HT.Material and methods. Patients with refractory HT were revealed during first month of program. The causes of refractory HT were analyzed. Combined antihypertensive therapy was prescribed to reach target level of blood pressure (BP. This therapy lasted 24 weeks and included angiotensin converting enzyme (ACE inhibitor, thiazid diuretic (indapamide and dihydropyridine calcium antagonist (nifedipine XL.Results. 200 patients with refractory HT were revealed. True refractory HT took place in 59,9% of patients and pseudo refractory HT – in 40,1% of patients. Lack of diuretics or combined antihypertensive therapy were the main reason of insufficient BP control. Proposed 3-drugs therapy resulted in reduction of systolic BP from 190 to 132 Hg mm and diastolic BP from 104 to 81 Hg mm. Target level of BP was reached in 94% patients. There were no side effects which demanded to stop therapy.Conclusion. High incidence of pseudorefractory HT (40,1% is revealed. Significant prevalence of renal disturbances especially chronic interstitial inflammatory could be responsible for refractory HT development. Use of 3-drugs therapy (ACE inhibitor, indapamide and nifedipine XL provides effective control of BP in refractory and pseudorefractory HT.

RESULTS OF OUTPATIENT PROGRAM ON EFFECTIVE THERAPY OF REFRACTORY ARTERIAL HYPERTENSION

Directory of Open Access Journals (Sweden)

M. M. Batyushin

2007-01-01

Full Text Available Aim. To increase in efficacy of antihypertensive therapy in patients with refractory arterial hypertension (HT.Material and methods. Patients with refractory HT were revealed during first month of program. The causes of refractory HT were analyzed. Combined antihypertensive therapy was prescribed to reach target level of blood pressure (BP. This therapy lasted 24 weeks and included angiotensin converting enzyme (ACE inhibitor, thiazid diuretic (indapamide and dihydropyridine calcium antagonist (nifedipine XL.Results. 200 patients with refractory HT were revealed. True refractory HT took place in 59,9% of patients and pseudo refractory HT – in 40,1% of patients. Lack of diuretics or combined antihypertensive therapy were the main reason of insufficient BP control. Proposed 3-drugs therapy resulted in reduction of systolic BP from 190 to 132 Hg mm and diastolic BP from 104 to 81 Hg mm. Target level of BP was reached in 94% patients. There were no side effects which demanded to stop therapy.Conclusion. High incidence of pseudorefractory HT (40,1% is revealed. Significant prevalence of renal disturbances especially chronic interstitial inflammatory could be responsible for refractory HT development. Use of 3-drugs therapy (ACE inhibitor, indapamide and nifedipine XL provides effective control of BP in refractory and pseudorefractory HT.

Refractory coeliac disease in a country with a high prevalence of clinically-diagnosed coeliac disease.

Science.gov (United States)

Ilus, T; Kaukinen, K; Virta, L J; Huhtala, H; Mäki, M; Kurppa, K; Heikkinen, M; Heikura, M; Hirsi, E; Jantunen, K; Moilanen, V; Nielsen, C; Puhto, M; Pölkki, H; Vihriälä, I; Collin, P

2014-02-01

Refractory coeliac disease (RCD) is thought to be a rare disorder, but the accurate prevalence is unknown. We aimed to identify the prevalence of and the risk factors for developing RCD in a Finnish population where the clinical detection rate of coeliac disease is high. The study involved 11 hospital districts in Finland where the number of treated RCD patients (n = 44), clinically diagnosed coeliac disease patients (n = 12 243) and adult inhabitants (n = 1.7 million) was known. Clinical characteristics at diagnosis of coeliac disease between the RCD patients and patients with uncomplicated disease were compared. The prevalence of RCD was 0.31% among diagnosed coeliac disease patients and 0.002% in the general population. Of the enrolled 44 RCD patients, 68% had type I and 23% type II; in 9% the type was undetermined. Comparing 886 patients with uncomplicated coeliac disease with these 44 patients that developed RCD later in life, the latter were significantly older (median 56 vs 44 years, P coeliac disease. Patients with evolving RCD had more severe symptoms at the diagnosis of coeliac disease, including weight loss in 36% (vs. 16%, P = 0.001) and diarrhoea in 54% (vs. 38%, P = 0.050). Refractory coeliac disease is very rare in the general population. Patients of male gender, older age, severe symptoms or seronegativity at the diagnosis of coeliac disease are at risk of future refractory coeliac disease and should be followed up carefully. © 2014 John Wiley & Sons Ltd.

Ten patients with refractory status epilepticus in an intensive care department

NARCIS (Netherlands)

ter Maaten, JC; van Schijndel, RJM; Heimans, JJ; Schreuder, WO

1998-01-01

Status epilepticus (SE) is a serious disease, associated with a high morbidity and mortality, particularly if refractory to initial therapy. We describe the clinical manifestations and outcome in ten cases with refractory SE admitted to our medical intensive care unit. Three of these selected group

Two-Step Oxidation of Refractory Gold Concentrates with Different Microbial Communities.

Science.gov (United States)

Wang, Guo-Hua; Xie, Jian-Ping; Li, Shou-Peng; Guo, Yu-Jie; Pan, Ying; Wu, Haiyan; Liu, Xin-Xing

2016-11-28

Bio-oxidation is an effective technology for treatment of refractory gold concentrates. However, the unsatisfactory oxidation rate and long residence time, which cause a lower cyanide leaching rate and gold recovery, are key factors that restrict the application of traditional bio-oxidation technology. In this study, the oxidation rate of refractory gold concentrates and the adaption of microorganisms were analyzed to evaluate a newly developed two-step pretreatment process, which includes a high temperature chemical oxidation step and a subsequent bio-oxidation step. The oxidation rate and recovery rate of gold were improved significantly after the two-step process. The results showed that the highest oxidation rate of sulfide sulfur could reach to 99.01 % with an extreme thermophile microbial community when the pulp density was 5%. Accordingly, the recovery rate of gold was elevated to 92.51%. Meanwhile, the results revealed that moderate thermophiles performed better than acidophilic mesophiles and extreme thermophiles, whose oxidation rates declined drastically when the pulp density was increased to 10% and 15%. The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the two-step pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample. Meanwhile, owing to the sensitivity of the microbial community under different pulp density levels, the optimization of microbial community in bio-oxidation is necessary in industry.

Study on blast furnace cooling stave for various refractory linings based on numerical modeling

International Nuclear Information System (INIS)

Mohanty, T R; Sahoo, S K; Moharana, M K

2016-01-01

Cooling technology for refractory lining of blast furnace is very important for the metallurgical industry, because it can substantially increase output and operation life of furnaces. A three dimensional mathematical model for the temperature field of the blast furnace stave cooler with refractory lining has been developed and analyzed. The temperature and heat dissipated by stave cooler is examined by using the finite element method. The cast steel stave is studied and computational analysis is made to know the effect of the cooling water velocity, temperature, and the lining material on the maximum temperature of the stave hot surface. The refractory lining materials, which are used in this experiment, are high alumina bricks with different stave materials (copper, aluminum and cast iron). The obtained numerical calculations are compared with that obtained from experiments performed at Rourkela Steel Plant, Odisha taking a stave in belly zone having maximum heat load shows very good agreement. (paper)

NbTaV-(Ti,W) refractory high-entropy alloys: Experiments and modeling

Energy Technology Data Exchange (ETDEWEB)

Yao, H.W. [Laboratory of Applied Physics and Mechanics of Advanced Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Qiao, J.W., E-mail: qiaojunwei@gmail.com [Laboratory of Applied Physics and Mechanics of Advanced Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Gao, M.C., E-mail: michael.gao@netl.doe.gov [National Energy Technology Laboratory, 1450 Queen Ave SW, Albany, OR 97321 (United States); AECOM, P.O. Box 1959, Albany, OR 97321 (United States); Hawk, J.A. [National Energy Technology Laboratory, 1450 Queen Ave SW, Albany, OR 97321 (United States); Ma, S.G. [Institute of Applied Mechanics and Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zhou, H.F. [Laboratory of Applied Physics and Mechanics of Advanced Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zhang, Y. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

2016-09-30

This study reports the design and development of ductile and strong refractory single-phase high-entropy alloys (HEAs) for high temperature applications, based on NbTaV with addition of Ti and W. Assisted by CALPHAD modeling, a single body-centered cubic solid solution phase was experimentally confirmed in the as-cast ingots using X-ray diffraction and scanning electron microscopy. The observed elemental segregation in each alloy qualitatively agrees with CALPHAD prediction. The Vickers microhardnesses (and yield strengths) of the alloys are about 3 (and 3.5–4.4) times that those estimated from the rule of mixture. While NbTaTiVW shows an impressive yield strength of 1420 MPa with fracture strain of 20%, NbTaTiV exhibits exceptional compressive ductility at room temperature.

Evaluation of the reusing of MGO-C refractory brick in refractory mixes

International Nuclear Information System (INIS)

Silva, R.D.S. da; Braganca, S.R.

2012-01-01

The residue from the use of MgO-C refractories in electric arc furnace presents, mostly, magnesium oxide in its composition and some slag contamination and impurities from the process of electrofusion scrap iron/steel. In this study, it was studied the characteristics of this residue and reused through its introduction into a commercial refractory mix, employed as material of coating and repair. This refractory mix was tested by thermogravimetric analysis, compressive strength, evaluation of plasticity and porosity as well as aspects of its installation, such as adhesion in situ. Results showed that there potential for reuse with the introduction of the waste in commercial mix was 30%, with little loss of compressive strength and plasticity. (author)

IMPROVED CORROSION RESISTANCE OF ALUMINA REFRACTORIES

Energy Technology Data Exchange (ETDEWEB)

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 this 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.

Theoretical and practical aspects about corrosion of refractories used in steel metallurgy: part 3: characterization of commercial refractories; Aspectos teoricos e praticos sobre a corrosao de refratarios utilizados na metalurgia: caracterizacao de refratarios comerciais

Energy Technology Data Exchange (ETDEWEB)

Braganca, S.R., E-mail: saulorb@ufrgs.br [Universidade Federal do Rio Grande Sul (DEMAT/UFRGS), RS (Brazil)

2012-07-01

In this study, it was reviewed the main aspects found in the literature about refractories corrosion, evaluating the feasibility of certain tests and relating them with experimental results. The physical properties and microstructure of commercial refractories were analyzed, considering the differences between them and the quality implications and probable life of the refractory. Thus, it was studied the various types of refractories used as lining on steel ladle. Magnesia-carbon and doloma-carbon refractories were analyzed, highlighting the differences between them. The examined refractory showed characteristics favoring high resistance to corrosion process, presenting a series of properties to be selected in accordance with industry practice. (author)

High density crystalline boron prepared by hot isostatic pressing in refractory metal containers

Science.gov (United States)

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.

THE EFFECT OF NANO-TITANIA ADDITION ON THE PROPERTIES OF HIGH-ALUMINA LOW-CEMENT SELF-FLOWING REFRACTORY CASTABLES

Directory of Open Access Journals (Sweden)

Sasan Otroj

2011-12-01

Full Text Available The self-flow characteristics and properties of high-alumina low-cement refractory castables added with nano-titania particles are investigated. For this reason, the reactive alumina in the castable composition is substituted by nano-titania powder in 0-1 %wt. range. The microstructures, phase composition, physical and mechanical properties of these refractory castables at different temperatures are studied. The results show that the addition of nano-titania particles has great effect on the self-flow characteristics, phase composition, physical and mechanical properties of these refractory castables. With increase of nano-titania particles in castable composition, the self-flow value and working time tend to decrease. With addition of 0.5 wt.% nano-titania in the castable composition, the mechanical strength of castable in all firing temperatures tends to increase. It is attributed to the formation of CA6 phase and enhanced ceramic bonding. Nano-titania particles can act as a nucleating agent for hibonite phase and decrease the formation temperature of hibonite. Because of perovskite phase formation, the addition of 1 wt.% nano-titania can decrease the mechanical strength of castable after firing.

Evaluation of Alternative Refractory Materials for the Main Flame Deflectors at KSC Launch Complexes

Science.gov (United States)

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.

High-temperature Young’s moduli and dilatation behavior of silica refractories

Czech Academy of Sciences Publication Activity Database

Pabst, W.; Gregorová, E.; Kloužek, Jaroslav; Kloužková, A.; Zemenová, P.; Kohoutková, M.; Sedlářová, I.; Lang, K.; Kotouček, M.; Nevřivová, L.; Všianský, D.

2016-01-01

Roč. 36, č. 1 (2016), s. 209-220 ISSN 0955-2219 Institutional support: RVO:67985891 Keywords : silica refractories * Young’s modulus * elastic modulus * dilatation * dilatometry Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass Impact factor: 3.411, year: 2016

Resistant and Refractory Hypertension: Antihypertensive Treatment Resistance vs Treatment Failure

Science.gov (United States)

Siddiqui, Mohammed; Dudenbostel, Tanja; Calhoun, David A.

2017-01-01

Resistant or difficult to treat hypertension is defined as high blood pressure that remains uncontrolled with 3 or more different antihypertensive medications, including a diuretic. Recent definitions also include controlled blood pressure with use of 4 or more medications as also being resistant to treatment. Recently, refractory hypertension, an extreme phenotype of antihypertensive treatment failure has been defined as hypertension uncontrolled with use of 5 or more antihypertensive agents, including a long-acting thiazide diuretic and a mineralocorticoid receptor antagonist. Patients with resistant vs refractory hypertension share similar characteristics and comorbidities, including obesity, African American race, female sex, diabetes, coronary heart disease, chronic kidney disease, and obstructive sleep apnea. Patients with refractory vs resistant hypertension tend to be younger and are more likely to have been diagnosed with congestive heart failure. Refractory hypertension might also differ from resistant hypertension in terms of underlying cause. Preliminary evidence suggests that refractory hypertension is more likely to be neurogenic in etiology (ie, heightened sympathetic tone), vs a volume-dependent hypertension that is more characteristic of resistant hypertension in general. PMID:26514749

Compatibility of refractory materials with boiling sodium

International Nuclear Information System (INIS)

Meacham, S.A.

1976-01-01

The program employed to determine the compatibility of commercially available refractories with boiling sodium is described. The effects of impurities contained within the refractory material, and their relations with the refractory's physical stability are discussed. Also, since consideration of refractories for use as an insulating material within Liquid Metal Fast Breeder Reactor Plants (LMFBR's) is currently under investigation; recommendations, based upon this program, are presented

REFRACTORY THROMBOCYTOPENIA AND NEUTROPENIA: A DIAGNOSTIC CHALLENGE

OpenAIRE

Emmanuel Gyan; François Dreyfus; Pierre Fenaux

2015-01-01

Background. The 2008 WHO classification identified refractory cytopenia with unilineage dysplasia (RCUD) as a composite entity encompassing refractory anemia, refractory thrombocytopenia (RT), and refractory neutropenia (RN), characterized by 10% or more dysplastic cells in the bone marrow respective lineage. The diagnosis of RT and RN is complicated by several factors.  Diagnosing RT first requires exclusion of familial thrombocytopenia, chronic auto-immune thrombocytopenia, concomitant medi...

Refractory bin for burning

Energy Technology Data Exchange (ETDEWEB)

McPherson, D.L.; McPherson, T.L.

1989-12-26

This patent describes a refractory bin. It has a generally rectangular horizontal cross sectional configuration. It has wall structures each comprising an upper and a lower pair of elongated horizontal vertically spaced generally parallel support beams each having a vertical flange defining a support edge along its upper surface, a first generally rectangular refractory panel arranged with its lower edge at the bottom of the bin and with its outer surface in flat face contacting relation with the vertical flanges of the lower pair of support beams, a plurality of brackets each having a horizontal part and a vertical part and being secured to the outer surface of the first refractory panel.

Decision Making during the Psychological Refractory Period

NARCIS (Netherlands)

Zylberberg, Ariel; Ouellette, Brian; Sigman, Mariano; Roelfsema, Pieter R.

2012-01-01

In spite of its massively parallel architecture [1], the human brain is fundamentally limited if required to perform two tasks at the same time [2, 3]. This limitation can be studied with the psychological refractory period (PRP) paradigm, where two stimuli that require speeded responses occur in

Talimogene Laherparepvec and Nivolumab in Treating Patients With Refractory Lymphomas or Advanced or Refractory Non-melanoma Skin Cancers

Science.gov (United States)

2018-05-21

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

Ketogenic diet treatment for pediatric super-refractory status epilepticus.

Science.gov (United States)

Appavu, Brian; Vanatta, Lisa; Condie, John; Kerrigan, John F; Jarrar, Randa

2016-10-01

We aimed to study whether ketogenic diet (KD) therapy leads to resolution of super-refractory status epilepticus in pediatric patients without significant harm. A retrospective review was performed at Phoenix Children's Hospital on patients with super-refractory status epilepticus undergoing ketogenic diet therapy from 2011 to 2015. Ten children with super-refractory status epilepticus, ages 2-16 years, were identified. 4/10 patients had immune mediated encephalitis, including Rasmussen encephalitis, anti-N-methyl-d-aspartate receptor encephalitis, and post-infectious mycoplasma encephalitis. Other etiologies included Lennox Gastaut Syndrome, non-ketotic hyperglycinemia, PCDH19 and GABRG2 genetic epilepsy, New Onset Refractory Status Epilepticus, and Febrile Infection-Related Epilepsy Syndrome. 4/10 patients' EEG features suggested focal with status epilepticus, and 6/10 suggested generalized with status epilepticus. Median hospital length was 61days and median ICU length was 27days. The median number of antiepileptic medications prior to diet initiation was 3.0 drugs, and the median after ketogenic diet treatment was 3.5 drugs. Median duration of status epilepticus prior to KD was 18days. 9/10 patients had resolution of super-refractory status epilepticus in a median of 7days after diet initiation. 8/9 patients were weaned off anesthesia within 15days of diet initiation, and within 1day of achieving ketonuria. 1/10 patients experienced side effects on the diet requiring supplementation. Most patients achieved resolution of status epilepticus on KD therapy, suggesting it could be an effective therapy that can be utilized early in the treatment of children with super refractory status epilepticus. Copyright © 2016. Published by Elsevier Ltd.

Updates in Refractory Status Epilepticus

Science.gov (United States)

Mahulikar, Advait; Suchdev, Kushak; Shah, Aashit

2018-01-01

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status. PMID:29854452

[Esophageal motility characteristics of refractory heartburn: a study based on high resolution manometry and 24 hour pH-impedance monitoring].

Science.gov (United States)

Wang, Kun; Duan, Liping; Xia, Zhiwei; Xu, Zhijie; Ge, Ying

2014-09-16

To analyze the esophageal motility characteristics of refractory heartburn with different reflux patterns and preliminarily clarify the roles of esophageal disorder in refractory heartburn. A total of 176 refractory heartburn patients were enrolled from 2009 to 2013. After gastroscopy and 24 hour pH-impedance monitoring, they were divided into 4 groups of reflux esophagitis (RE, n = 29), non-erosive reflux disease with acid reflux (NERD-acid, n = 51), NERD with weakly acidic reflux (NERD-weakly acid, n = 51) and non-reflux associated heartburn (n = 45). All subjects undertake high resolution manometry test and their esophageal motility functions were analyzed by the Chicago classification criteria 2012. Among them, 60.23% (106/176) patients presented esophageal motility disorders. And 42.61% (75/176) fulfilled the criteria of weak peristalsis, 7.39% (13/176) distal esophageal spasm, 4.55% (8/176) rapid contraction, 3.98% (7/176) EGJ outflow obstruction, 1.14% (2/176) hiatus hernia and 1 Jackhammer esophagus. The detection rates of esophageal motility disorder were similar among 4 groups and weak peristalsis was the most common disorder in all groups (41.38% in RE, 37.25% in NERD-acid patients, 54.90% in NERD-weakly acid and 35.56% in non-reflux associated heartburn patients). However, hypertensive motility disorders in non-reflux associated heartburn group (31.11%, 14/45) were more than GERD subgroups (11.45%, 15/131) (P heartburn patients. And the relax ratio of NERD-weakly acid was significantly higher than that in non-reflux associated heartburn patients (65% (50%-80%) vs 58% (42%-67%) , P heartburn patients without significant differences (P > 0.05). Esophageal weak peristalsis is one of the most common motility disorders in refractory heartburn patients, and esophageal hypertensive motility disorders are common in non-reflux associated heartburn patients. Esophageal manometry is necessary for the diagnosis and treatment of refractory heartburn.

Pembrolizumab in Treating Younger Patients With Recurrent, Progressive, or Refractory High-Grade Gliomas, Diffuse Intrinsic Pontine Gliomas, Hypermutated Brain Tumors, Ependymoma or Medulloblastoma

Science.gov (United States)

2018-06-18

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

Refractory status epilepticus

Directory of Open Access Journals (Sweden)

Sanjay P Singh

2014-01-01

Full Text Available Refractory status epilepticus is a potentially life-threatening medical emergency. It requires early diagnosis and treatment. There is a lack of consensus upon its semantic definition of whether it is status epilepticus that continues despite treatment with benzodiazepine and one antiepileptic medication (AED, i.e., Lorazepam + phenytoin. Others regard refractory status epilepticus as failure of benzodiazepine and 2 antiepileptic medications, i.e., Lorazepam + phenytoin + phenobarb. Up to 30% patients in SE fail to respond to two antiepileptic drugs (AEDs and 15% continue to have seizure activity despite use of three drugs. Mechanisms that have made the treatment even more challenging are GABA-R that is internalized during status epilepticus and upregulation of multidrug transporter proteins. All patients of refractory status epilepticus require continuous EEG monitoring. There are three main agents used in the treatment of RSE. These include pentobarbital or thiopental, midazolam and propofol. RSE was shown to result in mortality in 35% cases, 39.13% of patients were left with severe neurological deficits, while another 13% had mild neurological deficits.

Refractory status epilepticus

Science.gov (United States)

Singh, Sanjay P; Agarwal, Shubhi; Faulkner, M

2014-01-01

Refractory status epilepticus is a potentially life-threatening medical emergency. It requires early diagnosis and treatment. There is a lack of consensus upon its semantic definition of whether it is status epilepticus that continues despite treatment with benzodiazepine and one antiepileptic medication (AED), i.e., Lorazepam + phenytoin. Others regard refractory status epilepticus as failure of benzodiazepine and 2 antiepileptic medications, i.e., Lorazepam + phenytoin + phenobarb. Up to 30% patients in SE fail to respond to two antiepileptic drugs (AEDs) and 15% continue to have seizure activity despite use of three drugs. Mechanisms that have made the treatment even more challenging are GABA-R that is internalized during status epilepticus and upregulation of multidrug transporter proteins. All patients of refractory status epilepticus require continuous EEG monitoring. There are three main agents used in the treatment of RSE. These include pentobarbital or thiopental, midazolam and propofol. RSE was shown to result in mortality in 35% cases, 39.13% of patients were left with severe neurological deficits, while another 13% had mild neurological deficits. PMID:24791086

Low-temperature plasma spheroidizing of polydisperse powders of refractory materials

International Nuclear Information System (INIS)

Tsymbalist, M.M.; Rudenskaya, N.A.; Kuz'min, B.P.; Pan'kov, V.A.

2003-01-01

A model is developed for heating and melting of a spherical particle, when powder processing in low temperature plasma, with the aim of estimation of the dependence of the degree of fusion on particle size for various materials. Spheroidizing of various refractory material powders close in shape and size composition is experimentally performed. Experimental and calculation estimates of spheroidizing criteria for the materials studied are in a satisfactory agreement. The influence of basic physical properties of refractory materials and plasma processing parameters on the degree of particle spheroidizing is analyzed [ru

Development of refractory concrete for extreme conditions

International Nuclear Information System (INIS)

Pundiene, I; Antonovich, V; Stonys, R; Demidova-Buiziniene, I

2011-01-01

Comparative analysis is provided for the properties of medium-cement refractory concrete with microsilica based on mullite filler in relation to different type of deflocculant. The effect of different deflocculants on refractory concrete structure formation, hydration, rheology, strength and heat resistance is discussed. Corrosion resistance test, determined that samples with hybrid deflocculant showed better resistance for slag penetration than samples with only the sodium tripolyphosphate or polycarboxylate ether deflocculant. Moreover, a composition of hybrid deflocculant let to control the rate of the hydration process and to get features of refractory refractory concrete.

Lightweight cordierite–mullite refractories with low coefficients of ...

Indian Academy of Sciences (India)

of thermal conductivity and high mechanical properties ... compositions and microstructures of lightweight refractories were measured by X-ray .... of matrices were determined by calibration with EDAX ZAF .... Guzman I Ya 2003 Glass Ceram.

Retrospective analysis of the efficacy of omalizumab in chronic refractory urticaria

Science.gov (United States)

Viswanathan, Ravi K.; Moss, Mark H.

2013-01-01

Omalizumab has been shown to be effective in chronic urticaria (CU) patients in numerous reports. However, it remains unknown whether there are specific phenotypes of CU that are more responsive to omalizumab therapy. We sought to identify CU phenotypes responsive to treatment with omalizumab by characterizing patients and their response patterns. A retrospective chart review analysis of refractory CU patients unresponsive to high-dose H1-blockers and immunomodulators and subsequently treated with omalizumab at the University of Wisconsin Allergy Clinic was performed with particular focus on their autoimmune characteristics, response to therapy, and dosing parameters. We analyzed 19 refractory CU patients (16 patients failed or had toxic side effects to immunomodulators) treated with omalizumab with an overall response rate of 89% (17/19). Of these 19 patients, 9 patients (47%) had a complete response, 8 patients (42%) had a partial response, and 2 patients (11%) had no response. In comparing the response patterns to omalizumab, we found no statistically significant differences among “autoimmune positive” versus “autoimmune negative” patients. No statistically significant differences in responses were observed when comparing demographic parameters including age, gender, IgE levels, or dosing regimen. Our study shows that omalizumab has robust efficacy in refractory CU patients regardless of their autoimmune status, age, gender, IgE levels, or dosing protocol. PMID:23998242

Genetics Home Reference: iron-refractory iron deficiency anemia

Science.gov (United States)

... refractory iron deficiency anemia Iron-refractory iron deficiency anemia Printable PDF Open All Close All Enable Javascript ... expand/collapse boxes. Description Iron-refractory iron deficiency anemia is one of many types of anemia , which ...

Super-Refractory Status Epilepticus: Report of a Case and Review of the Literature.

Science.gov (United States)

Lapenta, Leonardo; Frisullo, Giovanni; Vollono, Catello; Brunetti, Valerio; Giannantoni, Nadia Mariagrazia; Sandroni, Claudio; Di Lella, Giuseppe; Della Marca, Giacomo

2015-10-01

Super-refractory status epilepticus (SE; ie, SE continuing or recurring despite 24 hours of general anesthesia) is a severe condition with high percentage of mortality and morbidity. Usually, this condition occurs because of serious brain damage; nevertheless, some patients develop super-refractory SE without identifiable etiology. Although not uncommonly encountered in neurointensive care, scientific data on this condition are still lacking in terms of treatment and prognosis. Herein, we report a case of super-refractory SE with recovery after 50 days, despite electroencephalographic (EEG) and magnetic resonance imaging (MRI) signs traditionally related to poor prognosis. A review of the literature on super-refractory SE is also presented. © EEG and Clinical Neuroscience Society (ECNS) 2014.

Normal and refractory concretes for LMFBR applications. Volume 1. Review of literature on high-temperature behavior of portland cement and refractory concretes. Final report

International Nuclear Information System (INIS)

Bazant, Z.P.; Chern, J.C.; Abrams, M.S.; Gillen, M.P.

1982-06-01

The extensive literature on the properties and behavior at elevated temperature of portland cement concrete and various refractory concretes was reviewed to collect in concise form the physical and chemical properties of castable refractory concretes and of conventional portland cement concretes at elevated temperature. This survey, together with an extensive bibliography of source documents, is presented in Volume 1. A comparison was made of these properties, the relative advantages of the various concretes was evaluated for possible liquid metal fast breeder reactor applications, and a selection was made of several materials of interest for such applications. Volume 2 concludes with a summary of additional knowledge needed to support such uses of these materials together with recommendations on research to provide that knowledge

Refractory hypertension: definition, prevalence, and patient characteristics.

Science.gov (United States)

Acelajado, Maria Czarina; Pisoni, Roberto; Dudenbostel, Tanja; Dell'Italia, Louis J; Cartmill, Falynn; Zhang, Bin; Cofield, Stacey S; Oparil, Suzanne; Calhoun, David A

2012-01-01

Among patients with resistant hypertension (RHTN), there are those whose blood pressure (BP) remains uncontrolled in spite of maximal medical therapy. This retrospective analysis aims to characterize these patients with refractory hypertension. Refractory hypertension was defined as BP that remained uncontrolled after ≥3 visits to a hypertension clinic within a minimum 6-month follow-up period. Of the 304 patients referred for RHTN, 29 (9.5%) remained refractory to treatment. Patients with refractory hypertension and those with controlled RHTN had similar aldosterone levels and plasma renin activity (PRA). Patients with refractory hypertension had higher baseline BP (175±23/97±15 mm Hg vs 158±25/89±15 mm Hg; P=.001/.005) and heart rate, and higher rates of prior stroke and congestive heart failure. During follow-up, the BP of patients with refractory hypertension remained uncontrolled (168.4±14.8/93.8±17.7 mm Hg) in spite of use of an average of 6 antihypertensive medications, while those of patients with controlled RHTN decreased to 129.3±11.2/77.6±10.8 mm Hg. Spironolactone reduced the BP by 12.9±17.8/6.6±13.7 mm Hg in patients with refractory hypertension and by 24.1±16.7/9.2±12.0 mm Hg in patients with controlled RHTN. In patients with RHTN, approximately 10% remain refractory to treatment. Similar aldosterone and PRA levels and a diminished response to spironolactone suggest that aldosterone excess does not explain the treatment failure. © 2011 Wiley Periodicals, Inc.

Evaluation of refractory materials for a nuclear waste incinerator

International Nuclear Information System (INIS)

Grotzky, V.K.; Kneale, P.A.; Teter, A.R.

1980-01-01

An experiment to find a suitable refractory lining for a nuclear waste incinerator has been completed. Eleven brick and six castable products were analyzed by optical and scanning microscopy. All the materials were fashioned into cup shapes and subjected to temperatures ranging from 800 to 1200 0 C for as long as six weeks. Some of the cups were charged weekly with pellets made from ash materials that would contact an incinerator liner. Refractory products containing a high percentage of aluminum oxide had the greatest resistance to cracking and slag buildup. 35 figures

Mullite-based coating on silicon carbide refractory obtained from PMSQ [poly(methylsilsesquioxane)

International Nuclear Information System (INIS)

Machado, Glauson Aparecido Ferreira

2017-01-01

Silicon carbide (SiC) presents low thermal expansion, high strength and thermal conductivity. For this reason it is used as kiln furniture for materials sintering. On the other hand, SiC degrades at high temperature under aggressive atmosphere. The use of protective coatings can avoid the right exposition of SiC surface to the furnace atmosphere. Mullite can be a suitable material as protective coating because of its high corrosion resistance and thermal expansion coefficient matching that of SiC (4,7 x 10 -6 /°C e 5,3 x 10 -6 /°C, respectively). In the present work a mullite coating obtained from ceramic precursor polymer and aluminium powder was studied to be applied over SiC refractories. Compositions were prepared with 10, 20, 30 and 50% (vol.) of aluminium powder added to the polymer. They were used aluminium powders with different distributions sizes These compositions were heat treated at different thermal cycles to determine a suitable condition to obtain a high mullite content. The composition with 20% of the smaller particle size Al powder was selected and used to be applied as a suspension over SiC refractory. The applied suspension, after dried, crosslinked and heat treated, formed a mullite coating over SiC refractory. Cycles of thermal shock were performed in coated and uncoated SiC samples to compare each other. They were carried out 26 cycles of thermal shock, in the following conditions: 600°C/30 min. and air cooling to room temperature. After each thermal shock, samples were analysed by mean of optical and electron microscopy, elastic modulus was also determined. After thermal shock cycles the coating presented good adhesion and no significant damage were observed. (author)

Improved high temperature refractory. [MgCr/sub 2/O/sub 4/ composite with ZrO/sub 2/

Science.gov (United States)

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.

Barrier Coatings for Refractory Metals and Superalloys

Energy Technology Data Exchange (ETDEWEB)

SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

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. 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.

Barrier Coatings for Refractory Metals and Superalloys

International Nuclear Information System (INIS)

SM Sabol; BT Randall; JD Edington; CJ Larkin; BJ Close

2006-01-01

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. 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

Oral tranexamic acid lightens refractory melasma.

Science.gov (United States)

Tan, Aaron Wei Min; Sen, Priya; Chua, Sze Hon; Goh, Boon Kee

2017-08-01

Melasma is a common acquired hyperpigmentary disorder, particularly among Asians and Hispanics, but its exact pathomechanism is poorly understood. Tranexamic acid has been found to lighten melasma by interfering with the interaction of melanocytes and keratinocytes by inhibiting the plasminogen/plasmin system. The aim was to evaluate the therapeutic effects of oral tranexamic acid in the treatment of melasma refractory to topical skin-lightening agents. This retrospective study analyses patients with melasma recruited from a tertiary dermatological centre in Singapore between 1 August 2009 and 31 March 2011. The patients chosen had refractory melasma treated with oral tranexamic acid 250 mg twice daily in addition to pre-existing combination topical therapy. Objective assessment using the physician's global assessment and melasma area and severity index (MASI) scores were performed based on a post-hoc analysis of photographic records by three independent physicians. A paired t-test was used to evaluate the changes in the MASI scores pre-therapy and post-treatment. Statistical significance was defined as P tranexamic acid for a mean period of 3.7 ± 0.33 months, in addition to combination topical therapy. Their mean age was 47.2 ± 1.61 years. The mean MASI scores after tranexamic acid treatment (2.7 ± 1.6) were significantly lower (P tranexamic acid can serve as a safe and useful adjunct in the treatment of refractory melasma. © 2016 The Australasian College of Dermatologists.

Modern approaches for management of the refractory immune thrombocytopenia in pregnancy

Directory of Open Access Journals (Sweden)

Davydova Iu.

2017-01-01

Full Text Available Background. Thrombocytopenia per se is one of the hematological diseases, which demands the repeated thrombocytes infusion. The last tendencies in the management of this disease show the enhanced amount of the necessary thrombocytes doses for treatment and the worldwide trend for the declining of donors. Considerably to these facts the new approaches for the thrombocytopenia treatment have been organized within last two decades. One of them is the finding of the safe, appropriate and effective growth factor for platelets, which could significantly improve the level of thrombocytes. The article describes the case of refractory ITP management in pregnancy. ITP diagnosed at 26 weeks of gestation, the platelet number at the time of diagnostics 20000. The other bone marrow disorders excluded by bone marrow biopsy. The in-patient of the High Risk Pregnancy Department (Obstetric Issues of the Extragenital Pathology from the 28 weeks of pregnancy. Modern approaches for treatment of ITP was describe in the article. Pregnant received therapy according to the latest guidelines. Delivery in term of 33–34 weeks. Integrated treatment of thrombocytopenia. Conclusions. The refractory ITP is a rare disease and could be occasionally seen during pregnancy, but the hemorrhagic complications could be extremely harmful for both mother and child and demand the preterm pregnancy termination. The management of refractory ITP during pregnancy should be performed according to the International recommendations for the thrombocytopenia treatment with all the reserve of the medications. The positive result of the ITP management and perinatal and obstetric outcomes has been achieved through the use of the entire arsenal of drugs, correct tactics of delivery with hemorrhage prevention be using the 4 T strategy and the adequate doses of the tranexamic acid (sangera and rhTPO (Emaplug (Yuriya-Farm, Ukraine. It was the first implementation of the subcutaneous rhTPO in

Refractory metal based superalloys

International Nuclear Information System (INIS)

Alonso, Paula R.; Vicente, Eduardo E.; Rubiolo, Gerardo H.

1999-01-01

Refractory metals are looked as promising materials for primary circuits in fission reactors and even as fusion reactor components. Indeed, superalloys could be developed which take advantage of their high temperature properties together with the benefits of a two- phase (intermetallic compound-refractory metal matrix) coherent structure. In 1993, researchers of the Office National d'Etudes et de Recherches Aerospatiales of France reported the observation of such a coherent structure in the Ta-Ti-Zr-Al-Nb-Mo system although the exact composition is not reported. The intermetallic compound would be Ti 2 AlMo based. However, the formation of this compound and its possible coexistence with a disordered bcc phase in the ternary system Ti-Al-Mo is a controversial subject in the related literature. In this work we develop a technique to obtain homogeneous alloys samples with 50 Ti-25 Al-25 Mo composition. The resulting specimens were characterized by optical and electronic metallography (SEM), microprobe composition measurements (EPMA) and X-ray diffraction (XRD) analyses. The results show the evidence for a bcc (A2→B2) ordering reaction in the Ti-Al-Mo system in the 50 Ti-25 Al-25 Mo composition. (author)

Phase II study of concomitant chemoradiotherapy in bulky refractory or chemoresistant relapsed lymphomas

International Nuclear Information System (INIS)

Girinsky, Theodore; Lapusan, Simona; Ribrag, Vincent; Koscielny, Serge; Ferme, Christophe; Carde, Patrice

2005-01-01

Purpose: To evaluate the local efficacy of concomitant chemoradiotherapy in patients with mostly refractory lymphoma. Methods and materials: Patients with refractory or chemoresistant-relapsed lymphoma and bulky life-threatening masses were included in this study. A split course of concomitant radiotherapy and chemotherapy (mostly cisplatin and etoposide) was delivered during a 6-week period. Weekly blood tests and a clinical examination using the Radiation Therapy Oncology Group guidelines were performed to assess acute toxicity. The tumor response was evaluated 1-3 months after treatment and at regular follow-up visits. Results: We enrolled 21 patients in the study between January 1998 and April 2003. Of the 21 patients, 60% had disseminated disease with bulky tumor masses and 85% had refractory lymphoma, of which most had been treated with at least two different chemotherapy regimens before concomitant chemoradiotherapy. Seventy-five percent received regimens containing cisplatinum and etoposide. The median radiation dose was 40 Gy (range, 12-62.5 Gy). Grade 3-4 hematologic toxicity and mucositis was observed in 70% and 30% of cases respectively, without any deaths. The overall response and complete remission rate was 70% and 20%, respectively. The 1-year overall survival and local progression-free survival rate was 20.4% and 54%, respectively. Three patients with localized disease were still alive 16, 33, and 48 months after treatment. Conclusion: Concomitant chemoradiotherapy for refractory or chemoresistant-relapsed lymphoma induced high hematologic toxicity, but seemed adequate for controlling local bulky tumor masses. No toxicity-related death was observed

Low- vs high- frequency Repetitive Transcranial Magnetic Stimulation as an add-on treatment for refractory depression

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julien eeche

2012-03-01

Full Text Available Objectives: Repetitive transcranial magnetic stimulation (rTMS seems to be effective as an antidepressant treatment, however, some confusion remain about the best parameters to apply and the efficacy of its association with pharmacological antidepressant treatments.Method: In a single blind randomized study14 patients with unipolar resistant depression to one antidepressant treatment were enrolled to received, in combination with venlafaxine (150 mg, either 20 sessions of 10Hz rTMS (2 000 pulses per session applied over le left dorsolateral prefrontal cortex (DLPFC or 20 sessions of 1 Hz rTMS (120 stimulations per sessions applied over the right DLPFC. Results: A similar antidepressant effect was observed in both groups with a comparable antidepressant delay of action (2 weeks and a comparable number of patients in remission after 4 weeks of daily rTMS sessions (66 vs 50 %.Conclusion: Low- and high- frequency rTMS seem to be effective as an add-on treatment to venlafaxine in pharmacological refractory major depression. Due to its short duration and its safety, low frequency rTMS may be a useful alternative treatment for patients with refractory depression.

Refractory Septic Shock Treated with Nephrectomy under the Support of Extracorporeal Membrane Oxygenation

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Young Kun Lee

2015-08-01

Full Text Available Conventional medical therapies have not been very successful in treating adults with refractory septic shock. The effects of direct hemoperfusion using polymyxin B and veno-arterial extracorporeal membrane oxygenation (ECMO for refractory septic shock remain uncertain. A 66-year-old man was admitted to the emergency department and suffered from sepsis-induced hemodynamic collapse. For hemodynamic improvement, we performed direct hemoperfusion using polymyxin B. Computed tomography scan of this patient revealed emphysematous pyelonephritis (EPN, for which he underwent emergent nephrectomy with veno-arterial ECMO support. To the best of our knowledge, this is the first report of successful treatment of EPN with refractory septic shock using polymyxin B hemoperfusion and nephrectomy under the support of ECMO.

Tungsten and refractory metals 3, proceedings

International Nuclear Information System (INIS)

Bose, A.; Dowding, R.J.

1996-01-01

The Third International Conference on Tungsten and Refractory Metals was held in Greater Washington DC at the McLean Hilton, McLean Virginia, on November 15--16, 1995. This meeting was the third in a series of conferences held in the Washington DC area. The first meeting was in 1992 and was entitled ''International Conference on Tungsten and Tungsten Alloys.'' In 1994, the scope of the meeting was expanded to include other refractory metals such as molybdenum, iridium, rhenium, tantalum and niobium. The tremendous success of that meeting was the primary motivation for this Conference. The broader scope (the inclusion of other refractory metals and alloys) of the Conference was kept intact for this meeting. In fact, it was felt that the developments in the technology of these materials required a common forum for the interchange of current research information. The papers presented in this meeting examined the rapid advancements in the technology of refractory metals, with special emphasis on the processing, structure, and properties. Among the properties there was emphasis on both quasi-static and dynamic rates. Another topic that received considerable interest was the area of refractory carbides and tungsten-copper composites. One day of concurrent session was necessary to accommodate all of the presentations

Effectiveness of intravenous levetiracetam as an adjunctive treatment in pediatric refractory status epilepticus.

Science.gov (United States)

Kim, Jon Soo; Lee, Jeong Ho; Ryu, Hye Won; Lim, Byung Chan; Hwang, Hee; Chae, Jong-Hee; Choi, Jieun; Kim, Ki Joong; Hwang, Yong Seung; Kim, Hunmin

2014-08-01

Intravenous levetiracetam (LEV) has been shown to be effective and safe in treating adults with refractory status epilepticus (SE). We sought to investigate the efficacy and safety of intravenous LEV for pediatric patients with refractory SE. We performed a retrospective medical-record review of pediatric patients who were treated with intravenous LEV for refractory SE. Clinical information regarding age, sex, seizure type, and underlying neurological status was collected. We evaluated other anticonvulsants that were used prior to administration of intravenous LEV and assessed loading dose, response to treatment, and any adverse events from intravenous LEV administration. Fourteen patients (8 boys and 6 girls) received intravenous LEV for the treatment of refractory SE. The mean age of the patients was 4.4 ± 5.5 years (range, 4 days to 14.6 years). Ten of the patients were neurologically healthy prior to the refractory SE, and the other 4 had been previously diagnosed with epilepsy. The mean loading dose of intravenous LEV was 26 ± 4.6 mg/kg (range, 20-30 mg/kg). Seizure termination occurred in 6 (43%) of the 14 patients. In particular, 4 (57%) of the 7 patients younger than 2 years showed seizure termination. No immediate adverse events occurred during or after infusions. The current study demonstrated that the adjunctive use of intravenous LEV was effective and well tolerated in pediatric patients with refractory SE, even in patients younger than 2 years. Intravenous LEV should be considered as an effective and safe treatment option for refractory SE in pediatric patients.

Method for hot pressing irregularly shaped refractory articles

Science.gov (United States)

Steinkamp, William E.; Ballard, Ambrose H.

1982-01-01

The present invention is directed to a method for hot pressing irregularly haped refractory articles with these articles of varying thickness being provided with high uniform density and dimensional accuracy. Two partially pressed compacts of the refractory material are placed in a die cavity between displaceable die punches having compact-contacting surfaces of the desired article configuration. A floating, rotatable block is disposed between the compacts. The displacement of the die punches towards one another causes the block to rotate about an axis normal to the direction of movement of the die punches to uniformly distribute the pressure loading upon the compacts for maintaining substantially equal volume displacement of the powder material during the hot pressing operation.

Refractories for steel-works

International Nuclear Information System (INIS)

Villanova, R.A.; Galant, C.L.; Haas, C.; Rosenbaum, V.

The routine procedures utilized for quality control of refractory materials used by PIRATINI's steel-works, are presented ' under an objetive and practical maner. The attention of the paper is concentrated upon the following' refractory types with higher consume: silicon-aluminous; aluminous; basic magnesia; basic chrom-magnesia. All steps of utilization are described, including specification, supplies programation, storage; sampling; physical tests, and also aplication procedures. Results from routine analysis during a six month period, by ' means of X-Ray Quantometry, using the fusion pearls procedure, are presented compared with Atomic Absorption [pt

Refractory migraine in a headache clinic population

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Fernandez-Torron Roberto

2011-08-01

Full Text Available Abstract Background Many migraineurs who seek care in headache clinics are refractory to treatment, despite advances in headache therapies. Epidemiology is poorly characterized, because diagnostic criteria for refractory migraine were not available until recently. We aimed to determine the frequency of refractory migraine in patients attended in the Headache Unit in a tertiary care center, according to recently proposed criteria. Methods The study population consisted of a consecutive sample of 370 patients (60.8% females with a mean age of 43 years (range 14-86 evaluated for the first time in our headache unit over a one-year period (between October 2008 and October 2009. We recorded information on clinical features, previous treatments, Migraine Disability Assessment Score (MIDAS, and final diagnosis. Results Overall migraine and tension-type headache were found in 46.4% and 20.5% of patients, respectively. Refractory migraine was found in 5.1% of patients. In refractory migraineurs, the mean MIDAS score was 96, and 36.8% were medication-overusers. Conclusions Refractory migraine is a relatively common and very disabling condition between the patients attended in a headache unit. The proposed operational criteria may be useful in identifying those patients who require care in headache units, the selection of candidates for combinations of prophylactic drugs or invasive treatments such as neurostimulation, but also to facilitate clinical studies in this patient group.

SINTERED REFRACTORY TUNGSTEN ALLOYS. Gesinterte hochschmelzende wolframlegierungen

Energy Technology Data Exchange (ETDEWEB)

Kieffer, R.; Sedlatschek, K.; Braun, H.

1971-12-15

Dependence of the melting point of the refractory metals on their positions in the periodic system - alloys of tungsten with other refractory metals - sintering of the alloys - processing of the alloys - technological properties.

Refractory hepatic encephalopathy in a patient with hypothyroidism: Another element in ammonia metabolism.

Science.gov (United States)

Díaz-Fontenla, Fernando; Castillo-Pradillo, Marta; Díaz-Gómez, Arantxa; Ibañez-Samaniego, Luis; Gancedo, Pilar; Guzmán-de-Villoria, Juan Adan; Fernández-García, Pilar; Bañares-Cañizares, Rafael; García-Martínez, Rita

2017-07-28

Hepatic encephalopathy (HE) remains a diagnosis of exclusion due to the lack of specific signs and symptoms. Refractory HE is an uncommon but serious condition that requires the search of hidden precipitating events ( i.e ., portosystemic shunt) and alternative diagnosis. Hypothyroidism shares clinical manifestations with HE and is usually considered within the differential diagnosis of HE. Here, we describe a patient with refractory HE who presented a large portosystemic shunt and post-ablative hypothyroidism. Her cognitive impairment, hyperammonaemia, electroencephalograph alterations, impaired neuropsychological performance, and magnetic resonance imaging and spectroscopy disturbances were highly suggestive of HE, paralleled the course of hypothyroidism and normalized after thyroid hormone replacement. There was no need for intervention over the portosystemic shunt. The case findings support that hypothyroidism may precipitate HE in cirrhotic patients by inducing hyperammonaemia and/or enhancing ammonia brain toxicity. This case led us to consider hypothyroidism not only in the differential diagnosis but also as a precipitating factor of HE.

Stochastic histories of refractory interstellar dust

International Nuclear Information System (INIS)

Liffman, K.; Chayton, D.D.

