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Sample records for ardennes b-2 reactor

  1. Foliar mineral composition, fertilization and dieback of Norway spruce in the Belgian Ardennes.

    PubMed

    Van Praag, H J; Weissen, F

    1986-09-01

    Needles from healthy Norway spruce (Picea abies (L.) Karst.) at Willerzie in the West Ardennes and from trees with symptoms of dieback at Langesthal in the East Ardennes were analyzed by age class for mineral composition. Both stands were on acid oligotrophic soils. At Willerzie, needles were sampled from plots fertilized 12 to 17 years earlier (dolomitic lime plus N, P and K) as well as unfertilized plots. Effects of fertilization included increased levels of calcium, manganese, phosphorus, and copper and reduced levels of total sulfur, sulfate-S, sulfate-S:total S, potassium and aluminum. Levels of calcium, magnesium, copper and boron were low at both sites and, at Langesthal, calcium and magnesium may have been deficient. Sulfur level was normal at Willerzie, but at Langesthal, mean sulfur content for needles of all age classes was 198 mg 100 g(-1) dry weight, a level that may be toxic. In older needles, the N:S ratio at Langesthal was below the threshold value of eight reported to be necessary for healthy growth. Other symptoms of stress observed were high sulfate-S:total S and nitrate-N:total N ratios. At Langesthal, manganese level was probably adequate although only one-fifth the level at Willerzie. Levels of aluminum and iron were very high at both sites. Most of the iron and much of the aluminum occurred as a surface deposit that could be removed by washing the needles in chloroform. PMID:14975893

  2. Evaluation of long-term bedload virtual velocity in gravel-bed rivers (Ardenne, Belgium)

    NASA Astrophysics Data System (ADS)

    Houbrechts, Geoffrey; Levecq, Yannick; Peeters, Alexandre; Hallot, Eric; Van Campenhout, Jean; Denis, Anne-Cécile; Petit, François

    2015-12-01

    In many gravel-bed rivers, bed material transfer has been interrupted or perturbed by anthropogenic activities. Currently, restoration projects are being conducted in many countries in order to re-establish bedload continuity. However, until now, few studies have provided indications of the velocity of bed material over the long-term (at least decade to century time-scale). In the context of river restoration projects (e.g. weir removal, addition of spawning gravel), these data are nevertheless crucial to predict the downstream propagation of the geomorphological and biological benefits (e.g. supply-transport equilibrium, morphological and substratum diversity). In our study, PIT-tag tracers were used in eight medium-sized gravel-bed rivers (Ardenne Region, Belgium) to propose a flow competence relationship based on specific stream power, on the one hand, and to determine the long-term virtual velocity of the bed material corresponding to the median diameter (D50) of the surface layer of riffles, on the other hand. After each flow event that exceeded the threshold for sediment entrainment, tagged particles were sought and located, even when they were buried in the subsurface layer. Afterwards, all of the data were used to estimate the virtual velocity of the bed material over the long-term using three approaches. Finally, the results were compared with long-term transport estimations based on iron slag dispersed by the rivers since the end of the middle ages.

  3. [Results and lessons after 10 years of universal neonatal hearing screening in the Champagne-Ardenne region of France].

    PubMed

    Chays, André; Labrousse, Marc; Makeieff, Marc

    2014-01-01

    In France, universal newborn hearing screening has been mandatory since April23rd, 2012, but it began in the Champagne-Ardenne region on January 15th 2004. More than 99 % of 160 196 newborns have since been systematically screened in this region. Bilateral hearing impairment was thus identified in 116 infants when they were around 3.5 months old. Earlier diagnosis improves the outcome of deafness, which is only diagnosed around age 20 months without screening. The authors report their experience and the lessons learnt.

  4. Impact of beaver ponds on river discharge and sediment deposition along the Chevral River, Ardennes, Belgium

    NASA Astrophysics Data System (ADS)

    Nyssen, Jan; Frankl, Amaury; Pontzeele, Jolien; De Visscher, Maarten; Billi, Paolo

    2013-04-01

    With the recovery of the European beaver (Castor fiber) and their capacity to engineer fluvial landscapes, questions arise as to how they influence river discharge and sediment transport. The Chevral river (Ardennes, Belgium) contains two beaver dam sequences which appeared in 2004 and count now about 30 dams. Flow discharges and sediment fluxes were measured at the in- and outflow of each dam sequence. Volumes of sediment deposited behind the dams were measured. Between 2004 and 2011, peak flows were topped off, and the magnitude of extreme events decreased. 1710 m³ of sediment were deposited behind the beaver dams, with an average sediment thickness of 25 cm. The thickness of the sediment layer is related to the area of the beaver ponds. Along the stream, beaver pond sediment thickness displayed a sinusoidal deposition pattern, in which ponds with thick sediment layers were preceded by a series of ponds with thinner sediment layers. A downstream textural coarsening in the dam sequences was also observed, probably due to dam failures subsequent to surges. Differences in sediment flux between the in- and outflow at the beaver pond sequence were related to the river hydrograph, with deposition taking place during the rising limbs and slight erosion during the falling limbs. The seven-year-old sequences have filtered 190 tons of sediment out of the Chevral river, which is of the same order of magnitude as the 374 tons measured in pond deposits, with the difference between the values corresponding to beaver excavations (60 tons), inflow from small tributaries, and runoff from the valley flanks. Hydrogeomorphic effects of C. fiber and C. canadensis activity are similar in magnitude. The detailed analysis of changes to hydrology in beaver pond sequences confirms the potential of beavers to contribute to river and wetland restoration and catchment management.

  5. Comparison of two landslide susceptibility assessments in the Champagne-Ardenne region (France)

    NASA Astrophysics Data System (ADS)

    Den Eeckhaut, M. Van; Marre, A.; Poesen, J.

    2010-02-01

    The vineyards of the Montagne de Reims are mostly planted on steep south-oriented cuesta fronts receiving a maximum of sun radiation. Due to the location of the vineyards on steep hillslopes, the viticultural activity is threatened by slope failures. This study attempts to better understand the spatial patterns of landslide susceptibility in the Champagne-Ardenne region by comparing a heuristic (qualitative) and a statistical (quantitative) model in a 1120 km² study area. The heuristic landslide susceptibility model was adopted from the Bureau de Recherches Géologiques et Minières, the GEGEAA - Reims University and the Comité Interprofessionnel du Vin de Champagne. In this model, expert knowledge of the region was used to assign weights to all slope classes and lithologies present in the area, but the final susceptibility map was never evaluated with the location of mapped landslides. For the statistical landslide susceptibility assessment, logistic regression was applied to a dataset of 291 'old' (Holocene) landslides. The robustness of the logistic regression model was evaluated and ROC curves were used for model calibration and validation. With regard to the variables assumed to be important environmental factors controlling landslides, the two models are in agreement. They both indicate that present and future landslides are mainly controlled by slope gradient and lithology. However, the comparison of the two landslide susceptibility maps through (1) an evaluation with the location of mapped 'old' landslides and through (2) a temporal validation with spatial data of 'recent' (1960-1999; n = 48) and 'very recent' (2000-2008; n = 46) landslides showed a better prediction capacity for the statistical model produced in this study compared to the heuristic model. In total, the statistically-derived landslide susceptibility map succeeded in correctly classifying 81.0% of the 'old' and 91.6% of the 'recent' and 'very recent' landslides. On the susceptibility map

  6. REACTOR

    DOEpatents

    Christy, R.F.

    1961-07-25

    A means is described for co-relating the essential physical requirements of a fission chain reaction in order that practical, compact, and easily controllable reactors can be built. These objects are obtained by employing a composition of fissionsble isotope and moderator in fluid form in which the amount of fissionsble isotcpe present governs the reaction. The size of the reactor is no longer a critical factor, the new criterion being the concentration of the fissionable isotope.

  7. REACTOR

    DOEpatents

    Szilard, L.

    1963-09-10

    A breeder reactor is described, including a mass of fissionable material that is less than critical with respect to unmoderated neutrons and greater than critical with respect to neutrons of average energies substantially greater than thermal, a coolant selected from sodium or sodium--potassium alloys, a control liquid selected from lead or lead--bismuth alloys, and means for varying the quantity of control liquid in the reactor. (AEC)

  8. GPS monitoring of vertical ground motion in northern Ardenne Eifel: five campaigns (1999 2003) of the HARD project

    NASA Astrophysics Data System (ADS)

    Demoulin, A.; Campbell, J.; Wulf, A. De.; Muls, A.; Arnould, R.; Görres, B.; Fischer, D.; Kötter, T.; Brondeel, M.; Damme, D. Van.; Jacqmotte, J. M.

    2005-09-01

    We present the HARD project of GPS monitoring of vertical ground motion in NE Ardenne and Eifel (western Europe). Its main purposes are to get a better insight into the present-day rates of vertical ground motion in intraplate settings and to identify the various causes of these motions. Since 1999, we have carried out yearly campaigns of simultaneous GPS measurements at 12 sites situated so as to sample the different tectonic subunits of the study area and especially to record potential displacements across the seismogenic Hockai fault zone. Five campaigns (1999 2003) have been processed currently. Key issues of the data processing with the Gamit software are discussed and first results are presented. Though temporally consistent in many cases, the obtained vertical motion rates are spatially highly variable. They are also much too high (several mm/year) to support a tectonic interpretation, and a long-term influence of groundwater level variations is proposed to account for the observed motions. This influence should be distinguished from seasonal variations and from inter-survey variations linked to the varying degree of soil and subsoil drying off during the successive spring surveys.

  9. REACTOR

    DOEpatents

    Roman, W.G.

    1961-06-27

    A pressurized water reactor in which automatic control is achieved by varying the average density of the liquid moderator-cooiant is patented. Density is controlled by the temperature and power level of the reactor ftself. This control can be effected by the use of either plate, pellet, or tubular fuel elements. The fuel elements are disposed between upper and lower coolant plenum chambers and are designed to permit unrestricted coolant flow. The control chamber has an inlet opening communicating with the lower coolant plenum chamber and a restricted vapor vent communicating with the upper coolant plenum chamber. Thus, a variation in temperature of the fuel elements will cause a variation in the average moderator density in the chamber which directly affects the power level of the reactor.

  10. Human laminin B2 chain

    SciTech Connect

    Pikkarainen, T.; Kallunki, T.; Tryggvason, K.

    1988-05-15

    The complete amino acid sequence of the human laminin B2 chains has been determined by sequencing of cDNA clones. The six overlapping clones studied cover approximately 7.5 kilobases of which 5312 nucleotides were sequenced from the 5' end. The open reading frame codes for a 33-residue signal peptide and a 1576-residue B2 chain proper, which is 189 residues less than in the highly homologous B1 chain. Computer analysis revealed that the B2 chain consists of distinct domains that contain helical structures, cysteine-rich repeats, and globular regions, as does the B1 chain. However, domain ..cap alpha.. and domain ..beta.. of the B1 chain have no counterpart in B2, and the number of cysteine-rich repeats is 12, or 1 less than in the B1 chain. The degree of homology between the two chains is highest in the cysteine repeat-containing domains III and V where 40% of the residues match. However, in helical domains I/II only 16% of residues match. The results demonstrate that the B1 and B2 chains of laminin are highly homologous proteins that are probably the products of related genes.

  11. Reactor

    DOEpatents

    Evans, Robert M.

    1976-10-05

    1. A neutronic reactor having a moderator, coolant tubes traversing the moderator from an inlet end to an outlet end, bodies of material fissionable by neutrons of thermal energy disposed within the coolant tubes, and means for circulating water through said coolant tubes characterized by the improved construction wherein the coolant tubes are constructed of aluminum having an outer diameter of 1.729 inches and a wall thickness of 0.059 inch, and the means for circulating a liquid coolant through the tubes includes a source of water at a pressure of approximately 350 pounds per square inch connected to the inlet end of the tubes, and said construction including a pressure reducing orifice disposed at the inlet ends of the tubes reducing the pressure of the water by approximately 150 pounds per square inch.

  12. The Vaporization of B2O3(l) to B2O3(g) and B2O2(g)

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Myers, Dwight L.

    2011-01-01

    The vaporization of B2O3 in a reducing environment leads to formation of both B2O3(g) and B2O2(g). While formation of B2O3(g) is well understood, many questions about the formation of B2O2(g) remain. Previous studies using B(s) + B2O3(l) have led to inconsistent thermodynamic data. In this study, it was found that after heating, B(s) and B2O3(l) appear to separate and variations in contact area likely led to the inconsistent vapor pressures of B2O2(g). To circumvent this problem, an activity of boron is fixed with a two-phase mixture of FeB and Fe2B. Both second and third law enthalpies of formation were measured for B2O2(g) and B2O3(g). From these the enthalpies of formation at 298.15 K are calculated to be -479.9 +/- 41.5 kJ/mol for B2O2(g) and -833.4 +/- 13.1 kJ/mol for B2O3(g). Ab initio calculations to determine the enthalpies of formation of B2O2(g) and B2O3(g) were conducted using the W1BD composite method and show good agreement with the experimental values.

  13. Assessing the Economic Cost of Landslide Damage in Low-Relief Regions: Case Study Evidence from the Flemish Ardennes (Belgium)

    NASA Astrophysics Data System (ADS)

    Vranken, L.; Van Turnhout, P.; Van Den Eeckhaut, M.; Vandekerckhove, L.; Vantilt, G.; Poesen, J.

    2012-04-01

    Several regions around the globe are at risk to incur damage from landslides. These landslides cause significant structural and functional damage to public and private buildings and infrastructure. Numerous studies investigated how natural factors and human activities control the (re-)activation of landslides. However, few studies have concentrated on a quantitative estimate of the overall damage caused by landslides at a regional scale. This study therefore starts with a quantitative economic assessment of the direct and indirect damage caused by landslides in the Flemish Ardennes (Belgium), a low-relief region (area=ca. 700 km2) susceptible to landslides. Based on focus interviews as well as on semi-structured interviews with homeowners, civil servants (e.g. from the technical services from the various towns), or with the owners and providers of lifelines such as electricity and sewage, we have quantitatively estimated the direct and indirect damage induced by landsliding and this for a 10 to 30 year period (depending on the type of infrastructure or buildings). Economic damage to public infrastructure and buildings was estimated for the entire region, while for private damage 10 cases with severe to small damage were quantified. For example, in the last 10 year, costs of road repair augmented to 814 560 €. Costs to repair damaged roads that have not yet been repaired, were estimated at 669 318 €. In the past 30 years, costs of measures to prevent road damage augmented to at least 14 872 380 €. More than 90% of this budget for preventive measures was spent 30 years ago, when an important freeway was damaged and had to be repaired. These preventive measures (building a grout wall and improving the drainage system) were effective as no further damage has been reported until present. To repair and prevent damage to waterworks and sewage systems, expenditures amounted to 551 044 € and this for the last 30 years. In the past 10 years, a new railway line

  14. 12 CFR 708b.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Definitions. 708b.2 Section 708b.2 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS MERGERS OF FEDERALLY-INSURED CREDIT UNIONS; VOLUNTARY TERMINATION OR CONVERSION OF INSURED STATUS § 708b.2 Definitions. (a) Continuing credit union means the credit...

  15. 32 CFR 806b.2 - Basic guidelines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Basic guidelines. 806b.2 Section 806b.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.2 Basic guidelines. This part implements the Privacy Act of...

  16. 32 CFR 806b.2 - Basic guidelines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Basic guidelines. 806b.2 Section 806b.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.2 Basic guidelines. This part implements the Privacy Act of...

  17. 32 CFR 806b.2 - Basic guidelines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Basic guidelines. 806b.2 Section 806b.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.2 Basic guidelines. This part implements the Privacy Act of...

  18. 32 CFR 806b.2 - Basic guidelines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Basic guidelines. 806b.2 Section 806b.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.2 Basic guidelines. This part implements the Privacy Act of...

  19. 32 CFR 806b.2 - Basic guidelines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Basic guidelines. 806b.2 Section 806b.2 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION PRIVACY ACT PROGRAM Overview of the Privacy Act Program § 806b.2 Basic guidelines. This part implements the Privacy Act of...

  20. 7 CFR 1b.2 - Policy.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Policy. 1b.2 Section 1b.2 Agriculture Office of the Secretary of Agriculture NATIONAL ENVIRONMENTAL POLICY ACT § 1b.2 Policy. (a) All policies and programs of... environment for present and future generations. (b) Each USDA agency is responsible for compliance with...

  1. 7 CFR 1b.2 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Policy. 1b.2 Section 1b.2 Agriculture Office of the Secretary of Agriculture NATIONAL ENVIRONMENTAL POLICY ACT § 1b.2 Policy. (a) All policies and programs of... environment for present and future generations. (b) Each USDA agency is responsible for compliance with...

  2. 18 CFR 1b.2 - Scope.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Scope. 1b.2 Section 1b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.2 Scope. This part applies to...

  3. 18 CFR 1b.2 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Scope. 1b.2 Section 1b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.2 Scope. This part applies to...

  4. 18 CFR 1b.2 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Scope. 1b.2 Section 1b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.2 Scope. This part applies to...

  5. 18 CFR 1b.2 - Scope.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Scope. 1b.2 Section 1b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.2 Scope. This part applies to...

  6. 18 CFR 1b.2 - Scope.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Scope. 1b.2 Section 1b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES RULES RELATING TO INVESTIGATIONS § 1b.2 Scope. This part applies to...

  7. 42 CFR 52b.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Definitions. 52b.2 Section 52b.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL INSTITUTES OF HEALTH CONSTRUCTION GRANTS § 52b.2 Definitions. As used in this part: Act means the Public Health Service Act,...

  8. 42 CFR 52b.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Definitions. 52b.2 Section 52b.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS NATIONAL INSTITUTES OF HEALTH CONSTRUCTION GRANTS § 52b.2 Definitions. As used in this part: Act means the Public Health Service Act,...

  9. B2C graphene, nanotubes, and nanoribbons.

    PubMed

    Wu, Xiaojun; Pei, Yong; Zeng, Xiao Cheng

    2009-04-01

    We report a first-principles prediction of a new two-dimensional inorganic material, namely, the B(2)C graphene in which the boron and carbon atoms are packed into a mosaic of hexagons and rhombuses. In the B(2)C graphene, each carbon atom is bonded with four boron atoms, forming a planar-tetracoordinate carbon (ptC) moiety, a notion first conceived by Hoffmann et al. The B(2)C graphene is possibly a metal with a small overlap in the energy of conduction and valence bands. Like the carbon graphene and nanotubes, a B(2)C graphene sheet can be rolled into various forms of B(2)C nanotubes as well. Depending on the roll-up vector, the B(2)C nanotubes may become either a metal or a semiconductor. All B(2)C graphene nanoribbons are predicted to be uniformly metallic, regardless of their width and edge structure.

  10. 12 CFR 264b.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Federal Reserve System (“Board”), officers, and other employees of the Board, including experts or... 12 Banks and Banking 3 2011-01-01 2011-01-01 false Definitions. 264b.2 Section 264b.2 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM...

  11. 18 CFR 3b.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF... finger or voice print or a photograph; (e) System of records means a group of any records under...

  12. 12 CFR 261b.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Board. (c) The term meeting means the deliberations of at least the number of individual agency members... Public Affairs Office of the Board and shall not have the right to participate in the meeting, unless... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Definitions. 261b.2 Section 261b.2 Banks...

  13. 12 CFR 264b.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 3 2010-01-01 2010-01-01 false Definitions. 264b.2 Section 264b.2 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM RULES... such. (c) Gift means a tangible or intangible present (other than a decoration) tendered by,...

  14. 18 CFR 3b.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE...

  15. 18 CFR 3b.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE...

  16. 18 CFR 3b.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE...

  17. 18 CFR 3b.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Definitions. 3b.2 Section 3b.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES COLLECTION, MAINTENANCE, USE, AND DISSEMINATION OF RECORDS OF IDENTIFIABLE...

  18. Neutron irradiation of MgB2 bulk superconductors

    SciTech Connect

    Eisterer, M; Zehetmayer, M; Tonies, S; Weber, H W.; Kambara, M; Babu, N H.; Cardwell, D A.; Greenwood, Lawrence R. )

    2001-12-01

    Sintered samples of MgB2 were irradiated in a fission reactor. Defects in the bulk microstructure are produced during this process mainly by the 10B(n,a7Li) reaction while collisions of fast neutrons with the lattice atoms induce much less damage. Self-shielding effects turn out to be very important and lead to a highly inhomogeneous defect distribution in the irradiated samples. The resulting disorder enhances the normal state resistivity and the upper critical field. The irreversibility line shifts to higher fields at low temperatures and the measured critical current densities increase following irradiation.

  19. Martensitic Transformations in B2 Cubic Alloys

    NASA Astrophysics Data System (ADS)

    Lashley, Jason; Thoma, Dan; Darling, Timothy; Migliori, Albert; Cooley, Jason; Hults, Larry; Singleton, John; Drymiotis, Fivos; Smith, Jim

    2003-03-01

    Many modern shape-memory materials are based on the ordered bcc structure, in particular the B2 structure. These structures may be subjected to a shearing motion to which the material has little resistance. Plausibly, this "Zener instability" can provide the means for these structures to undergo a martensitic phase transition, where the actual distances the atoms move are small enough that exact reversibility (shape-memory) is possible. There are many B2 structures but only some of them exhibit martensitic phase transitions. Some are equi-atomic, highly ordered alloys and some are off-stoichiometry that must be quenched to retain a non-equilibrium B2 structure. We have made thermal, transport, mechanical, Fermi surface topology, and elastic measurements on several B2 martensitic alloys and present our findings in terms of the differences between varios B2 alloys and other structures.

  20. Contribution of piezometric measurement to knowledge and management of low water levels: examples on the chalk aquifer in the Champagne Ardennes region

    NASA Astrophysics Data System (ADS)

    Stollsteiner, P.; Bessiere, H.; Nicolas, J.; Allier, D.; Berthet, O.

    2015-04-01

    This article is based on a BRGM study on piezometric indicators, threshold values of discharge and groundwater levels for the assessment of potentially-exploitable water resources of chalky watersheds. A method for estimating low water levels based on groundwater levels is presented from three examples representing chalk aquifers with different cycles: annual, combined and interannual. The first is located in Picardy and the two others in the Champagne-Ardennes region. Piezometers with annual cycles, used in these examples, are supposed to be representative of the aquifer hydro-dynamics. Except for multi-annual systems, the analysis between discharge measurements at a hydrometric station and groundwater levels measured at a piezometer representative of the main aquifer, leads to relatively precise and satisfactory relationships within a chalky context. These relationships may be useful for monitoring, validation, extension or reconstruction of the low water flow data. On the one hand, they allow definition of the piezometric levels corresponding to the different alert thresholds of river discharges. On the other hand, they clarify the proportions of low surface water flow from runoff or drainage of the aquifer. Finally, these correlations give an assessment of the minimum flow for the coming weeks. However, these correlations cannot be used to optimize the value of the exploitable water resource because it seems to be difficult to integrate the value of the effective rainfall that could occur during the draining period. Moreover, in the case of multi-annual systems, the solution is to attempt a comprehensive system modelling and, if it is satisfactory, using the simulated values to get rid of parasites or running the model for forecasting purposes.

  1. Chooz A, First Pressurized Water Reactor to be Dismantled in France - 13445

    SciTech Connect

    Boucau, Joseph; Mirabella, C.; Nilsson, Lennart; Kreitman, Paul J.; Obert, Estelle

    2013-07-01

    Nine commercial nuclear power plants have been permanently shut down in France to date, of which the Chooz A plant underwent an extensive decommissioning and dismantling program. Chooz Nuclear Power Station is located in the municipality of Chooz, Ardennes region, in the northeast part of France. Chooz B1 and B2 are 1,500 megawatt electric (MWe) pressurized water reactors (PWRs) currently in operation. Chooz A, a 305 MWe PWR implanted in two caves within a hill, began operations in 1967 and closed in 1991, and will now become the first PWR in France to be fully dismantled. EDF CIDEN (Engineering Center for Dismantling and Environment) has awarded Westinghouse a contract for the dismantling of its Chooz A reactor vessel (RV). The project began in January 2010. Westinghouse is leading the project in a consortium with Nuvia France. The project scope includes overall project management, conditioning of the reactor vessel (RV) head, RV and RV internals segmentation, reactor nozzle cutting for lifting the RV out of the pit and seal it afterwards, dismantling of the RV thermal insulation, ALARA (As Low As Reasonably Achievable) forecast to ensure acceptable doses for the personnel, complementary vacuum cleaner to catch the chips during the segmentation work, needs and facilities, waste characterization and packaging, civil work modifications, licensing documentation. The RV and RV internals will be segmented based on the mechanical cutting technology that Westinghouse applied successfully for more than 13 years. The segmentation activities cover the cutting and packaging plan, tooling design and qualification, personnel training and site implementation. Since Chooz A is located inside two caves, the project will involve waste transportation from the reactor cave through long galleries to the waste buffer area. The project will end after the entire dismantling work is completed, and the waste storage is outside the caves and ready to be shipped either to the ANDRA (French

  2. Fumonisin B2 production by Aspergillus niger.

    PubMed

    Frisvad, Jens C; Smedsgaard, Jørn; Samson, Robert A; Larsen, Thomas O; Thrane, Ulf

    2007-11-14

    The carcinogenic mycotoxin fumonisin B2 was detected for the first time in the industrially important Aspergillus niger. Fumonisin B2, known from Fusarium verticillioides and other Fusaria, was detected in cultures of three full genome sequenced strains of A. niger, in the ex type culture and in a culture of F. verticillioides by electrospray LC-MS analysis of methanolic extracts from agar plugs of cultures grown on several substrates. Whereas F. verticillioides produced fumonisins B1, B2, and B3 on agar media based on plant extracts, such as barley malt, oat, rice, potatoes, and carrots, A. niger produced fumonisin B2 best on agar media with a low water activity, including Czapek yeast autolysate agar with 5% NaCl. Of the media tested, only rice corn steep agar supported fumonisin production by both F. verticillioides and A. niger. However, A. niger had a different regulation of fumonisin production and a different quantitative profile of fumonisins, producing only B2 as compared to F. verticillioides. Fumonisin production by A. niger, which is a widely occurring species and an extremely important industrial organism, will have very important implications for biotechnology and especially food safety. A. niger is used for the production of citric acid and as producer of extracellular enzymes, and also as a transformation host for the expression of heterologous proteins. Certain strains of A. niger produce both ochratoxin A and fumonisins, so some foods and feeds may potentially contain two types of carcinogenic mycotoxins from this species.

  3. B2-Eirene modelling of ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Coster, D. P.; Schneider, R.; Neuhauser, J.; Bosch, H.-S.; Wunderlich, R.; Fuchs, C.; Mast, F.; Kallenbach, A.; Dux, R.; Becker, G.; Braams, B. J.; Reiter, D.; ASDEX Upgrade Team

    1997-02-01

    The extension of the computational region of the coupled fluid plasma, Monte-Carlo neutrals code, B2-Eirene, to the plasma center is discussed. The simulation of completely detached H-mode plasma is presented, as is the modelling of He and Ne compression.

  4. Infrared and Ultraviolet Spectra of Diborane(6): B2H6 and B2D6.

    PubMed

    Peng, Yu-Chain; Chou, Sheng-Lung; Lo, Jen-Iu; Lin, Meng-Yeh; Lu, Hsiao-Chi; Cheng, Bing-Ming; Ogilvie, J F

    2016-07-21

    We recorded absorption spectra of diborane(6), B2H6 and B2D6, dispersed in solid neon near 4 K in both mid-infrared and ultraviolet regions. For gaseous B2H6 from 105 to 300 nm, we report quantitative absolute cross sections; for solid B2H6 and for B2H6 dispersed in solid neon, we measured ultraviolet absorbance with relative intensities over a wide range. To assign the mid-infrared spectra to specific isotopic variants, we applied the abundance of (11)B and (10)B in natural proportions; we undertook quantum-chemical calculations of wavenumbers associated with anharmonic vibrational modes and the intensities of the harmonic vibrational modes. To aid an interpretation of the ultraviolet spectra, we calculated the energies of electronically excited singlet and triplet states and oscillator strengths for electronic transitions from the electronic ground state. PMID:27351464

  5. The B2 aluminides as alternative materials

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.

    1984-01-01

    The potential of the B2 aluminides as structural material alternatives for the strategic element containing superalloys currently used in gas turbine engines is being explored with emphasis on the equiatomic Fe and Ni aluminides. Although Co is a strategic material, the equiatomic Co aluminide is also being studied to gain a more complete understanding of these fourth period intermetallics. Research focuses on initial processing techniques such as ingot melting, power metallurgy, and rapid solidification with and without additional thermomechanical processing; high temperature deformation - primarily compressive creep; compositional effects within the binary B2 aluminides; third-element alloying addition effects on high temperature strength and oxidation resistance, and near room temperature ductility as influenced by processing, alloying, and grain size. Various programs now underway are reviewed and some highlights of research results are presented.

  6. Lattice Thermal Conductivity from Atomistic Simulations: ZrB2 and HfB2

    NASA Technical Reports Server (NTRS)

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  7. Electronic states of BP, BP +, BP -, B 2P 2, B2P2- and B2P2+

    NASA Astrophysics Data System (ADS)

    Linguerri, Roberto; Komiha, Najia; Oswald, Rainer; Mitrushchenkov, Alexander; Rosmus, Pavel

    2008-05-01

    Using augmented sextuple zeta basis sets and internally contracted multireference configuration interaction (MRCI) wavefunctions, potential energy, electric dipole and transition moments have been computed for the X 3Π, a 1Σ +, b 1Π and A 3Σ - states of BP, X 2Σ + and A 2Π states of BP - and X 4Σ - and A 4Π states of BP +. From these data spectroscopic constants, radiative transition probabilities and photoelectron spectra of BP - and BP have been evaluated. The non-vanishing spin-orbit coupling elements between the four low lying triplet and singlet states of the neutral BP have also been calculated from MRCI wavefunctions. The treatment of the corresponding perturbations in the manifold of dense rovibrational states in the three lowest states would require a precise knowledge of the electronic excitation energies. Our best singlet-triplet separations (X-a) are calculated to be 2412 cm -1 (MRCI) and 2482 cm -1 (restricted coupled cluster with perturbative triples (RCCSD(T))) with an estimated error bound of about ±200 cm -1. All three states have long radiative lifetimes with cascading among the rovibrational levels of different states. The ionization energy IE e of BP is calculated to be 9.22 eV (MRCI) and 9.48 eV (RCCSD(T)), the electron affinity EA e 2.51 eV (MRCI) and 2.74 eV (RCCSD(T)). The photoelectron spectra of BP and BP - have been obtained from the Franck-Condon factors of the MRCI potentials. For the UV spectroscopy the dipole allowed radiative transition probabilities are given for A 3Σ - ↔ X 3Π, b 1Π ↔ a 1Σ + of BP, A 2Π ↔ X 2Σ + of BP - and A 4Π ↔ X 4Σ - of BP +. The ionization energy IE e of B 2P 2 of 8.71 eV and the electron affinity EA e of 2.34 eV have been calculated by the RCCSD(T)/aVQZ approach. Also the harmonic vibrational wavenumbers for the electronic ground states of the ions B2P2+ and B2P2- are given.

  8. Assessment of liquid hydrogen cooled MgB2 conductors for magnetically confined fusion

    NASA Astrophysics Data System (ADS)

    Glowacki, B. A.; Nuttall, W. J.

    2008-02-01

    Importantly environmental factors are not the only policy-driver for the hydrogen economy. Over the timescale of the development of fusion energy systems, energy security issues are likely to motivate a shift towards both hydrogen production and fusion as an energy source. These technologies combine local control of the system with the collaborative research interests of the major energy users in the global economy. A concept Fusion Island Reactor that might be used to generate H2 (rather than electricity) is presented. Exploitation of produced hydrogen as a coolant and as a fuel is proposed in conjunction with MgB2 conductors for the tokomak magnets windings, and electrotechnical devices for Fusion Island's infrastructure. The benefits of using MgB2 over the Nb-based conductors during construction, operation and decommissioning of the Fusion Island Reactor are presented. The comparison of Nb3Sn strands for ITER fusion magnet with newly developed high field composite MgB2 PIT conductors has shown that at 14 Tesla MgB2 possesses better properties than any of the Nb3Sn conductors produced. In this paper the potential of MgB2 conductors is examined for tokamaks of both the conventional ITER type and a Spherical Tokamak geometry. In each case MgB2 is considered as a conductor for a range of field coil applications and the potential for operation at both liquid helium and liquid hydrogen temperatures is considered. Further research plans concerning the application of MgB2 conductors for Fusion Island are also considered.

  9. A monoclonal antibody targeting ErbB2 domain III inhibits ErbB2 signaling and suppresses the growth of ErbB2-overexpressing breast tumors

    PubMed Central

    Meng, Y; Zheng, L; Yang, Y; Wang, H; Dong, J; Wang, C; Zhang, Y; Yu, X; Wang, L; Xia, T; Zhang, D; Guo, Y; Li, B

    2016-01-01

    The anti-ErbB2 antibodies trastuzumab and pertuzumab in combination have recently been approved for the treatment of patients with ErbB2-positive metastatic breast cancer. Pertuzumab, which binds to ErbB2 near the center of domain II, and trastuzumab, which binds to the juxtamembrane region of ErbB2 domain IV, directly interfere with domain II- and domain IV-mediated heterodimerization contacts, respectively. In this study, we report a novel anti-ErbB2 antibody, 3E10, which binds to an epitope in domain III that appears to be located opposite to the dimerization interfaces in domain II and domain IV of ErbB2. Our data show that the 3E10 antibody inhibits ErbB2 heterodimerization via a mechanism that strikingly differs from trastuzumab and pertuzumab. It could be speculated that the 3E10 antibody may affect ErbB2 heterodimerization by causing major conformational changes of ErbB2. Furthermore, 3E10 provides synergistic inhibition of ErbB2 heterodimerization and signaling in combination with either trastuzumab or pertuzumab. The combination of these three anti-ErbB2 antibodies that have complementary mechanisms of action appears to be an extremely potent ErbB2 heterodimerization blocker. Compared with trastuzumab plus pertuzumab, the combination of trastuzumab, pertuzumab and 3E10 provides a more potent blockade of ErbB2 signaling. Consistent with this, trastuzumab plus pertuzumab plus 3E10 results in greater in vitro and in vivo antitumor activity in ErbB2-overexpressing breast tumor models, suggesting its potential use for treating ErbB2-overexpressing breast cancer. PMID:26999718

  10. 26 CFR 1.663(b)-2 - Election.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Election. 1.663(b)-2 Section 1.663(b)-2 Internal... TAXES Estates and Trusts Which May Accumulate Income Or Which Distribute Corpus § 1.663(b)-2 Election. (a) Manner and time of election; irrevocability—(1) When return is required to be filed. If a...

  11. Electronic Commerce in Tourism in China: B2B or B2C?

    NASA Astrophysics Data System (ADS)

    Li, Hongxiu; Suomi, Reima

    E-commerce has significantly changed the distribution channels of travel products in the world including China. Online channels are growing important in travel service distribution. In China tourism industry has been developed rapidly with the economic development, more and more international travel service providers are trying to expand their Chinese market through the Internet. This paper sheds lights on the e-commerce development models in China for international travel service providers. It explores the current e-tourism in China from the three different participants in the value chain in tourism industry - consumer, travel agent and travel service provider. The paper also identifies the barriers in B2C arena in international outbound travel market, and discusses the possible approaches for international travel service providers to develop their e-commerce in the huge Chinese market. The results in this study reveal that international travel service providers should focus on B2B model to expand their electronic market in China. B2C development in tourism largely depends on the change of Chinese customers' behavior and the change of international tourism regulations. The findings of the study are expected to assist international travel service providers to understand current e-tourism in China and to support their planning for future e-commerce development in China.

  12. Synthesis of MgB 2 film by electrochemical process

    NASA Astrophysics Data System (ADS)

    Sakurai, Hiroshi; Kuramochi, Takashi; Furuya, Yudai; Oike, Hiromi; Kato, Tadashi; Hoshi, Kazushi

    2008-07-01

    In order to synthesize MgB2 films, electrolysis is performed in an electrolyte comprising a fused mixture of B2O3, KCl and MgCl2 in a molar ratio of B2O3:KCl:MgCl2 = x:3.5:5. The results of the Meissner effects and X-ray diffraction measurements indicate the formation of MgB2 films on graphite and Si substrates. The superconducting critical temperature depends on both the synthesis temperature of the electrolysis and the amount of B2O3 in the electrolyte.

  13. Improved Superconducting properties in the Mg(11)B2 low activation superconductor prepared by low-temperature sintering.

    PubMed

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M; Somer, M

    2016-05-05

    Mg(11)B2 has a great application prospect in the superconducting coils for fusion reactor as the "low activation superconductors". The un-doped Mg(11)B2 and Cu-doped Mg(11)B2 bulks using (11)B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg(11)B2 low activation superconductors exhibit better Jc performance than all of other Mg(11)B2 samples reported in previous studies. As for Cu doped Mg(11)B2, minor Cu addition can obviously improve the Mg(11)B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg(11)B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields.

  14. Improved Superconducting properties in the Mg11B2 low activation superconductor prepared by low-temperature sintering

    NASA Astrophysics Data System (ADS)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M.; Somer, M.

    2016-05-01

    Mg11B2 has a great application prospect in the superconducting coils for fusion reactor as the “low activation superconductors”. The un-doped Mg11B2 and Cu-doped Mg11B2 bulks using 11B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg11B2 low activation superconductors exhibit better Jc performance than all of other Mg11B2 samples reported in previous studies. As for Cu doped Mg11B2, minor Cu addition can obviously improve the Mg11B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg11B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields.

  15. Improved Superconducting properties in the Mg(11)B2 low activation superconductor prepared by low-temperature sintering.

    PubMed

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M; Somer, M

    2016-01-01

    Mg(11)B2 has a great application prospect in the superconducting coils for fusion reactor as the "low activation superconductors". The un-doped Mg(11)B2 and Cu-doped Mg(11)B2 bulks using (11)B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg(11)B2 low activation superconductors exhibit better Jc performance than all of other Mg(11)B2 samples reported in previous studies. As for Cu doped Mg(11)B2, minor Cu addition can obviously improve the Mg(11)B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg(11)B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields. PMID:27149682

  16. Improved Superconducting properties in the Mg11B2 low activation superconductor prepared by low-temperature sintering

    PubMed Central

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M.; Somer, M.

    2016-01-01

    Mg11B2 has a great application prospect in the superconducting coils for fusion reactor as the “low activation superconductors”. The un-doped Mg11B2 and Cu-doped Mg11B2 bulks using 11B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg11B2 low activation superconductors exhibit better Jc performance than all of other Mg11B2 samples reported in previous studies. As for Cu doped Mg11B2, minor Cu addition can obviously improve the Mg11B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg11B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields. PMID:27149682

  17. B2(BO)6 0/- and B 2(BS) 6 0/- doubly bridged structures containing BO or BS as ligands.

    PubMed

    Li, Da-Zhi; Li, Si-Dian

    2014-09-01

    The investigation on the geometrical and electronic properties of B(2)(BO)(6) (0/-) and B(2)(BS)(6) (0/-) has been performed by density functional theory (DFT) using the B3LYP and BP86 methods. The chemical bonding in B(2)A(6) (A = H, BO, and BS) series is elucidated through the recently developed adaptive natural density partitioning (AdNDP). D(2h) B(2)(BO)(6) and B(2)(BS)(6) were found to possess two bridging η (2)-BO or η (2)-BS groups, as well as four terminal BO or BS groups that are analogs of diborane B(2)H(6). D(2)h B(2)(BO)(6) (-) and B(2)(BS)(6) (-) with two bridging η (2)-BO or η (2)-BS groups which are more stable than their corresponding D(3d) structures. The binding energy of B(2)(BO)(6) and B(2)(BS)(6) with respect to B(2)(BO)(6) (D2h) → 2B(BO)(3) (D(3h)) and B(2)(BS)(6)(D(2h)) → 2B(BS)(3) (D(3h)) are estimated to be (△)E = 19.8 and 40.6 kcal mol(-1) at CCSD(T)//B3LYP level, respectively. This finding advances the boronyl chemistry and helps establish the isolobal analogy between boron-rich oxide clusters and boranes. PMID:25159274

  18. Boron isotope effect in superconducting MgB2.

    PubMed

    Bud'ko, S L; Lapertot, G; Petrovic, C; Cunningham, C E; Anderson, N; Canfield, P C

    2001-02-26

    We report the preparation method of and boron isotope effect for MgB2, a new binary intermetallic superconductor with a remarkably high superconducting transition temperature T(c)(10B) = 40.2 K. Measurements of both temperature dependent magnetization and specific heat reveal a 1.0 K shift in T(c) between Mg11B2 and Mg10B2. Whereas such a high transition temperature might imply exotic coupling mechanisms, the boron isotope effect in MgB2 is consistent with the material being a phonon-mediated BCS superconductor.

  19. Unusual behaviour of (Np,Pu)B2C

    NASA Astrophysics Data System (ADS)

    Klimczuk, Tomasz; Boulet, Pascal; Griveau, Jean-Christophe; Colineau, Eric; Bauer, Ernst; Falmbigl, Matthias; Rogl, Peter; Wastin, Franck

    2015-02-01

    Two transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single-crystal X-ray data to be isotypic with the ThB2C-type (space group ?, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z = 9). Physical properties have been derived from polycrystalline bulk material in the temperature range from 2 to 300 K and in magnetic fields up to 9 T. Magnetic susceptibility and heat capacity data indicate the occurrence of antiferromagnetic ordering for NpB2C with a Neel temperature TN = 68 K. PuB2C is a Pauli paramagnet most likely due to a strong hybridization of s(p,d) electrons with the Pu-5f states. A pseudo-gap, as concluded from the Sommerfeld value and the electronic transport, is thought to be a consequence of the hybridization. The magnetic behaviour of {Np,Pu}B2C is consistent with the criterion of Hill.

  20. Plexin-B2 promotes invasive growth of malignant glioma.

    PubMed

    Le, Audrey P; Huang, Yong; Pingle, Sandeep C; Kesari, Santosh; Wang, Huaien; Yong, Raymund L; Zou, Hongyan; Friedel, Roland H

    2015-03-30

    Invasive growth is a major determinant of the high lethality of malignant gliomas. Plexin-B2, an axon guidance receptor important for mediating neural progenitor cell migration during development, is upregulated in gliomas, but its function therein remains poorly understood. Combining bioinformatic analyses, immunoblotting and immunohistochemistry of patient samples, we demonstrate that Plexin-B2 is consistently upregulated in all types of human gliomas and that its expression levels correlate with glioma grade and poor survival. Activation of Plexin-B2 by Sema4C ligand in glioblastoma cells induced actin-based cytoskeletal dynamics and invasive migration in vitro. This proinvasive effect was associated with activation of the cell motility mediators RhoA and Rac1. Furthermore, costimulation of Plexin-B2 and the receptor tyrosine kinase Met led to synergistic Met phosphorylation. In intracranial glioblastoma transplants, Plexin-B2 knockdown hindered invasive growth and perivascular spreading, and resulted in decreased tumor vascularity. Our results demonstrate that Plexin-B2 promotes glioma invasion and vascularization, and they identify Plexin-B2 as a potential novel prognostic marker for glioma malignancy. Targeting the Plexin-B2 pathway may represent a novel therapeutic approach to curtail invasive growth of glioblastoma.

  1. 26 CFR 1.403(b)-2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.403(b)-2 Definitions. (a) Application... 1450(b) of the Small Business Job Protection Act of 1996 (110 Stat. 1755, 1814) for special rules... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Definitions. 1.403(b)-2 Section...

  2. 26 CFR 1.663(b)-2 - Election.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Election. 1.663(b)-2 Section 1.663(b)-2 Internal... Election. (a) Manner and time of election; irrevocability—(1) When return is required to be filed. If a trust return is required to be filed for the taxable year of the trust for which the election is...

  3. 26 CFR 1.663(b)-2 - Election.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Election. 1.663(b)-2 Section 1.663(b)-2 Internal... Election. (a) Manner and time of election; irrevocability—(1) When return is required to be filed. If a trust return is required to be filed for the taxable year of the trust for which the election is...

  4. 26 CFR 1.663(b)-2 - Election.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Election. 1.663(b)-2 Section 1.663(b)-2 Internal... Election. (a) Manner and time of election; irrevocability—(1) When return is required to be filed. If a trust return is required to be filed for the taxable year of the trust for which the election is...

  5. 26 CFR 1.663(b)-2 - Election.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Election. 1.663(b)-2 Section 1.663(b)-2 Internal... Election. (a) Manner and time of election; irrevocability—(1) When return is required to be filed. If a trust return is required to be filed for the taxable year of the trust for which the election is...

  6. 26 CFR 53.4942(b)-2 - Alternative tests.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 17 2012-04-01 2012-04-01 false Alternative tests. 53.4942(b)-2 Section 53.4942....4942(b)-2 Alternative tests. (a) Assets test—(1) In general. A private foundation will satisfy the assets test under the provisions of this paragraph if substantially more than half of the...

  7. Vasopressor meets vasodepressor: The AT1-B2 receptor heterodimer.

    PubMed

    Quitterer, Ursula; AbdAlla, Said

    2014-04-01

    The AT1 receptor for the vasopressor angiotensin II is one of the most important drug targets for the treatment of cardiovascular diseases. Sensitization of the AT1 receptor system is a common feature contributing to the pathogenesis of many cardiovascular disorders but underlying mechanisms are not fully understood. More than a decade ago, evidence was provided for control of AT1R activation by heterodimerization with the B2 receptor for the vasodepressor peptide, bradykinin, a physiological counterpart of the vasoconstrictor angiotensin II. AT1-B2 receptor heterodimerization was shown to enhance AT1R-stimulated signaling under pathophysiological conditions such as experimental and human pregnancy hypertension. Notably, AT1R signal sensitization of patients with preeclampsia hypertension was attributed to AT1R-B2R heterodimerization. Vice versa, transgenic mice lacking the AT1-B2 receptor heterodimer due to targeted deletion of the B2R gene showed a significantly reduced AT1R-stimulated vasopressor response compared to transgenic mice with abundant AT1R-B2R heterodimerization. Biophysical methods such as BRET and FRET confirmed those data by demonstrating efficient AT1-B2 receptor heterodimerization in transfected cells and transgenic mice. Recently, a study on AT1R-specific biased agonism directed the focus to the AT1-B2 receptor heterodimer again. The β-arrestin-biased [Sar1,Ile4,Ile8]-angiotensin II promoted not only the recruitment of β-arrestin to the AT1R but also stimulated the down-regulation of the AT1R-associated B2 receptor by co-internalization. Thereby specific targeting of the AT1R-B2R heterodimer became feasible and could open the way to a new class of drugs, which specifically interfere with pathological angiotensin II-AT1 receptor system activation.

  8. 75 FR 23572 - Airworthiness Directives; Airbus Model A300 B2-1C, B2-203, B2K-3C, B4-103, B4-203, B4-2C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ... (75 FR 11428, March 11, 2010), for certain Airbus Model A300 B2-1C, B2-203, B2K-3C, B4-103, B4-203, B4... B2-1C, B2-203, B2K- 3C, B4-103, B4-203, B4-2C Airplanes; Model A310 Series Airplanes; and Model A300... applies to certain Airbus Model A300 B2-1C, B2-203, B2K-3C, B4-103, B4-203, B4-2C airplanes; Model...

  9. CRADA Final Report: ErbB2 Targeted Cancer Therapeutics

    SciTech Connect

    Lupu, Ruth

    2002-08-27

    The aim of the study was to design novel therapeutic strategies for the treatment of carcinomas which overexpress the erbB-2 oncogene product and/or the activator (HRG). erbB-2 is a tyrosine kinase growth factor receptor, that overexpression of which in invasive breast, prostate, ovarian and lung carcinomas correlates with poor prognosis and poor overall survival. In breast carcinomas, erbB-2 is overexpressed in 25%-30% of the invasive phenotype and in 70% of ductal carcinomas in situ. On the other hand, the erbB-2 activator, heregulin (HRG) is expressed in about 30% of invasive breast carcinomas and it is highly expressed in other carcinoIl1as including, ovarian, lung, and prostate. Interestingly, only 6% of invasive breast carcinomas co-express both HRG and erbB-2. It is known today that tumors that overexpress erbB-2 are a leading cause of death, making erbB-2 and its activator HRG critical targets for therapy. Targeting both the receptors and the activator would be beneficial for a significant number of cancer patients. At the final stages of the project we had obtained significant improvements over the peptide quality but not significant improvements were made towards the generation of humanized monoclonal antibodies.

  10. Substitution of Mn for Mg in MgB_2*

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, Michael D.; Johnston, David C.; Miller, Lance L.; Hill, Julienne M.

    2002-03-01

    The study of solid solutions in which the Mg in MgB2 is partially replaced by magnetic 3d or 4f atoms can potentially reveal important information on the superconducting state of MgB_2. As an end-member of the hypothetical Mg_1-xMn_xB2 system, MnB2 is isostructural with MgB2 and is an antiferromagnet below TN = 760 K which becomes canted at 157 K. A previous study by Moritomo et al.[1] examined the structure and properties of multi-phase samples with 0.01<= x<= 0.15. We attempted to obtain single-phase samples with x<= 0.25 by reacting the constituent elements in sealed Ta tubes and/or using prereacted MnBx synthesized using an arc furnace. The results of x-ray diffraction and magnetization measurements on those samples will be presented. * Supported by the USDOE under contract no. W-7405-Eng-82. [1] "Mn-substitution effects on MgB2 superconductor", Y.Moritomo et al. J. Phys. Soc. Japan b70, 1889 (2001).; “Effects of transition metal doping in MgB2 superconductor", Y. Moritomo at al. arXiv:cond-mat/0104568.

  11. The role of TiB2 in strengthening TiB2 reinforced aluminium casting composites

    NASA Astrophysics Data System (ADS)

    Chen, Z.; Kang, H.; Zhao, Y.; Zheng, Y.; Wang, T.

    2016-03-01

    With an aim of developing high quality in situ TiB2 reinforced aluminium foundry alloy based composites, the conventional direct synthesis method was modified into a two-step route. In step one we optimized the halide salt route to fabricate in situ TiB2 particulate reinforced aluminium matrix composites and in step two we investigated the effects of the Al-5wt.% TiB2 composite, as a “master composite”, on strengthening the practical foundry alloys. The in situ formed TiB2 particles play two roles while strengthening the composites: (1) The grain refinement effect that improves the quality of the alloy matrix; and (2) The interactions between the hard particulates and the matrix add extra increment to the material strength. In different alloy systems, TiB2 may play distinct roles in these two aspects (figure 1). Further analysis of the strengthening mechanisms shows that particle agglomeration behaviour during solidification is responsible for the latter one. The present work details the role of TiB2 in strengthening TiB2 reinforced aluminium casting composites.

  12. Properties of L=1 B(1) and B(2)* mesons.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahn, S H; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Anastasoaie, M; Ancu, L S; Andeen, T; Anderson, S; Andrieu, B; Anzelc, M S; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Assis Jesus, A C S; Atramentov, O; Autermann, C; Avila, C; Ay, C; Badaud, F; Baden, A; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Banerjee, P; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Bellavance, A; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Berntzon, L; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Biscarat, C; Blazey, G; Blekman, F; Blessing, S; Bloch, D; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Borissov, G; Bos, K; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Buchanan, N J; Buchholz, D; Buehler, M; Buescher, V; Burdin, S; Burke, S; Burnett, T H; Buszello, C P; Butler, J M; Calfayan, P; Calvet, S; Cammin, J; Caron, S; Carvalho, W; Casey, B C K; Cason, N M; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chan, K; Chandra, A; Charles, F; Cheu, E; Chevallier, F; Cho, D K; Choi, S; Choudhary, B; Christofek, L; Christoudias, T; Cihangir, S; Claes, D; Clément, C; Clément, B; Coadou, Y; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Crépé-Renaudin, S; Cutts, D; Cwiok, M; da Motta, H; Das, A; Davies, G; De, K; de Jong, S J; de Jong, P; De La Cruz-Burelo, E; Martins, C De Oliveira; Degenhardt, J D; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dong, H; Dudko, L V; Duflot, L; Dugad, S R; Duggan, D; Duperrin, A; Dyer, J; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Ermolov, P; Evans, H; Evdokimov, A; Evdokimov, V N; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Ford, M; Fortner, M; Fox, H; Fu, S; Fuess, S; Gadfort, T; Galea, C F; Gallas, E; Galyaev, E; Garcia, C; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Gelé, D; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Gollub, N; Gómez, B; Goussiou, A; Grannis, P D; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, J; Guo, F; Gutierrez, P; Gutierrez, G; Haas, A; Hadley, N J; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Hanagaki, K; Hansson, P; Harder, K; Harel, A; Harrington, R; Hauptman, J M; Hauser, R; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinmiller, J M; Heinson, A P; Heintz, U; Hensel, C; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hobbs, J D; Hoeneisen, B; Hoeth, H; Hohlfeld, M; Hong, S J; Hooper, R; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jarvis, C; Jesik, R; Johns, K; Johnson, C; Johnson, M; Jonckheere, A; Jonsson, P; Juste, A; Käfer, D; Kahn, S; Kajfasz, E; Kalinin, A M; Kalk, J R; Kalk, J M; Kappler, S; Karmanov, D; Kasper, J; Kasper, P; Katsanos, I; Kau, D; Kaur, R; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y M; Khatidze, D; Kim, H; Kim, T J; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kopal, M; Korablev, V M; Kothari, B; Kozelov, A V; Krop, D; Kryemadhi, A; Kuhl, T; Kumar, A; Kunori, S; Kupco, A; Kurca, T; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lazoflores, J; Lebrun, P; Lee, W M; Leflat, A; Lehner, F; Lellouch, J; Lesne, V; Leveque, J; Lewis, P; Li, J; Li, Q Z; Li, L; Lietti, S M; Lima, J G R; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobo, L; Lobodenko, A; Lokajicek, M; Lounis, A; Love, P; Lubatti, H J; Lyon, A L; Maciel, A K A; Mackin, D; Madaras, R J; Mättig, P; Magass, C; Magerkurth, A; Makovec, N; Mal, P K; Malbouisson, H B; Malik, S; Malyshev, V L; Mao, H S; Maravin, Y; Martin, B; McCarthy, R; Melnitchouk, A; Mendes, A; Mendoza, L; Mercadante, P G; Merkin, M; Merritt, K W; Meyer, J; Meyer, A; Michaut, M; Millet, T; Mitrevski, J; Molina, J; Mommsen, R K; Mondal, N K; Moore, R W; Moulik, T; Muanza, G S; Mulders, M; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Naumann, N A; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nomerotski, A; Novaes, S F; Nunnemann, T; O'Dell, V; O'Neil, D C; Obrant, G; Ochando, C; Onoprienko, D; Oshima, N; Osta, J; Otec, R; Y Garzón, G J Otero; Owen, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Pawloski, G; Penning, B; Perea, P M; Peters, K; Peters, Y; Pétroff, P; Petteni, M; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Pompos, A; Pope, B G; Popov, A V; Potter, C; da Silva, W L Prado; Prosper, H B; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Rani, K J; Ranjan, K; Ratoff, P N; Renkel, P; Reucroft, S; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rodrigues, R F; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santoro, A; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schieferdecker, P; Schliephake, T; Schmitt, C; Schwanenberger, C; Schwartzman, A; Schwienhorst, R; Sekaric, J; Sengupta, S; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Shpakov, D; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, R P; Snow, J; Snow, G R; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Souza, M; Spurlock, B; Stark, J; Steele, J; Stolin, V; Stone, A; Stoyanova, D A; Strandberg, J; Strandberg, S; Strang, M A; Strauss, M; Strauss, E; Ströhmer, R; Strom, D; Strovink, M; Stutte, L; Sumowidagdo, S; Svoisky, P; Sznajder, A; Talby, M; Tamburello, P; Tanasijczuk, A; Taylor, W; Telford, P; Temple, J; Tiller, B; Tissandier, F; Titov, M; Tokmenin, V V; Tomoto, M; Toole, T; Torchiani, I; Trefzger, T; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, S; Uvarov, L; Uzunyan, S; Vachon, B; van den Berg, P J; van Eijk, B; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vartapetian, A; Vasilyev, I A; Vaupel, M; Verdier, P; Vertogradov, L S; Verzocchi, M; Villeneuve-Seguier, F; Vint, P; Vokac, P; Von Toerne, E; Voutilainen, M; Vreeswijk, M; Wagner, R; Wahl, H D; Wang, L; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Weber, G; Weerts, H; Wenger, A; Wermes, N; Wetstein, M; White, A; Wicke, D; Wilson, G W; Williams, M R J; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yacoob, S; Yamada, R; Yan, M; Yasuda, T; Yatsunenko, Y A; Yip, K; Yoo, H D; Youn, S W; Yu, J; Yu, C; Yurkewicz, A; Zatserklyaniy, A; Zeitnitz, C; Zhang, D; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zieminski, A; Zivkovic, L; Zutshi, V; Zverev, E G

    2007-10-26

    This Letter presents the first strong evidence for the resolution of the excited B mesons B(1) and B(2)* as two separate states in fully reconstructed decays to B(+)(*)pi(-). The mass of B(1) is measured to be 5720.6+/-2.4+/-1.4 MeV/c(2) and the mass difference DeltaM between B(2)* and B(1) is 26.2+/-3.1+/-0.9 MeV/c;{2}, giving the mass of the B(2)* as 5746.8+/-2.4+/-1.7 MeV/c(2). The production rate for B(1) and B(2)* mesons is determined to be a fraction (13.9+/-1.9+/-3.2)% of the production rate of the B+ meson. PMID:17995320

  13. 32 CFR 242b.2 - Meetings of the Board.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... THE HEALTH SCIENCES § 242b.2 Meetings of the Board. (a) Regular meetings. (1) The Board shall hold at... the written request of three or more Regents, delivered to the Secretary, or upon the direction of...

  14. Bending strain tolerance of MgB2 superconducting wires

    NASA Astrophysics Data System (ADS)

    Kováč, P.; Hušek, I.; Melišek, T.; Kulich, M.; Kopera, L.

    2016-04-01

    This work describes the strain tolerance of MgB2 superconductors subjected to variable bending stresses. Bending of MgB2 wire was done at room temperature in different modes: (i) direct bending of straight annealed samples to variable diameters and by (ii) indirect bending by straightening of bent and annealed samples. I c-bending strain characteristics of samples made by in situ PIT and by the internal magnesium diffusion (IMD) process were measured at 4.2 K. The results show a good agreement between the direct and indirect bending mode, which allows easier estimation of limits important for the winding process of MgB2 superconductors with brittle filaments. A comparison of MgB2 wires made by in situ PIT and IMD processes showed improved strain tolerance for IMD due to better grain connectivity the low annealing temperature, which does not appear to reduce the mechanical strength of sheath material.

  15. 8 CFR 343b.2 - Number of applications required.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... CERTIFICATE OF NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.2 Number of applications required. A special certificate of naturalization is delivered to one foreign government official only. An...

  16. 8 CFR 343b.2 - Number of applications required.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CERTIFICATE OF NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.2 Number of applications required. A special certificate of naturalization is delivered to one foreign government official only. An...

  17. 8 CFR 343b.2 - Number of applications required.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... CERTIFICATE OF NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.2 Number of applications required. A special certificate of naturalization is delivered to one foreign government official only. An...

  18. 8 CFR 343b.2 - Number of applications required.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... CERTIFICATE OF NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.2 Number of applications required. A special certificate of naturalization is delivered to one foreign government official only. An...

  19. Thermal stability of hexagonal OsB2

    NASA Astrophysics Data System (ADS)

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Andrew Payzant, E.

    2014-11-01

    The synthesis of novel hexagonal ReB2-type OsB2 ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of 10B and 11B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched 11B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB2 phase was the main product of synthesis with a small quantity of Os2B3 phase present after synthesis as an intermediate product. In the second case, where coarse crystalline 11B powder was used as a raw material, only Os2B3 boride was synthesized mechanochemically. The thermal stability of hexagonal OsB2 powder was studied by heating under argon up to 876 °C and cooling in vacuo down to -225 °C. During the heating, the sacrificial reaction 2OsB2+3O2→2Os+2B2O3 took place due to presence of O2/water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B2O3 and precipitation of Os metal out of the OsB2 lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB2 changed significantly. The shrinkage of the a lattice parameter was recorded in 276-426 °C temperature range upon heating, which was attributed to the removal of B atoms from the OsB2 lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O2, the hexagonal OsB2 ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice parameters and no phase changes detected during cooling.

  20. Thermal stability of hexagonal OsB2

    SciTech Connect

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A; Payzant, E Andrew

    2014-01-01

    The synthesis of novel hexagonal ReB2-type OsB2 ceramic powder was performed by high energy ball milling of elemental Os and B powders. Two different sources of B powder have been used for this mechanochemical synthesis. One B powder consisted of a mixture of amorphous and crystalline phases and a mixture of 10B and 11B isotopes with a fine particle size, while another B powder was a purely crystalline (rhombohedral) material consisting of enriched 11B isotope with coarse particle size. The same Os powder was used for the synthesis in both cases. It was established that, in the first case, the hexagonal OsB2 phase was the main product of synthesis with a small quantity of Os2B3 phase present after synthesis as an intermediate product. In the second case, where coarse crystalline 11B powder was used as a raw material, only Os2B3 boride was synthesized mechanochemically. The thermal stability of hexagonal OsB2 powder was studied by heating under argon up to 876 C and cooling in vacuo down to 225 C. During the heating, the sacrificial reaction 2OsB2+3O2 2Os+2B2O3 took place due to presence of O2/water vapor molecules in the heating chamber, resulting in the oxidation of B atoms and formation of B2O3 and precipitation of Os metal out of the OsB2 lattice. As a result of such phase changes during heating, the lattice parameters of hexagonal OsB2 changed significantly. The shrinkage of the a lattice parameter was recorded in 276 426 C temperature range upon heating, which was attributed to the removal of B atoms from the OsB2 lattice due to oxidation followed by the precipitation of Os atoms and formation of Os metal. While significant structural changes occurred upon heating due to presence of O2, the hexagonal OsB2 ceramic demonstrated good phase stability upon cooling in vacuo with linear shrinkage of the lattice parameters and no phase changes detected during cooling.

  1. Phonon dispersion and electron-phonon coupling in MgB2 and AlB2.

    PubMed

    Bohnen, K P; Heid, R; Renker, B

    2001-06-18

    We present a first principles investigation of the lattice dynamics and electron-phonon coupling of the superconductor MgB2 and the isostructural AlB2 within the framework of density functional perturbation theory using a mixed-basis pseudopotential method. Complete phonon dispersion curves and Eliashberg functions alpha2F are calculated for both systems. The main differences are related to high frequency in-plane boron vibrations, which are strongly softened in MgB2 and exhibit an exceptionally strong electron-phonon coupling. We also report on Raman measurements, which support the theoretical findings. Implications for the superconducting transition temperature are briefly discussed.

  2. Magnetic lenses using different MgB2 bulk superconductors

    NASA Astrophysics Data System (ADS)

    Zhang, Z. Y.; Choi, S.; Matsumoto, S.; Teranishi, R.; Giunchi, G.; Figini Albisetti, A.; Kiyoshi, T.

    2012-02-01

    A magnetic lens allows the concentration of magnetic fields using the diamagnetism of superconductors. The important features of the magnetic lens are a tapered inner diameter from which the magnetic flux is extruded and a slit to suppress the circumference current that shields the magnetic flux. This concept was experimentally confirmed through the use of GdBaCuO bulks and a stack of NbTi/Nb/Cu sheets. We refer to this arrangement as a magnetic lens. The Mg-reactive liquid infiltration (Mg-RLI) process developed by Edison SpA is suitable for the production of large and high-density MgB2 bulks. Three MgB2 bulk magnetic lenses, each with a different microstructure, were fabricated following the Mg-RLI process. The properties of the MgB2 magnetic lenses were measured in a cryocooler system as well as in liquid helium. The results confirmed that the MgB2 bulk magnetic lenses could concentrate a magnetic field and that their field concentration properties were greatly affected by the temperature and the external field. In addition, the microstructure of the MgB2 bulk also had an influence on the magnetic properties at different external fields. The results indicated that the MgB2 lens might be utilized as a field amplifier in intermediate fields.

  3. Mechanical and thermal properties of bulk ZrB2

    NASA Astrophysics Data System (ADS)

    Nakamori, Fumihiro; Ohishi, Yuji; Muta, Hiroaki; Kurosaki, Ken; Fukumoto, Ken-ichi; Yamanaka, Shinsuke

    2015-12-01

    ZrB2 appears to have formed in the fuel debris at the Fukushima Daiichi nuclear disaster site, through the reaction between Zircaloy cladding materials and the control rod material B4C. Since ZrB2 has a high melting point of 3518 K, the ceramic has been widely studied as a heat-resistant material. Although various studies on the thermochemical and thermophysical properties have been performed for ZrB2, significant differences exist in the data, possibly due to impurities or the porosity within the studied samples. In the present study, we have prepared a ZrB2 bulk sample with 93.1% theoretical density by sintering ZrB2 powder. On this sample, we have comprehensively examined the thermal and mechanical properties of ZrB2 by the measurement of specific heat, ultrasonic sound velocities, thermal diffusivity, and thermal expansion. Vickers hardness and fracture toughness were also measured and found to be 13-23 GPa and 1.8-2.8 MPa m0.5, respectively. The relationships between these properties were carefully examined in the present study.

  4. Superconductivity in dense MgB2 wires.

    PubMed

    Canfield, P C; Finnemore, D K; Bud'ko, S L; Ostenson, J E; Lapertot, G; Cunningham, C E; Petrovic, C

    2001-03-12

    MgB2 becomes superconducting just below 40 K. Whereas porous polycrystalline samples of MgB2 can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB2 can be prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 microm, are better than 80% dense, and manifest the full chi = -1/4pi shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB2 is a highly conducting metal in the normal state with rho(40 K) = 0.38 microOmega cm. By using this value, an electronic mean-free path, l approximately 600 A can be estimated, indicating that MgB2 wires are well within the clean limit. Tc, Hc2(T), and Jc data indicate that MgB2 manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet.

  5. Nuclear microprobe analysis of 7Li profile induced in HfB 2 by a neutron irradiation

    NASA Astrophysics Data System (ADS)

    Simeone, D.; Deschanels, X.; Gosset, D.; Bonal, J. P.; Berthoumieux, E.

    2001-09-01

    HfB 2, a solid poor in boron, was irradiated by thermal neutrons in an experimental reactor. Using a nuclear microprobe, we have tracked lithium atoms produced by the 10B( n, α) 7Li reaction and compared the calculated and measured 7Li profiles in HfB 2 irradiated samples. This comparison shows that Li atoms do not diffuse during irradiation (323 K). The comparison of non-annealed and annealed irradiated HfB 2 plates clearly shows that lithium atoms do not migrate out of samples even at high temperatures (1273 K). These results associated to previous transmission electron microscopy (TEM) observations seem to show that lithium atoms are trapped by dislocation loops created by displacement cascades during neutron irradiation.

  6. Lattice Thermal Conductivity of Ultra High Temperature Ceramics ZrB2 and HfB2 from Atomistic Simulations

    NASA Technical Reports Server (NTRS)

    Lawson, John W.; Murray, Daw S.; Bauschlicher, Charles W., Jr.

    2011-01-01

    Atomistic Green-Kubo simulations are performed to evaluate the lattice thermal conductivity for single crystals of the ultra high temperature ceramics ZrB2 and HfB2 for a range of temperatures. Recently developed interatomic potentials are used for these simulations. Heat current correlation functions show rapid oscillations which can be identified with mixed metal-Boron optical phonon modes. Agreement with available experimental data is good.

  7. Electronic structure of scandium-doped MgB2

    NASA Astrophysics Data System (ADS)

    de La Peña, Omar; Agrestini, Stefano

    2005-03-01

    Recently has been reported the synthesis of a new superconducting alloy based on MgB2, where Mg is partially substituted with Sc. In order to analyze the effect of Sc doping on the structural and superconducting properties of Mg1-xScxB2, we have performed a detailed study of the electronic structure for this new diboride. The calculations have been done using the first-principles LAPW method, within the supercell approach for modeling the doping. In this work we report results for the electronic band structure, Fermi surface, and density of states. The effect of the Sc-d orbitals on the structural and electronic properties of Mg1-xScxB2 is analyzed. Increasing the Sc concentration (x) the σ-band is gradually filled, because Sc have one valence electron more than Mg. Interestingly, the analysis of the band structure shows that even for ScB2 the top of the σ-band remain above the Fermi level, nevertheless the σ-band presents high dispersion and has an important contribution of d states. In this way, in addition to the band filling effect, Sc doping gradually reduces the two-dimensional character of the σ- band in Mg1-xScxB2 as a result of increasing the sp(B)-d(Sc) hybridization. This research was partially supported by Consejo Nacional de Ciencia y Tecnolog'ia (CONACYT, M'exico) under Grant. No. 43830-F

  8. Preparation and characterisation of Ru doped MgB2

    NASA Astrophysics Data System (ADS)

    Grivel, J.-C.; Holte, O. J.

    2013-12-01

    Samples with Mg1-xRuxB2 nominal stoichiometry were prepared by sintering at 800 °C. The critical transition temperature decreases up to a substitution level of x ≈ 0.015. A maximum solubility limit slightly in excess of 1 at.% Ru for Mg is confirmed by energy dispersive spectroscopy measurements. From and beyond this limit, an unidentified phase appears in the X-ray diffraction patterns. Interestingly, the lattice parameters of the MgB2 phase are constant up to x = 0.015, but start to decrease for higher Ru contents. This feature could be related to the fact that a Mg-Ru impurity phase results in a Mg-deficient (Mg,Ru)B2 matrix.

  9. ORM-Based Semantics of B2B Transactions

    NASA Astrophysics Data System (ADS)

    Balsters, H.; van Blommestein, F.

    After widespread implementation of Enterprise Resource Planning and Personal Information Management, the next wave in the application of ICT is headed towards business to business (B2B) communication. B2B has a number of specific aspects, one of them being negotiation. This aspect has been largely neglected by present implementations of standard EDI- or XML-messaging and by B2B webservice implementations. In this paper a precise model is given of the negotiation process. The requirements of a potential Buyer and the offer of a potential Seller are matched and, if the negotiation is successful, a contract is concluded. The negotiation process model is represented in ORM, extended with dynamic constraints. Our model may be implemented in the databases of the trading partners and in message- or service definitions.

  10. EBSD analysis of MgB2 bulk superconductors

    NASA Astrophysics Data System (ADS)

    Koblischka-Veneva, A.; Koblischka, M. R.; Schmauch, J.; Inoue, K.; Muralidhar, M.; Berger, K.; Noudem, J.

    2016-04-01

    The grain orientation, the texture and the grain boundary misorientations are important parameters for the understanding of the magnetic properties of the bulk MgB2 samples intended for super-magnet applications. Such data can be provided by electron backscatter diffraction (EBSD) analysis. However, as the grain size (GS) of the MgB2 bulks is preferably in the 100-200 nm range, the common EBSD technique working in reflection operates properly only on highly dense samples. In order to achieve a reasonably good Kikuchi pattern quality on all samples, we apply here the newly developed transmission EBSD (t-EBSD) technique to several bulk MgB2 samples. This method requires the preparation of TEM slices by means of focused ion-beam milling, which are then analyzed within the SEM, operating with a specific sample holder. We present several EBSD mappings of samples prepared with different techniques and at various reaction temperatures.

  11. Expanding Interprofessional EHR Data in i2b2

    PubMed Central

    Westra, Bonnie L.; Christie, Beverly; Johnson, Steven G.; Pruinelli, Lisiane; LaFlamme, Anne; Park, Jung In; Sherman, Suzan G.; Byrne, Matthew D.; Ranallo, Piper; Speedie, Stuart

    2016-01-01

    Emerging issues of team-based care, precision medicine, and big data science underscore the need for health information technology (HIT) tools for integrating complex data in consistent ways to achieve the triple aims of improving patient outcomes, patient experience, and cost reductions. The purpose of this study was to demonstrate the feasibility of creating a hierarchical flowsheet ontology in i2b2 using data-derived information models and determine the underlying informatics and technical issues. This study is the first of its kind to use information models that aggregate team-based care across time, disciplines, and settings into 14 information models that were integrated into i2b2 in a hierarchical model. In the process of successfully creating a hierarchical ontology for flowsheet data in i2b2, we uncovered a variety of informatics and technical issues described in this paper. PMID:27570680

  12. Expanding Interprofessional EHR Data in i2b2.

    PubMed

    Westra, Bonnie L; Christie, Beverly; Johnson, Steven G; Pruinelli, Lisiane; LaFlamme, Anne; Park, Jung In; Sherman, Suzan G; Byrne, Matthew D; Ranallo, Piper; Speedie, Stuart

    2016-01-01

    Emerging issues of team-based care, precision medicine, and big data science underscore the need for health information technology (HIT) tools for integrating complex data in consistent ways to achieve the triple aims of improving patient outcomes, patient experience, and cost reductions. The purpose of this study was to demonstrate the feasibility of creating a hierarchical flowsheet ontology in i2b2 using data-derived information models and determine the underlying informatics and technical issues. This study is the first of its kind to use information models that aggregate team-based care across time, disciplines, and settings into 14 information models that were integrated into i2b2 in a hierarchical model. In the process of successfully creating a hierarchical ontology for flowsheet data in i2b2, we uncovered a variety of informatics and technical issues described in this paper. PMID:27570680

  13. Excitation, abundance, and distribution of HNCO in Sagittarius B2

    SciTech Connect

    Churchwell, E.; Wood, D.; Myers, P.C.; Myers, R.V.

    1986-06-01

    Snyder and Buhl (1972) have discovered isocyanic acid (HNCO) in Sgr B2. It is pointed out that HNCO is a particularly interesting interstellar molecule because under certain conditions it can be employed in a study of the far-infrared radiation field of the cloud in which it resides. The present study was mainly conducted with the aim to establish empirically the extent to which HNCO is populated by radiative processes in a source with a measured far-infrared radiation field. It is attempted to deduce the radiation field from the HNCO excitation conditions. Attention is given to an energy-level diagram of HNCO in the ground electronic and vibrational states, the antenna and receiver properties, a table with the observed parameters toward Sagittarius B2, the velocity structure, the HNCO intensity distribution, a summary of the Sgr B2 properties, the population distribution and column density, and the excitation of HNCO. 27 references.

  14. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Zinn, W.H.; Anderson, H.L.

    1958-09-16

    Means are presenied for increasing the reproduction ratio of a gaphite- moderated neutronic reactor by diminishing the neutron loss due to absorption or capture by gaseous impurities within the reactor. This means comprised of a fluid-tight casing or envelope completely enclosing the reactor and provided with a valve through which the casing, and thereby the reactor, may be evacuated of atmospheric air.

  15. Neuroendocrine secretory protein 7B2: structure, expression and functions.

    PubMed Central

    Mbikay, M; Seidah, N G; Chrétien, M

    2001-01-01

    7B2 is an acidic protein residing in the secretory granules of neuroendocrine cells. Its sequence has been elucidated in many phyla and species. It shows high similarity among mammals. A Pro-Pro-Asn-Pro-Cys-Pro polyproline motif is its most conserved feature, being carried by both vertebrate and invertebrate sequences. It is biosynthesized as a precursor protein that is cleaved into an N-terminal fragment and a C-terminal peptide. In neuroendocrine cells, 7B2 functions as a specific chaperone for the proprotein convertase (PC) 2. Through the sequence around its Pro-Pro-Asn-Pro-Cys-Pro motif, it binds to an inactive proPC2 and facilitates its transport from the endoplasmic reticulum to later compartments of the secretory pathway where the zymogen is proteolytically matured and activated. Its C-terminal peptide can inhibit PC2 in vitro and may contribute to keep the enzyme transiently inactive in vivo. The PC2-7B2 model defines a new neuroendocrine paradigm whereby proteolytic activation of prohormones and proneuropeptides in the secretory pathway is spatially and temporally regulated by the dynamics of interactions between converting enzymes and their binding proteins. Interestingly, unlike PC2-null mice, which are viable, 7B2-null mutants die early in life from Cushing's disease due to corticotropin ('ACTH') hypersecretion by the neurointermediate lobe, suggesting a possible involvement of 7B2 in secretory granule formation and in secretion regulation. The mechanism of this regulation is yet to be elucidated. 7B2 has been shown to be a good marker of several neuroendocrine cell dysfunctions in humans. The possibility that anomalies in its structure and expression could be aetiological causes of some of these dysfunctions warrants investigation. PMID:11439082

  16. Superconductivity of Metallic Boron in MgB2

    NASA Astrophysics Data System (ADS)

    Kortus, J.; Mazin, I. I.; Belashchenko, K. D.; Antropov, V. P.; Boyer, L. L.

    2001-05-01

    Boron in MgB2 forms stacks of honeycomb layers with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with an ionic component and considerable metallic density of states yield a sizable electron-phonon coupling. Together with high phonon frequencies, which we estimate via zone-center frozen phonon calculations to be between 300 and 700 cm-1, this produces a high critical temperature, consistent with recent experiments. Thus MgB2 can be viewed as an analog of the long sought, but still hypothetical, superconducting metallic hydrogen.

  17. Convergent De Novo Synthesis of Vineomycinone B2 Methyl Ester

    PubMed Central

    Chen, Qian; Zhong, Yashan; O’Doherty, George A.

    2013-01-01

    An efficient de novo synthesis of vineomycinone B2 methyl ester has been achieved. The longest linear route required only 14 steps from achiral commercially available starting materials (4.0% overall yield). The key transformations included the de novo asymmetric synthesis of two key fragments, which were joined by a convergent late stage Suzuki’s glycosylation for the construction of the aryl β-C-glycoside. A subsequent BBr3 one-pot debenzylation, demethylation and air oxidation provided vineomycinone B2 methyl ester. PMID:23778961

  18. Superconductivity of metallic boron in MgB2.

    PubMed

    Kortus, J; Mazin, I I; Belashchenko, K D; Antropov, V P; Boyer, L L

    2001-05-14

    Boron in MgB2 forms stacks of honeycomb layers with magnesium as a space filler. Band structure calculations indicate that Mg is substantially ionized, and the bands at the Fermi level derive mainly from B orbitals. Strong bonding with an ionic component and considerable metallic density of states yield a sizable electron-phonon coupling. Together with high phonon frequencies, which we estimate via zone-center frozen phonon calculations to be between 300 and 700 cm(-1), this produces a high critical temperature, consistent with recent experiments. Thus MgB2 can be viewed as an analog of the long sought, but still hypothetical, superconducting metallic hydrogen.

  19. Superconducting properties of MgB2 from first principles.

    PubMed

    Floris, A; Profeta, G; Lathiotakis, N N; Lüders, M; Marques, M A L; Franchini, C; Gross, E K U; Continenza, A; Massidda, S

    2005-01-28

    Solid MgB(2) has rather interesting and technologically important properties, such as a very high superconducting transition temperature. Focusing on this compound, we report the first nontrivial application of a novel density-functional-type theory for superconductors, recently proposed by the authors. Without invoking any adjustable parameters, we obtain the transition temperature, the gaps, and the specific heat of MgB(2) in very good agreement with experiment. Moreover, our calculations show how the Coulomb interaction acts differently on sigma and pi states, thereby stabilizing the observed superconducting phase.

  20. Differential Conductance Measurements of MgB2/I/Pb Heterojunctions and all-MgB2 Junctions

    NASA Astrophysics Data System (ADS)

    Cusick, David; Eckhardt, Matthew; Dai, Wenqing; Li, Qi; Chen, Ke; Cunnane, Daniel; Zhuang, C. G.; Xi, X. X.; Naito, Michio; Ramos, Roberto

    2015-03-01

    We present our work characterizing several types of Magnesium Diboride Josephson junctions, including MgB2/I/Pb heterojunctions and all-MgB2 junctions. We will report on the I-V and dI/dV-V data collected at various temperatures using both a cryocooler-based experimental platform between 2 and 20 Kelvin and using a 3He probe platform between 0.3 and 1.0 Kelvin. These were both developed by undergraduates in a liberal arts university. Using high-sampling rates with a 24-bit data acquisition card and access to a broad of range of temperatures, we track and report energy gap distributions and temperature-dependent features of dI/dV peaks of MgB2, comparing these with theoretical predictions. R.C.R. acknowledges support from National Science Foundation Grant # DMR-1206561.

  1. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  2. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  3. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  4. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  5. 26 CFR 1.167(b)-2 - Declining balance method.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Declining balance method. 1.167(b)-2 Section 1... Declining balance method. (a) Application of method. Under the declining balance method a uniform rate is... declining balance rate may be determined without resort to formula. Such rate determined under section...

  6. 26 CFR 53.4942(b)-2 - Alternative tests.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Taxes on Failure To Distribute Income § 53.4942(b)-2 Alternative tests. (a) Assets test—(1) In general. A private foundation will satisfy the assets test under the provisions of this paragraph if substantially more than half of the...

  7. 26 CFR 53.4942(b)-2 - Alternative tests.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... EXCISE TAXES (CONTINUED) FOUNDATION AND SIMILAR EXCISE TAXES Taxes on Failure To Distribute Income § 53.4942(b)-2 Alternative tests. (a) Assets test—(1) In general. A private foundation will satisfy the assets test under the provisions of this paragraph if substantially more than half of the...

  8. X-Ray-emitting Atmospheres of B2 Radio Galaxies

    NASA Astrophysics Data System (ADS)

    Worrall, D. M.; Birkinshaw, M.

    2000-02-01

    We report ROSAT PSPC spatial and spectral analyses of the eight B2 radio galaxies NGC 315, NGC 326, 4C 35.03, B2 0326+39, NGC 2484, B2 1040+31, B2 1855+37, and 3C 449, expected to be representative of the class of low-power radio galaxies. Multiple X-ray components are present in each, and the gas components have a wide range of linear sizes and follow an extrapolation of the cluster X-ray luminosity/temperature correlation, implying that there is no relationship between the presence of a radio galaxy and the gas fraction of the environment. No large-scale cooling flows are found. There is no correlation of radio-galaxy size with the scale or density of the X-ray atmosphere. This suggests that processes on scales smaller than those of the overall gaseous environments are the major influence on radio-source dynamics. The intergalactic medium is usually sufficient to confine the outer parts of the radio structures, in some cases even to within 5 kpc of the core. In the case of NGC 315, an extrapolation suggests that the pressure of the atmosphere may match the minimum pressure in the radio source over a factor of ~40 in linear size (a factor of ~1600 in pressure).

  9. AFLATOXIN B2: CHEMICAL IDENTITY AND BIOLOGICAL ACTIVITY.

    PubMed

    CHANG, S B; ABDEL-KADER, M M; WICK, E L; WOGAN, G N

    1963-11-29

    Aflatoxin B(2), a blue-fluorescent metabolite of Aspergillus flavus, was isolated from cultures grown on crushed wheat. Chemical structure of the compound was elucidated as dihydroaflatoxin B(1). Biological activity was determined in day-old male white Pekin ducklings. The criteria of activity were reduction in growth and liver size and the extent of bile-duct hyperplasia.

  10. 49 CFR 178.33b-2 - Type and size.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Specifications for Inside Containers, and Linings § 178.33b-2 Type and size. (a) Single-trip inside containers. (b) The maximum capacity of containers in this class shall not exceed one liter (61.0 cubic inches). The maximum...

  11. 49 CFR 178.33b-2 - Type and size.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Specifications for Inside Containers, and Linings § 178.33b-2 Type and size. (a) Single-trip inside containers. (b) The maximum capacity of containers in this class shall not exceed one liter (61.0 cubic inches). The maximum...

  12. 49 CFR 178.33b-2 - Type and size.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Specifications for Inside Containers, and Linings § 178.33b-2 Type and size. (a) Single-trip inside containers. (b) The maximum capacity of containers in this class shall not exceed one liter (61.0 cubic inches). The maximum...

  13. 49 CFR 178.33b-2 - Type and size.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Specifications for Inside Containers, and Linings § 178.33b-2 Type and size. (a) Single-trip inside containers. (b) The maximum capacity of containers in this class shall not exceed one liter (61.0 cubic inches). The maximum...

  14. Permanent magnet with MgB2 bulk superconductor

    NASA Astrophysics Data System (ADS)

    Yamamoto, Akiyasu; Ishihara, Atsushi; Tomita, Masaru; Kishio, Kohji

    2014-07-01

    Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2 K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB2) makes an excellent permanent bulk magnet, maintaining 3 T at 20 K for 1 week with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in this magnet is uniformly distributed, as for single-crystalline neodymium-iron-boron. Magnetic hysteresis loop of the MgB2 permanent bulk magnet was detrmined. Because MgB2 is a simple-binary-line compound that does not contain rare-earth metals, polycrystalline bulk material can be industrially fabricated at low cost and with high yield to serve as strong magnets that are compatible with conventional compact cryocoolers, making MgB2 bulks promising for the next generation of Tesla-class permanent-magnet applications.

  15. Hexagonal OsB2: Sintering, microstructure and mechanical properties

    DOE PAGESBeta

    Xie, Zhilin; Lugovy, Mykola; Orlovskaya, Nina; Graule, Thomas; Kuebler, Jakob; Mueller, Martin; Gao, Huili; Radovic, Miladin; Cullen, David A.

    2015-02-07

    In this study, the metastable high pressure ReB2-type hexagonal OsB2 bulk ceramics was produced by spark plasma sintering. The phase composition, microstructure, and mechanical behavior of the sintered OsB2 were studied by X-ray diffraction, optical microscopy, TEM, SEM, EDS, and nanoindentation. The produced ceramics was rather porous and contained a mixture of hexagonal (~80 wt.%) and orthorhombic (~20 wt.%) phases as identified by X-ray diffraction and EBSD analysis. Two boron-rich phases, which do not contain Os, were also identified by TEM and SEM/EDS analysis. Nanoindentation measurements yielded a hardness of 31 ± 9 GPa and Young’s modulus of 574 ±more » 112 GPa, indicating that the material is rather hard and very stiff; but, it is very prone to crack formation and propagation, which is indicative of a very brittle nature of this material. Improvements in the sintering regime are required in order to produce dense, homogeneous and single phase hexagonal OsB2 bulk ceramics.« less

  16. Genome Sequence of Enterotoxigenic Escherichia coli Strain B2C.

    PubMed

    Madhavan, T P Vipin; Steen, Jason A; Hugenholtz, Philip; Sakellaris, Harry

    2014-04-10

    Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrheal disease around the globe, causing an estimated 380,000 deaths annually. The disease is caused by a wide variety of strains. Here, we report the genome sequence of ETEC strain B2C, which was isolated from an American soldier in Vietnam.

  17. Semisynthesis of S-desoxybrevetoxin-B2 and brevetoxin-B2, and assessment of their acute toxicities.

    PubMed

    Selwood, Andrew I; Ginkel, Roel van; Wilkins, Alistair L; Munday, Rex; Ramsdell, John S; Jensen, Dwayne J; Cooney, Janine M; Miles, Christopher O

    2008-04-01

    Brevetoxins are neurotoxins associated with blooms of marine algae such as Karenia brevis and can accumulate in the marine food chain, causing intoxication of marine animals and people consuming seafood. Brevetoxin-B2 ( 5) is a toxic metabolite produced in shellfish exposed to algae that contain brevetoxin-B ( 1). S-Desoxybrevetoxin-B2 ( 4) has been proposed as a cometabolite produced during this transformation, and while LC-MS analyses suggest its presence in shellfish, it has not yet been isolated and characterized. Studies on these materials are severely constrained by the difficulty of obtaining and purifying them from natural sources. We have developed a convenient one-pot conversion of commercially available brevetoxin-B ( 1) into S-desoxybrevetoxin-B2 ( 4), and a simple method for converting 4 into brevetoxin-B2 ( 5). Full NMR and mass-spectral characterization of 4 and 5 confirmed their structures and showed that the ratio of diastereoisomers in the synthetic 4 and 5 was similar to that observed in naturally contaminated shellfish. The LD 50 values for 4, 5, and dihydrobrevetoxin-B ( 6) by ip injection in mice were 211, 400, and 250 microg/kg, respectively. The methodology for synthesis of brevetoxin metabolites should greatly facilitate toxicological, biochemical and immunochemical studies of these substances, as well as the production of analytical standards. PMID:18335998

  18. Precipitation method for barium metaborate (BaB2O4) synthesis from borax solution

    NASA Astrophysics Data System (ADS)

    Akşener, Eymen; Figen, Aysel Kantürk; Pişkin, Sabriye

    2013-12-01

    In this study, barium metaborate (BaB2O4, BMB) synthesis from the borax solution was carried out. BMB currently is used in production of ceramic glazes, luminophors, oxide cathodes as well as additives to pigments for aqueous emulsion paints and also β-BaB2O4 single crystals are the best candidate for fabrication of solid-state UV lasers operating at a wavelength of 200 nm due to excellent nonlinear optical properties. In the present study, synthesis was carried out from the borax solution (Na2B4O7ṡ10H2O, BDH) and barium chloride (BaCI2ṡ2H2O, Ba) in the glass-batch reactor with stirring. The effect of, times (5-15 min), molar ratio [stoich.ration (1.0:2.0), 1.25:2.0, 1.5:2.0, 2.5:2:0, 3.0:2.0, 3.5:2.0,4.0:2.0, 5.0:2.0] and also crystallization time (2-6 hour) on the BMB yield (%) was investigated at 80 °C reaction temperature. It is found that, BMB precipitation synthesis with 90 % yield can be performed from 0.50 molar ration (BDH:Ba), under 80 °C, 15 minute, and 6 hours crystallization time. The structural properties of BMB powders were characterized by using XRD, FT-IR and DTA-TG instrumental analysis technique.

  19. K-shell photoionization of Li, Be+ and B2+

    NASA Astrophysics Data System (ADS)

    Li, Jun; Liu, Jian Dang; Zhang, Song Bin; Ye, Bang Jiao

    2016-06-01

    K-shell photoionization (PI) of Li, Be+ and B2+ from ground state 1s22s2Se have been studied by using the R-matrix method with pseudostates. The K-shell PI process is featured with the contributions from the core-excited metastable states or dominated by the Auger states 2Po. The resonant parameters of the Auger states 2Po and the PI cross-sections have been calculated and compared with the available experimental and theoretical works. Our results agree very well with that of the published works. It is worth noting that compared with previous theoretical calculations, our results of B2+ show better agreements with the latest high-resolution advanced light source measurements [A. Müller et al., J. Phys. B 43 (2010) 135602].

  20. Oxidation of ZrB2-SiC

    NASA Technical Reports Server (NTRS)

    Opila, Elizabeth J.; Halbig, Michael C.

    2001-01-01

    In this paper the oxidation behavior of ZrB2-20 vol% SiC is examined. Samples were exposed in stagnant air in a zirconia furnace (Deltech, Inc.) at temperatures of 1327, 1627, and 1927 C for ten ten-minute cycles. Samples were removed from the furnace after one, five, and ten cycles. Oxidized material was characterized by mass change when possible, x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Oxidation kinetics, oxide scale development, and matrix recession were monitored as a function of time and temperature. Oxidation and recession rates of ZrB2 - 20 vol% SiC were adequately modeled by parabolic kinetics. Oxidation rates of this material are rapid, allowing only very short-term application in air or other high oxygen partial pressure environments.

  1. High-resolution photoemission study of MgB2.

    PubMed

    Takahashi, T; Sato, T; Souma, S; Muranaka, T; Akimitsu, J

    2001-05-21

    We have performed high-resolution photoemission spectroscopy on MgB2 and observed opening of a superconducting gap with a narrow coherent peak. We found that the superconducting gap is s like with the gap value ( Delta) of 4.5+/-0.3 meV at 15 K. The temperature dependence (15-40 K) of the gap value follows well the BCS form, suggesting that 2Delta/k(B)T(c) at T = 0 is about 3. No pseudogap behavior is observed in the normal state. The present results strongly suggest that MgB2 is categorized into a phonon-mediated BCS superconductor in the weak-coupling regime.

  2. Evidence for two superconducting gaps in MgB2.

    PubMed

    Chen, X K; Konstantinovic, M J; Irwin, J C; Lawrie, D D; Franck, J P

    2001-10-01

    We have measured the Raman spectra of polycrystalline MgB2 from 25 to 1200 cm(-1). A superconductivity-induced redistribution in the electronic Raman continuum was observed. Two pair-breaking peaks appear in the spectra, suggesting the presence of two superconducting gaps. The measured spectra were analyzed using a quasi-two-dimensional model in which two s-wave superconducting gaps open on two sheets of Fermi surface. For the gap values we have obtained Delta(1) = 22 cm(-1) ( 2.7 meV) and Delta(2) = 50 cm(-1) ( 6.2 meV). Our results suggest that a conventional phonon-mediated pairing mechanism occurs in the planar boron sigma bands and is responsible for the superconductivity of MgB2.

  3. Heterostructures of Bi-4334 and MgB2 superconductors

    NASA Astrophysics Data System (ADS)

    Padmavathi, M.; Singh, R.

    2016-05-01

    We report the studies on hetero structures of Bi-4334 and MgB2 superconductors. The two superconductors were arranged in the form of bulk multilayers using hydraulic pressure system. X-ray diffraction pattern and dc magnetization studies confirm the presence of both superconducting phases in this try-layer hetero structured sample. The d.c magnetization shows the superconducting onset at 77K and 39K for Bi-4334 and MgB2 phases respectively. Critical current density (Jc) is calculated from hysteresis loop of the sample in both in-plane field and out of plane field configurations. Inverted anisotropy in Jc is observed due to enhancement of ab-plane properties because of multilayer growth process. Morphology of the samples at surface and interface of two superconducting layers is discussed in view of Field emission scanning electron microscopy.

  4. Preparation and characterisation of Os doped MgB2

    NASA Astrophysics Data System (ADS)

    Grivel, J.-C.; Namazkar, S.; Alexiou, A.; Holte, O. J.

    2014-12-01

    Polycrystalline samples with Mg1-xOsxB2.04 nominal stoichiometry were made by reacting elemental powders at 800 °C under argon atmosphere. Based on XRD diffraction patterns, EDS analysis and magnetisation measurements, it is found that Os can replace up to about 1 at.% Mg in the MgB2 lattice. Beyond this doping level, unreacted Os and Mg-rich Mg-Os impurity phases are formed. The a-axis parameter contracts upon doping while the superconducting transition temperature decreases at a rate of 2.1 K/at.% Os substitution. At 10 K, Os doping induces an improvement of the normalised critical current density under applied magnetic fields in excess of 0.5 T, indicating a modest enhancement of flux pinning in this range.

  5. Active Protection of an MgB2 Test Coil

    PubMed Central

    Park, Dong Keun; Hahn, Seungyong; Bascuñán, Juan; Iwasa, Yukikazu

    2011-01-01

    This paper presents results of a study, experimental and computational, of a detect-and-activate-the-heater protection technique applied to a magnesium diboride (MgB2) test coil operated in semi-persistent mode. The test coil with a winding ID of 25 cm and wound with ~500-m long reacted MgB2 wire was operated at 4.2 K immersed in a bath of liquid helium. In this active technique, upon the initiation of a “hot spot” of a length ~10 cm, induced by a “quench heater,” a “protection heater” (PH) of ~600-cm long planted within the test coil is activated. The normal zone created by the PH is large enough to absorb the test coil’s entire initial stored energy and still keeps the peak temperature within the winding below ~260 K. PMID:22081754

  6. The Bi based superconductors doped with B 2O 3

    NASA Astrophysics Data System (ADS)

    Veverka, M.; Smrčková, O.; Sýkorová, D.; Vašek, P.

    1997-04-01

    The influence of the addition of B2O3on the properties of the oxide ceramic materials Bi-Pb-Sr-Ca-Cu-O was investigated. The samples with nominal com-posi-tion BiaPbbBcSr2Ca2Cu3Ox(a = 0.8-1.6,b = 0.06-0.26,c = 0.05-1.0) were prepared and studied by the measurement of the temperature dependence of the electrical resistivity and critical current density. The addition of a small amount of B2O3(c = 0.05,a = 1.8,b = 0.26) had positive influence on the critical current density. On the other hand, a high content of boron (c > 0.6,b = 0.26,a + b = 1.8) reversed the superconductor to an insulator.

  7. Stability of MnB2 with AlB2-type structure revealed by first-principles calculations and experiments

    NASA Astrophysics Data System (ADS)

    Gou, Huiyang; Steinle-Neumann, Gerd; Bykova, Elena; Nakajima, Yoichi; Miyajima, Nobuyoshi; Li, Yuan; Ovsyannikov, Sergey V.; Dubrovinsky, Leonid S.; Dubrovinskaia, Natalia

    2013-02-01

    MnB2 with the ReB2-type structure has been theoretically predicted to be a superhard material which could be synthesized at ambient pressure. However, this phase has not been observed experimentally to date. In the present work, we show that even applying moderate pressure does not facilitate the formation of ReB2-structured MnB2. Our high-pressure high-temperature experiments resulted in the synthesis of single crystals of MnB2 with the previously known AlB2-type structure. This is at odds with results from density functional theory-based calculations using the generalized gradient approximation (GGA). The discrepancy with the computational prediction was reconciled by including on-site repulsion (GGA + U), which found the anti-ferromagnetically ordered AlB2-type structure energetically favored over the ReB2-structure for MnB2.

  8. Superconductivity in MgB2 irradiated with energetic protons

    NASA Astrophysics Data System (ADS)

    Sandu, Viorel; Craciun, Liviu; Ionescu, Alina Marinela; Aldica, Gheorghe; Miu, Lucica; Kuncser, Andrei

    2016-09-01

    A series of MgB2 samples were irradiated with protons of 11.3 and 13.2 MeV. Magnetization data shows an insignificant reduction of the critical temperatures but a continuous decrease of the Meissner fraction with increasing fluence or energy. All samples show a consistent improvement of the critical current density compared to the virgin sample and an increase of the pinning energy at high fields as resulted from relaxation data.

  9. Modernization of B-2 Data, Video, and Control Systems Infrastructure

    NASA Technical Reports Server (NTRS)

    Cmar, Mark D.; Maloney, Christian T.; Butala, Vishal D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Spacecraft Propulsion Research Facility, commonly referred to as B-2, is NASA s third largest thermal-vacuum facility with propellant systems capability. B-2 has completed a modernization effort of its facility legacy data, video and control systems infrastructure to accommodate modern integrated testing and Information Technology (IT) Security requirements. Integrated systems tests have been conducted to demonstrate the new data, video and control systems functionality and capability. Discrete analog signal conditioners have been replaced by new programmable, signal processing hardware that is integrated with the data system. This integration supports automated calibration and verification of the analog subsystem. Modern measurement systems analysis (MSA) tools are being developed to help verify system health and measurement integrity. Legacy hard wired digital data systems have been replaced by distributed Fibre Channel (FC) network connected digitizers where high speed sampling rates have increased to 256,000 samples per second. Several analog video cameras have been replaced by digital image and storage systems. Hard-wired analog control systems have been replaced by Programmable Logic Controllers (PLC), fiber optic networks (FON) infrastructure and human machine interface (HMI) operator screens. New modern IT Security procedures and schemes have been employed to control data access and process control flows. Due to the nature of testing possible at B-2, flexibility and configurability of systems has been central to the architecture during modernization.

  10. Biotechnological production of vitamin B2-enriched bread and pasta.

    PubMed

    Capozzi, Vittorio; Menga, Valeria; Digesu, Anna Maria; De Vita, Pasquale; van Sinderen, Douwe; Cattivelli, Luigi; Fares, Clara; Spano, Giuseppe

    2011-07-27

    Lactic acid bacteria (LAB) were obtained from durum wheat flour samples and screened for roseoflavin-resistant variants to isolate natural riboflavin-overproducing strains. Two riboflavin-overproducing strains of Lactobacillus plantarum isolated as described above were used for the preparation of bread (by means of sourdough fermentation) and pasta (using a prefermentation step) to enhance their vitamin B2 content. Pasta was produced from a monovarietal semolina obtained from the durum wheat cultivar PR22D89 and, for experimental purposes, from a commercial remilled semolina. Several samples were collected during the pasta-making process (dough, extruded, dried, and cooked pasta) and tested for their riboflavin content by a high-performance liquid chromatography method. The applied approaches resulted in a considerable increase of vitamin B2 content (about 2- and 3-fold increases in pasta and bread, respectively), thus representing a convenient and efficient food-grade biotechnological application for the production of vitamin B2-enriched bread and pasta. This methodology may be extended to a wide range of cereal-based foods, feed, and beverages. Additionally, this work exemplifies the production of a functional food by a novel biotechnological exploitation of LAB in pasta-making. PMID:21678896

  11. Fine-Filament MgB2 Superconductor Wire

    NASA Technical Reports Server (NTRS)

    Cantu, Sherrie

    2015-01-01

    Hyper Tech Research, Inc., has developed fine-filament magnesium diboride (MgB2) superconductor wire for motors and generators used in turboelectric aircraft propulsion systems. In Phase I of the project, Hyper Tech demonstrated that MgB2 multifilament wires (<10 micrometers) could reduce alternating current (AC) losses that occur due to hysteresis, eddy currents, and coupling losses. The company refined a manufacturing method that incorporates a magnesium-infiltration process and provides a tenfold enhancement in critical current density over wire made by a conventional method involving magnesium-boron powder mixtures. Hyper Tech also improved its wire-drawing capability to fabricate fine multifilament strands. In Phase II, the company developed, manufactured, and tested the wire for superconductor and engineering current density and AC losses. Hyper Tech also fabricated MgB2 rotor coil packs for a superconducting generator. The ultimate goal is to enable low-cost, round, lightweight, low-AC-loss superconductors for motor and generator stator coils operating at 25 K in next-generation turboelectric aircraft propulsion systems.

  12. Modernization of B-2 Data, Video, and Control Systems Infrastructure

    NASA Technical Reports Server (NTRS)

    Cmar, Mark D.; Maloney, Christian T.; Butala, Vishal D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Spacecraft Propulsion Research Facility, commonly referred to as B-2, is NASA's third largest thermal-vacuum facility with propellant systems capability. B-2 has completed a modernization effort of its facility legacy data, video and control systems infrastructure to accommodate modern integrated testing and Information Technology (IT) Security requirements. Integrated systems tests have been conducted to demonstrate the new data, video and control systems functionality and capability. Discrete analog signal conditioners have been replaced by new programmable, signal processing hardware that is integrated with the data system. This integration supports automated calibration and verification of the analog subsystem. Modern measurement systems analysis (MSA) tools are being developed to help verify system health and measurement integrity. Legacy hard wired digital data systems have been replaced by distributed Fibre Channel (FC) network connected digitizers where high speed sampling rates have increased to 256,000 samples per second. Several analog video cameras have been replaced by digital image and storage systems. Hard-wired analog control systems have been replaced by Programmable Logic Controllers (PLC), fiber optic networks (FON) infrastructure and human machine interface (HMI) operator screens. New modern IT Security procedures and schemes have been employed to control data access and process control flows. Due to the nature of testing possible at B-2, flexibility and configurability of systems has been central to the architecture during modernization.

  13. Agent-based services for B2B electronic commerce

    NASA Astrophysics Data System (ADS)

    Fong, Elizabeth; Ivezic, Nenad; Rhodes, Tom; Peng, Yun

    2000-12-01

    The potential of agent-based systems has not been realized yet, in part, because of the lack of understanding of how the agent technology supports industrial needs and emerging standards. The area of business-to-business electronic commerce (b2b e-commerce) is one of the most rapidly developing sectors of industry with huge impact on manufacturing practices. In this paper, we investigate the current state of agent technology and the feasibility of applying agent-based computing to b2b e-commerce in the circuit board manufacturing sector. We identify critical tasks and opportunities in the b2b e-commerce area where agent-based services can best be deployed. We describe an implemented agent-based prototype system to facilitate the bidding process for printed circuit board manufacturing and assembly. These activities are taking place within the Internet Commerce for Manufacturing (ICM) project, the NIST- sponsored project working with industry to create an environment where small manufacturers of mechanical and electronic components may participate competitively in virtual enterprises that manufacture printed circuit assemblies.

  14. Strength anomaly in B2 FeAl single crystals

    SciTech Connect

    Yoshimi, K.; Hanada, S.; Yoo, M.H.; Matsumoto, N.

    1994-12-31

    Strength and deformation microstructure of B2 Fe-39 and 48%Al single crystals (composition given in atomic percent), which were fully annealed to remove frozen-in vacancies, have been investigated at temperatures between room temperature and 1073K. The hardness of as-homogenized Fe-48Al is higher than that of as-homogenized Fe-39Al while after additional annealing at 698K the hardness of Fe-48Al becomes lower than that of Fe-39Al. Fe-39Al single crystals slowly cooled after homogenizing at a high temperature were deformed in compression as a function of temperature and crystal orientation. A peak of yield strength appears around 0.5T{sub m} (T{sub m} = melting temperature). The orientation dependence of the critical resolved shear stress does not obey Schmid`s law even at room temperature and is quite different from that of b.c.c. metals and B2 intermetallics at low temperatures. At the peak temperature slip transition from <111>-type to <001>-type is found to occur macroscopically and microscopically, while it is observed in TEM that some of the [111] dislocations decompose into [101] and [010] on the (1096I) plane below the peak temperature. The physical sources for the positive temperature dependence of yield stress of B2 FeAl are discussed based on the obtained results.

  15. NUCLEAR REACTOR

    DOEpatents

    Treshow, M.

    1961-09-01

    A boiling-water nuclear reactor is described wherein control is effected by varying the moderator-to-fuel ratio in the reactor core. This is accomplished by providing control tubes containing a liquid control moderator in the reactor core and providing means for varying the amount of control moderatcr within the control tubes.

  16. NEUTRONIC REACTOR

    DOEpatents

    Daniels, F.

    1959-10-27

    A reactor in which at least a portion of the moderator is in the form of movable refractory balls is described. In addition to their moderating capacity, these balls may serve as carriers for fissionable material or fertile material, or may serve in a coolant capacity to remove heat from the reactor. A pneumatic system is used to circulate the balls through the reactor.

  17. Sintering process and critical current density of low activation Mg11B2 superconductors from low temperature to high temperature

    NASA Astrophysics Data System (ADS)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, Md; Somer, M.

    2016-08-01

    As the "low activation" superconductor, Mg11B2 has a potential application in superconducting coils for fusion reactor. In present work, the sintering process and critical current density of low activation Mg11B2 superconductors were systemically studied from low temperature to high temperature. It was found that the Jc and Hirr values of Mg11B2 bulks in present work are both obviously higher than that of those samples prepared in previous studies. Furthermore, the low-temperature sintered samples exhibit better Jc performance at high fields than the high-temperature sintered samples, due to strong grain boundaries pinning. On the other hand, the high-temperature sintered samples have higher Jc at low fields compared to low-temperature sintered samples, mainly owing to their better crystallinity and grain connectivity. The highest Jc value (2.20 ×105 A cm-2 at 20 K, self-field) is obtained in the Mg11B2 sample sintered at 850 °C for 45 min.

  18. Fractographic Analysis of HfB2-SiC and ZrB2-SiC Composites

    NASA Technical Reports Server (NTRS)

    Mecholsky, J.J., Jr.; Ellerby, D. T.; Johnson, S. M.; Stackpoole, M. M.; Loehman, R. E.; Arnold, Jim (Technical Monitor)

    2001-01-01

    Hafnium diboride-silicon carbide and zirconium diboride-silicon carbide composites are potential materials for high temperature leading edge applications on reusable launch vehicles. In order to establish material constants necessary for evaluation of in-situ fracture, bars fractured in four point flexure were examined using fractographic principles. The fracture toughness was determined from measurements of the critical crack sizes and the strength values, and the crack branching constants were established to use in forensic fractography of materials for future flight applications. The fracture toughnesses range from about 13 MPam (sup 1/2) at room temperature to about 6 MPam (sup 1/2) at 1400 C for ZrB2-SiC composites and from about 11 MPam (sup 1/2) at room temperature to about 4 MPam (sup 1/2) at 1400 C for HfB2-SiC composites.

  19. Research reactors

    SciTech Connect

    Tonneson, L.C.; Fox, G.J.

    1996-04-01

    There are currently 284 research reactors in operation, and 12 under construction around the world. Of the operating reactors, nearly two-thirds are used exclusively for research, and the rest for a variety of purposes, including training, testing, and critical assembly. For more than 50 years, research reactor programs have contributed greatly to the scientific and educational communities. Today, six of the world`s research reactors are being shut down, three of which are in the USA. With government budget constraints and the growing proliferation concerns surrounding the use of highly enriched uranium in some of these reactors, the future of nuclear research could be impacted.

  20. CONVECTION REACTOR

    DOEpatents

    Hammond, R.P.; King, L.D.P.

    1960-03-22

    An homogeneous nuclear power reactor utilizing convection circulation of the liquid fuel is proposed. The reactor has an internal heat exchanger looated in the same pressure vessel as the critical assembly, thereby eliminating necessity for handling the hot liquid fuel outside the reactor pressure vessel during normal operation. The liquid fuel used in this reactor eliminates the necessity for extensive radiolytic gas rocombination apparatus, and the reactor is resiliently pressurized and, without any movable mechanical apparatus, automatically regulates itself to the condition of criticality during moderate variations in temperature snd pressure and shuts itself down as the pressure exceeds a predetermined safe operating value.

  1. Synthesis of ZrB2 and ZrB2-SiC Powders Using a Sucrose-Containing System.

    PubMed

    Wang, Tingyu; Zhang, Yun; Li, Junping; Zhao, Bin; Li, Ruixing; Yin, Shu; Feng, Zhihai; Sato, Tsugio; Cai, Hongnian

    2015-09-01

    ZrB2 and ZrB2-SiC powders are synthesized by a sol-gel method from zirconium n-propoxide, tetraethyl orthosilicate (only for ZrB2-SiC), boric acid, and sucrose. After reduction at 1550 degrees C, both ZrB2 and ZrB2-SiC are unconsolidated, soft gray powders. The ZrB2-SiC particles have an equiaxed shape with a diameter of about 800 nm and a uniform size distribution. The SiC may be very finely distributed, because we barely find SiC among ZrB2 particles when using energy dispersive X-ray spectroscopy (EDS), although both ZrB2 and SiC are identified by X-ray diffractometry (XRD). PMID:26716344

  2. A MgB2 superferric racetrack magnet

    NASA Astrophysics Data System (ADS)

    Musenich, R.; Sorbi, M.; Tavilla, G.; Volpini, G.; Marabotto, R.; Modica, M.; Nardelli, D.

    2008-10-01

    A magnesium diboride, cryogen-free, H-dipole magnet with cold iron yoke was constructed and tested. The racetrack coil, 48 cm long, was wound with 350 m of nickel-clad, copper-MgB2 tape. The iron yoke forms a 2.6 cm gap. The magnet was connected to a cryocooler and tested at different temperatures ranging between 8.5 and 24 K. The maximum current, 263 A, was reached, without training, at 8.5 K. The corresponding field in the gap was 2.35 T.

  3. Superconductivity in MgB2: clean or dirty?

    PubMed

    Mazin, I I; Andersen, O K; Jepsen, O; Dolgov, O V; Kortus, J; Golubov, A A; Kuz'menko, A B; Van Der Marel, D

    2002-09-01

    A large number of experimental facts and theoretical arguments favor a two-gap model for superconductivity in MgB2. However, this model predicts strong suppression of the critical temperature by interband impurity scattering and, presumably, a strong correlation between the critical temperature and the residual resistivity. No such correlation has been observed. We argue that this fact can be understood if the band disparity of the electronic structure is taken into account, not only in the superconducting state, but also in normal transport.

  4. Two-band superconductivity in MgB2.

    PubMed

    Iavarone, M; Karapetrov, G; Koshelev, A E; Kwok, W K; Crabtree, G W; Hinks, D G; Kang, W N; Choi, Eun-Mi; Kim, Hyun Jung; Kim, Hyeong-Jin; Lee, S I

    2002-10-28

    The study of the anisotropic superconductor MgB2 using a combination of scanning tunneling microscopy and spectroscopy reveals two distinct energy gaps at Delta(1)=2.3 meV and Delta(2)=7.1 meV at 4.2 K. Different spectral weights of the partial superconducting density of states are a reflection of different tunneling directions in this multiband system. Temperature evolution of the tunneling spectra follows the BCS scenario [Phys. Rev. Lett. 3, 552 (1959)

  5. Phonon dispersion and lifetimes in MgB2.

    PubMed

    Shukla, Abhay; Calandra, Matteo; D'Astuto, Matteo; Lazzeri, Michele; Mauri, Francesco; Bellin, Christophe; Krisch, Michael; Karpinski, J; Kazakov, S M; Jun, J; Daghero, D; Parlinski, K

    2003-03-01

    We measure phonon dispersion and linewidth in a single crystal of MgB2 along the Gamma-A, Gamma-M, and A-L directions using inelastic x-ray scattering. We use density functional theory to compute the effect of both electron-phonon coupling and anharmonicity on the linewidth, obtaining excellent agreement with experiment. Anomalous broadening of the E(2g) phonon mode is found all along Gamma-A. The dominant contribution to the linewidth is always the electron-phonon coupling.

  6. Ideal tensile strength of B2 transition-metal aluminides

    NASA Astrophysics Data System (ADS)

    Li, Tianshu; Morris, J. W., Jr.; Chrzan, D. C.

    2004-08-01

    The ideal tensile strengths of the B2 -type (CsCl) transition-metal aluminides FeAl , CoAl , and NiAl have been investigated using an ab initio electronic structure total energy method. The three materials exhibit dissimilar mechanical behaviors under the simulated ideal tensile tests along [001], [110], and [111] directions. FeAl is weakest in tension along [001] whereas CoAl and NiAl are strongest in the same direction. The weakness of FeAl along [001] direction is attributed to the instability introduced by the filling of antibonding d states.