1988-01-01

The authors calculate histories for refractory dust particles in the interstellar medium. The double purposes are to learn something of the properties of interstellar dust as a system and to evaluate with specific assumptions the cosmic chemical memory interpretation of a specific class of isotopic anomalies. They assemble the profile of a particle population from a large number of stochastic, or Monte Carlo, histories of single particles, which are necessarily taken to be independent with this approach. They specify probabilities for each of the events that may befall a given particle and unfold its history by a sequence of random numbers. They assume that refractory particles are created only by thermal condensation within stellar material during its ejection from stars, and that these refractory particles can be destroyed only by being sputtered to a size too small for stability or by being incorporated into the formation of new stars. In order to record chemical detail, the authors take each new refractory particle to consist of a superrefractory core plus a more massive refractory mantle. They demonstrate that these superrefractory cores have effective lifetimes much longer than the turnover time of dust mass against sputtering. As examples of cosmic chemical memory they evaluate the 16 O-richness of interstellar aluminum and mechanisms for the 48 Ca/ 50 Ti correlation. Several related consequences of this approach are discussed

An evaluation of electric melter refractories for contact with glass used for the immobilisation of nuclear waste

International Nuclear Information System (INIS)

Hayward, P.J.; George, I.M.

1987-01-01

Corrosion tests have been performed on twelve candidate refractories in contact with borosilicate, titanosilicate, and aluminosilicate melts, in order to rank them for use in an all-electric melter for the production of waste form materials suitable for immobilising nuclear fuel recycle wastes. Viscosities and electrical conductivities of the melts have also been measured to enable optimum processing conditions to be determined. Of the materials tested, the choice of glass contact refractory for the Joule heated melting of the borosilicate and titanosilicate compositions is Monofrax K3 or SEPR 2161, in conjunction with tin oxide electrodes. The aluminosilicate glass waste form would require an alternative method of production (sol-gel processing, or sintering of a precursor frit), because of its high viscosity. (author)

An unusual case of refractory wheeze

Science.gov (United States)

Ramesh, Venkat; Acharya, Vishak; Pai, Narasimha; Krishnan, Ananda

2015-01-01

A 37-year-old man presented with a history of episodic wheeze and breathlessness of 3 years’ duration refractory to treatment. Physical examination revealed diffuse expiratory polyphonic rhonchi while the remainder of the examination including the cardiac examination was reported as normal. Pulmonary function testing revealed mild obstruction with bronchodilator reversibility. The patient was discharged on a 6-month course of antitubercular treatment (ATT) as bronchial brush cytology (obtained via bronchoscopy) was positive for acid-fast bacilli. The patient presented after completing 6 months of ATT with persistent symptoms, a loud S1 and a mid-diastolic murmur at the apex. High-resolution CT of the chest showed bilateral dependent ground glass opacities. An echocardiogram revealed a left atrial myxoma, and normal RV size and pressures. The patient underwent successful surgical removal of the same, and made a complete recovery. Refractory wheeze is a very unusual presentation of a left atrial myxoma. PMID:25733086

USE OF STRUCTURAL MRI IN PATIENTS WITH MEDICALLY REFRACTORY SEIZURES

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Ara G. Kaprelyan

2012-12-01

Full Text Available Introduction: Refractory epilepsy is common in patients with structural brain lesions including acquired disorders and genetic abnormalities. Recently, MRI is a precise diagnostic tool for recognition of different structural causes underlying medically intractable seizures.Objective: To evaluate the usefulness of MRI for detection of brain lesions associated with refractory epilepsy.Material and methods: 49 patients (20M and 29F; aged 48.6±24.7 years with refractory epilepsy were included in the study. They presented with partial (46.0%, secondary (31.0% or primary (23.0% generalized tonic-clonic seizures. Clinical diagnosis was based on the revised criteria of ILAE. Structural neuroimaging (MRI, EEG recording, and neurological examination were performed.Results: MRI detected different structural brain abnormalities totally in 36 (73.5% patients, including cerebral tumors (21p, cerebrovascular accidents (5p, hyppocampal sclerosis (3p, developmental malformations (2p, postencephalitic lesions (2p, arachnoid cysts (2p, and tuberous sclerosis (1p. Neuroimaging revealed normal findings in 13 (27.5% cases. EEG recordings showed focal epileptic activity in 38 (77.6% patients, including 33 cases with and 5 without structural brain abnormalities.Conclusion: This study revealed that structural brain lesions are commonly associated with refractory epilepsy. We suggested that MRI is a useful diagnostic method for assessment of patients with uncontrolled seizures or altered epileptic pattern.

Penetration and Effectiveness of Micronized Copper in Refractory Wood Species.

Science.gov (United States)

Civardi, Chiara; Van den Bulcke, Jan; Schubert, Mark; Michel, Elisabeth; Butron, Maria Isabel; Boone, Matthieu N; Dierick, Manuel; Van Acker, Joris; Wick, Peter; Schwarze, Francis W M R

2016-01-01

The North American wood decking market mostly relies on easily treatable Southern yellow pine (SYP), which is being impregnated with micronized copper (MC) wood preservatives since 2006. These formulations are composed of copper (Cu) carbonate particles (CuCO3·Cu(OH)2), with sizes ranging from 1 nm to 250 μm, according to manufacturers. MC-treated SYP wood is protected against decay by solubilized Cu2+ ions and unreacted CuCO3·Cu(OH)2 particles that successively release Cu2+ ions (reservoir effect). The wood species used for the European wood decking market differ from the North American SYP. One of the most common species is Norway spruce wood, which is poorly treatable i.e. refractory due to the anatomical properties, like pore size and structure, and chemical composition, like pit membrane components or presence of wood extractives. Therefore, MC formulations may not suitable for refractory wood species common in the European market, despite their good performance in SYP. We evaluated the penetration effectiveness of MC azole (MCA) in easily treatable Scots pine and in refractory Norway spruce wood. We assessed the effectiveness against the Cu-tolerant wood-destroying fungus Rhodonia placenta. Our findings show that MCA cannot easily penetrate refractory wood species and could not confirm the presence of a reservoir effect.

Supporting data for senary refractory high-entropy alloy CrxMoNbTaVW

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B. Zhang

2015-12-01

Full Text Available This data article is related to the research paper entitled “senary refractory high-entropy alloy CrxMoNbTaVW [1]”. In this data article, the pseudo-binary Cr-MoNbTaVW phase diagram is presented to show the impact of Cr content to the senary Cr-MoNbTaVW alloy system; the sub-lattice site fractions are presented to show the disordered property of the Cr-MoNbTaVW BCC structures; the equilibrium and Scheil solidification results with the actual sample elemental compositions are presented to show the thermodynamic information of the melted/solidified CrxMoNbTaVW samples; and the raw EDS scan data of the arc-melted CrxMoNbTaVW samples are also provided.

Response properties of the refractory auditory nerve fiber.

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Miller, C A; Abbas, P J; Robinson, B K

2001-09-01

The refractory characteristics of auditory nerve fibers limit their ability to accurately encode temporal information. Therefore, they are relevant to the design of cochlear prostheses. It is also possible that the refractory property could be exploited by prosthetic devices to improve information transfer, as refractoriness may enhance the nerve's stochastic properties. Furthermore, refractory data are needed for the development of accurate computational models of auditory nerve fibers. We applied a two-pulse forward-masking paradigm to a feline model of the human auditory nerve to assess refractory properties of single fibers. Each fiber was driven to refractoriness by a single (masker) current pulse delivered intracochlearly. Properties of firing efficiency, latency, jitter, spike amplitude, and relative spread (a measure of dynamic range and stochasticity) were examined by exciting fibers with a second (probe) pulse and systematically varying the masker-probe interval (MPI). Responses to monophasic cathodic current pulses were analyzed. We estimated the mean absolute refractory period to be about 330 micros and the mean recovery time constant to be about 410 micros. A significant proportion of fibers (13 of 34) responded to the probe pulse with MPIs as short as 500 micros. Spike amplitude decreased with decreasing MPI, a finding relevant to the development of computational nerve-fiber models, interpretation of gross evoked potentials, and models of more central neural processing. A small mean decrement in spike jitter was noted at small MPI values. Some trends (such as spike latency-vs-MPI) varied across fibers, suggesting that sites of excitation varied across fibers. Relative spread was found to increase with decreasing MPI values, providing direct evidence that stochastic properties of fibers are altered under conditions of refractoriness.

Development of electro fused aggregates for use in refractories for the burning zone of cement kilns; Desenvolvimento de agregados eletrofundidos para utilizacao em refratarios para a zona de queima de fornos de cimento

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Luis Leonardo Horne Curimbaba

2006-07-01

Electro fused aggregates are largely used in refractory production due to the better performance reached when they are employed. In this work electro fused aggregates were designed for application in refractories for the burning zone of cement kilns. Initially reaction evaluation was conducted aiming the identification of the most prone refractory systems when single refractory phases react with Portland cement phases at high temperatures. In the next step, raw materials of the best refractory systems were electro fused to generate different aggregate compositions. The electro fused aggregates properties were evaluated and the classified ones were used to produce refractory bricks for the burning zone of cement kilns. General characteristics of these bricks were measured and compared with a standard magnesia-spinel refractory. Aggregates of the system Mg O - TiO{sub 2} - Ca O, more specifically aggregates belonged to the compatibility triangle Mg O - Mg{sub 2}TiO{sub 4} - CaTiO{sub 3}, showed suitable characteristics for development of refractories for the burning zone cement kilns. (author)

Refractory alloy technology for space nuclear power applications

International Nuclear Information System (INIS)

Cooper, R.H. Jr.; Hoffman, E.E.

1984-01-01

Purpose of this symposium is twofold: (1) to review and document the status of refractory alloy technology for structural and fuel-cladding applications in space nuclear power systems, and (2) to identify and document the refractory alloy research and development needs for the SP-100 Program in both the short and the long term. In this symposium, an effort was made to recapture the space reactor refractory alloy technology that was cut off in midstream around 1973 when the national space nuclear reactor program began in the early 1960s, was terminated. The six technical areas covered in the program are compatibility, processing and production, welding and component fabrication, mechanical and physical properties, effects of irradiation, and machinability. The refractory alloys considered are niobium, molybdenum, tantalum, and tungsten. Thirteen of the 14 pages have been abstracted separately. The remaining paper summarizes key needs for further R and D on refractory alloys

Chemical compositions of refractory inclusions in the Murchison C2 chondrite

International Nuclear Information System (INIS)

Ekambaram, V.; Kawabe, I.; Tanaka, T.; Davis, A.M.; Grossman, L.

1984-01-01

Samples from ten refractory inclusions in Murchison, some of which are splits of inclusions whose mineralogical and petrographic characteristics are known, have been analysed for thirty-six elements by neutron activation. Six inclusions have group II or group III patterns or variants of such patterns. Two inclusions, BB-5 and MUCH-1, have large negative Yb anomalies unaccompanied by correspondingly large negative Eu anomalies. It is possible that the latter condensed originally with group III patterns and preferentially took up Eu in later exchange processes under reducing conditions. One inclusion, SH-2, has heavy REE enrichment factors that increase with the refractoriness of the REE, indicating the presence of an extremely high-temperature, or ultrarefractory, REE condensate, but it also has a heavy REE/light REE ratio that indicates mixing of that component with a lower-temperature REE condensate. The frequency of highly fractionated REE patterns and absence of group I patterns suggest that refractory inclusions in Murchison stopped equilibrating with the nebular gas at higher temperatures than most Allende-coarse-grained inclusions. The results are discussed. (author)

[Long-term outcomes of Ahmed glaucoma valve implantation for treating refractory glaucoma].

Science.gov (United States)

Xu, Yumei; Hong, Tao; Li, Wanming

2015-02-10

To explore the efficacies and complications of Ahmed glaucoma valve implantation for treating refractory glaucoma. A retrospective study of case series was conducted for 24 patients (26 eyes) with refractory glaucoma from February 2001 to July 2008 at our hospital. Ahmed glaucoma valve implantation was performed. Pre- and post-operative best spectacle-corrected visual acuity (BSCVA), intraocular pressure (IOP), number of medications and complications were recorded and analyzed. The follow-up period was 58-159 months. The post-operative values of IOP were 13.02+/-6.79, 11.43+/-5.24 and 18.56+/-6.43 mmHg at 1 day, 1 month and the last follow-up respectively. There were significant difference when compared with pre-operative IOP (37.59+/-10.76 mmHg, P glaucoma drugs after glaucoma valve implantation and the average number of medication was 1.72+/-0.98. There was significant difference with the pre-operative medication number 2.7 ± 0.7 (P = 0.001). The surgical success rate was 73.1%. And the causes of failure were endophthalmitis, corneal endothelial decompensation, persistent conjunctival wound non-healing, glaucoma valve exposure and loss of light perception.Early postoperative complications were ocular hypotony, shallow anterior chamber, hyphema, transient high IOP and tube occlusion. And long-term complications included encapsulated cyst formation, tube exposure, corneal endothelial decompensation and endophthalmitis. Ahmed glaucoma valve implantation is efficacious for refractory glaucoma.However, clinicians should pay attention to the prevention and treatment of complications.

Improved cooler design of electric arc furnace refractory in mining industry using thermal analysis modeling and simulation

International Nuclear Information System (INIS)

Istadi, I.; Bindar, Y.

2014-01-01

Production of steel and nickel using the electric arc furnace should be focused on the intensification of energy. Improvement of energy efficiency of the most consuming facilities was achieved by improving the use of alternative energy minimization such as reducing the heat lost of hot gases, minimizing the heat radiated through refractory linings of metallurgical furnaces, and cooling the highly thermally stressed components. The refractory of electric arc furnace should be modified to achieve the best cooling system of the furnace. In this physical modeling and simulation works, four modification scenarios of wall refractory designs were simulated, i.e. refractory with basic design, refractory with deep plate coolers, refractory with extra plate coolers, and refractory with wall falling film coolers. Finally, the use of deep plate cooler and the existing waffle cooler system was considered to be the best design of efficient electric arc furnace operationally. - Highlights: • Electric arc furnace design should be focused on the intensification of energy. • Refractory of electric arc furnace were modified to achieve the best cooling system. • Four modification scenarios of the wall refractory designs were simulated. • Use of deep plate cooler and existing waffle cooler system is the best cooling

Engineering data bases for refractory alloys

International Nuclear Information System (INIS)

Cooper, R.H. Jr.; Harms, W.O.

1985-01-01

Refractory alloys based on niobium, molybdenum, tantalum, and tungsten are required for the multi-100kW(e) space nuclear reactor power concepts that have been assessed in the SP-100 Program because of the extremely high temperatures involved. A review is presented of the technology efforts on the candidate refractory alloys in the areas of availability/fabricability, mechanical properties, irradiation effects, and compatibility. Of the niobium-base alloys, only Nb-1Zr has a data base that is sufficiently comprehensive for the high level of confidence required in the reference-alloy selection process for the reactor concept to be tested in the Ground Engineering System (GES) Phase of the SP-100 Program. Based on relatively short-term tests, the alloy PWC-11 (Nb-1Zr-0.1C) appears to have significantly greater creep strength than Nb-1Zr; however, concerns as to whether this precipitation-hardened alloy will remain thermally stable during seven years of full-power reactor operation need to be resolved. Additional information on the reference GES alloy will be needed for the detailed engineering design of a space power system and the fabrication of prototypical GES test components. Expedient development and demonstration of an adequate total manufacturing capability will be required if a high risk of significant schedule slippages and cost overruns is to be avoided. 4 refs., 1 fig., 3 tabs

A retrospective study on the management of patients with rituximab refractory follicular lymphoma.

Science.gov (United States)

Solal-Céligny, Philippe; Leconte, Pierre; Bardet, Aurélie; Hernandez, Juana; Troussard, Xavier

2018-01-01

Given that there are currently no clear recommendations regarding therapeutic options for rituximab refractory/relapsed follicular lymphoma patients, this study aimed to describe the real-life management of patients with refractory follicular lymphoma after systemic rituximab-containing regimens (rFL), and rFL patient characteristics. In this retrospective, national, multicentre study, descriptive analyses were mainly performed according to rituximab-containing regimen at rFL diagnosis [rituximab monotherapy (R-MONO), rituximab + chemotherapy (R-COMBO), and ongoing rituximab maintenance (R-MAINTAIN)]. The 459 analysed patients experienced rituximab-refractoriness between October 2013 and September 2015: R-MONO: 58 (13%), R-COMBO: 197 (43%), R-MAINTAIN: 204 (44%). Post-refractoriness strategies were heterogeneous: idelalisib ± rituximab (22%), without anti-lymphoma treatment (21%), rituximab-chemotherapy (21%) and stem cell transplantation (18%). Rituximab was continued in combination in 41% of cases. Chosen strategies varied according to patient age (without anti-lymphoma treatment: 28% of patients if ≥65 years vs. 12% if management and for the design of clinical trials in these patients. © 2017 John Wiley & Sons Ltd.

Refractory alloy technology for space nuclear power applications

Energy Technology Data Exchange (ETDEWEB)

Cooper, R.H. Jr.; Hoffman, E.E. (eds.)

1984-01-01

Purpose of this symposium is twofold: (1) to review and document the status of refractory alloy technology for structural and fuel-cladding applications in space nuclear power systems, and (2) to identify and document the refractory alloy research and development needs for the SP-100 Program in both the short and the long term. In this symposium, an effort was made to recapture the space reactor refractory alloy technology that was cut off in midstream around 1973 when the national space nuclear reactor program began in the early 1960s, was terminated. The six technical areas covered in the program are compatibility, processing and production, welding and component fabrication, mechanical and physical properties, effects of irradiation, and machinability. The refractory alloys considered are niobium, molybdenum, tantalum, and tungsten. Thirteen of the 14 pages have been abstracted separately. The remaining paper summarizes key needs for further R and D on refractory alloys. (DLC)

Temperature and Thermal Stress Analysis of Refractory Products

Directory of Open Access Journals (Sweden)

Shaoyang Shi

2013-05-01

Full Text Available Firstly current status of temperature and thermal stress research of refractory product at home and aboard are analyzed. Finite element model of two classical refractory products is building by using APDL language. Distribution law of temperature and thermal stress of two typical refractory products-ladles and tundish are analyzed and their structures are optimized. Stress of optimal structure is dropped obviously, and operation life is increased effectively.

Unusual cause of respiratory distress misdiagnosed as refractory asthma

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Al-Otair Hadil

2006-01-01

Full Text Available We report a young lady, who was labeled as a case of refractory asthma for a few years, based on history of shortness of breath on minimal exertion, noisy breathing and normal chest radiograph. Repeated upper airway exam by an otolaryngologist and computerized tomography scan, were normal. On presentation to our hospital, she was diagnosed to have fixed upper airway obstruction, based on classical flow-volume loop findings. Fibroptic bronchoscopy revealed a web-shaped subglottic stenosis. The histopathology of a biopsy taken from that area, showed non-specific inflammation. No cause for this stenosis could be identified. The patient was managed with rigid bronchoscopy dilatation, without recurrence. We report this case as idiopathic subglottic stenosis, that was misdiagnosed as refractory bronchial asthma, stressing the importance of performing spirometry in the clinic.

Classical management of refractory adult immune (idiopathic) thrombocytopenic purpura.

Science.gov (United States)

McMillan, R

2002-03-01

Treatment of chronic immune (idiopathic) thrombocytopenic purpura with corticosteroids and/or splenectomy results in safe platelet counts in over 70% of patients without additional treatment. Therapy of patients who are refractory to these two treatments may be difficult. The treatment approach to refractory ITP patients, described in this report, is arbitrarily divided into four levels: levels 1 through 3 represent treatments with increasing side effects; level 4 therapy may be tried when the others have failed. Patients undergoing these treatments may require concomitant intravenous gammaglobulin, high-dose corticosteroids or platelets, to maintain the platelet count in the setting of mucosal bleeding or severe thrombocytopenia. Copyright 2002, Elsevier Science Ltd. All rights reserved.

Approaches to refractory epilepsy

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Jerome Engel

2014-01-01

Full Text Available Epilepsy is one of the most common serious neurological conditions, and 30 to 40% of people with epilepsy have seizures that are not controlled by medication. Patients are considered to have refractory epilepsy if disabling seizures continue despite appropriate trials of two antiseizure drugs, either alone or in combination. At this point, patients should be referred to multidisciplinary epilepsy centers that perform specialized diagnostic testing to first determine whether they are, in fact, pharmacoresistant, and then, if so, offer alternative treatments. Apparent pharmacoresistance can result from a variety of situations, including noncompliance, seizures that are not epileptic, misdiagnosis of the seizure type or epilepsy syndrome, inappropriate use of medication, and lifestyle issues. For patients who are pharmacoresistant, surgical treatment offers the best opportunity for complete freedom from seizures. Surgically remediable epilepsy syndromes have been identified, but patients with more complicated epilepsy can also benefit from surgical treatment and require more specialized evaluation, including intracranial EEG monitoring. For patients who are not surgical candidates, or who are unwilling to consider surgery, a variety of other alternative treatments can be considered, including peripheral or central neurostimulation, ketogenic diet, and complementary and alternative approaches. When such alternative treatments are not appropriate or effective, quality of life can still be greatly improved by the psychological and social support services offered by multidisciplinary epilepsy centers. A major obstacle remains the fact that only a small proportion of patients with refractory epilepsy are referred for expert evaluation and treatment.

Identification of compounds that selectively target highly chemotherapy refractory neuroblastoma cancer stem cells.

Science.gov (United States)

Díaz-Carballo, David; Acikelli, Ali Haydar; Bardenheuer, Walter; Gustmann, Sebastian; Malak, Sascha; Stoll, Raphael; Kedziorski, Thorsten; Nazif, Mhd Ali; Jastrow, Holger; Wennemuth, Gunter; Dammann, Philip; Feigel, Martin; Strumberg, Dirk

2014-09-01

Relapse of cancer months or years after an apparently successful therapy is probably caused by cancer stem cells (CSCs) due to their intrinsic features like dormant periods, radiorefraction, and acquired multidrug resistance (MDR) phenotypes, among other mechanisms of cellular drug evasiveness. Thus, the lack of currently efficacious interventions remains a major problem in the treatment of malignancies, together with the inability of existing drugs to destroy specifically CSCs. Neuroblastomas per se are highly chemotherapy-refractory extracranial tumors in infants with very low survival rates. So far, no effective cytostatics against this kind of tumors are clinically available. Therefore, we have put much effort into the development of agents to efficiently combat this malignancy. For this purpose, we tested several compounds isolated from Cuban propolis on induced CSCs (iCSC) derived from LAN-1 neuroblastoma cells which expressed several characteristics of tumor-initiating cells both in in-vitro and in-vivo models. Some small molecules such as flavonoids and polycyclic polyprenylated acylphloroglucinols (PPAP) were isolated using successive RT-HPLC cycles and identified employing mass spectrometry and NMR spectroscopic techniques. Their cytotoxicity was first screened in sensitive cell systems by MTT proliferation assays and afterwards studied in less sensitive neuroblastoma iCSC models. We found several compounds with considerable anti-iCSC activity, most of them belonging to the PPAP class. The majority of the compounds act in a pleiotropic manner on the molecular biology of tumors although their specific targets remain unclear. Nevertheless, two substances, one of them a flavonoid, induced a strong disruption of tubulin polymerization. In addition, an unknown compound strongly inhibited replicative enzymes like toposimerases I/II and DNA polymerase. Here, we report for the first time cytotoxic activities of small molecules isolated from Caribbean propolis

Machining refractory alloys: an overview

International Nuclear Information System (INIS)

Christopher, J.D.

1984-01-01

Nontraditional machining is a generic term for those material removal processes that differ drastically from the historic operations such as turning, milling, drilling, tapping, and grinding. The use of primary energy modes other than mechanical, such as thermal, electrical, and chemical, sets these operations apart and reinforces their nontraditional label. Several of these newer processes have been very successful in machining close tolerance parts from refractory materials. This paper provides a general overview of both traditional and nontraditional aspects of machining refractory materials. 11 figures, 7 tables

Non-Contact Measurements of Creep Properties of Refractory Materials

Science.gov (United States)

Lee, Jonghyun; Bradshaw, Richard C.; Hyers, Robert W.; Rogers, Jan R.; Rathz, Thomas J.; Wall, James J.; Choo, Hahn; Liaw, Peter

2006-01-01

State-of-the-art technologies for hypersonic aircraft, nuclear electric/thermal propulsion for spacecraft, and more efficient jet engines are driving ever more demanding needs for high-temperature (>2000 C) materials. At such high temperatures, creep rises as one of the most important design factors to be considered. Since conventional measurement techniques for creep resistance are limited to about 17OO0C, a new technique is in demand for higher temperatures. This paper presents a non-contact method using electrostatic levitation (ESL) which is applicable to both metallic and non-metallic materials. The samples were rotated quickly enough to cause creep deformation by centrifugal acceleration. The deformation of the samples was captured with a high speed camera and then the images were analyzed to estimate creep resistance. Finite element analyses were performed and compared to the experiments to verify the new method. Results are presented for niobium and tungsten, representative refractory materials at 2300 C and 2700 C respectively.

Detection of Active Epstein-Barr Virus Infection in Duodenal Mucosa of Patients With Refractory Celiac Disease.

Science.gov (United States)

Perfetti, Vittorio; Baldanti, Fausto; Lenti, Marco Vincenzo; Vanoli, Alessandro; Biagi, Federico; Gatti, Marta; Riboni, Roberta; Dallera, Elena; Paulli, Marco; Pedrazzoli, Paolo; Corazza, Gino Roberto

2016-08-01

Refractory celiac disease is characterized by mucosal damage in patients with celiac disease despite a gluten-free diet. Little is known about the mechanisms that cause persistent intestinal inflammation in these patients. We performed a case-control study of 17 consecutive patients diagnosed with refractory celiac disease from 2001 through 2014 (median age, 51 y; 10 women) and 24 patients with uncomplicated celiac disease (controls) to determine whether refractory disease is associated with infection by lymphotropic oncogenic viruses. We performed real-time PCR analyses of duodenal biopsy samples from all patients to detect Epstein-Barr virus (EBV), human herpesvirus-8, and human T-cell lymphotropic virus-I, -II, or -III. We used in situ hybridization and immunohistochemical analyses to identify infected cells and viral proteins. We did not detect human herpesvirus-8 or human T-cell lymphotropic viruses in any of the biopsy specimens. However, 12 of 17 (70.5%) biopsy specimens from patients with refractory celiac disease were positive for EBV, compared with 4 of 24 (16.6%) biopsy specimens from controls (P disease and enteropathy-associated T-cell lymphoma. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Clinical observation on Ahmed glaucoma valve implantation for teenagers with refractory glaucoma

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Dong-Dao Song

2016-06-01

Full Text Available AIM:To observe the clinical effect of Ahmed glaucoma valve(AGVimplantation for teenagers with refractory glaucoma. METHODS: Twenty-seven patients(27 eyeswith refractory glaucoma were treated with AGV implantation in our hospital from October 2012 to October 2014. The patients were followed up for 12mo. The success rate of the operation, postoperative intraocular pressure, the best corrected visual acuity, as well as complications were recorded. RESULTS: The success rate of the operation was 85%. The intraocular pressure of the 27 patients decreased from 48.3±8.3mmHg before operations to 21.4±8.1mmHg(PPCONCLUSION: AGV implantation is characterized by a high success rate, simple operation, less complications and is an effective treatment for refractory glaucoma in adolescents.

External bioresorbable airway rigidification to treat refractory localized tracheomalacia.

Science.gov (United States)

Gorostidi, François; Reinhard, Antoine; Monnier, Philippe; Sandu, Kishore

2016-11-01

Our study evaluates the efficacy of extraluminal bioresorbable plates to treat refractory localized airway malacia in patients undergoing corrective surgery for complex multilevel laryngotracheal stenosis. Retrospective case series. Secondary malacic airway segments were characterized (severity, site, type) by a dynamic transnasal flexible laryngotracheobronchoscopy before surgery. Extraluminal bioresorbable plates were used to stabilize the malacic segment through a transcervical approach under intraoperative flexible endoscopic guidance. Results were evaluated subjectively and by a postoperative dynamic endoscopy. We report our experience in seven patients (6 children, 1 adult). External tracheal stiffening allowed complete or partial resolution of refractory proximal airway malacia in six of seven complex cases described (result in one case is awaited). It allowed quick decannulation in four of seven patients who experienced multiple previous failures. Decannulation failures were due to recurrence of stenosis. With up to 2 years of follow-up, we report no direct complications related to the presence of extraluminal bioresorbable plates around the airway. Extraluminal biodegradable tracheal stiffening represents a valid therapeutic option in select cases of upper airway malacia. It can be highly useful in cases of complex multilevel airway obstructions. External stiffening needs to be planned on a case-to-case basis according to the type of malacia and must be performed under endoscopic guidance. 4. Laryngoscope, 126:2605-2610, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Outcomes in Children Treated with Pentobarbital Infusion for Refractory and Super-Refractory Status Epilepticus.

Science.gov (United States)

Erklauer, Jennifer; Graf, Jeanine; McPherson, Mona; Anderson, Anne; Wilfong, Angus; Minard, Charles G; Loftis, Laura

2018-03-26

Functional neurologic outcome for children with refractory and super-refractory status epilepticus has not been well defined. Retrospective chart review including children age 0-17 years who received pentobarbital infusion from 2003 to 2016 for status epilepticus. Outcomes were defined in terms of mortality, need for new medical technology assistance at hospital discharge and functional neurologic outcome determined by pediatric cerebral performance category score (PCPC). Potential patient characteristics associated with functional neurologic outcome including age, sex, ethnicity, etiology of the status epilepticus, and duration of pentobarbital infusion were evaluated. Forty children met inclusion criteria. In-hospital mortality was 30% (12/40). Of survivors, 21% (6/28) returned to baseline PCPC while half (14/28) declined in function ≥ 2 PCPC categories at hospital discharge. 25% (7/28) of survivors required tracheostomy and 27% (7/26) required new gastrostomy. Seizures persisted at discharge for most patients with new onset status epilepticus while the majority of patients with known epilepsy returned to baseline seizure frequency. Etiology (p = 0.015), PCPC at admission (p = 0.0006), new tracheostomy (p = 0.012), and new gastrostomy tube (p = 0.012) were associated with increase in PCPC score ≥ 2 categories in univariable analysis. Duration of pentobarbital infusion (p = 0.005) and length of hospital stay (p = 0.056) were longer in patients who demonstrated significant decline in neurologic function. None of these variables maintained statistical significance when multiple logistic regression model adjusting for PCPC score at admission was applied. At long-term follow-up, 36% (8/22) of children demonstrated improvement in PCPC compared to discharge and 23% (5/22) showed deterioration including three additional deaths. Mortality in this population was high. The majority of children experienced some degree of disability at discharge. Despite

Development of models and online diagnostic monitors of the high-temperature corrosion of refractories in oxy/fuel glass furnaces : final project report.

Energy Technology Data Exchange (ETDEWEB)

Griffiths, Stewart K.; Gupta, Amul (Monofrax Inc., Falconer, NY); Walsh, Peter M.; Rice, Steven F.; Velez, Mariano (University of Missouri, Rolla, MO); Allendorf, Mark D.; Pecoraro, George A. (PPG Industries, Inc., Pittsburgh, PA); Nilson, Robert H.; Wolfe, H. Edward (ANH Refractories, Pittsburgh, PA); Yang, Nancy Y. C.; Bugeat, Benjamin () American Air Liquide, Countryside, IL); Spear, Karl E. (Pennsylvania State University, University Park, PA); Marin, Ovidiu () American Air Liquide, Countryside, IL); Ghani, M. Usman (American Air Liquide, Countryside, IL)

2005-02-01

This report summarizes the results of a five-year effort to understand the mechanisms and develop models that predict the corrosion of refractories in oxygen-fuel glass-melting furnaces. Thermodynamic data for the Si-O-(Na or K) and Al-O-(Na or K) systems are reported, allowing equilibrium calculations to be performed to evaluate corrosion of silica- and alumina-based refractories under typical furnace operating conditions. A detailed analysis of processes contributing to corrosion is also presented. Using this analysis, a model of the corrosion process was developed and used to predict corrosion rates in an actual industrial glass furnace. The rate-limiting process is most likely the transport of NaOH(gas) through the mass-transport boundary layer from the furnace atmosphere to the crown surface. Corrosion rates predicted on this basis are in better agreement with observation than those produced by any other mechanism, although the absolute values are highly sensitive to the crown temperature and the NaOH(gas) concentration at equilibrium and at the edge of the boundary layer. Finally, the project explored the development of excimer laser induced fragmentation (ELIF) fluorescence spectroscopy for the detection of gas-phase alkali hydroxides (e.g., NaOH) that are predicted to be the key species causing accelerated corrosion in these furnaces. The development of ELIF and the construction of field-portable instrumentation for glass furnace applications are reported and the method is shown to be effective in industrial settings.

Lipid Rescue Therapy and High-Dose insulin Euglycemic Therapy are Effective for Severe Refractory Calcium Channel Blocker Overdose: Case Report and Review of Literature

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Niko Bekjarovski

2013-09-01

How to cite this article: Bekjarovski NG. Lipid Rescue Therapy and High-Dose insulin Euglycemic Therapy are Effective for Severe Refractory Calcium Channel Blocker Overdose: Case Report and Review of Literature. Asia Pac J Med Toxicol 2013;2:114-6.

Spinning of refractory metals

International Nuclear Information System (INIS)

Chang Wenkua; Zheng Han

1989-01-01

The effects of spinning process parameters including max. pass percentage reduction, spinning temperature, feed rate, lubricant and annealing technology on the quality of shaped components are summarized and discussed in the present paper. The above mentioned parameters are adopted in the process of spinning of barrel-shaped and specially shaped components of refractory metals and their alloys W, Mo, Nb, Zr, TZM molybdenum alloy, C-103, C-752 niobium alloy etc. The cause of leading to usual defects of spun products of refractory metals such as lamellar as 'scaling', crack, swelling, wrinkle, etc. have been analysed and the ways to eliminate the defects have been put forward. 8 figs., 5 tabs. (Author)

Clinical and etiological profile of refractory rickets from western India.

Science.gov (United States)

Joshi, Rajesh R; Patil, Shailesh; Rao, Sudha

2013-07-01

To present clinical and etiological profile of refractory rickets from Mumbai. Case records of 36 patients presenting over 2½ y with refractory rickets were evaluated with respect to clinical presentation, biochemical, radiological features and where needed, ophthalmological examination, ultrasonography and special tests on blood and urine. Twenty three (63 %) patients had renal tubular acidosis (RTA)-distal RTA in 20 and proximal RTA in 3 patients; 5 (14 %) had vitamin D dependent rickets (VDDR I in 2 and VDDR II in 3 patients), 4 (11 %) had chronic renal failure (CRF) and 2 each (6 %) had hypophosphatemic rickets and chronic liver disease as cause of refractory rickets. A significant proportion of patients with RTA and VDDR showed skeletal changes of rickets in the first 2 y of life, while those with hypophosphatemic rickets presented later. Patients with hypophosphatemic rickets had predominant involvement of lower limbs, normal blood calcium and PTH levels and phosphorus leak in urine. All patients with RTA presented with failure to thrive, polyuria and marked rickets; blood alkaline phosphatase levels being normal in almost 50 % patients. Three (75 %) patients with rickets due to CRF had GFR rickets inspite of taking high dose of vitamin D orally. Refractory rickets is a disorder of multiple etiologies; a good history and clinical examination supplemented with appropriate investigations helps to determine its cause.

Application of metal oxide refractories for melting and casting reactive metals

International Nuclear Information System (INIS)

Jessen, N.C. Jr.; Holcombe, C.E. Jr.; Townsend, A.B.

1979-01-01

Extensive investigations have been conducted to develop metal oxide refractories for containment of molten uranium and uranium alloys. Since uranium and uranium alloys are readily susceptable to the formation of complex oxides, carbides, nitrides, intermetallic compounds, and suboxide reactions, severe problems exist for the production of quality castings. These contamination reactions are dependent on temperature, pressure, and molten metal interfacial reactions. The need for high purity metals to meet specification repeatedly has resulted in the development of improved metal oxide refractories and sophisticated furnace controls. Applications of Y 2 O 3 for use as a crucible and mold coating, precision molds and cores, and high temperature castable ceramics are discussed. Experimental results on melt impurity levels, thermal controls during melting, surface interactions and casting quality are presented

Development of diagnosis and repair system for steelmaking refractories; Seikoyo taikabutsu no shindan hoshu gijutsu no kakuritsu

Energy Technology Data Exchange (ETDEWEB)

Aso, S.; Harada, S.; Tsutsui, Y. [Nippon Steel Corp., Tokyo (Japan)

1996-06-01

The latest measurement equipment and repair method were introduced into the work area of all refractories in the process of torpedo cars, hot metal preliminary treatment, hot metal pans, secondary refining, and cast pans so as to improve the cost of the newest advanced steelmaking refractories. As a result, the refractory cost could be reduced by 10%. This paper introduces the improvement in RH refractories and refractories for hot metal preliminary treatment. As for basic items, in addition to the visual observation, the thickness of refractories was quantified using equipment (laser profile meter, thermotracer, and NS sensor) for the furnace stop in the minimum remaining length. An ITV was also installed in the facilities where the visual check is difficult to carry out. Repair is mainly done by spraying. A thermal spraying repair method with high durability was used for the repair. A method that relieves a thermal shock was used for preheating. Moreover, measures that make the temperature gradient in the thickness direction uniform by using newly developed microwave drying equipment were taken for drying of unburned refractories. 4 refs., 13 figs., 2 tabs.

Refractory disease in antineutrophil cytoplasmic antibodies associated vasculitis

NARCIS (Netherlands)

Rutgers, Abraham; Kallenberg, Cornelis

Purpose of review Induction treatment of antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) is not always successful and nonresponding patients are considered refractory. Recent findings Refractory disease should be subdefined to the treatment that was received.

Diagnosis and management of refractory celiac disease: a systematic review.

Science.gov (United States)

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.

Highly refractory Archaean peridotite cumulates: Petrology and geochemistry of the Seqi Ultramafic Complex, SW Greenland

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Kristoffer Szilas

2018-05-01

Full Text Available This paper investigates the petrogenesis of the Seqi Ultramafic Complex, which covers a total area of approximately 0.5 km2. The ultramafic rocks are hosted by tonalitic orthogneiss of the ca. 3000 Ma Akia terrane with crosscutting granitoid sheets providing an absolute minimum age of 2978 ± 8 Ma for the Seqi Ultramafic Complex. The Seqi rocks represent a broad range of olivine-dominated plutonic rocks with varying modal amounts of chromite, orthopyroxene and amphibole, i.e. various types of dunite (s.s., peridotite (s.l., as well as chromitite. The Seqi Ultramafic Complex is characterised primarily by refractory dunite, with highly forsteritic olivine with core compositions having Mg# ranging from about 91 to 93. The overall high modal contents, as well as the specific compositions, of chromite rule out that these rocks represent a fragment of Earth's mantle. The occurrence of stratiform chromitite bands in peridotite, thin chromite layers in dunite and poikilitic orthopyroxene in peridotite instead supports the interpretation that the Seqi Ultramafic Complex represents the remnant of a fragmented layered complex or a magma conduit, which was subsequently broken up and entrained during the formation of the regional continental crust.Integrating all of the characteristics of the Seqi Ultramafic Complex points to formation of these highly refractory peridotites from an extremely magnesian (Mg# ∼ 80, near-anhydrous magma, as olivine-dominated cumulates with high modal contents of chromite. It is noted that the Seqi cumulates were derived from a mantle source by extreme degrees of partial melting (>40%. This mantle source could potentially represent the precursor for the sub-continental lithospheric mantle (SCLM in this region, which has previously been shown to be ultra-depleted. The Seqi Ultramafic Complex, as well as similar peridotite bodies in the Fiskefjord region, may thus constitute the earliest cumulates that formed during the

Treatment of refractory/relapsed adult acute lymphoblastic leukemia with bortezomib- based chemotherapy

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Zhao J

2015-06-01

Full Text Available Junmei Zhao,* Chao Wang,* Yongping Song, Yuzhang Liu, Baijun FangHenan Key Lab of Experimental Haematology, Henan Institute of Haematology, Henan Tumor Hospital, Zhengzhou University, Zhengzhou, People’s Republic of China  *These authors contributed equally to this work Abstract: Nine pretreated patients aged >19 years with relapsed/refractory acute lymphoblastic leukemia (ALL were treated with a combination of bortezomib plus chemotherapy before allogeneic hematopoietic stem cell transplantation (allo-HSCT. Eight (88.9% patients, including two Philadelphia chromosome-positive ALL patients, achieved a complete remission. Furthermore, the evaluable patients have benefited from allo-HSCT after response to this reinduction treatment. We conclude that bortezomib-based chemotherapy was highly effective for adults with refractory/relapsed ALL before allo-HSCT. Therefore, this regimen deserves a larger series within prospective trials to confirm these results. Keywords: acute lymphoblastic leukemia, refractory, relapsed, bortezomib

Spinal cord stimulation for refractory angina in patients implanted with cardioverter defibrillators: five case reports

DEFF Research Database (Denmark)

Enggaard, Thomas P; Andersen, Claus; Scherer, Christian

2010-01-01

Patients implanted with a cardioverter defibrillator (ICD) who are suffering from refractory angina pectoris could benefit from spinal cord stimulation (SCS) due to the well-documented pain relieving effect. However, the combined treatment remains controversial. The aim of the study is to report...... successful long-term treatment with SCS in five patients implanted with cardioverter defibrillators. The combined treatments with ICD and thoracic epidural electrical stimulation were used in five patients with refractory angina pectoris. During the procedure of the implantation, testing with the maximal...... for refractory angina pectoris can be performed in patients implanted with cardioverter defibrillators without interference. However, individual testing during implantation or re-programming the devices is mandatory in order to assess optimal safety in each patient....

[Prevalence of target organ damage and factors associated with cardiovascular events in subjects with refractory hypertension].

Science.gov (United States)

Armario, Pedro; Oliveras, Anna; Hernández Del Rey, Raquel; Poch, Esteban; Larrouse, María; Roca-Cusachs, Alex; de la Sierra, Alejandro

2009-06-27

To asses the prevalence of target organ damage (TOD) and factors associated with cardiovascular events in subjects with refractory hypertension. Cross-sectional study of 146 patients with clinical diagnosis of refractory hypertension. TOD was defined as the presence of microalbuminuria (MA), renal failure (RF), left ventricular hypertrophy (LVH) or left atrial enlargement (LAE). Cardiovascular events were defined as the antecedent of stroke, coronary heart disease, heart failure or peripheral arterial disease. 24-h ambulatory blood pressure monitoring was (ABPM) performed with a validated Spacelabs 90207. The prevalence of LVH was 62.3%, and LAE was observed in 27.7% of the subjects. The prevalence of RF was 28.1% and MA was found in 41,4%. An association between MA and LVH was observed. After adjusting by age, the urinary albumin excretion (UAE) correlated with clinical blood pressure (BP) and BP during 24-h ABPM, whereas LVMI correlated with ambulatory BP but not with clinical BP. The prevalence of previous cardiovascular events was 22% and in the multivariate regression analysis, UAE was the only independent factor associated with the antecedent of cardiovascular events. In subjects with refractory hypertension, the prevalence of TOD was high, and an association between heart and renal organ damage was observed. UAE was independently associated with the antecedent of cardiovascular disease.

Structure, preparation and properties of refractory compounds and systems

International Nuclear Information System (INIS)

Holleck, H.; Thuemmler, F.

1977-01-01

At the beginning of this report the possibilities of hardness optimization of refractory carbides are generally discussed. Three papers deal with TaC-basis refractories and hard metals. In particular, carbides with very low nonmetal/metal ratios and composites with hard phases formed by decomposition of tantalum carbonitrides are discussed. Another contribution reports investigations concerning the influence of the microstructure on the hardness of polycristaline mixed carbides. In a series of four papers, results are presented on the work of optimization conventional WC hard metals by introduction of a Fe,Co,Ni-binder: The influence of composition, carbon content and sintering conditions, as well as the wetting behaviour between carbides and binder metals are discussed. Phase relations in the refractory nitride and refractory nitride-binder metal systems as well as phase stabilities of ordered transition metal phases are reported in three papers, fundamental in character. Finally, the work concerning chemical analysis of refractory systems is described. (orig.) [de

Multi-scale modelling of thermal shock damage in refractory materials

NARCIS (Netherlands)

Özdemir, I.

2009-01-01

Refractories are high-temperature resistant materials used extensively in many engineering structures and assemblies in a wide spectrum of applications ranging from metallurgical furnace linings to thermal barrier coatings. Such structures are often exposed to severe thermal loading conditions in

Sub-micrometer refractory carbonaceous particles in the polar stratosphere

Science.gov (United States)

Schütze, Katharina; Wilson, James Charles; Weinbruch, Stephan; Benker, Nathalie; Ebert, Martin; Günther, Gebhard; Weigel, Ralf; Borrmann, Stephan

2017-10-01

Eleven particle samples collected in the polar stratosphere during SOLVE (SAGE III Ozone loss and validation experiment) from January until March 2000 were characterized in detail by high-resolution transmission and scanning electron microscopy (TEM/SEM) combined with energy-dispersive X-ray microanalysis. A total of 4202 particles (TEM = 3872; SEM = 330) were analyzed from these samples, which were collected mostly inside the polar vortex in the altitude range between 17.3 and 19.9 km. Particles that were volatile in the microscope beams contained ammonium sulfates and hydrogen sulfates and dominated the samples. Some particles with diameters ranging from 20 to 830 nm were refractory in the electron beams. Carbonaceous particles containing additional elements to C and O comprised from 72 to 100 % of the refractory particles. The rest were internal mixtures of these materials with sulfates. The median number mixing ratio of the refractory particles, expressed in units of particles per milligram of air, was 1.1 (mg air)-1 and varied between 0.65 and 2.3 (mg air)-1. Most of the refractory carbonaceous particles are completely amorphous, a few of the particles are partly ordered with a graphene sheet separation distance of 0.37 ± 0.06 nm (mean value ± standard deviation). Carbon and oxygen are the only detected major elements with an atomic O/C ratio of 0.11 ± 0.07. Minor elements observed include Si, S, Fe, Cr and Ni with the following atomic ratios relative to C: Si/C: 0.010 ± 0.011; S/C: 0.0007 ± 0.0015; Fe/C: 0.0052 ± 0.0074; Cr/C: 0.0012 ± 0.0017; Ni/C: 0.0006 ± 0.0011 (all mean values ± standard deviation).High-resolution element distribution images reveal that the minor elements are distributed within the carbonaceous matrix; i.e., heterogeneous inclusions are not observed. No difference in size, nanostructure and elemental composition was found between particles collected inside and outside the polar vortex. Based on chemistry and nanostructure

Removal of Refractory Organics from Biologically Treated Landfill Leachate by Microwave Discharge Electrodeless Lamp Assisted Fenton Process

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Jiuyi Li

2015-01-01

Full Text Available Biologically treated leachate usually contains considerable amount of refractory organics and trace concentrations of xenobiotic pollutants. Removal of refractory organics from biologically treated landfill leachate by a novel microwave discharge electrodeless lamp (MDEL assisted Fenton process was investigated in the present study in comparison to conventional Fenton and ultraviolet Fenton processes. Conventional Fenton and ultraviolet Fenton processes could substantially remove up to 70% of the refractory organics in a membrane bioreactor treated leachate. MDEL assisted Fenton process achieved excellent removal performance of the refractory components, and the effluent chemical oxygen demand concentration was lower than 100 mg L−1. Most organic matters were transformed into smaller compounds with molecular weights less than 1000 Da. Ten different polycyclic aromatic hydrocarbons were detected in the biologically treated leachate, most of which were effectively removed by MDEL-Fenton treatment. MDEL-Fenton process provides powerful capability in degradation of refractory and xenobiotic organic pollutants in landfill leachate and could be adopted as a single-stage polishing process for biologically treated landfill leachate to meet the stringent discharge limit.

Refractory versus resistant hypertension: Novel distinctive phenotypes

Science.gov (United States)

Dudenbostel, Tanja; Siddiqui, Mohammed; Gharpure, Nitin; Calhoun, David A.

2017-01-01

Resistant hypertension (RHTN) is relatively common with an estimated prevalence of 10-20% of treated hypertensive patients. It is defined as blood pressure (BP) >140/90 mmHg treated with ≥3 antihypertensive medications, including a diuretic, if tolerated. Refractory hypertension is a novel phenotype of severe antihypertensive treatment failure. The proposed definition for refractory hypertension, i.e. BP >140/90 mmHg with use of ≥5 different antihypertensive medications, including a diuretic and a mineralocorticoid receptor antagonist (MRA) has been applied inconsistently. In comparison to RHTN, refractory hypertension seems to be less prevalent than RHTN. This review focuses on current knowledge about this novel phenotype compared with RHTN including definition, prevalence, mechanisms, characteristics and comorbidities, including cardiovascular risk. In patients with RHTN excess fluid retention is thought to be a common mechanism for the development of RHTN. Recently, evidence has emerged suggesting that refractory hypertension may be more of neurogenic etiology due to increased sympathetic activity as opposed to excess fluid retention. Treatment recommendations for RHTN are generally based on use and intensification of diuretic therapy, especially with the combination of a long-acting thiazide-like diuretic and an MRA. Based on findings from available studies, such an approach does not seem to be a successful strategy to control BP in patients with refractory hypertension and effective sympathetic inhibition in such patients, either with medications and/or device based approaches may be needed. PMID:29034321

Refractory chronic migraine

DEFF Research Database (Denmark)

Martelletti, Paolo; Katsarava, Zaza; Lampl, Christian

2014-01-01

The debate on the clinical definition of refractory Chronic Migraine (rCM) is still far to be concluded. The importance to create a clinical framing of these rCM patients resides in the complete disability they show, in the high risk of serious adverse events from acute and preventative drugs...... and in the uncontrolled application of therapeutic techniques not yet validated.The European Headache Federation Expert Group on rCM presents hereby the updated definition criteria for this harmful subset of headache disorders. This attempt wants to be the first impulse towards the correct identification...... of these patients, the correct application of innovative therapeutic techniques and lastly aim to be acknowledged as clinical entity in the next definitive version of the International Classification of Headache Disorders 3 (ICHD-3 beta)....

Intraarticular Pulsed Radiofrequency to Treat Refractory Lumbar Facet Joint Pain in Patients with Low Back Pain.

Science.gov (United States)

Chang, Min Cheol; Cho, Yun-Woo; Ahn, Da Hyun; Do, Kyung Hee

2018-04-01

Many treatment techniques have been used for refractory lumbar facet joint pain; however, their efficacy has been controversial. In this study, we investigated the clinical efficacy and safety of intra-articular pulsed radiofrequency for the treatment of refractory lumbar facet joint pain in patients with low back pain. Twenty patients with refractory lumbar facet joint pain were recruited, and each patient was treated via intra-articular pulsed radiofrequency. The treatment effects were measured with a numerical rating scale, and the technical accuracy of intra-articular pulsed radiofrequency treatment was evaluated independently by 2 radiologists. Any adverse events or complications also were checked. We performed intra-articular pulsed radiofrequency treatment at 48 levels of the lumbar facet joints in 20 patients (5 men and 15 women; mean age, 64.50 ± 10.65 years) with refractory lumbar facet joint pain. Pain scores were significantly reduced at 1 month, 3 months, and 6 months after treatment (P radiofrequency results in all 20 patients, without any serious adverse effects. Treatment using intra-articular pulsed radiofrequency is an alternative to other techniques in patients with refractory lumbar facet joint pain. Copyright © 2018 Elsevier Inc. All rights reserved.

Impact of prior treatment and depth of response on survival in MM-003, a randomized phase 3 study comparing pomalidomide plus low-dose dexamethasone versus high-dose dexamethasone in relapsed/refractory multiple myeloma

Science.gov (United States)

San Miguel, Jesus F.; Weisel, Katja C.; Song, Kevin W.; Delforge, Michel; Karlin, Lionel; Goldschmidt, Hartmut; Moreau, Philippe; Banos, Anne; Oriol, Albert; Garderet, Laurent; Cavo, Michele; Ivanova, Valentina; Alegre, Adrian; Martinez-Lopez, Joaquin; Chen, Christine; Renner, Christoph; Bahlis, Nizar Jacques; Yu, Xin; Teasdale, Terri; Sternas, Lars; Jacques, Christian; Zaki, Mohamed H.; Dimopoulos, Meletios A.

2015-01-01

Pomalidomide is a distinct oral IMiD® immunomodulatory agent with direct antimyeloma, stromal-support inhibitory, and immunomodulatory effects. The pivotal, multicenter, open-label, randomized phase 3 trial MM-003 compared pomalidomide + low-dose dexamethasone vs high-dose dexamethasone in 455 patients with refractory or relapsed and refractory multiple myeloma after failure of bortezomib and lenalidomide treatment. Initial results demonstrated significantly longer progression-free survival and overall survival with an acceptable tolerability profile for pomalidomide + low-dose dexamethasone vs high-dose dexamethasone. This secondary analysis describes patient outcomes by treatment history and depth of response. Pomalidomide + low-dose dexamethasone significantly prolonged progression-free survival and favored overall survival vs high-dose dexamethasone for all subgroups analyzed, regardless of prior treatments or refractory status. Both univariate and multivariate analyses showed that no variable relating to either the number (≤ or > 3) or type of prior treatment was a significant predictor of progression-free survival or overall survival. No cross-resistance with prior lenalidomide or thalidomide treatment was observed. Patients achieving a minimal response or better to pomalidomide + low-dose dexamethasone treatment experienced a survival benefit, which was even higher in those achieving at least a partial response (17.2 and 19.9 months, respectively, as compared with 7.5 months for patients with less than minimal response). These data suggest that pomalidomide + low-dose dexamethasone should be considered a standard of care in patients with refractory or relapsed and refractory multiple myeloma regardless of prior treatment. ClinicalTrials.gov: NCT01311687; EudraCT: 2010-019820-30. PMID:26160879

Effects of Temperature, Oxygen Partial Pressure, and Materials Selection on Slag Infiltration into Porous Refractories for Entrained-Flow Gasifiers

Science.gov (United States)

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

Refractory myasthenia gravis - clinical profile, comorbidities and response to rituximab.

Science.gov (United States)

Sudulagunta, Sreenivasa Rao; Sepehrar, Mona; Sodalagunta, Mahesh Babu; Settikere Nataraju, Aravinda; Bangalore Raja, Shiva Kumar; Sathyanarayana, Deepak; Gummadi, Siddharth; Burra, Hemanth Kumar

2016-01-01

Introduction: Myasthenia gravis (MG) is an antibody mediated autoimmune neuromuscular disorder characterized by fatigable muscle weakness. A proportion of myasthenia gravis patients are classified as refractory due to non responsiveness to conventional treatment. This retrospective study was done to evaluate clinical profile, epidemiological, laboratory, and features of patients with MG and mode of management using rituximab and complications. Methods: Data of myasthenia gravis patients admitted or presented to outpatient department (previous medical records) with MG between January 2008 and January 2016 were included. A total of 512 patients fulfilled the clinical and diagnostic criteria of myasthenia gravis of which 76 patients met the diagnostic certainty for refractory myasthenia gravis and were evaluated. Results: Out of 76 refractory MG patients, 53 (69.73%) patients fulfilled all the three defined criteria. The median age of onset of the refractory MG group was 36 years with a range of 27-53 years. In our study 25 patients (32.89%) belonged to the age group of 21-30 years. Anti-MuSK antibodies were positive in 8 non-refractory MG patients (2.06%) and 36 refractory MG patients (47.36%). Mean HbA 1C was found to be 8.6±2.33. The dose of administered prednisone decreased by a mean of 59.7% ( p =3.3x10 -8 ) to 94.6% ( p =2.2x10 -14 ) after the third cycle of rituximab treatment. Conclusion: The refractory MG patients are most commonly female with an early age of onset, anti-MuSK antibodies, and thymomas. Refractory MG patients have higher prevalence and poor control (HbA 1C >8%) of diabetes mellitus and dyslipidemia probably due to increased steroid usage. Rituximab is very efficient in treatment of refractory MG with adverse effects being low.

Time-resolved analysis of particle emissions from residential biomass combustion - Emissions of refractory black carbon, PAHs and organic tracers

Science.gov (United States)

Nielsen, Ingeborg E.; Eriksson, Axel C.; Lindgren, Robert; Martinsson, Johan; Nyström, Robin; Nordin, Erik Z.; Sadiktsis, Ioannis; Boman, Christoffer; Nøjgaard, Jacob K.; Pagels, Joakim

2017-09-01

Time-resolved particle emissions from a conventional wood stove were investigated with aerosol mass spectrometry to provide links between combustion conditions, emission factors, mixing state of refractory black carbon and implications for organic tracer methods. The addition of a new batch of fuel results in low temperature pyrolysis as the fuel heats up, resulting in strong, short-lived, variable emission peaks of organic aerosol-containing markers of anhydrous sugars, such as levoglucosan (fragment at m/z 60). Flaming combustion results in emissions dominated by refractory black carbon co-emitted with minor fractions of organic aerosol and markers of anhydrous sugars. Full cycle emissions are an external mixture of larger organic aerosol-dominated and smaller thinly coated refractory black carbon particles. A very high burn rate results in increased full cycle mass emission factors of 66, 2.7, 2.8 and 1.3 for particulate polycyclic aromatic hydrocarbons, refractory black carbon, total organic aerosol and m/z 60, respectively, compared to nominal burn rate. Polycyclic aromatic hydrocarbons are primarily associated with refractory black carbon-containing particles. We hypothesize that at very high burn rates, the central parts of the combustion zone become air starved, leading to a locally reduced combustion temperature that reduces the conversion rates from polycyclic aromatic hydrocarbons to refractory black carbon. This facilitates a strong increase of polycyclic aromatic hydrocarbons emissions. At nominal burn rates, full cycle emissions based on m/z 60 correlate well with organic aerosol, refractory black carbon and particulate matter. However, at higher burn rates, m/z 60 does not correlate with increased emissions of polycyclic aromatic hydrocarbons, refractory black carbon and organic aerosol in the flaming phase. The new knowledge can be used to advance source apportionment studies, reduce emissions of genotoxic compounds and model the climate impacts of

Optimization of the Technological Synthesis of Refractory Compounds

Science.gov (United States)

Gaidar, S. M.; Karelina, M. Yu.; Prikhod'ko, V. M.; Volkov, A. A.

2017-12-01

The results of experimental studies, which are related to the regulation of the fractional composition of refractory compounds by roll milling in using controlled roll opening and unbalanced peripheral speeds of rollers, are reported. The content of prepared fine, middle, and coarse fractions is within 50-80%; in this case, the milling time of synthesis products is less than the time of ball milling by an order of magnitude. The application of roll milling for refining the products of self-propagating high-temperature synthesis can be most efficient in using together with heat-generating reactor to solve the main problem of self-propagating synthesis (SHS), which is a problem for recent several decades (the problem is the creation of intense automated production of refractory compounds in using continuous manufacturing cycle within a energotechnological system with the recovery of a great quantity of heat released during SHS).

Refractory overactive bladder: Beyond oral anticholinergic therapy

Science.gov (United States)

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

Refractory overactive bladder: Beyond oral anticholinergic therapy

Directory of Open Access Journals (Sweden)

Ronald W Glinski

2007-01-01

Full Text Available 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

Immunotoxin – a new treatment option in patients with relapsed and refractory Hodgkin lymphoma

Directory of Open Access Journals (Sweden)

Novakovic Barbara Jezersek

2015-12-01

Full Text Available Background. Even though Hodgkin lymphoma is a highly curable disease, some of the patients have either a refractory disease or experience a relapse following a successful primary therapy. Durable responses and remissions in patients with relapsed or refractory disease may be achieved in approximately one-half with salvage chemotherapy followed by high dose chemotherapy (HDT and autologous hematopoietic cell rescue (SCT. On the other hand, patients who relapse after HDT and autologous SCT or those who have failed at least two prior multi-agent chemotherapy regimens and are not candidates for HDT have limited treatment options.

Bone marrow immunophenotyping by flow cytometry in refractory cytopenia of childhood

NARCIS (Netherlands)

A.M. Aalbers (Anna Maartje); M.M. van den Heuvel-Eibrink (Marry); I. Baumann (Irith); M.N. Dworzak (Michael); H. Hasle (Henrik); F. Locatelli (Franco); B. de Moerloose (Barbara); M. Schmugge; E. Mejstříková (Ester); M. Nováková (Michaela); M. Zecca (Marco); C.M. Zwaan (Christian Michel); J.G. te Marvelde (Jeroen); A.W. Langerak (Anton); J.J.M. van Dongen (Jacques); R. Pieters (Rob); C.M. Niemeyer (Charlotte); V.H.J. van der Velden (Vincent)

2015-01-01

textabstractRefractory cytopenia of childhood is the most common type of childhood myelodysplastic syndrome. Because the majority of children with refractory cytopenia have a normal karyotype and a hypocellular bone marrow, differentiating refractory cytopenia from the immune-mediated bone marrow

Investigation of aluminosilicate refractory for solid oxide fuel cell applications

Science.gov (United States)

Gentile, Paul Steven

Stationary solid oxide fuel cells (SOFCs) have been demonstrated to provide clean and reliable electricity through electro-chemical conversion of various fuel sources (CH4 and other light hydrocarbons). To become a competitive conversion technology the costs of SOFCs must be reduced to less than $400/kW. Aluminosilicate represents a potential low cost alternative to high purity alumina for SOFC refractory applications. The objectives of this investigation are to: (1) study changes of aluminosilicate chemistry and morphology under SOFC conditions, (2) identify volatile silicon species released by aluminosilicates, (3) identify the mechanisms of aluminosilicate vapor deposition on SOFC materials, and (4) determine the effects of aluminosilicate vapors on SOFC electrochemical performance. It is shown thermodynamically and empirically that low cost aluminosilicate refractory remains chemically and thermally unstable under SOFC operating conditions between 800°C and 1000°C. Energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) of the aluminosilicate bulk and surface identified increased concentrations of silicon at the surface after exposure to SOFC gases at 1000°C for 100 hours. The presence of water vapor accelerated surface diffusion of silicon, creating a more uniform distribution. Thermodynamic equilibrium modeling showed aluminosilicate remains stable in dry air, but the introduction of water vapor indicative of actual SOFC gas streams creates low temperature (active anode interface.

Rate of primary refractory disease in B and T-cell non-Hodgkin's lymphoma: correlation with long-term survival.

Directory of Open Access Journals (Sweden)

Corrado Tarella

Full Text Available BACKGROUND: Primary refractory disease is a main challenge in the management of non-Hodgkin's Lymphoma (NHL. This survey was performed to define the rate of refractory disease to first-line therapy in B and T-cell NHL subtypes and the long-term survival of primary refractory compared to primary responsive patients. METHODS: Medical records were reviewed of 3,106 patients who had undergone primary treatment for NHL between 1982 and 2012, at the Hematology Centers of Torino and Bergamo, Italy. Primary treatment included CHOP or CHOP-like regimens (63.2%, intensive therapy with autograft (16.9%, or other therapies (19.9%. Among B-cell NHL, 1,356 (47.8% received first-line chemotherapy with rituximab. Refractory disease was defined as stable/progressive disease, or transient response with disease progression within six months. RESULTS: Overall, 690 (22.2% patients showed primary refractory disease, with a higher incidence amongst T-cell compared to B-cell NHL (41.9% vs. 20.5%, respectively, p<0.001. Several other clinico-pathological factors at presentation were variably associated with refractory disease, including histological aggressive disease, unfavorable clinical presentation, Bone Marrow involvement, low lymphocyte/monocyte ration and male gender. Amongst B-cell NHL, the addition of rituximab was associated with a marked reduction of refractory disease (13.6% vs. 26.7% for non-supplemented chemotherapy, p<0.001. Overall, primary responsive patients had a median survival of 19.8 years, compared to 1.3 yr. for refractory patients. A prolonged survival was consistently observed in all primary responsive patients regardless of the histology. The long life expectancy of primary responsive patients was documented in both series managed before and after 2.000. Response to first line therapy resulted by far the most predictive factor for long-term outcome (HR for primary refractory disease: 16.52, p<0.001. CONCLUSION: Chemosensitivity to primary

Extracorporeal membrane oxygenation for refractory cardiac arrest

Directory of Open Access Journals (Sweden)

Steven A Conrad

2017-01-01

Full Text Available Extracorporeal cardiopulmonary resuscitation (ECPR is the use of rapid deployment venoarterial (VA extracorporeal membrane oxygenation to support systemic circulation and vital organ perfusion in patients in refractory cardiac arrest not responding to conventional cardiopulmonary resuscitation (CPR. Although prospective controlled studies are lacking, observational studies suggest improved outcomes compared with conventional CPR when ECPR is instituted within 30-60 min following cardiac arrest. Adult and pediatric patients with witnessed in-hospital and out-of-hospital cardiac arrest and good quality CPR, failure of at least 15 min of conventional resuscitation, and a potentially reversible cause for arrest are candidates. Percutaneous cannulation where feasible is rapid and can be performed by nonsurgeons (emergency physicians, intensivists, cardiologists, and interventional radiologists. Modern extracorporeal systems are easy to prime and manage and are technically easy to manage with proper training and experience. ECPR can be deployed in the emergency department for out-of-hospital arrest or in various inpatient units for in-hospital arrest. ECPR should be considered for patients with refractory cardiac arrest in hospitals with an existing extracorporeal life support program, able to provide rapid deployment of support, and with resources to provide postresuscitation evaluation and management.

Colectomy for refractory constipation

DEFF Research Database (Denmark)

Raahave, Dennis; Loud, Franck Bjørn; Christensen, Elsebeth

2010-01-01

OBJECTIVE: This study evaluated the type of colectomy, postoperative complications, functional results, and satisfaction in patients with constipation refractory to conservative therapy. Further, colonic transit time (CTT), faecal load (coprostasis), and colon length (redundancies) were compared ...

Breakdown resistance of refractory metals compared to copper

CERN Document Server

Taborelli, M; Kildemo, M

2004-01-01

The behaviour of Mo, W and Cu with respect to electrical breakdown in ultra high vacuum has been investigated by means of a capacitor discharge method. The maximum stable electric field without breakdown and the field enhancement factor, beta have been measured between electrodes of the same material in a sphere/plane geometry for anode and cathode, respectively. The maximum stable field increases as a function of the number of breakdown events for W and Mo. In contrast, no systematic increase is observed for Cu. The highest values obtained are typically 500 MV/m for W, 350 MV/m for Mo and only 180 MV/m for Cu. This conditioning, found for the refractory metals, corresponds to a simultaneous decrease of beta and is therefore related to the field emission properties of the surface and their modification upon sparking. Accordingly, high beta values and no applicable field increase occur for Cu even after repeated breakdown. The results are compared with RF breakdown experiments [1] performed on prototype 30 GHz...

Statistical experimental design for refractory coatings

International Nuclear Information System (INIS)

McKinnon, J.A.; Standard, O.C.

2000-01-01

The production of refractory coatings on metal casting moulds is critically dependent on the development of suitable rheological characteristics, such as viscosity and thixotropy, in the initial coating slurry. In this paper, the basic concepts of mixture design and analysis are applied to the formulation of a refractory coating, with illustration by a worked example. Experimental data of coating viscosity versus composition are fitted to a statistical model to obtain a reliable method of predicting the optimal formulation of the coating. Copyright (2000) The Australian Ceramic Society

Typical corrosion of alumina refractory in aluminum reflow oven

International Nuclear Information System (INIS)

Baldo, Jaoa B.

2014-01-01

The refractory linings of furnaces for secondary melting of aluminum, are exposed to intense attack by the molten metal. This occurs, because molten aluminum has a strong reducing power over the refractory oxide components, particularly Fe 2 O 3 , SiO 2 and TiO 2 . In this work, based on X-ray diffraction and scanning electron microscopy, it is presented a post mortem study of the mechanisms that lead to a premature wear of a 80% Al2O3 chemically bonded refractory bricks, used in the metal line of an aluminum re-melting furnace. The SEM analysis demonstrated that the oxides SiO 2 and TiO 2 contained in the refractory were reduced and transformed into their metallic elements causing an intense structural spalling. (author)

Azacitidine and lenalidomide as an alternative treatment for refractory acute myeloid leukemia: a case report.

Science.gov (United States)

Todaro, Juliana; Bollmann, Patrícia Weinschenker; Rother, Edna Terezinha; del Giglio, Auro

2015-01-01

Refractory acute myeloid leukemia (AML) is a difficult disease to control with second or third-line chemotherapy regimens. In this report, we describe using azacitidine in combination with lenalidomide as salvage therapy. 52-year-old female was diagnosed with refractory AML and high-risk cytogenetics: complex monosomal karyotype consisting of t (3, 3) in association with monosomy 7 and del 5q. Morphological remission associated with maintenance of the cytogenetic abnormality of chromosome 3 and disappearance of the abnormalities relating to chromosomes 5 and 7 was achieved after three cycles of combination therapy with azacitidine and lenalidomide. Azacitidine plus lenalidomide can be a therapeutic option for patients with refractory AML, as illustrated in this case.

Treatment of refractory chylothorax with externalized pleuroperitoneal shunts in children.

Science.gov (United States)

Wolff, A B; Silen, M L; Kokoska, E R; Rodgers, B M

1999-09-01

Traditional therapy for refractory chylothorax in the pediatric population has included pleurodesis and thoracic duct ligation. These procedures are associated with high morbidity and questionable success rates. We retrospectively reviewed our experience with 15 patients who underwent treatment for chylous effusions using pleuroperitoneal shunts with exteriorized pump chambers. Mean patient age at time of shunt placement was 2.1 (0.1 to 11.5) years and the most common indication (7 of 15) was refractory chylothorax following surgical correction of congenital heart disease. Mean chylothorax duration before shunt placement was 76 (5 to 810) days and shunts were in place for an average of 104 (12 to 365) days. A total of 19 chylous effusions (pleural or pericardial) were treated with shunts. Nine of 11 right-sided chylothoraces, 5 of 6 left-sided chylothoraces, and 2 of 2 chylopericardia resolved with shunt therapy (84% total). Pleuroperitoneal shunting failed to clear the effusion in 3 children. There were six episodes of shunt malfunction that were repaired and two episodes of infection. Inguinal or umbilical hernia developed in 4 patients. Externalized pleuroperitoneal shunting is a safe, effective, and minimally invasive treatment for children with refractory chylous effusions.

Review of alkali metal and refractory alloy compatibility for Rankine cycle applications

International Nuclear Information System (INIS)

DiStefano, J.R.

1989-01-01

The principal corrosion mechanisms in refractory metal-alkali systems are dissolution, mass transfer, and impurity reactions. In general, niobium, tantalum, molybdenum, and tungsten have low solubilities in the alkali metals, even to very high temperatures, and static corrosion studies have verified that the systems are basically compatible. Loop studies with niobium and tantalum based alloys do not indicate any serious problems due to temperature gradient mass transfer. Above 1000 K, dissimilar metal mass transfer is noted between the refractory metals and iron or nickel based alloys. The most serious corrosion problems encountered are related to impurity reactions associated with oxygen

Refractory materials based on compounds of Mg, Zr, Si and Ca

International Nuclear Information System (INIS)

Drygalska, E.; Piech, J.; Szczerba, J.

2003-01-01

Basic refractory materials modified with zirconium oxide or calcium zirconate find application in metallurgy and ceramic industry. Fundamental raw material for ZrO 2 production is zirconia sand, while synthetic calcium zirconate is produced in reaction of zirconium oxide with calcium oxide. Regarding these facts new highly refractory composite materials CZ and DZ were obtained from mixtures of zirconia sand and limestone of dolomite. These composite materials may contain stabilised ZrO 2 and/or calcium zirconate. Among other important components are periclase and calcium orthosilicates. All these phases have high melting points (above 2000 o C). This work describes thermal and technological properties and microstructure of CZ and DZ materials. The use of calcareous raw materials (limestone and dolomite) yields materials with good hydration resistance. These composites may be used as an additive modifying properties of magnesia products. (author)

Fire and explosion hazards of refractory compound powders

International Nuclear Information System (INIS)

Krivtsov, V.A.; Kostina, E.S.

1978-01-01

Data on fire and explosion hazards of refractory compound powders (HfC, ZrC,LaB 6 , ZrN, etc.) are presented. It is shown that refractory compounds can be fire- and exposion hazardous in various degrees. Qualitative and quantitative estimations of one of fire-hazard characteristics - smoldering temperature - are presented

Supersonic pulsed free-jet of atoms and molecules of refractory metals: laser induced fluorescence spectroscopic studies on zirconium atoms and zirconium oxide molecules

International Nuclear Information System (INIS)

Nakhale, S.G.

2004-11-01

The experimental setup for generating supersonic pulsed free-jet containing atoms and molecules of refractory nature has been built. The technique of laser vaporization in conjunction with supersonic cooling is used to generate these species. The cooled atoms and molecules in supersonic free-jet are probed by laser induced fluorescence spectroscopy. In particular, the technique has been used to perform low-resolution laser induced fluorescence spectroscopy, limited by laser linewidth, on cold Zr atoms and ZrO molecules. The translational temperatures of ∼ 26.5 K and the rotational temperatures of ∼ 81 K have been achieved. It is possible to achieve the Doppler width of few tens of MHz allowing it to perform high-resolution spectroscopy on these atomic and molecular species. Also because of low rotational temperature of molecules the spectral congestion is greatly reduced. In general, this technique can be applied to perform spectroscopy on atoms and molecules of refractory nature. (author)

Glatiramer Acetate-associated Refractory Immune Thrombocytopenic Purpura

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Iftach Sagy

2016-04-01

Full Text Available We present a case of glatiramer acetate-associated refractory immune thrombocytopenic purpura (ITP in a female patient with multiple sclerosis. A search of MEDLINE/PubMed did not find any connection between glatiramer acetate and thrombocytopenia, specifically ITP. The autoimmune reaction was resistant to conservative ITP treatment, and was eventually managed only by splenectomy. To the best of our knowledge, this is the first report of glatiramer acetate-associated ITP. Physicians should be aware of this condition, and consider performing routine blood counts at the beginning of glatiramer acetate treatment.

Mortality, morbidity and refractoriness prediction in status epilepticus: Comparison of STESS and EMSE scores.

Science.gov (United States)

Giovannini, Giada; Monti, Giulia; Tondelli, Manuela; Marudi, Andrea; Valzania, Franco; Leitinger, Markus; Trinka, Eugen; Meletti, Stefano

2017-03-01

Status epilepticus (SE) is a neurological emergency, characterized by high short-term morbidity and mortality. We evaluated and compared two scores that have been developed to evaluate status epilepticus prognosis: STESS (Status Epilepticus Severity Score) and EMSE (Epidemiology based Mortality score in Status Epilepticus). A prospective observational study was performed on consecutive patients with SE admitted between September 2013 and August 2015. Demographics, clinical variables, STESS-3 and -4, and EMSE-64 scores were calculated for each patient at baseline. SE drug response, 30-day mortality and morbidity were the outcomes measure. 162 episodes of SE were observed: 69% had a STESS ≥3; 34% had a STESS ≥4; 51% patients had an EMSE ≥64. The 30-days mortality was 31.5%: EMSE-64 showed greater negative predictive value (NPV) (97.5%), positive predictive value (PPV) (59.8%) and accuracy in the prediction of death than STESS-3 and STESS-4 (pstatus epilepticus proved refractory to non-anaesthetic treatment. All three scales showed a high NPV (EMSE-64: 87.3%; STESS-4: 89.4%; STESS-3: 87.5%) but a low PPV (EMSE-64: 40.9%; STESS-4: 52.9%; STESS-3: 32%) for the prediction of refractoriness to first and second line drugs. This means that accuracy for the prediction of refractoriness was equally poor for all scales. EMSE-64 appears superior to STESS-3 and STESS-4 in the prediction of 30-days mortality and morbidity. All scales showed poor accuracy in the prediction of response to first and second line antiepileptic drugs. At present, there are no reliable scores capable of predicting treatment responsiveness. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Mechanical properties of refractory concretes for boilers; Propriedades mecanicas de concretos refratarios para caldeiras

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Angioletto, E.; Pelisser, F.; Peterson, M.; Angioletto, E.; Rocha, M.R.; Arnt, A.B.C. [Universidade do Estado de Santa Catarina (UDESC), Criciuma, SC (Brazil)], E-mail: ean@unesc.net; Coelho, R. [Tractebel Energia, Florianpolis, SC (Brazil)

2010-07-01

Refractory concretes are used in extremely physically demanding conditions. An important example is concretes used as sealing systems in boilers, where their dimensional stability at high temperatures is fundamental to durability and has a strong impact on maintenance costs and system idleness. In this work, refractory concretes with different compositions were characterized and then tested by dilatometry, for compressive strength and in assays involving adherence between tensile concrete/metal inserts, simulating the fixing system in boilers. Analysis of the results showed that refractory concretes do not present retraction due to air during drying, eliminating the possibility of cracking. While casting the plate/prototype with metal inserts, satisfactory concrete/metal adherence was verified and surface cracking occurred that did not influence the tensile bond strength between the insert and the concrete. (author)

Sub-micrometer refractory carbonaceous particles in the polar stratosphere

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K. Schütze

2017-10-01

Full Text Available Eleven particle samples collected in the polar stratosphere during SOLVE (SAGE III Ozone loss and validation experiment from January until March 2000 were characterized in detail by high-resolution transmission and scanning electron microscopy (TEM/SEM combined with energy-dispersive X-ray microanalysis. A total of 4202 particles (TEM  =  3872; SEM  =  330 were analyzed from these samples, which were collected mostly inside the polar vortex in the altitude range between 17.3 and 19.9 km. Particles that were volatile in the microscope beams contained ammonium sulfates and hydrogen sulfates and dominated the samples. Some particles with diameters ranging from 20 to 830 nm were refractory in the electron beams. Carbonaceous particles containing additional elements to C and O comprised from 72 to 100 % of the refractory particles. The rest were internal mixtures of these materials with sulfates. The median number mixing ratio of the refractory particles, expressed in units of particles per milligram of air, was 1.1 (mg air−1 and varied between 0.65 and 2.3 (mg air−1. Most of the refractory carbonaceous particles are completely amorphous, a few of the particles are partly ordered with a graphene sheet separation distance of 0.37 ± 0.06 nm (mean value ± standard deviation. Carbon and oxygen are the only detected major elements with an atomic O∕C ratio of 0.11 ± 0.07. Minor elements observed include Si, S, Fe, Cr and Ni with the following atomic ratios relative to C: Si∕C: 0.010 ± 0.011; S∕C: 0.0007 ± 0.0015; Fe∕C: 0.0052 ± 0.0074; Cr∕C: 0.0012 ± 0.0017; Ni∕C: 0.0006 ± 0.0011 (all mean values ± standard deviation.High-resolution element distribution images reveal that the minor elements are distributed within the carbonaceous matrix; i.e., heterogeneous inclusions are not observed. No difference in size, nanostructure and elemental composition was found between

Determination of the resistance to tensile fracture of refractory mixtures of gunite

International Nuclear Information System (INIS)

Gomez Sanchez, A; Tomba Martinez, A.G

2004-01-01

The determination of the mechanical properties of cooled refractory mixtures is useful since it allows the materials to be compared for the purposes of selection and reports on their degree of internal cohesion, green or calcination, so that their structural ability can be estimated, especially during installation. Given the testing difficulties originating in the fragility of the ceramic materials, the tension test is not generally used in refractories. However, ASTM C-307 94 determines the tensile strength of cured chemical-resistant materials, for which this work considered the possibility of testing cement-based monolithic refractories in this non conventional condition. The tensile resistance to the fracture of three different refractory mixtures (A, B 1 and B 2 ), used in heat repairing by gunite in coking ovens, that were characterized by chemical, granulometric, and mineralogical analysis pycnometric density measurements. The pieces for the tests ('bone' type: length = 75 mm, maximum width = 40 mm, minimum width = 25 mm, thickness = 10 - 25 mm) were prepared by ramming of mixtures of material/water in a metallic mold; they were sinterized (1200 o C, 1h) and characterized by measures of bulk density, porosity and observation of the surface texture, in green and calcinated. The tensile tests, based on ASTM C-307 94, were performed in an Instron model 4467 machine in open air, at room temperature and position control (0.5 mm/min). The following values were obtained, in kPa: AW347±308; B 1 W738±130; B 2 W604±64. These values were lower than those for the tensile fracture module (MOR), although they displayed an equivalent order: A≤B 2 ≤B 1 . This was related to the characteristics of each refractory mixture and at the end of the pieces tested (CW)

Immunomodulatory therapy in refractory/recurrent ovarian cancer.

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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.

Low carbon content and carbon-free refractory materials with high thermal shock resistance; Thermoschockbestaendige feuerfeste Erzeugnisse mit geringerem Kohlenstoffgehalt bzw. kohlenstofffreie Erzeugnisse

Energy Technology Data Exchange (ETDEWEB)

Brachhold, Nora; Aneziris, C.G.; Stein, Volker; Roungos, Vasileios; Moritz, Kirsten [TU Bergakademie Freiberg (TUBAF) (DE). Inst. fuer Keramik, Glas- und Baustofftechnik (IKGB)

2012-07-01

Carbon bonded refractories are essential for steelmaking due to their excellent thermal shock resistance. The research on carbon reduced and carbon-free materials is necessary to manufacture high quality stainless steels tending carbon pick-up in contact to conventional refractory materials. Further advantages are reduced emissions of CO{sub 2} and energy saving potentials due to better heat insulation properties. The challenge is to develop alternative materials with lower carbon contents but with the necessary thermal shock resistance. The Priority Programme 1418 funded by the German Research Foundation (DFG) concentrates on this problem. In this article two materials are presented. First, the carbon content could be reduced by nanoscaled additives resulting in better bonding between matrix and oxidic components. Second, an AL{sub 2}O{sub 3}-rich carbon-free material is presented showing a very good thermal shock resistance due to its designed microstructure. Finally, a steel casting simulator is introduced to test the new materials under nearly real conditions. (orig.)

On the nature and origin of garnet in highly-refractory Archean lithosphere: implications for continent stabilisation

Science.gov (United States)

Gibson, Sally

2014-05-01

The nature and timescales of garnet formation in the Earth's subcontinental lithospheric mantle (SCLM) are important to our understanding of how this rigid outer shell has evolved and stabilised since the Archean. Nevertheless, the widespread occurrence of pyrope garnet in the sub-cratonic mantle remains one of the 'holy grails' of mantle petrology. The paradox is that garnet often occurs in mantle lithologies (dunites and harzburgites) which represent residues of major melting events (up to 40 %) whereas experimental studies on fertile peridotite suggest this phase should be exhausted by years. The garnets display systematic trends from ultra-depleted to enriched compositions that have not been recognised in peridotite suites from elsewhere (Gibson et al., 2013). Certain harzburgite members of the xenolith suite contain the first reported occurrence of pyrope garnets with rare-earth element (REE) patterns similar to hypothetical garnets proposed by Stachel et al. (2004) to have formed in the Earth's SCLM during the Archean, prior to metasomatism. These rare ultra-depleted low-Cr garnets occur in low temperature (~1050 oC) xenoliths derived from depths of ~120 km and coexist in chemical and textural equilibrium with highly-refractory olivine (Fo95.4) and orthopyroxene (Mg#=96.4). These phases are all more magnesian than generally encountered in global samples of depleted mantle, i.e. harzburgites and diamond inclusion suites. The Tanzanian ultra-depleted garnets form interconnecting networks ('necklaces') around grains of orthopyroxene, which is of key importance to their origin. This close spatial relationship of garnet and orthopyroxene together with the major, trace and REE contents of the ultra-depleted garnets, are consistent with an origin by isochemical exsolution. The significance of ultra-depleted low-Cr garnets has not previously been recognised in global suites of mantle xenoliths or diamond inclusions: they appear to have been overlooked, primarily

Immune-Inflammatory and Metabolic Effects of High Dose Furosemide plus Hypertonic Saline Solution (HSS Treatment in Cirrhotic Subjects with Refractory Ascites.

Directory of Open Access Journals (Sweden)

Antonino Tuttolomondo

Full Text Available Patients with chronic liver diseases are usually thin as a result of hypermetabolism and malnutrition expressed by reduced levels of leptin and impairment of other adyponectins such as visfatin.We evaluated the metabolic and inflammatory effects of intravenous high-dose furosemide plus hypertonic saline solutions (HSS compared with repeated paracentesis and a standard oral diuretic schedule, in patients with cirrhosis and refractory ascites.59 consecutive cirrhotic patients with refractory ascites unresponsive to outpatient treatment. Enrolled subjects were randomized to treatment with intravenous infusion of furosemide (125-250mg⁄bid plus small volumes of HSS from the first day after admission until 3 days before discharge (Group A, n:38, or repeated paracentesis from the first day after admission until 3 days before discharge (Group B, n: 21. Plasma levels of ANP, BNP, Leptin, visfatin, IL-1β, TNF-a, IL-6 were measured before and after the two type of treatment.Subjects in group A were observed to have a significant reduction of serum levels of TNF-α, IL-1β, IL-6, ANP, BNP, and visfatin, thus regarding primary efficacy endpoints, in Group A vs. Group B we observed higher Δ-TNF-α, Δ-IL-1β, Δ-IL-6, Δ-ANP, Δ-BNP, Δ-visfatin, Δ-Leptin at discharge.Our findings underline the possible inflammatory and metabolic effect of saline overload correction in treatment of cirrhosis complications such as refractory ascites, suggesting a possible role of inflammatory and metabolic-nutritional variables as severity markers in these patients.

Individualized 131I-mIBG therapy in the management of refractory and relapsed neuroblastoma.

Science.gov (United States)

George, Sally L; Falzone, Nadia; Chittenden, Sarah; Kirk, Stephanie J; Lancaster, Donna; Vaidya, Sucheta J; Mandeville, Henry; Saran, Frank; Pearson, Andrew D J; Du, Yong; Meller, Simon T; Denis-Bacelar, Ana M; Flux, Glenn D

2016-05-01

Iodine-131-labelled meta-iodobenzylguanidine (I-mIBG) therapy is an established treatment modality for relapsed/refractory neuroblastoma, most frequently administered according to fixed or weight-based criteria. We evaluate response and toxicity following a dosimetry-based, individualized approach. A review of 44 treatments in 25 patients treated with I-mIBG therapy was performed. Patients received I-mIBG therapy following relapse (n=9), in refractory disease (n=12), or with surgically unresectable disease despite conventional treatment (n=4). Treatment schedule (including mIBG dose and number of administrations) was individualized according to the clinical status of the patient and dosimetry data from either a tracer study or previous administrations. Three-dimensional tumour dosimetry was also performed for eight patients. The mean administered activity was 11089±7222 MBq and the mean whole-body dose for a single administration was 1.79±0.57 Gy. Tumour-absorbed doses varied considerably (3.70±3.37 mGy/MBq). CTCAE grade 3/4 neutropenia was documented following 82% treatments and grade 3/4 thrombocytopenia following 71% treatments. Further acute toxicity was found in 49% of patients. All acute toxicities resolved with appropriate therapy. The overall response rate was 58% (complete or partial response), with a further 29% of patients having stable disease. A highly personalized approach combining patient-specific dosimetry and clinical judgement enables delivery of high activities that can be tolerated by patients, particularly with stem cell support. We report excellent response rates and acceptable toxicity following individualized I-mIBG therapy.

[Therapy-resistant and therapy-refractory arterial hypertension].

Science.gov (United States)

Wallbach, M; Koziolek, M J

2018-05-02

Therapy-resistant and therapy-refractory arterial hypertension differ in prevalence, pathogenesis, prognosis and therapy. In both cases, a structured approach is required, with the exclusion of pseudoresistance and, subsequently, secondary hypertension. Resistant hypertension has been reported to be more responsive to intensified diuretic therapy, whereas refractory hypertension is presumed to require sympathoinhibitory therapy. Once the general measures and the drug-based step-up therapy have been exhausted, interventional procedures are available.

Refractory myasthenia gravis – clinical profile, comorbidities and response to rituximab

Science.gov (United States)

Sudulagunta, Sreenivasa Rao; Sepehrar, Mona; Sodalagunta, Mahesh Babu; Settikere Nataraju, Aravinda; Bangalore Raja, Shiva Kumar; Sathyanarayana, Deepak; Gummadi, Siddharth; Burra, Hemanth Kumar

2016-01-01

Introduction: Myasthenia gravis (MG) is an antibody mediated autoimmune neuromuscular disorder characterized by fatigable muscle weakness. A proportion of myasthenia gravis patients are classified as refractory due to non responsiveness to conventional treatment. This retrospective study was done to evaluate clinical profile, epidemiological, laboratory, and features of patients with MG and mode of management using rituximab and complications. Methods: Data of myasthenia gravis patients admitted or presented to outpatient department (previous medical records) with MG between January 2008 and January 2016 were included. A total of 512 patients fulfilled the clinical and diagnostic criteria of myasthenia gravis of which 76 patients met the diagnostic certainty for refractory myasthenia gravis and were evaluated. Results: Out of 76 refractory MG patients, 53 (69.73%) patients fulfilled all the three defined criteria. The median age of onset of the refractory MG group was 36 years with a range of 27–53 years. In our study 25 patients (32.89%) belonged to the age group of 21–30 years. Anti-MuSK antibodies were positive in 8 non-refractory MG patients (2.06%) and 36 refractory MG patients (47.36%). Mean HbA1C was found to be 8.6±2.33. The dose of administered prednisone decreased by a mean of 59.7% (p=3.3x10–8) to 94.6% (p=2.2x10–14) after the third cycle of rituximab treatment. Conclusion: The refractory MG patients are most commonly female with an early age of onset, anti-MuSK antibodies, and thymomas. Refractory MG patients have higher prevalence and poor control (HbA1C >8%) of diabetes mellitus and dyslipidemia probably due to increased steroid usage. Rituximab is very efficient in treatment of refractory MG with adverse effects being low. PMID:27790079

Clinical and microbiological features of refractory periodontitis subjects.

Science.gov (United States)

Colombo, A P; Haffajee, A D; Dewhirst, F E; Paster, B J; Smith, C M; Cugini, M A; Socransky, S S

1998-02-01

The purpose of this investigation was to compare the clinical parameters and the site prevalence and levels of 40 subgingival species in successfully treated and refractory periodontitis subjects. 94 subjects received scaling and root planing and if needed, periodontal surgery and systemically administered tetracycline. 28 refractory subjects showed mean full mouth attachment loss and/or > 3 sites showing attachment loss > 2.5 mm within 1 year post-therapy. 66 successfully treated subjects showed mean attachment level gain and no sites with attachment loss > 2.5 mm. Baseline subgingival plaque samples were taken from the mesial aspect of each tooth and the presence and levels of 40 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and % of sites colonized by each species (prevalence) was computed for each subject and differences between groups sought using the Mann-Whitney test. Most of the 40 species tested, including Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Bacteroides forsythus, were equally or less prevalent in the refractory group. Prevotella nigrescens was significantly more prevalent in successfully treated subjects, while refractory subjects harbored a larger proportion of Streptococcus species, particularly Streptococcus constellatus. The odds of a subject being refractory was 8.6 (p or = 3.5% of the total DNA probe count. Since few microbiological differences existed between treatment outcome groups using DNA probes to known species, the predominant cultivable microbiota of 33 subgingival samples from 14 refractory subjects was examined. 85% of the 1649 isolates were identified using probes to 69 recognized subgingival species. The remaining unidentified strains were classified by analyzing 16S rRNA gene sequences. Many sequenced isolates were of taxa not considered a common part of the oral microbiota such as Acinetobacter baumanni

Azacitidine and lenalidomide as an alternative treatment for refractory acute myeloid leukemia: a case report

Directory of Open Access Journals (Sweden)

Juliana Todaro

Full Text Available CONTEXT:Refractory acute myeloid leukemia (AML is a difficult disease to control with second or third-line chemotherapy regimens. In this report, we describe using azacitidine in combination with lenalidomide as salvage therapy.CASE REPORT:52-year-old female was diagnosed with refractory AML and high-risk cytogenetics: complex monosomal karyotype consisting of t (3, 3 in association with monosomy 7 and del 5q. Morphological remission associated with maintenance of the cytogenetic abnormality of chromosome 3 and disappearance of the abnormalities relating to chromosomes 5 and 7 was achieved after three cycles of combination therapy with azacitidine and lenalidomide.CONCLUSION:Azacitidine plus lenalidomide can be a therapeutic option for patients with refractory AML, as illustrated in this case.

Trend of the refractory technology in ICR and UNITECR; Taikabutsu kokusai kaigi oyobi toitsu taikabutsu kokusai kaigi no happyo kara mita taikabutsu gijutsu no doko

Energy Technology Data Exchange (ETDEWEB)

Taira, H.

1996-05-01

Technological trends have been compiled on the basis of the agendas of all the six events from the 1st International Conference on Refractories through the UNITECR `95 held in Japan. Although the number of articles presented increased from 52 to 187 during this period, yet there was a remarkable decrease in the number of articles in some fields related to refractories for iron and steel making, the said field involving pig iron melting preparatory treatment and torpedo cars. There is no great change in the number of articles about the MgO-C brick in use for building converters and electric furnaces that are typical kilns, with various countries presenting papers indicating that the brick is the representative of high-performance refractories being used across the world. There is a steady increase in the number of articles related to nonferrous metals, glass, and cement, and attracting attention is the papers concerning incinerators. The number of papers about basic technologies and new testing methods is constant. Attracting attention are papers for example on fine ceramics with its scope of application as refractories spreading, which reflects the technological trends across the world and the circumstances the host countries find themselves under. It is added here that Brazil rich in refractory resources presented many papers at the conference that it hosted. 27 refs., 7 tabs.

Supra-Tenon Capsule Implantation of the Ahmed Glaucoma Valve in Refractory Pediatric Glaucoma.

Science.gov (United States)

Elhefney, Eman M; Al-Sharkawy, Hossam T; Kishk, Hanem M

2016-09-01

To evaluate the efficacy of supra-Tenon capsule implantation of an Ahmed glaucoma valve (AGV) as a measure to decrease the fibrotic potential of the Tenon capsule on bleb formation and its subsequent effect on intraocular pressure (IOP) control in children with refractory glaucoma. Mansoura Ophthalmic Centre, Faculty of Medicine, Mansoura University, Egypt. A prospective interventional study. Twenty-two eyes of 12 children with refractory glaucoma underwent supra-Tenon capsule implantation of AGV. Ophthalmic examinations under general anesthesia including measurement of the corneal diameter and the IOP with Perkin's tonometer were performed preoperatively, on the first postoperative day, the first postoperative week, weekly for the first month, 2-weekly for the following 3 months, and monthly for at least 18 months. Postoperative complications and the number of glaucoma medications used preoperatively and postoperatively were recorded. The paired Student t test was used to compare preoperative and postoperative data. There were 12 eyes (54.6%) with refractory congenital glaucoma, 7 eyes (31.8%) with refractory pseudophakic glaucoma, and 3 eyes (13.6%) with refractory aphakic glaucoma. Patients included 10 male (83.3%) and 2 female (16.7%) children with a mean age of 16.3±9.7 months. The mean follow-up duration was 24.1±4.3 months. There was a statistically significant difference between the mean preoperative IOP (30.7±2.88 mm Hg) and the mean postoperative IOP (16.1±3.60 mm Hg) (t=16.22 and P=0.000, with a mean decrease in the IOP by 47.6%). The difference between the mean number of antiglaucoma medications before surgery (1.86±0.4) and after surgery (1.0±0.9) was also statistically significant (t=4.31 and P=0.000). Total success was achieved in 18 eyes (81.9%). Postoperative complications included tube exposure and slippage (10%), hypotony (10%), and hyphema (5%). Supra-Tenon capsule implantation of the AGV was successful in controlling the IOP with few

Irinotecan in patients with relapsed or cisplatin-refractory germ cell cancer: a phase II study of the German Testicular Cancer Study Group

OpenAIRE

Kollmannsberger, C; Rick, O; Klaproth, H; Kubin, T; Sayer, H G; Hentrich, M; Welslau, M; Mayer, F; Kuczyk, M; Spott, C; Kanz, L; Bokemeyer, C

2002-01-01

Despite generally high cure rates in patients with metastatic germ cell cancer, patients with progressive disease on first-line cisplatin-based chemotherapy or with relapsed disease following high-dose salvage therapy exhibit a very poor prognosis. Irinotecan has shown antitumour activity in human testicular tumour xenografts in nude mice. We have performed a phase II study examining the single agent activity of irinotecan in patients with metastatic relapsed or cisplatin-refractory germ cell...