  7. Analysis of the Defect Structure of B2 Feal Alloys

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo; Ferrante, John; Noebe, Ronald D.; Amador, Carlos

    1995-01-01

    The Bozzolo, Ferrante and Smith (BFS) method for alloys is applied to the study of the defect structure of B2 FeAI alloys. First-principles Linear Muffin Tin Orbital calculations are used to determine the input parameters to the BFS method used in this work. The calculations successfully determine the phase field of the B2 structure, as well as the dependence with composition of the lattice parameter. Finally, the method is used to perform 'static' simulations where instead of determining the ground state configuration of the alloy with a certain concentration of vacancies, a large number of candidate ordered structures are studied and compared, in order to determine not only the lowest energy configurations but other possible metastable states as well. The results provide a description of the defect structure consistent with available experimental data. The simplicity of the BFS method also allows for a simple explanation of some of the essential features found in the concentration dependence of the heat of formation, lattice parameter and the defect structure.

  8. Vortex-flux anomalies in MgB 2 polycrystals

    NASA Astrophysics Data System (ADS)

    Goeckner, H. P.; Claus, H.; Kouvel, J. S.

    2005-02-01

    For two MgB 2 polycrystalline samples prepared differently, magnetic hysteresis loops at 4.2 K revealed some striking magnetization ( M) anomalies at low magnetic fields ( H). In one sample, M drops abruptly by an amount that diminishes to zero as the maximum M, reached just before the drop, is reduced below a critical value (by reducing the slowly cycled H). The remanent magnetization ( Mrem), measured as the temperature ( T) was slowly raised from 4.2 K to Tc (39 K), was seen to decrease very rapidly just above 4.2 K and then remain constant up to ∼20 K, where it starts to descend gradually to zero at Tc. A similar set of anomalies was observed with the second sample, but where the hysteretic drop of M is rapid but not abrupt. However, both samples showed that the vortex-flux component of M remains nearly constant over a range of H just before the rapid drop of M, indicating that the vortices in the sample stay fairly constant in number before many of them exit the sample rapidly. For both MgB 2 samples, this whole set of anomalous properties disappears at temperatures above 5 K, where the slow steady descent of Mrem as T increases to Tc indicates that the size distribution of vortex pinning forces extends up to very high values.

  9. B2FH, the Cosmic Microwave Background and Cosmology*

    NASA Astrophysics Data System (ADS)

    Burbidge, G.

    In this talk I shall start by describing how we set about and carried out the work that led to the publication of Burbidge et al. (1957, hereafter B2FH). I then shall try and relate this work and the circumstances that surrounded it to the larger problem of the origin and formation of the universe. Here it is necessary to look back at the way that ideas developed and how, in many situations, astronomers went astray. Of course this is a personal view, though I very strongly believe that if he were still here, it is the approach that Fred Hoyle would take. I start by describing the problems originally encountered by Gamow and his associates in trying to decide where the helium was made. This leads me to a modern discussion of the origin of 2D, 3He, 4He and 7Li, originally described by B2FH as due to the x-process. While it is generally argued, following Gamow, Alpher, and Herman, that these isotopes were synthesised in a big bang I shall show that it is equally likely that these isotopes were made in active galactic nuclei, as was the cosmic microwave background (CMB), in a cyclic universe model. The key piece of observational evidence is that the amount of energy released in the conversion of hydrogen to helium in the universe is very close to the energy carried by the CMB, namely ~4.5 × 10-13 erg cm-3.

  10. Characterization of MgB2 Superconducting Hot Electron Bolometers

    NASA Technical Reports Server (NTRS)

    Cunnane, D.; Kawamura, J. H.; Wolak, M. A.; Acharya, N.; Tan, T.; Xi, X. X.; Karasik, B. S.

    2014-01-01

    Hot-Electron Bolometer (HEB) mixers have proven to be the best tool for high-resolution spectroscopy at the Terahertz frequencies. However, the current state of the art NbN mixers suffer from a small intermediate frequency (IF) bandwidth as well as a low operating temperature. MgB2 is a promising material for HEB mixer technology in view of its high critical temperature and fast thermal relaxation allowing for a large IF bandwidth. In this work, we have fabricated and characterized thin-film (approximately 15 nanometers) MgB2-based spiral antenna-coupled HEB mixers on SiC substrate. We achieved the IF bandwidth greater than 8 gigahertz at 25 degrees Kelvin and the device noise temperature less than 4000 degrees Kelvin at 9 degrees Kelvin using a 600 gigahertz source. Using temperature dependencies of the radiation power dissipated in the device we have identified the optical loss in the integrated microantenna responsible as a cause of the limited sensitivity of the current mixer devices. From the analysis of the current-voltage (IV) characteristics, we have derived the effective thermal conductance of the mixer device and estimated the required local oscillator power in an optimized device to be approximately 1 microwatts.

  11. Low-noise THz MgB2 Josephson mixer

    NASA Astrophysics Data System (ADS)

    Cunnane, Daniel; Kawamura, Jonathan H.; Acharya, Narendra; Wolak, Matthäus A.; Xi, X. X.; Karasik, Boris S.

    2016-09-01

    The potential applications for high frequency operation of the Josephson effect in MgB2 include THz mixers, direct detectors, and digital circuits. Here we report on MgB2 weak links which exhibit the Josephson behavior up to almost 2 THz and using them for low-noise heterodyne detection of THz radiation. The devices are made from epitaxial film grown in the c-axis direction by the hybrid physical-chemical vapor deposition method. The current in the junctions travels parallel to the surface of the film, thus making possible a large contribution of the quasi-two-dimensional σ-gap in transport across the weak link. These devices are connected to a planar spiral antenna with a dielectric substrate lens to facilitate coupling to free-space radiation for use as a detector. The IcRn product of the junction is 5.25 mV, giving confirmation of a large gap parameter. The sensitivity of the mixer was measured from 0.6 THz to 1.9 THz. At a bath temperature of over 20 K, a mixer noise temperature less than 2000 K (DSB) was measured near 0.6 THz.

  12. Multilayer MgB2 superconducting quantum interference filter magnetometers

    NASA Astrophysics Data System (ADS)

    Galan, Elias; Melbourne, Thomas; Davidson, Bruce A.; Xi, X. X.; Chen, Ke

    2016-04-01

    We report two types of all-MgB2 superconductive quantum interference filter (SQIF) magnetometers that can measure absolute magnetic fields with high sensitivity. In one configuration, the SQIFs were made of 20 multilayer nonplanar all-MgB2 superconducting quantum interference devices (SQUIDs) connected in parallel with loop areas ranging in size from 0.4 to 3.6 μm2. These devices are sensitive to magnetic fields parallel to the substrate and show a single antipeak from 3 to 16 K with a maximum transfer function of ˜16 V/T at 3 K and a field noise of ˜110 pT/Hz1/2 above 100 Hz at 10 K. In a second configuration, the SQIFs were made with 16 planar SQUIDs connected in parallel with loop areas ranging in size from 4 μm2 to 25 μm2 and are sensitive to the magnetic fields perpendicular to the substrate. The planar SQIF shows a single antipeak from 10 to 22 K with a maximum transfer function of 7800 V/T at 10 K and a field noise of ˜70 pT/Hz1/2 above 100 Hz at 20 K.

  13. B2H6 PLAD Doped PMOS Device Performance

    SciTech Connect

    Fang, Z.; Miller, T.; Winder, E.; Persing, H.; Arevalo, E.; Gupta, A.; Parrill, T.; Singh, V.; Qin, S.; McTeer, A.

    2006-11-13

    Plasma doping (PLAD) achieves high wafer throughput by directly extracting ions across the plasma sheath. PLAD profiles are typically surface peaked instead of retrograde as obtained from beamline (BL) implant. It may require optimization of PLAD energy and dose in order to match BL doping results. From device optimization point of view, it is necessary to understand the impact of doping parameters to device characteristics. In this paper we present the PMOS device performance with the poly gate and source drain (SD) implants carried out using B2H6 PLAD. The BL control conditions are 2-5 keV 11B+ 4-6x1015 cm-2. Equivalent device performance for p+ poly gate doping is obtained using PLAD with B2H6 / H2. In SD doping using same gas mixture, nearly 50% reduction in SD contact resistance is observed in the PLAD splits. The reduction in SD contact resistance leads to 10-15% increase in device on-current, hence demonstrating the process advantages of using PLAD in addition to having a high wafer throughput.

  14. The phonon-mediated superconductivity in B2C sheet

    NASA Astrophysics Data System (ADS)

    Drzazga, E. A.; Szczȩśniak, R.; Duda, A. M.

    2014-07-01

    The values of the thermodynamic parameters of the superconducting state induced by the electron-phonon interaction in the B2C sheet have been determined. It has been found that the critical temperature (TC) can change in the range from 20.4 K to 13 K for the Coulomb pseudopotential (μ⋆) ranging from 0.1 to 0.2. Generalization of the results for the atomic layer demonstrated that the maximum value of TC is equal to 25 K. Next for the B2C sheet, the order parameter (Δ), the thermodynamic critical field (HC), and the specific heat for the superconducting (CS) state and the normal (CN) state have been calculated. The obtained results show that the dimensionless thermodynamic ratios, RΔ≡2Δ(0)/kBTC, RH≡TCCN(TC)/HC2(0), and RC≡(CS(TC)-CN(TC))/CN(TC), deviate from the predictions of the classical BCS theory. In particular RΔ(μ⋆)∈<3.87,3.79>, RH(μ⋆)∈<0.155,0.157>, and RC(μ⋆)∈<1.67,1.62>. The numerical calculations have been conducted in the framework of the Eliashberg formalism.

  15. 16 CFR Appendix B2 to Part 305 - Upright Freezers With Automatic Defrost

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Upright Freezers With Automatic Defrost B2 Appendix B2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF... (âENERGY LABELING RULEâ) Pt. 305, App. B2 Appendix B2 to Part 305—Upright Freezers With...

  16. 16 CFR Appendix B2 to Part 305 - Upright Freezers With Automatic Defrost

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Upright Freezers With Automatic Defrost B2 Appendix B2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF...) Pt. 305, App. B2 Appendix B2 to Part 305—Upright Freezers With Automatic Defrost Range...

  17. 16 CFR Appendix B2 to Part 305 - Upright Freezers With Automatic Defrost

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 1 2012-01-01 2012-01-01 false Upright Freezers With Automatic Defrost B2 Appendix B2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF...) Pt. 305, App. B2 Appendix B2 to Part 305—Upright Freezers With Automatic Defrost Range...

  18. 16 CFR Appendix B2 to Part 305 - Upright Freezers With Automatic Defrost

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Upright Freezers With Automatic Defrost B2 Appendix B2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF...) Pt. 305, App. B2 Appendix B2 to Part 305—Upright Freezers With Automatic Defrost Range...

  19. 16 CFR Appendix B2 to Part 305 - Upright Freezers With Automatic Defrost

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Upright Freezers With Automatic Defrost B2 Appendix B2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF...) Pt. 305, App. B2 Appendix B2 to Part 305—Upright Freezers With Automatic Defrost Range...

  20. NEUTRONIC REACTOR

    DOEpatents

    Fraas, A.P.; Mills, C.B.

    1961-11-21

    A neutronic reactor in which neutron moderation is achieved primarily in its reflector is described. The reactor structure consists of a cylindrical central "island" of moderator and a spherical moderating reflector spaced therefrom, thereby providing an annular space. An essentially unmoderated liquid fuel is continuously passed through the annular space and undergoes fission while contained therein. The reactor, because of its small size, is particularly adapted for propulsion uses, including the propulsion of aircraft. (AEC)

  1. REACTOR COOLING

    DOEpatents

    Quackenbush, C.F.

    1959-09-29

    A nuclear reactor with provisions for selectively cooling the fuel elements is described. The reactor has a plurality of tubes extending throughout. Cylindrical fuel elements are disposed within the tubes and the coolant flows through the tubes and around the fuel elements. The fuel elements within the central portion of the reactor are provided with roughened surfaces of material. The fuel elements in the end portions of the tubes within the reactor are provlded with low conduction jackets and the fuel elements in the region between the central portion and the end portions are provided with smooth surfaces of high heat conduction material.

  2. 75 FR 11428 - Airworthiness Directives; Airbus Model A300 B2-1C, B2-203, B2K-3C, B4-103, B4-203, B4-2C...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-11

    ... FR 48024). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI... Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant economic impact, positive or... B2-1C, B2-203, B2K- 3C, B4-103, B4-203, B4-2C Airplanes; Model A310 Series Airplanes; and Model...

  3. Semantic ETL into i2b2 with Eureka!

    PubMed Central

    Post, Andrew R.; Krc, Tahsin; Rathod, Himanshu; Agravat, Sanjay; Mansour, Michel; Torian, William; Saltz, Joel H.

    Clinical phenotyping is an emerging research information systems capability. Research uses of electronic health record (EHR) data may require the ability to identify clinical co-morbidities and complications. Such phenotypes may not be represented directly as discrete data elements, but rather as frequency, sequential and temporal patterns in billing and clinical data. These patterns’ complexity suggests the need for a robust yet flexible extract, transform and load (ETL) process that can compute them. This capability should be accessible to investigators with limited ability to engage an IT department in data management. We have developed such a system, Eureka! Clinical Analytics. It extracts data from an Excel spreadsheet, computes a broad set of phenotypes of common interest, and loads both raw and computed data into an i2b2 project. A web-based user interface allows executing and monitoring ETL processes. Eureka! is deployed at our institution and is available for deployment in the cloud. PMID:24303265

  4. Semantic ETL into i2b2 with Eureka!

    PubMed

    Post, Andrew R; Krc, Tahsin; Rathod, Himanshu; Agravat, Sanjay; Mansour, Michel; Torian, William; Saltz, Joel H

    2013-01-01

    Clinical phenotyping is an emerging research information systems capability. Research uses of electronic health record (EHR) data may require the ability to identify clinical co-morbidities and complications. Such phenotypes may not be represented directly as discrete data elements, but rather as frequency, sequential and temporal patterns in billing and clinical data. These patterns' complexity suggests the need for a robust yet flexible extract, transform and load (ETL) process that can compute them. This capability should be accessible to investigators with limited ability to engage an IT department in data management. We have developed such a system, Eureka! Clinical Analytics. It extracts data from an Excel spreadsheet, computes a broad set of phenotypes of common interest, and loads both raw and computed data into an i2b2 project. A web-based user interface allows executing and monitoring ETL processes. Eureka! is deployed at our institution and is available for deployment in the cloud. PMID:24303265

  5. Scanning tunneling spectroscopy in MgB2.

    PubMed

    Karapetrov, G; Iavarone, M; Kwok, W K; Crabtree, G W; Hinks, D G

    2001-05-01

    We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39 K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a smearing parameter gamma. The value of the superconducting gap is 5 meV at 4.2 K, with no experimentally significant variation across the surface of the sample. The temperature dependence of the gap follows the BCS form, fully consistent with phonon-mediated superconductivity in this novel superconductor. The application of a magnetic field induces strong pair breaking as seen in the conductance spectra in fields up to 6 T.

  6. Semantic ETL into i2b2 with Eureka!

    PubMed

    Post, Andrew R; Krc, Tahsin; Rathod, Himanshu; Agravat, Sanjay; Mansour, Michel; Torian, William; Saltz, Joel H

    2013-01-01

    Clinical phenotyping is an emerging research information systems capability. Research uses of electronic health record (EHR) data may require the ability to identify clinical co-morbidities and complications. Such phenotypes may not be represented directly as discrete data elements, but rather as frequency, sequential and temporal patterns in billing and clinical data. These patterns' complexity suggests the need for a robust yet flexible extract, transform and load (ETL) process that can compute them. This capability should be accessible to investigators with limited ability to engage an IT department in data management. We have developed such a system, Eureka! Clinical Analytics. It extracts data from an Excel spreadsheet, computes a broad set of phenotypes of common interest, and loads both raw and computed data into an i2b2 project. A web-based user interface allows executing and monitoring ETL processes. Eureka! is deployed at our institution and is available for deployment in the cloud.

  7. Ionization delocalization and ALCHEMI of B2-ordered alloys

    SciTech Connect

    Anderson, I.M.; Bentley, J.

    1995-06-01

    Purpose of this paper is to demonstrate that the major assumption underlying the ALCHEMI formulation is justified: that the degree of ionization localization of an elemental shell can be accounted for by a linear coefficient; and to introduce a potential method, which would be applicable to B2-ordered alloys, of independently extracting the ratio of coefficients L{sub jk} necessary for delocalization correction. A Cr-doped FeAl alloy and a series of Fe-doped NiAl alloys with 0.25-12 at. % Fe were analyzed. Excellent linearity of the data substantiates the use of linear coefficients to model ionization localization. It was investigated whether the L{sub jk} acquired at a (110) systematics orientation could be accurately applied to ALCHEMI data acquired at (200).

  8. Integrated Product and Process Data for B2B Collaboration

    SciTech Connect

    Kulvatunyou, Boonserm; Ivezic, Nenad; Jones, Albert; Wysk, Richard A.

    2003-09-01

    Collaborative development of engineered products in a business-to-business (B2B) environment will require more than just the selection of components from an on-line catalogue. It will involve the electronic exchange of product, process, and production engineering information during both design and manufacturing. While the state-of-the-practice does include a variety of ways to exchange product data electronically, it does not extend to the exchange of manufacturing process data. The reason is simple; process data is usually tied to specific manufacturing resources. These resources are not known typically at product development time. This paper proposes an approach, called an Integrated Product and Process Data (IPPD), where manufacturing process data is considered during product development. This approach replaces traditional process plans, which are resource specific, with a resource-independent process representation. Such a representation will allow a much wider collaboration among business partners and provide the necessary base for collaborative product development.

  9. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1958-04-22

    A nuclear reactor for isotope production is described. This reactor is designed to provide a maximum thermal neutron flux in a region adjacent to the periphery of the reactor rather than in the center of the reactor. The core of the reactor is generally centrally located with respect tn a surrounding first reflector, constructed of beryllium. The beryllium reflector is surrounded by a second reflector, constructed of graphite, which, in tune, is surrounded by a conventional thermal shield. Water is circulated through the core and the reflector and functions both as a moderator and a coolant. In order to produce a greatsr maximum thermal neutron flux adjacent to the periphery of the reactor rather than in the core, the reactor is designed so tbat the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the materials in the reflector is approximately twice the ratio of neutron scattering cross section to neutron absorption cross section averaged over all of the material of the core of the reactor.

  10. NEUTRONIC REACTOR

    DOEpatents

    Metcalf, H.E.; Johnson, H.W.

    1961-04-01

    BS>A nuclear reactor incorporating fuel rods passing through a moderator and including tubes of a material of higher Thermal conductivity than the fuel in contact with the fuel is described. The tubes extend beyond the active portion of the reactor into contant with a fiuld coolant.

  11. Reactor building

    SciTech Connect

    Hista, J. C.

    1984-09-18

    Reactor building comprising a vessel shaft anchored in a slab which is peripherally locked. This reactor building comprises a confinement enclosure within which are positioned internal structures constituted by an internal structure floor, a vessel shaft, a slab being positioned between the general floor and the internal structure floor, the vesse

  12. Bond deformation paths and electronic instabilities of ultraincompressible transition metal diborides: Case study of OsB2 and IrB2

    NASA Astrophysics Data System (ADS)

    Zhang, R. F.; Legut, D.; Wen, X. D.; Veprek, S.; Rajan, K.; Lookman, T.; Mao, H. K.; Zhao, Y. S.

    2014-09-01

    The energetically most stable orthorhombic structure of OsB2 and IrB2 is dynamically stable for OsB2 but unstable for IrB2. Both diborides have substantially lower shear strength in their easy slip systems than their metal counterparts. This is attributed to an easy sliding facilitated by out-of-plane weakening of metallic Os-Os bonds in OsB2 and by an in-plane bond splitting instability in IrB2. A much higher shear resistance of Os-B and B-B bonds than Os-Os ones is found, suggesting that the strengthened Os-B and B-B bonds are responsible for hardness enhancement in OsB2. In contrast, an in-plane electronic instability in IrB2 limits its strength. The electronic structure of deformed diborides suggests that the electronic instabilities of 5d orbitals are their origin of different bond deformation paths. Neither IrB2 nor OsB2 can be intrinsically superhard.

  13. Oxidation of ZrB2-and HfB2-Based Ultra-High Temperature Ceramics: Effects of Ta Additions

    NASA Technical Reports Server (NTRS)

    Opila, Elizabeth; Levine, Stanley; Lorinez, Jonathan

    2003-01-01

    Several compositions of ZrB2- and HfB2-based Ultra-High Temperature Ceramics (UHTC) were oxidized in stagnant air at 1627 C in ten minute cycles for times up to 100 minutes. These compositions include: ZrB2 - 20v% SiC, HfB2 - 20v% SiC, ZrB2 - 20v% SiC - 20v% TaSi2, ZrB2 - 33v% SiC, HfB2 - 20v% SiC - 20v% TaSi2, and ZrB2 - 20v% SiC - 20v% TaC. The weight change due to oxidation was recorded. The ZrB2 - 20v% SiC - 20v% TaSi2 composition was also oxidized in stagnant air at 1927 C and in an arc jet atmosphere. Samples were analyzed after oxidation by x-ray diffraction, field emission scanning electron microscopy, and energy dispersive spectroscopy to determine the reaction products and to observe the microstructure. The ZrB2 - 20v% SiC - 20v% TaSi2 showed the lowest oxidation rate at 1627 C, but performed poorly under the more extreme tests due to liquid phase formation. Effects of Ta-additions on the oxidation of the diboride-based UHTC are discussed.

  14. Transport simulations of linear plasma generators with the B2.5-Eirene and EMC3-Eirene codes

    DOE PAGESBeta

    Rapp, Juergen; Owen, Larry W.; Bonnin, X.; Caneses, J. F.; Canik, John M.; Corr, Cormac; Lore, J. D.

    2014-12-20

    Linear plasma generators are cost effective facilities to simulate divertor plasma conditions of present and future fusion reactors. For this research, the codes B2.5-Eirene and EMC3-Eirene were extensively used for design studies of the planned Material Plasma Exposure eXperiment (MPEX). Effects on the target plasma of the gas fueling and pumping locations, heating power, device length, magnetic configuration and transport model were studied with B2.5-Eirene. Effects of tilted or vertical targets were calculated with EMC3-Eirene and showed that spreading the incident flux over a larger area leads to lower density, higher temperature and off-axis profile peaking in front of themore » target. In conclusion, the simulations indicate that with sufficient heating power MPEX can reach target plasma conditions that are similar to those expected in the ITER divertor. B2.5-Eirene simulations of the MAGPIE experiment have been carried out in order to establish an additional benchmark with experimental data from a linear device with helicon wave heating.« less

  15. Transport simulations of linear plasma generators with the B2.5-Eirene and EMC3-Eirene codes

    SciTech Connect

    Rapp, Juergen; Owen, Larry W.; Bonnin, X.; Caneses, J. F.; Canik, John M.; Corr, Cormac; Lore, J. D.

    2014-12-20

    Linear plasma generators are cost effective facilities to simulate divertor plasma conditions of present and future fusion reactors. For this research, the codes B2.5-Eirene and EMC3-Eirene were extensively used for design studies of the planned Material Plasma Exposure eXperiment (MPEX). Effects on the target plasma of the gas fueling and pumping locations, heating power, device length, magnetic configuration and transport model were studied with B2.5-Eirene. Effects of tilted or vertical targets were calculated with EMC3-Eirene and showed that spreading the incident flux over a larger area leads to lower density, higher temperature and off-axis profile peaking in front of the target. In conclusion, the simulations indicate that with sufficient heating power MPEX can reach target plasma conditions that are similar to those expected in the ITER divertor. B2.5-Eirene simulations of the MAGPIE experiment have been carried out in order to establish an additional benchmark with experimental data from a linear device with helicon wave heating.

  16. RNAs containing B2 repeated sequences are transcribed in the early stages of mouse embryogenesis.

    PubMed Central

    Vasseur, M; Condamine, H; Duprey, P

    1985-01-01

    An in situ hybridization technique was used to detect RNAs containing B2 sequences in the early mouse embryo. Accumulation of B2 sequences occurs early from the one cell stage. The level of B2 RNA decreases in the late two cell embryo, and then increases at the moment of second cleavage. In the blastocyst, inner cell mass cells contain more B2 transcripts than trophectoderm cells. In 7.5-day embryos the expression of B2 sequences is restricted to ectoderm and mesoderm. At all stages, transcription of the B2+ strand is greater than B2- strand. We detected B2+ RNAs in the nucleus and cytoplasm, whereas B2- RNAs were present only in the nucleus. Images Fig. 1. Fig. 2. Fig. 3. PMID:2411546

  17. Lattice Thermal Conductivity of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2 from Atomistic Simulations

    NASA Technical Reports Server (NTRS)

    Lawson, JOhn W.; Daw, Murray S.; Bauschlicher, Charles W.

    2011-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 are candidate materials for applications in extreme environments because of their high melting point, good mechanical properties and reasonable oxidation resistance. Unlike many ceramics, these materials have high thermal conductivity which can be advantageous, for example, to reduce thermal shock. Recently, we developed Tersoff style interatomic potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current. Results at room temperature and at elevated temperatures will be reported.

  18. Experiences and Future Expectations towards Online Courses--An Empirical Study of the B2C-and B2B-Segments

    ERIC Educational Resources Information Center

    Krämer, Andreas; Böhrs, Sandra

    2016-01-01

    This article explores the future potential for the development of online courses. The findings are based on an empirical study with 3 sample groups: (1) B2C segment in Germany, (2) B2C segment in the United States, and (3) B2B segment (international). In the first step the status quo of the use of e-learning in general and online courses in…

  19. Compact Reactor

    SciTech Connect

    Williams, Pharis E.

    2007-01-30

    Weyl's Gauge Principle of 1929 has been used to establish Weyl's Quantum Principle (WQP) that requires that the Weyl scale factor should be unity. It has been shown that the WQP requires the following: quantum mechanics must be used to determine system states; the electrostatic potential must be non-singular and quantified; interactions between particles with different electric charges (i.e. electron and proton) do not obey Newton's Third Law at sub-nuclear separations, and nuclear particles may be much different than expected using the standard model. The above WQP requirements lead to a potential fusion reactor wherein deuterium nuclei are preferentially fused into helium nuclei. Because the deuterium nuclei are preferentially fused into helium nuclei at temperatures and energies lower than specified by the standard model there is no harmful radiation as a byproduct of this fusion process. Therefore, a reactor using this reaction does not need any shielding to contain such radiation. The energy released from each reaction and the absence of shielding makes the deuterium-plus-deuterium-to-helium (DDH) reactor very compact when compared to other reactors, both fission and fusion types. Moreover, the potential energy output per reactor weight and the absence of harmful radiation makes the DDH reactor an ideal candidate for space power. The logic is summarized by which the WQP requires the above conditions that make the prediction of DDH possible. The details of the DDH reaction will be presented along with the specifics of why the DDH reactor may be made to cause two deuterium nuclei to preferentially fuse to a helium nucleus. The presentation will also indicate the calculations needed to predict the reactor temperature as a function of fuel loading, reactor size, and desired output and will include the progress achieved to date.

  20. NUCLEAR REACTOR

    DOEpatents

    Moore, R.V.; Bowen, J.H.; Dent, K.H.

    1958-12-01

    A heterogeneous, natural uranium fueled, solid moderated, gas cooled reactor is described, in which the fuel elements are in the form of elongated rods and are dlsposed within vertical coolant channels ln the moderator symmetrically arranged as a regular lattice in groups. This reactor employs control rods which operate in vertical channels in the moderator so that each control rod is centered in one of the fuel element groups. The reactor is enclosed in a pressure vessel which ls provided with access holes at the top to facilitate loading and unloadlng of the fuel elements, control rods and control rod driving devices.

  1. Structural investigation in the TiB 2-(Na 2O·B 2O 3·Al 2O 3) system

    NASA Astrophysics Data System (ADS)

    Buixaderas, Elena; Maria Anghel, Elena; Petrescu, Simona; Osiceanu, Petre

    2010-09-01

    Composites in the TiB 2-Na 2O·B 2O 3·Al 2O 3 systems, TiB 2-MBA (MB stands for sodium metaborate and A is Al 2O 3), were prepared by self-propagating high-temperature synthesis (SHS), in simultaneous mode. Selection of these compositions was ruled by the interesting properties of both TiB 2 and double borates of alkali metal and aluminum. The structure of the obtained materials was evaluated by micro-Raman spectroscopy, from room temperature up to 600 °C, and X-ray photoelectron spectroscopy (XPS). Formation of the TiB 2 and TiO 2- xB x phases along with TiO 2 as rutile were identified as titanium speciation in the grain phase embedded in a sodium aluminum borate matrix. Integration of the Raman spectra of the grain phases revealed a TiB 2 content of 16.99% and 23.32% for the two composite investigated 2TiB 2·2MBA and 3TiB 2·5MBA. A constrained-width model for the spectral deconvolution of the high-frequency Raman band was forwarded to calculate the proportion of tetrahedral boron atoms (7.424%) in the blank borate matrix Na 2B 2O 4·Al 2O 3 in solid phase.

  2. Kinetic analysis of MgB2 layer formation in advanced internal magnesium infiltration (AIMI) processed MgB2 wires

    PubMed Central

    Li, G. Z.; Sumption, M. D.; Collings, E. W.

    2015-01-01

    Significantly enhanced critical current density (Jc) for MgB2 superconducting wires can be obtained following the advanced internal Mg infiltration (AIMI) route. But unless suitable precautions are taken, the AIMI-processed MgB2 wires will exhibit incomplete MgB2 layer formation, i.e. reduced superconductor core size and hence suppressed current-carrying capability. Microstructural characterization of AIMI MgB2 wires before and after the heat treatment reveals that the reaction mechanism changes from a “Mg infiltration-reaction” at the beginning of the heat treatment to a “Mg diffusion-reaction” once a dense MgB2 layer is formed. A drastic drop in the Mg transport rate from infiltration to diffusion causes the termination of the MgB2 core growth. To quantify this process, a two-stage kinetic model is built to describe the MgB2 layer formation and growth. The derived kinetic model and the associated experimental observations indicate that fully reacted AIMI-processed MgB2 wires can be achieved following the optimization of B particle size, B powder packing density, MgB2 reaction activation energy and its response to the additions of dopants. PMID:26973431

  3. Damping and modulus measurements in B2 transition metal aluminides

    NASA Technical Reports Server (NTRS)

    Harmouche, M. R.; Wolfenden, A.

    1985-01-01

    The polycrystalline intermetallic alloys FeAl (50.9 to 58.2 percent Fe), NiAl (49.2 to 55.9 percent Ni) and CoAl (48.5 to 52.3 percent Co) have the B2 structure and are of interest for high temperature applications. The PUCOT (piezoelectric ultrasonic composite oscillator technique) has been used to measure mechanical damping or internal friction and Young's modulus has been used as a function of temperature and composition for these materials. The modulus data for six CoAl alloys at temperatures up to 1300 K are presented. Examples are given of the strain amplitude dependence of internal friction for four CoAl alloys. The curves showed the break away phenomenon and are interpreted in terms of a theory dealing with the pinning of dislocation lines and their eventual break away at large strain amplitudes. The dislocation density was calculated to be about 10 to the 8th per sq m. For all the compositions (X1) of CoAl studied, a single equation could be fitted to the data.

  4. Lightweight MgB2 superconducting 10 MW wind generator

    NASA Astrophysics Data System (ADS)

    Marino, I.; Pujana, A.; Sarmiento, G.; Sanz, S.; Merino, J. M.; Tropeano, M.; Sun, J.; Canosa, T.

    2016-02-01

    The offshore wind market demands a higher power rate and more reliable turbines in order to optimize capital and operational costs. The state-of-the-art shows that both geared and direct-drive conventional generators are difficult to scale up to 10 MW and beyond due to their huge size and weight. Superconducting direct-drive wind generators are considered a promising solution to achieve lighter weight machines. This work presents an innovative 10 MW 8.1 rpm direct-drive partial superconducting generator using MgB2 wire for the field coils. It has a warm iron rotor configuration with the superconducting coils working at 20 K while the rotor core and the armature are at ambient temperature. A cooling system based on cryocoolers installed in the rotor extracts the heat from the superconducting coils by conduction. The generator's main parameters are compared against a permanent magnet reference machine, showing a significant weight and size reduction. The 10 MW superconducting generator concept will be experimentally validated with a small-scale magnetic machine, which has innovative components such as superconducting coils, modular cryostats and cooling systems, and will have similar size and characteristics as the 10 MW generator.

  5. A Novel Stable Binary BeB2 phase

    PubMed Central

    Fan, Changzeng; Jin, Ye; Li, Jian; Dong, Xu

    2014-01-01

    Potential crystal structures of BeB2 were explored using ab initio evolutionary simulations. A new phase with a Cmcm space group was uncovered. It was determined that the Cmcm phase is mechanically and dynamically stable and has a lower enthalpy, from ambient pressure up to 13 GPa, than any previously proposed phases, as measured using first-principles calculations. The crystal structure, phonon dispersion, phase transitions, and mechanical and electronic properties of this phase were investigated. It was determined that the Cmcm phase may transform into the phase at pressures higher than 13 GPa. The band structures and density of states reveal that the Cmcm phase is metallic. In addition, the Vickers hardness was calculated using three empirical models. To explain the origin of the hardness, charge density difference maps and a Mulliken population analysis were carried out, which demonstrated that there are strong covalent interactions between B atoms. By analyzing the Crystal Orbital Hamilton Population (COHP) diagrams, it was determined that the total interaction of the Be-B bonds is stronger than that of the B-B bonds, indicating a very complex bonding feature in the new phase. It was predicted that the new Cmcm phase is nearly absent of superconductivity. PMID:25385147

  6. Solute hardening and softening effects in B2 nickel aluminides

    SciTech Connect

    Pike, L.M.; Liu, C.T.; Anderson, I.M.; Chang, Y.A.

    1998-11-01

    The effect of substitutional solute additions including Fe, Mn, and Pd on the hardness of B2-ordered NiAl alloys was investigated. The solid solution hardening behavior of intermetallics is more complex than that of typical metallic solid solutions because of complications arising from the site preference of the solute as well as the effects of the solute on the concentrations of other point defects, e.g., vacancies and anti-site defects. For this reason, care was taken to experimentally establish solute site preferences and point defect concentrations in the NiAl alloys before analyzing the hardness data. By taking these factors into account it was possible to rationalize the observed unusual hardening effects. Three distinct categories of solid solution hardening behavior were encountered. The first was hardening by the solute addition itself. This was observed in the case of Pd additions to Al-poor NiAl. However, when fe or Mn is added to Al-poor NiAl a second category is observed; these elements are seen to soften the material. The third category of behavior is observed when Fe is added to NiAl with a constant Al concentration of 50 at. %. In this case it is vacancies, rather than solute atoms, which harden the material.

  7. The reaction of B 2O 3 with the β-rhombohedral boron (111) surface

    NASA Astrophysics Data System (ADS)

    Wei Cho Foo; Ozcomert, John S.; Trenary, Michael

    1992-02-01

    We have studied the reaction of isotopically pure 10B 2O 3 with the (111) surface of β-rhombohedral boron using temperature-programmed desorption. The 10B 2O 3 was directly deposited on the boron surface from a Knudsen cell operated at 1200 K. The boron crystal contained the natural abundance ratio of the 11B : 10B isotopes of 4:1. The thermal desorption results show a B 2O 3 peak near 1200 K consisting solely of the 10B 2O 3 isotope followed by B 2O 2 and B 2O 3 peaks in the range 1300-1350 K with a B 2O 2: B 2O 3 peak area ratio of about 2:1. The higher temperature B 2O 2 and B 2O 3 desorption peaks follow zero-order desorp kinetics with an activation energy of 554 ± 41 kJmol-1. The higher temperature peaks show substantial incorporation of the 11B isotope from the substrate. The results are consistent with a reaction mechanism in which boron from the substrate first dissolves in the molten B 2O 3 layer and then reacts to form a B 6O suboxide which then decomposes to yield B 2O 3 and B 2O 2. However, we have no direct evidence for the presence of the B 6O suboxide on the surface.

  8. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.

    1960-04-01

    A nuclear reactor is described consisting of blocks of graphite arranged in layers, natural uranium bodies disposed in holes in alternate layers of graphite blocks, and coolant tubes disposed in the layers of graphite blocks which do not contain uranium.

  9. NEUTRONIC REACTOR

    DOEpatents

    Anderson, H.L.

    1960-09-20

    A nuclear reactor is described comprising fissionable material dispersed in graphite blocks, helium filling the voids of the blocks and the spaces therebetween, and means other than the helium in thermal conductive contact with the graphite for removing heat.

  10. Chemical Reactors.

    ERIC Educational Resources Information Center

    Kenney, C. N.

    1980-01-01

    Describes a course, including content, reading list, and presentation on chemical reactors at Cambridge University, England. A brief comparison of chemical engineering education between the United States and England is also given. (JN)

  11. NEUTRONIC REACTOR

    DOEpatents

    Hurwitz, H. Jr.; Brooks, H.; Mannal, C.; Payne, J.H.; Luebke, E.A.

    1959-03-24

    A reactor of the heterogeneous, liquid cooled type is described. This reactor is comprised of a central region of a plurality of vertically disposed elongated tubes surrounded by a region of moderator material. The central region is comprised of a central core surrounded by a reflector region which is surrounded by a fast neutron absorber region, which in turn is surrounded by a slow neutron absorber region. Liquid sodium is used as the primary coolant and circulates through the core which contains the fuel elements. Control of the reactor is accomplished by varying the ability of the reflector region to reflect neutrons back into the core of the reactor. For this purpose the reflector is comprised of moderator and control elements having varying effects on reactivity, the control elements being arranged and actuated by groups to give regulation, shim, and safety control.

  12. NUCLEAR REACTOR

    DOEpatents

    Miller, H.I.; Smith, R.C.

    1958-01-21

    This patent relates to nuclear reactors of the type which use a liquid fuel, such as a solution of uranyl sulfate in ordinary water which acts as the moderator. The reactor is comprised of a spherical vessel having a diameter of about 12 inches substantially surrounded by a reflector of beryllium oxide. Conventionnl control rods and safety rods are operated in slots in the reflector outside the vessel to control the operation of the reactor. An additional means for increasing the safety factor of the reactor by raising the ratio of delayed neutrons to prompt neutrons, is provided and consists of a soluble sulfate salt of beryllium dissolved in the liquid fuel in the proper proportion to obtain the result desired.

  13. REACTOR SHIELD

    DOEpatents

    Wigner, E.P.; Ohlinger, L.E.; Young, G.J.; Weinberg, A.M.

    1959-02-17

    Radiation shield construction is described for a nuclear reactor. The shield is comprised of a plurality of steel plates arranged in parallel spaced relationship within a peripheral shell. Reactor coolant inlet tubes extend at right angles through the plates and baffles are arranged between the plates at right angles thereto and extend between the tubes to create a series of zigzag channels between the plates for the circulation of coolant fluid through the shield. The shield may be divided into two main sections; an inner section adjacent the reactor container and an outer section spaced therefrom. Coolant through the first section may be circulated at a faster rate than coolant circulated through the outer section since the area closest to the reactor container is at a higher temperature and is more radioactive. The two sections may have separate cooling systems to prevent the coolant in the outer section from mixing with the more contaminated coolant in the inner section.

  14. NUCLEAR REACTOR

    DOEpatents

    Sherman, J.; Sharbaugh, J.E.; Fauth, W.L. Jr.; Palladino, N.J.; DeHuff, P.G.

    1962-10-23

    A nuclear reactor incorporating seed and blanket assemblies is designed. Means are provided for obtaining samples of the coolant from the blanket assemblies and for varying the flow of coolant through the blanket assemblies. (AEC)

  15. NEUTRONIC REACTORS

    DOEpatents

    Vernon, H.C.

    1959-01-13

    A neutronic reactor of the heterogeneous, fluid cooled tvpe is described. The reactor is comprised of a pressure vessel containing the moderator and a plurality of vertically disposed channels extending in spaced relationship through the moderator. Fissionable fuel material is placed within the channels in spaced relationship thereto to permit circulation of the coolant fluid. Separate means are provided for cooling the moderator and for circulating a fluid coolant thru the channel elements to cool the fuel material.

  16. NUCLEAR REACTOR

    DOEpatents

    Anderson, C.R.

    1962-07-24

    A fluidized bed nuclear reactor and a method of operating such a reactor are described. In the design means are provided for flowing a liquid moderator upwardly through the center of a bed of pellets of a nentron-fissionable material at such a rate as to obtain particulate fluidization while constraining the lower pontion of the bed into a conical shape. A smooth circulation of particles rising in the center and falling at the outside of the bed is thereby established. (AEC)

  17. NUCLEAR REACTOR

    DOEpatents

    Breden, C.R.; Dietrich, J.R.

    1961-06-20

    A water-soluble non-volatile poison may be introduced into a reactor to nullify excess reactivity. The poison is removed by passing a side stream of the water containing the soluble poison to an evaporation chamber. The vapor phase is returned to the reactor to decrease the concentration of soluble poison and the liquid phase is returned to increase the concentration of soluble poison.

  18. RNA binding by a novel helical fold of b2 protein from wuhan nodavirus mediates the suppression of RNA interference and promotes b2 dimerization.

    PubMed

    Qi, Nan; Cai, Dawei; Qiu, Yang; Xie, Jiazheng; Wang, Zhaowei; Si, Jie; Zhang, Jiamin; Zhou, Xi; Hu, Yuanyang

    2011-09-01

    Wuhan nodavirus (WhNV) is a newly identified member of the Nodaviridae family with a bipartite genome of positive-sense RNAs. A nonstructural protein encoded by subgenomic RNA3 of nodaviruses, B2, serves as a potent RNA silencing suppressor (RSS) by sequestering RNA duplexes. We have previously demonstrated that WhNV B2 blocks RNA silencing in cultured Drosophila cells. However, the molecular mechanism by which WhNV B2 functions remains unknown. Here, we successfully established an RNA silencing system in cells derived from Pieris rapae, a natural host of WhNV, by introducing into these cells double-stranded RNA (dsRNA)-expressing plasmids or chemically synthesized small interfering RNAs (siRNAs). Using this system, we revealed that the WhNV B2 protein inhibited Dicer-mediated dsRNA cleavage and the incorporation of siRNA into the RNA-induced silencing complex (RISC) by sequestering dsRNA and siRNA. Based on the modeled B2 3-dimensional structure, serial single alanine replacement mutations and N-terminal deletion analyses showed that the RNA-binding domain of B2 is formed by its helices α2 and α3, while helix α1 mediates B2 dimerization. Furthermore, positive feedback between RNA binding and B2 dimerization was uncovered by gel shift assay and far-Western blotting, revealing that B2 dimerization is required for its binding to RNA, whereas RNA binding to B2 in turn promotes its dimerization. All together, our findings uncovered a novel RNA-binding mode of WhNV B2 and provided evidence that the promotion effect of RNA binding on dimerization exists in a viral RSS protein. PMID:21734038

  19. RNA Binding by a Novel Helical Fold of B2 Protein from Wuhan Nodavirus Mediates the Suppression of RNA Interference and Promotes B2 Dimerization ▿

    PubMed Central

    Qi, Nan; Cai, Dawei; Qiu, Yang; Xie, Jiazheng; Wang, Zhaowei; Si, Jie; Zhang, Jiamin; Zhou, Xi; Hu, Yuanyang

    2011-01-01

    Wuhan nodavirus (WhNV) is a newly identified member of the Nodaviridae family with a bipartite genome of positive-sense RNAs. A nonstructural protein encoded by subgenomic RNA3 of nodaviruses, B2, serves as a potent RNA silencing suppressor (RSS) by sequestering RNA duplexes. We have previously demonstrated that WhNV B2 blocks RNA silencing in cultured Drosophila cells. However, the molecular mechanism by which WhNV B2 functions remains unknown. Here, we successfully established an RNA silencing system in cells derived from Pieris rapae, a natural host of WhNV, by introducing into these cells double-stranded RNA (dsRNA)-expressing plasmids or chemically synthesized small interfering RNAs (siRNAs). Using this system, we revealed that the WhNV B2 protein inhibited Dicer-mediated dsRNA cleavage and the incorporation of siRNA into the RNA-induced silencing complex (RISC) by sequestering dsRNA and siRNA. Based on the modeled B2 3-dimensional structure, serial single alanine replacement mutations and N-terminal deletion analyses showed that the RNA-binding domain of B2 is formed by its helices α2 and α3, while helix α1 mediates B2 dimerization. Furthermore, positive feedback between RNA binding and B2 dimerization was uncovered by gel shift assay and far-Western blotting, revealing that B2 dimerization is required for its binding to RNA, whereas RNA binding to B2 in turn promotes its dimerization. All together, our findings uncovered a novel RNA-binding mode of WhNV B2 and provided evidence that the promotion effect of RNA binding on dimerization exists in a viral RSS protein. PMID:21734038

  20. NUCLEAR REACTOR

    DOEpatents

    Grebe, J.J.

    1959-07-14

    High temperature reactors which are uniquely adapted to serve as the heat source for nuclear pcwered rockets are described. The reactor is comprised essentially of an outer tubular heat resistant casing which provides the main coolant passageway to and away from the reactor core within the casing and in which the working fluid is preferably hydrogen or helium gas which is permitted to vaporize from a liquid storage tank. The reactor core has a generally spherical shape formed entirely of an active material comprised of fissile material and a moderator material which serves as a diluent. The active material is fabricated as a gas permeable porous material and is interlaced in a random manner with very small inter-connecting bores or capillary tubes through which the coolant gas may flow. The entire reactor is divided into successive sections along the direction of the temperature gradient or coolant flow, each section utilizing materials of construction which are most advantageous from a nuclear standpoint and which at the same time can withstand the operating temperature of that particular zone. This design results in a nuclear reactor characterized simultaneously by a minimum critiral size and mass and by the ability to heat a working fluid to an extremely high temperature.

  1. Thermal vacuum integrated system test at B-2

    NASA Astrophysics Data System (ADS)

    Kudlac, M. T.; Weaver, H. F.; Cmar, M. D.

    2012-04-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Space Propulsion Research Facility, commonly referred to as B-2, is NASA's third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility during pump down of the vacuum chamber, operation of the liquid nitrogen heat sink (or cold wall) and the infrared lamp array. A vacuum level of 1.3 × 10-4 Pa (1 × 10-6 torr) was achieved. The heat sink provided a uniform temperature environment of approximately 77 K (139°R) along the entire inner surface of the vacuum chamber. The recently rebuilt and modernized infrared lamp array produced a nominal heat flux of 1.4 kW/m2 at a chamber diameter of 6.7 m (22 ft) and along 11 m (36 ft) of the chamber's cylindrical vertical interior. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface. The data acquired matched pretest predictions and demonstrated system functionality.

  2. Beyond the exchange--the future of B2B.

    PubMed

    Wise, R; Morrison, D

    2000-01-01

    Using the Internet to facilitate business-to-business commerce promises many benefits, such as dramatic cost reductions and greater access to buyers and sellers. Yet little is known about how B2B e-commerce will evolve. The authors argue that changes in the financial services industry over the past two decades provide important clues. Exchanges, they say, are not the primary source of value in information-intensive markets; value tends to accumulate among a diverse group of specialists that focus on such tasks as packaging, standard setting, arbitrage, and information management. Because scale and liquidity are vitally important to efficient trading, today's exchanges will consolidate into a relatively small set of mega-exchanges. Originators will handle the origination and aggregation of complex transactions before sending them on to mega-exchanges for execution. E-speculators, seeking to capitalize on an abundance of market information, will tend to concentrate where relatively standardized products can be transferred easily among a large group of buyers. In many markets, a handful of independent solution providers with well-known brand names and solid reputations will thrive alongside mega-exchanges. Sell-side asset exchanges will create the networks and provide the tools to allow suppliers to trade orders among themselves, sometimes after initial transactions with customers are made on the mega-exchanges. For many companies, traditional skills in such areas as product development, manufacturing, and marketing may become relatively less important, while the ability to understand and capitalize on market dynamics may become considerably more important. PMID:11184979

  3. Hot corrosion of the B2 nickel aluminides

    NASA Technical Reports Server (NTRS)

    Ellis, David L.

    1993-01-01

    The hot corrosion behavior of the B2 nickel aluminides was studied to determine the inherent hot corrosion resistance of the beta nickel aluminides and to develop a mechanism for the hot corrosion of the beta nickel aluminides. The effects of the prior processing of the material, small additions of zirconium, stoichiometry of the materials, and preoxidation of the samples were also examined. Additions of 2, 5, and 15 w/o chromium were used to determine the effect of chromium on the hot corrosion of the beta nickel aluminides and the minimum amount of chromium necessary for good hot corrosion resistance. The results indicate that the beta nickel aluminides have inferior inherent hot corrosion resistance despite their excellent oxidation resistance. Prior processing and zirconium additions had no discernible effect on the hot corrosion resistance of the alloys. Preoxidation extended the incubation period of the alloys only a few hours and was not considered to be an effective means of stopping hot corrosion. Stoichiometry was a major factor in determining the hot corrosion resistance of the alloys with the higher aluminum alloys having a definitely superior hot corrosion resistance. The addition of chromium to the alloys stopped the hot corrosion attack in the alloys tested. From a variety of experimental results, a complex hot corrosion mechanism was proposed. During the early stages of the hot corrosion of these alloys the corrosion is dominated by a local sulphidation/oxidation form of attack. During the intermediate stages of the hot corrosion, the aluminum depletion at the surface leads to a change in the oxidation mechanism from a protective external alumina layer to a mixed nickel-aluminum spinel and nickel oxide that can occur both externally and internally. The material undergoes extensive cracking during the later portions of the hot corrosion.

  4. Thermal Vacuum Integrated System Test at B-2

    NASA Technical Reports Server (NTRS)

    Kudlac, Maureen T.; Weaver, Harold F.; Cmar, Mark D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Space Propulsion Research Facility, commonly referred to as B-2, is NASA s third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility during pump down of the vacuum chamber, operation of the liquid nitrogen heat sink (or cold wall) and the infrared lamp array. A vacuum level of 1.3x10(exp -4)Pa (1x10(exp -6)torr) was achieved. The heat sink provided a uniform temperature environment of approximately 77 K (140deg R) along the entire inner surface of the vacuum chamber. The recently rebuilt and modernized infrared lamp array produced a nominal heat flux of 1.4 kW/sq m at a chamber diameter of 6.7 m (22 ft) and along 11 m (36 ft) of the chamber s cylindrical vertical interior. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface. The data acquired matched pretest predictions and demonstrated system functionality.

  5. 26 CFR 1.367(b)-2 - Definitions and special rules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., owns and operates a QBU (B2) in France, whose functional currency is the dollar. FC2 acquires FC1's... reorganization, B1 and B2 combine their operations into one QBU. Applying the rules of section 985(b), the functional currency of the combined operations of B1 and B2 is the euro. (ii) Result. FC2's acquisition...

  6. 26 CFR 1.367(b)-2 - Definitions and special rules.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., owns and operates a QBU (B2) in France, whose functional currency is the dollar. FC2 acquires FC1's... reorganization, B1 and B2 combine their operations into one QBU. Applying the rules of section 985(b), the functional currency of the combined operations of B1 and B2 is the euro. (ii) Result. FC2's acquisition...

  7. 26 CFR 1.367(b)-2 - Definitions and special rules.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., owns and operates a QBU (B2) in France, whose functional currency is the dollar. FC2 acquires FC1's... reorganization, B1 and B2 combine their operations into one QBU. Applying the rules of section 985(b), the functional currency of the combined operations of B1 and B2 is the euro. (ii) Result. FC2's acquisition...

  8. Expression of the ephrin receptor B2 in the embryonic chicken bursa of Fabricius

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chicken B-cells develop in a specific organ, the bursa of Fabricius. To understand the bursal microenvironment guiding B-cell development, previous studies identified ephrin (Eph) receptor B2 (EphB2) gene transcripts in the embryonic bursa. We hypothesize that the EphB2 receptors and their ligands r...

  9. 26 CFR 1.367(b)-2 - Definitions and special rules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., owns and operates a QBU (B2) in France, whose functional currency is the dollar. FC2 acquires FC1's... reorganization, B1 and B2 combine their operations into one QBU. Applying the rules of section 985(b), the functional currency of the combined operations of B1 and B2 is the euro. (ii) Result. FC2's acquisition...

  10. 26 CFR 1.669(b)-2 - Manner of exercising election.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 8 2012-04-01 2012-04-01 false Manner of exercising election. 1.669(b)-2 Section 1.669(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... Taxable Years Beginning Before January 1, 1969 § 1.669(b)-2 Manner of exercising election. (a) By...

  11. 26 CFR 1.669(b)-2 - Manner of exercising election.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 8 2013-04-01 2013-04-01 false Manner of exercising election. 1.669(b)-2 Section 1.669(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... Taxable Years Beginning Before January 1, 1969 § 1.669(b)-2 Manner of exercising election. (a) By...

  12. 26 CFR 1.669(b)-2 - Manner of exercising election.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Manner of exercising election. 1.669(b)-2 Section 1.669(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... Years Beginning Before January 1, 1969 § 1.669(b)-2 Manner of exercising election. (a) By whom...

  13. 17 CFR 240.13b2-1 - Falsification of accounting records.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Falsification of accounting records. 240.13b2-1 Section 240.13b2-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... Required Reports § 240.13b2-1 Falsification of accounting records. No person shall directly or...

  14. 17 CFR 240.13b2-1 - Falsification of accounting records.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Falsification of accounting records. 240.13b2-1 Section 240.13b2-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... Required Reports § 240.13b2-1 Falsification of accounting records. No person shall directly or...

  15. 17 CFR 240.13b2-1 - Falsification of accounting records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Falsification of accounting records. 240.13b2-1 Section 240.13b2-1 Commodity and Securities Exchanges SECURITIES AND EXCHANGE... Required Reports § 240.13b2-1 Falsification of accounting records. No person shall directly or...

  16. Superconducting Properties of MgB2 with Addition of Other AlB2-type Diborides and Carbon Sources, Prepared Using High Energy Ball Milling and HIP

    NASA Astrophysics Data System (ADS)

    Rodrigues, Durval; Silva, Lucas B. S. da; Metzner, Vivian C. V.; Hellstrom, Eric E.

    In the present work it is described the production of MgB2 samples by using the mixture of MgB2 with other diborides, (TaB2, VB2, and AlB2) which have the same C32 hexagonal structure as the MgB2, and simultaneous addition with the diborides and SiC, that contribute with C, to replace B in the crystalline structure of the matrix. As an important result, the critical current density (Jc) was improved at low magnetic fields when just the diborides are added. However, when SiC is added simultaneously with the diborides, the result is the improvement of Jc at high fields. The critical temperature (Tc) was maintained high.

  17. Research reactors - an overview

    SciTech Connect

    West, C.D.

    1997-03-01

    A broad overview of different types of research and type reactors is provided in this paper. Reactor designs and operating conditions are briefly described for four reactors. The reactor types described include swimming pool reactors, the High Flux Isotope Reactor, the Mark I TRIGA reactor, and the Advanced Neutron Source reactor. Emphasis in the descriptions is placed on safety-related features of the reactors. 7 refs., 7 figs., 2 tabs.

  18. NEUTRONIC REACTOR

    DOEpatents

    Ohlinger, L.A.; Wigner, E.P.; Weinberg, A.M.; Young, G.J.

    1958-09-01

    This patent relates to neutronic reactors of the heterogeneous water cooled type, and in particular to a fuel element charging and discharging means therefor. In the embodiment illustrated the reactor contains horizontal, parallel coolant tubes in which the fuel elements are disposed. A loading cart containing a magnzine for holding a plurality of fuel elements operates along the face of the reactor at the inlet ends of the coolant tubes. The loading cart is equipped with a ram device for feeding fuel elements from the magazine through the inlot ends of the coolant tubes. Operating along the face adjacent the discharge ends of the tubes there is provided another cart means adapted to receive irradiated fuel elements as they are forced out of the discharge ends of the coolant tubes by the incoming new fuel elements. This cart is equipped with a tank coataining a coolant, such as water, into which the fuel elements fall, and a hydraulically operated plunger to hold the end of the fuel element being discharged. This inveation provides an apparatus whereby the fuel elements may be loaded into the reactor, irradiated therein, and unloaded from the reactor without stopping the fiow of the coolant and without danger to the operating personnel.