The ketogenic diet and other dietary treatments for refractory epilepsy in children

Directory of Open Access Journals (Sweden)

Suvasini Sharma

2014-01-01

Full Text Available The ketogenic diet is a high-fat, low-carbohydrate, and restricted protein diet that is useful in patients with refractory epilepsy. The efficacy of the ketogenic diet is better than most of the new antiepileptic drugs. Other modifications of the diet are also beneficial, such as the modified Atkins diet and the low glycemic index treatment. There is a lack of awareness of the ketogenic diet as a treatment modality for epilepsy amongst pediatricians and neurologists. In this review, the use of the ketogenic diet and other dietary treatments in refractory epilepsy is discussed. The Indian experience with the use of these dietary treatments is also briefly reviewed.

The ketogenic diet and other dietary treatments for refractory epilepsy in children

Science.gov (United States)

Sharma, Suvasini; Jain, Puneet

2014-01-01

The ketogenic diet is a high-fat, low-carbohydrate, and restricted protein diet that is useful in patients with refractory epilepsy. The efficacy of the ketogenic diet is better than most of the new antiepileptic drugs. Other modifications of the diet are also beneficial, such as the modified Atkins diet and the low glycemic index treatment. There is a lack of awareness of the ketogenic diet as a treatment modality for epilepsy amongst pediatricians and neurologists. In this review, the use of the ketogenic diet and other dietary treatments in refractory epilepsy is discussed. The Indian experience with the use of these dietary treatments is also briefly reviewed. PMID:25221391

Defining refractory migraine: results of the RHSIS Survey of American Headache Society members.

Science.gov (United States)

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

The Role of Refractory Dissolved Organic Matter in Ocean Carbon Sequestration

DEFF Research Database (Denmark)

Jørgensen, Linda

The ocean assimilates a large amount of atmospheric CO2 and is potentially a buffer for climate change. A fraction of the assimilated CO2 is incorporated into algal biomass and further converted into refractory dissolved organic matter (DOM). Carbon bound in refractory DOM has the potential...... studies the prokaryotic production and degradation of oceanic refractory DOM and discusses the reasons for the persistent nature of this large DOM fraction. The first two papers investigate the microbial carbon pump, i.e. prokaryotic transfor-mation of organic carbon into refractory DOM. The results show...... DOM compounds in the ocean are rare—possibly too rare to sustain viable uptake and assimilation. Hence, the dilute concentration of individual compounds is a possible explanation for the apparent refractory nature of most DOM in the ocean. Understanding the mechanisms that control the quality...

Intraepithelial lymphocytes in refractory celiac disease : lost in transition

NARCIS (Netherlands)

Schmitz, Frederike

2014-01-01

Refractory coeliac disease type II (RCDII) is a severe complication of coeliac disease. Whereas celiac disease can successfully be treated by the strict avoidance of gluten, refractory celiac patients show no remission despite a gluten-free diet. The pathology of RCDII is only partially understood,

Atopy: a risk factor of refractory mycoplasma pneumoniae pneumonia?

Science.gov (United States)

Bao, Yi-Xiao; Li, Jing; Tian, Ye; Liu, Quang-Hua; Bao, Jun

2017-11-01

To investigate the relationship of pathogen DNA copies with clinic and laboratory features among children with Mycoplasma pneumoniae (MP) pneumonia. A total of 95 enrolled children with MP pneumonia were assigned into the high-MP-load group (>10 6 /mL) and the low-MP-load group (≤10 6 /mL) according to MP-DNA copies in bronchoalveolar lavage fluid (BALF). Clinical characteristics and any allergy history were collected. Aeroallergens and food allergens were detected with a skin test. Serum IgE and eosinophil cationic protein (ECP) were assessed using enzyme immunoassay. BALF levels of IL-4, IFN-γ, IL-8 and TNF-α were assessed by ELISA. Compared with the low-MP-load group, 72.7% in the high-MP-load group developed refractory MP pneumonia who failed to respond to at least 1-week treatment with macrolides (72.7% vs 41.9%, P = 0.005). More children in the high-load group than those in the low-load group presented with extrapulmonary manifestations, lung consolidation, pleural effusion and atopic conditions including any allergy history, positive findings of aeroallergen test and increased serum IgE and ECP (P  0.05). Atopy may be a risk factor for the presence and severity of refractory MP pneumonia due to the high pathogen load in airway. © 2016 John Wiley & Sons Ltd.

White-Coat Effect Is Uncommon in Patients With Refractory Hypertension.

Science.gov (United States)

Siddiqui, Mohammed; Judd, Eric K; Oparil, Suzanne; Calhoun, David A

2017-09-01

Refractory hypertension is a recently described phenotype of antihypertensive treatment failure defined as uncontrolled blood pressure (BP) despite the use of ≥5 different antihypertensive agents, including chlorthalidone and spironolactone. Recent studies indicate that refractory hypertension is uncommon, with a prevalence of ≈5% to 10% of patients referred to a hypertension specialty clinic for uncontrolled hypertension. The prevalence of white-coat effect, that is, uncontrolled automated office BP ≥135/85 mm Hg and controlled out-of-office BP hypertensive patients overall is ≈30% to 40%. The prevalence of white-coat effect among patients with refractory hypertension has not been previously reported. In this prospective evaluation, consecutive patients referred to the University of Alabama at Birmingham Hypertension Clinic for uncontrolled hypertension were enrolled. Refractory hypertension was defined as uncontrolled automated office BP ≥135/85 mm Hg with the use of ≥5 antihypertensive agents, including chlorthalidone and spironolactone. Automated office BP measurements were based on 6 serial readings, done automatically with the use of a BpTRU device unobserved in the clinic. Out-of-office BP measurements were done by 24-hour ambulatory BP monitor. Thirty-four patients were diagnosed with refractory hypertension, of whom 31 had adequate ambulatory BP monitor readings. White-coat effect was present in only 2 patients, or 6.5% of the 31 patients with refractory hypertension, suggesting that white-coat effect is largely absent in patients with refractory hypertension. These findings suggest that white-coat effect is not a common cause of apparent lack of BP control in patients failing maximal antihypertensive treatment. © 2017 American Heart Association, Inc.

Olanzapine is effective for refractory chemotherapy-induced nausea and vomiting irrespective of chemotherapy emetogenicity.

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Vig, Sierra; Seibert, Laurel; Green, Myke R

2014-01-01

The role of olanzapine added to a dopamine antagonist and benzodiazepine for the treatment of refractory chemotherapy-induced nausea and vomiting (CINV) is incompletely characterized in all levels of chemotherapy emetogenicity. This retrospective study evaluated the efficacy of the addition of olanzapine in adults experiencing refractory CINV stratified by chemotherapy emetogenicity. Thirty-three adults who experienced CINV refractory to guideline-recommended prophylaxis and breakthrough antiemetics (dopamine antagonists and benzodiazepines) and received at least one dose of olanzapine 5-10 mg per os were evaluated. Failure was defined as >5 emesis events in 24 h or more than 10 cumulative doses of rescue antiemetics following first olanzapine dose per treatment cycle. Post hoc analyses investigated variables impacting olanzapine efficacy. The addition of olanzapine demonstrated an overall success rate of 70 %. This success rate did not differ between chemotherapy regimens of high versus low-to-moderate emetogenicity (p = 0.79), prophylaxis with serotonin antagonist plus corticosteroid and aprepitant versus serotonin antagonist alone (p = 0.77), or age over 50 versus ≤50 years (p > 0.99). A trend toward greater benefit was seen in women (p = 0.08). The addition of olanzapine to a dopamine antagonist and benzodiazepine demonstrated high efficacy rates for refractory CINV irrespective of chemotherapy emetogenicity. The high success rates among all groups suggests that incomplete resolution of CINV with prophylactic serotonin antagonists and breakthrough dopamine antagonists plus benzodiazepine may benefit from the addition of olanzapine regardless of gender, degree of chemotherapy emetogenicity, number of prophylactic antiemetics, or age. The trend toward greater control of emesis in women merits further investigation.

Friction measurements of steel on refractory bricks

International Nuclear Information System (INIS)

Eiselstein, L.E.

1981-08-01

During startup or shutdown of a pool-type LMFBR, substantial shear stresses may arise between the base of the steel reactor vessel and the refractory brick support base. The magnitude of these stresses, which result from differences in thermal expansion, can be estimated if the friction coefficient is known. This report describes experiments to determine friction coefficients between 2 1/4 Cr-1Mo steel and several refractory materials and to examine effects to contact pressure, temperature, sliding velocity, lubricants, and surface condition

Treatment of refractory organic pollutants in industrial wastewater by wet air oxidation

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Mingming Luan

2017-02-01

Full Text Available Wet air oxidation (WAO is one of the most economical and environmentally-friendly advanced oxidation processes. It makes a promising technology for the treatment of refractory organic pollutants in industrial wastewaters. In wet air oxidation aqueous waste is oxidized in the liquid phase at high temperatures (125–320 °C and pressures (0.5–20 MPa in the presence of an oxygen-containing gas (usually air. The advantages of the process include low operating costs and minimal air pollution discharges. The present review is concerned about the literature published in the treatment of refractory organic pollutants in industrial wastewaters, such as dyes. Phenolics were taken as model pollutants in most cases. Reports on effect of treatment for the WAO of refractory organic pollutants in industrial wastewaters are reviewed, such as emulsified wastewater, TNT red water, etc. Discussions are also made on the mechanism and kinetics of WAO and main technical parameters influencing WAO. Finally, development direction of WAO is summed up.

Ketamine infusion for refractory status epilepticus: A case report of cardiac arrest.

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Koffman, Lauren; Yan Yiu, Ho; Farrokh, Salia; Lewin, John; Geocadin, Romergryko; Ziai, Wendy

2018-01-01

Refractory status epilepticus (RSE) has a high mortality rate and is often difficult to treat. When traditional therapies fail ketamine may be considered. There are limited reports of adverse cardiac events with the use of ketamine for RSE and no reports of cardiac arrest in this context. Evaluate the occurrence of cardiac arrhythmias associated with the use of ketamine for RSE. Retrospective chart review of nine patients who underwent ketamine infusion for RSE. Etiology of refractory status epilepticus included autoimmune/infectious process (Zeiler et al., 2014), ischemic stroke (Bleck, 2005) and subarachnoid hemorrhage (Bleck, 2005). Of the nine patients who received ketamine, two had documented cardiac events; one remained clinically stable and the other developed multiple arrhythmias, including recurrent episodes of asystole. Once ketamine was discontinued the latter patient stabilized with the addition of anti arrhythmic therapy. Ketamine is utilized to treat refractory status epilepticus, but should be used with caution in patients with subarachnoid hemorrhage, as there may be an increased risk of life threatening arrhythmias and cardiac arrest. Copyright © 2017 Elsevier Ltd. All rights reserved.

An effective method of surgical treatment of refractory glaucoma patients using Ex-PRESSTM filtering device

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Sergey Yuryevich Astakhov

2013-03-01

Full Text Available Based on data obtained from examination and subsequent follow-up of 47 patients (50 eyes with refractory glaucoma, an efficacy estimation of a new method of the Ex-PRESSTM filtering device implantation was performed. The data analysis showed that the proposed surgical procedure has a low level of intra- and post-operative complications, is characterized by technical ease, and provides a long term stabilization of the glaucomatous process. Therefore it is possible to draw a conclusion that the Ex-PRESSTM filtering device implantation is an effective method for the treatment of refractory glaucoma.

18F-FDG PET and high-resolution MRI co-registration for pre-surgical evaluation of patients with conventional MRI-negative refractory extra-temporal lobe epilepsy.

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Ding, Yao; Zhu, Yuankai; Jiang, Biao; Zhou, Yongji; Jin, Bo; Hou, Haifeng; Wu, Shuang; Zhu, Junming; Wang, Zhong Irene; Wong, Chong H; Ding, Meiping; Zhang, Hong; Wang, Shuang; Tian, Mei

2018-04-18

Epilepsy that originates outside of the temporal lobe can present some of the most challenging problems for surgical therapy, especially for patients with conventional magnetic resonance imaging (MRI)-negative refractory extra-temporal lobe epilepsy (ETLE). This study aimed to evaluate the clinical value of pre-surgical 18 F-fluoro-deoxy-glucose positron emission tomography ( 18 F-FDG PET) and high-resolution MRI (HR-MRI) co-registration in patients with conventional MRI-negative refractory ETLE, and compare their surgical outcomes. Sixty-seven patients with conventional MRI-negative refractory ETLE were prospectively included for pre-surgical 18 F-FDG PET and HR-MRI examinations. Under the guidance of 18 F-FDG PET and HR-MRI co-registration, HR-MRI images were re-read. Based on the image result changes from first reading to re-reading, patients were divided into three groups: Change-1 (lesions of subtle abnormality could be identified in re-read), Change-2 (non-specific abnormalities reported in the first reading were considered as lesions on HR-MRI re-read) and No-change. Post-surgical follow-ups were conducted for up to 59 months. Visual analysis of 18 F-FDG PET showed focal or regional abnormality in 46 patients (68.6%), while the abnormal rate increased to 94.0% (P evaluation by co-registration of 18 F-FDG PET and HR-MRI could improve the identification of the epileptogenic onset zone (EOZ), and may further guide the surgical decision-making and improve the outcome of the refractory ETLE with normal conventional MRI; therefore, it should be recommended as a standard procedure for pre-surgical evaluation of these patients.

Refractory benign esophageal strictures

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Gopal Goyal

2016-01-01

Full Text Available Refractory benign esophageal stricture (RBES is a frequently encountered problem worldwide. These strictures arise from various causes such as corrosive injury, radiation therapy, peptic origin, ablative therapy, and after surgery. Most strictures can be treated successfully with endoscopic dilatation using bougies or balloons, with only a few complications. Those patients who fail after serial dilatation with bougies or balloons will come to the category of refractory strictures. Dilatation combined with intralesional steroid injections can be considered for peptic strictures, whereas incisional therapy has been demonstrated to be effective for short anastomotic strictures. When these therapeutic options do not resolve the stenosis, stent placement should be considered. Self-bougienage can be proposed to a selected group of patients with a proximal stenosis. Most of the patients of RBES respond to above-mentioned treatment and occasional patient may require surgery as the final treatment option. This review aims to provide a comprehensive approach toward endoscopic management of RBESs based on current literature and personal experience.

Characterization of a High Strength, Refractory High Entropy Alloy, AlMo0.5NbTa0.5TiZr

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Jensen, Jacob

High entropy alloys (HEAs) are a relatively new class of materials that have garnered significant interest over the last decade due to their intriguing balance of properties including high strength, toughness, and corrosion resistance. In contrast to conventional alloy systems, HEAs are based on four or more principal elements with near equimolar concentrations and tend to have simple microstructures due to the preferential formation of solid solution phases. HEAs appear to offer new pathways to lightweighting in structural applications, new alloys for elevated temperature components, and new magnetic materials, but more thorough characterization studies are needed to assess the viability of the recently developed multicomponent materials. One such HEA, AlMo0.5NbTa0.5TiZr, was selected to be the basis for this characterization study in part due to its strength at elevated temperatures (sigma0.2 = 1600 MPa at T = 800 °C) and low density compared with commercially available Ni-based superalloys. The refractory element containing HEA composition was developed in order to balance the high temperature strength of the refractory elements with the desirable properties achieved by the high entropy alloying design approach for potential use in aerospace thermal protection and structural applications. Ingots of AlMo0.5NbTa0.5TiZr were cast by vacuum arc melting followed by hot isostatic pressing (HIP) and homogenization at 1400 °C for 24 hrs with a furnace cool of 10 °C/min. The resulting microstructure was characterized at multiple length scales using x-ray diffraction (XRD), scanning transmission electron microscopy (SEM), conventional and scanning transmission electron microscopy (TEM and STEM), and x-ray energy dispersive spectroscopy (XEDS). The microstructure was found to consist of a periodic, coherent two phase mixture, where a disordered bcc phase is aligned orthogonally in an ordered B2 phase. Through microstructural evolution heat treatment studies, the

Illness identity in young adults with refractory epilepsy.

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Luyckx, Koen; Oris, Leen; Raymaekers, Koen; Rassart, Jessica; Moons, Philip; Verdyck, Ludo; Mijnster, Teus; Mark, Ruth E

2018-03-01

Refractory epilepsy is an intrusive condition with important implications for daily functioning in emerging and young adulthood. The present study examined the degree to which refractory epilepsy is integrated in one's identity, and examined how such a sense of illness identity was related to health-related quality of life (HRQOL). A total of 121 18- to 40-year-old patients with refractory epilepsy (56.2% women) completed self-report questionnaires assessing the four illness identity states of acceptance, enrichment, engulfment, and rejection (Illness Identity Questionnaire (IIQ)); HRQOL (Quality of Life in Epilepsy Inventory - 31); and seizure frequency and severity (Liverpool Seizure Severity Scale (LSSS)). Illness identity scores were compared with a sample of 191 patients with a nonneurological chronic disease (congenital heart disease). Hierarchical regression analyses were conducted to assess the predictive value of illness identity for HRQOL when simultaneously controlling for demographic and clinical features. Patients with refractory epilepsy scored higher on rejection and engulfment and lower on acceptance when compared with patients with congenital heart disease. Further, seizure severity and number of medication side-effects were positively related to engulfment and negatively to acceptance. Finally, when simultaneously controlling for various demographic and clinical variables, illness identity significantly predicted HRQOL (with engulfment being the strongest and most consistent predictor). The extent to which patients with refractory epilepsy succeed in integrating their illness into their identity may have important implications for HRQOL. Clinicians should be especially attentive for signs that patients feel engulfed by their epilepsy. Copyright © 2018 Elsevier Inc. All rights reserved.

An Integrated Study on a Novel High Temperature High Entropy Alloy

Energy Technology Data Exchange (ETDEWEB)

Yang, Shizhong

2016-12-31

This report summarizes our recent works of theoretical modeling, simulation, and experimental validation of the simulation results on the new refractory high entropy alloy (HEA) design and oxide doped refractory HEA research. The simulation of the stability and thermal dynamics simulation on potential thermal stable candidates were performed and related HEA with oxide doped samples were synthesized and characterized. The HEA ab initio density functional theory and molecular dynamics physical property simulation methods and experimental texture validation techniques development, achievements already reached, course work development, students and postdoc training, and future improvement research directions are briefly introduced.

Mechanical and Physicochemical Evaluation of Alkaleri Fireclay for Refractory Application

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Job Ajala Amkpa

2017-04-01

Full Text Available The mechanical, chemical and physical property of Alkaleri fireclay was investigated for its appropriateness for refractory application. The chemical composition was performed and analyzed using the X-ray fluorescence (XRF spectrometer Bench top XRF analyzer technique. Chemical property result indicated that the clay contained 67.4 % silica (SiO2, 30.06 % aluminum (Al2O3, and other impurities. The clay was subjected to mechanical activation through sintering process at varied sintering temperatures of 900 °C, 1000 °C, 1100 °C and 1200 °C. At the best sintering temperature of 1200 °C, the cold crushing strength (CCS was 17.82 MPa, in the physical properties; apparent porosity was 22.8 %, bulk density was 1.8 g/cm3, and firing shrinkage was 8.9 %. The Alkaleri clay belongs to alumino-silicate fireclay group and therefore, suitable materials for refractory application of ladle, kiln dryer, boilers, cook stoves, furnace lining and bricks.

A refractory metal gate approach for micronic CMOS technology

International Nuclear Information System (INIS)

Lubowiecki, V.; Ledys, J.L.; Plossu, C.; Balland, B.

1987-01-01

In the future, devices scaling down, integration density and performance improvements are going to bring a number of conventional circuit design and process techniques to their fundamental limits. To avoid any severe limitations in MOS ULSI (Ultra Large Scale Integration) technologies, interconnection materials and schemes are required to emerge, in order to face the Megabits memory field. Among those, the gate approach will obviously take a keyrole, when the operating speed of ULSI chips will reach the practical upper limits imposed by parasitic resistances and capacitances which stem from the circuit interconnect wiring. Even if fairly suitable for MOS process, doped polycrystalline silicon is being gradually replaced by refractory metal silicide or polycide structures, which match better with low resistivity requirements. However, as we approach the submicronic IC's, higher conductivity materials will be paid more and more attention. Recently, works have been devoted and published on refractory metal gate technologies. Molybdenum or tungsten, deposited either by CVD or PVD methods, are currently reported even if some drawbacks in their process integration still remain. This paper is willing to present such an approach based on tungsten (more reliable than Molybdenum deposited by LPCVD (giving more conductive and more stable films than PVD). Deposition process will be first described. Then CMOS process flow will allow us to focus on specific refractory metal gate issues. Finally, electrical and physical properties will be assessed, which will demonstrate the feasibility of such a technology as well as the compatibility of the tungsten with most of the usual techniques

Evaluation of refractory temporal lobe epilepsy of nontumorous origin with qualitative and quantitative MR imaging

International Nuclear Information System (INIS)

Tanna, N.K.; Zimmerman, R.A.; Sperling, M.R.; Kohn, M.I.

1990-01-01

This paper reports that although MR imaging is superior to CT in the detection of focal lesions in refractory temporal lobe epilepsy (TLE), its role in the detection of mesial temporal sclerosis remains controversial. This is significant, as the latter represents a frequent cause of TLE and manifests with only subtle atrophic changes and occasional high signal abnormalities. PReoperative MR images of 47 patients who had undergone temporal lobectomy for nontumoral TLE and of 20 control subjects were valuated for focal atrophy and hippocampal high signal abnormalities. Quantitative measurements were performed in 33 patients and 20 control subjects with use of a new brain volumetric analysis program to determine volumes of temporal lobes

Coal-oil gold agglomeration assisted flotation to recover gold from refractory ore

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Otsuki, A.; Yue, C.

2017-07-01

This study aimed to investigate the applicability of coal-oil gold agglomeration (CGA) assisted flotation to recover gold from a refractory ore. The ore with the grade of 2-5 g/t was tested with the CGA-flotation process in six different size fractions from 38 to 300 urn using different collector types and dosages. In addition, the flotation without CGA was performed under the same condition for comparison. The results showed that the higher gold grade and recovery were achieved by applying the CGA-flotation, compared with the flotation without CGA. More than 20-60 times grade increase from the head grade was obtained with CGA-flotation. The elemental analysis of gold and sulphur explained their relationship with gold recovery. The results well indicated the applicability of CGA to upgrade the refractory gold ore.

Combined application of alginate dressing and human granulocyte-macrophage colony stimulating factor promotes healing in refractory chronic skin ulcers.

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Huang, Guobao; Sun, Tangqing; Zhang, Lei; Wu, Qiuhe; Zhang, Keyan; Tian, Qingfen; Huo, Ran

2014-06-01

The aim of the present study was to evaluate the clinical therapeutic effect of the combined application of alginate and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on the healing of refractory chronic skin ulcers. A single center, three arm, randomized study was performed at Jinan Central Hospital (Jinan, Shandong, China). A total of 60 patients with refractory chronic skin ulcers, which persisted for >1 month, were enrolled and randomly assigned into one of the following three groups: alginate dressing/rhGM-CSF group (group A), rhGM-CSF only group (group B) and conventional (vaseline dressing) group (group C). The wound area rate was measured, granulation and color were observed and pain was evaluated. The data were summarized and statistical analysis was performed. The results demonstrated that group A exhibited a significantly faster wound healing rate and lower pain score compared with the other groups (PCSF for the treatment of refractory chronic skin ulcers demonstrated significant advantages. It promoted the growth of granulation tissue, accelerated re-epithelialization and also effectively reduced wound pain, and thus improved the quality of life for the patient. This suggests that the combined application of alginate and rhGM-CSF may be an effective therapeutic strategy for the clinical treatment of refractory chronic skin ulcers.

Central Diabetes Insipidus in Refractory Antineutrophil Cytoplasmic Antibody-associated Vasculitis.

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Ohashi, Keiji; Morishita, Michiko; Watanabe, Haruki; Sada, Ken-Ei; Katsuyama, Takayuki; Miyawaki, Yoshia; Katsuyama, Eri; Narazaki, Mariko; Tatebe, Noriko; Watanabe, Katsue; Kawabata, Tomoko; Wada, Jun

2017-11-01

We herein describe two cases of refractory antineutrophil cytoplasmic antibody-associated vasculitis (AAV) complicated with diabetes insipidus (DI) possibly related to hypertrophic pachymeningitis (HP). One patient had microscopic polyangiitis and HP, which were refractory to cyclophosphamide, azathioprine, rituximab, mycophenolate mofetil (MMF), and mizoribine. Remission was finally achieved with the use of etanercept, but DI occurred 5 years later. The other patient had granulomatosis with polyangiitis, which that was refractory to cyclophosphamide, methotrexate, MMF, and rituximab. DI subsequently developed, but was successfully treated with etanercept. Dura mater hypertrophy was macroscopically observed in the latter case.

TIPSS Procedure in the Treatment of a Single Patient After Recent Heart Transplantation Because of Refractory Ascites Due to Cardiac Cirrhosis

International Nuclear Information System (INIS)

Fava, Mario; Meneses, Luis; Loyola, Soledad; Castro, Pablo; Barahona, Fernando

2008-01-01

We present the case of a female patient with arrhythmogenic dysplasia of the right ventricle who evolved to refractory heart failure, ascites, and peripheral edema. As a result, heart transplantation was performed. Subsequently, refractory ascites impaired the patient's respiratory function, resulting in prolonged mechanical ventilation. She was successfully treated with transjugular intrahepatic portosystemic shunt (TIPSS) placement, which allowed satisfactory weaning of ventilatory support.

Brentuximab Vedotin Treatment for Primary Refractory Hodgkin Lymphoma

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Hung-Bo Wu

2013-01-01

Full Text Available Up to 40% of patients with advanced Hodgkin lymphoma (HL become refractory or relapsed after current standard chemotherapy, among which primary refractory HL confers a particularly poor outcome. With intensive salvage chemotherapy and autologous stem cell transplantation, the long-term remission rate for these patients was only 30%, but more selective treatments with higher therapeutic index are needed. We report the experience of using a new anti-CD30 immunotoxin, brentuximab vedotin, in salvage treatment of a 30-year-old woman with primary refractory Hodgkin lymphoma. The patient presented with SVC syndrome due to the bulky mediastinal tumor and was confirmed to have classical Hodgkin lymphoma, nodular sclerosis type, stage IIIA. The tumor responded to induction chemotherapy transiently, but local progression was noted during subsequent cycles of treatment. Salvage radiotherapy to the mediastinal tumor, obtained no remission but was followed by rapid in-field progression and then lung metastasis. She declined stem cell transplantation and received salvage brentuximab vedotin (BV therapy, which induced dramatic shrinkage of tumor without significant side effects. Serial followup of PET/CT imaging confirmed a rapid and continuous complete remission for 12 months. Although durability of the remission needs further observation, this case illustrates the excellent efficacy of brentuximab vedotin in primary refractory Hodgkin lymphoma.

Optimization of phase analysis of refractory alloys in the gas-ion-reaction chamber

International Nuclear Information System (INIS)

Blumenkamp, H.J.; Hoven, H.; Koizlik, K.; Nickel, H.

1980-04-01

Reactor components outside the core which are under high thermal and mechanical stresses are made from refractory alloys. For basic research and for quality control, these materials are investigated by metallography, which is an independent group of characterization procedures as well as basis for many other methods. An important way of increasing the information about a material yielded by metallography is the expansions of phase contrast, in particular the phase contrasting in the gas-ion-reaction chamber. In this paper, the experimental procedure is described and the process of optimizing the procedure with respect to the Ni- and Fe-based refractory alloys examined in the IRW is discussed. (orig.) [de

The use of a formula-based ketogenic diet in children with refractory epilepsy

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Letícia Pereira de Brito Sampaio

Full Text Available ABSTRACT The ketogenic diet (KD is a nonpharmacologic treatment that has been used for refractory epilepsy since 1921. The KD is a high-fat, low-carbohydrate, and restricted protein diet, which is calculated and weighed for each individual patient. Introducing and maintaining the diet for a long time remains a challenge. In this study, we evaluated the acceptability, tolerance, and efficacy of a formula-based KD in 10 children with refractory epilepsy. The ketogenic formula tested herein caused only mild KD-related adverse events and adequate adherence. Moreover, 60% of patients had more than 50% seizure frequency reduction and 10% were seizure-free.

Post-operative morbidity and mortality of a cohort of steroid refractory acute severe ulcerative colitis: Nationwide multicenter study of the GETECCU ENEIDA Registry.

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Ordás, I; Domènech, E; Mañosa, M; García-Sánchez, V; Iglesias-Flores, E; Rodríguez-Moranta, F; Márquez, L; Merino, O; Fernández-Bañares, F; Gomollón, F; Vera, M; Gutiérrez, A; LLaó, J; Gisbert, J P; Aguas, M; Arias, L; Rodríguez-Lago, I; Muñoz, C; Alcaide, N; Calvet, X; Rodríguez, C; Montoro, M A; García, S; De Castro, M L; Piqueras, M; Pareja, L; Ribes, J; Panés, J; Esteve, M

2018-05-01

Despite the increased use of rescue medical therapies for steroid refractory acute severe ulcerative colitis, mortality related to this entity still remains high. We aimed to assess the mortality and morbidity related to colectomy and their predictive factors in steroid refractory acute severe ulcerative colitis, and to evaluate the changes in mortality rates, complications, indications of colectomy, and the use of rescue therapy over time. We performed a multicenter observational study of patients with steroid refractory acute severe ulcerative colitis requiring colectomy, admitted to 23 Spanish hospitals included in the ENEIDA registry (GETECCU) from 1989 to 2014. Independent predictive factors of mortality were assessed by binary logistic regression analysis. Mortality along the study was calculated using the age-standardized rate. During the study period, 429 patients underwent colectomy, presenting an overall mortality rate of 6.3% (range, 0-30%). The main causes of death were infections and post-operative complications. Independent predictive factors of mortality were: age ≥50 years (OR 23.34; 95% CI: 6.46-84.311; p  0.001). The mortality rate related to colectomy in steroid refractory acute severe ulcerative colitis varies greatly among hospitals, reinforcing the need for a continuous audit to achieve quality standards. The increasing use of rescue therapy is not associated with a worse outcome and may contribute to reducing emergency surgical interventions and improve outcomes.

Bendamustine mitoxantrone and rituximab (BMR): a new effective regimen for refractory or relapsed indolent lymphomas.

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Weide, Rudolf; Heymanns, Jochen; Gores, Annette; Köppler, Hubert

2002-02-01

Bendamustine (B) and mitoxantrone (M) have been shown to be potent cytotoxic drugs for the treatment of relapsed or refractory indolent lymphomas. The anti-CD20 monoclonal antibody rituximab (R) has produced an overall response rate (ORR) of 50% as a single agent in relapsed or refractory indolent lymphomas. We posed the question whether a combination of the above agents (BMR) could improve these results. This study was an open label, single center pilot study for patients with relapsed or refractory, CD20-positive (indolent) lymphoma or chronic lymphocytic leukaemia. The therapy consisted of bendamustine (80 mg/m2, day 1-3), mitoxantrone (10 mg/m2, day 1), rituximab (375 mg/m2, week 2-5). BM was repeated on day 36 or when the haematological parameters had recovered. The maximum therapy consisted of one BMR-cycle, followed by five BM courses. Treatment was stopped when the disease responded with PR/CR. During March 1999 and December 2000, 20 patients received the BMR-regimen (four secondary high grade lymphoma, 12 indolent lymphoma, four B-CLL). The median age of the patients was 67 years (range 36-82) and their performance status ranged from 0 to 3. Median number of previous treatment regimens was two (1-6). Of the lymphoma patients, 14 had stage IV disease, 1 stage III and 1 stage II. B-CLL patients were all Rai stage IV (Binet C). Overall response rate was 95% (19/20) with seven patients achieving a CR (35%) and 12 patients achieving a PR (60%). Median time to progression is 7 months (1-21) with a median observation time of 7 months (1-21). Response is still durable in 15/20 patients (75%) (1+ to 21+ months after therapy). Symptomatic, reversible grade three or four haematotoxicity occurred in 4/20 patients (20%). Non-symptomatic grade three or four haematotoxicity was seen in 9/20 patients (45%). No major non-haematological toxicity was observed. In conclusion, BMR is a well tolerated, very effective outpatient regimen of treatment for relapsed and refractory

Performance of CVD and CVR coated carbon-carbon in high temperature hydrogen

Science.gov (United States)

Adams, J. W.; Barletta, R. E.; Svandrlik, J.; Vanier, P. E.

As a part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings which will be time and temperature stable at extremely high temperatures in flowing hydrogen. These coatings must protect the underlying carbon structure from attack by the hydrogen coolant. Degradation which causes small changes in the reactor component, e.g. hole diameter in the hot frit, can have a profound effect on operation. The ability of a component to withstand repeated temperature cycles is also a coating development issue. Coatings which crack or spall under these conditions would be unacceptable. While refractory carbides appear to be the coating material of choice for carbon substrates being used in PBR components, the method of applying these coatings can have a large effect on their performance. Two deposition processes for these refractory carbides, chemical vapor deposition (CVD) and chemical vapor reaction (CVR), have been evaluated. Screening tests for these coatings consisted of testing of coated 2-D and 3-D weave carbon-carbon in flowing hot hydrogen at one atmosphere. Carbon loss from these samples was measured as a function of time. Exposure temperatures up to 3,000 K were used, and samples were exposed in a cyclical fashion cooling to room temperature between exposures. The results of these measurements are presented along with an evaluation of the relative merits of CVR and CVD coatings for this application.

Effectiveness of botulinum toxin A in treatment of refractory erythromelalgia

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Kuan-Hsiang Lin

2013-05-01

Full Text Available Erythromelalgia is characterized by intense burning pain, erythema, and heat in affected areas after precipitating factors such as warm temperature or stress. It is refractory to treatment in some situations. We describe a woman with adenosquamous cell carcinoma of the lung and medically refractory erythromelalgia. The symptoms of erythromelalgia presented as refractory to any medical treatment. Due to the unresponsive nature of her condition, botulinum toxin type A (onabotulinumtoxin A was injected over both of her cheeks, periodically for six cycles. Her symptoms responded dramatically to subcutaneous and intradermal injection of botulinum toxin type A. Repetitive injection demonstrated consistent and reproducible responses, and the efficacy was maintained for approximately 1 month. No adverse effects or complications were noted. Botulinum toxin type A might be safe and effective as an alternative treatment for refractory erythromelalgia, but further large-scale studies are required.

Interface Analyses Between a Case-Hardened Ingot Casting Steel and Carbon-Containing and Carbon-Free Refractories

Science.gov (United States)

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.

Efficacy of infliximab in refractory posterior uveitis in Behcet's disease patients

OpenAIRE

Ayman K. El Garf; Amira A. Shahin; Sherif A. Shawky; Mohammed A. Azim; Dina A. Effat; Sherry K. Abdelrahman

2018-01-01

Aim of the work: Ocular manifestations are the main cause of morbidity in Behcet's disease (BD). Infliximab (IFX), a chimeric monoclonal antibody directed against tumor necrosis factor-alpha, may be efficient in refractory uveitis due to BD. The aim of this study was to assess the efficacy and safety of IFX in the treatment of patients with BD-associated refractory posterior uveitis (PU). Patient and Methods: Twenty patients with refractory Behcet's PU received IFX therapy as intravenous infu...

Ketogenic diet in 3 cases of childhood refractory status epilepticus

DEFF Research Database (Denmark)

Sort, Rune; Born, Alfred P; Pedersen, Karen N.

2013-01-01

Refractory status epilepticus (RSE) in children is associated with a significant risk of death or neurological morbidity. Recently attention has been drawn to the ketogenic diet (KD) as an acute treatment, as it has shown promise in controlling seizures in otherwise refractory status epilepticus...

Usefulness of a pleuroperitoneal shunt for treatment of refractory pleural effusion in a patient receiving maintenance hemodialysis.

Science.gov (United States)

Habuka, Masato; Ito, Toru; Yoshizawa, Yuta; Matsuo, Koji; Murakami, Shuichi; Kondo, Daisuke; Kanazawa, Hiroshi; Narita, Ichiei

2018-03-23

Refractory pleural effusion can be a life-threatening complication in patients receiving maintenance hemodialysis. We report successful treatment of refractory pleural effusion using a Denver® pleuroperitoneal shunt in one such patient. A 54-year-old Japanese man, who had previously undergone left nephrectomy, was admitted urgently to our department because of a high C-reactive protein (CRP) level, right pleural effusion, and right renal abscess. Because antibiotics proved ineffective and his general state was deteriorating, he underwent emergency insertion of a thoracic drainage tube and nephrectomy, and hemodialysis was started. Although his general state improved slowly thereafter, the pleural effusion, which was unilateral and transudative, remained refractory and therefore he needed to be on oxygenation. To control the massive pleural effusion, a pleuroperitoneal shunt was inserted. Thereafter, his respiratory condition became stable without oxygenation and he was discharged. His general condition has since been well. Although pleural effusion is a common complication of maintenance hemodialysis, few reports have documented the use of pleuroperitoneal shunt to control refractory pleural effusion. Pleuroperitoneal shunt has been advocated as an effective and low-morbidity treatment for refractory pleural effusion, and its use for some patients with recurrent pleural effusion has also been reported, without any severe complications. In the present case, pleuroperitoneal shunt improved the patient's quality of life sufficiently to allow him to be discharged home without oxygenation. Pleuroperitoneal shunt should be considered a useful treatment option for hemodialysis patients with refractory pleural effusion.

Super Refractory Status Epilepticus

African Journals Online (AJOL)

user

et al did retrospective cohort study from 1 January st. 1994 to 31 March 1998 at Presbyterian Medical. Centre in Columbia, to determine the frequency, risk factors and impact on the outcome of RSE. They found out that 69% of seizures recurred after. Key Words: Super refractory status epilepticus, Zambia. Medical Journal of ...

Process technology - rare and refractory metals

International Nuclear Information System (INIS)

Gupta, C.K.; Bose, D.K.

1989-01-01

India has fairly rich resreves of rare and refractory metals. Abundant sources of ilmenite, rutile, zircon and rare earths are found in the placer deposits of the southern and eastern coasts of the country. Columbite-tantalite occur in mica and the mining belts of Bihar and cassiterite deposits are found in Bastar (Madhya Pradesh). Vanadium as a minor associate occurs in bauxites and in the vast deposits of titaniferrous magnetites. Over the years, research and development and pilot plant works in many research organisations in India have built up a sound technological base in the country for process metallurgy of many refractory and rare earth metals starting from their indigenous sources. The present paper provides a comprehensive view of the developments that have taken place till now on the processing of various refractory and rare earth metals with particular reference to the extensive work carried out at the Department of Atomic Energy. The coverage includes mineral benification separation of individual elements, preparation of pure intermediates, techniques of reduction to metal and final purification. The paper also reviews some of the recent developments that have been taken place in these fields and the potential application of these metals in the foreseeable future. (author). 22 refs., 18 fi g., 7 tabs

Radioactive iodine-refractory differentiated thyroid cancer: an uncommon but challenging situation

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Angelica; Iglesias, Laura; Schlumberger, Martin J. [Institut Gustave Roussy, Univ. Paris-Saclay, Villejuif (France); Klain, Michele [Univ. Federico II di Napoli (Italy); Pitoia, Fabian [Division of Endocrinology, Hospital de Clinicas, Univ. of Buenos Aires (Argentina)

2017-01-15

Radioiodine (RAI)-refractory thyroid cancer is an uncommon entity, occurring with an estimated incidence of 4-5 cases/year/million people. RAI refractoriness is more frequent in older patients, in those with large metastases, in poorly differentiated thyroid cancer, and in those tumors with high 18-fluorodeoxyglucose uptake on PET/CT. These patients have a 10-year survival rate of less than 10%. In recent years, new therapeutic agents with molecular targets have become available, with multi kinase inhibitors (MKIs) being the most investigated drugs. Two of these compounds, sorafenib and lenvatinib, have shown significant objective response rates and have significantly improved the progression-free survival in the two largest published prospective trials on MKI use. However, no overall survival benefit has been achieved yet. This is probably related to the crossover that occurs in most patients who progress on placebo treatment to the open treatment of these studies. In consequence, the challenge is to correctly identify which patients will benefit from these treatments. It is also crucial to understand the appropriate timing to initiate MKI treatment and when to stop it. The purpose of this article is to define RAI refractoriness, to summarize which therapies are available for this condition, and to review how to select patients who are suitable for them. (author)

Reuse of ultrafine mineral wool production waste in the manufacture of refractory concrete.

Science.gov (United States)

Stonys, R; Kuznetsov, D; Krasnikovs, A; Škamat, J; Baltakys, K; Antonovič, V; Černašėjus, O

2016-07-01

The paper deals with the mineral wool production waste (cupola dust - CD), presents CD characterization and aims to reuse CD in production of refractory concrete with calcium aluminate cement. The study of CD covers its chemical, phase and thermal analyses along with the morphological study and determination of particles size distribution. Zeta-potential, electrical conductivity and pH values of CD suspension are presented in the paper as well. Commercial microsilica additive in refractory concrete has been replaced with cupola dust. Compositions of refractory concrete have been prepared by incorporating 1%, 2% and 3% of CD. The bulk density, ultrasonic wave velocity, cold crushing strength and thermal shock resistance of the created refractory concrete have been determined. Based on experimental results, it has been found that cupola dust may be used for the production of refractory concrete. The environmental impact related to the CD reuse in refractory concrete production has been evaluated as well. Copyright © 2016 Elsevier Ltd. All rights reserved.

When myasthenia gravis is deemed refractory: clinical signposts and treatment strategies

Science.gov (United States)

Mantegazza, Renato; Antozzi, Carlo

2018-01-01

The prognosis for patients with myasthenia gravis (MG) has improved significantly over the past half century, including substantial reductions in mortality and morbidity. However, approximately 10% of patients fails to respond adequately to current therapies and are considered treatment refractory, or treatment intolerant, and up to 80% have disease that fails to achieve complete stable remission. Although patients with autoantibodies to muscle-specific tyrosine kinase (anti-MuSK positive) are more likely to become treatment refractory than those with autoantibodies to the acetylcholine receptor (anti-AChR positive), each of these serotypes is substantially represented in the refractory MG population. Other risk factors for becoming treatment refractory include history of thymoma or thymectomy and female sex. A modified treatment algorithm for MG is proposed: patients who have disease that fails to respond to the stepwise approach to therapy, are treatment intolerant, or who require chronic rescue measures despite ongoing therapy, should be considered treatment refractory and emerging therapies should be considered. Three emerging monoclonal antibody-based therapies are discussed: the anti-B-cell agent rituximab; the terminal complement activation inhibitor eculizumab; and belimumab, which targets B-cell activating factor. Increased understanding of molecular pathophysiology and accurate antibody subtyping in MG should lead to the use of new therapeutic agents and successful management of treatment-refractory patients. PMID:29403543

Accelerated Total Lymphoid Irradiation-containing Salvage Regimen for Patients With Refractory and Relapsed Hodgkin Lymphoma: 20 Years of Experience

Energy Technology Data Exchange (ETDEWEB)

Rimner, Andreas; Lovie, Shona [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Hsu, Meier [Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Chelius, Monica [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Zhang, Zhigang [Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Chau, Karen [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Moskowitz, Alison J.; Matasar, Matthew; Moskowitz, Craig H. [Lymphoma Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York (United States); Yahalom, Joachim, E-mail: yahalomj@mskcc.org [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York (United States)

2017-04-01

Purpose: We report the long-term results of integrated accelerated involved field radiation therapy (IFRT) followed by total lymphoid irradiation (TLI) as part of the high-dose salvage regimen followed by autologous bone marrow transplantation or autologous stem cell transplantation in patients with relapsed or refractory Hodgkin lymphoma (HL). Methods and Materials: From November 1985 to July 2008, 186 previously unirradiated patients with relapsed or refractory HL underwent salvage therapy on 4 consecutive institutional review board–approved protocols. All patients had biopsy-proven primary refractory or relapsed HL. After standard-dose salvage chemotherapy (SC), accelerated IFRT (18-20 Gy) was given to relapsed or refractory sites, followed by TLI (15-18 Gy) and high-dose chemotherapy. Overall survival (OS) and event-free survival (EFS) were analyzed by Cox analysis and disease-specific survival (DSS) by competing-risk regression. Results: With a median follow-up period of 57 months among survivors, 5- and 10-year OS rates were 68% and 56%, respectively; 5- and 10-year EFS rates were 62% and 56%, respectively; and 5- and 10-year cumulative incidences of HL-related deaths were 21% and 29%, respectively. On multivariate analysis, complete response to SC was independently associated with improved OS and EFS. Primary refractory disease and extranodal disease were independently associated with poor DSS. Eight patients had grade 3 or higher cardiac toxicity, with 3 deaths. Second malignancies developed in 10 patients, 5 of whom died. Conclusions: Accelerated IFRT followed by TLI and high-dose chemotherapy is an effective, feasible, and safe salvage strategy for patients with relapsed or refractory HL with excellent long-term OS, EFS, and DSS. Complete response to SC is the most important prognostic factor.

Accelerated Total Lymphoid Irradiation-containing Salvage Regimen for Patients With Refractory and Relapsed Hodgkin Lymphoma: 20 Years of Experience

International Nuclear Information System (INIS)

Rimner, Andreas; Lovie, Shona; Hsu, Meier; Chelius, Monica; Zhang, Zhigang; Chau, Karen; Moskowitz, Alison J.; Matasar, Matthew; Moskowitz, Craig H.; Yahalom, Joachim

2017-01-01

Purpose: We report the long-term results of integrated accelerated involved field radiation therapy (IFRT) followed by total lymphoid irradiation (TLI) as part of the high-dose salvage regimen followed by autologous bone marrow transplantation or autologous stem cell transplantation in patients with relapsed or refractory Hodgkin lymphoma (HL). Methods and Materials: From November 1985 to July 2008, 186 previously unirradiated patients with relapsed or refractory HL underwent salvage therapy on 4 consecutive institutional review board–approved protocols. All patients had biopsy-proven primary refractory or relapsed HL. After standard-dose salvage chemotherapy (SC), accelerated IFRT (18-20 Gy) was given to relapsed or refractory sites, followed by TLI (15-18 Gy) and high-dose chemotherapy. Overall survival (OS) and event-free survival (EFS) were analyzed by Cox analysis and disease-specific survival (DSS) by competing-risk regression. Results: With a median follow-up period of 57 months among survivors, 5- and 10-year OS rates were 68% and 56%, respectively; 5- and 10-year EFS rates were 62% and 56%, respectively; and 5- and 10-year cumulative incidences of HL-related deaths were 21% and 29%, respectively. On multivariate analysis, complete response to SC was independently associated with improved OS and EFS. Primary refractory disease and extranodal disease were independently associated with poor DSS. Eight patients had grade 3 or higher cardiac toxicity, with 3 deaths. Second malignancies developed in 10 patients, 5 of whom died. Conclusions: Accelerated IFRT followed by TLI and high-dose chemotherapy is an effective, feasible, and safe salvage strategy for patients with relapsed or refractory HL with excellent long-term OS, EFS, and DSS. Complete response to SC is the most important prognostic factor.

Refractory organic substances in the environment

National Research Council Canada - National Science Library

Frimmel, F. H

2002-01-01

... and its Quality Control in Fractions of Refractory Organic Substances and the Corresponding Original Water Samples 39 Introduction 39 Description of Analytical Methods 41 Sample Treatment 41 Fl...

A multicentre phase-II feasibility study evaluating gemcitabine /vinorelbine / prednisolone combination chemotherapy in relapsed / refractory hodgkin's lymphoma

International Nuclear Information System (INIS)

Naqi, N.; Ahmad, S.; Shah, I.; Khattak, J.

2013-01-01

Objective: To determine the efficacy and toxicity of Gemcitabine, Vinorelbine and Prednisolone (GVP) salvage chemotherapy in relapsed / refractory Hodgkin's Lymphoma (HL). Study Design: A phase-II non-randomized single arm study. Place and Duration of Study: This study was conducted at Combined Military Hospital and Medical College Lahore, Mayo Hospital, King Edward Medical University, Lahore, Allied Hospital, Punjab Medical College, Faisalabad and Combined Military Hospital, Rawalpindi, from January 2007 to December 2007. Methodology: Fifty adult patients with relapsed/refractory HL, adequate marrow reserve, hepatorenal and pulmonary functions, with radiological measurable disease and Karnofsky performance status of 0 - 2 non-candidates for stem cell transplantation, were enrolled. Four 28 days cycles of GVP (Gemcitabine 1000 mg/m2, Vinorelbine 30 mg/m2 on day 1 and 8 intravenously with oral Prednisolone 100 mg/day on day 1 - 5) were given. Response evaluation done according to Cotswolds meeting recommendations and toxicity was evaluated with NCI-CTC (National Cancer Institute - Common Terminology Criteria for adverse events v 3.0). Results: Forty patients completing 4 cycles of GVP, 14 refractory/early relapse and 26 late relapsed (one year postprimary treatment with ABVD) were available for evaluation. The overall response (CRu+PR) rate was 77.5% with better response 85% in late relapsed patients. Haematological toxicity was most common and seen in 70% of cases. Conclusion: GVP is well-tolerated regimen with high response rate and needs to be tested in late relapsed HL. (author)

The recovery of gold from refractory ores by the use of carbon-in-chlorine leaching

Science.gov (United States)

Greaves, John N.; Palmer, Glenn R.; White, William W.

1990-09-01

Recently, the U.S. Bureau of Mines examined the recovery of gold by chlorination of refractory carbonaceous and sulfidic ores, comparing various treatment methods in which a ground ore pulp is contacted with chlorine gas and activated carbon is added to the pulp for a carbon-in-chlorine leach (CICL). The objective of this research was to demonstrate the basic feasibility of CICL technology. Results showed that the organic carbon deactivating environment of CICL lowers, but does not eliminate, the adsorption of gold on activated carbon. In this environment, the refractory ore is altered, and gold is extracted and then recovered on activated carbon. With highly carbonaceous ores, CICL achieved a higher recovery than with primarily sulfidic refractory ores. Basic cyanide amenability testing of two carbonaceous ores achieved recoveries of only 5.5% and 46%. With CICL treatment, recoveries on carbon were 90% and 92%.

Beneficiation and leaching study of a muti-Au carrier and low grade refractory gold ore

Science.gov (United States)

Li, W. J.; Song, Y. S.; Chen, Y.; Cai, L. L.; Zhou, G. Y.

2017-09-01

Detailed mineralogy and beneficiation and leaching study of a muti-Au carrier, low grade refractory gold ore from a beneficiation plant in Henan Province, China, was investigated. Mineral liberation analysis, scanning electron microscopy, element phase analysis and etc. by a mineral liberation analyser were used for mineralogical characterization study of this ore. The present work describes an experimental study on the effect of traditional parameters (such as grinding fineness and reagent regimes), middling processing method and flowsheet construction on the total recovery and the assay of the floatation concentrate. Two-step floatation and part of middling combined to the floatation tailing for gold leaching process resulted in high gold grade (g.t-1) and gold recovery (%) for this refractory gold ore. This process opens the possibilities of maximizing Au grade and recoveries in a muti-Au carrier and low grade refractory gold ore where low recoveries are common.

Rates and Durability of Response to Salvage Radiation Therapy Among Patients With Refractory or Relapsed Aggressive Non-Hodgkin Lymphoma

International Nuclear Information System (INIS)

Tseng, Yolanda D.; Chen, Yu-Hui; Catalano, Paul J.; Ng, Andrea

2015-01-01

Purpose: To evaluate the response rate (RR) and time to local recurrence (TTLR) among patients who received salvage radiation therapy for relapsed or refractory aggressive non-Hodgkin lymphoma (NHL) and investigate whether RR and TTLR differed according to disease characteristics. Methods and Materials: A retrospective review was performed for all patients who completed a course of salvage radiation therapy between January 2001 and May 2011 at Brigham and Women's Hospital/Dana-Farber Cancer Institute. Separate analyses were conducted for patients treated with palliative and curative intent. Predictors of RR for each subgroup were assessed using a generalized estimating equation model. For patients treated with curative intent, local control (LC) and progression-free survival were estimated with the Kaplan-Meier method; predictors for TTLR were evaluated using a Cox proportional hazards regression model. Results: Salvage radiation therapy was used to treat 110 patients to 121 sites (76 curative, 45 palliative). Salvage radiation therapy was given as part of consolidation in 18% of patients treated with curative intent. Median dose was 37.8 Gy, with 58% and 36% of curative and palliative patients, respectively, receiving 39.6 Gy or higher. The RR was high (86% curative, 84% palliative). With a median follow-up of 4.8 years among living patients, 5-year LC and progression-free survival for curative patients were 66% and 34%, respectively. Refractory disease (hazard ratio 3.3; P=.024) and lack of response to initial chemotherapy (hazard ratio 4.3; P=.007) but not dose (P=.93) were associated with shorter TTLR. Despite doses of 39.6 Gy or higher, 2-year LC was only 61% for definitive patients with refractory disease or disease that did not respond to initial chemotherapy. Conclusions: Relapsed or refractory aggressive NHL is responsive to salvage radiation therapy, and durable LC can be achieved in some cases. However, refractory disease is associated with a

Therapeutic burst-suppression coma in pediatric febrile refractory status epilepticus.

Science.gov (United States)

Lin, Jainn-Jim; Chou, Cheng-Che; Lan, Shih-Yun; Hsiao, Hsiang-Ju; Wang, Yu; Chan, Oi-Wa; Hsia, Shao-Hsuan; Wang, Huei-Shyong; Lin, Kuang-Lin

2017-09-01

Evidence for the beneficial effect of therapeutic burst-suppression coma in pediatric patients with febrile refractory status epilepticus is limited, and the clinical outcomes of this treatment strategy are largely unknown. Therefore, the aim of this study was to explore the outcomes of therapeutic burst-suppression coma in a series of children with febrile refractory status epilepticus. We retrospectively reviewed consecutive pediatric patients with febrile refractory status epilepticus admitted to our pediatric intensive care unit between January 2000 and December 2013. The clinical characteristics were analyzed. Thirty-five patients (23 boys; age range: 1-18years) were enrolled, of whom 28 (80%) developed super-refractory status epilepticus. All of the patients received the continuous administration of intravenous antiepileptic drugs for febrile refractory status epilepticus, and 26 (74.3%) achieved therapeutic burst-suppression coma. All of the patients received mechanical ventilatory support, and 26 (74.3%) received inotropic agents. Eight (22.9%) patients died within 1month. The neurologically functional outcomes at 6months were good in six (27.3%) of the 22 survivors, of whom two returned to clinical baseline. The patients with therapeutic burst-suppression coma were significantly associated with hemodynamic support than the patients with electrographic seizures control (p=0.03), and had a trend of higher 1-month mortality rate, worse 6months outcomes, and a longer duration of hospitalization. Our results suggest that therapeutic burst-suppression coma to treat febrile refractory status epilepticus may lead to an increased risk of hemodynamic instability and a trend of worse outcomes. Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Retrospective analysis of rituximab therapy and splenectomy in childhood chronic and refractory immune thrombocytopenic purpura.

Science.gov (United States)

Ay, Yilmaz; Karapinar, Tuba H; Oymak, Yesim; Toret, Ersin; Demirag, Bengu; Ince, Dilek; Ozcan, Esin; Moueminoglou, Nergial; Koker, Sultan A; Vergin, Canan

2016-06-01

Immune thrombocytopenic purpura (ITP) results from accelerated platelet destruction mediated by autoantibodies to platelet glycoproteins. Some patients with chronic ITP are refractory to all therapies [steroids, intravenous immunoglobulin (IVIG), anti-D and immunosuppresive drugs] and have chronic low platelet counts and episodic bleeding. We retrospectively evaluated the efficacy and safety of rituximab treatment and splenectomy in paediatric patients diagnosed with chronic and refractory ITP who were unresponsive to steroids, IVIG, cyclosporine and mycophenolate mofetil. Records of patients with chronic and refractory ITP in 459 patients with primary ITP who were followed up in our hospital from January 2005 to December 2014 were reviewed. Fifteen of patients received rituximab and/or applied splenectomy. Fifteen chronic ITP patients (10 boys, five girls) with a mean age of 10 years were enrolled in the study. Two of these patients were suffering from Evans syndrome. The median time since diagnosis of ITP was 10 years. The median follow-up duration after starting Rituximab and splenectomy were 13 and 9.5 months, respectively.None of the seven patients who were treated with rituximab achieved a response. A splenectomy was performed in six of the seven patients who had been treated with rituximab. Complete and partial responses were achieved in 67 and 33% of the patients, respectively. We evaluated the clinical characteristics and responses of chronic ITP patients who did not receive rituximab therapy and underwent a splenectomy. The success rate was 100% in the eight patients with chronic and refractory ITP. Rituximab therapy might not be beneficial for some children with severe chronic ITP who are refractory to standard agents. A splenectomy might be useful and preferable to rituximab.

Role of Cholestyramine in Refractory Hyperthyroidism: A Case Report and Literature Review.

Science.gov (United States)

Alswat, Khaled A

2015-07-24

Hyperthyroidism is a common disease that usually responds to the conventional therapy of anti-thyroidal medications (methimazole or PTU) and beta-blocker. Refractory hyperthyroidism is a rare condition in which hyperthyroidism fails to respond to the above therapy. Cholestyramine has been shown to decrease thyroid hormone level when added to the ongoing anti-thyroidal medications. A 52-year-old woman with past medical history of enlarging goiter presented with obstructive symptoms of worsening shortness of breath and snoring. Admission thyroid function test showed mild hyperthyroidism (suppressed TSH, slightly high FT4, and high normal FT3) that worsened after she received a CT scan with contrast and failed to respond to a 3-week course of high-dose dexamethasone, high-dose carbimazole, and up-titrated propranolol. Five days after cholestyramine was added, her FT4 decreased by 30% and normalized after 12 days. The patient underwent total thyroidectomy as definitive treatment for the hyperthyroidism and for the obstructive symptoms. Cholestyramine is an effective additional treatment for hyperthyroidism and may be an effective treatment for refractory iodine-induced hyperthyroidism. The possibility of self-remission (natural course) is less likely given the dramatic and rapid response to cholestyramine.

Zirconium determination in refractories (gravimetric method)

International Nuclear Information System (INIS)

Capiotto, N.; Narahashi, Y.; Perish, P.G.; Souza, J.R. de

1991-01-01

A gravimetric method for zirconium determination in refractories is described. X-ray fluorescence analysis is also employed in this experiment and considerations about interfering elements are presented. (M.V.M.)

Correlation between Corneal Thickness and Degree of Myopic Refractory Error

Directory of Open Access Journals (Sweden)

A Mortazavi

2005-01-01

Full Text Available Background: corneal thickness is an important factor in refractive surgeries such as Radial Keratotomy (RK, Photo Refractive Keratotomy (PRK and Laser Insitu Keratomileusis (LASIK. This study evaluated the correlation between this factor and the degree of myopic refractory error. Methods: In this cross-sectional study, 224 myopic eyes (112 patients which had undergone LASIK operation were assessed. These patients had referred to Aban Eye Clinic, Isfahan, Iran, during August and September 2002. Corneal thickness was measured by ORB SCAN Topoghraphy, and cycloplegic refraction was performed with autorefratometery and retinoscopy. Suspected keratoconus cases and hyperopic patients were excluded. Results: The patients' age was 27.2 ± 1.36 in men (N = 35 and 30.13 ± 1.04 in women (N = 77. Mean value of myopic refractory error in male patients was 5.1 ± 0.24D and in female patients was 3.8 ± 0.36D. Mean of corneal thickness was 540 ± 5.25 µM and 530 ± 5.88 µM in male and female patients respectively. There was no correlation between the degree of myopia and corneal thickness in any of the patients. Also in this research, no relations between the age and myopia were found. Right eye (P > 0.5, r = 0.124 Left eye (P > 0.5, r = 0.104. Conclusion: Based on our findings, corneal thickness and myopic refectory error do not seem to have any relations. (r = 0.039, p = 0.684. Keywords: Corneal Thickness, Cornea, Myopia, LASIK, Refractory Error

Applications of radioisotopes for studying refractory wear-out in Bhilai Steel Plant

International Nuclear Information System (INIS)

Dubey, R.S.; Bose, U.P.; Shipstone, A.J.

1979-01-01

In Bhilai Steel Plant, investigations were carried out to study the refractory wear-out of (i) hearth bottom of blast furnaces, (ii) roof of open hearth furnaces, and (iii) hot metal mixer lining, by using radioisotope tracer techniques with a view to evaluate the life of the refractory lining at various locations and to help in planning its timely hot and cold repairs. The life of the refractory lining has the effective bearing on the overall production and hence on the economy of the plant. The two radiometric methods employed for studying the erosion of the refractory lining, by using isotope inserted bricks at various positions without damaging the lining are (i) based on recording the penetration of gamma rays emitting from the radioactive isotopes inserted at definite points of the brick lining and, (ii) by detecting the radioactivity of the pig iron or steel arising due to washing away of the respective radioactive isotopes previously inserted in the lining. In hot mixers also radioisotope sources were placed in the critical location of refractory lining and the washing out of radioisotope due to refractory brick wear out was detected by radiogauging at site. It has been found that radiotracer technique with periodic radiogauging is very useful method for tracing the radioisotope source if more than one refractory brick with isotope is placed, as in the case of open hearth furnaces. The results of radioanalysis revealed that radioactivity coming alongwith hot metal steel has been far below the permissible limit of concentration i.e. 20 micro-curie per ton of metal. Further, during dismantling of the residual refractory lining of open hearth furnaces or hot metal mixers, bricks containing radioisotopes have been successfully retrieved for safe disposal. (auth.)

Fragmentation process of vitrified ceramic waste (VCW) aiming its incorporation in silico-aluminous refractory concrete for production of refractory bricks

International Nuclear Information System (INIS)

Gomes, L.B.; Brandalise, R.N.; Santos, V. dos; Bergmann, C.P.

2012-01-01

Ceramic industry generates large amounts of waste, usually disposed in landfills. Reuse could minimize their generation and provides sustainable solutions. However, the energy cost of grinding these waste becomes a hindrance to their reuse. This work aims to obtain particle sizes of vitrified ceramic waste (VCW) using a fast, efficient and low cost fragmentation process as well as its use in refractory concrete. The results shows a wide range of particle size of VCW, which can be used as a promising source of raw material for production of refractory concrete. (author)

Depression in patients with refractory temporal lobe epilepsy

Directory of Open Access Journals (Sweden)

Eleonora Borges Gonçalves

2011-10-01

Full Text Available OBJECTIVE: To evaluate the comorbidity of depressive disorders in patients with refractory temporal lobe epilepsy (TLE. METHOD: We evaluated 25 consecutive patients with refractory TLE (16 women and 9 men, using semi-structured psychiatric interviews, according to the International Classification of Diseases (ICD-10, and the Beck Depression Inventory. RESULTS: Seventeen of 25 patients (68% had depressive disorder: 6 with dysthymia, three with major depressive episodes and 8 with recurrent depressive disorders. Two (8% were diagnosed with mixed anxiety and depression. Only 5 of 17 patients (29.4% were previously diagnosed with depressive disorder and received prior antidepressant treatment. Duration of epilepsy was significantly higher in patients with depressive disorder (p=0.016, but there was no relationship between depression and seizure frequency. CONCLUSION: This study confirmed that depressive disorders are common and underdiagnosed in patients with TLE refractory to AEDs. Patients with longer duration of epilepsy are at higher risk of having depression.

Alkali metal-refractory metal biphase electrode for AMTEC

Science.gov (United States)

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.

Plasma deposition of refractories

International Nuclear Information System (INIS)

Kudinov, V.V.; Ivanov, V.M.

1981-01-01

The problems of deposition, testing and application of plasma coating of refractory metals and oxides are considered. The process fundamentals, various manufacturing procedures and equipment for their realization are described in detail. Coating materials are given (Al, Mg, Al 2 O 3 , ZrO 2 , MgAlO 4 ) which are used in reactor engineering and their designated purposes are shown [ru

Biodegradable stents for the treatment of refractory or recurrent benign esophageal stenosis.

Science.gov (United States)

Imaz-Iglesia, Iñaki; García-Pérez, Sonia; Nachtnebel, Anna; Martín-Águeda, Belén; Sánchez-Piedra, Carlos; Karadayi, Bilgehan; Demirbaş, Ali Rıza

2016-06-01

Esophageal stents are used for the treatment of refractory and recurrent dyphagias. In 2007, esophageal biodegradable stents (EBS) were authorised as an alternative to existing metal and plastic stents in Europe. The advantages claimed for EBS are fewer complications concerning tissue ingrowth, stent migration and stent removal. We performed a systematic review to evaluate the efficacy and safety of EBS compared to fully-covered self-expanding metal stents, self-expanding plastic stents, and esophageal dilation for the treatment of refractory or recurrent benign esophageal stenosis. Three comparative studies (one randomized controlled trial and two cohort studies) were assessed. The studies used different inclusion criteria, had a very small (sample) size and the quality of the evidence was very low. Expert commentary: The current evidence is insufficient to determine the relative efficacy or safety of esophageal biodegradable stents. The results of this systematic review should be updated once new evidence is available.

Safety and efficacy of extracorporeal shock wave myocardial revascularization therapy for refractory angina pectoris.

Science.gov (United States)

Cassar, Andrew; Prasad, Megha; Rodriguez-Porcel, Martin; Reeder, Guy S; Karia, Darshak; DeMaria, Anthony N; Lerman, Amir

2014-03-01

To assess the safety and efficacy of extracorporeal shockwave myocardial revascularization (ESMR) therapy in treating patients with refractory angina pectoris. A single-arm multicenter prospective trial to assess safety and efficacy of the ESMR therapy in patients with refractory angina (class III/IV angina) was performed. Screening exercise treadmill tests and pharmacological single-photon emission computed tomography (SPECT) were performed for all patients to assess exercise capacity and ischemic burden. Patients were treated with 9 sessions of ESMR to ischemic areas over 9 weeks. Efficacy end points were exercise capacity by using treadmill test as well as ischemic burden on pharmacological SPECT at 4 months after the last ESMR treatment. Safety measures included electrocardiography, echocardiography, troponin, creatine kinase, and brain natriuretic peptide testing, and pain questionnaires. Fifteen patients with medically refractory angina and no revascularization options were enrolled. There was a statistically significant mean increase of 122.3±156.9 seconds (38% increase compared with baseline; P=.01) in exercise treadmill time from baseline (319.8±157.2 seconds) to last follow-up after the ESMR treatment (422.1±183.3 seconds). There was no improvement in the summed stress perfusion scores after pharmacologically induced stress SPECT at 4 months after the last ESMR treatment in comparison to that at screening; however, SPECT summed stress score revealed that untreated areas had greater progression in ischemic burden vs treated areas (3.69±6.2 vs 0.31±4.5; P=.03). There was no significant change in the mean summed echo score from baseline to posttreatment (0.4±5.1; P=.70). The ESMR therapy was performed safely without any adverse events in electrocardiography, echocardiography, troponins, creatine kinase, or brain natriuretic peptide. Pain during the ESMR treatment was minimal (a score of 0.5±1.2 to 1.1±1.2 out of 10). In this multicenter feasibility

Prognostic Factors for Refractory Status Epilepticus

Directory of Open Access Journals (Sweden)

J. Gordon Millichap

2013-03-01

Full Text Available Researchers at the Mayo Clinic, Rochester, MN studied the outcome and identified prognostic factors for refractory status epilepticus (RSE in 54 adult patients, median age 52 years [range 18-93].

Refractory disease in autoimmune diseases

NARCIS (Netherlands)

Vasconcelos, Carlos; Kallenberg, Cees; Shoenfeld, Yehuda

Refractory disease (RD) definition has different meanings but it is dynamic, according to knowledge and the availability of new drugs. It should be differentiated from severe disease and damage definitions and it must take into account duration of adequate therapy and compliance of the patient. It

Modelling of Equilibrium Between Mantle and Core: Refractory, Volatile, and Highly Siderophile Elements

Science.gov (United States)

Righter, K.; Danielson, L.; Pando, K.; Shofner, G.; Lee, C. -T.

2013-01-01

Siderophile elements have been used to constrain conditions of core formation and differentiation for the Earth, Mars and other differentiated bodies [1]. Recent models for the Earth have concluded that the mantle and core did not fully equilibrate and the siderophile element contents of the mantle can only be explained under conditions where the oxygen fugacity changes from low to high during accretion and the mantle and core do not fully equilibrate [2,3]. However these conclusions go against several physical and chemical constraints. First, calculations suggest that even with the composition of accreting material changing from reduced to oxidized over time, the fO2 defined by metal-silicate equilibrium does not change substantially, only by approximately 1 logfO2 unit [4]. An increase of more than 2 logfO2 units in mantle oxidation are required in models of [2,3]. Secondly, calculations also show that metallic impacting material will become deformed and sheared during accretion to a large body, such that it becomes emulsified to a fine scale that allows equilibrium at nearly all conditions except for possibly the length scale for giant impacts [5] (contrary to conclusions of [6]). Using new data for D(Mo) metal/silicate at high pressures, together with updated partitioning expressions for many other elements, we will show that metal-silicate equilibrium across a long span of Earth s accretion history may explain the concentrations of many siderophile elements in Earth's mantle. The modeling includes refractory elements Ni, Co, Mo, and W, as well as highly siderophile elements Au, Pd and Pt, and volatile elements Cd, In, Bi, Sb, Ge and As.

Improvements in or relating to refractory materials

International Nuclear Information System (INIS)

Peckett, J.W.A.

1980-01-01

A process is described for the production of a refractory material which includes heating an intermediate material containing carbon to cause a thermally induced reaction involving carbon in the intermediate material, wherein the intermediate material has been produced by heating a shaped gel precipitated gel, and the carbon in the intermediate material for participating in the thermally induced reaction has been produced from a gelling agent, or a derivative thereof, incorporated in the gel during gel precipitation. As examples, the refractory material may comprise uranium/plutonium oxide, or uranium/plutonium carbide, or thorium/uranium carbide, or tungsten carbide, or tungsten carbide/cobalt metal. (author)

Zirconium determination in refractories (gravimetric method)

International Nuclear Information System (INIS)

Capiotto, N.; Narahashi, Y.; Perish, C.G.; Souza, J.R.

1991-01-01

The zirconium determination in refractories is described, consisting in two separation methods for eliminating the interferences. The formatted product is calcined at 1100 0 C and determined gravimetrically as Zr P z 07. (author)

Genetics of refractoriness to Plasmodium falciparum in the mosquito Anopheles stephensi

NARCIS (Netherlands)

Feldmann, A.M.; Gemert, Geert-Jan van; Vegte-Bolmer, Marga G. van de; Jansen, Ritsert C.

1998-01-01

We previously selected a line of the malaria vector mosquito Anopheles stephensi refractory (resistant) to the human malaria parasite Plasmodium falciparum, using in vitro infections with P. falciparum gametocytes. This report presents data on the genetic background of refractoriness. The results of

Productivity Costs in Patients with Refractory Chronic Rhinosinusitis

Science.gov (United States)

Rudmik, Luke; Smith, Timothy L.; Schlosser, Rodney J.; Hwang, Peter H.; Mace, Jess C.; Soler, Zachary M.

2014-01-01

Objective Disease-specific reductions in patient productivity can lead to substantial economic losses to society. The purpose of this study was to: 1) define the annual productivity cost for a patient with refractory chronic rhinosinusitis (CRS) and 2) evaluate the relationship between degree of productivity cost and CRS-specific characteristics. Study Design Prospective, multi-institutional, observational cohort study. Methods The human capital approach was used to define productivity costs. Annual absenteeism, presenteeism, and lost leisure time was quantified to define annual lost productive time (LPT). LPT was monetized using the annual daily wage rates obtained from the 2012 US National Census and the 2013 US Department of Labor statistics. Results A total of 55 patients with refractory CRS were enrolled. The mean work days lost related to absenteeism and presenteeism was 24.6 and 38.8 days per year, respectively. A total of 21.2 household days were lost per year related to daily sinus care requirements. The overall annual productivity cost was $10,077.07 per patient with refractory CRS. Productivity costs increased with worsening disease-specific QoL (r=0.440; p=0.001). Conclusion Results from this study have demonstrated that the annual productivity cost associated with refractory CRS is $10,077.07 per patient. This substantial cost to society provides a strong incentive to optimize current treatment protocols and continue evaluating novel clinical interventions to reduce this cost. PMID:24619604

Productivity costs in patients with refractory chronic rhinosinusitis.

Science.gov (United States)

Rudmik, Luke; Smith, Timothy L; Schlosser, Rodney J; Hwang, Peter H; Mace, Jess C; Soler, Zachary M

2014-09-01

Disease-specific reductions in patient productivity can lead to substantial economic losses to society. The purpose of this study was to: 1) define the annual productivity cost for a patient with refractory chronic rhinosinusitis (CRS) and 2) evaluate the relationship between degree of productivity cost and CRS-specific characteristics. Prospective, multi-institutional, observational cohort study. The human capital approach was used to define productivity costs. Annual absenteeism, presenteeism, and lost leisure time was quantified to define annual lost productive time (LPT). LPT was monetized using the annual daily wage rates obtained from the 2012 U.S. National Census and the 2013 U.S. Department of Labor statistics. A total of 55 patients with refractory CRS were enrolled. The mean work days lost related to absenteeism and presenteeism were 24.6 and 38.8 days per year, respectively. A total of 21.2 household days were lost per year related to daily sinus care requirements. The overall annual productivity cost was $10,077.07 per patient with refractory CRS. Productivity costs increased with worsening disease-specific QoL (r = 0.440; p = 0.001). Results from this study have demonstrated that the annual productivity cost associated with refractory CRS is $10,077.07 per patient. This substantial cost to society provides a strong incentive to optimize current treatment protocols and continue evaluating novel clinical interventions to reduce this cost. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

HPA antibodies in Algerian multitransfused patients: Prevalence and involvement in platelet refractoriness.

Science.gov (United States)

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.

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials,

Directory of Open Access Journals (Sweden)

Erika Celis-Aguilar

Full Text Available Abstract Introduction: Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. Objective: To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Methods: Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8 mL of gentamicin intratympanic application at a 30 mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Results: Ten patients were included; nine patients with Meniere's disease and one patient with (late onset delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30 dB. Conclusions: Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials.

High-doses of proton pump inhibitors in refractory gastro-intestinal cancer: A case series and the state of art.

Science.gov (United States)

Falcone, Rosa; Roberto, Michela; D'Antonio, Chiara; Romiti, Adriana; Milano, Annalisa; Onesti, Concetta Elisa; Marchetti, Paolo; Fais, Stefano

2016-12-01

In recent years, proton pump inhibitors (PPIs) have been investigated at high-dose to modulate tumour microenvironment acidification thus restoring chemotherapeutic sensitivity. Moreover, several clinical data supports the role of cytotoxic drugs at low-dose continuously delivered as anticancer therapy. Clinical records of three patients affected with gastrointestinal cancer refractory to standard treatments, who had received a combination of high-dose rabeprazole and metronomic chemotherapy were reviewed. The first case, a 78-year-old man was treated for lung metastasis from colon adenocarcinoma. The second case, a 73-year-old man was treated for metastatic rectal cancer to the liver. The third one, a 68-year-old man, underwent the combination regimen for colon cancer with lung, liver and peritoneal metastases. Despite the failure of previous standard chemotherapy for metastatic disease, good clinical outcome was shown in these patients treated with an unconventional association of high-dose PPIs and metronomic chemotherapy. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Commercial low-Btu coal-gasification plant. Feasibility study: General Refractories Company, Florence, Kentucky. Volume I. Project summary. [Wellman-Galusha

Energy Technology Data Exchange (ETDEWEB)

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 the 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.

Felbamate in an adult population with severe refractory epilepsy.

LENUS (Irish Health Repository)

Kearney, H

2011-04-05

Felbamate (FBM) is efficacious in treating patients with refractory epilepsy but was withdrawn due to cases of aplastic anaemia, hepatic failure and five reported deaths. FBM is currently used in specialist centres and is only being used in one Irish centre to date. This papers aim is to review the efficacy and safety experience of FBM in Irish adult patients with refractory epilepsy. A retrospective chart review was done on patients\\' medical records. Patients were subdivided into responders and non responders based on change in seizure frequency and side effects were recorded for all. Of the 13 patients on FBM nine patients responded to FBM, four patients did not. FBM is a safe and efficacious alternative in an Irish adult population with refractory epilepsy. However close monitoring is still required given the potential fatal side effects that are possible with this anticonvulsant.

Development of a New Ferrous Aluminosilicate Refractory Material for Investment Casting of Aluminum Alloys

Science.gov (United States)

Yuan, Chen; Jones, Sam; Blackburn, Stuart

2012-12-01

Investment casting is a time-consuming, labour intensive process, which produces complex, high value-added components for a variety of specialised industries. Current environmental and economic pressures have resulted in a need for the industry to improve current casting quality, reduce manufacturing costs and explore new markets for the process. Alumino-silicate based refractories are commonly used as both filler and stucco materials for ceramic shell production. A new ceramic material, norite, is now being produced based on ferrous aluminosilicate chemistry, having many potential advantages when used for the production of shell molds for casting aluminum alloy. This paper details the results of a direct comparison made between the properties of a ceramic shell system produced with norite refractories and a typical standard refractory shell system commonly used in casting industry. A range of mechanical and physical properties of the systems was measured, and a full-scale industrial casting trial was also carried out. The unique properties of the norite shell system make it a promising alternative for casting aluminum based alloys in the investment foundry.

Refractory absence epilepsy associated with GLUT-1 deficiency syndrome.

LENUS (Irish Health Repository)

Byrne, Susan

2011-05-01

GLUT-1 deficiency syndrome (GLUT-1 DS) is a disorder of cerebral glucose transport associated with early infantile epilepsy and microcephaly. We report two boys who presented with refractory absence epilepsy associated with hypoglycorrhachia, both of whom have genetically confirmed GLUT-1 DS. We propose that these children serve to expand the phenotype of GLUT-1 DS and suggest that this condition should be considered as a cause of refractory absence seizures in childhood.

Treatment of Refractory Idiopathic Supraorbital Neuralgia Using Percutaneous Pulsed Radiofrequency.

Science.gov (United States)

Luo, Fang; Lu, Jingjing; Ji, Nan

2018-02-26

No ideal therapeutic method currently exists for refractory idiopathic supraorbital neuralgia patients who do not respond to conservative therapy, including medications and nerve blocks. Pulsed radiofrequency is a neuromodulation technique that does not produce sequelae of nerve damage after treatment. However, the efficacy of percutaneous pulsed radiofrequency for the treatment of refractory idiopathic supraorbital neuralgia is still not clear. The purpose of our study was to evaluate the efficacy and safety of pulsed radiofrequency treatment of the supraorbital nerve for refractory supraorbital neuralgia patients. We prospectively investigated the long-term effects of ultrasound-guided percutaneous pulsed radiofrequency in the treatment of 22 refractory idiopathic supraorbital neuralgia patients. A reduction in the verbal pain numeric rating scale score of more than 50% was used as the standard of effectiveness. The effectiveness rates at different time points within 2 years were calculated. After a single pulsed radiofrequency treatment, the effectiveness rate at 1 and 3 months was 77%, and the rates at 6 months, 1 year, and 2 years were 73%, 64%, and 50%, respectively. Except for a small portion of patients (23%) who experienced mild upper eyelid ecchymosis that gradually disappeared after approximately 2 weeks, no obvious complications were observed. In conclusion, the results of our study demonstrate that for patients with refractory idiopathic supraorbital neuralgia, percutaneous pulsed radiofrequency may be an effective and safe treatment choice. © 2018 World Institute of Pain.

LINX®, a novel treatment for patients with refractory asthma complicated by gastroesophageal reflux disease: a case report.

Science.gov (United States)

Sriratanaviriyakul, Narin; Kivler, Celeste; Vidovszky, Tamas J; Yoneda, Ken Y; Kenyon, Nicholas J; Murin, Susan; Louie, Samuel

2016-05-24

Gastroesophageal reflux disease is one of the most common comorbidities in patients with asthma. Gastroesophageal reflux disease can be linked to difficult-to-control asthma. Current management includes gastric acid suppression therapy and surgical antireflux procedures. The LINX® procedure is a novel surgical treatment for patients with gastroesophageal reflux disease refractory to medical therapy. To the best of our knowledge, we report the first case of successful treatment of refractory asthma secondary to gastroesophageal reflux disease using the LINX® procedure. Our patient was a 22-year-old white woman who met the American Thoracic Society criteria for refractory asthma that had remained poorly controlled for 5 years despite progressive escalation to step 6 treatment as recommended by National Institutes of Health-National Asthma Education and Prevention Program guidelines, including high-dose oral corticosteroids, high-dose inhaled corticosteroid plus long-acting β2-agonist, leukotriene receptor antagonist, and monthly omalizumab. Separate trials with azithromycin therapy and roflumilast did not improve her asthma control, nor did bronchial thermoplasty help. Additional consultations with two other university health systems left the patient with few treatment options for asthma, which included cyclophosphamide. Instead, the patient underwent a LINX® procedure after failure of maximal medical therapy for gastroesophageal reflux disease with the additional aim of improving asthma control. After she underwent LINX® treatment, her asthma improved dramatically and was no longer refractory. She had normal exhaled nitric oxide levels and loss of peripheral eosinophilia after LINX® treatment. Prednisone was discontinued without loss of asthma control. The only immediate adverse effects due to the LINX® procedure were bloating, nausea, and vomiting. LINX® is a viable alternative to the Nissen fundoplication procedure for the treatment of patients with

Safety, efficacy, and biomarkers of nivolumab with vaccine in ipilimumab-refractory or -naive melanoma.

Science.gov (United States)

Weber, Jeffrey S; Kudchadkar, Ragini Reiney; Yu, Bin; Gallenstein, Donna; Horak, Christine E; Inzunza, H David; Zhao, Xiuhua; Martinez, Alberto J; Wang, Wenshi; Gibney, Geoffrey; Kroeger, Jodi; Eysmans, Cabell; Sarnaik, Amod A; Chen, Y Ann

2013-12-01

Nivolumab, a human immunoglobulin G4-blocking antibody against the T-cell programmed death-1 checkpoint protein, has activity against metastatic melanoma. Its safety, clinical efficacy, and correlative biomarkers were assessed with or without a peptide vaccine in ipilimumab-refractory and -naive melanoma. In this phase I study, 90 patients with unresectable stage III or IV melanoma who were ipilimumab naive and had experienced progression after at least one prior therapy (cohorts 1 to 3, 34 patients) or experienced progression after prior ipilimumab (cohorts 4 to 6, 56 patients) received nivolumab at 1, 3, or 10 mg/kg every 2 weeks for 24 weeks, then every 12 weeks for up to 2 years, with or without a multipeptide vaccine. Nivolumab with vaccine was well tolerated and safe at all doses. The RECIST 1.1 response rate for both ipilimumab-refractory and -naive patients was 25%. Median duration of response was not reached at a median of 8.1 months of follow-up. High pretreatment NY-ESO-1 and MART-1-specific CD8(+) T cells were associated with progression of disease. At week 12, increased peripheral-blood T regulatory cells and decreased antigen-specific T cells were associated with progression. PD-L1 tumor staining was associated with responses to nivolumab, but negative staining did not rule out a response. Patients who experienced progression after nivolumab could respond to ipilimumab. In patients with ipilimumab-refractory or -naive melanoma, nivolumab at 3 mg/kg with or without peptide vaccine was well tolerated and induced responses lasting up to 140 weeks. Responses to nivolumab in ipilimumab-refractory patients or to ipilimumab in nivolumab-refractory patients support combination or sequencing of nivolumab and ipilimumab.

Mesenchymal stromal cell derived endothelial progenitor treatment in patients with refractory angina

DEFF Research Database (Denmark)

Friis, Tina; Haack-Sørensen, Mandana; Mathiasen, Anders B

2011-01-01

Abstract Aims. We evaluated the feasibility, safety and efficacy of intra-myocardial injection of autologous mesenchymal stromal cells derived endothelial progenitor cell (MSC) in patients with stable coronary artery disease (CAD) and refractory angina in this first in man trial. Methods and resu......Abstract Aims. We evaluated the feasibility, safety and efficacy of intra-myocardial injection of autologous mesenchymal stromal cells derived endothelial progenitor cell (MSC) in patients with stable coronary artery disease (CAD) and refractory angina in this first in man trial. Methods...... and results. A total of 31 patients with stable CAD, moderate to severe angina and no further revascularization options, were included. Bone marrow MSC were isolated and culture expanded for 6-8 weeks. It was feasible and safe to establish in-hospital culture expansion of autologous MSC and perform intra......-myocardial injection of MSC. After six months follow-up myocardial perfusion was unaltered, but the patients increased exercise capacity (p angina attacks (p Angina Questionnaire (SAQ) evaluations (p

Intravitreal dexamethasone implants for the treatment of refractory scleritis combined with uveitis in adult-onset Still's disease: a case report.

Science.gov (United States)

Ahn, Seong Joon; Hwang, Sun Jin; Lee, Byung Ro

2016-11-08

Adult-onset Still's disease is a systemic inflammatory disease which presents with uveitis and scleritis in the eye. Intravitreal dexamethasone implants are used for the treatment of refractory uveitis. A 19-year-old woman diagnosed to have adult-onset Still's disease for fevers, joint pain, and a salmon-colored bumpy rash presented with scleritis and uveitis in the left eye. Topical and systemic steroids with oral methotrexate failed to control the inflammation. We performed intravitreal injections of dexamethasone implants for side effects of steroid and refractory ocular inflammation. The therapy resulted in improvements in the patient's uveitis with reductions in scleral vessel engorgement and redness. There was no recurrence of uveitis or scleritis during 4 months following treatment. Intravitreal injections of dexamethasone implants may result in clinical improvements of refractory scleritis combined with uveitis.

Hirschsprung's Disease-Related Giant Sigmoid Volvulus Complicated by Refractory Hypertension in an Elderly Man.

Science.gov (United States)

Wu, Shaohan; Sun, Xiaofang; Yu, Yawei; Shen, Yiyu

2018-04-20

BACKGROUND Sigmoid volvulus (SV) is a life-threatening condition occasionally seen in adults. Adult Hirschsprung's disease (HD)-related SV is rarely complicated by difficult-to-control hypertension. In this report we present the case of an elderly man with a rare constellation of HD, SV, and refractory hypertension. CASE REPORT An 82-year-old man had long-term constipation, moderate abdominal pain, and progressive abdominal distension. A CT scan revealed the typical "coffee bean sign". Blood pressure was abnormal high. Subsequently, the patient's condition deteriorated. Therefore, he underwent a Hartmann's procedure. A giant and redundant sigmoid colon (length more than 60 cm, maximal diameter about 15 cm) was demonstrated to be the cause of SV during the process of surgery. Moreover, abdominal compartment syndrome caused by SV resulted in his high and refractory blood pressure (BP). Postoperative pathological results revealed HD in his sigmoid colon. CONCLUSIONS SV is rarely combined with conditions like refractory hypertension or HD among the elderly. Clinical features of SV typically present with long-term constipation, severe abdominal pain, and progressive abdominal distension. The "coffee bean sign" could be observed in imaging examinations. It is important to note that the management of SV is to relieve the obstruction and prevent recurrence, no matter which therapy is used in elderly patients with Hirschsprung's disease.

Clinical features and course of refractory anemia with ring sideroblasts associated with marked thrombocytosis

Science.gov (United States)

Broseus, Julien; Florensa, Lourdes; Zipperer, Esther; Schnittger, Susanne; Malcovati, Luca; Richebourg, Steven; Lippert, Eric; Cermak, Jaroslav; Evans, Jyoti; Mounier, Morgane; Raya, José Maria; Bailly, François; Gattermann, Norbert; Haferlach, Torsten; Garand, Richard; Allou, Kaoutar; Besses, Carlos; Germing, Ulrich; Haferlach, Claudia; Travaglino, Erica; Luno, Elisa; Pinan, Maria Angeles; Arenillas, Leonor; Rozman, Maria; Perez Sirvent, Maria Luz; Favre, Bernardine; Guy, Julien; Alonso, Esther; Ahwij, Nuhri; Jerez, Andrés; Hermouet, Sylvie; Maynadié, Marc; Cazzola, Mario; Girodon, François

2012-01-01

Background Refractory anemia with ring sideroblasts associated with marked thrombocytosis was proposed as a provisional entity in the 2001 World Health Organization classification of myeloid neoplasms and also in the 2008 version, but its existence as a single entity is contested. We wish to define the clinical features of this rare myelodysplastic/myeloproliferative neoplasm and to compare its clinical outcome with that of refractory anemia with ring sideroblasts and essential thrombocythemia. Design and Methods We conducted a collaborative retrospective study across Europe. Our database included 200 patients diagnosed with refractory anemia with ring sideroblasts and marked thrombocytosis. For each of these patients, each patient diagnosed with refractory anemia with ring sideroblasts was matched for age and sex. At the same time, a cohort of 454 patients with essential thrombocythemia was used to compare outcomes of the two diseases. Results In patients with refractory anemia with ring sideroblasts and marked thrombocytosis, depending on the Janus Kinase 2 V617F mutational status (positive or negative) or platelet threshold (over or below 600×109/L), no difference in survival was noted. However, these patients had shorter overall survival and leukemia-free survival with a lower risk of thrombotic complications than did patients with essential thrombocythemia (P<0.001) but better survival (P<0.001) and a higher risk of thrombosis (P=0.039) than patients with refractory anemia with ring sideroblasts. Conclusions The clinical course of refractory anemia with ring sideroblasts and marked thrombocytosis is better than that of refractory anemia with ring sideroblasts and worse than that of essential thrombocythemia. The higher risk of thrombotic events in this disorder suggests that anti-platelet therapy might be considered in this subset of patients. From a clinical point of view, it appears to be important to consider refractory anemia with ring sideroblasts and

Load-carrying capabilities of refractory alloys for space reactor power applications

International Nuclear Information System (INIS)

Horak, J.A.

1985-01-01

To achieve sufficient thermodynamic efficiency, space nuclear power systems must operate above 1000 0 C. A quantitative evaluation of the existing mechanical properties data for the refractory alloys relevant to space nuclear power systems design lifetimes up to seven years at temperatures up to 1400 0 C is being conducted. The most important properties for space nuclear power systems are long-term high-temperature (>1000 0 C) creep strength and ductility, low-temperature ( 0 C) fracture toughness [including ductile-to-brittle transition temperature, (DBTT)], and ductility at high strain rates; of special concern are the above properties for weldments of refractory alloys, composition, applied stress, test temperature, test environment (e.g., vacuum, lithium), and thermomechanical treatment (TMT) history. Currently being evaluated are, in order of ascending mp, selected alloys of niobium (e.g., Nb-1% Zr, Nb-1% Zr-0.1% C), molybdenum (e.g., Mo-13% Re), tantalum (e.g., ASTAR-811C), and tungsten (e.g., CVD W and W-25% Re). Creep properties of these alloys have been correlated via Larson-Miller, Manson-Hafered, and other empirical parameters; creep equations have been developed from these correlations. 12 figs., 8 tabs

Role of Radiation Therapy in Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma

DEFF Research Database (Denmark)

Ng, Andrea K; Yahalom, Joachim; Goda, Jayant S

2018-01-01

Approximately 30% to 40% of patients with diffuse large B-cell lymphoma (DLBCL) will have either primary refractory disease or relapse after chemotherapy. In transplant-eligible patients, those with disease sensitive to salvage chemotherapy will significantly benefit from high-dose therapy with a...

Religiosity is associated with hippocampal but not amygdala volumes in patients with refractory epilepsy

OpenAIRE

Wuerfel, J; Krishnamoorthy, E; Brown, R; Lemieux, L; Koepp, M; v Tebartz,; Trimble, M

2004-01-01

Method: Magnetic resonance images were obtained from 33 patients with refractory epilepsy and mesial temporal structure volumes assessed. Amygdala and hippocampal volumes were then compared in high and low scorers on the religiosity, writing, and sexuality sub-scales of the Neurobehavioural Inventory.

Cometary dust: the diversity of primitive refractory grains.

Science.gov (United States)

Wooden, D H; Ishii, H A; Zolensky, M E

2017-07-13

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'. © 2017 The Authors.

Low-Chrome/Chrome Free Refractories for Slagging Gasifiers

International Nuclear Information System (INIS)

Bennett, J.P.; Kwong, K.-S.; Powell, C.P.; Thomas, H.; Petty, A.V. Jr.

2007-01-01

Gasifiers are containment vessels used to react carbon-containing materials with oxygen and water, producing syngas (CO and H2) that is used in chemical and power production. It is also a potential source of H2 in a future hydrogen economy. Air cooled slagging gasifiers are one type of gasifier, operating at temperatures from 1275-1575 C and at pressures of 400 psi or higher. They typically use coal or petroleum coke as the carbon source, materials which contain ash impurities that liquefy at the gasification temperatures, producing liquid slag in quantities of 100 or more tons/day, depending on the carbon fed rate and the percent ash present in the feedstock. The molten slag is corrosive to refractory linings, causing chemical dissolution and spalling. The refractory lining is composed of chrome oxide, alumina, and zirconia; and is replaced every 3-24 months. Gasifier users would like greater on-line availability and reliability of gasifier liners, something that has impacted gasifier acceptance by industry. Research is underway at NETL to improve refractory service life and to develop a no-chrome or low-chrome oxide alternative refractory liner. Over 250 samples of no- or low-chrome oxide compositions have been evaluated for slag interactions by cup testing; with potential candidates for further studies including those with ZrO2, Al2O3, and MgO materials. The development of improved liner materials is necessary if technologies such as IGCC and DOE's Near Zero Emissions Advanced Fossil Fuel Power Plant are to be successful and move forward in the marketplace

Long-term evaluation of treatment of chronic, therapeutically refractory tinnitus by neurostimulation

NARCIS (Netherlands)

Staal, M. J.; Holm, A. F.; Mooij, J. J. A.; Albers, F. W. J.; Bartels, H.

2007-01-01

Objective: Long-term evaluation of treatment of chronic, therapeutically refractory tinnitus by means of chronic electrical stimulation of the vestibulocochlear nerve. Patients: Inclusion criteria were severe, chronic, therapeutically refractory, unilateral tinnitus and severe hearing loss at the

Refractory seizures due to a dural-based cavernoma masquerading as a meningioma.

Science.gov (United States)

Zeng, Xianwei; Mahta, Ali; Kim, Ryan Y; Saad, Ali G; Kesari, Santosh

2012-04-01

A 37-year-old female presented with medically intractable complex partial seizures with secondary generalization. She was found to have a dural-based lesion with radiologic features of meningioma. A gross total resection was performed and pathology confirmed a diagnosis of cavernous angioma and she became seizure free after the surgical resection. Cavernous angioma should be considered in differential diagnosis of a dural-based lesion manifesting with refractory seizures.

Tioguanine in the treatment of refractory coeliac disease--a single centre experience.

Science.gov (United States)

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.

Refractory, Abrasive and Other Industrial Mineral Operations

Data.gov (United States)

Department of Homeland Security — This map layer includes refractory, abrasive, and other industrial minerals operations in the United States. The data represent commodities covered by the Minerals...

Evaluation of nutritional status in children with refractory epilepsy

Directory of Open Access Journals (Sweden)

Testolin G

2006-04-01

Full Text Available Abstract Background children affected by refractory epilepsy could be at risk of malnutrition because of feeding difficulties (anorexia, chewing, swallowing difficulties or vomiting and chronic use of anticonvulsants, which may affect food intake and energy metabolism. Moreover, their energy requirement may be changed as their disabilities would impede normal daily activities. The aim of the present study was to evaluate nutritional status, energy metabolism and food intake in children with refractory epilepsy. Methods 17 children with refractory epilepsy (13 boys and 4 girls; mean age 9 ± 3,2 years; Body Mass Index 15,7 ± 3,6 underwent an anthropometric assessment, body composition evaluation by dual-energy X-ray absorptiometry, detailed dietetic survey and measurement of resting energy expenditure by indirect calorimetry. Weight-for-age, height-for-age (stunting and weight-for-height (wasting were estimated compared to those of a reference population of the same age. Results 40% of children were malnourished and 24% were wasted. The nutritional status was worse in the more disabled children. Dietary intake resulted unbalanced (18%, 39%, 43% of total daily energy intake derived respectively from protein, lipid and carbohydrate. Adequacy index [nutrient daily intake/recommended allowance (RDA × 100] was Conclusion many children with refractory epilepsy would benefit from individual nutritional assessment and management as part of their overall care.