  19. An unusual density evolution between SrCdB2O5 polymorphs.

    PubMed

    Zhang, Xingwen; Zhou, Zhengyang; Wu, Hongping; Pan, Shilie; Lei, Chen; Liu, Lu; Yang, Zhihua

    2015-09-28

    Owing to the effect of atomic vibrations, a high-temperature phase usually features a relatively smaller density when compared with a low-temperature phase. In this work, a new SrCdB2O5 phase has been discovered. According to the crystallization temperature from low to high, the new SrCdB2O5 phase can be regarded as the high-temperature β-SrCdB2O5 phase. The density of β-SrCdB2O5 is obviously larger than that of α-SrCdB2O5, meanwhile β-SrCdB2O5 is energetically favored. This unusual density evolution phenomenon has been investigated. In addition, the Pb(2+)-doped compounds, PbxSr1-xCdB2O5 (x = 0.125, 0.25, 0.375, 0.5), have also been investigated by powder refinement. PMID:26266583

  20. Vibrational modes and resonant Raman spectra of new B2C nanoribbons

    NASA Astrophysics Data System (ADS)

    Li, Xiaowei; Xu, Yuehua; Dong, Jinming

    2011-07-01

    The vibrational properties and first-order resonant Raman spectra of new B2C nanoribbons (B2C-NRs) have been studied by the density functional theory. It is found that there is a characteristic radial-breathing-like mode (RBLM) for all the calculated B2C-NRs with their frequency varying in a linear proportion to the inverse square root of the B2C-NR's width, whose slope depends closely on the types of B2C-NRs. The RBLM resonant peak's intensities and positions in the first-order resonant Raman spectra of the B2C-NRs are found to depend greatly on the polarizations of the incident and scattered light, and also the types of B2C-NRs.

  1. Polymorphism in two genes for B2 high sulfur proteins of wool.

    PubMed

    Rogers, G R; Hickford, J G; Bickerstaffe, R

    1994-12-01

    Variation in the nucleotide sequence of the B2 high-sulfur protein genes has not been reported previously. This paper reports 15 nucleotide substitutions in each of the genes for the B2A and B2C proteins and a length of polymorphism in the B2A gene which translates to the insertion/deletion of one 30-nucleotide repeat sequence. Evidence is presented for gene conversion occurring within the B2 high-sulfur multigene family. These DNA polymorphisms may account for some of the microheterogeneity observed in the B2 high-sulfur proteins and may also be useful genetic markers of the B2 high-sulfur protein gene loci for future use in analysing wool fibre characteristics.

  2. POWER REACTOR

    DOEpatents

    Zinn, W.H.

    1958-07-01

    A fast nuclear reactor system ls described for producing power and radioactive isotopes. The reactor core is of the heterogeneous, fluid sealed type comprised of vertically arranged elongated tubular fuel elements having vertical coolant passages. The active portion is surrounded by a neutron reflector and a shield. The system includes pumps and heat exchangers for the primary and secondary coolant circuits. The core, primary coolant pump and primary heat exchanger are disposed within an irapenforate tank which is filled with the primary coolant, in this case a liquid metal such as Na or NaK, to completely submerge these elements. The tank is completely surrounded by a thick walled concrete shield. This reactor system utilizes enriched uranium or plutonium as the fissionable material, uranium or thorium as a diluent and thorium or uranium containing less than 0 7% of the U/sup 235/ isotope as a fertile material.

  3. NEUTRONIC REACTOR

    DOEpatents

    Metcalf, H.E.

    1957-10-01

    A reactor of the type which preferably uses plutonium as the fuel and a liquid moderator, preferably ordinary water, and which produces steam within the reactor core due to the heat of the chain reaction is described. In the reactor shown the fuel elements are essentially in the form of trays and are ventically stacked in spaced relationship. The water moderator is continuously supplied to the trays to maintain a constant level on the upper surfaces of the fuel element as it is continually evaporated by the heat. The steam passes out through the spaces between the fuel elements and is drawn off at the top of the core. The fuel elements are clad in aluminum to prevent deterioration thereof with consequent contamimation of the water.

  4. NUCLEAR REACTOR

    DOEpatents

    Christy, R.F.

    1958-07-15

    A nuclear reactor of the homogeneous liquid fuel type is described wherein the fissionable isotope is suspended or dissolved in a liquid moderator such as water. The reactor core is comprised essentially of a spherical vessel for containing the reactive composition surrounded by a reflector, preferably of beryllium oxide. The reactive composition may be an ordinary water solution of a soluble salt of uranium, the quantity of fissionable isotope in solution being sufficient to provide a critical mass in the vessel. The liquid fuel is stored in a tank of non-crtttcal geometry below the reactor vessel and outside of the reflector and is passed from the tank to the vessel through a pipe connecting the two by air pressure means. Neutron absorbing control and safety rods are operated within slots in the reflector adjacent to the vessel.

  5. Bioconversion reactor

    DOEpatents

    McCarty, Perry L.; Bachmann, Andre

    1992-01-01

    A bioconversion reactor for the anaerobic fermentation of organic material. The bioconversion reactor comprises a shell enclosing a predetermined volume, an inlet port through which a liquid stream containing organic materials enters the shell, and an outlet port through which the stream exits the shell. A series of vertical and spaced-apart baffles are positioned within the shell to force the stream to flow under and over them as it passes from the inlet to the outlet port. The baffles present a barrier to the microorganisms within the shell causing them to rise and fall within the reactor but to move horizontally at a very slow rate. Treatment detention times of one day or less are possible.

  6. REACTOR CONTROL

    DOEpatents

    Fortescue, P.; Nicoll, D.

    1962-04-24

    A control system employed with a high pressure gas cooled reactor in which a control rod is positioned for upward and downward movement into the neutron field from a position beneath the reactor is described. The control rod is positioned by a coupled piston cylinder releasably coupled to a power drive means and the pressurized coolant is directed against the lower side of the piston. The coolant pressure is offset by a higher fiuid pressure applied to the upper surface of the piston and means are provided for releasing the higher pressure on the upper side of the piston so that the pressure of the coolant drives the piston upwardly, forcing the coupled control rod into the ncutron field of the reactor. (AEC)

  7. Catalytic reactor

    SciTech Connect

    Aaron, Timothy Mark; Shah, Minish Mahendra; Jibb, Richard John

    2009-03-10

    A catalytic reactor is provided with one or more reaction zones each formed of set(s) of reaction tubes containing a catalyst to promote chemical reaction within a feed stream. The reaction tubes are of helical configuration and are arranged in a substantially coaxial relationship to form a coil-like structure. Heat exchangers and steam generators can be formed by similar tube arrangements. In such manner, the reaction zone(s) and hence, the reactor is compact and the pressure drop through components is minimized. The resultant compact form has improved heat transfer characteristics and is far easier to thermally insulate than prior art compact reactor designs. Various chemical reactions are contemplated within such coil-like structures such that as steam methane reforming followed by water-gas shift. The coil-like structures can be housed within annular chambers of a cylindrical housing that also provide flow paths for various heat exchange fluids to heat and cool components.

  8. NEUTRONIC REACTORS

    DOEpatents

    Wigner, E.P.; Young, G.J.

    1958-10-14

    A method is presented for loading and unloading rod type fuel elements of a neutronic reactor of the heterogeneous, solld moderator, liquid cooled type. In the embodiment illustrated, the fuel rods are disposed in vertical coolant channels in the reactor core. The fuel rods are loaded and unloaded through the upper openings of the channels which are immersed in the coolant liquid, such as water. Unloading is accomplished by means of a coffer dam assembly having an outer sleeve which is placed in sealing relation around the upper opening. A radiation shield sleeve is disposed in and reciprocable through the coffer dam sleeve. A fuel rod engaging member operates through the axial bore in the radiation shield sleeve to withdraw the fuel rod from its position in the reactor coolant channel into the shield, the shield snd rod then being removed. Loading is accomplished in the reverse procedure.

  9. Bradykinin inhibits oxidative stress-induced senescence of endothelial progenitor cells through the B2R/AKT/RB and B2R/EGFR/RB signal pathways

    PubMed Central

    Fu, Cong; Li, Bing; Sun, Yuning; Ma, Genshan; Yao, Yuyu

    2015-01-01

    Circulating endothelial progenitor cells (EPCs) have multiple protective effects that facilitate repair of damage to tissues and organs. However, while various stressors are known to impair EPC function, the mechanisms of oxidative stress-induced EPC senescence remains unknown. We demonstrated that B2 receptor (B2R) expression on circulating CD34+ cells was significantly reduced in patients with diabetes mellitus (DM) as compared to healthy controls. Furthermore, CD34+ cell B2R expression in patients with DM was inversely correlated with plasma myeloperoxidase concentrations. Bradykinin (BK) treatment decreased human EPC (hEPC) senescence and intracellular oxygen radical production, resulting in reduced retinoblastoma 1 (RB) RNA expression in H2O2-induced senescent hEPCs and a reversal of the B2R downregulation that is normally observed in senescent cells. Furthermore, BK treatment of H2O2-exposed cells leads to elevated phosphorylation of RB, AKT, and cyclin D1 compared with H2O2-treatment alone. Antagonists of B2R, PI3K, and EGFR signaling pathways and B2R siRNA blocked BK protective effects. In summary, this study demonstrates that BK significantly inhibits oxidative stress-induced hEPC senescence though B2R-mediated activation of PI3K and EGFR signaling pathways. PMID:26360782

  10. BPO4@B2O3 and (BPO4@B2O3):Eu3+: The novel single-emitting-component phosphors for near UV-white LEDs

    NASA Astrophysics Data System (ADS)

    Cao, Xiyu; Liu, Wei; Jiang, Yu; Cao, Lixin; Su, Ge; Gao, Rongjie

    2016-08-01

    Nowadays much effort has been devoted to exploring novel luminescent materials with low-cost, high stability and excellent luminescent properties. In this paper, a new kind of luminescent material BPO4@B2O3 was prepared by using a facile method. The as-obtained samples contain numerous BPO4 nanoparticles enclosed by amorphous and crystalline B2O3 homogeneously, which exhibits a broad emission band ranging from 380 to 700 nm under near-UV irradiation. More importantly, it is worth noting that the BPO4@B2O3 phosphor exhibits the excellent thermal quenching property, which endows it with a promising prospect as phosphors for high power white LEDs. To further promote its application as white light phosphors, Eu3+ ions were doped into the BPO4@B2O3 samples and prepared the (BPO4@B2O3):Eu3+ phosphors with chromaticity coordinates (0.3022, 0.3122). The corresponding packaging of LEDs indicates that both BPO4@B2O3 and (BPO4@B2O3):Eu3+ can be considered as the promising phosphors for WLEDs.

  11. EphB2 promotes cervical cancer progression by inducing epithelial-mesenchymal transition.

    PubMed

    Gao, Qing; Liu, Wei; Cai, Jiangyi; Li, Mu; Gao, Yane; Lin, Wenjing; Li, Zongfang

    2014-02-01

    EphB2, a receptor tyrosine kinase for ephrin ligands, is overexpressed in various cancers and plays an important role in tumor progression. However, the expression and functions of EphB2 in cervical cancer remain unknown. In this study, we performed immunohistochemistry in clinical cervical specimens and found that EphB2 was overexpressed in the cervical cancer specimens, and its expression correlated with cancer progression. The percentage of EphB2-positive cells increased gradually from 28% in the normal cervix to 40% in high-grade squamous intraepithelial lesions, and ultimately to 69.8% in squamous cell carcinomas (P < .05). We overexpressed EphB2 in HeLa cells and silenced EphB2 in cervical cancer (C33A) cells, which expressed low and high levels of EphB2, respectively. Exogenous EphB2 promoted cell migration, invasion, and an epithelial-mesenchymal transition (EMT) signature, which is a complex process that occurs during organogenesis and cancer metastasis, whereas EphB2 silencing had the opposite effect (P < .05). Furthermore, HeLa cells with exogenous EphB2 exhibited a stem cell-like state that promoted tumorsphere formation in vitro and exhibited tumorigenesis potential in vivo (P < .05), whereas EphB2 silencing in C33A cells inhibited these stem cell properties (P < .05). In addition, we investigated the intracellular signaling pathways in cervical cancer and found that R-Ras expression correlated positively with EphB2 in clinical samples, and its activity was regulated by EphB2 in cervical cancer. These findings demonstrate that EphB2 plays an important role in cervical cancer progression by orchestrating an EMT program through R-Ras activation.

  12. NUCLEAR REACTOR

    DOEpatents

    Young, G.

    1963-01-01

    This patent covers a power-producing nuclear reactor in which fuel rods of slightly enriched U are moderated by heavy water and cooled by liquid metal. The fuel rods arranged parallel to one another in a circle are contained in a large outer closed-end conduit that extends into a tank containing the heavy water. Liquid metal is introduced into the large conduit by a small inner conduit that extends within the circle of fuel rods to a point near the lower closed end of the outer conduit. (AEC) Production Reactors

  13. NEUTRONIC REACTOR

    DOEpatents

    Fermi, E.; Szilard, L.

    1957-09-24

    Reactors of the type employing plates of natural uranium in a moderator are discussed wherein the plates are um-formly disposed in parallel relationship to each other thereby separating the moderator material into distinct and individual layers. Each plate has an uninterrupted sunface area substantially equal to the cross-sectional area of the active portion of the reactor, the particular size of the plates and the volume ratio of moderator to uranium required to sustain a chain reaction being determinable from the known purity of these materials and other characteristics such as the predictable neutron losses due to the formation of radioactive elements of extremely high neutron capture cross section.

  14. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.; Weinberg, A.W.; Young, G.J.

    1958-04-15

    A nuclear reactor which uses uranium in the form of elongated tubes as fuel elements and liquid as a coolant is described. Elongated tubular uranium bodies are vertically disposed in an efficient neutron slowing agent, such as graphite, for example, to form a lattice structure which is disposed between upper and lower coolant tanks. Fluid coolant tubes extend through the uranium bodies and communicate with the upper and lower tanks and serve to convey the coolant through the uranium body. The reactor is also provided with means for circulating the cooling fluid through the coolant tanks and coolant tubes, suitable neutron and gnmma ray shields, and control means.

  15. ErbB2 signaling at the crossing between heart failure and cancer.

    PubMed

    Vermeulen, Zarha; Segers, Vincent F M; De Keulenaer, Gilles W

    2016-11-01

    The dual role of ErbB2 (or HER-2) in tumor growth and in physiological adaptive reactions of the heart positions ErbB2 at the intersection between cancer and chronic heart failure. Accordingly, ErbB2-targeted inhibitory therapy of cancer may lead to ventricular dysfunction, and activation of ErbB2 for heart failure therapy may induce malignancy. The molecular processes leading to the activation of ErbB2 in tumors and cardiac cells are, however, fundamentally different from each other. Thus, it must be feasible to design drugs that specifically target either physiological or malignant ErbB2 signaling, to activate ErbB2 signaling in heart failure with no increased risk for cancer, and to inhibit ErbB2 signaling in cancer with no increased risk for heart failure. In this review, we present a state-of-the-art on how ErbB2 is regulated in physiological conditions and in tumor cells and how this knowledge translates into smart drug design. This leads to a new generation of drugs interfering with ErbB2 in a unique way tailored for a specific clinical goal. These exciting developments at the crossing between cancer and heart failure are an elegant example of interdisciplinary collaborations between clinicians, physiologists, pharmacologists, and molecular biologists. PMID:27596216

  16. Secretion of SerpinB2 from endothelial cells activated with inflammatory stimuli.

    PubMed

    Boncela, Joanna; Przygodzka, Patrycja; Wyroba, Elzbieta; Papiewska-Pajak, Izabela; Cierniewski, Czeslaw S

    2013-05-01

    Due to the lack of an N-terminal signal peptide, SerpinB2 (plasminogen activator inhibitor type 2) accumulates in cells and only a small percentage of it is secreted. The extracellular concentration of SerpinB2 significantly increases during inflammation. In the present study we investigated the mechanism with which SerpinB2 can be secreted from endothelial cells activated with LPS. We evaluated the intracellular distribution of SerpinB2 by double immunogold labeling followed by a high resolution electron microscopy analysis. We found that SerpinB2 gathers in the vesicular structures and in the endothelial cell periphery. These vesicles stained positive for the trans-Golgi network marker TGN46, which is consistent with their formation by the endoplasmatic reticulum (ER) and Golgi-dependent pathways. SerpinB2 was delivered to the plasma membrane, apparently together with TGN46 in the same vesicles, which after fusion with the membranes released cargo. Secretion of SerpinB2 was partially inhibited by brefeldin A. The secreted SerpinB2 was predominantly in its nonglycosylated 43kDa form as evaluated by Western immunoblotting. Our data suggest that increased expression of SerpinB2 by an inflammatory stimulus is sufficient to generate structures that resemble secretory vesicles. These vesicles may represent the mechanism by which high local concentrations of SerpinB2 are released at inflammation sites from endothelial cells.

  17. Role of Erbin in ErbB2-dependent breast tumor growth.

    PubMed

    Tao, Yanmei; Shen, Chengyong; Luo, Shiwen; Traoré, Wilfried; Marchetto, Sylvie; Santoni, Marie-Josée; Xu, Linlin; Wu, Biao; Shi, Chao; Mei, Jinghong; Bates, Ryan; Liu, Xihui; Zhao, Kai; Xiong, Wen-Cheng; Borg, Jean-Paul; Mei, Lin

    2014-10-21

    ErbB2 (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2), a receptor tyrosine kinase of the ErbB family, is overexpressed in around 25% of breast cancers. In addition to forming a heterodimer with other ErbB receptors in response to ligand stimulation, ErbB2 can be activated in a ligand-independent manner. We report here that Erbin, an ErbB2-interacting protein that was thought to act as an antitumor factor, is specifically expressed in mammary luminal epithelial cells and facilitates ErbB2-dependent proliferation of breast cancer cells and tumorigenesis in MMTV-neu transgenic mice. Disruption of their interaction decreases ErbB2-dependent proliferation, and deletion of the PDZ domain in Erbin hinders ErbB2-dependent tumor development in MMTV-neu mice. Mechanistically, Erbin forms a complex with ErbB2, promotes its interaction with the chaperon protein HSP90, and thus prevents its degradation. Finally, ErbB2 and Erbin expression correlates in human breast tumor tissues. Together, these observations establish Erbin as an ErbB2 regulator for breast tumor formation and progression.

  18. Neutronic reactor

    DOEpatents

    Wende, Charles W. J.

    1976-08-17

    A safety rod for a nuclear reactor has an inner end portion having a gamma absorption coefficient and neutron capture cross section approximately equal to those of the adjacent shield, a central portion containing materials of high neutron capture cross section and an outer end portion having a gamma absorption coefficient at least equal to that of the adjacent shield.

  19. Neutronic reactor

    DOEpatents

    Carleton, John T.

    1977-01-25

    A graphite-moderated nuclear reactor includes channels between blocks of graphite and also includes spacer blocks between adjacent channeled blocks with an axis of extension normal to that of the axis of elongation of the channeled blocks to minimize changes in the physical properties of the graphite as a result of prolonged neutron bombardment.

  20. NEUTRONIC REACTOR

    DOEpatents

    Creutz, E.C.; Ohlinger, L.A.; Weinberg, A.M.; Wigner, E.P.; Young, G.J.

    1959-10-27

    BS>A reactor cooled by water, biphenyl, helium, or other fluid with provision made for replacing the fuel rods with the highest plutonium and fission product content without disassembling the entire core and for promptly cooling the rods after their replacement in order to prevent build-up of heat from fission product activity is described.

  1. Sonochemical Reactors.

    PubMed

    Gogate, Parag R; Patil, Pankaj N

    2016-10-01

    Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation.

  2. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1962-12-25

    A reactor is described comprising a plurality of horizontal trays containing a solution of a fissionable material, the trays being sleeved on a vertical tube which contains a vertically-reciprocable control rod, a gas-tight chamber enclosing the trays, and means for conducting vaporized moderator from the chamber and for replacing vaporized moderator in the trays. (AEC)

  3. NEUTRONIC REACTORS

    DOEpatents

    Anderson, H.L.

    1958-10-01

    The design of control rods for nuclear reactors are described. In this design the control rod consists essentially of an elongated member constructed in part of a neutron absorbing material and having tube means extending therethrough for conducting a liquid to cool the rod when in use.

  4. Sonochemical Reactors.

    PubMed

    Gogate, Parag R; Patil, Pankaj N

    2016-10-01

    Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation. PMID:27573503

  5. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1960-09-27

    A unit assembly is described for a neutronic reactor comprising a tube and plurality of spaced parallel sandwiches in the tube extending lengthwise thereof, each sandwich including a middle plate having a central opening for plutonium and other openings for fertile material at opposite ends of the plate.

  6. ErbB2 Signaling Increases Androgen Receptor Expression in Abiraterone-Resistant Prostate Cancer

    PubMed Central

    Gao, Shuai; Ye, Huihui; Gerrin, Sean; Wang, Hongyun; Sharma, Ankur; Chen, Sen; Patnaik, Akash; Sowalsky, Adam G.; Voznesensky, Olga; Han, Wanting; Yu, Ziyang; Mostaghel, Elahe A.; Nelson, Peter S.; Taplin, Mary-Ellen; Balk, Steven P.; Cai, Changmeng

    2016-01-01

    Purpose ErbB2 signaling appears to be increased and may enhance AR activity in a subset of CRPC, but agents targeting ErbB2 have not been effective. This study was undertaken to assess ErbB2 activity in abiraterone-resistant prostate cancer (PCa), and determine whether it may contribute to androgen receptor (AR) signaling in these tumors. Experimental Design AR activity and ErbB2 signaling were examined in the radical prostatectomy specimens from a neoadjuvant clinical trial of leuprolide plus abiraterone, and in the specimens from abiraterone-resistant CRPC xenograft models. The effect of ErbB2 signaling on AR activity was determined in two CRPC cell lines. Moreover, the effect of combination treatment with abiraterone and an ErbB2 inhibitor was assessed in a CRPC xenograft model. Results We found that ErbB2 signaling was elevated in residual tumor following abiraterone treatment in a subset of patients, and was associated with higher nuclear AR expression. In xenograft models, we similarly demonstrated that ErbB2 signaling was increased and associated with AR reactivation in abiraterone-resistant tumors. Mechanistically, we show that ErbB2 signaling and subsequent activation of the PI3K/AKT signaling stabilizes AR protein. Furthermore, concomitantly treating CRPC cells with abiraterone and an ErbB2 inhibitor, lapatinib, blocked AR reactivation and suppressed tumor progression. Conclusions ErbB2 signaling is elevated in a subset of abiraterone-resistant prostate cancer patients and stabilizes AR protein. Combination therapy with abiraterone and ErbB2 antagonists may be effective for treating the subset of CRPC with elevated ErbB2 activity. PMID:26936914

  7. Development and Application of Interatomic Potentials for Ultra High Temperature Ceramics (UHTC): ZrB2 and HfB2

    NASA Technical Reports Server (NTRS)

    Lawson, John W.; Daw, Murray; Bauschlicher

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 are characterized by high melting point, good strength, and reasonable oxidation resistance. These materials are of interest for use as sharp leading edges for hypersonic vehicles among other applications. Progress in computational modeling of UHTCs has been limited in part due to the absence of suitable interatomic potentials. We present a Tersoff style parameterization of such potentials for ZrB2 and HfB2 appropriate for atomistic simulations. Parameters are fit to data generated from ab initio calculations. The accuracy of the potentials is assessed against further ab initio data. As a first non ]trivial application, molecular dynamics simulations are performed to evaluate the thermal conductivity of single crystals and the thermal resistance of high symmetry grain boundaries.

  8. Observation of b2 symmetry vibrational levels of the SO2C 1B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants

    DOE PAGESBeta

    Park, G. Barratt; Jiang, Jun; Saladrigas, Catherine A.; Field, Robert W.

    2016-04-14

    Here, the C 1B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X~ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C state below 1600 cm–1 of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, itmore » allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry, and to determine accurately the vibrational dependence of the rotational constants in the distorted C electronic state.« less

  9. Observation of b2 symmetry vibrational levels of the SO2 C̃ (1)B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants.

    PubMed

    Park, G Barratt; Jiang, Jun; Saladrigas, Catherine A; Field, Robert W

    2016-04-14

    The C̃ (1)B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X̃ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C̃ state below 1600 cm(-1) of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry and to determine accurately the vibrational dependence of the rotational constants in the distorted C̃ electronic state.

  10. Observation of b2 symmetry vibrational levels of the SO2 C ˜ 1B2 state: Vibrational level staggering, Coriolis interactions, and rotation-vibration constants

    NASA Astrophysics Data System (ADS)

    Park, G. Barratt; Jiang, Jun; Saladrigas, Catherine A.; Field, Robert W.

    2016-04-01

    The C ˜ 1B2 state of SO2 has a double-minimum potential in the antisymmetric stretch coordinate, such that the minimum energy geometry has nonequivalent SO bond lengths. However, low-lying levels with odd quanta of antisymmetric stretch (b2 vibrational symmetry) have not previously been observed because transitions into these levels from the zero-point level of the X ˜ state are vibronically forbidden. We use IR-UV double resonance to observe the b2 vibrational levels of the C ˜ state below 1600 cm-1 of vibrational excitation. This enables a direct characterization of the vibrational level staggering that results from the double-minimum potential. In addition, it allows us to deperturb the strong c-axis Coriolis interactions between levels of a1 and b2 vibrational symmetry and to determine accurately the vibrational dependence of the rotational constants in the distorted C ˜ electronic state.

  11. [[Length polymorphism of minisatellite repeat B2-VNTR of the bradykinin B2 receptor gene in healthy Russians and in patients with coronary heart disease].

    PubMed

    Suchkova, I O; Pavlinova, L I; Larionova, E E; Alenina, N V; Solov'ev, K V; Baranova, T V; Belotserkovskaia, E V; Sasina, L K; Bader, M; Denisenko, A D; Mustafina, O E; Khusnutdinova, E K; Patkin, E L

    2014-01-01

    Bradykinin B2 receptor is involved in many processes, including the regulation of blood pressure and smooth muscle contraction, vasodilation, inflammation, edema, cell proliferation, pain. It is suggested that this receptor may be one of the factors that have cardioprotective and infarct-limiting effects. It is assumed that certain genetic variants in both coding and non-coding regions ofBDKRB2 gene may influence its expression. In the 3'-untranslated region of BDKRB2 exon 3 the minisatellite repeat B2-VNTR is located. B2-VNTR has previously been shown to affect the BDKRB2 mRNA stability. Therefore, it is important to perform the molecular genetic analysis of this minisatellite in patients with different forms of coronary heart disease in order to reveal possible associations between specific B2-VNTR alleles and certain clinical forms of coronary heart disease. In the present study, a comparative analysis of the allele and genotype frequencies of B2-VNTR was carried out in groups of healthy individuals and patients with two clinical forms of coronary heart disease (angina pectoris and myocardial infarction), ethnically Russian. The results of the B2-VNTR length polymorphism analysis indicate that this tandem repeat may be attributed to a class of low polymorphic and non-hypervariable minisatellite. In all analyzed groups we revealed three B2-VNTR alleles, consisting of 43, 38 and 33 repeat units. Alleles of 43 and 33 repeats were major in all investigated groups. No statistically significant differences were found in the B2-VNTR allele and genotype frequencies between men and women in control group, and also between healthy men and men with angina pectoris and myocardial infarction. Thus, B2-VNTR length polymorphism was not associated with these clinical forms of coronary heart disease in Russian men. However, we do not exclude the possibility of association between the B2-VNTR short alleles (38 and 33 repeats) and cardioprotective effects of bradykinin B2 receptor

  12. CaMsrB2, pepper methionine sulfoxide reductase B2, is a novel defense regulator against oxidative stress and pathogen attack.

    PubMed

    Oh, Sang-Keun; Baek, Kwang-Hyun; Seong, Eun Soo; Joung, Young Hee; Choi, Gyung-Ja; Park, Jeong Mee; Cho, Hye Sun; Kim, Eun Ah; Lee, Sangku; Choi, Doil

    2010-09-01

    Reactive oxygen species (ROS) are inevitably generated in aerobic organisms as by-products of normal metabolism or as the result of defense and development. ROS readily oxidize methionine (Met) residues in proteins/peptides to form Met-R-sulfoxide or Met-S-sulfoxide, causing inactivation or malfunction of the proteins. A pepper (Capsicum annuum) methionine sulfoxide reductase B2 gene (CaMsrB2) was isolated, and its roles in plant defense were studied. CaMsrB2 was down-regulated upon inoculation with either incompatible or compatible pathogens. The down-regulation, however, was restored to the original expression levels only in a compatible interaction. Gain-of-function studies using tomato (Solanum lycopersicum) plants transformed with CaMsrB2 resulted in enhanced resistance to Phytophthora capsici and Phytophthora infestans. Inversely, loss-of-function studies of CaMsrB2 using virus-induced gene silencing in pepper plants (cv Early Calwonder-30R) resulted in accelerated cell death from an incompatible bacterial pathogen, Xanthomonas axonopodis pv vesicatoria (Xav) race 1, and enhanced susceptibility to a compatible bacterial pathogen, virulent X. axonopodis pv vesicatoria race 3. Measurement of ROS levels in CaMsrB2-silenced pepper plants revealed that suppression of CaMsrB2 increased the production of ROS, which in turn resulted in the acceleration of cell death via accumulation of ROS. In contrast, the CaMsrB2-transgenic tomato plants showed reduced production of hydrogen peroxide. Taken together, our results suggest that the plant MsrBs have novel functions in active defense against pathogens via the regulation of cell redox status.

  13. Mechanistic and Signaling Analysis of Muc4-ErbB2 Signaling Module: New Insights into the Mechanism of Ligand-Independent ErbB2 Activity

    PubMed Central

    Kozloski, Goldi A.; Carothers Carraway, Coralie A.; Carraway, Kermit L.

    2010-01-01

    SUMMARY The membrane mucin Muc4 is aberrantly expressed in numerous epithelial carcinomas and is currently used as a cancer diagnostic and prognostic tool. Muc4 can also potentiate signal transduction by modulating differential ErbB2 phosphorylation in the absence and in the presence of the ErbB3 soluble ligand heregulin (HRG-β1). These features of Muc4 suggest that Muc4 is not merely a cancer marker, but an oncogenic factor with a unique binding/activation relationship with the receptor ErbB2. In the present study, we examined the signaling mechanisms that are associated with the Muc4-ErbB2 module by analyzing ErbB2 differential signaling in response to Muc4 expression. Our study was carried out in the A375 human melanoma and BT-474 breast cancer cell lines as our model systems. Quantitative and comparative signaling modulations were evaluated by immunoblot using phospho-specific antibodies, and densitometry analysis. Signaling complex components were identified by chemical cross-linking, fractionation by gel filtration, immunoprecipitation and immunoblotting. Activated downstream signaling pathways were analyzed by an antibody microarray screen and immunoblot analyses. Our results indicate that Muc4 modulates ErbB2 signaling potential significantly by stabilizing and directly interacting with the ErbB2-ErbB3 heterodimer. Further analyses indicate that Muc4 promotes ErbB2 autocatalysis, but it has no effect on ErbB3 phosphorylation, although the chemical cross linking data indicated that the signaling module is composed of Muc4, ErbB2 and ErbB3. Our microarray analysis indicates that Muc4 expression promotes cell migration by increasing the phosphorylation of the focal adhesion kinase (FAK) and also through an increase in the levels of β-catenin. PMID:20432461

  14. Visible absorption spectroscopy of the B 2A1-X 2B2 transition of fluoroformyloxyl radical, FC(O)O

    NASA Astrophysics Data System (ADS)

    Maricq, M. Matti; Szente, Joseph J.; Li, Z.; Francisco, Joseph S.

    1993-01-01

    We report the visible absorption spectrum of the fluoroformyloxyl radical. The spectrum is assigned to the B 2A1-X 2B2 transition in FC(O)O. The origin of the excitation spectrum is observed at 13 150 cm-1 (760 nm). Extensive progressions in the OCO bending mode of the B state, ν'3 = 610 cm-1, dominate the spectrum. Three other progressions are observed: the OCO wag mode, ν'6 = 840 cm-1; the CF stretching mode, ν'2 = 1110 cm-1; and the asymmetric CO stretching mode, ν'4 = 2820 cm-1. Two series of hot bands also appear in the spectrum. From these bands the frequency of the OCO bending mode, ν`3 = 520 cm-1, is assigned for ground state FC(O)O. The experimental spectrum is compared to the results of ab initio MO calculations. These include second-order Møller-Plesset perturbation theory (UMP2) and quadratic configuration interactions theory with single and double excitations (QCISD) for both the X 2B2 and B 2A1 states. The origin of the B 2A1-X 2B2 transition and the predicted vibrational frequencies are found to be in reasonable agreement with experiment.

  15. Lattice Thermal Conductivity of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2 from Atomistic Simulations

    NASA Technical Reports Server (NTRS)

    Lawson, John W.; Daw, Murray S.; Bauschlicher, Charles W.

    2012-01-01

    Ultra high temperature ceramics (UHTC) including ZrB2 and HfB2 have a number of properties that make them attractive for applications in extreme environments. One such property is their high thermal conductivity. Computational modeling of these materials will facilitate understanding of fundamental mechanisms, elucidate structure-property relationships, and ultimately accelerate the materials design cycle. Progress in computational modeling of UHTCs however has been limited in part due to the absence of suitable interatomic potentials. Recently, we developed Tersoff style parameterizations of such potentials for both ZrB2 and HfB2 appropriate for atomistic simulations. As an application, Green-Kubo molecular dynamics simulations were performed to evaluate the lattice thermal conductivity for single crystals of ZrB2 and HfB2. The atomic mass difference in these binary compounds leads to oscillations in the time correlation function of the heat current, in contrast to the more typical monotonic decay seen in monoatomic materials such as Silicon, for example. Results at room temperature and at elevated temperatures will be reported.

  16. Microhardness and microstructure evolution of TiB2 reinforced Inconel 625/TiB2 composite produced by selective laser melting

    NASA Astrophysics Data System (ADS)

    Zhang, Baicheng; Bi, Guijun; Nai, Sharon; Sun, Chen-nan; Wei, Jun

    2016-06-01

    In this study, micron-size TiB2 particles were utilized to reinforce Inconel 625 produced by selective laser melting. Exceptional microhardness 600-700 HV0.3 of the composite was obtained. In further investigation, the microstructure and mechanical properties of Inconel 625/TiB2 composite can be significantly influenced by addition of TiB2 particles during SLM. It was found that the long directional columnar grains observed from SLM-processed Inconel 625 were totally changed to fine dendritic matrix due to the addition of TiB2 particles. Moreover, with laser energy density (LED) of 1200 J/m, a Ti, Mo rich interface around TiB2 particles with fine thickness can be observed by FESEM and EDS. The microstructure evolution can be determined by different laser energy density (LED): under 1200 J/m, γ phase in dendrite grains; under 600 J/m, γ phase in combination of dendritic and acicular grains; under 400 J/m, γ phase acicular grains. Under optimized LED 1200 J/m, the dynamic nanohardness (8.62 GPa) and elastic modulus (167 GPa) of SLM-processed Inconel 625/TiB2 composite are higher compared with those of SLM-processed Inconel 625 (3.97 GPa and 135 GPa, respectively).

  17. Spectroscopic and modeling investigations of the gas phase chemistry and composition in microwave plasma activated B2H6/CH4/Ar/H2 mixtures.

    PubMed

    Ma, Jie; Richley, James C; Davies, David R W; Ashfold, Michael N R

    2010-09-23

    A comprehensive study of microwave (MW) activated B2H6/CH4/Ar/H2 plasmas used for the chemical vapor deposition of B-doped diamond is reported. Absolute column densities of ground state B atoms, electronically excited H(n = 2) atoms, and BH, CH, and C2 radicals have been determined by cavity ring down spectroscopy, as functions of height (z) above a molybdenum substrate and of the plasma process conditions (B2H6, CH4, and Ar partial pressures; total pressure, p; and supplied MW power, P). Optical emission spectroscopy has also been used to explore variations in the relative densities of electronically excited H atoms, H2 molecules, and BH, CH, and C2 radicals, as functions of the same process conditions. These experimental data are complemented by extensive 2D(r, z) modeling of the plasma chemistry, which result in substantial refinements to the existing B/C/H/O thermochemistry and chemical kinetics. Comparison with the results of analogous experimental/modeling studies of B2H6/Ar/H2 and CH4/Ar/H2 plasmas in the same MW reactor show that: (i) trace B2H6 additions have negligible effect on a pre-established CH4/Ar/H2 plasma; (ii) the spatial extent of the B and BH concentration profiles in a B2H6/CH4/Ar/H2 plasma is smaller than in a hydrocarbon-free B2H6/Ar/H2 plasma operating at the same p, P, etc.; (iii) B/C coupling reactions (probably supplemented by reactions involving trace O2 present as air impurity in the process gas mixture) play an important role in determining the local BHx (x = 0-3) radical densities; and (iv) gas phase B atoms are the most likely source of the boron that incorporates into the growing B-doped diamond film. PMID:20735120

  18. Nodamura virus B2 amino terminal domain sensitivity to small interfering RNA.

    PubMed

    Ali, P Shaik Syed; John, Jasmine; Selvaraj, Manikandan; Kek, Teh Lay; Salleh, Mohd Zaki

    2015-05-01

    Nodamura virus (NoV) B2, a suppressor of RNA interference, binds double stranded RNAs (dsRNAs) and small interfering RNAs (siRNAs) corresponding to Dicer substrates and products. Here, we report that the amino terminal domain of NoV B2 (NoV B2 79) specifically binds siRNAs but not dsRNAs. NoV B2 79 oligomerizes on binding to 27 nucleotide siRNA. Mutation of the residues phenylalanine49 and alanine60 to cysteine and methionine, respectively enhances the RNA binding affinity of NoV B2 79. Circular dichroism spectra demonstrated that the wild type and mutant NoV B2 79 have similar secondary structure conformations.

  19. The neuroendocrine polypeptide 7B2 is an endogenous inhibitor of prohormone convertase PC2.

    PubMed Central

    Martens, G J; Braks, J A; Eib, D W; Zhou, Y; Lindberg, I

    1994-01-01

    The subtilisin-like prohormone convertase PC2 and the polypeptide 7B2 (an intracellularly cleaved protein of unknown function) are both selectively present in the regulated secretory pathway of neurons and endocrine cells. Here we demonstrate that intact recombinant 7B2 is a potent inhibitor of PC2 and prevents proPC2 cleavage in vitro, whereas the 7B2 cleavage product is virtually inactive. The PC2-related proteinase PC1/PC3 is not inhibited by 7B2. Furthermore, the carboxyl-terminal half of the 7B2 protein sequence is distantly related to the so-called potato inhibitor I family (which includes subtilisin inhibitors). Our findings indicate that 7B2 is a physiological inhibitor of PC2 and may provide alternative avenues for the manipulation of peptide hormone levels. Images PMID:8016065

  20. Fast creation of dense MgB2 phase in wires made by IMD process

    NASA Astrophysics Data System (ADS)

    Kováč, P.; Hušek, I.; Melišek, T.; Kopera, L.; Kulich, M.

    2016-10-01

    Single-core MgB2 wires have been made by internal magnesium diffusion (IMD) into boron process. Heat treatments were performed at variable periods (4-90 min) for two adjusted temperatures 635 °C and 650 °C, with an overshoot of ≈20 °C after 5 min. Critical currents of differently treated MgB2/Ti/GlidCop wires have been measured and related with the MgB2 layers. The fast creation MgB2 compound has been observed after 8 min annealing at both temperatures and showing the critical current maxima. The less uniform MgB2 containing cracks was created for longer annealing periods (≥10 min), which resulted in lowered critical currents and worsened thermal stability. The fast creation of dense MgB2 allows it to utilize a continual and short heat treatment process for high current density wires made by IMD.

  1. Improvement of skin wound healing in diabetic mice by kinin B2 receptor blockade.

    PubMed

    Desposito, Dorinne; Chollet, Catherine; Taveau, Christopher; Descamps, Vincent; Alhenc-Gelas, François; Roussel, Ronan; Bouby, Nadine; Waeckel, Ludovic

    2016-01-01

    Impaired skin wound healing is a major medical problem in diabetic subjects. Kinins exert a number of vascular and other actions limiting organ damage in ischaemia or diabetes, but their role in skin injury is unknown. We investigated, through pharmacological manipulation of bradykinin B1 and B2 receptors (B1R and B2R respectively), the role of kinins in wound healing in non-diabetic and diabetic mice. Using two mouse models of diabetes (streptozotocin-induced and db/db mice) and non-diabetic mice, we assessed the effect of kinin receptor activation or inhibition by subtype-selective pharmacological agonists (B1R and B2R) and antagonist (B2R) on healing of experimental skin wounds. We also studied effects of agonists and antagonist on keratinocytes and fibroblasts in vitro. Levels of Bdkrb1 (encoding B1R) and Bdkrb2 (encoding B2R) mRNAs increased 1-2-fold in healthy and wounded diabetic skin compared with in non-diabetic skin. Diabetes delayed wound healing. The B1R agonist had no effect on wound healing. In contrast, the B2R agonist impaired wound repair in both non-diabetic and diabetic mice, inducing skin disorganization and epidermis thickening. In vitro, B2R activation unbalanced fibroblast/keratinocyte proliferation and increased keratinocyte migration. These effects were abolished by co-administration of B2R antagonist. Interestingly, in the two mouse models of diabetes, the B2R antagonist administered alone normalized wound healing. This effect was associated with the induction of Ccl2 (encoding monocyte chemoattractant protein 1)/Tnf (encoding tumour necrosis factor α) mRNAs. Thus stimulation of kinin B2 receptor impairs skin wound healing in mice. B2R activation occurs in the diabetic skin and delays wound healing. B2R blockade improves skin wound healing in diabetic mice and is a potential therapeutic approach to diabetic ulcers.

  2. Preubiquitinated chimeric ErbB2 is constitutively endocytosed and subsequently degraded in lysosomes

    SciTech Connect

    Vuong, Tram Thu; Berger, Christian; Bertelsen, Vibeke; Rødland, Marianne Skeie; Stang, Espen; Madshus, Inger Helene

    2013-02-01

    The oncoprotein ErbB2 is endocytosis-deficient, probably due to its interaction with Heat shock protein 90. We previously demonstrated that clathrin-dependent endocytosis of ErbB2 is induced upon incubation of cells with Ansamycin derivatives, such as geldanamycin and its derivative 17-AAG. Furthermore, we have previously demonstrated that a preubiquitinated chimeric EGFR (EGFR-Ub{sub 4}) is constitutively endocytosed in a clathrin-dependent manner. We now demonstrate that also an ErbB2-Ub{sub 4} chimera is endocytosed constitutively and clathrin-dependently. Upon expression, the ErbB2-Ub{sub 4} was further ubiquitinated, and by Western blotting, we demonstrated the formation of both Lys48-linked and Lys63-linked polyubiquitin chains. ErbB2-Ub{sub 4} was constitutively internalized and eventually sorted to late endosomes and lysosomes where the fusion protein was degraded. ErbB2-Ub{sub 4} was not cleaved prior to internalization. Interestingly, over-expression of Ubiquitin Interaction Motif-containing dominant negative fragments of the clathrin adaptor proteins epsin1 and Eps15 negatively affected endocytosis of ErbB2. Altogether, this argues that ubiquitination is sufficient to induce clathrin-mediated endocytosis and lysosomal degradation of the otherwise plasma membrane localized ErbB2. Also, it appears that C-terminal cleavage is not required for endocytosis. -- Highlights: ► A chimera containing ErbB2 and a tetra-Ubiquitin chain internalizes constitutively. ► Receptor fragmentation is not required for endocytosis of ErbB2. ► Ubiquitination is sufficient to induce endocytosis and degradation of ErbB2. ► ErbB2-Ub4 is internalized clathrin-dependently.

  3. Vibrational spectrum of B2C in argon at 10 K

    NASA Astrophysics Data System (ADS)

    Larson, C. William; Domingo Presilla-Márquez, José

    1999-08-01

    The vibrational spectrum of B2C has been observed for the first time in solid argon by Fourier-transform infrared spectroscopy. Absorption frequencies of the three boron isotopomers of cyclic symmetric B2C, previously deduced by ab initio theory, are in accord with measured frequencies, which enables assignment of an absorption at 1392.8 cm-1 to the ν1(a1) fundamental of B2C(1A1).

  4. Sequestration and protection of double-stranded RNA by the betanodavirus b2 protein.

    PubMed

    Fenner, Beau J; Goh, Winnie; Kwang, Jimmy

    2006-07-01

    Betanodavirus B2 belongs to a group of functionally related proteins from the sense-strand RNA virus family Nodaviridae that suppress cellular RNA interference. The B2 proteins of insect alphanodaviruses block RNA interference by binding to double-stranded RNA (dsRNA), thus preventing Dicer-mediated cleavage and the subsequent generation of short interfering RNAs. We show here that the fish betanodavirus B2 protein also binds dsRNA. Binding is sequence independent, and maximal binding occurs with dsRNA substrates greater than 20 bp in length. The binding of B2 to long dsRNA is sufficient to completely block Dicer cleavage of dsRNA in vitro. Protein-protein interaction studies indicated that B2 interacts with itself and with other dsRNA binding proteins, the interaction occurring through binding to shared dsRNA substrates. Induction of the dsRNA-dependent interferon response was not antagonized by B2, as the interferon-responsive Mx gene of permissive fish cells was induced by wild-type viral RNA1 but not by a B2 mutant. The induction of Mx instead relied solely on viral RNA1 accumulation, which is impaired in the B2 mutant. Hyperediting of virus dsRNA and site-specific editing of 5-HT2C mRNA were both antagonized by B2. RNA editing was not, however, observed in transfected wild-type or B2 mutant RNA1, suggesting that this pathway does not contribute to the RNA1 accumulation defect of the B2 mutant. We thus conclude that betanodavirus B2 is a dsRNA binding protein that sequesters and protects both long and short dsRNAs to protect betanodavirus from cellular RNA interference.

  5. A role of nesfatin-1/NucB2 in dehydration-induced anorexia.

    PubMed

    Yoshimura, Mitsuhiro; Matsuura, Takanori; Ohkubo, Junichi; Maruyama, Takashi; Ishikura, Toru; Hashimoto, Hirofumi; Kakuma, Tetsuya; Mori, Masatomo; Ueta, Yoichi

    2014-07-15

    Nesfatin-1/NucB2, an anorexigenic molecule, is expressed mainly in the hypothalamus, particularly in the supraoptic nucleus (SON) and the paraventricular nucleus (PVN). Nesfatin-1/NucB2 is also expressed in the subfornical organ (SFO). Because the SON and PVN are involved in body fluid regulation, nesfatin-1/NucB2 may be involved in dehydration-induced anorexia. To clarify the effects of endogenous nesfatin-1/NucB2, we studied changes in nesfatin-1/NucB2 mRNA levels in the SFO, SON, and PVN in adult male Wistar rats after exposure to osmotic stimuli by using in situ hybridization histochemistry. Significant increases in nesfatin-1/NucB2 mRNA levels, ∼2- to 3-fold compared with control, were observed in the SFO, SON, and PVN following water deprivation for 48 h, consumption of 2% NaCl hypertonic saline in drinking water for 5 days, and polyethylene glycol-induced hypovolemia. In addition, nesfatin-1/NucB2 expression was increased in response to water deprivation in a time-dependent manner. These changes in nesfatin-1/NucB2 mRNA expression were positively correlated with plasma sodium concentration, plasma osmolality, and total protein levels in all of the examined nuclei. Immunohistochemistry for nesfatin-1/NucB2 revealed that nesfatin-1/NucB2 protein levels were also increased after 48 h of dehydration and attenuated by 24 h of rehydration. Moreover, intracerebroventricular administration of nesfatin-1/NucB2-neutralizing antibody after 48 h of water deprivation resulted in a significant increase in food intake compared with administration of vehicle alone. These results suggested that nesfatin-1/NucB2 is a crucial peptide in dehydration-induced anorexia.

  6. Increased Age-Related Cardiac Dysfunction in Bradykinin B2 Receptor-Deficient Mice.

    PubMed

    Feng, Wenjing; Xu, Xizhen; Zhao, Gang; Zhao, Junjie; Dong, Ruolan; Ma, Ben; Zhang, Yanjun; Long, Guangwen; Wang, Dao Wen; Tu, Ling

    2016-02-01

    Experimental evidence indicates that the kinin peptide binds to bradykinin B2 receptor (B2R) to trigger various beneficial effects on the cardiovascular system. However, the effects and underlying mechanisms of B2R in cardiac aging remain unknown. A significant age-dependent decrease in B2R expression in the myocardium was observed in C57BL/6J mice. Echocardiographic measurements showed that aging caused a significant cardiac dysfunction in C57BL/6J mice, and importantly B2R deficiency augmented this dysfunction in aging mice. The deficiency of B2R expression in the aging heart repressed p53-pGC-1α-induced mitochondria renewal, increased reactive oxygen species production, and destroyed mitochondrial ultrastructure. Age-related decrease or lack of B2R increased oxidative stress, macrophage infiltration, and inflammatory cytokine expression and compromised antioxidant enzyme expression. Moreover, the inflammatory signals were mainly mediated by the activation of p38 MAPK, JNK, and subsequent translocation of nuclear factor-kappa B to the nucleus. In summary, our data provide evidence that B2R deficiency contributes to the aging-induced cardiac dysfunction, which is likely mediated by increased mitochondrial dysfunction, oxidative stress, and inflammation. This study indicates that preventing the loss of cardioprotective B2R expression may be a novel approach for the prevention and treatment of age-related cardiac dysfunction.

  7. Properties of in situ made MgB2 in Nb or Ti sheath

    NASA Astrophysics Data System (ADS)

    Kováč, P.; Hušek, I.; Kopera, L.; Melišek, T.; Rosová, A.; Dobročka, E.

    2013-02-01

    Pure Nb and Ti have been used as sheath materials for MgB2 wires examined experimentally. The reason for this research is to compare the effects of these metallic sheaths on the basic properties of MgB2 superconductor. Single-core SiC doped MgB2 wires with Nb and/or Ti sheaths have been made by a powder-in-tube in situ process. Different transport currents, phase compositions and grain connectivity were observed for Nb- and Ti sheathed MgB2 heat treated at temperatures 650-850 °C/30 min. It was found that the critical current density of MgB2/Nb annealed above 700 °C rapidly decreases, while Jc of MgB2/Ti is systematically increasing with temperature. This is explained by the positive role of Ti absorbing impurities from the MgB2 core and by the negative effect of boron diffusion into Nb, reducing the quantity and worsening the quality of the MgB2 core. The obtained results show clearly that a Ti sheath offers the application of higher heat treatment temperatures (above 700 °C) and consequently the achievement of higher critical current densities in comparison to MgB2/Nb.

  8. Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis.

    PubMed

    Zhou, Xiaoli; Chen, Kai; Wang, Yongjun; Schuman, Mariano; Lei, Han; Sun, Zhongjie

    2016-06-01

    Deficiency of the antiaging gene Klotho (KL) induces renal damage and hypertension through unknown mechanisms. In this study, we assessed whether KL regulates expression of CYP11B2, a key rate-limiting enzyme in aldosterone synthesis, in adrenal glands. We found that haplodeficiency of KL(+/-) in mice increased the plasma level of aldosterone by 16 weeks of age, which coincided with spontaneous and persistent elevation of BP. Blockade of aldosterone actions by eplerenone reversed KL deficiency-induced hypertension and attenuated the kidney damage. Protein expression of CYP11B2 was upregulated in adrenal cortex of KL(+/-) mice. KL and CYP11B2 proteins colocalized in adrenal zona glomerulosa cells. Silencing of KL upregulated and overexpression of KL downregulated CYP11B2 expression in human adrenocortical cells. Notably, silencing of KL decreased expression of SF-1, a negative transcription factor of CYP11B2, but increased phosphorylation of ATF2, a positive transcription factor of CYP11B2, which may contribute to upregulation of CYP11B2 expression. Therefore, these results show that KL regulates adrenal CYP11B2 expression. KL deficiency-induced spontaneous hypertension and kidney damage may be partially attributed to the upregulation of CYP11B2 expression and aldosterone synthesis. PMID:26471128

  9. Superconducting MgB2 flowers: growth mechanism and their superconducting properties

    NASA Astrophysics Data System (ADS)

    Seong, Won Kyung; Ranot, Mahipal; Lee, Ji Yeong; Yang, Cheol-Woong; Lee, Jae Hak; Oh, Young Hoon; Ahn, Jae-Pyoung; Kang, Won Nam

    2016-04-01

    We report for the first time the growth and the systematic study of the growth mechanism for flower-like MgB2 structures fabricated on the substrates for solid-state electronics by the hybrid physical-chemical vapor deposition (HPCVD) technique. The MgB2 flower has a width of 30 μm and a height of 10 μm. The superconductivity of MgB2 flowers was confirmed by a magnetization measurement, and the transition temperature is 39 K, which is comparable with high-quality bulk samples. The excellent current-carrying capability was demonstrated by MgB2 flowers. To understand the nucleation and growth mechanism of MgB2 flowers a very systematic study was performed by a high-resolution transmission electron microscope (HRTEM) and atom probe (AP) microscopy. The HRTEM revealed that the seed grain of a MgB2 flower has a [101¯0] direction, and the flower is composed of micro-columnar MgB2 grains having pyramidal tips and which are grown along the (0001) plane. A clear understanding of the growth mechanism for MgB2 flowers could lead to the growth of other low-dimensional MgB2 structures for superconducting electronic devices.

  10. MgB2 superconducting whiskers synthesized by using the hybrid physical-chemical vapor deposition.

    PubMed

    Wang, Yazhou; Zhuang, Chenggang; Gao, Jingyun; Shan, Xudong; Zhang, Jingmin; Liao, Zhimin; Xu, Hongjun; Yu, Dapeng; Feng, Qingrong

    2009-02-25

    In this work, MgB(2) whiskers were fabricated on a copper substrate by using the hybrid physical-chemical vapor deposition, which was one of the most effective ways to make high quality pure MgB(2) films, with the possible growth mechanism discussed. The whiskers are hexagonal and conelike and grow along the [0001] direction with a single-crystal structure. The onset transition temperature is approximately 39 K, which is among the best in the published nanostructure MgB(2) papers. Fabrication of nanoscale MgB(2) whiskers provides the fundamental understanding of the effect of dimensionality and size on superconductivity.

  11. Isotope Effect on Electron-Phonon Coupling in Multiband Superconductor MgB2

    NASA Astrophysics Data System (ADS)

    Mou, Daixiang; Taufour, Valentin; Wu, Yun; Huang, Lunan; Bud'Ko, Serguei; Canfield, Paul; Kaminski, Adam

    We systematically investigate the isotope effect of electron-phonon coupling in multi-band superconductor MgB2 by laser based Angle Resolved Photoemission Spectroscopy. The kink structure around 70 meV on two σ bands, which is caused by electron coupling to E2 g phonon mode, is shifted to higher binding energy in Mg10B2 than that in Mg11B2. The measured shifting energy of 3.5 meV is consistent with theoretical calculation based on harmonic phonon in MgB2. Our temperature dependent measurement also indicates the isotope effect of kink structure is not dependent on superconducting transition.

  12. Al-doped MgB2 materials studied using electron paramagnetic resonance and Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Bateni, Ali; Erdem, Emre; Repp, Sergej; Weber, Stefan; Somer, Mehmet

    2016-05-01

    Undoped and aluminum (Al) doped magnesium diboride (MgB2) samples were synthesized using a high-temperature solid-state synthesis method. The microscopic defect structures of Al-doped MgB2 samples were systematically investigated using X-ray powder diffraction, Raman spectroscopy, and electron paramagnetic resonance. It was found that Mg-vacancies are responsible for defect-induced peculiarities in MgB2. Above a certain level of Al doping, enhanced conductive properties of MgB2 disappear due to filling of vacancies or trapping of Al in Mg-related vacancy sites.

  13. Beyond Cohort Selection: An Analytics-Enabled i2b2.

    PubMed

    Gabetta, Matteo; Malovini, Alberto; Bucalo, Mauro; Zini, Elisa; Tibollo, Valentina; Priori, Silvia G; Vettoretti, Simone; Larizza, Cristiana; Bellazzi, Riccardo; Barbarini, Nicola

    2016-01-01

    The i2b2 software is a widely adopted solution for secondary use of clinical data for clinical research, specifically designed for cohort identification. i2b2 is still lacking functionalities for data analysis. The aim of this work is to empower the i2b2 framework enabling clinical researchers to perform statistical analyses for accelerating the process of hypothesis testing. To this aim we have developed a flexible extension of i2b2 able to exploit different statistical engines. We have implemented some first applications for basic statistics and survival analyses, exploiting this extension and accessible through suitable user interfaces designed with a special consideration for usability.

  14. Electrochemical synthesis of superconductive MgB 2 from molten salts

    NASA Astrophysics Data System (ADS)

    Yoshii, Kenji; Abe, Hideki

    2003-05-01

    We have found that superconductive MgB2 can be electrochemically synthesized from molten salts. The electrolysis was performed in an Ar flow at 600 °C on fused mixtures composed of MgCl2, MgB2O4, Na2B2O4 and alkali halides such as KCl, NaCl, and LiCl. Superconductivity was observed for a wide variety of electrolytes. It was also found that the magnetic and electrical transport properties are the most improved for samples prepared from MgCl2-NaCl-KCl-MgB2O4 electrolytes.