Short term outcome of Ahmed glaucoma valve implantation in management of refractory glaucoma in a tertiary hospital in Oman

Science.gov (United States)

Shah, Manali R.; Khandekar, Rajiv B.; Zutshi, Rajiv; Mahrooqi, Rahima

2013-01-01

Background: We present outcomes of Ahmed Glaucoma Valve (AGV) implantation in treating refractory glaucoma in a tertiary hospital in Oman. Refractory glaucoma was defined as previously failed conventional glaucoma surgery and an uncontrolled intraocular pressure (IOP) of more than 21 mm Hg despite treatment with three topical and/or oral therapy. Materials and Methods: This historical cohort study was conducted in 2010. Details of medical and surgical treatment were recorded. Ophthalmologists examined eyes and performed glaucoma surgeries using AGV. The best corrected distant vision, IOP, and glaucoma medications were prospectively reviewed on 1st day, 1st, 6th, 12th week postoperatively, and at the last follow up. Result: Glaucoma specialists examined and treated 40 eyes with refractory glaucoma of 39 patients (20 males + 19 females). Neo-vascular glaucoma was present in 23 eyes. Vision before surgery was glaucoma medications (2.38; SD 1.1) was reduced compared to the mean number of postoperative medications (1.92; SD 0.9) at 12 weeks. Conclusion: We succeeded in reducing visual disabilities and the number of anti-glaucoma medications used to treat refractory glaucoma by AGV surgery. PMID:23772122

Treatment of refractory epilepsy with natalizumab in a patient with multiple sclerosis. Case report

Directory of Open Access Journals (Sweden)

Constantin Gabriela

2010-09-01

Full Text Available Abstract Background Multiple sclerosis (MS is considered an autoimmune disease of the central nervous system and therapeutic inhibition of leukocyte migration with natalizumab, an anti-alpha4 integrin antibody, is highly effective in patients with MS. Recent studies performed in experimental animal models with relevance to human disease suggested a key role for blood-brain barrier damage and leukocyte trafficking mechanisms also in the pathogenesis of epilepsy. In addition, vascular alterations and increased leukocyte accumulation into the brain were recently documented in patients with refractory epilepsy independently on the disease etiology. Case report Here we describe the clinical course of a 24-year-old patient with MS in whom abrupt tonic-clonic generalized seizures manifested at disease onset. Although MS had a more favorable course, treatment with glatiramer acetate and antiepileptic drugs for 7 years had no control on seizure generation and the patient developed severe refractory epilepsy. Interestingly, generalized seizures preceded new MS relapses suggesting that seizure activity may contribute to MS worsening creating a positive feedback loop between the two disease conditions. Notably, treatment with natalizumab for 12 months improved MS condition and led to a dramatic reduction of seizures. Conclusion Our case report suggests that inhibition of leukocyte adhesion may represent a new potential therapeutic approach in epilepsy and complement the traditional therapy with anti-epileptic drugs.

An update on field test results for an engineered refractory for slagging gasifiers

Energy Technology Data Exchange (ETDEWEB)

Dogan, O.N.; Alman, D.E.; Jablonski, P.D.; Hawk, J.A.

2006-05-01

The widespread commercial adaptation of slagging gasifier technology to produce power, fuel, and/or chemicals from coal will depend in large measure on the technology’s ability to prove itself both economic and reliable. Improvements in gasifier reliability, availability, and maintainability will in part depend on the development of improved performance structural materials with longer service life in this application. Current generation refractory materials used to line the air-cooled, slagging gasifier vessel, and contain the gasification reaction, often last no more than three to 18 months in commercial applications. The downtime required for tear-out and replacement of these critical materials contributes to gasifier on-line availabilities that fall short of targeted goals. In this talk we will discuss the development of an improved refractory material engineered by the NETL for longer service life in this application, and provide an update on recent field test results.

Improvement of castable refractories for RH snorkel; RH shinshitsukanyo futeikeizai no kaizen

Energy Technology Data Exchange (ETDEWEB)

Nishi, K.; Obana, T.; Fijii, T.; Shimizu, I. [Harima Ceramics Corp., Hyogo (Japan)

1999-11-01

Relating to corrosion of RH submerged nozzle, resistance against iron oxide of monolithic refractories was examined. Corrosion and seepage of refractories were measured by rotating corrosion, refractories include alumina-spinel castable, which is applied to RH under tank, and alumina-magnesia castable, which is generally used for RH, submerged nozzle. Alumina-spinel castable is superior in resistance against iron oxide than alumina-magnesia castable, and the resistance decreased with increase of stainless fiber addition to castable. Alumina-spinel castable without stainless fiber was suitable for bottom end of the dipping pipe. (NEDO)

Clinical Options in Relapsed or Refractory Hodgkin Lymphoma: An Updated Review

Directory of Open Access Journals (Sweden)

Roberta Fedele

2015-01-01

Full Text Available Hodgkin lymphoma (HL is a potentially curable lymphoma, and modern therapy is expected to successfully cure more than 80% of the patients. Second-line salvage high-dose chemotherapy and autologous stem cell transplantation (auto-SCT have an established role in the management of refractory and relapsed HL, leading to long-lasting responses in approximately 50% of relapsed patients and a minority of refractory patients. Patients progressing after intensive treatments, such as auto-SCT, have a very poor outcome. Allogeneic SCT represents the only strategy with a curative potential for these patients; however, its role is controversial. Based on recent knowledge of HL pathology, biology, and immunology, antibody-drug conjugates targeting CD30, small molecule inhibitors of cell signaling, and antibodies that inhibit immune checkpoints are currently explored. This review will discuss the clinical results regarding auto-SCT and allo-SCT as well as the current role of emerging new treatment strategies.

New-Onset Refractory Status Epilepticus: More Investigations, More Questions

Directory of Open Access Journals (Sweden)

Philippe Dillien

2016-06-01

Full Text Available A 27-year-old previously healthy woman was admitted to the hospital with recurrent seizures. Status epilepticus developed that became refractory to third-line therapy with propofol and barbiturates. The patient had a very extensive diagnostic workup including autoimmune, viral and genetic investigations. A tentative immune therapy was proposed with high doses of steroids and plasma exchanges. Our patient had an inherited heterozygous single nucleotide variant in the sequence c.1280A>G [p.Lys427Arg] of the SMC3 gene that was insufficient to explain the seizures. Surprisingly, IgM antibodies against Japanese encephalitis virus were positive on the serum drawn 11 days after symptom onset, as detected by ELISA and the immunofluorescence antibody (IFA technique. IgG antibodies were also positive using the IFA technique, but not with ELISA. The same investigations as well as the detection of the viral genome by the q-RT-PCR technique were negative on cerebrospinal fluid. Despite the suspicion of a viral infection, we concluded that our patient had a new-onset refractory status epilepticus of cryptogenic origin. Termination of the status epilepticus was obtained after 47 days, with a possible benefit from the introduction of ketamine.

Ruxolitinib in steroid refractory graft-vs.-host disease: a case report

Directory of Open Access Journals (Sweden)

Enrico Maffini

2016-08-01

Full Text Available Abstract Background Allogeneic hematopoietic stem cell transplantation (HSCT is potentially curative in a variety of hematological malignancies. Graft-vs.-host disease (GvHD remains a life-threatening complication. Standard treatment is high-dose (HD corticosteroids. Steroid-refractory (SR GvHD is associated with poor prognosis. At present, second-line treatment is ill-defined and includes a number of agents. Novel insights into the pathophysiology of acute GvHD (aGvHD highlight the relevant role of the host inflammatory response governed by several kinase families, including Janus kinases (JAK1/2. Ruxolitinib, a JAK1/2 inhibitor approved for intermediate-2/high-risk myelofibrosis, was recently employed in SR-GvHD with encouraging overall response rates. Clinical experience however remains limited. Case presentation A 51-year-old male with refractory anemia with excess blast type-2 underwent a myeloablative allogeneic HSCT from a 9/10 HLA-matched unrelated donor after conditioning with busulfan and cyclophosphamide. GvHD prophylaxis consisted of cyclosporine, methotrexate, and thymoglobulin. CD34+ cells/kg infused were 8.69 × 106 kg. On day 29, the patient developed overall grade IV aGvHD with biopsy proven stage IV gastrointestinal (GI GvHD refractory to HD corticosteroids. Patient conditions rapidly deteriorated and became critical despite the addition of mycophenolate mofetil and budesonide. On day 33, Ruxolitinib was started, and on day 39 the patient clinical conditions gradually improved. Complete resolution of aGvHD was also confirmed by histology on day 54. Conclusions At 5 months from HSCT, the patient is well and in continuous hematological complete remission without flare of GvHD. Ruxolitinib was discontinued on day 156. Ruxolitinib is feasible and effective in SR-aGvHD though large prospective clinical trials are warranted.

Thermodynamics of carbon deoxidation and aluminium deoxidation of refractory metals

International Nuclear Information System (INIS)

Garg, S.P.; Sundaram, C.V.

1975-01-01

Carbon has been used for removing the last traces of oxygen from many refractory metals by evaporation of CO at high temperature and vacuum. Similar purification can also be achieved employing aluminium deoxidation by evaporation of Al 2 Osub(g). In the present paper a theoretical thermodynamic approach has been attempted to evaluate the deoxidation tendencies of refractory metals of groups IV to VI by these two processes. Expressions have been theoretically derived, relating the concentration product of carbon and oxygen in the metal (which is a measure of the carbon deoxidation tendency of the metal) with temperature and pressure, for various M-C-O systems. Similarly the relative vapour pressure values of Alsub(2)Osub(g),Alsub(g)andMO(g) (suboxide of the metal) over various M-Al-O systems have been calculated as a function of aluminium and oxygen contents of the metal. From these analyses, it has been shown that a substantial amount of oxygen can be removed from M-Al-O alloys by aluminium deoxidation. The estimated values are compared with the reported values based on experiment. (author)

Corrosão de refratários utilizados na siderurgia. Parte III: caracterização de refratários comerciais Corrosion of refractories used in steel metallurgy. Part III: characterization of commercial refractories

Directory of Open Access Journals (Sweden)

S. R. Bragança

2013-03-01

Full Text Available Foi realizada uma revisão dos principais aspectos encontrados na literatura especializada sobre corrosão de refratários, avaliando-se a viabilidade de determinados ensaios e relacionando-se com resultados experimentais. As propriedades físicas e microestruturais de refratários comerciais foram estudadas, considerando-se as diferenças entre elas e implicações com a qualidade e provável vida útil do refratário. Assim, investigou-se os diversos tipos de refratários utilizados como revestimento em uma panela de aço, como de sobre-linha (freeboard, linha de escória e linha de metal. Os refratários magnésia-carbono e doloma-carbono foram avaliados, destacando-se também as diferenças entre eles. Os materiais analisados mostraram características favoráveis a uma elevada resistência ao processo de corrosão, apresentando uma série de propriedades a serem escolhidas de acordo com a prática industrial.The main aspects found in the literature about refractories corrosion were reviewed, evaluating the feasibility of certain tests and relating them with experimental results. The physical properties and microstructure of commercial refractories were analyzed, considering the differences between them and the quality implications and probable life of the refractory. Thus, this study comprised various types of refractories used as lining on steel ladle, as on freeboard, slag line and metal line. Magnesia-carbon and doloma-carbon refractories were analyzed, highlighting the differences between them. The examined materials showed characteristics favoring high resistance to corrosion process, presenting a series of properties to be selected in accordance with industry practice.

The effect of various sintering temperature on used refractory towards its physical properties

Science.gov (United States)

Sudibyo; Wulandari, Y. R.; Amin, M.; Azhar

2018-01-01

The used magnesia refractory from the kiln of cement industry was successfully recycled to new refractory using Kaolin as an adhesive. In this work, the temperatures of sintering were varied from 1000°C to 1500°C. The result shows that the increment temperature effects in sintering process will enhance refractory physical properties such as bulk density, cold crushing strength or pressure strength and thermal conductivity. Meanwhile, the porosity was decreased as the increase of the sintering temperature.

Artigo revisão: atuação dos antioxidantes em refratários contendo carbono Review article: performance of the antioxidants in carbon containing refractories

Directory of Open Access Journals (Sweden)

A. P. Luz

2007-12-01

Full Text Available Os materiais refratários contendo carbono têm despertado grande atenção nos últimos anos, uma vez que são amplamente utilizados na indústria siderúrgica em virtude de suas excelentes propriedades. A presença do carbono nos refratários contribui para o aumento da resistência ao choque térmico, da energia de fratura e da resistência ao ataque por escória. Entretanto, a principal desvantagem do seu uso é a sua alta susceptibilidade a oxidação. Com o objetivo de manter o carbono presente na estrutura do material refratário o maior tempo possível, algumas medidas são requeridas para reduzir sua oxidação sob condições operacionais. Desta forma, o uso de substâncias conhecidas como antioxidantes tem sido extensivamente estudado. Os principais antioxidantes, suas características e formas de atuação são abordados nesta revisão. A formação de novos compostos devido à reação entre os antioxidantes com o carbono, nitrogênio, oxigênio e o próprio material refratário pode provocar um preenchimento parcial dos poros e redução da taxa de interdifusão dos gases, havendo assim a prevenção da oxidação do carbono presente no refratário.Carbon containing refractories have received great attention over the last years, as they are widely used in the steel making industry due to their better properties, such as: higher thermal shock resistance, fracture energy and slag resistance. However, their main disadvantage is the carbon oxidation. Aiming to keep carbon in the structure of the refractory material some actions are required in order to reduce its oxidation under operational conditions. Therefore, the use of materials known as antioxidants has been extensively studied. The main antioxidants, their characteristics and performance are discussed in the present review article. The formation of new compounds due to the reaction of the antioxidants with carbon, nitrogen, oxygen and the refractory material can induce a pore

Rapid pacing results in changes in atrial but not in ventricular refractoriness

NARCIS (Netherlands)

Schoonderwoerd, BA; Van Gelder, IC; Tieleman, RG; Bel, KJ; Crijns, HJGM

It is well known that atrial tachycardia causes atrial electrical remodeling, characterized by shortening of atrial effective refractory periods (AERPs) and loss of physiological adaptation of AERP to rate. However, the nature and time course of changes in ventricular effective refractory periods

Transient refractory material dissolution by a volumetrically-heated melt

Energy Technology Data Exchange (ETDEWEB)

Seiler, Jean Marie, E-mail: jean-marie.seiler@cea.fr [CEA, DEN, DTN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Ratel, Gilles [CEA, DEN, DTN, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Combeau, Hervé [Institut Jean Lamour, UMR 7198, Lorraine University, Ecole des Mines de Nancy, Parc de Saurupt, 54042 Nancy Cedex (France); Gaus-Liu, Xiaoyang; Kretzschmar, Frank; Miassoedov, Alexei [Karlsruhe Institut of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2014-12-15

Highlights: • We describe a test investigating ceramic dissolution by a molten non-eutectic melt. • The evolution of the interface temperature between melt and refractory is measured. • A theoretical model describing dissolution kinetics is proposed. • When dissolution stops, interface temperature is the liquidus temperature of the melt. - Abstract: The present work addresses the question of corium–ceramic interaction in a core catcher during a core-melt accident in a nuclear power plant. It provides an original insight into transient aspects concerning dissolution of refractory material by a volumetrically heated pool. An experiment with simulant material (LIVECERAM) is presented. Test results clearly show that dissolution of solid refractory material can occur in a non-eutectic melt at a temperature which is lower than the melting temperature of the refractory material. During the dissolution transient, the interface temperature rises above the liquidus temperature, corresponding to the instantaneous average composition of the melt pool. With constant power dissipation in the melt and external cooling of the core-catcher, a final steady-state situation is reached. Dissolution stops when the heat flux (delivered by the melt to the refractory) can be removed by conduction through the residual thickness of the ceramic, with T{sub interface} = T{sub liquidus} (calculated for the average composition of the final liquid pool). The final steady state corresponds to a uniform pool composition and uniform interface temperature distribution. Convection in the pool is governed by natural thermal convection and the heat flux distribution is therefore similar to what would be obtained for a single component pool. An interpretation of the experiment with two model-based approaches (0D and 1D) is presented. The mass transfer kinetics between the interface and the bulk is controlled by a diffusion sublayer within the boundary layer. During the dissolution transient

A review of refractory materials for vapor-anode AMTEC cells

Science.gov (United States)

King, Jeffrey C.; El-Genk, M. S.

2000-01-01

Recently, refractory alloys have been considered as structural materials for vapor-anode Alkali Metal Thermal-to-Electric Conversion (AMTEC) cells, for extended (7-15 years) space missions. This paper reviewed the existing database for refractory metals and alloys of potential use as structural materials for vapor-anode sodium AMTEC cells. In addition to requiring that the vapor pressure of the material be below 10-9 torr (133 nPa) at a typical hot side temperature of 1200 K, other screening considerations were: (a) low thermal conductivity, low thermal radiation emissivity, and low linear thermal expansion coefficient; (b) low ductile-to-brittle transition temperature, high yield and rupture strengths and high strength-to-density ratio; and (c) good compatibility with the sodium AMTEC operating environment, including high corrosion resistance to sodium in both the liquid and vapor phases. Nb-1Zr (niobium-1% zirconium) alloy is recommended for the hot end structures of the cell. The niobium alloy C-103, which contains the oxygen gettering elements zirconium and hafnium as well as titanium, is recommended for the colder cell structure. This alloy is stronger and less thermally conductive than Nb-1Zr, and its use in the cell wall reduces parasitic heat losses by conduction to the condenser. The molybdenum alloy Mo-44.5Re (molybdenum-44.5% rhenium) is also recommended as a possible alternative for both structures if known problems with oxygen pick up and embrittlement of the niobium alloys proves to be intractable. .

Application of x-ray fluorescence (XRF) absolute analysis method for silica refractories

International Nuclear Information System (INIS)

Asakura, Hideo; Yamada, Yasujiro; Kansai, Kouhei; Tomatsu, Ichirou; Murata, Mamoru

2015-01-01

X-ray fluorescence (XRF) analysis is a rapid and precise quantitative analytical method for the determination of major and trace elements in many industries and academics. XRF analytical values are relative due to the use of the calibration curves calculated from measuring the reference standard materials such as Japanese Refractory Reference Materials (JRRM) series with certified values determined by wet chemical analysis. The development of the XRF analytical method from relative to absolute analysis will help much to determine the absolute values of samples from the fields where reference standard samples have not been prepared, and thus can be applied widely in many industries. The implement of the absolute XRF analysis for silica refractories requires high purity reagents and/or reference standard solution for the binary basic calibration curve, and theoretical matrix correction coefficients for the multi-components silica refractories analysis. The reproducibility and repeatability of this method for Al 2 O 3 5 mass% sample were 0.009 and 0.006 mass% in Al 2 O 3 and showed better values that those of ICP-AES recognized as an absolute method in JIS R 2212-2, which yielded 0.028 and 0.031 mass%, respectively. The XRF absolute analysis for JRRM 200 series, 201a and 205a does not show a bias but coincides with their certified values. (author)

Seizures, refractory status epilepticus, and depolarization block as endogenous brain activities

Science.gov (United States)

El Houssaini, Kenza; Ivanov, Anton I.; Bernard, Christophe; Jirsa, Viktor K.

2015-01-01

Epilepsy, refractory status epilepticus, and depolarization block are pathological brain activities whose mechanisms are poorly understood. Using a generic mathematical model of seizure activity, we show that these activities coexist under certain conditions spanning the range of possible brain activities. We perform a detailed bifurcation analysis and predict strategies to escape from some of the pathological states. Experimental results using rodent data provide support of the model, highlighting the concept that these pathological activities belong to the endogenous repertoire of brain activities.

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials.

Science.gov (United States)

Celis-Aguilar, Erika; Hinojosa-González, Ramon; Vales-Hidalgo, Olivia; Coutinho-Toledo, Heloisa

Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8mL of gentamicin intratympanic application at a 30mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Ten patients were included; nine patients with Meniere's disease and one patient with (late onset) delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30dB. Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials). Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

A randomized controlled trial of the ketogenic diet in refractory childhood epilepsy

NARCIS (Netherlands)

Lambrechts, D.A.J.E.; de Kinderen, R.J.A.; Vles, J.S.H.; de Louw, A.J.A.; Aldenkamp, A.P.; Majoie, H.J.M.

2017-01-01

Objective: To evaluate the efficacy and tolerability of the ketogenic diet (KD) during the first 4 months of a randomized controlled trial (RCT) in refractory epilepsy patients aged 1–18 years. Methods: Children and adolescents with refractory epilepsy, not eligible for epilepsy surgery, were

Ixabepilone: a new chemotherapeutic option for refractory metastatic breast cancer

Directory of Open Access Journals (Sweden)

Shannon Puhalla

2008-09-01

Full Text Available Shannon Puhalla, Adam BrufskyUPMC Magee-Womens Cancer Program, University of Pittsburgh, Pittsburgh, Pennsylvania, USAAbstract: Taxane therapy is commonly used in the treatment of metastatic breast cancer. However, most patients will eventually become refractory to these agents. Ixabepilone is a newly approved chemotherapeutic agent for the treatment of metastatic breast cancer. Although it targets microtubules similarly to docetaxel and paclitaxel, ixabepilone has activity in patients that are refractory to taxanes. This review summarizes the pharmacology of ixapebilone and clinical trials with the drug both as a single agent and in combination. Data were obtained using searches of PubMed and abstracts of the annual meetings of the American Society of Clinical Oncology and the San Antonio Breast Cancer Symposium from 1995 to 2008. Ixapebilone is a semi-synthetic analog of epothilone B that acts to induce apoptosis of cancer cells via the stabilization of microtubules. Phase I clinical trials have employed various dosing schedules ranging from daily to weekly to 3-weekly. Dose-limiting toxicites included neuropathy and neutropenia. Responses were seen in a variety of tumor types. Phase II studies verified activity in taxane-refractory metastatic breast cancer. The FDA has approved ixabepilone for use as monotherapy and in combination with capecitabine for the treatment of metastatic breast cancer. Ixabepilone is an efficacious option for patients with refractory metastatic breast cancer. The safety profile is similar to that of taxanes, with neuropathy and neutropenia being dose-limiting. Studies are ongoing with the use of both iv and oral formulations and in combination with other chemotherapeutic and biologic agents.Keywords: ixabepilone, epothilone, metastatic breast cancer, taxane-refractory

Methods of use of calcium hexa aluminate refractory linings and/or chemical barriers in high alkali or alkaline environments

Science.gov (United States)

McGowan, Kenneth A; Cullen, Robert M; Keiser, James R; Hemrick, James G; Meisner, Roberta A

2013-10-22

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 greater 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.

Cannabidiol as potential treatment in refractory pediatric epilepsy.

Science.gov (United States)

Paolino, Maria Chiara; Ferretti, Alessandro; Papetti, Laura; Villa, Maria Pia; Parisi, Pasquale

2016-01-01

In recent years there has been great scientific and public interest focused on the therapeutic potential of compounds derived from cannabis for the treatment of refractory epilepsy in children. From in vitro and in vivo studies on animal models, cannabidiol (CBD) appears to be a promising anticonvulsant drug with a favorable side-effect profile. In humans, CBD efficacy and safety is not supported by well-designed trials and its use has been described by anecdotal reports. It will be necessary to investigate CBD safety, pharmacokinetics and interaction with other anti-epileptic drugs (AEDs) alongside performing double-blinded placebo-controlled trials in order to obtain conclusive data on its efficacy and safety in children.

Application of monolithic lining to tundish and extension of tundish life with improvement of refractories; Tandeisshu futeiseika to taikabutsu kaizen ni yoru jumyo kojo

Energy Technology Data Exchange (ETDEWEB)

Mori, Eiichiro; Fujta, Takashi; Tanikawa, Kanji [Kobe Steel Corp., Hyogo (Japan)

1999-06-01

As a part of realization of monolithic liming of a tundish lining refractory, a study on 2CC and 3CC tundish monolithic refractories was carried out to improve placing efficiency and extend its life. Main inspection points were set on (1) casting facility specifications and (2) structure and material. A force feeding pump system with a high degree of freedom for placing layout was selected. It was judged preferable than a hopper dolly type ladle repair facility in the degree of freedom for a placing site and facility expenses, though little inferior at maintenance. A force feeding pump is combined with a boom to enable the facility to cast for plural objects. Low expansion and creep properties were given to the refractory by reviewing the addition of the expansive material and the structure was improved by setting anchor blocks at corner parts. The cost of refractories was reduced and labor saving of refractory placing workers was achieved by widely extending the life. (NEDO)

Clinical outcomes of intravenous immunoglobulin therapy in refractory uveitis.

Science.gov (United States)

Garcia-Geremias, M; Carreño, E; Epps, S J; Lee, R W J; Dick, A D

2015-04-01

Intravenous immunoglobulin (IVIg) therapy has multiple mechanisms of immunomodulatory action. We wished therefore to assess its efficacy in a spectrum of patients with refractory uveitis. Retrospective review of clinical charts was conducted to document response to IVIg treatment in consecutive patients with treatment-refractory uveitis. Main outcome measures were control of intraocular inflammation, visual acuity, progression of the disease, and complications. Four (two male) patients, with a mean age at the beginning of the treatment of 47 years (range: 39-64), were included in the study. Indication for treatment was patients with active non-infectious uveitis refractory to steroids and immunomodulatory therapy. All patients received a course of 0.5 g/kg per day of IVIg for three consecutive days, repeating this course at a mean of 11 week (range: 2-39 weeks) intervals when indicated clinically. The median duration of the IVIg therapy was 7 months (range: 3-14 months). In three patients treatment resulted in stabilisation and prevention of progression of the disease, and additionally in two patients it facilitated a decrease in prednisolone dose. Treatment failed to induce long-term remission in one patient with recurrence of macular oedema. IVIg was well tolerated with neither immediate nor longer-term adverse events observed. In three out of four cases IVIg was an effective adjunctive therapy and well tolerated for the management of treatment-refractory uveitis.

High efficacy and safety of low-dose CD19-directed CAR-T cell therapy in 51 refractory or relapsed B acute lymphoblastic leukemia patients.

Science.gov (United States)

Pan, J; Yang, J F; Deng, B P; Zhao, X J; Zhang, X; Lin, Y H; Wu, Y N; Deng, Z L; Zhang, Y L; Liu, S H; Wu, T; Lu, P H; Lu, D P; Chang, A H; Tong, C R

2017-12-01

Refractory or relapsed B lymphoblastic leukemia (B-ALL) patients have a dismal outcome with current therapy. We treated 42 primary refractory/hematological relapsed (R/R) and 9 refractory minimal residual disease by flow cytometry (FCM-MRD + ) B-ALL patients with optimized second generation CD19-directed CAR-T cells. The CAR-T-cell infusion dosages were initially ranged from 0.05 to 14 × 10 5 /kg and were eventually settled at 1 × 10 5 /kg for the most recent 20 cases. 36/40 (90%) evaluated R/R patients achieved complete remission (CR) or CR with incomplete count recovery (CRi), and 9/9 (100%) FCM-MRD + patients achieved MRD - . All of the most recent 20 patients achieved CR/CRi. Most cases only experienced mild to moderate CRS. 8/51 cases had seizures that were relieved by early intervention. Twenty three of twenty seven CR/CRi patients bridged to allogeneic hematopoietic stem cell transplantation (allo-HCT) remained in MRD - with a median follow-up time of 206 (45-427) days, whereas 9 of 18 CR/CRi patients without allo-HCT relapsed. Our results indicate that a low CAR-T-cell dosage of 1 × 10 5 /kg, is effective and safe for treating refractory or relapsed B-ALL, and subsequent allo-HCT could further reduce the relapse rate.

Advances in refractories for the metallurgical industries III: proceedings of the international symposium

Energy Technology Data Exchange (ETDEWEB)

Allaire, C.; Rigaud, M. [eds.] [Ecole Polytchnique, Montreal, PQ (Canada)

1999-07-01

In the three years since the last symposium key innovations have been made in the penetration of monoliths in all sectors of the metallurgical industries. The symposium was presented within the 38th Annual Conference of Metallurgists of the Canadian Institute of Mining, Metallurgy and Petroleum. Broad international coverage was maintained with papers originating from 12 different countries including: Australia, Canada, China, France, Germany, India, Iran, Japan, Korea, Mexico, New Zealand, Norway, and the United States. The 27 papers presented are divided into seven sessions to reflect the interests of the participants. The sessions included mold fluxes I and II, aluminum refractories, alumina castables, andalusite castables, continuous casting of refractories, aluminum refractories II and copper-nickel refineries. One paper on refractories for exhaust gas scrubbers is abstracted separately.

Selection of refractory materials for acid tanks at the CSN continuous pickling line

International Nuclear Information System (INIS)

Silva, Sidiney Nascimento; Marques, Oscar Rosa; Bueno, Mauricio Chaves; Longo, Elson; Silva Pinheiro, Adriano da

1997-01-01

Aiming at the revamping of the CSN continuous pickling line 4 acid tanks, a Post Mortem study of the refractory lining was carried out. The collected samples were characterized through techniques such as chemical analysis, mercury porosimetry, X-ray diffraction and scanning electronic microscopy. Trying to reproduce the operational conditions closely, laboratorial simulations were carried out. Such simulations lead to the addition of some alterations on the test method proposed by ABNT. Primarily, the sulfuric acid was substituted by hydrochloric acid (30%), containing iron in solution (130g/l). As result, it was concluded that acid resistant refractories containing a smaller alumina and /or corundum and mullite concentrations, presenting a smaller open porosity and average pore diameter, have a better performance face to corrosion due to hydrochloric acid solution. In addition, abrasion wear resistance tests, according to the ASTM-G65-85 standard were carried out in order to select different materials to the acid tanks cells. (author)

Refractory status epilepticus and glutamic acid decarboxylase antibodies in adults: presentation, treatment and outcomes.

Science.gov (United States)

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: 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.

Refractory septic shock in children: a European Society of Paediatric and Neonatal Intensive Care definition

NARCIS (Netherlands)

Morin, Luc; Ray, Samiran; Wilson, Clare; Remy, Solenn; Benissa, Mohamed Rida; Jansen, Nicolaas J. G.; Javouhey, Etienne; Peters, Mark J.; Kneyber, Martin; De Luca, Daniele; Nadel, Simon; Schlapbach, Luregn Jan; Maclaren, Graeme; Tissieres, Pierre

2016-01-01

Purpose Although overall paediatric septic shock mortality is decreasing, refractory septic shock (RSS) is still associated with high mortality. A definition for RSS is urgently needed to facilitate earlier identification and treatment. We aim to establish a European society of paediatric and

Refractory septic shock in children : a European Society of Paediatric and Neonatal Intensive Care definition

NARCIS (Netherlands)

Morin, Luc; Ray, Samiran; Wilson, Clare; Remy, Solenn; Benissa, Mohamed Rida; Jansen, Nicolaas J. G.; Javouhey, Etienne; Peters, Mark J.; Kneyber, Martin; De Luca, Daniele; Nadel, Simon; Schlapbach, Luregn Jan; Maclaren, Graeme; Tissieres, Pierre

2016-01-01

Although overall paediatric septic shock mortality is decreasing, refractory septic shock (RSS) is still associated with high mortality. A definition for RSS is urgently needed to facilitate earlier identification and treatment. We aim to establish a European society of paediatric and neonatal

[Surgery of refractory ischemic arrhythmia].

Science.gov (United States)

Viganò, M; Graffigna, A; Salerno, G

1992-03-01

Since June 1980, 138 patients have undergone surgical treatment for refractory ventricular tachycardia due to ischemic heart disease. Electrically guided surgical ablation (EGSA) of the focus was performed in 117 patients, while 14 patients underwent application of automatic implantable cardioverter-defibrillator (AICD), and 8 patients underwent heart transplantation. During the whole period considered, among the EGSA patients an operative mortality of 13 patients was observed (11.4%), with a late mortality of another 14 patients (13.4%). Two early and six late recurrences were described, and 4 cases of sudden or unexplained death, with 2 cases clearly due to an arrhythmic event. Multivariate analysis showed preoperative ejection fraction lower than 25% as a powerful predictor of early mortality (32% vs 0%). Actuarial survival rate of patients with LVEF lower than 25% was 67 +/- 12% vs 95 +/- 2% at one year and 37 +/- 25% vs 94 +/- 8% at 8 years. A high operative mortality was then observed in patients who underwent aneurysmectomy alone or visually guided procedures as compared to electrically guided procedures (75% or 3 deaths out of 4 patients vs 8.5% or 10 out of 113 patients, respectively). Patients who received an AICD with or without associated procedures showed 1 case of in-hospital mortality and no late mortality; in 6 patients at least one shock was delivered; in two patients the AICD was implanted during an EGSA procedure, due to multiple or difficult origins of the arrhythmias. Of patients who underwent heart transplantation one case of later mortality was observed due to malignancy.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhancement of the life of refractories through the operational experience of plasma torch melter

Energy Technology Data Exchange (ETDEWEB)

Moon, Young Pyo [Technology Institute, Korea Radioactive waste Agency (KORAD), Daejeon (Korea, Republic of); Choi, Jaang Young [Chungnam National University, Daejeon (Korea, Republic of)

2016-06-15

The properties of wastes for melting need to be considered to minimize the maintenance of refractory and to discharge the molten slags smoothly from a plasma torch melter. When the nonflammable wastes from nuclear facilities such as concrete debris, glass, sand, etc., are melted, they become acid slags with low basicity since the chemical composition has much more acid oxides than basic oxides. A molten slag does not have good characteristics of discharge and is mainly responsible for the refractory erosion due to its low liquidity. In case of a stationary plasma torch melter with a slant tapping port on the wall, a fixed amount of molten slags remains inside of tapping hole as well as the melter inside after tapping out. Nonmetallic slags keep the temperature higher than melting point of metal because metallic slags located on the bottom of melter by specific gravity difference are simultaneously melted when dual mode plasma torch operates in transferred mode. In order to minimize the refractory erosion, the compatible refractories are selected considering the temperature inside the melter and the melting behavior of slags whether to contact or noncontact with molten slags. An acidic refractory shall not be installed in adjacent to a basic refractory for the resistibility against corrosion.

Effect of elevated temperatures on the mechanical behavior of basalt textile reinforced refractory concrete

International Nuclear Information System (INIS)

Rambo, Dimas Alan Strauss; Andrade Silva, Flávio de; Toledo Filho, Romildo Dias; Fonseca Martins Gomes, Otávio da

2015-01-01

Highlights: • The thermo-mechanical behavior of basalt TRC is investigated. • The fiber polymer coating can become a deterministic factor in the TRC response. • Pre-heating the TRC at 150 °C leads to a matrix–polymer interlocking mechanism. • Above 400 °C a sudden drop in the TRC tensile response is observed. - Abstract: The work in hand presents the results of an experimental investigation on the thermo-mechanical properties of a textile refractory composite reinforced with polymer coated basalt fibers under tensile loading. The composites were produced as a laminate material using basalt bi-directional fabric layers as reinforcement. A high alumina cement matrix was used in the matrix composition which was designed using the compressible packing method. A series of uniaxial tensile tests was performed under temperatures ranging from 25 to 1000 °C. The cracking mechanisms were discussed and compared to that obtained at room temperature. Thermogravimetry and X-ray diffraction analysis were used to study the deterioration/phase changes as a function of the studied temperatures. Scanning electron microscopy (SEM) was used to study the damage processes in the fiber–matrix interfaces after exposure to high temperatures. The obtained results indicated that the presence and the type of coating can become a deterministic factor in the tensile response of the composite submitted to elevated temperatures. A sudden drop in the serviceability limit state of the composite was observed above 400 °C, caused by the degradation of the polymer used as a fiber surface coating, the degradation of the basalt fiber and by the dehydration process of the refractory matrix

Refractory heartburn: comparison of intercellular space diameter in documented GERD vs. functional heartburn.

Science.gov (United States)

Vela, Marcelo F; Craft, Brandon M; Sharma, Neeraj; Freeman, Janice; Hazen-Martin, Debra

2011-05-01

Refractory heartburn despite acid suppression may be explained by ongoing gastroesophageal reflux disease (GERD) or functional heartburn (FH), i.e., symptoms without evidence of GERD. Impedance-pH monitoring (impedance-pH) detects acid and nonacid reflux and is useful for evaluating acid-suppressed, refractory patients. Intercellular space diameter (ISD) of esophageal epithelium measured by transmission electron microscopy (TEM) is a marker of epithelial damage present in both erosive and nonerosive reflux disease. ISD has not been used to study refractory heartburn or FH. Our aim was to compare ISD in healthy controls and refractory heartburn patients with GERD and FH. In refractory heartburn patients (heartburn more than twice/week for at least 2 months despite proton pump inhibitor (PPI) b.i.d.), erosive esophagitis and/or abnormal impedance-pH (increased acid exposure or positive symptom index) defined GERD; normal esophagogastroduodenoscopy (EGD)/impedance-pH defined FH. Asymptomatic, healthy controls had normal EGD and pH-metry. Mean ISD in each subject, determined by blinded TEM of esophageal biopsies, was the average of 100 measurements (10 measurements in each of 10 micrographs). In all, 11 healthy controls, 11 FH, and 15 GERD patients were studied. Mean ISD was significantly higher in GERD compared with controls (0.87 vs. 0.32 μm, P=0.003) and FH (0.87 vs. 0.42 μm, P=0.012). Mean ISD was similar in FH and controls (0.42 vs. 0.32 μm, P=0.1). The proportion of patients with abnormal ISD was significantly higher for GERD compared with FH (60 vs. 9%, P=0.014). ISD is increased in refractory heartburn patients with GERD but not those with FH. Our findings suggest that measurement of ISD by TEM might be a useful tool to distinguish GERD from FH in patients with refractory heartburn.

Cyclosporine treatment of steroid-refractory ulcerative colitis during pregnancy.

Science.gov (United States)

Branche, Julien; Cortot, Antoine; Bourreille, Arnaud; Coffin, Benoît; de Vos, Martine; de Saussure, Philippe; Seksik, Philippe; Marteau, Philippe; Lemann, Marc; Colombel, Jean-Frédéric

2009-07-01

Cyclosporine is considered a safe and effective treatment of severe steroid-refractory ulcerative colitis (UC). However, few data are available concerning its safety profile in pregnant women. We report here the experience of 5 GETAID centers. In a retrospective study data on patients with severe UC treated with cyclosporine during pregnancy were extracted from medical records of consecutive patients treated between 2001 and 2007. Eight patients (median age 30.5 years old) were identified. At the time of flare-up the median duration of pregnancy was 11.5 weeks of gestation (range 4-25). Seven patients had pancolitis. All patients had more than 3 commonly used clinical and biological severity criteria. Three patients had severe endoscopic lesions and 5 patients had not. All patients received intravenous corticosteroids for at least 7 days before introduction of cyclosporine. Two patients received azathioprine during treatment with cyclosporine. No severe infections or other complications due to treatment were observed. Treatment was effective in 7/8 patients. One patient received infliximab due to cyclosporine therapy failure with a good outcome. No colectomy was performed during pregnancy. Seven pregnancies were conducted to term, but 1 in utero death occurred due to maternal absence of S-protein. Two newborns were premature, including 1 case of hypotrophy. No malformations were observed. In our experience, treatment with cyclosporine for steroid-refractory UC during pregnancy can be considered safe and effective.

Ibrutinib, lenalidomide, and rituximab in relapsed or refractory mantle cell lymphoma (PHILEMON)

DEFF Research Database (Denmark)

Jerkeman, Mats; Eskelund, Christian Winther; Hutchings, Martin

2018-01-01

BACKGROUND: Regimens based on ibrutinib alone and lenalidomide and rituximab in combination show high activity in patients with relapsed or refractory mantle cell lymphoma. We hypothesised that the combination of all three drugs would improve efficacy compared with previously published data...... performance status score of 0-3, and at least one site of measurable disease, and who met criteria for several laboratory-assessed parameters. Treatment was divided into an induction phase of 12 cycles of 28 days with all three drugs and a maintenance phase with ibrutinib and rituximab only (cycle duration 56...... days), given until disease progression or unacceptable toxicity. In the induction phase, patients received intravenous (375 mg/m2) or subcutaneous (1400 mg) rituximab once a week during cycle 1 and then once every 8 weeks. Oral ibrutinib (560 mg once a day) was given to patients every day in the cycle...

Material development for waste to energy plants. Overlay welding and refractory linings. Final report

Energy Technology Data Exchange (ETDEWEB)

Noergaard Hansson, A.

2011-02-15

Waste is an extremely corrosive fuel. In order to recover a higher percentage of the energy in waste, waste incineration plants have developed from purely heat producing units to heat and power producing units. The change in concept results in higher material temperatures and thereby faster material degradation. As a result material failures have been observed in many waste incineration plants. The purpose of this project was to develop materials with higher resistance to the corrosive elements, in order to reduce the cost of maintenance, increase the availability, and increase the efficiency. The focus is on overlay welding and refractory linings. Inconel 625, alloy 50, alloy 686, and Super 625 offer equivalent corrosion protection at panel walls. 100% overlay performs better than 50% overlay. The corrosion morphology changes with increasing temperature from pitting and general corrosion to pitting and selective corrosion (dendritic core or grain boundaries). The previously observed detrimental effect of Fe on the corrosion resistance was not confirmed. It probably depends on factors such as microstructure of the alloy and local metal temperature. Ni-overlay also reduces the corrosion rates on superheater tubes. However, the superheater environment is less aggressive than the water wall environment. Failure of refractory linings is linked to excess porosity, detrimental reactions between raw materials and other mix constituents, volume growth reactions between base material and salt depositions, and thermal stress induced crack formation. Free water and not decomposition of hydrates causes spalling and cracking during the initial heating of refractory linings. Finite Element analysis confirms the stress levels between steel and refractory with the higher stress level at the top of the panel wall tube. A number of LCC mixes were formulated, adjusted and tested. Mixes with low open porosities ({approx} 10%) and state of the art resistance to KCl were achieved. (LN)

Colectomy for refractory constipation

DEFF Research Database (Denmark)

Raahave, Dennis; Loud, Franck Bjørn; Christensen, Elsebeth

2010-01-01

OBJECTIVE: This study evaluated the type of colectomy, postoperative complications, functional results, and satisfaction in patients with constipation refractory to conservative therapy. Further, colonic transit time (CTT), faecal load (coprostasis), and colon length (redundancies) were compared...... had at hemicolectomy, 11 patients a subtotal colectomy and 3 patients an ileostomy. Two patients had an anastomotic leak and one died. In 11 patients, further surgery was necessary, because of recurrent constipation. Abdominal pain disappeared and defecation patterns improved significantly to 1-4 per...

Refractory alloy component fabrication

International Nuclear Information System (INIS)

Young, W.R.

1984-01-01

Purpose of this report is to describe joining procedures, primarily welding techniques, which were developed to construct reliable refractory alloy components and systems for advanced space power systems. Two systems, the Nb-1Zr Brayton Cycle Heat Receiver and the T-111 Alloy Potassium Boiler Development Program, are used to illustrate typical systems and components. Particular emphasis is given to specific problems which were eliminated during the development efforts. Finally, some thoughts on application of more recent joining technology are presented. 78 figures

Ketogenic Diet in Super-Refractory Status Epilepticus

OpenAIRE

Smith, Garnett; Press, Craig A.

2017-01-01

Researchers from the Children’s National Health System in Washington, D.C. studied the feasibility, rate of complications, and effect on seizures of initiating the Ketogenic Diet (KD) in pediatric patients with Super-Refractory Status Epilepticus (SRSE).

Wettability between TiN,TiC Containing Carbon Composite Refractory and Molten Slag or Hot Metal

Institute of Scientific and Technical Information of China (English)

SHIYue－xun; LIYingand; 等

1994-01-01

In order to develop a new-type TiC-TiN containing carbon composite refractory so as to improve the service life of blast furnace hearth,the wettability between the carbon refractory and molten slag or metal has been mea-sured.It was indicated that the carbon refractory is wet-ted by slag(θ≤90°） when(TiC+TiN)>33.52%,The effects of TiN or TiC on wetting behavior are basi-cally identical.When the amount of TiC in the carbon com-posite refractory is greater than 60% it will be wetted by hot metal;therefore,the carbon composite refractory will be wetted by slag but not permeated by hot metal when the amount of TiC is restricted.

Refractory Coated/Lined Low Density Structures, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — This project addresses the development of refractory coated or lined low density structures applicable for advanced future propulsion system technologies. The...

Refractory Hypertension: Determination of Prevalence, Risk Factors and Comorbidities in a Large, Population-Based Cohort

Science.gov (United States)

Calhoun, David A.; Booth, John N.; Oparil, Suzanne; Irvin, Marguerite R.; Shimbo, Daichi; Lackland, Daniel T.; Howard, George; Safford, Monika M.; Muntner, Paul

2014-01-01

Refractory hypertension is an extreme phenotype of antihypertensive treatment failure. Participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study, a large (n=30,239), population-based cohort were evaluated to determine the prevalence of refractory hypertension and associated cardiovascular risk factors and comorbidities. Refractory hypertension was defined as uncontrolled blood pressure (systolic/diastolic ≥ 140/90 mm Hg) on ≥ 5 antihypertensive drug classes. Participants with resistant hypertension (systolic/diastolic ≥140/90 mm Hg on ≥ 3 orhypertensive participants served as comparator groups. Of 14,809 REGARDS participants receiving antihypertensive treatment, 78 (0.5%) had refractory hypertension. The prevalence of refractory hypertension was 3.6% among participants with resistant hypertension(n=2,144) and 41.7% among participants on 5 or more antihypertensive drug classes. Among all hypertensive participants, African American race, male gender, living in the stroke belt or buckle, higher body mass index, lower heart rate, reduced estimated glomerular filtration rate, albuminuria, diabetes and history of stroke and coronary heart disease were associated with refractory hypertension. Compared to resistant hypertension, prevalence ratios for refractory hypertension were increased for African Americans (3.00, 95% CI 1.68 – 5.37) and those with albuminuria (2.22, 95% CI 1.40 – 3.52) and diabetes (2.09, 95% CI 1.32 – 3.31). The median 10-year Framingham risk for coronary heart disease and stroke was higher among participants with refractory hypertension compared to either comparator group. These data indicate that while resistant hypertension is relatively common among treated hypertensive patients, true antihypertensive treatment failure is rare. PMID:24324035

Super-refractory status epilepticus in West China.

Science.gov (United States)

Tian, L; Li, Y; Xue, X; Wu, M; Liu, F; Hao, X; Zhou, D

2015-07-01

This study aims to determine the general frequency, mortality, and risk factors of super-refractory status epilepticus (SRSE) versus non-refractory status epilepticus (NRSE) and refractory status epilepticus (RSE). This work is a retrospective study. Clinical data of patients who were diagnosed with status epilepticus (SE) in the neurological ward and neuro-intensive care unit of West China Hospital from January 2009 to December 2012 were collected and analyzed. A total of 98 patients were included in the study. The percentages of NRSE, RSE, and SRSE were 67.3%, 20.4%, and 12.2%, respectively. Convulsive SE was the main seizure type among the three groups. The most common cause of NRSE was related to epilepsy (EP). However, 67.7% of SRSE cases were caused by acute encephalitis. Moreover, 47% of SE and 40% of RSE cases had a history of EP, whereas only 8.3% of SRSE cases had such history (P  0.05). The general mortality of SE was 7.1%, whereas that of SRSE was 50%. During follow-up, most SRSE patients who survived have developed symptomatic EP. This study was the first to use the statistical percentage of SRSE. Approximately 12.2% of SE cases will result in SRSE, which is a challenging medical situation for doctors. Patients with first episodes and acute encephalitis were also prone to develop SRSE. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Refractory experience in circulating fluidized bed combustors, Task 7

Energy Technology Data Exchange (ETDEWEB)

Vincent, R.Q.

1989-11-01

This report describes the results of an investigation into the status of the design and selection of refractory materials for coal-fueled circulating fluidized-bed combustors. The survey concentrated on operating units in the United States manufactured by six different boiler vendors: Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Keeler Dorr-Oliver, Pyropower, and Riley Stoker. Information was obtained from the boiler vendors, refractory suppliers and installers, and the owners/operators of over forty units. This work is in support of DOE's Clean Coal Technology program, which includes circulating fluidized-bed technology as one of the selected concepts being evaluated.

CLINICAL EVALUATION OF EFFECTIVENESS OF ITRACONAZOLE IN PREOPERATIVE AND REFRACTORY POSTOPERATIVE PATIENTS OF ALLERGIC FUNGAL SINUSITIS

Directory of Open Access Journals (Sweden)

Ch. Venkatasubbaiah

2016-07-01

Full Text Available BACKGROUND Allergic Fungal Sinusitis (AFS is a noninvasive type of fungal sinusitis, clinically and pathologically a unique entity of chronic rhinosinusitis. The aetiology, pathogenesis, and treatment of AFS are subject to controversy. In spite of aggressive endoscopic surgery, pre- and postoperative steroids and immunotherapy recurrence rates are high. Many additions are made to its original description and management since its early description in 1980. The aim of the present paper was to evaluate clinically. The response to high-dose itraconazole before endoscopic sinus surgery and in refractory postoperative patients. Related literature was reviewed in the light of the present study. MATERIALS AND METHODS A 2 year prospective study conducted on 68 AFS patients divided into two groups to clinically evaluate the results after using oral itraconazole preoperatively in one group and in refractory postoperative period in another. RESULTS The mean age of patients with typical AFS was 36±3.9 years. Patients with AFS with an average follow up of 21 months were included. Recurrence was 6/34 (17.64% in itraconazole group and revision FESS done in 3/34 (08.82%. Recurrence in patients without itraconazole was 16/34 (47.05% and refractory to conventional treatment, but responded to itraconazole in 14/16 (87.50%. Revision surgery required in 2/16 (12.50% after starting oral itraconazole. No side effects or reactions were observed in a total of 7920 doses administered. CONCLUSION Itraconazole is well tolerated by patients and effective in shrinking the polyposis preoperatively with low recurrence. Postoperative refractory AFS is amenable in (87.50% of patients avoiding repeat FESS. Overall, low recurrence rate and minimizing revision surgery when compared to patients treated without itraconazole was evident in the study.

Mechanical activation of ceramic powders and its influence on the quality of the refractory linings

International Nuclear Information System (INIS)

Ceganac, Z.; Acimovic, Z.; Andric, Lj.; Petrov, M.; Mihajlovic, S.

2003-01-01

In the paper we present results of the investigation of the influence of mechanical activation of ceramic powders-talc and alumina, on the quality of refractory linings for casting applications. It is shown that additional fine grinding of ceramic powders increases the quality of the refractory lining. Grinding and activation of the particles with various granulations contributes to the creation of the homogenous continuous layer of refractory lining on the sand moulds and cores, as well as on the evaporating polystyrene patterns for applications in the Lost foam casting process. Refractory linings obtained within the activation of particles procedure have better adherence to moulds, cores and evaporating patterns. (Original)

Value of 3.0 T MR imaging in refractory partial epilepsy and negative 1.5 T MRI.

Science.gov (United States)

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.

Testing Consent Order on Refractory Ceramic Fibers

Science.gov (United States)

This notice announces that EPA has signed signed an enforceable testing consent order under the Toxic Substances Control Act (TSCA), 15 U.S.C. section 2601 at seq., with three of the primary producers of refractory ceramic fibers (RCF).

Destruction of Refractory Carbon in Protoplanetary Disks

Energy Technology Data Exchange (ETDEWEB)

Anderson, Dana E.; Blake, Geoffrey A. [Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Bergin, Edwin A. [Department of Astronomy, University of Michigan, 1085 S. University, Ann Arbor, MI 48109-1107 (United States); Ciesla, Fred J. [Department of Geophysical Sciences, The University of Chicago, 5734 South Ellis Ave., Chicago, IL 60637 (United States); Visser, Ruud [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748, Garching (Germany); Lee, Jeong-Eun [School of Space Research, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of)

2017-08-10

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 on 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.

Improving outcomes of refractory celiac disease – current and emerging treatment strategies

Directory of Open Access Journals (Sweden)

Woodward J

2016-08-01

Full Text Available Jeremy Woodward Department of Gastroenterology and Clinical Nutrition, Addenbrooke’s Hospital, Cambridge, UK Abstract: Intestinal inflammation and symptoms of celiac disease (CD usually respond well to gluten withdrawal, but rare cases are refractory to diet. Two types of refractory CD are discriminated on the basis of the presence or absence of an atypical population of mucosal lymphocytes that may progress to enteropathy-associated T-cell lymphoma. Challenges remain in the secure diagnosis of both types of refractory disease, and evidence on which to base treatment recommendations is flawed by the small numbers of reported patients and the use of different diagnostic strategies. Recent advances in our understanding of the mechanisms of the condition in conjunction with the development of immunomodulatory agents for managing other inflammatory diseases are helping to shape future approaches to targeted therapy. Progression will depend on collaboration and recruitment to trials. In the meantime, there is evidence to suggest that earlier diagnosis and better follow-up and management of CD may prevent the development of refractoriness. Keywords: celiac disease, gluten, small intestine, lymphoma, lymphocytes

The Influence of Fibre Content on the Performance of Steel Fibre ...

African Journals Online (AJOL)

The Influence of Fibre Content on the Performance of Steel Fibre Refractory Concrete. ... Little information is available on the effect of fibre content on refractory performance and in particular resistance to thermal shock. This study has examined the influence of fibre content of stainless steel melt extract fibres on the ...

International Thermonuclear Experimental Reactor (ITER) divertor plate performance and lifetime considerations

International Nuclear Information System (INIS)

Mattas, R.F.

1990-03-01

The ITER divertor plate performance during the technology phase of operation has been analyzed. High-Z materials, such as tungsten and tantalum, have been considered as plasma side materials, and refractory metal alloys, Ta-10W, TZM, Nb-1Zr, and V-15Cr-5Ti, plus copper alloys have been considered as the structural materials. The fatigue lifetime have been predicted for structural plates and for duplex plates with the plasma side material bonded to the structure. The results indicate that refractory alloys have a comparable or improved performance to copper alloys. Peak allowable heat fluxes for these analyses are in the range of 15--20 MW/m 2 for 2 mm thick structural plates and 7--11 MW/m 2 for 4 mm thick duplex plates. 4 refs., 55 figs., 6 tabs

Service life prediction for refractory materials

Czech Academy of Sciences Publication Activity Database

Boccaccini, D. N.; Cannio, M.; Volkov-Husović, T. D.; Kamseu, E.; Romagnoli, M.; Veronesi, P.; Leonelli, C.; Dlouhý, Ivo; Boccaccini, A. R.

2008-01-01

Roč. 43, č. 12 (2008), s. 4079-4090 ISSN 0022-2461 R&D Projects: GA ČR(CZ) GA106/05/0495 Institutional research plan: CEZ:AV0Z20410507 Keywords : refractory materials * ultrasonic velocity * fracture toughness Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.181, year: 2008

Refractory chronic cluster headache

DEFF Research Database (Denmark)

Mitsikostas, Dimos D; Edvinsson, Lars; Jensen, Rigmor H

2014-01-01

Chronic cluster headache (CCH) often resists to prophylactic pharmaceutical treatments resulting in patients' life damage. In this rare but pragmatic situation escalation to invasive management is needed but framing criteria are lacking. We aimed to reach a consensus for refractory CCH definition...... for clinical and research use. The preparation of the final consensus followed three stages. Internal between authors, a larger between all European Headache Federation members and finally an international one among all investigators that have published clinical studies on cluster headache the last five years...

Successful Treatment of Opioid-Refractory Cancer Pain with Short-Course, Low-Dose Ketamine.

Science.gov (United States)

Waldfogel, Julie M; Nesbit, Suzanne; Cohen, Steven P; Dy, Sydney M

2016-12-01

Opioids remain the mainstay of treatment for severe cancer pain, but up to 20% of patients have persistent or refractory pain despite rapid and aggressive opioid titration, or develop refractory pain after long-term opioid use. In these scenarios, alternative agents and mechanisms for analgesia should be considered. This case report describes a 28-year-old man with metastatic pancreatic neuroendocrine cancer with severe, intractable pain despite high-dose opioids including methadone and a hydromorphone patient-controlled analgesia (PCA). After treatment with short-course, low-dose ketamine, his opioid requirements decreased by 99% and pain ratings by 50%, with the majority of this decrease occurring in the first 48 hours. As this patient's pain and opioid regimen escalated, he likely experienced some component of central sensitization and hyperalgesia. Administration of ketamine reduced opioid consumption by 99% and potentially "reset" neuronal hyperexcitability and reduced pain signaling, allowing for improved pain control.

Welding and joining of single crystals of BCC refractory metals

International Nuclear Information System (INIS)

Hiraoka, Yutaka; Fujii, Tadayuki

1989-01-01

Welding and joining is one of key technologies for the wider utilizations of a material. In the present work, the applicability of welding and joining for a single crystal of BCC refractory metal was investigated. Electron-beam welding and tungsten-inert-gas welding by a melt-run technique, and high-temperature brazing by using brazing metals such as Mo-40%Ru alloy, vanadium or platinum were conducted for molybdenum single crystal which had been prepared by means of secondary recrystallization. 12 refs.,12 figs., 2 tabs. (Author)

Study on the efficiency of ceramic coating for avoiding oxidation in carbon refractories

International Nuclear Information System (INIS)

Santos, I.M.G.; Cruz Junior, F.; Paskocimas, C.A.; Leite, E.R.; Longo, Elson; Varela, J.A.

1997-01-01

A ceramic coating made of sodium phosphossilicate and clay was developed to the protection of refractories against carbon oxidation during the pre-heating of siderurgical equipment. This search has the objective of comparing the refractory behaviour with and without coating, according to temperature, time and atmosphere. The results show that the coating is more efficient at higher temperatures. An important point is that the efficiency is smaller after long thermal is that the efficiency is smaller after long thermal treatments and at very aggressive conditions. In spite of this the oxidation is still smaller than in refractory without coating. (author)

Early predictors of refractory status epilepticus: an international two-center study.

Science.gov (United States)

Sutter, R; Kaplan, P W; Marsch, S; Hammel, E M; Rüegg, S; Ziai, W C

2015-01-01

Status epilepticus (SE) refractory to first- and second-line antiepileptic drugs carries high mortality. Little is known on early prediction of refractory SE (RSE)—an essential tool for planning appropriate therapy. Our aim was to identify and validate independent early RSE predictors in adults. Clinical and laboratory data on consecutive intensive care unit patients with SE from two academic care centers (a derivation data set from a Swiss center and a validation data set from a US center) were assessed. Multivariable analysis was performed with the derivation set to identify RSE predictors at SE onset. Their external validity was evaluated with an independent validation set. Measures of calibration and discrimination were assessed. In all, 302 patients were analyzed (138 with and 164 without RSE), 171 in the derivation data set and 131 in the validation data set. Acute SE etiology, coma/stupor and serum albumin RSE in the derivation data set [odds ratio (OR) 2.02, 95% confidence interval (CI) 1.01-4.07; OR 4.83, 95% CI 2.42-9.68; OR 2.45, 95% CI 1.16-5.16]. The prediction model showed good measures of calibration (Hosmer-Lemesow goodness-of-fit test P = 0.99) and discrimination (area under the receiver operating characteristic curve 0.8) on the derivation data set—results that were similar in the validation data set (Hosmer-Lemeshow P = 0.24; area under the receiver operating characteristic curve 0.73). This study confirms the independent prognostic value of readily available parameters for early RSE prediction. Prospective studies are needed to identify additional robust predictors, which could be added to the proposed model for further optimization towards a reliable prediction scoring system. © 2014 EAN.

Iron Refractory Iron Deficiency Anaemia: A Rare Cause of Iron Deficiency Anaemia

LENUS (Irish Health Repository)

McGrath, T

2018-01-01

We describe the case of a 17-month-old boy with a hypochromic microcytic anaemia, refractory to oral iron treatment. After exclusion of dietary and gastrointestinal causes of iron deficiency, a genetic cause for iron deficiency was confirmed by finding two mutations in the TMPRSS6 gene, consistent with a diagnosis of iron-refractory iron deficiency anaemia (IRIDA).

Directed light fabrication of refractory metals

International Nuclear Information System (INIS)

Lewis, G.K.; Thoma, D.J.; Nemec, R.B.; Milewski, J.O.

1997-01-01

Directed Light Fabrication (DLF) is a metal, rapid fabrication process that fuses metal powders to full density into a solid replica of a computer modeled component. It has been shown feasible for forming nearly any metal and also intermetallics to near net shape with a single process. DLF of refractory pure metals is feasible, bypassing the extensive series of conventional processing steps used for processing these high melting point materials. Tungsten, tantalum, and rhenium were processed and show a continuous resolidified microstructure. Porosity was a problem for the tantalum and rhenium powders produced by chemical reduction processes but not for the tungsten powder spherodized in a plasma arc. Chemical analysis of powder compared to the DLF deposit showed reductions in carbon, oxygen and hydrogen, indicating that process parameters may also be optimized for evolution of residual gases in the deposits

Phase I/II study on docetaxel, gemcitabine and prednisone in castrate refractory metastatic prostate cancer

DEFF Research Database (Denmark)

Buch-Hansen, Trine Zeeberg; Bentzen, Lise Nørgaard; Hansen, Steinbjoern

2010-01-01

DGP, maximum of eight courses, until progression or unacceptable toxicity. Docetaxel 75 mg/m(2) was administered intravenously day 1, gemcitabine was given day 1 and 8 in doses increasing from 600 to 1,000 mg/m(2) every third week. Patients had castrate refractory metastatic prostate cancer (CRMPC......), adequate function of liver, kidney and bone marrow; ECOG performance status...

Predictive factors and outcomes for ibrutinib therapy in relapsed/refractory mantle cell lymphoma-a "real world" study.

Science.gov (United States)

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.

Refractory tertiary hyperparathyroidism after calcimimetics and delayed parathyroidectomy in a kidney transplant recipient

Directory of Open Access Journals (Sweden)

Ekamol Tantisattamo

2012-06-01

Normally, parathyroidectomy is performed 1 year posttransplantion unless severe bone disease, refractory hypercalcemia, or difficulty controlling phosphate wasting occurs. Phosphate wasting from hyperparathyroidism in our patient indicated parathyroidectomy; however, the surgery was delayed for 3 years while cinacalcet had been used. Post parathyroidectomy, hyperparathyroidism still persisted. Both cinacalcet and parathyroidectomy are imperfect to reverse hyperparathyroidism. Timely parathyroidectomy may determine the reversal of electrolyte and metabolic bone diseases; however, a delayed procedure may not have the same benefit. Since hyperparathyroidism is associated with higher incidence of kidney allograft dysfunction and postoperative mortality, should there be a level where pretransplant parathyroidectomy is performed?

Tailored therapy guided by multichannel intraluminal impedance pH monitoring for refractory non-erosive reflux disease.

Science.gov (United States)

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%, Pacid reflux (66.6%). In conclusion, a tailored approach to refractory NERD, guided by MII-pH monitoring, demonstrated to be effective

Human herpesvirus-8 positive iatrogenic Kaposi's sarcoma in the setting of refractory ulcerative colitis.

Science.gov (United States)

Duh, Erica; Fine, Sean

2017-12-16

Although Kaposi sarcoma (KS) has been more traditionally considered an AIDS-defining illness, it may also be seen in individuals on immunosuppresive therapy. We report a case of a patient who presented to the hospital in the setting of increasingly refractory ulcerative colitis. Computed tomography scan of the abdomen was consistent with sigmoid diverticulititis and blood cultures were positive for Klebsiella. After a course of antibiotics with resolution of infection, a colonoscopy was performed to evaluate his diverticulitis and incidentally revealed a new rectal tumor. Immunohistochemistry showed the tumor was consistent with KS, with cells staining strongly positive for human herpesvirus-8. This case not only illustrates a rare case of KS found in an HIV-negative individual, but it also highlights the importance of considering an alternative diagnosis in a patient refractory to medical treatment. We discuss the management and care of an ulcerative colitis patient diagnosed with KS on immunosuppressive therapy.

Direct brazing of ceramics, graphite, and refractory metals

International Nuclear Information System (INIS)

Canonico, D.A.; Cole, N.C.; Slaughter, G.M.

1976-03-01

ORNL has been instrumental in the development of brazing filler metals for joining ceramics, graphite, and refractory metals for application at temperatures above 1000 0 C. The philosophy and techniques employed in the development of these alloys are presented. A number of compositions are discussed that have been satisfactorily used to braze ceramics, graphite, and refractory metals without a prior surface treatment. One alloy, Ti--25 percent Cr--21 percent V, has wet and flowed on aluminum oxide and graphite. Further, it has been utilized in making brazes between different combinations of the three subject materials. The excellent flowability of this alloy and alloys from the Ti--Zr--Ge system is evidenced by the presence of filler metal in the minute pores of the graphite and ceramics

Bone hydatid disease refractory to nitazoxanide treatment

NARCIS (Netherlands)

Schipper, Hans G.; Simsek, Suat; van Agtmael, Michiel A.; van Lienden, Krijn P.

2009-01-01

We report a patient with bone hydatid disease that was refractory to both long-term daily treatment with albendazole, combined with cimetidine or administered as monotherapy ( approximately 15 years) and a relatively short course of nitazoxanide combined with albendazole (3 months). Despite

Toll-like receptor 2 expression in refractory periapical lesions.

Science.gov (United States)

Desai, S V; Love, R M; Rich, A M; Seymour, G J

2011-10-01

To investigate the expression of TLR2 in refractory periapical lesions. Refractory periapical lesion biopsies were histopathologically and clinically categorized into asymptomatic periapical granuloma (n=10), symptomatic periapical granuloma (n=10) or periapical cyst (n=10) and prepared for immunohistochemical staining using antibodies to TLR2, CD3 and CD19 or staining with methyl green pyronin. Sections were viewed under light microscopy and the presence or absence of the target cells was correlated with the histopathological and clinical data. Additionally, TLR2 expression was quantified by counting TLR(+) cells. Various mononuclear inflammatory cells in the bacteria-induced periapical lesions were reactive to TLR2 antibody, with many showing morphological similarities to lymphocytes and plasma cells. Lymphocytes were the most numerous cells in the inflammatory infiltrate. In refractory periapical granuloma, CD3(+) T cells were more numerous, whereas in periapical cysts, CD19(+) B cells were more numerous. There was a statistically significant (Pperiapical granuloma than asymptomatic periapical granuloma or periapical cyst. The presence of TLR-expressing cells in periapical granulomas and cysts provides further evidence that periapical cysts are likely to be sustained by the immune system via reaction to bacterial antigens. © 2011 International Endodontic Journal.

Morphometric brain characterization of refractory obsessive-compulsive disorder: diffeomorphic anatomic registration using exponentiated Lie algebra.

Science.gov (United States)

Tang, Wanjie; Li, Bin; Huang, Xiaoqi; Jiang, Xiaoyu; Li, Fei; Wang, Lijuan; Chen, Taolin; Wang, Jinhui; Gong, Qiyong; Yang, Yanchun

2013-10-01

Few studies have used neuroimaging to characterize treatment-refractory obsessive-compulsive disorder (OCD). This study sought to explore gray matter structure in patients with treatment-refractory OCD and compare it with that of healthy controls. A total of 18 subjects with treatment-refractory OCD and 26 healthy volunteers were analyzed by MRI using a 3.0-T scanner and voxel-based morphometry (VBM). Diffeomorphic anatomical registration using exponentiated Lie algebra (DARTEL) was used to identify structural changes in gray matter associated with treatment-refractory OCD. A partial correlation model was used to analyze whether morphometric changes were associated with Yale-Brown Obsessive-Compulsive Scale scores and illness duration. Gray matter volume did not differ significantly between the two groups. Treatment-refractory OCD patients showed significantly lower gray matter density than healthy subjects in the left posterior cingulate cortex (PCC) and mediodorsal thalamus (MD) and significantly higher gray matter density in the left dorsal striatum (putamen). These changes did not correlate with symptom severity or illness duration. Our findings provide new evidence of deficits in gray matter density in treatment-refractory OCD patients. These patients may show characteristic density abnormalities in the left PCC, MD and dorsal striatum (putamen), which should be verified in longitudinal studies. © 2013. Published by Elsevier Inc. All rights reserved.

Higher dose intra-arterial milrinone and intra-arterial combined milrinone-nimodipine infusion as a rescue therapy for refractory cerebral vasospasm.

Science.gov (United States)

Duman, Enes; Karakoç, Fatma; Pinar, H Ulas; Dogan, Rafi; Fırat, Ali; Yıldırım, Erkan

2017-12-01

Background Cerebral vasospasm (CV) is a major cause of delayed morbidity and mortality in patients with subarachnoid hemorrhage (SAH). Various cerebral protectants have been tested in patients with aneurysmal SAH. We aimed to research the success rate of treatment of CV via intra-arterial milrinone injection and aggressive pharmacological therapy for refractory CV. Methods A total of 25 consecutive patients who received intra-arterial milrinone and nimodipine treatment for CV following SAH between 2014 and 2017 were included in the study. Patients who underwent surgical clipping were excluded. Refractory vasospasm was defined as patients with CV refractory to therapies requiring ≥3 endovascular interventions. Overall, six patients had refractory CV. Long-term neurological outcome was assessed 6-18 months after SAH using a modified Rankin score and Barthel index. Results The median modified Rankin scores were 1 (min: 0, max: 3) and Barthel index scores were 85 (min: 70, max: 100) From each vasospastic territory maximal 10-16 mg milrinone was given to patients; a maximum of 24 mg milrinone was given to each patient in a session and a maximum of 42 mg milrinone was given to a patient in a day. Both milrinone and nimodipine were given to three patients. There was a large vessel diameter increase after milrinone and nimodipine injections. No patient died due to CV; only one patient had motor dysfunction on the right lower extremity. Conclusion Higher doses of milrinone can be used effectively to control refractory CV. For exceptional patients with refractory CV, high dose intra-arterial nimodipine and milrinone infusion can be used as a rescue therapy.

An Approach to Diagnosis and Endovascular Treatment of Refractory Ascites in Liver Transplant: A Pictorial Essay and Clinical Practice Algorithm.

Science.gov (United States)

Pereira, Keith; Salsamendi, Jason; Fan, Ji

2015-10-01

Recipients of liver transplant are surviving longer as both the surgical procedure and postsurgical care have improved. Despite improvements, serious complications from the procedure remain that significantly affect patient outcome and may result in retransplant. Refractory ascites is one complication, occurring in about 5.6% of transplant recipients. Management of refractory ascites after liver transplant presents a challenge to the multidisciplinary team caring for these patients. We discuss approaches to the diagnosis and treatment of refractory ascites after liver transplant, based on a literature review, with a primary focus on vascular causes. These approaches are illustrated by case examples highlighting our experiences at an academic tertiary medical center. We propose a clinical practice algorithm for optimal endovascular treatment of refractory ascites after liver transplant. The cornerstone of refractory ascites care is diagnosis and treatment of the cause. Vascular causes are not infrequently encountered and, if not treated early, are associated with graft loss and high morbidity and mortality and are major indications for retransplant. For patients with recurrent disease or graft rejection needing large volume paracentesis, the use of a transjugular intrahepatic portosystemic shunt may serve as a bridge to more definitive treatment (retransplant), although it may not be as effective for managing ascites as splenic artery embolization, arguably underused, which is emerging as a potential alternative treatment option. A multidisciplinary strategy for the diagnosis and care of patients with refractory ascites after liver transplant is crucial, with endovascular treatment playing an important role. The aim is for this document to serve as a concise and informative reference to be used by those who may care for patients with this rare yet serious diagnosis.

New Molecular Targeted Therapy and Redifferentiation Therapy for Radioiodine-Refractory Advanced Papillary Thyroid Carcinoma: Literature Review

Directory of Open Access Journals (Sweden)

Kai-Pun Wong

2012-01-01

Full Text Available Although the majority of papillary thyroid carcinoma could be successfully managed by complete surgical resection alone or resection followed by radioiodine ablation, a small proportion of patients may develop radioiodine-refractory progressive disease which is not amenable to surgery, local ablative treatment or other treatment modalities. The use of FDG-PET/CT scan for persistent/recurrent disease has improved the accuracy of restaging as well as cancer prognostication. Given that patients with RAI-refractory disease tend to do significantly worse than those with radioiodine-avid or non-progressive disease, an increasing number of phase I and II studies have been conducted to evaluate the efficacy of new molecular targeted drugs such as the tyrosine kinase inhibitors and redifferentiation drugs. The overall response rate of these drugs ranged between 0–53%, depending on whether the patients had been previously treated with these drugs, performance status and extent of disease. However, drug toxicity remains a major concern in administration of target therapies. Nevertheless, there are also ongoing phase III studies evaluating the efficacy of these new drugs. The aim of the review was to summarize and discuss the results of these targeted drugs and redifferentiation agents for patients with progressive, radioiodine-refractory papillary thyroid carcinoma.

Treatment of relapsed or refractory acute leukemia in childhood with bisantrene combined with high dose aracytine.

Science.gov (United States)

Leblanc, T; Deméocq, F; Leverger, G; Baruchel, A; Lemerle, S; Vannier, J P; Nelken, B; Guillot, T; Schaison, G

1994-01-01

Bisantrene is an anthracene derivative which has demonstrated activity in acute myeloblastic leukemia (AML) and in lymphoma. The present study was designed to assess the reinduction rate and toxicity of bisantrene (250 mg/m2/d x 5) associated with aracytine (100 mg/m2 twice a day x 5) in refractory and relapsed acute childhood leukemia. Patients who relapsed after bone marrow transplantation were eligible. Twenty-six children were included. Diagnoses were as follows: 13 AML, 9 acute lymphoblastic leukemia (ALL), and 4 undifferentiated leukemia (AUL). All patients had been very highly pretreated, especially with anthracyclines, and most of them were of poor prognosis. The overall response rate was 46% with a 95% confidence interval ranging from 27-65%. According to diagnosis, complete remission (CR) rates are: AML: 5/13, ALL: 5/9, and AUL: 2/4. Four children died, three from infection and one from acute lysis syndrome. The major toxicity was infection with grade 3 and 4 episodes occurring in 42% of patients. No significant cardiac toxicity was noted. Hepatic and renal toxicity was noted. Hepatic and renal toxicity were limited and transient. Bisantrene in association with aracytine is effective in both AML and ALL of childhood. Bisantrene should be evaluated with a five-day schedule in other pediatric malignancies. In children with acute leukemia previously treated with high dose aracytine, new combination regimen is warranted.

Medical versus surgical treatment for refractory or recurrent peptic ulcer.

Science.gov (United States)

Gurusamy, Kurinchi Selvan; Pallari, Elena

2016-03-29

Refractory peptic ulcers are ulcers in the stomach or duodenum that do not heal after eight to 12 weeks of medical treatment or those that are associated with complications despite medical treatment. Recurrent peptic ulcers are peptic ulcers that recur after healing of the ulcer. Given the number of deaths due to peptic ulcer-related complications and the long-term complications of medical treatment (increased incidence of fracture), it is unclear whether medical or surgical intervention is the better treatment option in people with recurrent or refractory peptic ulcers. To assess the benefits and harms of medical versus surgical treatment for people with recurrent or refractory peptic ulcer. We searched the specialised register of the Cochrane Upper GI and Pancreatic Diseases group, the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, and trials registers until September 2015 to identify randomised trials and non-randomised studies, using search strategies. We also searched the references of included studies to identify further studies. We considered randomised controlled trials and non-randomised studies comparing medical treatment with surgical treatment in people with refractory or recurrent peptic ulcer, irrespective of language, blinding, or publication status for inclusion in the review. Two review authors independently identified trials and extracted data. We planned to calculate the risk ratio, mean difference, standardised mean difference, or hazard ratio with 95% confidence intervals using both fixed-effect and random-effects models with Review Manager 5 based on intention-to-treat analysis. We included only one non-randomised study published 30 years ago in the review. This study included 77 participants who had gastric ulcer and in whom medical therapy (histamine H2 receptor blockers, antacids, and diet) had failed after an average duration of treatment of 29 months. The

Response to parenteral iron therapy distinguish unexplained refractory iron deficiency anemia from iron-refractory iron deficiency anemia.

Science.gov (United States)

Akin, M; Sarbay, H; Guler, S; Balci, Y I; Polat, A

2016-04-01

We evaluated that response to parenteral iron therapy could be helpful in distinguishing the types of iron deficiency anemia. This study analyzed responses to IV iron sucrose therapy of 15 children with unexplained refractory iron deficiency anemia (URIDA). We compared the results at diagnosis, 6 weeks and 6 months after the therapy. Results were compared with responses of 11 patients' results with iron-refractory iron deficiency anemia (IRIDA) from our previous study. Six weeks after the start of treatment, ferritin, MCV, MCH and Hb values were in normal range in 10 patients. The increase in Hb, MCH, MCV, and ferritin values ranged 2.6-3.5 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. In five patients, Hb, MCH, and MCV mean (range) values [11.2 g/dL (11-12.2), 24.5 pg (24-25.6), and 67 fL (65-70)] were nearly normal but ferritin mean (range) values [9.8 ng/mL (8-11)] were below normal. Six weeks after the start of treatment, Hb, MCH, MCV and ferritin values of patients with IRIDA were increased. The increase in Hb, MCH, MCV, and ferritin values ranged 0.8-2.7 g/dL, 1.7-4.2 pg, 2-9 fL, and 13-25 ng/mL, respectively. IRIDA is only partially responsive to parenteral iron supplementation. In conclusion, this study demonstrated that the response to intravenous iron therapy for the URIDA cases improved blood parameters more effectively than hereditary IRIDA. Response to parenteral iron therapy would be helpful to distinguish unexplained refractory IDA from hereditary IRIDA for clinicians who do not have access to hepcidin or TMPRS6 mutation analysis. © 2016 John Wiley & Sons Ltd.

Report of a Phase II Study of Clofarabine and Cytarabine in De Novo and Relapsed and Refractory AML Patients and in Selected Elderly Patients at High Risk for Anthracycline Toxicity

Science.gov (United States)

Cooper, Barry; Holmes, Houston; Vance, Estil; Berryman, Robert Brian; Maisel, Christopher; Li, Sandy; Saracino, Giovanna; Tadic-Ovcina, Mirjana; Fay, Joseph

2011-01-01

Purpose. To determine the efficacy and safety of clofarabine and cytarabine (Ara-C) in adult patients with relapsed or refractory acute myeloid leukemia (AML) and in elderly patients with untreated AML and heart disease. Patients and Methods. Patients with relapsed/refractory AML and older patients for whom there was a concern over toxicity from additional anthracyclines received 5 days of clofarabine, 40 mg/m2 per day i.v. over 1 hour, followed 4 hours later by Ara-C, 1,000 mg/m2 per day i.v. over 2 hours. Results. Thirty patients were enrolled. The median age was 67 years (range, 38–82 years) and 18 (60%) had received at least one prior therapy. Eleven (37%) patients had a history of cardiovascular disease and were considered to be at high risk for anthracycline toxicity. High-risk cytogenetic abnormalities were present in 14 (47%) patients. The overall response rate (complete remission [CR] plus partial remission) was 53%, including a CR in 14 patients (47%). Responses were observed in all cytogenetic risk groups and in patients who had received up to five prior therapies. The median disease-free survival interval was 9.5 months. The 30-day mortality rate was 20% (de novo AML, 8%; relapsed/refractory AML, 28%). Of the 14 patients achieving a CR, half were able to proceed to curative hematopoietic stem cell transplantation. Conclusions. Clofarabine in combination with Ara-C is effective in both untreated and previously treated patients with AML. In addition, it represents a useful remission induction strategy to serve as a bridge to transplantation in older patients with AML. PMID:21273514

Colonic exclusion and combined therapy for refractory constipation.

Science.gov (United States)

Peng, Hong-Yun; Xu, Ai-Zhong

2006-12-28

To investigate the therapeutic effectiveness of colonic exclusion and combined therapy for refractory constipation. Thirty-two patients with refractory constipation were randomly divided into treatment group (n = 14) and control group (n = 18). Fourteen patients in treatment group underwent colonic exclusion and end-to-side colorectal anastomosis. Eighteen patients in control group received subtotal colectomy and end-to-end colorectal anastomosis. The therapeutic effects of the operations were assessed by comparing the surgical time, incision length, volume of blood losses, hospital stay, recovery rate and complication incidence. All patients received long-term follow-up. All operations were successful and patients recovered fully after the operations. In comparison of treatment group and control group, the surgical time (h), incision length (cm), volume of blood losses (mL), hospital stay (d) were 87 +/- 16 min vs 194 +/- 23 min (t = 9.85), 10.4 +/- 0.5 cm vs 21.2 +/- 1.8 cm (t = 14.26), 79.5 +/- 31.3 mL vs 286.3 +/- 49.2 mL (t = 17.24), and 11.8 +/- 2.4 d vs 18.6 +/- 2.6 d (t = 6.91), respectively (P 0.05), 21.4% vs 33.3% (P = 0.73 > 0.05), respectively. Colonic exclusion has better therapeutic efficacy on refractory constipation. It has many advantages such as shorter surgical time, smaller incision, fewer blood losses and shorter hospital stay.

Ultrasonographic Evaluation of the Radial Nerves in Patients with Unilateral Refractory Lateral Epicondylitis.

Science.gov (United States)

Gürçay, Eda; Karaahmet, Özgür Zeliha; Kara, Murat; Onat, Sule Sahin; Ata, Ayse Merve; Ünlü, Ece; Özçakar, Levent

2017-03-01

To evaluate the possible radial nerve entrapment of patients with unilateral refractory lateral epicondylitis (LE) by using ultrasound (US) and electroneuromyography. Cross-sectional study. Three physical medicine and rehabilitation departments. Consecutive 44 patients (15 M, 29 F) with unilateral refractory LE. All patients underwent detailed clinical, electrophysiological and ultrasonographic evaluations. Ultrasound imaging was used to evaluate thickness and presence of abnormal findings of the common extensor tendon (CET) and cross-sectional area (CSA) of the radial nerve (at spiral groove and before bifurcation) bilaterally. Unaffected sides of the patients were taken as controls. When compared with the unaffected sides, CET thickness and radial nerve CSAs (at both levels) were higher, and abnormal US findings regarding LE (47.7% vs. 6.8%) were more common on the affected sides than nonaffected sides (all P   0.05). When subgroup analyses were performed after taking into account the hand dominance, affected and dominant sides were found to be the same in 31 and different in 13 patients. In subgroups, CETs and radial nerve CSAs at both levels were higher on the affected sides (all P  < 0.01). Radial nerves and the CETs seem to be swollen on the affected sides, independent from the hand dominance of the patients with refractory LE. These results morphologically support the previous literature that attributes some of the chronic complaints of these patients actually to radial nerve entrapment. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Prospective Evaluation of the Effect of Thigh Dissection for Removal of Transobturator Mid Urethral Slings on Refractory Thigh Pain.

Science.gov (United States)

King, A B; Tenggardjaja, C; Goldman, H B

2016-10-01

Transobturator slings have higher rates of de novo neurologic symptoms than retropubic slings, most commonly related to the thigh. Cases refractory to conservative management may require removal of the thigh portion of the sling. In this series we prospectively examine the effect of thigh dissection with mesh removal on refractory thigh pain. All thigh dissections for refractory neurologic symptoms after transobturator sling placement were followed prospectively from October 2012 to October 2015. Patients were assessed preoperatively, with a pain score using a visual analog scale, and postoperatively with a global response assessment. A total of 12 thigh dissections were performed from October 2012 to October 2015 in 8 patients. Mean (±SD) time from original mesh placement to presentation was 2.7 (±1.5) years. Average preoperative pain score was 7.9 (±1.7) out of 10, with pain in the thigh in all patients. Seven cases involved unilateral thigh dissection and 1 had concomitant bilateral thigh dissection. Five patients underwent concurrent transvaginal excision. On postoperative evaluation the average global response rating was 1.6, with 1 defined as very much better and 2 defined as much better. Of the 8 patients 3 went on to have the contralateral side done with an average global response rating of 1.3 (±0.6). One patient underwent further treatment for stress urinary incontinence with placement of a retropubic mid urethral sling. Our prospective series supports the use of thigh dissection in patients with refractory neurologic symptoms after transobturator sling placement. The procedure can be performed safely with positive outcomes for the patient. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Treatment for Relapsed/Refractory AML Based on a High Throughput Drug Sensitivity Assay

Science.gov (United States)

2018-04-11

Adult Acute Megakaryoblastic Leukemia (M7); Adult Acute Minimally Differentiated Myeloid Leukemia (M0); Adult Acute Monoblastic Leukemia (M5a); Adult Acute Monocytic Leukemia (M5b); Adult Acute Myeloblastic Leukemia With Maturation (M2); Adult Acute Myeloblastic Leukemia Without Maturation (M1); Adult Acute Myeloid Leukemia With 11q23 (MLL) Abnormalities; Adult Acute Myeloid Leukemia With Del(5q); Adult Acute Myeloid Leukemia With Inv(16)(p13;q22); Adult Acute Myeloid Leukemia With t(16;16)(p13;q22); Adult Acute Myeloid Leukemia With t(8;21)(q22;q22); Adult Acute Myelomonocytic Leukemia (M4); Adult Erythroleukemia (M6a); Adult Pure Erythroid Leukemia (M6b); Chronic Myelomonocytic Leukemia; Myelodysplastic/Myeloproliferative Neoplasm, Unclassifiable; Previously Treated Myelodysplastic Syndromes; Recurrent Adult Acute Myeloid Leukemia; Refractory Anemia With Excess Blasts

Antipsychotic Polypharmacy in a Treatment-Refractory Schizophrenia Population Receiving Adjunctive Treatment With Electroconvulsive Therapy

DEFF Research Database (Denmark)

Kristensen, Diana; Hageman, Ida; Bauer, Jeanett

2013-01-01

Antipsychotic polypharmacy (APP) is frequent, but its pattern is unknown in treatment-refractory schizophrenia-spectrum patients receiving electroconvulsive therapy (ECT).......Antipsychotic polypharmacy (APP) is frequent, but its pattern is unknown in treatment-refractory schizophrenia-spectrum patients receiving electroconvulsive therapy (ECT)....

A stepwise protocol for the treatment of refractory gastroesophageal reflux-induced chronic cough

Science.gov (United States)

Xu, Xianghuai; Lv, Hanjing; Yu, Li; Chen, Qiang; Liang, Siwei

2016-01-01

Background Refractory gastroesophageal reflux-induced chronic cough (GERC) is difficult to manage. The purpose of the study is to evaluate the efficacy of a novel stepwise protocol for treating this condition. Methods A total of 103 consecutive patients with suspected refractory reflux-induced chronic cough failing to a standard anti-reflux therapy were treated with a stepwise therapy. Treatment commences with high-dose omeprazole and, if necessary, is escalated to subsequent sequential treatment with ranitidine and finally baclofen. The primary end-point was overall cough resolution, and the secondary end-point was cough resolution after each treatment step. Results High-dose omeprazole eliminated or improved cough in 28.1% of patients (n=29). Further stepwise of treatment with the addition of ranitide yielded a favorable response in an additional 12.6% (n=13) of patients, and subsequent escalation to baclofen provoked response in another 36.9% (n=38) of patients. Overall, this stepwise protocol was successful in 77.6% (n=80) of patients. The diurnal cough symptom score fell from 3 [1] to 1 [0] (Z=6.316, P=0.000), and the nocturnal cough symptom score decreased from 1 [1] to 0 [1] (Z=–4.511, P=0.000), with a corresponding reduction in the Gastroesophageal Reflux Diagnostic Questionnaire score from 8.6±1.7 to 6.8±0.7 (t=3.612, P=0.000). Conversely, the cough threshold C2 to capsaicin was increased from 0.49 (0.49) µmol/L to 1.95 (2.92) µmol/L (Z=–5.892, P=0.000), and the cough threshold C5 was increased from 1.95 (2.92) µmol/L to 7.8 (5.85) µmol/L (Z=–5.171, P=0.000). Conclusions Sequential stepwise anti-reflux therapy is a useful therapeutic strategy for refractory reflux-induced chronic cough. PMID:26904227

Morphological differentiation of severe aplastic anaemia from hypocellular refractory cytopenia of childhood

DEFF Research Database (Denmark)

Baumann, Irith; Führer, Monika; Behrendt, Sonja

2012-01-01

To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood.......To evaluate the reproducibility and reliability of the histomorphological criteria differentiating severe aplastic anaemia (SAA) and hypoplastic refractory cytopenia of childhood (RCC), the most frequently acquired hypocellular bone marrow conditions of childhood....

Advances in multidisciplinary individualized treatment of refractory hepatic alveolar echinococcosis

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ABUDUAINI Abulizi

2015-04-01

Full Text Available Hepatic alveolar echinococcosis (HAE is a zoonotic parasitic disease that seriously threatens the population in western China and compromises patients′ quality of life. With the continuous improvement in radical resection rate in recent years, late-stage HAE patients that were incurable in the past now have the opportunity for radical resection. However, patients who are not suitable candidates for radical resection still suffer from various complications and poor quality of life. Therefore, HAE is still considered a refractory and complex disease. The simple empirical treatment model provided by traditional professional discussion is unable to satisfy the treatment of advanced refractory HAE as it is unable to integrate specialized, standardized clinical skills for diagnosis and treatment. Multidisciplinary individualized treatment (MDT organically integrates the advantages of the available treatment into a reasonable individualized comprehensive treatment regimen. This review summarizes the advances in MDT for HAE as the best option to increase long-term survival, and suggests MDT as the first-line treatment for late-stage refractory hepatic alveolar echinococcosis.

Immunomodulatory therapy in refractory/recurrent ovarian cancer

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Chao-Yu Chen

2015-04-01

Conclusion: 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.

Improvement of refractories for bottom of DC-Arc furnace; Chokuryudenkiro no roshoyo taikabutsu no kaizen

Energy Technology Data Exchange (ETDEWEB)

Kawahara, Toshihiro; Suzuki, Koichi; Okamoto, Yutaka; Tokuchi, Kazumasa [Asahi Glass Corp., Tokyo (Japan)

1999-06-01

A conductive refractory furnace bottom type DC electric furnace has disadvantages of large material cost, large working cost and long working period in refractory replacement due to a large amount of refractory installation. The furnace bottom has three layers of permanent bricks, wear bricks and a hot repair material, and durability improvement of wear bricks is an important issue. From the study results for 4 years in a real furnace the following conclusions were obtained: (1) The use of MgO-C based unburned bricks of 15% carbon content as wear bricks reduced the erosion speed by about 20% compared with a conventional MgO-C based burned bricks of 20% carbon content, (2) The resistivity value of the MgO-C based unburned brick decreased to a value equivalent to that of MgO-C based burned brick, which gave no problem in electro conductivity, (3) The addition of the hot repair material over 260 degree C of furnace bottom temperature and stable forming of a protective coating layer of 200-400 mm thickness enabled high durability over 6,400 heats of wear bricks, and (4) The use of the permanent bricks for 15,477 heats promised possible further use. (NEDO)

Human adipose cells in vitro are either refractory or responsive to insulin, reflecting host metabolic state.

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Vladimir A Lizunov

Full Text Available While intercellular communication processes are frequently characterized by switch-like transitions, the endocrine system, including the adipose tissue response to insulin, has been characterized by graded responses. Yet here individual cells from adipose tissue biopsies are best described by a switch-like transition between the basal and insulin-stimulated states for the trafficking of the glucose transporter GLUT4. Two statistically-defined populations best describe the observed cellular heterogeneity, representing the fractions of refractive and responsive adipose cells. Furthermore, subjects exhibiting high systemic insulin sensitivity indices (SI have high fractions of responsive adipose cells in vitro, while subjects exhibiting decreasing SI have increasing fractions of refractory cells in vitro. Thus, a two-component model best describes the relationship between cellular refractory fraction and subject SI. Since isolated cells exhibit these different response characteristics in the presence of constant culture conditions and milieu, we suggest that a physiological switching mechanism at the adipose cellular level ultimately drives systemic SI.

Reoperation for refractory epilepsy in childhood: a second chance for selected patients.

Science.gov (United States)

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.

Remission induction using alemtuzumab can permit chemotherapy-refractory chronic lymphocytic leukemia (CLL) patients to undergo allogeneic stem cell transplantation.

Science.gov (United States)

Knauf, Wolfgang; Rieger, Kathrin; Blau, Wolfgang; Hegenbart, Ute; Von Gruenhagen, Ulrich; Niederwieser, Dietger; Thiel, Eckhard

2004-12-01

The outcome of allogeneic stem cell transplantation depends upon the disease status before transplantation. Patients with refractory disease are at high risk for relapse. To improve the curative potential of the transplant procedure, we treated 3 chemotherapy-refractory CLL patients with alemtuzumab before allogeneic stem cell transplantation. Prior to therapy, all patients suffered from B-symptoms, and had massive adenopathy, splenomegaly, thrombocytopenia, and anemia; two patients had hepatomegaly. Alemtuzumab greatly reduced tumor mass in blood and bone marrow, B-symptoms resolved, and organomegaly improved. Two patients became blood product independent. All patients proceeded to transplantation after conditioning with TBI 2 Gy (n=1) or Treosulfan (n=2) in combination with Fludarabine either from an HLA-matched sibling (n=2) or from an HLA-matched unrelated donor (n=1). All patients engrafted, and are alive and well. Two patients reached complete remission (CR); one patient attained stable partial remission (PR). These heavily pre-treated refractory patients gained substantial clinical benefit from alemtuzumab, and received successful allografts.

Use of high performance technologies in the treatment of chronic neuropathic pain

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Streltov Ion

2018-03-01

Full Text Available Spinal cord neurostimulation is a minimally invasive treatment method for chronic neuropathic pain that is refractory to treatment, and is part of top technology in field. Relatively recent introduction of this method in the Neurosurgery Clinic “Prof. Dr. N. Oblu” of Iasi has aligned the clinic’s therapeutic arsenal to world standards. This has made it possible to treat in Romania a category of patients who would be treated abroad until now. Our clinic has entered the “National Program for diagnostic and treatment using high performance equipment” - Subprogram of treatment of neuropathic pain by implant of a spinal cord neurostimulator and is currently the only one in Romania where this treatment can be done. This represents a new step in the transformation process of the Clinical Hospital Emergency “Prof. Dr. N. Oblu” Iasi in a real Center of Excellence in the field Neurosurgery. The team dealing with the implant consists of 3 neurosurgeons, a neurologist, pa sychologist and an anesthetist, trained in a specialized foreign center.

Corrosion of K-3 glass-contact refractory in sodium-rich aluminosilicate melts

International Nuclear Information System (INIS)

Lu, X.D.; Gan, H.; Buechele, A.C.; Pegg, I.L.

1999-01-01

The corrosion of the glass-contact refractory Monofrax K-3 in two sodium-rich aluminosilicate melts has been studied at 1,208 and 1,283 C using a modified ASTM procedure with constant agitation of the melt by air bubbling. The results for the monolithic refractory indicate a fast initial stage involving phase dissolution and transformation and a later passivated stage in which the surface of the refractory has been substantially modified. The composition of the stable spinel phase in the altered layer on monolithic coupons of K-3 is almost identical to the equilibrium composition bracketed by the dissolution of powdered K-3 into under-saturated melts on the other. The temperature and melt shear viscosity were found to have significant effects on the rates of K-3 dissolution and transformation

New applications and novel processing of refractory metal alloys

International Nuclear Information System (INIS)

Briant, C.L.

2001-01-01

Refractory metals have often been limited in their application because of their propensity to oxidize and to undergo a loos of yield strength at elevated temperatures. However, recent developments in both processing and alloy composition have opened the possibility that these materials might be used in structural applications that were not considered possible in the past. At the same time, the use of refractory metals in the electronics industry is growing, particularly with the use of tantalum as a diffusion barrier for copper metallization. Finally, the application of grain boundary engineering to the problem of intergranular fracture in these materials may allow processes to be developed that will produce alloys with a greater resistance to fracture. (author)

Simulação termodinâmica e sua aplicação na avaliação do desempenho de materiais refratários Thermodynamic simulation and its application to evaluate the performance of refractory materials

Directory of Open Access Journals (Sweden)

A. P. Luz

2011-09-01

Full Text Available A corrosão, oxidação e o desgaste de materiais refratários têm sido objeto de vários estudos ao longo dos últimos anos. Por se tratarem de fenômenos complexos que ocorrem em temperaturas elevadas e em condições extremas de uso, a aplicação de simulações termodinâmicas na avaliação do desempenho destes materiais tem ganho cada vez mais destaque. Com o objetivo de verificar quais os tipos de cálculos que podem ser elaborados e quais as vantagens e desvantagens deste tipo de análise, neste trabalho é proposto o uso do programa FactSage® no estudo do desempenho de diversos refratários. O propósito deste trabalho vai além de uma simples revisão dos cálculos já efetuados na literatura, uma vez que várias outras simulações termodinâmicas foram elaboradas e discutidas. Os resultados destas avaliações comprovam que as informações provenientes destas análises podem auxiliar no entendimento das etapas e reações envolvidas na corrosão e desgaste dos refratários. No entanto, nenhum indicativo dos aspectos cinéticos e da distribuição espacial de cada produto de reação formado é fornecido nestes cálculos. Assim, para o completo entendimento dos mecanismos de reação são necessárias ambas as análises, termodinâmica e microestrutural.Corrosion, oxidation and wear of the refractory materials have been studied during the latest years. These phenomena are complex and usually are carried out at high temperatures and severe working conditions. Thus, the use of thermodynamic simulations to evaluate the refractories performance has been receiving a particular attention lately. In order to verify which calculations can be developed and the advantages and disadvantages of these analyses, the use of Factsage® software to study the performance of several refractories is proposed in this work. The aim of this paper goes beyond of a simple review of the calculations presented in the literature, because several

Iatrogenic colorectal Kaposi sarcoma complicating a refractory ...