  15. Microstructure and properties of TiB 2-containing coatings prepared by arc spraying

    NASA Astrophysics Data System (ADS)

    Fang, Jian-Jun; Li, Zhu-Xin; Shi, Yao-Wu

    2008-04-01

    Low cost arc spraying and cored wires were used to deposit composite coatings consisting of TiB 2 and TiB 2/Al 2O 3 hard particles in a Ni(Cr) and stainless steel 304L matrix. Four coatings were prepared namely Ni(Cr)-TiB 2, Ni(Cr)-TiB 2/Al 2O 3, 304L-TiB 2 and 304L-TiB 2/Al 2O 3. The microstructural characteristics of powders and coatings were observed by scanning electron microscopy (SEM). Phase compositions of powders were analyzed by X-ray diffraction (XRD). Although all the analyzed coatings exhibited similar lamella structure, remarkable differences not only in the morphology of hard phase and matrix but also in the size and distribution of hard phases were observed from one coating to another. Tribological behavior of the coatings was analyzed in room temperature dry sliding wear tests (block-on-ring configuration), under 75 N at low velocity (0.5 m/s). The coatings showed far high wear resistance than low carbon steel substrate under same conditions examined. Wear loss of 304L-TiB 2 and Ni(Cr)-TiB 2 coatings were lower nearly 15 times than that of steel substrate. TiB 2 hard phases in coatings bonded well with metal matrix contributed to high wear resistance.

  16. NUCLEAR REACTOR

    DOEpatents

    Grebe, J.J.

    1959-12-15

    A reactor which is particularly adapted tu serve as a heat source for a nuclear powered alrcraft or rocket is described. The core of this reactor consists of a porous refractory modera;or body which is impregnated with fissionable nuclei. The core is designed so that its surface forms tapered inlet and outlet ducts which are separated by the porous moderator body. In operation a gaseous working fluid is circulated through the inlet ducts to the surface of the moderator, enters and passes through the porous body, and is heated therein. The hot gas emerges into the outlet ducts and is available to provide thrust. The principle advantage is that tremendous quantities of gas can be quickly heated without suffering an excessive pressure drop.

  17. NUCLEAR REACTOR

    DOEpatents

    Treshow, M.

    1958-08-19

    A neuclear reactor is described of the heterogeneous type and employing replaceable tubular fuel elements and heavy water as a coolant and moderator. A pluraltty of fuel tubesa having their axes parallel, extend through a tank type pressure vessel which contatns the liquid moderator. The fuel elements are disposed within the fuel tubes in the reaetive portion of the pressure vessel during normal operation and the fuel tubes have removable plug members at each end to permit charging and discharging of the fuel elements. The fuel elements are cylindrical strands of jacketed fissionable material having helical exterior ribs. A bundle of fuel elements are held within each fuel tube with their longitudinal axes parallel, the ribs serving to space them apart along their lengths. Coolant liquid is circulated through the fuel tubes between the spaced fuel elements. Suitable control rod and monitoring means are provided for controlling the reactor.

  18. REACTOR MONITORING

    DOEpatents

    Bugbee, S.J.; Hanson, V.F.; Babcock, D.F.

    1959-02-01

    A neutron density inonitoring means for reactors is described. According to this invention a tunnel is provided beneath and spaced from the active portion of the reactor and extends beyond the opposite faces of the activc portion. Neutron beam holes are provided between the active portion and the tunnel and open into the tunnel near the middle thereof. A carriage operates back and forth in the tunnel and is adapted to convey a neutron detector, such as an ion chamber, and position it beneath one of the neutron beam holes. This arrangement affords convenient access of neutron density measuring instruments to a location wherein direct measurement of neutron density within the piles can be made and at the same time affords ample protection to operating personnel.

  19. NEUTRONIC REACTOR

    DOEpatents

    Wade, E.J.

    1958-09-16

    This patent relates to a reflector means for a neutronic reactor. A reflector comprised of a plurality of vertically movable beryllium control members is provided surrounding the sides of the reactor core. An absorber of fast neutrons comprised of natural uramum surrounds the reflector. An absorber of slow neutrons surrounds the absorber of fast neutrons and is formed of a plurality of beryllium blocks having natural uranium members distributcd therethrough. in addition, a movable body is positioned directly below the core and is comprised of a beryllium reflector and an absorbing member attached to the botiom thereof, the absorbing member containing a substance selected from the goup consisting of natural urantum and Th/sup 232/.

  20. Nuclear reactor

    DOEpatents

    Wade, Elman E.

    1979-01-01

    A nuclear reactor including two rotatable plugs and a positive top core holddown structure. The top core holddown structure is divided into two parts: a small core cover, and a large core cover. The small core cover, and the upper internals associated therewith, are attached to the small rotating plug, and the large core cover, with its associated upper internals, is attached to the large rotating plug. By so splitting the core holddown structures, under-the-plug refueling is accomplished without the necessity of enlarging the reactor pressure vessel to provide a storage space for the core holddown structure during refueling. Additionally, the small and large rotating plugs, and their associated core covers, are arranged such that the separation of the two core covers to permit rotation is accomplished without the installation of complex lifting mechanisms.

  1. REACTOR UNLOADING

    DOEpatents

    Leverett, M.C.

    1958-02-18

    This patent is related to gas cooled reactors wherein the fuel elements are disposed in vertical channels extending through the reactor core, the cooling gas passing through the channels from the bottom to the top of the core. The invention is a means for unloading the fuel elements from the core and comprises dump values in the form of flat cars mounted on wheels at the bottom of the core structure which support vertical stacks of fuel elements. When the flat cars are moved, either manually or automatically, for normal unloading purposes, or due to a rapid rise in the reproduction ratio within the core, the fuel elements are permtted to fall by gravity out of the core structure thereby reducing the reproduction ratio or stopping the reaction as desired.

  2. Neutronic reactor

    DOEpatents

    Lewis, Warren R.

    1978-05-30

    A graphite-moderated, water-cooled nuclear reactor including a plurality of rectangular graphite blocks stacked in abutting relationship in layers, alternate layers having axes which are normal to one another, alternate rows of blocks in alternate layers being provided with a channel extending through the blocks, said channeled blocks being provided with concave sides and having smaller vertical dimensions than adjacent blocks in the same layer, there being nuclear fuel in the channels.

  3. NUCLEAR REACTORS

    DOEpatents

    Koch, L.J.; Rice, R.E. Jr.; Denst, A.A.; Rogers, A.J.; Novick, M.

    1961-12-01

    An active portion assembly for a fast neutron reactor is described wherein physical distortions resulting in adverse changes in the volume-to-mass ratio are minimized. A radially expandable locking device is disposed within a cylindrical tube within each fuel subassembly within the active portion assembly, and clamping devices expandable toward the center of the active portion assembly are disposed around the periphery thereof. (AEC)

  4. NUCLEAR REACTORS

    DOEpatents

    Long, E.; Ashby, J.W.

    1958-09-16

    ABS>A graphite moderator structure is presented for a nuclear reactor compriscd of an assembly of similarly orientated prismatic graphite blocks arranged on spaced longitudinal axes lying in common planes wherein the planes of the walls of the blocks are positioned so as to be twisted reintive to the planes of said axes so thatthe unlmpeded dtrect paths in direction wholly across the walls of the blocks are limited to the width of the blocks plus spacing between the blocks.

  5. NEUTRONIC REACTORS

    DOEpatents

    Anderson, J.B.

    1960-01-01

    A reactor is described which comprises a tank, a plurality of coaxial steel sleeves in the tank, a mass of water in the tank, and wire grids in abutting relationship within a plurality of elongated parallel channels within the steel sleeves, the wire being provided with a plurality of bends in the same plane forming adjacent parallel sections between bends, and the sections of adjacent grids being normally disposed relative to each other.

  6. NUCLEAR REACTOR

    DOEpatents

    Grebe, J.J.

    1961-01-24

    A core structure for neutronic reactors adapted for the propulsion of aircraft and rockets is offered. The core is designed for cooling by gaseous media, and comprises a plurality of hollow tapered tubular segments of a porous moderating material impregniated with fissionable fuel nested about a common axis. Alternate ends of the segments are joined. In operation a coolant gas passes through the porous structure and is heated.

  7. In situ study of p-type amorphous silicon growth from B2H6:SiH4 mixtures: Surface reactivity and interface effects

    NASA Astrophysics Data System (ADS)

    Collins, R. W.

    1988-09-01

    In situ ellipsometry provides monolayer sensitivity to the reaction of B2H6:SiH4 doping gas mixtures with p- and i-type plasma-enhanced chemical vapor deposited (PECVD) amorphous silicon (a-Si:H) surfaces at 180 and 250 °C. This low-temperature reaction, leading to the slow growth (1-3 Å/min) of a-Si:H:B by CVD (without plasma excitation), requires a clean a-Si:H surface and both B2H6 and SiH4 in the doping gas. We suggest that the high B content of CVD a-Si:H:B at p-i and i-p interfaces and on the film-coated regions of single-chamber reactors, may contribute to poor interface characteristics and residual contamination in devices.

  8. REACTOR CONTROL

    DOEpatents

    Ruano, W.J.

    1957-12-10

    This patent relates to nuclear reactors of the type which utilize elongited rod type fuel elements immersed in a liquid moderator and shows a design whereby control of the chain reaction is obtained by varying the amount of moderator or reflector material. A central tank for containing liquid moderator and fuel elements immersed therein is disposed within a surrounding outer tank providing an annular space between the two tanks. This annular space is filled with liquid moderator which functions as a reflector to reflect neutrons back into the central reactor tank to increase the reproduction ratio. Means are provided for circulating and cooling the moderator material in both tanks and additional means are provided for controlling separately the volume of moderator in each tank, which latter means may be operated automatically by a neutron density monitoring device. The patent also shows an arrangement for controlling the chain reaction by injecting and varying an amount of poisoning material in the moderator used in the reflector portion of the reactor.

  9. Review of magnetic features observed in (A,A')Ni 2B 2C solid solutions

    NASA Astrophysics Data System (ADS)

    Kuznietz, Moshe; Gonçalves, António P.; Almeida, Manuel

    2002-08-01

    The nickel-borocarbides ANi 2B 2C [A=Y, Ln (lanthanide), An(actinide)], crystallizing in the body-centred tetragonal LuNi 2B 2C-type structure, are classified according to the existence or coexistence of superconducting and antiferromagnetic states (AF). The magnetic features observed in polycrystalline (A,A')Ni 2B 2C solid solutions, adopting the same crystal structure, are reviewed and discussed. Published data on the magnetism in (A,Ln)Ni 2B 2C systems (ANi 2B 2C nonmagnetic, A=Y,La,Lu) indicate a gradual rise in the threshold content, x( m), in (Y 1- xLn x)Ni 2B 2C (Ln=Gd,Tb,Dy,Ho,Er) for the establishment of AF states. (A,A')Ni 2B 2C systems with magnetic end compounds show gradual variation in magnetic features when A and A' are both heavy Ln. The behaviour of (A,A')Ni 2B 2C systems of light A (Pr or U) and heavy A' (Dy or Tm) depends on the magnetic structures of the end compounds. In intermediate compositions, incomplete moment compensation in (Pr,Dy)Ni 2B 2C decreases TN, while different moment directions in the end compounds in (U,Dy)Ni 2B 2C lead to a directional frustration of ordered moments. Such a frustration in (U,Tm)Ni 2B 2C is related to different magnetic structures of the end compounds.

  10. Phosphorylation and Alternative Splicing of 7B2 Reduce Prohormone Convertase 2 Activation

    PubMed Central

    Ramos-Molina, Bruno

    2015-01-01

    FAM20C is a secretory kinase responsible for the phosphorylation of multiple secreted proteins in mammalian cells; it has been shown to phosphorylate serine residues within a variety of different bone proteins. In this work we demonstrate that FAM20C also phosphorylates threonines, specifically those within the N-terminal domain of the neuroendocrine chaperone 7B2. Analysis of the primary sequence of 7B2 revealed that three threonine residues in its N-terminal domain are located within FAM20C consensus motifs: Thr73, Thr99, and Thr111. The individual substitution of Thr73 and Thr111 residues by neutral alanines caused a marked decrease in the total phosphorylation of 7B2. Furthermore, the phosphomimetic substitution of Thr111 by Glu clearly diminished the ability of 7B2 to activate pro-prohormone convertase 2 (PC2) in 7B2-lacking SK-N-MC neuroblastoma cells, suggesting that the phosphorylation of this residue critically impacts the 7B2-proPC2 interaction. However, the phosphomimetic mutation did not alter 7B2's ability to function as an antiaggregant for human islet amyloid polypeptide. FAM20C-mediated phosphorylation of a common alternatively spliced variant of human 7B2 that lacks Ala100 (thus eliminating the Thr99 phosphorylation consensus site) was similar to the Ala-containing protein, but this variant did not activate proPC2 as efficiently as the Ala-containing protein. Although threonines within 7B2 were phosphorylated efficiently, FAM20C was incapable of performing the well-known regulatory threonine phosphorylation of the molecular chaperone binding immunoglobulin protein. Taken together, these results indicate that FAM20C plays a role in 7B2-mediated proPC2 activation by phosphorylating residue Thr111; and that 7B2 function is regulated by alternative splicing. PMID:25811241

  11. Inhibition of ErbB-2 induces TFF3 downregulation in breast cancer cell lines.

    PubMed

    Yue, Lu; Xiang, Jinyu; Shen, Zan; Wang, Zhihao; Yao, Yasai; Zhou, Quan; Ding, Aiping; Qiu, Wensheng

    2014-07-01

    ErbB-2 gene plays an important role in carcinoma formation whose overexpression was observed in many types of tumors, including breast cancer. Dysregulation of Trefoil factor 3 (TFF3), which is thought to function in the development and progression of breast cancer, was found to be upregulated in ErbB2-overexpressing breast cancers and cells. However, a putative interaction between ErbB-2 and TFF3 in breast cancer remains unknown. To determine whether TFF3 has an important role in breast tumor, its levels were measured by immunohistochemistry in 130 cases of breast infiltrating duct carcinoma and 30 cases of normal breast tissue with a specific monoclonal antibody raised against human TFF3. Patients who were positive for ErbB-2 also had high expression levels of TFF3 (p < 0.05). Also, after infecting the SK-BR-3 cells with lentivirus-mediated ErbB2-specific shRNA (Lenti-ShERBB2), we detected the expressions of ErbB-2 and TFF3 by real-time polymerase chain reaction and Western blotting, respectively. Compared with the control groups, ErbB-2 mRNA expression was decreased in the Lenti-ShERBB2 infection group, and Western blotting indicated a concordant ErbB-2 protein reduction. On the other hand, TFF3 expression at both mRNA and protein levels was significantly downregulated by ErbB-2 silencing in SK-BR-3. These findings are a proof of the foundation for a certain relationships of ErbB-2 and TFF3, which may serve as novel therapeutic markers of ErbB2-overexpressing breast cancers in the future.

  12. ZrB2 thin films deposited on GaN(0001) by magnetron sputtering from a ZrB2 target

    NASA Astrophysics Data System (ADS)

    Tengdelius, Lina; Lu, Jun; Forsberg, Urban; Li, Xun; Hultman, Lars; Janzén, Erik; Högberg, Hans

    2016-11-01

    ZrB2 films were deposited on 900 °C-preheated or non-preheated GaN(0001) surfaces by direct current magnetron sputtering from a compound target. Analytical transmission electron microscopy and scanning transmission electron microscopy with energy dispersive X-ray spectroscopy and electron energy loss spectroscopy revealed a 0001 fiber textured ZrB2 film growth following the formation of a 2 nm thick amorphous BN layer onto the GaN(0001) at a substrate temperature of 900 °C. The amorphous BN layer remains when the substrate temperature is lowered to 500 °C or when the preheating step is removed from the process and results in the growth of polycrystalline ZrB2 films. The ZrB2 growth phenomena on GaN(0001) is compared to on 4H-SiC(0001), Si(111), and Al2O3(0001) substrates, which yield epitaxial film growth. The decomposition of the GaN surface during vacuum processing during BN interfacial layer formation is found to impede epitaxial growth of ZrB2.

  13. Effects of ZrB2 on substructure and wear properties of laser melted in situ ZrB2p/6061Al composites

    NASA Astrophysics Data System (ADS)

    Zeng, Yida; Chao, Yuhjin; Luo, Zhen; Cai, Yangchuan; Huang, Yongxian

    2016-03-01

    Aluminum matrix composites reinforced by in situ ZrB2 particles were successfully fabricated from an Al-KBF4-K2ZrF6 system via a direct melt reaction. A laser surface melting strategy is used to improve the surface strength of the in situ ZrB2p/6061Al composite, which includes a series of laser-melted composites with different laser power processed by a 2 kW YAG laser generator. XRD and EDS results demonstrated the existence of ZrB2 nanoparticles in the composite. After laser melting, the penetration depth of the molten pool increases with increasing power density. OM and SEM analysis indicate that the laser melting process yields narrower cellular spacing of the matrix and partly disperses the ZrB2 particle clusters. Compared with laser-melted matrix alloys, the crystal orientations near the melted layers edge of the composite are almost random due to heterogeneous nucleation in the melt and the pinning effect of laser-dispersed ZrB2 nanoparticles at the solidification front. Wear test results show that the laser melted layer performs better at wear resistance than both the substrate and the matrix AA6061 by measuring wear mass loss. Compared with composite samples prepared without laser melting, the wear mass loss of the laser melted composites decreased from 61 to 56 mg under a load of 98 N for 60 min.

  14. A Decompositional Approach to Executing Quality Data Model Algorithms on the i2b2 Platform.

    PubMed

    Mo, Huan; Jiang, Guoqian; Pacheco, Jennifer A; Kiefer, Richard; Rasmussen, Luke V; Pathak, Jyotishman; Denny, Joshua C; Thompson, William K

    2016-01-01

    The Quality Data Model (QDM) is an established standard for representing electronic clinical quality measures on electronic health record (EHR) repositories. The Informatics for Integrated Biology and the Bedside (i2b2) is a widely used platform for implementing clinical data repositories. However, translation from QDM to i2b2 is challenging, since QDM allows for complex queries beyond the capability of single i2b2 messages. We have developed an approach to decompose complex QDM algorithms into workflows of single i2b2 messages, and execute them on the KNIME data analytics platform. Each workflow operation module is composed of parameter lists, a template for the i2b2 message, an mechanism to create parameter updates, and a web service call to i2b2. The communication between workflow modules relies on passing keys ofi2b2 result sets. As a demonstration of validity, we describe the implementation and execution of a type 2 diabetes mellitus phenotype algorithm against an i2b2 data repository. PMID:27570665

  15. 26 CFR 48.6416(b)(2)-2 - Exportations, uses, sales, and resales included.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Administrative Provisions of Special Application to Retailers and Manufacturers Taxes § 48.6416(b)(2)-2... special motor fuel, will be considered to be an overpayment under section 6416(b)(2)(B) if the article or... article, or under section 4041 (a)(1) or (a)(2) on the sale of diesel fuel or special motor fuel, will...

  16. SerpinB2 is critical to Th2 immunity against enteric nematode infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    SerpinB2, a member of the serine protease inhibitor family, is expressed by macrophages and up-regulated significantly by inflammation. Recent studies implicated a role for SerpinB2 in the control of Th1 and Th2 immune responses, but the mechanisms of these effects are unknown. In the current study...

  17. Kinin B2 receptor deletion and blockage ameliorates cisplatin-induced acute renal injury.

    PubMed

    Estrela, Gabriel R; Wasinski, Frederick; Bacurau, Reury F; Malheiros, Denise M A C; Câmara, Niels O S; Araújo, Ronaldo C

    2014-09-01

    Cisplatin treatment has been adopted in some chemotherapies; however, this drug can induce acute kidney injury due its ability to negatively affect renal function, augment serum levels of creatinine and urea, increase the acute tubular necrosis score and up-regulate cytokines (e.g., IL-1β and TNF-α). The kinin B2 receptor has been associated with the inflammation process, as well as the regulation of cytokine expression, and its deletion resulted in an improvement in the diabetic nephropathy status. To examine the role of the kinin B2 receptor in cisplatin-induced acute kidney injury, kinin B2 receptor knockout mice were challenged with cisplatin. Additionally, WT mice were treated with a B2 receptor antagonist after cisplatin administration. B2 receptor-deficient mice were less sensitive to this drug than the WT mice, as shown by reduced weight loss, better preservation of kidney function, down regulation of inflammatory cytokines and less acute tubular necrosis. Moreover, treatment with the kinin B2 receptor antagonist effectively reduced the levels of serum creatinine and blood urea after cisplatin administration. Thus, our data suggest that the kinin B2 receptor is involved in cisplatin-induced acute kidney injury by mediating the necrotic process and the expression of inflammatory cytokines, thus resulting in declined renal function. These results highlight the kinin B2 receptor antagonist treatment in amelioration of nephrotoxicity induced by cisplatin therapy.

  18. Kinin B2 receptor can play a neuroprotective role in Alzheimer's disease.

    PubMed

    Caetano, A L; Dong-Creste, K E; Amaral, F A; Monteiro-Silva, K C; Pesquero, J B; Araujo, M S; Montor, W R; Viel, T A; Buck, H S

    2015-10-01

    Alzheimer's disease (AD) is characterized by cognitive decline, presence of amyloid-beta peptide (Aβ) aggregates and neurofibrillary tangles. Kinins act through B1 and B2 G-protein coupled receptors (B1R and B2R). Chronic infusion of Aβ peptide leads to memory impairment and increases in densities of both kinin receptors in memory processing areas. Similar memory impairment was observed in C57BL/6 mice (WTAβ) but occurred earlier in mice lacking B2R (KOB2Aβ) and was absent in mice lacking B1R (KOB1Aβ). Thus, the aim of this study was to evaluate the participation of B1R and B2R in Aβ peptide induced cognitive deficits through the evaluation of densitiesof kinin receptors, synapses, cell bodies and number of Aβ deposits in brain ofWTAβ, KOB1Aβ and KOB2Aβ mice. An increase in B2R density was observed in both WTAβ and KOB1Aβ in memory processing related areas. KOB1Aβ showed a decrease in neuronal density and an increase in synaptic density and, in addition, an increase in Aβ deposits in KOB2Aβ was observed. In conclusion, memory preservation in KOB1Aβ, could be due to the increase in densities of B2R, suggesting a neuroprotective role for B2R, reinforced by the increased number of Aβ plaques in KOB2Aβ. Our data point to B2R as a potential therapeutic target in AD.

  19. [Serologic characteristics and population distribution of subtypes B2 and AB2 of ABO blood group].

    PubMed

    Duan, Fu-Cai; Wang, Ming-Lu; Zhou, Ke-Li; Li, Da-Yuan; Zhang, Qin-Yong; Ma, Ai-Ping; Yang, He-Ying; Li, Jian-Hua; Liu, Yuan-Yuan; Xiao, Fang; Gao, Ying-Xue

    2010-10-01

    This study was aimed to investigate the serologic characteristics, genetic background and population distribution of B2 and AB2 subtype in Chinese ABO blood group. The classic blood group serological technology was used to detect ABO blood group of the propositus and their family members, the anti-B1 serum prepared by yourself was used to investigate the distribution of B1/B2 and AB1/AB2 subtype of the blood donor. The results indicated that the antigen of propositus was AB2 subtype and that of his child was B2 subtype. The anti-B1 antibody was detected in blood serum of propositus; the antigen of 3 from 2318 blood donors with B blood group were found to be B2 subtype, the antigen of 2 from 826 blood donors with AB blood group were found to be AB2 subtype. The investigation on propositus and the 3 B2 blood donor families showed that B2 antigen displays genetic characteristics of blood group. It is concluded that B2/AB2 subtype is from family inheritance, while B2 subtype is amounted to 0.129% in B blood group, and AB2 subtype is amounted to 0.224% in AB blood group.

  20. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... media organizations. 9b.2 Section 9b.2 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS... media organizations. In order to obtain a Department of State press building pass, press correspondents employed by United States media organizations must: (a) Present to the Office of Press...

  1. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... media organizations. 9b.2 Section 9b.2 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS... media organizations. In order to obtain a Department of State press building pass, press correspondents employed by United States media organizations must: (a) Present to the Office of Press...

  2. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... media organizations. 9b.2 Section 9b.2 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS... media organizations. In order to obtain a Department of State press building pass, press correspondents employed by United States media organizations must: (a) Present to the Office of Press...

  3. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... media organizations. 9b.2 Section 9b.2 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS... media organizations. In order to obtain a Department of State press building pass, press correspondents employed by United States media organizations must: (a) Present to the Office of Press...

  4. 22 CFR 9b.2 - Press correspondents employed by United States media organizations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... media organizations. 9b.2 Section 9b.2 Foreign Relations DEPARTMENT OF STATE GENERAL REGULATIONS... media organizations. In order to obtain a Department of State press building pass, press correspondents employed by United States media organizations must: (a) Present to the Office of Press...

  5. 26 CFR 31.3406(b)(2)-3 - Window transactions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Window transactions. 31.3406(b)(2)-3 Section 31... SOURCE Collection of Income Tax at Source § 31.3406(b)(2)-3 Window transactions. (a) Requirement to backup withhold. Withholding under section 3406 applies to a window transaction (as defined in...

  6. 26 CFR 31.3406(b)(2)-3 - Window transactions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Window transactions. 31.3406(b)(2)-3 Section 31... SOURCE Collection of Income Tax at Source § 31.3406(b)(2)-3 Window transactions. (a) Requirement to backup withhold. Withholding under section 3406 applies to a window transaction (as defined in...

  7. 17 CFR 270.24b-2 - Filing copies of sales literature.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 4 2014-04-01 2014-04-01 false Filing copies of sales literature. 270.24b-2 Section 270.24b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... literature. Copies of material filed with the Commission for the sole purpose of complying with section...

  8. 17 CFR 270.24b-2 - Filing copies of sales literature.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 3 2012-04-01 2012-04-01 false Filing copies of sales literature. 270.24b-2 Section 270.24b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... literature. Copies of material filed with the Commission for the sole purpose of complying with section...

  9. 17 CFR 270.24b-2 - Filing copies of sales literature.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Filing copies of sales literature. 270.24b-2 Section 270.24b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... literature. Copies of material filed with the Commission for the sole purpose of complying with section...

  10. 17 CFR 270.24b-2 - Filing copies of sales literature.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Filing copies of sales literature. 270.24b-2 Section 270.24b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... literature. Copies of material filed with the Commission for the sole purpose of complying with section...

  11. 17 CFR 270.24b-2 - Filing copies of sales literature.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Filing copies of sales literature. 270.24b-2 Section 270.24b-2 Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION... literature. Copies of material filed with the Commission for the sole purpose of complying with section...

  12. 26 CFR 1.669(b)-2 - Manner of exercising election.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Manner of exercising election. 1.669(b)-2... Taxable Years Beginning Before January 1, 1969 § 1.669(b)-2 Manner of exercising election. (a) By whom election is to be made. Except as otherwise provided in this paragraph, a taxpayer whose tax liability...

  13. 26 CFR 1.669(b)-2 - Manner of exercising election.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Manner of exercising election. 1.669(b)-2... Taxable Years Beginning Before January 1, 1969 § 1.669(b)-2 Manner of exercising election. (a) By whom election is to be made. Except as otherwise provided in this paragraph, a taxpayer whose tax liability...

  14. 29 CFR 783.26 - The section 6(b)(2) minimum wage requirement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false The section 6(b)(2) minimum wage requirement. 783.26... The section 6(b)(2) minimum wage requirement. Section 6(b), with paragraph (2) thereof, requires the... prescribed by” paragraph (1) of the subsection is the minimum wage rate applicable according to the...

  15. 29 CFR 783.26 - The section 6(b)(2) minimum wage requirement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false The section 6(b)(2) minimum wage requirement. 783.26... The section 6(b)(2) minimum wage requirement. Section 6(b), with paragraph (2) thereof, requires the... prescribed by” paragraph (1) of the subsection is the minimum wage rate applicable according to the...

  16. 29 CFR 783.26 - The section 6(b)(2) minimum wage requirement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false The section 6(b)(2) minimum wage requirement. 783.26... The section 6(b)(2) minimum wage requirement. Section 6(b), with paragraph (2) thereof, requires the... prescribed by” paragraph (1) of the subsection is the minimum wage rate applicable according to the...

  17. 29 CFR 783.26 - The section 6(b)(2) minimum wage requirement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false The section 6(b)(2) minimum wage requirement. 783.26... The section 6(b)(2) minimum wage requirement. Section 6(b), with paragraph (2) thereof, requires the... prescribed by” paragraph (1) of the subsection is the minimum wage rate applicable according to the...

  18. 29 CFR 783.26 - The section 6(b)(2) minimum wage requirement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false The section 6(b)(2) minimum wage requirement. 783.26... The section 6(b)(2) minimum wage requirement. Section 6(b), with paragraph (2) thereof, requires the... prescribed by” paragraph (1) of the subsection is the minimum wage rate applicable according to the...

  19. 26 CFR 20.2056(b)-2 - Marital deduction; interest in unidentified assets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Marital deduction; interest in unidentified assets. 20.2056(b)-2 Section 20.2056(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16,...

  20. 26 CFR 20.2056(b)-2 - Marital deduction; interest in unidentified assets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 14 2011-04-01 2010-04-01 true Marital deduction; interest in unidentified assets. 20.2056(b)-2 Section 20.2056(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16,...

  1. 26 CFR 20.2056(b)-2 - Marital deduction; interest in unidentified assets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 14 2013-04-01 2013-04-01 false Marital deduction; interest in unidentified assets. 20.2056(b)-2 Section 20.2056(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16,...

  2. 26 CFR 20.2056(b)-2 - Marital deduction; interest in unidentified assets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 14 2014-04-01 2013-04-01 true Marital deduction; interest in unidentified assets. 20.2056(b)-2 Section 20.2056(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16,...

  3. 26 CFR 20.2056(b)-2 - Marital deduction; interest in unidentified assets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 14 2012-04-01 2012-04-01 false Marital deduction; interest in unidentified assets. 20.2056(b)-2 Section 20.2056(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16,...

  4. 26 CFR 1.415(b)-2 - Multiple annuity starting dates. [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Multiple annuity starting dates. 1.415(b)-2 Section 1.415(b)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... Multiple annuity starting dates....

  5. Kinin B2 receptor deletion and blockage ameliorates cisplatin-induced acute renal injury.

    PubMed

    Estrela, Gabriel R; Wasinski, Frederick; Bacurau, Reury F; Malheiros, Denise M A C; Câmara, Niels O S; Araújo, Ronaldo C

    2014-09-01

    Cisplatin treatment has been adopted in some chemotherapies; however, this drug can induce acute kidney injury due its ability to negatively affect renal function, augment serum levels of creatinine and urea, increase the acute tubular necrosis score and up-regulate cytokines (e.g., IL-1β and TNF-α). The kinin B2 receptor has been associated with the inflammation process, as well as the regulation of cytokine expression, and its deletion resulted in an improvement in the diabetic nephropathy status. To examine the role of the kinin B2 receptor in cisplatin-induced acute kidney injury, kinin B2 receptor knockout mice were challenged with cisplatin. Additionally, WT mice were treated with a B2 receptor antagonist after cisplatin administration. B2 receptor-deficient mice were less sensitive to this drug than the WT mice, as shown by reduced weight loss, better preservation of kidney function, down regulation of inflammatory cytokines and less acute tubular necrosis. Moreover, treatment with the kinin B2 receptor antagonist effectively reduced the levels of serum creatinine and blood urea after cisplatin administration. Thus, our data suggest that the kinin B2 receptor is involved in cisplatin-induced acute kidney injury by mediating the necrotic process and the expression of inflammatory cytokines, thus resulting in declined renal function. These results highlight the kinin B2 receptor antagonist treatment in amelioration of nephrotoxicity induced by cisplatin therapy. PMID:24975837

  6. In situ epitaxial MgB2 thin films for superconducting electronics.

    PubMed

    Zeng, Xianghui; Pogrebnyakov, Alexej V; Kotcharov, Armen; Jones, James E; Xi, X X; Lysczek, Eric M; Redwing, Joan M; Xu, Shengyong; Li, Qi; Lettieri, James; Schlom, Darrell G; Tian, Wei; Pan, Xiaoqing; Liu, Zi-Kui

    2002-09-01

    The newly discovered 39-K superconductor MgB2 holds great promise for superconducting electronics. Like the conventional superconductor Nb, MgB2 is a phonon-mediated superconductor, with a relatively long coherence length. These properties make the prospect of fabricating reproducible uniform Josephson junctions, the fundamental element of superconducting circuits, much more favourable for MgB2 than for high-temperature superconductors. The higher transition temperature and larger energy gap of MgB2 promise higher operating temperatures and potentially higher speeds than Nb-based integrated circuits. However, success in MgB2 Josephson junctions has been limited because of the lack of an adequate thin-film technology. Because a superconducting integrated circuit uses a multilayer of superconducting, insulating and resistive films, an in situ process in which MgB2 is formed directly on the substrate is desirable. Here we show that this can be achieved by hybrid physical-chemical vapour deposition. The epitaxially grown MgB2 films show a high transition temperature and low resistivity, comparable to the best bulk samples, and their surfaces are smooth. This advance removes a major barrier for superconducting electronics using MgB2.

  7. A Decompositional Approach to Executing Quality Data Model Algorithms on the i2b2 Platform.

    PubMed

    Mo, Huan; Jiang, Guoqian; Pacheco, Jennifer A; Kiefer, Richard; Rasmussen, Luke V; Pathak, Jyotishman; Denny, Joshua C; Thompson, William K

    2016-01-01

    The Quality Data Model (QDM) is an established standard for representing electronic clinical quality measures on electronic health record (EHR) repositories. The Informatics for Integrated Biology and the Bedside (i2b2) is a widely used platform for implementing clinical data repositories. However, translation from QDM to i2b2 is challenging, since QDM allows for complex queries beyond the capability of single i2b2 messages. We have developed an approach to decompose complex QDM algorithms into workflows of single i2b2 messages, and execute them on the KNIME data analytics platform. Each workflow operation module is composed of parameter lists, a template for the i2b2 message, an mechanism to create parameter updates, and a web service call to i2b2. The communication between workflow modules relies on passing keys ofi2b2 result sets. As a demonstration of validity, we describe the implementation and execution of a type 2 diabetes mellitus phenotype algorithm against an i2b2 data repository.

  8. 26 CFR 1.652(b)-2 - Allocation of income items.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Allocation of income items. 1.652(b)-2 Section 1... (CONTINUED) INCOME TAXES Trusts Which Distribute Current Income Only § 1.652(b)-2 Allocation of income items... different beneficiaries, or unless local law requires such an allocation. For example: Assume that under...

  9. Synthesis of TiB2/Fe-Cr-Al nanocomposite powder.

    PubMed

    Sachan, Ritesh; Park, Jong-Woo

    2008-10-01

    In this study, a route for synthesizing TiB2/Fe-Cr-Al nanocomposite is proposed via high energy ball milling by using directly coarse powders of TiB2, Fe, Cr and Al. Various compositions of these powder mixtures are milled up to 48 hrs to investigate the effect of composition on the crystalline refinement. The crystalline size is analyzed by an X-ray diffractometer for powder samples containing 30 to 100 wt% TiB2 (the rest of the powder consists of Fe-20 wt%Cr-5 wt%Al composition). The crystalline size after 48 hrs of ball milling decreases with increasing TiB2, and then again increases after reaching a minimum value of 18 nm at 70% TiB2. By transmission electron microscopic analysis, it is confirmed that particles of TiB2 are significantly reduced and finely dispersed in the Fe-Cr-Al matrix. The particle size of TiB2 is found around 20-25 nm, reinforced in the matrix. Considering the results of this study, the proposed mechanical milling route can be recommended as a promising way for fabrication of TiB2/Fe-Cr-Al nanocomposite powder. PMID:19198473

  10. A Decompositional Approach to Executing Quality Data Model Algorithms on the i2b2 Platform

    PubMed Central

    Mo, Huan; Jiang, Guoqian; Pacheco, Jennifer A.; Kiefer, Richard; Rasmussen, Luke V.; Pathak, Jyotishman; Denny, Joshua C.; Thompson, William K.

    2016-01-01

    The Quality Data Model (QDM) is an established standard for representing electronic clinical quality measures on electronic health record (EHR) repositories. The Informatics for Integrated Biology and the Bedside (i2b2) is a widely used platform for implementing clinical data repositories. However, translation from QDM to i2b2 is challenging, since QDM allows for complex queries beyond the capability of single i2b2 messages. We have developed an approach to decompose complex QDM algorithms into workflows of single i2b2 messages, and execute them on the KNIME data analytics platform. Each workflow operation module is composed of parameter lists, a template for the i2b2 message, an mechanism to create parameter updates, and a web service call to i2b2. The communication between workflow modules relies on passing keys ofi2b2 result sets. As a demonstration of validity, we describe the implementation and execution of a type 2 diabetes mellitus phenotype algorithm against an i2b2 data repository. PMID:27570665

  11. Improved Serodiagnosis of Cystic Echinococcosis Using the New Recombinant 2B2t Antigen

    PubMed Central

    Hernández-González, Ana; Santivañez, Saúl; García, Héctor H.; Rodríguez, Silvia; Muñoz, Santiago; Ramos, Guillermo; Orduña, Antonio; Siles-Lucas, Mar

    2012-01-01

    A standardized test for the serodiagnosis of human cystic echinococcosis (CE) is still needed, because of the low specificity and sensitivity of the currently available commercial tools and the lack of proper evaluation of the existing recombinant antigens. In a previous work, we defined the new ELISA-B2t diagnostic tool for the detection of specific IgGs in CE patients, which showed high sensitivity and specificity, and was useful in monitoring the clinical evolution of surgically treated CE patients. Nevertheless, this recombinant antigen gave rise to false-negative results in a percentage of CE patients. Therefore, in an attempt to improve its sensitivity, we constructed B2t-derived recombinant antigens with two, four and eight tandem repeat of B2t units, and tested them by ELISA on serum samples of CE patients and patients with related parasites. The best diagnostic values were obtained with the two tandem repeat 2B2t antigen. The influence of several clinical variables on the performance of the tests was also evaluated. Finally, the diagnostic performance of the 2B2t-ELISA was compared with that of an indirect haemagglutination commercial test. The 2B2t recombinant antigen performed better than the HF and B2t antigens, and the IHA commercial kit. Therefore, this new 2B2t-ELISA is a promising candidate test for the serodiagnosis of CE in clinical settings. PMID:22802975

  12. Molecular characterization and diversity of puroindoline b-2 variants in cultivated and wild diploid wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cloning and phylogenetic analysis of puroindoline b-2 variants in common wheat (Triticum aestivum L.) and its relatives would advance the understanding of the genetic diversity and evolution of puroindoline b-2 gene in common wheat and its related species. In the present study, common wheat (AABBDD)...

  13. Distribution coefficients of vitamin B2 in hydrophilic organic solvent-aqueous salt solution systems

    NASA Astrophysics Data System (ADS)

    Korenman, Ya. I.; Mokshina, N. Ya.; Zykov, A. V.

    2010-03-01

    Distribution coefficients of vitamin B2 in hydrophilic solvent ( n-butanol, isopropanol, acetone, ethyl acetate, and their mixtures)-aqueous salt (potassium chloride, sodium fluoride, and ammonium sulfate salting-out agents) solution systems were calculated. The synergic effect and optimum proportions of components in the solvent mixture for efficient extraction of vitamin B2 from aqueous solutions were established.

  14. Chitin and L(+)-lactic acid production from crab (Callinectes bellicosus) wastes by fermentation of Lactobacillus sp. B2 using sugar cane molasses as carbon source.

    PubMed

    Flores-Albino, Belem; Arias, Ladislao; Gómez, Jorge; Castillo, Alberto; Gimeno, Miquel; Shirai, Keiko

    2012-09-01

    Crab wastes are employed for simultaneous production of chitin and L(+)-lactic acid by submerged fermentation of Lactobacillus sp. B2 using sugar cane molasses as carbon source. Response surface methodology was applied to design the culture media considering demineralization. Fermentations in stirred tank reactor (2L) using selected conditions produced 88% demineralization and 56% deproteinization with 34% yield of chitin and 19.5 gL(-1) of lactic acid (77% yield). The chitin purified from fermentation displayed 95% degree of acetylation and 0.81 and 1 ± 0.125% of residual ash and protein contents, respectively.

  15. Downregulation of kinin B1 receptor function by B2 receptor heterodimerization and signaling.

    PubMed

    Zhang, Xianming; Brovkovych, Viktor; Zhang, Yongkang; Tan, Fulong; Skidgel, Randal A

    2015-01-01

    Signaling through the G protein-coupled kinin receptors B1 (kB1R) and B2 (kB2R) plays a critical role in inflammatory responses mediated by activation of the kallikrein-kinin system. The kB2R is constitutively expressed and rapidly desensitized in response to agonist whereas kB1R expression is upregulated by inflammatory stimuli and it is resistant to internalization and desensitization. Here we show that the kB1R heterodimerizes with kB2Rs in co-transfected HEK293 cells and natively expressing endothelial cells, resulting in significant internalization and desensitization of the kB1R response in cells pre-treated with kB2R agonist. However, pre-treatment of cells with kB1R agonist did not affect subsequent kB2R responses. Agonists of other G protein-coupled receptors (thrombin, lysophosphatidic acid) had no effect on a subsequent kB1R response. The loss of kB1R response after pretreatment with kB2R agonist was partially reversed with kB2R mutant Y129S, which blocks kB2R signaling without affecting endocytosis, or T342A, which signals like wild type but is not endocytosed. Co-endocytosis of the kB1R with kB2R was dependent on β-arrestin and clathrin-coated pits but not caveolae. The sorting pathway of kB1R and kB2R after endocytosis differed as recycling of kB1R to the cell surface was much slower than that of kB2R. In cytokine-treated human lung microvascular endothelial cells, pre-treatment with kB2R agonist inhibited kB1R-mediated increase in transendothelial electrical resistance (TER) caused by kB1R stimulation (to generate nitric oxide) and blocked the profound drop in TER caused by kB1R activation in the presence of pyrogallol (a superoxide generator). Thus, kB1R function can be downregulated by kB2R co-endocytosis and signaling, suggesting new approaches to control kB1R signaling in pathological conditions. PMID:25289859

  16. Loss of superconductivity with the addition of Al to MgB2 and a structural transition in Mg1-x AlxB2.

    PubMed

    Slusky, J S; Rogado, N; Regan, K A; Hayward, M A; Khalifah, P; He, T; Inumaru, K; Loureiro, S M; Haas, M K; Zandbergen, H W; Cava, R J

    2001-03-15

    The basic magnetic and electronic properties of most binary compounds have been well known for decades. The recent discovery of superconductivity at 39 K in the simple binary ceramic compound magnesium diboride, MgB2, was therefore surprising. Indeed, this material has been known and structurally characterized since the mid 1950s (ref. 2), and is readily available from chemical suppliers (it is commonly used as a starting material for chemical metathesis reactions). Here we show that the addition of electrons to MgB2, through partial substitution of Al for Mg, results in the loss of superconductivity. Associated with the Al substitution is a subtle but distinct structural transition, reflected in the partial collapse of the spacing between boron layers near an Al content of 10 per cent. This indicates that superconducting MgB2 is poised very near a structural instability at slightly higher electron concentrations.

  17. Residual microstructure associated with impact craters in TiB2/2024Al composite.

    PubMed

    Guo, Q; Sun, D L; Jiang, L T; Han, X L; Chen, G Q; Wu, G H

    2012-02-01

    Residual microstructures associated with hypervelocity impact craters in 55 vol.% TiB(2)/2024Al composite were investigated by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). TiB(2)-Al interface, TiB(2) particles and Al matrix before and after hypervelocity impact were compared to discuss the effect of hypervelocity impact. A new Al(x)O(1-x) phase with the fcc structure and the crystal parameter of 0.69 nm was formed at TiB(2)-Al interface. Stacking fault with width of 10-20 nm was formed along the (001) plane of TiB(2) particle. Formation of nanograins (≈ 100 nm) was observed within Al matrix, moreover, lamellar S' phase was transformed into lenticular or spherical S phase after hypervelocity impact. PMID:22019497

  18. Properties of MgB2 films deposited on single crystal Ag layers

    NASA Astrophysics Data System (ADS)

    Liu, Z. H.; Wei, Y. K.; Zhang, C.; Feng, Q. R.; Ma, P.; Wang, Y.

    2014-04-01

    We have recently developed a method to deposit MgB2 thin films on single crystal Ag layers, and found that thin Ag layers reduced the the superconductivity of MgB2 not much, which may be a possible material to fabricate MgB2 SNS Josephson junctions. The single crystal Ag layers were deposited on (0 0 0 1) SiC substrates, and then the MgB2 thin films were deposited on the Ag layers. All the measurements included the XRD, M-T and M-H curves. The transition temperature of MgB2 films decreases from 39 K to 37 K, while the thickness of Ag layers grows from 0 to 20 nm, and the critical current density at 4.2 K decreases from 1.76 MA/cm2 to 1.24 MA/cm2, too.

  19. i2b2t2: Unlocking Visualization for Clinical Research

    PubMed Central

    Harris, Daniel R.; Henderson, Darren W.

    2016-01-01

    We introduce a tool that extracts clinical data sets and provides visualizations from clinical data warehouses that use the Informatics for Integrating Biology and the Bedside (i2b2) query tool. Our tool, i2b2t2 (i2b2 to Tableau), can extract and visualize any i2b2 query into a portable format that researchers can easily explore without needing a highly technical or statistical background. This user-friendly format provides a quick visual summary of the queried population and is easily extendable to develop more intricate and robust visualizations. Extraction and visualization can be provided as a service by clinical data warehouses to expedite the release of data sets for research. i2b2t2 also encourages visualization as a self-service; a motivated researcher can develop custom visualizations for exploration or publication. PMID:27570658

  20. Phase formation in the BaB2O4-BaF2 system

    NASA Astrophysics Data System (ADS)

    Bekker, T. B.; Fedorov, P. P.; Kokh, A. E.

    2012-07-01

    It is shown that the BaB2O4-BaF2 system is quasi-binary with the following eutectics coordinates: 760°C, 59 mol % BaF2, 41 mol % BaB2O4. Due to the intense pyrohydrolysis during the growth of β-BaB2O4 crystals from the 55.6 mol % BaB2O4-44.4 mol % BaF2 composition, the Ba5B4O11 compound is formed in the system. This process leads to the cocrystallization of the β-BaB2O4 and Ba5B4O11 phases and impedes the formation of high-quality crystals.

  1. Doping effect of nano-diamond on superconductivity and flux pinning in MgB2

    NASA Astrophysics Data System (ADS)

    Cheng, C. H.; Zhang, H.; Zhao, Y.; Feng, Y.; Rui, X. F.; Munroe, P.; Zeng, H. M.; Koshizuka, N.; Murakami, M.

    2003-10-01

    The doping effect of diamond nanoparticles on the superconducting properties of MgB2 bulk material has been studied. It is found that the superconducting transition temperature Tc of MgB2 is suppressed by the diamond doping, however, the irreversibility field Hirr and the critical current density Jc are systematically enhanced. Microstructural analysis shows that the diamond-doped MgB2 superconductor consists of tightly-packed MgB2 nano-grains (~50-100 nm) with highly dispersed and uniformly distributed diamond nanoparticles (~10-20 nm) inside the grains. The high density of dislocations and diamond nanoparticles may be responsible for the enhanced flux pinning in the diamond-doped MgB2.

  2. Tunnel junctions on as-grown MgB 2 films

    NASA Astrophysics Data System (ADS)

    Ueda, Kenji; Naito, Michio

    2004-08-01

    We prepared MgB 2 films by coevaporation of pure Mg and B metals in an ultra high vacuum chamber. These films have c-axis orientation and a slightly depressed Tc (∼35 K). We fabricated various tunnel junctions (SIN and SIS) using these as-grown MgB 2 films. Of these, Au/MgO/MgB 2 junctions showed typical SIN characteristics with a clear superconducting gap of Δ∼2.5 meV. This gap value may correspond to the smaller gap in the multi-gap scenario. Preliminary MgB 2/Al 2O 3/MgB 2 junctions exhibited SIS characteristics, although not ideal, with a similar value of Δ.

  3. i2b2t2: Unlocking Visualization for Clinical Research.

    PubMed

    Harris, Daniel R; Henderson, Darren W

    2016-01-01

    We introduce a tool that extracts clinical data sets and provides visualizations from clinical data warehouses that use the Informatics for Integrating Biology and the Bedside (i2b2) query tool. Our tool, i2b2t2 (i2b2 to Tableau), can extract and visualize any i2b2 query into a portable format that researchers can easily explore without needing a highly technical or statistical background. This user-friendly format provides a quick visual summary of the queried population and is easily extendable to develop more intricate and robust visualizations. Extraction and visualization can be provided as a service by clinical data warehouses to expedite the release of data sets for research. i2b2t2 also encourages visualization as a self-service; a motivated researcher can develop custom visualizations for exploration or publication. PMID:27570658

  4. Nuclear Reactors. Revised.

    ERIC Educational Resources Information Center

    Hogerton, John F.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: How Reactors Work; Reactor Design; Research, Teaching, and Materials Testing; Reactors (Research, Teaching and Materials); Production Reactors; Reactors for Electric Power…

  5. Nuclear reactor

    DOEpatents

    Pennell, William E.; Rowan, William J.

    1977-01-01

    A nuclear reactor in which the core components, including fuel-rod assemblies, control-rod assemblies, fertile rod-assemblies, and removable shielding assemblies, are supported by a plurality of separate inlet modular units. These units are referred to as inlet module units to distinguish them from the modules of the upper internals of the reactor. The modular units are supported, each removable independently of the others, in liners in the supporting structure for the lower internals of the reactor. The core assemblies are removably supported in integral receptacles or sockets of the modular units. The liners, units, sockets and assmblies have inlet openings for entry of the fluid. The modular units are each removably mounted in the liners with fluid seals interposed between the opening in the liner and inlet module into which the fluid enters and the upper and lower portion of the liner. Each assembly is similarly mounted in a corresponding receptacle with fluid seals interposed between the openings where the fluid enters and the lower portion of the receptacle or fitting closely in these regions. As fluid flows along each core assembly a pressure drop is produced along the fluid so that the fluid which emerges from each core assembly is at a lower pressure than the fluid which enters the core assembly. However because of the seals interposed in the mountings of the units and assemblies the pressures above and below the units and assemblies are balanced and the units are held in the liners and the assemblies are held in the receptacles by their weights as they have a higher specific gravity than the fluid. The low-pressure spaces between each module and its liner and between each core assembly and its module is vented to the low-pressure regions of the vessel to assure that fluid which leaks through the seals does not accumulate and destroy the hydraulic balance.

  6. REACTOR COMPONETN

    DOEpatents

    Creutz, E.C.

    1959-10-27

    A reactor fuel element comprised of a slug of fissionable material disposed in a sheath of corrosion resistantmaterial is described. The sheath is in the form of a tubular container closed at one end and is in tight-fitting engagement with the peripheral sunface of the slug. An inner cap is insented into the open end of the sheath against the slug, which end is then bent around the inner cap and welded thereto. An outer cap is then welded around its peripheny to the bent portion of the container.

  7. NUCLEAR REACTORS

    DOEpatents

    Long, E.; Ashley, J.W.

    1958-12-16

    A graphite moderator structure is described for a gas-cooled nuclear reactor having a vertical orlentation wherein the structure is physically stable with regard to dlmensional changes due to Wigner growth properties of the graphite, and leakage of coolant gas along spaces in the structure is reduced. The structure is comprised of stacks of unlform right prismatic graphite blocks positioned in layers extending in the direction of the lengths of the blocks, the adjacent end faces of the blocks being separated by pairs of tiles. The blocks and tiles have central bores which are in alignment when assembled and are provided with cooperatlng keys and keyways for physical stability.

  8. Adoption of the B2SAFE EUDAT replication service by the EPOS community

    NASA Astrophysics Data System (ADS)

    Cacciari, Claudio; Fares, Massimo; Fiameni, Giuseppe; Michelini, Alberto; Danecek, Peter; Wittenburg, Peter

    2014-05-01

    B2SAFE is the EUDAT service for moving and replicating data between sites and storage systems for different purposes. The goal of B2SAFE is to keep the data from a repository safe by replicating it across different geographical and administrative zones according to a set of well-defined policies. It is also a way to store large volumes of data permanently at those sites which are providing powerful on-demand data analysis facilities. In particular, B2SAFE operates on the domain of registered data where data objects are referable via persistent identifiers (PIDs). B2SAFE is more than just copying data because the PIDs must be carefully managed when data objects are moved or replicated. The EUDAT B2SAFE Service offers functionality to replicate datasets across different data centres in a safe and efficient way while maintaining all information required to easily find and query information about the replica locations. The information about the replica locations and other important information is stored in PID records, each managed in separate administrative domains. The B2SAFE Service is implemented as an iRODS module providing a set of iRODS rules or policies to interface with the EPIC handle API and uses the iRODS middleware to replicate datasets from a source data (or community) centre to a destination data centre. The definition of the dataset(s) to replicate is flexible and up to the communities using the B2SAFE service. While the B2SAFE is internally using the EPIC handle API, communities have the choice to use any PID system they prefer to assign PIDs to their digital objects. A reference to one or more EUDAT B2SAFE PIDs is returned by the B2SAFE service when a dataset is replicated. The presentation will introduce the problem space of B2SAFE, presents the achievements that have been made during the last year for enabling communities to make use of the B2SAFE service, demonstrates a EPOS use cases, outlines the commonalities and differences between the policies

  9. Hybrid adsorptive membrane reactor

    NASA Technical Reports Server (NTRS)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  10. Hybrid adsorptive membrane reactor

    DOEpatents

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  11. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    SciTech Connect

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A.

    2009-09-25

    The orphan receptor tyrosine kinase ErbB2 (also known as HER2 or Neu) transforms cells when overexpressed, and it is an important therapeutic target in human cancer. Structural studies have suggested that the oncogenic (and ligand-independent) signalling properties of ErbB2 result from the absence of a key intramolecular 'tether' in the extracellular region that autoinhibits other human ErbB receptors, including the epidermal growth factor (EGF) receptor. Although ErbB2 is unique among the four human ErbB receptors, here we show that it is the closest structural relative of the single EGF receptor family member in Drosophila melanogaster (dEGFR). Genetic and biochemical data show that dEGFR is tightly regulated by growth factor ligands, yet a crystal structure shows that it, too, lacks the intramolecular tether seen in human EGFR, ErbB3 and ErbB4. Instead, a distinct set of autoinhibitory interdomain interactions hold unliganded dEGFR in an inactive state. All of these interactions are maintained (and even extended) in ErbB2, arguing against the suggestion that ErbB2 lacks autoinhibition. We therefore suggest that normal and pathogenic ErbB2 signalling may be regulated by ligands in the same way as dEGFR. Our findings have important implications for ErbB2 regulation in human cancer, and for developing therapeutic approaches that target novel aspects of this orphan receptor.