African Journals Online (AJOL)

Kaposi sarcoma is a mesenchymal tumor associated to a human herpes virus-8. It often occurs in human immunodeficiency virus-positive subjects. Colorectal localization is rare. We report the case of a colorectal Kaposi sarcoma complicating a refractory ulcerative colitis treated with surgery after the failure of ...

Efficacy and Safety of Rituximab in Children with Refractory Nephrotic Syndrome; A Multicenter Clinical Trial

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Yo Han Ahn

2014-06-01

Conclusions: In this interim analysis of clinical trial to evaluate the efficacy and safety of RTX in children with refractory NS, RTX treatment for refractory NS was safe and effective, especially in patients with DNS.

Evaluation of nutritional status in children with refractory epilepsy.

Science.gov (United States)

Bertoli, S; Cardinali, S; Veggiotti, P; Trentani, C; Testolin, G; Tagliabue, A

2006-04-26

children affected by refractory epilepsy could be at risk of malnutrition because of feeding difficulties (anorexia, chewing, swallowing difficulties or vomiting) and chronic use of anticonvulsants, which may affect food intake and energy metabolism. Moreover, their energy requirement may be changed as their disabilities would impede normal daily activities. The aim of the present study was to evaluate nutritional status, energy metabolism and food intake in children with refractory epilepsy. 17 children with refractory epilepsy (13 boys and 4 girls; mean age 9 +/- 3,2 years; Body Mass Index 15,7 +/- 3,6) underwent an anthropometric assessment, body composition evaluation by dual-energy X-ray absorptiometry, detailed dietetic survey and measurement of resting energy expenditure by indirect calorimetry. Weight-for-age, height-for-age (stunting) and weight-for-height (wasting) were estimated compared to those of a reference population of the same age. 40% of children were malnourished and 24% were wasted. The nutritional status was worse in the more disabled children. Dietary intake resulted unbalanced (18%, 39%, 43% of total daily energy intake derived respectively from protein, lipid and carbohydrate). Adequacy index [nutrient daily intake/recommended allowance (RDA) x 100] was nutritional assessment and management as part of their overall care.

Adalimumab for the treatment of refractory noninfectious paediatric uveitis.

Science.gov (United States)

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.

Evaluation of nutritional status in children with refractory epilepsy

Science.gov (United States)

Bertoli, S; Cardinali, S; Veggiotti, P; Trentani, C; Testolin, G; Tagliabue, A

2006-01-01

Background children affected by refractory epilepsy could be at risk of malnutrition because of feeding difficulties (anorexia, chewing, swallowing difficulties or vomiting) and chronic use of anticonvulsants, which may affect food intake and energy metabolism. Moreover, their energy requirement may be changed as their disabilities would impede normal daily activities. The aim of the present study was to evaluate nutritional status, energy metabolism and food intake in children with refractory epilepsy. Methods 17 children with refractory epilepsy (13 boys and 4 girls; mean age 9 ± 3,2 years; Body Mass Index 15,7 ± 3,6) underwent an anthropometric assessment, body composition evaluation by dual-energy X-ray absorptiometry, detailed dietetic survey and measurement of resting energy expenditure by indirect calorimetry. Weight-for-age, height-for-age (stunting) and weight-for-height (wasting) were estimated compared to those of a reference population of the same age. Results 40% of children were malnourished and 24% were wasted. The nutritional status was worse in the more disabled children. Dietary intake resulted unbalanced (18%, 39%, 43% of total daily energy intake derived respectively from protein, lipid and carbohydrate). Adequacy index [nutrient daily intake/recommended allowance (RDA) × 100] was nutritional assessment and management as part of their overall care. PMID:16640779

Refractory metal particles in refractory inclusions in the Allende meteorite

International Nuclear Information System (INIS)

Fuchs, L.H.; Blander, M.

1980-01-01

An examination of refractory metal particles in five calcium-aluminum-rich inclusions in the Allende meteorite indicates a complex variety of compositions and large departures from equilibrium. These particles appear to 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 perhaps ordered phases) and the formation of metastable condensates appears to have been involved in the modification of these materials to their present state. Only a small fraction of our observations cannot be reconciled with this picture because of a lack of knowledge of some of the phase equilibria which might have bee involved

Wetting of refractory metals with copper base alloys

International Nuclear Information System (INIS)

Anikeev, E.F.; Kostikov, V.I.; Chepelenko, V.N.; Batov, V.M.

1978-01-01

The effect is studied of phosphorus upon the wetting of molybdenum, niobium and tantalum by an alloy of the system copper-silver (10%) as a function of contact time and phosphorus concentration. Experiments have been conducted in vacuum of 5x10 -4 mm Hg at 900 deg C. It is established that the introduction of phosphorus into a copper-silver alloy improves the wetting of molybdenum, niobium and tantalum. Formation of intermetallic compounds on the alloy-refractory metal interface can be avoided by adjusting the time of contact of the solder with molybdenum, niobium and tantalum. As a solder with 2.9% phosphorus spreads well over copper, it is suggested to use said solder for brazing copper and the investigated refractory metals in items intended for service at temperatures of up to 600 deg C

Refractory compounds for repairing coke-oven brickwork

Energy Technology Data Exchange (ETDEWEB)

Hanganu, M.; Dragomir, C. (and others)

1984-01-01

A number of refractory compounds are presented, based on aluminium phosphate, phosphoric acid, sodium silicate and fire-clay and mullitic zirconium mastic, including their composition, properties and application (by impregnation, spray application or pouring), which are suitable for repairing various types of coke-oven brickwork. The results obtained are given.

PET and SPECT in medically non-refractory complex partial seizures. Temporal asymmetries of glucose consumption, Benzodiazepine receptor density

International Nuclear Information System (INIS)

Matheja, P.; Kuwert, T.; Wolf, K.; Schober, O.; Stodieck, S.R.G.; Diehl, B.; Ringelstein, E.B.; Schuierer, G.

1998-01-01

Aim: In contrast to medically refractory complex partial seizures (CPS), only limited knowledge exists on cerebral perfusion and metabolism in medically non-refractory CPS. The aim of this study was to investigate the frequency of temporal asymmetries in regional cerebral glucose consumption (rCMRGlc), regional cerebral blood flow (rCBF), and regional cerebral benzodiazepine receptor density (BRD) in this group of patients. Methods: The study included 49 patients with medically non-refractory cryptogenic CPS (age: 36.0±16.1 years). rCMRGlc was studied with F-18-FDG-PET (FDG), rCBF with Tc-99m-ECD-SPECT (ECD), and BRD with I-123-iomazenil-SPECT (IMZ). All studies were performed interictally and within four weeks in each patient. Duration of epilepsy ranged from 0.1 to 42 years (median 4.0 years). SPECT was performed with the triple-headed SPECT camera Multispect 3, PET with the PET camera ECAT EXACT 47. Using linear profiles, glucose consumption, as well as uptake of ECD and IMZ, were measured in four temporal regions of interest (ROIs), and asymmetry indices were calculated (ASY). The results were compared to 95% confidence intervals determined in control subjects. Results: Thirty-five of the 49 (71%) patients had at least one significantly elevated ASY; temporal rCMRGlc was asymmetrical in 41% of the patients, temporal BRD in 29%, and temporal rCBF in 24%. One patient had an asymmetry of all three variables, two of temporal rCMRGlc and BRD, three of temporal rCMRGlc and rCBF, and another four of rCBF and BRD. Fourteen patients had an isolated temporal asymmetry in rCMRGlc, seven in BRD, and four in rCBF. A discrepancy in lateralization between the three modalities was not observed. Conclusion: The majority of patients with medically non-refractory CPS have focal abnormalities of blood flow and metabolism in their temporal lobe. In this group of patients, FDG-PET demonstrates abnormalities with the highest frequency of the three modalities studied, followed by IMZ

Thoracic radiation therapy before autologous bone marrow transplantation in relapsed or refractory Hodgkin's disease

International Nuclear Information System (INIS)

Tsang, R.W.; Gospodarowicz, M.K.; Sutcliffe, S.B.; Crump, M.; Keating, A.

1999-01-01

The aim of this study was to assess the relationship between radiation therapy (RT) and treatment-related mortality in patients receiving high-dose chemotherapy (HDCT) and autologous bone marrow transplantation (ABMT) for recurrent/refractory Hodgkin's disease (HD). Between December 1986 and December 1992, 59 patients previously treated at the Princess Margaret Hospital underwent HDCT (etoposide 60 mg/kg, melphalan 160 mg/m 2 ) and ABMT, performed for refractory (13 patients) or relapsed (46 patients) HD. RT was incorporated in the salvage treatment with the intent to achieve complete control of disease prior to ABMT. RT was given before ABMT in 33 patients, and after ABMT in 4 patients. Treatment-related (TR) mortality was defined as any death occurring within 100 days of ABMT. Autopsies were performed for all patients with TR deaths. With a median follow-up of 4.6 years (range 1.2-7.4 years), the actuarial overall survival was 41%±14% at 5 years. We observed 37 deaths, and 10 of these were TR deaths. Among the 24 patients who received thoracic RT before ABMT, there were 8 TR deaths, 3 of these solely attributable to radiation pneumonitis. The remaining 5 TR deaths all had respiratory failure with complicating sepsis as a major medical problem. The interval from RT to ABMT was shorter for 8 patients dying of TR death (mean 37 days; range 0-103 days), than for the 16 survivors (mean 105 days; range 0-263 days) (P=0.026). Among 9 patients with ABMT within 50 days of thoracic RT, 6 had TR death. In contrast, among the 35 patients without thoracic RT (26 no RT, 9 non-thoracic RT), there were only 2 TR deaths. The 4 patients treated with mantle RT post-ABMT had no serious pulmonary complications. The use of thoracic RT before HDCT and ABMT was associated with a high post-transplant mortality rate. It was most evident in patients who received thoracic RT within 50 days prior to ABMT, or when the target volume included large volume of lung. We recommend that the use of

Self-propagating high temperature synthesis as a method of determination of formation heat of refractory compounds

International Nuclear Information System (INIS)

Maslov, V.M.; Neganov, A.S.; Borovinskaya, I.P.; Merzhanov, A.G.

1978-01-01

Determination possibility of formation heats of refractory compounds in the process of direct synthesis from elements in a special calorimeter in the combustion regime is studied. Determined are formation heats of carbides - ZrCsub(0.92), Hf Csub(0.93), TaCsub(0.86), borides - ZrB 2 , HfB 2 NbB, NbB 2 , TaB, TaB 2 , MoB and silicides - ZrSi, ZrSi 2 , MoSi 2 . The results of chemical and x-ray phase analyses of the synthesized compounds are also given. Total error of formation heat determination methods does not surpass 2.0%

Long-term effects of electrical neurostimulation in patients with unstable angina : Refractory to conventional therapies

NARCIS (Netherlands)

de Vries, Jessica; DeJongste, Mike J. L.; Zijlstra, Felix; Staal, Michiel

2007-01-01

Background. Patients with unstable angina pectoris may become refractory to conventional therapies. Electrical neurostimulation with transcutaneous electrical stimulation and/or spinal cord stimulation has been shown to be effective for patients with refractory unstable angina pectoris in hospital

Lenvatinib in Advanced Radioiodine-Refractory Thyroid Cancer - A Retrospective Analysis of the Swiss Lenvatinib Named Patient Program.

Science.gov (United States)

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.

Degradation of Alumina and Magnesia Chrome refractory bricks in Portland cement kiln – Corrected version*

Directory of Open Access Journals (Sweden)

Ben Addi K.

2014-05-01

Full Text Available In cement plants, the refractory products are particularly confronted to partially liquid oxide phases at temperature ranging between 900°C and 1700°C. All constituents of these products have to resist not only to thermal constraints, but also to the thermochemical solicitations which result from contact material/coating. In order to study the phenomenon of degradation of refractory bricks in cement kilns and to identify the causes of their degradation, we proceed to the examination of industrial cases in cement kiln. Many chemical tests of the degraded refractory bricks have been done and the results acquired were compared to the ones not used. The analysis of the results is doing using different techniques (Loss of ignition, X-ray Fluorescence, X-ray Diffraction. The results show that the degradation of the used bricks in the clinkering and cooling zone is due to the infiltration of aggressive elements such us sulphur, alkali (Na2O, K2O .... The chemical interaction between the Portland clinker phases and refractory material has also an importance on the stability of the coating and consequently on the life of the refractories.

Bulk Vitrification Castable Refractory Block Protection Study

Energy Technology Data Exchange (ETDEWEB)

Hrma, Pavel R.; Bagaasen, Larry M.; Beck, Andrew E.; Brouns, Thomas M.; Caldwell, Dustin D.; Elliott, Michael L.; Matyas, Josef; Minister, Kevin BC; Schweiger, Michael J.; Strachan, Denis M.; Tinsley, Bronnie P.; Hollenberg, Glenn W.

2005-05-01

Bulk vitrification (BV) was selected for a pilot-scale test and demonstration facility for supplemental treatment to accelerate the cleanup of low-activity waste (LAW) at the Hanford U.S. DOE Site. During engineering-scale (ES) tests, a small fraction of radioactive Tc (and Re, its nonradioactive surrogate) were transferred out of the LAW glass feed and molten LAW glass, and deposited on the surface and within the pores of the castable refractory block (CRB). Laboratory experiments were undertaken to understand the mechanisms of the transport Tc/Re into the CRB during vitrification and to evaluate various means of CRB protection against the deposition of leachable Tc/Re. The tests used Re as a chemical surrogate for Tc. The tests with the baseline CRB showed that the molten LAW penetrates into CRB pores before it converts to glass, leaving deposits of sulfates and chlorides when the nitrate components decompose. Na2O from the LAW reacts with the CRB to create a durable glass phase that may contain Tc/Re. Limited data from a single CRB sample taken from an ES experiment indicate that, while a fraction of Tc/Re is present in the CRB in a readily leachable form, most of the Tc/Re deposited in the refractory is retained in the form of a durable glass phase. In addition, the molten salts from the LAW, mainly sulfates, chlorides, and nitrates, begin to evaporate from BV feeds at temperatures below 800 C and condense on solid surfaces at temperatures below 530 C. Three approaches aimed at reducing or preventing the deposition of soluble Tc/Re within the CRB were proposed: metal lining, sealing the CRB surface with a glaze, and lining the CRB with ceramic tiles. Metal liners were deemed unsuitable because evaluations showed that they can cause unacceptable distortions of the electric field in the BV system. Sodium silicate and a low-alkali borosilicate glaze were selected for testing. The glazes slowed down molten salt condensate penetration, but did little to reduce the

EFFICACY OF RECURRENT RITUXIMAB TREATMENT IN PATIENT WITH SEVERE REFRACTORY SYSTEMIC JUVENILE RHEUMATOID ARTHRITIS

Directory of Open Access Journals (Sweden)

E.I. Alexeeva

2011-01-01

Full Text Available The article contains clinical case description of a severe systemic juvenile rheumatoid arthritis, that was refractory to classic immunosuppressant therapy. The disease was characterized by such extraarticular manifestations as fever, lymphadenopathy,  hepatosplenomegaly, polyserositis, generalized joint involvement and high activity in lab tests. As a result of severe clinical course of the disease, patients develop bilateral aseptic bone necrosis in coxofemoral joints and coxarthrosis. Against the background of glucocorticosteroid treatment the patient has developed hormone-dependency and hormone resistance. Inclusion into the treatment of anti-CD20 monoclonal antibodies (rituximab has stopped systemic manifestations of the disease, inflammation in the joints, normalized lab activity rates. The positive therapeutic effect allowed to perform surgery due to bilateral coxarthrosis. These results show that rituximab is highly effective in children with systemic juvenile rheumatoid arthritis, that is resistant to classic immunosupressants and glucocorticoides. Key words: children, systemic juvenile rheumatoid arthritis, rituximab, recurrent treatment, prosthetics, hip joint. (Voprosy sovremennoi pediatrii — Current Pediatrics. — 2011; 10 (5: 157–163.

Simultaneous suppression of TGF-β and ERK signaling contributes to the highly efficient and reproducible generation of mouse embryonic stem cells from previously considered refractory and non-permissive strains.

Science.gov (United States)

Hassani, Seyedeh-Nafiseh; Totonchi, Mehdi; Farrokhi, Ali; Taei, Adeleh; Larijani, Mehran Rezaei; Gourabi, Hamid; Baharvand, Hossein

2012-06-01

Mouse embryonic stem cells (ESCs) are pluripotent stem cell lines derived from pre-implantation embryos. The efficiency of mESC generation is affected by genetic variation in mice; that is, some mouse strains are refractory or non-permissive to ESC establishment. Developing an efficient method to derive mESCs from strains of various genetic backgrounds should be valuable for establishment of ESCs in various mammalian species. In the present study, we identified dual inhibition of TGF-β and ERK1/2, by SB431542 and PD0325901, respectively led to the highly efficient and reproducible generation of mESC lines from NMRI, C57BL/6, BALB/c, DBA/2, and FVB/N strains, which previously considered refractory or non-permissive for ESC establishment. These mESCs expressed pluripotency markers and retained the capacity to differentiate into derivatives of all three germ layers. The evaluated lines exhibited high rates of chimerism when reintroduced into blastocysts. To our knowledge, this is the first report of efficient (100%) mESC lines generation from different genetic backgrounds. The application of these two inhibitors will not only solve the problems of mESC derivation but also clarifies new signaling pathways in pluripotent mESCs.

Pembrolizumab and Vorinostat in Treating Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma, Follicular Lymphoma, or Hodgkin Lymphoma

Science.gov (United States)

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

Therapeutic laryngoscopy during exercise: A novel non-surgical therapy for refractory EILO.

Science.gov (United States)

Olin, J Tod; Deardorff, Emily H; Fan, Elizabeth M; Johnston, Kristina L; Keever, Valerie L; Moore, Camille M; Bender, Bruce G

2017-06-01

Exercise-induced laryngeal obstruction (EILO) may affect as many as 6% of the adolescent population, with some patients experiencing symptoms refractory to conservative interventions. This report describes therapeutic laryngoscopy during exercise, a novel, non-surgical intervention that harnesses real-time laryngoscopy video as biofeedback to control laryngeal aperture during high-intensity exercise. Additionally, we quantitate patient-reported perceptions of procedure safety, tolerability, learning value, and effectiveness. Clinical EILO patients with symptoms refractory to conventional respiratory retraining and other therapies were referred for the procedure which features laryngoscopy video as biofeedback during serial physician-guided 1-min exercise sprints. We quantify perceptions of procedure safety, tolerability, learning value, and effectiveness through questionnaires offered to all patients as well as observers of the procedure. Forty-one patients and 37 parent observers were approached for feedback; 88% of patients and 95% of observers consented to participation. Patients and observers reported perceptions of safety and tolerability (81% and 86%, respectively), learning value (78% and 91%, respectively), and effectiveness (58% and 80%, respectively) with patient age predicting some responses. Seventy-five percent of patients noted that "Since the procedure, my breathing during exercise has improved," and 85% of this group noted that therapeutic laryngoscopy during exercise was "the most important therapy leading to my breathing improvement." The procedure also provided insight into the psychological experience of patients, a domain not clinically apparent prior to the procedure. Our data support further study of therapeutic laryngoscopy during exercise as a possible intervention for patients with refractory EILO. Pediatr Pulmonol. 2017;52:813-819. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Steam explosion studies with single drops of molten refractory materials

International Nuclear Information System (INIS)

Nelson, L.S.

1980-01-01

Laser heating, levitation melting, and metal combustion were used to prepare individual drops of molten refractory materials which simulate LWR fuel melt products. Drop temperatures ranged from approx. = 1500 to > 3000K. These drops, several millimeters in diameter, were injected into water and subjected to pressure transients (approx. = 1MPa peak pressures) generated by a submerged exploding bridgewire. Molten oxides of Fe, Al and Zr could be induced to explode with bridgewire initiation. High speed films showed the explosions with exceptional clarity, and pressure transducer records could be correlated with individual frames in the films. Pressure spikes one or two MPa high were generated whenever an explosion occurred. Debris particles were mostly spheroidal, with diameters in the range 10 to 1000 μm

Microstructural features of alumina refractories with mullite-zirconia aggregates

Directory of Open Access Journals (Sweden)

Ferrari, C. R.

2003-02-01

Full Text Available Refractory materials are often subjected to high temperatures and loads and their performance depends on their microstructural evolution during use. In this context, microstructural changes were monitored in alumina-based refractories containing mullite-zirconia aggregates and heat-treated at 1400°C and 1500°C for 2, 6, and 18 days. With the purpose of inducing in situ mullite formation, bricks containing microsilica were also prepared and heat-treated at 1500°C for 6 days for the sake of comparison. These heat treatments allowed for an evaluation of the use of refractories from the standpoint of temperature and time. In this work, scanning electron microscopy and X-ray diffraction analyses were made to identify the phases in the materials. The Rietveld method was also used for quantitative phase analyses. Interfacial reactions occurred between alumina and aggregates and between alumina and microsilica, causing the system to become mullitized. The effect of in situ-formed mullite was particularly evident in the results of the modulus of rupture of the materials containing microsilica. Creep tests revealed a reduction in the creep rate of materials treated at 1500°C for 18 days.

El comportamiento de los materiales refractarios, cuando sometidos a altas temperaturas y a grandes esfuerzos mecánicos, está íntimamente relacionado con la evolución microestuctural, durante su uso. En este contexto, fue realizado un estudio de la evolución microestructural de los materiales refractarios de alumina conteniendo diferentes porcentajes de agregado de mullita–circona, sometidos a tratamientos térmicos por 2, 6 y 18 días, en temperaturas de 1400 y 1500oC. Fueron confeccionados, algunos ladrillos conteniendo microsílice, con la idea de se introducir la formación de mullita en situ. Para la comparación de los ladrillos, fueron realizados tratamientos térmicos por un periodo de 6 días en 1500oC. Estos tratamientos térmicos permitieron

Tocilizumab for refractory organising pneumonia associated with Sjögren's disease.

Science.gov (United States)

Justet, Aurelien; Ottaviani, Sebastien; Dieudé, Philippe; Taillé, Camille

2015-05-14

Lung involvement in primary Sjögren syndrome occurs in approximately 10-20% of patients. Tocilizumab, an anti-interleukin-6 receptor antibody, has demonstrated efficacy and safety in small series of systemic sclerosis, and systemic lupus erythematosus, but its effect on interstitial lung manifestations of connective tissue diseases is not well known. We report the use of tocilizumab in a refractory organising pneumonia associated with Sjögren's disease. Our observation suggests that tocilizumab could be an alternative therapeutic in refractory organising pneumonia. 2015 BMJ Publishing Group Ltd.

Rikkunshito improves globus sensation in patients with proton-pump inhibitor-refractory laryngopharyngeal reflux.

Science.gov (United States)

Tokashiki, Ryoji; Okamoto, Isaku; Funato, Nobutoshi; Suzuki, Mamoru

2013-08-21

To investigate the effect of rikkunshito on laryngopharyngeal reflux (LPR) symptoms and gastric emptying in patients with proton-pump inhibitor (PPI)-refractory LPR. In total, 22 patients with LPR were enrolled. Following a 2-wk treatment with PPI monotherapy, PPI-refractory LPR patients were randomly divided into two treatment groups (rikkunshito alone or rikkunshito plus the PPI, lansoprazole). LPR symptoms were assessed using a visual analog scale (VAS) score, gastrointestinal symptoms were assessed using the gastrointestinal symptom rating scale (GSRS), and gastric emptying was assessed using the radio-opaque marker method prior to and 4 wk following treatments. The 4-wk treatment with rikkunshito alone and with rikkunshito plus the PPI significantly decreased the globus sensation VAS scores. The VAS score for sore throat was significantly decreased following treatment with rikkunshito plus PPI but not by rikkunshito alone. Neither treatment significantly changed the GSRS scores. Rikkunshito improved delayed gastric emptying. We found a significant positive correlation between improvements in globus sensation and in gastric emptying (r² = 0.4582, P sensation in patients with PPI-refractory LPR, in part, because of stimulation of gastric emptying. Thus, rikkunshito is an effective treatment for PPI-refractory LPR.

Phase II study of nab-paclitaxel in refractory small bowel adenocarcinoma and CpG island methylator phenotype (CIMP)-high colorectal cancer.

Science.gov (United States)

Overman, M J; Adam, L; Raghav, K; Wang, J; Kee, B; Fogelman, D; Eng, C; Vilar, E; Shroff, R; Dasari, A; Wolff, R; Morris, J; Karunasena, E; Pisanic, R; Azad, N; Kopetz, S

2018-01-01

Hypermethylation of promoter CpG islands [CpG island methylator phenotype (CIMP)] represents a unique pathway for the development of colorectal cancer (CRC), characterized by lack of chromosomal instability and a low rate of adenomatous polyposis coli (APC) mutations, which have both been correlated with taxane resistance. Similarly, small bowel adenocarcinoma (SBA), a rare tumor, also has a low rate of APC mutations. This phase II study evaluated taxane sensitivity in SBA and CIMP-high CRC. The primary objective was Response Evaluation Criteria in Solid Tumors version 1.1 response rate. Eligibility included Eastern Cooperative Oncology Group performance status 0/1, refractory disease, and SBA or CIMP-high metastatic CRC. Nab-paclitaxel was initially administered at a dose of 260 mg/m2 every 3 weeks but was reduced to 220 mg/m2 owing to toxicity. A total of 21 patients with CIMP-high CRC and 13 with SBA were enrolled from November 2012 to October 2014. The efficacy-assessable population (patients who received at least three doses of the treatment) comprised 15 CIMP-high CRC patients and 10 SBA patients. Common grade 3 or 4 toxicities were fatigue (12%), neutropenia (9%), febrile neutropenia (9%), dehydration (6%), and thrombocytopenia (6%). No responses were seen in the CIMP-high CRC cohort and two partial responses were seen in the SBA cohort. Median progression-free survival was significantly greater in the SBA cohort than in the CIMP-high CRC cohort (3.2 months compared with 2.1 months, P = 0.03). Neither APC mutation status nor CHFR methylation status correlated with efficacy in the CIMP-high CRC cohort. In vivo testing of paclitaxel in an SBA patient-derived xenograft validated the activity of taxanes in this disease type. Although preclinical studies suggested taxane sensitivity was associated with chromosomal stability and wild-type APC, we found that nab-paclitaxel was inactive in CIMP-high metastatic CRC. Nab-paclitaxel may represent a novel

[Nursing management of a refractory cardiac death donor].

Science.gov (United States)

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.

Open and Laparoscopic Colposuspension in Girls with Refractory Urinary Incontinence

Directory of Open Access Journals (Sweden)

Barbara Anna Dobrowolska-Glazar

2017-12-01

Full Text Available IntroductionLower urinary tract symptoms (LUTS are very common in children. Standard treatments consist of urotherapy, antibiotic prophylaxis, anti-muscarinics, physical therapy, and the treatment of coexisting constipation. A small group of girls also present with stress incontinence or with stress-induced urge incontinence. In cases of persistent LUTS due to congenital bladder neck insufficiency (BNI, surgical treatment might be considered. The aim of this paper is to assess the results of open and laparoscopic colposuspension in children with refractory urinary incontinence (UI.Materials and methodsThe results of 18 open and 18 laparoscopic consecutive colposuspensions were analyzed. All patients had UI and failed conservative treatment. BNI was proven by repeated perineal ultrasound and video-urodynamic study. The laparoscopic procedure was performed preperitoneally and the open procedure was via a transverse lower abdominal incision. The same postoperative protocol was used in both groups.ResultsThe mean operation time was 65 min for the open and 90 min for the lap procedure (p < 0.05. Full success was achieved in 7/18 in the open and in 8/18 in the lap group and partial response was seen in 3/18 and in 5/18, respectively (p = 0.64. No intraoperative complications occurred in this cohort.ConclusionOpen and laparoscopic colposuspension can be used to treat refractory UI in children with BNI when non-invasive methods fail.

Refractory metal joining for first wall applications

International Nuclear Information System (INIS)

Cadden, C.H.; Odegard, B.C.

2000-01-01

The potential use of high temperature coolant (e.g. 900 deg. C He) in first wall structures would preclude the applicability of copper alloy heat sink materials and refractory metals would be potential replacements. Brazing trials were conducted in order to examine techniques to join tungsten armor to high tungsten (90-95 wt%) or molybdenum TZM heat sink materials. Palladium-, nickel- and zirconium-based filler metals were investigated using brazing temperatures ranging from 1000 deg. C to 1275 deg. C. Palladium-nickel and palladium-cobalt braze alloys were successful in producing generally sound metallurgical joints in tungsten alloy/tungsten couples, although there was an observed tendency for the pure tungsten armor material to exhibit grain boundary cracking after bonding. The zirconium- and nickel-based filler metals produced defect-containing joints, specifically cracking and porosity, respectively. The palladium-nickel braze alloy produced sound joints in the Mo TZM/tungsten couple. Substitution of a lanthanum oxide-containing, fine-grained tungsten material (for the pure tungsten) eliminated the observed tungsten grain boundary cracking

Refractory metal joining for first wall applications

Energy Technology Data Exchange (ETDEWEB)

Cadden, C.H. E-mail: chcadde@sandia.gov; Odegard, B.C

2000-12-01

The potential use of high temperature coolant (e.g. 900 deg. C He) in first wall structures would preclude the applicability of copper alloy heat sink materials and refractory metals would be potential replacements. Brazing trials were conducted in order to examine techniques to join tungsten armor to high tungsten (90-95 wt%) or molybdenum TZM heat sink materials. Palladium-, nickel- and zirconium-based filler metals were investigated using brazing temperatures ranging from 1000 deg. C to 1275 deg. C. Palladium-nickel and palladium-cobalt braze alloys were successful in producing generally sound metallurgical joints in tungsten alloy/tungsten couples, although there was an observed tendency for the pure tungsten armor material to exhibit grain boundary cracking after bonding. The zirconium- and nickel-based filler metals produced defect-containing joints, specifically cracking and porosity, respectively. The palladium-nickel braze alloy produced sound joints in the Mo TZM/tungsten couple. Substitution of a lanthanum oxide-containing, fine-grained tungsten material (for the pure tungsten) eliminated the observed tungsten grain boundary cracking.

Refractory metal joining for first wall applications

Science.gov (United States)

Cadden, C. H.; Odegard, B. C.

2000-12-01

The potential use of high temperature coolant (e.g. 900°C He) in first wall structures would preclude the applicability of copper alloy heat sink materials and refractory metals would be potential replacements. Brazing trials were conducted in order to examine techniques to join tungsten armor to high tungsten (90-95 wt%) or molybdenum TZM heat sink materials. Palladium-, nickel- and zirconium-based filler metals were investigated using brazing temperatures ranging from 1000°C to 1275°C. Palladium-nickel and palladium-cobalt braze alloys were successful in producing generally sound metallurgical joints in tungsten alloy/tungsten couples, although there was an observed tendency for the pure tungsten armor material to exhibit grain boundary cracking after bonding. The zirconium- and nickel-based filler metals produced defect-containing joints, specifically cracking and porosity, respectively. The palladium-nickel braze alloy produced sound joints in the Mo TZM/tungsten couple. Substitution of a lanthanum oxide-containing, fine-grained tungsten material (for the pure tungsten) eliminated the observed tungsten grain boundary cracking.

Pulsed radiofrequency of brachial plexus under ultrasound guidance for refractory stump pain: a case report

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Zheng B

2017-11-01

Full Text Available Bixin Zheng, Li Song, Hui Liu Department of Pain Management, West China Hospital of Sichuan University, Chengdu, China Abstract: The post-amputation (pain syndrome, including stump pain, phantom limb sensation, and phantom limb pain is common but difficult to treat. Refractory stump pain in the syndrome is an extremely challenging and troublesome clinical condition. Patients respond poorly to drugs, nerve blocks, and other effective treatments like spinal cord stimulation and surgery. Pulsed radiofrequency (PRF technique has been shown to be effective in reducing neuropathic pain. This report describes a patient with persistent and refractory upper limb stump pain being successfully relieved with PRF of brachial plexus under ultrasound guidance after a 6-month follow-up period, suggesting that PRF may be considered as an alternative treatment for refractory stump-neuroma pain. Keywords: ultrasound guidance, pulsed radiofrequency, brachial plexus, refractory stump pain 

Phase I/II study of azacitidine and capecitabine/oxaliplatin (CAPOX) in refractory CIMP-high metastatic colorectal cancer: evaluation of circulating methylated vimentin.

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Overman, Michael J; Morris, Van; Moinova, Helen; Manyam, Ganiraju; Ensor, Joe; Lee, Michael S; Eng, Cathy; Kee, Bryan; Fogelman, David; Shroff, Rachna T; LaFramboise, Thomas; Mazard, Thibault; Feng, Tian; Hamilton, Stanley; Broom, Bradley; Lutterbaugh, James; Issa, Jean-Pierre; Markowitz, Sanford D; Kopetz, Scott

2016-10-11

Hypermethylation of promoter CpG islands (CIMP) has been strongly implicated in chemotherapy resistance and is implicated in the pathogenesis of a subset of colorectal cancers (CRCs) termed CIMP-high. This phase I/II study in CRC (phase II portion restricted to CIMP-high CRC), treated fluoropyrimidine/oxaliplatin refractory patients with azacitidine (75 mg/m2/day subcutaneously D1-5) and CAPOX (capecitibine and oxaliplatin) every three weeks. Twenty-six patients (pts) were enrolled in this study: 15 pts (12 treated at MTD) in phase I and 11 pts in phase II. No dose limiting toxicities were observed. A total of 14 pts were CIMP-high. No responses were seen. CIMP-high status did not correlate with efficacy endpoints [stable disease (SD) or progression-free survival (PFS)] or baseline vimentin methylation level. Changes in vimentin methylation over time did not correlate with efficacy outcomes. Baseline methylated vimentin correlated with tumor volume (PCIMP-high pts, but no objective responses. Serum methylated vimentin may be associated with benefit from a regimen including a hypomethylation agent, although this study is not able to separate a potential prognostic or predictive role for the biomarker.

Development of industrial x-ray computed tomography and its application to refractories

International Nuclear Information System (INIS)

Aiba, Yoshiro; Oki, Kazuo; Nakamura, Shigeo; Fujii, Masashi.

1985-01-01

An industrial X-ray computed tomography was developed under the influence of the rapid spread of the use of the X-ray CT scanner in the medical field and improvements of the equipment. Although current nondestructive testing machines of refractories use the ultrasonic inspection method or the X-ray fluoroscopic method, these equipments cannot produce a tomogram or cannot carry out quantitative evaluation. By using an industrial X-ray computed tomography, submerged nozzles for continuous casting of steel were analyzed with interesting results. The features of the industrial X-ray computed tomography applied for refractory nozzles are as follows: (1) It promptly detects interior defects. (2) It can measure dimensions and shapes. (3) It can numerically express the distribution of density. Accordingly, it is expected that the industrial X-ray computed tomography will widely be used in the fields of development and quality control of refractories and advanced ceramic materials. (author)

C-Reactive Protein Levels at Diagnosis of Acute Graft-versus-Host Disease Predict Steroid-Refractory Disease, Treatment-Related Mortality, and Overall Survival after Allogeneic Hematopoietic Stem Cell Transplantation

DEFF Research Database (Denmark)

Minculescu, Lia; Kornblit, Brian Thomas; Friis, Lone Smidstrups

2018-01-01

, and their prognosis is especially poor. There is experimental evidence that coexisting inflammation aggravates aGVHD. Because C-reactive protein (CRP) is a systemic inflammatory marker, we aimed to investigate whether plasma CRP concentrations at the diagnosis of aGVHD can predict the risk of failing first-line...... of aGVHD diagnosis. According to local protocol, patients with failed response to high-dose steroid therapy (2 mg/kg) were treated with the TNF-α inhibitor infliximab and categorized as having steroid-refractory disease. Of 148 patients with grade II-IV aGVHD, 28 (19%) developed steroid......-refractory disease. In these patients, plasma CRP concentration at diagnosis ranged between patients who developed steroid-refractory disease compared with those who responded to high-dose corticosteroid therapy (odds ratio, 1.50; 95% confidence interval, 1...

Compatibility of refractory alloys with space reactor system coolants and working fluids

International Nuclear Information System (INIS)

DeVan, J.H.; DiStefano, J.R.; Hoffman, E.E.

1984-01-01

The bulk of this report deals with compatibility studies in liquid lithium and boiling potassium. Substantial information is also presented concerning the reactivity of niobium and tantalum alloys with residual gases in high and ultrahigh vacuum atmospheres. The remaining information, which is much less extensive, covers the compatibility behavior of molybdenum and tungsten alloys in alkali metals and a qualitative assessment of the use of refractory metals for containing helium in a closed Brayton cycle. 22 references, 29 figures, 14 tables

Diode and Nd:YAG laser in a case of refractory acne keloidalis nuchae

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Ravi Kumar Chittoria

2015-03-01

Full Text Available Acne keloidalis nuchae (AKN is a disease of unclear etiology that mainly affects males. Medical treatment of AKN is difficult, with refractory cases often requiring ablation by laser or surgical resection. We report herein, a 23-year-old male with refractory AKN treated successfully with combined laser ablation, using an 810-nm diode laser and a 1064-nm Nd:YAG laser.

Outcomes of Ahmed valve surgery for refractory glaucoma in Dhahran, Saudi Arabia

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Tariq Alasbali

2015-06-01

Full Text Available AIM:To evaluate the outcomes of Ahmed glaucoma valve (AGV implantation surgery for refractory glaucoma.METHODS:This one-armed historical cohort study was conducted in 2011. Refractory glaucoma was defined as eyes with an intraocular pressure (IOP greater than 21 mm Hg with maximally tolerated glaucoma medications, failed surgeries, or both. For all eyes with refractory glaucoma that underwent AGV implantation, data were collected on IOP, the best corrected visual acuity (BCVA and glaucoma medications preoperatively and 4, 6, 12, 24 and 56wk postoperatively. Logarithm values of IOP were calculated and compared.RESULTS: The study group was comprised of 30 patients (30 eyes, 16 males and 14 females with refractory glaucoma. Mean preoperative IOP was 39.3±13.8 mm Hg. Postoperative mean IOP was 15.7±7.1 mm Hg, 19.6±12.8 mm Hg and 13.9±14.2 mm Hg at 12, 24 and 56wk respectively. BCVA was ≥ 6/60 in 11 eyes preoperatively, and five eyes had BCVA≥6/60 at 56wk postoperatively. Preoperatively, more than four medications were used to treat glaucoma in 21 eyes. At 12wk postoperatively, no medications were required to control IOP in 20 eyes. At 56wk postoperatively, at least one medication was required to control IOP in 10 eyes. Over the entire follow up period, four eyes were treated with yttrium aluminium garnet (YAG laser and 14 eyes required a second surgery. The AGV was removed in four eyes.CONCLUSION: AGV implantation reduced IOP and the number of medications required to control refractory glaucoma. However, there was a higher risk of decreased vision. Long-term follow up and prompt intervention are recommended.

An unusual case of refractory wheeze

OpenAIRE

Ramesh, Venkat; Acharya, Vishak; Pai, Narasimha; Krishnan, Ananda

2015-01-01

A 37-year-old man presented with a history of episodic wheeze and breathlessness of 3?years? duration refractory to treatment. Physical examination revealed diffuse expiratory polyphonic rhonchi while the remainder of the examination including the cardiac examination was reported as normal. Pulmonary function testing revealed mild obstruction with bronchodilator reversibility. The patient was discharged on a 6-month course of antitubercular treatment (ATT) as bronchial brush cytology (obtaine...

Efficacy of Self-Expandable Metallic Stent Inserted for Refractory Hemorrhage of Duodenal Cancer

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Takashi Orii

2016-05-01

Full Text Available Because of advances in the technology of gastrointestinal endoscopy and improvements in the quality of stents, it has become routine to place a stent as palliative therapy for malignant gastrointestinal obstruction. On the other hand, stent placement for malignant gastrointestinal hemorrhage has scarcely been reported, although it may be performed for hemorrhage of the esophageal varicose vein. We recently experienced a patient with refractory hemorrhage from an unresectable duodenal cancer who underwent placement of a self-expandable metallic stent (SEMS and thereafter had no recurrence of the hemorrhage. A 46-year-old man underwent laparotomy to radically resect a cancer in the third portion of the duodenum, which invaded widely to the superior mesenteric vein and its branches and was considered unresectable. After stomach-partitioning gastrojejunostomy was performed, chemotherapy was initiated according to the regimen of chemotherapy of far advanced gastric cancer. One year and 4 months after induction of chemotherapy, gastrointestinal hemorrhage occurred. Upper gastrointestinal endoscopy revealed the hemorrhage oozing from the duodenal cancer, and endoscopic hemostasis, such as injection of hypertonic saline epinephrine and argon plasma coagulation, was unsuccessful. Twenty days after emergence of the hemorrhage, an endoscopic covered SEMS was placed with confirmation by fluoroscopy. Immediately after placement of the stent, the tarry stool stopped and the anemia ceased to progress. The recurrence of the hemorrhage has not been confirmed without migration of the stent. SEMS is an effective hemostatic procedure for malignant refractory hemorrhage.

Pre-surgical predictors for psychiatric disorders following epilepsy surgery in patients with refractory temporal lobe epilepsy and mesial temporal sclerosis.

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Filho, Gerardo Maria de Araújo; Mazetto, Lenon; Gomes, Francinaldo Lobato; Marinho, Murilo Martinez; Tavares, Igor Melo; Caboclo, Luís Otávio Sales Ferreira; Centeno, Ricardo Silva; Yacubian, Elza Márcia Targas

2012-11-01

Psychiatric outcomes of patients submitted to epilepsy surgery have gained particular interest given the high prevalence of pre-surgical psychiatric disorders (PD) in this population. The present study aimed to verify the possible pre-surgical predictors for psychiatric disorders following epilepsy surgery in a homogeneous series of patients with refractory temporal lobe epilepsy and mesial temporal sclerosis (TLE-MTS). Data from 115 TLE-MTS patients (65 females; 56.5%) who underwent cortico-amygdalohippocampectomy were included. Pre- and post-surgical psychiatric evaluations were performed using DSM-IV criteria. Pre-surgical PD - particularly mood, anxiety and psychotic disorders - were diagnosed in 47 patients (40.8%). Twenty-seven patients (54% of those with pre-surgical PD) demonstrated a remission of psychiatric symptoms on post-surgical psychiatric evaluation. Eleven patients (9.6%) developed de novo PD. The presence of pre-surgical depression (OR=3.32; p=0.008), pre-surgical interictal psychosis (OR=4.39; p=0.009) and epileptiform discharges contralateral to the epileptogenic zone (OR=2.73; p=0.01) were risk factors associated with post-surgical PD. Although epilepsy surgery is considered to be the best treatment option for patients with refractory TLE-MTS, the relatively high psychiatric comorbidities observed in surgical candidates and their possible negative impact on post-surgical outcomes require a careful pre-surgical evaluation of clinical, sociodemographic and psychiatric factors. Copyright © 2012 Elsevier B.V. All rights reserved.

Risk Factors for Elevated Preoperative Alkaline Phosphatase in Patients with Refractory Secondary Hyperparathyroidism.

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Yang, Meng; Zhang, Ling; Huang, Linping; Sun, Xiaoliang; Ji, Haoyang; Lu, Yao

2017-12-01

Elevated preoperative levels of alkaline phosphatase (ALP) in patients with refractory secondary hyperparathyroidism are correlated with postoperative hypocalcemia and mortality. The aim of this study was to identify the predictors of preoperative ALP in patients with secondary hyperparathyroidism. From April 2012 to December 2015, 220 patients with refractory secondary hyperparathyroidism undergoing total parathyroidectomy without autotransplantation were reviewed. A total of 164 patients presented with elevated preoperative ALP. Univariate analysis showed that patients with elevated ALP were significantly younger. The elevated ALP group had significantly higher levels of preoperative parathyroid hormone (PTH), lower preoperative serum calcium, higher preoperative phosphorus, lower postoperative hypocalcemia, and a longer hospital stay. Logistic regression analysis showed that elevated preoperative PTH was a significant independent risk factor for elevated preoperative ALP (P = 0.000), and its value of 1624 pg/mL was the optimal cutoff point. Factors predictive of elevated preoperative ALP in patients with secondary hyperparathyroidism include preoperative PTH. Earlier surgery, aggressive calcium supplementation, and more careful or aggressive postoperative care for high-risk patients are needed.

Primary pulmonary lymphoma mimicking a refractory lung abscess: A case report.

Science.gov (United States)

Matsumoto, Takeshi; Otsuka, Kojiro; Funayama, Yuki; Imai, Yukihiro; Tomii, Keisuke

2015-04-01

The current study presents a case of primary pulmonary lymphoma (PPL) mimicking refractory lung abscess that was diagnosed at autopsy. An 80-year-old male with clinically inapparent aspiration presented with a large cavitated mass and pleural effusion. A lung abscess and empyema was diagnosed, therefore, antibiotics were administered and the pleural effusion was drained. Various examinations, including a biopsy, yielded no specific diagnosis. The lesion was considered inoperable due to the poor general condition of the patient. Subsequently, the mass that had been diagnosed as a refractory lung abscess became enlarged and a repeat biopsy resulted in a diagnosis of diffuse large B-cell lymphoma. The patient succumbed to sudden respiratory failure, and the final diagnosis of PPL was confirmed at autopsy. PPL is a rare disease that accounts for 0.45% of all pulmonary malignant tumors and is difficult to diagnose in inoperable cases. Therefore, patients with PPL who do not undergo surgery can be misdiagnosed and consequently treated inappropriately. PPL should therefore be considered in the differential diagnosis of a refractory lung abscess.

Benefit–risk assessment of golimumab in the treatment of refractory ulcerative colitis

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Pugliese D

2016-02-01

Full Text Available Daniela Pugliese, Carla Felice, Rosario Landi, Alfredo Papa, Luisa Guidi, Alessandro Armuzzi Inflammatory Bowel Disease Unit, Complesso Integrato Columbus, Catholic University, Rome, Italy Abstract: Significant advances in the management of patients with ulcerative colitis (UC have been made since the introduction of anti-tumor necrosis factor (TNF-alpha agents, especially for those who fail or do not tolerate conventional therapies. Two drugs, infliximab first, then adalimumab afterward, showed effectiveness in inducing and maintaining long-term remission both in pivotal trials as well as in clinical practice. However, approximately 25% of patients with UC, who fail or do not tolerate all available therapies, require a colectomy for refractory disease. The therapeutic scenario of UC has been recently upgraded by the introduction of golimumab, the latest anti TNF-alpha agent to be approved. Golimumab is a totally humanized monoclonal antibody, administered by a subcutaneous injection every 4 weeks. Treatment with golimumab has shown to be effective to induce sustained clinical benefit in tough-to-treat patients with UC, including steroid and/or immunosuppressive refractory and steroid-dependent patients. In this review, we summarize all available efficacy and safety data of golimumab in UC, analyzing the potential therapeutic position for the treatment of refractory patients with UC. Keywords: ulcerative colitis, refractoriness, anti-TNF-alpha, golimumab 

18F-FDG PET Reveals Fronto-temporal Dysfunction in Children with Fever-Induced Refractory Epileptic Encephalopathy

International Nuclear Information System (INIS)