  12. EphrinB2 regulates the emergence of a hemogenic endothelium from the aorta

    PubMed Central

    Chen, Inn-Inn; Caprioli, Arianna; Ohnuki, Hidetaka; Kwak, Hyeongil; Porcher, Catherine; Tosato, Giovanna

    2016-01-01

    Adult-type intraembryonic hematopoiesis arises from specialized endothelial cells of the dorsal aorta (DA). Despite the critical importance of this specialized endothelium for establishment of hematopoietic stem cells and adult hematopoietic lineages, the mechanisms regulating its emergence are incompletely understood. We show that EphrinB2, a principal regulator of endothelial cell function, controls the development of endothelium producing adult-type hematopoiesis. The absence of EphrinB2 impairs DA-derived hematopoiesis. Transmembrane EphrinB2 and its EphB4 receptor interact in the emerging DA, which transiently harbors EphrinB2+ and EphB4+ endothelial cells, thereby providing an opportunity for bi-directional cell-to-cell signaling to control the emergence of the hemogenic endothelium. Embryonic Stem (ES) cell-derived EphrinB2+ cells are enriched with hemogenic endothelial precursors. EphrinB2 silencing impairs ES generation of hematopoietic cells but not generation of endothelial cells. The identification of EphrinB2 as an essential regulator of adult hematopoiesis provides important insight in the regulation of early hematopoietic commitment. PMID:27250641

  13. Investigation of the interactions between the EphB2 receptor and SNEW peptide variants

    PubMed Central

    Ma, Buyong; Kolb, Stephanie; Diprima, Michael; Karna, Molleshree; Tosato, Giovanna; Yang, Qiqi; Huang, Qiang; Nussinov, Ruth

    2015-01-01

    EphB2 interacts with cell surface-bound ephrin ligands to relay bidirectional signals. Overexpression of the EphB2 receptor protein has been linked to different types of cancer. The SNEW (SNEWIQPRLPQH) peptide binds with high selectivity and moderate affinity to EphB2, inhibiting Eph-ephrin interactions by competing with ephrin ligands for the EphB2 high-affinity pocket. We used rigorous free energy perturbation calculations to reevaluate the binding interactions of SNEW peptide with EphB2 receptor, followed by experimental testing of the computational results. Our results provide insight into dynamic interactions of EphB2 with SNEW peptide. While the first four residues of the SNEW peptide are already highly optimized, change of the C-terminal end of the peptide has the potential to improve SNEW binding affinity. We found that a PXSPY motif that can be similarly aligned with several other EphB2 binding peptides. PMID:25410963

  14. The composition of EphB2 clusters determines the strength in the cellular repulsion response

    PubMed Central

    Schaupp, Andreas; Sabet, Ola; Dudanova, Irina; Ponserre, Marion; Bastiaens, Philippe

    2014-01-01

    Trans interactions of erythropoietin-producing human hepatocellular (Eph) receptors with their membrane-bound ephrin ligands generate higher-order clusters that can form extended signaling arrays. The functional relevance of the cluster size for repulsive signaling is not understood. We used chemical dimerizers and fluorescence anisotropy to generate and visualize specific EphB2 cluster species in living cells. We find that cell collapse responses are induced by small-sized EphB2 clusters, suggesting that extended EphB2 arrays are dispensable and that EphB2 activation follows an ON–OFF switch with EphB2 dimers being inactive and trimers and tetramers being fully functional. Moreover, the strength of the collapse response is determined by the abundance of multimers over dimers within a cluster population: the more dimers are present, the weaker the response. Finally, we show that the C-terminal modules of EphB2 have negative regulatory effects on ephrin-induced clustering. These results shed new light on the mechanism and regulation of EphB2 activation and provide a model on how Eph signaling translates into graded cellular responses. PMID:24469634

  15. Ab initio calculations of optical properties of B2C graphene sheet

    NASA Astrophysics Data System (ADS)

    Shahrokhi, Masoud; Naderi, Sirvan; Fathalian, Ali

    2012-06-01

    The electronic and the linear optical properties of a monolayer B2C graphene sheet are investigated through the density functional theory. The dielectric tensor is derived within the random phase approximation (RPA). Specifically, the dielectric function, absorption coefficient, optical conductivity, extinction index, loss function, reflectivity, and the refraction index of the monolayer B2C graphene sheet are calculated for both parallel and perpendicular electric field polarizations. The results show that the optical spectra are anisotropic along these two polarizations. For the electric field parallel to monolayer B2C graphene E∥x, adding the intraband transitions contribution, will change the optical spectra of a monolayer B2C graphene sheet significantly, while in the electric field perpendicular to monolayer B2C graphene E∥z did not change. Adding the intraband transitions contribution shows that the dielectric function has singularity at zero frequency because of the metallic behavior of a monolayer B2C graphene sheet. Also by considering the intraband transitions contribution for energy loss function in the electric field parallel to monolayer B2C graphene, the first plasmon frequency peak has been shifted from 2.76 eV to 4 eV.

  16. Structure and properties of oxygen-containing thin films and bulk MgB2

    NASA Astrophysics Data System (ADS)

    Prikhna, T.; Shapovalov, A.; Goldacker, W.; Eisterer, M.; Kozyrev, A.; Shaternik, V.; Boutko, V.; Gusev, A.; Weber, H. W.; Karpets, M.; Basyuk, T.; Sverdun, V.; Moshchil, V.; Belogolovskiy, M.; Sergienko, N.

    2015-12-01

    A structural Auger spectroscopy study of MgB2 thin (∼140 nm) oxygen-containing polycrystalline films produced by magnetron sputtering and 99% dense MgB2 bulks synthesized at 2 GPa allows us to conclude that jc of MgB2 depends to a high extent on the amount and distribution of oxygen in the material matrix. jc reached 7.8-2.7 MA/cm2 below 1T at 20 K in the films and 0.3-0.9 MA/cm2 (depending on the boron used) in the bulks. The higher jc in MgB2 thin films can be associated with finer oxygen-enriched Mg-B-O inclusions and their higher density in the film structure compared to the bulk. Calculations of the total electron density of states (DOS) in MgB2, MgB1.75O0.25, MgB1.5O0.5 and MgBO showed that all the compounds are conductors with metal-like behaviour. The DOS is even higher in MgB1.5O0 5 than in MgB2 and the binding energy is similar. So, the experimentally found presence of some dissolved oxygen in MgB2 does not contradict its high SC performance. The introduction of a high amount of oxygen into the MgB2 structure does not dramatically reduce the material's Tc and allows obtaining highjc as observed in our MgB2 films and bulks.

  17. Molecular cloning and characterization of SoxB2 gene from Zhikong scallop Chlamys farreri

    NASA Astrophysics Data System (ADS)

    He, Yan; Bao, Zhenmin; Guo, Huihui; Zhang, Yueyue; Zhang, Lingling; Wang, Shi; Hu, Jingjie; Hu, Xiaoli

    2013-11-01

    The Sox proteins play critical roles during the development of animals, including sex determination and central nervous system development. In this study, the SoxB2 gene was cloned from a mollusk, the Zhikong scallop ( Chlamys farreri), and characterized with respect to phylogeny and tissue distribution. The full-length cDNA and genomic DNA sequences of C. farreri SoxB2 ( Cf SoxB2) were obtained by rapid amplification of cDNA ends and genome walking, respectively, using a partial cDNA fragment from the highly conserved DNA-binding domain, i.e., the High Mobility Group (HMG) box. The full-length cDNA sequence of Cf SoxB2 was 2 048 bp and encoded 268 amino acids protein. The genomic sequence was 5 551 bp in length with only one exon. Several conserved elements, such as the TATA-box, GC-box, CAAT-box, GATA-box, and Sox/sry-sex/testis-determining and related HMG box factors, were found in the promoter region. Furthermore, real-time quantitative reverse transcription PCR assays were carried out to assess the mRNA expression of Cf SoxB 2 in different tissues. SoxB2 was highly expressed in the mantle, moderately in the digestive gland and gill, and weakly expressed in the gonad, kidney and adductor muscle. In male and female gonads at different developmental stages of reproduction, the expression levels of Cf SoxB2 were similar. Considering the specific expression and roles of SoxB 2 in other animals, in particular vertebrates, and the fact that there are many pallial nerves in the mantle, cerebral ganglia in the digestive gland and gill nerves in gill, we propose a possible essential role in nervous tissue function for Sox B 2 in C. farreri.

  18. Depletion of the xynB2 gene upregulates β-xylosidase expression in C. crescentus.

    PubMed

    Corrêa, Juliana Moço; Mingori, Moara Rodrigues; Gandra, Rinaldo Ferreira; Loth, Eduardo Alexandre; Seixas, Flávio Augusto Vicente; Simão, Rita de Cássia Garcia

    2014-01-01

    Caulobacter crescentus is able to express several enzymes involved in the utilization of lignocellulosic biomasses. Five genes, xynB1-5, that encode β-xylosidases are present in the genome of this bacterium. In this study, the xynB2 gene, which encodes β-xylosidase II (CCNA_02442), was cloned under the control of the PxylX promoter to generate the O-xynB2 strain, which overexpresses the enzyme in the presence of xylose. In addition, a null mutant strain, Δ-xynB2, was created by two homologous recombination events where the chromosomal xynB2 gene was replaced by a copy that was disrupted by the spectinomycin-resistant cassette. We demonstrated that C. crescentus cells lacking β-xylosidase II upregulates the xynB genes inducing β-xylosidase activity. Transcriptional analysis revealed that xynB1 (RT-PCR analysis) and xynB2 (lacZ transcription fusion) gene expression was induced in the Δ-xynB2 cells, and high β-xylosidase activity was observed in the presence of different agro-industrial residues in the null mutant strain, a characteristic that can be explored and applied in biotechnological processes. In contrast, overexpression of the xynB2 gene caused downregulation of the expression and activity of the β-xylosidase. For example, the β-xylosidase activity that was obtained in the presence of sugarcane bagasse was 7-fold and 16-fold higher than the activity measured in the C. crescentus parental and O-xynB2 cells, respectively. Our results suggest that β-xylosidase II may have a role in controlling the expression of the xynB1 and xynB2 genes in C. crescentus.

  19. Differential Distribution of Bradykinin B(2) Receptors in the Rat and Human Cardiovascular System.

    PubMed

    Figueroa, Carlos D.; Marchant, Alejandra; Novoa, Ulises; Förstermann, Ulrich; Jarnagin, Kurt; Schölkens, Bernward; Müller-Esterl, Werner

    2001-01-01

    -Bradykinin, a major vasodilator peptide, plays an important role in the local regulation of blood pressure, blood flow, and vascular permeability; however, the cellular distribution of the major bradykinin B(2) receptor in the cardiovascular system is not precisely known. Immunoblot analysis with an anti-peptide antibody to the bradykinin B(2) receptor or chemical cross-linkage with [(125)I]Tyr(0)-bradykinin revealed a band of 69+/-3 kDa at varying intensity in the homogenates of the endothelium and tunica media of the rat aorta and endocardium. Immunostaining showed that the B(2) receptor is abundant in the endothelial linings of the aorta, other elastic arteries, muscular arteries, capillaries, venules, and large veins, where it localizes preferentially to the luminal face of the endothelial cells. In marked contrast, small arterioles (ie, the principal blood-pressure regulating vessels) of the mesenterium, heart, urinary bladder, brain, salivary gland, and kidney had a different staining pattern in which B(2) receptor was prominent in the perivascular smooth muscle cells of the tunica media. A similar distribution pattern was found in mouse as well as in human tissues, indicating that the particular distribution pattern of the B(2) receptor in arterioles is not a species-specific phenomenon. During development, the distribution of B(2) receptor in the heart changes; for example, in the heart of newborn rats, the B(2) receptor was abundant in the myocardium, whereas in the adult heart, the receptor was present in the endocardium of atria, atrioventricular valves, and ventricles but not in the myocardium. Thus, B(2) receptors are localized differentially in different parts of the cardiovascular system: the arterioles have smooth muscle-localized B(2) receptors, and large elastic vessels have endothelium-localized receptors.

  20. The role of starch doping on the superconducting properties of MgB2

    NASA Astrophysics Data System (ADS)

    Tripathi, D.; Moharana, S. S.; Dey, T. K.

    2014-09-01

    The effect of different amount of starch addition on structural and superconducting properties of superconducting MgB2 has been discussed. The samples are synthesized by conventional solid reaction method. XRD analysis confirms that carbon, which is produced during synthesis due to decomposition of starch, is substituted in the B sites. High resolution transmission electron microscope (HRTEM) picture infers the presence of large number of nanosized precipitates (size ∼10-20 nm) in starch doped MgB2 pellets. Superconducting transition temperature (Tc0) of MgB2 (∼38 K) decreases due to the addition of starch. The critical current density (Jc) of starch added MgB2 samples, however, shows significant improvement in whole field range, especially at high magnetic fields. MgB2 added with 2 wt.% of starch gives the best performance amongst the investigated samples and at 20 K displays ∼42 times enhancement in Jc under 4 T field compared to that for pure MgB2. The field dependence of the critical current density (Jc) of starch added MgB2 is explained fairly well in terms of collective pinning theory. An excellent scaling of the reduced critical current density, Jn(=Jc/Jc(0)) and the reduced field hn (=H/H0) is observed for both pure and starch added MgB2 polycrystalline pellets at different temperatures, where Jc(0) and H0 are the fitting parameters obtained from collective pinning model. However, the normalized pinning force density (FP/Fp(max)) of starch added samples does not display any scaling, but shows an excellent correspondence with modified Dew-Hughes expression. The presence of anisotropy and grain orientation is thought to be responsible for the absence of scaling of normalized pinning force density in starch added MgB2 pellets.

  1. Existence of three subtypes of bradykinin B2 receptors in guinea pig.

    PubMed

    Seguin, L; Widdowson, P S; Giesen-Crouse, E

    1992-12-01

    We describe the binding of [3H]bradykinin to homogenates of guinea pig brain, lung, and ileum. Analysis of [3H]bradykinin binding kinetics in guinea pig brain, lung, and ileum suggests the existence of two binding sites in each tissue. The finding of two binding sites for [3H]bradykinin in ileum, lung, and brain was further supported by Scatchard analysis of equilibrium binding in each tissue. [3H]Bradykinin binds to a high-affinity site in brain, lung, and ileum (KD = 70-200 pM), which constitutes approximately 20% of the bradykinin binding, and to a second, lower-affinity site (0.63-0.95 nM), which constitutes the remaining 80% of binding. Displacement studies with various bradykinin analogues led us to subdivide the high- and lower-affinity sites in each tissue and to suggest the existence of three subtypes of B2 receptors in the guinea pig, which we classify as B2a, B2b, and B2c. Binding of [3H]bradykinin is largely to a B2b receptor subtype, which constitutes the majority of binding in brain, lung, and ileum and represents the lower-affinity site in our binding studies. Receptor subtype B2c constitutes approximately 20% of binding sites in the brain and lung and is equivalent to the high-affinity site in brain and lung. We suggest that a third subtype of B2 receptor (high-affinity site in ileum), B2a, is found only in the ileum. All three subtypes of B2 receptors display a high affinity for bradykinin, whereas they show different affinities for various bradykinin analogues displaying agonist or antagonist activities.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. c-erbB-2 oncogene expression in salivary gland tumours.

    PubMed

    Kärjä, V; Syrjänen, S; Kataja, V; Syrjänen, K

    1994-01-01

    Prompted by recent findings on the amplification of c-erbB-2 (HER-2, neu) oncogene in salivary gland tumours, the present study was conducted to analyse the expression of c-erbB-2 in both benign and malignant salivary gland tumours, with special emphasis on its prognostic significance and relevance to clinical data. A series of 219 salivary gland tumours (with pertinent clinical data), including 103 malignant and 116 benign tumours, were analysed immunohistochemically using a monoclonal antibody to c-erbB-2 protein. Smoking was not a risk factor for malignant tumours, smokers being equally represented in both groups: 18.4 and 21.6% in malignant and benign series, respectively. Multi-variate analysis of the extensive clinical data did not disclose any other risk factors either. Cellular membrane staining for c-erbB-2 was present in 36 (35.0%) carcinomas and 41 (35.3%) benign tumours. Among the malignant tumours, c-erbB-2 expression was most frequent in adenoid cystic carcinomas (57.7%) followed by adenocarcinomas (39.3%). Among the benign tumours, 47% of Warthin's tumours and 33.3% of the pleomorphic adenomas showed staining for c-erbB-2. The highest prevalence of c-erbB-2 immunoreactivity was seen in adenocarcinomas of the parotid gland (81.8%), followed by undifferentiated carcinomas (75%) and adenoid cystic carcinomas (73.3%) in that location. Age at diagnosis, number of recurrences, analysis as well as time to relapse or metastases were similar in c-erbB-2-positive and -negative malignant tumours. Also mortality in c-erbB-2-positive and -negative salivary gland cancers was similar.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Control Means for Reactor

    DOEpatents

    Manley, J. H.

    1961-06-27

    An apparatus for controlling a nuclear reactor includes a tank just below the reactor, tubes extending from the tank into the reactor, and a thermally expansible liquid neutron absorbent material in the tank. The liquid in the tank is exposed to a beam of neutrons from the reactor which heats the liquid causing it to expand into the reactor when the neutron flux in the reactor rises above a predetermincd danger point. Boron triamine may be used for this purpose.

  4. Procyanidin dimer B2-mediated IRAK-M induction negatively regulates TLR4 signaling in macrophages

    SciTech Connect

    Sung, Nak-Yun; Yang, Mi-So; Song, Du-Sub; Kim, Jae-Kyung; Park, Jong-Heum; Song, Beom-Seok; Park, Sang-Hyun; Lee, Ju-Woon; Park, Hyun-Jin; Kim, Jae-Hun; Byun, Eui-Baek; Byun, Eui-Hong

    2013-08-16

    Highlights: •Pro B2 elevated the expression of IRAK-M, a negative regulator of TLR signaling. •LPS-induced expression of cell surface molecules was inhibited by Pro B2. •LPS-induced production of pro-inflammatory cytokines was inhibited by Pro B2. •Pro B2 inhibited LPS-induced activation of MAPKs and NF-κB through IRAK-M. •Pro B2 inactivated naïve T cells by inhibiting LPS-induced cytokines via IRAK-M. -- Abstract: Polyphenolic compounds have been found to possess a wide range of physiological activities that may contribute to their beneficial effects against inflammation-related diseases; however, the molecular mechanisms underlying this anti-inflammatory activity are not completely characterized, and many features remain to be elucidated. In this study, we investigated the molecular basis for the down-regulation of toll-like receptor 4 (TLR4) signal transduction by procyanidin dimer B2 (Pro B2) in macrophages. Pro B2 markedly elevated the expression of the interleukin (IL)-1 receptor-associated kinase (IRAK)-M protein, a negative regulator of TLR signaling. Lipopolysaccharide (LPS)-induced expression of cell surface molecules (CD80, CD86, and MHC class I/II) and production of pro-inflammatory cytokines (tumor necrosis factor-α, IL-1β, IL-6, and IL-12p70) were inhibited by Pro B2, and this action was prevented by IRAK-M silencing. In addition, Pro B2-treated macrophages inhibited LPS-induced activation of mitogen-activated protein kinases such as extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase and the translocation of nuclear factor κB and p65 through IRAK-M. We also found that Pro B2-treated macrophages inactivated naïve T cells by inhibiting LPS-induced interferon-γ and IL-2 secretion through IRAK-M. These novel findings provide new insights into the understanding of negative regulatory mechanisms of the TLR4 signaling pathway and the immune-pharmacological role of Pro B2 in the immune response against the development

  5. Nucleosome Assembly Alters the Accessibility of the Antitumor Agent Duocarmycin B2 to Duplex DNA.

    PubMed

    Zou, Tingting; Kizaki, Seiichiro; Pandian, Ganesh N; Sugiyama, Hiroshi

    2016-06-20

    To evaluate the reactivity of antitumor agents in a nucleosome architecture, we conducted in vitro studies to assess the alkylation level of duocarmycin B2 on nucleosomes with core and linker DNA using sequencing gel electrophoresis. Our results suggested that the alkylating efficiencies of duocarmycin B2 were significantly decreased in core DNA and increased at the histone-free linker DNA sites when compared with naked DNA conditions. Our finding that nucleosome assembly alters the accessibility of duocarmycin B2 to duplex DNA could advance its design as an antitumor agent.

  6. Improvement of skin wound healing in diabetic mice by kinin B2 receptor blockade.

    PubMed

    Desposito, Dorinne; Chollet, Catherine; Taveau, Christopher; Descamps, Vincent; Alhenc-Gelas, François; Roussel, Ronan; Bouby, Nadine; Waeckel, Ludovic

    2016-01-01

    Impaired skin wound healing is a major medical problem in diabetic subjects. Kinins exert a number of vascular and other actions limiting organ damage in ischaemia or diabetes, but their role in skin injury is unknown. We investigated, through pharmacological manipulation of bradykinin B1 and B2 receptors (B1R and B2R respectively), the role of kinins in wound healing in non-diabetic and diabetic mice. Using two mouse models of diabetes (streptozotocin-induced and db/db mice) and non-diabetic mice, we assessed the effect of kinin receptor activation or inhibition by subtype-selective pharmacological agonists (B1R and B2R) and antagonist (B2R) on healing of experimental skin wounds. We also studied effects of agonists and antagonist on keratinocytes and fibroblasts in vitro. Levels of Bdkrb1 (encoding B1R) and Bdkrb2 (encoding B2R) mRNAs increased 1-2-fold in healthy and wounded diabetic skin compared with in non-diabetic skin. Diabetes delayed wound healing. The B1R agonist had no effect on wound healing. In contrast, the B2R agonist impaired wound repair in both non-diabetic and diabetic mice, inducing skin disorganization and epidermis thickening. In vitro, B2R activation unbalanced fibroblast/keratinocyte proliferation and increased keratinocyte migration. These effects were abolished by co-administration of B2R antagonist. Interestingly, in the two mouse models of diabetes, the B2R antagonist administered alone normalized wound healing. This effect was associated with the induction of Ccl2 (encoding monocyte chemoattractant protein 1)/Tnf (encoding tumour necrosis factor α) mRNAs. Thus stimulation of kinin B2 receptor impairs skin wound healing in mice. B2R activation occurs in the diabetic skin and delays wound healing. B2R blockade improves skin wound healing in diabetic mice and is a potential therapeutic approach to diabetic ulcers. PMID:26443866

  7. Improving magnetic properties of MgB2 bulk superconductors by synthetic engine oil treatment

    NASA Astrophysics Data System (ADS)

    Taylan Koparan, E.; Savaskan, B.; Yanmaz, E.

    2016-08-01

    The present study focuses on the effects of standby time of the MgB2 samples immersed in synthetic engine oil on the critical current density (Jc(H)), magnetic field dependence of the pinning force density fp(b) and Tc performances of MgB2 bulk superconductors. Synthetic engine oil was used as a product which is cheap and a rich carbon source. Manufactured MgB2 pellet samples were immersed at different standby time of 30 min, 120 min, 300 min and 1440 min in synthetic engine oil after the first heating process. Finally, MgB2 samples immersed in synthetic engine oil were sintered at 1000 °C and kept for 15 min in Ar atmosphere. The critical current density of all of MgB2 samples immersed at different standby time in engine oil in whole field range was better than that of the pure MgB2 sample because of the number of the pinning centers. The MgB2 sample immersed at 300 min standby time in synthetic engine oil has the best performance compared to other samples. The Jc value for the pure sample is 2.0 × 103 A/cm2, whereas for the MgB2 sample immersed at 300 min standby time in engine oil the Jc is enhanced to 4.8 × 103A/cm2 at 5 K and 3 T. The superconducting transition temperature (Tc) did not change with the increasing standby time of the samples in synthetic engine oil at all. The best diamagnetic property was obtained from the sample which kept in synthetic engine oil for 300 min. Synthetic engine oil treatment results in remarkable improvement of the critical current density and pinning force performances of MgB2 superconductors. It was found that all MgB2 samples have a different pinning property at different measuring temperatures. Using synthetic engine oil as a product which is cheap and a rich carbon source in MgB2 bulk superconductors makes MgB2 samples immersed in synthetic engine oil a good candidate for industrial applications.

  8. Improved critical current density of MgB2--carbon nanotubes composite.

    PubMed

    Shekhar, Chandra; Giri, Rajiv; Malik, S K; Srivastav, O N

    2007-06-01

    In the present study, we report a systematic study of doping/admixing of carbon nanotubes (CNTs) in different concentrations in MgB2. The composite material corresponding to MgB2-x at.% CNTs (35 at.% > or = x > or = 0 at.%) have been prepared by solid-state reaction at ambient pressure. All the samples in the present investigation have been subjected to structural/microstructural characterization employing XRD, Scanning electron microscopic (SEM), and Transmission electron microscopic (TEM) techniques. The magnetization measurements were performed by Physical property measurement system (PPMS) and electrical transport measurements have been done by the four-probe technique. The microstructural investigations reveal the formation of MgB2-carbon nanotube composites. A CNT connecting the MgB2 grains may enhance critical current density due to its size (approximately 5-20 nm diameter) compatible with coherence length of MgB2 (approximately 5-6 nm) and ballistic transport current carrying capability along the tube axis. The transport critical current density (Jct) of MgB2 samples with varying CNTs concentration have been found to vary significantly e.g., Jct of the MgB2 sample with 10 at.% CNT addition is approximately 2.3 x 10(3) A/cm2 and its value for MgB2 sample without CNT addition is approximately 7.2 x 102 A/cm2 at 20 K. In order to study the flux pinning effect of CNTs doping/ admixing in MgB2, the evaluation of intragrain critical current density (JJ) has been carried out through magnetic measurements on the fine powdered version of the as synthesized samples. The optimum result on Jc is obtained for 10 at.% CNTs admixed MgB2 sample at 5 K, the Jc reaches approximately 5.2 x 10(6) A/cm2 in self field, -1.6 x 10(6) A/cm2 at 1 T, approximately 2.9 x 10(5) A/cm2 at 2.6 T, and approximately 3.9 x 10(4) A/cm2 at 4 T. The high value of intragrain Jc in 10 at.% CNTs admixed MgB2 superconductor has been attributed to the incorporation of CNTs into the crystal matrix of

  9. Doping Effect of Nano-Ybco Additive on MgB2

    NASA Astrophysics Data System (ADS)

    Rui, X. F.; Sun, X. F.; Xu, X. L.; Zhang, L.; Zhang, H.

    The effect of YBCO nanoparticles added into MgB2 on Tc, Jc, and flux pinning was studied for MgB2(YBCO)x with x=0, 5, 10, 15 wt%. Phase analysis shows that none of elements are doped into the MgB2 lattice in the samples with YBCO addition. For the samples with YBCO addition, the Jc-H characteristics behave poorly in comparison with the pure sample. Our experimental results show that the nanoscale size of addition dosen't comprise the only condition for its effectiveness as pinning centers.

  10. Pharmacological effects of recombinant human tissue kallikrein on bradykinin B2 receptors

    PubMed Central

    Charest-Morin, Xavier; Raghavan, Arvind; Charles, Matthew L; Kolodka, Tadeusz; Bouthillier, Johanne; Jean, Mélissa; Robbins, Mark S; Marceau, François

    2015-01-01

    Tissue kallikrein (KLK-1), a serine protease, initiates the release of bradykinin (BK)-related peptides from low-molecular weight kininogen. KLK-1 and the BK B2 receptor (B2R) mediate beneficial effects on the progression of type 2 diabetes and renal disease, but the precise role of KLK-1 independent of its kinin-forming activity remains unclear. We used DM199, a recombinant form of human KLK-1, along with the isolated human umbilical vein, a robust bioassay of the B2R, to address the previous claims that KLK-1 directly binds to and activates the human B2R, with possible receptor cleavage. DM199 (1–10 nmol/L) contracted the isolated vein via the B2R, but in a tachyphylactic, kinin-dependent manner, without desensitization of the tissue to exogenously added BK. In binding experiments with recombinant N-terminally tagged myc-B2Rs expressed in HEK 293a cells, DM199 displaced [3H]BK binding from the rabbit myc-B2R, but not from the human or rat myc-B2Rs. No evidence of myc-B2R degradation by immunoblot analysis was apparent following treatment of these 3 myc-B2R constructs with DM199 (30 min, ≤10 nmol/L). In HEK 293 cells stably expressing rabbit B2R-GFP, DM199 (11–108 pmol/L) elicited signaling-dependent endocytosis and reexpression, while a higher concentration (1.1 nmol/L) induced a partially irreversible endocytosis of the construct (microscopy), paralleled by the appearance of free GFP in cells (immunoblotting, indicative of incomplete receptor down-regulation). The pharmacology of DM199 at relevant concentrations (<10 nmol/L) is essentially based on the activity of locally generated kinins. Binding to and mild down-regulation of the B2R is possibly a species-dependent idiosyncratic response to DM199. PMID:26038695

  11. Pharmacological effects of recombinant human tissue kallikrein on bradykinin B2 receptors.

    PubMed

    Charest-Morin, Xavier; Raghavan, Arvind; Charles, Matthew L; Kolodka, Tadeusz; Bouthillier, Johanne; Jean, Mélissa; Robbins, Mark S; Marceau, François

    2015-03-01

    Tissue kallikrein (KLK-1), a serine protease, initiates the release of bradykinin (BK)-related peptides from low-molecular weight kininogen. KLK-1 and the BK B2 receptor (B2R) mediate beneficial effects on the progression of type 2 diabetes and renal disease, but the precise role of KLK-1 independent of its kinin-forming activity remains unclear. We used DM199, a recombinant form of human KLK-1, along with the isolated human umbilical vein, a robust bioassay of the B2R, to address the previous claims that KLK-1 directly binds to and activates the human B2R, with possible receptor cleavage. DM199 (1-10 nmol/L) contracted the isolated vein via the B2R, but in a tachyphylactic, kinin-dependent manner, without desensitization of the tissue to exogenously added BK. In binding experiments with recombinant N-terminally tagged myc-B2Rs expressed in HEK 293a cells, DM199 displaced [(3)H]BK binding from the rabbit myc-B2R, but not from the human or rat myc-B2Rs. No evidence of myc-B2R degradation by immunoblot analysis was apparent following treatment of these 3 myc-B2R constructs with DM199 (30 min, ≤10 nmol/L). In HEK 293 cells stably expressing rabbit B2R-GFP, DM199 (11-108 pmol/L) elicited signaling-dependent endocytosis and reexpression, while a higher concentration (1.1 nmol/L) induced a partially irreversible endocytosis of the construct (microscopy), paralleled by the appearance of free GFP in cells (immunoblotting, indicative of incomplete receptor down-regulation). The pharmacology of DM199 at relevant concentrations (<10 nmol/L) is essentially based on the activity of locally generated kinins. Binding to and mild down-regulation of the B2R is possibly a species-dependent idiosyncratic response to DM199.

  12. Terahertz surface impedance of epitaxial MgB2 thin film

    NASA Astrophysics Data System (ADS)

    Jin, B. B.; Kuzel, P.; Kadlec, F.; Dahm, T.; Redwing, J. M.; Pogrebnyakov, A. V.; Xi, X. X.; Klein, N.

    2005-08-01

    We report on terahertz (THz) surface impedance measurement of an epitaxial MgB2 thin film using time domain THz spectroscopy. We show that the surface resistance of the MgB2 film is much lower than that of YBa2Cu3O7-δ and copper in the THz range. A linear dependence of the surface reactance on frequency is observed, yielding a penetration depth of about 100nm at low temperatures. The measurements agree qualitatively with calculations based on impurity scattering in the Born limit. Our results clearly indicate that MgB2 thin films have a great potential for THz electronic applications.

  13. NEUTRONIC REACTOR

    DOEpatents

    Stewart, H.B.

    1958-12-23

    A nuclear reactor of the type speclfically designed for the irradiation of materials is discussed. In this design a central cyllndrical core of moderating material ls surrounded by an active portlon comprlsed of an annular tank contalning fissionable material immersed ln a liquid moderator. The active portion ls ln turn surrounded by a reflector, and a well ls provided in the center of the core to accommodate the materlals to be irradiated. The over-all dimensions of the core ln at least one plane are equal to or greater than twice the effective slowing down length and equal to or less than twlce the effective diffuslon length for neutrons in the core materials.

  14. NEUTRONIC REACTOR

    DOEpatents

    Wigner, E.P.

    1957-09-17

    A reactor of the type having coolant liquid circulated through clad fuel elements geometrically arranged in a solid moderator, such as graphite, is described. The core is enclosed in a pressure vessel and suitable shielding, wherein means is provided for circulating vapor through the core to superheat the same. This is accomplished by drawing off the liquid which has been heated in the core due to the fission of the fuel, passing it to a nozzle within a chamber where it flashes into a vapor, and then passing the vapor through separate tubes extending through the moderator to pick up more heat developed in the core due to the fission of the fuel, thereby producing superheated vapor.

  15. NEUTRONIC REACTOR

    DOEpatents

    Daniels, F.

    1962-12-18

    A power plant is described comprising a turbine and employing round cylindrical fuel rods formed of BeO and UO/sub 2/ and stacks of hexagonal moderator blocks of BeO provided with passages that loosely receive the fuel rods so that coolant may flow through the passages over the fuels to remove heat. The coolant may be helium or steam and fiows through at least one more heat exchanger for producing vapor from a body of fluid separate from the coolant, which fluid is to drive the turbine for generating electricity. By this arrangement the turbine and directly associated parts are free of particles and radiations emanating from the reactor. (AEC)

  16. Nuclear reactor

    DOEpatents

    Yant, Howard W.; Stinebiser, Karl W.; Anzur, Gregory C.

    1977-01-01

    A nuclear reactor, particularly a liquid-metal breeder reactor, whose upper internals include outlet modules for channeling the liquid-metal coolant from selected areas of the outlet of the core vertically to the outlet plenum. The modules are composed of a highly-refractory, high corrosion-resistant alloy, for example, INCONEL-718. Each module is disposed to confine and channel generally vertically the coolant emitted from a subplurality of core-component assemblies. Each module has a grid with openings, each opening disposed to receive the coolant from an assembly of the subplurality. The grid in addition serves as a holdown for the assemblies of the corresponding subplurality preventing their excessive ejection upwardly from the core. In the region directly over the core the outlet modules are of such peripheral form that they nest forming a continuum over the core-component assemblies whose outlet coolant they confine. Each subassembly includes a chimney which confines the coolant emitted by its corresponding subassemblies to generally vertical flow between the outlet of the core and the outlet plenum. Each subplurality of assemblies whose emitted coolant is confined by an outlet module includes assemblies which emit lower-temperature coolant, for example, a control-rod assembly, or fertile assemblies, and assemblies which emit coolant of substantially higher temperature, for example, fuel-rod assemblies. The coolants of different temperatures are mixed in the chimneys reducing the effect of stripping (hot-cold temperature fluctuations) on the remainder of the upper internals which are composed typically of AISI-304 or AISI-316 stainless steel.

  17. 26 CFR 1.367(b)-2 - Definitions and special rules.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (QBU) (B1) in France, whose functional currency is the euro. FC2, an unrelated foreign corporation, owns and operates a QBU (B2) in France, whose functional currency is the dollar. FC2 acquires...

  18. Safety Analysis Report: X17B2 beamline Synchrotron Medical Research Facility

    SciTech Connect

    Gmuer, N.F.; Thomlinson, W.

    1990-02-01

    This report contains a safety analysis for the X17B2 beamline synchrotron medical research facility. Health hazards, risk assessment and building systems are discussed. Reference is made to transvenous coronary angiography. (LSP)

  19. Beyond Cohort Selection: An Analytics-Enabled i2b2.

    PubMed

    Gabetta, Matteo; Malovini, Alberto; Bucalo, Mauro; Zini, Elisa; Tibollo, Valentina; Priori, Silvia G; Vettoretti, Simone; Larizza, Cristiana; Bellazzi, Riccardo; Barbarini, Nicola

    2016-01-01

    The i2b2 software is a widely adopted solution for secondary use of clinical data for clinical research, specifically designed for cohort identification. i2b2 is still lacking functionalities for data analysis. The aim of this work is to empower the i2b2 framework enabling clinical researchers to perform statistical analyses for accelerating the process of hypothesis testing. To this aim we have developed a flexible extension of i2b2 able to exploit different statistical engines. We have implemented some first applications for basic statistics and survival analyses, exploiting this extension and accessible through suitable user interfaces designed with a special consideration for usability. PMID:27577448

  20. Pressure induced structural phase transition of OsB 2: First-principles calculations

    NASA Astrophysics Data System (ADS)

    Ren, Fengzhu; Wang, Yuanxu; Lo, V. C.

    2010-04-01

    Orthorhombic OsB 2 was synthesized at 1000 °C and its compressibility was measured by using the high-pressure X-ray diffraction in a Diacell diamond anvil cell from ambient pressure to 32 GPa [R.W. Cumberland, et al. (2005)]. First-principles calculations were performed to study the possibility of the phase transition of OsB 2. An analysis of the calculated enthalpy shows that orthorhombic OsB 2 can transfer to the hexagonal phase at 10.8 GPa. The calculated results with the quasi-harmonic approximation indicate that this phase transition pressure is little affected by the thermal effect. The calculated phonon band structure shows that the hexagonal P 6 3/ mmc structure (high-pressure phase) is stable for OsB 2. We expect the phase transition can be further confirmed by the experimental work.

  1. Elevated temperature slow plastic deformation of NiAl/TiB2 particulate composites

    NASA Technical Reports Server (NTRS)

    Whittenberger, J. Daniel; Mannan, S. K.; Sprissler, B.; Viswanadham, R. K.

    1988-01-01

    The 'XD' process for production of discontinuously-reinforced metal-matrix composites has been used to enhance the high-temperature strength of NiAl-TiB2 composites with particulate densities of up to 30 vol pct. SEM, TEM, and optical characterizations of the resulting microstructures showed the average TiB2 particle size to be about 1 micron, while the average grain of the NiAl matrix was of the order of 10 microns. Elevated temperature compression tests conducted at 1200 and 1300 K indicated flow strengths to increase with TiB2 content, so that the 20 vol pct TiB2-reinforced composite was three times stronger than the unreinforced NiAl; this is ascribed to the very high density of microstructural tangled dislocations, loops, and subgrain boundaries connecting the particles.

  2. 2. VIEW OF NORTHERN WATER TANK (FEATURE B2), FACING SOUTH. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF NORTHERN WATER TANK (FEATURE B-2), FACING SOUTH. THE ADIT ROAD IS SHOWN IN THE RIGHT SIDE OF THE PHOTO. - Nevada Lucky Tiger Mill & Mine, Water Tanks, East slope of Buckskin Mountain, Paradise Valley, Humboldt County, NV

  3. Superconducting characteristics of short MgB2 wires of long level sensor for liquid hydrogen

    NASA Astrophysics Data System (ADS)

    Takeda, M.; Inoue, Y.; Maekawa, K.; Matsuno, Y.; Fujikawa, S.; Kumakura, H.

    2015-12-01

    To establish the worldwide storage and marine transport of hydrogen, it is important to develop a high-precision and long level sensor, such as a superconducting magnesium diboride (MgB2) level sensor for large liquid hydrogen (LH2) tanks on board ships. Three 1.7- m-long MgB2 wires were fabricated by an in situ method, and the superconducting characteristics of twenty-four 20-mm-long MgB2 wires on the 1.7-m-long wires were studied. In addition, the static level-detecting characteristics of five 500-mm-long MgB2 level sensors were evaluated under atmospheric pressure.

  4. Electronic structure of MgB2 from angle-resolved photoemission spectroscopy.

    PubMed

    Uchiyama, H; Shen, K M; Lee, S; Damascelli, A; Lu, D H; Feng, D L; Shen, Z-X; Tajima, S

    2002-04-15

    The first angle-resolved photoemission spectroscopy results from MgB2 single crystals are reported. Along the GammaK and GammaM directions, we observed three distinct dispersive features approaching the Fermi energy. These can be assigned to the theoretically predicted sigma (B 2p(x,y)) and pi (B 2p(z)) bands. In addition, a small parabolic-like band is detected around the Gamma point, which can be attributed to a surface-derived state. The overall agreement between our results and the band calculations suggests that the electronic structure of MgB2 is of a conventional nature, thus implying that electron correlations are weak and may be of little importance to superconductivity in this system.

  5. Coherent phonon decay and the boron isotope effect for MgB2.

    PubMed

    Alarco, Jose A; Talbot, Peter C; Mackinnon, Ian D R

    2014-12-14

    Ab initio DFT calculations for the phonon dispersion (PD) and the phonon density of states (PDOS) of the two isotopic forms ((10)B and (11)B) of MgB2 demonstrate that use of a reduced symmetry super-lattice provides an improved approximation to the dynamical, phonon-distorted P6/mmm crystal structure. Construction of phonon frequency plots using calculated values for these isotopic forms gives linear trends with integer multiples of a base frequency that change in slope in a manner consistent with the isotope effect (IE). Spectral parameters inferred from this method are similar to that determined experimentally for the pure isotopic forms of MgB2. Comparison with AlB2 demonstrates that a coherent phonon decay down to acoustic modes is not possible for this metal. Coherent acoustic phonon decay may be an important contributor to superconductivity for MgB2.

  6. Epitaxial growth of MgB2 films at ambient temperature

    NASA Astrophysics Data System (ADS)

    Shishido, Hiroaki; Yoshida, Takuya; Nakagami, Takatoshi; Ishida, Takekazu

    We grew crystalline MgB2 thin films using molecular beam epitaxy at a low substrate temperature of 110 °C under an ultrahigh vacuum of about 10-6 Pa. MgB2 thin films were deposited on the (001) surface of a 4H-SiC substrate with an epitaxial Mg buffer layer. The epitaxial growth was confirmed by X-ray diffraction measurements. MgB2 thin films show a sharp superconducting transition at 27.2 K, with a relatively narrow superconducting transition width ΔTc = 0.9 K. The growth temperature was lower than any in prior reports on superconducting MgB2 thin films. The presence of the epitaxial Mg buffer layer is crucial for reducing the epitaxial temperature.

  7. Crystallization behavior of MgB2 films fabricated on copper cathodes via electrochemical technique

    NASA Astrophysics Data System (ADS)

    Yang, Huazhe; Sun, Xiaguang; Yu, Xiaoming; Qi, Yang

    2012-11-01

    An electrochemical technique was devised and settled to prepare MgB2 films on copper cathodes in MgCl2-Mg(BO2)2-NaCl-KCl molten salts. X-ray diffraction and scanning probe microscopy were adopted to investigate the phase composition and elements distribution of sample. R-T curve of film was monitored through standard four-probe method. Transmission electron microscope and scanning electron microscope analysis were chosen to investigate the crystallization behavior and morphology of the films at different electrolytic temperatures. The results indicated that MgB2 films were successfully fabricated on the copper cathodes, and the optimal electrolytic temperature was 601 °C. It was presumed that the non-conducting MgO impurities hindered continuous growth of MgB2 grain, which may result in dendritic growth of MgB2 grain.

  8. First-principles study of hydrogen storage on Ti-decorated B2C sheet

    NASA Astrophysics Data System (ADS)

    Guo, Y. H.; Xu, B.; Xia, Y. D.; Yin, J.; Liu, Z. G.

    2012-06-01

    The hydrogen storage capacity of Ti decorated B2C sheet has been investigated by first-principles plane-wave calculation. It is revealed that a single Ti atom adsorbed on the B2C sheet can strongly bind up to four hydrogen molecules. The adsorption energy is in the range of -0.36--0.82 eV/H2, which is suitable for ambient temperature hydrogen storage. Considering the fact that Ti can be loaded on both sides of B2C sheet, corresponding gravimetric storage capacity of Ti/B2C system was also calculated and it can reach to about 7.0 wt%, exceeding the minimum requirement of 6.0 wt% for applications.

  9. EphB2 guides axons at the midline and is necessary for normal vestibular function

    NASA Technical Reports Server (NTRS)

    Cowan, C. A.; Yokoyama, N.; Bianchi, L. M.; Henkemeyer, M.; Fritzsch, B.

    2000-01-01

    Mice lacking the EphB2 receptor tyrosine kinase display a cell-autonomous, strain-specific circling behavior that is associated with vestibular phenotypes. In mutant embryos, the contralateral inner ear efferent growth cones exhibit inappropriate pathway selection at the midline, while in mutant adults, the endolymph-filled lumen of the semicircular canals is severely reduced. EphB2 is expressed in the endolymph-producing dark cells in the inner ear epithelium, and these cells show ultrastructural defects in the mutants. A molecular link to fluid regulation is provided by demonstrating that PDZ domain-containing proteins that bind the C termini of EphB2 and B-ephrins can also recognize the cytoplasmic tails of anion exchangers and aquaporins. This suggests EphB2 may regulate ionic homeostasis and endolymph fluid production through macromolecular associations with membrane channels that transport chloride, bicarbonate, and water.

  10. Proton Mobility in b2 Ion Formation and Fragmentation Reactions of Histidine-Containing Peptides

    NASA Astrophysics Data System (ADS)

    Nelson, Carissa R.; Abutokaikah, Maha T.; Harrison, Alex G.; Bythell, Benjamin J.

    2016-03-01

    A detailed energy-resolved study of the fragmentation reactions of protonated histidine-containing peptides and their b2 ions has been undertaken. Density functional theory calculations were utilized to predict how the fragmentation reactions occur so that we might discern why the mass spectra demonstrated particular energy dependencies. We compare our results to the current literature and to synthetic b2 ion standards. We show that the position of the His residue does affect the identity of the subsequent b2 ion (diketopiperazine versus oxazolone versus lactam) and that energy-resolved CID can distinguish these isomeric products based on their fragmentation energetics. The histidine side chain facilitates every major transformation except trans-cis isomerization of the first amide bond, a necessary prerequisite to diketopiperazine b2 ion formation. Despite this lack of catalyzation, trans-cis isomerization is predicted to be facile. Concomitantly, the subsequent amide bond cleavage reaction is rate-limiting.

  11. [Partial group-specific phytohemagglutinins anti-B1 and anti-B2].

    PubMed

    Potapov, M I

    2004-01-01

    Saline phytohemagglutinins (PHA) were detected in the aril of seeds Evonymus alata and E. sacrosancta (anti-B1) and in seeds Sophora japonica (anti-B2). They are highly sensitive to samples used in the detection of incomplete antibodies. Sophora contains also an incomplete partial PHA anti-B2 of the blocking type. As for extracts, they obviously do not contain PHA to erythrocytes of animals. PMID:15008090

  12. Discovery of Benzimidazole CYP11B2 Inhibitors with in Vivo Activity in Rhesus Monkeys

    PubMed Central

    2015-01-01

    We report the discovery of a benzimidazole series of CYP11B2 inhibitors. Hit-to-lead and lead optimization studies identified compounds such as 32, which displays potent CYP11B2 inhibition, high selectivity versus related CYP targets, and good pharmacokinetic properties in rat and rhesus. In a rhesus pharmacodynamic model, 32 produces dose-dependent aldosterone lowering efficacy, with no apparent effect on cortisol levels. PMID:26005536

  13. An ANFIS-based on B2C electronic commerce transaction

    SciTech Connect

    Lin, Juan; Liu, Chenlian; Guo, Yongning

    2014-10-06

    The purpose of this study is to use an adaptive-network-based fuzzy inference system to model a fuzzy logic-based system (FIS) for supporting decision-making process in B2C electronic commerce transaction. Firstly we introduce FIS in B2C electronic commerce transaction and ANFIS. Then we use ANFIS to model FIS with different membership functions(MF). Lastly we give a conclusion.

  14. Anisotropic normal-state properties of the MgB2 superconductor

    NASA Astrophysics Data System (ADS)

    de la Mora, Pablo; Castro, Miguel; Tavizon, Gustavo

    2005-02-01

    Based on the experimentally-found existence of two superconducting gaps in MgB2 (one gap associated to the boron σ-states and the other to the boron π-states), the different contributions to the transport properties, electrical conductivity and Hall coefficient were studied using the full potential-linearized augmented plane wave method and the generalized gradient approximation. Four different relaxation times were needed to adjust the electrical conductivity and Hall coefficient to experimental values. MgB2 doping was analysed in the rigid band approximation; this permitted a detailed study of the partial substitution of magnesium for aluminium (Mg1-xAlxB2). Other substitutions such as AB2 (A = Be, Sc, Zr, Nb and Ta) are also discussed. The MgB2 σ-bands (boron σ-states), which are associated to the large gap, are very anisotropic at EF, while the π bands have very little anisotropic character. In Mg1-xAlxB2, Tc diminishes with Al content; the other compounds are not superconductors or have a low Tc. In this work it was found that with electron doping, such as Al substitution, the σ-band conductivity decreases and the corresponding bands become less anisotropic. The σ-band contribution for BeB2 and ScB2 at EF is very small and the anisotropy is much lower. For Zr, Nb and Ta there are no σ-bands at EF. These results give a clear connection between superconductivity and the character of the σ-band, band conductivity, and band anisotropy. This gives a plausible explanation for the diminution of Tc with different doping of MgB2.

  15. Exceptional quantum subgroups for the rank two Lie algebras B2 and G2

    NASA Astrophysics Data System (ADS)

    Coquereaux, R.; Rais, R.; Tahri, E. H.

    2010-09-01

    Exceptional modular invariants for the Lie algebras B2 (at levels 2, 3, 7, and 12) and G2 (at levels 3 and 4) can be obtained from conformal embeddings. We determine the associated algebras of quantum symmetries and discover or recover, as a by-product, the graphs describing exceptional quantum subgroups of type B2 or G2 that encode their module structure over the associated fusion category. Global dimensions are given.

  16. An ANFIS-based on B2C electronic commerce transaction

    NASA Astrophysics Data System (ADS)

    Lin, Juan; Liu, Chenlian; Guo, Yongning

    2014-10-01

    The purpose of this study is to use an adaptive-network-based fuzzy inference system to model a fuzzy logic-based system (FIS) for supporting decision-making process in B2C electronic commerce transaction. Firstly we introduce FIS in B2C electronic commerce transaction and ANFIS. Then we use ANFIS to model FIS with different membership functions(MF). Lastly we give a conclusion.

  17. Nature of the Carbohydrate and Phosphate Associated with ColB2 and EDP208 Pilin

    PubMed Central

    Armstrong, G. D.; Frost, L. S.; Vogel, H. J.; Paranchych, W.

    1981-01-01

    Studies were carried out to elucidate the nature of phosphate and sugar linkages to F-like conjugative pili encoded by the ColB2Fdr (compatibility group FII) and EDP208 (compatibility group FV) plasmids. Both types of pili, when in the intact undissociated state, were found to contain approximately 3 mol of phosphate and 3 mol of sugar per mol of pilin. However, further purification of the two types of pilin by gel filtration chromatography in the presence of sodium dodecyl sulfate (SDS) removed all of the carbohydrate from EDP208 pilin and approximately 65% of the carbohydrate from ColB2 pilin. Approximately 0.8 to 1.0 mol of glucose per mol of protein remained associated with ColB2 pilin after SDS gel filtration chromatography, but it was not possible to determine whether this was covalently linked to the pilin, or tightly associated in an SDS-resistant manner. SDS-gel chromatography did not remove phosphate from either ColB2 or EDP208 pilins. 31P nuclear magnetic resonance studies indicated that the pilin-associated phosphate is involved in a phosphodiester linkage. Acetone precipitation or chloroform-methanol extraction of the purified pilin material reduced the phosphate associated with EDP208 pilin to less than 0.04 molecule per pilin monomer. ColB2 pilin, under the same conditions, retained approximately 0.5 phosphate per pilin monomer. The extracted phosphate-containing moieties were identified as phosphatidylglycerol and phosphatidylethanolamine by thin-layer chromatography. Since the 31P nuclear magnetic resonance spectra for both ColB2 and EDP208 were identical and no signal other than that of a phosphodiester was detected in the ColB2 spectrum, the phosphate remaining with the ColB2 pilin after chloroform-methanol extraction is most likely due to a tightly bound noncovalent residue. Images PMID:6110653

  18. Transposable B2 SINE elements can provide mobile RNA polymerase II promoters.

    PubMed

    Ferrigno, O; Virolle, T; Djabari, Z; Ortonne, J P; White, R J; Aberdam, D

    2001-05-01

    Short interspersed elements (SINEs) are highly abundant components of mammalian genomes that are propagated by retrotransposition. SINEs are recognized as a causal agent of human disease and must also have had a profound influence in shaping eukaryotic genomes. The B2 SINE family constitutes approximately 0.7% of total mouse genomic DNA (ref. 2) and is also found at low abundance in humans. It resembles the Alu family in several respects, such as its mechanism of propagation. B2 SINEs are derived from tRNA and are transcribed by RNA polymerase (pol) III to generate short transcripts that are not translated. We find here, however, that one B2 SINE also carries an active pol II promoter located outside the tRNA region. Indeed, a B2 element is responsible for the production of a mouse Lama3 transcript. The B2 pol II promoters can be bound and stimulated by the transcription factor USF (for upstream stimulatory factor), as shown by transient transfection experiments. Moreover, this pol II activity does not preclude the pol III transcription necessary for retrotransposition. Dispersal of B2 SINEs by retrotransposition may therefore have provided numerous opportunities for creating regulated pol II transcription at novel genomic sites. This mechanism may have allowed the evolution of new transcription units and new genes. PMID:11326281

  19. The Synthesis of B2(SIDip)2 and its Reactivity Between the Diboracumulenic and Diborynic Extremes.

    PubMed

    Böhnke, Julian; Braunschweig, Holger; Dellermann, Theresa; Ewing, William C; Hammond, Kai; Jimenez-Halla, J Oscar C; Kramer, Thomas; Mies, Jan

    2015-11-01

    A new compound with the formula L-B2-L wherein the stabilizing ligand (L) is 1,3-bis[diisopropylphenyl]-4,5-dihydroimidazol-2-ylidene (SIDip) has been synthesized, isolated, and characterized. The π-acidity of the SIDip ligand, intermediate between the relatively non-acidic IDip (1,3-bis[diisopropylphenyl]imidazol-2-ylidene) ligand and the much more highly acidic CAAC (1-[2,6-diisopropylphenyl]-3,3,5,5-tetramethylpyrrolidin-2-ylidene) ligand, gives rise to a compound with spectroscopic, electrochemical, and structural properties between those of L-B2-L compounds stabilized by CAAC and IDip. Reactions of all three L-B2-L compounds with CO demonstrate the differences caused by their respective ligands, as the π-acidities of the CAAC and SIDip carbenes enabled the isolation of bis(boraketene) compounds (L(OC)B-B(CO)L), which could not be isolated from reactions with B2(IDip)2. However, only B2(IDip)2 and B2(SIDip)2 could be converted into bicyclic bis(boralactone) compounds.

  20. Impaired cortical neurogenesis in plexin-B1 and -B2 double deletion mutant.

    PubMed

    Daviaud, Nicolas; Chen, Karen; Huang, Yong; Friedel, Roland H; Zou, Hongyan

    2016-08-01

    Mammalian cortical expansion is tightly controlled by fine-tuning of proliferation and differentiation of neural progenitors in a region-specific manner. How extrinsic cues interface with cell-intrinsic programs to balance proliferative versus neurogenic decisions remains an unsolved question. We examined the function of Semaphorin receptors Plexin-B1 and -B2 in corticogenesis by generating double mutants, whereby Plexin-B2 was conditionally ablated in the developing brain in a Plexin-B1 null mutant background. Absence of both Plexin-Bs resulted in cortical thinning, particularly in the caudomedial cortex. Plexin-B1/B2 double, but not single, mutants exhibited a reduced neural progenitor pool, attributable to decreased proliferation and an altered division mode favoring cell cycle exit. This resulted in deficient production of neurons throughout the neurogenic period, proportionally affecting all cortical laminae. Consistent with the in vivo data, cultured neural progenitors lacking both Plexin-B1 and -B2 displayed decreased proliferative capacity and increased spontaneous differentiation. Our study therefore defines a novel function of Plexin-B1 and -B2 in transmitting extrinsic signals to maintain proliferative and undifferentiated states of neural progenitors. As single mutants displayed no apparent cortical defects, we conclude that Plexin-B1 and -B2 play redundant or compensatory roles during forebrain development to ensure proper neuronal production and neocortical expansion. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 882-899, 2016.

  1. Role of kinin B2 receptors in opioid-induced hyperalgesia in inflammatory pain in mice.

    PubMed

    Grastilleur, Sébastien; Mouledous, Lionel; Bedel, Jerome; Etcheverry, Jonathan; Bader, Michael; Girolami, Jean-Pierre; Fourcade, Olivier; Frances, Bernard; Minville, Vincent

    2013-03-01

    Postoperative pain management is a clinical challenge that can be complicated by opioid-induced hyperalgesia (OIH). Kinin receptors could mediate both the acute and chronic phases of inflammation and pain. A few recent studies suggest that dynorphin A could maintain neuropathic pain by activating the bradykinin (BK) receptor. Thus, the effect of a single administration of sufentanil (a μ-opioid receptor agonist) was investigated in a model of carrageenan-induced inflammatory pain using three strains of mice, i.e., knockout mice for one kinin receptor, B1R or B2R (B1KO, B2KO), and wild-type C57/BL6J mice (WT) treated with either a B1R (R954) or a B2R antagonist (HOE140) or a KKS inhibitor (aprotinin). Pain was assessed and compared between the different groups using two behavioral tests exploring mechanical (von Frey filaments) and thermal (Hargreaves test) sensitivity. Pretreatment with sufentanil induced a sustained increase in pain sensitivity with a delayed return to baseline values characterizing an OIH in carrageenan-injected mice only. Sufentanil-induced OIH was not observed in B2KO but persisted in B1KO and was blunted by aprotinin and the B2R antagonist only. Collectively, our data indicate that the B2R receptor and BK synthesis or availability are essential peripheral steps in the mechanism leading to OIH in a pain context.

  2. Regulation of ErbB2 localization and function in breast cancer cells by ERM proteins

    PubMed Central

    Asp, Nagham; Kvalvaag, Audun; Sandvig, Kirsten; Pust, Sascha

    2016-01-01

    The ERM protein family is implicated in processes such as signal transduction, protein trafficking, cell proliferation and migration. Consequently, dysregulation of ERM proteins has been described to correlate with carcinogenesis of different cancer types. However, the underlying mechanisms are poorly understood. Here, we demonstrate a novel functional interaction between ERM proteins and the ErbB2 receptor tyrosine kinase in breast cancer cells. We show that the ERM proteins ezrin and radixin are associated with ErbB2 receptors at the plasma membrane, and depletion or functional inhibition of ERM proteins destabilizes the interaction of ErbB2 with ErbB3, Hsp90 and Ebp50. Accompanied by the dissociation of this protein complex, binding of ErbB2 to the ubiquitin-ligase c-Cbl is increased, and ErbB2 becomes dephosphorylated, ubiquitinated and internalized. Furthermore, signaling via Akt- and Erk-mediated pathways is impaired upon ERM inhibition. Finally, interference with ERM functionality leads to receptor degradation and reduced cellular levels of ErbB2 and ErbB3 receptors in breast cancer cells. PMID:27029001

  3. Role of kinin B2 receptors in opioid-induced hyperalgesia in inflammatory pain in mice.

    PubMed

    Grastilleur, Sébastien; Mouledous, Lionel; Bedel, Jerome; Etcheverry, Jonathan; Bader, Michael; Girolami, Jean-Pierre; Fourcade, Olivier; Frances, Bernard; Minville, Vincent

    2013-03-01

    Postoperative pain management is a clinical challenge that can be complicated by opioid-induced hyperalgesia (OIH). Kinin receptors could mediate both the acute and chronic phases of inflammation and pain. A few recent studies suggest that dynorphin A could maintain neuropathic pain by activating the bradykinin (BK) receptor. Thus, the effect of a single administration of sufentanil (a μ-opioid receptor agonist) was investigated in a model of carrageenan-induced inflammatory pain using three strains of mice, i.e., knockout mice for one kinin receptor, B1R or B2R (B1KO, B2KO), and wild-type C57/BL6J mice (WT) treated with either a B1R (R954) or a B2R antagonist (HOE140) or a KKS inhibitor (aprotinin). Pain was assessed and compared between the different groups using two behavioral tests exploring mechanical (von Frey filaments) and thermal (Hargreaves test) sensitivity. Pretreatment with sufentanil induced a sustained increase in pain sensitivity with a delayed return to baseline values characterizing an OIH in carrageenan-injected mice only. Sufentanil-induced OIH was not observed in B2KO but persisted in B1KO and was blunted by aprotinin and the B2R antagonist only. Collectively, our data indicate that the B2R receptor and BK synthesis or availability are essential peripheral steps in the mechanism leading to OIH in a pain context. PMID:23324378

  4. Wettability and Reactivity of ZrB2 Substrates with Liquid Al

    NASA Astrophysics Data System (ADS)

    Nowak, R.; Sobczak, N.; Bruzda, G.; Wojewoda-Budka, J.; Litynska-Dobrzynska, L.; Homa, M.; Kaban, I.; Xi, L.; Jaworska, L.

    2016-08-01

    Wetting characteristics of the Al/ZrB2 system were experimentally determined by the sessile drop method with application of separate heating of the ZrB2 and Al samples and combined with in situ cleaning of Al drop from native oxide film directly in vacuum chamber. The tests were performed in ultrahigh vacuum of 10-6 mbar at temperatures 710, 800, and 900 °C as well as in flowing inert gas (Ar) atmosphere at 1400 °C. The results evidenced that liquid Al does not wet ZrB2 substrate at 710 and 800 °C, forming high contact angles ( θ) of 128° and 120°, respectively. At 900 °C, wetting phenomenon ( θ < 90°) occurs in 29th minute and the contact angle decreases monotonically to the final value of 80°. At 1400 °C, wetting takes place immediately after drop deposition with a fast decrease in the contact angle to 76°. The solidified Al/ZrB2 couples were studied by scanning and transmission electron microscopy coupled with x-ray energy diffraction spectroscopy. Structural characterization revealed that only in the Al/ZrB2 couple produced at the highest temperature of 1400 °C new phases (Al3Zr, AlB2 and α-Al2O3) were formed.

  5. Wettability and Reactivity of ZrB2 Substrates with Liquid Al

    NASA Astrophysics Data System (ADS)

    Nowak, R.; Sobczak, N.; Bruzda, G.; Wojewoda-Budka, J.; Litynska-Dobrzynska, L.; Homa, M.; Kaban, I.; Xi, L.; Jaworska, L.

    2016-01-01

    Wetting characteristics of the Al/ZrB2 system were experimentally determined by the sessile drop method with application of separate heating of the ZrB2 and Al samples and combined with in situ cleaning of Al drop from native oxide film directly in vacuum chamber. The tests were performed in ultrahigh vacuum of 10-6 mbar at temperatures 710, 800, and 900 °C as well as in flowing inert gas (Ar) atmosphere at 1400 °C. The results evidenced that liquid Al does not wet ZrB2 substrate at 710 and 800 °C, forming high contact angles (θ) of 128° and 120°, respectively. At 900 °C, wetting phenomenon (θ < 90°) occurs in 29th minute and the contact angle decreases monotonically to the final value of 80°. At 1400 °C, wetting takes place immediately after drop deposition with a fast decrease in the contact angle to 76°. The solidified Al/ZrB2 couples were studied by scanning and transmission electron microscopy coupled with x-ray energy diffraction spectroscopy. Structural characterization revealed that only in the Al/ZrB2 couple produced at the highest temperature of 1400 °C new phases (Al3Zr, AlB2 and α-Al2O3) were formed.

  6. Degradation of aromatic compounds and degradative pathway of 4-nitrocatechol by Ochrobactrum sp. B2.

    PubMed

    Zhong, Qiuzan; Zhang, Haiyan; Bai, Wenqin; Li, Mei; Li, Baotong; Qiu, Xinghui

    2007-12-01

    The potential capacity of a soil methyl parathion-degrading bacterium strain, Ochrobactrum sp. B2, for degrading various aromatic compounds were investigated. The results showed B2 was capable of degrading diverse aromatic compounds, but amino-substituted benzene compounds, at a concentration up to 100 mg L(-1) in 4 days. B2 could use 4-nitrocatechol (4-NC) as a sole carbon and energy source with release of nitrite ion. The pathway for 4-NC degradation via 1,2,4-benzenetriol (BT) and hydroquinone (HQ) formation in B2 was proposed based on the identification and quantification of intermediates by gas chromatography-mass spectrometry (GC-MS), and high performance liquid chromatography (HPLC). Degradation studies carried out on a plasmid-cured derivative showed that the genes for 4-NC degradative pathway was plasmid-borne in B2, suggesting that B2 degrades both p-nitrophenol and 4-NC by enzymes encoded by genes on the same plasmid.

  7. High critical currents in iron-clad superconducting MgB2 wires.

    PubMed

    Jin, S; Mavoori, H; Bower, C; van Dover, R B

    2001-05-31

    Technically useful bulk superconductors must have high transport critical current densities, Jc, at operating temperatures. They also require a normal metal cladding to provide parallel electrical conduction, thermal stabilization, and mechanical protection of the generally brittle superconductor cores. The recent discovery of superconductivity at 39 K in magnesium diboride (MgB2) presents a new possibility for significant bulk applications, but many critical issues relevant for practical wires remain unresolved. In particular, MgB2 is mechanically hard and brittle and therefore not amenable to drawing into the desired fine-wire geometry. Even the synthesis of moderately dense, bulk MgB2 attaining 39 K superconductivity is a challenge because of the volatility and reactivity of magnesium. Here we report the successful fabrication of dense, metal-clad superconducting MgB2 wires, and demonstrate a transport Jc in excess of 85,000 A cm-2 at 4.2 K. Our iron-clad fabrication technique takes place at ambient pressure, yet produces dense MgB2 with little loss of stoichiometry. While searching for a suitable cladding material, we found that other materials dramatically reduced the critical current, showing that although MgB2 itself does not show the 'weak-link' effect characteristic of the high-Tc superconductors, contamination does result in weak-link-like behaviour.

  8. Quantum confinement induced band gaps in MgB2 nanosheets

    NASA Astrophysics Data System (ADS)

    Xu, Bo Z.; Beckman, Scott P.

    2016-09-01

    The discovery of two-dimensional semiconducting materials, a decade ago, spawned an entire sub-field within solid-state physics that is focused on the development of nanoelectronics. Here we present a new class of semiconducting two-dimensional material based on hexagonal MgB2. Although MgB2 is a semimetal, similar to the other well-studied transition metal diborides, we demonstrate that, unlike the transition metal diborides, thinning MgB2, to create nanosheets, opens a band gap in the density of states. We predict that a 7 Å thick MgB2 nanosheet will have a band gap of 0.51 eV. MgB2 nanosheets differ from other two-dimensional semiconductors in that the band gap is introduced by (001) surfaces and is opened by the quantum confinement effect. The implications of these findings are that nanostructured MgB2 is not merely a new composition, but also has intrinsic mechanisms for tuning its electronic properties, which may facilitate the development of nanoelectronics.

  9. Significant enhancement of the superconducting properties of MgB2 by polyvinyl alcohol additives

    NASA Astrophysics Data System (ADS)

    Zeng, R.; Lu, L.; Dou, S. X.

    2008-08-01

    We report a systematic study of the effects of polymer addition on the lattice parameters, microstructure and superconducting properties of MgB2. Polyvinyl alcohol [-C2H4O-]n (PVA) as a typical polymer was used as an additive to MgB2. It was found that PVA additions have the following features: (1) the polymer can have a very low oxygen (O) content or even none at all, and PVA has a low O content (C:O = 2:1), which reduces the impurities brought into MgB2 from the doping, and (2) PVA decomposes at a temperature of 400-650 °C, which means that the reaction occurs in the same temperature range as MgB2 formation, providing highly reactive C, which homogeneously substitutes for B at this low-temperature range. The above considerations significantly enhance the critical current, Jc, the irreversibility field, Hirr, and the upper critical field, Hc2, of MgB2 compared to un-doped samples or those doped with other carbon sources. In this work, suitable PVA doping levels improved both the connectivity and flux pinning, so that the Jc of PVA-doped MgB2 was improved over the whole field range.

  10. Disorder in carbon-doped HPCVD MgB2 thin films

    NASA Astrophysics Data System (ADS)

    Zhu, Ye; Voyles, P. M.; Pogrebnyakov, A. V.; Xi, X. X.

    2007-03-01

    Carbon-doped MgB2 films prepared by hybrid physical-chemical vapor deposition have the highest Hc2 (˜70 T at 0 K for H parallel to ab plane) of all MgB2 materials. We have characterized the nanoscale structure and chemistry of one such film by TEM and STEM. The C concentration in the Mg(B1-xCx)2 grains from EELS is not dramatically higher than that of C-doped bulk MgB2, so doping does not explain the high Hc2. Instead, the doped film has a variety of forms of structural disorder at length scales down to 5 nm, which may be sufficient to explain the Hc2 of these films. These include MgB2 domains with a 30 degree rotation about the c-axis, small angle rotations about c-axis, and a small tilt of the c-axis. There are also amorphous, C-rich regions between some MgB2 domains. The amorphous phase comes from the oversupply of C during growth, which may also cause the other disorder by interrupting epitaxial film growth. This work is supported by the FRG on MgB2, NSF DMR-0514592.

  11. The Synthesis of B2(SIDip)2 and its Reactivity Between the Diboracumulenic and Diborynic Extremes.

    PubMed

    Böhnke, Julian; Braunschweig, Holger; Dellermann, Theresa; Ewing, William C; Hammond, Kai; Jimenez-Halla, J Oscar C; Kramer, Thomas; Mies, Jan

    2015-11-01

    A new compound with the formula L-B2-L wherein the stabilizing ligand (L) is 1,3-bis[diisopropylphenyl]-4,5-dihydroimidazol-2-ylidene (SIDip) has been synthesized, isolated, and characterized. The π-acidity of the SIDip ligand, intermediate between the relatively non-acidic IDip (1,3-bis[diisopropylphenyl]imidazol-2-ylidene) ligand and the much more highly acidic CAAC (1-[2,6-diisopropylphenyl]-3,3,5,5-tetramethylpyrrolidin-2-ylidene) ligand, gives rise to a compound with spectroscopic, electrochemical, and structural properties between those of L-B2-L compounds stabilized by CAAC and IDip. Reactions of all three L-B2-L compounds with CO demonstrate the differences caused by their respective ligands, as the π-acidities of the CAAC and SIDip carbenes enabled the isolation of bis(boraketene) compounds (L(OC)B-B(CO)L), which could not be isolated from reactions with B2(IDip)2. However, only B2(IDip)2 and B2(SIDip)2 could be converted into bicyclic bis(boralactone) compounds. PMID:26427026

  12. Critical determination of the frequency of c-erbB-2 amplification in breast cancer.

    PubMed Central

    Hubbard, A. L.; Doris, C. P.; Thompson, A. M.; Chetty, U.; Anderson, T. J.

    1994-01-01

    Tissues from 323 methacarn-fixed and paraffin-embedded breast cancers were assessed for c-erbB-2 gene amplification by differential polymerase chain reaction (dPCR). The sensitivity of dPCR was ascertained using cell lines with c-erbB-2 amplification, and the relationship between dPCR ratio value and gene copy number was established. In clinical material the technique was not affected by the DNA contribution of normal tissue elements or by cancer DNA ploidy change. c-erbB-2 gene amplification was detected in 55% of invasive cancers and in 66% of in situ cancers. c-erbB-2 protein overexpression in breast cancer cells, as determined by specific immunohistochemistry, was only detected in 11% of invasive cancers and 43% of in situ cancers. Comparisons show that a substantial number of cancers with c-erbB-2 amplification lack detectable protein overexpression. This illustrates the complex nature of c-erbB-2 gene disregulation in cancer and suggests that multiple combinations of biological events and consequences are possible. Images Figure 3 PMID:7915911

  13. EphrinB2 drives perivascular invasion and proliferation of glioblastoma stem-like cells

    PubMed Central

    Krusche, Benjamin; Ottone, Cristina; Clements, Melanie P; Johnstone, Ewan R; Goetsch, Katrin; Lieven, Huang; Mota, Silvia G; Singh, Poonam; Khadayate, Sanjay; Ashraf, Azhaar; Davies, Timothy; Pollard, Steven M; De Paola, Vincenzo; Roncaroli, Federico; Martinez-Torrecuadrada, Jorge; Bertone, Paul; Parrinello, Simona

    2016-01-01

    Glioblastomas (GBM) are aggressive and therapy-resistant brain tumours, which contain a subpopulation of tumour-propagating glioblastoma stem-like cells (GSC) thought to drive progression and recurrence. Diffuse invasion of the brain parenchyma, including along preexisting blood vessels, is a leading cause of therapeutic resistance, but the mechanisms remain unclear. Here, we show that ephrin-B2 mediates GSC perivascular invasion. Intravital imaging, coupled with mechanistic studies in murine GBM models and patient-derived GSC, revealed that endothelial ephrin-B2 compartmentalises non-tumourigenic cells. In contrast, upregulation of the same ephrin-B2 ligand in GSC enabled perivascular migration through homotypic forward signalling. Surprisingly, ephrin-B2 reverse signalling also promoted tumourigenesis cell-autonomously, by mediating anchorage-independent cytokinesis via RhoA. In human GSC-derived orthotopic xenografts, EFNB2 knock-down blocked tumour initiation and treatment of established tumours with ephrin-B2-blocking antibodies suppressed progression. Thus, our results indicate that targeting ephrin-B2 may be an effective strategy for the simultaneous inhibition of invasion and proliferation in GBM. DOI: http://dx.doi.org/10.7554/eLife.14845.001 PMID:27350048

  14. Alginate/chitosan nanoparticles for encapsulation and controlled release of vitamin B2.

    PubMed

    Azevedo, Maria A; Bourbon, Ana I; Vicente, António A; Cerqueira, Miguel A

    2014-11-01

    This work aims at evaluating encapsulation and controlled release of vitamin B2 from alginate/chitosan nanoparticles. Ionotropic polyelectrolyte pre-gelation was used as production method being chitosan and alginate used as main materials. Nanoparticles were characterized in terms of average size, polydispersity index (PDI), zeta potential and vitamin entrapment efficiency. The average size for alginate/chitosan nanoparticles was 119.5±49.9nm for samples without vitamin B2 and 104.0±67.2nm with the encapsulation of vitamin B2, presenting a PDI of 0.454±0.066 and 0.319±0.068, respectively. The nanoparticles showed encapsulation efficiency and loading capacity values of 55.9±5.6% and 2.2±0.6%, respectively. Release profiles were evaluated at different conditions showing that the polymeric relaxation was the most influent phenomenon in vitamin B2 release. In order to study their stability nanoparticles were stored at 4°C being particles sizes and PDI evaluated during 5 months showing the results that vitamin B2-loaded nanoparticles are more stable (in terms of size and PDI) than nanoparticles without vitamin B2.

  15. R Engine Cell: integrating R into the i2b2 software infrastructure

    PubMed Central

    Segagni, Daniele; Ferrazzi, Fulvia; Larizza, Cristiana; Tibollo, Valentina; Napolitano, Carlo; Priori, Silvia G

    2011-01-01

    Informatics for Integrating Biology and the Bedside (i2b2) is an initiative funded by the NIH that aims at building an informatics infrastructure to support biomedical research. The University of Pavia has recently integrated i2b2 infrastructure with a registry of inherited arrhythmogenic diseases. Within this project, the authors created a novel i2b2 cell, named R Engine Cell, which allows the communication between i2b2 and the R statistical software. As survival analyses are routinely performed by cardiology researchers, the authors have first concentrated on making Kaplan–Meier analyses available within the i2b2 web interface. To this aim, the authors developed a web-client plug-in to select the patient set on which to perform the analysis and to display the results in a graphical, intuitive way. R Engine Cell has been designed to easily support the integration of other R-based statistical analyses into i2b2. PMID:21262924

  16. Congenital hyperreninemic hypoaldosteronism unlinked to the aldosterone synthase (CYP11B2) gene.

    PubMed

    Kayes-Wandover, K M; Tannin, G M; Shulman, D; Peled, D; Jones, K L; Karaviti, L; White, P C

    2001-11-01

    Isolated hyperreninemic hypoaldosteronism presenting in infancy is usually caused by mutations in the CYP11B2 gene encoding aldosterone synthase. We studied five patients in four unrelated kindreds with hyperreninemic hypoaldosteronism, in whom we were unable to find such mutations. All presented in infancy with failure to thrive, hyponatremia, hyperkalemia, markedly elevated plasma renin activity, and low or inappropriately normal aldosterone levels. All had normal cortisol levels and no signs or symptoms of congenital adrenal hyperplasia. All responded to fludrocortisone treatment. There were no mutations detected in exons or splice junctions of CYP11B2. Linkage of the disorder to CYP11B2 was studied in two unrelated consanguineous patients and in an affected sib pair. The consanguineous patients were each heterozygous for at least one of three polymorphic microsatellite markers near CYP11B2, excluding linkage to CYP11B2. However, linkage of the disease to CYP11B2 could not be excluded in the affected sib pair. Genes involved in the regulation of aldosterone biosynthesis, including those encoding angiotensinogen, angiotensin-converting enzyme, and the AT1 angiotensin II receptor were similarly excluded from linkage. These results demonstrate the existence of an inherited form of hyperreninemic hypoaldosteronism distinct from aldosterone synthase deficiency. The affected gene(s) remain to be determined.

  17. Investigation of lauric acid dopant as a novel carbon source in MgB 2 wire

    NASA Astrophysics Data System (ADS)

    Lee, C. M.; Lee, S. M.; Park, G. C.; Joo, J.; Lim, J. H.; Kang, W. N.; Yi, J. H.; Jun, B.-H.; Kim, C.-J.

    2010-11-01

    We fabricated lauric acid (LA) doped MgB 2 wires and investigated the effects of the LA doping. For the fabrication of the LA-doped MgB 2 wires, B powder was mixed with LA at 0-5 wt.% of the total amount of MgB 2 using an organic solvent, dried, and then the LA-treated B and Mg powders were mixed stoichiometrically. The powder mixture was loaded into an Fe tube and the assemblage was drawn and sintered at 900 °C for 3 h under an argon atmosphere. We observed that the LA doping induced the substitution of C for the B sites in MgB 2 and that the actual content of C increased monotonically with increasing LA doping level. The LA-doped MgB 2 wires exhibited a lower critical temperature ( Tc), but better critical current density ( Jc) behavior in a high magnetic field: the 5 wt.% LA-doped sample had a Jc value of 5.32 × 10 3 A/cm 2, which was 2.17 times higher than that of the pristine sample (2.45 × 10 3 A/cm 2) at 5 K and 6 T, suggesting that LA is an effective C dopant in MgB 2 for enhancing the high-field Jc performance.

  18. Two novel human anti-ErbB2 immunoagents are active on trastuzumab-resistant tumours

    PubMed Central

    Gelardi, T; Damiano, V; Rosa, R; Bianco, R; Cozzolino, R; Tortora, G; Laccetti, P; D'Alessio, G; De Lorenzo, C

    2010-01-01

    Background: Overexpression of ErbB2 receptor in breast cancer is associated with disease progression and poor prognosis. Trastuzumab, the only humanised anti-ErbB2 antibody currently used in breast cancer, has proven to be effective; however, a relevant problem for clinical practice is that a high fraction of breast cancer patients shows primary or acquired resistance to trastuzumab treatment. Methods: We tested on trastuzumab-resistant cells two novel human anti-tumour immunoconjugates engineered in our laboratory by fusion of a human anti-ErbB2 scFv, termed Erbicin, with either a human RNase or the Fc region of a human IgG1. Both Erbicin-derived immunoagents (EDIAs) are selectively cytotoxic for ErbB2-positive cancer cells in vitro and vivo, target an ErbB2 epitope different from that recognised by trastuzumab and do not show cardiotoxic effects. Results: We report that EDIAs are active also on trastuzumab-resistant tumour cells both in vitro and in vivo, most likely because of the different epitope recognised, as EDIAs, unlike trastuzumab, were found to be able to inhibit the signalling pathway downstream of ErbB2. Conclusion: These results suggest that EDIAs are immunoagents that could not only fulfil the therapeutic need of patients ineligible to trastuzumab treatment due to cardiac dysfunction but also prove to be useful for breast cancer patients unresponsive to trastuzumab treatment. PMID:20051960

  19. Connectivity, Doping, and Anisotropy in Highly Dense Magnesium Diboride (MgB2)

    NASA Astrophysics Data System (ADS)

    Li, Guangze

    Magnesium diboride (MgB2) is a superconducting material which can be potentially used in many applications such as magnetic resonance imaging system (MRI), wind turbine generators and high energy physics facilities. The major advantages of MgB2 over other superconductors include its relatively high critical temperature of about 39 K, its low cost of raw materials, its simple crystal structure, and its round multifilament form when in the form of superconducting wires. Over the past fourteen years, much effort has been made to develop MgB2 wires with excellent superconducting properties, particularly the critical current density J c. However, this research has been limited by technical difficulties such as high porosity and weak connectivity in MgB2, relatively small flux pinning strength, low upper critical field B c2 and relatively high anisotropy. The goal of this dissertation is to understand the relationship between superconducting properties, microstructure, and reaction mechanisms in MgB 2. In particular, the influences of connectivity, B c2, anisotropy and flux pinning were investigated in terms of the effects of these variables on the Jcs and n-values of MgB2 superconducting wires (n-value is a parameter which indicates the sharpness of resistive V-I transition). The n -values of traditional "Powder in Tube (PIT)" processed MgB2 wires were improved by optimizing precursor species after the identification of microstructural defects such as so-called "sausaging problems". Also, it was found that "high porosity and weak connectivity" was one of the most critical issues which limited the J c performance in typical MgB2. To overcome this problem, highly dense, well-connected MgB2 conductors were successfully fabricated by adopting an innovative "Advanced Internal Magnesium Infiltration (AIMI)" process. A careful study on the reaction kinetics together with the microstructural evidence demonstrated how the MgB2 layer was formed as the infiltration process

  20. Ab initio Computations of the Electronic, Mechanical, and Thermal Properties of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2

    NASA Technical Reports Server (NTRS)

    Lawson, John W.; Bauschlicher, Charles W.; Daw, Murray

    2011-01-01

    Refractory materials such as metallic borides, often considered as ultra high temperature ceramics (UHTC), are characterized by high melting point, high hardness, and good chemical inertness. These materials have many applications which require high temperature materials that can operate with no or limited oxidation. Ab initio, first principles methods are the most accurate modeling approaches available and represent a parameter free description of the material based on the quantum mechanical equations. Using these methods, many of the intrinsic properties of these material can be obtained. We performed ab initio calculations based on density functional theory for the UHTC materials ZrB2 and HfB2. Computational results are presented for structural information (lattice constants, bond lengths, etc), electronic structure (bonding motifs, densities of states, band structure, etc), thermal quantities (phonon spectra, phonon densities of states, specific heat), as well as information about point defects such as vacancy and antisite formation energies.

  1. Direct Observation of b_2 Vibrational Levels in the ^1B_2 tilde{C} State of SO_2: Precise Measurement of ν_3 Level Staggerings

    NASA Astrophysics Data System (ADS)

    Park, Barratt; Jiang, Jun; Womack, Carrie; Richter, Peter; Field, Robert W.; Whitehill, Andrew Richard; Ono, Shuhei

    2014-06-01

    The ^1B_2 tilde{C} STATE OF SO_2 has been the subject of extensive investigation because it is important in the atmospheric photodissociation of SO_2. The state has a double-minimum potential in the dissociation coordinate, ν_3, arising from vibronic interactions, leading to a staggering of vibrational levels with v_3 odd vs. even. We report the first direct observations of the v_3 fundamental and of other levels with b_2 vibrational symmetry (odd v_3). Our work has made use of LIF, IR-UV double resonance, and coherent MODR techniques. Implications of the precision measurement of v_3 staggerings to the determination of double-minimum potential barrier and to vibronic coupling will be discussed.

  2. Mechanical properties of ZrB2- and HfB2-based ultra-high temperature ceramics fabricated by spark plasma sintering

    SciTech Connect

    Zapata-Solvas, E.; Jayaseelan, D.; Lin, Hua-Tay; Brown, P.; Lee, W.E.

    2013-01-01

    Flexural strengths at room temperature, at 1400 C in air and at room temperature after 1 h oxidation at 1400 C were determined for ZrB2- and HfB2-based ultra-high temperature ceramics (UHTCs). Defects caused by electrical discharge machining (EDM) lowered measured strengths significantly and were used to calculate fracture toughness via a fracture mechanics approach. ZrB2 with 20 vol.% SiC had room temperature strength of 700 90 MPa, fracture toughness of 6.4 0.6 MPa, Vickers hardness at 9.8 N load of 21.1 0.6 GPa, 1400 C strength of 400 30 MPa and room temperature strength after 1 h oxidation at 1400 C of 678 15 MPa with an oxide layer thickness of 45 5 m. HfB2 with 20 vol.% SiC showed room temperature strength of 620 50 MPa, fracture toughness of 5.0 0.4 MPa, Vickers hardness at 9.8 N load of 27.0 0.6 GPa, 1400 C strength of 590 150 MPa and room temperature strength after 1 h oxidation at 1400 C of 660 25 MPa with an oxide layer thickness of 12 1 m. 2 wt.% La2O3 addition to UHTCs slightly reduced mechanical performance while increasing tolerance to property degradation after oxidation and effectively aided internal stress relaxation during spark plasma sintering (SPS) cooling, as quantified by X-ray diffraction (XRD). Slow crack growth was suggested as the failure mechanism at high temperatures as a consequence of sharp cracks formation during oxidation.

  3. DISSOCIATION OF B2H6 AND ADSORPTION OF THE FRAGMENTS OF B2H6 ON THE STEPPED Ge(100) SURFACE

    NASA Astrophysics Data System (ADS)

    Türkmenoğlu, Mustafa; Katircioğlu, Şenay

    2012-06-01

    In this work, the p-type doping of the SA type stepped Ge(100) surface by a diborane (B2H6) gas flow has been simulated by the possible dissociation and adsorption models. The most probable dissociation model of B2H6 and adsorption models of the fragments of B2H6 on the stepped Ge(100) surface have been determined by the local minimum total energy and/or binding energy calculations based on the Density functional (B3LYP/6-3g) and Hartree-Fock (HF/STO-3g) theories, respectively. The present calculations have shown that, the step region (for both up and down terraces) of the stepped Ge(100) surface has the most attractive sites for BH3 molecules determined to be the first dissociation fragments of B2H6 by an external energy of 1.3 eV. It has been found that, at the first step of the adsorption, BH3 can dissociate to BH2 and BH fragments on the stepped Ge(100) surface. While BH3 and BH2 products prefer to be attached to a single surface Ge atom, BH is bridged between two adjacent surface Ge atoms. According to the present optimization calculations, the p-type doping process of the stepped Ge(100) surface has started with the adsorption of BH3 on the electron deficient site (buckled down) of the Ge dimer bond close to the step edge and ended with the substitutional occupation of the Ge site in the layers of the surface by B atom. The beginning of the p-type doping of the stepped Ge(100) surface has been illustrated by the electronic states of B appeared in the optical energy gap of Ge very close to the edge of the HOMO.

  4. Reactor safety method

    DOEpatents

    Vachon, Lawrence J.

    1980-03-11

    This invention relates to safety means for preventing a gas cooled nuclear reactor from attaining criticality prior to start up in the event the reactor core is immersed in hydrogenous liquid. This is accomplished by coating the inside surface of the reactor coolant channels with a neutral absorbing material that will vaporize at the reactor's operating temperature.

  5. NEUTRONIC REACTOR MANIPULATING DEVICE

    DOEpatents

    Ohlinger, L.A.

    1962-08-01

    A cable connecting a control rod in a reactor with a motor outside the reactor for moving the rod, and a helical conduit in the reactor wall, through which the cable passes are described. The helical shape of the conduit prevents the escape of certain harmful radiations from the reactor. (AEC)

  6. Nuclear reactor

    DOEpatents

    Thomson, Wallace B.

    2004-03-16

    A nuclear reactor comprising a cylindrical pressure vessel, an elongated annular core centrally disposed within and spaced from the pressure vessel, and a plurality of ducts disposed longitudinally of the pressure vessel about the periphery thereof, said core comprising an annular active portion, an annular reflector just inside the active portion, and an annular reflector just outside the active a portion, said annular active portion comprising rectangular slab, porous fuel elements radially disposed around the inner reflector and extending the length of the active portion, wedge-shaped, porous moderator elements disposed adjacent one face of each fuel element and extending the length of the fuel element, the fuel and moderator elements being oriented so that the fuel elements face each other and the moderator elements do likewise, adjacent moderator elements being spaced to provide air inlet channels, and adjacent fuel elements being spaced to provide air outlet channels which communicate with the interior of the peripheral ducts, and means for introducing air into the air inlet channels which passes through the porous moderator elements and porous fuel elements to the outlet channel.

  7. Protective Effect of Procyanidin B2 against CCl4-Induced Acute Liver Injury in Mice.

    PubMed

    Yang, Bing-Ya; Zhang, Xiang-Yu; Guan, Sheng-Wen; Hua, Zi-Chun

    2015-07-03

    Procyanidin B2 has demonstrated several health benefits and medical properties. However, its protective effects against CCl4-induced hepatotoxicity have not been clarified. The present study aimed to investigate the hepatoprotective effects of procyanidin B2 in CCl4-treated mice. Our data showed that procyanidin B2 significantly decreased the CCl4-induced elevation of serum alanine aminotransferase activities, as well as improved hepatic histopathological abnormalities. Procyanidin B2 also significantly decreased the content of MDA but enhanced the activities of antioxidant enzymes SOD, CAT and GSH-Px. Further research demonstrated that procyanidin B2 decreased the expression of TNF-α, IL-1β, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), as well as inhibited the translocation of nuclear factor-kappa B (NF-κB) p65 from the cytosol to the nuclear fraction in mouse liver. Moreover, CCl4-induced apoptosis in mouse liver was measured by (terminal-deoxynucleotidyl transferase mediated nick end labeling) TUNEL assay and the cleaved caspase-3. Meanwhile, the expression of apoptosis-related proteins Bax and Bcl-xL was analyzed by Western blot. Results showed that procyanidin B2 significantly inhibited CCl4-induced hepatocyte apoptosis, markedly suppressed the upregulation of Bax expression and restored the downregulation of Bcl-xL expression. Overall, the findings indicated that procyanidin B2 exhibited a protective effect on CCl4-induced hepatic injury by elevating the antioxidative defense potential and consequently suppressing the inflammatory response and apoptosis of liver tissues.

  8. Functional expression of bradykinin B1 and B2 receptors in neonatal rat trigeminal ganglion neurons.

    PubMed

    Kawaguchi, Aya; Sato, Masaki; Kimura, Maki; Yamazaki, Takaki; Yamamoto, Hitoshi; Tazaki, Masakazu; Ichinohe, Tatsuya; Shibukawa, Yoshiyuki

    2015-01-01

    Bradykinin (BK) and its receptors (B1 and B2 receptors) play important roles in inflammatory nociception. However, the patterns of expression and physiological/pathological functions of B1 and B2 receptors in trigeminal ganglion (TG) neurons remain to be fully elucidated. We investigated the functional expression of BK receptors in rat TG neurons. We observed intense immunoreactivity of B2 receptors in TG neurons, while B1 receptors showed weak immunoreactivity. Expression of the B2 receptor colocalized with immunoreactivities against the pan-neuronal marker, neurofilament H, substance P, isolectin B4, and tropomyosin receptor kinase A antibodies. Both in the presence and absence of extracellular Ca(2+) ([Ca(2+)]o), BK application increased the concentration of intracellular free Ca(2+) ([Ca(2+)]i). The amplitudes of BK-induced [Ca(2+)]i increase in the absence of [Ca(2+)]o were significantly smaller than those in the presence of Ca(2+). In the absence of [Ca(2+)]o, BK-induced [Ca(2+)]i increases were sensitive to B2 receptor antagonists, but not to a B1 receptor antagonist. However, B1 receptor agonist, Lys-[Des-Arg(9)]BK, transiently increased [Ca(2+)]i in primary cultured TG neurons, and these increases were sensitive to a B1 receptor antagonist in the presence of [Ca(2+)]o. These results indicated that B2 receptors were constitutively expressed and their activation induced the mobilization of [Ca(2+)]i from intracellular stores with partial Ca(2+) influx by BK. Although constitutive B1 receptor expression could not be clearly observed immunohistochemically in the TG cryosection, cultured TG neurons functionally expressed B1 receptors, suggesting that both B1 and B2 receptors involve pathological and physiological nociceptive functions.

  9. MgB2: doped or with pressure, four systems same behaviour

    NASA Astrophysics Data System (ADS)

    de La Mora, Pablo; Ruiz-Chavarria, Sabina; Estevez, Ulises; Tavizon, Gustavo

    2007-03-01

    MgB2, the intermediate Tc superconductor, can be doped with carbon, aluminium and scandium and it has been also studied experimentally under pressure, in these four cases Tc diminishes. In previous studies we have shown, with electronic structure calculations, that when Mg is substituted with Sc [(Mg,Sc)B2] the drop of Tc can be associated with the loss of electrical anisotropy of the σ-bands [1]. When Mg is substituted with Al [(Mg,Al)B2] or B is substituted with C [Mg(B,C)2] then, with a change of doping scale, a common Tc curve is obtained for both systems, comparison with the σ-DOS shows that Tc drop is due to σ-band-filling and to σ-band anisotropy loss [2]. In further studies we have found that both these features, σ-band anisotropy reduction and the loss of σ-band-carriers, can be associated to the drop of Tc in these three doped systems [Mg(B,C)2, Mg,Al)B2 and (Mg,Sc)B2] and in MgB2 under pressure. All these studies show that: (a) with a change of doping scale then Tc in both the C and Al doped systems follows the same curve which is very close to the σ-DOS; (b) for the four systems both the σ-band anisotropy and the number of σ-carriers are two fundamental physical properties of the relatively high Tc in MgB2. [1] J. Phys.: Condens. Matter 18 (2006) 1403-1412 [2] cond-mat/0606019

  10. Procyanidin b2 cytotoxicity to mcf-7 human breast adenocarcinoma cells.

    PubMed

    Avelar, Monalisa M; Gouvêa, Cibele M C P

    2012-07-01

    Procyanidins have attracted some attention due to their demonstrated chemopreventive action, a relatively new and promising strategy to prevent cancer. Breast cancer is one of the leading causes of death in women worldwide and its treatment needs improvements. The aim of this work was to verify the procyanidin dimmer B2 cytotoxic effect to MCF-7 human breast cancer cells. MCF-7 cells were cultured in RPMI medium, containing 20% fetal bovine serum and antibiotics in a CO2 chamber. The cells were treated with different concentrations of B2 and its cytotoxic potential was assessed by the sulforhodamine B assay, morphologically through haematoxylin-eosin staining and by DNA fragmentation analysis. The significance of differences between experimental conditions was determined using the ANOVA test, followed by the Tukey test when P<0.05. Cell proliferation decreased in a concentration and time-dependent manner upon procyanidin dimmer B2 treatment, being 19.20 μM the IC50. Procyanidin dimmer B2 treatment displayed concentration and time-dependent decline in MCF-7 cells compared to control and also induced morphological alterations compatible with cell-death induction. Cell condensation and cell diameter decreased (3.5 folds compared to control cells), after 48 h cell-exposure to 50 μM procyanidin dimmer B2, but the DNA ladder formation was not observed. In conclusion, our results demonstrated that procyanidin dimmer B2 exhibits cytotoxic activity to MCF-7 cells and it could be a potential antineoplastic agent. Further studies are necessary to clarify the procyanidin dimmer B2 mechanism of action. The evaluation of biological efficacy of individual components is an important step towards drug discovery and development.

  11. Changes in c-erbB-2 Immunoexpression in Feline Endometrial Adenocarcinomas.

    PubMed

    Saraiva, A L; Payan-Carreira, R; Gärtner, F; Faria, F; Lourenço, L M; Pires, M A

    2016-02-01

    Human epidermal growth factor receptor type 2 (c-erbB-2), an oncoprotein with potential prognostic marker and therapeutic use, is overexpressed in several human and animal tumours. But information regarding this molecule in feline tumours is scarce. This study aimed to assess the changes in the immunohistochemical expression of c-erbB-2 in feline endometrial adenocarcinomas (FEA) compared to normal endometrium. An immunohistochemistry assay using a specific antibody against c-erbB-2 was performed in FEA samples (n = 34) and in normal endometrium in the follicular (FS; n = 12) and luteal (LS; n = 11) stages. In FEA, the c-erbB-2 immunoexpression was assessed in neoplastic epithelial cells whilst in normal endometria it was individually evaluated in the surface and the superficial and deep glandular epithelia (SE, SGE and DGE, respectively). In FS and in LS, all the epithelia were positive for c-erbB-2; positivity was higher in the SE and the SGE than in DGE. Twenty of the 34 FEA samples (58.8%) were positive for c-erbB-2 immunolabelling. Nevertheless, its expression was higher in all the epithelia in the FS compared to FEA (p ≤ 0.0001) or the LS (p = 0.016). The results presented herein suggest that c-erbB-2 molecule is differently expressed in the feline endometrium through the oestrous cycle and though it may also be involved in feline endometrial carcinogenesis, a question remains unanswered on the importance of additional pathways of epithelial proliferation in the neoplastic changes in feline endometrium. PMID:26638806

  12. Action Irmpd Spectroscopy of B_2 Fragment Ions from Qaxig and Naxig Pentapeptides

    NASA Astrophysics Data System (ADS)

    Morrison, L.; Chamot-Rooke, J.; Wysocki, V.

    2013-06-01

    The N-terminal fragments of peptides in MS/MS studies, or "b" ions, have been the subject of controversy for many years. The result of amide bond cleavage, these ions can be generated by two main pathways, forming either a head-to-tail cyclic peptide or a 5-membered oxazolone ring structure. The b_2 ion is particularly interesting because the head-to-tail isomer, or diketopiperazine, is typically more stable than the oxazolone but requires a high energy trans-cis isomerization of the peptide bond in order to form. Although amino acid identity in the first two positions is known to influence diketopiperazine vs. oxazolone formation, the factors that influence diketopiperazine formations are still incompletely understood. Action IRMPD (infrared multi-photon dissociation) spectroscopy was used to interrogate the gas-phase structures of the b_2 ions from QAXIG and NAXIG (X = L, D, or E) peptides. Irradiation of b_2 ions in the 1000 to 2000 cm^{-1} range interrogates the amide, amine, and carbonyl vibrational modes characteristic of diketopiperazine and oxazolone b_2 ions. Examination of the b_{2} structures of QAXIG and NAXIG peptides by this strategy has yielded novel information regarding the formation pathway of the diketopiperazine structure in the gas phase. Peptides without a basic residue in one of the first two positions are shown to generate diketopiperazine b_2 ions, which suggests that a bridging side chain is critical for b_2 ion formation by this pathway. Moreover, the third residue is shown for the first time to play a role in discriminating between the oxazolone and diketopiperazine product ions.

  13. LCEs for Naval Reactor Benchmark Calculations

    SciTech Connect

    W.J. Anderson

    1999-07-19

    The purpose of this engineering calculation is to document the MCNP4B2LV evaluations of Laboratory Critical Experiments (LCEs) performed as part of the Disposal Criticality Analysis Methodology program. LCE evaluations documented in this report were performed for 22 different cases with varied design parameters. Some of these LCEs (10) are documented in existing references (Ref. 7.1 and 7.2), but were re-run for this calculation file using more neutron histories. The objective of this analysis is to quantify the MCNP4B2LV code system's ability to accurately calculate the effective neutron multiplication factor (k{sub eff}) for various critical configurations. These LCE evaluations support the development and validation of the neutronics methodology used for criticality analyses involving Naval reactor spent nuclear fuel in a geologic repository.

  14. Processed VirB2 is the major subunit of the promiscuous pilus of Agrobacterium tumefaciens.

    PubMed

    Lai, E M; Kado, C I

    1998-05-01

    Previous studies have implicated the obligatory requirement for the vir regulon (or "virulon") of the Ti plasmid for the transfer of oncogenes from Agrobacterium tumefaciens to plant cells. The machinery used in this horizontal gene transfer has been long thought to be a transformation or conjugative delivery system. Based on recent protein sequence comparisons, the proteins encoded by the virB operon are strikingly similar to proteins involved in the synthesis and assembly of conjugative pili such as the conjugative pilus of F plasmid in Escherichia coli. The F pilus is composed of TraA pilin subunits derived from TraA propilin. In the present study, evidence is provided showing that the counterpart of TraA is VirB2, which like TraA propilin is processed into a 7.2-kDa product that comprises the pilus subunit as demonstrated by biochemical and electron microscopic analyses. The processed VirB2 protein is present exocellularly on medium on which induced A. tumefaciens had grown and appears as thin filaments of 10 nm that react specifically to VirB2 antibody. Exocellular VirB2 is produced abundantly at 19 degreesC as compared with 28 degreesC, an observation that parallels the effect of low temperature on the production of vir gene-specific pili observed previously (K. J. Fullner, L. C. Lara, and E. W. Nester, Science 273:1107-1109, 1996). Export of the processed VirB2 requires other virB genes since mutations in these genes cause the loss of VirB2 pilus formation and result in processed VirB2 accumulation in the cell. The presence of exocellular processed VirB2 is directly correlated with the formation of pili, and it appears as the major protein in the purified pilus preparation. The evidence provides a compelling argument for VirB2 as the propilin whose 7.2-kDa processed product is the pilin subunit of the promiscuous conjugative pilus, hereafter called the "T pilus" of A. tumefaciens. PMID:9573157

  15. Supporting the Health Quality Measures Format in i2b2.

    PubMed

    Klann, Jeffrey G; Murphy, Shawn N

    2013-01-01

    The Health Quality Measures Format (HQMF) is an HL7 standard for expressing computable queries of clinical data. It is becoming increasingly consequential for both quality measurement and population health research. A variety of national leadership is involved in its development and deployment, including the Meaningful Use incentive program, the Query Health initiative, the Joint Commission, the National Quality Forum (NQF), and the Food and Drug Administration. Here we analyze the structure of HQMF and apply this to computation of HQMF on Informatics for Integrating Biology and the Bedside (i2b2). i2b2 is a widely used, modular, open-source clinical research data repository. We implement a translator to convert between HQMF and i2b2-XML format that covers the subset of HQMF supported in i2b2-XML, which will be expanded in the next release of i2b2. This translator is part of the freely-available reference implementation of the QueryHealth initiative. PMID:24303250

  16. Infralimbic EphB2 Modulates Fear Extinction in Adolescent Rats.

    PubMed

    Cruz, Emmanuel; Soler-Cedeño, Omar; Negrón, Geovanny; Criado-Marrero, Marangelie; Chompré, Gladys; Porter, James T

    2015-09-01

    Adolescent rats are prone to impaired fear extinction, suggesting that mechanistic differences in extinction could exist in adolescent and adult rats. Since the infralimbic cortex (IL) is critical for fear extinction, we used PCR array technology to identify gene expression changes in IL induced by fear extinction in adolescent rats. Interestingly, the ephrin type B receptor 2 (EphB2), a tyrosine kinase receptor associated with synaptic development, was downregulated in IL after fear extinction. Consistent with the PCR array results, EphB2 levels of mRNA and protein were reduced in IL after fear extinction compared with fear conditioning, suggesting that EphB2 signaling in IL regulates fear extinction memory in adolescents. Finally, reducing EphB2 synthesis in IL with shRNA accelerated fear extinction learning in adolescent rats, but not in adult rats. These findings identify EphB2 in IL as a key regulator of fear extinction during adolescence, perhaps due to the increase in synaptic remodeling occurring during this developmental phase. PMID:26354908

  17. Direct effects of (-)-epicatechin and procyanidin B2 on the respiration of rat heart mitochondria.

    PubMed

    Kopustinskiene, Dalia M; Savickas, Arunas; Vetchý, David; Masteikova, Ruta; Kasauskas, Arturas; Bernatoniene, Jurga

    2015-01-01

    Flavonol (-)-epicatechin and its derived dimer procyanidin B2, present in high amounts in cocoa products, have been shown to exert beneficial effects on the heart and cardiovascular system; however, their mechanism of action has not been fully elucidated. We studied effects of (-)-epicatechin and procyanidin B2 on the oxidative phosphorylation of isolated rat heart mitochondria. (-)-Epicatechin and procyanidin B2 had stimulating effect (up to 30% compared to control) on substrate-driven (State 2) mitochondrial respiration. Their effect was dependent on the respiratory substrates used. (-)-Epicatechin at higher concentrations (from 0.27 µg/mL) significantly decreased (up to 15%) substrate- and ADP-driven (State 3) mitochondrial respiration in case of pyruvate and malate oxidation only. Procyanidin B2 (0.7-17.9 ng/mL) inhibited State 3 respiration rate up to 19%, the most profound effect being expressed with succinate as the substrate. (-)-Epicatechin at concentrations of 0.23 µg/mL and 0.46 µg/mL prevented loss of the cytochrome c from mitochondria when substrate was succinate, supporting the evidence of membrane stabilizing properties of this flavonol. Thus, both (-)-epicatechin and procyanidin B2 directly influenced mitochondrial functions and the observed effects could help to explain cardiometabolic risk reduction ascribed to the consumption of modest amounts of cocoa products.

  18. Microcin determinants are associated with B2 phylogroup of human fecal Escherichia coli isolates.

    PubMed

    Micenková, Lenka; Bosák, Juraj; Štaudová, Barbora; Kohoutová, Darina; Čejková, Darina; Woznicová, Vladana; Vrba, Martin; Ševčíková, Alena; Bureš, Jan; Šmajs, David

    2016-06-01

    Escherichia coli strains are classified into four main phylogenetic groups (A, B1, B2, and D) and strains of these phylogroups differ in a number of characteristics. This study tested whether human fecal E. coli isolates belonging to different phylogroups differ in prevalence of bacteriocinogenic isolates and prevalence of individual bacteriocinogenic determinants. A set of 1283 fecal E. coli isolates from patients with different diseases was tested for the presence of DNA regions allowing classification into E. coli phylogroups and for the ability to produce bacteriocins (23 colicins and 7 microcins). Of the isolates tested, the most common was phylogroup B2 (38.3%) followed by phylogroups A (28.3%), D (26.3%) and B1 (7.2%). Altogether, 695 bacteriocin producers were identified representing 54.2% of all tested isolates. The highest prevalence of bacteriocin producers was found in group B2 (60.3%) and the lowest in group B1 (44.6%). Determinants encoding colicins E1, Ia, and microcin mV were most common in phylogroup A, determinants encoding microcins mM and mH47 were most common in phylogroup B2, and determinant encoding mB17 was most common in phylogroup D. The highest prevalence of bacteriocinogeny was found in phylogroup B2, suggesting that bacteriocinogeny and especially the synthesis of microcins was associated with virulent and resident E. coli strains.

  19. Improved Jc-B properties of MgB2 multifilamentary wires and tapes

    NASA Astrophysics Data System (ADS)

    Wang, Chengduo; Wang, Dongliang; Zhang, Xianping; Yao, Chao; Wang, Chunlei; Ma, Yanwei; Oguro, Hidetoshi; Awaji, Satoshi; Watanabe, Kazuo

    2012-12-01

    MgB2 multifilamentary wires and tapes were fabricated by the in situ powder-in-tube (PIT) process using acetone doped milled precursor powders. The critical current density of MgB2 is strongly enhanced by high energy milling and acetone doping. Furthermore, the liquid acetone can restrain the agglomeration of milled powder, which is beneficial to the fabrication of MgB2 multifilamentary wires. At 4.2 K and 10 T, the Jc of the 80 h doped Fe/Cu wire is 2.9 × 103 A cm-2, 20 times larger than that of the 1 h pure one (the ‘1 h’ and ‘80 h’, refer to ball milling times). The Jc of 80 h doped Fe/Monel tape is up to 9.2 × 103 A cm-2 at 4.2 K and 10 T. The Jc values of Nb barrier wires are comparable to those of the Fe barrier MgB2 wires. These results indicate that the addition of liquid C-containing material during high energy milling may be an effective way to get excellent properties of MgB2 for practical applications.

  20. Influence of microstructures and crystalline defects on the superconductivity of MgB2

    NASA Astrophysics Data System (ADS)

    Serquis, A.; Liao, X. Z.; Zhu, Y. T.; Coulter, J. Y.; Huang, J. Y.; Willis, J. O.; Peterson, D. E.; Mueller, F. M.; Moreno, N. O.; Thompson, J. D.; Nesterenko, V. F.

    2002-07-01

    This work studies the influence of microstructures and crystalline defects on the superconductivity of MgB2, with the objective to improve its flux pinning. A MgB2 sample pellet that was hot isostatic pressed (HIPed) was found to have significantly increased critical current density (Jc) at higher fields than its un-HIPed counterpart. The HIPed sample had a Jc of 10 000 A/cm2 in 50 000 Oe (5 T) at 5 K. This was 20 times higher than that of the un-HIPed sample, and the same as the best Jc reported by other research groups. Microstructures observed in scanning and transmission electron microscopy indicate that the HIP process eliminated porosity present in the MgB2 pellet resulting in an improved intergrain connectivity. Such improvement in intergrain connectivity was believed to prevent the steep Jc drop with magnetic field H that occurred in the un-HIPed MgB2 pellet at H>45 000 Oe(4.5 T) and T=5 K. The HIP process was also found to disperse the MgO that existed at the grain boundaries of the un-HIPed MgB2 pellet and to generate more dislocations in the pellets. These dispersed MgO particles and dislocations improved flux pinning also at H<45 000 Oe. The HIPing process was also found to lower the resistivity at room temperature.

  1. Role of the bradykinin B2 receptor in a rat model of local heart irradiation

    PubMed Central

    Lieblong, Benjamin J.; Sridharan, Vijayalakshmi; Srivastava, Anup K.; Moros, Eduardo G.; Sharma, Sunil K.; Boerma, Marjan

    2016-01-01

    Purpose Radiation-induced heart disease (RIHD) is a delayed effect of radiotherapy for cancers of the chest, such as breast, esophageal, and lung. Kinins are small peptides with cardioprotective properties. We previously used a rat model that lacks the precursor kininogen to demonstrate that kinins are involved in RIHD. Here, we examined the role of the kinin B2 receptor (B2R) in early radiation-induced signaling in the heart. Materials and methods Male Brown Norway rats received the B2R-selective antagonist HOE-140 (icatibant) via osmotic minipump from 5 days before until 4 weeks after 21 Gy local heart irradiation. At 4 weeks, signaling events were measured in left ventricular homogenates and nuclear extracts using western blotting and real-time polymerase chain reaction. Numbers of CD68-positive (monocytes/macrophages), CD2-positive (T-lymphocytes), and mast cells were measured using immunohistochemistry. Results Radiation-induced c-Jun phosphorylation and nuclear translocation were enhanced by HOE-140. HOE-140 did not modify endothelial nitric oxide synthase (eNOS) phosphorylation or alter numbers of CD2-positive or mast cells, but enhanced CD68-positive cell counts in irradiated hearts. Conclusions B2R signaling may regulate monocyte/macrophage infiltration and c-Jun signals in the irradiated heart. Although eNOS is a main target for kinins, the B2R may not regulate eNOS phosphorylation in response to radiation. PMID:25955317

  2. The role of various boron precursor on superconducting properties of MgB2/Fe

    NASA Astrophysics Data System (ADS)

    Safran, S.; Kılıçarslan, E.; Kılıç, A.; Gencer, A.

    2014-09-01

    The superconducting properties of Fe sheathed MgB2 wire has been studied as a function of precursor B powder particle size. The in situ processed MgB2 samples were prepared by means of conventional solid state reaction method with magnesium powder (99.8%, 325 mesh) and three different types of amorphous boron powders (purity; 98.8%, >95% and 91.9%) from two sources, Pavezyum (Turkish supplier) and Sigma Aldrich. The particle sizes of Turkish boron precursor powder were selected between 300 and 800 nm. The structural and magnetic properties of the prepared samples were investigated by means of the X-ray powder diffraction (XRD) and ac susceptibility measurements. The XRD patterns showed that the diffraction peaks for our samples belong to the main phase of the MgB2 diffraction patterns. The highest critical temperature, Tc = 38.4 K was measured for the MgB2 sample which was fabricated by using the 98.8% B. The critical current density of this sample was extracted from the magnetization measurements and Jc = 5.4 × 105 A cm-2 at 5 K and B = 2 T. We found that the sample made by using the 98.8% boron showed almost 2 times higher Jc than that of obtained from 91.9% B powder.

  3. The phase analysis of spark plasma sintered MgB2 after ball milling.

    PubMed

    Kang, Deuk-Kyun; Kim, Dong-Woong; Kim, Cheol-Jin; Ahn, In-Shup

    2010-01-01

    Mg and amorphous B powders below 10 and 3 micro meter were used as raw materials, and mixed by planetary-mill for 9 hours at argon atmosphere. MgB2 bulk was fabricated at the various temperatures by Spark Plasma Sintering. In the sintering process, mixed powders were sintered in graphite mold, at the pressure of 55 Mpa. The fabricated MgB2 samples were evaluated with XRD, EDS, FE-SEM, PPMS. MgB2, MgO and Fe phases were observed from XRD result. In the results, MgO and Fe were impurity which may affect superconducting properties of MgB2 samples, and it's distribution could be confirmed from EDS mapping result. In order to confirm the formation of MgB2 phase, DTA was used as heating rate of 10 degrees C/min at Ar atmosphere from room temperature to 1200 degrees C. In the PPMS result, the Tc (critical temperature) was about 21 K, and the density of spark plasma sintered samples increased to 1.87 g/cm3 by increasing sintering temperature.

  4. Theoretical investigation of superconductivity in MgB2-xCx alloys

    NASA Astrophysics Data System (ADS)

    Sharma, Gargee; Sharma, Smita

    2016-05-01

    In this paper we investigated the superconducting properties of MgB2-xCx alloys where x is the concentration (0.0, 0.03, 0.11 and 0.20). The superconducting state parameters, namely, the electron-phonon coupling strength (λ), Coulomb pseudopotential (μ*), transition temperature (Tc), isotope effect exponent (α) and interaction strength (NoV) of MgB2-xCx alloys have been investigated in the BCS-Eliashberg-McMillan framework, as modified for MgB2-xCx alloys. Pseudo ions with average properties have been considered to replace different types of ions in the system. It is observed that all the superconducting parameters go on decreasing as the concentration of C is increased. The magnitudes of λ and Tc indicate that MgB2-xCx is strong-to-intermediate coupling superconductor. It is also observed that Tc is composition dependent. Present computations yield almost linear variation of Tc with concentration x of C in the MgB2-xCx system, which is in agreement with the experimental data. A linear Tc equation is proposed by fitting the present results.

  5. Evaluations of MgB2 Coatings on 2'' Copper Discs for Superconducting Radio Frequency Applications

    NASA Astrophysics Data System (ADS)

    Withanage, Wenura; Tan, Teng; Lee, Namhoon; Banjade, Huta; Eremeev, Grigory; Welander, Paul; Valente-Feliciano, Anne-Marie; Kustom, Robert; Wolak, Matthäus; Nassiri, Alireza; Xi, Xiaoxing

    We propose that coating the inner walls of copper RF cavities with superconducting MgB2 (Tc = 39 K) can result in a viable alternative to the already established niobium-based SRF technology. This approach improves the thermal conductivity, allows for operation at higher temperatures, and reduces the need for large helium refrigeration, thereby resulting in lower operational costs. For our studies, we grew MgB2 films via hybrid physical chemical vapor deposition (HPCVD) on 2'' Cu substrates. Since Mg and Cu readily form an alloy at higher temperatures, the HPCVD setup was modified in order to achieve lower deposition temperatures, minimize alloy formation, and provide high quality MgB2 films. This method yielded MgB2 coatings on 2'' Cu discs with transition temperatures around 38 K. The samples were characterized with regards to their RF attributes and showed similar performance in comparison to Nb reference samples. The presented results show that MgB2 coated copper can be a suitable alternative for use in SRF cavities.

  6. Mechanical Properties of In-Situ FeAl-TiB2 Intermetallic Matrix Composites

    NASA Astrophysics Data System (ADS)

    Kim, Jonghoon; Park, Bonggyu; Park, Yongho; Park, Ikmin; Lee, Heesoo

    Intermetallic matrix composites reinforced with ceramic particles have received a great deal of attention. Iron aluminide is known to be a good material for the matrix in such composites. Two processes were used to fabricate FeAl-TiB2 intermetallic matrix composites. One was liquid melt in-situ mixing, and the other was arc melting and suction casting processes. FeAl-TiB2 IMCs obtained by two different methods were investigated to elucidate the influence of TiB2 content. In both methods, the grain size in the FeAl alloy decreased with the presence of titanium diboride. The grain size of in-situ FeAl-TiB2 IMCs became smaller than that of arc FeAl-TiB2 IMCs. Significant increase in fracture stress and hardness was achieved in the composites. The in-situ process gives clean, contamination-free matrix/reinforcement interface which maintained good bonding causing high load bearing capability. This contributed to the increase in the mechanical properties of composites.

  7. Hexagonal OsB2 reduction upon heating in H2 containing environment

    DOE PAGESBeta

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Payzant, E. Andrew

    2014-10-23

    The stability of hexagonal ReB2 type OsB2 powder upon heating under reforming gas was investigated. Pure Os metal particles were detected by powder X-ray diffraction starting at 375⁰ C and complete transformation of OsB2 to metallic Os was observed at 725⁰ C. The mechanisms of precipitation of metallic Os is proposed and changes in the lattice parameters of OsB2 upon heating are analysed in terms of the presence of oxygen or water vapour in the heating chamber. Previous studies suggested that Os atoms possess (0) valence, while B atoms possess both (+3) and ( 3) valences in the alternating boron/osmiummore » sheet structure of hexagonal (P63/mmc, No. 194) OsB2; if controllable method for Os removal from the lattice could be found, the opportunity would arise to form two-dimensional (2D) layers consisting of pure B atoms.« less

  8. Theranostic Protein Targeting ErbB2 for Bioluminescence Imaging and Therapy for Cancer

    PubMed Central

    Han, Xiao-Jian; Sun, Ling-Fei; Nishiyama, Yuki; Feng, Bin; Michiue, Hiroyuki; Seno, Masaharu; Matsui, Hideki; Tomizawa, Kazuhito

    2013-01-01

    A combination of molecular-targeted cancer imaging and therapy is an emerging strategy to improve cancer diagnosis and minimize the side effects of conventional treatments. Here, we generated a recombinant protein, EC1-GLuc-p53C, by fusing EC1 peptide, an artificial ligand of ErbB2, with Gaussia luciferase (GLuc) and a p53-activating peptide, p53C. EC1-GLuc-p53C was expressed and purified from E. coli BL21. In vitro experiments showed that EC1-GLuc-p53c was stable in luminescent activity and selectively targeted ErbB2-overexpressing BT474 cells for bioluminescence imaging. Moreover, the internalized EC1-GLuc-p53C in BT474 cells exerted its function to reactivate p53 and significantly inhibited cellular proliferation. In tumor-bearing mice, the ErbB2-targeted bioluminescence imaging and therapeutic effect of EC1-GLuc-p53C were also observed specifically in BT474 tumors but not in MCF7 tumors, which does not overexpress ErbB2. Thus, the present study demonstrates EC1-GLuc-p53C to be an effective theranostic reagent targeting ErbB2 for bioluminescence imaging and cancer therapy. PMID:24069396

  9. Infralimbic EphB2 Modulates Fear Extinction in Adolescent Rats.

    PubMed

    Cruz, Emmanuel; Soler-Cedeño, Omar; Negrón, Geovanny; Criado-Marrero, Marangelie; Chompré, Gladys; Porter, James T

    2015-09-01

    Adolescent rats are prone to impaired fear extinction, suggesting that mechanistic differences in extinction could exist in adolescent and adult rats. Since the infralimbic cortex (IL) is critical for fear extinction, we used PCR array technology to identify gene expression changes in IL induced by fear extinction in adolescent rats. Interestingly, the ephrin type B receptor 2 (EphB2), a tyrosine kinase receptor associated with synaptic development, was downregulated in IL after fear extinction. Consistent with the PCR array results, EphB2 levels of mRNA and protein were reduced in IL after fear extinction compared with fear conditioning, suggesting that EphB2 signaling in IL regulates fear extinction memory in adolescents. Finally, reducing EphB2 synthesis in IL with shRNA accelerated fear extinction learning in adolescent rats, but not in adult rats. These findings identify EphB2 in IL as a key regulator of fear extinction during adolescence, perhaps due to the increase in synaptic remodeling occurring during this developmental phase.

  10. Infralimbic EphB2 Modulates Fear Extinction in Adolescent Rats

    PubMed Central

    Cruz, Emmanuel; Soler-Cedeño, Omar; Negrón, Geovanny; Criado-Marrero, Marangelie; Chompré, Gladys

    2015-01-01

    Adolescent rats are prone to impaired fear extinction, suggesting that mechanistic differences in extinction could exist in adolescent and adult rats. Since the infralimbic cortex (IL) is critical for fear extinction, we used PCR array technology to identify gene expression changes in IL induced by fear extinction in adolescent rats. Interestingly, the ephrin type B receptor 2 (EphB2), a tyrosine kinase receptor associated with synaptic development, was downregulated in IL after fear extinction. Consistent with the PCR array results, EphB2 levels of mRNA and protein were reduced in IL after fear extinction compared with fear conditioning, suggesting that EphB2 signaling in IL regulates fear extinction memory in adolescents. Finally, reducing EphB2 synthesis in IL with shRNA accelerated fear extinction learning in adolescent rats, but not in adult rats. These findings identify EphB2 in IL as a key regulator of fear extinction during adolescence, perhaps due to the increase in synaptic remodeling occurring during this developmental phase. PMID:26354908

  11. Apoptosis induced by boric anhydrite (B2O3) after partial hepatectomy in rat liver.

    PubMed

    Ozen, A; Canbek, M

    2016-01-01

    Boron is one of the important elements that have a cell-growth suppressing effect. The apoptotic effects of B(2)O(3) that were investigated in rats on liver regeneration following 70 % partial hepatectomy (PH). Wistar albino male rats were used and divided into 4 groups (n = 7). The Saline control groups were given only a single dose of saline; the B(2)O(3)-treated groups that were only given a single dose of 1800 mg.kg(-1) B(2)O(3) by means of intraperitoneal injections following hepatectomy. Three and 6 hours after surgical procedures, all the groups were dissected and liver tissue samples were taken from the groups for NF-κB for caspase-3 gene and protein levels investigation by RT-PCR and TaqMan Protein Assay and histological analyses by TUNEL assay. B(2)O(3)-treated animals were examined and it was observed that NF-κB levels were decreased; however, caspase-3 gene expression and protein levels were increased significantly. This study demonstrated that B(2)O(3) induces caspase-3 and inhibits NF-κB at the early stage of liver regeneration (Fig. 4, Ref. 26).

  12. EphrinB2 repression through ZEB2 mediates tumour invasion and anti-angiogenic resistance

    PubMed Central

    Depner, C.; zum Buttel, H.; Böğürcü, N.; Cuesta, A. M.; Aburto, M. R.; Seidel, S.; Finkelmeier, F.; Foss, F.; Hofmann, J.; Kaulich, K.; Barbus, S.; Segarra, M.; Reifenberger, G.; Garvalov, B. K.; Acker, T.; Acker-Palmer, A.

    2016-01-01

    Diffuse invasion of the surrounding brain parenchyma is a major obstacle in the treatment of gliomas with various therapeutics, including anti-angiogenic agents. Here we identify the epi-/genetic and microenvironmental downregulation of ephrinB2 as a crucial step that promotes tumour invasion by abrogation of repulsive signals. We demonstrate that ephrinB2 is downregulated in human gliomas as a consequence of promoter hypermethylation and gene deletion. Consistently, genetic deletion of ephrinB2 in a murine high-grade glioma model increases invasion. Importantly, ephrinB2 gene silencing is complemented by a hypoxia-induced transcriptional repression. Mechanistically, hypoxia-inducible factor (HIF)-1α induces the EMT repressor ZEB2, which directly downregulates ephrinB2 through promoter binding to enhance tumour invasiveness. This mechanism is activated following anti-angiogenic treatment of gliomas and is efficiently blocked by disrupting ZEB2 activity. Taken together, our results identify ZEB2 as an attractive therapeutic target to inhibit tumour invasion and counteract tumour resistance mechanisms induced by anti-angiogenic treatment strategies. PMID:27470974

  13. Apps to display patient data, making SMART available in the i2b2 platform

    PubMed Central

    Wattanasin, Nich; Porter, Alyssa; Ubaha, Stella; Mendis, Michael; Phillips, Lori; Mandel, Joshua; Ramoni, Rachel; Mandl, Kenneth; Kohane, Isaac; Murphy, Shawn N.

    2012-01-01

    The Substitutable Medical Apps, Reusable Technologies (SMART) project provides a framework of core services to facilitate the use of substitutable health-related web applications. The platform offers a common interface used to “SMART-ready” health IT systems allowing any SMART application to be able to interact with those systems. At Partners Healthcare, we have SMART-enabled the Informatics for Integrating Biology and the Bedside (i2b2) open source analytical platform, enabling the use of SMART applications directly within the i2b2 web client. In i2b2, viewing the patient in an EMR-like view enables a natural-feeling medical review process for each patient. PMID:23304371

  14. Definitive experimental evidence for two-band superconductivity in MgB2.

    PubMed

    Tsuda, S; Yokoya, T; Takano, Y; Kito, H; Matsushita, A; Yin, F; Itoh, J; Harima, H; Shin, S

    2003-09-19

    The superconducting-gap of MgB2 has been studied by high-resolution angle-resolved photoemission spectroscopy. The results show that superconducting gaps with values of 5.5 and 2.2 meV open on the sigma band and the pi band, respectively, but both the gaps close at the bulk transition temperature, providing a definitive experimental evidence for the two-band superconductivity with strong interband pairing interaction in MgB2. The experiments validate the role of k-dependent electron-phonon coupling as the origin of multiple-gap superconductivity as well as the high transition temperature of MgB2.

  15. Magnetization and electric transport properties of single-crystal MgB2 nanowires.

    PubMed

    Wu, Cen-Shawn; Chang, Yu-Cheng; Chen, Weimeng; Chen, Chinping; Feng, Qingrong

    2012-11-23

    High quality single-crystal magnesium diboride (MgB(2)) nanowires with lengths exceeding 10 μm were successfully synthesized by hybrid physical chemical vapor deposition. The magnetization and electrical transport properties of single-crystal MgB(2) nanowires (NWs) were measured. The superconducting transition temperature of the NWs was 37 K, as confirmed by magnetization measurements. The disordered behavior of the nanowires was observed by four-terminal current-voltage characteristic measurements of an individual NW from T = 10 to 300 K. The temperature-dependent resistivity curves for seven NWs collapsed into a universal curve described by the variable range hopping model, showing intrinsic nonmetallic transport properties. This implies that the granular superconducting defect states are critical to the superconductivity of the individual MgB(2) NWs.

  16. Three-dimensional MgB2-type superconductivity in hole-doped diamond.

    PubMed

    Boeri, Lilia; Kortus, Jens; Andersen, O K

    2004-12-01

    We substantiate by numerical and analytical calculations that the recently discovered superconductivity below 4 K in 3% boron-doped diamond is caused by electron-phonon coupling of the same type as in MgB2, albeit in three dimensions. Holes at the top of the zone-centered, degenerate sigma-bonding valence-band couple strongly to the optical bond-stretching modes. The increase from two to three dimensions reduces the mode softening crucial for T(c) reaching 40 K in MgB2. Even if diamond had the same bare coupling constant as MgB2, which could be achieved with 10% doping, T(c) would be only 25 K. Superconductivity above 1 K in Si (Ge) requires hole doping beyond 5% (10%).

  17. Anisotropy of superconducting MgB2 as seen in electron spin resonance and magnetization data.

    PubMed

    Simon, F; Jánossy, A; Fehér, T; Murányi, F; Garaj, S; Forró, L; Petrovic, C; Bud'ko, S L; Lapertot, G; Kogan, V G; Canfield, P C

    2001-07-23

    We observed the conduction electron spin resonance (CESR) in fine powders of MgB2 both in the superconducting and normal states. The Pauli susceptibility is chi(s) = 2.0 x 10(-5) emu/mole in the temperature range of 450 to 600 K. The spin relaxation rate has an anomalous temperature dependence. The CESR measured below T(c) at several frequencies suggests that MgB2 is a strongly anisotropic superconductor with the upper critical field, H(c2), ranging between 2 and 16 T. The high-field reversible magnetization data of a randomly oriented powder sample are well described assuming that MgB2 is an anisotropic superconductor with H(ab)(c2)/H(c)(c2) approximately 6-9.

  18. Enhancement of critical current density of MgB2 by doping Ho2O3

    NASA Astrophysics Data System (ADS)

    Cheng, C.; Zhao, Y.

    2006-12-01

    Mg1-x(Ho2O3)xB2 alloys were prepared by in situ solid state reaction to study the effect of magnetic Ho2O3 dopant on flux pinning behavior of MgB2. Crystal structure, Tc, and Hc2 were not affected by Ho2O3 doping; however, Jc and Hirr were significantly enhanced. In 5T field, the best sample (x =3%) reached Jc of 1.0×103, 2.0×104, and 1.2×105A/cm2 at 20, 10, and 5K, respectively, much higher than those achieved by nonmagnetic impurity, such as Ti-, Zr-, and Y2O3-doped MgB2. The observed magnetic HoB4 nanoparticles were attributed to be the source for the enhanced flux pinning effects.

  19. Study of the microwave electrodynamic response of MgB 2 thin films

    NASA Astrophysics Data System (ADS)

    Andreone, A.; Cassinese, A.; Cantoni, C.; Di Gennaro, E.; Lamura, G.; Maglione, M. G.; Paranthaman, M.; Salluzzo, M.; Vaglio, R.

    2002-08-01

    We present a study on the power dependence of the microwave surface impedance in thin films of the novel superconductor MgB 2. 500 nm thick samples exhibiting critical temperatures ranging between 26 and 38 K are synthesized by an ex situ post-anneal of e-beam evaporated boron in the presence of an Mg vapor at 900 °C. Preliminary results on films grown in situ by a high rate magnetron sputtering technique from stoichiometric MgB 2 and Mg targets are also reported. Microwave measurements have been carried out employing a dielectrically loaded niobium superconducting cavity operating at 19.8 GHz and 4 K. The study shows that the electrodynamic response of MgB 2 films is presently dominated by extrinsic sources of dissipation, appearing already at low microwave power, likely to be ascribed to the presence of grain boundaries and normal inclusions in the samples.

  20. Continuum observation of Sagittarius B2 at 23 and 43 GHz

    NASA Astrophysics Data System (ADS)

    Akabane, Kenji; Sofue, Yoshiaki; Hirabayashi, Hisashi; Morimoto, Masaki; Inoue, Makoto

    The source Sgr B2 has been mapped with a single-dish resolution of ≡40arcsec at frequencies of 23 GHz and 43 GHz. An extended thermal component was found, and has been compared with that in lower frequency observations. The core region of Sgr B2 (containing the compact sources MD4 and MD5) was resolved at both 23 GHz and 43 GHz. The compact components MD4 and MD5 have complex thermal spectra which may indicate inhomogeneities within each compact core. A new source, G0.64-0.06, was found in the southern area of the extended thermal component. The 43-GHz map made with the Nobeyama 45-m telescope was compared with a 10.7-GHz map made with the Effelsberg 100-m telescope. This comparison suggests that there may be some nonthermal emission in the southern area of Sgr B2.

  1. Bifunctional epitope-agonist ligands of the bradykinin B(2) receptor.

    PubMed

    Gera, Lajos; Roy, Caroline; Marceau, François

    2013-03-01

    Two bradykinin (BK) B(2) receptor agonists N-terminally extended with the myc epitope were synthesized and evaluated: myc-KPG-BK and myc-KGP-B-9972. The latter was modeled on the inactivation-resistant agonist B-9972 (D-Arg(0), Hyp(3), Igl(5), Oic(7), Igl(8)-BK) and is also resistant to endosomal inactivation. Despite a large loss of affinity relative to the parent peptide, the tagged analogs are conventional agonists in the umbilical vein contractility assay and compete for [(3)H]BK binding at the rabbit B(2) receptor. Endocytosed myc-KGP-B-9972 most effectively carried AlexaFluor-488-conjugated anti-myc monoclonal antibodies into intact cells expressing the B(2) receptor. Results support the prospects of functionally-active cargoes entering cells in a pharmacologically controlled manner.

  2. Galactomannan Downregulates the Inflammation Responses in Human Macrophages via NFκB2/p100

    PubMed Central

    Toledano, Víctor; Hernández-Jiménez, Enrique; Cubillos-Zapata, Carolina; Flandez, Marta; Álvarez, Enrique; Varela-Serrano, Aníbal; Cantero, Ramón; Valles, Gema; García-Rio, Francisco; López-Collazo, Eduardo

    2015-01-01

    We show that galactomannan, a polysaccharide consisting of a mannose backbone with galactose side groups present on the cell wall of several fungi, induces a reprogramming of the inflammatory response in human macrophages through dectin-1 receptor. The nuclear factor kappa-light-chain-enhancer of activated B cells 2 (NFκB2)/p100 was overexpressed after galactomannan challenge. Knocking down NFκB2/p100 using small interfering RNA (siRNA) indicated that NFκB2/p100 expression is a crucial factor in the progression of the galactomannan-induced refractoriness. The data presented in this study could be used as a modulator of inflammatory response in clinical situations where refractory state is required. PMID:26441484

  3. Intrinsic fluorescence spectra characteristics of vitamin B1, B2, and B6

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Xiao, Xue; Zhao, Xuesong; Hu, Lan; Lv, Caofang; Yin, Zhangkun

    2015-11-01

    This paper presents the intrinsic fluorescence characteristics of vitamin B1, B2 and B6 measured with 3D fluorescence Spectrophotometer. Three strong fluorescence areas of vitamin B2 locate at λex/λem=270/525nm, 370/525nm and 450/525nm, one fluorescence areas of vitamin B1 locates at λex/λem=370/460nm, two fluorescence areas of vitamin B6 locates at λex/λem=250/370nm and 325/370nm were found. The influence of pH of solution to the fluorescence profile was also discussed. Using the PARAFAC algorithm, 10 vitamin B1, B2 and B6 mixed solutions were successfully decomposed, and the emission profiles, excitation profiles, central wavelengths and the concentration of the three components were retrieved precisely through about 5 iteration times.

  4. Physics Among Lightweights: Boride Superconductors (Superconductivity in MgB2)

    SciTech Connect

    Canfield, Paul C.

    2001-06-13

    Recently there has been a great deal of excitement about the intermetallic superconductor MgB2. MgB2 has a superconducting transition temperature Tc {approx} 40 K, can be synthesized as single phase powders and wire segments, has a remarkably low normal state resistivity, and manifests a promising critical current density in the superconducting state. In this colloquium I will review recent discoveries associated with intermetallic borides and try to show how MgB2 fits into the basic gestalt of intermetallic compounds. In addition I will try to explain why anybody should care about this and why some physicists find the topic of novel states in intermetallic compounds to be an extremely interesting research topic.

  5. Extinction coefficient of H2CC(3B2) at 137 nm

    NASA Technical Reports Server (NTRS)

    Fahr, A.; Laufer, A. H.

    1985-01-01

    In spite of the conduction of numerous studies regarding the vinylidene free radical, its role and importance as a reactive intermediate is not well characterized. Laufer (1980, 1983) has reported the absorption spectrum of metastable H2CC(3B2), the lowest excited state, in the vacuum ultraviolet and has measured several aspects of its quenching properties. The present study provides a measurement of the extinction coefficient of H2CC(3B2). Knowledge of the vinylidene concentration is required to convert readily available absorption data into an extinction coefficient or cross section. In the current work, the H2CC(3B2) concentration was determined in an investigation of the photodissociation of vinyl chloride.

  6. User-Interface Design Characteristics of Fortune 500 B2C E-Commerce Sites and Industry Differences

    ERIC Educational Resources Information Center

    Zhao, Jensen J.; Truell, Allen D.; Alexander, Melody W.

    2006-01-01

    This study examined the user-interface design characteristics of 107 Fortune 500 B2C e-commerce Web sites and industry differences. Data were collected from corporate homepages, B2C product/service pages, B2C interactive shopping pages, as well as customer satisfaction of 321 online shoppers. The findings indicate that (a) to attract online…

  7. 24 CFR 1720.225 - Suspension order under § 1710.45(b)(2) of this chapter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Suspension order under § 1710.45(b)(2) of this chapter. 1720.225 Section 1720.225 Housing and Urban Development Regulations Relating to....45(b)(2) of this chapter. A suspension pursuant to § 1710.45(b)(2) of this chapter shall be...

  8. THE VITAMIN B(1) AND B(2) G CONTENT OF LIVER EXTRACT AND BREWERS' YEAST CONCENTRATE.

    PubMed

    Miller, D K; Rhoads, C P

    1934-02-28

    1. Liver extract powder, No. 343 Lilly, and the same material prepared for parenteral use, when administered daily by mouth in amounts derived from 2.5 gm. of fresh whole liver, to rats weighing from 40 to 50 gm., contain sufficient vitamin B(1) to support normal growth, provided the animals receive in addition an adequate amount of vitamin B(2) G. Moreover, liver extract in the forms mentioned, administered in the same amounts, does not contain sufficient vitamin B(2) G to maintain normal growth of similar rate when all other necessary constituents of the diet are provided. 2. Liver extract (Lilly) in the form prepared for parenteral use, when administered daily by intraperitoneal injections, in amounts derived from 2.5 gm. of fresh whole liver, to rats under standard experimental conditions, does not contain sufficient vitamin B(2) G to maintain normal growth. Furthermore, the amount of vitamin B(1) present in liver extract in this form is not as effective in supporting normal growth when given by intraperitoneal injection as it is when given by mouth. 3. Vegex, when administered daily in amounts of 50, 150, and 250 mg. to rats of 40 to 50 gm. in weight contains sufficient vitamin B(1) to maintain normal growth of the rats, provided the animals receive in addition an adequate amount of vitamin B(2) G. However, vegex in the same amounts does not contain sufficient vitamin B(2) G to support normal growth of similar rats when all other necessary constituents of the diet are provided. 4. These experiments indicate that the extrinsic, anti-anemic factor of Castle and the thermostable growth-promoting food constituent, commonly known as vitamin B(2) G, are not identical.

  9. Numerical modelling and comparison of MgB2 bulks fabricated by HIP and infiltration growth

    NASA Astrophysics Data System (ADS)

    Zou, J.; Ainslie, M. D.; Fujishiro, H.; Bhagurkar, A. G.; Naito, T.; Babu, N. Hari; Fagnard, J.-F.; Vanderbemden, P.; Yamamoto, A.

    2015-07-01

    MgB2 in bulk form shows great promise as trapped field magnets (TFMs) as an alternative to bulk (RE)BCO materials to replace permanent magnets in applications such as rotating machines, magnetic bearings and magnetic separation, and the relative ease of fabrication of MgB2 materials has enabled a number of different processing techniques to be developed. In this paper, a comparison is made between bulk MgB2 samples fabricated by the hot isostatic pressing (HIP), with and without Ti-doping, and infiltration growth (IG) methods and the highest trapped field in an IG-processed bulk MgB2 sample, Bz = 2.12 at 5 K and 1.66 T at 15 K, is reported. Since bulk MgB2 has a more homogeneous Jc distribution than (RE)BCO bulks, studies on such systems are made somewhat easier because simplified assumptions regarding the geometry and Jc distribution can be made, and a numerical simulation technique based on the 2D axisymmetric H-formulation is introduced to model the complete process of field cooling (FC) magnetization. As input data for the model, the measured Jc(B,T) characteristics of a single, small specimen taken from each bulk sample are used, in addition to measured specific heat and thermal conductivity data for the materials. The results of the simulation reproduce the experimental results extremely well: (1) indicating the samples have excellent homogeneity, and (2) validating the numerical model as a fast, accurate and powerful tool to investigate the trapped field profile of bulk MgB2 discs of any size accurately, under any specific operating conditions. Finally, the paper is concluded with a numerical analysis of the influence of the dimensions of the bulk sample on the trapped field.

  10. Quadrupolar interaction of ^57Fe in compounds RENi_2B_2C: Experimental and Theoretical Studies

    NASA Astrophysics Data System (ADS)

    Zeng, Zhi; Guenzburger, Diana; Sanchez, D. R. S.; Bud'Ko, S. L.; Fontes, Magda B.; Baggia-Saitovitch, E. M.; Ellis, D. E.

    1996-03-01

    ^57Fe Mössbauer spectra were taken with the RE(Ni_0.99^57Fe_0.01)_2B_2C (RE=Tb, Dy, Ho, Er) samples in a variable temperature helium crysostat to study the interplay between superconductivity and magnetism in the RENi_2B_2C (RE=Dy, Ho, Er, Tm) compounds. The rare earth dependent quadrupole splitting (QS) from ^57Fe Mössbauer spectra decreases with the lanthanide contraction^footnotetext^The lanthanide contraction causes an increase in the ratio c/a along the RE series. from QS=0.27mm/s for TbNi_2B_2C to QS=0.14mm/s for ErNi_2B_2C. Self-consistent frist-principles electronic structure calculation[1] were performed for clusters with 71 atoms (Fe-12RE-14Ni-32B-12C), which were embedded in the charge denisity of several shells of neighbours in the crystal, representing the doped compounds RE(Ni_0.93Fe_0.07)_2B_2C (RE=Gd, Tb, Dy, Ho, and Er). The quadrupole splitting was obtained with the nuclear quadrupole moment Q=0.16b of ^57Fe[2]. The calculated results are in good agreement with experiment. The theoretical results give negative signs for all the QS values; which have not been determined by experiment, except for the compounds with Tb and Ho, for which they are negative. REFERENCES D.E. Ellis, Int. J. Quant. Chem. Suppl. 2, 35(1968); D.E. Ellis and G.S. Painter, Phys. Rev. B, 2, 2887(1970). Ohilipp Dufek, Peter Blaha and K. Schwarz, Phys. Rev. Lett. 75, 3545(1995).

  11. Suppression of superconductivity in epitaxial MgB2 ultrathin films

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Wang, Yue; Wang, Da; Zhang, Yan; Liu, Zheng-Hao; Feng, Qing-Rong; Gan, Zi-Zhao

    2013-07-01

    MgB2 ultrathin films have potential to make sensitive superconducting devices such as superconducting single-photon detectors working at relatively high temperatures. We have grown epitaxial MgB2 films in thicknesses ranging from about 40 nm to 6 nm by using the hybrid physical-chemical vapor deposition method and performed electrical transport measurements to study the thickness dependence of the superconducting critical temperature Tc. With reducing film thickness d, although a weak depression of the Tc has been observed, which could be attributed to an increase of disorder (interband impurity scattering) in the film, the Tc retains close to the bulk value of MgB2 (39 K), being about 35 K in the film of 6 nm thick. We show that this result, beneficial to the application of MgB2 ultrathin films and in accordance with recent theoretical calculations, is in contrast to previous findings in MgB2 films prepared by other methods such as co-evaporation and molecular-beam epitaxy, where a severe Tc suppression has been observed with Tc about one third of the bulk value in films of ˜5 nm thick. We discuss this apparent discrepancy in experiments and suggest that, towards the ultrathin limit, the different degrees of Tc suppression displayed in currently obtained MgB2 films by various techniques may arise from the different levels of disorder present in the film or different extents of proximity effect at the film surface or film-substrate interface.

  12. Plexin-B2 negatively regulates macrophage motility, Rac, and Cdc42 activation.

    PubMed

    Roney, Kelly E; O'Connor, Brian P; Wen, Haitao; Holl, Eda K; Guthrie, Elizabeth H; Davis, Beckley K; Jones, Stephen W; Jha, Sushmita; Sharek, Lisa; Garcia-Mata, Rafael; Bear, James E; Ting, Jenny P-Y

    2011-01-01

    Plexins are cell surface receptors widely studied in the nervous system, where they mediate migration and morphogenesis though the Rho family of small GTPases. More recently, plexins have been implicated in immune processes including cell-cell interaction, immune activation, migration, and cytokine production. Plexin-B2 facilitates ligand induced cell guidance and migration in the nervous system, and induces cytoskeletal changes in overexpression assays through RhoGTPase. The function of Plexin-B2 in the immune system is unknown. This report shows that Plexin-B2 is highly expressed on cells of the innate immune system in the mouse, including macrophages, conventional dendritic cells, and plasmacytoid dendritic cells. However, Plexin-B2 does not appear to regulate the production of proinflammatory cytokines, phagocytosis of a variety of targets, or directional migration towards chemoattractants or extracellular matrix in mouse macrophages. Instead, Plxnb2(-/-) macrophages have greater cellular motility than wild type in the unstimulated state that is accompanied by more active, GTP-bound Rac and Cdc42. Additionally, Plxnb2(-/-) macrophages demonstrate faster in vitro wound closure activity. Studies have shown that a closely related family member, Plexin-B1, binds to active Rac and sequesters it from downstream signaling. The interaction of Plexin-B2 with Rac has only been previously confirmed in yeast and bacterial overexpression assays. The data presented here show that Plexin-B2 functions in mouse macrophages as a negative regulator of the GTPases Rac and Cdc42 and as a negative regulator of basal cell motility and wound healing.

  13. ErbB2 oncogene expression supports the acute pancreatitis-chronic pancreatitis sequence.

    PubMed

    Standop, Jens; Standop, Silke; Itami, Atsushi; Nozawa, Fumiaki; Brand, Randall E; Büchler, Markus W; Pour, Parviz M

    2002-10-01

    The pathogenesis of chronic pancreatitis remains controversial. According to the general opinion, chronic pancreatitis is a de novo disease with a silent but progressive restructure of the pancreas in response to environmental, nutritional or genetic factors. The necrosis-fibrosis sequence hypothesis, on the other hand, postulates that relapsing attacks of acute pancreatitis with subsequent development of fibrosis leads to chronic pancreatitis. Since in our previous studies the expression of two anti-ErbB2 growth factor receptor (ErbB2) antibodies was shown to discriminate between primary chronic pancreatitis, normal tissue, and secondary chronic pancreatitis caused by pancreatic cancer, we studied the ErbB2 expression in tissues obtained from acute, recurrent acute, and chronic pancreatitis to investigate a possible evolution of the ErbB2 expression pattern during the course of the disease. We subjected 14 normal pancreas, 15 chronic pancreatitis, and 12 acute pancreatitis (three with recurrent acute pancreatitis) specimens to immunohistochemical studies using polyclonal anti-ErbB2 antibodies from Santa Cruz and Dako. The immunoreactivity of islet cells in acute pancreatitis cases with the Santa Cruz antibody was less than that in normal pancreas in relation to the degree of tissue damage and fibrosis, and was negative in recurrent acute and chronic pancreatitis tissues. The Dako antibody, on the other hand, revealed a membrane staining of ductal and ductular cells only in chronic pancreatitis specimens and in some areas of recurrent acute pancreatitis. In conclusion, the similarities in the immunoreactivity of anti-ErbB2 antibodies in recurrent acute pancreatitis and chronic pancreatitis support the hypothesis that acute pancreatitis can be a forerunner of chronic pancreatitis.

  14. The receptor tyrosine kinase EphB2 promotes hepatic fibrosis in mice

    PubMed Central

    Mimche, Patrice N.; Brady, Lauren M.; Bray, Christian F.; Mimche, Sylvie M.; Thapa, Manoj; King, Thayer P.; Quicke, Kendra; McDermott, Courtney D.; Lee, Choon M.; Grakoui, Arash; Morgan, Edward T.; Lamb, Tracey J.

    2015-01-01

    Beyond the well-defined role of the Eph receptor tyrosine kinases in developmental processes, cell motility, cell trafficking/adhesion and cancer, nothing is known about their involvement in liver pathologies. During blood-stage rodent malaria infection we have found that EphB2 transcripts and proteins were upregulated in the liver, a result likely driven by elevated surface expression on immune cells including macrophages. This was significant for malaria pathogenesis because EphB2−/− mice were protected from malaria-induced liver fibrosis despite having a similar liver parasite burden compared with littermate control mice. This protection was correlated with a defect in the inflammatory potential of hepatocytes from EphB2−/− mice resulting in a reduction in adhesion molecules, chemokines/chemokines receptors RNA levels and infiltration of leukocytes including macrophages/Kupffer cells which mediate liver fibrosis during rodent malaria infections. These observations are recapitulated in the well-established carbon tetrachloride (CCL4) model of liver fibrosis in which EphB2−/− CCL4-treated mice showed a significant reduction of liver fibrosis compared to CCL4-treated littermate mice. Depletion of macrophages by clodronate-liposome abrogates liver EphB2 mRNA and proteins up-regulation and fibrosis in malaria-infected mice. Conclusion: During rodent malaria, EphB2 expression promotes malaria-associated liver fibrosis. To our knowledge, our data is the first to reveal the implication of the EphB family of receptor tyrosine kinases in liver fibrosis or in the pathogenesis of malaria infection. PMID:25784101

  15. Cannabinoids reduce ErbB2-driven breast cancer progression through Akt inhibition

    PubMed Central

    2010-01-01

    Background ErbB2-positive breast cancer is characterized by highly aggressive phenotypes and reduced responsiveness to standard therapies. Although specific ErbB2-targeted therapies have been designed, only a small percentage of patients respond to these treatments and most of them eventually relapse. The existence of this population of particularly aggressive and non-responding or relapsing patients urges the search for novel therapies. The purpose of this study was to determine whether cannabinoids might constitute a new therapeutic tool for the treatment of ErbB2-positive breast tumors. We analyzed their antitumor potential in a well established and clinically relevant model of ErbB2-driven metastatic breast cancer: the MMTV-neu mouse. We also analyzed the expression of cannabinoid targets in a series of 87 human breast tumors. Results Our results show that both Δ9-tetrahydrocannabinol, the most abundant and potent cannabinoid in marijuana, and JWH-133, a non-psychotropic CB2 receptor-selective agonist, reduce tumor growth, tumor number, and the amount/severity of lung metastases in MMTV-neu mice. Histological analyses of the tumors revealed that cannabinoids inhibit cancer cell proliferation, induce cancer cell apoptosis, and impair tumor angiogenesis. Cannabinoid antitumoral action relies, at least partially, on the inhibition of the pro-tumorigenic Akt pathway. We also found that 91% of ErbB2-positive tumors express the non-psychotropic cannabinoid receptor CB2. Conclusions Taken together, these results provide a strong preclinical evidence for the use of cannabinoid-based therapies for the management of ErbB2-positive breast cancer. PMID:20649976

  16. Melittin stimulates liver glycogenolysis and the release of prostaglandin D2 and thromboxane B2.

    PubMed Central

    García-Sáinz, J A; Hernández-Sotomayor, S M; Macías-Silva, M

    1990-01-01

    Melittin stimulates glycogenolysis and induces vasoconstriction in perfused rat liver. The effect was rapid and associated with production and release of prostaglandin D2 and thromboxane B2. Indomethacin blocked the release of these eicosanoids and the stimulation of glycogenolysis induced by melittin. Ibuprofen blocked the release of prostaglandin D2 induced by melittin and markedly attenuated that of thromboxane B2. Interestingly, the initial burst of glucose output induced by melittin was not inhibited by ibuprofen, although the duration of the glycogenolytic action of the peptide was greatly diminished. PMID:2375756

  17. Isotope effect on electron-phonon interaction in the multiband superconductor MgB2

    DOE PAGESBeta

    Mou, Daixiang; Manni, Soham; Taufour, Valentin; Wu, Yun; Huang, Lunan; Bud'ko, S. L.; Canfield, P. C.; Kaminski, Adam

    2016-04-07

    We investigate the effect of isotope substitution on the electron-phonon interaction in the multiband superconductor MgB2 using tunable laser-based angle-resolved photoemission spectroscopy. The kink structure around 70 meV in the σ band, which is caused by electron coupling to the E2g phonon mode, is shifted to higher binding energy by ~3.5 meV in Mg10B2 and the shift is not affected by superconducting transition. Furthermore, these results serve as the benchmark for investigations of isotope effects in known, unconventional superconductors and newly discovered superconductors where the origin of pairing is unknown.

  18. Experimental hybrid power transmission line with liquid hydrogen and MgB2-based superconducting cable

    NASA Astrophysics Data System (ADS)

    Kostyuk, V. V.; Antyukhov, I. V.; Blagov, E. V.; Vysotsky, V. S.; Katorgin, B. I.; Nosov, A. A.; Fetisov, S. S.; Firsov, V. P.

    2012-03-01

    Results of developing and testing an experimental hybrid power transmission line with liquid hydrogen and superconducting power (SCP) cable based on magnesium diboride (MgB2) are presented. Critical currents of the MgB2 based prototype SCP cable have been determined for the first time at the forced flow of liquid hydrogen in a temperature interval of 20-26 K. Various regimes of SCP cable cryostatting with both subcooled saturated liquid hydrogen have been tested in a broad range of supply rates (7-220 g/s) and pressures (0.15-0.4 MPa).

  19. Low-Temperature Synthesis of Superconducting Nanocrystalline MgB 2

    DOE PAGESBeta

    Lu, Jun; Xiao, Zhili; Lin, Qiyin; Claus, Helmut; Fang, Zhigang Zak

    2010-01-01

    Magnesium diboride (MgB 2 ) is considered a promising material for practical application in superconducting devices, with a transition temperature near 40 K. In the present paper, nanocrystalline MgB 2 with an average particle size of approximately 70 nm is synthesized by reacting LiBH 4 with MgH 2 at temperatures as low as 450 ° C. This synthesis approach successfully bypasses the usage of either elemental boron or toxic diborane gas. The superconductivity of the nanostructures is confirmed by magnetization measurements, showing a superconducting critical temperature of 38.7 K.

  20. In search of the elusive IrB2: Can mechanochemistry help?

    NASA Astrophysics Data System (ADS)

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Lapidus, Saul H.; Kata, Dariusz; Rutkowski, Paweł; Lis, Jerzy

    2016-01-01

    The previously unknown hexagonal ReB2-type IrB2 diboride and orthorhombic IrB monoboride phases were produced by mechanochemical syntheses. High energy ball milling of elemental Ir and B powder for 30 h, followed by annealing of the powder at 1050 °C for 48 h, resulted in the formation of the desired phases. Both traditional laboratory and high resolution synchrotron X-ray diffraction (XRD) analyses were used for phase identification of the synthesized powder. In addition to XRD, scanning electron microscopy and transmission electron microscopy were employed to further characterize the microstructure of the phases produced.

  1. The preliminary study of the quench protection of an MgB2

    NASA Astrophysics Data System (ADS)

    Juster, F. P.; Berriaud, C.; Bonelli, A.; Pasquet, R.; Przybilski, H.; Schild, T.; Scola, L.

    2014-01-01

    In the framework of general studies currently carried out at CEA/Saclay in collaboration with Sigmaphi Company on dry MgB2 magnet operating at 10 K and medium range field, 1 T up to 4 T., we plan to build a prototype-coil with a commercial MgB2 wire. This coil, the nominal axial magnetic field of which is 1 tesla, will be placed in a 3 teslas background field generated by a classical NbTi coil. This paper deals with the preliminary quench protection studies including stability and quench propagation modeling.

  2. In search of the elusive IrB2: Can mechanochemistry help?

    DOE PAGESBeta

    Xie, Zhilin; Blair, Richard G.; Orlovskaya, Nina; Cullen, David A.; Lapidus, Saul H.; Kata, Dariusz; Rutkowski, Paweł; Lis, Jerzy

    2015-10-20

    We produced hexagonal ReB2-type IrB2 diboride and orthorhombic IrB monoboride phases, that were previously unknown and saw them produced by mechanochemical syntheses. High energy ball milling of elemental Ir and B powder for 30 h, followed by annealing of the powder at 1050 °C for 48 h, resulted in the formation of the desired phases. Both traditional laboratory and high resolution synchrotron X-ray diffraction (XRD) analyses were used for phase identification of the synthesized powder. Additionally, scanning electron microscopy and transmission electron microscopy were employed, along with XRD, to further characterize the microstructure of the phases produced.

  3. Concise synthesis of calystegines B2 and B3via intramolecular Nozaki-Hiyama-Kishi reaction.

    PubMed

    Wang, Hong-Yao; Kato, Atsushi; Kinami, Kyoko; Li, Yi-Xian; Fleet, George W J; Yu, Chu-Yi

    2016-06-01

    The key step in the concise syntheses of calystegine B2 and its C-2 epimer calystegine B3 was the construction of cycloheptanone 8via an intramolecular Nozaki-Hiyama-Kishi (NHK) reaction of 9, an aldehyde containing a Z-vinyl iodide. Vinyl iodide 9 was obtained by the Stork olefination of aldehyde 10, derived from carbohydrate starting materials. Calystegines B2 (3) and B3 (4) were synthesized from d-xylose and l-arabinose derivatives respectively in 11 steps in excellent overall yields (27% and 19%). PMID:27161660

  4. MgB2 ultrathin films fabricated by hybrid physical chemical vapor deposition and ion milling

    NASA Astrophysics Data System (ADS)

    Acharya, Narendra; Wolak, Matthäus A.; Tan, Teng; Lee, Namhoon; Lang, Andrew C.; Taheri, Mitra; Cunnane, Dan; Karasik, Boris. S.; Xi, X. X.

    2016-08-01

    In this letter, we report on the structural and transport measurements of ultrathin MgB2 films grown by hybrid physical-chemical vapor deposition followed by low incident angle Ar ion milling. The ultrathin films as thin as 1.8 nm, or 6 unit cells, exhibit excellent superconducting properties such as high critical temperature (Tc) and high critical current density (Jc). The results show the great potential of these ultrathin films for superconducting devices and present a possibility to explore superconductivity in MgB2 at the 2D limit.

  5. Isotope effect on electron-phonon interaction in the multiband superconductor MgB2

    NASA Astrophysics Data System (ADS)

    Mou, Daixiang; Manni, Soham; Taufour, Valentin; Wu, Yun; Huang, Lunan; Bud'ko, S. L.; Canfield, P. C.; Kaminski, Adam

    2016-04-01

    We investigate the effect of isotope substitution on the electron-phonon interaction in the multiband superconductor MgB2 using tunable laser-based angle-resolved photoemission spectroscopy. The kink structure around 70 meV in the σ band, which is caused by electron coupling to the E2 g phonon mode, is shifted to higher binding energy by ˜3.5 meV in Mg 10B2 and the shift is not affected by superconducting transition. These results serve as the benchmark for investigations of isotope effects in known, unconventional superconductors and newly discovered superconductors where the origin of pairing is unknown.

  6. Observation of interband pairing interaction in a two-band superconductor: MgB2.

    PubMed

    Geerk, J; Schneider, R; Linker, G; Zaitsev, A G; Heid, R; Bohnen, K-P; v Löhneysen, H

    2005-06-10

    The recently discovered anisotropic superconductor MgB2 is the first of its kind showing the intriguing properties of two-band superconductivity. By tunneling experiments using thin film tunnel junctions, electron-coupled phonon spectra were determined showing that superconductivity in MgB2 is phonon mediated. In a further analysis, which involves first principles calculations, the strongest feature in these spectra could be traced back to the key quantity of two-band superconductivity, the interband pairing interaction. For the phonons, this interaction turns out quite selective. It involves mainly low-energy optical phonon modes, where the boron atoms move perpendicular to the boron planes.

  7. Pair-breaking and superconducting state recovery dynamics in MgB2.

    PubMed

    Demsar, J; Averitt, R D; Taylor, A J; Kabanov, V V; Kang, W N; Kim, H J; Choi, E M; Lee, S I

    2003-12-31

    We present studies of the photoexcited quasiparticle dynamics in MgB2 where, using femtosecond optical techniques, Cooper pair-breaking dynamics (PBD) have been temporally resolved for the first time. The PBD are strongly temperature and photoexcitation intensity dependent. Analysis of the PBD using the Rothwarf-Taylor equations suggests that the anomalous PBD arises from the fact that in MgB2 photoexcitation is initially followed by energy relaxation to high frequency phonons instead of, as commonly assumed, e-e thermalization. Furthermore, the bare quasiparticle recombination rate and the probability for pair breaking by phonons have been determined.

  8. Magnetic vortex flux pinning in silicon-oil-doped MgB2

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Ik; Ghorbani, S. R.

    2010-12-01

    The field dependence of the critical current density, jc (B), of MgB2 doped with 10 wt.% of a liquid precursor, silicon oil, was measured. The obtained jc (B) was enhanced compared with the value of pure MgB2. The temperature dependence of the crossover field, Bsb(T), from the region of a single vortex to the region of small vortex bundle pinning shows that δl pinning, which is associated with mean-free-path fluctuations of the charge carriers, is dominant in this superconductor.

  9. Modelling the B2C Marketplace: Evaluation of a Reputation Metric for e-Commerce

    NASA Astrophysics Data System (ADS)

    Gutowska, Anna; Sloane, Andrew

    This paper evaluates recently developed novel and comprehensive reputation metric designed for the distributed multi-agent reputation system for the Business-to-Consumer (B2C) E-commerce applications. To do that an agent-based simulation framework was implemented which models different types of behaviours in the marketplace. The trustworthiness of different types of providers is investigated to establish whether the simulation models behaviour of B2C e-Commerce systems as they are expected to behave in real life.

  10. Transport Anisotropy in ErNi2B2C Along c-AXIS

    NASA Astrophysics Data System (ADS)

    Lee, W. C.

    The resistivities along c-axis ρc(H, T) of ErNi2 B2C have been measured with H⊥ and H‖ c-axis for 2 < T < 300 K and the superconducting upper critical field Hc2(T) curves of ErNi2B2C were constructed for each magnetic fields. Our Hc2(T) curves have been compared and discussed with those from ρab(H, T) measurements which explain the anisotropy and its temperature dependence of Hc2(T) are thought to arise from magnetic pair breaking and the anisotropic field dependence of Néel temperature TN originated from Er+3 sublattice.

  11. The production of CO(+) (B2Sigma +) from dissociative photoionization excitation of CO2

    NASA Astrophysics Data System (ADS)

    Wu, C. Y. R.; Judge, D. L.

    1986-04-01

    The dissociative photoionization excitation process in CO2 is studied. In contrast to previous studies, attention is focused on the vibrational and rotational levels produced in fragment ions, partial cross-section measurements for producing such fragment ions in a specific quantum state, and the mechanisms that govern the dissociative ionization excitation processes. The partial fluorescence cross section for the production of CO(+) (B2Sigma +) from CO2 over a wide wavelength range was measured. It is concluded that the production of the CO(+) (B2Sigma +) fragment near the threshold is through a direct dissociative photoionization process.

  12. The production of CO(+) (B2Sigma +) from dissociative photoionization excitation of CO2

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Judge, D. L.

    1986-01-01

    The dissociative photoionization excitation process in CO2 is studied. In contrast to previous studies, attention is focused on the vibrational and rotational levels produced in fragment ions, partial cross-section measurements for producing such fragment ions in a specific quantum state, and the mechanisms that govern the dissociative ionization excitation processes. The partial fluorescence cross section for the production of CO(+) (B2Sigma +) from CO2 over a wide wavelength range was measured. It is concluded that the production of the CO(+) (B2Sigma +) fragment near the threshold is through a direct dissociative photoionization process.

  13. ErbB2 Dephosphorylation and Anti-Proliferative Effects of Neuregulin-1 in ErbB2-Overexpressing Cells; Re-evaluation of Their Low-Affinity Interaction

    PubMed Central

    Wang, Ran; Iwakura, Yuriko; Araki, Kazuaki; Keino-Masu, Kazuko; Masu, Masayuki; Wang, Xue-yi; Takei, Nobuyuki; Higashiyama, Shigeki; Nawa, Hiroyuki

    2013-01-01

    Neuregulin-1 binds to ErbB3 and ErbB4 and regulates cancer proliferation and differentiation. Neuregulin-1 had been suggested to also react with ErbB2, but this argument becomes controversial. Here, we re-evaluated the cellular responses and ErbB2 interaction of neuregulin-1 in ErbB2 overexpressing cell lines. In a competitive ligand-binding assay, we detected significant replacement of [35S]-labeled neuregulin-1 with nano molar ranges of cold neuregulin-1 in L929 cells expressing ErbB2 alone and SKOV3 cells carrying sulf-1 cDNA but not in these parental cells. The concentration of neuregulin-1 significantly decreased thymidine incorporation and phosphorylation of ErbB2 (Tyr877, Tyr1396, and Tyr1121) in ErbB2-overexpressing cancer cells as well as in L929 cells expressing ErbB2. A crosslinking assay ascertained the presence of neuregulin-1 immunoreactivity in the ErbB2 immune complexes of L929 expressing ErbB2 alone. These results suggest that the higher concentrations of neuregulin-1 exert an anti-oncogenic activity to attenuate ErbB2 auto-phosphorylation potentially through its low-affinity interaction with ErbB2. PMID:23466678

  14. Glucuronidation and Methylation of Procyanidin Dimers B2 and 3,3’’-Di-O-Galloyl-B2 and Corresponding Monomers Epicatechin and 3-O-Galloyl-Epicatechin in Mouse Liver

    PubMed Central

    Shrestha, Suraj P.; Thompson, John A.; Wempe, Michael F.; Gu, Mallikarjuna; Agarwal, Rajesh; Agarwal, Chapla

    2012-01-01

    Purpose The 3,3’’-di-O-galloyl ester of procyanidin B2 (B2G2) is a component of grape seed extract that inhibits growth of human prostate carcinoma cell lines. In preparation for studies in mice, its hepatic metabolism was examined in vitro and compared to B2 and the corresponding monomers, epicatechin (EC) and 3-O-galloyl-epicatechin (ECG). Methods Compounds were incubated with liver microsomes or cytosol containing cofactors for glucuronidation, sulfation or methylation, and products analyzed by liquid chromatography-mass spectrometry (LC-MS). B2G2 was administered orally to mice and plasma analyzed by LC-MS for unmodified procyanidin and metabolites. Results Glucuronides and methyl ethers of B2 and B2G2 were formed in small amounts. In contrast, EC and ECG were largely or completely converted to glucuronides, sulfates and methyl ethers under the same incubation conditions. B2G2 given orally to mice was partially absorbed intact; no significant metabolites were detected in plasma. Conclusions Glucuronidation and methylation of procyanidins B2 and B2G2 occurred but were minor processes in vitro. B2G2 was partially absorbed intact in mice after oral dosing and did not undergo significant metabolism. Unlike the flavanol monomers EC and ECG, therefore, B2G2 bioavailability should not be limited by metabolism. These results paved the way for ongoing pharmacokinetic and efficacy studies. PMID:22068277

  15. Multiscale Modeling of Ultra High Temperature Ceramics (UHTC) ZrB2 and HfB2: Application to Lattice Thermal Conductivity

    NASA Technical Reports Server (NTRS)

    Lawson, John W.; Daw, Murray S.; Squire, Thomas H.; Bauschlicher, Charles W.

    2012-01-01

    We are developing a multiscale framework in computational modeling for the ultra high temperature ceramics (UHTC) ZrB2 and HfB2. These materials are characterized by high melting point, good strength, and reasonable oxidation resistance. They are candidate materials for a number of applications in extreme environments including sharp leading edges of hypersonic aircraft. In particular, we used a combination of ab initio methods, atomistic simulations and continuum computations to obtain insights into fundamental properties of these materials. Ab initio methods were used to compute basic structural, mechanical and thermal properties. From these results, a database was constructed to fit a Tersoff style interatomic potential suitable for atomistic simulations. These potentials were used to evaluate the lattice thermal conductivity of single crystals and the thermal resistance of simple grain boundaries. Finite element method (FEM) computations using atomistic results as inputs were performed with meshes constructed on SEM images thereby modeling the realistic microstructure. These continuum computations showed the reduction in thermal conductivity due to the grain boundary network.

  16. Human papilloma virus transformed CaSki cells constitutively express high levels of functional SerpinB2.

    PubMed

    Major, Lee; Schroder, Wayne A; Gardner, Joy; Fish, Richard J; Suhrbier, Andreas

    2011-02-01

    Many malignant tissues, including human papilloma virus (HPV)-associated cancers, express SerpinB2, also known as plasminogen activator inhibitor type-2 (PAI-2). Whether SerpinB2 is expressed by the HPV-transformed cancer cells, and if so, whether SerpinB2 is mutated or behaves aberrantly remains unclear. Here we show that HPV-transformed CaSki cells express high levels of constitutive wild-type SerpinB2, with cellular distribution, glycosylation, secretion, cleavage, induction and urokinase binding similar to that reported for primary cells. Neutralization of secreted SerpinB2 failed to affect CaSki cell migration or growth. Lentivirus-based over-expression of SerpinB2 also had no effect on growth, and we were unable to confirm a role for SerpinB2 in binding or regulating expression of the retinoblastoma protein. CaSki cells thus emerge as a useful tool for studying SerpinB2, with the physiological function of SerpinB2 expression by tumor cells remaining controversial. Using CaSki cells as a source of endogenous SerpinB2, we confirmed that SerpinB2 efficiently binds the proteasomal subunit member β1. PMID:20974129

  17. 26 CFR 1.50B-2 - Electing small business corporations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 1 2010-04-01 2010-04-01 true Electing small business corporations. 1.50B-2... business corporations. (a) General rule—(1) In general. In the case of an electing small business... be apportioned separately. In determining who are shareholders of an electing small...

  18. A Cross-Industry Review of B2B Critical Success Factors.

    ERIC Educational Resources Information Center

    Eid, Riyad; Trueman, Myfanwy; Ahmed, Abdel Moneim

    2002-01-01

    Presents a comprehensive review of B2B (business-to- business) international Internet marketing and identifies 21 critical success factors in five categories: marketing strategy, including management support, strategic goals, and collaboration; Web site factors, including Web site design; global factors, including multilanguage sites and cultural…

  19. First-principles calculations of elastic and electronic properties of NbB(2) under pressure.

    PubMed

    Li, Xiao-Feng; Ji, Guang-Fu; Zhao, Feng; Chen, Xiang-Rong; Alfè, Dario

    2009-01-14

    The structural parameters, elastic constants and electronic structure of NbB(2) under pressure are investigated by using first-principles plane-wave pseudopotential density functional theory within the generalized gradient approximation (GGA). The obtained results are in agreement with the available theoretical data. It is found that the elastic constants and the Debye temperature of NbB(2) increase monotonically and the anisotropies weaken with pressure. The band structure and density of states (DOS) of NbB(2) under pressure are also presented. It is the σ hole that determines the superconductivity in NbB(2), and the features of the σ bands are unchanged after applying pressure except for a shift of position. The density of states (DOS) at the Fermi level decreases with increasing pressure, in conjunction with Bardeen-Cooper-Schrieffer (BCS) theory, which can predict T(c) decreasing with pressure, in agreement with the trend of the theoretical T(c) versus pressure.

  20. Hot Extrusion of Ex-Situ MgB2 Powder

    NASA Astrophysics Data System (ADS)

    Nachtrab, William T.; Rudziak, Mark K.; Wong, Terence

    2008-03-01

    We investigated the fabrication of ex-situ processed MgB2 round wire by hot extrusion. Composite ex-situ MgB2 monocore billets were fabricated with a composite sheath consisting of either an AISI 304 or AISI 430 stainless steel clad with copper. The stainless steel was intended to serve as reinforcement for the powder core and maintain mechanical compatibility between the MgB2 core and the copper cladding. The composite billets were extruded at temperatures between 593 and 900 °C at a reduction ratio of 5.2 (81% RA). The billets having the 304 SS barrier cracked during extrusion, while the billets with 430 SS were successfully extruded. Several additional monocore billets with 430 SS/Cu sheath were extruded at 650 °C and reduction ratio of 5.0 (80% RA). The extruded rods were cold drawn, restacked in a copper tube in an 18 filament array, and subsequently cold drawn to 2 mm diameter. A 61 filament restack billet was also assembled and hot extruded at 538 °C and R = 5.0. The results demonstrate that hot extrusion has the potential to be a viable method for fabricating multifilament round MgB2 wire.